SEMI S23 Application Guide and Total Equivalent Energy (TEE)
CalcII User’s Guide
International SEMATECH Manufacturing Initiative
Technology Transfer #06094783D-ENG
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SEMI S23 Application Guide and Total Equivalent Energy (TEE) CalcII
User’s Guide
Technology Transfer #06094783D-ENG
International SEMATECH Manufacturing Initiative
October 29, 2010
Abstract:
This user’s guide supplements SEMI S23-0708, Guide for Conservation of Energy, Utilities, and
Materials Used by Semiconductor Manufacturing Equipment, by providing guidance in the
selection and use of utility measurement instruments and recommendations for resource reduction.
This revision includes instructions for using the current S23 Total Equivalent Energy Calculator
(TEE CalcII), which converts various semiconductor manufacturing equipment utility
consumption rates into equivalent annual electrical energy usage. The data gathered and
calculations made are based on the SEMI S23 energy efficiency and roadmapping guidelines. This
revision of the TEE Calculator incorporates input from member companies and includes many
new features.
ISMI FURNISHES THE GUIDE "AS-IS" AND WITHOUT ANY EXPRESSED OR IMPLIED
WARRANTY OF ANY KIND AND HEREBY EXPRESSLY DISCLAIMS ANY IMPLIED
WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. ISMI
WILL HAVE NO LIABILITY WITH RESPECT TO ANY FAILURE OF THE GUIDE. ISMI
WILL NOT BE LIABLE FOR ANY LOSS OF PROFIT, LOSS OF USE, INTERRUPTION OF
BUSINESS OR DIRECT, INCIDENTAL, CONSEQUENTIAL OR SPECIAL DAMAGES, FOR
PERSONAL OR PROPERTY INJURY ARISING FROM THE USE OF THIS GUIDE.
Keywords:
Energy Use Reduction, Environmental Standards
Authors:
Ralph M. Cohen
Approvals:
James Beasley, Project Manager
Ron Remke, Program Manager
Jope Draina, Director
Laurie Modrey, Technology Transfer Team Leader
iii
Table of Contents
1
2
3
4
ISMI
EXECUTIVE SUMMARY .....................................................................................................1
BACKGROUND.....................................................................................................................1
RECOMMENDED PRACTICES FOR UTILITY MEASUREMENT ..................................2
3.1 Recommended Practices for Utility Measurement .........................................................2
3.1.1 Liquid Flow Rate.................................................................................................2
3.1.2 Exhaust, Makeup Air, and Circulating Airflow Rate..........................................6
3.1.3 Compressed Gas (Air, Nitrogen, Vacuum, etc.) Flow Rate..............................10
3.1.4 Fluid Temperature Measurement (Liquid and Gaseous) ..................................12
3.1.5 Fluid Pressure Measurement (Liquid and Gaseous) .........................................14
3.1.6 Heat Dissipation to Space .................................................................................17
3.1.7 Electrical Power ................................................................................................18
3.2 Recommended Practice for Equipment Testing............................................................19
3.2.1 Establishing the Test Plan .................................................................................19
3.2.2 Guidance on Testing Procedures and Data Reporting ......................................21
3.2.3 S23 TEE Report Content...................................................................................24
3.2.4 Data Collection Methods/Analysis/Assumptions .............................................25
3.3 Recommended Practices for Reducing Utility Usage...................................................26
3.3.1 Chilled Water ....................................................................................................26
3.3.2 Process Cooling Water (PCW)..........................................................................27
3.3.3 Compressed Gas................................................................................................27
3.3.4 Exhaust..............................................................................................................28
3.3.5 Fan/Filter Selection (Minienvironment) ...........................................................29
3.3.6 Optimizing Pipe and Duct Size .........................................................................30
3.3.7 Electricity ..........................................................................................................30
3.4 Recommended Practices for Specific Equipment .........................................................30
3.4.1 Role of Economics ............................................................................................30
3.4.2 Process vs. Idle Mode .......................................................................................31
3.4.3 Liquid Pumps ....................................................................................................31
3.4.4 Packaged Chillers and Heat Exchangers...........................................................32
3.4.5 Power Supplies/RF Generators .........................................................................33
3.4.6 Heat Exchangers................................................................................................33
3.4.7 Fans and Ductwork ...........................................................................................33
3.4.8 Filters ................................................................................................................34
3.4.9 Minienvironments .............................................................................................34
USING THE TEE CALCII UTILITY-TO-ENERGY CONVERSION TOOL .....................37
4.1 S23 TEE Calculator Overview......................................................................................37
4.1.1 Similarities to TEE CalcI ..................................................................................37
4.1.2 Changes from TEE CalcI ..................................................................................37
4.2 S23 TEE Calculator Software Requirements and Installation Details..........................38
4.3 Basic Steps to Use the S23 TEE Calculator..................................................................40
4.4 Instructions for Using the S23 TEE Calculator.............................................................41
4.4.1 S23 TEE Calculator Homepage View...............................................................42
4.4.2 Creating Equipment ..........................................................................................42
4.4.3 Creating a Component ......................................................................................49
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4.4.4 Energy Conversion Factors ...............................................................................53
4.4.5 Creating a Report ..............................................................................................58
4.4.6 Providing feedback............................................................................................66
4.4.7 Documentation ..................................................................................................67
4.5 Revision Control ...........................................................................................................67
4.6 Flow Diagrams ..............................................................................................................67
5
REFERENCES ......................................................................................................................69
APPENDIX A – SAMPLE TEE EQUIPMENT REPORT ............................................................70
List of Figures
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12
Figure 13
Figure 14
Figure 15
Figure 16
Figure 17
Figure 18
Figure 19
Figure 20
Figure 21
Figure 22
Figure 23
Equipment/Component/Sub-Component Relationship ..............................................2
Liquid Rotameter........................................................................................................3
Installed Paddlewheel Transmitter .............................................................................4
Paddlewheel Flow Transmitters .................................................................................5
Example of a Rectangular Duct Velocity Traverse Points Using the Log-T
Rule ............................................................................................................................7
Example of a Round Duct Velocity Traverse Points Using the Log-Linear
Rule ............................................................................................................................7
Pitot Tube Cross Section and Schematic....................................................................9
Examples of Several Types of MFMs ......................................................................11
Typical RTD With Cable for Connecting to Transmitter/Data Logger ....................13
Typical Multi-Channel Data Logger With Removable Memory Card.....................13
Examples of High Accuracy Test Gauges ................................................................15
Example of Magnetically Coupled Aneroid Bellows Differential Pressure
Gauge .......................................................................................................................16
Illustrations of Heat Burden .....................................................................................17
Relationship Among Sub-Components, Components, and Equipment....................21
Request Access to the TEE Calculator .....................................................................39
Log-in Screen/Access Code Window.......................................................................40
S23 TEE Calculator Home Window ........................................................................41
Equipment “Add New” Window..............................................................................43
Equipment “Add New” Window, Highlighting Process, Idle, Standby, and
Shutdown Percentage Fields ....................................................................................44
Adding/Removing Components from Equipment and Viewing Components .........45
Searching Equipment Data Base ..............................................................................45
Deleting Private Equipment (Not Shared) ...............................................................46
Shared Equipment Cannot be Deleted or Edited......................................................47
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Figure 24
Figure 25
Figure 26
Figure 27
Figure 28
Figure 29
Figure 30
Figure 31
Figure 32
Figure 33
Figure 34
Figure 35
Figure 36
Figure 37
Figure 38
Figure 39
Figure 40
Figure 41
Figure 42
Figure 43
Figure 44
Figure 45
Figure 46
Figure 47
Equipment Web Share Options, Company Share View ...........................................48
Equipment Window, Categories Tab View...............................................................49
Component Window.................................................................................................50
Example of Component Input Data..........................................................................51
Component Data Input Window...............................................................................52
Energy Conversion Factors Window for Gaseous Fluids ........................................53
Energy Conversion Factors Window for Liquid Fluids ...........................................54
HVAC ECF Window ................................................................................................55
Add New ECF Set Window .....................................................................................56
Typical ECF Calculator Window .............................................................................57
ECF Share Window ..................................................................................................58
Report Type Selection ..............................................................................................59
Compare Equipment Graphically Window ..............................................................60
Equipment Comparison Graph and PDF Export Function.......................................60
Equipment TEE Report Window..............................................................................61
TEE Equipment Report Export Options...................................................................62
Component Comparison Component Selection Window.........................................63
Example of a Component Comparison Report.........................................................64
Equipment Comparison Report Equipment Selection Window ...............................65
Equipment Category Report Category Selection Window.......................................66
Feedback Window ....................................................................................................67
Creating a User Account ..........................................................................................67
Creating Components and Equipment Flow Diagram .............................................68
Creating Reports Flow Diagram ..............................................................................68
List of Tables
Table 1
Table 2
Table 3
Table 4
Table 5
Table 6
Table 7
Table 8
ISMI
SEMI S23 Utilities to be Measured............................................................................1
Comparison of Liquid Flow Measurement Methods .................................................5
Point Grid for Velocity Traverse in Rectangular and Round Ducts ...........................6
Comparison of Air Flow Measurement Methods.....................................................10
Comparison of Gas Flow Measurement Methods....................................................12
Comparison of Temperature Measurement Methods ...............................................14
Comparison of Pressure Measurement Methods......................................................16
Summary of the Types of Measurements Required by S23 vs. Equipment
Types ........................................................................................................................19
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Table 9
Table 10
Table 11
Table 12
Table 13
Table 14
Table 15
Table 16
Level of Accuracy for S23 Measurements That Would be Acceptable to
Semiconductor Manufacturers .................................................................................20
Typical Component-Level Utility Data Required for the TEE Calculator...............22
Component-Level Typical Calculation Performed by the TEE Calculator..............23
SEMI Recommended Additional Data .....................................................................25
Typical High Efficiency Fan Filter Unit Performance .............................................29
Motor Power vs. Efficiency......................................................................................33
Flow vs. Velocity and Friction Loss by Pipe Size....................................................36
Information Provided in TEE Report .......................................................................63
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Acknowledgments
The TEE CalcII calculator was created primarily by Tabatha Sikes of Handsdown Software with
engineering and technical direction provided by the author. Valuable suggestions were provided
by member companies with special thanks to Mark Denome of Applied Materials.
ISMI
Technology Transfer #06094783D-ENG
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1
EXECUTIVE SUMMARY
This user’s guide supplements SEMI S23-0708, Guide for Conservation of Energy, Utilities, and
Materials Used by Semiconductor Manufacturing Equipment, by providing guidance in the
selection and use of utility measurement instruments. Each category of measurement instrument
is reviewed including practical considerations when using and correcting for non-standard
conditions. Comparison tables highlighting relative cost, accuracy, and ease of use or installation
are also included, and acceptable measurement accuracies are tabulated. Recommendations for
resource reduction are provided, considering the facility system and the impacts of the key
parameters influencing resource use for that facility.
Instructions are also included for using the International SEMATECH Manufacturing Initiative
(ISMI) S23 Total Equivalent Energy Calculator (TEE CalcII), a desktop software application
provided by ISMI. This revision incorporates input from member companies and includes many
new features..
2
BACKGROUND
Three documents were used in developing this guide: 1
 SEMI E6-0303, Guide for Semiconductor Equipment Installation, prescribes the
process for semiconductor equipment manufacturers to collect and report utility data in
processing and idle modes.
 SEMI S23-0708, Guide for Conservation of Energy, Utilities, and Materials Used by
Semiconductor Manufacturing Equipment, prescribes a method to collect, analyze, and
report energy-consuming semiconductor manufacturing equipment utility data as well
as a method to convert energy consumption into kW-hour/cubic meter equivalents. It
also defines broad energy conservation strategies.
 Semiconductor Equipment Association of Japan (SEAJ) E-002E, Guideline for Energy
Quantification, provides additional detail and clarification augmenting SEMI S23 as
well as useful reporting templates and examples.
SEMI S23 recommends, at a minimum, that users measure the utilities listed in Table 1 while the
equipment is processing material and while it is idling.
Table 1
Utility or Material
Exhaust
Vacuum
Dry Air / Nitrogen (N2)
Cooling Water
Ultrapure Water (UPW)A
Electricity
SEMI S23 Utilities to be Measured
Basic Use Rate Metrics and Units
3
Pressure (Pa); Flow (m /hr); Inlet Temp (°C);
Outlet Temp (°C)
Pressure (Pa); Flow (m3/hr)
Pressure (Pa); Flow (m3/hr)
Supply Pressure (KPa); Return Pressure (KPa); Flow
(l/hr); Inlet Temp (°C); Outlet Temp (°C)
Purity Requirements; Inlet Temp (°C); Flow (l/hr)
Real PowerB (Watts)
Related SEMI Standard E6
Sections (0303 Version)
Section 18
Section 17
Section 16
Section 13
Section 13
Section 12
Note A: “Ultrapure Water” is also known as “Deionized Water.”
Note B: “Real Power” is also known as “True Power.”
1
Copyrighted SEMI standards material is used by permission of SEMI.
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As shown in Figure 1, equipment is composed of components, which are composed of subcomponents. This convention is important when using the S23 TEE Calculator because the user
“builds” equipment by defining and then selecting components. The TEE Calculator provides
input only at the equipment and component level; sub-components cannot be defined separately
from a component.
Equipment
Component 1
Component 2
Sub-component 1
Sub-component 2
Sub-component 3
Sub-component 4
(vacuum pump & power supply)
Power, N2, POW
(chamber)
Exhaust & Power
(vacuum pump & power supply)
Power, N2, POW
(chamber)
Exhaust & Power
Example: Process vs. Idle and Sub-component/Component/Equipment Relationship for equipment comprised of
two components.
Figure 1
3
Equipment/Component/Sub-Component Relationship
RECOMMENDED PRACTICES FOR UTILITY MEASUREMENT
The following section summarizes measurement methods, including recommended practices, for
persons fulfilling SEMI E6 and SEMI S23 reporting requirements. It describes measurements of
temperature, pressure, liquid and gaseous flow, and electrical power. This section also discusses
the relative ease of application, accuracy of each method, and relative costs.
3.1
Recommended Practices for Utility Measurement
3.1.1
Liquid Flow Rate
Four measuring devices are commonly used to determine the flow rate of liquids in pipes for
systems such as ultrapure water, process cooling water, and chilled water flow. Ultrasonic,
paddlewheel/turbine, and Pitot-type velocity measuring instruments are affected by fluid
turbulence. A minimum of 7.5 pipe diameters of straight pipe upstream of the sensor and 3 pipe
diameters downstream are needed. If the sensing element is located downstream of several
90° bends in different planes, the minimum straight pipe upstream increases to 18 pipe
diameters. The ASME PTC 19.5, Flow Measurement, provides detailed recommendations for
locating the sensor to minimize measurement error.
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3.1.1.1 Ultrasonic
Ultrasonic devices measure the transit time of acoustic signals in the flowing fluid stream. The
energy is directed through the pipe wall from a transmitter affixed to the pipe and subsequently
detected by a receiver also affixed to the pipe. This method has the advantage of being non-intrusive
(i.e., the sensors are clamped temporarily to the outside of the pipe). Another advantage is that the
signal can be easily data-logged, recorded, or transmitted. Some units require gas bubbles or
suspended solids in the fluid stream to be able to determine the flow rate. The instrument measures
velocity but can convert it to a flow rate from operator inputs of pipe size, material, and wall
thickness. The pipe sizes that can be measured range from 12.7 mm to 2.5 m (1/2 inch to 100-inch)
diameter. Ultrasonic flowmeters can measure flow only in rigid piping.
3.1.1.2 Rotameter (Variable Area Flow Meter)
The rotameter is the most commonly used indicating fluid flow meter in the semiconductor
industry. It requires relatively little space, is reasonably accurate, and is typically inexpensive,
especially in the smaller sizes. A rotameter uses a tapered, calibrated measuring column and float
suspended within the column. Quality and fragility vary greatly. Units can be fabricated from
extruded plastic, machined plastic, glass/bronze fitted, or glass/stainless steel fitted. The
rotameter is installed in-line with the column oriented vertically. A specific flow range, specific
gravity or density, viscosity, and fitting size must be specified, necessitating some attention to the
application (ultrapure water [UPW]/deionized water [DIW] and process cooling water [PCW]
would be considered ordinary “water”). Some units have magnetically coupled indicators that
eliminate reading the float position. One needs to be aware of the part of the float to “read” as
manufacturers have specific requirements (center of ball/float, bottom of ball/float, etc.).
Rotameter flow rate is not easily data-logged, recorded, or transmitted to a monitoring system
beyond a high or low flow limit. See Figure 2 for an example of a low cost rotameter.
Figure 2
ISMI
Liquid Rotameter
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3.1.1.3 Paddlewheel
A paddlewheel flow meter is a moderate cost process measurement and control instrument. It
essentially counts magnetic pulses from a rotating paddlewheel with embedded magnets in the
blade ends. It works well with clean, low viscosity fluids (water). The flow sensor is installed inline or into the branch of a “tee.” Specific gravity, viscosity, and pipe size must be selected,
necessitating attention to the application. Readout can be analog or digital, and the signal can be
data-logged or transmitted. Several levels of quality and features are available at commensurate
costs. Long-term reliability may be an issue with some products because there are no bearings at
the rotating shaft to limit wear. Turbine flow meters are similar to paddlewheel flow meters but
are more accurate and reliable. Figure 3 is a drawing of a paddlewheel flow meter installed in a
pipe using a thread-o-let. The rotating paddlewheel can be seen in each flow transmitter in
Figure 4.
Paddlewheel or
turbine flowmeter
(thread into
threadolet)
Pipe
containing
liquid
Threadolet
(welded to
pipe wall)
FLOW
Figure 3
Installed Paddlewheel Transmitter
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D
0.926 H
0.712 H
0.500 H
H
0.288 H
0.074 H
0.061 D
0.235 D
0.437 D
0.563 D
0.765 D
0.939 D
Figure 4
Paddlewheel Flow Transmitters
3.1.1.4 Averaging Pitot Tube
The Pitot tube is a very basic method of measuring fluid velocity by measuring total and static
pressure. This method is economical for larger pipes (~ 50 mm/2 inches or larger). The averaging
Pitot tube simultaneously measures velocity pressure at several points within the flow stream and
provides an average value that can be converted directly into a flow velocity. Knowing the pipe
cross-sectional area, the flow rate can be calculated. The Pitot tube is threaded into a weldolet
attached to the pipe (perpendicular to flow) and is connected to a differential pressure
manometer, gauge, or transmitter with tubing. Manufacturers of these devices provide graphs to
convert the pressure readings into velocity or flow. If the Pitot tube is connected to an electronic
transmitter, the readings can be data-logged; otherwise, readings must be recorded manually.
Long-term, it is more reliable than a turbine meter. Averaging Pitot tubes are specified for a
given pipe diameter. The indicated values must compensate for the viscosity and specific gravity
of the measured fluid. The sensor and tubes must be installed so that air is not trapped. The
above methods of measuring liquid flow rate are summarized in Table 2.
Table 2
Comparison of Liquid Flow Measurement Methods
Cost
Accuracy
Type of Installation
Ease of Setup
and Operation
Ultrasonic
High
2–4%
Non-intrusive
Difficult
Rotameter
Low
0.5–5%
In-line
Easy
Paddlewheel
Low
2%
In-line or insertion
Moderate
Moderate
0.25%
Insertion
Moderate
Low–Moderate
2–4%
In-line or insertion
Moderate
Type
Turbine
Averaging Pitot + Differential
Pressure Transmitter (DPT) or
Gauge
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3.1.2
Exhaust, Makeup Air, and Circulating Airflow Rate
The four commonly used measuring devices for determining airflow rate all measure or are used
to derive the velocity or volumetric flow of the fluid. After calculating the cross-sectional area of
a duct, the flow is determined using the equation Flow = Velocity  Area. The hotwire
anemometer, Pitot tube, and calibrated orifice plate or Venturi nozzle are useful for measuring
duct velocity, while the hotwire anemometer and vane anemometer are useful for measuring the
velocity across an open exhaust hood or filter faces. To measure duct velocity with a Pitot tube or
hot wire anemometer, holes must be drilled into the duct wall so that the device can be
positioned at each of the sampling points. Flow into or out of the hole during measurement must
be restricted, and the hole should be plugged after the measurements are completed.
A general caveat when making velocity measurements in ducts or across large open faces of
exhaust hoods is as follows: to be accurate, a sampling grid should be established so that velocity
is measured using the log-Tchebycheff (log-T) rule for rectangular ducts and the log-linear rule
for round ducts (see Figure 5 and Figure 6, respectively, for sample applications) rather than
using the “center of equal areas” or measuring at a fixed interval (e.g., every 50 mm [2 inches))
across the duct. The point location is shown in Table 3. Note that the log-linear rule for circular
ducts results in a point location that is not constant from the edge of the duct toward the center.
This is because the points are located approximately in the center of equal concentric areas. The
plane of measurement should be located 7.5 duct diameters downstream and 3 duct diameters
upstream of duct disturbances for acceptable accuracy. A longer straight run from upstream
obstructions improves point reading stability. Setting up correct sampling grids is discussed
thoroughly in reference guides (e.g., Industrial Ventilation: A Manual of Recommended Practice
published by the American Conference of Governmental Industrial Hygienists or ASHRAE
Fundamentals, the 2005 edition or earlier, Section 14). One should become familiar with these
recommendations to produce accurate and repeatable results. A general guideline is to measure at
least 25 points in a square or rectangular duct with points no more than 15 cm (6 inches) apart.
For round ducts, at least 6 points per diameter on 3 diameters that are 120° apart should be
measured.
Table 3
Point Grid for Velocity Traverse in Rectangular and Round Ducts
# of Points for Traverse Lines
Position Relative to Inner Wall (log-T rule for rectangular ducts)
5
0.074
0.288
0.500
0.712
0.926
6
0.061
0.235
0.437
0.563
0.765
7
0.053
0.203
0.366
0.500
0.634
0.797
0.947
# of Measuring Points per
Diameter
0.939
Position Relative to Inner Wall (log-Linear rule for circular ducts)
6
0.032
0.135
0.321
0.679
0.865
0.968
8
0.021
0.117
0.184
0.345
0.655
0.816
0.883
0.981
0.019
0.077
0.153
0.217
0.361
0.639
0.783
0.847
0.923
0.981
10
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D
0.926 H
0.712 H
0.500 H
H
0.288 H
0.074 H
0.061 D
0.235 D
0.437 D
0.563 D
0.765 D
0.939 D
Figure 5
Example of a Rectangular Duct Velocity Traverse Points Using the Log-T
Rule
0.032 D
0.135 D
0.321 D
0.679 D
0.865 D
0.968 D
D
Figure 6
ISMI
Example of a Round Duct Velocity Traverse Points Using the Log-Linear
Rule
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3.1.2.1 Thermal Anemometer
This type of instrument measures velocity by determining the temperature difference between
reference points: one point is the ambient air stream temperature while the other point is heated a
fixed amount but is allowed to be cooled by the air flowing past it. The temperatures are
measured with thermocouples, resistance temperature devices (RTDs), or thermistors. The
minimum velocity capability (typically <0.05 meters/sec [mps] or 10 feet/min [fpm]) is the
lowest of all the velocity instruments. However, dust and corrosive gases limit anemometers’
usefulness in process applications because of fouling. These instruments are best used to measure
face velocities across exhaust hoods or filters and velocity in small ducts free of process gas.
Some instruments may have data-logging capability.
3.1.2.2 Pitot Tube With Differential Pressure Gauge or Electronic Pressure Transducer
The Pitot tube with an inclined manometer, differential pressure gauge, or electronic differential
pressure transducer is a very practical instrument for measuring duct velocity. The Pitot tube has
one orifice that faces into the air stream that measures total pressure and others that are
perpendicular to the air stream that measure static pressure. These orifices are connected to the
differential pressure measuring device with flexible tubing. The algebraic difference between the
two pressures is called “velocity pressure.” This can be converted to velocity by a simple
formula (see ASHRAE Fundamentals or Industrial Ventilation). Figure 7 illustrates the
orientation of the two orifices to the air stream and the connection of the differential gauge. The
formula, derived from Bernoulli’s equation, is as follows (in Imperial units):
1/ 2
g 

V  C   2  VP  c 
 

Eq. [1]
where: V = Velocity (fpm)
C = 136.8 (IPS conversion)
VP = Velocity pressure units (inches H2O)
 = Air density units (lbm/ft3)
gc = Gravitational constant = 32.174 lbm-ft/lbf-sec2
At standard air density (1 atmosphere and 70°F), this equation simplifies to
V  4005  VP 1 / 2
Eq. [2]
If the temperature of the fluid stream is other than at standard conditions of temperature, then a
density correction must be applied.
Another form of this equation using S.I. units is as follows:
1/ 2

 1013.25   T   100,000 
  VP 
V  C  

  

 B   293   100,000  Ps 
Eq. [3]
where: V = velocity (mps)
C = 1.291 (S.I. conversion(
B = Local barometric pressure (mbar)
T = Air stream temperature (°K)
VP = Velocity pressure units (Pascal)
Ps = Duct static pressure (Pascal) and may be ignored below 2500 Pascal
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Using metric units, the equation takes the following form:
1/ 2

 760   T   10350 
  VP 
V  C  

  

 B   293   10350  Ps 
Eq. [4]
where: V = Velocity (mps)
C = 4.05 (Metric conversion)
B = Local barometric pressure (mm Hg)
T = Air stream temperature (°K)
VP = Velocity pressure units (mm H2O)
Ps = Duct static pressure (mm H2O) and may be ignored below 250 mm H2O
Pitot tubes are available in different lengths and diameters to measure velocity in ducts of any
size. The minimum velocity capability is ~3 mps (600 fpm) with an inclined manometer or
magnetically coupled differential pressure gauge but lower (<0.05 mps or 100 fpm) with a
sensitive differential pressure transducer. If a transducer is used, the readings may be datalogged. Because process equipment ducts are typically designed to operate in the range of
4–10 mps (800–2000 fpm), it should be possible to use the Pitot tube with an appropriate
differential pressure measuring device. Pitot tube grids are also available that can be installed
inside ducts to provide an average velocity pressure value for the entire duct, simultaneously,
without conducting a duct traverse for each measurement. This saves data collection time. Pitot
tube grids may be less precise than a Pitot tube (2% to 40% vs. 1% to 6%) because of the
fundamental difference in operating principle: converting velocity pressure at each measurement
point to velocity and then averaging all velocity measurements vs. averaging all velocity pressure
measurements and converting them to a single velocity value.
Static Taps
(several, equally
spaced circumference)
Streamlines
Stagnation Point
Differential
Manometer
Figure 7
ISMI
Pitot Tube Cross Section and Schematic
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3.1.2.3 Calibrated Orifice Plate or Flow Nozzle With Differential Pressure Gauge or
Electronic Differential Pressure Transducer
The orifice plate or flow nozzle provides a fixed flow obstacle in the air stream. Pressures
measured up- and downstream of the orifice are converted to a velocity value. The advantage of
using an orifice plate is that a single measurement provides the velocity, eliminating the need to
conduct a duct traverse. This is useful for permanent duct installations (e.g., in a lab). Minimum
velocity capability is similar to a Pitot tube.
3.1.2.4 Revolving Vane-Anemometer
The revolving vane-anemometer has an air flow-driven, rotating wheel that induces magnetic
pulses or generates a small current in an electronic circuit. The rate of the pulses or current is
calibrated to the speed of the air that rotates the wheel. This instrument is a less expensive
alternative to the thermal anemometer but has a minimum velocity capability of approximately
0.05 m/s (100 feet/min). It is most useful for measuring velocity on filter faces or across exhaust
hood faces. The above methods for measuring air flow rate are summarized in Table 4.
Table 4
Type
Thermal Anemometer
Pitot Tube + DPT or Gauge
Orifice + DPT or Gauge
Vane Anemometer
Comparison of Air Flow Measurement Methods
Cost
Accuracy
Minimum Velocity
Ease of Use
Moderate–High
2–8%*
0.05 mps (10 fpm)
Moderate
Low
1–6%
0.5 mps (100 fpm) w/DPT
Moderate
Low–Moderate
1–6%
0.5 mps (100 fpm) w/DPT
Easy only if orifice
is pre-installed
Moderate
2–6%
0.5 mps (100 fpm)
Easy
* <25 mps or 5000 fpm.
3.1.3
Compressed Gas (Air, Nitrogen, Vacuum, etc.) Flow Rate
Measuring gas flow is straightforward for bulk, compressed gases (e.g., air, nitrogen, oxygen,
argon, hydrogen). The semiconductor equipment industry has generally standardized the mass
flow meter (MFM) and the rotameter; however, different instruments have a markedly different
effect on the cleanliness of the gas. The associated safety hazards of working with flammable
and inert gases should not be overlooked.
Vacuum flow measurement is not as straightforward. Due to the low density of gas near an
absolute vacuum, the velocity must be quite high to obtain a sufficient pressure drop across a
Venturi or orifice to allow measurement. The pressure drop measured is proportional to the gas
density; therefore, at 48.8 Torr (711 mm Hg or 28 inch Hg) vacuum, the density is ~6% that of
standard conditions. Hence, to obtain a measurable differential pressure, the piping must be
designed to provide a velocity of at least 12.7 mps (2500 fpm) across the Venturi or orifice.
3.1.3.1 Thermal Mass Flow Meter (MFM)
MFMs may also be used for measuring flow rates, if properly selected. These are the most
accurate instruments for gas flow measurement discussed here. They also are available in a noncontaminating design. MFMs determine the flow by measuring the temperature difference
between two RTDs in the flow stream (or a sidestream) as a result of electrically heating the
stream. In-line process gas mass flow controllers (MFCs) are available up to 25.4 mm (1 inch)
outside diameter (OD) (~2,500 lpm range). Larger in-line MFMs, as well as insertion units
(tapped into the side of piping), are available in sizes from 9.5–203 mm (0.375 inch–8 inch)
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diameter. MFMs require a known and controlled upstream pressure; all but the sidestream type
MFM/MFC requires uniform velocity (10–12 equivalent diameters of straight tubing run).
MFMs or MFCs provide an electronic digital readout and can be interfaced to data log. Figure 8
shows several typical mass flow meters.
Figure 8
Examples of Several Types of MFMs
3.1.3.2 Rotameter (Variable Area Flow Meter)
Gas rotameters are similar to their liquid rotameter counterparts (see Section 3.1.1.2). Accurate
results depend on density corrections. Gas temperature and pressure must be known and
specified to calibrate the rotameter. If the stream being measured is at a different temperature or
pressure than the specified values for the rotameter or is a different gas, then corrections need to
be applied to the indicated values. For example, if a rotameter is specified for compressed air at
20°C (68°F ) and 483 kPa (70 psig) but will be used to measure compressed air at 30°C (86°F)
and 690 kPa (100 psig), then the difference in density between the two conditions would cause
an error. The density of air at 30°C and 690 kPa is 30% greater than the density of air at 20°C
and 483 kPa. The equation governing flow through a rotameter shows that flow varies
approximately as the square root of the inverse of gas density. Therefore, in this example, a 30%
increase in density gives a rotameter-indicated flow 14% greater than the actual flow. Since the
flow equation also depends on several other factors (e.g., float dimensions and density, rotameter
tube cross-sectional area), the user should have the supplier provide corrections and calibrations
for the specific rotameter being used. Because the specific gravity of air and nitrogen (at standard
temperature and pressure) varies by 3.4%, the error in using a rotameter calibrated for air to
measure nitrogen (or vice versa) would be ~1.7%.
The decision to use a rotameter for gases of a given purity should be based on the application and
the user’s need to maintain a given purity level at the equipment.
3.1.3.3 Ultrasonic (Non-Intrusive)
Ultrasonic measurements are non-intrusive. The minimum size tube that currently can be
measured is 19 mm (0.75 inch) O.D. To obtain the best accuracy, the pressure and temperature of
the gas must be known as well as tube wall thickness and material. The tubing must be rigid.
While an ultrasonic flow meter can be useful for measuring flow through the facility mains and
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sub-mains, it has limited use in equipment measurement until the minimum size capability is
reduced to 12.7 mm (0.5 inch) O.D. or smaller. Accuracy is lagging in smaller sizes; for 6 inches
and smaller, accuracy is only 4–10%. These instruments have data-logging capability. The above
methods for measuring gas flow rate are summarized in Table 5.
Table 5
Cost
Accuracy
Cleanliness
Ease of Install/
Operation
Moderate
1.5–2%
High
Moderate
Rotameter
Low
0.5–5%
Low
Easy
Ultrasonic
High
2–10%
High
Difficult
Type
MFM/MFC
3.1.4
Comparison of Gas Flow Measurement Methods
Fluid Temperature Measurement (Liquid and Gaseous)
Temperature is measured by a change in a material’s electrical properties, expansion of a liquid,
expansion of metals, or emission of infrared light from the object. Methods using these principles
are highlighted below.
Installing the temperature elements directly in the flow stream provides the quickest response
and greatest accuracy. However, to be able to remove temperature elements from flow streams
without shutting down and draining the piping, thermowells need to be installed in the piping.
Proper installation involves orientation with respect to the flow stream, well immersion length,
well immersion in the flow stream, well diameter vs. pipe diameter, and temperature element
length in relation to thermowell length. An immersion length of 11.4–26.7 cm (4.5–10.5 inches)
is adequate for semiconductor equipment facility applications. If the temperature being measured
differs from the surroundings by more than 30°C (50°F), then the portion of the thermowell
external to the pipe must be minimized and insulated. See ASME PTC 19.3-2004, Temperature
Measurement Instruments and Apparatus, for further guidance. Since equipment cooling lines
are small compared to the thermowell diameter, consideration should be given to oversizing the
piping containing the thermowells to prevent excessive pressure drops.
3.1.4.1 RTDs With Transmitter and Data Logger
Platinum resistance temperature detectors are stable and accurate with a standard of
100  at 0°C. Since fluid temperatures vary during process ramps (up and down), data logging
and graphing are more convenient than recording data manually. The transmitter consists of a
bridge circuit with an analog output (e.g., 4–20 mA) that is scaled to the RTD temperature range.
The data can be recorded using a data logger and then downloaded to a computer hard drive
through a suitable interface card (analog to digital). (See Figure 9 and Figure 10 for typical
examples.) Resolution to 0.05°C or 0.1°F is adequate. Due to multiple sources of error (RTD,
transmitter, analog:digital [A:D] converter), the accuracy of the measurement system should be
evaluated before collecting data. To do this, all elements are connected and then the indicated
value of the temperature compared to a standard (e.g., a precision bulb thermometer or calibrated
RTD).
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
Figure 9
Typical RTD With Cable for Connecting to Transmitter/Data Logger
Figure 10
Typical Multi-Channel Data Logger With Removable Memory Card
RTD with Transmitter and Digital Readout
This setup is similar to those with a data logger except that the data must be recorded
manually. Sufficient points should be taken over the time period to assure that the minimum
and maximum for each stream throughout the processing cycle are recorded.

Thermistor
Sintered metallic oxides are used to measure temperature because their resistance decreases
dramatically with rising temperatures. These instruments can use transmitters, digital
readouts, and data loggers similar to RTD instruments.

Precision Glass Bulb Thermometer
The precision glass bulb thermometer offers a fully manual, low cost approach. Proper
installation is important, including attention to heat transfer within the thermowell. Accuracy
can be better than a thermocouple if the selected range matches the measured range but not
as good as an RTD. Since glass is fragile and mercury is hazardous, one must use caution
with bulb thermometers. Colored alcohol-filled thermometers offer an alternative to
mercury.

Bi-Metallic Dial Thermometer
While convenient and inexpensive, accuracy is inadequate for the precise work of equipment
characterization. The bi-metallic thermometer is ideal for manually monitoring equipment to
verify operation within an allowable range.
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
Infrared (IR) Thermometer
Two of the issues limiting IR thermography from being useful in this application are that
surface emissivity (a value must be entered in the thermometer setup) must be known and
that accuracy varies with temperature. Its primary advantage is that temperatures can be
ascertained without physical contact; however, accuracy is inadequate for equipment
characterization. IR thermometers can be useful in studies of insulation effectiveness and
comparisons among objects. Accuracy can be improved by calibrating with a more accurate
technology.

Thermocouple with Potentiometer or A:D Converter
The type “T” thermocouple, using copper and constantan, has a range of -150 to 370°C. It
produces ~50 mV per °C. It must be calibrated using a precise standard. Using
thermocouples is slightly more difficult than RTDs or thermistors due to the care required to
wire and the need to use a reference junction or an electronic substitute.
The above methods for measuring temperature are summarized in Table 6.
Table 6
Comparison of Temperature Measurement Methods
Cost
Accuracy
Ease of Installation
Ease
Operation
High
±0.1°C (±0.2°F)
Moderate–Difficult
Moderate
RTD w/ Digital Readout
Medium–High
±0.1°C (±0.2°F)
Moderate
Easy
Thermistor w/Digital Readout
Medium–High
±0.1°C (±0.2°F)
Moderate
Easy
Precision Bulb Thermometer
Low–Medium
±0.3°C (±0.5°F)
Easy
Easy
Low
±0.5°C (±1.0°F)
Easy
Easy
Infrared
Medium–High
~0.3–1°C
(~0.5–2°F)
Easy–No Installation
Easy–Moderate
Thermocouple w/ A:D
Converter and Digital Readout
Medium–High
±0.1°C (±0.2°F)
Moderate
Moderate
Type
RTD w/ Data Logger
Bi-Metallic Dial
3.1.5
Fluid Pressure Measurement (Liquid and Gaseous)
Pressure measurement is more segmented by application than temperature or flow
measurements. Pressure measurements in semiconductor fab equipment must span from near
vacuum to pressures of 10 atmospheres or more, both liquids and gases, and from “dirty”
(exhaust streams or process cooling) to ultra high purity (process gases or DIW). Instruments
that can be used include bourdon gauges, strain gauges, aneroid bellows gauges, or manometers.
Care must be taken to measure the true “static” pressure of the exhaust duct and to exclude any
component of the velocity pressure. Static pressure taps for air streams are fabricated from
stainless steel tubing and have several small holes drilled circumferentially around the part of the
tube that is positioned parallel to the flow stream. Placement in non-turbulent regions of the duct
is also important. Steady readings are indicative of placement out of these turbulent regions.
3.1.5.1 Bourdon Tube Gauge (for High Pressure Liquid or Gaseous)
These gauges are available in a range of accuracy from “gross” (> 5%) to precise (0.1%) with
cost adjusted accordingly. As gauges become more accurate, the size typically increases and the
geared movement coupling the bourdon tube to the indicating needle is more precise (see
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Figure 11 for examples of precision gauges). The faceplate for more precise gauges is designed
to eliminate parallax reading error as well. Bourdon tube gauges are inherently streamcontaminating due to the dead end passage, material, and manufacturing process that does not
fully inert the Bourdon tube during welding; attempts have been made to produce “clean” gauges
that may be adequate for some applications.
When measuring pressure in a UPW stream, a diaphragm isolator is used between the gauge and
the stream to eliminate the “deadleg” that allows bacteria growth.
Figure 11
Examples of High Accuracy Test Gauges
3.1.5.2 Strain Gauge Pressure Transducer With Digital Readout (for High Pressure
Gaseous and High Purity)
This is the one technology that can cover virtually all semiconductor fab equipment needs for
SEMI S23 measurements, although it is also the most expensive. Because different instrument
ranges and purity specifications are required, several instruments are needed. For high purity or
corrosive applications, 316 stainless or a high nickel content alloy wetted parts should be
specified as well as internal surface cleaning by electropolishing. Data logging can be substituted
for the digital readout, if desired.
3.1.5.3 Magnetically Coupled Aneroid Bellows Differential Pressure Gauge
(i.e., Magnehelic) (for Low Pressure Gaseous)
This gauge offers a low differential pressure measuring capability (down to 125 Pascal or
0.5 inch w.c.). It is useful for measuring exhaust and supply air pressures when specified with a
suitable range. Because the static pressure capability of some of these instruments is low
(~1 atmosphere), they must NOT be used in higher pressure applications. Figure 12 shows this
type of gauge. This gauge makes water-filled column manometers obsolete in that they are
reasonably accurate, easier to use, and cost only slightly more. The wetted parts are not
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Figure 12
Example of Magnetically Coupled Aneroid Bellows Differential Pressure
Gauge
compatible with highly corrosive fluid streams but in a dead-end service application (e.g.,
exhaust static pressure), deterioration is either a non-issue or occurs very slowly. The general
classification of “aneroid bellows gauge” includes instruments designed to measure low
differential pressures with high static pressures (10 atmospheres or more) that are useful when
measuring the pressure drop across a Pitot tube, a calibrated orifice, or a Venturi to determine a
gaseous flow rate (see Sections 3.1.2.2 and 3.1.2.3).
3.1.5.4 Column Manometer (Water- or Mercury-Filled U-Tube or Inclined)
This can be considered a “bedrock” technology: it is basic, simple, reliable, accurate, and
inexpensive. There are some caveats, however. If the range of the gauge is incorrect, the water or
mercury can be either “blown out” or sucked into the process stream with undesirable or even
hazardous results. Also, this technology is designated for low purity only since contaminating
streams (water or mercury) are in direct “communication” through the sensing tube with the
process stream.
The above methods for measuring pressure are summarized in Table 7.
Table 7
Type
Comparison of Pressure Measurement Methods
Application
Cost
Accuracy
Cleanliness
Precision Bourdon Tube
Gauge
High pressure liquid or gas
Moderate–High
0.1%
Low
Strain Gauge Transducer
w/Digital Readout
Low or high purity liquid or
gas, exhaust or supply air
High
0.01–3%
Low–High
Aneroid or Magnetically
Coupled Bellows Gauge
Low pressure, low purity
gas; exhaust
Moderate
0.5–6%
(4% if > 150 Pa)
Low
Water-Filled Column
Manometer
Exhaust or supply air
Low–Moderate
1–5%
Low
Mercury-Filled Column
Manometer
High pressure liquid or gas
Low–Moderate
1–5%
Low
Bourdon Tube Gauge
High pressure liquid or gas
Low
1–5%
Low–Medium
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3.1.6
Heat Dissipation to Space
Knowledge of how heat dissipates into a space is useful in equipment evaluation and important
to facility designers. All cleanrooms are designed with a finite capacity to remove heat. If
equipment is introduced into the equipment set that dissipates more heat to the space than the
facility can accommodate in that footprint, the temperature of the space will be above
specification locally. Since heat is more economically removed by cooling water than by cool air,
it is preferable to remove most of the waste heat by cooling water.
Heat dissipation into a space can be measured in two ways. The first is direct, while the second is
indirect. The approach used is governed by the equipment configuration as well as the facility in
which to make measurements.
The heat dissipated into the space is also referred to as “heat burden” in SEMI S23 and the
S23 TEE Calculator. Heat burden is represented in Figure 13.
Equipment
+ Energy
= Heat
Some of the heat is removed by heat exhaust and the process cooling water system.
Therefore, heat into the cleanroom minus heat removed by exhaust and process cooling water system
equals the required heat burden to the cleanroom.
If the heat burden is not removed with air conditioning, the temperature in the cleanroom will rise.
Figure 13
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Illustrations of Heat Burden
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3.1.6.1 Indirect
To determine heat dissipation indirectly, the total power consumed by the equipment or produced
through a chemical reaction is first measured and then all measurable power paths emanating
from the equipment, except for the heat radiated or convected to the space, are subtracted from
that value. Algebraically, power to space [kW] = power in [kW] + exothermic reaction [kW]
(if any) – cooling water dissipation [kW] (if any) – exhaust dissipation [kW] (if any). Because
some of these values will vary through the processing cycle, they should all be data-logged to
calculate total annual usage.
SEMI S23 (Table 2) provides ECFs for determining annual kilowatt-hours (kWh) of energy used
to remove heat by exhaust or water, plus a “burden” to be used for the central chilled water plant
energy consumption. Table R1-3 provides an example applying the same ECFs to calculate
annual kWh. These factors are derived from the basic thermodynamic equation: Heat = mass
flow rate  specific heat  temperature change.
3.1.6.2 Direct
If all of the air flowing across the equipment can be measured for flow and temperature rise, then
the heat dissipation can be measured directly. Since this is not the prescribed method in
SEMI S23, an explanation is outside the scope of this document.
3.1.7
Electrical Power
If process equipment has a three-phase electrical load other than pure resistance (heating
element, incandescent lighting), then a three-phase A-C power meter must be used to accurately
measure what is termed “real power” or “effective power.” This device measures both the real
power (wattmeter) and the apparent power (volts  amps  1.732 for 3-phase power) and
determines the ratio between them, known as the “power factor.” Since a customer pays for the
“real power,” it is desirable for the power factor to be near unity (PF = 1). When only singlephase power is required for the equipment, an ammeter and voltmeter can be used to measure the
power consumption.
Because power consumption often varies throughout the equipment’s production steps, the
electrical power should be recorded with a data logger during a full cycle to calculate an average
and determine peaks for facility design.
Instruments that cannot perform the measurements in less than 250 msec should not be used
because they will not be able to adequately characterize the dynamic nature of the electrical load
presented by processing equipment.
The voltage and current measurements should be made with digital instruments capable of
reporting the true root mean square (RMS) value of the voltage and current waveforms,
respectively. The power meter should support and report voltage and current measurements
simultaneously with other measurements. Analog, moving-coil, electrodynamics, or other types
of voltage or current measurement are not suitable for applications in which a full
characterization of a load is necessary. The meter should be used according to the manufacturer’s
instructions, including instrument placement and appropriate settings.
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3.2
Recommended Practice for Equipment Testing
3.2.1
Establishing the Test Plan
3.2.1.1 Specific Utilities
The utilities of interest are only those listed in SEMI S23 0708 that have listed energy conversion
factors (ECFs). Specifically, they are exhaust, vacuum, nitrogen, oil free air, high pressure oil
free air, chiller cooled process cooling water, tower cooled process cooling water, ambient
deionized water, and hot deionized water. Manufacturing equipment may have additional
utilities. These can be measured and reported but are not currently relevant to SEMI S23.
3.2.1.2 Test Points and Required Accuracy
SEMI S23 0708 provides guidance on the minimum set of required measurement points. This is
the same list of points provided in the S23 TEE Energy Calculator (see Table 1). Table 8 also
lists typical measuring points by equipment type.
Table 8
Summary of the Types of Measurements Required by S23 vs. Equipment
Types
N2, Dry Air
(flow rate)
Vacuum
(flow rate)
Cooling
Water (flow
rate, temp
in/out
Process Equipment
including Power
Supply/RF Generator
X
X
X
Vacuum Pump
X
Measurement Points
(Equipment Type)
UPW/DIW
(use flow
rate)
Exhaust
(flow rate,
temp exiting
equip.)
Electrical
Power
Fuel
Used
(heat
rate)
X
X
X
X
X
X
Heat Exchanger + Pump
X
X
Chiller + Pump
X
X
Environmental Chamber
X
X
Circulation Fan
Exhaust Fan
X
X
X
The user must decide whether utilities will be measured for the entire piece of process equipment
or for each component, sub-component, or a combination of components and sub-components.
Measuring to the sub-component level will give a level of data that may allow greater
understanding but at a higher cost and requiring more analysis. Ease of measuring in different
locations within the equipment will also bear on the decision as well as how the data will be
used. Absolute guidance cannot be given.
If the user wishes to verify that their utility operating parameters are similar to those used to
derive the ECFs then additional data for each utility must be measured. Refer to SEMI S23 0708.
The new version of the TEE Calculator does not support use of non-standard ECFs.
More information about instrumentation and required accuracy is provided in all of Section 3.1,
earlier in this document. The reader should also refer to the table of contents.
Table 9 includes recommended instrument accuracy.
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Table 9
Level of Accuracy for S23 Measurements That Would be Acceptable to
Semiconductor Manufacturers
Parameter
Accuracy
Parameter
Accuracy
Liquid Flow
5%
Temperature
0.3°C/0.5°F
Air Flow
6%
Liquid pressure**
3%
Gas Flow
5%
Gaseous pressure <150 Pa**
6%
Power
5%
Gaseous pressure >150 Pa**
4%
Note: ** not required to use the S23 TEE Calculator
When setting up the instruments for automatic data logging, ensure that the instruments are
ranged properly to measure flows incurred during both idle and processing and that sampling rate
is adequate to capture short term fluctuations. If step changes in measured parameters from idle
to process are infrequent, manual data logging may be possible.
3.2.1.3 Location of Points
To locate measuring points (liquid, gas, exhaust) far enough from bends that turbulence does not
adversely affect the readings, follow the guidance in Sections 3.1.1 and 3.1.2.
Making electrical connections for voltage and current measurements may be challenging if there
are many sub-components and space is limited. Select test probes appropriate to the situation.
Temporary installation of current transformers may be preferable to clamp-on amperage probes,
and hard wiring for voltage measurement may be preferable to alligator clips or probe tips.
In all cases, plan for each measured point and buy or rent the necessary equipment before the
test. Once all measurement points have been identified, mark the location of each test point on a
drawing to ensure that points have not been omitted.
3.2.1.4 Test Equipment
List all the test equipment used in the test report. Include manufacturer, model, utility measured,
measurement range, most recent calibration date, and recommended calibration interval. Also,
include data loggers or chart recorders.
3.2.1.5 Calibration
The frequency and method of calibration vary with the instrument. Equipment manufacturers
may have their own internal calibration labs and standards. If not, independent standards labs can
be used. The history of the instrument’s stability and the instrument manufacturer’s
recommendation should be used to guide calibration frequency.
Order precision instruments with calibration curves. Compare subsequent calibrations to those
curves. Calibrate instruments at least annually, although more frequent calibrations can be done
to establish instrument stability.
3.2.1.6 Safety
Safety will not be addressed specifically. It is assumed that each company and person working
with electricity, gases, exhaust, and fluids is trained to recognize hazards and take precautions to
protect themselves from electrocution, asphyxiation, eye injury, and poisoning that can result
from an improper methodology.
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3.2.2
Guidance on Testing Procedures and Data Reporting
3.2.2.1 Data Needed to Use the TEE Calculator
The TEE Calculator has been configured to accommodate data measured at the component and
equipment level. If components are broken into sub-components, each sub-component is treated
as a distinct component. See the example in Figure 14.
Component 1
Subcomponent 1
(vacuum pump &
power supply)
Power, N2,
PCW
Component 2
Subcomponent 2
(chamber)
Exhaust &
Power
Subcomponent 3
(vacuum pump
and power
supply)
Power, N2, PCW
Subcomponent 4
(chamber)
Exhaust &
Power
User measures: % time at
max/min flow or power and
max/min flow or power for
each component utility down to
Sub-component
Equipment 1: Two
component tool
Power, N2, exhaust, PCW
Define: % process/idle for each component
and max./min. flow or power for each
component utility. TEE Calculator sums all
component utilities, properly ratioed for
process/idle/percent.
Figure 14
Relationship Among Sub-Components, Components, and Equipment
To ensure measurements of the total equivalent energy to process a given number of wafers are
accurate, measure energy from all sub-components and components as simultaneously as
possible. The measured data must capture the minimum and maximum power or utility flow and
the duration or percentage of time at the minimum and maximum rate for each component as it is
not expected that every component is loaded for an identical percentage of the processing cycle.
The required data may be more easily understood from the sample spreadsheets. See also
Section 4, which explains data entry for the TEE Calculator. See Table 10 and Table 11.
TEE Calculator users can either collect data at the component level only and have the TEE
Calculator sum the data for all defined equipment components OR collect data at the equipment
level only, but not both. The fewest data collection points are likely with a sampling scheme that
measures at the equipment level, but practical reasons may govern choosing to measure at the
component level (access, routing of individual gas and power lines to each component, etc.).
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After completing calculations at the component level, the TEE is summed for the defined piece
of equipment consisting of one or more components. The heat burden is then calculated based on
the user-defined equipment-level process/idle/other percentages. The calculator was configured
to calculate heat burden based on the SEMI S23 format of equipment basis. Consequently, the
user should enter process/idle/other percentages when entering equipment information.
If the user does not have max/min flow and power information and wants to use data that have
already been averaged over the processing cycle, a value of 100% is entered for “processing” and
0% for “idle” along with the average value measured or calculated entered in the “Max
flow/power” blanks in the user input form (shown as Col. C in Table 11). An “Idling
flow/power” must still be entered (shown as Col E in Table 10,) for the calculator to properly
calculate the idle TEE if the component has idle time.
Table 10
Test Component 1
Typical Component-Level Utility Data Required for the TEE Calculator
80%
Processing % of year
15%
Idling % of year
5%
Other % of year
See notes
% times, are for a full process cycle
% Time at Max
Flow/Power While
Processing
Max Flow/Power
% Time at Idling or
Min Flow/Power While
Processing
Idling
Flow/Power
Col B
Col C
Col D
Col E
Exhaust
50%
450
50%
200
M3/hr
N2
90%
10
10%
5
M3/hr
Unit
PV
90%
5
10%
2.5
M3/hr
Dry Air
90%
10
10%
5
M3/hr
HP Dry Air
100%
5
0%
3
M3/hr
PCW chilled
100%
2.3
0%
M3/hr
PCW evap
100%
1.1
0%
M3/hr
UPW
100%
10
0%
M3/hr
Hot UPW
100%
5
0%
M3/hr
Mean real power
90%
100
10%
Note1
Note 2
30
kW
User provides measured data. SEMI S23-0708, recommends using values of 70% processing, 25% idle, and 5%
inactive, but any relevant values can be used.
Max/Min flow is calculated from either component data or measured directly at equipment.
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Table 11
See notes
below
Math:
Exhaust
Component-Level Typical Calculation Performed by the TEE Calculator
Average
Processing
Flow/Power
Idling
Flow/Power
Col H
Col I
ECF
Processing
TEE [kWh/hr]
Idling TEE
[kWh/hr]
Processing TEE
Annual [kWh/yr]
Idling TEE
Annual
[kWh/yr
Col J
Col K
Col L
Col M
Col N
Col L  %
Idle  hrs/yr
Col B  Col C
+ Col D 
Col E
Col E
Constants
Col H  Col J
Col I  Col J
Col K  %
Processing x
hrs/yr
325
200
0.0037
1.2
0.7
8427
972
N2
9.5
5
0.25
2.4
1.3
16644
1643
PV
4.75
2.5
0.06
0.3
0.2
1997
197
Dry Air
9.5
5
0.147
1.4
0.7
9787
966
5
3
0.175
0.9
0.5
6132
690
PCW
Chilled
2.3
0
1.563
3.6
0.0
25193
0
PCW Evap
1.1
0
0.26
0.3
0.0
2004
0
UPW
10
0
9
90.0
0.0
630720
0
Hot UPW
5
0
92.2
461.0
0.0
3230688
0
Mean Real
Power
93
30
1
93
30
651744
39420
HP Dry Air
Note1 Column (“Col”) references to Col B through E refer to columns noted in Table 11.
Note2 TEE Calculator performs calculations in Col H, I, K, L, M, and N.
3.2.2.2 Sampling
Data can be recorded manually or automatically (with a data logger). Any instrument with a
current or voltage output can be connected to a data logger or a computer can be used as a data
logger through an electronic interface card.
Automatic data collection is preferred if the process variable changes frequently during the
process cycle and if unattended data collection and digital data manipulation are preferred.
The frequency of sampling is based on the stability of the process variable being measured. The
degree of stability can be determined using analog instruments before deciding how often to log
datapoints. Alternatively, a high data-logging rate (e.g., every 5–15 seconds for non-electrical
points and milliseconds for electrical points) can be set and then adjusted based on an analysis of
the stability of the logged points.
Be aware of the time constant of the instrument (i.e., how long the instrument takes to reach
equilibrium for a given measured value). For example, pressure readings reach stability almost
instantaneously, but temperatures may take 30 seconds or longer. If a process variable changes
more quickly than an instrument can accurately measure it or record the value, then the data will
be inaccurate.
ISMI
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3.2.2.3 Test Duration
To comply with SEMI S23, the test should last long enough to process 10 substrates or, if not
processing substrates, then at least 30 minutes. Minimum and maximum values should be
determined for each utility as well as a time split (in %) between the minimum and maximum
values. Idle time measurement between processing cycles should also be at least 30 minutes and
an average value determined. Because setting up the test is expensive, measure long enough to
be certain that the data quality is acceptable.
3.2.2.4 Acceptable Test Methods
See Section 3.2.1.2 and Table 9.
3.2.2.5 Data Analysis/Reporting Format (Tabular, Graphical, Supporting Documentation,
Dealing With Non-Linear Graphical Data)
Download data collected with data loggers to spreadsheets and graph it with easily understood
datapoint labels with units and scales included on all axes. Similarly, transcribe any data
collected manually to spreadsheets and graph as above.
Where data are non-linear, use “best fit” techniques to establish average values for the time
interval or average the logged values from the spreadsheets and report the average values
calculated for the time intervals. Do not average values that cannot be averaged: e.g., velocity
pressure cannot be averaged, but velocity can be.
3.2.3
S23 TEE Report Content
3.2.3.1 Management Summary
Describe only the equipment, the equipment configuration, main processing parameters, and
TEE result for the equipment, including TEE per wafer pass. If this was a follow-up study,
describe what changed in the equipment and the net change in TEE.
3.2.3.2 Equipment and Test Scope
Describe the subcomponents, components, and equipment to a level adequate to be able to
differentiate this equipment from other competitive equipment and to be able to later refer to the
report and understand exactly what was tested. Include a block diagram showing the
interconnection between components and sub-components with the utilities measured clearly
defined. Show utility line sizes (wire, duct, tube, pipe) for all utilities measured.
Describe the “process cycle” for this equipment: how long the equipment operate while
measuring utility flow rates and the amount of product (numbers of wafers) processed during that
time.
Table R1-1 from SEMI S23-0708 recommends data to be recorded for each equipment test.
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Table 12
SEMI Recommended Additional Data
Data Title
Description
Date
When the measurements were taken.
Equipment Under Test (EUT)
The equipment from which the measurements were taken.
Provide information such as general description, model
number, and serial number.
EUT Configuration
The configuration of the equipment during the
measurements, such as sub-systems that were or were not
used and optional hardware that was installed.
Test Location
Where the measurement testing was done such as the
particular test laboratory or manufacturing location.
Principal Test Personnel
The principal personnel involved in developing the test plan
and conducting the testing.
Test Recipe
The recipe used when conducting the test.
Test Throughput (per hour)
How many substrates or other material quantity was
processed per hour during the test.
Throughput Calculation Method
How is throughput determined?
Wafer Size
What size wafer is processed by the equipment.
Test Duration
How long the equipment was operating for gathering the test
data.
Test Setup
How the several pieces of test equipment were connected to
the EUT.
Test Equipment and Relevant Calibration
Information for measuring:
The test equipment that was used to measure the use rate
of each utility or material and its relevant calibration
information such as when the test equipment was last
calibrated and when it should be calibrated again.
Exhaust
Vacuum
Dry Air
Nitrogen
Process Gas (at or above atmospheric pressure)
Process Gas (below atmospheric pressure)
Process Solids
Process Liquids
Cooling Water
Ultra Pure Water (UPW)
Electricity
Heat Load
High Pressure Dry Air
Hot UPW
Note: Republished with permission from Semiconductor Equipment and Materials International, Inc. (SEMI) © 2009.
3.2.4
Data Collection Methods/Analysis/Assumptions
3.2.4.1 Methods
List the instrumentation used to collect data (make, model, most recent calibration date and
estimated or stated accuracy). Provide diagrams, schematics, and/or photographs showing where
the instruments were connected. Explain the data collection plan (frequency of sampling,
sampling time, and total duration for each measured value), and the way average values were
determined from the measured data.
List any assumptions used in data collection. For example, power consumption was constant
during processing or temperature was constant during processing.
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3.2.4.2 Results
Provide raw data clearly marked to indicate the datapoint measured. For example, “Vacuum
pump #1 PCW flow [gpm]” is acceptable, but “FT105-3” is not acceptable unless a key explains
the abbreviated labels. If data loggers are used, raw data will be printouts indicating date, time,
and value from start of sampling to end of sampling. Graphs are an acceptable and a preferred
substitute for tabular data. Clearly show the average value (minimum/maximum or process/idle)
determined for each measured variable in the table or graph.
If the measured data was entered into the calculator and TEE per year was determined, then the
report should include that value as well as a calculation of TEE per wafer pass. Calculate this
value by dividing Total Equivalent Energy (kWh/year) derived by the TEE Calculator by the
number of wafer passes that would occur during the year.
3.2.4.3 Discussion/Summary
Using the data collected and output from the TEE Calculator, summarize the results with graphs
of each measured utility and provide minimum and maximum flow rates, power consumption,
and duration of minimum and maximum flow rates and power consumption during the
processing cycle.
Include graphs of total equivalent energy by utility, a Pareto of total equivalent energy by
component, pie chart comparisons between idle and processing total equivalent energy and
comparison to other tools by the same manufacturer (total equivalent energy and process vs. idle.
3.2.4.4 Recommendations
Include any observations about ways to reduce the total equivalent energy usage, problems
encountered making measurements and their resolution, and any other comments pertinent to
testing the equipment or the results.
3.3
Recommended Practices for Reducing Utility Usage
3.3.1
Chilled Water
Few equipment manufacturers use this facility system directly. Typically, it is plumbed
throughout the wafer fab for the air conditioning system (cooling and dehumidification) and to
the process cooling water heat exchanger. The supply temperature is selected based on need and
economics. It has a setpoint, typically between 36°F and 55°F (2.2°C and 12.8°C). One or two
systems may have different temperature setpoints, as well: one toward the lower end of the range
and one toward the higher end of the range. Because the efficiency of central chilled water
systems is better than that of small packaged chillers (kW power consumed per kW cooling
effect), direct use would save energy but might increase the total cost due to additional piping
systems in the sub-fab. Using chilled water that has a temperature below the dewpoint of the
surrounding air will cause condensation on equipment surfaces unless the surfaces are adequately
insulated.
Another way to reduce energy consumption would be for process equipment designers to
standardize a higher inlet temperature requirement for process cooling water (increase from
10–12.8°C (50–55°F) to 15.6–18.3°C (60–65°F) so that a higher temperature chilled water
system can be used to remove heat from the process cooling water loop. This will be successful
only if all suppliers can raise their specified maximum inlet temperature. For a 760 liter/sec (lps)
(12,000 gal/min [gpm]) system operating with a 3.9°C (7°F) temperature differential,
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~ 6 million kWh/year would be saved due to the higher efficiency of removing the heat with a
10°C (55°F) chilled water loop rather than a 3.9°C (39°F) loop.
3.3.2
Process Cooling Water (PCW)
When a PCW system or systems are isolated from the facility chilled water system, the PCW
system or systems can operate at a higher temperature than the chilled water system, have a
higher differential pressure between supply and return, and be chemically isolated to assure fluid
cleanliness and corrosion treatment adapted to a system containing copper, aluminum, and
ferrous metals. Three principal factors govern efficiency in using PCW systems to remove heat
from equipment.
3.3.2.1 Supply/Return Temperature
If a higher process equipment inlet temperature is applied, the process equipment heat exchanger
may need to be enlarged or the process equipment chiller may need to be modified to accept the
higher inlet temperature. If the temperature differential between the equipment supply and return
is increased, the flow rate can be reduced, saving both pump energy and ultimately allowing the
piping size to be reduced. While a typical facility chilled water system design temperature
differential is 8.9°C (16°F), the PCW average design differential for the past 25 years has
remained at 4.2°C (7.5°F). For a 760 liter/sec (12,000 gpm) system, this adds
1.8 million kWh/year in pumping energy and prevents reducing the flow rate to 360 liter/sec
(5625 gpm).
3.3.2.2 Supply/Return Pressure
PCW systems require approximately 310 kPa (45 psi) differential to overcome equipment piping
and internal restrictions. This is more than 2X the differential of facility system equipment. If all
equipment could reduce flow restrictions to a lower common value (e.g., 207 kPa [30 psi]), then
the differential pressure of the system could be lowered. For a 760 lps (12,000 gpm) system, this
would save 1.2 million kWh/year in pumping energy.
Can the PCW supply temperature, differential temperature, and differential pressure
requirements for equipment be improved? What would the impact be on heat exchanger size and
how would the changes impact equipment cost and performance?
3.3.2.3 Flow Control
PCW flow should be restricted to maintain the minimum flow required to adequately remove
equipment-generated heat at all times. Currently, not all equipment have thermostatic or
process:idle flow reducing controls. Since the PCW system controls typically respond to reduced
flow demand by reducing supply pump speed, controlling equipment flow can save some energy.
However, this is the least important of the three factors.
3.3.3
Compressed Gas
The gases of interest from an energy conservation standpoint are those for which electrical
energy is used for on-site compression rather than cryogenic gases that develop pressure by
evaporating cryogenic liquid. The compressed air system and on-site nitrogen plant are
significant energy users. Work at SEMATECH and elsewhere has highlighted opportunities for
consumption reduction, pressure reduction, and replacement of nitrogen with clean, dry
compressed air.
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3.3.3.1 Pressure at Point of Connection (POC)
For nitrogen generated on site and compressed air, the required pressure at the POC drives
energy consumption. An additional 103 kPa (15-psi) of pressure requires ~3% more power. Since
the incremental cost is low (< $15K for a 212 m3/min [7500 scfm] compressed air system at
$ 0.06/kwh), efforts to reduce supply pressure may be unjustified. However, if a single piece of
equipment is developed with a supply pressure requirement above the currently installed facility
capability, it then dictates that an entirely new system is added to factories with a major capital
cost component as well as a higher operating cost.
3.3.3.2 Flow Control
Since gas systems operate to match demand, efforts to reduce flow will result in savings
approximately proportional to the reduction. The degree to which this is true depends on how the
facility system is designed to accommodate start-up and low flow conditions. Centrifugal
compressors have turndown limits (15% typically), which suggests that flow reduction at the
equipment may be negated by an oversized facility system or one that is still being ramped with
a partially fitted out fab. Rotary screw compressors have superior turndown capability (~ 80%)
but are slightly less efficient, overall.
Central process vacuum compressors can also be retrofitted with variable speed drives so that the
system responds to flow reduction by reducing capacity using a slower motor speed to maintain a
constant system setpoint pressure.
3.3.4
Exhaust
The energy consumed to exhaust equipment is proportional to the quantity of exhaust and the
pressure required to move the exhaust air stream. The basic principle of minimizing exhaust flow
is to fully isolate the hazard and then minimize the aperture between the hazard and the operator.
Beyond that, there are several techniques for minimizing flow, e.g., multi-sided slots around tank
surfaces, push-pull exhaust, full-containment with robotic manipulation, etc. References such as
Industrial Ventilation: A Manual of Recommended Practice, published by the American
Conference of Governmental Industrial Hygienists, 1998, or ASHRAE Handbook: HVAC
Applications, 1999 edition, Chapter 29, may be helpful. Equipment suppliers should not apply
arbitrary rules such as “providing so many air changes per hour” or “so many meters/second face
velocity;” instead the industry should use computational fluid dynamics (CFD) to model
equipment in development or use tracer gas analysis (see SEMI F15-93) to validate exhaust rates
for operating equipment. SEMATECH has undertaken several exhaust reduction and
optimization studies (see Section 5).
Using a heat exchanger to recover heat from heat exhaust is not cost-effective unless the exhaust
stream is very hot, 65°C (150°F). However, if the stream has no other contaminants than heat
and perhaps some particulates, it may be possible to discharge the warm stream into the
cleanroom return plenum or into another adjacent space that requires outside air.
Dampers should be inspected for in-leakage, especially blast gate dampers.
3.3.4.1 Pressure at POC
Once flow is minimized, suction pressure at the POC can be investigated. Currently, the typical
facility allowance for equipment is (-)500 Pascal (-2 inch w.c.). Constant pressure should be
maintained automatically by an end-of-duct pressure control loop and variable speed fans.
Unless all equipment can achieve an across-the-board pressure reduction, however, there will be
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little or no benefit to total facility exhaust energy consumption since normally equipment are
connected to a common system. If a single piece of equipment or several pieces of equipment
have a requirement greater than the norm, it may be beneficial to redesign that equipment to
provide a booster fan for the equipment(s) to make up for the deficiency.
Several references (e.g., ASHRAE Fundamentals, the 2005 edition, Chapter 35 or SMACNA
HVAC Duct System Design) provide information on the impact of duct transitions and fitting
geometry on pressure loss.
For an exhaust system of 4250 m3/min (150,000 cfm), a flow reduction of 10% and an operating
pressure reduction of 62.5 Pa (0.25 inch w.c.) would result in an annual savings of
~360,000 kWh.
3.3.4.2 Flow Control
Controlling the flow (stopping if inactive) in equipment or hoods is not done as frequently in
semiconductor manufacturing as in research laboratories. Reasons are many, including the small
percentage of the total energy bill (<10%), often 24/7 operation, relatively high cost of controls,
corrosiveness of exhaust on flow control devices, and the need to minimize system perturbation
from equipment changing flow. Flow reduction in inactive or periodically used equipment
presents a significant challenge. Since all equipment connected to a variable flow exhaust system
must have individual flow controls whether or not the equipment will use variable flow,
economics can be greatly improved by identifying and isolating the variable flow equipment to a
dedicated variable flow exhaust system.
To evaluate the cost effectiveness of flow reduction strategies, the annual cost per unit of exhaust
(e.g., Euros/CMH or $/cfm, etc.) must first be determined. The capital cost should also be
ascertained if the flow reduction could be applied to new construction. Since reduced exhaust
directly impacts fresh air makeup, the impact on energy and capital cost is considerable.
3.3.5
Fan/Filter Selection (Minienvironment)
Minienvironment efficiency can be addressed in terms of watts per unit of airflow (cubic
meters/sec or cubic feet/minute). The factors governing “real power” consumption are fan and
motor efficiency, losses in the flow control mechanism (typically either a variable speed motor
control or pressure drop across a throttling damper), and filter pressure drop. A filter’s pressure
drop depends on the total filter media area (not just face area) and face velocity.
Table 13 shows the performance parameters for a typical high efficiency fan filter unit.
Another useful parameter to define is cost per unit of airflow rate. Given this parameter and
power per unit of airflow, one can make an intelligent decision on changes that reduce power
consumption but increase total cost.
Table 13
Typical High Efficiency Fan Filter Unit Performance
Parameter
Face Velocity
English Units
0.406 m/s
80 fpm
Static Pressure
154 Pa
0.62 inch w.c.
Unit Power Consumption
208 W
208 W
Power/Unit Air Flow
ISMI
Metric Units
3
0.10 W/m /hour
0.17 W/cfm
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3.3.6
Optimizing Pipe and Duct Size
The size of the duct or piping inside the equipment as well as between the equipment and lateral
plays a large part in dictating the required pressure differential or “driving force” across the
equipment for PCW and exhaust. Owners could develop a Pareto of required exhaust pressure or
fluid pressure/differential pressure by equipment for their equipment sets. They then can work
with equipment suppliers to determine what extra cost would be incurred to improve the
differential pressure requirement by an incremental amount corresponding to an across-the-fab
energy reduction. A favorable scenario would be one in which improvements to a few pieces of
equipment would significantly reduce system differential pressure. For each system, the object
would be to have the least extra capital cost for the greatest energy savings.
3.3.7
Electricity
3.3.7.1 Supply Voltage
Generally, supplying equipment at a higher standard voltage is preferred to a lower voltage. For
example, 480 V is preferred to 208 V. Higher voltage eliminates an extra transformation step and
transformation loss; reduces the number of required facility substations, saving capital and space;
and allows longer wire runs due to the lower voltage drop per length. It also can reduce
conductor size (since power is proportional to voltage and current), saving cost and space. Threephase power is a standard for 208 V and above. Motors should be specified as three-phase due to
their lower cost and superior efficiency.
3.3.7.2 Variable Speed Drives (VSDs)
Electrical VSDs operate by stopping the flow of current to the device for a part of the sinusoidal
cycle. Reliability is acceptable, and cost has been declining as more have been installed. They
are available in ~0.1–500 kW (or fractional horsepower to hundreds of horsepower) and both
single- and three-phase. Speed is set either by hand or by a control signal input. Because current
is frequently interrupted, VSDs tend to decrease motor-bearing life. This is overcome by
specifying “VSD-compatible motors.” Electrical arcing across the bearing has sometimes
resulted in rapid wear and early failure. Installing motor shaft grounds or insulating the bearings
from the motor frames can overcome this problem. These issues and solutions are well
understood by motor and drive specialists.
3.4
Recommended Practices for Specific Equipment
3.4.1
Role of Economics
Nearly every equipment improvement that reduces energy consumption has a corresponding cost
increase. Although some design improvements are nearly “free,” most equipment improvement
costs need to be justified. Each user has a method to determine cost effectiveness (e.g., simple
payback, internal rate of return, or net present value). The supplier’s role is to characterize and
report the cost impacts to the end user—capital, installation, maintenance, consumables,
equipment life, etc.—and the corresponding annual energy use reduction, allowing the user to
perform an economic analysis.
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3.4.2
Process vs. Idle Mode
Equipment does not process wafers continuously. Hence, turning off or reducing the flow of
utilities when they are not needed in both process and idle modes is ideal; however, not all
utilities ramp up and down with usage. For example, reducing the flow of bulk gases, electricity,
and cooling saves money (although there are limits to turndown that come into play during a new
plant startup). But unless expensive pressure or flow controllers are used at each piece of
equipment, exhaust is difficult to turn down without impacting the flow from adjacent
equipment.
In general, the equipment supplier should assess opportunities to reduce utilities during idle
mode, work with the end user to determine potential cost savings, and then determine whether
the cost savings will be sufficient to pay for the cost of the additional controls to limit gas,
exhaust, cooling water, or vacuum flow or to reduce speed of vacuum pumps or cooling pump
motors.
3.4.3
Liquid Pumps
3.4.3.1 Type of Pump vs. Energy Consumption
Numerous types of pumps move fluids, e.g., centrifugal, diaphragm, and reciprocating positive
displacement (piston or plunger). The object in selecting one for minimum energy consumption
should be to minimize excess capacity and head (pressure) and maximize pump efficiency. For
example, compare an air-operated diaphragm pump to a centrifugal pump for a clean water
application. Using one supplier of each (diaphragm vs. centrifugal), at a flow of 0.63 lps
(10 gpm) and 241 kPa (35 psig) head, the diaphragm pump using compressed air requires ~4X as
much electrical energy to operate—(6.13 lps [13 scfm] of air at 655 kPa [95 psig] and 3.1 kW or
0.24 kW/scfm for compressed air vs. 0.74 kW or a ¾ horsepower motor). Installation and
operating advantages of each type of pump as well as total capital cost for the pumps and
installation would need to be considered to make the appropriate decision. Also, for the same
type of pump, efficiency can vary considerably; it is recommended to check several
manufacturers before making a selection.
3.4.3.2 Adequate Pressure vs. Excessive Pressure
Calculating the exact equipment pressure and flow requirement is seldom possible, often
resulting in oversized pumps. To absorb the excess capacity, a discharge valve is throttled. This
inefficiency can be overcome two ways:
1.
“Trim” (machine to a smaller diameter) the impeller to the exact requirement. This
makes sense if there is time to do the necessary testing after installing, there are
sufficient numbers of pumps in identical applications, or there is a large amount of
energy to be saved.
2.
Add a variable speed drive to reduce the motor/pump speed to the required
flow/pressure. This is commonly done in facilities cooling and heating systems. Some
motor-drive combinations produce significantly more acoustic noise than others; testing
or experience should guide the selection of these components (see Section 3.1.7).
ISMI
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3.4.4
Packaged Chillers and Heat Exchangers
3.4.4.1 Individual Chillers vs. Central System With Heat Exchanger
Most suppliers of individual chiller packages also offer heat exchanger packages. If only cooling
is needed and the required supply temperature is high enough (typically 15–20°C or 59–68°F), a
heat exchanger package can be considered using PCW to provide the cooling. Package
refrigeration is required for lower temperatures.
A non-conventional but more energy efficient solution would be to consider using the facilitychilled water system instead of PCW to provide direct cooling through a heat exchanger. The
facility-chilled water system typically supplies chilled water between 2.2–12.8°C (36–55°F) vs.
PCW at 11–16°C (52–61°F) (all temperatures depend on the user’s preference). With a 3°C
(~5°F) approach for the “warm” side of the heat exchanger, using the facility-chilled water
system with a heat exchanger, one could obtain 9–15°C (48–59°F) fluid for the equipment. The
facility-chilled water system uses less electrical energy than the packaged chiller, perhaps onethird to one-half less, but adds capital cost to pipe the water to the equipment heat exchangers.
Pipe insulation would be needed on the lower temperature piping and heat exchanger surfaces to
prevent condensation.
3.4.4.2 Simultaneous Heating and Cooling
Some packaged temperature control units can both cool and heat the process fluid. Energy
efficient design precludes simultaneous heating and cooling. Also, when in heating mode,
refrigeration compressors and PCW flow for condensing should ideally be “off.”
3.4.4.3 Capacity Modulation
In order of preference (best to worst) are variable speed compressors, cycling compressors,
unloading compressors, and hot gas bypass.
3.4.4.4 Condensing Temperature
The PCW setpoint of 11–16°C (52–61°F) is quite a low temperature to be used for refrigerant
condensing. Some pumping energy may be saved with only minor impact on packaged chiller
power by installing thermostatic valves to control the chiller package condensing temperature at
a higher value.
Installing a separate condenser water loop for the equipment chiller packages and any other
process equipment that can operate at a higher temperature could be evaluated. In some locales, a
closed circuit evaporative cooler can be used. For example, with site wet bulb temperatures of
18–24°C (65–75°F), 24–30°C (75–86°F), cooling water could be provided. The negative impact
of operating cost on the packaged chillers from raising the condenser supply temperature and
adding capital cost would need to be compared to the positive impact of reducing the facilitychilled water plant and PCW system capacities.
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3.4.5
Power Supplies/RF Generators
3.4.5.1 Improved Efficiency of ACDC Converters (Rectification and Regulation)
Power supplies could be sized more accurately to their loads; units are often oversized by a
factor of 2 to 3 decreasing efficiency from ~80% to 70% or less. The trend in processing has
been to decrease power consumption, but power supply sizing does not reflect that trend.
Advances in ACDC rectifiers (higher frequency and improved amplifier designs) are not
necessarily being applied. Cost/benefit analyses for improvements should be provided by
suppliers.
3.4.6
Heat Exchangers
3.4.6.1 Pressure Drop
Industrial heat exchanger applications are normally specified at a 35–103 kPa (5–15 psi)
differential. Plate and frame heat exchangers can achieve pressure differentials on the low end of
this range. However, there is no benefit in specifying and designing a heat exchanger package
with a low pressure differential on the cold side when parallel circuits with equipment are
installed on the same PCW system with pressure differentials 2–3X as great. There is a benefit,
however, in having a low pressure differential specified for the “hot side” of the exchanger since
it is a separately pumped circuit between the equipment and the heat exchanger.
3.4.6.2 Temperature Differential
The average PCW system temperature differential is ~3°C (5.5°F), which necessitates an
excessively high circulation rate. A reasonable target would be 8.3°C (15°F) or higher. Some
equipment is already achieving this.
3.4.7
Fans and Ductwork
3.4.7.1 Motor and Fan Efficiency
Efficiency of AC electric squirrel cage induction motors varies by speed, size, and type (open or
enclosed). ANSI/ASHRAE/IESNA Standard 90.1-2004, Energy Standard for Buildings Except
Low-Rise Residential Buildings, provides values that would be an excellent target (see Table 14).
Table 14
Motor Power vs. Efficiency
Type
Open
Open
Open
Enclosed
Enclosed
Enclosed
Speed (RPM)
3600
1800
1200
3600
1800
1200
kW (HP)
0.75 (1)
82.5
80.0
75.5
82.5
80.0
1.1 (1.5)
82.5
84.0
84.0
82.5
84.0
85.5
1.5 (2)
84.0
84.0
85.5
84.0
84.0
86.5
2.25 (3)
84.0
86.5
85.5
85.5
87.5
87.5
3.75 (5)
85.5
87.5
87.5
87.5
87.5
87.5
5.6 (7.5)
87.5
88.5
88.5
88.5
89.5
89.5
7.5 (10)
88.5
89.5
90.2
89.5
89.5
89.5
11.2 (15)
89.5
91.0
90.2
90.2
91.0
90.2
Note:
ISMI
Table derived from ANSI/ASHRAE/IESNA Standard 90.1-2004.
Technology Transfer #06094783D-ENG
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The mechanical efficiency of fans varies with fan type, size, speed, air density, and pressure
developed. Small fans used in minienvironments are low in efficiency (<50%), while larger fans
used in environmental chamber circulation schemes could approach 70% under ideal conditions.
Although not available in very small sizes, backward curved and backward curved airfoil-bladed
fans are the most efficient. The best approach to optimizing fan efficiency is to compare different
manufacturer’s offerings with respect to features, capacity, pressure capability, noise, power
consumption, and cost for the same application. Then a technical and cost analysis can be
completed.
3.4.7.2 Duct Design
Power to operate a fan is proportional to the air flow rate and the pressure developed. While flow
rate may be fixed by the process, the pressure developed not only consists of the resistance to
flow of the required system elements such as filters and cooling heat transfer surfaces but also is
influenced by how well the system is designed to minimize pressure losses as the air flows
through the system. Duct size and smoothness, elbow radius, transition length and geometry,
length of the straight duct entering and leaving a fan and location of elbows at the fan entrance
and discharge, damper size and type, and velocity through system elements (filters, cooling heat
transfer surface) all influence system pressure loss. In general, lower velocity reduces friction
losses—and hence fan power and operating cost—but increases capital cost and component size.
A tradeoff analysis should be completed. Evaluation is not straightforward, but excellent
references are available. The SMACNA Duct System Design and ASHRAE Fundamentals are
two suggested references. A positive outcome from duct design improvements is an across-theboard reduction in exhaust system pressure achieved by a pressure requirement reduction for
equipment with the highest exhaust pressure requirements. Note that reductions by equipment
NOT currently driving the system pressure will not reduce facility operating costs and will not be
cost-effective.
3.4.7.3 Variable Speed Application
Wherever a damper is used to throttle excess pressure (e.g., mini-environment or environmental
chamber), applying a variable speed drive to the fan motor should be considered. Fan power
varies approximately as the cube of speed; therefore, a small reduction in speed can save
considerable power (25% speed reduction = 50 + % power reduction).
3.4.8
Filters
Filter pressure drop is governed by the type of media, air velocity through the media, and total
area of the media. From an energy consumption standpoint, a low initial pressure drop and low
face velocity are desired outcomes. Normally, improving these increases capital cost by
increasing the filter depth or the total area of the filter pack and possibly equipment size. Filter
manufacturers also offer a variety of filter media at different efficiencies vs. pressure drop and
cost. Once the costs and impacts on power consumption are known, a cost effectiveness analysis
can be completed.
3.4.9
Minienvironments
Since minienvironments consist of fans and filters, the discussion of fan efficiency, pressure drop
vs. filter depth/filter design, and variable speed drive applies to efforts to decrease power
consumption.
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3.4.9.1 Environmental Chambers
Since environmental chambers consist of fans, filters, chillers, heat exchangers, and ductwork,
the discussion of fan efficiency, pressure drop vs. filter depth/filter design, ductwork, packaged
chillers, heat exchangers, and variable speed drive applies to efforts to decrease power
consumption.
3.4.9.2 Cooling/Heating/Humidity Control Methodology
The elements of an environmental chamber temperature control system consist of an air
cooling/dehumidifying heat exchanger, an air reheater, a humidifier, a refrigeration system,
piping, controls, and the above discussed fans, filters, and duct. Because functionality is not an
issue with current products, inquiry should focus on a few key areas that impact energy
consumption:

How is the cooling heat exchanger optimized?
Is the cooling coil optimized with respect to fin spacing and fin profile vs. number of
rows to achieve the lowest airside pressure drop? Is the coil face area large enough to
optimize the pressure drop vs. first cost?

Do humidifying and dehumidifying occur simultaneously?
Is there a need to dehumidify at all if the space dewpoint, setpoint, and variation are
identical to the environmental chamber dewpoint, setpoint, and variation?

How is humidification accomplished?
What is the kWh per mass of water evaporated? Is the most efficient means of
humidification being used?

How is the air reheated?
Is any waste heat from refrigeration used?

How is refrigeration capacity controlled?
Are there multiple compressors with unloading (e.g., 2 stage  2 compressors or 2 stage
 1 compressor)? Is hot gas bypass used? What increment of capacity is unloaded by
hot gas bypass (e.g., last 25% or 50%)?

What is the efficiency of the refrigeration process as defined by the coefficient of
performance?
ANSI/ASHRAE/IESNA Standard 90.1-2004, Energy Standard for Buildings Except
Low-Rise Residential Buildings, recommends a target COP between 5.0 and 6.0 for
small centrifugal chillers. Environmental chamber refrigeration systems are not likely to
achieve these results, but the methodology for comparison is applicable. Comparing
work “out”—or in this case, cooling effect to energy “in”—will allow comparisons
among suppliers and configurations.
3.4.9.3 Piping
Piping and duct optimization are similar in approach (see Section 3.4.7). Facility designers have
developed guidance for sizing larger pipes and ducts for cost-effective designs. This is usually in
either maximum velocity per pipe/duct size or pressure drop per unit length. Developing general
guidance for equipment internal piping based on a cost-benefit analysis may be complicated by
ISMI
Technology Transfer #06094783D-ENG
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the impact of enlarging the pipe and duct (or airway) within the equipment. However, suppliers
should still try to optimize capital cost against energy consumption.
Design information is available in many supplier catalogs, technical guides, and handbooks
(e.g., +GF+ Plastics, Harrington Plastics, Harvel Plastics, Swagelock, Cameron Hydraulic Data
by Ingersol-Dresser, or Technical Paper 410: Flow of Fluids Through Valves, Fittings, and Pipe
by Crane). If tubing is used, the tables in some of these guides may not be applicable, but
formulas for calculating pressure drop may be applied.
Since piping friction varies approximately with flow “squared” and inversely with pipe diameter
to the 5th power, only a small increase in pipe size will dramatically reduce friction. For
example, the data in Table 15 are representative for schedule 80 PVC piping.
Table 15
Flow vs. Velocity and Friction Loss by Pipe Size
Size
20 mm
25 mm
32 mm
I.D.
16 mm
21 mm
27 mm
Flow (lps)
Velocity
(mps)
Friction Loss
(kPa/m)
Velocity
(mps)
Friction Loss
(kPa/m)
Velocity
(mps)
Friction Loss
(kPa/m)
0.13
0.90
0.79
0.48
0.17
0.29
0.09
0.32
2.25
4.43
1.20
0.95
0.71
0.27
0.44
3.15
8.13
1.67
1.74
1.0
0.49
2.28
3.31
1.43
0.94
0.63
Note: In metric units, “Size” refers to nominal outside diameter; I.D. refers ~ to internal diameter equivalent to
nominal English sizes.
Size
½"
¾"
1"
Flow (gpm)
Velocity
(fps)
Friction Loss
(psi/100 ft)
Velocity
(fps)
Friction Loss
(psi/100 ft)
Velocity
(fps)
Friction Loss
(psi/100 ft)
2
2.95
3.48
1.57
0.74
0.94
0.38
5
7.39
19.59
3.92
4.19
2.34
1.19
7
10.34
35.97
5.49
7.69
3.28
2.19
7.84
14.65
4.68
4.16
10
Note: In English units, “Size” refers to nominal dimension.
If guidance is to be developed, it is recommended that it be based on a maximum allowable
friction loss per meter or per 100 feet (of “equivalent” length: pipe + fittings converted to
equivalent length of pipe) rather than velocity. As Table 15 shows, for a given velocity, the
friction loss is greater in smaller pipe diameters. A typical facility system guideline for small
hydronic piping has been to limit friction loss to 0.5 kPa/m (2.2 psi per 100 feet). Process cooling
systems use a higher limit (~ 0.9 kPa/m or 4 psi/100 feet), possibly because space limitations
within equipment require smaller pipe sizes and possibly because these systems have greater
available differential pressure. But without studying this situation on a cost:benefit basis, the
optimal value for allowable friction loss in equipment piping is still unknown.
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4
USING THE TEE CALCII UTILITY-TO-ENERGY CONVERSION TOOL
4.1
S23 TEE Calculator Overview
The ISMI Total Equivalent Energy Calculator (TEECalc) is a web-based application written in
Visual Basic.net/ado.net using an asp.net interface with an SQL Server 2008 database. It is
compatible with Internet Explorer 6 or higher, Mozilla Firefox, and Safari web browsers. To
protect users’ confidential data, TEE CalcII incorporates a custom web authentication and
security system, including SQL injection and session high jacking protection. Session
authentication requires users to register their email accounts with the provider to enable the twostep login procedure.
TEE CalcII provides data storage and the ability to share data with other users or keep the data
private; graph comparisons between equipment; and calculate total equivalent energy (TEE) by
equipment, functional area, or other user-defined fab spaces or variables.
4.1.1
Similarities to TEE CalcI

Peak and Idle flow rates/power and percentage of time at Peak and Idle are entered at the
Component level and for each utility.

Processing, idling, and shutdown percentages are entered at the component level as well. If a
piece of equipment has multiple components, the percentages can be the same but do not
need to be.

In accordance with SEMI S23, the Energy Conversion Factors (ECFs) for chiller-cooled
process cooling water is modified by TEE CalcII using the input value of the differential
temperature.

Flow rate inputs are required to be in standard units for the SI or IPS system of units;
conversion from other units or from “actual” conditions is not supported.
4.1.2
Changes from TEE CalcI
4.1.2.1 Database and Export Features

Can share the database of equipment, components, and ECFs with other users. May select
individual users or entire company entities.

Can sub-divide database of equipment and components into categories (e.g., Litho, Etch,
Implant, Test, Sub-fab, Support, etc.) rather than having a single folder. Users may define
the categories.

Can search for a component or equipment by name, key word, etc.

Can export output data to Excel (as a *.csv file)
4.1.2.2 Calculations and ECFs

Allows the user to decide whether a piece of equipment will be assigned the same
process/idle/standby/off percentages for ALL its components or whether the individually
assigned percentages for each component will be used for the TEE calculations.

Adds a “standby” state for components (% of year and power/flow during standby)

Uses distinct processing, idle, and standby state power and flow values.
ISMI
Technology Transfer #06094783D-ENG
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
Calculates custom ECFs, and adds user-defined ECFs. User-defined ECFs can be “above” or
“below” the line of total TEE.

Accounts for Fuel and HVAC energy with ECFs. The user can change the values.

Specifies a delta-T (temperature) for chiller PCW at the component level, and allows the
PCW ECF to be configured for each component individually rather than at the equipment
level.

Calculates the component-weighted average chiller PCW delta-T based on the constituent
component delta-T and flow, and uses the resulting value to automatically assign the correct
chiller PCW ECF for the TEE and heat burden calculations.
4.1.2.3 Reports

Adds a menu-driven report selection feature (multiple report types)

Sums TEE (energy values) for multiple pieces of equipment by category (i.e., certain
equipment, functional area, subfab only, cleanroom only, fab only, and any other userdefinable space).

Displays output report and/or graph in a separate browser as a PDF that the user can view,
print, or save. The PDF file can be password-protected.

Provides data in columns in a report comparing components and equipment rather than
providing separate pages for each component.
4.1.2.4 Graphing

Compares up to 10 pieces of equipment graphically.

Can graph the above summations of TEE (energy values) by categories or by specific utility.
S23 TEE Calculator Software Requirements and Installation Details
4.2
To run TEE CalcII, the following are required:

Internet provider through at least a DSL link

Microsoft Windows XP SP3 or Vista operating system

Internet Explorer 6 or higher, Mozilla Firefox, or Safari web browser

Javascript enabled on user’s computer

An email account that is registered with ISMI/SEMATECH to which the session Access
Code will be sent (see Figure 15 and section 4.3).
The S23 TEE Calculator resides on a host server instead of on the user’s computer.
This offers several advantages:

Application updates – When the program is updated by adding a feature or by fixing an
error, the change is automatically integrated without having to uninstall/reinstall a
program on the user’s computer.
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
Data sharing – Users are in control of the data; it may be shared with designated
persons or entities. This avoids the need to export the data and sending it by email or in
any other physical form (CD, etc.).

Security – Only registered users can access the program; access is terminated as soon as
the registered email address is cancelled (user leaves the employer).
Go to http://www.teecalc.com, and click the Request Access button to register for TEE CalcII.
Fill in the requested information and click Send button. See Request Access (Figure 15).
Figure 15
ISMI
Request Access to the TEE Calculator
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4.3
Basic Steps to Use the S23 TEE Calculator
1.
Set up a user account with ISMI/SEMATECH
2.
Log in and change your password:
a)
Log in with your user name and password
b) Retrieve the Access Code (an eight digit number) from your e-mail account inbox)
c)
Type or copy/paste the number into the blank space entitled “Access Code” on the login screen
d) Click Verify
See the Log-in Screen/Access Code window (Figure 16). The user interface Home Window
(Figure 17) will appear on your screen.
Figure 16
Log-in Screen/Access Code Window
3.
Use the default SEMI S23 ECF set or define an ECF set
4.
Create Components (one or more) in the database
5.
Create Equipment (one or more) in the database
6.
Decide if any component, equipment, or ECF sets are to be shared with other users
(optional)
7.
Associate Components with Equipment
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8.
Produce a report (TEE Component Comparison, TEE Equipment Comparison, TEE
Equipment, TEE Category)
9.
View graphs comparing Equipment annual TEE (total equivalent energy) usage
10. Export reports and save as Excel or PDF files (optional)
For detailed information about TEE CalcII functions, see the individual sections pertaining to
each function.
4.4
Instructions for Using the S23 TEE Calculator
The S23 TEE Calculator Home Window contains the following seven buttons across the top of
the home page (Figure 17):

Home

Equipment

Components

Energy Conversion Factors

Reports

Feedback

Documentation
Figure 17
ISMI
S23 TEE Calculator Home Window
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4.4.1
S23 TEE Calculator Homepage View
The following activities can be initiated from the S23 TEE Calculator Home Window
(Figure 17). For further explanation and details, see the referenced sections:





Equipment button (Section 4.4.2)
–
Define a new piece of Equipment
–
Establish sharing parameters
–
Copy/update/delete existing Equipment
Components button (Section 4.4.3)
–
Define a new Component
–
Establish sharing parameters
–
Copy/update/delete existing Components
Energy Conversion Factor button (Section 4.4.4)
–
View the current S23 Energy Conversion Factors
–
Create custom ECF sets
–
Add user-defined utilities and ECF values
Reports button (Section 4.4.5)
–
View several types of reports including a TEE Component Comparison, TEE
Equipment Comparison, TEE Equipment, and TEE Category. The most
comprehensive report (TEE Equipment) includes both a high level summary and
detailed calculations for hourly TEE, annual TEE, associated Heat Burden, and air
conditioning load for each component. Calculations are performed and reported for
Equipment processing, idle, and standby states. (See Definitions and Part I of
Application Guide for further explanation of Heat Burden.)
–
View a graphic comparison of annual TEE of user-selected equipment (up to 10
pieces of equipment can be compared) by Equipment name or selected Category.
Send Message to ISMI button (Section 4.4.6)
–

Documentation button (Section 4.4.7)
–
4.4.2
Format a message to ISMI to report a problem, ask a question, make a comment, or
suggest an improvement to TEE CalcII.
Access the User’s Guide to TEE CalcII.
Creating Equipment
To create a new piece of process equipment
1.
Click the Equipment button on the Home window; then click the Add New button at
the top left corner of the window. Fill in the blanks to define a piece of equipment. See
Equipment “Add New” window (Figure 18).
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2.
Process, Idle, Standby, Shutdown (Figure 19):
a)
The percentages for Process, Idle, Standby, and Other that are assigned in this view
must add up to 100%.
b) SEMI S23-0708 recommends that values of 70%, 25%, and 5% be used for
Process, Idle, and Shutdown, respectively, but TEE CalcII will use any values
assigned in this view. You can also assign a value for a fourth category, Standby, an
operating state with a lower utility consumption than Idle. Although a warning will
be given in the TEE report if the SEMI S23 recommended values are not used, your
input values will still be used for the calculations.
c)
The percentage values assigned are used in the TEE calculations only if the user
chooses to assign these values to all components belonging to the given piece of
equipment. The default calculation will use the component-level percentages that
were assigned to each component during component definition. The default
provides the greatest accuracy, recognizing that all components associated with a
piece of equipment may not be loaded for the same time percentages. Equipmentlevel percentages are assigned just before outputting a report (see Section 4.4.5 for
an illustration).
After the information is filled in, click the Save button.
Figure 18
ISMI
Equipment “Add New” Window
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Figure 19
3.
Equipment “Add New” Window, Highlighting Process, Idle, Standby, and
Shutdown Percentage Fields
Assigning Components to Equipment
To create Components, see the instructions in Section 4.4.3. The lower portion of the
“Add New” window has two boxes entitled “Available Components” and
“Assigned Components.” Once Components have been created, they will appear in
the “Available Components” box.
4.
Adding a Component to Equipment

5.
To assign a Component to this Equipment, click a Component in the “Available
Components” box, then click the “right arrow” between the boxes. The selected
Component will appear in the “Assigned Components” box.
Removing a Component

To remove a Component from this Equipment, click the Component in the
“Assigned Components” box, then click the “left arrow” between the boxes. The
selected component will disappear from the “Assigned components” box.
See Figure 20; note the green arrow for Adding/Removing a Component.
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Figure 20
6.
Adding/Removing Components from Equipment and Viewing Components
Searching pieces of Equipment in the user database

After one or more pieces of Equipment have been defined, you can view all of the
pieces of Equipment by using the Search button. Search options include “name,”
“description,” “category,” “key word,” or “all.” Once the search is completed, you
an view a piece of equipment from the search by using the View button.
See Figure 21; note the yellow arrow at the “Search” button and the search result
using the “All” option.
Figure 21
ISMI
Searching Equipment Data Base
Technology Transfer #06094783D-ENG
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7.
Deleting a piece of Equipment from the database

Any piece of Equipment named in the equipment window can be deleted from the
database by clicking the Delete button to the right of the “Assigned Components”
box. Note: you must be the owner of the equipment to be able to delete it. If
another user is sharing it with you, you cannot delete that piece of equipment. See
the difference between Deleting private Equipment (Figure 22) and Shared
equipment cannot be deleted (Figure 23). Shared equipment cannot be updated or
deleted by a non-owner.
Figure 22
Deleting Private Equipment (Not Shared)
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8.
Copying a piece of Equipment in the user database including Equipment shared by other
users

When a piece of Equipment is being “viewed,” click Copy (bottom right corner of
screen). The Equipment name will change to “Copy of …..” Then click Save
(bottom right corner of screen) to save the equipment to your database. Before
saving, you may change the name from “Copy of …” to a unique name.
Figure 23
9.
Shared Equipment Cannot be Deleted or Edited
Sharing a piece of Equipment

You can share Equipment, Components, or ECF sets with other users by scrolling
down to the “Web Share” line below the Equipment data input area. Using the
drop-down menu, select either Private, Share with selected companies, or Share
with selected users. You can select one or more companies or one or more users
from the list of registered users using the “share with selected users” option and the
“lookup menu.” See Equipment Web Share Options (Figure 24). You may also use
this area to deselect users that were previously selected for data sharing.
Note: To use shared components, equipment, or ECF sets, you must first copy each
of them so that they become in effect the users. If you do not do this, any shared
equipment or components will not be included in a subsequent report.
ISMI
Technology Transfer #06094783D-ENG
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Figure 24
Equipment Web Share Options, Company Share View
10. Categories tab

The third sub-tab in the Equipment window is the Categories tab, which is used to
create or view existing Categories of equipment. The categories can be functional
areas, spaces in the fab, or any other user division. Categories are used as a way to
sort equipment to prepare a Category report that calculates TEE by the defined
category, e.g., Litho, Diffusion, the sub-fab, or the clean support area. You may
delete only those categories that you have created (see Figure 25).
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Figure 25
4.4.3
Equipment Window, Categories Tab View
Creating a Component
To create a new component
1.
Click the Components button at the Home window. A blank Component window will
open. See Figure 26 for an example of a defined Component.
2.
Enter the requested information.
a)
Fill in Component Name
b) Select the appropriate engineering units for the data being entered from the pulldown box (either SI or IPS units). Note: Express utility data in standard or normal
conditions of temperature and pressure. The program cannot correct quantities that
are not at standard or normal conditions. No matter what input units are used, the
Calculator output will be in SI units in accordance with SEMI S23.
c)
ISMI
Note that percent “Processing,” “Idle,” “Standby,” and “Shutdown” needs to be
specified for each component. The values do not need to be the same as other
components associated with a piece of equipment. Having different values for each
component is an enhancement from the original TEE Calculator. However, SEMI
S23-0708 recommends default values of 70% processing, 25% idle, and 5%
shutdown. SEMI S23 does not currently address “% Standby” but may in the
future.
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Figure 26
Component Window
d) Fill in the utility data table including the following:

Percentage of time (during a process cycle; excludes idle time) at maximum
flow

Percentage of time (during a process cycle; excludes idle time) at minimum
flow

Maximum flow rate or power consumed (assumed during processing “state”)
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
Minimum flow rate or power consumed ( during processing “state”)

Flow rate or power consumed during idle state

Flow rate or power consumed during standby state

Differential temperature (outlet temperature minus inlet temperature) for
exhaust, cooling tower cooled (evaporative) process cooling water, and chillercooled process cooling water. TEE CalcII will automatically calculate a time
(using user-defined process, idle, standby, and off percentages) and flow rate
averaged differential temperature that will then used to calculate the ECF value
for chiller-cooled process cooling water. The differential temperature values
are used for the Heat Burden and HVAC calculations. The HVAC value is the
amount of TEE consumed by the air conditioning system to offset the Heat
Burden into the space from Equipment.
The above input method (steps 2a–2d) allows each utility for each component
to have a different flow/power minimum and maximum during the processing
cycle. This capability gives greater accuracy and more flexibility to attaining a
valid TEE estimate.
If only the average flow or power during the process cycle is known, you may
use it by entering values of

“100” under the “Percent time at Max” column

“0” under the “Percent time at Min”

Average process cycle flow rate or power under the “Flow/power Max”
column
This will automatically provide the correct information to the program.
See Figure 27 for a clarification.
e)
After all data have been entered, click Update. “Record Update” should appear if
the function has been completed correctly. See the Component Data Input window
(Figure 28).
Max = 10 scfh
while processing
Avg. = 7.5
Min = 5 scfh
Idle = 4.5 scfh
50% Max
50% Min
1 process cycle
70% of year
Figure 27
ISMI
25% of yr
Example of Component Input Data
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f)
After updating (saving) the component record, you may either create another
component or perform another function by clicking another button along the top of
the screen.
g) You may also delete, update, or copy components from the component window,.
(Figure 28).

The Copy component button lets you copy the component currently in view.
TEE CalcII will give the new component the name “Copy of …” You should
change this to a unique name and then click Update to save the new
component. Note: You must copy components that are being shared by another
user before running a report.
Figure 28
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Component Data Input Window
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
The Delete component button lets you delete the component currently in view
if you are the owner of that component. You may not delete shared components
(components created by another user).

The Update component button lets you save the component after changes have
been made to the data fields.
h) Sharing components in the user database

4.4.4
Components can be shared like Equipment database sharing. See Section 4.4.2,
item 9, and Figure 24 for instructions on database sharing.
Energy Conversion Factors
1.
ECFs in units of kW-hour/meters3 (also expressed as kilowatts per meters3/hour) were
derived from SEMI S23-0708. TEE CalcII uses these default values for the ECFs to convert
utility flow rates into total annual kilowatt-hours (kWh/year) on a component and
equipment-by-equipment basis. You can define non-standard (non-SEMI S23) ECF sets and
apply them in this version of TEE Calc as well, allowing you to perform “what-if” analysis.
If a non-SEMI S23 ECF is used, it will be “flagged” in the reports. Click the Select pulldown menu button, and select either the SEMI S23 ECF set or another ECF set. SEMI S23
ECFs are automatically selected for TEE calculations at the component level if no other ECF
set is selected.
2.
You may also copy an ECF set, modify it, rename it, and save it with a new name.
Figure 29 shows the Energy Conversion Factors window for gaseous fluids and the values used
in TEE CalcII.
Figure 29
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Energy Conversion Factors Window for Gaseous Fluids
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3.
The effect on the ECF value for chiller-cooled Process Cooling Water (PCW) caused by
changing the differential temperature between supply and return piping may be seen by
inputting that value using the pull-down button. Figure 30 shows the Energy Conversion
Factors window for liquid fluids and the values used in TEE CalcII. After changing the ECF,
you can save the value by clicking the Save icon that appears in the view. Note that the ECF
that appears on this view has no effect on the TEE calculations in any reports; a time and
flow rate-averaged ECF for chiller-cooled PCW is calculated internally and given in the
reports.
Figure 30
Energy Conversion Factors Window for Liquid Fluids
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4.
An HVAC ECF is included to calculate the annual TEE required to offset the Heat Burden
from equipment (Heat burden = electric power consumed by tool – heat removed by exhaust
and cooling water). The SEMI S23 value of 0.287 kWh per kWh (1 kWh per ton of cooling)
of heat burden is the default value. Figure 31 shows the HVAC ECF window.
Figure 31
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HVAC ECF Window
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5.
You may also add an ECF set by clicking Add New Set. This opens a screen with all of the
SEMI S23 utilities. Up to 10 non-SEMI S23 utilities can be added and the utilities
designated as either “above” or “below” the line. The TEE from the non-SEMI S23 utilities
is either added to the annual TEE total for SEMI S23 utilities or the non-SEMI S23 utilities
are kept as a separate sub-total. The designation is made in the Report window. Figure 32
shows the Add New Set window.
Figure 32
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Add New ECF Set Window
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6.
Adjacent to each ECF is a Microsoft Excel icon to help define ECF values. Click the icon to
open a spreadsheet containing the variables that approximately define that ECF. By altering
the values of the variables, the value of the ECF will change so that you can easily
determine an approximate non-SEMI S23 ECF value. Use engineering judgment in deriving
non-SEMI S23 ECF values. Figure 33 shows an example of the Excel ECF Calculator. 2
Figure 33
2
Typical ECF Calculator Window
The ECF Calculator was created by Ralph M. Cohen Consultancy.
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7.
Custom ECF sets can be shared with other users. Click the Share tab, select the ECF set to
share, select the Web share option using the pull-down menu, and select companies or
parties with whom the ECF set is to be shared. Then click the Update button. This window
may also be used to determine whether an ECF set is being shared with another user.
Figure 34 shows the ECF Share window, identifies the user(s) currently sharing the set, and
other users with the same company. To share with another user, type the user name into the
box identified with a red arrow.
Figure 34
4.4.5
ECF Share Window
Creating a Report
1.
Creating a report is essentially the end result of completing all data input. To view a report,
click Reports in the command line of the Home window.
2.
Click on the drop-down menu button for five report options:

Compare Equipment Graphically – provides a bar graph of TEE for each utility for one
piece of equipment

Equipment TEE Report – provides the most detailed summary in tabular form of the
TEE for one piece of equipment broken out by component, considering the equipment
operating state. Summarizes computations.
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
Component Comparison Report – provides a detailed comparison of TEE for
components by utility

Equipment Comparison Report – provides a summary- level comparison of TEE for
equipment by utility

Equipment Category Report – provides a summary-level rollup of equipment placed in
user-defined categories, e.g. Litho, sub-fab, wet bench, nitrogen, etc.
Note: for all reports except the Compare Equipment Graphically report, clicking the box Add
custom utility TEE to S23 Utilities Equipment Totals will add the TEE resulting from any
non-S23 utilities that were added through the Component input sheet and special ECF set
definition to the total TEE; the default (not clicking the box) provides a separate sub-total.
Figure 35 shows the Report window and drop-down menu report choices.
Figure 35
3.
Report Type Selection
Detailed instructions for each report type

ISMI
Compare Equipment Graphically
–
Click option. A menu of available equipment appears.
–
Highlight a piece of equipment, then click the right arrow to move it to “Equipment
to Compare” box (right arrow circled in Figure 36).
–
Select up to 10 pieces of equipment to compare; equipment may be selected by
name or category.
–
After selections are made, click the Compare Equipment button at bottom of
window. A bar graph will open in a new window. The graph may be exported to a
PDF file (see Figure 37).
–
Close the Graph window but clicking the “back” arrow in your browser.
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Figure 36
Compare Equipment Graphically Window
Equipment Comparison Graph
Export to PDF
Equipment
Power Supply
Ralph Test 0803
Ralph Test 0910
Ralph Test 728
Shared Equipment
Spreadsheet Tester
Training Demo Equipment
Figure 37
Equipment Comparison Graph and PDF Export Function
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
Equipment TEE Report
–
Click option. A menu of available equipment will appear.
–
Highlight a piece of equipment, then click the right arrow to move it to “Equipment
to the Compare box (right arrow circled in Figure 38).
–
Select up to 10 pieces of equipment.
Note: Before generating the report, decide whether you want to perform the
calculations using the component-defined Process/Idle/Standby percentages
(default method) OR using the equipment-defined Process/Idle/Standby
percentages. Clicking the box Use Equipment Percentages will override the
component percentages in the calculations. When component percentages are used,
equipment percentages at the top right corner of the report appear as “N/A.” If nonSEMI S23 recommended equipment percentages are used, a note will appear.
Figure 38
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Equipment TEE Report Window
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–
After selections are made, click the Generate TEE Report button at the bottom of
the window to calculate the added values. Available reports will be shown under the
heading “Generated Reports.” View the reports by clicking the equipment name.
Only one report can be viewed, but you can scroll through all of the generated
reports using the forward and back arrows at the top left corner of the window. You
can export reports in a PDF file (see Figure 39) that is either open or passwordprotected or in an Excel file. These files can be renamed and saved to your
computer.
–
Close the Equipment TEE Report window by clicking the red close window (red
“X”) button in the upper right corner. Be sure to close the report window and not
the TEE CalcII window.
Figure 39
TEE Equipment Report Export Options
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–
Table 16 shows the information provided a TEE Report and its layout.
Table 16
Information Provided in TEE Report
User supplied equipment information
Process/Idle/Standby percentages
S23 equipment annual TEE totals by utility
Non-S23 equipment annual TEE totals by utility
Annual heat burden summary
Idle and Idle+Standby:Process ratios
Detailed S23 component data calculations (hourly and annual TEE)
Detailed non-S23 utility component data calculations
TEE totals by component
Component Process/Idle/Standby percentage and annual hours
Data used for heat burden calculation
ECFs for S23 utilities
ECFs for user-defined (non-S23) utilities

Component Comparison Report
–
The format and features of this report are similar to the TEE Equipment Report but
it allows you to compare different components to assess their TEE consumption.
Unlike the equipment report, TEE is not summed except by component.
–
You can select components for the report and export the reports just as the TEE
Equipment Report.
–
To close the report, use the arrows in the upper left corner of the window.
Figure 40 shows the Component Comparison Report component selection window.
Figure 41 shows an example of a Component Comparison Report (partial).
Figure 40
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Component Comparison Component Selection Window
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Figure 41
Example of a Component Comparison Report
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
Equipment Comparison Report
–
The format and features of this report are similar to the TEE Equipment Report but
it allows you to compare different pieces of equipment to assess their TEE
consumption. Unlike the TEE Equipment report, TEE is not shown for individual
components.
–
You can select components for the report and export the reports just as the TEE
Equipment Report.
–
To close the report, use the arrows in the upper left corner of the window.
Figure 42 shows the Equipment Comparison Report equipment selection window.
Figure 42

ISMI
Equipment Comparison Report Equipment Selection Window
Equipment Category Report
–
The format and features of this report are designed to give you the TEE of all
pieces of equipment in the designated category.
–
The report includes the TEE total for the category. Categories can include all
equipment in a processing area (e.g., Litho, Diffusion, Etch, etc.), a physical space
(e.g., fab, sub-fab, support, etc.), or all equipment using a particular utility. You
have some flexibility in defining category reports, with category and sub-category
labeling available. The report will be based on meeting ALL of the sort category
criteria, not ANY of the sort category criteria.
–
Figure 43 shows the Equipment Category Report category selection window.
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Figure 43
4.4.6
1.
2.
Equipment Category Report Category Selection Window
Providing feedback
Click the Feedback button in the Home row at the top of the window. Figure 30 shows the
Feedback window. A pull-down menu gives several options for selecting the message type:

General Question

Reporting a problem

Suggesting an improvement

Submitting a comment
Fill in the subject and add your comments. When ready, click Send.
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Figure 44
4.4.7
1.
Feedback Window
Documentation
Click the Documentation button in the Home row at the top of the window to access a
current copy of this user’s manual.
4.5
Revision Control
Whenever TEE Calc has been updated, the change is automatically integrated into program the
next time you run it. The current version reference is always shown in the log-in area after
logging in (e.g., TEE CalcII V0.0912).
4.6
Flow Diagrams
See Figure 45–Figure 47 for flow diagrams showing TEE Calc use and features.
Create User Account
Fill in requested information
Receive user name and
password from administrator
Log in and use calculator
Figure 45
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Creating a User Account
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Create Component(s)
Create Equipment
Fill in required fields for
process/idle/standby/off %
and other descriptive
information
Fill in required fields for flow/
power, min/max %'s,
delta T's, etc.
Assign components
Select ECF set, add utilities
Save data
Save data
Go to other operations
Figure 46
Go to other operations`
Creating Components and Equipment Flow Diagram
Select Report Type
"TEE Report"
"Compare
Equipment
Graphically"
"Component
Comparison"
"Equipment
Comparison"
"Equipment
Category"
Select up to 10
pieces of equipment
Select components
Select equipment
Select category
Click Compare
Equipment, view/
print graph
Click Compare
Components, view/
print report
Click Compare
Equipment, view/
print report
View/print report
Export to PDF
Export to PDF or
Excel file
Export to PDF or
Excel file
Export to PDF or
Excel file
Select Equipment
Click/skip
Use Equipment
Percentages and/
or Add Custom
Utility TEE to Total
View/print Report
Export to PDF or
Excel file
Return to Reports or other operations
Figure 47
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Creating Reports Flow Diagram
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5
REFERENCES
[1] SEMI S23 0708, Guide for Conservation of Energy, Utilities, and Materials Used by
Semiconductor Manufacturing Equipment, May 13, 2008
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Appendix A – Sample TEE Equipment Report
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ISMI
Technology Transfer #06094783D-ENG
International SEMATECH Manufacturing Initiative
Technology Transfer
2706 Montopolis Drive
Austin, TX 78741
http://ismi.sematech.org
e-mail: info@sematech.org