Background Statement for SEMI Draft Document 4920
New Standard: PRACTICE FOR DETERMINING WAFER NEAR-EDGE
GEOMETRY USING ROLL-OFF AMOUNT, ROA
Note: This background statement is not part of the balloted item. It is provided solely to assist the recipient in
reaching an informed decision based on the rationale of the activity that preceded the creation of this document.
Note: Recipients of this document are invited to submit, with their comments, notification of any relevant patented
technology or copyrighted items of which they are aware and to provide supporting documentation. In this context,
“patented technology” is defined as technology for which a patent has issued or has been applied for. In the latter
case, only publicly available information on the contents of the patent application is to be provided.
Background Statement
The measurement method of edge roll off (ERO) established as a preliminary standard was expired on March 9,
2009. Despite the expiration, the ballot was performed as the Revision at Cycle 6, 2009 and the result was super
clean at the committee adjudication during SEMICON Japan 2009. This was, however, a mistake in office procedure,
and was not allowed by SEMI Standards Regulations.
Since the related industry has been still interested in and has controlled ERO to improve the performance of
lithography and CMP processes, the new standard without modification of the preliminary document provides them
with the benefit.
Voting result of Doc.4920 will be adjudicated at the North America Silicon Wafer Committee meeting during
SEMICON West 2010.
Semiconductor Equipment and Materials International
3081 Zanker Road
San Jose, CA 95134-2127
Phone:408.943.6900 Fax: 408.943.7943
DRAFT
SEMI Draft Document 4920
New Standard: PRACTICE FOR DETERMINING WAFER NEAR-EDGE
GEOMETRY USING ROLL-OFF AMOUNT, ROA
1 Purpose
1.1 Wafer near-edge geometry can significantly affect the yield of semiconductor device processing.
1.2 Knowledge of near-edge geometrical properties can help the producer and consumer determine if the
dimensional characteristics of a specimen wafer satisfy given geometrical requirements.
1.3 The ROA metric is suitable for quantifying near-edge geometry of wafers used in semiconductor device
processing.
1.4 Consideration should be given to the use of this or other proposed edge geometry metrics as a process control
tool rather than a material exchange specification.
2 Scope
2.1 This practice covers calculation of the near-edge geometry metric roll-off amount (ROA). 1
F
F
2.2 Calculation of ROA is based on height data that are representative of a height data profile associated with one or
more of the front surface, the back surface, or thickness.
2.3 This practice covers selection of the point at which the ROA is determined and the reference line to be utilized
for this determination.
2.4 This practice is applicable to notched 200 and 300 mm diameter wafers having dimensions in accordance with
wafer categories 1.9.2 and 1.15 of SEMI M1.
2.5 This practice has been shown to be suitable for quantifying near-edge geometry to improve CMP performance
at wafer edge. 2 , 3 ROA values in that study were measured using an edge-referenced coordinate system. On the
other hand, measurement systems for high volume production geometry (e.g., whole-wafer flatness) uses a centerreferenced coordinate system.
F
F
F
F
2.6 This practice allows for the use of either an edge-referenced or a center-referenced coordinate system.
2.7 There are other metrics for near-edge geometrical properties, some of which quantify more specific aspects.
These are outside the scope of this practice.
2.8 This practice does not cover acquisition of the height data array. However, it gives the required characteristics
of the height data array.
NOTICE: This standard does not purport to address safety issues, if any, associated with its use. It is the
responsibility of the users of this standard to establish appropriate safety and health practices and determine the
applicability of regulatory or other limitations prior to use.
3 Limitations
3.1 Deficiencies of data such as inadequate spatial resolution, mis-positioning, noise, etc. in the height data array
used to calculate the ROA may lead to erroneous results.
3.2 The selection of the reference segment, the ROA measurement point, the measuring surface, and the type of the
reference line is to be decided between the relevant parties. To make these conditions clear, a method for reporting
ROA is provided in ¶ 10.1.8.
M. Kimura, Y. Saito, H. Hiroshi, and K. Yakushiji, “A New Method for the Precise Measurement of Wafer Roll off of Silicon Polished Wafer”
Jpn. J. Appl. Phys. 38, 38 (1999).
2
Japan Electronics and Information Technology Industries Association (JEITA) Technical Report, “The Impact of Edge Roll-off on CMP
performance” JEITA EMR-3001 (2004).
3
The development of edge roll off measurement method for silicon wafers by JEITA Silicon Technologies Committee is hereby acknowledged.
This method, “Edge Roll-Off Measurement Method for Silicon Wafers,” is to be published as a standard in the JEITA EMR series.
1
This is a draft document of the SEMI International Standards program. No material on this page is to be construed as an offi cial or adopted standard. Permission is granted to
reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document development) activity. All other
reproduction and/or distribution without the prior written consent of SEMI is prohibited.
Page 1
Doc. 4920  SEMI
LETTER (YELLOW) BALLOT
Document Number: 4920
Date: 2/6/2016
Semiconductor Equipment and Materials International
3081 Zanker Road
San Jose, CA 95134-2127
Phone:408.943.6900 Fax: 408.943.7943
DRAFT
3.3 Because the diameter tolerance of 200 or 300 mm wafers is 0.2 mm (see SEMI M1, Table 9) the difference
from nominal to real radius may be up to 0.1 mm. This difference may significantly affect the ROA calculation by
shifting the positions of the measurement and reference segment points between the edge-referenced and centerreferenced cases by the radius difference. Since the wafer surface height changes rapidly along the radius, the
difference between ROA values determined with edge-referenced coordinates and center referenced coordinates can
be significant.
3.4 Due to the existence of notch, the edge reference measurement is not applicable to the notch area.
4 Referenced Standards and Documents
4.1 SEMI Standards
SEMI M1 — Specifications for Polished Monocrystalline Silicon Wafers
SEMI M20 — Practice for Establishing a Wafer Coordinate System
SEMI M59 — Terminology for Silicon Technology
NOTICE: Unless otherwise indicated, all documents cited shall be the latest published versions.
5 Terminology
5.1 General terms, acronyms, and symbols used in silicon wafer technology are listed and defined in SEMI M59.
5.2 Other Terminology
5.2.1 Abbreviations and Acronyms
5.2.1.1 ERO — Edge Roll Off.
5.2.1.2 L-ROA— Linear Referenced ROA.
5.2.1.3 P-ROA — Polynomial Referenced ROA.
5.2.1.4 ROA — Edge Roll Off Amount.
5.2.2 Definitions
5.2.2.1 center referenced.— property of a measurement or calculation with the radial measurement position
established using the wafer center as the origin.
5.2.2.2 edge referenced — property of a measurement or calculation with the radial measurement position
established using the physical edge as the origin.
5.2.2.3 edge roll off (ERO) — surface deviations of a large-diameter silicon wafer near the edge, but excluding
effects due to wafer edge profiling, surface roughness, and global bending, such as warp, of the wafer.
5.2.2.4 edge roll off amount (ROA) — the displacement from the reference line at the measurement point in the
edge vicinity of an un-chucked wafer. ROA is defined as positive in the direction away from the reference line.
5.2.2.5 edge roll off measurement point — the radial position where the edge roll off is measured. It is labeled x0
for an edge-referenced measurement or r0 for a center-referenced measurement.
5.2.2.6 linear-referenced ROA (L-ROA) — the roll off value when a straight line is employed as the reference.
5.2.2.7 near edge geometry — the topography of a surface of a large diameter silicon wafer in the outer region of
the fixed quality area (FQA).
5.2.2.8 physical edge — the farthest extremity of the wafer. It is used as a reference point of an edge-referenced
coordinate system when finding the profile of the edge region.
5.2.2.9 polynomial-referenced ROA (P-ROA) — the roll off value when a cubic curve is employed as the reference.
5.2.2.10 reference line — either a straight line or a cubic curve extrapolated by curve fitting from a section of an
ideal surface that does not include edge roll off.
5.2.2.11 reference segment — the section of the ideal surface that does not include edge roll off.
This is a draft document of the SEMI International Standards program. No material on this page is to be construed as an offi cial or adopted standard. Permission is granted to
reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document development) activity. All other
reproduction and/or distribution without the prior written consent of SEMI is prohibited.
Page 2
Doc. 4920  SEMI
LETTER (YELLOW) BALLOT
Document Number: 4920
Date: 2/6/2016
Semiconductor Equipment and Materials International
3081 Zanker Road
San Jose, CA 95134-2127
Phone:408.943.6900 Fax: 408.943.7943
DRAFT
6 Summary of Practice
6.1 Measurement positions and measurement coordinate system are selected.
6.2 The ERO measurement point and the reference segments end points are selected and reported.
6.3 The type of reference line used is selected and reported.
6.4 Height data arrays of one or more of the front surface, the back surface, or thickness are acquired along the
radial direction at the measurement positions.
6.5 The ROA is calculated for each measurement position.
6.6 ROA is reported for each measurement position and surface(s) analyzed.
6.7 Statistical quantities for ROA, as agreed upon by the parties to the test are calculated and reported for each
wafer.
7 Apparatus
7.1 Measuring Equipment — Suitable for acquiring the height data array over the entire FQA, except for
instrument-dependent exclusion areas, and transferring it to the calculation equipment.
NOTE 1: A test method for acquiring the height data array is outside the scope of this practice.
7.1.1 The equipment shall perform all necessary calculations and corrections needed to produce the height data
array internally and automatically, including instrument-dependent exclusion areas. The equipment shall be
equipped with a means of detecting and either deleting or identifying invalid data (over-range signal).
7.1.2 Height resolution shall to be 10 nm or smaller.
7.1.3 Height data array data point spacing shall be 0.1 mm or less.
7.1.4 The acquisition spatial resolution shall be appropriate for the height data array data point spacing and shall be
agreed upon between the parties to the test.
7.2 Calculation Software — To perform the calculations of this practice and to provide outputs of the results,
including statistical parameters as agreed upon by the parties to the test.
8 Procedure
8.1 Define recipe for calculation:
8.1.1 Select edge-referenced or center-referenced coordinates (see ¶ 3.3 for cautionary warnings).
X
X
8.1.2 Select the measurement position(s).
NOTE 2: Recommended positions are the following eight angular ones, 0º, 45º, 90º, 135º, 180º, 225º, 275º, and 315º as defined
in the R- coordinate system of SEMI M20 (see Figure 1). This practice does not define the measuring method for the notch
portion of the wafer and its neighborhood.
This is a draft document of the SEMI International Standards program. No material on this page is to be construed as an offi cial or adopted standard. Permission is granted to
reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document development) activity. All other
reproduction and/or distribution without the prior written consent of SEMI is prohibited.
Page 3
Doc. 4920  SEMI
LETTER (YELLOW) BALLOT
Document Number: 4920
Date: 2/6/2016
Semiconductor Equipment and Materials International
3081 Zanker Road
San Jose, CA 95134-2127
Phone:408.943.6900 Fax: 408.943.7943
DRAFT
Y
90°
135°
45°
180°
0°
225°
X
315°
275°
270°
Figure 1
Recommended Measurement Positions on the Front Surface of the Specimen Wafer
8.1.3 Select the reference line as a straight line (L-ROA) or a third order polynomial (cubic) curve (P-ROA).
8.1.4 Select the locations of the measurement point and reference segment end points. Designate these as x0, x1, and
x2, respectively, (x2 > x1) when using edge-referenced coordinates or r0, r1, and r2, respectively (r1 > r2) –when using
center-referenced coordinates (see figure 2).
ROA (1)
0
x: Distance from
the edge (mm)
1
x [mm]
ROA (149)
r [mm]
149
r: Distance
from
0
the center (mm)
Center
Figure 2
Recommended Measurement Positions on the Front Surface of the Specimen Wafer
8.1.4.1 The default location of the reference segment for L-ROA is between x1 = 3 mm and x2 = 6 mm for the edge
referenced case, or between r1 = (R–3) mm and r2 = (R–6) mm for the center referenced case, where R is the nominal
wafer radius. The default edge roll off measurement point for L-ROA is taken as x0 = 1 mm for the edge referenced
case, or r0 = (R–1) mm for the center referenced case. See Appendix 1 for a discussion of the reasons why these
default values are selected for the reference segment end points.
8.1.4.2 The default location of the reference segment for P-ROA is between x1 = 5 mm and x2 = 20 mm for the edge
referenced case or between r1 = (R–5) mm and r2 = (R–20) mm for the center referenced case. The default edge roll
off measurement point for L-ROA is r0 = 1 mm for the edge referenced case or r0 = (R–1) mm for the center
referenced case. See Appendix 1 for a discussion of the reasons why these default values are selected for the
reference segment end points.
8.1.5 Select the surface or surfaces to obtain the height data array as one or more of the following: front surface,
back surface, or thickness.
8.1.6 Determine statistics to be reported for each wafer. As a minimum, these shall include maximum, average,
range, and standard deviation.
8.2 Acquire the height data array in accordance with a method agreed upon by all parties to the practice.
This is a draft document of the SEMI International Standards program. No material on this page is to be construed as an offi cial or adopted standard. Permission is granted to
reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document development) activity. All other
reproduction and/or distribution without the prior written consent of SEMI is prohibited.
Page 4
Doc. 4920  SEMI
LETTER (YELLOW) BALLOT
Document Number: 4920
Date: 2/6/2016
Semiconductor Equipment and Materials International
3081 Zanker Road
San Jose, CA 95134-2127
Phone:408.943.6900 Fax: 408.943.7943
DRAFT
9 Calculations
NOTE 3: The following calculations are performed automatically within the equipment. An outline of the calculation structures
is provided here to indicate the nature of the procedure.
9.1 For each profile, determine reference line as:
9.1.1 The least square line in case L-ROA is selected, or
9.1.2 The least square cubic order polynomial curve in case P-ROA is selected.
9.2 Calculate the distance between the measured profile and reference line at the ERO measurement point (see
Figure 2).
9.3 Record ROA as the distance between the measured profile and the reference line at the edge roll off
measurement point (see Figure 3).
P-ROA
Profile
Profile
L-ROA
Measured profile
Measured profile
Linear reference line
x0=1
x1=3
Cubic polynomial
reference line
x2=6
x0=1 x1=5
x2=20
Location (mm)
Location (mm)
Figure 3
L-ROA Measurement Method (left hand) and P-ROA Measurement Method (right hand)
9.4 Calculate statistics (see ¶ 8.1.6 ) for each wafer for each surface (front surface, back surface, and thickness) for
which ROA was calculated.
X
X
9.5 For multi-measurement tests, calculate the standard deviations of each set of wafer measurements and such
other statistical parameters as agreed to by the parties to the test.
10 Report
10.1 Report the following information:
10.1.1 Date, time of test,
10.1.2 Identification of operator,
10.1.3 Location (laboratory) of test,
10.1.4 Identification of measuring instruments, including measuring equipment and calculation equipment
(identification of make, model, software version, etc.),
10.1.5 Acquisition spatial resolution and data point spacing,
10.1.6 Lot identification and wafer identification,
10.1.7 Description of sampling plans, if any, and
10.1.8 Measurement conditions, as follows:
10.1.8.1 Surface measured (front surface, back surface, or thickness)
10.1.8.2 Type of the reference line (a linear reference line or a polynomial cubic reference curve),
10.1.8.3 Origin of coordinate (center-reference or edge reference),
This is a draft document of the SEMI International Standards program. No material on this page is to be construed as an offi cial or adopted standard. Permission is granted to
reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document development) activity. All other
reproduction and/or distribution without the prior written consent of SEMI is prohibited.
Page 5
Doc. 4920  SEMI
LETTER (YELLOW) BALLOT
Document Number: 4920
Date: 2/6/2016
Semiconductor Equipment and Materials International
3081 Zanker Road
San Jose, CA 95134-2127
Phone:408.943.6900 Fax: 408.943.7943
DRAFT
10.1.8.4 Edge roll off measurement point,
10.1.8.5 The reference segment end points, and
10.1.9 ROA data and its angular position of the measurement (in degrees, in accordance with the R- coordinate
system of SEMI M20) for each wafer measured for each position.
10.2 In addition, report all statistical quantities (e.g., average, range, standard deviation, other) as agreed to by the
parties to the test for each wafer measured (see ¶ 8.1.6 ).
X
X
NOTE 4: In reporting statistical properties of measurements on a wafer surface, the name of the statistical quantity should be
substituted for the angular position.
10.3 For multi-measurement tests, also report the standard deviation of each set of wafer measurements and such
other statistical parameters as have been agreed to by the parties to the test.
11 Keywords
11.1 ERO; ROA; near-edge geometry; semiconductor; silicon; wafers
This is a draft document of the SEMI International Standards program. No material on this page is to be construed as an offi cial or adopted standard. Permission is granted to
reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document development) activity. All other
reproduction and/or distribution without the prior written consent of SEMI is prohibited.
Page 6
Doc. 4920  SEMI
LETTER (YELLOW) BALLOT
Document Number: 4920
Date: 2/6/2016
Semiconductor Equipment and Materials International
3081 Zanker Road
San Jose, CA 95134-2127
Phone:408.943.6900 Fax: 408.943.7943
DRAFT
APPENDIX 1
REFERENCE SEGMENT LOCATIONS
NOTICE: The material in this appendix is an official part of SEMI (doc#) and was approved by full letter ballot procedures
on (date of approval).
A1-1 Edge roll off is the displacement of un-chucked wafer surface profile in the edge vicinity from a reference
line (virtual ideal surface) and ROA (roll off amount) is defined as the vertical (z direction) distance from the
reference line to the surface at a specific point on the radius. The reference line represents a virtual ideal straight
line or curve without the edge roll off and is determined from the surface profile of the edge vicinity and inner
(toward the wafer center) part of the wafer in order to avoid any influence of the edge roll off. If sori, bow, and
warp (hereinafter called global bending) do not exist, the reference line is determined by extrapolating a line from
the inner surface profile. However, in case that global bending exists, it is necessary to eliminate its effect.
A1-2 In general, the global bending of the wafer surface has a relatively small spatial frequency compared to the
edge roll off so that this practice includes a choice between two kinds of reference lines. One is a reference line
(linear reference) by fitting a straight line to a short segment that is hardly biased by the global bending, and the
other is a reference line (curved reference) by fitting a third order polynomial line to the wafer global bending. As
for the short segment, the 3 mm segment that is from 3–6 mm is employed according to the literature of Kimura
et al. 1 As for the third order polynomial line, the 15 mm segment that is from 5–20 mm is employed as a
recommended segment based on the following reason.
X
X
A1-2.1 As shown in Figure A1-1, assuming that the edge roll off is independent of the global bending, the amount
of the edge roll off should not be changed by the existence of the global bending. On the other hand, the global
bending does not exist in the thickness profile so that straight line can be fitted to it as a reference line. From these
points of view, if the curved reference line reflects the global bending well, the sum of the front surface ROA and
back surface ROA calculated using each reference line must be exactly the same as thickness ROA calculated
separately using the linear reference line. If it is not, the global bending influences the front surface ROA and back
surface ROA, and it means that roll off is not correctly evaluated.
A1-2.2 Then, measuring real wafers (JEITA obtained 9 wafers in 2003), the thickness ROA is compared to the sum
of the front surface ROA and the back surface ROA calculated using various reference segments. For all 9 wafers, 8
points along every 45 orientation on each wafers were measured. As for the front surface ROA and the back
surface ROA, the curve reference line ROA is calculated using 8 kinds of curved reference segment, [3,6], [5,10],
[5,20], [5,25], [10, 15], [10.20], [10, 25]. As for thickness ROA, it is calculated by the straight line of the
recommended segment. Figure A1-2 is 8 graphs in which the sum of the front surface ROA and the back surface
ROA is plotted against the thickness ROA for each reference segment. To evaluate the ROA calculation error
caused by global bending, the mean square of the difference between the thickness ROA and sum of the front
surface ROA and the back surface ROA is calculated by the following equation:
Calculated error 

[ROA t  (ROA f  ROA b )] 2
N
(A1-1)
where ROAt, ROAf and ROAb are the thickness ROA, the front surface ROA and the back surface ROA respectively.
Table A1-1 shows the calculated results and that the minimum error was obtained in 5–20 mm segment. It is
concluded from this that the 15 mm segment from 5–20 mm is the most appropriate one. Of course, these results
were tested for limited wafers and it is quite possible to choose another segment by agreement among users, since,
for example, there is another proposal by Riedel et al. 4
F
F
F. Riedel, H. -A. Gerber, and P. Wagner, “Metrics for Wafer Edge Roll-Off Measurement” SEMI Standards Silicon Wafer Workshop
(SEMICON Europa 2005, Munich, Germany, April 14, 2005).
4
This is a draft document of the SEMI International Standards program. No material on this page is to be construed as an offi cial or adopted standard. Permission is granted to
reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document development) activity. All other
reproduction and/or distribution without the prior written consent of SEMI is prohibited.
Page 7
Doc. 4920  SEMI
LETTER (YELLOW) BALLOT
Document Number: 4920
Date: 2/6/2016
Semiconductor Equipment and Materials International
3081 Zanker Road
San Jose, CA 95134-2127
Phone:408.943.6900 Fax: 408.943.7943
DRAFT
Actual shape of a wafer
ERO
Component of ERO
Component of global bending
Figure A1-1
Components of ERO and global bending
Table A1-1 Calculated Results Using Equation (A1-1) for Each Set of
Reference Segments for Front and Back Surface P-ROA
Reference Segment
Calculated Error
3–6 mm
0.378
5–10 mm
0.201
5–15mm
0.049
5–20 mm
0.029
5–25 mm
0.056
10–15 mm
0.542
10–20 mm
0.127
10–25 mm
0.201
This is a draft document of the SEMI International Standards program. No material on this page is to be construed as an offi cial or adopted standard. Permission is granted to
reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document development) activity. All other
reproduction and/or distribution without the prior written consent of SEMI is prohibited.
Page 8
Doc. 4920  SEMI
LETTER (YELLOW) BALLOT
Document Number: 4920
Date: 2/6/2016
Semiconductor Equipment and Materials International
3081 Zanker Road
San Jose, CA 95134-2127
Phone:408.943.6900 Fax: 408.943.7943
DRAFT
Document Number: 4920
Date: 2/6/2016
0.75
0.5
0.25
0
-0.25
-0.25
0
0.25
0.5
0.75
1
Thickness L-ROA(1.0) [ 3, 6] (μm)
1.25
Reference Segment : [ 5, 10 ]
1.25
1
0.75
0.5
0.25
0
-0.25
-0.25
1.25
1
0.75
0.5
0.25
0
-0.25
-0.25
0
0.25
0.5
0.75
1
Thickness L-ROA(1.0) [ 3, 6] (μm)
1.25
Reference Segment : [ 5, 20 ]
1.25
1
0.75
0.5
0.25
0
-0.25
-0.25
0.75
0.5
0.25
0
-0.25
0
0.25
0.5
0.75
1
Thickness L-ROA(1.0) [ 3, 6] (μm)
1.25
1
0.75
0.5
0.25
0
-0.25
1.25
-0.25
1
0.75
0.5
0.25
0
-0.25
-0.25
0
0.25
0.5
0.75
1
Thickness L-ROA(1.0) [ 3, 6] (μm)
0
0.25
0.5
0.75
1
Thickness L-ROA(1.0) [ 3, 6] (μm)
1.25
(f) Reference Segment 10–15 mm
Reference Segment : [ 10, 20 ]
Front Surface P-ROA(1.0) +
Back Surface P-ROA(1.0) (μm)
Front Surface P-ROA(1.0) +
Back Surface P-ROA(1.0) (μm)
(e) Reference Segment 5–25 mm
1.25
1.25
Reference Segment : [ 10, 15 ]
1
-0.25
0
0.25
0.5
0.75
1
Thickness L-ROA(1.0) [ 3, 6] (μm)
(d) Reference Segment 5–20 mm
Reference Segment : [ 5, 25 ]
Front Surface P-ROA(1.0) +
Back Surface P-ROA(1.0) (μm)
Front Surface P-ROA(1.0) +
Back Surface P-ROA(1.0) (μm)
(c) Reference Segment 5–15 mm
1.25
1.25
(b) Reference Segment 5–10 mm
Reference Segment : [ 5, 15 ]
Front Surface P-ROA(1.0) +
Back Surface P-ROA(1.0) (μm)
Front Surface P-ROA(1.0) +
Back Surface P-ROA(1.0) (μm)
(a) Reference Segment 3–6 mm
0
0.25
0.5
0.75
1
Thickness L-ROA(1.0) [ 3, 6] (μm)
1.25
(g) Reference Segment 10–20 mm
1.25
Reference Segment : [ 10, 25 ]
1
0.75
0.5
0.25
0
-0.25
-0.25
0
0.25
0.5
0.75
1
Thickness L-ROA(1.0) [ 3, 6] (μm)
1.25
(h) Reference Segment 10–25 mm
Figure A1-2
Comparison of the Thickness L-ROA with reference segment [3,6] with the sum of the Front Surface P-ROA
and the Back Surface P-ROA for Each Reference Segment. The description (*) and [*, *] in each axis title are
indicated as the measurement point and reference segment, respectively.
This is a draft document of the SEMI International Standards program. No material on this page is to be construed as an offi cial or adopted standard. Permission is granted to
reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document development) activity. All other
reproduction and/or distribution without the prior written consent of SEMI is prohibited.
Page 9
Doc. 4920  SEMI
LETTER (YELLOW) BALLOT
Front Surface P-ROA(1.0) +
1
Front
BackSurface
SurfaceP-ROA(1.0)
P-ROA(1.0)+(μ
Back Surface P-ROA(1.0)
(m)
m)
Front Surface P-ROA(1.0) +
Back Surface P-ROA(1.0) (μm)
Reference Segment : [ 3, 6 ]
1.25
Semiconductor Equipment and Materials International
3081 Zanker Road
San Jose, CA 95134-2127
Phone:408.943.6900 Fax: 408.943.7943
DRAFT
NOTICE: SEMI makes no warranties or representations as to the suitability of the standard(s) set forth herein for
any particular application. The determination of the suitability of the standard(s) is solely the responsibility of the
user. Users are cautioned to refer to manufacturer’s instructions, product labels, product data sheets, and other
relevant literature respecting any materials or equipment mentioned herein. These standards are subject to change
without notice.
By publication of this standard, Semiconductor Equipment and Materials International (SEMI) takes no position
respecting the validity of any patent rights or copyrights asserted in connection with any item mentioned in this
standard. Users of this standard are expressly advised that determination of any such patent rights or copyrights, and
the risk of infringement of such rights are entirely their own responsibility.
This is a draft document of the SEMI International Standards program. No material on this page is to be construed as an offi cial or adopted standard. Permission is granted to
reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document development) activity. All other
reproduction and/or distribution without the prior written consent of SEMI is prohibited.
Page 10
Doc. 4920  SEMI
LETTER (YELLOW) BALLOT
Document Number: 4920
Date: 2/6/2016