Universal Microsystems
Gas Flow Restrictors for the
Semiconductor Industry
Company founded in 1999
Partnership with TEM Filter
3350 Scott Blvd. Santa Clara, CA
Universal Microsystems, 3350 Scott Blvd. Bldg 47, Santa, Clara, CA 95054
Uses for Gas Flow Restrictors
• Replace MFC in fixed process applications
– steady pressure, single flow set point
• Safety — limit flow in case of line failure
• Tamperproof needle valve replacement
• Flow splitting
• eliminates multiple MFCs
• Back fill a chamber in a fixed time
Universal Microsystems, 3350 Scott Blvd. Bldg 47, Santa, Clara, CA 95054
UMS Gas Flow Restrictors
• Orifice inside 316L SS container
• High accuracy calibration (± 1.0%)
• Three orifice materials available
– SS, & Single crystal sapphire or silicon
• Quick turn production
Universal Microsystems, 3350 Scott Blvd. Bldg 47, Santa, Clara, CA 95054
Orifice Flow vs Pressure
Flow, sccm
500
400
Atmosphere Outlet
Vacuum Outlet
300
Sonic
200
100
Sub-sonic
0
15 17 19 21 23 25 27 29 31 33 35
Pressure, Psia
Universal Microsystems, 3350 Scott Blvd. Bldg 47, Santa, Clara, CA 95054
Orifice Characteristics
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Completely stable
No Particle Generation
Minimal dry down time
Precision of flow at specified pressure
– +/- 5% standard, +/- 2% available
• Orifice will not clog like a filter
Universal Microsystems, 3350 Scott Blvd. Bldg 47, Santa, Clara, CA 95054
Restrictor body types available
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1/4 “ Male/Male VCR
1/8” Male/Male VCR
1/4” Female/Male VCR
1/4” BulkHead VCR
Ni media Filter/Restrictor Combination
1 1/8” surface mount sandwich
Universal Microsystems, 3350 Scott Blvd. Bldg 47, Santa, Clara, CA 95054
B-Series
M/M VCR
Flow Restrictor
22-161414-00
.625”
1.55”
.75”
• VCR Male Union
• Flow Direction Arrow
• External Part No. Label
Universal Microsystems, 3350 Scott Blvd. Bldg 47, Santa, Clara, CA 95054
F/M or M/F Versions
•Gland to gland 1.80”
•Diameter 0.75”
•Wrench Flats 5/8”
Universal Microsystems, 3350 Scott Blvd. Bldg 47, Santa, Clara, CA 95054
Filter/Restrictor Combination
Precise flow at a specified
pressure
•Specifications
No more than 1 particle/ft3
Less than 10 ppb THC
Less than 10 ppb moisture
99.9999999% removal rating
at rated flow
He leak check to 10-9 atm
sccm/sec
Universal Microsystems, 3350 Scott Blvd. Bldg 47, Santa, Clara, CA 95054
Surface Mount Sandwich Restrictor
Top
¼”
Flow
• Restrictor can be inserted
into either port
• 3 Port version available
2-port IGS configuration
1 1/8” body size
Universal Microsystems, 3350 Scott Blvd. Bldg 47, Santa, Clara, CA 95054
UMS Flow Restrictor Specifications
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Surface finish, 7-8 Ra electropolish
Base Material, 316L SS,
Orifice material, Si, Sapphire, or SS
Seal for Si (Viton or Kalrez)
He leak check 10-9 atm-cc/sec
Maximum pressure, 200 psia
Temperature range, 50 to 250 oF
Universal Microsystems, 3350 Scott Blvd. Bldg 47, Santa, Clara, CA 95054
Sapphire Orifices
Orifice diameters from 0.003” to 0.040”
Variation in diameter is +/- 2.5µm
Nozzle side
CrossSection
Different manufacturing runs likely to see
different means but tight distribution
-2.5 µm
+2.5 µm
Universal Microsystems, 3350 Scott Blvd. Bldg 47, Santa, Clara, CA 95054
Silicon Orifices
• Used for diameters < 0.003”
Cross-section
nozzle side
– or non-integer .001” units
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50 µm
Flow from nozzle side 10-15% greater
Avoid placing downstream from F plasma
Option: sputter deposit Al203 (both sides)
Opportunity to enlarge undersized orifices
– Oxidation and strip - 50 - 1000 nm
Universal Microsystems, 3350 Scott Blvd. Bldg 47, Santa, Clara, CA 95054
Stainless Steel Orifices
Cross-section
250 µm
• Mechanical drill OK down to 0.030”
Use EDM down to 0.004”
• EDM precision is +/- 1.5% at .008”
• EDM most expensive of three types
Universal Microsystems, 3350 Scott Blvd. Bldg 47, Santa, Clara, CA 95054
Standard Orifices & N2 flow @ 20 psig
• Flow range -15 sccm to 40 slm
• Flow steps in ~ 10%
• Sapphire orifices designated
with N or R, SS orifices with F
and Si orifices with S
• N orifices nozzle side inlet
R orifices nozzle side outlet
Universal Microsystems, 3350 Scott Blvd. Bldg 47, Santa, Clara, CA 95054
How to find required orifice
• This procedure converts the application gas
flow at the application pressure into the
equivalent N2 flow at 20 psig
• Match the converted flow to the flow table
Universal Microsystems, 3350 Scott Blvd. Bldg 47, Santa, Clara, CA 95054