Universal Microsystems

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Universal Microsystems

• Gas Flow Restrictors for the Semiconductor
  Industry
• Company founded in 1999
• Partnership with TEM Filter
• 3350 Scott Blvd. Santa Clara, CA

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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

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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

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Orifice Flow vs Pressure
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Orifice Characteristics

• 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

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Restrictor body types available

• 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

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B-Series M/M VCR Flow Restrictor
.625
22-161414-00
.75
1.55

• VCR Male Union
• Flow Direction Arrow
• External Part No. Label

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F/M or M/F Versions

• Gland to gland 1.80
• Diameter 0.75
• Wrench Flats 5/8

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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

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Surface Mount Sandwich Restrictor

• Restrictor can be inserted into either port
• 3 Port version available

2-port IGS configuration1 1/8 body size
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UMS Flow Restrictor Specifications

• 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

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Sapphire Orifices
Orifice diameters from 0.003 to 0.040 Variation
in diameter is /- 2.5µm Different
manufacturing runs likely to see different
means but tight distribution
Nozzle side
Cross-Section
-2.5 µm
2.5 µm
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Silicon Orifices

• Used for diameters lt 0.003
• or non-integer .001 units
• 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

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Stainless Steel Orifices

• 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

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Standard Orifices N2 flow _at_ 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 inletR orifices nozzle
  side outlet

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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