Showing posts with label vacuum heater. Show all posts
Showing posts with label vacuum heater. Show all posts

ALD Vacuum Chamber Pedestal Heater with Extended Sleeve

ALD Vacuum Chamber Pedestal Heater with Extended Sleeve

BACKGROUND
Heating solution for an ALD Vacuum Chamber Heater testing 6” (152mm) wafers up to 450⁰C.  There were obvious space constraints at the customer site requiring an extended sleeve of 25”.  The extra-long length enabled the placement of the wafer on the top surface eliminating the need to modify the existing chamber.  

SCOPE
The Vacuum Pedestal Heater needed to satisfy the following:
  • Temperature 450⁰C  
  • 25” Long sleeve with 2.75 CF Flange on the bottom 
  • Body must pass Helium Leak rate of 1 x 10̄¯9 cc/sec He 
  • 6” overall diameter for 6” (152mm) wafers
  • Top surface must have a flatness of  ± .005” 
  • Thermocouple for additional temperature measurement
  • 1,000  Watt (± 10%) , 120 Volt
  • Material was 304 Stainless Steel
OUTCOME
The Vacuum Pedestal Heater was ramped in atmosphere to 450⁰C in approximately 45 minutes.  Due to the 360⁰ weld, there was some deflection on the top surface causing it to be out of tolerance.  After the 450⁰C ramp, the Vacuum Pedestal Heater was polished down to below ± .005”.  A leak test was performed to spec and cleaned to high purity standards then shipped in clean room bags.

200mm 8” Copper Molybdenum (CuMo) Vacuum Heater Chuck

Vacuum Heater Chuck

BACKGROUND

Having better uniformity specifications than aluminum with a higher temperature threshold, the Copper Molybdenum (CuMo) Vacuum Heater Chuck displayed stellar performance during ramp-up and heater stabilization. Thermal conductivity (TC) typically 210 to 255 W/m.K (with rolling process) compared to Aluminum at 205 W/m.K. Using a compressed style configuration, we utilized a 304 stainless steel bottom housing since the uniformity requirement was top end specific. This increased heat transfer towards the top CuMo side while reducing customer cost.

200mm 8” Stainless Vacuum Heater Electrical and Performance Specs:

  • High temperature up to 850°C
  • Temperature uniformity 550⁰C (+/-3⁰C)
  • 108 mtorr, pass best config. baseline (~0.4 torr/min)
  • 120 Volt or 208 Volt Up to 750 Watt (+/-10%)
  • External thermocouple optional
  • Surface Finish: As per customer specification
BCE
510-274-1990