Diffusion Furnace Instructions

Things to have ready:

  1. Quartz boat, with wafers loaded evenly spaced

  2. Quartz boat holder

  3. High Temperature gloves

Procedure:

Things to turn on:

  1. In service corridor:
  2. Compressed Nitrogen
  3. Compressed Oxygen
  4. At the machine:
  5. Cooling water
  6. Open Nitrogen Turret
  7. Set flow meter at 50
  8. Make sure Nitrogen is running through furnace tube
  9. Turn on Power at wall box
  10. Turn on Power Switch at back of machine
  11. Go to front of machine
  12. Turn on Power switch for the control and the element

  13. The power light should be on and the power output gauges should be at100% (5)output

  14. Set three Temp dials to 800

  15. Wait for furnace to reach desired temperature

  16. While waiting check water level in bubbler at back of furnace, fill as necessary

  17. Turn power gauge on bubbler heater past 20 then down to 15

  18. Once temperature reached set power dials so that all outputs are 20-50%

  19. Turn on Oxygen at turret               

  20. Switch Furnace valve from nitrogen to oxygen

  21. Turn off Nitrogen at wall turret                                                                                 





  22. Take cap off end of quartz tube

  23. Use quartz boat holder to place quartz boat in opening of Quartz tube

  24. Use glass rod to push quartz boat into tube opening (ONLY PUSH BOAT IN ENOUGH TO BE ABLE TO REPLACE THE END CAP, pushing boat in to far to fast will break all the wafers)

  25. Replace end cap

  26. Remove small plug held onto end cap with metal clamp

  27. Use glass rod to push quartz wafer boat 5 inches into the furnace every 1 minute

  28. Once boat at center of furnace (When pushing rod reaches tape mark nearest furnace) remove rod and replace small plug

  29. Wait for necessary time

  30. Remove plug on end cap

  31. Use glass rod to remove wafer boat 5 inches out of the furnace every 1 minute

  32. Once boat at end of tube remove glass rod, replace small plug into endcap

  33. Remove endcap and place down on table

  34. Place wafer boat holder in front of tube opening

  35. Use glass rod to pull boat into boat holder

  36. Replace endcap and allow wafers to cool under hood for 10 minutes

  37. Turn off Control panel power and heater element power

  38. Turn off Oxygen supply and bubbler heater

  39. Turn On Nitrogen supply

  40. Allow nitrogen to flow through tube until the tube cools to 200 C

  41. Once tube cooled turn off Nitrogen and cooling water

procedure prepared by Francisco Tejada, Spring 2003; modified by La Vida Cooper, Spring 2003.