Aluminum Evaporation
Aluminum will be evaporated onto the surface of the wafer to form low-resistance
connections to the active devices.
Equipment
LDS 1820 Thermal Evaporator or Cooke CVE301 Thermal Evaporator
Supplies
LDS 1820
- Demelloy (1%Si in Al alloy)
- IPA
- Blue wipers
- Hi-vac grease
Cooke 301
- (1) three inch piece of Al wire
- IPA
- Blue wipers
- Hi-vac grease
Operating parameters
LDS 1820
- Turbo cross over: 30 mTorr
- Evaporation pressure: <5 x 10-6 Torr
- Evaporation recipe: 4
- Evaporation rate: 10Å/second
- Total film thickness: 2000Å
Cooke 301
- Diffusion pump cross over: 80 microns
- Evaporation pressure: 1 x 10-5 Torr
- Filament current: 40 - 60 A
- Evaporation time: 3 seconds after evaporation starts
Equipment/controls/tools locations
LDS 1820
- Located behind diffusion furnace
- Controls located in the rack to the right of the evaporator
Cooke 301
- Located behind diffusion furnace
Operating precautions
Implosion Hazard
The Cooke 301 uses a glass bell jar that poses an implosion hazard. The
pressure exerted on the bell jar by the atmosphere can be extreme. If the
bell jar fails, the glass can potentially cause serious injuries.
Operating procedure
See Appendix A.
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