Mock CMOS Processing Update:
Complete Process
MEMS course structures: Polymerization removal
Below are the pictures from the oxide etch after doing a pirahna clean
and then after performing a xenon difluoride etch.
Here is what the processing steps were:
Photoresist Patterning
Photoresist used: AZ 4210
Approx. thickness: 1.5 um
Hard Bake: 5 minutes at 200C on hot plate
Aluminum Etch
Type of etch: Wet Isotropic Etch
Chemical used: Transene Type APre-mixed Aluminum Etch
Machine used: None
Temperature of etch: 45-50 degrees Celsius
Advertised etch rate: 100 Angstroms/minute
Etch time: 40 seconds
Titanium/Tungsten Etch
Type of etch: Wet Isotropic Etch
Chemical used: Hydrogen Peroxide
Machine used: None
Temperature of etch: 45-50 degrees Celsius
Advertised etch rate: 60 Angstroms/minute
Etch time: 2 minutes
Oxide Etch
Type of etch: Dry Anisotropic Etch
Chemical used: CF4
Machine used: Technics RIE system
Etch time: 30 minutes
Pirahna clean
Type of etch: Isotropic Etch
Chemical used: 3 H2SO4: 1 H2O2
Etch time: 5 minutes
Xenon Difluoride Etch
Type of etch: Dry Isotropic Etch
Chemical used: XeF2
Machine used: Xetch Xenon Difluoride system
Etch time: 30 cylces, 60 second cycles
After pirahna clean (Click to enlarge)
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After xenon difluoride etch (Click to enlarge)
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