Recipe

Gasses:

CHF3

50 sccm

O2

2.5 sccm
Pressure0.8 Pa (as low as possible)
RF Power50 W
Bias potential-

Etch characteristics

Etch is anisotropic
Etch rate: 10 nm/min

Selectivity

AZ etch rate: 10 nm/min (selectivity 1)

Remarks

Strong aspect ratio dependence
Strong aspect ratio dependence
Wafer uniformity: 15%
Reproducibility: 15%
Etch rate almost proportional to the rf power
PMMA inhibits etching at high pressure
Hard baked AZ 1420 recommended mask