Dry Etch Recipe for SiGe alloy in Chlorine based RIE

Recipe

Gases:

BCl3

15.0 sccm

Cl2

15.0 sccm

He

17.5 sccm
Pressure2.0 Pa
RF Power65 W
Bias potential10 V

Etch characteristics

Etch rate: 60 nm/min (for Si0.75Ge0.25)
Etching is anisotropic

Selectivity

Selective over all non-organic materials

Remarks

Considerable loading effect
Reproducibility: 10 %
Etch rate almost proportional to RF power
Etch rate depends on Si/Ge ratio
The wafer heats up considerably during etching (mask choice!)
Recommended mask is hard baked AZ 1420