Recipe

Gasses:

BCl3

15 sccm

Cl2

7,5 sccm

N2

50 sccm
Pressure15 Pa
RF Power70 W
Substrate temperatureambient

Etch characteristics

Etch rate: 17 nm/min
Etching is anisotropic

Selectivity

Etch rate of AZ 1420: 80 nm/min (selectivity 2)
Etch rate of SiO2: 25 nm/min (selectivity 6)

Remarks

Considerable loading effect
The native AlOx top layer etches very slowly
Reproducibility depends strongly on the AlOx top layer
The wafer heats up considerably during etching (mask choice!)
Anisotropy is due to the inhibiting effect of carbon compounds (mask choice!)
Recommended mask is hard baked AZ 1420 or HPR (120 oC)