Cobra III-V engraving processes

Semi-insulating GaAs
Selectivity with SiO2 : 40:1
Selectivity with photoresist : 9:1

Al evaporated
Selectivity with SiO2 : 20:1
Selectivity with photoresist : 4:1

Si
Selectivity with SiO2 : 3:1
Selectivity with photoresist : 0,6:1

InP
Selectivity with SiO2 : 15:1
Selectivity with photoresist : /