Table 1: Coupling parameters of ICP.

ICP P/W 700
RF RP/W Passivation: 10
Etching: 25
Gas flow/sccm Passivation: C4F8 = 100
Etching: SF6 = 100
Time/s Passivation: 10
Etching: 10
Cycle number 30
Helium pressure/Torr 10
Total gas pressure/mTorr 40
Substrate temperature/°C 10