Etch profile under a resist mask — three methods compared

Pick a method, then press Play

Speed

Grey = film to etch · dark = substrate · orange = resist mask · red = etch front · teal = C₄F₈ passivation · dashed lines = original mask edge

Bosch DRIE Cycle Simulation

Bosch DRIE Cycle — SiO₂ / Ta₂O₅ Trench

Alternating CHF₃ etch and C₄F₈ passivation produce scalloped sidewalls

Phase: ETCH (CHF₃)

Etch depth/cycle: Passivation:

Red = etch front | Teal = passivation layer | Grey = SiO₂/Ta₂O₅ | Dark = Si substrate