BCl3/N2 dry etching of InP, InAlP, and InGaP

Etch rates for InP, InAlP, and InGaP can be controlled between ∼1500 A/min and ≳1 μm/min by varying the microwave power, rf power, or N2 composition in BCl3N2 discharges under electron cyclotron resonance conditions. The surface morphology of InGaP is poor at low microwave power (250 W), but becomes very smooth at high powers (1000 W). InP has exactly the opposite dependence on microwave power, while InAlP shows little change in morphology over a wide range of powers. The high ion current under electron cyclotron resonance conditions enables etching of In‐based semiconductors without the need for high sample temperatures to enhance desorption of InClX species.