High etch rates of GaN with magnetron reactive ion etching in BCl3 plasmas

Abstract

Magnetron reactive ion etching of GaN in BCl3 plasmas was investigated as a function of cathode power density, flow rate, and pressure. GaN etch rates were achieved (350 nm/min), which were twice the highest etch rate previously reported, and at low cathode bias voltages (<100 V). Auger electron spectroscopy measurements revealed the etched surfaces to be Ga deficient to a depth of 10 nm, with a surface chlorine residue of <1 at. %. Magnetron dry etching appears well suited to applications such as mesa definitions for photonic devices in the GaN materials system.