Magnetron reactive ion etching of AlN and InN in BCl3 plasmas

Abstract

Magnetron reactive ion etching of AlN and InN in BCl3 discharges is found to produce anisotropic pattern transfer over a wide range of conditions. Maximum etch rates of ∼1250 Å min−1 for AlN and ∼1000 Å min−1 for InN were obtained for low pressures (2–12 mTorr) and low cathode self-bias voltages (≤−100 V). Auger electron spectroscopy and secondary ion mass spectrometry measurements showed the presence of <1 at. % boron and chlorine residue on as-etched AlN and InN. Dry etching appeared to produce a change in the surface region stoichiometry of InN.