Hydrogen incorporation in GaN, AlN, and InN duringCl 2 /CH 4 /H 2 /Ar ECR plasma etching

Hydrogen concentrations up to ~1020 cm-3 in GaN and AlN and ~1019 cm-3 in InN are found to be incorporated during ECR plasma etching in Cl2/CH4/H2Ar at 170°C. Even very short duration (40 s) etch treatments produce hydrogen incorporation depths ≥0.2 µm ahead of the etch front, and may lead to electrical passivation effects within this region. Post-etch annealing at 450 – 500°C restores the initial conductivity.