Dry etching of GaN using chemically assisted Ion beam etching with HCI and H2/Cl2

Abstract

The dry etching characteristics of GaN were investigated using chemically assisted ion beam etching (CAIBE) with HCI and H2/Cl2 gas. Etch rates using CAIBE/HC1 were investigated as a function of Ar ion beam energy and substrate temperature. These results were compared to CAIBE/C12. Etch rates were also investigated for CAIBE/H2/Cl2 for various ratios of H2:C12. Highly anisotropic submicron lines are demonstrated using CAIBE/HC1. Auger electron spectroscopy was used to investigate surface stoichiometric changes of samples etched with CAIBE/HC1, CAIBE/H2/Cl2,, and CAIBE/C12. The diffusion of deuterium into GaN during etching was also investigated using secondary ion mass spectrometry.