Characteristics of chemically assisted ion beam etching of gallium nitride

Abstract

Chemically assisted ion beam etching (CAIBE) characteristics of gallium nitride (GaN) have been investigated using a 500-eV Ar ion beam directed onto a sample in a Cl2 ambient. Enhanced etch rates were obtained for samples etched in the presence of Cl2 over those etched only by Ar ion milling at a substrate temperature of 20 °C. The CAIBE etch rates were further enhanced at higher substrate temperatures whereas etch rates for Ar ion milling were not influenced by substrate temperature. Etch rates as high as 210 nm/min are reported. The etch rates reported here are the highest so far reported for GaN. Anisotropic etch profiles and smooth etched surfaces in GaN have been achieved with CAIBE.