CHARACTERISTICS OF CHEMICALLY ASSISTED ION-BEAM ETCHING OF GALLIUM NITRIDE

Chemically assisted ion beam etching (CAIBE) characteristics of galliu m nitride (GaN) have been investigated using a 500-eV Ar ion beam dire cted 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 A r ion milling at a substrate temperature of 20-degrees-C. The CAIBE et ch rates were further enhanced at higher substrate temperatures wherea s etch rates for Ar ion milling were not influenced by substrate tempe rature. Etch rates as high as 210 nm/min are reported. The etch rates reported here are the highest so far reported for GaN. Anisotropic etc h profiles and smooth etched surfaces in GaN have been achieved with C AIBE.