Dry etching of AlxGa1-xN using chemically assisted ion beam etching

The dry etching characteristics of AlxGa1-xN grown by metal-organic chemical vapour deposition have been investigated using chemically assisted ion beam etching with an Ar ion beam and Cl-2 gas. Etch rates were investigated as a function of Al composition in AlxGa1-xN ranging from GaN to AlN and as a function of ion beam energy. Anisotropic etched structures with smooth surfaces are demonstrated in Al0.4Ga0.6N layers. Auger electron spectroscopy of etched AlGaN surfaces shows that the stoichiometry is essentially unchanged after etching.