Journal of Crystal Growth, Vol.230, No.3-4, 558-563, 2001
Investigation of metal-GaN and metal-AlGaN contacts by XPS depth profiles and by electrical measurements
Metal/GaN Schottky contacts have been studied by X-ray photoelectron spectroscopy (XPS). Au/GaN, Pt/GaN, Pd/ GaN are sharp while Ti/GaN is diffuse with the following composition, starting from the surface: Ti+TiN, Ti + TixGayN, Ti + TixGayN + Ga, GaN + Ga. Au/AlGaN and Ni/AlGaN contacts are much broader than Au/GaN: Al and Ga are found more than 100 Angstrom away from the interface. Schottky barrier height was measured for the Au/GaN, Pd/GaN, Pt/GaN, Au/AlGaN and Ni/AlGaN contacts.