Influence of ambient oxidation on electronic structure of epitaxial GaN films

The surface and interface properties play significant role in governing the design and performance of a device. The ambient oxidation of the surface changes the electronic structure of III-Nitride semiconductors and perturbs 76 the device performance and reliability upto a great extent. The present reports electronic, structure and chemical states analysis of epitaxial GaN films grown on various substrates at different temperature were probed via highly surface sensitive X-ray/Ultraviolet photoelectron spectroscopic (XPS and UPS) and microscopic (FESEM/AFM) measurements. The mechanism of ambient oxidation and other growth relation parameters on surface and interface properties was explored. (author)