Interface chemistry and electronic structure of GaN/MgAl2O4 revealed by angle-resolved photoemission spectroscopy

By modifying the MgAl2O4 substrate surface using chemical etching and thermal passivation, high-quality GaN films have been achieved on the MgAl2O4(111) substrate via metalorganic chemical vapor deposition. The interface chemistry and electronic structure of GaN/MgAl2O4 interface have been investigated by angle-resolved photoemission spectroscopy. It has been noted that thermal passivation leads to the formation of Al2O3 buffered layer, which remains thermally stable during deposition and are primarily responsible for the epitaxial growth of GaN on MgAl2O4(111) substrate. (C) 2010 American Institute of Physics. [doi:10.1063/1.3505153]