Interfacial structure of molecular beam epitaxial grown cubic-GaN films onGaAs(001) probed by x-ray gazing-angle specular reflection

We report on a study of interfacial structure of GaN films grown on GaAs(00 1) substrates by plasma-assisted molecular beam epitaxy using x-ray grazing -angle specular reflection. We show that interfacial layers with electron d ensities differing from those of GaN and GaAs were formed upon deposition o f GaN. It is also found that the interfacial structure of our systems depen ds strongly on the course of the initial layer deposition. The phase purity of the GaN films was examined by x-ray reciprocal space mapping. A simple kinetic growth model suggested by our results has been presented. (C) 1999 American Institute of Physics. [S0003-6951(99)01920-8].