Epitaxial growth of GaN films on Cr-compound buffer layers by plasma assisted molecular beam epitaxy

Abstract

Epitaxial GaN layers were successfully grown on Al2O3 substrate with CrN buffer layer by plasma assisted molecular beam epitaxy (PA MBE). In order to form CrN layer, two kinds of formation methods are used such as nitridation of Cr-metal and conventional MBE growth without extra process. With reflection high energy electron diffraction pattern analysis and x-ray diffraction (XRD) measurement, it was confirmed that formed CrN layers have a cubic structured (111) CrN with single phase at all growth temperatures. Based on photoluminescence and XRD measurements, we suggest that the procedure of CrN buffer layer formation is more preferred the conventional MBE growth to nitrided Cr metal layer for GaN growth.