Palsma cleaning and nitridation of sapphire substrates for Al_xGa_1-xN epitaxy as studied by arxps and XPD

摘要

The influenceof plasma and thermal treatments on the structure and composition of sapphire (001) surfaces have been studied by hemispherically recorded x-ray photoelectron spectroscopy in view of substrate preparation for the epitaxy of GaN.Producing well-oridered surfaces, O_2 plasma based treatments are found to effiicently remove surface contamination.AlN films with good short-range order are obtained by a simple high temperature nitridation step in the MOCVD reactor.