GROWTH OF SI-DOPED ALXGA1-XN ON (0001) SAPPHIRE SUBSTRATE BY METALORGANIC VAPOR-PHASE EPITAXY

Effects of Si-doping on the electrical and luminescence properties of GaN and Al0.1Ga0.9N epitaxial films have been studied. GaN and Al0.1Ga0.9N films were grown by MOVPE on (0001) sapphire substrates using AlN buffer layers. SiH4 was used as Si source gas. The conductivities of n-type GaN film and n-type Al0.1Ga0.9N film were found to be controllable by varying the flow rate of SiH4 during growth. Cathodoluminescence spectra of both GaN:Si film and Al0.1Ga0.9N:Si film are strong near the bandedge emission, and their intensity increases with increasing Si concentration. These results indicate that (1) GaN:Si and Al0.1Ga0.9N:Si films grown using AlN buffer layers have a high quality and (2) Si replaces group-III (Ga or Al) elements at lattice sites in the GaN film and also in the Al0.1Ga0.9N film.