Growth of Si-doped Al xGa 1– xN on (0001) sapphire substrate by metalorganic vapor phase epitaxy

Abstract

Effects of Si-doping on the electrical and luminescence properties of GaN and A1 0.1Ga 0.9N epitaxial films have been studied. GaN and A1 0.1Ga 0.9N films were grown by MOVPE on (0001) sapphire substrates using A1N buffer layers. SiH 4 was used as Si source gas. The conductivities of n-type A1 0.1Ga 0.9N film were found to be controllable by varying the flow rate of SiH 4 during growth. Cathodoluminescence spectra of both GaN :Si film and A1 0.1Ga 0.9N :Si film are strong near the bandedge emission, and their intensity increases with increasing Si concentration. These results indicate that (1) GaN :Si and A1 0.1Ga 0.9N :Si films grown using A1N buffer layers have a high quality and (2) Si replaces group-III (Ga or A1) elements at lattice sites in the GaN film and also in the A1 0.1Ga 0.9N film.