Development of chemical beam epitaxy for the deposition of gallium nitride

Kingsley CR, Whitaker TJ, Wee ATS, Jackman RB, Foord JS

Modern approaches to the growth of high quality gallium nitride thin films have focused on the use of metal-organic vapour phase epitaxy or plasma-assisted gas source molecular beam epitaxy. However, both of these techniques possess limitations. The present study therefore examined a new approach to GaN deposition using chemical beam epitaxy and the new nitrogen precursor, hydrogen azide. Thin films of gallium nitride (GaN) were successfully prepared. X-ray photoelectron spectroscopy reveals that stoichiometric materials is formed with little or no contamination when HN3 and a range of Ga precursors react on the substrate at temperatures down to 450°C. The results indicate that the incorporation efficiency of N in the GaN film from HN3 is high, suggesting the precursor may provide a more attractive route to the deposition of GaN films under low pressure molecular beam conditions than is currently offered using ammonia or plasma-excited nitrogen beam sources. Electrical measurements on the grown films are also reported. © 1995.