Growth of non‐polar (1120) and semi‐polar (1126) AlN and GaN films on the R‐plane sapphire

In this paper, we present detailed studies of growth of AlN and GaN films on R‐plane sapphire substrates. Contrary to previously reported work that GaN grows with its A‐plane (112 0) parallel to the R‐plane (11 02) of sapphire, our studies indicate that the crystallographic orientation of the III‐nitride films grown on such substrates depends strongly on the kinetic conditions of growth of the AlN buffer. Specifically, the group III‐rich conditions of growth of AlN buffer lead to nitride films having the (112 0) planes parallel to the sapphire surface, while growth of the buffer under N rich conditions leads to nitride films with the (112 6) planes parallel to the sapphire surface. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)