Growth of non‐polar (11$ \bar 2 $0) and semi‐polar (11$ \bar 2 $6) AlN and GaN films on the R‐plane sapphire

Abstract

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 (110) parallel to the R-plane (102) 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 (110) planes parallel to the sapphire surface, while growth of the buffer under N rich conditions leads to nitride films with the (116) planes parallel to the sapphire surface. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)