"M. Sumiya,T. Ohnishi,K. Tanaka,A. Ohtomo,M. Kawasaki,H. Koinuma,K. Ohtsuka,S. Fuke","Control of the polarity and surface morphology of GaN films deposited on C-plane sapphire",,"MRS Internet Journal of Nitride Semiconductor Research",,"Vol. 4","No. Suppl. 1","pp. G6.23",1999,Dec.