The GaN, InN, and AlGaN were grown by metalorganic vapor phase epitaxy using 1,1-dimethylhydrazine as a N source, instead of NH3. Then GaN with atomically flat surfaces and dislocation densities comparable to those in GaN grown with NH3 was obtained at a growth temperature of 925C and a V/III ratio of 25; which were much lower than those for NH3-metalorganic vapor phase epitaxy. Carbon incorporation from the source precursors was avoidable in H growth ambients but was considerable in inert ambients. For InN, the (inert) N2 ambient also resulted in C-related deposits, while the H2 ambient permitted InN to be grown but caused In segregation. For AlGaN, the entire Al solid composition could be attained by growth under atmospheric pressure at 925C. Although the edge dislocation density increased with increasing Al composition, the screw dislocation density was as low as 106/cm2. The findings strongly suggested that 1,1-dimethylhydrazine was a promising alternative to NH3for the growth of GaN and AlGaN but was rather unsuitable for the growth of In-containing alloys.

Metalorganic Vapor Phase Epitaxy of GaN, InN, and AlGaN Using 1,1-Dimethylhydrazine as a Nitrogen Source. M.Funato, S.Ujita, Y.Kawakami: Japanese Journal of Applied Physics, 2007, 46, 6767-72