Thick Ga1−xInxN epitaxial films were grown onto GaN templates having various crystal orientations. Reciprocal space mapping of asymmetrical X-ray diffraction showed that 1.1μm-thick Ga0.95In0.05N could be coherently grown onto m-plane GaN, while those grown onto a-plane and c-plane GaN exhibited partial relaxation. A 700nm-thick Ga0.95In0.05N film with a threading dislocation density of approximately 108/cm2 could be successfully grown onto a GaN template by using a grooved underlying layer. The mechanism of strain relaxation in c-, a- and m-plane Ga1−xInxN films was considered.

Realization of Low-Dislocation-Density, Smooth Surface, and Thick GaInN Films on m-Plane GaN Templates. A.Miura, T.Nagai, R.Senda, T.Kawashima, M.Iwaya, S.Kamiyama, H.Amano, I.Akasaki: Journal of Crystal Growth, 2008, 310[14], 3308-12