Realization of low-dislocation-density, smooth surface, and thick GalnN films on m-plane GaN templates

摘要

We grew thick Ga_(1-x)In_xN epitaxial films on GaN templates having different crystal orientations. Reciprocal space mapping of asymmetrical X-ray diffraction showed that 1.1-μm-thick Ga_(0.95)In_(0.05)N could be coherently grown on m-plane GaN, while those grown on a-plane and c-plane GaN showed partial relaxation. A 700-nm-thick Ga_(0.95)In_(0.05)N film with a threading dislocation density of approximately 1 ×10~8cm~(-2) can be successfully grown on a GaN template using a grooved underlying layer. The mechanism of strain relaxation in c-, a- and m-plane Ga_(1-x)In_xN films is discussed.