Films of GaN were grown, by plasma-assisted molecular-beam epitaxy, onto SiC substrates. The width of the X-ray rocking curve for the (10•2) reflection exhibited a distinct minimum for Ga/N flux ratios which were only slightly greater than unity. At this minimum, the surface morphology was relatively rough; with a hill-and-valley topography. On the basis of transmission electron micrographs, the reduction in rocking curve width was attributed to an enhanced annihilation of edge dislocations, due to their tendency to cluster at topographic valleys.

Role of Ga Flux in Dislocation Reduction in GaN Films Grown on SiC(0001). C.D.Lee, A.Sagar, R.M.Feenstra, C.K.Inoki, T.S.Kuan, W.L.Sarney, L.Salamanca-Riba: Applied Physics Letters, 2001, 79[21], 3428-30