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. Correlated with this minimum, the surface morphology was somewhat rough, with a hill and valley topography. Based upon transmission electron micrographs, the reduction in rocking-curve width was attributed to an enhanced annihilation of edge dislocations due to their tendency to cluster in 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