Initial stage of GaN growth and its implication to defect formation in films - art. no. 033304

In situ scanning tunneling microscopy (STM) observations of initial growth processes of GaN by molecular-beam epitaxy reveal important differences bet ween growth on vicinal versus flat SiC(0001) substrates. Based on stop-grow th STM studies, we explain why there are orders of magnitude reductions in the density of threading screw dislocations in the vicinal films. It is sho wn that on vicinal surfaces, three-dimensional (3D) islands develop into a characteristic shape. The islands coalesce much sooner than on flat surface s. Consequently, fewer defects are created at their boundaries.