Interface atomic arrangement between the nitride semiconductor and silicon

GaN epilayers were grown by MOVPE using a low temperature AlN nucleation layer. The substrate temperatures for the deposition of the nucleation layer and the main layer are about 720/spl deg/C and 1145/spl deg/C respectively. Cross-section TEM used to observe the image of GaN epilayer on silicon substrates. These GaN epilayers exhibit a specular surface, suggesting a two-dimensional growth mode. The observed microstructure shows the threading dislocation density is /spl sim/1/spl times/10/sup 10/cm/sup -2/. The lattice mismatch is found to be relieved by a periodic array of misfit dislocations.