Published online by Cambridge University Press: 10 February 2011
The growth of GaN on silicon (Si) substrates by MOCVD is reported in this paper. The use of a high-temperature AIN buffer layer appears to be necessary to establish an initial template morphology for the subsequent growth of GaN. Nucleation modes of GaN on SiO2, (100) Si, and (111) Si are compared; it is shown that the spatial coherency among the nuclei is most preserved when the growth occurred on the hexagonal Si (111) surface. To circumvent the problem associated with cracking due to a thermal expansion mismatch, we also investigate the possibility of using a silicon-on-insulator (SOI) scheme.