CVD growth of 3C–SiC on various orientations of Si substrates for the substrate of nitride semiconductors

Single crystal growth of 3C–SiC on (100), (110), (111), and (211) Si substrates was carried out by CVD with the source gases of Si2Cl6 and C3H8, for its applications as substrates for nitride semiconductors. Depending on the substrate orientations, the flow rate of C3H8 during the growth of carbonized buffer layer and the C/Si ratio in the supplied source gases during the CVD growth were varied and optimized. The crystal orientation of 3C–SiC epitaxial layers was identical with that of Si substrates on (100), (111), (211) substrates, although that on (110) Si substrates was twined (111) 3C–SiC. It revealed from the growth on hemispherically polished (111) substrates that off-axis toward 〈2–1–1〉 is effective to achieve smooth surface on (111) Si substrates. The surface morphology of as-grown (211) 3C–SiC was superior to that of other substrate orientations. The present research enabled various orientations of single crystal 3C–SiC/Si structures being available for substrates of nitride semiconductors. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)