DEPOSITION AND DOPING OF SILICON-CARBIDE BY GAS-SOURCE MOLECULAR-BEAMEPITAXY

Thin films of silicon carbide (SiC) have been deposited at 1400-1450 d egrees C on vicinal and on-axis 6H-SiC(0001) substrates by gas-source molecular beam epitaxy using the SiH4-C2H4-H-2 gas system. Polytype co ntrol (6H- or 3C-SiC) was established by utilizing substrates of parti cular orientations. Residual, unintentionally incorporated nitrogen im purity levels were affected by changing the SiH4/C2H4 gas flow ratio, in agreement with the ''site-competition epitaxy'' model. II? situ dop ing was achieved by intentional introduction of nitrogen and aluminum into the growing crystal. (C) 1997 American Institute of Physics.