Deposition and doping of silicon carbide by gas-source molecular beam epitaxy

Thin films of silicon carbide (SiC) have been deposited at 1400-1450 degrees 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 control (6H- or 3C-SiC) was established by utilizing substrates of particular orientations. Residual, unintentionally incorporated nitrogen impurity levels were affected by changing the SiH4/C2H4 gas flow ratio, in agreement with the ''site-competition epitaxy'' model. II? situ doping was achieved by intentional introduction of nitrogen and aluminum into the growing crystal. (C) 1997 American Institute of Physics.