The effect of CVD growth conditions of 6H-SiC epilayers on Al incorporation

Results obtained in studying CVD-grown p-type undoped epitaxial 6H-SiC laye rs by secondary-ion mass spectrometry are reported. The possible sources of background impurity, the mechanism of its incorporation into a layer, and the relationship between stoichiometry and adsorption, on the one hand, and the "site competition" effect, on the other, are discussed. The accumulati on of aluminum in the adsorption layer of SiC is attributed to its surface activity. The increase in Al concentration with growing carbon concentratio n is related to the formation of silicon vacancies occupied by aluminum ato ms. (C) 2001 MAIK "Nauka/Interperiodica".