HYDROGEN INCORPORATION IN EPITAXIAL LAYERS OF 4H-SILICON-CARBIDE AND 6H-SILICON-CARBIDE GROWN BY VAPOR-PHASE EPITAXY

The incorporation of hydrogen during vapor phase epitaxy was investiga ted using secondary ion mass spectroscopy, low temperature photolumine scence, and capacitance-voltage measurements. It was found that hydrog en incorporation is strongly dependent on the concentration of the acc eptor dopants aluminum and boron, regardless of changes in the doping concentration caused by varying the concentration ratio between carbon and silicon or the dopant precursor flow. An electrical passivation o f the acceptor dopants was found and could be reduced by annealing at temperatures above 1000 degrees C. At the same anneal temperature hydr ogen-related photoluminescence was considerably reduced and the diffus ion of hydrogen was detected. (C) 1997 Elsevier Science S.A.