Influence of growth conditions on the structural perfection of beta-SiC epitaxial layers fabricated on 6H-SiC substrates by vacuum sublimation

We report on the influence of the surface quality of substrate, growth rate and vapour phase composition in the growth cell on, both, the size of double position twins (and correspondingly the density of double position boundaries) in beta-SiC epitaxial layers and on the perfection of interfacial layers in beta-SiC/6H-SiC structures. The growth of beta-SiC was done by vacuum sublimation on the (0001)Si-face of 6H-SiC Lely substrates. Epitaxial layers of beta-SiC, with 5-6 mm(2) double position twins and low (10(1)-10(2) cm(2)) defect density, have been grown. The resulting beta-SiC/6H-SiC heterostructures had no damaged intermediate layers at the interface. (C) 1997 Published by Elsevier Science S.A.