On-axis homoepitaxial growth on Si-face 4H-SiC substrates

Homoepitaxial growth has been performed on Si-face nominally on-axis 4H-SiC substrates using horizontal Hot-wall chemical vapor deposition system. Special attention was paid to the surface preparation before starting the growth. In-situ surface preparation, starting growth parameters and growth temperature are found to play a vital role to maintain the polytype stability in the epilayer. High quality epilayers with 100% 4H-SiC were obtained on full 2 '' substrates. Different optical and structural techniques were used to characterize the material and to understand the growth mechanisms. It was found that the replication of the basal plane dislocation from the substrate into the epilayer can be completely eliminated. The on-axis grown epitaxial layers were of high quality and did not show surface morphological defects, typically seen in off-axis grown layers, but had a high surface roughness. (C) 2008 Elsevier B.V. All rights reserved.