Epitaxial growth of SiC on complex substrates

Epitaxial growth of SiC on complex substrates was carried out at substrate temperature from 1200 degreesC to 1400 degreesC. Three kinds of new complex substrates, c-plane sapphire, AlN/sapphire, and GaN/AlN/sapphire, were use d in this study. We obtained a growth rate in the range of 1-6 mum/h. Thick (6 mum) SIC epitaxial layers with no cracks were successfully obtained on AlN/sapphire and GaN/AlN/sapphire substrates. X-ray diffraction patterns ha ve confirmed that single-crystal SiC was obtained on these complex substrat es. Analysis of optical transmission spectra of the SIC grown on sapphire s ubstrates shows the lowest-energy gap near 2.2 eV, which is the value for c ubic SiC. The undoped SIC showed n-type electrical conductivity. (C) 2001 E lsevier Science B.V. All rights reserved.