Chemical vapor deposition of 4H-SiC epitaxial layers on porous SiC substrates

Epitaxial 4H-SiC layers were grown by chemical vapor deposition (CVD) on po rous silicon carbide. Porous SiC substrates were fabricated by the formatio n of a 2 to 15 mum thick porous SiC layer on commercial off-axis 4H-SiC sub strates. The thickness of CVD grown layers was about 2.5 mum. The concentra tion N-d-N-a in the layers was about 7x10(15) cm(-3). The layers were inves tigated for their surface roughness, crystal structure, deep level concentr ation, and minority carrier diffusion length. It was found that the charact eristics of SiC epitaxial layers grown on porous SiC substrates were signif icantly improved compared to those of SiC layers grown on standard SiC subs trates. (C) 2001 American Institute of Physics.