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

Abstract

Epitaxial 4H–SiC layers were grown by chemical vapor deposition (CVD) on porous silicon carbide. Porous SiC substrates were fabricated by the formation of a 2 to 15 μm thick porous SiC layer on commercial off-axis 4H–SiC substrates. The thickness of CVD grown layers was about 2.5 μm. The concentration Nd–Na in the layers was about 7×1015 cm−3. The layers were investigated for their surface roughness, crystal structure, deep level concentration, and minority carrier diffusion length. It was found that the characteristics of SiC epitaxial layers grown on porous SiC substrates were significantly improved compared to those of SiC layers grown on standard SiC substrates.