Growth of Thick Epitaxial 4H-SiC Layers by Chemical Vapor Deposition

Thick, low-doped epitaxial layers have been grown on 4H-SiC substrates by chemical vapor deposition. The layers were grown in a hot-wall type reactor to thicknesses in excess of 150 microns and with a thickness uniformity of 5 percent or better. The intrinsic doping of the layers is normally n-type in the low 10 exp -14/cu cm as determined from mercury probe C-V profiling and photoluminescence measurements. The residual background impurities of Al, B, and Ti are generally low. Higher concentrations of these may, however, be present at the substrate/epi interface. (Author)