Growth and characterization of high-purity SiC single crystals

High-purity SiC single crystals with diameter up to 50 mm have been grown b y the physical vapor transport method. Finite element analysis was used for thermal modeling of the crystal growth cavity in order to reduce stress in the grown crystal. Crystals are grown in high-purity growth ambient using purified graphite furniture and high-purity SiC sublimation sources. Undope d crystals up to 50 mm in diameter with micropipe density less than 100 cm( -2) have been grown using this method. These undoped crystals exhibit resis tivities in the 10(3) Omega cm range and are p-type due to the the presence of residual acceptor impurities, mainly boron. Semi-insulating SiC materia l is obtained by doping the crystal with vanadium. Vanadium has a deep dono r level located near the middle of the band gap, which compensates the resi dual acceptor resulting in semi-insulating behavior. (C) 2000 Elsevier Scie nce B.V. All rights reserved.