Growth and Characterization of Large Diameter 6H and 4H SiC Single Crystals

Over the past year, II-VI has transitioned from 2" to 3" commercial SiC substrates. Large-diameter semi-insulating 6H-SiC and n-type 4H-SiC single crystals are grown using the Advanced PVT growth process. Expansion of boule diameter from 2 to 3 and up to 4.25 inches has been carried out using a specially designed growth technique. Stable semi-insulating properties in 6H-SiC are achieved by precise vanadium compensation. The technique of compensation is optimized to produce a controlled and spatially uniform 10 distribution of vanadium and high and spatially uniform electrical resistivity reaching 10(10-)10(11)-Omega center dot cm. N-type 3-inch 4H-SiC crystals are grown using doping with nitrogen, and 3-inch 4H-SiC substrates show uniform resistivity of about 0.018 Omega center dot cm. The best quality semi-insulating (SI) 3" 6H-SiC substrates demonstrate micropipe density of 3 cm(-2), and n-type 3" 4H-SiC substrates - about 1 cm(-2). X-ray rocking curve topography of the produced 3" SiC substrates is used for evaluation of their crystal quality.