Bulk growth of high-purity 6H-SiC single crystals by halide chemical-vapor deposition

High-purity 6H-SiC single crystals were grown by the halide chemical-vapor deposition process. Growth was performed in a vertical hot-wall reactor with a separate injection of a silicon precursor (silicon tetrachloride) and a carbon precursor (propane). Typical growth rates were between 100 and 300 mu m/h. The crystals contain very low concentrations of residual impurities. The main contaminants, namely, nitrogen and boron, are in the 10(14) atoms cm(-3) range. Crystals grown under Si-rich conditions were n type with low room temperature electron concentrations in the 10(14)-10(15) atoms cm(3) range and with room-temperature electron mobilities approaching 400 cm(2)/V s. The resistivity of the material increased up to 10(10)Omega cm with increasing C/Si ratio. Deep levels spectra show that the electron traps density decreases with increasing C/Si ratio. (C) 2005 American Institute of Physics.