US Patent 7547360 Reduction of carbon inclusions in sublimation grown SiC single crystals

In a method of SiC single crystal growth, a SiC single crystal seed and polycrystalline SiC source material are provided in spaced relation inside of a graphite growth crucible along with at least one compound capable of forming SiO gas in the growth crucible. The growth crucible is heated whereupon the gaseous SiO forms and reacts with carbon in the growth crucible thereby avoiding the introduction of carbon into the SiC single crystal before and during the growth thereof and the SiC source material vaporizes and is transported via a temperature gradient in the growth crucible to the seed crystal where it precipitates and forms a SiC single crystal.