METHOD OF CASTING CRYSTALINE SILICON

摘要

A polycrystalline silicon ingot is prepared by (1) coating quartz of carbon crucible with a slurry mixed silicon nitride powder containing small amount of calcium chloride with ultra pure water, (2) filling a raw silicon in a water free casting crucible, (3) dissolving the silicon by heating the bottom of the crucible to 1,450 deg.C, (4) solidifying by cooling at the rate of 0.5-8.0 deg.C/min. In the substitute of silicon nitride containing calcium chloride, calcium chloride can be filled and coated to protect the wall of quartz and carbon crucible.