POLYCRYSTALLINE WAFER, METHOD FOR PRODUCING SAME AND METHOD FOR CASTING POLYCRYSTALLINE MATERIAL

摘要

This method for casting a polycrystalline material is characterized by controlling the cooling speed of a melt in an electromagnetic casting. This method for producing a polycrystalline wafer is characterized by cutting polycrystalline ingots obtained by this casting method, dividing the ingots into polycrystalline blocks, and slicing the polycrystalline blocks. Furthermore, this polycrystalline wafer is characterized in that the strength (Vickers' hardness) of a rim portion is high compared to a center portion.