Polycrystalline Silicon Powder for Slurry and Method for Producing Same, Polycrystalline Silicon Powder Slurry for Mold Release Material and Method for Producing Same, Polycrystalline Silicon Powder for Mold Release Material, Mold Release Material, and Polycrystalline Silicon Ingot Casting Mold and Method for Producing Same

Abstract

A silicon nitride powder to be used in a slurry for forming a mold release layer of a polycrystalline silicon casting mold, wherein the specific surface area thereof is 5-50 m2/g, the proportion of amorphous silicon nitride is 1.0-25.0 mass %, and the oxygen content is 0.6-2.5 mass %. A silicon nitride powder slurry for use in mold release material and capable of forming, on a polycrystalline silicon casting mold, a mold release layer which exhibits favorable mold release properties and exhibits favorable adhesion to the casting mold after casting the polycrystalline silicon ingot, and a method for producing the same. A silicon nitride powder for mold release material, a silicon nitride powder for a slurry use for obtaining the silicon nitride powder slurry for use in the mold release material, and a method for producing the same. A polycrystalline silicon casting mold which exhibits favorable mold release properties of a polycrystalline silicon ingot; and method for producing the same.

Dependencies are inferred from the claim text.