| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide silicon nitride powder for a mold releasing agent capable of reducing the amount of impurity contamination into a polycrystal silicon ingot, suppressing exfoliation of the mold releasing agent, and obtaining the polycrystal silicon ingot at excellent yield. <P>SOLUTION: This invention relates to: silicon nitride powder for a mold releasing agent in which a particle size distribution is 1.6-3.0 μm in terms of D50, 3.9-14.0 μm in terms of D90, and 11-68 μm in terms of D100; silicon nitride powder for a mold releasing agent in which the ratio of a β phase is 30-70 mass%; silicon nitride powder for a mold releasing agent in which Fe, Al and Ca which are impurities are each ≤100 ppm; and a method for producing the silicon nitride powder for a mold releasing agent in which silicon nitride powder produced by a direct nitriding method is crushed by using a vibration mill. <P>COPYRIGHT: (C)2013,JPO&INPIT |
