| 摘要 |
PROBLEM TO BE SOLVED: To manufacture high purity silicon nitride powder suitable for use as a release agent for production of polycrystalline silicon through direct nitriding of metallic silicon easy to mass-produce by lowering the contents of metal impurities present by≥10μg/g, such as Al, Ca and Mg and impurities which are B, P and As as dopants of p- and n-type semiconductors. SOLUTION: In a method for manufacturing silicon nitride powder in which metallic silicon powder as a starting material or a starting material mixture of metallic silicon powder and silicon nitride powder is batchwise or continuously supplied to a nitriding furnace in a nitriding gas atmosphere, the metallic silicon powder is p-type single-crystalline silicon scrap having≥0.4Ωcm resistivity and/or n-type single-crystalline silicon scrap having≥0.1Ωcm resistivity and the nitriding gas atmosphere is formed by diminishing a metallic component in gas discharged from the nitriding furnace, adding a consumed nitriding component to a prescribed concentration and circulating the gas. COPYRIGHT: (C)2004,JPO
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