| 摘要 |
PROBLEM TO BE SOLVED: To obtain a jig without a wafer being contaminated when used in the high-temp. heat treatment in a hydrogen atmosphere (hydrogen annealing) in the method for producing the jig for treating an Si wafer as a semiconductor substrate at a high temp. by etching the surface layer of the jig product with a hydrofluoric acid soln. before the treatment. SOLUTION: In the method for producing a quartz glass heat-treating jig for treating an Si wafer at >=1100 deg.C, a synthetic quartz glass produced by subjecting silicon tetrachloride to a vapor-phase reaction is preferably used as the base material of the quartz glass. Further, the surface layer of the jig product is etched off by >=50μm with a hydrofluoric acid soln. to decrease the contents of Fe, Cu, Cr and Ni as the impurities in the product respectively to <=10ppb and the content of the OH group impurities in the product to 100-1000ppm. Consequently, the release of the impurities from the quartz glass is reduced. Besides, a layer rich in impurities is left when the surface layer is etched by <50μm.
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