| 摘要 |
PROBLEM TO BE SOLVED: To suppress contamination of a wafer by a metal impurity from a heat treatment furnace member, etc., while utilizing the merit of high- temperature anneal using hydrogen. SOLUTION: With a vertical diffusion furnace used, a silicon wafer SW is loaded on a wafer holding boat 1 in its quartz, and a high-temperature annealing is performed with the wafer SW in a mixed atmosphere of hydrogen and argon. Measurement of the concentration of a metal impurity of an acquired wafer (Fe-B concentration by SPV (surface photo-potential) method) confirms that the Fe-B concentration at the peripheral part of the wafer SW decreases as the mixture ratio of hydrogen decreases, from 100% (conventional example only with hydrogen) to 50%, 25%, and 10%.
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