| 摘要 |
PROBLEM TO BE SOLVED: To shorten a carrier life time, without subjecting to a long-time thermal processing such as intrinsic gettering without introducing a noble metal by a method, wherein a semiconductor substrate is heated at a specified temperature decreasing speed in a specified temperature band, and a temperature for taking out the semiconductor substrate is specified. SOLUTION: A thermal processing of a semiconductor substrate is performed at a temperature decrease rate of 1.0 to 8.0 deg.C/min in a temperature band of 600 to 800 deg.C, and temperatures at taking out (unloading) the semiconductor substrate are set to 700 deg.C. In order to obtain such a temperature decrease rate, provisions for a special apparatus are not necessarily needed. Namely, because the temperature decrease rate for normal furnace body is determined by the radiation of the furnace body, and is substantially in the range of 2.5 to 3.5 deg.C/min, not depending on the (vertical, lateral) type or the manufacture. When passing these temperature decrease rate and temperature band, a large number of minute defects occur inside a Si wafer so as to efficiently lessen a carrier time. These minute defects disappear by performing an appropriate thermal processing thereafter.
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