| 摘要 |
PROBLEM TO BE SOLVED: To prevent the lowering of breakdown strength in a P-N junction part by eliminating the defects of an impurity layer formed by ion implantation. SOLUTION: An impurity region 30 is formed by ion implantation of B, which are p-type impurities, to an n--type epitaxial layer 2. A surface layer part of the impurity region 30 is removed. Consequently, a surface layer part whose crystallinity is not disturbed is removed, and a part whose crystallinity is disturbed is left by ion implantation. Then, when a p-type base region 3 is formed by activating B, recrystallization occurs only from the position side of deepest ion implantation. As a result, crystal defects are not left in the p-type base region 3 and lowering of the breakdown strength in a P-N junction part of the p-type base region 3 and the n--type epitaxial layer 2 can be prevented.
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