| 摘要 |
In the interior of a semiconductor substrate that forms an n- drift layer, a p+ collector layer is provided in the surface layer on the back face side and an n+ field stop layer is provided in a region deeper than the p+ collector layer on the back face side. The collector electrode contacts the p+ collector layer. When forming the p+ collector layer and the n+ field stop layer, impurity ions are implanted in the back face of the semiconductor substrate (Step S5). Next, the impurity ions are activated by a first annealing to form the p+ collector layer (Step S6). Then, proton irradiation is performed on the back face of the semiconductor substrate (Step S7). Next, the protons are used for donor formation by means of a second annealing to form a field stop layer (Step S8). The first annealing is performed at a higher annealing temperature than the second annealing. Subsequently, a collector electrode is formed on the back face of the semiconductor substrate (Step S9). As a result, the occurrence of poor electrical properties can be avoided. |
