| 摘要 |
In the present invention, the following are provided: a first step in which a first conductivity-type impurity is implanted, using multiple ion implantations of different acceleration energies, in a second main surface of a semiconductor substrate having a first main surface and the second main surface, thereby forming a first impurity region in the semiconductor substrate; a second step in which a second conductivity-type impurity is implanted in the second main surface, using acceleration energy which is lower than the multiple ion implantations, thereby forming a second impurity region in the semiconductor substrate so that between the first impurity region and the second impurity region a non-implantation region in which the impurity is not implanted is retained; a heat-processing step in which a buffer layer is formed using the first conductivity-type impurity, a collector layer is formed using the second conductivity-type impurity, and heat processing is carried out on the semiconductor substrate so that a non-diffusion region where the first conductivity-type impurity and the second conductivity-type impurity do not diffuse is retained between the buffer layer and the collector layer; and a step in which is formed a collector electrode that makes contact with the collector layer. |
