| 摘要 |
According to one embodiment, in a reverse conducting-insulated gate bipolar transistor, the buffer layer is provided on the backside of the second base layer, has a higher impurity concentration in comparison with the second base layer. The first collector layer is in contact with a portion of the backside of the buffer layer, has a higher impurity concentration in comparison with the second base layer. The second collector layer is in contact with a portion of the backside of the buffer layer, is provided so as to surround the first collector layer, has a higher impurity concentration in comparison with the first base layer. The third collector layer is in contact with a portion of the backside of the buffer layer, is provided so as to surround the second collector layer, has a higher impurity concentration in comparison with the second collector layer. |
