| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the on-voltage of an insulated gate type bipolar transistor of reverse conducting type. <P>SOLUTION: According to one embodiment, an insulated gate type bipolar transistor of reverse conducting type comprises: a second base layer of type N; a buffer layer of type N; a first collector layer of type N; a second collector layer of type P; a third collector layer of type P; and a collector electrode. The buffer layer is disposed on the reserve side of the second base layer, and has a higher impurity concentration than the second base layer. The first collector layer abuts on part of the reverse side of the buffer layer, and has a higher impurity concentration than the second base layer. The second collector layer abuts on part of the reverse side of the buffer layer and is disposed so as to enclose the first collector layer, and has a higher impurity concentration than the first base layer. The third collector layer abuts on part of the reverse side of the buffer layer and is disposed so as to enclose the second collector layer, and has a lower impurity concentration than the second collector layer. <P>COPYRIGHT: (C)2012,JPO&INPIT |
