| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve switching characteristics. <P>SOLUTION: A semiconductor device comprises: a first semiconductor layer of a first conductive type; second semiconductor layers of a first conductive type and third semiconductor layers of a second conductive type that are alternately formed on the first semiconductor layer in the direction substantially parallel to the primary surface of the first semiconductor layer; a fourth semiconductor layer of a second conductive type formed on the second semiconductor layers and the third semiconductor layers; fifth semiconductor layers of a first conductive type selectively formed on the surface of the fourth semiconductor layer; controlling electrodes provided via an insulating film in trenches that penetrate from the surfaces of the fifth semiconductor layers to the fourth semiconductor layer and are in contact with the second semiconductor layers; a first main electrode connected to the first semiconductor layer; a second main electrode connected to the fourth semiconductor layer and the fifth semiconductor layers; and a sixth semiconductor layer of a first conductive type provided between the fourth semiconductor layer and the second semiconductor layers. The impurity concentration of the sixth semiconductor layer is higher than that of the second semiconductor layers. <P>COPYRIGHT: (C)2012,JPO&INPIT |
