| abstract |
The SiC semiconductor device has a p-type region 5 having a low concentration region 5b and a high concentration region 5c so as to fill the trench 5a formed in the cell region and the p-type region 5b with the low concentration region 5b And the p + -type deep layer is formed by the high concentration region 5c. Accordingly, the SJ structure can be formed by the p-type column by the low-concentration region 5b and the n-type column by the n-type drift layer 2, whereby the on-resistance can be reduced. Further, since the drain potential can be blocked by turning off the p + -type deep layer by the high concentration region 5c, the electric field applied to the gate insulating film 8 can be relaxed and the gate insulating film 8 can be broken . Therefore, the SiC semiconductor device can realize both reduction of on-resistance and prevention of breakdown of the gate insulating film 8. |