| 摘要 |
PROBLEM TO BE SOLVED: To effectively mitigate an electric field concentration in a trench MIS structure in a semiconductor device.SOLUTION: A semiconductor device comprises: a first semiconductor layer; a second semiconductor layer; a third semiconductor layer; a groove having a lateral face and a bottom face; a first insulator which is composed chiefly of a first insulating material and which is a film formed from the lateral face to the bottom face and has a lateral face film part and a bottom face film part; a second insulator which is composed chiefly of a second insulating material having a dielectric constant higher than that of the first insulating material, and formed at a corner of a region surrounded by the lateral face film part and the bottom face film part; and an electrode formed inside the groove via the first insulator and the second insulator. A thickness Th1 of a portion based on a surface of the bottom face film part out of portions of the second insulator, which is located at the corner is larger than a thickness Th2 of a portion based on a surface of the lateral face film part out of the portions of the second insulator, which sandwiches the lateral face film part with the second semiconductor layer.SELECTED DRAWING: Figure 3 |
