SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING SAME

摘要

A first groove (21) and a second groove (25) are provided on the obverse side of a first electroconductive semiconductor substrate (29), and the first groove (21) is filled with a gate electrode (3) formed of an electroconductive body. The obverse side of the semiconductor substrate (29) is provided with a first impurity region (22) so as to contact the first groove (21). A first insulation film (24) is provided between the first groove (21) and the gate electrode (3), the first insulation film (24) having a bottom half (31) that is thicker than the top half, which contacts the first impurity region (22). A second insulation film (26) is provided inside the second groove (25). The bottom half (31) of the first insulation film (24) and the bottom half (33) of the second insulation film (26) are connected. It is thus possible, with a simple manufacturing process, to simultaneously improve dV/dt-Rg tradeoff and Rg turn-on controllability of an IGBT and enhance the IE effect.