SEMICONDUCTOR DEVICE, POWER MODULE AND MANUFACTURING METHOD FOR THE SEMICONDUCTOR DEVICE

A method for manufacturing a semiconductor device includes forming a trench on a first main surface of a conductive semiconductor substrate. The method includes laminating conductive layers, each of which is a first or a second conductive layer, along a surface normal direction of a side surface of the trench, while forming dielectric layers between a conductive layer closest to the side surface of the trench and the side surface of the trench, and between the corresponding conductive layers; and removing the first conductive layer and the dielectric layer, which are formed on a bottom portion of the trench, to electrically connect the second conductive layer to the semiconductor substrate at the bottom portion of the trench. After a portion of the first main surface, the portion being outside of the trench, is covered with an insulating protective film, the first conductive layer and the dielectric layer are removed.