SEMICONDUCTOR DEVICE

摘要

A semiconductor device is provided with an N−-type drift layer, a N+-type diffusion well region provided on a surface part of the N−-type drift layer, a P-type channel well region, an N+-type diffusion well region, a gate insulating film, a gate electrode laminated on the gate insulating film, a drain trench, a field plate provided in the drain trench with a silicon oxide film and an insulating film interposed therebetween and a field plate electrode formed on the field plate. The field plate is tapered toward a base part of the drain trench. A distance between a side wall of the drain trench and a side face of the field plate is increased toward the base part side.

主权项

1. A semiconductor device comprising:
a drift layer made of a first conductive type semiconductor; a first electrode provided on a back side of the drift layer and electrically connected to the drift layer; a first well region provided on a surface part of the drift layer and made of a semiconductor of a second conductive type opposite to the first conductive type; a second well region provided on a surface part of the first well region and made of a semiconductor of the first conductive type; a second electrode electrically connected to the second well region; a gate electrode provided above the first and second well regions and the drift layer with a gate insulating film interposed between the gate electrode and the first and second well regions and the drift layer; and a field plate embedded in a first trench formed adjacent to the gate electrode on the surface part of the drift layer with an insulating film interposed between the field plate and the first trench and insulated from the gate electrode, wherein the first trench includes a base part and a side wall, the field plate is tapered toward the base part, and a distance between the side wall and a side face of the field plate is increased toward the base part side.