Patent ID: 9673309
Date: 2017-06-06
CPC Classifications: H01L

Claim:
1. A semiconductor device, having a trench structure that includes: a first trench that is formed in a surface layer of a first conductive type semiconductor layer; a second conductive type base region that is selectively formed on the surface layer of the first conductive type semiconductor layer at a depth shallower than the first trench, along one side wall of the first trench; an emitter region that is formed on a surface layer of the base region so as to contact the one side wall of the first trench; and a second conductive type floating potential region that is selectively formed on the surface layer of the first conductive type semiconductor layer along the other side wall of the first trench, the semiconductor device comprising: a first insulation film that is disposed along the one side wall of the first trench; a second insulation film that is disposed along the other side wall of the first trench; a first gate electrode that is disposed inside the first insulation film along the one side wall of the first trench; a shield electrode that is disposed inside the second insulation film along the other side wall of the first trench; a third insulation film that is embedded in the first trench between the first gate electrode and the shield electrode; an inter-layer insulation film that covers the first gate electrode, the shield electrode and the emitter region; a second gate electrode that is disposed on the inter-layer insulation film; an emitter electrode that is disposed on the inter-layer insulation film at a distance from the second gate electrode; a fixed-potential electrode that is disposed on the inter-layer insulation film at a distance from the second gate electrode; a first contact hole that is selectively disposed on the inter-layer insulation film in a portion between the second gate electrode and the first gate electrode, and in which a first contact plug for conductively connecting the second gate electrode and the first gate electrode is embedded; a second contact hole that is selectively disposed on the inter-layer insulation film in a portion between the fixed-potential electrode and the shield electrode, and in which a second contact plug for conductively connecting the fixed-potential electrode and the shield electrode is embedded; and a third contact hole that is selectively disposed on the inter-layer insulation film in a portion between the emitter electrode and the emitter region, and in which a third contact plug for conductively connecting the emitter electrode and the emitter region is embedded; wherein the first trench has an annular planar shape, and the first gate electrode and the shield electrode have a planar shape such that the first gate electrode surrounds the shield electrode.