Patent ID: 8841719
Filing Date: 2014-09-23
Classification: H01L

Abstract:
1. A semiconductor device comprising: a drift layer having a first conductive type; a channel region having a second conductive type and disposed on the drift layer; a first impurity region having the first conductive type and disposed in a surface portion of the channel region, wherein the first impurity region is spaced apart from the drift layer via the channel region sandwiched therebetween, and has an impurity concentration higher than the drift layer; a gate electrode disposed on a first surface of the channel region via a gate insulation film; a second impurity region having the first or second conductive type and contacting the drift layer, wherein the second impurity region is spaced apart from the channel region, and has an impurity concentration higher than the drift layer; a first electrode electrically coupled with the first impurity region and the channel region; a second electrode electrically coupled with the second impurity region; an element portion including a semiconductor element having an insulation gate structure, wherein the semiconductor element is provided in such a manner that a part of the channel region opposite to the gate electrode via the gate insulation film provides a reverse type channel so that current flows between the first electrode and the second electrode through the channel; and an outer periphery region disposed on an outer periphery of the element portion, wherein the element portion further includes a contact portion, through which the first electrode is electrically coupled with the first impurity region and the channel region, wherein the contact portion extends on the first surface of the channel region, wherein the contact portion includes an end portion and an inner portion, wherein the end portion of the contact portion is disposed on an outer periphery region side, and the inner portion of the contact portion is disposed on an inner side from the end portion of the element portion, wherein a resistance per unit area in the end portion of the contact portion is higher than a resistance per unit area in the inner portion of the contact portion, wherein the element portion further includes an interlayer film on the first surface of the channel region, wherein the interlayer film includes an opening, through which a part of the first impurity region and a part of the channel region are exposed from the interlayer film, wherein the contact portion is provided by the opening of the interlayer film, and wherein a width of the opening of the interlayer film in the end portion of the contact portion is narrower than a width of the opening of the interlayer film in the inner portion of the contact portion so that the resistance per unit area of a path from the drift layer to the first electrode in the end portion of the contact portion is higher than the resistance per unit area of a path from the drift layer to the first electrode in the inner portion of the contact portion.