SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD OF THE SAME

摘要

In a semiconductor device, a trench includes a first trench that has an opening portion on a surface of a base layer, and a second trench that is communicated with the first trench and in which a distance between opposed side walls is greater than opposed side walls of the first trench and a bottom portion is located in a drift layer. A wall surface of a connecting portion of the second trench connecting to the first trench is rounded. Therefore, an occurrence of a large electrical field concentration in the vicinity of the connecting portion between the first trench and the second trench can be suppressed. Also, when electrons are supplied from a channel region to the drift layer, it is less likely that a flow direction of the electrons will be sharply changed in the vicinity of the connecting portion. Therefore, an on-state resistance can be reduced.

主权项

1. A semiconductor device comprising:
a first conductivity-type drift layer; a second conductivity-type base layer disposed adjacent to a front surface of the drift layer; a plurality of trenches passing through the base layer to reach the drift layer, and being extended in a predetermined direction; a gate insulation film formed on a wall surface of each of the trenches; a gate electrode disposed on the gate insulation film; a first conductivity-type emitter layer disposed on a side portion of the trench in a surface layer portion of the base layer; a second conductivity-type collector layer disposed to be separated from the emitter layer through the drift layer; an emitter electrode electrically connected to the base layer and the emitter layer; and a collector electrode electrically connected to the collector layer, wherein the trench includes a first trench that has an opening portion on a surface of the base layer and a second trench that is communicated with the first trench and in which a distance between opposed side walls of the second trench is greater than a distance between opposed side walls of the first trench, and a bottom portion of the second trench is located in the drift layer, and a wall surface of a connecting portion of the second trench connecting to the first trench is rounded.