Patent ID: 9685505
Date: 2017-06-20
CPC Classifications: H01L

Claim:
1. A semiconductor device, comprising: a semiconductor layer of a first conductivity type, having a peripheral area and a cell area inside of the peripheral area; a region of a second conductivity type in the semiconductor layer in the cell area; and a plurality of guard rings of the second conductivity type in the semiconductor layer in the peripheral area, each having a substantially same depth as the region of the second conductivity type in the cell area, wherein the plurality of guard rings include at least one first ring that has a diffusion region in a depth profile in the semiconductor layer that is wider at a top thereof, wherein the region of the second conductivity type in the cell area includes a cell-side column in the depth profile in the semiconductor layer that forms a superjunction structure, and wherein the guard rings are respectively formed of a periphery-side column in the depth profile in the semiconductor layer that has a substantially same depth as the cell-side column.