Patent ID: 9640609
Date: 2017-05-02
CPC Classifications: H01L

Claim:
1. An edge termination structure for a semiconductor device, comprising: a plurality of spaced apart concentric floating guard rings in a silicon carbide semiconductor layer that at least partially surrounds a semiconductor junction in the edge termination structure, wherein the plurality of spaced apart concentric floating guard rings each have a highly doped portion and a lightly doped portion; wherein the highly doped portion and the lightly doped portion of each of the plurality of spaced apart concentric floating guard rings have an associated dopant concentration; and wherein the lightly doped portion of the floating guard rings has at least two portions, a first portion having a first depth no greater than a depth of the highly doped portion of the floating guard rings and having a first doping concentration and a second portion having a second depth greater than the depth of the highly doped portion of the floating guard rings, extending beneath the highly doped portion, having a planar bottom surface and one sidewall that is aligned with a sidewall of the highly doped portion and having a second doping concentration, greater than the first doping concentration.