Patent ID: 8110853

Claim:
The semiconductor structure, comprising: a semiconductor substrate which includes a top substrate surface which defines a reference direction perpendicular to the top substrate surface; a first transistor on the semiconductor substrate; a guard ring on the semiconductor substrate, wherein the guard ring comprises a semiconductor material doped with a doping polarity, wherein a first doping profile of a first doped transistor region of the first transistor in the reference direction and a second doping profile of a first doped guard-ring region of the guard ring in the reference direction are essentially a same doping profile, and wherein the guard ring forms a closed loop around the first transistor; and a deep trench isolation region, wherein the deep trench isolation region has a third depth in the reference direction, wherein the guard ring has a second depth in the reference direction, wherein the third depth is greater than the second depth, wherein the deep trench isolation region is in direct physical contact with the guard ring, and wherein the deep trench isolation region forms a closed loop around the first transistor.