Patent ID: 7541247

Claim:
A semiconductor structure fabrication method, comprising: providing a semiconductor structure which includes a semiconductor substrate, wherein the semiconductor substrate includes a top substrate surface which defines a reference direction perpendicular to the top substrate surface; simultaneously forming a first doped transistor region of a first transistor and a first doped guard-ring region of a guard ring on the semiconductor substrate, wherein the first doped transistor region and the first doped guard-ring region comprise dopants of a first doping polarity; and then simultaneously forming a second doped transistor region of the first transistor and a second doped guard-ring region of the guard ring on the semiconductor substrate, wherein the second doped transistor region and the second doped guard-ring region comprise dopants of the first doping polarity, wherein the second doped guard-ring region is in direct physical contact with the first doped guard-ring region, and wherein the guard ring forms a closed loop around the first and second doped transistor regions.