Patent ID: 8492801

Claim:
A semiconductor structure, at least comprising: a substrate having a first conductive type; a deep well having a second conductive type, extending down from a surface of the substrate; two first wells having the first conductive type, extending down from the surface of the substrate and formed within the deep well; a second well having the first conductive type, extending down from the surface of the substrate and formed between the two first wells within the deep well, and an implant dosage of the second well lighter than an implant dosage of each of the two first wells, wherein the second well and the two first wells have the same well depths; two first doping regions having the first conductive type, respectively formed within the two first wells and spaced apart from the second well, wherein the two first doping regions extend down from the surface of the substrate and an implant dosage of each of the two first doping regions is higher than the implant dosage of each of the two first wells; and two third wells having the first conductive type, extending down from the surface of the substrate and respectively contacting two outer side surfaces of the deep well.