Patent ID: 7821046

Claim:
A CMOS image sensor structure comprising: a p-type substrate underlying a pixel array region and a peripheral region, the p-type substrate having a p-type substrate region and a p-type epitaxial region; an n-type region (N-Tub region) having an n-type peripheral sidewall (N+ guard ring) within the p-type epitaxial region, the N-Tub region extending under the pixel array region and below field oxide regions which surround the pixel array region, the pixel array region enclosed by a peripheral p-well sidewall (p-type ground ring), the p-type ground ring extending below the field oxide regions and providing an electrical connection to the p-type epitaxial region, wherein the pixel array region has a plurality of pixels including red pixels, green pixels, and blue pixels; and p-type conductive implant regions that electrically connect the p-type epitaxial region to the p-type substrate through the N-Tub region at each red pixel location, wherein each of the red pixels in the plurality of pixels is located above a corresponding one of the p-type conductive implant regions, wherein only the red pixels are located above the p-type conductive implant regions, and wherein the green pixels and the blue pixels are not located above any of the p-type conductive implant regions.