Patent ID: 7541627

Claim:
A light-sensing pixel, having a p type doped region, in a CMOS image sensor, comprising: a first doped charge collecting region buried within the p type doped region and configured to operate as a depleted potential well; a first n+ type doped plug extending from near the surface of the image sensor to the first charge collecting region; a second doped charge collecting region buried within the p type doped region, the second charge collecting region vertically separated from the first charge collecting region by the p type doped region and configured to operate as a depleted potential well; a second n+ type doped plug extending from near the surface of the image sensor to the second charge collecting region; a first extension with n+ type doping coupled to and between the first charge collecting region and the first plug, the first extension having a different doping concentration than the first charge collecting region; and a second extension with n+ type doping coupled to and between the second charge collecting region and the second plug, the second extension having a different doping concentration than the second charge collecting region.