Patent ID: 9659987
Date: 2017-05-23
CPC Classifications: H01L

Claim:
1. An active pixel sensor (APS), comprising: a semiconductor substrate comprising a pixel region and a collector region, wherein the pixel region extends continuously from a top surface of the semiconductor substrate to a top boundary of the collector region that is spaced below the top surface of the semiconductor substrate, and wherein the pixel region contacts the collector region at the top boundary to define a PN junction; a photodetector buried in the semiconductor substrate, wherein the photodetector comprises the collector region; a vertical transfer gate extending into the semiconductor substrate with a channel region in electrical communication with the photodetector; a pixel transistor arranged directly over the photodetector, wherein the pixel transistor is configured to facilitate pixel operation and is independent of the vertical transfer gate, and wherein the pixel transistor is arranged laterally between and spaced from a sidewall boundary of the collector region and the vertical transfer gate; and an implant isolation region arranged in the semiconductor substrate, directly over the photodetector, and surrounding and electrically isolating the pixel transistor, wherein the implant isolation region comprises an inner vertical boundary and an outer vertical boundary laterally enclosing the inner vertical boundary, wherein the implant isolation region is a doped semiconductor region with an opposite doping type as the collector region of the photodetector, and wherein the collector region and the pixel region each have a single doping type.