Patent ID: 8018016

Claim:
A back-illuminated image sensor, comprising: a sensor layer of a first conductivity type having a frontside and a backside opposite the frontside; an insulating layer disposed on the backside of the sensor layer; a circuit layer electrically connected to the sensor layer and adjacent to the frontside of the sensor layer; one or more frontside regions of a second conductivity type formed in at least a portion of the frontside of the sensor layer; a backside region of the second conductivity type formed in the backside of the sensor layer; a plurality of frontside photodetectors of the first conductivity type for converting light incident on the backside of the sensor layer into photo-generated charges, wherein the plurality of frontside photodetectors is disposed in the sensor layer and adjacent to the frontside; a discrete plurality of backside photodetectors of the first conductivity type separate from the plurality of frontside photodetectors for converting light incident on the backside of the sensor layer into photo-generated charges, wherein the plurality of backside photodetectors is disposed in the sensor layer and contiguous to portions of the backside region of the second conductivity type, and wherein each frontside photodetector is paired with a respective backside photodetector to form photodetector pairs and a portion of the sensor layer is contiguously disposed between each frontside photodetector and paired respective backside photodetector; and one or more connecting regions of the second conductivity type contiguously disposed between respective frontside regions and the backside region and laterally adjacent to each photodetector pair for electrically connecting the frontside and backside regions to one another.