Patent ID: 7166880

Claim:
An array of sensor groups formed on a semiconductor substrate, said array including: a first sensor group including at least two vertically stacked sensors, wherein the sensors of the first sensor group include a top sensor having a top surface that defines a normal axis, each of the sensors of the first sensor group has a different spectral response, is configured to be biased to function as a photodiode, and has a carrier-collection element configured to collect photo-generated carriers when said sensor is biased to function as a photodiode; and a second sensor group including at least two vertically stacked sensors, wherein each of the sensors of each of the second sensor group has a different spectral response, is configured to be biased to function as a photodiode, and has a carrier-collection element configured to collect photo-generated carriers when said sensor is biased to function as a photodiode, wherein the carrier-collection element of at least one of the sensors of the first sensor group is a relatively large element having an area, projected on a plane perpendicular to the normal axis, that is larger than the area projected on said plane of the carrier-collection element of another one of the sensors of the first sensor group, and the relatively large carrier-collection element is included in and shared by both the first sensor group and the second sensor group.