Patent ID: 8097890

Claim:
An image sensor, comprising: a plurality of micro-lenses disposed on a semiconductor substrate, wherein each micro-lens in the plurality of micro-lenses comprises photoresist, a first micro-lens in the plurality of micro-lenses having a first focal length corresponding to a first transmissiveness at a first location of a gray scale mask; a second micro-lens in the plurality of micro-lenses having a second focal length corresponding to a second transmissiveness at a second location of the gray scale mask, wherein the first focal length is different from the second focal length, wherein the first transmissiveness is different from the second transmissiveness, and wherein the first and the second micro-lenses are patterned into blocks by the gray scale mask in a single exposure; and a third micro-lens in the plurality of micro-lenses having a third focal length corresponding to a third transmissiveness at a third location of the gray scale mask, wherein the first focal length, the second focal length, and the third focal lengths are different from each other, wherein the first transmissiveness, the second transmissiveness, and the third transmissiveness are different from each other, and wherein the first, the second, and the third micro-lenses are patterned into blocks by the gray scale mask in the single exposure.