Patent ID: 8101453

Claim:
A method for fabricating an image sensor comprising: forming a photodiode over a semiconductor substrate; forming an interlayer dielectric layer over the semiconductor substrate including the photodiode; forming a wave guide in the interlayer dielectric layer by performing an ion implantation process; forming a color filter over the interlayer dielectric layer including the wave guide; forming a planarization layer over the color filter; and forming a micro lens over the planarization layer, wherein forming the wave guide comprises: forming a photoresist pattern over the interlayer dielectric layer exposing the uppermost surface of the interlayer dielectric layer; performing the ion implantation process to implant ions of a wave guide material into the interlayer dielectric layer; removing the photoresist pattern after performing the ion implantation process; and, performing an annealing process with respect to the semiconductor substrate to thereby diffuse the implanted wave guide material after removing the photoresist pattern, wherein performing the ion implantation process comprises: implanting ions of the wave guide material at a first implantation dosage; implanting ions of the wave guide material at a second implantation dosage smaller than the first implantation dosage; and implanting ions of the wave guide material at a third implantation dosage smaller than the second implantation dosage.