Patent ID: 7632700

Claim:
A method of forming an image sensor, the method comprising: forming a pixel cell comprising a photo-conversion device at a surface of a substrate; forming a dielectric layer over the pixel cell; forming at least two substantially flat photonic crystal filters over one another by: forming a first layer of photonic crystal material over the dielectric layer, etching the first photonic crystal material layer to form a plurality of pillars spaced apart from each other, each pillar formed having a height and a horizontal cross sectional shape, depositing over and between the pillars a layer of a material having a dielectric constant different than a dielectric constant of the pillars, the pillar height, the pillar shape, and the material layer formed such that the filter selectively permits light of particular wavelengths to reach said photo-conversion device, planarizing the material layer and the pillars such that the first layer of photonic crystal material has a planarized surface that is substantially parallel to the surface of the substrate, and forming a second substantially flat photonic crystal filter over the first layer of photonic crystal material; and forming a micro-lens over the at least two photonic crystal filters.