Patent ID: 8847297

Claim:
An image sensor comprising: a substrate including at least a first and second photoelectric transformation device; an interconnection structure on the substrate, the interconnection structure including one or more intermetal dielectric layers, the interconnection structure defining at least a first cavity and a second cavity such that the first and second cavities are aligned corresponding to the first and second photoelectric transformation devices, respectively, and each of the first and second cavities has at least two side portions and bottom portion; a moisture absorption barrier layer on a top surface of a top one of the one or more intermetal dielectric layers of the interconnection structure and inside the first and second cavities; a light guide unit on the moisture absorption barrier layer, the light guide unit including a light transmittance material filling the first and second cavities; and a color filter on the light guide unit, wherein the color filter is located above the first and second cavities and outside the first and second cavities, wherein the moisture absorption barrier layer has a uniform thickness along the two side portions and the bottom of the first and second cavities, and on a top surface of the top intermetal dielectric layer in a first region, the first region being a portion of the top intermetal dielectric layer beginning at the first cavity and ending at the second cavity, and wherein, in the first region, the moisture absorption barrier layer is directly above the top surface of the top intermetal dielectric layer such that no intervening layers exist in between the top surface of the top intermetal dielectric layer and the moisture absorption barrier layer.