Abstract: An image sensor having improved sensitivity and method for making same include a substrate having an active pixel region with a peripheral circuit region surrounding the active pixel region; a plurality of photo conversion elements disposed in the active pixel region, each photodiode is configured for receiving light through a lens and an opening formed between a plurality of layers of interlayer dielectrics formed on top of each other above the substrate; and a plurality of interconnections electrically connecting to the photo conversion elements disposed within the active pixel region, wherein the distance between the lens and the photo conversion elements is shorter than the distance between the substrate and the top interlayer dielectric in the peripheral circuit region.