CMOS IMAGE SENSOR WITH DUAL DAMASCENE GRID DESIGN HAVING ABSORPTION ENHANCEMENT STRUCTURE

摘要

The present invention relates to an image sensor integrated chip having a grid structure which reduces crosstalk between pixel regions of an image sensor chip. According to some embodiments of the present invention, an integrated chip comprises an image sensing element disposed in a substrate. An absorption reinforcement structure is disposed along a rear surface of the substrate. A grid structure is disposed on the absorption enhancement structure. The grid structure defines an opening disposed on the image sensing element, and extends from the top of the absorption enhancement structure to a position in the absorption enhancement structure. The grid structure may reduce crosstalk between adjacent image sensing elements by preventing radiation reflected from a non-flat surface of the absorption enhancement structure from moving to an adjacent pixel region by extending the grid structure into the absorption enhancement structure.