FRONT SIDE IMPLANTED GUARD RING STRUCTURE FOR BACKSIDE

摘要

A method of forming a backside illuminated image sensor includes forming a guard ring structure of a predetermined depth in a front-side surface of a semiconductor substrate, the guard ring structure outlining a two-dimensional array of pixels, each pixel of the array of pixels separated from an adjacent pixel by the guard ring structure. The method further includes forming at least one image sensing element on the front-side surface of the semiconductor substrate, the at least one image sensing element being formed in a pixel of the array of pixels and surrounded by the guard ring structure. The method further includes reducing a thickness of the semiconductor substrate until the guard ring structure is co-planar with a back-side surface of the semiconductor substrate.