INTRALEVEL CONDUCTIVE LIGHT SHIELD

摘要

A conductive light shield is formed over a first dielectric layer of a via level in a metal interconnect structure. The conductive light shield is covers a floating drain of an image sensor pixel cell. A second dielectric layer is formed over the conductive light shield and at least one via extending from a top surface of the second dielectric layer to a bottom surface of the first dielectric layer is formed in the metal interconnect structure. The conductive light shield may be formed within a contact level between a top surface of a semiconductor substrate and a first metal line level, or may be formed in any metal interconnect via level between two metal line levels. The inventive image sensor pixel cell is less prone to noise due to the blockage of light over the floating drain by the conductive light shield.