Patent ID: 8940574
Filing Date: 2015-01-27
Classification: H01L

Abstract:
1. A method comprising: forming a plurality of image sensors on a front side of a semiconductor substrate, wherein the plurality of image sensors forms an array; forming a dielectric layer over a backside of the semiconductor substrate; patterning the dielectric layer into a plurality of grid-filling regions, wherein each of the plurality of grid-filling regions overlaps one of the plurality of image sensors, and wherein the step of patterning comprises removing first portions of the dielectric layer that overlap first alternating ones of the plurality of image sensors in each row and each column of the array; forming a metal layer on top surfaces and sidewalls of the plurality of grid-filling regions; etching the metal layer to remove the metal layer on the top surface of each grid-filling region thereby forming a metal grid on sidewalls of the plurality of grid-filling regions, wherein the metal grid comprises a first plurality of metal features continuously extending through a plurality of rows of the array, and a second plurality of metal features continuously extending through a plurality of columns of the array, and wherein the first plurality of metal features and the second plurality of metal features cross each other; filling a transparent material into grid openings of the metal grid, wherein the transparent material is a clear-colored material; and forming a plurality of color filters over the metal grid and the transparent material.