Stacked grid for more uniform optical input

An image sensor comprising:

• a plurality of pixel sensors arranged as an array within a semiconductor substrate;
• a metallic grid arranged over the array of pixel sensors and having a plurality of metallic grid openings corresponding to the plurality of pixel sensors, wherein centers of the metallic grid openings near an edge of the array are laterally shifted from centers of the corresponding pixel sensors by metallic grid shift amounts that are proportional to distances of corresponding pixel sensors from a center of the array;
• and
• a dielectric grid arranged over the metallic grid and having a plurality of dielectric grid openings corresponding to the plurality of pixel sensors, wherein centers of the dielectric grid openings near the edge of the array are laterally shifted from centers of the corresponding pixel sensors by dielectric grid shift amounts that are proportional to the distances of corresponding pixel sensors from the center of the array;
• wherein a metallic grid shift amount for one of the pixel sensors differs from a dielectric grid shift amount for the one of the pixel sensors, and wherein the centers of the metallic and dielectric grid openings near the edge of the array are laterally shifted from the centers of the corresponding pixel sensor in multiple orthogonal directions.

An image sensor comprising:

• a semiconductor substrate arranged over a back-end-of-line (BEOL) metallization stack, and comprising an array of pixel sensors arranged in the semiconductor substrate;
• a metallic grid arranged over the semiconductor substrate and comprising an array of metallic grid segments, wherein the metallic grid segments correspond to the pixel sensors and are laterally offset from the corresponding pixel sensors;
• a capping layer covering the metallic grid and filling metallic grid openings respectively in the metal grid segments, wherein the metallic grid openings comprise a pair of neighboring metallic grid openings laterally spaced by a region of the metallic grid that has a trapezoidal cross-sectional profile and that is vertically elongated;
• and
• a dielectric grid arranged over the capping layer and comprising an array of dielectric grid segments, wherein the dielectric grid segments correspond to the metallic grid segments and are laterally offset from the corresponding metallic grid segments, wherein the dielectric grid further comprises a pair of neighboring dielectric grid openings, wherein the neighboring dielectric grid openings are laterally spaced by a line-shaped region of the dielectric grid that has opposite sidewalls respectively in the neighboring dielectric grid openings, and wherein the opposite sidewalls are directly over one of the pixel sensors.