Image sensor

摘要

An image sensor is formed by a pixel array including a plurality of pixels. Certain ones of the pixels include, above their active areas, a first optical grating formed of periodically spaced apart parallel strips separated from the active area by a first insulator. Those pixels further include, in another metal level, a second optical grating formed of periodically spaced apart parallel strips separated from the first grating by a second insulator. The second optical grating is laterally shifted with respect to the first grating in a direction orthogonal to a longitudinal direction of the parallel strips.

主权项

1. An image sensor, comprising:
a pixel array including a plurality of pixels, wherein each pixel comprises an active photodiode area and a structure over the active photodiode area comprising:
a first metal level including a first optical grating for the corresponding active photodiode area formed of periodically spaced apart parallel strips that are positioned to partially block light from reaching the corresponding active photodiode area and are separated from the corresponding active photodiode area by a first insulator;a second metal level including a second optical grating for the corresponding active photodiode area formed of periodically spaced apart parallel strips that are positioned to partially block light from reaching the corresponding active photodiode area and are separated from the first grating by a second insulator, anda third metal level positioned between the first and second metal levels; wherein the second optical grating is shifted with respect to the first grating in a direction orthogonal to a longitudinal direction of the strips.