Identical/symmetrical metal shielding

Abstract

An image sensor comprising a unit cell having a plurality of pixels; the unit cell comprising: a plurality of photodetectors having two or more subsets, wherein each subset has a different a physical shape; and an obscuring layer creating an aperture associated with each photodetector; wherein the obscuring layer is positioned such that any physical translation of the obscuring layer relative to the photodetector produces substantially equal The change.

Description

technical field [0001] The present invention relates generally to the field of image sensors, and more particularly, to an image sensor in which misalignment of a light shield does not change the size of the aperture. Background technique [0002] Referring to FIG. 1 , there is shown a prior art pixel 10 having a photodiode 20 , circuitry 30 , and isolation 40 and interconnect layers 50 . An interconnect layer is required to connect photodiodes 20 and circuitry 30 and to connect pixels 10 into pixel array 70 . The holes (defined by layers 50 a , 50 b and the boundaries of photodiodes 20 not covered by layer 50 b ) are set by the alignment of photodiodes 20 and interconnection layer 50 . Misalignment of the photodiode 20 relative to the interconnect layer 50 can cause the aperture to change size, which affects pixel performance. [0003] Referring to FIG. 2 , there is shown a prior art pixel supercell 80 consisting of a plurality of pixels 10 , such as a first pixel 10 a an...

AI Technical Summary

Problems solved by technology

Assuming that the layout of the first pixel will be different from the layout of the second pixel due to the sharing of components, the misalignment of the photodiode 20 relative to the interconnection layer 50 will result in holes (by layers 50a, 50b and not covered by layer 50 The boundary definition of the photodiode 20) changes in size between the first pixel 10a and the second pixel 10b differently, which affects the pixel performance

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