Color-optimized image sensor

摘要

An image sensor pixel array includes a photoelectric conversion unit comprising a photoelectron accumulation region of n-type in a substrate of p-type and vertically below a gate electrode of a transistor. A light guide transmits a light of red or green or yellow color across the gate electrode to the photoelectron accumulation region. The gate electrode may be made thinner by a wet etch. An etchant for thinning the gate electrode may be introduced through an opening in an insulating film on the substrate. The light guide may be formed in the opening after the thinning. An anti-reflection stack may be formed at a bottom of the opening prior to forming the light guide.

主权项

1. A pixel array of an image sensor supported by a substrate of a first conductivity type, comprising:
a first pixel configured to detect a blue light; and, a second pixel, the second pixel comprising:
a photodetector that comprises a charge accumulation region of a second conductivity type in the substrate;a first gate of a first transistor, the first gate being vertically above at least a portion of the charge accumulation region; and,a first light guide, the first light guide being configured to transmit a light of red or green or yellow color to the portion of the charge accumulation region across the first gate, the first light guide using total internal reflection at its sidewalls to prevent the light from exiting laterally.