Patent ID: 11876110
Assignee: OMNIVISION TECHNOLOGIES, INC.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. An image sensor, comprising:
a plurality of pixels arranged in rows and columns of a pixel array disposed in a semiconductor material, wherein each pixel comprises a plurality of photodiodes, wherein the plurality of pixels are configured to receive an incoming light through an illuminated surface of the semiconductor material,
wherein each pixel comprises:
a first photodiode comprising a silicon (Si) material; and
a second photodiode comprising the Si material and a silicon germanium (SiGe) material,
wherein each of the plurality of first photodiodes has a light sensitivity that is lower than each of the plurality of second photodiodes, and each individual second photodiode is arranged in between adjacent first photodiodes,
wherein a concentration of Ge of the SiGe material varies through a depth of the SiGe material in a vertical direction from the illuminated surface of the semiconductor material to an non-illuminated surface of the semiconductor material opposite to the illuminated surface of the semiconductor material, and
wherein the concentration of Ge of the SiGe material:
increases from zero concentration at the non-illuminated surface of the semiconductor material to a maximum concentration at a first depth located within the SiGe material, and
decreases from the maximum concentration to zero at a second depth located between the first depth and the illuminated surface of the semiconductor material.