CMOS image sensor having enhanced near infrared quantum efficiency
US9991309B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 5, 2017 |
| Grant date | Jun 5, 2018 |
| Priority date | — |
| Expiry date | Jul 5, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F39/807
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image sensor comprises a semiconductor material having an illuminated surface and a non-illuminated surface; a photodiode formed in the semiconductor material extending from the illuminated surface to receive an incident light through the illuminated surface, wherein the received incident light generates charges in the photodiode; a transfer gate electrically coupled to the photodiode to transfer the generated charges from the photodiode in response to a transfer signal; a floating diffusion electrically coupled to the transfer gate to receive the transferred charges from the photodiode; a near infrared (NIR) quantum efficiency (QE) enhancement structure comprising at least two NIR QE enhancement elements within a region of the photodiode, wherein the NIR QE enhancement structure is configured to modify the incident light at the illuminated surface of the semiconductor material by at least one of diffraction, deflection and reflection, to redistribute the incident light within the photodiode to improve an optical sensitivity, including near-infrared light sensitivity, of the image sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.