Unit pixel in CMOS image sensor with enhanced reset efficiency
US6900485B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 23, 2003 |
| Grant date | May 31, 2005 |
| Priority date | — |
| Expiry date | Dec 23, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/77
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A unit pixel in a CMOS image sensor is employed to reduce a threshold voltage of a reset transistor by modifying a unit pixel circuit. The unit pixel in the CMOS image sensor including: a semiconductor substrate including an epitaxial layer in which an active area and a FOX area are defined; a photodiode formed in the epitaxial layer; a transfer transistor including source/drain regions disposed between the photodiode and a floating diffusion node, wherein a control signal is applied to a gate thereof; a reset transistor including source/drain regions disposed between the floating diffusion node and a VDD terminal, wherein a control signal is applied to a drain thereof; a drive transistor of which a gate is connected to the floating diffusion node and a drain is connected to the VDD terminal; and a selection transistor of which a drain is connected to the drain of the drive transistor and a source is connected to an output terminal, wherein a control signal is applied to a gate thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.