Dual conversion gain pixel using Schottky and ohmic contacts to the floating diffusion region and methods of fabrication and operation
US7718459B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 2005 |
| Grant date | May 18, 2010 |
| Priority date | — |
| Expiry date | Sep 2, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F39/813
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The exemplary embodiments provide an imager with dual conversion gain charge storage and thus, improved dynamic range. A dual conversion gain element (e.g., Schottky diode) is coupled between a floating diffusion region and a respective capacitor. The dual conversion gain element switches in the capacitance of the capacitor, in response to charge stored at the floating diffusion region, to change the conversion gain of the floating diffusion region from a first conversion gain to a second conversion gain. In an additional aspect, the exemplary embodiments provide an ohmic contact between the gate of a source follower transistor and the floating diffusion region which assists in the readout of the dual conversion gain output signal of a pixel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.