Image sensor having a source follower transistor with a multi-thickness gate dielectric
US10964738B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 2018 |
| Grant date | Mar 30, 2021 |
| Priority date | — |
| Expiry date | Jan 3, 2039 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/11
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image sensor includes one or more photodiodes disposed in a semiconductor material to receive image light and generate image charge, and a floating diffusion to receive the image charge from the one or more photodiodes. One or more transfer transistors is coupled to transfer image charge in the one or more photodiodes to the floating diffusion, and a source follower transistor is coupled to amplify the image charge in the floating diffusion. The source follower includes a gate electrode (coupled to the floating diffusion), source and drain electrodes, and an active region disposed in the semiconductor material between the source and drain electrodes. A dielectric material is disposed between the gate electrode and the active region and has a first thickness and a second thickness. The second thickness is greater than the first thickness, and the second thickness is disposed closer to the drain electrode than the first thickness.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.