Inserted reflective shield to improve quantum efficiency of image sensors
US8629523B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 2010 |
| Grant date | Jan 14, 2014 |
| Priority date | — |
| Expiry date | Oct 7, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F77/413
Abstract
The structures of reflective shields and methods of making such structures described enable reflection of light that has not be absorbed by photodiodes in image sensor devices and increase quantum efficiency of the photodiodes. Such structures can be applied (or used) for any image sensors to improve image quality. Such structures are particular useful for image sensors with smaller pixel sizes and for long-wavelength light (or rays), whose absorption length (or depth) could be insufficient, especially for backside illumination (BSI) devices. The reflective shields could double, or more than double, the absorption depth for light passing through the image sensors and getting reflected back to the photodiodes. Concave-shaped reflective shields have the additional advantage of directing reflected light toward the image sensors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.