Integrated light sensors with back reflectors for increased quantum efficiency
US6498336B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 15, 2000 |
| Grant date | Dec 24, 2002 |
| Priority date | — |
| Expiry date | Dec 27, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F77/407
Abstract
An image (or other light) sensor has a reflective element under each light-sensing element. The reflective element is positioned to reflect incident light that passes through the light-sensing element without being absorbed, back towards the light-sensing element for a second chance at being absorbed. The present invention increases the effective quantum efficiency of each light-sensing element without having to increase the thickness of the absorption region within the light-sensing element. In one embodiment, each reflective element is a discrete mirror that is positioned within the sensor packaging adjacent to (e.g., below) the integrated image sensor. In another embodiment, each reflective element is an integral part of the integrated circuit that contains the image sensor, such as a light-reflecting region formed within the substrate below the corresponding light-sensing element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.