CCD frame transfer photosensitive matrix with vertical anti-blooming system
US4916501A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 19, 1989 |
| Grant date | Apr 10, 1990 |
| Priority date | — |
| Expiry date | Jun 19, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F39/158
Abstract
The disclosed photosensitive matrix comprises, in a standard way, a P type semiconductor substrate, an N type channel layer separated by narrow insulating zones into a plurality of columns and, on a thin layer of insulating oxide placed on the channel layer, a network of transfer gates extending perpendicularly to the insulating zones, dividing the columns into a large number of "pixels". According to the invention, the matrix has, between the substrate and the channel layer, a weakly doped P type base layer, in which are buried anti-blooming diodes consisting of a narrow, strongly doped N type drain extending in a direction parallel to the insulation zones. Beneath the drain, there is a strongly doped, P type protective screen. The arrangement gives an optical aperture of the matrix close to unity and a spectral response that is improved towards the red side of the spectrum owing to the thickness of the base layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.