CCD frame transfer photosensitive matrix with vertical anti-blooming system

Abstract

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.

Inventors

• 👤 Yves Thenoz
• 👤 Francois Roy

Bibliographic Details