Image sensor with anti-blooming gate

Abstract

The invention concerns active-pixel electronic image sensors. The pixel comprises a photodiode (PH) designed in a semiconductor active layer () and maintained at a nil reference potential, and above the active layer an anti-blooming gate (G) adjacent on one side to the photodiode and on another side to an evacuation drain (). The sensor comprises means for applying to the anti-blooming gate, during most of the duration of integration, a blocking potential creating beneath the gate a potential barrier of a first height, and, during a series of brief pulses over the duration of integration, an anti-blooming potential creating a potential barrier of a second height, lower than the first. The fact of only applying the anti-blooming voltage during the brief pulses reduces the dark noise induced by tunneling effect by the electric field between gate and photodiode.