| 摘要 |
The invention relates to image sensors and more particularly those which are intended to capture images at low luminance levels. An active-pixel image sensor is provided, each pixel comprising, on the surface of a semiconductor active layer, a photodiode region adjacent a transfer gate itself adjacent a charge storage region, the transfer gate permitting, when it receives a transfer pulse, the transfer of charge from the photodiode region to the storage region. The photodiode region is adjacent an accelerating gate isolated from the semiconductor active layer. Switching means are provided so as to apply to the accelerating gate, during an integration phase preceding the transfer pulse, a series of high-potential/low-potential alternations inducing an electric field alternately in one direction and in the other direction between the photodiode region and the active layer region located beneath the accelerating gate. Impacts with atoms of the lattice create secondary electrons, thereby increasing the sensitivity of the sensor. |
