ACTIVE PIXEL IMAGE SENSOR IN ELECTRON MULTIPLICATION CMOS TECHNOLOGY

摘要

In a CMOS active pixel comprising an amplification stage AMP with insulated grid between the photosensitive element PH of the pixel and a reading node SN associated with the charge/voltage conversion circuit, a separator grid Gpiv is provided between the two accumulation grids G1, G2 of the amplification stage, with one of the two transfer grids TR1, TR2 being situated between the photodiode and one accumulation grid G1, and the other being situated between the other accumulation grid G2 and the reading node. The adjacent accumulation grid G1 is entirely included within the transfer grid TR1, defining, on one side of the accumulation grid, a portion of the grid between the two accumulation grids which is narrower than a main portion of the transfer grid on the opposite side, and this narrow portion forms the separator grid Gpiv. In this way it is possible to regulate the barrier height of the region under the separator grid which forms a pivot region for switching charges from one accumulation region to the other.