Stacked Image Sensor Using Chlorine-doped Crystalline Selenium Photoconversion Layer Composed of Size-controlled Polycrystalline Particles

Abstract

We demonstrate a stacked CMOS image sensor overlaid with a chlorine (Cl)-doped crystalline selenium (c-Se) photoconversion layer. The size of the polycrystalline particles (grains) of c-Se, which is strongly related to the quality of the captured image, is decreased by Cl doping into c-Se; hence the surface flatness of c-Se has markedly improved. We successfully prevent the emergence of white spots in the image, which are caused by the localization of the electric field, by applying a Cl-doped c-Se as a photoconversion layer.