A simulation analysis of backside-illuminated multi-collection-gate image sensor employing Monte Carlo method

Ultra-high speed image sensors have been developed and applied to various field of science and engineering. Toward the temporal resolution of 1ns, we have proposed a new structure of an image sensor, a backside-illuminated multi-collection-gate image sensor (BSI MCG image sensor). In order to evaluate the performance, it is necessary to simulate the paths of photoelectrons from the generation site to a collecting gate. The performance depends on several factors, including randomness in motion of the electrons which is considerable in the design of the sensor operating at the sub-nanosecond time scale. It is impossible to address this factor by using a device simulation based on the drift diffusion model. A Monte Carlo method is an effective tool to evaluate the effect of the randomness. In this paper, factors affecting the temporal resolution of the sensor are studied by using the Monte Carlo simulator.