Empirical dark current modeling for complementary metal oxide semiconductor active pixel sensor

We present an empirical dark current model for CMOS active pixel sensors (APSs). The model is based on experimental data taken of a 256 × 256 APS chip fabricated via HP in a standard 0.5-μm CMOS technology process. This quantitative model determines the pixel dark current dependence on two contributing factors: the "ideal" dark current determined by the photodiode junction, introduced here as a stable shot noise influence of the device active area, and a leakage current due to the device active area shape, i.e., the number of corners present in the photodiode and their angles. This part is introduced as a process-induced structure stress effect.