Investigation of α particle induced damage and annealing behavior in CMOS active pixel sensors for radiation detection applications

This paper investigates the radiation effects of α particle on Complementary Metal-Oxide-Semiconductor (CMOS) Active Pixel Sensors (APS). By analyzing the variation patterns of dark signals in CMOS APS after 72 h of α particle irradiation and 120 h of room-temperature annealing, the study explores the mechanisms of α particle induced radiation damage and the corresponding annealing effects. Experimental results show that under the same irradiation conditions, the number of damaged pixels is positively correlated with the α particle fluence. The dark image of CMOS APS is highly sensitive to α particle , with the number of dark signals in the effective pixel area increasing in proportion to the total fluence. As irradiation time or cumulative dose increases, the pedestal pixel values rise continuously, and the number of dark signals in high-value regions also grows. The annealing experiment results indicate that room-temperature annealing has a certain recovery effect on APS radiation damage, suggesting that the charged-particle radiation damage caused by α particle is not necessarily permanent. The findings of this study reveal clear patterns in the radiation damage and annealing effects of CMOS APS, which can help mitigate and compensate for signal degradation caused by radiation damage, thereby improving detection accuracy.