Reliability modelling and assessment of CMOS image sensor under radiation environment

The Complementary Metal-Oxide Semiconductor (CMOS) image sensor is a critical component with the function of providing accurate positioning in many space application systems. Under long-time operation in space environments, there are radiation related degradation and various uncertainties affecting the positioning accuracy of CMOS image sensors, which further leads to a reliability reduction of CMOS image sensors. Obviously, the reliability of CMOS image sensors is related to their specified function, degradation, and uncertainties; however, current research has not fully described this relationship. In this paper, a comprehensive approach to reliability modelling of CMOS image sensors is proposed based on the reliability science principles. Firstly, the performance margin modelling of centroid positioning accuracy is conducted. Then, the degradation model of CMOS image sensors is derived considering the dark current increase induced by the total ionizing dose effects. Finally, various uncertainties are analyzed and quantified, and the measurement equation of reliability is proposed. A case study of a CMOS image sensor is conducted to apply the proposed method, and the sensitivity analysis can provide suggestions for design and use of CMOS image sensors to ensure reliability. A simulation study is conducted to present the advantages of the proposed comprehensive approach.