Comparison of transient response characteristics in the CIS detector irradiated by gamma rays and X rays

Abstract The transient responses of the CMOS image sensor (CIS) detectors during radiation are one of the key issues to the detector design, reliability and applicability in space and nuclear environments. The transient radiation experiments of the CIS detectors irradiated by gamma rays and X rays were carried out to compare the difference and the similarity of the transient responses. The CISs have 4 Megapixels and pinned photodiode (PPD) pixel architecture with a standard 0.18 μ m CMOS technology. The white spots and lines of the dark images induced by gamma rays and X rays during radiation are analyzed to compare the difference and the similarity of transient response characteristics. The comparison of the DSNU fluctuation of the CIS detectors versus the continuous frames induced by gamma rays and X rays are also analyzed. The theoretical analysis of the difference is presented by radiation particle transportation simulation using GEANT4. The mechanisms of the transient responses in the CIS detectors are demonstrated by combining the experimental results and theoretical analysis.