Total Ionizing Dose Effects on CMOS Image Sensors with Deep-Trench Isolation

Abstract

We have investigated Total Ionizing Dose (TID) effects on a 1.4μm-pitch, Deep-Trench Isolation (DTI) CMOS image sensor for its use in radiation environment. Our investigation includes characterization and TCAD simulations (with parametric modeling) of the image sensor before and after irradiation with 60Co gamma rays source for TID from 3 to 100 Krad. We have obtained agreements between measured results and simulated ones on degradations of the characteristics Quantum Efficiency (QE) and dark current (Idark). The agreements validate our modeling and simulation approach to evaluating these characteristics. It has been shown that TID causes evolution of interface states of different parts of the pixel, which are responsible for QE and Idark degradations. TID effects on different parts of the pixel can be identified and quantified.