Degradation of spectral response and dark current of CMOS image sensors in deep-submicron technology due to γ-irradiation

Abstract

In this paper, a model for the spectral response of 4-T (4-Transistor) CMOS image sensors in deep-submicron technology is developed to study the sensor's sensitivity towards gamma-ray irradiation. It is found that the spectral degradation due to gamma-rays is mainly through changes in the top-layer material characteristics and Si/SiO2 interface. There is a non-trivial contribution of STI (shallow trench isolations) towards the dark current of the sensor, and it turns out to be highly sensitive to radiation damage.