Modeling dark signal of CMOS image sensors irradiated by reactor neutron using Monte Carlo method

摘要

The dark signal degradation of the CMOS image sensor （CIS） was induced by neutron radiation,and it was modeled by Geant4, which is a three-dimensional Monte Carlo code. The simplified model of theCIS array was established according to the actual pixel geometry, material, and doping concentration. Nuclearelastic interaction and capture interaction were included in the physical processes, and the displacementdamage dose in the space charge region of the pixel was calculated. The mean dark signal and dark signaldistribution were modeled using Geant4, and the physical mechanisms were analyzed. The modeling resultswere in good agreement with the experimental and theoretical results.