Characterization and analysis of electrical crosstalk in a linear array of CMOS image sensors

Abstract

In this paper, the influences of the depth and width of the oxide trench isolation between pixels, pixel epitaxial layer thickness for different impurity doping concentrations, and light exposure time on electrical crosstalk are characterized in an array of pinned photodiode CMOS image sensor pixels. The simulation results show that with a proper and simultaneous selection of epitaxial layer doping concentration and epitaxial layer thickness, the electrical crosstalk at long wavelengths can be reduced above 66%. The use of oxide trench isolation depth less than pixel p-well depth leads to an increase in electrical crosstalk of more than 12%. The effect of increasing light exposure time on increasing electrical crosstalk can be minimized by selecting proper epitaxial layer thicknesses.