Intercolor-Filter Crosstalk Model for Image Sensors With Color Filter Array

A color crosstalk model for an area image sensor with a color filter (CF) array is proposed, which quantifies the crosstalk in a physically intuitive manner by introducing “inter-CF optical crosstalk (inter-CF crosstalk).” The model separates the structural design originated crosstalk from the CF material itself, revealing the sole characteristics of microstructures on a photodiode. A constrained nonlinear estimation is used to solve the model equation of system matrices with an objective function focusing on matching between the modeled quantum efficiency spectra and measured ones at both the peak and crosstalk regions. The model is applied to 1.1-μm backside-illuminated CMOS image sensors having four different kinds of optical structures on the photodiode of the same design, and successfully provides the ground of comparison with excellent matching between the models and the measurement results.