Crosstalk Reduction in a RGBW CFA Image Sensor

The demands for near-infrared (NIR) image sensors keep increasing for camera applications. For high sensitivity in NIR imaging, RGBW color filter array is used with the white color filter adapted for the infrared pixel. However, the crosstalk also increases with high sensitivity. Crosstalk is one of the important optical performance, especially affecting modulation transfer function (MTF). In this paper, the crosstalk is studied and reduced by a NIR-cutoff layer. By optical simulation, the crosstalk in each of the R, G, and B pixels is reduced by about 10%. The overall crosstalk in the pixels was reduced from 75.5% to 48.2%. Therefore, this paper shows that the crosstalk at NIR wavelengths is improved while maintaining the high sensitivity characteristics of RGBW CFA image sensors.