Reduction of Electrical Crosstalk in Hybrid Backside Illuminated CMOS Imagers using Deep Trench Isolation

Abstract

Hybrid backside illuminated CMOS imagers with zero pixel-to-pixel electrical crosstalk were developed. The application of highly doped polysilicon filled high aspect ratio trenches between pixels to reduce crosstalk is unique. These 1μm wide 50μm deep trenches enforce a lateral drift field between pixels, which counteracts diffusion and drastically reduces electrical crosstalk. Quantitative crosstalk characterization of trenched and non-trenched imagers is presented.