High-performance silver-dielectric interference filters for RGBIR imaging
Résumé
New architectures of interference silver-dielectric multilayer filters inspired from induced transmission designs are investigated with the prospect of high-performance red-greenblue (RGB) complementary metal oxide semiconductor imaging. The optimized designs provide combined colorimetric, signal-to-noise ratio and sensitivity performances similar to the traditional organic color filters, but without the equirement of an external infrared (IR)-cut filter, which enables the integration of additional channels such as white or IR, in addition to RGB. Due to the sub-micrometer thickness of the stacks, this is a unique solution for fully integrated, high-performance multispectral filters patterned in very small pixels. The concept is demonstrated by a wafer-scale prototype with RGBIR filters patterned down to 1.4 mu m adjacent pixels with up to 80% transmission.