Sub-micrometer Nanostructure-based RGB Filters for CMOS Image Sensors

TL;DR

This paper presents the development of sub-micrometer RGB spectral filters using amorphous silicon nanostructures, enabling high-resolution CMOS image sensors with potentially improved color filtering capabilities.

Contribution

It introduces a novel approach to create miniature, tunable spectral filters based on dielectric nanostructures for high-resolution imaging.

Findings

Successfully fabricated sub-micrometer RGB filter arrays

Achieved optimized transmissive colors for primary RGB

Demonstrated potential for integration into high-resolution sensors

Abstract

Digital color imaging relies on spectral filters on top of a pixelated sensor, such as a CMOS image sensor. An important parameter of imaging devices is their resolution, which depends on the size of the pixels. For many applications, a high resolution is desirable, consequently requiring small spectral filters. Dielectric nanostructures, due to their resonant behavior and its tunability, offer the possibility to be assembled into flexible and miniature spectral filters, which could potentially replace conventional pigmented and dye-based color filters. In this paper, we demonstrate the generation of transmissive structural colors based on uniform-height amorphous silicon nanostructures. We optimize the structures for the primary RGB colors and report the construction of sub-micrometer RGB filter arrays for a pixel size down to 0.5 {\mu}m.