All-dielectric metasurface-based color filter in CMOS image sensor

The development of all-dielectric metasurfaces vigorously prompts the applications of optical metasurfaces for a CMOS (Complementary Metal-oxide-semiconductor) image sensor. 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, a transmission filter based on a GMR (Guided Mode Resonance) mode of all-dielectric metasurface is adopted as an example to study the effect of application scenario of integrated CMOS image sensor chip and manufacturing mistakes, such as the small size of pixel, special dielectric environment around, surface roughness and structural defects. Numerical calculations based on the FDTD (finite difference time domain) method are used to study the relationship between the robustness of the metasurfaces and the optical resonant modes. More important, a method simplifying different manufacturing mistakes as basic geometry structure during the FDTD simulation is also proposed and demonstrated. This work deepens our understanding of the working mechanism of all-dielectric metasurfaces and paves the way for their use in CMOS image sensor.