Nanostructured optical filters in CMOS for multispectral, polarization and image sensors

Sub-wavelength gratings and hole arrays in metal films are applicable for polarization and spectral selective sensors, respectively. We demonstrate the fabrica-tion of wire grid polarizers using standard complementary metal-oxide semiconductor (CMOS) processes. Extraordinary optical transmission of hole arrays was achieved by using the dedicated layer of a modified CMOS process. The structures were simulated using the finite-difference time-domain (FDTD) method and fabricated using the work flow of integrated circuits. A high-speed polarization image sensor with a pixel size of 6 µm was designed and demonstrated, and multispectral sensing was implemented using nanostructures with different spectral filter performances on a single chip