CMOS-compatible a-Si metalenses on a 12-inch glass wafer for fingerprint imaging

Abstract

Metalenses made of artificial sub-wavelength nanostructures have shown the capability of light focusing and imaging with a miniaturized size. Here, we report the demonstration of mass-producible amorphous silicon metalenses on a 12-inch glass wafer via the complementary metal-oxide-semiconductor compatible process. The measured numerical aperture of the fabricated metalens is 0.496 with a focusing spot size of 1.26 μm at the wavelength of 940 nm. The metalens is applied in an imaging system to test the imaging resolution. The minimum bar of the resolution chart with a width of 2.19 μm is clearly observed. Furthermore, the same system demonstrates the imaging of a fingerprint, and proofs the concept of using metalens array to reduce the system size for future compact consumer electronics.