A metasurface is a layer of subwavelength‐scale nanostructures that can be used to design functional devices in ultrathin form. Various metasurface‐based optical devices – coined as flat optics devices – have been realized with distinction performances in research laboratories using electron beam lithography. To make such devices mass producible at low cost, metasurfaces over a large area have also been defined with lithography steppers and scanners, which are commonly used in semiconductor foundries. This work reviews the metasurface process platforms and functional devices fabricated using complementary metal‐oxide‐semiconductor‐compatible mass manufacturing technologies. Taking both fine critical dimension and mass production into account, the platforms developed at the Institute of Microelectronics (IME), A*STAR using advanced 12‐inch immersion lithography have been presented with details, including process flow and demonstrated optical functionalities. These developed platforms aim to drive the flat optics from lab to fab.

The demonstration of a color display metasurface on a 12-inch silicon wafer with critical dimension (CD) below 100 nm by complementary metal-oxide semiconductor (CMOS) compatible technology is reported for the first time. The 193 nm ArF deep UV immersion lithography is leveraged instead of electron beam lithography (EBL) to pattern the metasurface, which greatly improves the efficiency while keeping a high resolution. The demonstrated metasurface successfully generates the resonant modes and reflects the lights at resonance wavelengths, giving its display in red, green, and blue (RGB) colors. The wafer-level uniformities of CD and reflection characteristic of the metasurface are measured and analyzed. The experimental data show that they are well controlled in the fabrication process. The work provides a promising route towards mass production of dielectric metasurfaces.

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.

Millimeter and terahertz wave photodetectors have long been of great interest due to a wide range of applications, but they still face challenges in detection performance. Here, we propose a new strategy for the direct detection of millimeter and terahertz wave photons based on localized surface-plasmon-polariton (SPP)-induced non-equilibrium electrons in antenna-assisted subwavelength ohmic metal–semiconductor–metal (OMSM) structures. The subwavelength OMSM structure is used to convert the absorbed photons into localized SPPs, which then induce non-equilibrium electrons in the structure, while the antenna increases the number of photons coupled into the OMSM structure. When the structure is biased and illuminated, the unidirectional flow of the SPP-induced non-equilibrium electrons forms a photocurrent. The energy of the detected photons is determined by the structure rather than the band gap of the semiconductor. The detection scheme is confirmed by simulation and experimental results from the devices, made of gold and InSb, and a room temperature noise equivalent power (NEP) of 1.5 × 10⁻¹³ W Hz^−1/2 is achieved.