Atomic Layer Deposition Tuning of Subwavelength Aluminum Grating for Angle-Insensitive Plasmonic Color

The angle-insensitive and tunable nature of metal-insulator-metal slits makes them an interesting candidate for plasmonic displays and colorant applications. The realization of these structures in the visible regime and over reasonably large areas has only been recently possible due to advances in nanofabrication. However, previous demonstrations are of inverted grooves etched into a dielectric, coated with a metal and then probed from the substrate-leaving them unable to be tuned postfabrication, as the regions of confined fields become inaccessible. Second, these demonstrations use area and time-limited fabrication processes such as EBL or FIB milling. Here, we demonstrate 8 in. wafer scale angle-insensitive plasmonic color through vertical metal-insulator-metal slit waveguides in which the resulting resonances can be accessed and tuned through external media. To illustrate this, we use atomic layer deposition to change the effective refractive index of the surrounding media and tune resonance locations throughout the entire visible regime. The tunable single-peak absorption resonance results in the reproduction of the cyan, yellow, and magenta (CYM) color space. The system's angle insensitivity and large scale allow the creation of polarization-dependent images and logos which can find use in novel plasmonic optical components and further demonstrate the potential of such systems to be integrated with dynamically tunable optical media.