Thickness Dependencies and Angstrom Scale Reductive Nanopatterning of Chalcogenide Films

Layered chalcogenides can exhibit a wide range of relevant and tunable electronic, optical, magnetic, and coupled properties—even when vanishingly thin. The many property mapping variations of Atomic Force Microscopy are ideal for investigating these effects, particularly to map ferroelectric or magnetic domains, conductivity, or photovoltaic responses. Leveraging advances in precision reductive nanopatterning, achieved with custom feedback in an Atomic Force Microscope, we extend such studies into the thickness dimension. Both by preparing thickness gradients from 100nm down to an underlying substrate, and by implementing Tomographic AFM for full 3D nanoscale mapping, we uniquely investigate chalcogenide specimens as a function of thickness. For example, domain pinning is observed for CuInP₂S₆ supported on a back electrode when less than 10 nm thick. Examples of truly Angstrom scale depth patterning are also presented, enabling distinct layer exposure as well as the preparation of pilot dimensions of metamaterial devices.