Wafer-Scale Top-Down Patterning of Metal Halide Perovskites

Abstract

Metal halide perovskites (MHPs) are promising semiconductor materials for next-generation integrated photonics and electronics because they can be deposited from solution at low temperatures, enabling their monolithic integration with conventional semiconductor substrates. However, ionic bonding renders them vulnerable to many standard semiconductor lithography steps involving solvents, developers, or plasma exposure, limiting their integration into standard semiconductor processing. In this work, we demonstrate 150 mm wafer-scale integration of cesium lead bromide (CsPbBr3) MHP thin films using a standard top-down lithographic approach. A chemically amplified resist, polymethyl methacrylate (CAR-PMMA), and a perovskite-compatible developer were employed to enable direct photolithography and pattern transfer via reactive ion etching (RIE). We assessed the structural, optical, and morphological properties of the thin films after patterning via X-ray diffraction, ultraviolet-visible absorption and photoluminescence spectroscopy, and spectroscopic ellipsometry, atomic force and electron scanning microscopy, confirming their robustness. Our wafer-scalable approach reduces the need for complex multilayer resist stacks, is compatible with i-line stepper lithography for sub-micron device feature sizes, and advances the semiconductor-technology-compatible integration of CsPbBr3-based devices.