Electron Beam Patterning of Metal–Organic Frameworks
Yurun Miao, Michael Tsapatsis
Abstract
Development in patterning technique of metal–organic frameworks (MOFs) will facilitate their integration in microelectronics, but controlling the structure of MOFs at the nanoscale remains a major challenge. We demonstrate that an electron beam (e-beam) can be used to pattern a zinc-imidazolate MOF, ZIF-L, at unprecedented resolution in a direct-write lithographic approach, where the electron-irradiated MOF functions either as a positive- or negative-tone resist depending on the level of exposure and developing solvent used. Nanosheets with adjustable thickness and other nanostructures can be obtained using a low e-beam with a controlled penetration depth. In addition, electron irradiation in ZIF-L leads to spatially directed crystallization to a prototypical MOF ZIF-8 via ligand-vapor treatment. This versatile strategy opens the door to e-beam-based processing of MOF materials for various applications.