Prof. Michael Tsapatsis : Reaction Engineering Principles of Electron-Induced Transformations in Metal-Organic Thin Films and their Use in Membrane and Micro-chip Manufacturing
Abstract : This talk will motivate and address the question of how to harness low-energy-electron-induced chemistry in amorphous zeolitic imidazolate frameworks (aZIFs) (a type of MOF) to realize fully dry, high-resolution lithography and generate novel nanostructured materials for advanced manufacturing and separations. Low-energy electrons (<100 eV), produced directly by electron beams or indirectly through extreme ultraviolet and beyond extreme ultraviolet (EUV/BEUV) irradiation, induce chemical changes in solids. These changes can be viewed as irreversible damage to these materials, but they can also be viewed as a way to controllably modified ZIF chemistry and structure. In 2018, we were first to report that ZIFs undergo electron-induced solubility changes enabling patterning. We later measured low-energy electron-induced radiolytic reaction rates of imidazoles, and showed that exposure to electrons transforms ZIF films into cyano-zinc thin films with altered and sometimes enhanced separation performance. Building on this reactivity, we developed an all-dry resist platform based on amorphous ZIF films grown by atomic/molecular layer deposition (ALD/MLD). Patterning is achieved through electron or EUV/BEUV or other irradiation that can generate low-energy electrons, followed by vapor-phase, non-plasma etching that complexes zinc and volatilizes imidazole, eliminating liquid developers. This approach enables nanoscale patterns with high fidelity and reduces the environmental footprint of lithographic processing. More recently, based on a ZIF thin film formation approach introduced by EPFL, using ultra-dilute precursor solutions, we extended wafer-scale ZIF deposition methods to include spin-coated ZIF films, achieving promising performance for EUV and BEUV lithography. These advances establish a versatile materials-chemistry toolkit where electron-stimulated reactions are coupled with mass transport to fabricate functional nanostructures. The presentation will highlight underlying mechanisms, process innovations, and potential applications in microelectronics and membrane technologies.
Bio : Michael Tsapatsis is a Bloomberg Distinguished Professor of Chemical and Biomolecular Engineering at Johns Hopkins University (JHU) with a joint appointment in the Applied Physics Laboratory. Before joining JHU (September 1, 2018) he was on the faculty of the Department of Chemical Engineering and Materials Science at the University of Minnesota since September 2003 where he held the Amundson Chair and the McKnight Presidential Endowed Chair. Before joining the University of Minnesota, he was a faculty member in the Chemical Engineering Department at the University of Massachusetts Amherst (1994-2003). He received an Engineering Diploma (1988) from The University of Patras, Greece, and MS (1991) and Ph.D. (1994) degrees from the California Institute of Technology (Caltech) working with G.R. Gavalas. He was a post-doctoral fellow with M.E. Davis at Caltech (1993/94). His research group’s accomplishments include development of hierarchical mesoporous zeolite catalysts, oriented molecular sieve films, 2D zeolites, molecular sieve/polymer nanocomposites for membrane applications, crystal structure determination of adsorbents that are now used in a commercial process, and synthesis of precisely sized oxide nanoparticles that have been commercialized. In the last decade, he is developing novel uses of metal-organic thin films for applications in the microelectronics industry as resists for lithography. He was elected to the US National Academy of Engineering (2015) for contributions to the “design and synthesis of zeolite-based materials for selective separation and reaction.” He co-authored the 2019 National Academies Report “A Research Agenda for a New Era in Separations Science” and he currently serves an Associate Editor for Science Advances. He has mentored over 100 Ph.D. students and post-doctoral fellows and has taught courses in reaction engineering, catalysis, separations, transport phenomena, and process design with emphasis on energy efficiency and process intensification.
Bio : Michael Tsapatsis is a Bloomberg Distinguished Professor of Chemical and Biomolecular Engineering at Johns Hopkins University (JHU) with a joint appointment in the Applied Physics Laboratory. Before joining JHU (September 1, 2018) he was on the faculty of the Department of Chemical Engineering and Materials Science at the University of Minnesota since September 2003 where he held the Amundson Chair and the McKnight Presidential Endowed Chair. Before joining the University of Minnesota, he was a faculty member in the Chemical Engineering Department at the University of Massachusetts Amherst (1994-2003). He received an Engineering Diploma (1988) from The University of Patras, Greece, and MS (1991) and Ph.D. (1994) degrees from the California Institute of Technology (Caltech) working with G.R. Gavalas. He was a post-doctoral fellow with M.E. Davis at Caltech (1993/94). His research group’s accomplishments include development of hierarchical mesoporous zeolite catalysts, oriented molecular sieve films, 2D zeolites, molecular sieve/polymer nanocomposites for membrane applications, crystal structure determination of adsorbents that are now used in a commercial process, and synthesis of precisely sized oxide nanoparticles that have been commercialized. In the last decade, he is developing novel uses of metal-organic thin films for applications in the microelectronics industry as resists for lithography. He was elected to the US National Academy of Engineering (2015) for contributions to the “design and synthesis of zeolite-based materials for selective separation and reaction.” He co-authored the 2019 National Academies Report “A Research Agenda for a New Era in Separations Science” and he currently serves an Associate Editor for Science Advances. He has mentored over 100 Ph.D. students and post-doctoral fellows and has taught courses in reaction engineering, catalysis, separations, transport phenomena, and process design with emphasis on energy efficiency and process intensification.
Practical information
- Informed public
- Free
Organizer
- Institute of Chemical Sciences and Engineering
Contact
- Wendy Queen
[email protected]