Extreme-Ultraviolet (EUV) light holds strong promise as a light source for producing tomorrow's complex and compact integrated circuits. Unfortunately, practical economic use is currently precluded by low cost-efficiency for high volume manufacturing. The EUV source uses tin (Sn) droplets to produce the 13.5nm light, which is collected and transmitted into a scanner by collector optics. Sn deposits on the collector surface and degrades the EUV reflectivity. Cleaning Sn using hydrogen radicals is a potential solution. This Grant Opportunity for Academic Liaison with Industry (GOALI) award supports the Applied Research Institute at the University of Illinois at Urbana Champaign to perform basic research in collaboration with its industrial partners to advance the fundamental understanding of the underlying physics and chemistry of Sn etch process using hydrogen radicals. This research will prove to be a milestone in the success of the next generation chip manufacturing process, which will enable a cost effective implementation of the technology to print smarter chips and eventually improve the speed and performance of electronic devices. An overarching goal of this research is the integration of research findings into academic courses, student involvement with industry, and attracting young scientists into the vast field of plasma engineering.
This project is a hypothesis-driven, theoretical and experimental study of Sn cleaning from optics in a complex plasma environment. It focuses on fundamental understanding of reactive particle formation in hydrogen plasma, its arrival and interaction with surfaces, adsorption mechanisms, bond formation with the surface to be etched, and then finally the formation and desorption of product molecules under the EUV source operating environment. The team will perform a thorough computational analysis of the dependencies of hydrogen plasma conditions and etch rate. Etching experiments will be run to validate the etch rates predicted by the models. Collaborative industrial partners will help by providing necessary equipment, metrologies and the plasma source to advance this research. The research will answer fundamental questions in the field of plasma material interaction, surface science, plasma processing and etching.
