ECLIPSE-PFAS: Sustainable Use of Etch Gases in Semiconductor Manufacturing

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

This award is made in response to Dear Colleague Letter 24-130, as part of the ECosystem for Leading Innovation in Plasma Science and Engineering (ECLIPSE) interdisciplinary program. This grant supports research that addresses the sustainable use of etch gases in semiconductor manufacturing, which is increasingly important for the US microelectronics industry and associated supply chain, and national prosperity and security. Semiconductor manufacturing of a chip (the “brain” in smart phones) is like building an “entire city on a fingernail”, where each “building” has a specific function, together they make the “city” work. With limited and precious “real estate, the fingernail”, each new version of the “city” gets smaller with taller “skyscrapers” thus achieving improved performance and making the smart phone more and more powerful. The process of manufacturing these chips uses chemical etch gases such as PFAS (per- and polyfluoroalkyl substances) that pose environmental and health concerns. This award supports fundamental research that seeks to provide knowledge to discover and use novel environmentally friendly etch gases and break them down to minimize their emission to the environment. Findings from this research intend to benefit the U.S. economy, environment and society. Research outcomes are integrated into existing curricula on semiconductor manufacturing with new modules focusing on plasma physics and chemistry, plasma-surface interaction, and related chemical processes to realize sustainable semiconductor manufacturing. In addition to educational benefits, this award provides hands-on training to students and helps prepare them for job opportunities in the semiconductor industry. This project aims to address the sustainable use of etch gases in semiconductor manufacturing with a combined modeling and experimental approach. While plasmas are effective in breaking the Carbon-Fluorine (C-F) bonds in per- and polyfluoroalkyl substances (PFAS) gases, the challenges remain in how to avoid the reformation of C-F bonds that can lead to the production of PFAS byproducts. Specifically, this proposal looks to evaluate the thermodynamics and kinetics related to the dissociation of PFAS gases, understand the effect of reactive oxygen and hydrogen species, delineate the role of secondary gases or catalysts in shifting the equilibrium of product formation, and assess the efficacy of the overall process in terms of processing performance and environmental impact. The experimentally validated data will be shared with the artificial intelligence/machine learning community where there is a need for training data. If successful, this research will help minimize the impact of PFAS, enable more efficient process in fabricating of microelectronics, and lay the foundation to address the effect of increasing semiconductor manufacturing on the environment in the United States. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.