EAGER: Ionic Liquid Ion Sources and Nanomanufacturing

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

The objective of this EArly-Grant for Exploratory Research (EAGER) project is to study the fundamental science and engineering of nano-ion emitters based on room temperature molten salts (ionic liquids - ILs). The context of this project is related to applications in nanomanufacturing, space propulsion and other fields. It is possible with ionic liquid ion sources (ILIS) to field-evaporate nearly monochromatic positive or negative ion beams from a virtual point. These characteristics are ideal for applications at the nano-scale as these ions potentially can be focused to sizes commensurate with the source, which according to recent estimates is a few nm. In addition, the high efficiency and brightness enables micro and nanoengineered propulsion devices for very small satellites (0.1-10 kg). Many of these ions are chemically reactive, in principle enhancing etching rates without recurring to chemical assistance in wafer processing applications. With the vast number of available ILs it should be possible to tailor ion beam composition to specific applications. The main goal is to improve our understanding of ILIS sources through theory and experiment. Particular attention will be given to (1) the determination of the focusability of ion beams, (2) their reactive etching characteristics and other interactions with materials, (3) their potential for nanomanufacture in dense arrays for high throughput and (4) contribute to the theory of molecular ion emission. The research objectives and methods are centered around a series of challenges and missing knowledge described in this proposal. The uniqueness and novelty of ionic liquid ion sources open up a number of relevant research avenues, ranging from the design of the source and its implementation in arrays to the theory of molecular ion evaporation and the interaction of ions with materials. Few advances in field evaporation ion sources have been made beyond the invention of the liquid metal ion source more than 30 years ago. The introduction of ILIS has the potential to revitalize the field and is expected that important scientific and engineering contributions will result from NSF support in this new area. It is anticipated that ILIS sources will have relevant impact on industrial applications, such as nanomanufacturing, ion microscopy, lithography and implantation on a variety of solid-state materials, and in propulsion applications for small satellites. It is also expected that relevant collaborations will emerge as research results are documented in scientific journals. This research will have an important impact on the educational curriculum of undergraduate and graduate students enrolled in interdisciplinary programs at MIT. In addition, this NSF support will be pivotal in continuing involvement in outreach programs, such as MIT's Summer Research Program (MSRP), which supports education in science and engineering of under-represented groups and the Undergraduate Research Opportunities Program (UROP). Coordinated outreach activities will be organized with local educators and research institutions at all levels, inviting them to participate with their students in laboratory demonstrations, lectures and other scientific activities with the objective of encouraging young students to pursue an education in science, technology, engineering and mathematics.