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All PhD students conclude their studies by writing a dissertation, but it's rare when a dissertation becomes a book. NPRE graduate Martin Neumann’s work is one of the rarities.

Lithium Sputtering, Deposition and Evaporation: Controlled Thin Film Engineering, first published in June by VDM Verlag, evolved from Neumann's 2007 dissertation, "Litihum Debris Removal by Sputtering and Evaporation for EUV Optics and Applications."

"I hope it will be a reference book," Neumann said. "It will sit on a lot of shelves of libraries in major research universities here and around the world." He has donated a copy to the University of Illinois library system.

A native of Pekin, Illinois, Neumann has earned three degrees in NPRE, a bachelor's in 1999, a master's in 2004, and a doctorate in 2007. Interested in developing and integrating emerging technology with medicine, Neumann is pursuing a medical degree while he continues to work as a postdoc with NPRE Prof. David Ruzic in the Center for Plasma Material Interactions.

As a sponsor for the Center, VDM Verlag contacted Neumann about publishing his research as a book.

"I was shocked," Neumann recalled, although he believes the work is "a well laid-out, very methodical approach" on controlling lithium deposition and modeling lithography in computer chip technology.

According to the book's description, "The ability to selectively deposit thin films of lithium and remove them from surfaces is an emerging area of technology development in various fields including EUV lithography, lithium ion battery development, and in the fusion community."

Through Neumann's work, "A lithium magnetron source was developed for lithium deposition and characterized to yield a mapping of the temperature and density of the plasma, ionization fraction, and lithium deposition. From here, a secondary plasma source was developed and studied in the same manner to also provide information on the electron density, temperature, and ionization fraction so as to accurately model and measure the deposition flux of lithium and sputter flux on the sample surface.

"The simultaneous process of deposition, evaporation, and sputtering of lithium is modeled and corroborated with experimental observations to develop a predictive model for the precise thickness of lithium thin films that can be engineered in any setting for any application."

One review of the book called it "a great fundamental explanation of sputtering and magnetron sputtering. While focused on lithium, the physics discussed are relevant and adaptable for all sputtering systems. This text also develops a detailed model for magnetron sputtering in 3-D space. While relevant for EUV applications, this work is applicable to all applications involving thin film engineering."

Lithium deposition is used in the making of silicon wafers for computer chips, and ion batteries in products such as hybrid automobiles, cell phones and other mobile electronics. By better controlling the deposition, Neumann said, the chips and batteries can be made smaller, allowing for the products to be smaller. When a hybrid car's batteries are smaller, more batteries can be built into the vehicle, giving it longer-lasting power.

Neumann said his work has applications for medicine because lithography provides for a low-energy x-ray source that can image single cells.

"If you can see how a cell grows, you can image cancer cells at an earlier state and with more detail," he said.

Neumann credits Ruzic and NPRE Profs. George Miley and Jim Stubbins for their assistance in the research. He also thanks Gary Eden, professor of electrical and computer engineering at Illinois, and Mark Kushner, Director of the Michigan Institute of Plasma Science at the University of Michigan.

Contact: Susan K. Mumm, editor/alumni affairs coordinator, Department of Nuclear, Plasma and Radiological Engineering, 217/347-2166 or 217/821-6866.