Researchers at the University of Illinois Urbana-Champaign have developed a method that could streamline the way companies produce microchips.
Manufacturing the most advanced microchips requires a technology called extreme ultraviolet lithography (EUVL). This only reached high-volume manufacturing at the end of 2019. Though chips are being produced, a downside of EUVL is that tin contaminates a critical component called the collector mirror, which needs to then be removed and cleaned with hydrogen plasma, a process that slows manufacturing speed and adds extra cost.
The method created by a team led by Professor David Ruzic and consisting of his current and former students (Dren Qerimi, Andrew Herschberg, Gianluca Panici, Parker Hays, and Tyler Pohlman) uses an annular surface wave plasma (SWP) antenna technology that is integrated into the collector for in-situ (in their original place) tin removal. They showed that by affixing eight SWP antennas to the mirror — two to the inner cone and six to the outer perimeter — the collector is kept free from tin buildup during etching eliminating down time in the tool and reducing expense.
“This is the culmination of the work we have been doing with ASML – the company who makes the machines. Their machines pattern virtually every chip in the world, and ASML is funding us in a major way,” Ruzic, the Abel Bliss Professor of Engineering, said. “We show how the mirrors can be kept clean in-situ (in their original places), greatly extending the lifetime and up-time of their devices. There is also a path to actually have this technology deployed.”
ASML-funded work in Prof. Ruzic’s group continues looking at ways to improve the drive lasers, how to understand the behavior of Sn atoms and ions in the device, and experiments on stannane, the byproduct of the tin removal.
“This breakthrough is another example of the great work Professor Ruzic does with his students in the Plasma area of our department,” NPRE professor and department head Rizwan Uddin said. “Students can get started working on important research projects and be a part of studies like this one as soon as they join the department. The experience they get in groups like Professor Ruzic’s is important to their future success.”
The paper detailing this research was recently published and highlighted in the Journal of Applied Physics, and you can read it here.