Student refines tools for precision microchip manufacturing

Inside the humming, meticulously controlled environment of Cornell's NanoScale Science and Technology Facility (CNF), Nandan Reddy Muthangi knows that even the slightest miscalculation can undo hours of work. Clad in cleanroom gear, he carefully calibrates the settings on a 3D lithography system and begins etching microscopic structures - work that could help improve the reliability of microchip production that will power future technologies.

A Master of Engineering (M.Eng.) student in the Semiconductor and Quantum Materials Pathway at the Cornell Duffield College of Engineering, Muthangi is advancing new methods for building semiconductor test chips for systems used to ensure reliability in manufacturing. Most semiconductor devices such as microchips are made through tightly controlled, microscopic steps. Even the smallest defect can impact performance or cause failure, making precise metrology technologies essential for catching issues early and guiding the manufacturing process.

Through his M.Eng. degree program, Muthangi partnered with the company Xallent to advance this approach by developing high-resolution test chips capable of detecting smaller variations than conventional tools. By improving how precisely measurements can be made, the chips will help manufacturers produce more reliable devices at scale.

Inside CNF - a state-of-the-art nanofabrication facility in Duffield Hall, where researchers engineer materials and devices at the nanoscale - Muthangi works through the full fabrication process. He begins with lithography, patterning microscopic structures onto substrates using tools like contact aligners, followed by metal deposition and etching steps to build and refine the features. He then evaluates the results, measuring thickness, surface quality and structural integrity. It's a complex workflow that requires constant iteration.

"Some days I'm in the cleanroom fabricating, and other days I'm reading research papers and trying to understand why something didn't work," Muthangi said. "If the output is different than what I expected, I switch gears and try to explore a new way."

Designing, building and testing devices is at the heart of Muthangi's work and the partnerships that fuel Cornell's M.Eng. program. Through this collaboration, Xallent - a Cornell-spinoff company now based in Albany, New York, that develops high-precision semiconductor testing tools - leverages Muthangi's data and Cornell's advanced fabrication resources to refine its engineering approaches. At the same time, Muthangi gains valuable experience on a project with tangible industry impact.

"That blend of deep technical knowledge and hands-on practice is central to our Materials Science and Engineering M.Eng. program," said Kintu Early, director of the program and a professor of practice. "The projects that our students work on, whether with industry or faculty, help prepare them for careers in some of the most critical and rapidly evolving industries."

For Muthangi, the experience has been transformative. Coming from a computer science background, he was unfamiliar to the cleanroom environment. But guidance from Cornell faculty and staff helped him build the knowledge and technical expertise.

Beyond the technical skills, the M.Eng. program has inspired Muthangi's career goals. After graduating, he hopes to work in semiconductor process or manufacturing and, long term, is interested in combining that knowledge with artificial intelligence to reimagine how microchip production is managed.

"If you look around, almost everything relies on a chip - electronics, medical devices, transportation," Muthangi said. "As these devices continue to shrink, it's important we continue to improve how we test and manufacture them. I want to be part of that."