New Materials Modification Method Could Reduce Cost of Microelectronics

A new method of shaping materials could reduce the cost of fabricating microelectronics such as those used in cellphones.

Nov. 8, 2023 - The burst of flames caused by microwaving grapes inspired a UC Irvine engineering researcher to develop a new method of shaping materials that could reduce the cost of fabricating microelectronics.

Maxim Shcherbakov, an assistant professor of electrical engineering and computer science, explains the classic science fair physics experiment, “If you put two grapes into a microwave and hit the start button, in a few seconds, the grapes bump into each other and erupt in a bright flash of sparks or fire (plasma) generated at the point of contact.”

The wavelength of the microwave radiation is about 15 centimeters, much larger than the size of a grape. “The equations governing electromagnetic waves, Maxwell’s equations, are scalable,” he said. “This made me realize that if I reduced all the dimensions of the scene to the microscale, I could leverage the same material modification effect but using light instead of microwaves.” 

Being able to structure materials at the nanoscale is crucial for producing most of the microelectronics we use daily in our cars, computers, household appliances, smart watches, cellphones and more. Using ultrafast infrared (femtosecond) lasers to modify materials is not new. However, in most cases, the minimum size at which the material can be modified is comparable to the wavelength of light one uses.

Maxim Shcherbakov

“We use specially designed microparticles that can funnel light into much smaller spots, modifying materials such as silicon at a scale of down to almost one-hundredth of a wavelength,” said Shcherbakov. He published the new technique, called femtosecond laser-assisted nanostructuring of engineered microstructures (FLANEM), in Nature Communications.

FLANEM expands the nanofabrication toolbox and offers exciting opportunities for high-throughput optical methods of nanoscale structuring of solid materials, such as silicon and other semiconductors. This finding is timely as the nation gears up its efforts to increase microelectronics and semiconductor manufacturing as part of the CHIPS and Science Act.

“The advanced machinery used in nanoelectronics is extremely costly because it relies on extreme ultraviolet light (very short wavelength) to pattern the materials,” said Shcherbakov. “We hope to adopt FLANEM to enable the use of cheaper tabletop light sources, reducing microelectronic chip production expenditures and alleviating the costs for end users. There are still some intermediate steps to be solved, but we’ve made the first and most important step by overcoming the diffraction limit with FLANEM.” 

– Lori Brandt