Downscaling Transistors Could Advance Semiconductor Design



(Image provided by Tillmann Kubis)

Purdue University engineer Tillmann Kubis has created CasFET, or cascade field effect transistor, technology. The key aspect is the superlattice perpendicular to the transistor’s transport direction, which allows for switchable cascade states.

An innovation by Purdue University researchers could help the semiconductor industry design transistors that are smaller, use less power and switch from on to off at smaller applied voltages. As a result, the innovation could lead to better and more powerful central processing unit generations, which can compute more operations with less energy.

Tillmann Kubis is the Katherine Ngai Pesic & Silvaco Research Assistant Professor of Electrical and Computer Engineering in Purdue's Elmore Family School of Electrical and Computer Engineering. He said it has become more difficult to meet the performance requirements of nanotransistors.

"They need a high enough ON-current and low enough OFF-current, with a small enough difference to switch between both," Kubis said. "These challenges have significantly slowed the downscaling of transistors around the last eight years, making it increasingly difficult to introduce more powerful CPU generations."

Kubis and James Charles, a senior research associate in the Elmore Family School of Electrical and Computer Engineering, have created CasFET, or cascade field effect transistor, technology. It introduces a new switching method to transistors, one that is like the effects observed in quantum cascade lasers.

"CasFET is a more general approach than transistor technology we had developed several years ago. It offers more flexibility in the choice of materials and voltage settings," Kubis said. "In technical terms, CasFET does not require band-to-band tunneling. Because of this, semiconductor designers could be able to develop faster-switching and more energy-efficient transistors."

Kubis and Charles continue to develop the first CasFET prototype.

"Once that is showing the performance goals, we will continue with defining a concrete CasFET prototype design," Kubis said.

Kubis disclosed the CasFET innovation to the Purdue Research Foundation Office of Technology Commercialization, which has applied for patent protection from the U.S. Patent and Trademark Office. It is available for further commercialization by contacting Dipak Narula, assistant director of business development.

About Purdue Research Foundation Office of Technology Commercialization

The Purdue Research Foundation Office of Technology Commercialization operates one of the most comprehensive technology transfer programs among leading research universities in the U.S. Services provided by this office support the economic development initiatives of Purdue University and benefit the university's academic activities through commercializing, licensing and protecting Purdue intellectual property. The office recently moved into the Convergence Center for Innovation and Collaboration in Discovery Park District, adjacent to the Purdue campus. In fiscal year 2020, the office reported 148 deals finalized with 225 technologies signed, 408 disclosures received and 180 issued U.S. patents. The office is managed by the Purdue Research Foundation, which received the 2019 Innovation and Economic Prosperity Universities Award for Place from the Association of Public and Land-grant Universities. In 2020, IPWatchdog Institute ranked Purdue third nationally in startup creation and in the top 20 for patents. The Purdue Research Foundation is a private, nonprofit foundation created to advance the mission of Purdue University. Contact for more information.