The researchers say their innovation, called a cascade field effect transistor (CasFET), 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 technology could lead to better and more powerful central processing unit (CPU) generations, which can compute more operations with less energy.
The technology, say the researchers, is designed to help meet the performance requirements of nanotransistors, which present several challenges.
"They need a high enough ON-current and low enough OFF-current, with a small enough difference to switch between both," says Tillmann Kubis, the Katherine Ngai Pesic & Silvaco Research Assistant Professor of Electrical and Computer Engineering in Purdue's Elmore Family School of Electrical and Computer Engineering. "These challenges have significantly slowed the downscaling of transistors around the last eight years, making it increasingly difficult to introduce more powerful CPU generations."
The CasFET introduces a new switching method to transistors - one that is like the effects observed in quantum cascade lasers. The key aspect of the technology is the superlattice perpendicular to the transistor’s transport direction (see image), which allows for switchable cascade states.
"CasFET is a more general approach than transistor technology we had developed several years ago," says Kubis. "It offers more flexibility in the choice of materials and voltage settings, 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."
The researchers say they are continuing to develop the first CasFET prototype.
"Once that is showing the performance goals," says Kubis, "we will continue with defining a concrete CasFET prototype design."
The Purdue Research Foundation Office of Technology Commercialization has applied for patent protection of the technology from the U.S. Patent and Trademark Office. It is available for further commercialization by contacting Dipak Narula, assistant director of business development.
Ferroelectric semiconductor FET