I-Corps: Optimized mm-Wave Transistors for 5G Applications

The broader impact/commercial potential of this I-Corps project is the development of a transistor for better heat dissipation capability for high-frequency semiconductor devices. In general, the demand for millimeter (mm)-wave transistors is steadily increasing. In these devices, electromagnetic wave propagation effects and heat dissipation are among the most limiting factors for production.

The proposed technologies in this project are applied to the design and fabrication of optimized mm-wave transistors. These transistors demonstrate superior performance compared to currently available technologies. In addition, the devices have a smaller footprint compared to conventional transistors performing the same functionality.

The new designs result in more devices per wafer, and each individual device may be capable of producing higher power and operating over a wider bandwidth. Such performance enhancements may allow savings in cost per component. Moreover, the new transistors may have characteristics enabling them to meet more stringent performance specifications.

Subsequently, new systems with advanced functionalities may be designed that will open new market areas.

This I-Corps project is based on the development of a fabrication technology that is applicable to high-frequency semiconductor devices. The proposed technology describes novel transistor electrode designs to match the phase velocity of the propagating waves on the input and output electrodes. This enables relaxation of the current limitations on the electrode width, which reduces the number of fingers needed to meet the desired device gain, output power, and other performance parameters.

The competitive advantage of the proposed technology is to allow fabricating wider transistors, which provides more radio frequency power. The thermal management issues and their associated challenges in mm-wave transistors also are addressed in this project. The proposed technology modifies the substrates enabling them to act as better heat absorbers by enhancing their overall thermal conductance.

The novelty in this technology is founded on improvements in thermal properties of the die to extract the heat generated at the surface and/or in the active layer at the junctions, offering enhanced capabilities for heat removal. Results from research on the analysis of the transistor performances demonstrate the promise of this technology.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.