MATERIAL AND DEVICE ENGINEERING OF GA2O3 RF ELECTRONICS
Abstract
The ultrawide-bandgap Ga2O3 semiconductor shows promise as the next leap in high-power radiofrequency (RF) electronics. Despite intensive pursuit of Ga2O3 RF transistors in recent years, ample research opportunities remain in both materials and devices to improve key performance metrics. In this project, we will develop Ga2O3 hot-electron transistors (HETs) that harness non-equilibrium transport effects through heterojunction engineering to reduce carrier transit delay. During device operation, electrons are injected over a large emitter barrier into a base transit region where they travel at a very high velocity toward a collector barrier that filters low-energy electrons. Designing the base with a thickness less than the hot-electron mean free path serves to minimize scattering events and thus enable quasi-ballistic operation. These novel devices can theoretically exhibit superior high-frequency performance and will allow the first studies into the benefits of quasi-ballistic transport on the speed of Ga2O3 transistors. At the same time, the Ga2O3 HET is an effective spectroscopy tool for obtaining an in-depth understanding of hotelectron phenomena and ballistic transport physics that underlie device operation. To this end, the HET will be used as both an emitter and an analyzer of hot-electron momentum states to measure the hot-electron mean free path and to extract the launch and arrival energies of hot electrons at the emitter and collector barriers, respectively. Analytical and computational transport models will be developed to simulate the transfer characteristics of heterojunction barriers for comparison with experimental results. These tasks and objectives will be accomplished via synergistic collaboration with the Taiwan team, who will perform doping studies, band-offset measurements, and defect characterization using capacitance–voltage and admittance spectroscopy techniques to guide material growth by molecular beam epitaxy at AFRL. The outcomes of this research promise next-generation Ga2O3 RF devices with significantly higher frequency and power-handling capacity than the current state-of-the-art.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 17, 2022
- Source ID
- FA23862114071
Entities
People
- Man Hoi Wong
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Massachusetts