High-Voltage Gallium Oxide Devices for Space Power Electronics - 20027

Future NASA science and exploration missions require significant performance improvements over the state-of-the-art in Power Management and Distribution (PMAD) systems. Space qualified, high voltage power electronics can lead to higher efficiency and significant SWaP-C advantage at the system architecture level and serve as an enabling technology for diverse applications. Gallium Oxide (Ga2O3) is an ultra-wide bandgap semiconductor technology with superior electronic properties for high-voltage power applications. Ga2O3 devices offer higher temperature operation, lower on-resistance, higher breakdown voltages, and higher power conversion efficiency than Silicon power devices. However, their performance in the space environment, including high-energy radiation and wide temperature fluctuations, is largely unknown. A thorough characterization and design effort is essential for advancing this technology to meeting NASA requirements. CFDRC, in collaboration with the University at Buffalo (UB), Vanderbilt University, and KYMA Technologies, will utilize a proven experimental and physics-based modeling approach to address this challenge. In Phase I, we performed irradiation testing for single event effects (SEEs) of -Ga2O3 power MOSFETs from UB (up to 8 kV rating), generated device response data, and identified potential handling/testing challenges with this technology. TCAD modeling of SEEs was performed for insight into physical mechanisms. In Phase II, we will perform additional heavy-ion testing as a function of temperature and bias. Extensive TCAD-based modeling will be performed to identify radiation and temperature dependent mechanisms, and device structure/process modifications for improved radiation tolerance. Promising solutions will be prototyped, tested, and delivered to NASA, along with a technology development roadmap. Participation by KYMA in Phase II and beyond will ensure manufacturability of the space-qualified, -Ga2O3 power MOSFET technology. NASA science and exploration missions require high-voltage power electronics that can reliably operate in the space radiation environment. Gallium Oxide (Ga2O3) is a promising new technology with superior electronic properties for high-voltage power applications. However, Ga2O3 devices need to be evaluated thoroughly for vulnerability to radiation effects. Recent R&D efforts have provided significant insight into heavy-ion induced failure mechanisms in other wide bandgap (WBG) devices. We propose to enhance and apply this knowledge to understand the mechanisms for ultra-WBG Ga2O3 devices, optimize their designs, and design and prototype devices to meet NASA targets. Innovations: (1) Insight into factors influencing the selection of Ga2O3 device technologies for NASA (voltage rating, safe operating areas, performance trade-offs); (2) Validated models of Ga2O3 devices for analysis and design; (3) Design guidelines to achieve radiation tolerance and electrical performance targets; (4) Prototypes of Ga2O3 device variants proven to meet NASA goals (TRL at end of Phase II: 4). (1) Characterize high-voltage Ga2O3 MOSFETs for electrical and radiation response via modeling and experiments, obtain insight into mechanisms; (2) Develop design guidelines for radiation-tolerant MOSFETs, build prototypes, and test; (3) Develop physics-based (TCAD) modeling capability for analyses and design of Ga2O3 devices. PHASE I RESULTS: (1) Performed baseline electrical characterization of MOSFETs; (2) Developed TCAD model of the device and verified against measured data; (3) Performed single-event effect (SEE) testing of devices and identified technology-related issues; (4) Performed TCAD simulations of SEEs as a function of device/operational parameters; (5) Derived plan for technology development in Phase II. PHASE II TASKS: (1) Fabricate new baseline Ga2O3 MOSFETs with improved layout and packaging; (2) Perform electrical and SEE testing; (3) Perform detailed TCAD simulations to understand/verify underlying mechanisms behind electrical and SEE response; (4) Perform extensive parametric simulations across design space, identify hardening guidelines; (5) Fabricate radiation tolerant variants of MOSFETs, verify performance via testing. PHASE II DELIVERABLES: (1) Data sets from electrical and SEE testing of Ga2O3 MOSFETs; (2) Verified TCAD models for the MOSFET; (3) Insight into mechanisms; (4) Design guidelines and improved MOSFET prototypes.
Benefits: Radiation tolerant, high voltage/high temperature Ga2O3 power electronics is an enabling technology for power management and distribution in spacecrafts and scientific instruments. It directly supports NASA goals for Lunar and Planetary Surface PMAD and the Kilopower program. It also benefits Remote Sensing Instruments and Sensors related to NASA Science and Exploration missions. The modeling and analysis tools for electronic qualification will be a Cross-Cutting Technology for all NASA missions requiring high voltage power electronics. Radiation tolerant Ga2O3 power electronics are applicable in DoD space systems (communication, surveillance, missile defense), commercial satellites, and nuclear power systems. High-voltage/high-temperature tolerant Ga2O3 power devices have applications in power conditioning systems (avionics and electric ships), solid-state drivers for heavy electric motors, PMAD and control electronics.