Vertical Ga2O3 power devices
Energy efficient semiconductor switches for medium to high voltage converters in electric transportation systems and the power grid
About the Technology
The electrification of energy sources in every sector of our life, such as in electric cars and solar/wind power farms, calls for an increasingly efficient and more compact power conversion technology. Modern power converters use numerous semiconductor switches to modulate the form of electric power, for example, the power transistors inside the DC to AC traction inverters of the electric vehicle drivetrain. These semiconductor switches are traditionally made with silicon. However, by replacing silicon with materials with a larger bandgap that can handle higher power, the power loss in the conversion stage can be drastically reduced while shrinking the system footprint. In particular, Ga2O3 can potentially provide even better performance compared to other compound semiconductors at a fraction of the cost due to its larger bandgap and mature substrate melt-growth technology. Vertical power transistors are considered the holy grail of power semiconductors and are widely used in high-power applications. However, unlike SiC, a cost-effective and highly reliable high-performance vertical Ga2O3 transistor has not been demonstrated to date. Recently, we have proposed and demonstrated a novel vertical Ga2O3 device structure (patented as “Vertical Diffused Barrier Field-Effect-Transistor (VDBFET)”) that is poised to solve this problem. The HIT project aims to improve the breakdown voltage of the VDBFET prototype, paving the way for future generations of the device and nurturing its eventual commercialization.
K. Zeng, R. Soman, Z. Bian, S. Jeong and S. Chowdhury, "Vertical Ga2O3 MOSFET With Magnesium Diffused Current Blocking Layer," in IEEE Electron Device Letters, vol. 43, no. 9, pp. 1527-1530, Sept. 2022.