The team has developed a novel MOS gate stack technology based on high-k dielectrics for SiC Power MOSFETs replacing today´s SiO2 gate oxides. The conventional gate oxide is a weak point of today´s SiC MOSFETS as it suffers from highly defective oxide/SiC interfaces and the intense electric field across the gate oxide negatively impacts device performance as well as reliability. The innovation has been successfully verified and demonstrated by fabricating fully functional vertical high-k power SiC MOSFETs for several voltage classes, namely 1.2kV, 1.7kV and 3.3kV. The on-state performance could be improved by 35% compared to devices with SiO2 gate oxide, and improved threshold voltage stability could be demonstrated. The devices with the developed high-k gate stack technology show virtually no Vth-shift during static as well as dynamic characterization. A major impact can be expected from this significantly improved SiC MOSFET technology which will boost high performance SiC power electronics with improved energy efficiency in several applications including e-mobility.
This year's SEMIKRON Young Engineer Award is given to Michael Basler from Fraunhofer Institute for Applied Solid State Physics IAF in Freiburg, Germany for his work on ‘Monolithic Integration for GaN Power ICs’.
GaN power ICs technology combines the wide bandgap performance with a lateral structure and a low-cost Si carrier substrate. A common GaN power integration technology platform with several active and passive devices, as well as analog and digital circuits has been intensively investigated. These building blocks can be used to integrate periphery components of the power electronics systems to the GaN power devices consisting of driving, sensing, protection, control, interface, and auxiliary power supply.
The researcher has pushed the GaN-on-Si technology by pioneering concepts and demonstrated two innovative monolithic-integrated GaN power ICs with outstanding performance, a synchronous buck converter with half-bridge, driver and control for highly-compact DC-DC conversion as well as an active rectifier diode with power switch, control and auxiliary power supply for highly-compact AC-DC rectification.
The innovation is a milestone towards further spread of the GaN power IC technology in applications and products, not only enabling superior performance, but also low cost, high efficiency and low consumption of resources and energy.