10089219Innovations in SiC Power MOSFET Gate technology through the use of ALD oxidesActiveCollaborative R&DInnovate UKSilicon carbide (SiC) power metal-oxide-semiconductor field effect transistors (MOSFETs) are being widely adopted in electric vehicle (EV) power conversion applications. After adoption by Tesla, Hyundai, and many other OEMs, SiC MOSFETs have been proven a more efficient alternative to legacy silicon power devices, leading to the rapid expansion of the SiC industry. Hitachi Energy Switzerland ('Hitachi') has a proven track record of developing automotive grade SiC power MOSFETs with a reputation for products with novel MOS interfaces. Oxford Instruments Plasma Technology ('OIPT') have developed a novel oxide deposition process that uses a remote plasma source in a commercial atomic layer deposition (ALD) system. It was demonstrated that this process is highly suitable for the formation of gate oxides in wide bandgap semiconductors. A research team at the University of Warwick ('UoW') has recently developed an ALD silicon dioxide (SiO2) deposition process on SiC that has the potential to be commercialised. This project will bring together the three groups and their relative expertise to demonstrate the potential of ALD oxides in the formation of EV-grade 1.2 kV SiC MOSFETs. The motivation behind this project is to address one of the most pressing issues in the adaptation of this technique by fundamentally changing the way of forming a crucial part of the device, the gate oxide. Conventional dielectric/SiC interfaces are suffering from high density of defect states, hampering the further uptake of this technology. This proof-of-concept project will demonstrate the viability and advantages of utilising ALD deposited oxides (SiO2 and high-k dielectrics such as aluminium oxide, Al2O3) in a commercial SiC MOSFET device. Key outputs of the project will include: \* The first demonstration of a commercially relevant planar 1.2 kV SiC MOSFET that contains OIPT's remote plasma ALD-deposited silicon dioxide (SiO2) and high-k dielectric (e.g. Al2O3) gate oxides. \* A demonstration of the excellent interface quality (e.g. high channel mobilities due to low density of interface traps) in these structures through extraction of key performance indicators such as specific on-resistance or channel mobilities. Demonstration of process benefits by benchmarking with existing commercial products. \* Long-term reliability testing on the demonstrator MOSFETs will demonstrate whether the ALD oxides remain stable over the lifetime of a commercial automotive semiconductor product. \* Integration of the novel ALD oxidation process into a research-grade trench MOS capacitor and trench MOSFET structure.