SiC-Emerging Power Device Technology for Next-Generation Electrically Powered Environmentally Friendly Vehicles

The automotive industry is developing a range of electrically powered environmentally friendly vehicles such as hybrid vehicles (HVs), plug-in hybrid vehicles, full electric vehicles, and fuel cell vehicles to help reduce tailpipe CO2 emissions and achieve energy diversification. HVs are regarded as one of the most practical types of environmentally friendly vehicle and have already been widely accepted in the market. Toyota Motor Corporation has positioned HV systems as a core technology that can be applied to all next-generation electrically powered environmentally friendly vehicles and is currently working to enhance the performance of HV system components. Because of its low loss and high-temperature operation properties, silicon carbide (SiC) is regarded as a highly promising material for power semiconductor devices to help reduce the size and weight of the power control unit, one of the key components of a HV system. Wide-ranging activities are under way to meet the challenges of adopting SiC in an automotive environment, such as the development of crystal growth technologies, device structures, process technologies, defect analysis, and application to on-board systems. This paper describes the current situation and future prospects for on-board SiC power devices and the development of SiC-based technologies.