Status and Prospects of SiC Power Devices

抄録

Silicon Carbide (SiC) power devices offer significant benefits of improved efficiency, dynamic performance and reliability of electronic and electric systems. The challenges and prospects of SiC power device development are reviewed considering different device types. A close correlation between an exponential increase of current handling capability during the last ten years and improvement in substrate quality is demonstrated. The voltage range of silicon and SiC unipolar and bipolar power devices with respect to the on-state voltage is determined based on device simulations. 4H-SiC unipolar devices are potentially superior to all silicon devices up to 5kV design voltage and to all SiC bipolar devices up to 5-6kV design voltage for temperatures up to 150°C. The low end of SiC unipolar devices is determined to be around 200V design voltage provided substrate resistance is reduced by reducing the thickness of the substrate down to 100μm. The influence of reduced channel mobility on the specific on-resistance of 4H-SiC and 3C-SiC DMOSFETs is shown. It has been demonstrated that 3C-SiC DMOSFETs could be a better choice compared to 4H-SiC DMOSFETs in the voltage range below 1.2kV utilising better channel mobility and larger substrate size obtainable in the near future in 3C-SiC polytype. An impact of the super junction (SJ) concept on silicon and SiC MOSFET specific on-resistance limits is demonstrated.