A research group led by Jun Suda and Tsunenobu Kimoto, associate professor and professor, respectively, at the Graduate School of Engineering, Kyoto University, prototyped a silicon carbide (SiC)-based BJT (bipolar junction transistor) whose withstand voltage is higher than 20kV.
The university claims that the withstand voltage is the world's highest. The group announced an SiC-based PiN diode with a withstand voltage of 21.7kV in June 2012.
The withstand voltage of a common power transistor using silicon (Si) can be about only 6k to 8kV due to limitations related to its physical properties. On the other hand, with SiC, which is resistant to insulation breakdown and heat, it is easier to realize a voltage higher than that of a Si-based power transistor.
This time, the group achieved the withstand voltage of 20kV by using a structure that mitigates electric field concentration caused by applying a high voltage and a surface protection technology in addition to SiC.
The latest results were published on the November 2012 issue of Electron Device Letters (EDL).