Investigations of SiC VDMOSFET With Floating Island Structure Based on TCAD

摘要

Using TCAD simulations, the silicon carbide metal-oxide-semiconductor field-effect transistor with p-type floating islands (SiC FLIMOSFET) is systematically investigated in this paper. The doping concentration (N-FLI), length (L), and position (D1) of floating islands are optimized according to breakdown voltage (BV), electric field distribution, and on-resistance. The results show that N-FLI = 1 x 10(17) cm(-3), L = 2.5 mu m, and D1 = 9.0 mu m are superior values for FLI structure considering tradeoff between BV and on-resistance. With the same BV capacity, the on-resistance of SiC FLIMOSFET is decrease by 32% comparing to the conventional SiC VDMOSFET. Besides, the dynamic property shows 16.5% reduction of FoM R-on . Q(GD) in the SiC FLIMOSFET. Significantly, comparing to the conventional structure, the electro-thermal simulation indicates that the SiC FLIMOSFET has a higher robustness under short-circuit condition owing to the reduction of thermal stress in SiC/SiO2 interface. All the results show that the SiC FLIMOSFET has a good potential in SiC power device.