Structure design and characteristics analysis of 4H-SiC PiN switching diodes

A novel structure of 4H-SiC PiN switching diode with gradual changing doping concentration in n-base region is proposed in order to improve the switching characteristics. The device characteristics are simulated by ISE-TCAD. It is shown that there are about 30% increment in the softness parameters S and 10% shorter in reverse recovery time t
_rr
, compared with conventional SiC PiN switching diode with constant doping in n-base region. Simultaneously, as the conductivity modulation effect in the n-base region, the forward I-V characteristics are almost invariant.