Low Ron,sp.diff and Ultra-high Voltage 4H-SiC n-channel IGBTs with carrier lifetime enhancement process

In this paper, we report our latest development in 4H-SiC n-channel IGBTs. A blocking voltage of 15kV was achieved by a 150μm thick n-type drift layer and multiple field rings. In additional, a carrier lifetime enhancement process with a thermal oxidation process was applied to improve the forward conduction characteristics. After this process, the carrier lifetime was increased to about 3.05μs. The 4H-SiC n-channel IGBTs, with an active area of 1.06mm2, exhibited a forward voltage drop of 6.4V and a collector current of 1A with a gate bias of 20 V. At the 300W/cm2 power limit, the chip showed a forward voltage drop of 5.4V, with the collector current density of 55A/cm2 when V G of 20V, and a differential specific on-resistance of 21.2mΩ-cm2 on this point.