Breakdown of gate oxide of SiC-MOSFETs and Si-IGBTs under high temperature and high gate voltage

摘要

New results of gate oxide stress tests with the step-by-step increase of the gate voltage are shown for SiC-MOSFETs. In comparison to these results, a similar gate stress test was carried out for Si-IGBTs as well. For both tests, the test temperature was set to 150°C with the last voltage step leading to the intrinsic breakdown. The test was done for three different manufacturers of SiC-MOSFETs and two different manufacturers of Si-IGBTs. Different breakdown distributions for the different manufacturers of SiC-MOSFETs and IGBTs are shown. Only one manufacturer of SiC-MOSFETs shows a similar breakdown behavior like the IGBTs. For SiC-MOSFETs, a threshold voltage drift after the positive gate bias was found, different for the manufacturers.