Experimental Investigations on Parasitic Turn-on of 1.2kV SiC MOSFET Discrete Devices

Abstract:
The paper presents detailed experimental investigations on Parasitic Turn-on (PTO) of 1.2 kV SiC MOSFETs discrete devices in TO247-4L package. PTO correlation to capacitance profiles is shown using two devices with different Ciss/Crss ratios. Key focuses are on the devices that are highly susceptible to PTO for better understanding the device behavior under PTO. Investigations include the approach for measuring the non-trivial HS VGS pull-up signal during BD turn-off and its correlation to measured current. PTO dependent on different Rg_ext will be shown to demonstrate the effectiveness of this method to evaluate device’s PTO ruggedness. PTO measurements at high temperature will also be presented and compared to PTO at RT. Interesting effect of reduced PTO at high temperature compared to RT is presented.