Power cycle method for accelerating bipolar degradation of SiC MOSFET body diode

Abstract

The invention discloses a power cycle method for accelerating bipolar degradation of a SiC MOSFET body diode, and the method comprises the steps: firstly determining a proper repeated surge current, and carrying out temperature evaluation of power cycle at normal temperature and high temperature; carrying out repeated surge current power cycle test on the body diode of an SiC MOSFET discrete device I at normal temperature; performing repeated surge current power cycle test on the body diode of an SiC MOSFET discrete device II of the same model at a high temperature; when the body diodes of theSiC MOSFET discrete device I and the SiC MOSFET discrete device II are aged to a certain degree, measuring degradation of static characteristics (forward IV characteristics) and dynamic characteristics (reverse recovery current waveform) of body diodes of the SiC MOSFET discrete device I and the SiC MOSFET discrete device I Repeated surge current power circulation at high temperature overcomes the limitation of direct current stress power circulation, is simple to control and high in reliability, has no continuous heat accumulation in the power circulation period, has no influence on packaging characteristics, can be carried out in a high-temperature environment, improves the aging efficiency and accelerates bipolar degradation.

Description

technical field [0001] The invention belongs to the field of SiC power semiconductor devices, in particular to a power cycle method for accelerating bipolar degradation of SiC MOSFET body diodes. Background technique [0002] Compared with the semiconductor Si material, the wide bandgap semiconductor SiC has a larger band gap (3 times that of Si), a higher thermal conductivity (3 times that of Si), a higher electron saturation velocity (2 times that of Si), etc. Excellent material properties, stronger temperature resistance and higher applicable frequency, are widely used in power electronic systems with high power density and high conversion efficiency. However, SiC bipolar power devices have the problem of bipolar degradation. When electron and hole recombination occurs in SiC power semiconductor devices for a long time and the recombination energy exceeds a certain value, SiC power semiconductor devices will age, and the pre-existing basal plane position Fault (BPD) expa...

AI Technical Summary

Problems solved by technology

The power cycle test control in this test method is complex and costly. Real-time junction temperature monitoring and more complex switch control are required to avoid the impact of factors such as thermal runaway on the package, and it is usually carried out at room temperature, and the aging efficiency is low.

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