Investigating the Effect of Voltage and Current Stress on Temperature Dependent On-State Resistance in GaN HEMT Power Devices

Abstract:
The temperature-dependent on-state resistance Rds,on of GaN devices can be affected by charge trapping caused by current or voltage stress. A commercial 600V GaN GIT device has been evaluated in this respect under conditions of hard switching and pure current mode. It has been observed that, in contrast to non-monotonic behaviour exhibited under voltage stress, on-state resistance Rds,on shows a low sensitivity to current influence and a fairly linear temperature depedence in pure current mode. This characteristic permits to reasonably use Rds,on as a temperature sensitive electrical parameter (TSEP) in GaN devices, e. g. for the purpose of thermal characterisation.