Impact of the backside potential on the current collapse of GaN SBDs and HEMTs

This paper shows both experimentally and in simulation that the amount of current collapse for GaN SBDs and HEMTs strongly depends on the node to which the backside is connected, i.e., how the device is packaged, and the underlying physics is explained. It is shown that the difference in current collapse is not due to a difference in charge trapping. The reduction in current collapse for a backside-to-anode/source connection is due to a compensating switching charge that is not present when the backside is connected to the cathode/drain, for which stronger current collapse is observed.