Improvements on Dynamic On-State Resistance in Normally-off GaN HEMTs

The use of gallium nitride (GaN) wide-bandgap power semiconductors with small on-state resistance and small parasitic capacitances promises minimized conduction and switching losses in power electronic converters. The increase of the dynamic on-state resistance in normally-off GaN High Electron Mobility Transistors (HEMT) related to charge trapping and hot electron injection directly affects conduction losses and reduces the achievable benefit of GaN devices in power electronics. This paper demonstrates that the extend of dynamic Ron-increase significantly depends on the operation conditions and exemplarily shows recent improvements of commercially available devices.