Effective suppression of current collapse in AlGaN/GaN high-electron-mobility transistors
Gallium nitride (GaN) with its wide bandgap of 3.4 eV is considered as a key semiconductor material for realizing ultra-low-loss power devices. However, GaN-based devices are still plagued by current collapse, which is the temporary reduction of current after application of high voltage and/or power stress, and widely believed to be due to the capture of electrons in traps. Due to the GaN wider band gap, a more extensive variety of traps having longer associated time constants can exist in this material. In addition, the high critical electric field of GaN has facilitated operation up to hundreds of volts for GaN-based devices, leading to extreme charge injection and trapping of carriers. In this work we present some of the measures we are undertaking to combat the current collapse phenomenon towards the widespread acceptance and implementation of GaN-based devices.