Effects of Deep Trapping States at High Temperatures on Transient Performance of AlGaN/GaN Heterostructure Field-Effect Transistors

Kinetic studies on the current collapse of a normally-OFF AlGaN/GaN heterostructure field-effect transistor under a high voltage have been performed above room temperature. The ON-state resistance after the ON switching from the OFF state increases at high temperatures, contrary to the expectation that the emission of electrons is enhanced at elevated temperatures. This result indicates that elevating the temperature enhances not only the emission of electrons but also their capture. We experimentally observe that the enhancement of the capture process at high temperatures originates from the energy barrier for the capture of electrons, the value of which is determined to be $0.17\pm 0.04$ eV. The origin of the energy barrier for the capture process is explained by a configuration coordinate diagram.