Anomalous dynamic performance in heterogeneous Ga₂O₃-on-SiC MOSFETs fabricated using ion-implantation cutting process

Abstract We present the first investigation into the dynamic characteristics of heterogeneous Ga 2 O 3 -on-SiC (GaOSiC) MOSFETs fabricated using an ion implantation process. A noteworthy aspect of this study is the intriguing impact of performance optimization behavior within the Ga 2 O 3 layer under the quiescent drain voltage ( V D-qb ) stress. In contrast to the typical electron trapping-induced current collapse, the GaOSiC MOSFET exhibited an unexpected enhancement in current under specific V D-qb , which may be attributed to the residual hydrogen (H) induced by the ion-cutting process. By employing dynamic I-V testing, we observed conventional current collapse over a range of durations, spanning from microseconds (μs) to milliseconds (ms), under V D-qb stress. Nevertheless, as the duration of the V D-qb stress was extended to tens of milliseconds, an anomalous reduction in dynamic R ON was observed. We attribute this anomalous behavior to the configuration transition of H-related defects induced by the V D-qb stress, leading to an increased carrier concentration ( n e ) in Ga 2 O 3 . This performance enhancement behavior exhibits a significantly longer time constant when compared to the electron trapping process that typically leads to conventional current collapse. The activation energy ( E a ) for electron trapping in the devices subjected to milliseconds of V D-qb stress corresponding to the conventional current collapse behavior is determined to be 0.7 eV. Furthermore, we found that, at room temperature, electron trapping predominantly occurs within the first few milliseconds of V D-qb stress. However, at elevated temperatures, the electron trapping process extends over several tens of seconds (equivalent to thousands of V D-qb periods), continuously degrading dynamic R ON . Overall, our study provides novel insights into the dynamic performance of heterogeneous GaOSiC MOSFETs.