【Device Papers】Investigating Reverse Low-Bias Conduction Mechanisms in Ga₂O₃ Schottky Barrier Diodes Using Pulsed Current Methods

      Researchers from the Korea Aerospace University have published a dissertation titled "Investigating Reverse Low-Bias Conduction Mechanisms in Ga₂O₃ Schottky Barrier Diodes Using Pulsed Current Methods" in ACS Applied Electronic Materials.

Abstract

      This study presents a comparative analysis of direct current (DC) and pulsed current (PC) measurement methods applied to Ga₂O₃ Schottky barrier diodes (SBDs), particularly under reverse bias conditions. Significant discrepancies between the two methods are observed for Ga₂O₃ SBDs, while commercial Si SBDs show no noticeable differences under comparable conditions. The discrepancies are attributed to the wide bandgap characteristics of Ga₂O₃, which result in deeper trap levels and more pronounced charge trapping and detrapping behavior compared to Si. PC measurements of Ga₂O₃ SBDs reveal two distinct conduction regions: Schottky emission dominates at low reverse bias, while Fowler–Nordheim (FN) tunneling becomes the primary conduction mechanism at higher reverse bias. Time-dependent trapping effects are further investigated by varying the pulse width time (T_w). The results show that as T_w increases, the reverse current decreases and eventually saturates. This behavior highlights the influence of trapped charges, which impede the flow of subsequent electrons and reduce the overall current density. The effective Schottky barrier height determined by the Schottky emission is found to be highly sensitive to the trapped charges, while the barrier height obtained by FN tunneling remains largely unaffected. This work highlights the importance of utilizing dynamic measurement techniques, including PC, to accurately characterize the intrinsic properties of wide-band gap semiconductors like Ga₂O₃. In addition, the insights gained into the interplay between the Schottky emission and FN tunneling provide valuable guidance for optimizing the performance and reliability of Ga₂O₃-based devices in high-power and high-frequency applications.

DOI：

https://doi.org/10.1021/acsaelm.5c00134