In this study, the effect of p-NiO guard ring length on the properties of vertical GaN Schottky barrier diode was investigated extensively. The forward biased current-voltage characteristics of all diodes with different guard ring length follow the thermionic emission theory, showing nearly the same ideality factor and Schottky barrier height value. While the series resistance increases by nearly two times with the increasing guard ring lengths because the increasing depletion region at the p-NiO/n-GaN junction compresses the conduction path. Under reverse bias, the breakdown voltage of the SBD without any termination is relatively low due to the electric field crowding. The p-NiO guard ring is effective to enhance the breakdown voltage although the leakage current is comparable. However, the breakdown voltage decreases with the increasing guard ring length, which may be ascribed to the tunneling leakage caused by the imperfect p-NiO/n-GaN interface.

在这项研究中，广泛研究了p-NiO保护环长度对垂直GaN肖特基势垒二极管性能的影响。具有不同保护环长度的所有二极管的正向偏置电流-电压特性均遵循热电子发射理论，显示出几乎相同的理想因子和肖特基势垒高度值。随着保护环长度的增加，串联电阻几乎增加了两倍，这是因为p-NiO / n-GaN结上的耗尽区增加，从而压缩了导电路径。在反向偏置下，由于电场拥挤，没有任何端接的SBD的击穿电压相对较低。尽管泄漏电流相当，但p-NiO保护环可有效提高击穿电压。然而，