Low Frequency Noise of as-fabricated and Proton Irradiated Au-W/β-Ga₂O₃ Vertical Schottky Diodes

Gallium oxide has recently attracted a tremendous amount of research interest for applications in high-power electronics and clean energy innovations. Low frequency noise characterization is an important experimental tool for assessing the materials quality and reliability of wide-bandgap device technologies. In this work, we characterize the low-frequency noise of as-fabricated and proton-irradiated Au-W/β-Ga₂O₃ vertical Schottky barrier diodes at different forward bias voltages. We find that the current noise spectral density exhibits 1/f-type behavior for all forward bias voltages at low frequency indicating that the low frequency noise of these devices is dominated by excess noise. We also investigate the dependence of the current noise spectral density on forward bias current, revealing that different noise sources dominate in different current transport regimes. Using the noise figure of merit adapted for wide bandgap semiconductor devices, we find that the as-fabricated Au-W/β-Ga₂O₃ devices have similar noise levels as well-established technologies such as GaN. Furthermore, the as-fabricated and proton irradiated devices show similar noise levels, indicating that proton irradiation does not induce significant radiation damage in these devices. These findings contribute to a better understanding of electronic noise in Ga₂O₃-based Schottky diodes, serving as a valuable tool for assessing materials quality and device physics for energy applications in extreme environments.