Surface Pretreatment by Low-Temperature O-2 Gas Annealing for Performance Improvement in Pt/beta-Ga2O3 Schottky Barrier Diodes

We report a method for improving the electrical performance of Pt/beta-Ga2O3 Schottky barrier diodes (SBDs) through surface pretreatment using lowtemperature O-2 gas annealing. We found that subjecting the beta-Ga2O3 surface to 5 min of O-2 gas pretreatment at 400 degrees C before anode metal deposition resulted in an 18% increase in breakdown voltage (V-br) and a 42% improvement in power figure-of-merit (PFOM) compared to control devices. X-ray photoelectron spectroscopy (XPS) analysis revealed that the O-2 gas pretreatment caused the oxidation of the Ga2+ states on the surface, which increased the Schottky barrier height (q phi(b)) and improved the ideality factor of the SBDs. However, when the pretreatment time was extended to 15 min, we observed the evidence of the reduction process of the oxidized Ga2+, which resulted in a degraded Vbr and a reduced qfb of the SBDs. Overall, our findings suggest that low-temperature O-2 gas annealing is a promising approach for engineering the Schottky interface of beta-Ga2O3 SBDs and improving their performance.

Automated summary

We propose a method to enhance the electrical performance of Pt/beta-Ga2O3 Schottky barrier diodes (SBDs) by treating the surface with low-temperature O-2 gas annealing. The pretreatment of beta-Ga2O3 surface with O-2 gas for 5 minutes at 400 degrees C increases the breakdown voltage (Vbr) by 18% and improves power figure-of-merit (PFOM) by 42% compared to control devices. X-ray photoelectron spectroscopy (XPS) analysis reveals that O-2 gas pretreatment leads to oxidation of Ga2+ states on the surface, resulting in increased Schottky barrier height (q phi(b)) and improved ideality factor of the SBDs. However, prolonging the pretreatment time to 15 minutes leads to reduction of the oxidized Ga2+, causing degraded Vbr and reduced qfb of the SBDs. Overall, our study demonstrates the promising potential of low-temperature O-2 gas annealing for optimizing the Schottky interface of beta-Ga2O3 SBDs and enhancing their performance.