Effective surface diffusion of nickel on single crystal β-Ga2O3 for Schottky barrier modulation and high thermal stability

β-Ga2O3 Schottky barrier diodes (SBDs) were demonstrated with Ni Schottky contact deposited by the confined magnetic field-based sputtering (CMFS) method. A shallow interfacial layer was formed by the diffusion of Ni into β-Ga2O3 after post-annealing treatment, which significantly influenced the electrical performance of the CMFS-Ni/β-Ga2O3 SBDs. The CMFS method was used to vary the Schottky barrier height and the ideality factor from 0.84 to 1.33 eV and 1.20 to 1.04, respectively. The leakage current of the CMFS-SBDs was only 10% of the leakage current using E-beam Ni-based SBDs, and the thermal stability of the CMFS-SBDs also was much higher than that of the E-beam Ni SBDs. We confirmed that the effective diffusion of Ni atoms could substitute for Ga through the activation of the β-Ga2O3 with CMFS.