We present our findings on the utilization of a high permittivity dielectric, RESURF, in β-Ga2O3 trench Schottky barrier diodes. Our research demonstrates the achievement of ultra-low reverse leakage current in both small -scale and large-scale devices, with a breakdown voltage exceeding 1kV, thanks to the high-k RESURF technology. Furthermore, we assess the switching performance of these large-area devices and illustrate their competitive standing when compared to state-of-the-art commercial SiC devices. Additionally, we provide evidence of the superior thermal stability exhibited by high-k trench devices in comparison to SiC devices.