Based on the low cost fabricated 650 V and 1200 V 4H-SiC Schottky barrier diode (SBD), technology computer-aided design (TCAD) of SBD model was calibrated to fit the measurement data. To achieve further performance improvement of a SBD, a novel junction barrier Schottky (JBS) diode structure that consists of a deep trench PN junction with dual-epitaxial layer process is proposed. Based on the calibrated TCAD SBD model, the new proposed dual-epitaxial trench JBS (DET-JBS) structure on the same overall epilayer thickness and doping as the fabricated 1200 V SBD, shows a 4 orders of magnitude lower leakage current and 45% higher breakdown voltage (BV). Moreover, achieving a low leakage JBS diode with 14% higher BV compared to the planar JBS, without scarifying on the forward voltage (VF) performance.