Fabrication and evaluation of high voltage n-type 4H-SiC Schottky barrier diodes (SBDs) using 27μm thick epitaxial layers were presented. To achieve the ideal value of the breakdown voltage, various parameters of junction termination extension (JTE) were investigated. We concluded that the termination of triple rings with the concentrations of 6×1017, 3×1017, 1.5×1017cm−1 outwardly was best with the simulations. The SBDs with this termination showed the blocking voltage up to 3.4kV, which is almost the ideal value. We also investigated the distribution of leakage currents at -600V in SBDs with various diameters up to 4mm. High yield was obtained in the SBDs with the diameters below 2mm. The SBDs with high leakage currents showed the excess currents in the low forward voltage region and lots of bright spots could be observed by optical beam induced current analysis.