The effect of oxidation temperature on interfacial properties of n-type 4H-SiC metal-oxide-semiconductor capacitors has been systematically investigated. Thermal dry oxidation process with three different oxidation temperatures 1200 degrees C, 1300 degrees C and 1350 degrees C were employed to grow SiO2 dielectric, following by the standard post-oxidation annealing (POA) in NO ambience at 1175 degrees C for 2 h. The root mean square (RMS) roughness measured by Atomic Force Microscopy for the thermally grown SiO2 before POA process is reduced with increasing the oxidation temperature, obtaining an atomically flat surface with a RMS of 0.157 nm from the sample oxidized at 1350 degrees C. Several kinds of electrical measurements were used to evaluate the densities of near interface traps and effective fixed dielectric charge for the samples, exhibiting a trend reduced with increasing the oxidation temperature. The interface state density of 3 x 10(11) cm(-2)eV(-1) at 0.2 eV from the conduction band edge was achieved from conductance method measurement for the sample oxidized at 1350 degrees C. The results from Secondary Ion Mass Spectroscopy and X-ray Photoelectron Spectroscopy demonstrate that high oxidation temperature can reduce the width of transition layer, the excess Si and silicon suboxide compositions near the interface, leading to,effective improvement of the interfacial properties. (C) 2016 Elsevier B.V. All rights reserved.