Interfacial characteristics of metal oxide-silicon carbide (MOSiC) structure with different thickness of SiO₂, thermally grown in steam ambient on Si-face of 4H-SiC (0 0 0 1) substrate were investigated. Variations in interface trapped level density ($D_{\text{it}}$) was systematically studied employing high-low (H-L) frequency $C–V$ method. It was found that the distribution of $D_{\text{it}}$ within the bandgap of 4H-SiC varied with oxide thickness. The calculated $D_{\text{it}}$ value near the midgap of 4H-SiC remained almost stable for all oxide thicknesses in the range of $10^9 –10^{10}$ cm^-2 eV^-1. The $D_{\text{it}}$ near the conduction band edge had been found to be of the order of 10¹¹ cm^-2 eV^-1 for thicker oxides and for thinner oxides $D_{\text{it}}$ was found to be the range of 10¹⁰ cm^-2 eV^-1. The process had direct relevance in the fabrication of MOS-based device structures.