Disclosed are a MOS transistor having a low resistance ohmic contact characteristic and a manufacturing method thereof capable of improving a drive current of the MOS transistor. A gate oxide layer, a gate electrode, and a spacer are formed on a silicon substrate, and a silicon carbide layer is deposited thereon. A photolithography process is performed, and the silicon carbide layer is etched except for predetermined portions corresponding to source-drain regions and the gate electrode. Then, a metal layer is formed on the resulting structure after performing a source-drain ion implantation process. The metal layer is heated to form a salicide layer on the gate electrode and the source-drain diffusion regions. Then, the unreacted metal layer is removed, thereby forming the MOS transistor.