Provided is an e-fuse structure of a semiconductor device. the e-fuse structure may include a fuse link formed of a first metal material to connect a cathode with an anode, a capping dielectric covering a top surface of the fuse link, and a dummy metal plug penetrating the capping dielectric and being in contact with a portion of the fuse link. The dummy metal plug may include a metal layer and a barrier metal layer interposed between the metal layer and the fuse link. The barrier metal layer may be formed of a second metal material different from the first metal material.