A thin semiconductor layer is formed and patterned on a semiconductor substrate to form a thin semiconductor fuselink on shallow trench isolation and between an anode semiconductor region and a cathode semiconductor region. During metallization, the semiconductor fuselink is converted to a thin metal semiconductor alloy fuselink as all of the semiconductor material in the semiconductor fuselink reacts with a metal to form a metal semiconductor alloy. The inventive electrical fuse comprises the thin metal semiconductor alloy fuselink, a metal semiconductor alloy anode, and a metal semiconductor alloy cathode. The thin metal semiconductor alloy fuselink has a smaller cross-sectional area compared with prior art electrical fuses. Current density within the fuselink and the divergence of current at the interface between the fuselink and the cathode or anode comparable to prior art electrical fuses are obtained with less programming current than prior art electrical fuses.