We have observed visible light emission from Co-silicided junctions by emission microscopy. It was found that leakage current across the junction was accompanied by weak emission of light arising from spots distributed spatially on the electrode. In addition, the emission characteristics depended on the annealing temperature of the metallization process. It can be concluded that a plausible leakage origin is anomalous diffusion of Co, resulting in a locally high electric field. We also measured the energy dependence of the emission intensity and found that the emission intensity increases with decreasing photon energy. ©1997 American Institute of Physics.