In conventional self-aligned nickel (Ni) silicide (SALICIDE) process, Ni silicidation is usually carried out by using tungsten–halogen lamp annealing and pn junction leakage current increases with the miniaturization of junction area and depth. The junction leakage is closely related to Ni-silicide thickness determined by absorption coefficient of infrared light from the halogen lamp. We proposed a new method for Ni silicidation based on natural convective heat transfer to the wafer and confirmed that this method can drastically improve the pattern dependence of pn junction leakage because of better uniformity of Ni-silicide thickness independent of pattern size of active areas.