Effects of an external electric field during annealing on the Ni- and Nb-silicide formation were investigated. Formation of Nb- and Ni-silicides can be accelerated or retarded in the presence of an external electric field during the annealing. It was found that enhancement of silicidation depends not on the polarity of the applied voltage, but on V . The activation energies E a of Nb-silicides are found not be affected by the applied voltage, but the pre-exponential factors L 0 of the linear reaction rate constant are found to be 1.1 10 6 and 6.3 10 7 cm/s for 0 and ±1 kV, respectively.