Using a field-aided lateral crystallization technique, we were able to crystallize amorphous silicon films at temperatures in the range of 400 $sim$ 500 $^circ$C. Amorphous silicon films coated with a 50 AA-thick nickel catalyst, except for 120 $mu$m patterns, were furnace annealed in an applied electric field of 180 V/cm for 5 hours. A comparison between the field-aided lateral crystallization (FALC) process and the metal-induced lateral crystallization (MILC) process in which an electric field was not applied was also performed on identically prepared samples in order to study the effect of the electric field. The degree of crystallization reached 88 % at a temperature of 500 $^circ$C in case of the FALC process, and the crystallization velocity of the FALC sample at 500 $^circ$C was about 70 times faster than that of the MILC sample at the same crystallization temperature. In addition, reasonably fast crystallization was achieved in FALC samples even at 400 $^circ$C. The activation energies of the FALC process and the MILC process turned out to be 1.47 eV and 1.9 eV, respectively. Such a difference in the activation energy is attributed to the electric-field-enhanced diffusivity of Ni atoms during the crystallization procedure.