In the laser annealing of silicon by Nd : YAG laser irradiation a dose dependence of the annealing threshold and final impurity depth distribution has been observed. Impurity depth distributions and damage profiles observed by Rutherford backscattering are consistent with the notion of the formation of a thin liquid layer and subsequent regrowth of the crystal upon cooling. We conclude that the annealing behavior is very sensitive to the time of formation of the liquid layer during the laser pulse.