The kinetics of thermal desorption from an excimer laser-melted surface, where diffusion into the bulk competed with desorption, were analyzed numerically and were compared with experimental data (Auger electron spectroscopy, time-of-flight mass spectrometry, secondary-ion mass spectrometry, transient reflectivity) for Cl on Si. The model calculations involved non-equilibrium thermal diffusion, phase transitions, segregation, and first-order and second-order desorption kinetics. Upon assuming that the pre-exponential factors of the desorption rates did not change for the liquid surface, as compared with the solid one, activation desorption energies were found which were lower by about 0.5eV for the liquid surface than for the Si(100):Cl solid surface. This difference was of the same order of magnitude as the latent heat of melting. The segregation coefficient of Cl at the liquid/solid interface was less than 0.02 at a recrystallization speed of about 6m/s. The calculations also provided information on the dynamics of desorption and melting. The desorption rate from the liquid attained a value of about 1ML/ns, where ML was defined to be the density of atoms in a (100) plane.

B.Dragnea, J.Boulmer, J.P.Budin, D.Débarre, B.Bourguignon: Physical Review B, 1997, 55[20], 13904-15