A novel technique to achieve non-thermal annealing of implanted semiconductor dopants is proposed on the basis of photon-induced phonon excitation process as low-temperature nano-surface modification of semiconductors. The present approach is based on the concept that the energy required for re-crystallization and activation of the dopants is supplied to the dopant layer via nonequillibrium adiabatic process induced by ultra-short pulse laser irradiation at room temperature. Ultra-short pulse laser beam with a pulse duration of 100 fs has been used in the present study for investigations on phonon excitation features via pump-probe measurement of reflectivity and for demonstration of room-temperature re-crystallization and activation of ion-implanted silicon substrates.