Thermoelasticity effect on Si film irradiated by ultra-short pulse laser

An ultrafast thermoelasticity model for the thermomechanical behaviors in semiconductors irradiated by ultra-short pulse laser is presented based on the complete self-consistent model. It accounts for the coupling effect between lattice temperature and strain rate, as well as for the hot-electron-blast effect in momentum transfer. A finite difference method is developed for solving the coupled, nonlinear, transient differential equations under uniaxial strain condition. Numerical analysis is performed for a 2 μm silicon film heated by a 500 fs laser pulse to obtain the temporal and spatial evolution of the carrier temperature and density, the lattice temperature, the thermal stress and the hot-electron blast force. The results show that the ultrafast thermoelasticity effect has very littl