Laser Short-Pulse Heating: Influence of Spatial Distribution of Absorption Coefficient on Temperature Field in Silicon Film

Abstract

Laser short-pulse heating of silicon film is considered and effect of the spatial distribution of absorption coefficient on electron and lattice site temperatures is examined. The high absorption region in the silicon film resembles the presence of absorbed particles in this region, since the absorption coefficient of silicon at the wavelength of the laser irradiation is significantly low. Electron and lattice temperatures are predicted using the electron kinetic theory approach. Three different spatial distributions of absorption coefficient are considered in the simulations. It is found that electron temperature attains the highest for the case of high absorption coefficient located in the surface region of the silicon film. As the high absorption region moves inside the film, electron and lattice temperatures become low.