Laser Short-Pulse Interaction of Aluminum and Silicon Films

In the present study, laser short-pulse heating of an aluminum film surface which is attached to a silicon film is examined. The two-equation model including the phonon diffusion is used to determine electron and phonon temperatures in the aluminum film while radiative phonon transport is incorporated to determine equilibrium temperature in the silicon film. Since electron diffusion from the aluminum film interface to the silicon film interface does not take place, only the phonon transport is considered across the interface. The thermal boundary resistance at the interface is incorporated in the analysis. The transfer matrix method is used to determine the photon absorption in the aluminum film due to the laser irradiation pulse. It is found that phonon temperature decays sharply in the aluminum film toward the interface due to the presence of the thermal boundary resistance. The reflected radiative phonons from the hack surface of the silicon film modify temperature distribution in the neighborhood of the silicon film interface.