Transient optical transmission measurement in excimer-laser irradiation of amorphous silicon films

The transient temperature field development during heating of an amorphous silicon (a-Si) film, deposited on a fused quartz substrate, by pulsed excimer laser irradiation is studied. Static reflectivity and transmissivity measurements are used to obtain the thin film optical properties at elevated temperatures. Experimental in-situ, transient, optical transmission data are compared with heat transfer modeling resullts. The variation with temperature of the material complex refractive index across the thin film thickness is taken into account. The effects of the film thickness and thermal diffusivity, as well as of the laser pulse shape, are discussed