Study of excimer laser induced melting and solidification of Si by time-resolved reflectivity measurements

In this paper we present the interpretation and analysis of time-resolved reflectivity measurements for excimer laser irradiated silicon. A nonequilibrium melting model is used to calculate the temperature distribution in the sample and the position of the solid-liquid interface. Calculations of the reflectivity of the probe beam are performed to obtain time-resolved reflectivity signals from basic principles, independent of the experiments, which can be compared with experimental data to reveal information about dynamics of the heating and cooling process. We propose more accurate methods for the determination of the melting threshold, the melt front position and the reflectivity of the sample for excimer laser light. From model calculations and experimental data we determine the reflectivity of the solid and liquid silicon for ArF excimer laser light.