LASER SPECTROSCOPY METHODS FOR NONDESTRUCTIVE ANALYSIS OF POLYCRYSTALLINE SILICON THIN FILMS AND SILICON SURFACES

摘要

The laser spectroscopy method was used for nondestructive analysis of silicon thin films and surfaces with various orientations and morphologies. We estimated the crystalline volume fraction, porosity and average grain size by using Raman spectroscopy data. The electronic structure of polycrystalline silicon (poly-Si) film was studied by using laser picosecond spectroscopy which was set in pump-probe scheme for detection reflected signal. Measurements of correlation function as a function of delay time between the pump laser radiation and probe radiation are result of characterization the decay of career density on sample's surface. The quantum beats in time-resolved reflectivity measurements data were caused by relaxation of excited electrons from the surface or detect states in grain boundary of silicon crystal. The correlation between oxygen incorporation in film and evolution of correlation function was, also, studied.