The Role of Heat Treatment on Phase Transformation and Change the Electronic Properties of Silicon Films

In this study, amorphous silicon films were deposited by physical vapor deposition using electron beam (EBPVD). The process of deposition was carried out under high vacuum (torr 10-6) which led to the formation of an amorphous coating with controlled thicknesses. After sampling procedure, the samples were put under heat treatments at 800 oC under inert gas environment and their structural and electrical properties were analyzed before and after annealing conditions. The results obtained from microraman revealed the amorphous structure in the initial coatings which had been formed because of the increased thickness of the coating and due to the presence of more defects in nano-crystals. Moreover, we witnessed the development, growth, and integration of nano-crystals and formation of a poly crystal structure. Consequently, nano-crystals formation resulted in development of sp2 and sp3 bonds, which, in turn, increased the electrical conductivity of the coatings in that condition. Finally, as the thickness of the samples coatings increased, their electrical conductivity was also greatly enhanced.