Preparation of Polycrystalline Silicon Films by Aluminium Induced Crystallization at Low Temperatures

The preparation of high quality polycrystalline silicon films at low temperature (600℃) has been recently become one of the hot spots, owing to the requirement of preparing polycrystalline silicon thin film transistors in the active matrix liquid crystal display on the substrate of common glass. In this paper, the new process for crystallization of amorphous silicon films, named the metal induced lateral crystallization of amorphous silicon films at low temperatures, was developed. Aluminium thin films were evaporated on the top of the amorphous silicon films and selectively formed by photolithograph. The films were subsequently annealed in N2 atmosphere. The crystallization mechanism of a-St thin film by Al induced was discussed. The results show that the amorphous silicon right under the Al layer can be crystallized by annealing at 560℃ for 6h and the thin films are polycrystalline silicon thin films.