Polycrystalline silicon thin films processed with silicon ion implantation and subsequent solid-phase crystallization: Theory, experiments, and thin-film transistor applications

TLDR: In this article, a review of the self-implantation method for polycrystalline silicon thin transistors is presented, and the mechanism of selective amorphization by the silicon self implantation and the crystallization by thermal annealing is discussed.

Abstract: A review is presented of the self‐implantation method which has been developed to achieve high‐quality polycrystalline silicon thin films on insulators with enhanced grain sizes and its applications to thin‐film transistors (TFTs). In this method, silicon ions are implanted into an as‐deposited polycrystalline silicon thin film to amorphize most of the film structure. Depending on ion implantation conditions, some seeds with 〈110〉 orientation remain in the film structure due to channeling. The film is then thermally annealed at relatively low temperatures, typically in the range of 550–700 °C. With optimized process conditions, average grain sizes of 1 μm or greater can be obtained. First, an overview is given of the thin‐film transistor technology which has been the greatest motivation for the research and development of the self‐implantation method. Then the mechanism of selective amorphization by the silicon self‐implantation and the crystallization by thermal annealing is discussed. An analytical mode...