Crystallization of polycrystalline silicon thin film by excimer laser annealing, ELA

Silicon thin film is widely used as transistor. It performance depends on it crystal structure. The larger the crystallization the better the current flow. The goal of this work is to enhance the grain size. In the attempt, an amorphous silicon thin film was prepared by low pressure physical vapour deposition (PVD) and dopant by cooper. The silicon film was heat treated for four hours, using conventional oven. The treated silicon film was then annealed by using ultraviolet light of argon fluoride (ArF) excimer laser, at variable energy density. The microstructure of thin film was observed using metalurgical technique via FESEM, and the grain size was precisely measured via image processing using Matrox Inspector software. The results obtained indicated that, the grain size of the a-Si film is increases via energy density. The critical energy density is found to be at 352 mJ cm´2, and the corresponds optimum grain size is 120 nm. Beyond that limits, the crystallization is reduced due to the melting causing the reduction of grain size.