Influence of post-annealing on the mechanical and electrical properties of boron-doped nanocrystalline silicon thin films

This work presents the influence of post-annealing on mechanical and electrical properties of boron-doped hydrogenated nanocrystalline silicon (nc-Si:H) thin films deposited on Corning 7059 glass and Si substrate by plasma enhanced chemical vapor deposition (PECVD) technique. The basic mechanical properties of the films are measured by means of nanoindentation system. Using a four point resistivity test system, electrical properties of the films are characterized. It is found that, the value of elastic modulus and hardness of the films become larger after annealing. For those deposited by higher radio frequency (RF), the mechanical properties are enhanced notably. Annealing also affects the resistivity of films. With annealing temperature increasing, the resistivity of films decrease sharply. When annealing temperature up to 450degC, the resistivity of films become stable. Thin films still have a good quality at 500degC of annealing temperature and have a lowest resistivity.