Annealing effects on the optical and structural properties of Si thin films deposited by ion beam sputtering technique

The silicon thin films has been prepared on glass substrates at room temperature by ion beam sputtering technology using Si targssset (99.999% purity) and then are annealed at different temperatures ranging from 150 degrees C to 450 degrees C for 24 h under vacuum conditions. The effects of the annealing temperatures on the optical and structural properties of the Si thin films were studied. The results show that the refractive index, extinction coefficient and forbidden band width of the Si thin films show a downward trend with the increase of annealing temperature, resulting in a significant improvement in the absorption of the Si thin films in the visible and near-infrared region. The roughness has the same trend. However, the crystal structure and surface morphology of the Si thin films have not changed significantly after annealed. The research indicates that annealing treatment can effectively change the optical properties and structural properties of the Si thin films which has guiding significance for the selection of optimal heat treatment temperature for Si film modification.