The effect of original crystalline phase on solid phase crystallization of hydrogenated silicon thin films

Hydrogenated amorphous silicon (a-Si:H) and microcrystalline silicon (μc-Si:H) films fabricated on glass substrate are crystallized through solid phase crystallization process. In this study, the crystalline phase in μc-Si:H films could decrease process temperature, but prevent the film from crystallized completely. In counterpart, the a-Si:H films need higher annealing temperature to achieve crystallization, but could reach a better crystallinity. The fact that μc-Si:H films do not crystallize completely is attributed to the initial microcrystals in the μc-Si:H films, which avoid the relaxation of the film structure and inhibit the crystallization process. In addition, the effusion of hydrogen could promote the relaxation of a-Si but not induce direct crystallization.