Samples were implanted with 500keV S ions, through 120nm-thick films of amorphous hydrogenated Si, to give a concentration of 2 x 1020/cm3. They were then annealed (700 to 1000C, 0.25h, Ar). It was found that the diffusivity of the S decreased with increasing implantation dose (figure 1).

M.Sakaguchi, K.Yokota, A.Shiomi, H.Mori, A.Chayahara, Y.Fujii, K.Hirai, H.Takano, M.Kumagai: Japanese Journal of Applied Physics, 1996, 35[1-3], 1624-9