The presence of F in amorphous films was reported to have a beneficial effect upon their electronic properties. Consequently, the diffusion parameters of this material were studied. A computer model was developed for amorphous Si, and molecular dynamics methods were used to simulate the process of F diffusion in amorphous material. The molecular dynamics were generated from first principles by using Si-Si and Si-F potentials. A new simulation scheme was proposed that generated amorphous Si samples directly from the crystalline phase. The model allowed for dangling bonds, vacancies and micro-voids. Such models could be used to determine bond strength distributions and diffusion mechanisms as functions of temperature and concentration.

A.Silverman, J.Adler, R.Weil: Thin Solid Films, 1990, 193/194, 571-6