Dopant diffusion in amorphous silicon


In this work we investigate the diffusion of high-concentration ultrashallow boron, fluorine, phosphorus, and arsenic profiles in amorphous silicon. We demonstrate that boron diffuses at high concentrations in amorphous silicon during low-temperature thermal annealing. Isothermal and isochronal anneal sequences indicate that there is an initial transient enhancement of diffusion. We have observed this transient diffusion characteristic both in amorphous silicon preamorphized by germanium ion implantation and also in amorphous silicon preamorphized by silicon ion implantation. We also show that the boron diffusivity in the amorphous region is similar with and without fluorine, and that the lack of diffusion for low-concentration boron profiles indicates that boron diffusion in amorphous silicon is driven by high concentrations. Ultrashallow high-concentration fluorine profiles diffuse quite rapidly in amorphous silicon, and like boron, undergo a definite transient enhancement. In contrast, ultrashallow high- concentration phosphorus and arsenic profiles did not significantly diffuse in our experiments.

This is a preview of subscription content, access via your institution.


  1. 1.

    S. P. Jeng et al, Appl. Phys. Lett. 61, 1310 (1992).

    CAS  Article  Google Scholar 

  2. 2.

    M. Y. Tsai et al, J. Appl. Phys. 50, 188 (1979).

    CAS  Article  Google Scholar 

  3. 3.

    S. Solmi et al, J. Appl. Phys. 69, 2135 (1991).

    CAS  Article  Google Scholar 

  4. 4.

    R. Fair, J. Electrochem. Soc. 137, 667 (1990).

    CAS  Article  Google Scholar 

  5. 5.

    R. Angelucci et al, J. Electrochem. Soc. 134, 3130 (1987).

    CAS  Article  Google Scholar 

  6. 6.

    J. M. Jacques et al, Appl. Phys. Lett. 82, 3469 (2003).

    CAS  Article  Google Scholar 

  7. 7.

    R. Duffy et al, Appl. Phys. Lett. in press (2004).

    Google Scholar 

  8. 8.

    S. Pantelides, Solid State Communications 84, 221 (1992).

    CAS  Article  Google Scholar 

  9. 9.

    S. Roordaet al, Phys. Rev. B 44, 3702 (1991).

  10. 10.

    S. Roorda et al, Phys. Rev. Lett. 62, 1880 (1989).

    CAS  Article  Google Scholar 

  11. 11.

    R. G. Elliman et al, IEEE Conf. on Ion Impl. Tech. 1998, p.1055.

    Google Scholar 

  12. 12.

    G. R. Nash et al, Appl. Phys. Lett. 75, 3671 (1999).

    CAS  Article  Google Scholar 

  13. 13.

    D. C. Streit et al, J. Vac. Sci. Technol. B 5, 752 (1987).

    CAS  Article  Google Scholar 

  14. 14.

    S. Coffa et al, Phys. Rev. B 45, 8355 (1992).

    CAS  Article  Google Scholar 

  15. 15.

    R. A. Street et al, Philos. Mag. B 56, 305 (1987).

    CAS  Article  Google Scholar 

  16. 16.

    A. Y. Kuznetsov et al, Appl. Phys. Lett. 66, 2229 (1995).

    CAS  Article  Google Scholar 

  17. 17.

    A. Nylandsted Larsen et al, J. Appl. Phys. 73, 691 (1993).

    Article  Google Scholar 

  18. 18.

    A. Agarwal et al, Appl. Phys. Lett. 74, 2331 (1999).

    CAS  Article  Google Scholar 

  19. 19.

    P. M. Zagwijn et al, J. Appl. Phys. 76, 5719 (1994).

    CAS  Article  Google Scholar 

  20. 20.

    D. J. Eaglesham et al, Appl. Phys. Lett. 65, 2305 (1994).

    CAS  Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to R. Duffy.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Duffy, R., Venezia, V., Heringa, A. et al. Dopant diffusion in amorphous silicon. MRS Online Proceedings Library 810, 25–30 (2003).

Download citation