A Model for Low-Resistivity TiSi2 Formation on Narrow Polysilicon Lines.

We’re sorry, something doesn't seem to be working properly.

Please try refreshing the page. If that doesn't work, please contact support so we can address the problem.

Abstract

The sheet resistance of TiSi2 films formed on patterned sub-half micron n+ polysilicon lines has been observed to be higher than the sheet resistance of unpatterned blanket TiSi2 films. We have investigated this phenomenon, and determined that the TiSi2 thickness is not a function of linewidth, and that the resistivity increase in narrow n+ lines is caused primarily by incomplete phase transformation to the low-resistivity C54 phase. We have determined a physical model for the kinetics of this phase transformation, based on an Arrhenius-type atomic re-arrangement process, and we have determined an activation energy (Ea) of phase transformation for different linewidths. We have observed that this Ea increases non-linearly as a function of decreasing linewidth, contrary to conventional belief. We have hypothesized that this increase is due to increasing dominance of edge-related phenomena such as contaminant segregation, strain etc. Finally, we have demonstrated that by supplying this Ea through a high temperature (825°C) anneal, even applied for a short time (15 s), low sheet resistances (<4 Ω/ü) can be obtained down to 0.35 μ m lines.

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

References

  1. [1]

    Karen Maex. “Suicides for integrated circuits: TiSi2 and CoSi2”. Materials Science and Engineering, R11: 53, 1993.

    CAS  Google Scholar 

  2. [2]

    R.W. Mann and L. A. Clevenger. “The C49 to C54 Phase Transformation in TiSi2 thin Films”. J. Electrochem. Soc, 141(5): 1347, 1994.

    CAS  Article  Google Scholar 

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to Pushkar P. Apte.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Apte, P.P., Pollack, G. A Model for Low-Resistivity TiSi2 Formation on Narrow Polysilicon Lines.. MRS Online Proceedings Library 355, 539–544 (1994). https://doi.org/10.1557/PROC-355-539

Download citation