Skip to main content Accessibility help

A chemical role of refractory metal caps in Co silicidation: Evidence of SiO2 reduction by Ti cap

  • E. Kondoh (a1), T. Conard (a1), B. Brijs (a1), S. Jin (a1), H. Bender (a1), M. de Potter (a1) and K. Maex (a1)...


An interfacial SiO2 hampers a silicidation reaction between Co and Si. A refractory metal cap is believed to block ambient oxygen diffusing toward the Co/Si interface. However, an interfacial SiO2 can also be present prior to and/or during the annealing. This work reports on our findings of the interaction between SiO2 and Co layers capped with refractory metals. It was found that Ti diffuses through the Co layer and segregates underneath the Co, which leads to the reduction of SiO2 and the formation of free Si. The free Si in-diffuses and reaches the original Ti surface. On the other hand, TiN shows a very inert behavior compared to Ti. The results are discussed in connection with Co silicidation processes.



Hide All
1.Maex, K., Mater. Sci. Eng. R11, 53 (1993).
2.Dass, M.L.A, Fraser, D.B., and Wei, C., Appl. Phys. Lett. 58, 1308 (1991).
3.Hong, F., Rozgonyi, G.A., Patnaik, B.K., Appl. Phys. Lett. 64, 2241 (1994).
4.Vantomme, A., Nicolet, M-A., Bai, G., and Fraser, D.B., Appl. Phys. Lett. 62, 243 (1993).
5.Wang, Q.F., Lauwers, A., Jonckx, F., de Potter, M., Chen, C-C., and Maex, K., in Silicide Thin Films—Fabrications, Properties, and Applications, edited by Tung, R.T., Maex, K., Pellegrini, P.W., and Allen, L.H. (Mater. Res. Soc. Symp. Proc. 402, Pittsburgh, PA, 1996), p. 221.
6.Berti, A.C. and Bolkohovsky, V., in Proceedings of the 9th VLSI Multilevel Interconnection Conference (VMIC), Santa Clara, CA, June 9–10, 1992, p. 267.
7.Maex, K., Kondoh, E., Lauwers, A., Steegen, A., de Potter, M., Besser, P., and Proost, J., in Rapid Thermal and Integrated Processing VII, edited by Öztürk, M.C., Roozeboom, F., Timans, P.J., and Pas, S.H. (Mater. Res. Soc. Symp. Proc. 525, Pittsburgh, PA, 1998), p. 297.
8.Lauwers, A., Besser, P., de Potter, M., Kondoh, E., Roelandts, N., Steegen, A., Stucchi, M., and Maex, K., in International Interconnect Technology Conference, San Francisco, CA, June 1–3, 1998.
9.Besser, P.R., Lauwers, A., Roelandts, N., Maex, K., Blum, W., Alvis, R., Stucchi, M., and de Potter, M. in Advanced Interconnects and Contact Materials and Processes for Future Integrated Circuits, edited by Murarka, S.P., Eizenberg, M., Fraser, D.B., Madar, R., and Tung, R. (Mater. Res. Soc. Symp. Proc. 514, Warrandale, PA, 1998), p. 375.
10.Chen, B-S. and Chen, M-O., J. Electrochem. 141, 1931 (1994).
11.Swartz, J.C., Gigante, J.R., Costello, J.A., Burnell, D.M., and Ghoshtagore, R.N., J. Electron. Mater. 2, 171 (1990).
12.Morgan, A.E., Ritz, K.N., Broadbent, E.K., and Bhansali, A.S., J. Appl. Phys. 67, 6265 (1990).
13.Ho, H.L., Nguyen, T., Chang, J.C., Machesney, B., and Geiss, P., J. Mater. Res. 8, 467 (1993).
14.Nguyen, T., Ho, H.L., Kotecki, D.E., and Nguyen, T.D., J. Appl. Phys. 79, 1123 (1996).
15.Kondoh, E., Donaton, R.A., Jin, S., Bender, H., and Maex, K., Appl. Surf. Sci. 136, 87 (1998).
16.Kondoh, E., Vereecke, G., Heyns, M.M., Maex, K., Gutt, T., and Nényei, Z., in Rapid Thermal and Integrated Processing VII, edited by Öztürk, M.C., Roozeboom, F., Timans, P.J., and Pas, S.H. (Mater. Res. Soc. Symp. Proc 525, Warrandale, PA, 1998), p. 51.
17.Hansen, M., Constitution of Binary Alloys (McGraw-Hill, New York, 1958);
Hansen, M., Constitution of Binary Alloys, 2nd supplement (McGraw-Hill, New York, 1969).
18.Smithells Metals Reference Book, 6th ed. (Butterworth, London, 1983).
19.Liu, P., Li, B-Z., Sun, Z., Gu, Z-G., Huang, W-N., Zhou, Z-Y., Ni, R-S., Lin, C-L., Zou, S-C., Hong, F., and Rozgonyi, G.A., J. Appl. Phys. 74, 1700 (1993).
20.CRC Handbook of Physics and Chemistry, 64th ed. (CRC, Boca Raton, FL, 1983).
21.Lee, H.S. and Wolga, G.J., J. Electrochem. Soc. 137, 2618 (1990).
22.Properties of Silicides, edited by K. Maex and M. Van Rossum (INSPEC, London, 1995).
23.Landolt–Börnstein, Numerical Data and Functional Relationships in Science and Technology, edited by O. Madelung and W. Martienssen (Springer-Verlag, Berlin, 1990), Group 3, Vol. 26.


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed