In our previous studies, thin Ti-rich layers were found to uniformly cover SiO2/Si substrate surfaces at the interface with Cu(Ti) alloy films after annealing at elevated temperature. These Ti-rich layers were also found to prevent intermixing between the Cu(Ti) alloy films and the substrate, resulting in a simple barrier formation technique, called “self-formation of the diffusion barrier,” which is attractive for fabrication of ultra-large scale integrated (ULSI) interconnect structures. In the present study, to understand the mechanism of self-formation of the Ti-rich barrier layers on the substrate surface, the effects of SiO2/Si, SiN/SiO2/Si and NaCl substrate materials on the interfacial microstructure were investigated. The microstructures were analyzed by transmission electron microscopy (TEM) and secondary ion mass spectrometry (SIMS), and correlated with the electrical properties of the Cu(Ti) interconnects. It was concluded that the chemical reaction of Ti with the substrate materials was essential for the self-formation of the Ti-rich layers.
Similar content being viewed by others
References
S.P. Murarka, Mater. Sci. Eng. R. 19, 87 (1997).
The International Technology Roadmap for Semiconductors (ITRS), http://www.itrs.net/Links/2003ITRS/Interconnect2003. pdf, 2003
M.T. Bohr, Y.A. El-Mansy, IEEE Trans. Electron. Dev. 45, 620 (1998)
S.P. Murarka, Mater. Sci. Technol. 17, 479 (2001)
Y. Morand, Microelectron. Eng. 50, 391 (2000)
M. Moriyama, K. Matsunaga, M. Murakami, J. Electron. Mater. 32, 261 (2003)
M. Moriyama, K. Matsunaga, T. Morita, S. Tsukimot, M. Murakami, Mater. Trans. 45, 3033 (2004)
M. Murakami, M. Moriyama, S. Tsukimoto, K. Ito, Mater. Trans. 46, 1737 (2005)
M. Moriyama, M. Shimada, H. Masuda, M. Murakami, Trans. Mater. Res. Soc. Jpn. 29, 51 (2004)
M. Shimada, M. Moriyama, K. Ito, S. Tsukimoto, M. Murakami, J. Vac. Sci. Technol. B 24, 190 (2006)
P.J. Ding, W.A. Lanford, S. Hymes, S.P. Murarka, J. Appl. Phys. 75, 3627 (1994)
D. Adams, T.L. Alford, N.D. Theodore, S.W. Russell, R.L. Spreitzer, J.W. Mayer, Thin Solid Films 262, 199 (1995)
C.J. Liu, J.S. Chen, Appl. Phys. Lett. 80, 2678 (2002)
C.J. Liu, J.S. Jeng, J.S. Chen, Y.K. Lin, J. Vac. Sci. Technol. B 20, 2361 (2002)
M.J. Frederick, R. Goswami, G. Ramanath, J. Appl. Phys. 93, 5966 (2003)
M.J. Frederick, G. Ramanath, J. Appl. Phys. 95, 3202 (2004)
S. Tsukimoto, T. Morita, M. Moriyama, K. Ito, M. Murakami, J. Electron. Mater. 34, 592 (2005)
Y. Waseda ed., Metal Databook, 4th ed. (Japan Institute of Metal, 2004), p.␣101 (in Japanese)
Acknowledgements
This work was supported by Grants-in-Aid for Scientific Research from The Ministry of Education, Culture, Sports, Science and Technology (Grant No. 18360324), and the Nanotechnology Program on Cu Thin Films of the New Energy and Industrial Technology Development Organization (NEDO) of Japan.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Ito, K., Tsukimoto, S., Kabe, T. et al. Effects of Substrate Materials on Self-Formation of Ti-Rich Interface Layers in Cu(Ti) Alloy Films. J. Electron. Mater. 36, 606–613 (2007). https://doi.org/10.1007/s11664-007-0097-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11664-007-0097-5