Abstract
The authors report effects of placing a very thin metallic interlayer, such as W and Ni, in between the Cu film and the Si substrate on cyclic thermal stress-induced interfacial sliding and hillock growth in Cu. Cu-Si samples with no interlayer were the most prone to both interfacial sliding and hillock growth, whereas samples with the Ni interlayer were the most resistant against these deleterious phenomena. While the rate of interfacial sliding decreased with each consecutive thermal cycle, hillocks continued to grow undeterred. The obtained experimental results are discussed, considering the compressive stress field generated in the Cu film.
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References
Z. Suo: Reliability of interconnect structures. In Volume 8: Interfacial and Nanoscale Failure, Comprehensive Structural Integrity (I. Milne, R.O. Ritchie and B. Karihaloo, Editors-in-Chief), edited by W. Gerberich and W. Yang (Elsevier, Amsterdam, 2003) pp. 265–324.
D. Shamiryan, T. Abell, F. Iacopi, and K. Maex: Low-k dielectric materials. Mater. Today 7, 34–39 (2004).
M.F. Dorner and W.D. Nix: Stresses and deformation processes in thin films on substrates. CRC Crit. Rev. Solid State Mater. Sci. 14, 225–267 (1988).
D. Fridline: Finite element modeling of electromigration and stress voiding in microelectronic interconnects. Ph.D. thesis, Brown University, 2001.
M.A. Korhonen, C.A. Paszkiet, and C.Y. Li: Mechanisms of thermal stress relaxation and stress induced voiding in narrow aluminum based metallizations. J. Appl. Phys. 69, 8083–8095 (1991).
A.I. Sauter and W.D. Nix: Thermal stresses in Al lines bonded to substrates. IEEE Trans. Compd. Hybrids Manuf. Technol. 15, 594–600 (1992).
J.W. Hutchinson and Z. Suo: Mixed mode cracking in layered materials. Adv. Appl. Mech. 29, 163–191 (1992).
H. Tohmyoh, M. Yasuda, and M. Saka: Controlling Ag whisker growth using very thin metallic films. Scr. Mater. 63, 289–292 (2010).
A. Kosinova, D. Wang, P. Schaaf, A. Sharma, L. Klinger, and E. Rabkin: Whiskers growth in thin passivated Au films. Acta Mater. 149, 154–163 (2018).
M.W. Chen and I. Dutta: Atomic force microscopy study of plastic deformation and interfacial sliding in Al thin film: Si substrate systems due to thermal cycling. Appl. Phys. Lett. 77, 4298–4300 (2000).
I. Dutta, M.W. Chen, K.A. Peterson, and T. Shultz: Plastic deformation and interfacial sliding in Al and Cu thin film: Si substrate systems due to thermal cycling. J. Electron. Mater. 30, 1537–1548 (2001).
P. Kumar and I. Dutta: Influence of electric current on diffusionally accommodated sliding at hetero-interfaces. Acta Mater. 59, 2096–2108 (2011).
P. Kumar and I. Dutta: Effect of substrate surface on electromigration-induced sliding at hetero-interfaces. J. Phys. D Appl. Phys. 46, 155303 (2013).
K.A. Peterson, I. Dutta, and M.W. Chen: Diffusionally accommodated interfacial sliding in metal-silicon systems. Acta Mater. 51, 2831–2846 (2003).
D.K. Kim, W.D. Nix, R.P. Vinci, M.D. Deal, and J.D. Plumer: Study of the effect of grain boundary migration on hillock formation in Al thin films. J. Appl. Phys. 90, 781–788 (2001).
M. Burkhard, S. Kuwano, T. Fujita, I. Dutta, and M.W. Chen: Correlation between whisker growth, dissolution pitting and Si precipitation in an Al thin film on Si during heat treatment. J. Mater. Sci. 45, 3367–3374 (2010).
P. Jagtap, A. Chakraborty, P. Eisenlohr, and P. Kumar: Identification of whisker grain in Sn coatings by analyzing crystallographic micro-texture using electron back-scatter diffraction. Acta Mater. 134, 346–359 (2017).
P. Jagtap, V. Sethuraman, and P. Kumar: Critical evaluation of relative importance of stress and stress gradient in whisker growth in Sn coatings. J. Electron. Mater. 47, 5229–5242 (2018).
I. Dutta, P. Kumar, and M.S. Bakir: Interface-related reliability challenges in 3-D interconnect system with through-silicon vias. JOM 63, 70–77 (2011).
P. Kumar, I. Dutta, and M.S. Bakir: Interfacial effects during thermal cycling of Cu-filled through-silicon vias (TSV). J. Electron. Mater. 41, 322–335 (2012).
E. Zschech, H.J. Engelmann, M.A. Meyer, V. Kahlert, A.V. Vairagar, S.G. Mhaisalkar, K. Ahila, M.Y. Yan, K.N. Tu, and V. Sukharev: Effect of interface strength on electromigration-induced inlaid copper interconnect degradation: experiment and simulation. Z. Metallkd. 96, 966–971 (2005).
E.A. Brandes and G.B. Brook (Eds): Smithells Metals Reference Book. 7th ed. (Butterworth-Heinemann Ltd., Oxford, 1992).
M. Vijayakumar, A.M. Sriramamurthy, and S.V.N. Naidu: Calculated phase diagram of Cu–W, Ag–W and Au–W binary system. Calphad 12, 177–184 (1988).
D. Josell, T.P. Weihs, and H. Gao: Diffusional creep: stresses and strain rates in thin films and multilayers. MRS Bull. 27, 39–44 (2002).
N. Okamoto, F. Wang, and T. Watanabe: Adhesion of electrodeposited copper, nickel and silver films on copper, nickel and silver substrates. Mater. Trans. 45, 3330–3333 (2004).
P. Jagtap, P.R. Narayan, and P. Kumar: Effect of substrate composition on whisker growth in Sn coatings. J. Electron. Mater. 47, 4177–4189 (2018).
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The authors thank the Department of Science and Technology (DST), Government of India for financial support (DSTO #1164 and #1526).
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Somaiah, N., Kanjilal, A. & Kumar, P. Effects of an interfacial layer on stress relaxation mechanisms active in the Cu-Si thin film system during thermal cycling. MRS Communications 10, 164–172 (2020). https://doi.org/10.1557/mrc.2020.6
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DOI: https://doi.org/10.1557/mrc.2020.6