Abstract
Cu-to-Cu bonding to connect through-silicon vias in three-dimensional integrated-circuit packaging is the most important interconnection technology in the next-generation semiconductor industry. Soldering is an economic and fast process in comparison with diffusion bonding methods. Ga has high solubility of up to 20 at.% in the Cu-rich face-centered cubic (FCC) phase and high mobility at moderate temperatures. In this work, an attempt has been made to evaluate Ga-based Cu-to-Cu interconnection by transient liquid-phase (TLP) bonding. The Cu/Ga interfacial reactions at temperatures ranging from 160°C to 300°C were examined. For reactions at temperatures lower than 240°C, the reaction path is Cu/γ 3-Cu9Ga4/θ-CuGa2/liquid, where the γ 3-Cu9Ga4 and θ-CuGa2 phases are thin planar and thick scalloped layers, respectively, while for the reactions at 280°C and 300°C, the scalloped γ 3-Cu9Ga4 phase is the only reaction product. The phase transformation kinetics, reaction mechanisms, and microstructural evolution in the Cu/Ga couples are elaborated. In addition, reactions of Cu/Ga/Cu sandwich couples at 160°C were investigated. The original Cu/liquid/Cu couples isothermally transformed to Cu/γ 3-Cu9Ga4/ θ-CuGa2/γ 3-Cu9Ga4/Cu couples as the reaction progressed. However, cracks were observed in the θ-CuGa2 phase regions after metallographic processing. The brittle θ-CuGa2 phase is undesirable for Ga-based TLP bonding.
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References
M. Motoyoshi, Proc. IEEE 97 (1), 43 (2009).
J.H. Lau, Microelectron. Int. 28, 8 (2011).
S. Kühne and C. Hierold, Sens. Actuators A 172, 341 (2011).
K.N. Chen, C.S. Tan, A. Fan, and R. Reif, Electrochem. Solid-State Lett. 7, G14 (2004).
C.-T. Ko and K.-N. Chen, Microelectron. Reliab. 50, 481 (2010).
Y.-S. Tang, Y.-J. Chang, and K.-N. Chen, Microelectron. Reliab. 52, 312 (2012).
K. Bobzin, E. Lugscheider, F. Ernst, R. Nickel, N. Bagcivan, D. Parkot, A. Schlegel, S. Ferrara, T. Kashko, and N. Leick, Microsyst. Technol. 14, 1887 (2008).
G. Selvaduray and M. Abtewa, Mater. Sci. Eng. 27, 95 (2000).
J.F. Li, P.A. Agyakwa, and C.M. Johnson, Acta Mater. 59, 1198 (2011).
W. Zhang, R. Agarwal, P. Limaye and W. Ruythooren, Electronic Components and Technology Conference 2009 (San Diego, CA, 2009), pp. 345–349.
G. Zeng, S. Xue, L. Zhang, and L. Gao, J. Mater. Sci.: Mater. Electron. 22, 565 (2011).
C.M.L. Wu, D.Q. Yu, C.M.T. Law, and L. Wang, Mater. Sci. Eng.: R: Rep. 44, 1 (2004).
ASM International, ASM Handbook 1992, vol. 3 (Materials Park, OH: ASM International, 1992).
G.O. Cook and C.D. Sorensen, J. Mater. Sci. 46, 5305 (2011).
W.D. Macdonald and T.W. Eagar, Annu. Rev. Mater. Sci. 22, 23 (1992).
F.J.J. Vanloo, Prog. Solid State Chem. 20, 47 (1990).
J.S. Park and J.M. Kim, Materials 3, 264 (2010).
N.S. Stoloff and M.M. Shea, Mater. Sci. Eng. 12, 245 (1973).
C.F. Old and M.G. Nicholas, J. Mater. Sci. 14, 1 (1979).
C.-H. Wang, H.-H. Chen, P.-Y. Li, and P.-Y. Chu, Intermetallics 22, 166 (2012).
M. Schaefer, R.A. Fournelle, J. Liang, J. Electron. Mater. 27, 1167 (1998).
H.K. Kim and K.N. Tu, Phys. Rev. B 53, 16027 (1996).
W.P. Lin, C.H. Sha, and C.C. Lee, IEEE Trans. Compon. Packag. Manuf. Technol. 2, 903 (2012).
R.P. Van Ingen, R.H.J. Fastenau, and E.J. Mittemeijer, J. Appl. Phys. 76, 1871 (1994).
R. Kubiak, J. Less Common Met. 116, 307 (1986).
C.W. Fairhurst and J.B. Cohen, Acta Crystallogr. B 28, 371 (1972).
K. Takemura and H. Fujihisa, Phys. Rev. B 47, 8465(1993).
J.K. Brandon, R.Y. Brizard, W.B. Pearson, and D.J.N. Tozer, Acta Crystallogr. B 33, 527 (1977).
Y. Watanabe, Y. Fujinaga, and H. Iwasaki, Acta Crystallogr. B 39, 306 (1983).
F.J. Garcıa-Garcıa, A.K. Larsson, and S. Furuseth, J. Solid State Chem. 166, 352 (2002).
L. Bosio, J. Chem. Phys. 68, 1221 (1978).
A.E. Gunnaes, A. Olsen, and H. Herø, J. Microsc. 185, 188 (1997).
O.I. Tikhomirova, M.V. Pikunov, I.D. Marchukova, I.N. Tochenova and I.P. Izotova, Soviet Mater. Sci. 5, 355 (1972) (a translation of Fiziko-khimicheskaya mekhanika materialov/Academy of Sciences of the Ukrainian SSR).
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Lin, Sk., Cho, Cl. & Chang, Hm. Interfacial Reactions in Cu/Ga and Cu/Ga/Cu Couples. J. Electron. Mater. 43, 204–211 (2014). https://doi.org/10.1007/s11664-013-2721-x
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DOI: https://doi.org/10.1007/s11664-013-2721-x