Abstract
Electroplated (EP) Cu films demonstrate a microstructural transition at room temperature, known as self-annealing, that involves grain growth and texture changes. In this paper, we have investigated the annealing behavior of EP Cu films grown on a Cu seed layer deposited on top of a TaN barrier layer. A grazing incident x-ray diffraction (GIXRD) pattern shows stronger x-ray reflections form Cu (111) and (220) planes but weaker reflections from (200), (311), and (222) planes in all the EP Cu samples. Nanoindentation was performed on all the samples using the continuous stiffness measurement technique. The elastic modulus varied from 121 GPa to 132 GPa, while the hardness varied from 1 GPa to 1.3 GPa, depending on the annealing conditions. The surface morphology and roughness of the Cu films were characterized using atomic force microscopy (AFM). The tribological properties of the copper films were measured using the Bench Top chemical mechanical polishing (CMP) tester (CETR, Inc., Campbell, CA). Nanoindentation was performed on the samples after CMP, and an increase in hardness and modulus was observed. This may be attributed to the work hardening of the Cu films during CMP.
Similar content being viewed by others
References
S.M. Merchant, S.H. Kang, M. Sanganeria, B. van Schravendijk, and T. Mountsier, JOM 53, 43 (2001).
J. Tao, N.W. Cheung, and C. Hu, IEEE Electron Device Lett. 14, 249 (1993).
H.K. Kang, I. Asano, C. Ryu, and S.S. Wong, Proc. 10th Int. VLSI Multilevel Interconnection Conf. (Tampa, FL: VLSI Multilevel Interconnection Conference, 1993), pp. 223–229.
K.P. Rodbell, E.G. Colgan, and C.K. Hu, Proc. Advanced Metallization for Devices and Circuits—Science, Technology, and Manufacturability (Pittsburgh, PA: Materials Research Society, 1994), pp. 59–70.
S. Lagrange, S.H. Brongersma, M. Judelewicz, A. Saerens, I. Vervoort, E. Richard, R. Palmans, and K. Maex, Microelectron. Eng. 50, 449 (2000).
J.M. Harper, C. Cabral, Jr., P.C. Andricacos, L. Gignac, I.C. Noyan, K.P. Rodbell, and C.K. Hu, J. Appl. Phys. 86, 2516 (1999).
A. Furuya, Y. Oshita, and A. Ogura, J. Vac. Sci. Technol. A 18, 2854 (2000).
C. Lingk, M.E. Gross, and W.L. Brown, J. Appl. Phys. 87, 2232 (2000).
S.H. Brongersma, E. Richard, I. Vervoort, H. Bender, W. Vandervorst, S. Lagrange, G. Beyer, and K. Maex, J. Appl. Phys. 86, 3642 (1999).
L. Vanasupa, Y-C. Joo, P.R. Besser, and S. Pramanick, J. Appl. Phys. 85, 2583 (1999).
C-Y. Yang, J.S. Jeng, and J.S. Chen, Thin Solid Films 420–421, 398 (2002).
M.T. Perez-Prado and J.J. Vlassak, Scripta Mater. 47, 817 (2002).
H. Lee, S.S. Wong, and S.D. Lopatin, J. Appl. Phys. 93, 3796 (2003).
K. Ueno, T. Ritzdorf, and S. Grace, J. Appl. Phys. 86, 4930 (1999).
C. Lingk and M.E. Gross, J. Appl. Phys. 84, 5547 (1998).
W.H. The, L.T. Koh, S.M. Chen, J. Xie, C.Y. Li, and P.D. Foo, Microelectron. J. 32, 579 (2001).
J. Proost, T. Hirato, T. Furuhara, K. Maex, and J.-P. Celis, J. Appl. Phys. 87, 2792 (2000).
T.-H. Fang and W.-J. Chang, Microelectron. Eng. 65, 231 (2003).
S.H. Kang, Y.S. Obeng, M.A. Decker, M. Oh, S.M. Merchant, S.K. Karthikeyan, C.S. Seet, and A.S. Oates, J. Electron. Mater. 30, 1506 (2001).
A.K. Sikder, I.M. Irfan, A. Kumar, and J.M. Anthony, J. Electron. Mater. 30, 1527 (2001).
A.K. Sikder, F. Giglio, J. Wood, A. Kumar, and J.M. Anthony, J. Electron. Mater. 30, 1522 (2001).
M.F. Doerner and W.D. Nix, J. Mater. Res. 1, 601 (1986).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Sikder, A.K., Kumar, A., Shukla, P. et al. Effect of multistep annealing on mechanical and surface properties of electroplated Cu thin films. J. Electron. Mater. 32, 1028–1033 (2003). https://doi.org/10.1007/s11664-003-0085-3
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s11664-003-0085-3