Increasing the mean grain size in copper films and features

Abstract

A new grain-growth mode is observed in thick sputtered copper films. This new grain-growth mode, also referred to in this work as super secondary grain growth (SSGG) leads to highly concentric grain growth with grain diameters of many tens of micrometers, and drives the system toward a {100} texture. The appearance, growth dynamics, final grain size, and self-annealing time of this new grain-growth mode strongly depends on the applied bias voltage during deposition of these sputtered films, the film thickness, the post-deposition annealing temperature, and the properties of the copper diffusion barrier layers used in this work. Moreover, a clear rivalry between this new growth mode and the regularly observed secondary grain-growth mode in sputtered copper films was found. The microstructure and texture evolution in these films is explained in terms of surface/interface energy and strain-energy density minimizing driving forces, where the latter seems to be an important driving force for the observed new growth mode. By combining these sputtered copper films with electrochemically deposited (ECD) copper films of different thickness, the SSGG growth mode could also be introduced in ECD copper, but this led to a reduced final SSGG grain size for thicker ECD films. The knowledge about the thin-film level is used to also implement this new growth mode in small copper features by slightly modifying the standard deposition process. It is shown that the SSGG growth mode can be introduced in narrow structures, but optimizations are still necessary to further increase the mean grain size in features.

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References

  1. 1

    D.C. Edelstein: Copper chip technology in Proceedings of SPIE Conference, Multilevel Interconnect Technology II edited by M. Graef, and D.N. Patel, Vol. 3508, SPIE Bellingham, WA 1998 8

  2. 2

    M.M. Chow, J.E. Cronin, W.L. Guthrie, W. Kaanta, B. Luther, W.J. Patrick, K.A. Perry, C.L. Standley Method for producing coplanar multi-level metal insulator films on a substrate and for forming patterned conductive lines simultaneously with stud vias. U.S. Patent No. 4 789 648, December 6, 1988

    Google Scholar 

  3. 3

    P.C. Andricacos, C. Uzoh, J.O. Dukovic, J. Horkans, H. Deligianni: Damascene copper electroplating for chip interconnections. IBM J. Res. Dev. 42, 567 1998

    CAS  Article  Google Scholar 

  4. 4

    D. Josell, D. Wheeler, W.H. Huber, T.P. Moffat: Superconformal electrodeposition in submicron features. Phys. Rev. Lett. 87, 016101 2001

    Article  Google Scholar 

  5. 5

    S.H. Brongersma, E. Kerr, I. Vervoort, A. Saerens, K. Maex: Grain growth, stress, and impurities in electroplated copper. J. Mater. Res. 17, 582 2002

    CAS  Article  Google Scholar 

  6. 6

    S.H. Brongersma, E. Richard, I. Vervoort, H. Bender, W. Vandervorst, S. Lagrange, G. Beyer, K. Maex: Two-step room temperature grain growth in electroplated copper. J. Appl. Phys. 86, 3642 1999

    CAS  Article  Google Scholar 

  7. 7

    S.H. Brongersma, K. Vanstreels, W. Wu, W. Zhang, D. Ernur, J. D’Haen, V. Terzieva, M. Van Hove, T. Clarysse, L. Carbonell, W. Vandervorst, W. De Ceuninck, K. Maex Copper grain growth in reduced dimensions, Proc. IEEE International Interconnect Technology Conference IITC San Francisco, CA 2004 48–52

  8. 8

    C.V. Thompson: Secondary grain growth in thin films of semiconductors: Theoretical aspects. J. Appl. Phys. 58, 763 1985

    CAS  Article  Google Scholar 

  9. 9

    S. Rossnagel: Ionization by radio frequency inductively coupled plasma in Ionized Physical Vapor Deposition, edited by S. Rossnagel (Academic Press, San Diego, CA, 2000

  10. 10

    B.L. Chin, G. Yao, P. Ding, J. Fu, L. Chen Barrier and seed technologies for sub-0.10 micron copper chips. Semicond. Int. (2001), pp. 107–113

    Google Scholar 

  11. 11

    P. Gopalraja, J. Forster: Nonlinear wave interaction in a magnetron plasma. Appl. Phys. Lett. 77(22), 3526 2000

    CAS  Article  Google Scholar 

  12. 12

    Rohm and Haas Electronic Materials Philadelphia, PA http://electronicmaterials.rohmhaas.com

  13. 13

    KLA-Tencor Milpitas, CA http://www.kla-tencor.com

  14. 14

    P.A. Flinn: Principles and applications of wafer curvature techniques for stress measurements in thin films in Thin Films: Stresses and Mechanical Properties edited by J.C. Bravman, W.D. Nix, D.M. Barnett, and D.A. Smith Mater. Res. Soc. Symp. Proc. Pittsburgh, PA 130, 1989 41

    CAS  Google Scholar 

  15. 15

    Institute for Materials Research http://www.imo.uhasselt.be/pac/SEM1.htm

  16. 16

    C.V. Thompson: Experimental and theoretical aspects of grain growth in thin films. Mater. Sci. Forum 94-96, 245 1992

    Google Scholar 

  17. 17

    J.E. Sanchez, E. Arzt: Effects of grain orientation on hillock formation and grain growth in aluminum films on silicon substrates. Scripta Metall. Mater. 27, 285 1992

    CAS  Article  Google Scholar 

  18. 18

    C.V. Thompson: Texture evolution during grain growth in polycrystalline films. Scripta Metall. Mater. 28, 167 1993

    CAS  Article  Google Scholar 

  19. 19

    J.M.E. Harper, C. Cabral Jr., P.C. Andricacos, L. Gignac, I.C. Noyan, K.P. Rodbell, C.K. Hu: Mechanisms for microstructure evolution in electroplated copper thin films near room temperature. J. Appl. Phys. 86, 2516 1999

    CAS  Article  Google Scholar 

  20. 20

    C.V. Thompson: Coarsening of particles on a planar substrate: Interface energy anistropy and application to grain growth in thin films. Acta Metall. 36, 2929 1988

    CAS  Article  Google Scholar 

  21. 21

    M. McLean, B. Gale: Surface energy anisotropy by an improved thermal grooving technique. Philos. Mag. 20, 1033 1969

    CAS  Article  Google Scholar 

  22. 22

    Z. Jian-Min, M. Fei, X. Ke-Wei: Calculation of the surface energy of fcc metals with modified embedded-atom method. Chin. Phys. 13, 1082 2004

    Article  Google Scholar 

  23. 23

    M. Murikami, P. Chaudhari: Dependence of strains on crystal orientation in Pb thin films. Thin Solid Films 46, 109 1977

    Article  Google Scholar 

  24. 24

    E.M. Zielinski, R.P. Vinci, J.C. Bravman: Effects of barrier layer and annealing on abnormal grain growth in copper thin films. J. Appl. Phys. 76, 4516 1994

    CAS  Article  Google Scholar 

  25. 25

    E.M. Zielinski, R.P. Vinci, J.C. Bravman: The effects of processing on the microstructure of copper thin films on tantalum barrier layers in Materials Reliability in Microelectronics V edited by A.S. Oates, W.F. Filter, R. Rosenberg, A.L. Greer, and K. Gadepally Mater. Res. Soc. Symp. Proc. Pittsburgh, PA 391, 1995 303

    CAS  Google Scholar 

  26. 26

    J.W. Patten, E.D. McClanahan, J.W. Johnson: Room-temperature recrystallization in thick bias-sputtered copper deposits. J. Appl. Phys. 42, 4371 1971

    CAS  Article  Google Scholar 

  27. 27

    M. Chen, S. Rengarajan, P. Hey, Y. Dordi, H. Zhang, I. Hashim, P. Ding, B. Chin: Room temperature self-annealing of electroplated and sputtered copper films in Advanced Interconnects and Contacts edited by D.C. Edelstein, T. Kikkawa, M.C. Öztürk, K-N. Tu, and E.J. Weitzman Mater. Res. Soc. Symp. Proc. Warrendale, PA 1999 564, 413

    CAS  Google Scholar 

  28. 28

    S.M. Rossnagel, T.S. Kuan: Time development of microstructure and resistivity for very thin Cu Films. J. Vac. Sci. Technol., A 20, 1911 2002

    CAS  Article  Google Scholar 

  29. 29

    E.V. Barnat, D. Nagakura, P.I. Wang, T.M. Lu: Real time resistivity measurements during sputter deposition of ultrathin copper films. J. Appl. Phys. 91, 1667 2002

    CAS  Article  Google Scholar 

  30. 30

    C. Detavernier, D. Deduytsche, R.L. Van Meirhaege, J. De Baerdemaeker, C. Dauwe: Room-temperature grain growth in sputter-deposited Cu films. Appl. Phys. Lett. 82, 1863 2003

    CAS  Article  Google Scholar 

  31. 31

    S.P. Murarka, S.W. Hymes: Copper metallization for ULSI and beyond. Crit. Rev. Solid State Mater. Sci. 20, 87 1995

    CAS  Article  Google Scholar 

  32. 32

    P. Chaudhari: Mechanisms of stress relief in polycrystalline films. IBM J. Res. Dev. 13, 197 1969

    Article  Google Scholar 

  33. 33

    S-J. Hwang, Y-D. Lee, Y-B. Park, J-H. Lee, C-O. Jeong, Y-C. Joo: In situ study of stress relaxation mechanisms of pure Al thin films during isothermal annealing. Scripta Mater. 54, 1841 2006

    CAS  Article  Google Scholar 

  34. 34

    S.H. Brongersma, K. Vanstreels, W. Wu, W. Zhang, D. Ernur, J. D’Haen, V. Terzieva, M. Van Hove, T. Clarysse, L. Carbonell, W. Vandervorst, W. De Ceuninck, K. Maex: Copper grain growth in reduced dimensions. Proc. IEEE International Interconnect Technology Conference IITC San Francisco, CA 2004 48–50

  35. 35

    S.H. Brongersma, I. Vervoort, E. Richard, K. Maex: A grain size limitation inherent to electroplated copper films. Proc. of the IITC CA 2000 31–33

  36. 36

    D.P. Field, T. Muppidi, J.E. Sanchez: Electron backscatter diffraction characterization of inlaid Cu lines for interconnect applications. Scanning 25(6), 309 2003

    CAS  Article  Google Scholar 

  37. 37

    C. Lingk, M.E. Gross, W.L. Brown: X-ray diffraction pole figures evidence for (111) sidewall texture of electroplated Cu in submicron damascence trenches. Appl. Phys. Lett. 74, 682 1999

    CAS  Article  Google Scholar 

  38. 38

    P.R. Besser, E. Zschech, W. Blum, D. Winter, R. Oretega, S. Rose, M. Herrick, M. Gall, S. Thrasher, M. Tiner, B. Baker, G. Braeckelmann, L. Zhao, C. Simpson, C. Capasso, H. Kawasaki, E. Weitzman: Microstructural characterization of inlaid copper interconnect lines. J. Electron. Mater. 30, 320 2001

    CAS  Article  Google Scholar 

  39. 39

    D.N. Lee, H.J. Lee: Effect of stresses on the evolution of annealing textures in Cu and Al interconnects. J. Electron. Mater. 32, 1012 2003

    CAS  Article  Google Scholar 

  40. 40

    K.P. Rodbell, D.B. Knorr, J.D. Mis: The microstructure, mechanical stress, texture, and electromigration behavior of Al-Pd alloys. J. Electron. Mater. 22, 597 1993

    CAS  Article  Google Scholar 

  41. 41

    M.J. Attardo, R. Rosenberg: Electromigration damage in aluminum film conductors. J. Appl. Phys. 41, 2381 1970

    CAS  Article  Google Scholar 

  42. 42

    A.N. Campbell, E.M. Russel, D.B. Knorr: Relationship between texture and electromigration lifetime in sputtered Al-1%Si thin films. J. Electron. Mater. 22, 589 1993

    CAS  Article  Google Scholar 

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Acknowledgment

The research was partly performed in the framework of Projects 1.2.16/D2/841 and 1.2.14/PO/841 of the Objective 2 Programme for Limburg (Belgium) of the European Regional Development Fund, entitled “Integrated Material Research for Development and Application in the Automotive Sector.”

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Correspondence to K. Vanstreels.

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Vanstreels, K., Brongersma, S., Tokei, Z. et al. Increasing the mean grain size in copper films and features. Journal of Materials Research 23, 642–662 (2008). https://doi.org/10.1557/JMR.2008.0080

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