Advertisement

Materials for ULSI metallization - Overview of Electrical Properties

  • S. Tsukimoto
  • K. Ito
  • M. Murakami
Chapter

Abstract

Since performance of ULSI Si devices was found to be controlled by RC delay (where R is the electrical resistance at the interconnects and C is the capacitance of the insulators), efforts have been continued to reduce the wiring resistance and the insulator capacitance. Replacement of aluminum alloy interconnect materials by copper (which has about 40% lower resistivity compared with the aluminum alloy) reduced not only the device switching times but also the fabrication cost. However, the resistivity of the Cu wires was demonstrated experimentally to increase rapidly [1, 2] when the line width approached to the mean free path (∼39 nm) of the conducting electrons as predicted by theories [3–5]. Figure 9.1 shows theoretical resistivity calculated as a function of line widths with two average grain sizes (D) using Mayadas and Shatzkes (MS) model [5] with P = 0 and R = 0.5, which were experimentally determined [2].

Keywords

Barrier Layer Alloy Film Effective Resistivity Room Temperature Storage Si3N4 Layer 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. 1.
    Moriyama, M.; Shimada, M.; Masuda, H.; and Murakami, M.: Determination of parameters to control electrical resistivities of nano-scale copper interconnects. Trans. Mater. Res. Soc. Jpn. 29, 51 (2004)Google Scholar
  2. 2.
    Shimada, M.; Moriyama, M.; Ito; K., Tsukimoto, S.; and Murakami, M.: Electrical resistivity of polycrystalline Cu interconnects with nano-scale linewidth. J. Vac. Sci. Technol. B 24, 190 (2006)CrossRefGoogle Scholar
  3. 3.
    Fuchs, K.: The conductivity of thin metallic films according to the electron theory of metals. Proc. Camb. Phil. Soc. 34(8), 100 (1938)CrossRefGoogle Scholar
  4. 4.
    Sondheimer, E. H.: The mean free path of electrons in metals. Adv. Phys. 1(1), 1 (1952)CrossRefGoogle Scholar
  5. 5.
    Mayadas, A. F. and Shatzkes, M.: Electrical-resistivity model for polycrystalline films: the case of arbitrary reflection at external surfaces. Phys. Rev. B 1, 1382 (1970)CrossRefGoogle Scholar
  6. 6.
    Lingk, C. and Gross, M. E.: Recrystallization kinetics of electroplated Cu in damascene trenches at room temperature. J. Appl. Phys. 84(10), 5547 (1998)CrossRefGoogle Scholar
  7. 7.
    Harper, J. M. E.; Cabral, Jr., C.; Andricacos, P. C.; Gignac, L.; Noyan, I. C.; Rodbell, K. P.; and Hu, C. K.: Mechanisms for microstructure evolution in electroplated copper thin films near room temperature. J. Appl. Phys. 86(5), 2516 (1999)CrossRefGoogle Scholar
  8. 8.
    Brongersma, S. H.; Richard, E.; Vervoot, I.; Bender, H.; Vandervorst, W.; Lagrange, S.; Beyer, G.; and Maex, K.: Two-step room temperature grain growth in electroplated copper. J. Appl. Phys. 86, 3642 (1999)CrossRefGoogle Scholar
  9. 9.
    Chaudhari, P.: Grain growth and stress relief in thin films. J. Vac. Sci. Technol. 9(1), 520 (1972)CrossRefGoogle Scholar
  10. 10.
    Moriyama, M.; Matsunaga, K.; and Murakami, M.: The effect of strain on abnormal grain growth in Cu thin films. J. Electron. Mater. 32, 261 (2003)CrossRefGoogle Scholar
  11. 11.
    Moriyama, M.; Matsunaga, K.; Morita, T.; Tsukimoto, S.; and Murakami, M.: The effect of strain distribution on abnormal grain growth in Cu thin films. Mater. Trans. 45, 3033 (2004)CrossRefGoogle Scholar
  12. 12.
    Murakami, M.; Kuan, T-S.; and Blech, I. A.: Mechanical Properties of Thin Films on Substrates in Treatize on Mater. Sci. Technol., Preparation and Properties of Thin Films, Tu, K. N. and Rosenberg, R. (Ed.) (Academic Press, Inc., New York, NY) 24, 163 (1982)Google Scholar
  13. 13.
    Ding, P. J.; Lanford, W. A.; Hymes, S.; and Murarka, S. P.: Effects of the addition of small amounts of Al to copper: Corrosion, resistivity, adhesion, morphology, and diffusion. J. Appl. Phys. 75(7), 3627 (1994)CrossRefGoogle Scholar
  14. 14.
    Adams, D.; Alford, T. L.; Theodore, N. D.; Russell, S. W.; Spreitzer, R. L.; and Mayer, J. W.: Passivation of Cu via refractory metal nitridation in an ammonia ambient. Thin Solid Films 262, 199 (1995)CrossRefGoogle Scholar
  15. 15.
    Liu, C. J. and Chen, J. S.: Effects of the addition of small amounts of Al to copper: Corrosion, resistivity, adhesion, morphology, and diffusion. Appl. Phys. Lett. 80(15), 2678 (2002)CrossRefGoogle Scholar
  16. 16.
    Liu, C. J.; Jeng, J. S.; Chen, J. S.; and Lin, Y. K.: Effects of Ti addition on the morphology, interfacial reaction, and diffusion of Cu on SiO2. J. Vac. Sci. Technol. B 20(6), 2361 (2002)CrossRefGoogle Scholar
  17. 17.
    Frederick, M. J.; Goswami, R.; and Ramanath, G.: Sequence of Mg segregation, grain growth, and interfacial MgO formation in Cu–Mg alloy films on SiO2 during vacuum. J. Appl. Phys. 93(10), 5966 (2003)CrossRefGoogle Scholar
  18. 18.
    Frederick, M. J. and Ramanath, G.: Interfacial phase formation in Cu–Mg alloy films on SiO2. J. Appl. Phys. 95(6), 3202 (2004)CrossRefGoogle Scholar
  19. 19.
    Hoshino, K.; Yagi, H.; and Tsuchikawa, H.: Effect of titanium addition to copper interconnect on electromigration open circuit failure. Proc. 7th Int. VLSI Multilevel Interconnection Conf. Piscataway, NJ; IEEE. , 357 (1990)CrossRefGoogle Scholar
  20. 20.
    Li, J.; Mayer, J. W.; and Colgan, E. G.: Oxidation and protection in copper and copper alloy thin films. J. Appl. Phys. 70(5), 2820 (1991)CrossRefGoogle Scholar
  21. 21.
    Hu, C.-K.; Luther, B.; Kaufman, F. B.; Hummel, J.; Uzoh, C.; and Pearson, D. J.: Copper interconnection integration and reliability. Thin Solid Films 262(1–2), 84 (1995)CrossRefGoogle Scholar
  22. 22.
    Tsukimoto, S.; Morita, T.; Moriyama, M.; Ito, K.; and Murakami, M.: Formation of Ti diffusion barrier layers in thin Cu(Ti) alloy films. J. Electron. Mater. 34(5), 592 (2005)CrossRefGoogle Scholar
  23. 23.
    Smith, C. S.: Trans. AIME 188, 1021 (1950)Google Scholar
  24. 24.
    Ritzdorf, T.; Graham, L.; Jin, S.; Mu, C.; and Fraser, D. B.: Self-annealing of electrochemically deposited copper films in advanced interconnect applications. Proc. Int. Interconnect Technology Conf. (New York: IEEE), 166 (1998)Google Scholar
  25. 25.
    Gross, M. E.; Takahashi, K.; Lingk, C.; Ritzdorf, T.; and Gibbons, K.: The role of additives in electroplating of void-free Cu in sub-micron damascene features. Advanced Metallization Conf. 1998, Sandhu, G. S., et al. (Ed.) MRS, Pittsburgh, PA, 51 (1999)Google Scholar
  26. 26.
    Lingk, C. and Gross, M. E.: Recrystallization kinetics of electroplated Cu in damascene trenches at room temperature. J. Appl. Phys. 84(10), 5547 (1998)CrossRefGoogle Scholar
  27. 27.
    Lingk, C.; Brown, M. E.; Lai, W. Y. -C.; Miner, J. F.; Ritzdorf, T.; Turner, J.; Gibbons, K.; Klawuhn, E.; and Zhang, F.: Room temperature recrystallization of electroplated Cu in damascene trenches: kinetics and mechanisms. Advanced Metallization Conf. 1998, Sandhu, G. S., et al. (Ed.) MRS, Pittsburgh, PA, 89 (1999)Google Scholar
  28. 28.
    Walther, D.; Gross, M. E.; Evans-Lutterodt, K.; Brown, W. L.; Oh, M.; Merchant, S.; and Naresh, P.: Room temperature recrystallization of electroplated copper thin films: methods and mechanisms. Mater. Res. Soc. Symp. Proc. 612, D. 10.1., 1 (2000)Google Scholar
  29. 29.
    Cabral, C. Jr. et al.: Room temperature evolution of microstructure and resistivity in electroplated copper films. Advanced Metallization Conf. 1998, Sandhu, G. S., et al. (Ed.), MRS, Pittsburgh, PA, 81 (1999)Google Scholar
  30. 30.
    Jiang, Q.-T. and Smekalin, K.: Variations in Cu CMP removal rate due to Cu film self-annealing. Advanced Metallization Conf. 1998, Sandhu, G. S., et al. (Ed.), MRS, Pittsburgh, PA, 209 (1999)Google Scholar
  31. 31.
    Harper, J. M. E.; Cabral, C. Jr.; Andricacos, P. C.; Gignac, L.; Noyan, I. C.; Rodbell, K. P.; and Hu, C. K.: Mechanisms for microstructure evolution in electroplated copper thin films near room temperature. J. Appl. Phys. 86(5), 2516 (1999)CrossRefGoogle Scholar
  32. 32.
    Ueno, K.; Ritzdorf, T.; and Grace, S.: Seed effect on self-annealing of electroplated copper films. Advanced Metallization Conf. 1998, Sandhu, G. S., et al. (Eds.), MRS, Pittsburgh, PA, 95 (1999)Google Scholar
  33. 33.
    Brongersma, S. H.; Richard, E.; Vervoot, I.; Bender, H.; Vandervorst, W.; Lagrange, S.; Beyer, G.; and Maex, K.: Two-step room temperature grain growth in electroplated copper. J. Appl. Phys. 86(7), 3642 (1999)CrossRefGoogle Scholar
  34. 34.
    Chaudhari, P.: Grain growth and stress relief in thin films. J. Vac. Sci. Technol. 9(1), 520 (1972)CrossRefGoogle Scholar
  35. 35.
    Cabral, C. Jr.; Andricacos, P. C.; Gignac, L.; Noyan, I. C.; Rodbell, K. P.; Shaw, T. M.; Rosenberg, R.; Harper, J. M. E.; DeHaven, P. W.; Locke, P. S.; Malhotra, S.; Uzoh, C.; and Klepeis, S. J.: Room temperature evolution of microstructure and resistivity in electroplated copper films. MRS Conf. Proc. ULSI XIV. 81(1999)Google Scholar
  36. 36.
    Murakami, M. and Wook, R. W.: Strain relaxation mechanisms of thin deposited films. CRC Critical Review in Sol. Stat. Mater. Sci. 11, 317 (1983)Google Scholar
  37. 37.
    Murakami, M.; Moriyama, M.; Tsukimoto, S.; and Ito, K.: Grain growth mechanism of Cu thin films. Mater. Trans. 46(7), 1737 (2005)CrossRefGoogle Scholar
  38. 38.
    Liu, C. J.; Jeng, J. S.; Chen, J. S.; and Lin, Y. K.: Effects of Ti addition on the morphology, interfacial reaction, and diffusion of Cu on SiO2. J. Vac. Sci. Technol. B 20(6), 2361 (2002)CrossRefGoogle Scholar
  39. 39.
    Subramanian, P. R.; Chakrabarti, D. J.; and Laughlin, D. E.: Phase diagrams of binary copper alloys, ASM International, Materials Park, OH, 447 (1994)Google Scholar

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  1. 1.Department of Materials Science and EngineeringKyoto UniversityKyotoJapan

Personalised recommendations