Journal of Applied Electrochemistry

, Volume 44, Issue 1, pp 189–198 | Cite as

Electrodeposition of nanocrystalline copper thin films from 1-ethyl-3-methylimidazolium ethylsulphate ionic liquid

  • Tomin Liu
  • Rui Vilar
  • Sónia Eugénio
  • Joseph Grondin
  • Yann Danten
Research Article

Abstract

Copper thin films are increasingly important as interconnectors for the creation of smaller and better performing integrated circuits and electrodeposition from ionic liquid-based electrolytes could provide a greener fabrication method for these films. The electrodeposition of copper from copper(I) and copper(II) salt solutions in a low cost, widely available ionic liquid, 1-ethyl-3-methylimidazolium ethylsulphate, was studied using a range of different deposition potentials and temperatures. Three different electrolytes containing ~0.1 M of copper(I) chloride(CuCl), copper(II) chloride (CuCl2) and copper(II) sulphate (CuSO4) were used. Under similar deposition conditions, the films obtained from CuCl and CuSO4-based electrolytes presented better continuity than films obtained from CuCl2-based electrolyte. Continuous films with a homogeneous structure were obtained by electrodeposition from CuCl and CuSO4-based solutions at a constant potential of −1.8 V and a temperature of 35 °C. Under similar deposition parameters, the films deposited from CuCl2-based electrolyte presented the largest particle size, while those deposited from copper(I) chloride and CuSO4-based solutions presented finer microstructures. X-ray diffraction analysis and energy dispersive X-ray spectroscopy showed that the deposits were crystalline and consisted mainly of copper, with traces of oxygen and sulphur resulting from residues of the ionic liquid. The films presented a nanocrystalline microstructure consisting of particles about 25 nm, aggregated in clusters.

Keywords

Electrodeposition Ionic liquid EMIM-EtSO4 Copper CuCl CuCl2 

References

  1. 1.
    Andricacos PC, Uzoh C, Dukovic JO, Horkans J, Deligianni H (1998) Damascene copper electroplating for chip interconnections. IBM J Res Dev 42(5):567–574CrossRefGoogle Scholar
  2. 2.
    Wolf S (2002) Processing for the VLSI Era. 4: Deep-submicron process technology, vol 4. Lattice Press, Sunset BeachGoogle Scholar
  3. 3.
    Beica R, Sharbono C, Ritzdorf T, IEEE (2008) Through silicon via copper electrodeposition for 3D integration. In: Proceedings of 58th electronic components & technology conference. IEEE, Lake Buena Vista, pp 577–583Google Scholar
  4. 4.
    Endres F, Abbott A, MacFarlane D (2008) Electrodeposition from ionic liquids. Wiley VCH, WeinheimCrossRefGoogle Scholar
  5. 5.
    Tomkiewicz M (2010) Environmental aspects of electrodeposition. In: Schlesinger M, Paunovic M (eds) Modern electroplating, 5th edn. Wiley, Hoboken, pp 555–574Google Scholar
  6. 6.
    Anastas P, Warner J (1998) Green chemistry: theory and practice. Oxford University Press, New YorkGoogle Scholar
  7. 7.
    Chen PY, Sun IW (1999) Electrochemical study of copper in a basic 1-ethyl-3-methylimidazolium tetrafluoroborate room temperature molten salt. Electrochim Acta 45(3):441–450. doi:10.1016/s0013-4686(99)00275-3 CrossRefGoogle Scholar
  8. 8.
    Murase K, Nitta K, Hirato T, Awakura Y (2001) Electrochemical behaviour of copper in trimethyl-n-hexylammonium bis((trifluoromethyl)sulfonyl)amide, an ammonium imide-type room temperature molten salt. J Appl Electrochem 31(10):1089–1094. doi:10.1023/a:1012255601793 CrossRefGoogle Scholar
  9. 9.
    El Abedin SZ, Saad AY, Farag HK, Borisenko N, Liu QX, Endres F (2007) Electrodeposition of selenium, indium and copper in an air- and water-stable ionic liquid at variable temperatures. Electrochim Acta 52(8):2746–2754. doi:10.1016/j.electacta.2006.08.064 CrossRefGoogle Scholar
  10. 10.
    Leong TI, Sun IW, Deng MJ, Wu CM, Chen PY (2008) Electrochemical study of copper in the 1-ethyl-3-methylimidazolium dicyanamide room temperature ionic liquid. J Electrochem Soc 155(4):F55–F60. doi:10.1149/1.2840627 CrossRefGoogle Scholar
  11. 11.
    Brooks NR, Schaltin S, Van Hecke K, Van Meervelt L, Binnemans K, Fransaer J (2011) Copper(I)-containing ionic liquids for high-rate electrodeposition. Chem-A Eur J 17(18):5054–5059. doi:10.1002/chem.201003209 CrossRefGoogle Scholar
  12. 12.
    Abbott AP, El Ttaib K, Frisch G, McKenzie KJ, Ryder KS (2009) Electrodeposition of copper composites from deep eutectic solvents based on choline chloride. Phys Chem Chem Phys 11(21):4269–4277. doi:10.1039/b817881j CrossRefGoogle Scholar
  13. 13.
    Fernandez A, Garcia J, Torrecilla JS, Oliet M, Rodriguez F (2008) Volumetric, transport and surface properties of bmim MeSO4 and emim EtSO4 ionic liquids as a function of temperature. J Chem Eng Data 53(7):1518–1522. doi:10.1021/je8000766 CrossRefGoogle Scholar
  14. 14.
    Froba AP, Kremer H, Leipertz A (2008) Density, refractive index, interfacial tension, and viscosity of ionic liquids EMIM EtSO4, EMIM NTf2, EMIM N(CN)(2), and OMA NTf2 in dependence on temperature at atmospheric pressure. J Phys Chem B 112(39):12420–12430. doi:10.1021/jp804319a CrossRefGoogle Scholar
  15. 15.
    Cullity B (1956) Elements of X-ray diffraction. Addison-Wesley Publishing Company, Inc, ReadingGoogle Scholar
  16. 16.
    Holbrey JD, Reichert WM, Swatloski RP, Broker GA, Pitner WR, Seddon KR, Rogers RD (2002) Efficient, halide free synthesis of new, low cost ionic liquids: 1,3-dialkylimidazolium salts containing methyl- and ethyl-sulfate anions. Green Chem 4(5):407–413. doi:10.1039/b204469b CrossRefGoogle Scholar
  17. 17.
    Yang JZ, Wang B, Zhang QG, Tong J (2007) Study on solid-liquid phase equilibria in ionic liquid-1. The solubility of alkali chloride (MCl) in ionic liquid EMISE. Fluid Phase Equilib 251(1):68–70. doi:10.1016/j.fluid.2006.10.018 CrossRefGoogle Scholar
  18. 18.
    Greef R, Peat R, Peter L, Pletcher D, Robinson J (1990) Instrumental methods in electrochemistry. Elis Horwood Limited, ChichesterGoogle Scholar
  19. 19.
    Brett C, Brett A (2005) Electrochemistry principles, methods and applications. Oxford University Press, New YorkGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  • Tomin Liu
    • 1
    • 2
  • Rui Vilar
    • 1
  • Sónia Eugénio
    • 1
  • Joseph Grondin
    • 2
  • Yann Danten
    • 2
  1. 1.Department of Chemical Engineering and ICEMS, Instituto de Ciências e Engenharia de Materiais e Superfícies, Instituto Superior TécnicoUniversidade Técnica de LisboaLisbonPortugal
  2. 2.Institut des Sciences MoléculairesUniversité Bordeaux 1, CNRS UMR 5255Talence CedexFrance

Personalised recommendations