Tribology Letters

, Volume 25, Issue 2, pp 93–102

Molecular dynamics study of pattern transfer in nanoimprint lithography



A molecular dynamics simulations model of nanoimprint lithography (NIL) is proposed in order to study the pattern transfer and its related phenomena. The proposed model is similar to a real NIL process imprinting an α-quartz stamp with a rectangular line pattern into an amorphous poly-(methylmethacrylate) (PMMA) film. The polymer deformation behavior and the adhesion and friction effects between the stamp and the polymer film are investigated and their dependency on the pattern aspect ratio is discussed. Force fields including bond, angle, torsion, van der Waals, and electrostatic potentials are used to describe intermolecular and intramolecular interacting forces. Nosé-Hoover thermostat is used to control the temperature of the polymer film and cell multipole method is adopted to treat long range interactions. The deformation of the polymer film is observed for two stamps having different aspect ratio patterns. The distributions of density and stress in the polymer film are calculated for the detail analysis of deformation behavior. For a high aspect ratio pattern (aspect ratio = 2.5, imprint depth = 8.0 nm), large amount of springback of the residual polymer film is observed, which is mainly due to the residual compressive stress left in the polymer film. However, for a low aspect ratio pattern (aspect ratio = 1.0, imprint depth = 3.0 nm), the springback is not observed. In addition, adhesion and friction forces are obtained by dividing the polymer film into subregions and calculating the interacting force between each subregion and the stamp. While the adhesion force is nearly constant regardless of the pattern aspect ratio, the friction force increases as the pattern aspect ratio grows, so the friction force becomes larger than the adhesion force when the pattern aspect ratio increases.


nanoimprint lithography molecular dynamics simulation polymer deformation adhesion friction 


  1. 1.
    S.Y. Chou, P.R. Krauss, P.J. Renstrom, Appl. Phys. Lett. 67 (1995) 3114CrossRefGoogle Scholar
  2. 2.
    S.Y. Chou, P.R. Krauss, P.J. Renstrom, J. Vac. Sci. Technol. B 14 (1996) 4129CrossRefGoogle Scholar
  3. 3.
    S.Y. Chou, P.R. Krauss, W. Zhang, L.J. Guo, L. Zhuang, J. Vac. Sci. Technol. B 15 (1997) 2897CrossRefGoogle Scholar
  4. 4.
    M.D. Austin, H. Ge, W. Wu, M. Li, Z. Yu, D. Wasserman, S.A. Lyon, S.Y. Chou, Appl. Phys. Lett. 84 (2004) 5299CrossRefGoogle Scholar
  5. 5.
    S.Y. Chou, C. Keimel, J. Gu, Nature 417 (2002) 835CrossRefGoogle Scholar
  6. 6.
    Y. Hirai, S. Yoshida, N. Takagi, Y. Tanaka, H. Yabe, K. Sasaki, H. Sumitani, K. Yamamoto, Jpn. J. Appl. Phys. 42 (2003) 3863CrossRefGoogle Scholar
  7. 7.
    L.J. Guo, J. Phys. D: Appl. Phys. 37 (2004) R123CrossRefGoogle Scholar
  8. 8.
    H.C. Scheer, H. Schulz, T. Hoffmann, C.M. Sotomayor Torres, J. Vac. Sci. Technol. B 16 (1998) 3917CrossRefGoogle Scholar
  9. 9.
    L.J. Heyderman, H. Schift, C. David, J. Gobrecht, T. Schweizer, Microelectronic Eng. 54 (2000) 229CrossRefGoogle Scholar
  10. 10.
    H.C. Scheer, H. Schulz, Microelectronic Eng. 54 (2001) 311CrossRefGoogle Scholar
  11. 11.
    D.S. Macintyre, S. Thoms, Microelectronic Eng. 78–79 (2005) 670CrossRefGoogle Scholar
  12. 12.
    G.L.W. Cross, B.S. O’Connel, J.B. Pethica, Appl. Phys. Lett. 86 (2004) 081902CrossRefGoogle Scholar
  13. 13.
    C. Martin, L. Ressier, J.P. Peyrade, Physica E 17 (2003) 523CrossRefGoogle Scholar
  14. 14.
    Y. Hirai, S. Yoshida, N. Takagi, J. Vac. Sci. Technol. B 21 (2003) 2765CrossRefGoogle Scholar
  15. 15.
    Y. Hirai, T. Konishi, T. Yoshikawa, S. Yoshida, J. Vac. Sci. Technol. B 22 (2004) 3288CrossRefGoogle Scholar
  16. 16.
    W.B. Young, Microelectronic. Eng. 77 (2005) 405CrossRefGoogle Scholar
  17. 17.
    A. Koike, J. Phys. Chem. B 103 (1999) 4578CrossRefGoogle Scholar
  18. 18.
    Y.R. Jeng C.C. Chen S.H. Shyu, Tribol. Lett. 15 (2003) 293CrossRefGoogle Scholar
  19. 19.
    S. Bair, C. McCabe, P.T. Cummings, Phys. Rev. Lett. 88 (2002) 058302CrossRefGoogle Scholar
  20. 20.
    W.C.D. Cheong, L.C. Zhang, Nanotechnology 11 (2000) 173CrossRefGoogle Scholar
  21. 21.
    I. Szlufarska R.K. Kalia A. Nakano P. Vashishta, Appl. Phys. Lett. 85 (2004) 378CrossRefGoogle Scholar
  22. 22.
    C.Y. Tang, L.C. Zhang, Nanotechnology 16 (2005) 15. CrossRefGoogle Scholar
  23. 23.
    R. Komanduri, N. Chandrasekaran, L.M. Raff, Phys. Rev. B 61 (2000) 14007CrossRefGoogle Scholar
  24. 24.
    Y.R. Jeng, P.C. Tsai, T.H. Fang, Tribol. Lett. 18 (2005) 315CrossRefGoogle Scholar
  25. 25.
    C.D. Lorenz, E.B. Webb III, M.J. Stevens, M. Chandross, G.S. Grest, Tribol. Lett. 19 (2005) 93CrossRefGoogle Scholar
  26. 26.
    Q.C. Hsu, C.D. Wu, T.H. Fang, Jpn. J. Appl. Phys. 43 (2004) 7665CrossRefGoogle Scholar
  27. 27.
    J.H. Kang, K.S. Kim, K.W. Kim, J. Korean Soc. Mech. Eng A 29 (2005) 852CrossRefGoogle Scholar
  28. 28.
    O. Okada, K. Oka, S. Kuwajima, S. Toyoda, K. Tanabe, Comput. Theo. Polymer Sci. 10 (2000) 371CrossRefGoogle Scholar
  29. 29.
    H. Sun, Macromolecules 28 (1995) 701CrossRefGoogle Scholar
  30. 30.
    H. Sun, D. Rigby, Spectrochimica Acta Part A 53 (1997) 1301CrossRefGoogle Scholar
  31. 31.
    H. Kittel, Introduction to Solid State Physics (Wiley, New York, 1986)Google Scholar
  32. 32.
    M.P. Allen, D.J. Tildesley, Computer Simulation of Liquids (Clarendon Press, Oxford, 1987)Google Scholar

Copyright information

© Springer Science+Business Media, Inc. 2007

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringKorea Advanced Institute of Science and Technology (KAIST)Yuseong-Gu, DaejeonRepublic of Korea

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