Effect of nitrogen flow ratio on the microstructure evolution and nanoindented mechanical property of the Ta–Si–N thin films


The relations among the process, microstructure, and nanomechanical properties of cosputtered Ta–Si–N thin films have been investigated. The microstructure evolution and varied hardness and elastic modulus property of Ta–Si–N were influenced by nitrogen flow ratios [FN2% = FN2/(Far + FN2) × 100%] during cosputtering together with phase formation and the composition of films. The microstructure of Ta–Si–N formed at a low 2–10 FN2% was an amorphous-like phase with nanocrystalline grains embedded in an amorphous matrix, while polycrystalline Ta–Si–N was obtained at a high 20–30 FN2%. The cubic TaN phase or (Ta1–x,Six)N solid solution is much easier to form polycrystallites than noncubic Ta5Si3, Ta2Si, and Ta2N phases from grazing incidence x-ray diffractometry results. Amorphous-like Ta–Si–N films had much higher nanohardness, stiffness, elastic recovery percentage, and a closer boundary compared to polycrystalline films. A maximum nanohardness of 15.2 GPa was obtained at 3 FN2%. An increased hardness of polycrystalline films at 20–30 FN2% is attributed to the higher amount of the hard TaN phase.

This is a preview of subscription content, access via your institution.

FIG. 1
FIG. 2
FIG. 3
FIG. 4
FIG. 5
FIG. 6


  1. 1

    S. PalDey S.C. Deevi: Properties of single layer and gradient (Ti,Al)N coatings. Mater. Sci. Eng., A 342, 58 2003

    Article  Google Scholar 

  2. 2

    E. Kolawa, J.S. Chen, J.S. Reid, P.J. Pokela M.A. Nicolet: Tantalum-based diffusion-barriers in Si/Cu VLSI metallizations. J. Appl. Phys. 70, 1369 1991

    CAS  Article  Google Scholar 

  3. 3

    R. Hubner, M. Hecker, N. Mattern, A. Voss, J. Acker, V. Hoffmann, K. Wetzig, H.J. Engelmann, E. Zschech, H. Heuer C. Wenzel: Influence of nitrogen content on the crystallization behavior of thin Ta–Si–N diffusion barriers. Thin Solid Films 468, 183 2004

    CAS  Article  Google Scholar 

  4. 4

    C.K. Chung, T.S. Chen, C.C. Peng B.H. Wu: Thermal stability of Ta–Si–N nanocomposite thin films at different nitrogen flow ratios. Surf. Coat. Technol. 201, 3947 2006

    CAS  Article  Google Scholar 

  5. 5

    S.J. Suresha, R. Bhide, V. Jayaram S.K. Biswas: Processing, microstructure and hardness of TiN/(Ti, Al)N multilayer coatings. Mater. Sci. Eng., A 429, 252 2006

    Article  Google Scholar 

  6. 6

    S. Veprek, M.G.J. Veprek-Heijman, P. Karvankova J. Prochazka: Different approaches to superhard coatings and nanocomposites. Thin Solid Films 476, 1 2005

    CAS  Article  Google Scholar 

  7. 7

    J. Musil: Hard and superhard nanocomposite coatings. Surf. Coat. Technol. 125, 322 2000

    CAS  Article  Google Scholar 

  8. 8

    J.W. Nah, W.S. Choi, S.K. Hwang C.M. Lee: Chemical state of (Ta, Si)N reactively sputtered coating on a high-speed steel substrate. Surf. Coat. Technol. 123, 1 2000

    CAS  Article  Google Scholar 

  9. 9

    C.K. Chung P.J. Su: Material characterization and nanohardness measurement of nanostructured Ta–Si–N film. Surf. Coat. Technol. 188–89, 420 2004

    Article  Google Scholar 

  10. 10

    C.K. Chung T.S. Chen: Effect of microstructures on the electrical and optoelectronic properties of nanocrystalline Ta–Si–N thin films by reactive magnetron cosputtering. Scripta Mater. 57, 611 2007

    CAS  Article  Google Scholar 

  11. 11

    B. Zhu, R.J. Asaro, P. Krysl, K. Zhang J.R. Weertman: Effects of grain size distribution on the mechanical response of nanocrystalline metals: Part II. Acta Mater. 54, 3307 2006

    CAS  Article  Google Scholar 

  12. 12

    K.S. Kumar, H. Van Swygenhoven S. Suresh: Mechanical behavior of nanocrystalline metals and alloys. Acta Mater. 51, 5743 2003

    CAS  Article  Google Scholar 

  13. 13

    R. Sanjines, M. Benkahoul, C.S. Sandu, P.E. Schmid F. Levy: Relationship between the physical and structural properties of NbzSiyNx thin films deposited by dc reactive magnetron sputtering. J. Appl. Phys. 98, 123511 2005

    Article  Google Scholar 

  14. 14

    W.C. Oliver G.M. Pharr: An important technique for determining hardness and elastic-modulus using load and displacement sensing indentation experiments. J. Mater. Res. 7, 1564 1992

    CAS  Article  Google Scholar 

  15. 15

    I.N. Sneddon: The relation between load and penetration in the axisymmetric Boussinesq problem for a punch of arbitrary profile. Int. J. Eng. Sci. 3, 47 1965

    Article  Google Scholar 

  16. 16

    X.D. Li B. Bhushan: A review of nanoindentation continuous stiffness measurement technique and its applications. Mater. Charact. 48, 11 2002

    CAS  Article  Google Scholar 

  17. 17

    JCPDS Nos. 26-0985, 32-1283, 06-0552, 72-127518-1312. International Center for Diffraction Data Newton Square, PA, 1997

  18. 18

    B.D. Cullity: Elements of X-Ray Diffractions 2nd ed. Addison-Wesley Press Lond 1987 Chaps. 3–4

    Google Scholar 

  19. 19

    S. Zhang, D. Sun, Y.Q. Fu H.J. Du: Recent advances of superhard nanocomposite coatings: A review. Surf. Coat. Technol. 167, 113 2003

    CAS  Article  Google Scholar 

  20. 20

    J. Schiotz K.W. Jacobsen: A maximum in the strength of nanocrystalline copper. Science 301, 1357 2003

    CAS  Article  Google Scholar 

Download references


This work was partially sponsored by the National Science Council under Grant Nos. NSC 95-2221-E-006-047-MY3 and NSC 96-2628-E-006-080-MY3. We would like to express our sincere thanks to the microelectronic thin films laboratory for access to sputtering equipment. We also give great thanks to the Center for Micro/Nano Science and Technology (CMNST) and the Center for Precious Instruments at National Cheng Kung University, Tainan, Taiwan, for access to analysis equipment and technical support.

Author information



Corresponding author

Correspondence to C.K. Chung.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Chung, C., Chen, T. Effect of nitrogen flow ratio on the microstructure evolution and nanoindented mechanical property of the Ta–Si–N thin films. Journal of Materials Research 23, 494–499 (2008). https://doi.org/10.1557/JMR.2008.0065

Download citation