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Stress Induced Degradation of High-k Gate Dielectric Ta2O5 Thin Films on Silicon

  • Upendra KashniyalEmail author
  • Kamal P. Pandey
Conference paper
Part of the Springer Proceedings in Physics book series (SPPHY, volume 215)

Abstract

This work describes the influence of constant current stress induced degradation in reactively sputtered Ta2O5 thin film in pure argon and argon plus nitrogen within plasma. Capacitors were fabricated and the interface was characterized using I-V and C-V methods. X-ray diffraction (XRD) technique revealed the presence of N2 content in Ta2O5 films. A comparison between Ta2O5 films doped with and without N2 with respect to flat band shift and leakage current density is also presented. Post deposition annealing at 650° CreducesO/Ta ratio because of the formation of suboxides. It results in high quality TaOx film with high capacitance and low leakage current. On being stressed, flat band voltage in annealed devices shifts towards negative direction as a result positive charge traps are observed in high-k thin films. Incorporation of nitrogen in Ta2O5 dielectric films retain the intrinsic effect that significantly diminish the electron leakage current through deactivating the Vo (oxygen vacancy) related gap states.

Notes

Acknowledgements

Authors thank Prof. B. R. Singh, IIIT-Allahabad for his constant support and encouragement.

References

  1. 1.
    S.H. Lo, D.A. Buchanan, Y. Taur, W. Wang, Quantum-mechanical modeling of electron tunneling current from the inversion layer of ultra-thin-oxide nMOSFET’s. IEEE Electron Device Lett. 18(5), 209–211 (1997)ADSCrossRefGoogle Scholar
  2. 2.
    G.D. Wilk, R.M. Wallace, J.M. Anthony, High-κ gate dielectrics: current status and materials properties considerations. J. Appl. Phys. 89(10), 5243–5275 (2001)ADSCrossRefGoogle Scholar
  3. 3.
    R.M. Wallace, G.D. Wilk, High-κ dielectric materials for microelectronics. Crit. Rev. Solid State Mater. Sci. 28(4), 231–285 (2003)ADSCrossRefGoogle Scholar
  4. 4.
    M. Houssa, M. Naili, V.V. Afanas’ev, M.M. Heyns, A. Stesmans, Electrical and physical characterization of high-k dielectric layers, in Proceedings of IEEE International Symposium on VLSI Technology, Systems, and Applications, pp. 196–199 (2001)Google Scholar
  5. 5.
    R.M. Wallace, G. Wilk, Alternative gate dielectrics for microelectronics. MRS Bull. 27(3), 186–191 (2002)CrossRefGoogle Scholar
  6. 6.
    S.P. Garg, N. Krishnamurthy, A. Awasthi, M. Venkatraman, The O–Ta (oxygen–tantalum) system. J. Phase Equilibria 17(1), 63–77 (1996)CrossRefGoogle Scholar
  7. 7.
    M.M. Howard, C.A. Ventrice, H. Geisler, D.A. Hite, P.T. Sprunger, Growth morphology and electronic structure of ultra-thin TaOx films on Ag (100), in MRS Online Proceedings Library Archive, vol. 623 (2000)Google Scholar
  8. 8.
    H. Sawada, K. Kawakami, Electronic structure of oxygen vacancy in Ta2O5. J. Appl. Phys. 86(2), 956–959 (1999)ADSCrossRefGoogle Scholar
  9. 9.
    A.P. Huang, P.K. Chu, Improvement of interfacial and dielectric properties of sputtered Ta2O5 thin films by substrate biasing and the underlying mechanism. J. Appl. Phys. 97(11), 114106 (2005)ADSCrossRefGoogle Scholar
  10. 10.
    E. Atanassova, A. Paskaleva, Breakdown fields and conduction mechanisms in thin Ta2O5 layers on Si for high density DRAMs. Microelectron. Reliab. 42(2), 157–173 (2002)CrossRefGoogle Scholar
  11. 11.
    E. Atanassova, D. Spassov, Hydrogen annealing effect on the properties of thermal Ta2O5 on Si. Microelectron. J. 30(3), 265–274 (1999)CrossRefGoogle Scholar
  12. 12.
    Y.S. Kim, M.Y. Sung, Y.H. Lee, B.K. Ju, M.H. Oh, The influence of surface roughness on the electric conduction process in amorphous Ta2O5 thin films. J. Electrochem. Soc. 146(9), 3398–3402 (1999)CrossRefGoogle Scholar
  13. 13.
    T. Hori, Gate Dielectric and MOS ULSI. Principles, Technologies and Applications. In Springer Series in Electronics and Photonics, vol. 34 (1997)Google Scholar
  14. 14.
    W.K. Choi, L.S. Tan, J.Y. Lim, S.G. Pek, Electrical characterisation of RF sputtered tantalum oxide films rapid thermal annealed with Ar, N2, O2 and N2O. Thin Solid Films 343, 105–107 (1999)ADSCrossRefGoogle Scholar
  15. 15.
    K.H. Goh, H.J. Lee, S.K. Lau, P.C. Teh, S. Ramesh, C.Y. Tan, Y.H. Wong, Investigation of the effect of anodization time and annealing temperature on the physical properties of ZrO2 thin film on a Si substrate. Mater. Res. Express 4(8), 086414 (2017)ADSCrossRefGoogle Scholar
  16. 16.
    S. Knebel et al. Reliability comparison of ZrO2 based DRAM High-k dielectrics under DC and AC Stress. IEEE Trans. Device Mater. Reliab. (2017)Google Scholar
  17. 17.
    H.E. Cheng, C.T. Mao, The effect of substrate temperature on the physical properties of tantalum oxide thin films grown by reactive radio-frequency sputtering. Mater. Res. Bull. 38(14), 1841–1849 (2003)CrossRefGoogle Scholar
  18. 18.
    E. Atanassova, A. Paskaleva, High temperature N/sub 2/annealing-a promising way for improving the structure of Ta/sub 2/O/sub 5/and its interface with Si, in 24th IEEE International Conference on Microelectronics, vol. 2 (2004), pp. 467–470Google Scholar
  19. 19.
    Y.S. Lai, K.J. Chen, J.S. Chen, Investigation of the interlayer characteristics of Ta2O5 thin films deposited on bare, N2O, and NH3 plasma nitridated Si substrates. J. Appl. Phys. 91(10), 6428–6434 (2002)ADSCrossRefGoogle Scholar
  20. 20.
    U. Kashniyal, K.P. Pandey, Stress induced degradation and reliability of Al2O3 thin film on silicon. Vacuum 152, 109–113 (2018)ADSCrossRefGoogle Scholar
  21. 21.
    E.H. Nicollian, J.R. Brews, MOS (Metal Oxide Semiconductor) Physics and Technology (Wiley, New York, 1982)Google Scholar
  22. 22.
    A. Rao, J. D’sa, S. Goyal, B.R. Singh, Conduction and field induced degradation in thin ZrO2 films sputtered in nitrogen containing plasma on silicon. J. Mater. Sci.: Mater. Electron. 25(3), 1583–1588 (2014)Google Scholar
  23. 23.
    N.K. Ponon, D.J.R. Appleby, E. Arac, P.J. King, S. Ganti, K.S.K. Kwa, A. O’Neill, Effect of deposition conditions and post deposition anneal on reactively sputtered titanium nitride thin films. Thin Solid Films 578, 31–37 (2015)ADSCrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Department of Electronics and CommunicationShambhunath Institute of Engineering and TechnologyAllahabadIndia

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