Advertisement

Investigation of a Self-Aligned Cobalt Silicide Process for Ohmic Contacts to Silicon Carbide

  • Mattias EkströmEmail author
  • Andrea Ferrario
  • Carl-Mikael Zetterling
Open Access
Article

Abstract

Previous studies showed that cobalt silicide can form ohmic contacts to p-type 6H-SiC by directly reacting cobalt with 6H-SiC. Similar results can be achieved on 4H-SiC, given the similarities between the different silicon carbide polytypes. However, previous studies using multilayer deposition of silicon/cobalt on 4H-SiC gave ohmic contacts to n-type. In this study, we investigated the cobalt silicide/4H-SiC system to answer two research questions. Can cobalt contacts be self-aligned to contact holes to 4H-SiC? Are the self-aligned contacts ohmic to n-type, p-type, both or neither? Using x-ray diffraction, it was found that a mixture of silicides (\(\hbox {Co}_2\hbox {Si}\) and CoSi) was reliably formed at 800\(^\circ \)C using rapid thermal processing. The cobalt silicide mixture becomes ohmic to epitaxially grown n-type (\(1\times 10^{19} \hbox {cm}^{-3}\)) if annealed at 1000\(^\circ \)C, while it shows rectifying properties to epitaxially grown p-type (\(1\times 10^{19} \hbox {cm}^{-3}\)) for all tested anneal temperatures in the range 800–1000\(^\circ \)C. The specific contact resistivity (\(\rho _\mathrm{C}\)) to n-type was \(4.3 \times 10^{-4}\) \(\mathrm {\Omega }\)\(\,\hbox {cm}^{2}\). This work opens the possibility to investigate other self-aligned contacts to silicon carbide.

Keywords

Cobalt (Co) rapid thermal processing (RTP) self-aligned silicide silicon carbide (4H-SiC) transfer length method (TLM) 

Notes

Acknowledgments

Thanks goes to Tomas Kubart for assisting in the cobalt deposition. Thanks goes to Gunnar Malm, who provided much appreciated feedback on the manuscript. The authors thank the Knut and Alice Wallenberg Foundation for funding this research as a part of the Working on Venus project.

Open Access

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

References

  1. 1.
    A. Stavrinidis, G. Konstantinidis, K. Vamvoukakis, and K. Zekentes, Mater. Sci. Forum (2017).  https://doi.org/10.4028/www.scientific.net/MSF.897.407 Google Scholar
  2. 2.
    H. Elahipanah, A. Asadollahi, M. Ekström, A. Salemi, C.M. Zetterling, and M. östling, ECS J. Solid State Sci. Technol. (2017).  https://doi.org/10.1149/2.0041705jss Google Scholar
  3. 3.
    M. Ekström, S. Hou, H. Elahipanah, A. Salemi, M. östling, and C.M. Zetterling, Mater. Sci. Forum (2018).  https://doi.org/10.4028/www.scientific.net/MSF.924.389 Google Scholar
  4. 4.
    S.Y. Jiang, X.Y. Li, and Z.Z. Chen, IEEE Trans Electron Devices (2018).  https://doi.org/10.1109/TED.2017.2784098 Google Scholar
  5. 5.
    V.K. Sundaramoorthy, R.A. Minamisawa, L. Kranz, L. Knoll, and G. Alfieri, Mater. Sci. Forum (2018).  https://doi.org/10.4028/www.scientific.net/MSF.924.413 Google Scholar
  6. 6.
    N. Kiritani, M. Hoshi, S. Tanimoto, K. Adachi, S.I. Nishizawa, T. Yatsuo, H. Okushi, and K. Arai, Mater. Sci. Forum (2003).  https://doi.org/10.4028/www.scientific.net/MSF.433-436.669 Google Scholar
  7. 7.
    K.C. Kragh-Buetow, R.S. Okojie, D. Lukco, and S.E. Mohney, Semicond. Sci. Technol. (2015).  https://doi.org/10.1088/0268-1242/30/10/105019 Google Scholar
  8. 8.
    H. Shimizu, A. Shima, Y. Shimamoto, and N. Iwamuro, Jpn. J. Appl. Phys. (2017).  https://doi.org/10.7567/JJAP.56.04CR15 Google Scholar
  9. 9.
    D.X. Xu, S.R. Das, C.J. Peters, and L.E. Erickson, Thin Solid Films (1998).  https://doi.org/10.1016/S0040-6090(98)00547-1 Google Scholar
  10. 10.
    J.P. Gambino, E.G. Colgan, and Mater. Chem. Phys. (1998).  https://doi.org/10.1016/S0254-0584(98)80014-X Google Scholar
  11. 11.
    S.L. Zhang, and M. Östling, Crit. Rev. Solid State Mater. Sci. (2003).  https://doi.org/10.1080/10408430390802431 Google Scholar
  12. 12.
    C.K. Lau, Y.C. See, D.B. Scott, J.M. Bridges, S.M. Perna, and R.D. Davies, IEEE International Electron Devices Meeting (IEDM) (1982), pp. 714–717Google Scholar
  13. 13.
    K. Maex, Mater. Sci. Eng. R (1993).  https://doi.org/10.1016/0927-796X(93)90001-J Google Scholar
  14. 14.
    Z. Zhang, S.L. Zhang, M. Östling, and J. Lu, Appl. Phys. Lett. (2006).  https://doi.org/10.1063/1.2194313 Google Scholar
  15. 15.
    N. Lundberg, and M. Östling, Solid-State Electron. (1996).  https://doi.org/10.1016/0038-1101(96)00071-8 Google Scholar
  16. 16.
    T. Kimoto and J.A. Cooper, Fundamentals of Silicon Carbide Technology (Wiley, Singapore, 2014), p. 33.Google Scholar
  17. 17.
    A.O. Evwaraye, S.R. Smith, and W.C. Mitchel, Appl. Phys. Lett. (1995).  https://doi.org/10.1063/1.115233 Google Scholar
  18. 18.
    V.V. Afanas’ev, M. Bassler, G. Pensl, M.J. Schulz, and E. Stein von Kamienski, J. Appl. Phys. (1996).  https://doi.org/10.1063/1.361254 Google Scholar
  19. 19.
    G. Pasold, F. Albrecht, J. Grillenberger, U. Grossner, C. Hülsen, W. Witthuhn, and R. Sielemann, J. Appl. Phys. (2003).  https://doi.org/10.1063/1.1539539 Google Scholar
  20. 20.
    S.K. Lee, C.M. Zetterling, and M. Östling, J. Electron. Mater. (2001).  https://doi.org/10.1007/s11664-001-0023-1 Google Scholar
  21. 21.
    N.I. Cho, K.H. Jung, and Y. Choi, Semicond. Sci. Technol. (2004).  https://doi.org/10.1088/0268-1242/19/3/003 Google Scholar
  22. 22.
    S.J. Yang, C.K. Kim, I.H. Noh, S.W. Jang, K.H. Jung, and N.I. Cho, Diam. Relat. Mater. (2004).  https://doi.org/10.1016/j.diamond.2003.10.067 Google Scholar
  23. 23.
    K. Smedfors, C.M. Zetterling, and M. Östling, Mater. Sci. Forum (2015).  https://doi.org/10.4028/www.scientific.net/MSF.821-823.440 Google Scholar
  24. 24.
    K. Smedfors, Ohmic Contacts for High Temperature Integrated Circuits in Silicon Carbide (KTH Royal Institute of Technology, Stockholm, 2014).Google Scholar
  25. 25.
    A. Ferrario, Processing and characterization of self-aligned Ni/Al and Co ohmic contacts to 4H-SiC (KTH Royal Institute of Technology, Stockholm, 2018).Google Scholar
  26. 26.
    T. Fujimura, and S.I. Tanaka, J. Mater. Sci. (1999).  https://doi.org/10.1023/A:1004750016287 Google Scholar
  27. 27.
    C.S. Lim, J.S. Ha, J.H. Ryu, K.H. Auh, I.T. Bae, M. Ishimaru, and Y. Hirotsu, Mater. Trans. (2002).  https://doi.org/10.2320/matertrans.43.1225 Google Scholar
  28. 28.
    R.S. Okojie, and D. Lukco, J. Appl. Phys. (2016).  https://doi.org/10.1063/1.4968572 Google Scholar
  29. 29.
    M. Vivona, G. Greco, C. Bongiorno, S. Di Franco, R. Lo Nigro, S. Scalese, S. Rascunà, M. Saggio, and F. Roccaforte, Mater. Sci. Forum (2018).  https://doi.org/10.4028/www.scientific.net/MSF.924.377 Google Scholar
  30. 30.
    R. Nipoti, M. Puzzanghera, M. Canino, G. Sozzi, and P. Fedeli, Mater. Sci. Forum (2018).  https://doi.org/10.4028/www.scientific.net/MSF.924.385 Google Scholar
  31. 31.
    D.K. Schroder, Semiconductor Material and Device Characterization, 3rd edn. (Wiley, New Jersey, 2006), pp. 135–157.Google Scholar
  32. 32.
    L. Jablonka, L. Riekehr, Z. Zhang, S.L. Zhang, and T. Kubart, Appl. Phys. Lett. (2018).  https://doi.org/10.1063/1.5011109 Google Scholar
  33. 33.
    R. Pretorius, J.M. Harris, and M.A. Nicolet, Solid-State Electron. (1978).  https://doi.org/10.1016/0038-1101(78)90335-0 Google Scholar
  34. 34.
    T. Nguyen, H.L. Ho, D.E. Kotecki, and T.D. Nguyen, J. Appl. Phys. (1996).  https://doi.org/10.1063/1.362667 Google Scholar
  35. 35.
    M.H. Juang, and H.C. Cheng, Thin Solid Films (1992).  https://doi.org/10.1016/0040-6090(92)90703-E Google Scholar

Copyright information

© The Author(s) 2019

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Authors and Affiliations

  1. 1.Department of Electronics, School of Electrical Engineering and Computer ScienceKTH Royal Institute of TechnologyKistaSweden

Personalised recommendations