Skip to main content
Log in

Electrical, Morphological, and Compositional Characterization of Screen-Printed Al Contacts Annealed in Horizontal and Vertical Configurations

  • Published:
Journal of Electronic Materials Aims and scope Submit manuscript

Abstract

The electrical, morphological, and compositional characteristics of screen-printed Al paste contacts on p-doped Si wafers have been investigated in horizontal and vertical thermal annealing configurations over a wide temperature range. The horizontal configuration refers to an industrial six-zone conveyor belt rapid thermal annealing furnace. The vertical configuration refers to a modified three-zone quartz tube furnace with vertically stacked wafers. The contact resistivity was measured by using the transmission line method. In the horizontal configuration, the resistivity exhibited a pronounced minimum at temperature of ∼ 870°C, while higher temperatures resulted in a rapid increase in the contact resistivity. In contrast, the resistivity variation in the vertical configuration was linear. The lowest contact resistivities measured were 136 mΩ cm2 in the horizontal and 103 mΩ cm2 in the vertical configuration, demonstrating a 24% reduction with the latter approach. The surface morphology and composition of the Al/Si contact interface were determined by field-emission scanning electron microscopy and energy-dispersive x-ray spectroscopy. The measured elemental concentrations were curve-fit to accurately measure the width of the interface regions. The Al/Si contact region was observed to consist of five parts: (a) a top sintered paste layer of Al/Si spheres, (b) voids between the Al/Si spheres, (c) an Al/Si eutectic region, (d) an epitaxially grown Al-doped Si layer, and (e) the lightly Al-diffused Si substrate. Sintered Al/Si spheres were observed to consist of a solid core of Al embedded in a thin shell of Al, Al2O3, SiO2, and Si. The rapid rise in resistivity at high temperatures is attributed to enhanced oxidation of Al and Si islands, resulting in thicker Al2O3/SiO2 films between metallic Al spheres. The lower resistivity observed in the vertical configuration was attributed to larger, more uniform Al–Si eutectic regions, higher density of Al/Si films within the paste region, and transformation of sintered Al spheres into larger pseudosquare islands. The proposed Al/Si interface model was further supported by the higher resistance measured for the pulsed laser-based Al/Si contact with high Si concentrations in the Al/Si eutectic region. An approximately linear reduction in resistivity as a function of time over a broad range varying from microseconds to seconds reinforced the proposed model and suggests that longer, steady-state annealing is the preferred approach to achieve the lowest contact resistivity.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Renewables 2018 Global status report (2018). www.ren21.net. Accessed 29 March 2019.

  2. S.H. Zaidi, D.S. Ruby, and J.M. Gee, IEEE Trans. Electron Devices 48, 1200 (2001).

    Article  Google Scholar 

  3. S.M. Ahmad, S.L. Cheow, N.L. Ludin, K. Sopian, and S.H. Zaidi, Res. Phys. 7, 2183 (2017).

    Google Scholar 

  4. S.M. Ahmad, C.S. Leong, R.W. Winder, K. Sopian, and S.H. Zaidi, J. Electron. Mater. 47, 6791 (2018).

    Article  Google Scholar 

  5. J. Del Alamo, J. Eguren, and A. Luque, Solid-State Electron. 24, 415 (1981).

    Article  Google Scholar 

  6. C.S. Solanki, Solar Photovoltaics Fundamentals, Technologies and Applications (Delhi: PHI Learning, 2011), p. 80.

    Google Scholar 

  7. S.M. Sze and K.K. Ng, Physics of Semiconductor Devices (New York: Wiley, 2007), p. 187.

    Google Scholar 

  8. B. Sopori, V. Mehta, P. Rupnowski, H. Moutinho, A. Shaikh, C. Khadilkar, M. Bennett, and D. Carlson, MRS Proceedings vol. 1123 (2008), p. 5.

  9. R. Hoenig, Ph.D. Thesis, University of Freiburg, Freiburg (2014).

  10. I.B. Cooper, A. Ebong, J.S. Renshaw, R. Reedy, M. Al-Jassim, and A. Rohatgi, IEEE Electron Device Lett. 31, 461 (2010).

    Article  Google Scholar 

  11. E. Cabrera, S. Olibet, J. Glatz-Reichenbach, R. Kopecek, D. Reinke, and G. Schubert, J. Appl. Phys. 110, 114511 (2011).

    Article  Google Scholar 

  12. Y. Yang, S. Seyedmohammadi, U. Kumar, D. Gnizak, E. Graddy, and A. Shaikh, Energy Procedia 8, 607 (2011).

    Article  Google Scholar 

  13. D.M. Huljic, D. Biro, R. Preu, C.C. Castillo, and R. Ludemann, in 28th IEEE PVSC (2000).

  14. J.W. Jeong, A. Rohatgi, V. Yelundur, A. Ebong, M.D. Rosenblum, and J.P. Kalejs, IEEE Trans. Electron Devices 48, 2836 (2001).

    Article  Google Scholar 

  15. P.N. Vinod, Semicond. Sci. Technol. 20, 966 (2005).

    Article  Google Scholar 

  16. H.H. Berger, J. Electrochem. Soc. 119, 507 (1972).

    Article  Google Scholar 

  17. D.K. Schroder and D.L. Meier, IEEE Trans. Electron Devices ED-31, 637 (1984).

    Article  Google Scholar 

  18. D.L. Meier and D.K. Schroder, IEEE Trans. Electron Devices ED-31, 647 (1984).

    Article  Google Scholar 

  19. P.N. Vinod, J. Mater. Sci.: Mater. Electron. 22, 1248 (2011).

    Google Scholar 

  20. G.K. Reeves and H.B. Harrison, IEEE Electron Device Lett. 3, 111 (1982).

    Article  Google Scholar 

  21. E.G. Woelk, H. Krautle, and H. Beneking, IEEE Trans. Electron Devices 33, 19 (1986).

    Article  Google Scholar 

  22. A. Ebong and N. Chen, in 9th International Conference on High Capacity Optical Networks and Enabling Technologies (HONET) (2012).

  23. C.P. Winsor, Proc. Natl. Acad. Sci. 18, 1 (1932).

    Article  Google Scholar 

  24. J.O. McCaldin and H. Sankur, Appl. Phys. Lett. 19, 524 (1971).

    Article  Google Scholar 

  25. I. Egry, Scr. Metall. Mater. 28, 1273 (1993).

    Article  Google Scholar 

  26. J.L. Murray and A.J. McAlister, Bull. Alloy Phase Diagr. 5, 74 (1984).

    Article  Google Scholar 

  27. T. Yoshikawa and K. Morita, J. Electrochem. Soc. 150, 465 (2003).

    Article  Google Scholar 

  28. O. Krause, H. Ryssel, and P. Pichler, J. Appl. Phys. 91, 5645 (2002).

    Article  Google Scholar 

  29. M.A. Trunov, M. Schoenitz, and E.L. Dreizin, Combust. Theory Model. 10, 603 (2006).

    Article  Google Scholar 

  30. F. Huster, in 20th EUPVSEC (2005).

  31. V.A. Popovich, M.P.F.H.L. van Maris, M. Janssen, I.J. Bennett, and I.M. Richardson, Mater. Sci. Appl. 4, 118 (2013).

    Google Scholar 

  32. M. Balucani, L. Serenelli, K. Kholostov, P. Nenzi, M. Miliciani, F. Mura, M. Izzi, and M. Tucci, Energy Procedia 43, 100 (2013).

    Article  Google Scholar 

  33. E. Urrejola, K. Peter, H. Plagwitz, and G. Schubert, Appl. Phys. Lett. 98, 96 (2011).

    Google Scholar 

  34. J. Krause, R. Woehl, M. Rauer, C. Schmiga, J. Wilde, and D. Biro, Sol. Energy Mater. Solar Cells 95, 2151 (2011).

    Article  Google Scholar 

  35. T. Lauermann, B. Fröhlich, G. Hahn, and B. Terheiden, Prog. Photovolt. 23, 10 (2015).

    Article  Google Scholar 

  36. T.-S. Shih and Z.-B. Liu, Mater. Trans. 47, 1347 (2006).

    Article  Google Scholar 

Download references

Acknowledgments

The authors would like to thank the Malaysian government for partial funding of this research through PRGS, FRGS, ERGS, AP, and MIDA Grants. We would also like to thank Ms. S. Seow for invaluable assistance with SEM and EDX measurements.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Samir Mahmmod Ahmad.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Ahmad, S.M., Leong, C.S., Winder, R.W. et al. Electrical, Morphological, and Compositional Characterization of Screen-Printed Al Contacts Annealed in Horizontal and Vertical Configurations. J. Electron. Mater. 48, 6382–6396 (2019). https://doi.org/10.1007/s11664-019-07409-x

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11664-019-07409-x

Keywords

Navigation