Electrical Characterization of Sputter Deposition Induced Defects in n-GaN


We have used current-voltage (I-V) measurements to assess and compare the electrical characteristics of resistively evaporated and sputter deposited Au Schottky contacts on epitaxially grown GaN. These I-V measurements revealed that resistively deposited Au contacts exhibited excellent rectification properties: high barrier height, low reverse current and good ideality factor (n = 1.04). In contrast, sputter deposited contacts had poor characteristics: low barrier height, high reverse current and non-linear forward I-V characteristics. The cause of this is thought to be defects introduced at and near the surface during sputter deposition. Deep level transient spectroscopy (DLTS) showed that at least four defects, with energy levels at 0.22±0.02 eV, 0.30±0.01 eV, 0.40±0.01 eV and 0.45±0.10 eV below the conduction band, were introduced in the GaN during sputter deposition. The first of these defects has similar electronic properties as a radiation induced defect in GaN, speculated to be the nitrogen vacancy, while the second appears to be the same as a defect in the as-grown material. The latter two defects have not previously been observed in as-grown or processed epitaxial GaN.

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  1. [1]

    S. Nakamura and G. Fasol, in “The blue laser diode”, (Springer Verlag, 1997).

    Google Scholar 

  2. [2]

    K. Doverspike, A. E. Wickenden, S. C. Binarii, D. K. Gaskill and J. A. Freitas, Mat. Res. Soc. Symp. Proc. Vol. 395, p 897 (1996).

    CAS  Article  Google Scholar 

  3. [3]

    L. I. Maissel: in “Handbook of thin film technology”, (ed. L. I. Maissel and R. Glan), 1–4; 1970, New York, McGraw-Hill.

    Google Scholar 

  4. [4]

    F. H. Mullins and A. Brunnschweiler, Solid State Electron. 19, 47 (1976).

    Article  Google Scholar 

  5. [5]

    E. Grussell, S. Berg and L. P. Andersson, J. Electrochem. Soc. 127, 1573 (1980).

    Article  Google Scholar 

  6. [6]

    D. A. Vanderbroucke, R. L. van Mierhaegte, W. H. Lafrere and F. Cardon, Semicond. Sci. Technol. 2, 293 (1987).

    Article  Google Scholar 

  7. [7]

    S. J. Fonash, S. Ashok and R. Singh, Appl. Phys. Lett. 39, 423 (1981).

    CAS  Article  Google Scholar 

  8. [8]

    F. D. Auret, S. A. Goodman, Y. Leclerc, G. Myburg and C. Schutte, Materials Science and Technology 13, 945 (1997).

    CAS  Article  Google Scholar 

  9. [9]

    D. V. Lang, J. Appl. Phys. 45, 3023 (1974).

    CAS  Article  Google Scholar 

  10. [10]

    P. Hacke, T. Detchprohm, K. Hiramatsu and N. Sawaki, Appl. Phys. Lett. 63, 2676, (1993).

    CAS  Article  Google Scholar 

  11. [11]

    S. Ruvimov, Z. Liliental-Weber, J. Washburn, K. J. Duxstad, E. E. Hailer, Z.-F. Fan, S. N. Mohammed, W. Kim, A. E. Botchkarev and H. Morkoc, Appl. Phys. Lett. 69, 1556, (1996).

    CAS  Article  Google Scholar 

  12. [12]

    P. Hacke, T. Detchprohm, K. Hiramatsu, N. Sawaki, K. Tadatomo and K. Miyake, J. Appl. Phys. 76, 304 (1994).

    CAS  Article  Google Scholar 

  13. [13]

    W. Götz, N. M. Johnson, H. Amano and I. Akasaki, Appl. Phys. Lett. 65, 463 (1994).

    Article  Google Scholar 

  14. [14]

    Q. Y. Ma, M. T. Schmidt, X. Wu, H. L. Evans and E. S. Yang, J. Appl. Phys. 64, 2469 (1988).

    CAS  Article  Google Scholar 

  15. [15]

    F. D. Auret, S. A. Goodman, F. K. Koschnick, J.-M. Spaeth, B. Beaumont and P. Gibart, Appl. Phys. Lett. (L98-6265), January 18, 1999.

    Google Scholar 

  16. [16]

    Z-Q. Fang, D. C. Look, W. Kim, Z. Fan, A. Botchkarev and H. Morkoc, Appl. Phys. Lett. 72, 2277 (1998).

    CAS  Article  Google Scholar 

  17. [17]

    D. Haase, M. Schmid, W. Kürner, A. Dörnen, V. Häirle, F. Scholtz, M. Burkard and H. Schweitzer, Appl. Phys. Lett. 69, 2525 (1996).

    CAS  Article  Google Scholar 

  18. [18]

    F. D. Auret, G. Myburg, S. A. Goodman, L. J. Bredell and W. O. Barnard, Nucl. Instr. and Meth. in Phys. Res. B67, 411 (1992).

    Google Scholar 

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Auret, F.D., Goodman, S.A., Koschnick, F.K. et al. Electrical Characterization of Sputter Deposition Induced Defects in n-GaN. MRS Online Proceedings Library 537, 613 (1998). https://doi.org/10.1557/PROC-537-G6.13

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