Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-11-25T03:55:37.690Z Has data issue: false hasContentIssue false

Mechanism of Current Leakage in Ni Schottky Diodes on Cubic GaN and AlxGa1-xN Epilayers

Published online by Cambridge University Press:  01 February 2011

Donat J. As
Affiliation:
[email protected], University of Paderborn, Department Physics, Warburger Strasse 100, Paderborn, NRW, 33098, Germany, +49 5251 60 3567, +49 5251 60 3490
Stefan Potthast
Affiliation:
[email protected], University of Paderborn, Department of Physics, Germany
Jara Fernandez
Affiliation:
[email protected], University of Paderborn, Department of Physics, Germany
Klaus Lischka
Affiliation:
[email protected], University of Paderborn, Department of Physics, Germany
Hiroyuki Nagasawa
Affiliation:
[email protected], HOYA Advanced Semiconductor Technologies Co., Ltd., Japan
Masayuki Abe
Affiliation:
[email protected], HOYA Advanced Semiconductor Technologies Co., Ltd.
Get access

Abstract

Ni Schottky-diodes (SDs) 300 μm in diameter were fabricated by thermal evaporation using contact lithography on cubic GaN and AlxGa1-xN epilayers. Phase-pure cubic GaN and c-Al0.3Ga0.7N/GaN structures were grown by plasma assisted molecular beam epitaxy (MBE) on 200 µm thick free-standing 3C-SiC (100) substrates. The quality of the cubic group III-nitride epilayers was checked by high resolution X-ray diffractometry, atomic force microscopy and photoluminescence at room temperature and at 2 K. Large deviations from the thermionic emission transport were observed in the current voltage (I-V) behavior of these SDs. Detailed analysis of the I-V characteristics at 300 K and at low temperature showed that a thin surface barrier is formed at the Ni semiconductor interface. Thermal annealing in air at 200°C alters the composition of this thin surface barrier and reduces the leakage current by three orders of magnitude. The doping density dependence of breakdown voltages derived from the reverse breakdown voltage characteristics of c-GaN SDs is in good agreement with theoretically calculated values and follows the expected trend. From these experimental data a blocking voltage of higher than 600V is extrapolated for c-GaN films with a doping level of ND = 5×1015 cm-3.

Type
Research Article
Copyright
Copyright © Materials Research Society 2006

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1. Morkoc, H. and Liu, L., “GaN-based modulation-doped FETs and heterojunction bipolar transitors”, in edited by Ruterana, P., Albrecht, M. and Neugebauer, J., (WILEY-VCH Verlag GmbH, 2003) pp. 547 Google Scholar
2. Adivarahan, V., Simin, G., Yang, J.W., Lunev, A., Asif Khan, M., Pala, N., Shur, M. and Gaska, R., Appl. Phys. Lett. 77 (6), 863 (2000).CrossRefGoogle Scholar
3. Miller, E.J., Dang, X.Z. and Yu, J., J. Appl. Phys. 88 (10), 5951 (2000).CrossRefGoogle Scholar
4. Karmalkar, S., Sathaiya, D.M. and Shur, M.S., Appl. Phys. Lett. 82 (22), 3976 (2003).CrossRefGoogle Scholar
5. Chand, S. and Bala, S., Appl. Surf. Sci. 252, 358 (2005).CrossRefGoogle Scholar
6. Kotani, S., Hashizume, T. and Hasegawa, H., J. Vac. Sci. Technol. B 22 (4), 2179 (2004).CrossRefGoogle Scholar
7. Dessenne, F., Cichocka, D., Desplanques, P. and Fauquembergue, R., Mat. Sci. and Eng. B 50, 315 (1997).CrossRefGoogle Scholar
8. Abe, M., Nagasawa, H., Potthast, S., Fernandez, J., Schörmann, J., As, D.J. and Lischka, K., IEICE Transaction on Electronics, will be published in July (2006).Google Scholar
9. Maxisch, T. and Baldereschi, A., phys. stat. sol. (c) 2 (7), 2540 (2005).Google Scholar
10. As, D.J., “Growth and characterization of MBE-grown cubic GaN, InxGa1 -xN, and AlyGa1 -yN”, in Optoelectronic Properties of Semiconductors and Superlattices, Vol.19, edited by Manasreh, M.O. and Ferguson, I.T., (Taylor & Francis Books, Inc., 2003) pp. 323 Google Scholar
11. As, D.J., Potthast, S., Schörmann, J., Li, S.F., Lischka, K., Nagasawa, H. and Abe, M., Proc. of ICSCRM (Pittsburgh),, FA2. EPI IV p. 82 Sept. (2005).Google Scholar
12. Wolff, T., Rapp, M. and Rotter, T., phys. stat. sol. (c) 1 (10), 2491 (2004).CrossRefGoogle Scholar
13. Schroder, D.K., in “Semiconductor Material and Device Characterization”, Wiley and Sons, New York (1990)Google Scholar
14. Donoval, D., Barus, M. and Zdimal, M., Solid State Electronics 34 (12), 1365 (1991).CrossRefGoogle Scholar
15. Hasegawa, H. and Oyama, S., J. Vac. Sci. Technol. B 20 (4), 1647 (2002).CrossRefGoogle Scholar
16. Oyama, S., Hashizume, T. and Hasegawa, H., Appl. Surf. Sci. 190, 322 (2002).CrossRefGoogle Scholar
17. Guo, J.D., Pan, F.M., Feng, M.S., Guo, R.J., Chou, P.F. and Chang, C.Y., J. Appl. Phys. 80 (3), 1623 (1996).CrossRefGoogle Scholar
18. Bandic, Z.Z., Bridger, P.M., Piquette, E.C. and McGill, T.C., Appl. Phys. Lett. 74 (9), 1266 (1999).CrossRefGoogle Scholar
19. Dang, G.T., Zhang, A.P., Mshewa, M.M., Ren, F., Chyi, J.I., Lee, C.M., Chuo, C.C., Chi, G.C., Han, J., Chu, S.N.G., Wilson, R.G., Cao, X.A. and Pearton, S.J., J. Vac. Sci. Technol. A 18 (4), 1135 (2000).CrossRefGoogle Scholar
20. Matocha, K., Chow, T.P. and Gutmann, R.J., Materials Science Forum 383–393, 1531 (2002).CrossRefGoogle Scholar