Abstract
Effects of annealing ambient of an oxygen and nitrogen mixed gas on the electrical properties were studied for Au-based ohmic contacts (NiAu, CoAu, CuAu, PdAu, and PtAu) to p-type GaN. Addition of oxygen to the nitrogen gas reduced the specific contact resistances (ρc) and resitivities of the p-GaN epilayers (ρs) of the contacts after annealing at temperatures of 500–600°C. The microstructural analysis at the p-GaN/metal interfaces did not detect the heterostructural intermediate semiconductor layer at the GaN/metal interfaces. The reason for reduction of both the ρc and ρs values by the oxygen gas addition was believed to be due to formation of the p-GaN epilayer with high hole concentrations, caused by removal of hydrogen atoms which bonded with Mg atoms.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
S. Nakamura and G. Fahsol, The Blue Laser Diodes, (Berlin: Springer Verlag, 1997), Chap. 2.
H. Ishikawa, S. Kobayashi, Y. Koide, S. Yamazaki, S. Nagai, J. Umezaki, M. Koike and M. Murakami, J. Appl. Phys. 81, 1315 (1997).
M. Murakami and Y. Koide, Critical Riviews in Solid State and Materials Sciences 23, 1 (1998).
N. Shibata, J. Umezaki, M. Asai, T. Uemura, T. Kozawa, T. Mori and T. Owaki, Japanese Unexamined Patent, No. 09064337A.
H.H. Berger, Solid-State Electron. 15, 145 (1972).
S. Nakamura, N. Iwasa, M. Senoh and T. Mukai, Jpn. J. Appl. Phys. 31, 1258 (1992).
M.S. Brandt, J.W. Ager III, W. Götz, N.M. Johnson, J.S. Harris, Jr., R.J. Molnar and T.D. Moustakas, Phys. Rev. B 49, 14758 (1994).
J. Neugebauer and C.G. Vande Walle, Phys. Rev. Lett. 75, 4452 (1995).
Y. Okamoto, M. Saito and A. Oshiyama, Jpn. J. Appl. Phys. 35, L807 (1996).
W. Götz, N.M. Johnson, D.P. Bour, M.D. McCluskey and E.E. Haller, Appl. Phys. Lett. 69, 3725 (1996).
F.A. Padovani and R. Stratton, Solid-State Electron. 9, 695 (1966).
A.Y.C. Yu, Solid-State Electron. 13, 239 (1970).
N. Mohammad, W. Kim, A. Salvador and H. Morkoç, MRS Bulletin February, 22 (1997).
M. Suzuki, T. Kawakami, T. Arai, A. Kobayashi, Y. Koide, T. Uemura, N. Shibata and M. Murakami, Appl. Phys. Lett. 74, 275 (1999).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Koide, Y., Maeda, T., Kawakami, T. et al. Effects of annealing in an oxygen ambient on electrical properties of ohmic contacts to p-type GaN. J. Electron. Mater. 28, 341–346 (1999). https://doi.org/10.1007/s11664-999-0037-7
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/s11664-999-0037-7