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GaN epitaxial layers on inhomogeneous buffer layer: electrical and optical properties

Published online by Cambridge University Press:  15 July 2004

C. Grazzi*
Affiliation:
Erlangen-Nürnberg University, Department of Materials Science and Engineering, Institute of Microcharacterisation, Cauerstr. 6, D-91058 Erlangen, Germany
A. Castaldini
Affiliation:
INFM and University of Bologna, Department of Physics, V. le Berti Pichat 6/2, 40127 Bologna, Italy
A. Cavallini
Affiliation:
INFM and University of Bologna, Department of Physics, V. le Berti Pichat 6/2, 40127 Bologna, Italy
H. P. D. Schenk
Affiliation:
Centre de Recherche sur l'Hétéro-Épitaxie et ses Applications (CRHEA-CNRS), rue Bernard Grégory, 06560 Valbonne, France
P. Gibart
Affiliation:
Lumilog S.A., 2720, Chemin Saint Bernard, Les Moulins I, 06220 Vallauris, France
H. P. Strunk
Affiliation:
Erlangen-Nürnberg University, Department of Materials Science and Engineering, Institute of Microcharacterisation, Cauerstr. 6, D-91058 Erlangen, Germany
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Abstract

This paper reports on first results obtained on GaN epitaxial layer grown on a single wafer with a lateral variation in defect density. The chemically homogeneous GaN epitaxial layer was deposited by metalorganic chemical vapour deposition onto a specially prepared buffer layer. A chemical gradient in the nitrogen contents of the precursor flux was induced during the growth of the GaN buffer layer. This condition leads a corresponding gradient of the dislocation density within the epilayer. The electrical and optical properties of the GaN epilayer have been analysed by means of electron beam induced current, photoluminescence and photocurrent techniques. All our measurements reveal lateral gradients in the epilayer properties as concern (i) the density of recombining centres in the GaN film and (ii) their recombination activity, both radiative and nonradiative. This paper shows that a proper combination of beam based techniques can contribute to the detailed analysis of the well know yellow luminescence band which in the GaN epilayer here investigated consist of four well distinct peaks.

Keywords

Type
Research Article
Copyright
© EDP Sciences, 2004

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References

H. P. D. Schenk, P. Vennéguès, O. Tottereau, T. Riemann, J. Christen, to be published in J. Cryst. Growth
Hacke, P., Detchprohm, T., Hiramatsu, K., Sawaki, N., Tadatoma, K., Miyake, K., J. Appl. Phys. 76, 304 (1994) CrossRef
Ponce, F. A., Major Jr, J. S.., W. E. Plano, D. F. Welch, Appl. Phys. Lett. 65, 2302 (1994) CrossRef
Castaldini, A., Cavallini, A., Polenta, L., Mat. Res. Soc. Symp. Proc. 588, 51 (2000) CrossRef
Donolato, C., Appl. Phys. Lett. 43, 120 (1983) CrossRef
Donolato, C., Solid State Electron. 28, 1143 (1985) CrossRef
Dingle, R., Ilegems, M., Solid State Commun. 9, 175 (1971) CrossRef
Ogino, T., Aoki, M., Jpn J. Appl. Phys. 19, 2395 (1980) CrossRef
Neugebauer, J., Van de Walle, C. G., Appl. Phys. Lett. 69, 503 (1996) CrossRef
Mattila, T., Nieminen, R. M., Phys. Rev. B 55, 9571 (1997) CrossRef
Elsner, J., Jones, R., Heggie, M. I., Sitch, P. K., Haugk, M., Frauenheim, Th., Öberg, S., Briddon, P. R., Phys. Rev. B 58, 12571 (1998) CrossRef
Reshchikov, M. A., Morkoç, H., Park, S. S., Lee, K. Y., Appl. Phys. Lett. 78, 3041 (2001) CrossRef