Hostname: page-component-77c89778f8-swr86 Total loading time: 0 Render date: 2024-07-18T14:41:09.507Z Has data issue: false hasContentIssue false
  • English
  • Français

High sensitivity of Franz-Keldysh oscillations in photoreflectance spectra for probing morphology in AlxGa 1−xN/GaN heterostructures

Published online by Cambridge University Press:  17 January 2007

H. Takeuchi ,
Y. Yamamoto ,
Y. Kamo ,
T. Kunii ,
T. Oku ,
S. Wakaiki  and
M. Nakayama
H. Takeuchi*
Affiliation:
R & D Department, High Frequency and Optical Device Works, Mitsubishi Electric Corporation, 4-1 Mizuhara, Itami, Hyogo 664-8641, Japan
Y. Yamamoto
Affiliation:
R & D Department, High Frequency and Optical Device Works, Mitsubishi Electric Corporation, 4-1 Mizuhara, Itami, Hyogo 664-8641, Japan
Y. Kamo
Affiliation:
R & D Department, High Frequency and Optical Device Works, Mitsubishi Electric Corporation, 4-1 Mizuhara, Itami, Hyogo 664-8641, Japan
T. Kunii
Affiliation:
R & D Department, High Frequency and Optical Device Works, Mitsubishi Electric Corporation, 4-1 Mizuhara, Itami, Hyogo 664-8641, Japan
T. Oku
Affiliation:
R & D Department, High Frequency and Optical Device Works, Mitsubishi Electric Corporation, 4-1 Mizuhara, Itami, Hyogo 664-8641, Japan
S. Wakaiki
Affiliation:
Department of Applied Physics, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
M. Nakayama
Affiliation:
Department of Applied Physics, Graduate School of Engineering, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan
*
Takeuchi.Hideo@db.MitsubishiElectric.co.jp
Get access

Abstract

We demonstrate that Franz-Keldysh oscillations (FKOs) observed by photoreflectance (PR) spectroscopy are highly sensitive to the surface morphology of AlxGa1−xN layers in AlxGa1−x N heterostructures. Three Al0.2Ga0.8N/GaN heterostructures with different surface-morphology profiles, which are confirmed with atomic force microscopy, have been investigated. The X-ray-diffraction patterns are hardly affected by the Al0.2Ga0.8N/GaN-layer morphology. In contrast, it is revealed that cracks and pits dominating the morphology remarkably reduce the amplitude of the FKOs from the Al0.2Ga0.8N/GaN layer, which is attributed to the following two mechanisms related to the cracks and pits. One is lifetime broadening due to carrier scattering, and the other is the suppression of the modulation magnitude for the built-in electric field, which is caused by the trapping and recombination of photogenerated carriers at the surface.

Keywords

Type
Research Article
Information
The European Physical Journal - Applied Physics , Volume 37 , Issue 2 , February 2007 , pp. 119 - 122
Copyright
© EDP Sciences, 2007

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

S. Karmalkar, M.S. Shur, R. Gaska, in Wide energy bandgap electronic devices, edited by F. Ren, J.C. Zolper (World Scientific, Singapore, 2003), Chap. 3
Ambacher, O., Smart, J., Shealy, J.R., Weimann, N.G., Chu, K., Murphy, M., Schaff, W.J., Eastman, L.F., Dimitrov, R., Wittmer, L., Stutzmann, M., Rieger, W., Hilsenbeck, J., J. Appl. Phys. 85, 3222 (1999) CrossRef
Keller, S., Parish, G., Fini, P.T., Heikman, S., Chen, C.-H., Zhang, N., DenBaars, S.P., Mishra, U.K., Wu, Y.-F., J. Appl. Phys. 86, 5850 (1999) CrossRef
Zhou, Y., Chu, R., Liu, J., Chen, K.J., Lau, K.M., Phys. Status Solidi C 2, 2663 (2005) CrossRef
T. Kikkawa, M. Nagahara, N. Okamoto, Y. Tateno, Y. Yamaguchi, N. Hara, K. Joshin, P.M. Asbeck, in Technical Digest of 2001 International Electron Devices Meeting (IEEE, Piscataway, 2001), pp. 585–588
Mitrofanov, O., Manfra, M., Weimann, N., Appl. Phys. Lett. 82, 4361 (2003) CrossRef
Pollak, F.H., Shen, H., Mat. Sci. Eng. R 10, 275 (1993)
M. Cardona, Modulation Spectroscopy (Academic Press, New York, 1969), Chap. VII
Liliental-Weber, Z., Chen, Y., Ruvimov, S., Washburn, J., Phys. Rev. Lett. 79, 2835 (1997) CrossRef
Chen, Y., Takeuchi, T., Amano, H., Akasaki, I., Yamada, N., Kaneko, Y., Wang, S.Y., Appl. Phys. Lett. 72, 710 (1998) CrossRef
Vurgaftman, I., Meyer, J.R., Ram-Mohan, L.R., J. Appl. Phys. 89, 5815 (2001). The parameters for Al0.2Ga0.8N are estimated using a linear interpolation CrossRef
Aspnes, D.E., Phys. Rev. 153, 972 (1967) CrossRef
Enderlein, R., Phys. Status Solidi 20, 295 (1967) CrossRef
Aspnes, D.E., Phys. Rev. B 10, 4228 (1974) CrossRef
Gil, B., Briot, O., Phys. Rev. B 55, 2530 (1997) CrossRef