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Characterization of III-V Semiconductor Structures Using Electron Beam Electroreflectance (EBER) spectroscopy.

Published online by Cambridge University Press:  26 February 2011

M. H. Herman,
I. D. Ward,
S. E. Buttrill Jr and
G. L. Francke
M. H. Herman
Affiliation:
Charles Evans & Associates, 301 Chesapeake Drive, Redwood City, CA 94063
I. D. Ward
Affiliation:
Charles Evans & Associates, 301 Chesapeake Drive, Redwood City, CA 94063
S. E. Buttrill Jr
Affiliation:
Charles Evans & Associates, 301 Chesapeake Drive, Redwood City, CA 94063
G. L. Francke
Affiliation:
Charles Evans & Associates, 301 Chesapeake Drive, Redwood City, CA 94063
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Abstract

EBER is a form of modulated reflectance spectroscopy in which a low energy electron beam alters the sample surface potential. For III-V semiconductors, the spectra are characteristic of electroreflectance, including excitonic, interband, and impurity transitions. The study of these transitions provides accurate estimations of band gaps in bulk and thick film samples. Measurements of the band gap energy in compounds such as AlxGa1-xAs provide highly precise evaluations of their composition.

Additionally, EBER spectra of quantum well structures and heterojunctions provide useful information about the composition and quality of materials and interfaces. For quantum wells, detected features suggest the presence of allowed, disallowed, and resonant states. In EBER spectra of HEMT structures, peaks are apparent resulting from transitions between the valence band and the states in which the electrons are confined. We present examples of EBER determination of AlGaAs composition, single GaAs/AlGaAs quantum well evaluation, and HEMT characterization.

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References

REFERENCES

1 Included in this group are the “first derivative” modulation spectroscopies of piezoreflectance (PzR), and thermoreflectance (TR), and the “third derivative” or electric field modulation spectroscopies of photoreflectance (PR), electrolyte electroreflectance (EER), surface barrier electroreflectance (SBER), and Electron Beam Electroreflectance (EBER). Previously EBER was described as “cathodoreflectance” in the literature.Google Scholar
2 See for example Semiconductors and Semimetals, Vol 9, edited by Willardson, R. K. and Beer, A. C., (Academic Press, New York, 1972).Google Scholar
3 Herman, M. H. and Bowman, R. C. Jr, (unpublished).Google Scholar
4 Monte Carlo simulations show that the 240eV electrons thermalize in most semiconductors within about 15Å of the surface.Google Scholar
5 The mechanism of EBER (cathodoreflectance) has been investigated by earlier researchers. See Broser, I., Hoffman, R.-A. and Schulz, H.-J., Solid State Comm. 8, 587–591 (1970). See also J. H. McCoy and D. B. Wittry, Appl. Phys. Lett. 13(8), 272–274 (1968).Google Scholar
6 This has been found for both interband and excitonic transitions. For the excitonic case, see Blossey, D. F. and Handler, P., in Semiconductors and Semimetals, Vol 9, edited by Willardson, R. K. and Beer, A. C., (Academic Press, New York, 1972), p. 257. The interband case is discussed by D. E. Aspnes, Surface Science 37, 418–442 (1973).Google Scholar
7 The PR mechanism has been substantiated by several groups. See for example Wang, E. Y. and Albers, W. A., Physics Letters 27A(6), 347–348 (1968). D. E. Aspnes, Solid State Comm. 8, 267–270 (1970). F. Cardiera and M. Cardona, Solid State Comm. 2, 879–882 (1969).Google Scholar
8 Herman, M. H., Tober, R. L., and McFarlane, R. A. (unpublished).Google Scholar
9 See for example Garland, J. W., and Raccah, P. M., SPIE 659, 32–43 (1986).Google Scholar
10 Casey, H. C. and Panish, M. B., Heterostructure Lasers (Academic, New York, 1978), Part A, in S. Adachi, J. Appl. Phys. 1985, reprinted in Gallium Arsenide: Key pavers in physics: no.1, edited by J. S. Blakemore, (American Institute of Physics, 1987), p. 62.Google Scholar
11 Reddy, U. K., Ji, G., Henderson, T., Morkoc, H. and Schulman, J. N., J. Appl. Phys. A2(1), 145–151 (1987).CrossRefGoogle Scholar
12 Herman, M. H., Buttrill, S. E. Jr, Francke, G. L. and Chambers, F. A., “Electron Beam Electroreflectance (EBER) analysis of single AlxGa1-xAs/GaAs quantum wells,” presented at the Electronic Materials Conference, June 1988, Boulder, Colorado (unpublished).Google Scholar
13 Glembocki, O. J., Shanabrook, B. V., Bottka, N., Beard, W. T., and Comas, J., Appl. Phys. Lett. 46(10), 970–2 (1985) and N. Bottka, D. K. Gaskill, R. S. Sillmon, R. Henry, and R. Glosser, J. Electr. Mater. 17(2), 161–170 (1988).Google Scholar
14 Aina, O., Mattingly, M., Juan, F. Y. and Bhattacharya, P. K., Appl. Phys. Lett. 50(1), 43–45 (1987).Google Scholar
15 Shanabrook, B. V. (private communication).Google Scholar
16 This factor is calculated by assuming the confined electrons have an infinite mass. Therefore, the Rydberg is increased by the ratio of the heavy hole mass to the usual interband reduced mass. The ionization field is proportional to the square of the reduced mass.Google Scholar