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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.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 144: Symposium W – Advances in Materials, Processing and Devices in III-V Compound Semiconductors , 1988 , 21
Copyright
Copyright © Materials Research Society 1989

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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
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