J. Phys. IV France 7 (1997) C2-697-C2-698
SEXAFS Study of the GaAs/InP InterfaceM.G. Proietti1, S. Turchini2, F. Martelli3, J. Garcia1, T. Prosperi2, D. Chandesris4 and J. Vogel4
1 ICMA-CSIC, Universidad de Zaragoza, Facultad de Ciencias, Plaza S. Francisco s.n., 50009 Zaragoza, Spain
2 ICMAT-CNR, cp. 10, 00016 Monterotondo Stazione, Italy
3 Fondazione Ugo Bordoni, via B. Castiglione 59, 00142 Roma, Italy
4 LURE, bâtiment 209D, 91405 Orsay, France
Extended X-Ray Absorption Fine Structure measurements have been performed at the Ga and As K-edge of a nominal 3 ML GaAs grown by Molecular Beam Epitaxy on a InP(100) substrate deoxidized in As amiosphere. We exploited the in-plane linear polarization of the synchrotron radiation measuring SEXAFS spectra taken with the polarization vector parallel and pependicular to the growth direction. By comparing the ratio of the coordination numbers of the pairs As-Ga, As-In, Ga-As, taken at the two different angles of the polarization vector, a quantitative model of the interface is obtained. Two well defined layers form on the InP substrate giving rise to the following sample structure : 3 ML GaAs/3 ML InAs/InP. This rules out the formation of InGaAs or InGaAsP layers at the interface.
© EDP Sciences 1997