STRUCTURAL CHARACTERIZATION OF ZnSe/GaAs INTERFACE BY X-RAY REFLECTION

A.Ulyanenkov¹, A.Takase², M.Kuribayashi², K.Ishida², K.Kimura³, L.-H.Kuo³, T.Yasuda³, S.Miwa⁴, T.Yao^4,5, H.Tomita⁶, and S.Komiya⁶

¹Institute of Nuclear Problems, Bobruiskaya Str. 11, 220050 Minsk, Belarus
²Science University of Tokyo, Noda-shi, Chiba 278, Japan
³Joint Research Center for Atom Technology, 1-1-4 Higashi, Tsukuba 305, Japan
⁴Angstrom Technology Partnership (ATP), 1-1-4 Higashi, Tsukuba 305, Japan
⁵Institute for Materials Research, 2-2-1, Katahira, Aoba-ku, Sendai 980, Japan
⁶Fujitsu Laboratories Ltd., 10-1 Morinosato-Wakamiya, Atsugi 243-01, Japan

Keywords: ZnSe/GaAs, x-ray reflectivity, Ga₂Se₃

ZnSe/GaAs heterostructures have been investigated by x-ray reflectivity method. Two samples grown by the molecular beam epitaxy (MBE) differed in initial growing conditions, the first was prepared by Se-treatment of GaAs substrate, and the second one was exposed by Zn before ZnSe film growth. The analysis of structure and morphology of interface between ZnSe film and GaAs substrate was emphasised. The experimental x-ray reflectivity curves at different wavelengths were simulated by means of distorted-wave Born approximation (DWBA) method [1]. The fitting of experimental data indicated the presence of Ga₂Se₃ transition layer between ZnSe film and GaAs substrate for Se-treated sample, confirming the preference of Zn-treatment during the MBE growing process to improve the interface quality [2]. The extracted from best fit value of Ga₂Se₃ concentration at interface being non-equal to unity, allows to assume the discontinuity of transition layer, i.e. the island-like morphology of latter [3].

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