Enhanced As-Sb intermixing of GaSb monolayer superlattices in low-temperature grown GaAs

V. V. Chaldyshev, N. A. Bert, Yu G. Musikhin, A. A. Suvorova, V. V. Preobrazhenskii, M. A. Putyato, B. R. Semyagin, P. Werner, U. Gösele

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26 Citations (Scopus)

Abstract

As-Sb compositional intermixing was studied by transmission electron microscopy (TEM) in GaAs films grown by molecular-beam epitaxy at low temperature (LT) and δ doped with antimony. The TEM technique was calibrated by imaging the as-grown films with δ layers containing various amounts of Sb. The calibration allowed us to deduce the effective As-Sb interdiffusion coefficient from apparent thickness of the Sb δ layers in the films subjected to isochronal anneals at 400-600 °C. The As-Sb intermixing in LT GaAs was found to be much enhanced when compared to conventional material. Its temperature dependence yields a diffusion coefficient of DAs-Sb=2 × 10-14exp(-0.62±0.15eV/kt) cm2s-1. Since the kick-out mechanism operating under equilibrium conditions is valid for As-Sb interdiffusion in GaAs, the enhanced intermixing was attributed to an oversaturation of arsenic self-interstitials in the LT GaAs films. The effective activation energy for As-Sb interdiffusion in LT GaAs seems to be reasonably close to the migration enthalpy of As interstitials, whereas their concentration was roughly estimated as 1018cm-3.

Original languageEnglish
Pages (from-to)1294-1296
Number of pages3
JournalApplied Physics Letters
Volume79
Issue number9
DOIs
Publication statusPublished - 27 Aug 2001
Externally publishedYes

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