This article is cited in 7 papers

INSTRUMENTS AND METHODS OF INVESTIGATION

Atomic structures on a GaAs(001) surface grown by molecular beam epitaxy

R. Z. Bakhtizin^a, T. Hashizume^b, Q.-K. Xue^c, T. Sakurai<sup>c

a</sup> Bashkir State University, Ufa
^b Hitachi Central Research Laboratory
^c Institute for Materials Research, Tohoku University

Abstract: A unique apparatus for in-situ atomic-resolution study of solid state structures grown by molecular beam epitaxy (MBE) is developed, in which a scanning tunneling microscope (STM) is combined with an MBE chamber within the same vacuum system. The utility of the apparatus is demonstrated by examining atomic structures on a molecular-beam-epitaxial GaAs(001) surface over a wide range of [As]/[Ga] ratios. By varying the As surface coverage, the 2×4 — α, β, γ and c(4×4) phases are examined in detail. High-resolution STM images indicate that 2×4 — α, β, and γ phases in the outermost surface layer have essentially the same unit cell consisting of two As dimers and two As dimer vacancies. Using the STM images, reflection high-energy electron diffraction (RHEED) patterns and dynamical RHEED calculations, the existing structural models for the 2×4 phases are analysed and a new model of the As-rich GaAs(001) surface is proposed, found to be consistent with most of the previous observations.

PACS: 61.14.Hg, 61.16.Di, 68.55.Bd

Received: October 1, 1997

DOI: 10.3367/UFNr.0167.199711f.1227

 English version: Physics–Uspekhi, 1997, 40:11, 1175–1187

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