<i>Ab Initio</i>-Based Approach to Structural Change in InAs (001)-(2×3) Wetting Layer Surfaces during MBE Growth<i><sup> </sup></i>

Access this Article

Author(s)

    • Ito Tomonori
    • Department of Physics Engineering, Graduate School of Engineering, Mie University
    • Akiyama Toru
    • Department of Physics Engineering, Graduate School of Engineering, Mie University
    • Nakamura Kohji
    • Department of Physics Engineering, Graduate School of Engineering, Mie University

Abstract

The structural change in InAs(001)-(2×3) wetting layer surfaces grown on GaAs is investigated using <i>ab initio-</i>based approach incorporating temperature <i>T</i> and beam equivalent pressure <i>p</i>. Our calculated results reveal that the (2×3) surface fully covered by As dimers is unstable while the (<i>n</i>×3) surfaces (<i>n</i> =4, 6, and 8) with (<i>n</i> −1) dimers including In-As and one missing dimer is more stable at the conventional molecular beam epitaxial (MBE) growth conditions such as <i>T</i> = 703 K under <i>p</i><sub>In</sub> = 1:0×10<sup>-7</sup> Torr and <i>p</i><sub>As<sub>4</sub></sub> = 7:5×10<sup>-</sup><sup>7</sup> Torr. On the (<i>n</i>×3) surfaces, In atoms are incorporated through In-As dimer formation with As desorption. The resultant (4×3) surface consists of three In-As dimers and one missing dimer. The (6×3) surface has three In-As dimers, two As dimers, and one missing dimer. Only one In-As dimer emerges with six As dimers and one missing dimer on the (8×3) surface. The missing dimer region becomes favorable site for further In adsorption. Moreover, the (8×3) can easily change to the (4×3) with In adsorption and subsequent As dimer desorption on the initial (8×3). The existence ratio <i>R</i> for the (4×3) and (6×3) units is respectively estimated to be <i>R</i> = 0:70 and 0.30 satisfying 0.375 ML desorption of As on the (2×3) to form the (2×4)α2. This is consistent with experimental results. Consequently, the (<i>n</i>×3) surfaces including In-As dimers appear during MBE growth instead of the (2×3) surface with As-dimers. [DOI: 10.1380/ejssnt.2015.190]

Journal

  • e-Journal of Surface Science and Nanotechnology

    e-Journal of Surface Science and Nanotechnology 13(0), 190-194, 2015

    The Surface Science Society of Japan

Codes

Page Top