Surface morphology of MBE-grown GaAs(001)−(2 × 4) and GaAs(001)-faceted surfaces investigated by scanning tunneling microscopy

• Published in: Surface science Vol. 287; pp. 514 - 519
• Main Authors: Bressler-Hill, V., Maboudian, R., Wassermeier, M., Wang, X.-S., Pond, K., Petroff, P.M., Weinberg, W.H.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Lausanne Elsevier B.V 10.05.1993; Amsterdam Elsevier Science; New York, NY
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Physics; Solid surfaces and solid-solid interfaces; Surface structure and topography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Crystal growth; Surface effect; Gallium Arsenides; Scanning tunneling microscopy; Image analysis; Statistical analysis; Growth rate; Molecular beam condensation; Epitaxial film; Island structure; Surface
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/0039-6028(93)90833-6

Scanning tunneling microscopy is used to study the morphology of nominally flat p-type (2 × 4)-reconstructed GaAs(001) and faceted n-type GaAs(001) surfaces. On the flat surfaces the effect of the MBE growth rate on the island structures was investigated. A detailed statistical analysis of the STM images of individual growths was performed to calculate the step-density and the step-length ratio of the islands. The density of the steps parallel to the dimers, A-type steps, is about twice the density of the steps perpendicular to the dimers, B-type steps. The length ratio of step A to step B was calculated to be 2.4 : 1. The images obtained on the faceted surface reveal predominantly a (2 × 4) local ordering. There is also an increased anisotropy in the local island shape in comparison to the flat surfaces.