Atomic Structure of the Stoichiometric GaAs(114) Surface

Abstract

The stoichiometric GaAs(114) surface has been prepared using molecular beam epitaxy followed by annealing in ultrahigh vacuum. Based on in situ scanning tunneling microscopy measurements and first-principles electronic-structure calculations, we determine the surface reconstruction which we call alpha2(2x1). Contrary to what is expected for a high-index surface, it is surprisingly elementary. The (2x1) unit cell contains two As dimers and two rebonded Ga atoms. The surface energy is calculated as 53 meV/Å(2), which falls well within the range of low-index GaAs surface energies.

Electronic structure of theGaAs(114)A‐(2×1)andGaAs(

“…This leads to two plausible stable surface reconstructions: the previously reported GaAs͑114͒A-␣2͑2 ϫ 1͒ structure 8,11 and, following the labeling convention, a new GaAs͑114͒B-␣2͑2 ϫ 1͒ surface. The terminology for the ͑114͒A and ͑114͒B surfaces is rather similar to that used for the ͑111͒A and ͑111͒B surfaces.…”

“…It is this combination of rebonded and nonrebonded atoms at step edges that leads to a highly stable surface geometry for both polar and nonpolar semiconductor surfaces. 8,9 The GaAs͑114͒ surface exhibits what has been termed an ␣2͑2 ϫ 1͒ reconstruction, whose structure has been proposed and verified with STM imaging by Márquez et al 8 Further work by Márquez et al 11 has provided theoretically determined relaxed atomic geometries of the ␣2͑2 ϫ 4͒ and ␤2͑2 ϫ 4͒ reconstructions of GaAs͑114͒A.…”

Growth mechanisms and optical properties of GaAs-based semiconductor microstructures by selective area epitaxy

“…5 is a typical example of a well faceted microstructure. The facets correspond generally to the families f1 1 0g and f1 1 1g, which are known to be the crystal facets in III-V semiconductors with the lowest energy [15,16].…”

Structural properties of InAs‐based nanostructures grown on GaAs(001) and GaAs(111)A by area selective epitaxy

“…High selective growth was achieved at this low substrate temperature by using MEE and a low In flux. AFM measurements revealed that the grown structures have a height of (140±8) nm and developed facets mostly belonging to the {110} and {111} families, which are low energy crystal facets in III-V semiconductors [15,16]. No substantial growth takes places, once vertical facets are formed at the GaAs/SiO 2 edge.…”