Sb-induced reconstructions on Si(113): Adatoms as the key elements

Abstract

The adatom site is identified and determined as the main structural element of Sb-induced surface reconstructions of Si͑113͒ by means of x-ray standing waves, x-ray photoelectron spectroscopy, and low-energy electron diffraction ͑LEED͒ in combination with density functional theory calculations. The analysis yields that the Sb adatom site can be found prevalently at Sb coverages below 1 ML. With increasing coverage, the relative amount of Sb residing in adatom sites is reduced in favor of mainly Sb tetramer formation, leading to a complex mixture of ͑2 ϫ 2͒ reconstructions at coverages above 1 ML. The observation of ͑1 ϫ 2͒ LEED patterns can be explained by the formation of small antiphase domains of ͑2 ϫ 2͒ reconstructions. Upon annealing, partial desorption of Sb leads to the formation of a missing-row structure with a ͑1 ϫ n͒ LEED pattern.

Ga and In adsorption on Si(112): Adsorption sites and superstructure

“…This combination has already been successfully applied to a variety of adsorbate systems on silicon surfaces. 25,[30][31][32][33] In the present case, this approach confirms the model by Snijders et al for Ga/Si(112), whereas the only available models for In/Si(112), which imply a 7×1 reconstruction, 18,23 can be ruled out, and a different model is suggested instead.…”

“…An electronic high-energy cutoff of 20 Ry was found to be sufficient in order to ensure convergence not only with respect to the total energy, but also regarding the resulting geometric structure and, more specifically, its Fourier components in the XSW simulation, which poses an additional criterion in the quantitative XSW analysis of DFT-calculated structures. 32 The electron-ion interaction has been considered in the form of ab-initio norm-conserving pseudopotentials. 43,44 In the repeated-slab models of the (3×1), (4×1), (5×1), and (6×1) supercells, 6 Si bilayers have been implemented to account for the relaxation of the upper-most surface layers.…”

Atomic structure of chlorinated Si(113) surfaces

“…This is evidence for the rearrangement of surface atoms into a Cl-induced ͑2 ϫ 2͒ reconstruction, very likely in coexistence with a variety of ͑2 ϫ n͒-like reconstructions similar to the case of Sb adsorption on Si͑113͒. 24 To investigate more closely the surface structure that leads to this complex LEED pattern, STM was performed on surfaces with similar coverages. The micrograph presented in Fig.…”

“…28 An electronic high-energy cutoff of 16 Ry and a 2 ϫ 2 ϫ 1 set of k ជ points were found to be adequate in order to ensure convergence also with special focus on the resulting geometric structure, which poses an additional and sharp criterion in the XSW analysis of DFT-calculated structures. 24 As pseudopotentials, norm-conserving potentials 29,30 have been employed. In the repeated-slab calculations, 12 atomic Si layers have been implemented to account for the relaxation of the uppermost surface layers.…”