Step-induced optical anisotropy of Si(111): H surfaces

[摘要] The step-induced optical anisotropy of the hydrogenated Si(lll) surface has been calculated using a real-space multigrid method together with ab initio pseudopotentials. The investigated step configurations give rise to relatively similar anisotropy spectra with maxima close to the E-1 and E-2 critical points of the silicon bulk band structure. The spectrum for [11 (2) over bar] steps resembles the reflectance anisotropy for Si(110):H and is in good agreement with measurements for Si(lll):H vicinally cut toward [11 (2) over bar]. Our results for [(1) over bar (1) over bar 2] steps, however, are qualitatively different from the corresponding measurements for surfaces miscut toward [(1) over bar (1) over bar 2]. This apparent discrepancy can be resolved if the formation of staircaselike structures of monohydride terminated steps is assumed.

[关键词] AB-INITIO CALCULATION;REFLECTANCE ANISOTROPY;ELECTRONIC-STRUCTURE;EPITAXIAL-GROWTH;VICINAL SI(111);SEMICONDUCTORS;SPECTROSCOPY;APPROXIMATION;SI(001);MODEL