Coherent scattering from silicon mocrystal surface

TL;DR

This study uses coherent x-ray scattering to reveal atomic step roughness on a silicon monocrystal surface, demonstrating the technique's sensitivity to surface features and potential for studying step dynamics.

Contribution

It introduces a method to detect atomic step roughness on silicon surfaces using coherent x-ray scattering near the anti-Bragg position.

Findings

Atomic step roughness detected on silicon surface.

Speckle pattern analysis confirms monoatomic step sensitivity.

Technique paves the way for studying surface step dynamics.

Abstract

Using coherent x-ray scattering, we evidenced atomic step roughness at the [111] vicinal surface of a silicon monocrystal of 0.05 degree miscut. Close to the (1/2 1/2 1/2) anti-Bragg position of the reciprocal space which is particularly sensitive to the [111] surface, the truncation rod exhibits a contrasted speckle pattern that merges into a single peak closer to the (111) Bragg peak of the bulk. The elongated shape of the speckles along the[111] direction confirms the monoatomic step sensibility of the technique. This experiment opens the way towards studies of step dynamics on crystalline surfaces.