Potential Dependence of Electrochemical Etching Reaction of Si(111) Surface in a Fluoride Solution Studied by Electrochemical and Scanning Tunneling Microscopic Techniques

Abstract

Silicon surface nanostructures, which can be easily prepared by electrochemical etching, have attracted considerable attention because of its useful physical properties that facilitate application in diverse fields. In this work, electrochemical and electrochemical-scanning tunneling microscopic (EC-STM) techniques were employed to study the evolution of surface morphology during the electrochemical etching of Si( 111)-H in a fluoride solution. The results exhibited that silicon oxide of the Si(111) surface was entirely stripped and then the surface became hydrogen terminated, atomically flat, and anisotropic in the fluoride solution during chemical etching. At the potential more negative than the flat band one, the surface had a tendency to be eroded very slowly, whereas the steps of the terrace were not only etched quickly but the triangular pits also deepened on anodic potentials. These results provided information on the conditions required for the preparation of porous nanostructures on the Si(111) surface, which may be applicable for sensor (or device) preparation (Nanotechnology and Functional Materials for Engineers, Elsevier 2017, pp. 67-91).

Porous Si (111) Fabrication Using Electrochemical Anodization: Effects of Electrode Distance and Current Density

“…These results agreed with Asoh et al [9] and Radzali et al [10], in which they reported about triangle pores shape and their distribution on Si(111). Concluded that the low anodic dark current during etching could form the triangular-shaped structure on the hydride-terminated Si(111) surfaces [11]. Meanwhile, considered that the formation of triangular-shaped pores correlated the characteristic faceted which photo-anodization etching in (111) orientation due to the anisotropy of Si(111) dissolution [12].…”

Оптимизация технологии изготовления дифракционных Si-решеток треугольного профиля для мягкого рентгеновского и экстремального ультрафиолетового излучения

“…Для уменьшения шероховатости отражающей поверхности Si-решеток применяют разные приемы, например, добавляют поверхностно-активные вещества в травитель [10]. Анизотропное травление в растворе NH 4 F может обеспечить атомно гладкую поверхность [11] 1) в щелочном неорганическом травителе (далеетравитель № 1) без добавки поверхностно-активного вещества (ПАВ) (фрагмент № 1) и с добавкой ПАВ (фрагмент № 3) (рис. 4);…”

Optimization of triangular-profiled Si-grating fabrication technology for EUV and SXR applications

“…To reduce roughness of the Sigrating reflective surfaces, different techniques are used, for instance, adding surfactants to the etchant [10]. Anisotropic etching in the NH 4 F solution can provide an atomically smooth surface [11] with the root-mean-square (RMS) roughness of 1.1 Å [5].…”