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

  • Bae, Sang-Eun (Nuclear Chemistry Research Team, Korea Atomic Energy Research Institute) ;
  • Youn, Young-Sang (Department of Chemistry, Yeungnam University) ;
  • Lee, Chi-Woo (Department of Advanced Materials Chemistry, Korea University)
  • Received : 2020.04.08
  • Accepted : 2020.04.28
  • Published : 2020.11.30


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).