Current transient analysis of the oxidizing process in the complete anodic regime of the Si–HF system

Abstract

Potential step experiments from anodic potential to open circuit potential in the electrochemical system Si–HF result in a transient current peaks, provided that oxide was present at the electrode surface. The current transients can be analyzed quantitatively and provide information about the anodic oxide and the electrode processes. In this paper it is shown that the complete I– V-characteristics (including the region of porous silicon layer (PSL) formation) is governed by the oxidation process, that the points of inflection (and not the maxima) indicate changes in electrode processes, and that several linear relations between electrode processes and external parameters can be obtained from evaluating the experiments. The findings are consistent with the view that the electrode processes can be seen as results of the interaction of current bursts which may be synchronized by stochastic processes in time and space and indicate in addition that simple, albeit not yet fully understood mechanisms cause the amazing multitude of phenomena occurring at the Si–liquid interface.