Study of the Orientation Dependent Etching and Initial Anodization of Si in Aqueous KOH

Abstract

A series of electrochemical measurements have been performed on a variety of n‐ and p‐type Si wafers of {100} and {111} orientation in aqueous . It has been determined that {100} surfaces have similar, systematic features regardless of carrier type and doping level below 10²⁰cm⁻³, while {111} surfaces have a different set of similar systematic features. These results suggest the presence of a different prepassive layer on each of these surfaces. In addition, ellipsometric measurements have been carried out in the voltage range beyond the passivation potential to clarify the anodization process.