Anisotropy Effects in Electrochemical Etching of p(+)-Si

作者：Astrova E V^*; Ulin V P; Zharova Yu A; Shul'pina I L; Nashchekin A V

来源：Journal of the Electrochemical Society, 2012, 159(3): D172-D180.

DOI：10.1149/2.095203jes

Relationship between the rate of electrochemical formation of porous layers and the crystallographic directions of their propagation in p(+)-Si crystals has been studied. Results of analysis of the surface faceting revealed in the course of electrochemical etching of differently oriented cylindrical crystals are presented. A more detailed study of the anisotropy of pore growth rates has been performed for the first time by local anodization of wafers through a mask having the form of narrow long wedges which radiate from the center in all directions (wagon-wheel mask). First experiments carried out by this technique demonstrated that the orientation differences in the rate of porous layer formation are small (similar to 10%) and decrease in the sequence V(100) > V(112) > V(110) > V(111). The potential of the wagon-wheel technique is analyzed as applied to the process of electrochemical pore formation. Among the technique advantages there are visualization of the etching rate distribution and simplicity in the extraction of quantitative data on the propagation anisotropy of freely moving fronts. The anisotropy-related specific features observed in local pore formation are discussed as well.

• 出版日期2012