Primary Current Distribution Model for Electrochemical Etching of Silicon through a Circular Opening

A. Ivanov [1], U. Mescheder [1],
[1] Hochschule Furtwangen University, Furtwangen im Schwarzwald, Germany
Veröffentlicht in 2015

Primary current distribution model for anodization of low-doped p-type silicon through a circular opening in frontside insulating mask is developed. The model is applied in two regimes of the process – pore formation and electropolishing – by definition of current density dependent functions of porosity and dissolution valence based on experimental results. As found also experimentally, transformation of etch forms from convex to concave occurring at specific etch depths are simulated using the model. The depth, at which this shape transformation occurred, is approximately twice larger in the model than in the experiment, which is assumed to be the result of using the simplified model with primary current distribution. Larger values of anisotropy were observed in the experiment than in the model.