Numerical Simulation of wet-chemical etching

The concentration of dissolved material in an etch-hole is computed in order to construct a numerical simulation of wet-chemical etching. Using a number of assumptions an approximate convection-diffusion equation is formulated. In this way, analytical descriptions for the concentration in different parts of the domain are obtained. By a coupling of these descriptions the concentration can be computed. The result is validated by comparison with a finite-volume method. Results of the boundary-layer method are given for an etch-hole geometry