Numerical solution of an etching problem (Q1071484)

After a short description of the chemical background of etching processes, a simplified mathematical model is formulated. This contains two parameters that determine the etching profile. Two approaches for obtaining a numerical solution are discussed. First, the problem in terms of a variational inequality is reformulated and some new results on its numerical solution are presented. Then, how the problem can be solved by means of a moving grid method as well is explored. Results obtained by both methods are presented and compared. The latter method is applicable to a much wider class of boundary conditions, but the variational inequality approach seems attractive for other reasons. Finally this work is compared with some experimental results.