Anisotropic crystal etching is the common technique used in Micro Electromechanical systems (MEMS) manufacturing. It uses the property of some single crystal materials, like silicon, of having different etching rates in different crystal directions when the material is etched in special chemicals, such as potassium hydroxide (KOH). Predicting the resulting shape of the structure under such conditions requires full three-dimensional simulation of the evolution of the etched surface.
