Application of the Level Set Method in Three-Dimensional Simulations of the Profile Evolution
Branislav Radjenović *
Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Zemun, Serbia
Marija Radmilović-Radjenović
Institute of Physics, University of Belgrade, Pregrevica 118, 11080 Zemun, Serbia
Petar Beličev
Vinča Institute of Nuclear Sciences, University of Belgrade, P.O.Box 522, 11000 Belgrade, Serbia
*Author to whom correspondence should be addressed.
Abstract
In this paper, the angular dependence of the etching rate is applied in the three-dimensional simulations of the profile evolution during etching process. Etching rates are determined from the silicon symmetry properties by the interpolation technique using experimentally obtained values. The influence of the KOH concentration on the etch rate is also discussed. As the etchant concentration increases the etching rate decreases, while increasing etching temperature resulted in increased etching rate. Three-dimensional simulation results were obtained using an extension of the sparse field method for solving level set equations that describe the time evolution of the surface during etching process. The obtained simulation results illustrate that relatively simple model with only four parameters describes convex corner undercutting correctly.
Keywords: Chemical etching, silicon, etchants, crystal, solution