Multiscale modeling of anisotropic wet chemical etching of crystalline silicon

Laboratory of Physics, Helsinki University of Technology P.O. Box 1100, 02015 Espoo, Finland

Received: 30 April 2002
Accepted: 15 August 2002

Abstract

We combine ab initio and Monte Carlo simulations in multiscale modelling of anisotropic wet chemical etching of silicon. The anisotropy of the macroscopic etching patterns observed in the experiments is explained by two mechanisms at an atomistic scale: the weakening of backbonds following termination of surface sites and the existence of significant interaction between the surface-terminating species ( and ). For the first time, we demonstrate that the and interactions have an essential role, directly controlling the appearance of the fastest-etched planes in the macroscopic etching patterns.