The influence of atomic configuration of (h k l) planes on adsorption processes associated with anisotropic etching of silicon

The effect of isopropyl alcohol (IPA) on anisotropic etching process of monocrystalline silicon in KOH solution has been considered. The differences in planes developing during the etching in KOH and KOH + IPA solutions has been analysed. The atomic configuration of different (h k l) planes was modelled with a computer program "Cerius". Dangling bonds configuration, their spacings and inclination angles towards the etched (h k l) surface were used for explanation of the differences in etching rates and surface smoothness among different planes. The theoretical analysis, confirmed with the experimental results, allowed us to establish the role of isopropyl alcohol (IPA) in the etching process. Obtained results can be very useful for selection of other modifiers of etching solutions to create new shapes of 3D structures in silicon for micromechanical applications. (C) 2001 Elsevier Science B.V. All rights reserved.