In Part I we introduced a construction
method for analytical orientation dependent growth and etch rate functions.
In this article, this network construction principle is applied to wet
chemical etching of silicon in concentrated aqueous potassium hydroxide.
Detailed measurements of the etch rate as a function of crystal surface
orientation are used to fit the phenomenological parameters in the network
etch rate function. In this function, for each crystal facet, two surface
processes are accounted for, etching through misorientation step flow and
etching through nucleation of pits. The fitting procedure identifies additional
mesoscopic, surface processes which influence the orientation dependence
of the etch rate. These processes correspond to instabilities of the surface.
In the {111} region step bunching occurs which evolves into microfaceting
for larger inclination angles. Moreover, for certain experimental circumstances,
the fast etching {110} region breaks up into a staircase structure of terraces.
Additional network elements are defined to account for these instabilities.
The step-bunching instability is treated using an ad hoc approach. With
these amendments the experimental etch rate functions can be fitted to
an accuracy of about 5% by a network function with nine parameters. This
shows that it is possible to reproduce the essential features of an experimental
growth or etch rate function using an analytical function with a limited
number of physically meaningful parameters. (C) 2000 American Institute
of Physics. [S0021-8979(00)01712-6].