  Electrochemical etching of semiconductors, beside technical applications,
provides an interesting experimental setup for self-organized structure
formation capable of regular, diameter-modulated, and branching pores. The
underlying dynamical processes governing current transfer and structure
formation are described by the Current-Burst-Model: all dissolution processes
are assumed to occur inhomogeneously in time and space as a Current Burst (CB);
properties and interactions between CB's are described by a number of material-
and chemistry- dependent ingredients, like passivation and aging of surfaces in
different crystallographic orientations, giving a qualitative understanding of
resulting pore morphologies.
