On the Mechanism of Chemically Etching Germanium and Silicon

The electrode potential of germanium or silicon in a chemical etching solution is a function of solution pH, rate of etching, physical condition of the surface, conductivity type, and resistivity. The results suggest that excess holes and electrons are produced at the surface of the semiconductor during chemical etching. Holes are injected at cathode sites, but only a portion of these holes are consumed at anode sites since the anode reaction involves current multiplication.