Evidence for nonuniform flow of charge carriers through semiconductor junctions

Abstract

Photoelectrochemical etching (photoetching) of many semiconductors leads to a pitted morphology with small etch pits (>109 cm−2) uniformly distributed over the entire semiconductor surface. It is shown here that the etch pit density increases with doping density and decreases with forward bias. These results suggest that charge flow within semiconductor junctions is highly nonuniform due to the existence of microscopic electric fields induced by the ionized donors within the space-charge layer. Numerical results for a set of CdSe and CdTe crystals are reported.