Selective electrochemical process for creating semiconductor nano- and micro-patterns

Abstract

A porous semiconductor is created by electrochemical etching. Selected regions of a semiconductor are first treated to reduce the threshold potential at which pore formation occurs, and then an electrochemical etch is carried out on the semicnoductor at a potential at least equal to the reduced threshold potential for the selected regions and less than the threshold potential for untreated regions. The selective treatment preferably involves implantation with the same ions as the semiconductor, i.e. Si ions for silicon. The treatment results in the formation of highly defined etch patterns or patterns of porous material depending on the process conditions.