Methods for plasma etching of silicon

摘要

A method of plasma etching, in particular of anisotropic plasma etching, of laterally defined structures in a silicon substrate, using a process gas, includes having at least one passivating material precipitated on the side walls of the laterally defined structures at least from time to time prior to and/or during etching. In an exemplary method, at least one of the compounds selected from the group ClF₃, BrF₃, or IF₅ is added to the process gas as a fluorine-delivering etching gas. In another exemplary method, NF₃ is added to the process gas, at least from time to time, as an additive consuming the passivating material. Finally, in another exemplary method, a light and easily ionizable gas, in particular H₂, He, or Ne, is added, at least from time to time, to the process gas. The three exemplary methods may be combined.