Anisotropic plasma etching of silicon using sulfur hexafluoride etching gas especially to produce recesses of precise lateral dimensions in silicon wafers

摘要

Anisotropic plasma etching of structures in silicon comprises a polymer deposition phase and an etching phase using an etching gas containing oxygen. In the anisotropic plasma etching of structures in silicon, involving a polymerization step of coating lateral structure boundaries defined by an etch mask with a polymer which is partially removed during subsequent etching and redeposited onto the etched deeper lying parts of the sidewall, etching is carried out with an etching gas containing 3-40 vol. % oxygen.