Method of anisotropic etching of substrates

摘要

Anisotropic etching of silicon substrate (40) comprises: etching in presence of gas etchant and passivating gas, passivating the substrate (14) by controlling excitation power and substrate bias, and repeating the etching step (48). Mixed gas is introduced into a chamber containing the substrate (14). The etching in mixed gas is carried out by controlling excitation power and substrate bias during a first period of time to remove material from the substrate surface, to provide an exposed surface. The passivation is achieved by controlling excitation power and substrate bias during a second period to cover the exposed surface with a polymer layer. The mixed gas is the same during etching and passivation.