Plasma etching method

摘要

In a plasma etching method, with respect to a substrate to be processed, which has a base layer, a silicon oxide film, and an etching mask formed in this order, the etching mask having an etching pattern formed thereon and being formed of polysilicon, a silicon-containing deposit is deposited on a surface of the etching mask using a plasma generated from a processing gas, while applying a negative direct current voltage to an upper electrode formed of silicon. Furthermore, in the plasma etching method, the silicon oxide film is etched using plasma generated from a first CF-based gas using, as a mask, the etching mask having the silicon-containing deposit deposited thereon.

主权项

1. A plasma etching method comprising:
providing a substrate including a base layer, a silicon oxide film disposed on the base layer, and an etching mask formed of a polysilicon and having an etching pattern; a deposition step of depositing a silicon-containing deposit on the substrate by a plasma of a processing gas while applying a negative DC voltage to an upper electrode made of silicon, wherein during the deposition step the silicon-containing deposit is deposited on the etching mask; and an etching step of etching the silicon oxide film by a plasma of a first CF-based gas while using as a mask the etching mask having the silicon-containing deposit deposited thereon, wherein the silicon-containing deposit includes silicon that originated from the upper electrode.