ETCHING METHOD AND ETCHING APPARATUS

摘要

A mask material layer (102) of a desired pattern is formed on a silicon oxide film (101). The exposed parts of the silicon oxide film (101) is etched in accordance with the pattern of the mask material layer (102) by plasma etching by using a mixed gas fed at a rate such that the ratio (C5F8+O2/Ar) of the total flow rate of C5F8+O2 to the flow rate of Ar is 0.02 (2%) or less. Thus, a generally vertical right-angled portion is formed in the silicon oxide film (101). Therefore, no microtrenches are formed, and etching into a desired pattern is precisely effected.