Patent ID: 7582220

Claim:
An etching method for etching an organic etching target film, the method comprising: forming the organic etching target film on a protective film placed inside an airtight processing chamber, the organic etching film containing Si; introducing a processing gas into the airtight processing chamber, the processing gas containing CF 4 , N 2 , and Ar; generating a plasma in the airtight processing chamber for etching the organic etching target film; and etching the organic etching target film until the protective film is exposed, wherein a resist layer is used as a mask on the organic etching target film, wherein the etching process ceases once the protective film is exposed, wherein the processing gas has a selection ratio greater than approximately 2.0, the selection ratio defined by an etching rate of the organic etching target film divided by an etching rate of the resist layer, and wherein a volume percentage density ratio of CF 4 , N 2 , and Ar is within a range: 1:1:6≦vol. % of CF 4 : vol. % of N 2 : vol. % of Ar≦1:4:6.