| 摘要 |
PROBLEM TO BE SOLVED: To provide an etching method by which the etched shape of a film to be etched can be improved by removing the residue formed on the etched surface of the object. SOLUTION: A film to be etched is composed of an upper flare film 210 and a lower SiO2 film (or SiN film) 220. The film is etched by using a process gas containing at least N2, H2, and CF4 at the time of just-etching the film to be etched, or at least N2 and H2 at the time of over-etching the film, and the pattern of the SiO2 or SiN film 220 is used as an etching mask 230. The flow rate of the CF4 is substantially adjusted to 0.2-0.4% of that of the process gas. When the flow rate of the CF4 is >=0.2%, the residue resulting from the Si contained in the film to be etched can be removed sufficiently. When the flow rate is <=0.4%, on the other hand, the etching of the shoulder section of the etching mask 230 becomes difficult.
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