摘要 |
After forming a first insulating film of a silicon nitride film, a silicon nitrided oxide film or a silicon carbide film, a second insulating film of a silicon oxide film is formed on the first insulating film. In a chamber of a high density plasma etching system, the second insulating film is selectively etched by using a first etching gas including a fluorocarbon gas having a cyclic structure as a principal constituent, so as to form an upper hole in the second insulating film. Subsequently, in the same chamber, the first insulating film is selectively etched by using a second etching gas including an oxygen gas as a principal constituent, so as to form a lower hole continuous to the upper hole in the first insulating film.
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