| CPC H01L 21/31116 (2013.01) [H01L 21/67069 (2013.01)] | 2 Claims |
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1. A substrate processing method for etching a silicon oxide film formed on a substrate, comprising:
performing a first selective etching process to selectively etch the silicon oxide film while maintaining another film by supplying a hydrogen fluoride gas into a chamber in a state in which a pressure in the chamber is a first pressure lower than an atmospheric pressure; and
performing a second selective etching process to selectively etch the silicon oxide film while maintaining the another film by supplying the hydrogen fluoride gas into the chamber in a state in which the pressure in the chamber is a second pressure lower than the atmospheric pressure, wherein
the first pressure is not greater than 600 Torr and is not lower than 100 Torr,
the second pressure is not greater than 50 Torr,
in the second selective etching process, a melting point and a boiling point of a reaction product generated in the first selective etching process and remaining on the silicon oxide film are lowered, and
in the second selective etching process, the silicon oxide film is etched while the reaction product remaining on the silicon oxide film is sublimated.
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