| abstract |
The method of one embodiment includes the steps of: (i) supplying a first gas to the chamber, the first gas being perfluorotetraethylene glycol dimethyl ether gas; and (ii) simultaneously with the step of supplying the first gas, or After the step of supplying the first gas, a plasma of a second gas for etching the porous film is generated in order to etch the porous film. The partial pressure of the first gas in the chamber, or the pressure of the first gas in the chamber when only the first gas is supplied to the chamber, is higher than the temperature of the workpiece in the execution of the step of supplying the first gas. The critical pressure of capillary condensation of the first gas in the porous membrane is lower than the saturated vapor pressure of the first gas. |