| abstract |
A method for selectively etching a first region made of silicon oxide with respect to a second region made of silicon nitride is provided. The method includes steps (a) and (b). In the step (a), the object to be processed is exposed to the fluorocarbon gas plasma, and a protective film thicker than the protective film formed on the first region is formed on the second region. In the step (b), the first region is etched by the fluorocarbon gas plasma. In the step (a), the temperature of the object to be processed is set to a temperature of 60 ° C. or higher and 250 ° C. or lower. [Selection] Figure 1 |