Etching method

An etching method performed by an etching apparatus, the etching method comprising:

• placing, on a mount table of the etching apparatus, a wafer that includes a multi-layer film including a first silicon-containing film and a second silicon-containing film different from the first silicon-containing film and a single-layer film including the first silicon-containing film;
• setting a temperature of the wafer at −35° C. or lower;
• supplying, by a first radio-frequency power supply of the etching apparatus, a first radio-frequency power with a first frequency to generate plasma from a hydrogen-containing gas and a fluorine-containing gas;
• applying a second radio-frequency power with a second frequency lower than the first frequency to the mount table by a second radio-frequency power supply of the etching apparatus, at least one of the first radio-frequency power and the second radio-frequency power being a pulse wave;
• and
• controlling a duty ratio of the pulse wave.

An etching method performed by an etching apparatus, the etching method comprising:

• placing, on a mount table of the etching apparatus, a wafer that includes a multi-layer film including a first film and a second film different from the first film and a single-layer film including the first film;
• outputting, by a first radio-frequency power supply of the etching apparatus, a first radio-frequency power with a first frequency to generate plasma from a process gas;
• applying a second radio-frequency power with a second frequency lower than the first frequency to the mount table by a second radio-frequency power supply of the etching apparatus;
• and
• stopping the application of the second radio-frequency power, wherein
• the application of the second radio-frequency power to the mount table and the stopping of the application of the second radio-frequency power are repeated to concurrently etch the multi-layer film and the single-layer film.