Plasma processing method
View Patent ↗A plasma processing method is provided for reducing dimensions of a film to be etched from patterned dimensions, and is capable of reducing dimensions without causing deformation or collapse of the film to be etched. A plasma processing method for trimming a tantalum film by plasma etching using a resist, an antireflective film disposed under the resist, and a mask film disposed under the antireflective film, includes the steps of trimming the antireflective film and the mask film by plasma etching with the resist as a mask; removing the resist and the antireflective film subjected to the trimming, by plasma; and trimming the tantalum film by plasma etching with a mask film obtained after the resist and the antireflective film subjected to the trimming are removed by plasma, as a mask.
1. A plasma processing method for trimming a tantalum film by plasma etching using a resist, an antireflective film disposed under the resist, and a mask film disposed under the antireflective film, the plasma processing method comprising the steps of:
trimming the antireflective film and the mask film by plasma etching with the resist as a mask;
removing the resist after the antireflective film and the mask film are trimmed and the antireflective film subjected to the trimming, by plasma; and
trimming the tantalum film by plasma etching with a mask film obtained after the antireflective film and the mask film are trimmed and the antireflective film subjected to the trimming is removed by plasma, as a mask.
2. The plasma processing method according to claim 1 , wherein a thickness of the mask film is 1/10 or less of a thickness of the tantalum film.
3. The plasma processing method according to claim 2 , wherein
the mask film is a chromium film, and
trimming of the antireflective film and the mask film is conducted by plasma etching using a mixed gas of chlorine gas and oxygen gas.
4. The plasma processing method according to claim 3 , wherein
trimming of the tantalum film is conducted by plasma etching using a mixed gas of chlorine gas, methane tetrafluoride gas, and helium gas.
5. A plasma processing method for trimming a tantalum film by plasma etching using a resist, an antireflective film disposed under the resist, and a chromium film disposed under the antireflective film, the plasma processing method comprising the steps of:
trimming the antireflective film and the chromium film by plasma etching with the resist as a mask using a mixed gas of chlorine gas and oxygen gas;
removing the resist after the antireflective film and the chromium film are trimmed and the antireflective film subjected to the trimming, by plasma; and
trimming the tantalum film by plasma etching with a chromium film obtained after the antireflective film and the chromium film are trimmed and the antireflective film subjected to the trimming are removed by plasma, as a mask using a mixed gas of chlorine gas, methane tetrafluoride gas, and helium gas.