Abstract: An plasma etching method for etching a film layer includes a plurality of times repeating a step set including a first step of introducing a gas containing hydrogen fluoride into a processing chamber and supplying hydrogen fluoride molecules to the surface of an oxide film, a second step of exhausting the interior of the processing chamber in vacuum to remove the hydrogen fluoride, and a third step of introducing a gas containing hydrogen nitride into the processing chamber and supplying hydrogen nitride to the surface of the oxide film to form a compound layer containing nitrogen, hydrogen, and fluorine on the surface of the film layer, and removing the compound layer formed on the surface of the film layer. Foreign object contamination is prevented by inhibiting mixing of hydrogen fluoride gas and hydrogen nitride gas, and the etching amount is controlled by the number of times of repeating application thereof.

Abstract: An plasma etching method for etching a film layer includes a plurality of times repeating a step set including a first step of introducing a gas containing hydrogen fluoride into a processing chamber and supplying hydrogen fluoride molecules to the surface of an oxide film, a second step of exhausting the interior of the processing chamber in vacuum to remove the hydrogen fluoride, and a third step of introducing a gas containing hydrogen nitride into the processing chamber and supplying hydrogen nitride to the surface of the oxide film to form a compound layer containing nitrogen, hydrogen, and fluorine on the surface of the film layer, and removing the compound layer formed on the surface of the film layer. Foreign object contamination is prevented by inhibiting mixing of hydrogen fluoride gas and hydrogen nitride gas, and the etching amount is controlled by the number of times of repeating application thereof.

Abstract: Line-wiggling and striation caused by collapse of a pattern after a silicon dioxide film is etched by plasma with the use of a multilayer resist mask are prevented or suppressed. In a plasma etching method of etching a film to be etched by plasma with the use of a multilayer resist mask, the multilayer resist mask includes an upper layer resist, an inorganic intermediate film, and a lower layer resist, and the method includes a side wall protective film forming step of forming a side wall protective film on a side wall of the lower layer resist.