Abstract: In a plasma processing method for conducting etching on an object to be processed by generating plasma from depositional gas introduced into a processing chamber and exposing the object to be processed to the plasma in a state in which radio frequency power is applied, the object to be processed is etched under etching conditions that a deposit film on an inner wall of the processing chamber becomes amorphous by repeating a first period during which the object to be processed is exposed to plasma and a second period during which the object to be processed is exposed to plasma and an etching rate is lower as compared with the first period. Consequently, particles due to increase in the number of processed sheets of the object to be processed can be suppressed.

Abstract: Provided are a plasma processing apparatus with a radio-frequency power supply supplying temporally modulated intermittent radio-frequency power which can be controlled with high precision in a wide repetition frequency band, and a plasma processing method using the plasma processing apparatus. A plasma processing apparatus includes: a vacuum vessel; a plasma generating section plasma in the vacuum vessel; a stage installed in the vacuum vessel and mounted with a sample; and a radio-frequency power supply applying temporally modulated intermittent radio-frequency power to the stage, wherein the radio-frequency power supply has two or more different frequency bands and temporally modulates the radio-frequency power by a repetition frequency which has the same range of analog signals used in each of the frequency band.

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.