Plasma processing method

A plasma processing method, comprising:

• an adsorption step of forming a reaction layer on an etching target film by plasma generated using a reactive gas;
• and
• a desorption step of removing the reaction layer by using a rare gas in a metastable state generated by plasma, wherein
• the adsorption step and the desorption step are repeated,
• radio frequency power for generating the plasma in the adsorption step is smaller than radio frequency power for generating the plasma in the desorption step, and
• the method proceeds from the adsorption step to the desorption step in a state where the plasma is maintained, or proceeds from the desorption step to the adsorption step in a state where the plasma is maintained.

A plasma processing method, comprising:

• an adsorption step of forming a reaction layer on an etching target film by plasma generated using a reactive gas;
• and
• a desorption step of removing the reaction layer by using a rare gas in a metastable state generated by plasma, wherein
• the adsorption step and the desorption step are repeated,
• a pressure in the adsorption step is higher than a pressure in the desorption step, and
• a temperature of a sample stage on which a sample having the etching target film is placed in the adsorption step is the same as a temperature of the sample stage in the desorption step.