To provide an etching method which is based on an ALE method to enable reduction of damage to a substrate to be processed and to be superior in controllability of the etching amount, and also to provide a plasma etching device.
A method for etching a substrate to be processed includes: (a1) a step S1 for supplying etchant gas into a processing container in which the substrate to be processed is housed; (b1) a step S2 for exhausting the processing container; (c1) a step S3 for supplying rare gas into the processing container; and (d1) a step S4 for supplying microwaves into the processing container and exciting plasma of the rare gas in the processing container. A series of steps including a step for supplying the enchant gas, a step for exhausting, a step for supplying the rare gas, and a step for exciting the plasma of the rare gas may be repeated.
Yoshiki Kuroki
Junji Kashiwaoka