Plasma processing method and plasma processing apparatus

Abstract

In cycle etching in which a depo process and an etching process are repeated, a depo film thickness over a pattern is controlled precisely, and etching is executed to have a desired shape stably for a long time. There are included the depo process (S) of introducing a reactive gas having a deposit property to a processing chamber and forming a deposit layer over the surface of a pattern to be etched of a substrate to be etched, the etching process (S) of removing a reaction product of the deposit layer and the surface of the pattern to be etched, and a monitoring process (S) of irradiating light to the pattern to be etched at the time of the depo process of cycle etching for executing two processes alternately and working a fine pattern and monitoring a change amount of the film thickness of the deposit layer by change of a coherent light having a specific wavelength reflected by the pattern to be etched, the depo process being for forming the deposit layer, in which a processing condition of processes for forming the deposit layer of the next cycle and onward of cycle etching is determined so that an indicator of the depo film thickness calculated from the change amount of the film thickness of the deposit layer monitored falls in a predetermined range compared to reference data.