PLASMA PROCESSING APPARATUS AND METHOD FOR PLASMA PROCESSING

摘要

The present invention provides a plasma processing device or a method thereof which precisely detects the residual thickness of a film of an object to be processed during an etching process. The strength of coherent light of a plurality of wavelengths obtained from a wafer surface during the process is detected. Time series data of time differentiation of the strength of the coherent light of the wavelengths detected in a randomized time is detected. Actual differentiation waveform pattern data which uses a wavelength as a parameter is detected using the time series data regarding the wavelengths. A residual thickness of the randomized time is measured using a result which compares the actual differentiation waveform pattern data with differentiation waveform pattern data for detection which is formed using the residual thickness of the film of the object to be processed of a film structure having a thickness of two different lower films before a wafer is processed, and reference differentiation waveform pattern data which uses the wavelength of the coherent light as the parameter. The arrival to a target of the process is determined using the residual thickness.