PLASMA STABILITY DETERMINATION METHOD AND PLASMA PROCESSING DEVICE

摘要

In determining the stability of plasma in a plasma processing device that performs plasma processing by turning into plasma a processing gas supplied into a processing container, the method of this invention comprises: detecting, while plasma is being generated inside the processing container, the light emission intensity of the plasma inside the processing container; generating, from the results of light emission intensity detection, a first function representing the relationship between time and light emission intensity; differentiating the first function with respect to time to calculate a derivative and generating a second function from the relationship between the absolute value of the derivative and time; and integrating the second function with respect to time to calculate the integrated value and determining the stability of the plasma on the basis of the calculated integrated value.