Patent ID: 8083960

Claim:
An etching endpoint determination method for determining an endpoint of etching processing which is implemented in a plasma etching apparatus that introduces a processing gas into a vacuum processing chamber via a gas introduction means, produces plasma by feeding high-frequency energy to the introduced processing gas, and uses the produced plasma to perform plasma processing on a workpiece stored in the processing chamber, comprising the steps of: sampling light of a pre-set wavelength from light emitted by the plasma produced in the vacuum processing chamber, acquiring as time-sequential data the luminous intensity of the sampled light of the specific wavelength, and computing a regression line on the basis of the acquired time-sequential data; and computing distances in a time-base direction between the regression line and the time-sequential data which are obtained at the first step, wherein an endpoint of etching processing is determined based on the distances in the time-base direction obtained at the second step.