Patent ID: 8486290

Claim:
An etching apparatus comprising: a chamber configured to enclose a plasma etching treatment; an electrode configured to generate plasma; a gas supply/exhaust system; a spectrometer configured to monitor optical emission of the plasma; and a calculator system configured to process a signal monitored by the spectrometer, and configured to display, on a terminal, a result of a processing, the calculator system including: an optical-emission-intensity waveform acquiring unit configured to acquire a plurality of optical-emission-intensity waveforms along an etching-treatment time axis, in plasma emission data obtained during one or more etching treatments; a waveform-change-existence judging unit configured to determine an existence, or lack thereof, of change amongst the plurality of optical emission intensity waveforms acquired by the optical-emission-intensity waveform acquiring unit; a waveform-correlation-matrix calculating unit configured to calculate a correlation matrix between the optical emission intensity waveforms determined to have changed by the waveform-change-existence judging unit; a waveform classifying unit configured to set each column or each row of the correlation matrix calculated by the waveform-correlation-matrix calculating unit to be a vector corresponding to an optical emission intensity waveform, configured to evaluate a similarity between optical emission intensity waveforms, based on values of the vectors, and configured to classify the optical emission intensity waveforms into groups; and a representative-waveform selecting unit configured to select a representative optical emission intensity waveform from a group classified by the waveform classifying unit, configured to specify the selected representative optical emission intensity waveform as an optical emission intensity waveform affecting performance of etching on a wafer or treatment result of etching on a wafer, configured to determine a wavelength at which the optical emission intensity waveform is obtained as an optical emission wavelength to be monitored, and configured to display a determination result on the terminal.