| 摘要 |
PURPOSE:To detect the end point of ashing precisely and stably by detecting the intensity of light of at least two or more of spectral lines in transition light within a specific wave range from C0 in plasma and comparing the intensity of these lights. CONSTITUTION:The angle of rotation of a diffraction grating is changed and some spectral line in b<3>SIGMA-a<3>pi transition light within the range of wavelengths 296-300nm from CO is extracted, and the spectral line is projected to a photomultiplier 17, the intensity of light is converted into electric signals, and the maximum value of the electric signals is memorized temporarily in a detector 13. The diffraction grating 15 is turned, another spectral line is selected similarly, and the maximum value of the spectral line is memorized to the detector 13. The rotational temperature of plasma is obtained from the ratio of the intensity of these two maximum values, and the variation of a rotational temperature in the vicinity of an organic film and the rotational temperature of a plasma region in the vicinity of an electrode is compared from the alteration of the rotational temperature of plasma or by mounting two monochromators 14, thus detecting the end point of ashing. Accordingly, the adjustment of the detector by the change of the conditions of ashing is unnecessitated, thus stably detecting the end point of ashing accurately.
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