| 摘要 |
PURPOSE:To make it possible to detect an end point even in the case of an eatching of 2-layer film system of the same kind component materials, by monitoring the intensity change of nuclear magnetic resonance absorption line of a reaction gas species in an etching process. CONSTITUTION:When an etching reaches on a lower N-type burried layer 11 neighbouring to a lower separating layer 10 of a silicon substrate 4, a gas species whose main component is chloride of antimony begins to exist in a gas generated by a reaction gas and the etching. The resonance spectrum line of the gas species containing antimony of 57.3% natural existance probability and <121>Sb nucleus in a magnetic field of 10<4>[G] appears at 10.2[MHz]. In a neighbouring frequency range, that is 9-11[MHz], a spectrum line due to <13>C of carbon tetrachloride being an etchant apperars at 10.7[MHz]. The intensity of spectrum line due to <121>Sb is about twice as large as the one due to <13>C. The 10.2[MHz] line due to <121>Sb is noticed and monitored.
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