To realize a method for accurately monitoring the treatment of substrate to be treated in a vacuum treatment chamber, using a gas in plasma state, utilizing a Pirani gage of fast response and a method for manufacturing a semiconductor device which accurately detects the end of treatment of the substrate to be treated, using the gas in the plasma state.
Gas for treatment is introduced into a treatment chamber 21 subjected to pressure reduction, and the specific heat of the gas on introduction at a prescribed place in this treating chamber 21 is measured beforehand by using a Pirani gage 24 of fast response. Treatment of a substrate 20 to be treated is executed b having the state of this gas change, and the specific heat of the gas of which the state is changed from that before the treatment to that after the treatment is measured by the Pirani gage 24. The result of this measurement is compared with a measured value obtained beforehand and the state of progress of the treatment, the end point of the treatment in particular, is detected therefrom. The end point of the treatment of a wafer or the like, for which the gas in the state of plasma is used, can be detected accurately and quickly.
YOSHIDA YUKIMASA
OKUMURA KATSUYA
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