| 摘要 |
PURPOSE:To improve the reproducibility of the endpoint decision of etching treatment by a method wherein settings of the optimum DC component elimination value and the optimum amplification degree are automatically performed. CONSTITUTION:A quantity of light at the time of etching treatment is converted into an electric signal by an electric signal converting means 20 such as a photomultiplier, etc., and after the electric signal was converted into other quantity of electricity by a converter 21 such as an I-V converter, etc., the quantity of electricity is inputted in a memory holding means, for example, in a sample holder 22. The output of the memory holding means 22 is inputted in a unit for setting DC component elimination value, for example, in a microcomputer 23, and at the same time, it inputted in a DC quantity eliminator 24 as well. In the DC component eliminator 24, the DC quantity elimination value set in the unit 23 is eliminated from the inputted value inputted from the memory holding means 22. After being amplified in an amplifier 25, the output of the DC component eliminator 24 is inputted in the unit 23. The unit 23 decides the endpoint of etching treatment on the basis of the output of the amplifier 25. The unit 23 outputs a signal for setting the amplification degree in the amplifier 25 as well. |
