| 摘要 |
PURPOSE:To make it possible in the high speed etching process to judge the etching end point with high reliability, by performing end point judgment and output automatic correction in the different end point judgment system. CONSTITUTION:Through the transparent window 20, the plasma ray enters the spectroscope 21, for example, in which the plasma ray of specified wave length is selectively taken out. By the photoelectric converter 22, the plasma ray of specified wave length is converted to the analog electric signal, which is amplified by the amplifier 23. By the A/D converter 24, the amplified analog electric signal is converted to the digital data which is delivered to the compara tor 25. In the comparator 25, the input digital data is compared with the refer ence value for judgment which is previously set and inputted and the end point judgment is made. In the high speed etching process, the etching end point judgment of the n-th wafer 40 is performed in the end point judging system 26, and the automatic correction for output in this case is performed in the end point judgment system 26'. |
