METHOD AND APPARATUS FOR JUDGING END POINT OF PLASMA TREATMENT

摘要

PURPOSE:To realize the end point judgement with excellent reproducibility even if the number of samples subjected to a plasma treatment is increased by a method wherein the attenuation factor of an observation window provided in the wall of a treatment chamber is measured before the plasma treatment of the sample in the treatment chamber is started and a light emission intensity is corrected in accordance with the attenuation factor and the end point is judged in accordance with the light emission intensity. CONSTITUTION:An observation window 20 is provided in the wall of a treatment chamber 10 facing a discharge space 13. A light transmitting window 30 is provided in the wall of the treatment chamber 10 facing the ovservation window 20. In this case, the observation window 20 and the light transmitting window 30 are made of the same material, in other words, transparent material with the same attenuation factor. The time elapsed since the start of the plasma treatment of a sample 100 is inputted to an end point judging part 94. Therefore, 1st degree differentiation or 2nd degree differentiation of a function of light emission intensity/plasma treatment time is processed in the end point judging part 94 and the time when the 1st degree differential or the 2nd degree differential is satisfied by a predetermined judgement reference value preset and inputted by a data setting part is judged as the end point of the plasma treatment of the sample 100.