Decision method of end point of ashing and ashing device

Abstract

Abstract PURPOSE:To decide an end point with excellent reproducibility at low cost by obtaining a correction value by using the intensity of emission at two points measured and deciding the end point of ashing by the intensity corrected of emission. CONSTITUTION:When the inside of a treating chamber 1 is maintained at fixed pressure, a magnetron 8 is operated and a gas surrounded by a discharge tube 2 and a reflecting plate 9 is changed into plasma, the intensity of emission is kept constant at a certain low value as the section A of an input waveform V0. When a treating gas feeder 4 and a dopant gas feeder 5 are controlled at flow rates at the time of, ashing in a treating gas and a dopant gas, the intensity of emission is kept constant at a certain high value as the section B of the input waveform V0. When ashing is completed approximately at that time, the intensity of emission lowers as the section C of the input waveform V0. Accordingly, since the difference of the intensity of emission between the section A and the section B and the section on B and the section C is brought to approximately the same extent, the difference of the intensity of emission between the intermediate time (the section B) of ashing and the time of completion (the section C) of ashing is expanded and displayed when a section between the intensity of emission a0 and b0 is amplified maximally, thus easily detecting the end point of ashing, then deciding the end point with excellent reproducibility at low cost.

Inventors

• 👤 Tsunehiko Tsubone
• 👤 Yoshinao Kawasaki
• 👤 Katsuyoshi Kudo
• 👤 Minoru Soraoka
• 👤 Shiyouji Ikuhara

Bibliographic Details