| 摘要 |
PURPOSE:To enable an actual etching terminal to be detected accurately thereby enabling the optimum etching process to be performed by a method wherein the difference between the latest sampled lighting intensity and the lighting intensity sampled before the specified period is measured while the latest sampling is judged to be the etching terminal subjected to the coincidence of difference in the lighting intensity with the set up value and so forth. CONSTITUTION:The lighting intensity (b) of specific processing light emitted during etching process is sampled per specified sample period T so as to measure the difference between the latest lighting intensity and that sampled before the specified period. Then, the latest sampling in the preceding period is judged to be the etching terminal T2 subjected to the coincidence of the difference in the lighting intensity with the previously set up value (e) so that the said etching process may be terminated at the T3 after the lapse of overetching (f) for specific term from the etching terminal T2. For example, a vacuum chamber 1 wherein a substrate 3 is etched is fitted with a photoelectric converter 5 provided with a spectrofilter 4 so that the voltage signal from the converter 5 may be converted into digital voltage signal V to be transmitted to a microcomputer 7 for controlling the etching process as mentioned above. |
