METHOD AND DEVICE FOR MONITORING SITE AND ON-LINE OF TRENCH FORMING PROCESS

摘要

PURPOSE: To monitor online in the site of trench formation process. CONSTITUTION: Spectrometers 30A and 30B are so tuned as to view the same kind of radiation. By subtracting side part signal Il of the spectrometer 30A from an upper part signal It of the spectrometer 30B, an interferometric component signal Ii is extracted. By utilizing the amplitude and period of the interferometric component signal Ii which is a sine-like signal of quasi-periodic and damping, a trench depth and the thickness of re-deposited layer are judged real time, thus trench formation process is continuously monitored.