公开(公告)号：JPH09330893A

公开(公告)日：1997-12-22

申请号：JP5916397

申请日：1997-03-13

Applicant: IBM

Inventor： REPIN RI ,  SUTEIIBUN JII BAABII ,  AANORUDO HARUPERIN

IPC: H01L21/304 ,  B24B37/04 ,  B24B49/02 ,  G01B7/06 ,  G01N27/00 ,  G01R27/00

Abstract: PROBLEM TO BE SOLVED: To hold abrasive history of all wafers and give detection sensitivity by a method wherein a sensor for generating a signal answering a film removal process is coupled to a positive feedback amplifier having a mode selector and this positive feedback amplifier is coupled to an analyzer. SOLUTION: A sensor 100 is coupled to a film to be grounded and generates a signal, and variations of the signal are propotional to variations of a thickness of a film when removed under the sensor. Accordingly, when a thickness of the film is decreased, a signal further varies. The signal from the sensor 100 is supplied to a positive feedback amplifier 104 by connecting means 102. The positive feedback amplifier 104 can increase a signal (frequency mode), and automatically set a gain (automatic amplitude mode), and supplies the signal to a filter 106, and removes high-dimensional higher harmonics if necessary. Next, the filtered signal is supplied to an analyzer 108, which monitors the signal and transmits data to a computer.