AUTOMATIC ABRASIVE CLOTH LIFE DETECTION METHOD AND SURFACE POLISHING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an automatic abrasive cloth life detection method capable of accurately determining that the service life of an abrasive cloth expires and an abnormality occurs on the abrasive cloth.;SOLUTION: An abrasive cloth 3 is stuck on the upper surface of a turn table 2, and a wafer 1 as a worked material is held on the front surface of a polishing head 5. Process monitoring systems 15 to 18 measure the drive torque of the turn table 2, analyze the frequency of the drive torque, and calculate a spectrum intensity corresponding to a preset specific frequency (for example, the speed of the turn table 2). Next, the calculated spectrum intensity is compared with a preset reference value to determine whether an abnormality is present or absent on the abrasive cloth 3. When it is judged that any abnormality occurs, the operation of the polishing device is stopped according to a specified sequence.;COPYRIGHT: (C)2002,JPO