JUDGING DEVICE AND MONITORING METHOD FOR TERMINATION POINT OF POLISHING PROCESS

摘要

PROBLEM TO BE SOLVED: To detect the termination point of a polishing process precisely by monitoring the change of the concentration of a material in the slurry on the downstream side of a raw material. SOLUTION: A monitoring element with two electrodes 128 is used to monitor the conductivity change of an outflow object or an outflow object component passing through a conduit 142. The electrodes 128 measure the conductivity change of an abrasive slurry or an abrasive slurry component after a material causing a conductivity change is removed from a raw material. A valve 145 controls the flow of the outflow object in the conduit 142 so that a large quantity of the slurry is kept above and below the electrodes 128, thereby the conductivity measurement of the electrodes 128 can be kept constant. A controller 120 controls a motor 106 to stop a platen 102 being rotated and/or controls a motor 114 to stop a raw material carrier 110 being rotated in response to the change of the signal transferred from the electrodes 128.