METHOD OF DETECTING POLISHING END POINT OF DEVICE WAFER

摘要

PROBLEM TO BE SOLVED: To provide a method for detecting timing of a chemical mechanical polishing end point of a substrate in a damascene step and a capacitor material burying step. SOLUTION: A wafer 1 provided with an iron thin film layer as an index in one layer structure of a substrate to be polished is used, a waste solution of a polishing agent slurry 13 is recovered as a continuous flow at the beginning of chemical mechanical polishing or in the middle thereof, color-developing reagent for reaction with iron ions is continuously mixed into the recovered continuous flow to obtain a sample 26 as a continuous flow, the color of the sample is read by a color identification sensor 300 in the form of a digital value (Ii), and a chemical mechanical polishing end point of the substrate is determined when the value of the digital value (Ii) reaches a digital value (Io) of the sample as the polishing agent slurry waste flow at the polishing end point of chemical mechanical polishing when the digital value is previously input to a controller CPU.