Patent ID: 7960188
Filing Date: 2011-06-14
Classification: H01L

Abstract:
1. A method of polishing a substrate having an insulating film, a barrier film formed on the insulating film, and a metal film formed on the barrier film, a part of the metal film forming metal interconnects, said method comprising: performing a first polishing process of removing the metal film; after the first polishing process, performing a second polishing process of removing the barrier film; after the second polishing process, performing a third polishing process of polishing the insulating film and the metal film simultaneously; during the second polishing process and the third polishing process, monitoring a polishing state of the substrate with an eddy current sensor; and terminating the third polishing process when an output signal of the eddy current sensor reaches a predetermined threshold, wherein the predetermined threshold is a value determined by subtracting a predetermined value from a value of the output signal of the eddy current sensor at a time of an end point of the second polishing process, and the predetermined value is a value of a variation in the output signal value of the eddy current sensor which corresponds to a predetermined amount of the insulating film to be polished.