CHEMICAL MECHANICAL POLISHING APPARATUS AND DEVICE OF MEASURING WAFER METAL LAYER THICKNESS USED THEREIN

摘要

The present invention relates to a chemical mechanical polishing device and a method for measuring the thickness of a wafer polishing layer by using the same. The chemical mechanical polishing device for a wafer comprises: a polishing plate having an upper surface covered with a polishing pad and rotating about its axis; a polishing head rotating while pressing a wafer to the polishing pad; a conditioner for modifying the surface of the polishing pad by a rotating conditioning disk while being in contact with the surface of the polishing pad; a sensor for receiving a received signal having at least one component among a thickness and a distance; and a control unit for detecting the thickness of the polishing layer of the wafer by reflecting a signal component according to changes in the thickness of the polishing pad from a first received signal received by the sensor under the conditioning disk to a second received signal received by the sensor under the wafer. The device and the method of the present invention can acquire distance information between the sensor and the conditioning disk from the first received signal received from the conditioning disk when the sensor for measuring the thickness of the polishing layer passes under the conditioning disk and acquire information about the thickness variation of the polishing pad through the acquired distance information, thereby accurately measuring the final thickness or thickness variation of the polishing layer by reflecting the thickness variation of the polishing pad from the first received signal in calculating the thickness of the polishing layer from the second received signal received from the polishing layer of the wafer.