END POINT DETECTION APPARATUS FOR CHEMICAL MECHANICAL POLISHING IN SEMICONDUCTOR DEVICE AND MEASURING METHOD THEREOF

摘要

PURPOSE: An end point detection apparatus for a chemical mechanical polishing(CMP) in a semiconductor device and a measuring method thereof are to check a variation of an actual polishing target layer by measuring a variation of an electrochemical potential. CONSTITUTION: The end point detection apparatus comprises a polishing liquid layer and a reference electrode(25). The polishing liquid layer is formed between a wafer(15) and a platen region(11). The reference electrode is installed in the platen region that is in contact with the wafer to be thereby connected with the wafer. The reference electrode forms a salt bridge by inserting a tube. The tube is filled with an agar containing KCl.. The back sides of the reference electrode and the wafer are connected with a voltmeter(21) through an electrical contact wire(19). The contact wire uses a carbon brush in the backside of the wafer. A mercury electrode is used in the reference electrode.