Patent ID: 6402598
Filing Date: 2002-06-11
Classification: B24B,H01L

Abstract:
A chemical mechanical polishing (CMP) apparatus for planarizing a surface of a semiconductor wafer, the CMP apparatus comprising:a base; a polishing pad disposed on said base; a polishing head disposed above said base for holding a wafer and pressing the wafer against said polishing pad, said polishing head including a vacuum chuck comprising a membrane at the bottom thereof, and an annular retaining ring extending around said membrane and spaced therefrom so as to define a gap therebetween terminating at a space within said polishing head, said retainer ring having a plurality of purge holes extending radially therethrough and open to said space; and a load-cup supported on said base, said load-cup including a washing basin sized to accommodate said polishing head, a pedestal disposed at the bottom of the washing basin, first nozzles oriented so as to spray deionized water toward the top surface of said pedestal, second nozzles oriented so as to spray deionized water upwardly toward a central portion of a top opening of the washing basin, and third nozzles disposed at the side of the load-cup and oriented so as to spray deionized water in a radially inward direction with respect to the washing basin, whereby when said polishing head is lowered into said washing basin of the load-cup, deionized water sprayed from said second nozzles wash the bottom surface of the polishing head, and deionized water from said third nozzles is sprayed through said purge holes in the retainer ring for washing away contaminants induced into said space.