Polishing Pad and a Chemical-Mechanical Polishing Method

Abstract

The present invention provides a polishing pad, which has a flatness area and an emboss area on its polishing surface, wherein the flatness area is a flat surface with a roughness less than 20 um, for polishing a wafer; the emboss area has grooves, holes or a combination thereof, for pulling up a wafer from the polishing surface after polishing. By using the polishing pad according to the invention, a wafer may have a higher surface flatness after Chemical-Mechanical Polishing (CMP); and after polishing, the wafer is moved to the emboss area of the polishing pad, so that the wafer may be easily pulled up from the polishing pad surface.

1 . A polishing pad, comprising:
 a flatness area, and   an emboss area on its polishing surface, wherein the emboss area surrounds the flatness area and the outer contour line of the emboss area coincides with the edge contour of the polishing surface.   
     
     
         2 . The polishing pad according to  claim 1 , wherein:
 the flatness area is a flat surface with a roughness less than 20 um, for polishing a wafer; and the emboss area has grooves, holes or a combination thereof, for pulling up the wafer from the polishing surface after polishing.   
     
     
         3 . The polishing pad according to  claim 1 , wherein:
 the minimum distance between any point on the inner contour line of the emboss area and the edge of the polishing surface is 20.5% to 40% of the diameter of the wafer to be polished.   
     
     
         4 . The polishing pad according to  claim 1 , wherein:
 the distance between any point on the outer contour line of the flatness area and the geometric center of the polishing surface is greater than 120% of the diameter of the wafer to be polished.   
     
     
         5 . The polishing pad according to  claim 4 , wherein:
 the distance between any point on the outer contour line of the flatness area and the geometric center of the polishing surface is 120% to 150% of the diameter of the wafer to be polished.   
     
     
         6 . The polishing pad according to  claim 1 , wherein:
 the flatness area and polishing surface are arranged in the form of concentric circles, and the emboss area is an annular area formed by the polishing surface and the flatness area.   
     
     
         7 . The polishing pad according to  claim 6 , wherein:
 the diameter of the polishing surface is D 1 , and 18 inches≦D 1 ≦28 inches; and the diameter of the flatness area is D 2 , and 3 inches≦D 1 -D 2 ≦6 inch.   
     
     
         8 . The polishing pad according to  claim 1 , wherein:
 the number of the grooves, holes or a combination thereof in the emboss area is greater than two.   
     
     
         9 . The polishing pad according to  claim 1 , wherein:
 the grooves in the emboss area are in the form of individual lattice, ring, XY grid, spoke, helix or a combination of any two or more thereof.   
     
     
         10 . The polishing pad according to  claim 1 , wherein:
 the cross-sections of the holes in the emboss area are in the form of individual circle, ellipse, polygon or a combination of any two or more thereof.   
     
     
         11 . The polishing pad according to  claim 1 , wherein:
 the emboss area has a plurality of annular grooves arranged in the form of concentric rings.   
     
     
         12 . The polishing pad according to  claim 11 , wherein:
 the spacing between the adjacent concentric rings is 0.1 mm to 2 mm.   
     
     
         13 . The polishing pad according to  claim 11 , wherein:
 the width of the grooves is 0.15 mm to 0.5 mm, the depth of the grooves is 0.25 mm to 0.5 mm, and the minimum distance between adjacent grooves is 0.1 mm to 10 mm.   
     
     
         14 . The polishing pad according to  claim 1 , wherein:
 the emboss area has a plurality circular holes arranged in the form of concentric rings.   
     
     
         15 . The polishing pad according to  claim 14 , wherein:
 the diameter of the holes is 5 mm to 12 mm.   
     
     
         16 . The polishing pad according to  claim 14 , wherein:
 the spacing between the concentric rings is 0.1 mm to 2 mm.   
     
     
         17 . The polishing pad according to  claim 1 , wherein:
 the emboss area has a plurality annular grooves arranged in the form of concentric rings and a plurality circular holes arranged in the form of concentric rings.   
     
     
         18 . The polishing pad according to  claim 17 , wherein:
 the spacing between the concentric rings is 0.1 mm to 2 mm.   
     
     
         19 . The polishing pad according to  claim 1 , wherein:
 the polishing pad also has a liner layer set on a non-polishing surface.   
     
     
         20 . A chemical-mechanical polishing method, wherein:
 performing chemical-mechanical polishing on a wafer using the flatness area of the polishing pad of  claim 1 ,   moving the polished wafer to the emboss area of the polishing pad of  claim 1 , and   pulling up the wafer is pulled up from the polishing pad.