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 μm, 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 separated from the polishing pad surface.

1 . A polishing pad comprising:
 a flatness area, and   an emboss area on its polishing surface, wherein the flatness area surrounds the emboss area and the geometric center of the emboss area coincides with the geometric center 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 μm, and the emboss area has grooves, holes or a combination thereof.   
     
     
         3 . The polishing pad according to  claim 1 ,
 wherein the distance between any point on the outer contour line of the emboss area and the geometric center of the polishing surface is 20.5% to 40% of the diameter of a wafer to be polished.   
     
     
         4 . The polishing pad according to  claim 1 ,
 wherein the distance between any two points on the inner and outer contour lines of the flatness area respectively is greater than 120% of the diameter of a wafer to be polished.   
     
     
         5 . The polishing pad according to  claim 4 ,
 wherein the shortest distance between any point on the inner contour line of the flatness area and the outer contour line of the flatness area is 120% to 150% of the diameter of the wafer to be polished.   
     
     
         6 . The polishing pad according to  claim 1 ,
 wherein the emboss area and polishing surface are arranged in the form of concentric circles, and the flatness area is an annular area formed by the polishing surface and the emboss area.   
     
     
         7 . The polishing pad according to  claim 6 ,
 wherein the diameter of the polishing surface is D 1 , and 18 inch≦D 1 ≦28 inch; and   wherein the diameter of the emboss area is D 2 , and 3 inch≦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 several 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 several 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 several annular grooves arranged in the form of concentric rings and several 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,
 performing chemical-mechanical polishing on a wafer using the flatness area of the polishing pad of  claim 1 ,   then the polished wafer is moved to the emboss area, and the wafer is separated from the polishing pad.   moving the polished wafer to the emboss area of the polishing pad of  claim 1 , and   separating the wafer from the polishing pad.