Polishing pad and methods for manufacturing and using the same

Abstract

This invention provides a polishing pad, which includes a substrate and a plurality of discrete abrasive blocks fixed on the substrate, wherein the abrasive blocks are of at least two kinds of heights. This invention would not reduce the polishing rate dramatically during the process for polishing a wafer by using the polishing pad in the long run. Therefore a thickness of the wafer to be polished is able to be controlled accurately, thereby improving the effect and yield of polishing the wafer. The present invention further provides a method for manufacturing the polishing pad. The polishing pad according to this invention is manufactured conveniently by using this method. Correspondingly, a method for using the polishing pad is also provided in this invention.

1 . A polishing pad, comprising:
 a substrate; and   a plurality of discrete abrasive blocks fixed on the substrate, wherein the plurality of abrasive blocks comprises abrasive blocks of at least two different heights.   
     
     
         2 . The polishing pad according to  claim 1 , wherein each of the different heights of the abrasive blocks is in a range from about 10 μm to about 50 μm. 
     
     
         3 . The polishing pad according to  claim 1 , wherein a height difference between any two different heights of the abrasive blocks is at least from about 3 μm to about 5 μm. 
     
     
         4 . The polishing pad according to  claim 1 , wherein the plurality of abrasive blocks comprise 2 to 20 different heights. 
     
     
         5 . The polishing pad according to  claim 1 , wherein a width of the abrasive blocks is from about 50 μm to about 200 μm. 
     
     
         6 . A method for manufacturing a polishing pad, comprising:
 preparing a mixture by mixing a plurality of abrasive particles and organic polymers;   coating a substrate with the mixture;   compressing the mixture with a mold so as to form a plurality of discrete abrasive blocks on the substrate, wherein the plurality of abrasive blocks comprise abrasive blocks of at least two different heights, and the mold has a corresponding pattern so as to form the abrasive blocks; and   fixing the discrete abrasive blocks on the substrate.   
     
     
         7 . The method according to  claim 6 , wherein the abrasive particles comprise one or more materials selected from the group consisting of cerium dioxide, silicon dioxide, adamas, zirconium oxide, aluminum oxide, and silicon nitride. 
     
     
         8 . The method according to  claim 6 , wherein the abrasive blocks have 2 to 20 different heights. 
     
     
         9 . The method according to  claim 6 , wherein each of the different heights of the abrasive blocks is in a range from about 10 μm to about 50 μm. 
     
     
         10 . The method according to  claim 6 , wherein the abrasive blocks are arranged in order of height from highest to lowest height or from lowest to highest height, or are arranged alternating high and low height on the substrate. 
     
     
         11 . The method according to  claim 6 , wherein a height difference between any two different heights of the abrasive blocks is at least from about 3 μm to about 5 μm. 
     
     
         12 . A method for polishing a wafer with the polishing pad of  claim 1 , comprising:
 providing the polishing pad having a plurality of different heights of abrasive blocks fixed thereon; and   bringing a wafer into contact with the polishing pad; and   adding a polishing slurry to perform polishing.