Polishing pad

Abstract

A polishing pad is described as comprising, (a) particulate polymer which can be chosen from particulate thermoplastic polymer (e.g., particulate thermoplastic polyurethane), particulate crosslinked polymer (e.g., particulate crosslinked polyurethane and/or particulate crosslinked polyepoxide) and mixtures thereof; and (b) organic polymer binder (e.g., polyurethane binder and/or polyepoxide binder), which can bind the particulate polymer together, wherein said organic polymer binder can be prepared in-situ . The particulate polymer and organic polymer binder can be distributed substantially across the work surface the polishing pad, and the pad can have a percent pore volume of from 2 percent by volume to 50 percent by volume, based on the total volume of said polishing pad.

1 . A polishing pad assembly comprising: 
 (a) a polishing pad having an work surface and a back surface;    (b) a backing sheet having an upper surface and a lower surface; and    (c) an adhesive means interposed between and in adhesive contact with the back surface of said polishing pad and the upper surface of said backing sheet,    wherein said polishing pad comprises, 
 (i) particulate polymer thermoplastic particulate polymer, crosslinked particulate polymer, particulate polymer comprised of interpenetrating polymer networks, and mixtures thereof, and  
 (ii) an organic polymer binder chosen from thermoplastic organic polymer binders, crosslinked organic polymer binders, organic polymer binders comprised of interpenetrating polymer networks, and mixtures thereof.  
   
     
     
         2 . The polishing pad assembly of  claim 1  wherein said adhesive means is selected from: an adhesive assembly comprising, an upper adhesive layer in contact with the back surface of said polishing pad, a lower adhesive layer in contact with the upper surface of said backing sheet, and an adhesive support sheet interposed between said upper and lower adhesive layers; and an adhesive layer.  
     
     
         3 . A method of preparing a polishing pad which comprises particulate polymer and an organic polymer binder, comprising the step of reacting an organic polymer binder precursor in the essentially immediate presence of said particulate polymer.  
     
     
         4 . The method of  claim 3  wherein said precursor is selected from the group consisting of monomers, prepolymers, resins and mixtures thereof.  
     
     
         5 . A method for chemical mechanical planarization of a substrate comprising the step of contacting said substrate with a polishing pad, wherein said pad comprises particulate polymer and an organic polymer binder which binds said particulate polymer together, and 
 wherein said organic polymer binder is prepared by chemically reacting at least one organic polymer binder precursor in the presence of said particulate polymer, and wherein said particulate polymer and said organic polymer binder are distributed substantially uniformly across working surface of said pad, and said pad has a percent pore volume of from 2 percent by volume to 50 percent by volume, based on the total volume of said polishing pad.    
     
     
         6 . The method of  claim 5  wherein said precursor is selected from the group consisting of monomers, prepolymers, resins and mixtures thereof.  
     
     
         7 . A polishing pad comprising particulate polymer wherein said particulate polymer is held together with substantially no sintering of the particles of said particulate polymer.  
     
     
         8 . The polishing pad of  claim 7  further comprising an organic polymer binder.  
     
     
         9 . The polishing pad of  claim 7  wherein said particulate polymer is chosen from thermoplastic particulate polymer, crosslinked particulate polymer, particulate polymer comprised of interpenetrating polymer networks and mixtures thereof.  
     
     
         10 . The polishing pad of  claim 8  wherein said organic polymer binder is chosen from thermoplastic organic polymer binders, crosslinked organic polymer binders, interpenetrating polymer networks and mixtures thereof.  
     
     
         11 . The polishing pad of  claim 7  wherein said particulate polymer is chosen from polyvinylchloride, polyvinylfluoride, polyethylene, polypropylene, nylon, polycarbonate, polyester, poly(meth)acrylate, polyether, polyamide, polyurethane, polyepoxide, polystyrene, polyimide, polysulfone and mixtures thereof.  
     
     
         12 . The polishing pad of  claim 7  wherein said particulate polymer has an average particle size of from 20 microns to 500 microns.  
     
     
         13 . The polishing pad of  claim 8  wherein said organic polymer binder is selected from polyurethane binders, polyepoxide binders, urethane-modified polyepoxide binders, (meth)acrylic-modified polyurethane binders, and mixtures thereof.  
     
     
         14 . The polishing pad of  claim 8  wherein said particulate polymer is present in said polishing pad in an amount of from 51 percent by weight to 95 percent by weight, based on the total weight of said particulate polymer and said organic polymer binder; and said organic polymer binder is present in said polishing pad in an amount of from 5 percent by weight to 49 percent by weight, based on the total weight of said particulate polymer and said organic polymer binder.  
     
     
         15 . The polishing pad of  claim 7  wherein said polishing pad has an average pore size of from 1 to 1000 microns.  
     
     
         16 . The polishing pad of  claim 8  wherein said particulate polymer and said organic polymer binder are distributed substantially uniformly across work surface of said pad, and said pad has a percent pore volume of from 2 percent by volume to 50 percent by volume, based on the total volume of said polishing pad.  
     
     
         17 . The polishing pad of  claim 8  wherein said organic polymer binder is prepared in-situ.  
     
     
         18 . The polishing pad of  claim 17  wherein said in-situ preparation comprises an organic polymer binder precursor.  
     
     
         19 . The polishing pad of  claim 7  wherein said polishing pad has a work surface, said work surface having surface features selected from channels, grooves, perforations and combinations thereof.  
     
     
         20 . The polishing pad of  claim 8  wherein at least one of said particulate polymer and said organic polymer binder further comprises an abrasive particulate material.  
     
     
         21 . The polishing pad of  claim 20  wherein said abrasive particulate material is selected from aluminum oxide, silicon carbide, titanium diboride, boron carbide, silicon nitride, tungsten carbide, titanium carbide, diamond, boron nitride, garnet, fused alumina zirconia, silica, iron oxide, chromia, ceria, zirconia, titania, tin oxide, manganese oxide and mixtures thereof.