Polishing pad, method of producing same, and polishing method

Abstract

A polishing pad is formed with a non-foamed member shaped as a plate having a flat surface and abrading particles affixed inside and on the surfaces of this non-foamed member. Its average surface roughness is in the range of 0.5 μm-10 μm, and its Shore D hardness is within the range of 50-85. Grooves are formed on the surface of the polishing pad for collecting debris generated during the polishing operation and serving also as flow routes of a polishing liquid for distributing it uniformly over the surface of the polishing pad.

1 . A polishing pad comprising: 
 a non-foamed member in a shape of a plate, having a flat surface; and    abrading particles affixed inside and on surfaces of said non-foamed member.    
     
     
         2 . The polishing pad of  claim 1  having Shore D hardness within the range of 50-85.  
     
     
         3 . The polishing pad of  claim 1  having Shore D hardness within the range of 70-85.  
     
     
         4 . The polishing pad of  claim 1  wherein said non-foamed member comprises a resin material selected from the group consisting of polyurethane resins, polyethylene resins, polystyrene resins, vinyl polychloride resins and acryl resins.  
     
     
         5 . The polishing pad of  claim 1  wherein said abrading particles comprise particles selected from the group consisting of primary particles, secondary particles and mixed particles of primary and secondary particles.  
     
     
         6 . The polishing pad of  claim 5  wherein said primary particles have an average diameter of 0.005 μm-0.5 μm.  
     
     
         7 . The polishing pad of  claim 5  wherein said secondary particles have an average diameter of 0.01 μm-20 μm.  
     
     
         8 . The polishing pad of  claim 1  wherein said abrading particles comprise particles of one or more materials selected from the group consisting of cerium oxide, silicon oxide, alumina, silicon carbide, zirconia, iron oxide, manganese dioxide, titanium oxide and diamond.  
     
     
         9 . The polishing pad of  claim 1  wherein said non-foamed member contains said abrading particles at 10 volume %-60 volume %.  
     
     
         10 . The polishing pad of  claim 1  wherein said non-foamed member has thickness in the range of 0.5 mm-3 mm.  
     
     
         11 . The polishing pad of  claim 1  with average surface roughness in the range of 0.5 μm-10 μm.  
     
     
         12 . The polishing pad of  claim 1  having grooves formed on the surface thereof.  
     
     
         13 . The polishing pad of  claim 1  further comprising an adhesive sheet including a base sheet having a front surface and a back surface both coated with an adhesive material, said adhesive sheet being attached to a back surface of said non-foamed member through the adhesive material on the front surface of said adhesive sheet.  
     
     
         14 . The polishing pad of  claim 13  wherein said base sheet comprises an elastic sheet.  
     
     
         15 . A method of producing a polishing pad, said method comprising the steps of: 
 preparing a dispersed liquid by mixing a resin solution, abrading particles and a hardener;    preparing a non-foamed dispersed liquid by reducing pressure and thereby defoaming said dispersed liquid;    forming a block of plate-shaped non-foamed member having said abrading particles affixed inside and on surfaces by hardening said non-foamed dispersed liquid; and    forming said block into a desired thickness.    
     
     
         16 . The method of  claim 15  wherein said desired thickness is in the range of 1 mm-6 mm.  
     
     
         17 . The method of  claim 15  further comprising the step of forming grooves on a surface of said block formed into said desired thickness.  
     
     
         18 . A method of polishing a surface of a workpiece, said method comprising the steps of: 
 providing a polishing machine having a lapping plate with the polishing pad of  claim 1  attached to a surface of said lapping plate, means for rotating said lapping plate, a holder for holding said workpiece and means for supplying a polishing liquid or polishing slurry;    causing said lapping plate to rotate;    supplying said polishing liquid or polishing slurry on a surface of said polishing pad attached to said lapping plate; and    pressing said surface of said workpiece held by said holder onto said surface of said polishing pad.