Polishing tool and manufacturing method therefor

Abstract

A polishing tool applicable to various types of polishing objects is provided that enables to stabilize the polishing speed and to obtain superior surface details while reducing the formation of defects such as scratches on the polished surface. The tool is operated by pressing and sliding on the polishing object in a swinging motion and the surface is polished with abrasive particles imbedded in a matrix comprised primarily of a thermoplastic resin such as butadiene styrene, polybutadiene or MBS resin of acryl rubber group. The polishing tool includes fixed-abrasive polishing tool that contains abrasive particles within the polishing tool, or a polishing pad containing non-fixed-abrasive particles.

What is claimed is:  
     
         1 . A polishing tool for polishing an object, wherein the polishing tool is comprised primarily by a thermoplastic resin.  
     
     
         2 . A polishing tool according to  claim 1 , wherein the polishing tool is a fixed-abrasive polishing tool that contains abrading particles within the tool.  
     
     
         3 . A polishing tool according to  claim 1 , wherein the polishing tool is a non-fixed-abrasive polishing pad.  
     
     
         4 . A polishing tool according to  claim 2 , wherein the abrading particles include cerium oxide (CeO 2 ), alumina (Al 2 O 3 ), silicon carbide (SiC), silicon dioxide (SiO 2 ), zirconia (ZrO 2 ), iron oxides (FeO, Fe 3 O 4 ), manganese oxide (MnO 2 , Mn 2 O 3 ), magnesium oxide (MgO), calcium oxide (CaO), barium oxide (BaO), zinc oxide (ZnO), barium carbonate (BaCO 3 ), calcium carbonate (CaCO 3 ), diamond (C), or a composite material comprised by those recited above.  
     
     
         5 . A polishing tool according to  claim 1 , wherein the polishing tool is formed by injection molding to charge a feed material under pressure into a mold of a specific shape.  
     
     
         6 . A polishing tool according to  claim 1 , wherein a material comprising the polishing tool further comprises an interface activation agent.  
     
     
         7 . A polishing tool according to  claim 1 , wherein a material comprising the polishing tool further comprises a hydrophilic substance or said material is modified by adding the hydrophilic substance.  
     
     
         8 . A fixed-abrasive polishing tool for polishing an object, said polishing tool comprising: 
 abrading particles; and    a resin for binding said abrading particles in a matrix of said resin, wherein said resin comprises thermoplastic resin.    
     
     
         9 . A fixed-abrasive polishing tool according to  claim 8 , wherein the abrading particles include cerium oxide (CeO 2 ), alumina (Al 2 O 3 ), silicon carbide (SiC), silicon dioxide (SiO 2 ), zirconia (ZrO 2 ), iron oxides (FeO, Fe 3 O 4 ), manganese oxide (MnO 2 , Mn 2 O 3 ), magnesium oxide (MgO), calcium oxide (CaO), barium oxide (BaO), zinc oxide (ZnO), barium carbonate (BaCO 3 ), calcium carbonate (CaCO 3 ), diamond (C), or a composite material comprised by those recited above.  
     
     
         10 . A fixed-abrasive polishing tool according to  claim 8 , wherein a porosity is formed in said polishing tool.  
     
     
         11 . A fixed-abrasive polishing tool according to  claim 10 , wherein a range of composition of fixed-abrasives (percentages of abrading particles (Vg), binder (Vb) and air porosity (Vp)) in volume percent (vol %) are: 10%<abrading particles (Vg)<50%, 30%<binder (Vb)<80%, and 0%<air porosity (Vp)<40%.  
     
     
         12 . A method for making a fixed-abrasive polishing tool comprising: 
 using abrading particles and a thermoplastic resin as raw materials;    filling a forming fixture with a mixture of abrading particles and the thermoplastic resin into a mold; and    forming the fixed-abrasive polishing tool.    
     
     
         13 . A method according to  claim 12 , wherein said forming is performed by heating-cooling the mixture and/or pressing the mixture.  
     
     
         14 . A method according to  claim 12 , wherein said mixing of the abrading particles and the thermoplastic resin is carried out prior to or during filling or after filling a forming fixture with the raw materials.  
     
     
         15 . A method for making a fixed-abrasive polishing tool, said method comprising: 
 mixing powdery abrading particles or a slurry and raw materials of the thermoplastic resin to form a dispersion liquid;    polymerizing or manufacturing the thermoplastic resin; and    making a mixture containing the polymerized thermoplastic resin and the abrading particles in the dispersion liquid during the step of polymerizing or manufacturing the thermoplastic resin.    
     
     
         16 . A method according to  claim 15 , said method further comprising: 
 performing a mist drying step of said polymerized mixture.    
     
     
         17 . A method according to  claim 16 , wherein said mist drying step comprising a spray drying step.  
     
     
         18 . A method according to  claim 16 , wherein said mixture is formed with particles by the mist drying step and a diameter of the particles is in a range of 1˜500 μm.  
     
     
         19 . A method for making a fixed-abrasive polishing tool comprising: 
 mixing abrading particles and a resin in a liquid;    drying said mixed liquid to obtain dried mixed material; and    forming said dried mixed material into the fixed-abrasive polishing tool.    
     
     
         20 . A method according to  claim 19 , wherein said abrading particles are provided in a state of slurry.  
     
     
         21 . A method according to  claim 19 , wherein said resin is provided in a state of powder and mixed with abrading particles in water or a solvent.  
     
     
         22 . A method according to  claim 19 , wherein said resin is provided in a liquid state where the resin is dispersed or dissolved in water or a solvent.  
     
     
         23 . A method according to  claim 19 , wherein said drying step comprises a mist drying step.  
     
     
         24 . A method according to  claim 23 , wherein said mist drying step is performed by a spray dryer.  
     
     
         25 . A method according to  claim 19 , wherein said polishing tool is formed by filling the said mixed powder into a mold.  
     
     
         26 . A method according to  claim 19 , wherein pulverizing is performed to obtain a powder in a range of 1-500 μm during or after drying said mixed liquid.  
     
     
         27 . A method for making a fixed-abrasive polishing tool comprising: 
 mixing abrading particles and a liquid resin to form a mixed liquid;    drying and comminuting said mixed liquid to obtain dried mixed material; and    forming said dried mixed material into the fixed-abrasive polishing tool.    
     
     
         28 . A method according to  claim 27 , wherein abrading particles are provided as a powder or dried slurry.  
     
     
         29 . A method according to  claim 28 , wherein said drying step of slurry comprises a spray drying step.  
     
     
         30 . A method for making a fixed-abrasive polishing tool comprising: 
 mixing powder of abrading particles and a powder of resin in a liquid to form a mixed liquid;    drying and comminuting said mixed liquid to obtain dried mixed material; and    forming said dried mixed material into the fixed-abrasive polishing tool.    
     
     
         31 . A method according to  claim 30 , wherein said liquid comprises water or a solvent.  
     
     
         32 . A method according to  claim 31 , wherein said powder of abrading particles is obtained by drying slurry.  
     
     
         33 . A method according to  claim 32 , wherein said drying step of slurry comprises a spray drying step.  
     
     
         34 . A method for making a fixed-abrasive polishing tool comprising: 
 mixing slurry containing abrasive particles and a liquid resin to form a mixed liquid;    drying said mixed liquid to obtain dried mixed material; and    forming said dried mixed material into the fixed-abrasive polishing tool.    
     
     
         35 . A method according to  claim 34 , wherein said forming is performed by molding said dried mixed material into a mold.  
     
     
         36 . A method according to  claim 34 , wherein said drying step comprises a mist drying step.  
     
     
         37 . A method according to  claim 34 , wherein said drying step comprises a spray drying step.  
     
     
         38 . A polishing apparatus for polishing a semiconductor wafer, comprising: 
 a topring for holding the wafer; and    a polishing tool, said polishing tool comprised primarily by a thermoplastic resin.    
     
     
         39 . A polishing apparatus according to  claim 38 , wherein said semiconductor wafer has patterns comprised by high portions and low portions.  
     
     
         40 . A polishing apparatus for polishing a semiconductor wafer, comprising: 
 a topring for holding the wafer; and    a fixed-abrasive polishing tool, said polishing tool comprising abrading particles and a resin for binding said abrading particles in a matrix of said resin, said resin comprises thermoplastic resin.    
     
     
         41 . A polishing apparatus according to  claim 40 , wherein a range of composition of fixed-abrasive polishing tool (percentages of abrading particles (Vg), binder (Vb) and air porosity (Vp)) in volume percent (vol %) are: 10%<abrading particles (Vg)<50%, 30%<binder (Vb)<80%, and 0%<air porosity (Vp)<40%.  
     
     
         42 . A polishing apparatus according to  claim 40 , wherein said semiconductor wafer has patterns comprised by high portions and low portions.  
     
     
         43 . A polishing apparatus according to  claim 40 , further comprising: a dresser for dressing a polishing surface of said fixed-abrasive polishing tool.  
     
     
         44 . A polishing apparatus according to  claim 40 , wherein said fixed-abrasive polishing tool is mounted on a base.  
     
     
         45 . A polishing apparatus according to  claim 44 , wherein a polishing tool comprised by said fixed-abrasive polishing tool and said base is mounted detachably on a polishing table.  
     
     
         46 . A polishing apparatus according to  claim 45 , wherein said polishing tool is fixed to said polishing table by clamps.  
     
     
         47 . A polishing apparatus for polishing a semiconductor wafer, comprising: 
 at least one topring for holding the wafer; and    at least two polishing tables providing polishing surfaces respectively, wherein one of said polishing table having a fixed-abrasive polishing tool, said polishing tool comprising abrading particles and a thermoplastic resin for binding said abrading particles.    
     
     
         48 . A method of polishing a substrate comprising: 
 polishing the substrate firstly by a fixed-abrasive polishing tool, said polishing tool comprising abrading particles and a thermoplastic resin for binding said abrading particles; and    finishing the substrate secondly by a finishing pad.    
     
     
         49 . A method according to  claim 48 , wherein said first polishing is performed by supplying liquid not containing abrading particles.  
     
     
         50 . A method according to  claim 48 , wherein said first polishing is performed by supplying water containing additive agent.  
     
     
         51 . A method according to  claim 48 , wherein said finishing step is performed by supplying water.