Polishing pad with window for planarization

Abstract

The present invention relates to a polishing pad. In particular, the polishing pad of the present invention can include a window. The polishing pad of the present invention can be useful for polishing articles and can be especially useful for chemical mechanical polishing or planarization of a microelectronic device, such as a semiconductor wafer. The window of the polishing pad is at least partially transparent and thus, can be particularly useful with polishing or planarizing tools that are equipped with through-the-platen wafer metrology.

In the claims:  
     
         1 . A polishing pad comprising: 
 a. a first layer having an opening; and    b. a second layer wherein at least a portion of said second layer comprises an at least partially transparent window,    and wherein said first layer is at least partially connected to said second layer, and wherein said first layer absorbs at least two percent by weight of polishing slurry based on total weight of said first layer.    
     
     
         2 . The polishing pad of  claim 1  wherein said first layer absorbs 50% or less by weight of polishing slurry based on total weight of said first layer.  
     
     
         3 . The polishing pad of  claim 1  wherein said first layer is selected from particulate polymer and crosslinked polymer binder; particulate polymer and an organic polymer binder; sintered particles of thermoplastic resin; pressure sintered powder compacts of thermoplastic polymer; polymeric matrices impregnated with a plurality of polymeric microelements wherein each polymeric microelement can have a void space therein, or combinations thereof.  
     
     
         4 . The polishing pad of  claim 1  wherein said first layer has a thickness of at least 0.020 inches.  
     
     
         5 . The polishing pad of  claim 4  wherein said first layer has a thickness of 0.150 inches or less.  
     
     
         6 . The polishing pad of  claim 1  wherein said second layer is selected from substantially non-volume compressible polymers and metallic films and foils.  
     
     
         7 . The polishing pad of  claim 1  wherein said second layer is selected from polyolefins; cellulose-based polymers; acrylics; polyesters and co-polyesters; polycarbonate; polyamides; high performance plastics; or mixtures thereof.  
     
     
         8 . The polishing pad of  claim 1  wherein said second layer is selected from low density polyethylene, high density polyethylene ultra-high molecular weight polyethylene or polypropylene; cellulose acetate or cellulose butyrate; PET or PETG; nylon 6/6 or nylon 6/12; polyetheretherketone, polyphenylene oxide, polysulfone, polyimide, or polyetherimide; or mixtures thereof.  
     
     
         9 . The polishing pad of  claim 1  wherein said second layer has a thickness of at least 0.0005 inches.  
     
     
         10 . The polishing pad of  claim 9  wherein said second layer has a thickness of 0.0650 inches or less.  
     
     
         11 . The polishing pad of  claim 1  wherein said first and second layers are at least partially connected by an adhesive material.  
     
     
         12 . The polishing pad of  claim 11  wherein said adhesive material is selected from contact adhesives, pressure sensitive adhesives, structural adhesives, hot melt adhesives, thermoplastic adhesives, and curable adhesives, thermosetting adhesives; and combinations thereof.  
     
     
         13 . The polishing pad of  claim 1  wherein said opening in said first layer is at least partially aligned with said window in said second layer.  
     
     
         14 . The polishing pad of  claim 1  further comprising a third layer at least partially connected to said second layer, said third layer having an opening.  
     
     
         15 . The polishing pad of  claim 14  wherein said third layer is selected from natural rubber, synthetic rubbers, thermoplastic elastomer, foam sheet and combinations thereof.  
     
     
         16 . The polishing pad of  claim 14  wherein said third layer has a thickness of at least 0.04 inches.  
     
     
         17 . The polishing pad of  claim 16  wherein said third layer has a thickness of 0.100 inches or less.  
     
     
         18 . The polishing pad of  claim 14  wherein said first, second and third layers are at least partially connected by an adhesive material.  
     
     
         19 . The polishing pad of  claim 14  wherein said opening in said first layer, said window in said second layer and said opening in said third layer are at least partially aligned.  
     
     
         20 . A polishing pad comprising: 
 a. a first layer having an opening; and    b. a second layer wherein at least a portion of said second layer comprises an at least partially transparent window,    and wherein said first layer is at least partially connected to said second layer, and wherein said first layer has a porosity of at least two percent by volume based on total volume of said first layer.    
     
     
         21 . The polishing pad of  claim 20  wherein said first layer has a porosity of 50% or less by volume based on total volume of said first layer.  
     
     
         22 . The polishing pad of  claim 20  wherein said first layer is selected from particulate polymer and crosslinked polymer binder; particulate polymer and an organic polymer binder; sintered particles of thermoplastic resin; pressure sintered powder compacts of thermoplastic polymer; polymeric matrices impregnated with a plurality of polymeric microelements wherein each polymeric microelement can have a void space therein, or combinations thereof.  
     
     
         23 . The polishing pad of  claim 20  wherein said first layer has a thickness of at least 0.020 inches.  
     
     
         24 . The polishing pad of  claim 23  wherein said first layer has a thickness of 0.150 inches or less.  
     
     
         25 . The polishing pad of  claim 20  wherein said second layer is selected from substantially non-volume compressible polymers and metallic films and foils.  
     
     
         26 . The polishing pad of  claim 20  wherein said second layer is selected from polyolefins; cellulose-based polymers; acrylics; polyesters and co-polyesters; polycarbonate; polyamides; high performance plastics; or mixtures thereof.  
     
     
         27 . The polishing pad of  claim 1  wherein said second layer is selected from low density polyethylene, high density polyethylene ultra-high molecular weight polyethylene or polypropylene; cellulose acetate or cellulose butyrate; PET or PETG; nylon 6/6 or nylon 6/12; polyetheretherketone, polyphenylene oxide, polysulfone, polyimide, or polyetherimide; or mixtures thereof.  
     
     
         28 . The polishing pad of  claim 20  wherein said second layer has a thickness of at least 0.0005 inches.  
     
     
         29 . The polishing pad of  claim 28  wherein said second layer has a thickness of 0.0650 inches or less.  
     
     
         30 . The polishing pad of  claim 20  wherein said first and second layers are at least partially connected by an adhesive material.  
     
     
         31 . The polishing pad of  claim 30  wherein said adhesive material is selected from contact adhesives, pressure sensitive adhesives, structural adhesives, hot melt adhesives, thermoplastic adhesives, curable adhesives, thermosetting adhesives and combinations thereof.  
     
     
         32 . The polishing pad of  claim 20  wherein said opening in said first layer is at least partially aligned with said window in said second layer.  
     
     
         33 . The polishing pad of  claim 20  further comprising a third layer at least partially connected to said second layer, said third layer having an opening.  
     
     
         34 . The polishing pad of  claim 33  wherein said third layer is selected from natural rubber, synthetic rubbers, thermoplastic elastomer, foam sheet and combinations thereof.  
     
     
         35 . The polishing pad of  claim 33  wherein said third layer has a thickness of at least 0.04 inches.  
     
     
         36 . The polishing pad of  claim 35  wherein said third layer has a thickness of 0.100 inches or less.  
     
     
         37 . The polishing pad of  claim 30  wherein said first, second and third layers are at least partially connected by an adhesive material.  
     
     
         38 . The polishing pad of  claim 30  wherein said opening in said first layer, said window in said second layer and said opening in said third layer are at least partially aligned.  
     
     
         39 . A polishing pad comprising: 
 a. a first layer having an opening; and    b. a second layer wherein at least a portion of said second layer comprises an at least partially transparent window,    and wherein said first layer is at least partially connected to said second layer, and wherein said first layer has a percent volume compressibility greater than said second layer.    
     
     
         40 . The polishing pad of  claim 39  wherein said first layer has a percent volume compressibility of at least 0.3% when a load of 20 psi is applied.  
     
     
         41 . The polishing pad of  claim 40  wherein said first layer has a percent volume compressibility of 3% or less when a load of 20 psi is applied.  
     
     
         42 . The polishing pad of  claim 39  wherein said second layer is substantially non-volume compressible.  
     
     
         43 . The polishing pad of  claim 39  wherein said first layer is selected from particulate polymer and crosslinked polymer binder; particulate polymer and an organic polymer binder; sintered particles of thermoplastic resin; pressure sintered powder compacts of thermoplastic polymer; polymeric matrices impregnated with a plurality of polymeric microelements wherein each polymeric microelement can have a void space therein, or combinations thereof.  
     
     
         44 . The polishing pad of  claim 39  wherein said second layer is selected from substantially non-volume compressible polymers and metallic films and foils.  
     
     
         45 . The polishing pad of  claim 39  wherein said second layer is selected from polyolefins; cellulose-based polymers; acrylics; polyesters and co-polyesters; polycarbonate; polyamides; high performance plastics; or mixtures thereof.  
     
     
         46 . The polishing pad of  claim 39  wherein said second layer is selected from low density polyethylene, high density polyethylene ultra-high molecular weight polyethylene or polypropylene; cellulose acetate or cellulose butyrate; PET or PETG; nylon 6/6 or nylon 6/12; polyetheretherketone, polyphenylene oxide, polysulfone, polyimide, or polyetherimide; or mixtures thereof.  
     
     
         47 . The polishing pad of  claim 39  wherein said first and second layers are at least partially connected by an adhesive material.  
     
     
         48 . The polishing pad of  claim 47  wherein said adhesive material is selected from contact adhesives, pressure sensitive adhesives, structural adhesives, hot melt adhesives, thermoplastic adhesives, curable adhesives, thermosetting adhesives and combinations thereof.  
     
     
         49 . The polishing pad of  claim 39  wherein said opening in said first layer is at least partially aligned with said window in said second layer.  
     
     
         50 . The polishing pad of  claim 39  further comprising a third layer at least partially connected to said second layer, said third layer having an opening.  
     
     
         51 . The polishing pad of  claim 50  wherein said third layer is selected from natural rubber, synthetic rubbers, thermoplastic elastomer, foam sheet and combinations thereof.  
     
     
         52 . The polishing pad of  claim 50  wherein said first, second and third layers are at least partially connected by an adhesive material.  
     
     
         53 . The polishing pad of  claim 50  wherein said opening in said first layer, said window in said second layer and said opening in said third layer are at least partially aligned.  
     
     
         54 . The polishing pad of  claim 39  wherein at least a portion of said window comprises a coating.  
     
     
         55 . The polishing pad of  claim 54  wherein said coating comprises a resin coating.  
     
     
         56 . The polishing pad of  claim 55  wherein said resin coating is selected from thermoplastic acrylic resins, thermoset acrylic resins, urethane systems, epoxy resins, polyester resins, or mixtures thereof.  
     
     
         57 . The polishing pad of  claim 39  wherein said first layer comprises grooves on a polishing surface.  
     
     
         58 . The polishing pad of  claim 39  wherein said first layer comprises a pattern on a polishing surface.  
     
     
         59 . A method of preparing a polishing pad comprising at least partially connecting a first layer having an opening to a second layer, wherein at least a portion of said second layer comprises an at least partially transparent window, and wherein said first layer absorbs at least two percent by weight of polishing slurry based on total weight of said first layer.  
     
     
         60 . The method of  claim 59  further comprising at least partially connecting a third layer having an opening to said second layer.  
     
     
         61 . The method of  claim 59  wherein said first and second layers are at least partially connected by an adhesive material.  
     
     
         62 . A method of preparing a polishing pad comprising at least partially connecting a first layer having an opening to a second layer, wherein at least a portion of said second layer comprises an at least partially transparent window, and wherein said first layer has a porosity of at least two percent by volume based on total volume of said first layer.  
     
     
         63 . The method of  claim 62  further comprising at least partially connecting a third layer having an opening to said second layer.  
     
     
         64 . The method of  claim 62  wherein said first and second layers are at least partially connected by an adhesive material.  
     
     
         65 . A method of preparing a polishing pad comprising at least partially connecting a first layer having an opening to a second layer, wherein at least a portion of said second layer comprises an at least partially transparent window, and wherein first layer has a percent volume compressibility greater than said second layer.  
     
     
         66 . The method of  claim 65  further comprising at least partially connecting a third layer having an opening to said second layer.  
     
     
         67 . The method of  claim 65  wherein said first and second layers are at least partially connected by an adhesive material.  
     
     
         68 . A polishing pad comprising: 
 a. a first layer having an opening;    b. a second layer wherein at least a portion of said second layer comprises an at least partially transparent window; and    c. a third layer having an opening,    wherein said first layer is at least partially connected to said second layer and said second layer is at least partially connected to said third layer, and wherein said third layer is softer than said first layer.