Sub-pad formation utilizing uv-curable formulation

Abstract

The disclosure provides a UV-cured sub-pad for chemical-mechanical planarization comprising (a) a (meth)acrylate monomer unit and (b) an oligomer unit selected from a difunctional (meth)acrylate-capped polyether urethane oligomer unit, a difunctional (meth)acrylate-capped polyester urethane oligomer unit, a difunctional (meth)acrylate-capped urethane oligomer unit, and a combination thereof. The disclosure also provides a polishing pad for chemical-mechanical planarization comprising a top sheet and a UV-cured sub-pad, a method of preparing the polishing pad, and an apparatus for performing the method of preparing the polishing pad for chemical-mechanical planarization.

1 . A UV-cured sub-pad for chemical-mechanical planarization comprising
 (a) a (meth)acrylate monomer unit and   (b) an oligomer unit selected from a difunctional (meth)acrylate-capped polyether urethane oligomer unit, a difunctional (meth)acrylate-capped polyester urethane oligomer unit, a difunctional (meth)acrylate-capped urethane oligomer unit, or a combination thereof.   
     
     
         2 . The UV-cured sub-pad of  claim 1 , wherein the sub-pad is circular and has a diameter of about 50 cm to about 100 cm. 
     
     
         3 . The UV-cured sub-pad of  claim 1 , wherein the sub-pad has a thickness of about 0.1 mm to about 2 mm. 
     
     
         4 . The UV-cured sub-pad of  claim 1 , wherein the sub-pad has a thickness of about 0.5 mm to about 1 mm. 
     
     
         5 . The UV-cured sub-pad of  claim 1 , wherein the sub-pad comprises a (meth)acrylate monomer unit formed from acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, methyl acrylate, methyl methacrylate, ethyl methacrylate, isobornyl acrylate, isobornyl methacrylate, isoamyl acrylate, isoamyl methacrylate, isodecyl acrylate, isodecyl methacrylate, hexanediol diacrylate, hexanediol dimethacrylate, trimethylolpropane triacrylate, 2-(tert-butyl) methacrylate, 2-(tert-butylamino)ethyl methacrylate, trimethylolpropane trimethacrylate, salts thereof, or combinations thereof. 
     
     
         6 . The UV-cured sub-pad of  claim 1 , wherein the sub-pad comprises a difunctional (meth)acrylate-capped polyether urethane oligomer unit. 
     
     
         7 . The UV-cured sub-pad of  claim 1 , wherein the sub-pad comprises a difunctional (meth)acrylate-capped polyester urethane oligomer unit. 
     
     
         8 . The UV-cured sub-pad of  claim 1 , wherein the sub-pad comprises a difunctional (meth)acrylate-capped urethane oligomer unit. 
     
     
         9 . The UV-cured sub-pad of  claim 1 , wherein the sub-pad has a hardness of about 30 Shore A to about 100 Shore A. 
     
     
         10 . A polishing pad for chemical-mechanical planarization comprising:
 a top sheet and a UV-cured sub-pad, the UV-cured sub-pad for chemical-mechanical planarization comprising   (a) a (meth)acrylate monomer unit and   (b) an oligomer unit selected from a difunctional (meth)acrylate-capped polyether urethane oligomer unit, a difunctional (meth)acrylate-capped polyester urethane oligomer unit, a difunctional (meth)acrylate-capped urethane oligomer unit, and a combination thereof,   wherein the UV-cured sub-pad is bound to a surface of the top sheet.   
     
     
         11 . The polishing pad of  claim 10 , wherein the UV-cured sub-pad is bound to a surface of the top sheet without an adhesive. 
     
     
         12 . The polishing pad of  claim 10 , wherein the UV-cured sub-pad is bound directly to a surface of the top sheet by way of UV curing. 
     
     
         13 . The polishing pad of  claim 10 , wherein the polishing pad is circular and has a diameter of about 50 cm to about 100 cm. 
     
     
         14 . The polishing pad of  claim 10 , wherein the polishing pad has a thickness of about 0.5 mm to about 4 mm. 
     
     
         15 . A method of preparing a polishing pad for chemical-mechanical planarization comprising:
 (i) providing a top sheet having a polishing side and a side opposite the polishing side,   (ii) applying a UV-curable composition to the side opposite the polishing side,   (iii) uniformly spreading the UV-curable composition on the side opposite the polishing side, and   (iv) UV curing the UV-curable composition to provide the polishing pad.   
     
     
         16 . The method of  claim 15 , wherein the UV-curable composition comprises
 (a) a (meth)acrylate monomer and   (b) an oligomer selected from a difunctional (meth)acrylate-capped polyether urethane oligomer, a difunctional (meth)acrylate-capped polyester urethane oligomer, a difunctional (meth)acrylate-capped urethane oligomer, and a combination thereof.   
     
     
         17 . The method of  claim 15 , wherein the (meth)acrylate monomer is acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, methyl acrylate, methyl methacrylate, ethyl methacrylate, isobornyl acrylate, isobornyl methacrylate, isoamyl acrylate, isoamyl methacrylate, isodecyl acrylate, isodecyl methacrylate, hexanediol diacrylate, hexanediol dimethacrylate, trimethylolpropane triacrylate, 2-(tert-butyl) methacrylate, 2-(tert-butylamino)ethyl methacrylate, trimethylolpropane trimethacrylate, salts thereof, or combinations thereof. 
     
     
         18 . The method of  claim 15 , wherein the UV-curable composition comprises a difunctional (meth)acrylate-capped polyether urethane oligomer. 
     
     
         19 . The method of  claim 15 , wherein the UV-curable composition comprises a difunctional (meth)acrylate-capped polyester urethane oligomer. 
     
     
         20 . The method of  claim 15 , wherein the UV-curable composition comprises a difunctional (meth)acrylate-capped urethane oligomer unit.