Polishing pads with improved planarization efficiency

Abstract

Embodiments of the disclosure include a polishing pad for planarizing a surface of a substrate during a polishing process. The polishing pad includes a base layer, comprising a first material composition, and a polishing layer disposed over the base layer. The polishing layer includes a second material composition that is exposed at a polishing surface of the polishing pad, wherein the polishing surface is configured to contact the surface of the substrate during the polishing process. The second material composition includes a polishing layer material having a hardness that is greater than 50 on a Shore D scale, a yield point strength, a yield point strength strain, a break point strength, and an elongation at break point strain, wherein a magnitude of a difference between the elongation at break point strain and the yield point strength strain is greater than the magnitude of yield point strength strain when measured at room temperature.

What is claimed is: 
     
         1 . A polishing pad for planarizing a surface of a substrate during a polishing process, comprising:
 a base layer, comprising a first material composition; and   a polishing layer disposed over the base layer, wherein
 the polishing layer comprises a second material composition that is exposed at a polishing surface of the polishing pad, 
 the polishing surface is configured to contact the surface of the substrate during the polishing process, 
 the second material composition comprises a polishing layer material having:
 a hardness that is greater than 50 on a Shore D scale; 
 a yield point strength; 
 a yield point strength strain; 
 a break point strength; and 
 an elongation at break point strain, 
 wherein a magnitude of a difference between the elongation at break point strain and the yield point strength strain is greater than the magnitude of yield point strength strain when measured at room temperature. 
 
   
     
     
         2 . The polishing pad of  claim 1 , wherein the break point strength is less than the yield point strength. 
     
     
         3 . The polishing pad of  claim 2 , wherein the hardness of the second material composition is greater than 60 on a Shore D scale. 
     
     
         4 . The polishing pad of  claim 1 , wherein the hardness of the second material composition is in a range from 65 to 78 on a Shore D scale. 
     
     
         5 . The polishing pad of  claim 1 , wherein the magnitude of the difference between the elongation at break point strain and the yield point strength strain is at least 2 times greater than the magnitude of yield point strength strain. 
     
     
         6 . The polishing pad of  claim 5 , wherein the polishing layer material further includes:
 a glass transition temperature (Tg) of between about 60-80 C;   a tensile Modulus of about 100-2,000 MPa at 40 C; and   an E′ ratio at 30 C-90 C of between about 1 and 5.   
     
     
         7 . The polishing pad of  claim 1 , wherein the polishing surface of the polishing layer material comprises:
 a contact ratio of at least 0.8% at a measurement depth (D M ) of 4 μm after performing a standard pad conditioning process.   
     
     
         8 . The polishing pad of  claim 1 , wherein the polishing surface of the polishing layer material comprises:
 a contact ratio of at least 2% at a measurement depth (D M ) of 4 μm after performing a standard pad conditioning process.   
     
     
         9 . A polishing pad for planarizing a surface of a substrate during a polishing process, comprising:
 a base layer, comprising a first material composition; and   a polishing layer disposed over the base layer, wherein
 the polishing layer comprises a second material composition that is exposed at a polishing surface of the polishing pad, 
 the polishing surface is configured to contact the surface of the substrate during the polishing process, and 
 the second material composition comprises a polishing layer material having:
 a hardness that is greater than 50 on a Shore D scale; and 
 a mechanical strain ratio (ε B /ε Y ) of greater than 2. 
 
   
     
     
         10 . The polishing pad of  claim 9 , wherein the polishing layer material has a hardness that is greater than 65 on the Shore D scale. 
     
     
         11 . The polishing pad of  claim 9 , wherein
 the hardness is between 65 and 78 on the Shore D scale, and   the polishing layer material has a tensile modulus of between 1000 and 2000 MPa and an elongation at break of greater than about 60%.   
     
     
         12 . The polishing pad of  claim 9 , wherein resin precursor components used to form the polishing layer material comprise an oligomer, one or more monomers, and a reactive diluent. 
     
     
         13 . The polishing pad of  claim 12 , wherein
 the oligomer comprises a tri-functional urethane;   the one or more monomers comprise a difunctional polyether acrylate; and   the reactive diluent comprises a monofunctional urethane acrylate.   
     
     
         14 . The polishing pad of  claim 12 , wherein
 the oligomer comprises a difunctional polyester acrylate;   the one or more monomers comprise a difunctional epoxy acrylate; and   the reactive diluent comprises a monofunctional methacrylate.   
     
     
         15 . The polishing pad of  claim 12 , wherein the polishing layer material comprises an aromatic monofunctional acrylate, a low viscosity aliphatic trifunctional monomer, a trifunctional aliphatic acrylate, and a monofunctional aliphatic acrylamide. 
     
     
         16 . The polishing pad of  claim 15 , wherein the polishing surface of the polishing layer comprises:
 a contact ratio of at least 0.8% at a measurement depth (D M ) of 4 μm after performing a standard pad conditioning process.   
     
     
         17 . The polishing pad of  claim 10 , wherein the second material composition has a break point strength that is less than its yield point strength. 
     
     
         18 . A method of planarizing a surface of a substrate during a polishing process, comprising:
 conditioning a polishing surface of a polishing pad;   delivering a ceria containing polishing slurry composition to the polishing surface of the polishing pad; and   urging the surface of the substrate against the polishing surface of the polishing pad while the ceria containing polishing slurry composition is disposed across the polishing surface of the polishing pad,   wherein the polishing pad comprises:
 a base layer, comprising a first material composition; and 
 a polishing layer disposed over the base layer, wherein
 the polishing layer comprises a second material composition that is exposed at the polishing surface of the polishing pad, and 
 the second material composition comprises a polishing layer material having:
 a hardness that is greater than 50 on a Shore D scale; 
 a yield point strength; 
 a yield point strength strain; 
 a break point strength; and 
 an elongation at break point strain, 
 wherein a magnitude of a difference between the elongation at break point strain and the yield point strength strain is greater than the magnitude of yield point strength strain when measured at room temperature. 
 
 
   
     
     
         19 . The method of  claim 18 , wherein the second material composition further comprises:
 a hardness that is greater than 68 on a Shore D scale; and   a mechanical strain ratio (εB/εY) of greater than 2.   
     
     
         20 . The method of  claim 19 , wherein the polishing surface of the polishing layer comprises:
 a contact ratio of at least 0.8% at a measurement depth (D M ) of 4 μm after conditioning the polishing surface of the polishing pad using a standard pad conditioning process.