Polishing Pad with Floating Elements and Method of Making and Using the Same

Abstract

The disclosure is directed to polishing pads with floating polishing elements bonded to a support layer, for example by thermal bonding, and to methods of making and using such pads in a polishing process. In one exemplary embodiment, the polishing pad includes a multiplicity of polishing elements, at least some of which may be porous, each polishing element affixed to a major surface of a support layer so as to restrict lateral movement of the polishing elements with respect to one or more of the other polishing elements, but remaining moveable in an axis substantially normal to the support layer. In certain embodiments, the polishing pad may additionally include a compliant layer affixed to the support layer opposite the polishing elements, and optionally, a polishing composition distribution layer. In some embodiments using porous polishing elements, the pores are distributed substantially at a polishing surface of the polishing elements.

1 . A polishing pad comprising a plurality of polishing elements, each of the polishing elements bonded to a major side of a support layer so as to restrict lateral movement of the polishing elements with respect to one or more of the other polishing elements, but remaining moveable in an axis substantially normal to a polishing surface of the polishing elements. 
     
     
         2 . A polishing pad comprising a support layer having a first major side and a second major side opposite the first major side, and
 a plurality of polishing elements bonded to the first major side of the support layer, wherein each polishing element has an exposed polishing surface, and   wherein the polishing elements extend from the first major side of the support layer along a first direction substantially normal to the first major side.   
     
     
         3 . The polishing pad of  claim 2 , wherein each polishing element is bonded to the first major side of the support layer without use of an adhesive. 
     
     
         4 . The polishing pad of  claim 3 , further comprising a guide plate including a plurality of apertures extending through the guide plate from a first major surface to a second major surface, wherein at least a portion of each polishing element extends into a corresponding aperture, and wherein each polishing element extends outwardly from the second major surface of the guide plate. 
     
     
         5 . The polishing pad of  claim 4 , wherein a portion of each polishing element passes through the corresponding aperture. 
     
     
         6 . The polishing pad of  claim 4 , wherein each polishing element has a flange, and wherein each polishing element is affixed to the first major side by engagement of the corresponding flange to the support layer. 
     
     
         7 . The polishing pad of  claim 2 , wherein the guide plate comprises a polymer, a copolymer, a polymer blend, a polymer composite, or combinations thereof. 
     
     
         8 . The polishing pad of  claim 2 , wherein the guide plate maintains the orientation of the polishing elements along the first direction, while allowing the polishing elements to independently translate along the first direction with respect to the guide plate. 
     
     
         9 . The polishing pad of  claim 2 , further comprising a polishing composition distribution layer covering at least a portion of the first major surface of the guide plate. 
     
     
         10 . The polishing pad of  claim 1 , further comprising a polishing composition distribution layer covering at least a portion of the major side of the support layer. 
     
     
         11 . The polishing pad of  claim 9  or  10 , wherein each polishing element extends along the first direction at least about 0.25 mm above a plane including the polishing composition distribution layer. 
     
     
         12 . The polishing pad of  claim 9  or  10 , wherein at least some of the polishing elements have polishing surfaces flush with an exposed surface of the polishing composition distribution layer. 
     
     
         13 . The polishing pad of  claim 9  or  10 , wherein at least some of the polishing elements have polishing surfaces recessed below an exposed surface of the polishing composition distribution layer. 
     
     
         14 . The polishing pad of  claim 12  or  13 , wherein the polishing composition distribution layer comprises an abradable material having a hardness less than a hardness of the polishing elements. 
     
     
         15 . The polishing pad of  claim 9  or  10 , wherein the polishing composition distribution layer comprises at least one hydrophilic polymer. 
     
     
         16 . The polishing pad of  claim 9  or  10 , wherein the polishing composition distribution layer comprises a foam. 
     
     
         17 . The polishing pad according to any one of  claim 1 ,  2 ,  9 , or  10 , further comprising a compliant layer affixed to the support layer on a side opposite the major side of the support layer and the polishing elements. 
     
     
         18 . The polishing pad of  claim 17 , wherein the compliant layer is affixed to the support layer by an adhesive layer at an interface between the compliant layer and the support layer. 
     
     
         19 . The polishing pad of  claim 17 , wherein the compliant layer comprises polymeric material selected from silicone, natural rubber, styrene-butadiene rubber, neoprene, polyurethane, polyethylene, and combinations thereof. 
     
     
         20 . The polishing pad of  claim 9  or  10 , wherein a compliance of the polishing composition distribution layer is less than a compliance of the compliant layer. 
     
     
         21 . The polishing pad of  claim 17 , further comprising a pressure sensitive adhesive layer affixed to the compliant layer opposite the plurality of polishing elements. 
     
     
         22 . The polishing pad according to any one of  claim 1 ,  2 ,  9 , or  10 , wherein each polishing element extends along the first direction at least about 0.25 mm above a plane including the support layer. 
     
     
         23 . The polishing pad according to any one of  claim 1 ,  2 ,  9 , or  10 , wherein at least one of the polishing elements comprises a porous polishing element, wherein each porous polishing element comprises a plurality of pores. 
     
     
         24 . The polishing pad according to  claim 23 , wherein substantially all of the polishing elements are porous polishing elements. 
     
     
         25 . The polishing pad according to  claim 23 , wherein the pores comprising each porous polishing element are distributed throughout substantially the entire porous polishing element. 
     
     
         26 . The polishing pad according to  claim 23 , wherein at least a portion of each polishing surface comprises the plurality of pores. 
     
     
         27 . The polishing pad of  claim 26 , wherein the plurality of pores comprising the polishing surface comprise a plurality of channels having a cross-sectional shape selected from the group consisting of cylindrical, triangular, rectangular, trapezoidal, hemispherical, and combinations thereof. 
     
     
         28 . The polishing pad of  claim 27 , wherein the depth of each channel in the first direction is from about 100 micrometers to about 7500 micrometers. 
     
     
         29 . The polishing pad of  claim 27 , wherein the cross-sectional area of each channel is from about 75 square micrometers to about 3×10 6  square micrometers. 
     
     
         30 . The polishing pad of  claim 23 , wherein the plurality of pores comprises a closed cell foam. 
     
     
         31 . The polishing pad of  claim 23 , wherein the plurality of pores comprises an open cell foam. 
     
     
         32 . The polishing pad of  claim 23 , wherein the plurality of pores exhibits a unimodal distribution of pore size. 
     
     
         33 . The polishing pad of  claim 23 , wherein the plurality of pores exhibits a mean pore size from about 1 nanometer to about 100 micrometers. 
     
     
         34 . The polishing pad of  claim 33 , wherein the plurality of pores exhibits a mean pore size from about 1 micrometer to about 50 micrometers. 
     
     
         35 . The polishing pad of  claim 23 , wherein the polishing elements are arranged in a two-dimensional array pattern on the major side of the support layer. 
     
     
         36 . The polishing pad according to any one of  claim 1 ,  2 ,  9 , or  10 , wherein each polishing element is thermally bonded to the support layer. 
     
     
         37 . The polishing pad according to any one of  claim 1 ,  2 ,  9 , or  10 , wherein at least some of the polishing elements are selected to have a cross-section, taken in the first direction, selected from circular, elliptical, triangular, square, rectangular, and trapezoidal. 
     
     
         38 . The polishing pad according to any one of  claim 1 ,  2 ,  9 , or  10 , wherein the plurality of polishing elements are formed as a unitary sheet of polishing elements with the support layer. 
     
     
         39 . The polishing pad according to any one of  claim 1 ,  2 ,  9 , or  10  wherein at least a portion of the polishing elements comprise a thermoplastic polyurethane, a polyacrylate, polyvinyl alcohol, or combinations thereof. 
     
     
         40 . The polishing pad according to any one of  claim 1 ,  2 ,  9 , or  10 , wherein the polishing elements have at least one dimension from about 0.1 mm to about 30 mm. 
     
     
         41 . The polishing pad according to any one of  claim 1 ,  2 ,  9 , or  10 , wherein the support layer comprises a thermoplastic polyurethane 
     
     
         42 . The polishing pad according to any one of  claim 1 ,  2 ,  9 , or  10 , wherein at least a portion of the polishing elements comprise abrasive particulates. 
     
     
         43 . The polishing pad according to any one of  claim 1 ,  2 ,  9 , or  10 , wherein the polishing elements are arranged in a two-dimensional array pattern on the major side of the support layer. 
     
     
         44 . The polishing pad according to any one of  claim 1 ,  2 ,  9 , or  10 , wherein at least one polishing element is transparent. 
     
     
         45 . The polishing pad of  claim 44 , wherein the support layer is transparent. 
     
     
         46 . The polishing pad according to  claim 17 , wherein the support layer, the guide plate, the polishing composition distribution layer, at least one polishing element, or a combination thereof is transparent. 
     
     
         47 . The polishing pad according to  claim 18 , wherein the support layer, the guide plate, the polishing composition distribution layer, the compliant layer, the adhesive, layer, at least one polishing element, or a combination thereof is transparent. 
     
     
         48 . A method of using a polishing pad comprising:
 contacting a surface of a substrate with a polishing surface of a polishing pad according to any one of  claims 1  to  47 ;   relatively moving the polishing pad with respect to the substrate to abrade the surface of the substrate.   
     
     
         49 . The method of  claim 48 , further comprising providing a polishing composition to an interface between the polishing pad surface and the substrate surface. 
     
     
         50 . A method of making a polishing pad comprising:
 forming a plurality of polishing elements;   bonding the polishing elements to a support layer to form a polishing pad according to any one of  claims 1  to  47 .   
     
     
         51 . The method of  claim 50 , further comprising arranging the plurality of polishing elements in a pattern before thermally bonding the polishing elements to the support layer. 
     
     
         52 . The method of  claim 51 , wherein at least a portion of the polishing elements comprise porous polishing elements. 
     
     
         53 . The method according to  claim 52 , wherein at least some of the polishing elements comprise substantially non-porous polishing elements. 
     
     
         54 . The method of  claim 52 , wherein the porous polishing elements are formed by injection molding of a gas saturated polymer melt, injection molding of a reactive mixture that evolves a gas upon reaction to form a polymer, injection molding of a mixture comprising a polymer dissolved in a supercritical gas, injection molding of a mixture of incompatible polymers in a solvent, injection molding of porous thermoset particulates dispersed in a thermoplastic polymer, and combinations thereof. 
     
     
         55 . The method of  claim 52 , wherein the porous polymer elements comprise pores formed substantially at a polishing surface of the porous polishing element. 
     
     
         56 . The method of  claim 55 , wherein the pores are formed by injection molding, calendaring, mechanical drilling, laser drilling, needle punching, gas dispersion foaming, chemical processing, and combinations thereof. 
     
     
         57 . The method according to  claim 51 , wherein arranging the plurality of polishing elements in a pattern comprises arranging the polishing elements in a template, arranging the polishing elements on the support layer, and combinations thereof. 
     
     
         58 . The method according to  claim 50 , wherein bonding the polishing elements to the support layer comprises thermal bonding, actinic radiation bonding, adhesive bonding, and combinations thereof.