CHEMICAL MECHANICAL POLISHING PAD
A chemical mechanical polishing pad includes a polishing layer. The polishing layer comprises a matrix polymer and 1 to 20 wt % based on total weight of the polishing layer of non-reactive, non-expandable polymeric particles dispersed in the matrix polymer and less than 2 wt % expandable polymeric microspheres. An SEM of a cut surface of the polishing layer shows a crescent shaped opening adjacent to at least a portion of the polymer particles and separating a surface of that portion of the polymer particles from the matrix polymer.
1 . A chemical mechanical polishing pad having a polishing layer, wherein the polishing layer comprises a matrix polymer and 1 to 20 wt % based on total weight of the polishing layer of non-reactive, non-expandable polymeric particles dispersed in the matrix polymer and less than 2 wt % expandable polymeric microspheres, wherein an SEM of a cut surface of the polishing layer shows a crescent shaped opening adjacent to at least a portion of the polymer particles and separating a surface of that portion of the polymer particles from the matrix polymer.
2 . The chemical mechanical polishing pad of claim 1 wherein the non-reactive, non-expandable polymeric particles comprise cross-linked polymethylmethacrylate.
3 . The chemical mechanical polishing pad of claim 1 wherein the non-reactive, non-expandable polymeric particles have an average particle size D50 particle size of 5 to 15 microns.
4 . The chemical mechanical polishing pad of claim 1 wherein the matrix polymer is ductile.
5 . The chemical mechanical polishing pad of claim 1 wherein the matrix polymer is a polyurethane comprising the reaction product an isocyanate terminated prepolymer and an amine curative wherein the isocyanate terminated prepolymer comprises a reaction product of a polyol prepolymer, toluene diisocyanate, a low molecular weight polyol wherein the reaction product is further reacted with an amine curative.
6 . The chemical mechanical polishing pad of claim 5 wherein the isocyanate prepolymer comprises a blend of a first reaction product of a polypropylene glycol, toluene diisocyanate and the low molecular weight polyol and a second reaction product of a polytetramethylene glycol, toluene diisocyanate and the low molecular weight polyol, wherein the first reaction product and the second reaction product are present in a weight ratio of 1:20 to 1:1.
7 . The chemical mechanical polishing pad of claim 1 having a density of at least 1.1 grams per cubic centimeter.
8 . The chemical mechanical polishing pad of claim 1 further including grooves on the surface of the polishing layer.
9 . The chemical mechanical polishing pad of claim 8 wherein the grooves are machined into the surface of the polishing layer.
10 . The chemical mechanical polishing pad of claim 1 wherein the non-reactive, non-expandable polymeric particles are porous.