Broad spectrum, endpoint detection window chemical mechanical polishing pad and polishing method

Abstract

A chemical mechanical polishing pad is provided, comprising: a polishing layer having a polishing surface; and, a broad spectrum, endpoint detection window block having a thickness along an axis perpendicular to a plane of the polishing surface; wherein the broad spectrum, endpoint detection window block, comprises an olefin copolymer; wherein the olefin copolymer, comprises, as initial components: ethylene, a branched or straight chain C 3-30 α-olefin; a silane; and, optionally, a polyolefin; wherein the broad spectrum, endpoint detection window block exhibits a uniform chemical composition across its thickness; wherein the broad spectrum, endpoint detection window block exhibits a spectrum loss ≦60%; and, wherein the polishing surface is adapted for polishing a substrate selected from a magnetic substrate, an optical substrate and a semiconductor substrate.

We claim: 
     
         1 . A chemical mechanical polishing pad comprising:
 a polishing layer having a polishing surface; and,   a broad spectrum, endpoint detection window block having a thickness, T W , along an axis perpendicular to a plane of the polishing surface;   wherein the broad spectrum, endpoint detection window block, comprises an olefin copolymer; wherein the olefin copolymer is a reaction product of initial components comprising: ethylene; a branched or straight chain C 3-30  α-olefin; a silane; and, optionally, a polyolefin; wherein the broad spectrum, endpoint detection window block exhibits a uniform chemical composition across its thickness, T W ; wherein the broad spectrum, endpoint detection window block exhibits a spectrum loss ≦60%; and, wherein the polishing surface is adapted for polishing a substrate selected from a magnetic substrate, an optical substrate and a semiconductor substrate.   
     
     
         2 . The chemical mechanical polishing pad of  claim 1 , wherein the broad spectrum, endpoint detection window block is ≧90 wt % of the olefin copolymer; wherein the broad spectrum, endpoint detection window block comprises <1 ppm halogen; wherein the broad spectrum, endpoint detection window block comprises <1 liquid filled polymeric capsule; and, wherein the broad spectrum, endpoint detection window block has an average thickness, T W-avg , along an axis perpendicular to the plane of the polishing layer of 5 to 75 mils. 
     
     
         3 . The chemical mechanical polishing pad of  claim 2 , wherein the olefin copolymer is a reaction product of initial components comprising:
 20 to 90 wt % ethylene;   10 to 80 wt % of an α-olefin selected from the group consisting of propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and mixtures thereof;   0.1 to 5 wt % of a silane selected from the group consisting of vinyltrimethoxysilane, vinyltriethoxysilane, γ-(meth)acryloxy propyl trimethoxy silane and mixtures thereof; and,   0 to 10 wt % of a polyolefin selected from the group consisting of butadiene; isoprene; 4-methyl-1,3-pentadiene; 1,3-pentadiene; 1,4-pentadiene; 1,5-hexadiene; 1,4-hexadiene; 1,3-hexadiene; 1,3-octadiene; 1,4-octadiene; 1,5-octadiene; 1,6-octadiene; 1,7-octadiene; 7-methyl-1,6-octadiene; 4-ethylidene-8-methyl-1,7-nonadiene; 5 ,9-dimethyl-1,4,8-decatriene; and, mixtures thereof.   
     
     
         4 . The chemical mechanical polishing pad of  claim 2 , wherein the olefin copolymer is a reaction product of initial components comprising:
 60 to 90 wt % ethylene;   10 to 40 wt % of an α-olefin selected from the group consisting of propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and mixtures thereof;   0.1 to 3 wt % of a silane selected from the group consisting of vinyltrimethoxysilane, vinyltriethoxysilane, γ-(meth)acryloxy propyl trimethoxy silane and mixtures thereof; and,   0 to 6 wt % polyolefin of a polyolefin selected from the group consisting of butadiene; isoprene; 4-methyl-1,3-pentadiene; 1,3-pentadiene; 1,4-pentadiene; 1,5-hexadiene; 1,4-hexadiene; 1,3-hexadiene; 1,3-octadiene; 1,4-octadiene; 1,5-octadiene; 1,6-octadiene; 1,7-octadiene; 7-methyl-1,6-octadiene; 4-ethylidene-8-methyl-1,7-nonadiene; 5,9-dimethyl-1,4,8-decatriene; and, mixtures thereof.   
     
     
         5 . The chemical mechanical polishing pad of  claim 2 , wherein the olefin copolymer is a reaction product of initial components comprising:
 65 to 75 wt % ethylene;   20 to 35 wt % of 1-octene; and,   1 to 3 wt % of vinyltrimethoxysilane.   
     
     
         6 . The chemical mechanical polishing pad of  claim 2 , wherein the broad spectrum, endpoint detection window block is a plug in place window. 
     
     
         7 . A method of chemical mechanical polishing of a substrate comprising:
 providing a chemical mechanical polishing apparatus having a platen, a light source and a photosensor;   providing at least one substrate selected from a magnetic substrate, an optical substrate and a semiconductor substrate;   providing a chemical mechanical polishing pad of  claim 2 ;   installing onto the platen the chemical mechanical polishing pad;   optionally providing a polishing medium at an interface between the polishing surface and the substrate;   creating dynamic contact between the polishing surface and the substrate, wherein at least some material is removed from the substrate; and,   determining a polishing endpoint by transmitting light from the light source through the broad spectrum, endpoint detection window block and analyzing the light reflected off the surface of the substrate back through the broad spectrum, endpoint detection window block incident upon the photosensor.