Microreplicated polishing pad including fluorinated polymer window

Abstract

Polishing pads include a polishing layer having a thickness and including a polymer having a working surface and a second surface opposite the working surface are described. In particular, polishing pads where the working surface includes a window, a plurality of precisely shaped pored, a plurality of precisely shaped asperities, and a land region are described. The window has a thickness different from the thickness of the polishing layer and includes a fluorinated polymer. The window has at least 20% transmission for any wavelength of light between 200 nm and 800 nm.

1 . A polishing pad, comprising:
 a polishing layer having a thickness and comprising a polymer having a working surface and a second surface opposite the working surface;   wherein the working surface includes a window, a plurality of precisely shaped pores, a plurality of precisely shaped asperities, and a land region;   wherein the window has a thickness different from the thickness of the polishing layer and includes a fluorinated polymer;   wherein the window has at least 20% transmission for any wavelength light between 200 nm-800 nm;   wherein each pore has a pore opening, each asperity has an asperity base, and a plurality of the asperity bases are substantially coplanar relative to at least one adjacent pore opening;   wherein the depth of the plurality of precisely shaped pores is less than the thickness of the land region adjacent to each precisely shaped pore; and   wherein the thickness of the polishing layer is at least three times greater than the thickness of the window.   
     
     
         2 . The polishing pad of  claim 1 , wherein the polishing layer, except for the window, is a unitary sheet. 
     
     
         3 . The polishing pad of  claim 1 , wherein the fluorinated polymer is ethylene tetrafluoroethylene. 
     
     
         4 . The polishing pad of  claim 1 , wherein the thickness of the window is between 50 and 150 micrometers. 
     
     
         5 . The polishing pad of  claim 1 , wherein the thickness of the polishing layer is between 300 and 500 micrometers. 
     
     
         6 . The polishing pad of  claim 1 , wherein the fluorinated polymer is a thermoplastic polymer. 
     
     
         7 . The polishing pad of  claim 1 , wherein the fluorinated polymer includes one or more of polyvinylfluoride, polyvinylidene fluoride, polytetrafluoroethylene, polychlorotrifluoroethylene, a perfluoroalkoxy polymer, fluorinated ethylene-propylene, polyethylenetetrafluoroethylene, polyethylenechlorotrifluoroethylene, a perfluorinated elastomer or perfluoroelastomer, a fluoroelastomer/vinylidene fluoride based copolymer, a fluoroelastomer/tetrafluoroethylene-propylene, perfluoropolyether, polyperfluorosulfonic acid, a copolymer of hexafluoropropylene tetrafluoroethylene and ethylene, a copolymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride, or polyperfluoropolyoxetaneethylene, including blends and mixtures thereof. 
     
     
         8 . The polishing pad of  claim 1 , wherein the window is substantially free of ultraviolet stabilizers. 
     
     
         9 . The polishing pad of  claim 1 , wherein the window has at least 50% transmission for any wavelength light between 200 nm-800 nm. 
     
     
         10 . The polishing pad of  claim 1 , wherein the window has a top surface facing the plurality of precisely shaped asperities, and wherein the top surface is substantially coplanar with the plurality of asperity bases. 
     
     
         11 . The polishing pad of  claim 1 , further comprising a subpad, wherein the subpad is adjacent to the second surface of the polishing layer, and wherein the subpad includes a cutout, the cutout being aligned in a thickness direction of the polishing pad with the window. 
     
     
         12 . The polishing pad of  claim 11 , further comprising a foam layer, wherein the foam layer is interposed between the second surface of the polishing layer and the subpad, and wherein the foam layer includes a cutout, the cutout of the foam layer being aligned with a thickness direction of the polishing pad with the subpad and with the window. 
     
     
         13 . The polishing pad of  claim 11 , further including a polymeric liner disposed on a surface of the subpad further from the polishing layer. 
     
     
         14 . The polishing pad of  claim 12 , further including a polymeric liner disposed on a surface of the subpad further from the polishing layer.