Printing chemical mechanical polishing pad having window or controlled porosity

Abstract

A method of fabricating a polishing pad includes determining a desired distribution of voids to be introduced within a polymer matrix of a polishing layer of the polishing pad. Electronic control signals configured to be read by a 3D printer are generated which specify the locations where a polymer matrix precursor is to be deposited, and specify the locations of the desired distribution of voids where no material is to be deposited. A plurality of layers of the polymer matrix corresponding to the plurality of the first locations is successfully deposited with the 3D printer. Each layer of the plurality of layers of polymer matrix is deposited by ejecting a polymer matrix precursor from a nozzle. The polymer matrix precursor is solidified to form a solidified polymer matrix having the desired distribution of voids.

What is claimed is: 
     
         1 . A method of fabricating a polishing pad, comprising:
 successively depositing a plurality of layers with a 3D printer, each layer of the plurality of layers including a polishing material portion and a window portion, the polishing material portion deposited by ejecting a polishing material precursor from a first nozzle and solidifying the polishing material precursor to form a solidified polishing material, the window portion deposited by ejecting a window precursor from a second nozzle and solidifying the window precursor to form a solidified transparent window, wherein curing of the polishing material precursor and the window precursor form polymer matrixes having a same composition.   
     
     
         2 . The method of  claim 1 , wherein ejecting the polishing material precursor from the first nozzle and ejecting the window precursor from the second nozzle forms an interface that directly bonds the solidified transparent window and the solidified polishing material. 
     
     
         3 . The method of  claim 1 , wherein the polishing material precursor comprises opacity-inducing additives and the window precursor lacks such additives. 
     
     
         4 . The method of  claim 1 , wherein solidifying the polishing material precursor comprising curing the polymer matrix precursor with light. 
     
     
         5 . The method of  claim 4 , wherein solidifying the polishing material precursor comprising curing the polymer matrix precursor with ultraviolet (UV) or infrared (IR) light. 
     
     
         6 . The method of  claim 1 , wherein the polishing material precursor comprises a urethane monomer. 
     
     
         7 . The method of  claim 6 , wherein the polishing material precursor comprises polyurethane. 
     
     
         8 . The method of  claim 1 , comprises printing on selected areas of the polishing layer to form grooves in a top surface of the polishing layer, wherein the grooves comprises regions where no polymer matrix precursor is deposited. 
     
     
         9 . A system for fabricating a polishing pad, comprising:
 a 3D printer having a first nozzle to eject a polishing material precursor and a second nozzle to eject a window precursor; and   a computer configured to cause the 3D printer to successively deposit a plurality of layers by ejecting the polishing material precursor from the first nozzle and ejecting a window precursor from a second nozzle and with each layer of the plurality of layers including a polishing material portion and a window portion, such that solidification of the polishing material precursor forms a solidified polishing material and solidification of the window precursor forms a solidified transparent window, and such that curing of the polishing material precursor and the window precursor form polymer matrixes having a same composition.   
     
     
         10 . The system of  claim 9 , wherein ejecting the polishing material precursor from the first nozzle and ejecting the window precursor from the second nozzle forms an interface that directly bonds the solidified transparent window and the solidified polishing material. 
     
     
         11 . The system of  claim 9 , comprising a source for the polishing material precursor and a source for the second nozzle, and wherein the polishing material precursor comprises opacity-inducing additives and the window precursor lacks such additives. 
     
     
         12 . The system of  claim 11 , wherein the polymer matrix precursor comprises a urethane monomer. 
     
     
         13 . The system of  claim 9 , wherein computer is configured to cause printing on selected areas of the polishing layer to form grooves in a top surface of the polishing layer, wherein the grooves comprises regions where no polymer matrix precursor is deposited. 
     
     
         14 . The system of  claim 9 , wherein the 3D printer comprises a light source to solidify the polishing material precursor. 
     
     
         15 . The system of  claim 14 , wherein the light sources comprises a ultraviolet (UV) or infrared (IR) light source.