Polishing pads having improved pore structure

Abstract

Embodiments herein generally relate to polishing pads and methods of forming polishing pads. A method of forming a polishing pad includes (a) dispensing droplets of a pre-polymer composition and droplets of a sacrificial material composition onto a surface of a previously formed print layer according to a predetermined droplet dispense pattern. The method includes (b) at least partially curing the dispensed droplets of the pre-polymer composition to form a print layer. The method includes (c) sequentially repeating (a) and (b) to form a polishing layer having a plurality of pore-features formed therein. The pre-polymer composition includes a multifunctional acrylate component. A curing rate of the dispensed droplets of the pre-polymer composition including the multifunctional acrylate component when exposed to a first dose of electromagnetic radiation is greater than a curing rate of the pre-polymer composition without the multifunctional acrylate component when exposed to the same first dose of electromagnetic radiation.

1 . A method of forming a polishing pad, comprising:
 (a) dispensing droplets of a pre-polymer composition and droplets of a sacrificial material composition onto a surface of a previously formed print layer according to a predetermined droplet dispense pattern; and   (b) at least partially curing the dispensed droplets of the pre-polymer composition to form a print layer; and   (c) sequentially repeating (a) and (b) to form a polishing layer having a plurality of pore-features formed therein, wherein:   the pre-polymer composition comprises a multifunctional acrylate component,   a curing rate of the dispensed droplets of the pre-polymer composition comprising the multifunctional acrylate component when exposed to a first dose of electromagnetic radiation is greater than a curing rate of the pre-polymer composition without the multifunctional acrylate component when exposed to the same first dose of electromagnetic radiation, and   the plurality of pore-features comprise openings defined in a surface of the polishing layer, voids that are formed in the polishing layer below the surface, pore-forming features comprising the sacrificial material composition, or combinations thereof.   
     
     
         2 . The method of  claim 1 , wherein a concentration of the multifunctional acrylate component in the pre-polymer composition is about 20 wt % or less. 
     
     
         3 . The method of  claim 1 , wherein the multifunctional acrylate component comprises at least one diacrylate or triacrylate having a molecular weight of about 200 g/mol or greater. 
     
     
         4 . The method of  claim 1 , wherein the multifunctional acrylate component comprises at least one of tripropylene glycol diacrylate, poly(propylene glycol) diacrylate, trimethylyol triacrylate, neopentyl glycol diacrylate, ethoxylated neopentyl glycol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, or combinations thereof. 
     
     
         5 . The method of  claim 1 , wherein a ratio of the curing rate of the pre-polymer composition with the multifunctional acrylate component to the curing rate of the pre-polymer composition without the multifunctional acrylate component is about 1.6 or greater. 
     
     
         6 . The method of  claim 1 , wherein a volume of a pore-feature space of an individual one of the plurality of pore-features comprises at least 50% of a volume of the sacrificial material composition dispensed to form the corresponding pore-features. 
     
     
         7 . The method of  claim 1 , wherein the curing rate of the pre-polymer composition with the multifunctional acrylate component reduces inter-mixing between adjacent droplets of the pre-polymer composition and the sacrificial material composition when compared to the curing rate of the pre-polymer composition without the multifunctional acrylate component. 
     
     
         8 . The method of  claim 1 , wherein:
 the curing rate of the pre-polymer composition with the multifunctional acrylate component satisfies a threshold condition for inter-mixing between adjacent droplets of the pre-polymer composition and the sacrificial material composition,   the threshold condition for inter-mixing corresponds to a volume of pore-feature space of individual ones of the plurality pore-features comprising at least 50% of a volume of the sacrificial material composition dispensed to form the corresponding pore-features.   
     
     
         9 . The method of  claim 1 , wherein when the curing rate of the pre-polymer composition with the multifunctional acrylate component meets or exceeds a threshold curing rate, at least 5% of the plurality of pore-features are isolated from other ones of the plurality of pore-features within the polishing layer. 
     
     
         10 . The method of  claim 1 , wherein the pre-polymer composition further comprises at least one of phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, butylcarbamatoethyl acrylate, isobornyl acrylate, or combinations thereof. 
     
     
         11 . The method of  claim 1 , wherein the multifunctional acrylate component reduces swelling of the polishing pad when exposed to an aqueous polishing fluid when compared to a polishing pad formed using the pre-polymer composition without the multifunctional acrylate component. 
     
     
         12 . The method of  claim 1 , wherein the multifunctional acrylate component increases a surface contact angle of a water droplet disposed on the polishing layer compared to a polishing layer formed using the pre-polymer composition without the multifunctional acrylate component. 
     
     
         13 . A method of forming a polishing pad, comprising:
 (a) dispensing droplets of a pre-polymer composition and droplets of a sacrificial material composition onto a surface of a previously formed print layer according to a predetermined droplet dispense pattern; and   (b) at least partially curing the dispensed droplets of the pre-polymer composition to form a print layer comprising a plurality of pore-features; and   (c) sequentially repeating (a) and (b) to form a polishing layer, wherein:   the pre-polymer composition comprises a surface active agent,   wherein a volume of a pore-feature space of an individual one of the plurality of pore-features comprises at least 50% of a volume of the sacrificial material composition dispensed to form the corresponding pore-features, and   the plurality of pore-features comprise openings defined in a surface of the polishing layer, voids that are formed in the polishing layer below the surface, pore-forming features comprising the sacrificial material composition, or combinations thereof.   
     
     
         14 . The method of  claim 13 , wherein the surface active agent comprises at least one of polybutylated phenol, nonylphenol, 2-methyl-4-t-octylphenol, 4,6-di-t-butyl-2-methylphenol, or combinations thereof. 
     
     
         15 . The method of  claim 13 , wherein a concentration of the surface active agent in the pre-polymer composition is about 1 wt % or less. 
     
     
         16 . The method of  claim 13 , wherein the surface active agent increases the hydrophobicity of the dispensed droplets of the pre-polymer composition. 
     
     
         17 . A polishing pad, comprising:
 a plurality of polishing elements, each comprising:
 an individual surface that forms a portion of a polishing surface of the polishing pad; and 
 one or more sidewalls extending downwardly from the individual surface to define a plurality of channels disposed between the polishing elements, wherein: 
   each of the polishing elements has a plurality of pore-features formed therein,   each of the polishing elements is formed of a pre-polymer composition and a sacrificial material composition,   a volume of pore-feature space of an individual one of the plurality of pore-features comprises at least 50% of a volume of the sacrificial material composition dispensed to form the corresponding pore-features, and   the plurality of pore-features comprise openings defined in the polishing surface, voids that are formed in the polishing elements below the polishing surface, pore-forming features comprising the sacrificial material composition, or combinations thereof.   
     
     
         18 . The polishing pad of  claim 17 , wherein the pre-polymer composition comprises a multifunctional acrylate component. 
     
     
         19 . The polishing pad of  claim 17 , wherein the pre-polymer composition comprises a surface active agent. 
     
     
         20 . The polishing pad of  claim 17 , wherein:
 a concentration of a polyethylene glycol monoacrylate component in the sacrificial material composition is about 30 wt % or greater,   a concentration of a polyethylene glycol diacrylate component in the sacrificial material composition is about 10 wt % or less, and   a concentration of a polyethylene glycol component in the sacrificial material composition is about 40 wt % or less.