Formulation for a chemical mechanical polishing pad with high planarization efficiency and CMP pad made therewith

Abstract

To provide CMP polishing pads or layers made of a polyurethane reaction product of a reaction mixture.SOLUTION: The reaction mixture comprises (i) a liquid aromatic isocyanate component comprising one or more aromatic diisocyanates or a linear aromatic isocyanate-terminated urethane prepolymer, and (ii) a liquid polyol component comprising a) one or more polymeric polyols and b) 12 to 40 wt.%, based on the total weight of the liquid polyol component, of a curative mixture of one or more short-chain difunctional polyols having 2 to 9 carbon atoms and a liquid aromatic diamine, where the molar ratio of the liquid aromatic diamine to the total moles of the short-chain difunctional polyols and liquid aromatic diamine ranges from 15:85 to 40:60. The reaction mixture comprises 48 to 68 wt.% of hard segment materials.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a chemical mechanical planarization polishing (CMP) pad and a method for making the same. More particularly, the present invention relates to a CMP polishing pad that is a polyurethane reaction product of a two-component reaction mixture including a liquid aromatic diisocyanate component and a liquid polyol component (including a monoalkylene diol, such as ethylene glycol), with a liquid aromatic diamine curing agent. [Background technology]

[0002] In the CMP process, a polishing pad is combined with a polishing solution, such as an abrasive-containing polishing slurry and / or an abrasive-free reactive liquid, to remove excess material from semiconductor, optical, or magnetic substrates in a manner that planarizes or maintains their flatness. There is a continuing need for CMP polishing pads that offer improved layer uniformity or planarization performance combined with acceptable removal rates. However, the industry remains reliant on a compromise between planarization efficiency (PE) and defectivity, with higher PEs resulting in more defects. Known CMP polishing pads are formed from reaction mixtures containing aromatic diamines as curing agents. Higher concentrations of aromatic diamines result in faster reaction times and improved mechanical properties, such as higher tensile strength and modulus. However, while such CMP polishing pads with high tensile modulus and hardness can provide good planarization efficiency, they are compromised by increased polishing defects.

[0003] Huang et al., U.S. Patent Application Publication No. 2009 / 0062414 (A1), discloses a CMP polishing pad made by foaming an aliphatic isocyanate containing urethane prepolymer with an inert gas in the presence of a polysiloxane-polyalkylene oxide surfactant, and curing the foam with a curing agent containing an aromatic diamine and triol. The resulting CMP polishing pad exhibits improved damping performance and a densitometric value of 0.6 to 1.0 g / cm. 3 However, the resulting polishing pad cannot provide an acceptable removal rate for polishing.

[0004] U.S. Patent Application Publication No. 20180148537 to Barton et al. discloses CMP polishing pads made by reacting a liquid aromatic isocyanate compound with a liquid polyol using one or more polyamine or diamine curing agents. However, this reference fails to recognize the importance of blending a short-chain polyol with a diamine in affecting the planarization efficiency of the resulting polishing pad.

[0005] The present inventors have sought to solve the problem of providing a more flexible formulation tool for producing chemical mechanical polishing layers or pads that are useful for polishing dielectric and silicon oxide substrates and that retain good removal rate and planarization efficiency (PE) performance without undesirably increasing defectivity and hardness. Summary of the Invention

[0006] 1. In accordance with the present invention, a chemical mechanical polishing (CMP polishing) pad for polishing a substrate selected from at least one of a magnetic substrate, an optical substrate, and a semiconductor substrate comprises a polishing layer adapted for polishing the substrate, the polishing layer comprising: (i) a liquid aromatic isocyanate component comprising one or more aromatic diisocyanates or linear aromatic isocyanate-terminated urethane prepolymers; 、 a liquid aromatic isocyanate component having an unreacted isocyanate (NCO) concentration of 20 to 40 wt %, or preferably 18 to 34 wt %, based on the total solids weight of the liquid aromatic isocyanate component; preferably, a liquid aromatic isocyanate component comprising a linear methylene diphenyl diisocyanate (MDI) prepolymer; (ii) a liquid polyol component, a) one or more polymer polyols (e.g., polytetramethylene glycol (PTMEG), polypropylene glycol (PPG)), polyols having 5 to 7 hydroxyl groups (e.g., hexafunctional polyols or mixtures thereof); b) 12 to 40 wt.% of the total weight of the liquid polyol component %, or preferably 15 to 25% by weight of one or more short-chain difunctional polyols having 2 to 9 carbon atoms (e.g., ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, tripropylene glycol and mixtures thereof; preferably ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol and triethylene glycol), a liquid polyol component comprising a curing agent mixture of a liquid aromatic diamine that is liquid under ambient conditions [e.g., dimethylthio-toluenediamine, diethyltoluenediamine; tert-butyltoluenediamine (e.g., 5-tert-butyl-2,4- or 3-tert-butyl-2,6-toluenediamine); chlorotoluenediamine; and N,N'-dialkylaminodiphenylmethane and mixtures thereof; preferably, any liquid aromatic diamine selected from chlorotoluenediamine or dimethylthio-toluenediamine, diethyltoluenediamine (DETDA) and N,N'-dialkylaminodiphenylmethane; The present invention also includes a polyurethane reaction product of a substantially water-free and organic solvent-free two-component reaction mixture comprising: a molar ratio of the liquid aromatic diamine to the total moles of the short-chain difunctional polyol and the liquid aromatic diamine ranging from 15:85 to 40:60, or preferably from 23:77 to 35:65; the reaction mixture further comprises 48 to 68 wt %, or preferably from 58 to 63 wt %, of a hard segment material based on the total weight of the reaction mixture; the CMP polishing layer has a hardness ranging from 50 Shore A (15 seconds) to 68 Shore D (15 seconds), or preferably from 55 Shore A (15 seconds) to 50 Shore D (15 seconds), and a density ranging from 0.45 to 0.9 g / mL, or preferably from 0.60 to 0.85 g / mL; and preferably, the CMP polishing layer is free of trace elements other than those formed by gas, water, or CO2-amine adducts.

[0007] 2. According to the present invention, in the reaction mixture for forming a chemical mechanical polishing (CMP polishing) layer described in the above item 1, which does not contain an organic solvent, (i) A liquid aromatic isocyanate component selected from methylene diphenyl diisocyanate (MDI); toluene diisocyanate (TDI); naphthalene diisocyanate (NDI); paraphenylene diisocyanate (PPDI); or o-toluidine diisocyanate (TODI); modified diphenylmethane diisocyanate (e.g., carbodiimide-modified diphenylmethane diisocyanate, allophanate-modified diphenylmethane diisocyanate, biuret-modified diphenylmethane diisocyanate); a linear isocyanate-terminated urethane prepolymer having a hard segment weight fraction of 84 to 100 wt%, preferably 90 to 100 wt%, more preferably MDI or a linear isocyanate-terminated urethane prepolymer of MDI or an MDI dimer, together with one or more isocyanate extenders selected from ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, tripropylene glycol, and mixtures thereof.

[0008] 3. According to the present invention, in the reaction mixture for forming a chemical mechanical polishing (CMP polishing) layer according to any one of the above items 1 and 2, which does not contain an organic solvent, ii) b) the curing agent mixture comprises one or more short chain difunctional polyols having 2 to 9 carbon atoms and a liquid aromatic diamine; The liquid aromatic diamine is selected from dimethylthio-toluenediamine, an isomeric mixture of 2,4-diamino-3,5-dimethylthiotoluene; 3,5-dimethylthio-2,4-toluenediamine; diethyltoluenediamine; tert-butyltoluenediamine (e.g., 5-tert-butyl-2,4- or 3-tert-butyl-2,6-toluenediamine); chlorotoluenediamine; and N,N'-dialkylaminodiphenylmethane and mixtures thereof; preferably chlorotoluenediamine or dimethylthiotoluenediamine, an isomeric mixture of the isomers 2,4-diamino-3,5-dimethylthiotoluene and 3,5-dimethylthio-2,4-toluenediamine, diethyltoluenediamine (DETDA), and N,N'-dialkylaminodiphenylmethane.

[0009] 4. According to the present invention, in the organic solvent-free reaction mixture for forming a chemical mechanical polishing (CMP polishing) layer described in any one of items 1, 2, and 3 above, the stoichiometric ratio of the sum of the total moles of amine (NH2) groups and the total moles of hydroxyl (OH) groups in the reaction mixture to the total moles of unreacted isocyanate (NCO) groups in the reaction mixture is in the range of 0.85:1.0 to 1.15:1.0, or preferably 0.9:1.0 to 1.1:1.0.

[0010] 5. According to the chemical mechanical polishing pad of the present invention described in any one of items 1, 2, 3, or 4 above, the polishing pad or polishing layer has a density of 0.45 to 0.9 g / mL, or preferably 0.60 to 0.85 g / mL, produced from c) water or CO2-amine adduct in ii) a liquid polyol component.

[0011] 6. According to the chemical mechanical polishing pad of the present invention described in any one of items 1, 2, 3, 4, or 5 above, the polishing pad further comprises a subpad or backing layer, such as a polymer-impregnated nonwoven fabric or a polymer sheet, on the bottom side of the polishing layer, so that the polishing layer forms the upper part of the polishing pad.

[0012] 7. In yet another aspect, the present invention provides a method for manufacturing a chemical mechanical (CMP) polishing pad having a polishing layer adapted for polishing a substrate. The method comprises: Providing a binary reaction mixture according to any one of items 1, 2, 3, 4, 5, or 6 above; c) water or a CO2-amine adduct (e.g., CO2-alkanolamine) in the liquid polyol component ii) sufficient to generate a density of the CMP polishing pad or layer, e.g., 250 to 3000 ppm, or preferably 500 to 2000 ppm, of water, or 0.05 to 2 wt. %, or preferably 0.1 to 1.5 wt. %, based on the total weight of the two-component reaction mixture; Mixing the liquid aromatic isocyanate component (i) and the liquid polyol component (ii) in, for example, a static mixer or an impingement mixer; applying the reaction mixture in one component to an open mold surface, preferably an open mold surface having a male shape that forms a female groove pattern on the top surface of a CMP polishing pad or layer; A method for producing a chemical mechanical (CMP) polishing pad is provided, comprising the steps of curing a reaction mixture at ambient temperature to 130°C to form a molded polyurethane reaction product, e.g., initially curing at ambient temperature to 130°C for a period of 1 to 30 minutes, preferably 30 seconds to 5 minutes; removing the polyurethane reaction product from the mold; and then final curing at a temperature of 60 to 130°C for a period of 1 minute to 18 hours, preferably 5 minutes to 60 minutes, to form a CMP polishing pad or layer.

[0013] 8. The step of forming a polishing pad by the method of the present invention described in item 7 above further includes a step of laminating or spraying a subpad layer, such as a polymer-impregnated nonwoven fabric or a porous or non-porous polymer sheet, onto the bottom side of the polishing layer, so that the polishing layer forms the top surface of the polishing pad.

[0014] 9. The surface of the CMP polishing pad is formed directly in the mold by the method of the present invention described in either item 7 or 8 above.

[0015] 10. The method of the present invention described in any one of items 7, 8, or 9 above, wherein the step of applying the reaction mixture as one component comprises overcoating the mold, followed by curing to form a polyurethane reaction product, removing the polyurethane reaction product from the mold, and then punching or cutting the periphery of the polyurethane reaction product to the desired diameter of the CMP polishing pad.

[0016] 11. According to yet another aspect, the present invention provides a method for polishing a substrate, comprising the steps of: providing a substrate selected from at least one of a magnetic substrate, an optical substrate, and a semiconductor substrate (e.g., containing a dielectric or silicon oxide); providing a chemical mechanical polishing (CMP) polishing pad described in any one of items 1 to 6 above; generating dynamic contact between the polishing surface of a polishing layer of the CMP polishing pad and the substrate to polish the surface of the substrate; and conditioning the polishing surface of the polishing pad with an abrasive grain conditioner.

[0017] Unless otherwise specified, temperature and pressure conditions are ambient temperature and standard pressure. All ranges listed are inclusive and combinable.

[0018] Unless otherwise indicated, any term containing parentheses refers, in the alternative, to the entire term without the parentheses, and to the term without the parentheses, as well as to combinations of each alternative. Thus, the term "(poly)isocyanate" refers to an isocyanate, polyisocyanate, or mixtures thereof.

[0019] For purposes of this specification, reaction mixtures are expressed in weight percent unless otherwise stated.

[0020] All ranges are inclusive and combinable. For example, the term "in the range of 50 to 3000 cP, or 100 cP or more" encompasses 50 to 100 cP, 50 to 3000 cP, and 100 to 3000 cP, respectively.

[0021] As used herein, the term "ASTM" refers to publications by ASTM International, West Conshohocken, Pennsylvania.

[0022] As used herein, the term "average number of isocyanate groups" refers to the weighted average of the number of isocyanate groups in a mixture of aromatic isocyanate compounds. For example, a 50:50 weight percent mixture of MDI (2 NCO groups) and an isocyanurate of MDI (considered to have 3 NCO groups) has an average of 2.5 isocyanate groups.

[0023] As used herein, the term "hard segment" of a polyurethane reaction product or raw materials derived from (i) the liquid polyol component and (ii) the liquid aromatic isocyanate component refers to the portion of the specified reaction mixture that includes any diol, glycol, diglycol, diamine or triamine, diisocyanate, triisocyanate, or reaction products thereof. Thus, "hard segment" excludes polyethers, or polyglycols (e.g., polyethylene glycol or polypropylene glycol), or polyoxyethylenes with three or more ether groups.

[0024] As used herein, the term "trace elements other than those formed by gas, water, or CO2-amine adduct" refers to trace elements selected from hollow core polymeric materials, e.g., polymeric microspheres, liquid-filled hollow core polymeric materials, e.g., fluid-filled polymeric microspheres, and fillers, e.g., boron nitride. Pores formed in the CMP polishing layer by gases or blowing agents that only form gases, e.g., CO2-amine adducts, are not considered trace elements.

[0025] As used herein, the term "polyisocyanate" means any isocyanate group-containing molecule that contains two or more isocyanate groups.

[0026] As used herein, the term "polyurethane" refers to polymerization products derived from di- or polyfunctional isocyanates, such as polyetherureas, polyisocyanurates, polyurethanes, polyureas, polyurethaneureas, copolymers thereof, and mixtures thereof.

[0027] As used herein, the term "reaction mixture" includes any non-reactive additives, such as trace elements and any additives that reduce the hardness of the polyurethane reaction product in a CMP polishing pad according to ASTM D2240-15(2015).

[0028] As used herein, the term "stoichiometry" of a reaction mixture refers to the ratio of molar equivalents of (free OH + free NH2 groups) to free NCO groups in the reaction mixture.

[0029] As used herein, the term "SG," or "specific gravity," refers to the weight / volume ratio of a rectangular cut-out piece from a polishing pad or layer according to the present invention.

[0030] As used herein, the term "Shore D hardness" refers to the 15-second hardness of a given CMP polish measured according to ASTM D2240-15(2015), "Standard Test Method for Rubber Property-Durometer Hardness." Hardness was measured on a Rex Hybrid hardness tester (Rex Gauge Company, Inc., Buffalo Grove, Illinois) equipped with a D probe. Six samples were stacked and rotated for each hardness measurement, and each tested pad was conditioned prior to testing by placing it at 50 percent relative humidity and 23°C for five days using the method outlined in ASTM D2240-15(2015) to improve hardness test reproducibility. For purposes of this invention, the Shore D hardness of the polyurethane reaction product of the polishing layer or pad includes the Shore D hardness of the reaction, including any additives to enhance hardness. The term "Shore A" hardness refers to the same 15-second hardness measurement using the larger A probe for softer materials.

[0031] As used herein, the term "solids" refers to any materials remaining in the polyurethane reaction product of the present invention. Thus, solids include reactive liquids and non-volatile additives and liquids that do not volatilize upon curing. Solids exclude water and volatile solvents.

[0032] As used herein, unless otherwise stated, the term "substantially water-free" means that no water has been added to a given composition and that no water has been added to the materials that go into the composition. A "substantially water-free" reaction mixture can contain water present in the raw materials in the range of 50 to 2000 ppm, preferably 50 to 1000 ppm, or can contain water of reaction produced in the condensation reaction or steam from the ambient moisture in which the reaction mixture is being used.

[0033] As used herein, unless otherwise stated, the term "organic solvent-free" means that no organic solvent has been added to the composition, and preferably the composition does not contain any organic solvent.

[0034] As used herein, unless otherwise stated, the term "viscosity" refers to the viscosity of a given material in its undiluted form (100%) as measured at a given temperature using a rheometer in a 50 mm parallel plate configuration with a 100 μm gap and set to an oscillatory shear rate sweep from 0.1 to 100 rad / sec.

[0035] As used herein, unless otherwise stated, the term "wt % NCO" refers to the amount of unreacted or free isocyanate groups in a given isocyanate or isocyanate-terminated urethane prepolymer composition.

[0036] As used herein, the term "wt. %" stands for percent by weight.

[0037] In accordance with the present invention, the inventors have discovered that CMP polishing pads made from reaction mixtures containing at least one short-chain difunctional polyol having 2 to 9 carbon atoms in the liquid polyol component as part of the curing agent mixture provide porous CMP polishing layers with Shore D (15 seconds) hardness greater than 30, which provides an attractive removal rate profile and enables polishing with low defectivity. In particular, reducing the content of the liquid aromatic diamine and replacing a portion of this diamine with a short-chain diol surprisingly increases planarization efficiency, despite a decrease in tensile properties and hardness. The increase in planarization efficiency (PE) accompanied by a decrease in tensile properties and hardness is surprising.

[0038] The reaction mixture of the present invention can comprise an ultra-rapid curing composition in which (i) a liquid aromatic isocyanate component and (ii) a liquid polyol component can gel in a gel time as short as 15 seconds at 65°C. The reaction must be slow enough so that the reaction mixture can be mixed in a static or impingement mixer. The only limitation on gel time is that the reaction mixture must react slowly enough so as not to clog the mixhead in which it is mixed and to adequately fill the mold upon application of the reaction mixture to the mold surface.

[0039] The hard segment of the reaction mixture ensures good mechanical properties and can comprise 56.25 to 68% by weight of the reaction mixture, including portions of both the liquid polyol component and the liquid aromatic isocyanate component.

[0040] As part of the hard segment of the reaction mixture, (i) the liquid aromatic isocyanate component is preferably methylene diphenyl diisocyanate (MDI), which is less toxic than toluene diisocyanate (TDI). The liquid aromatic isocyanate component can include a linear isocyanate-terminated urethane prepolymer formed from short-chain diols such as glycols and diglycols, preferably monoethylene glycol (MEG), dipropylene glycol (DPG), or tripropylene glycol (TPG).

[0041] Preferably, the (i) liquid aromatic isocyanate component of the present invention contains no more than 5% by weight, or more preferably no more than 1% by weight, of aliphatic isocyanate, based on the total weight of the liquid aromatic isocyanate.

[0042] The soft segment of the reaction mixture can include, as the polymer polyol, one or more difunctional polyether polyols in an amount of up to 88% by weight of the (ii) liquid polyol component. Suitable soft polyols are PTMEG and PPG. Available examples of PTMEG-containing polyols include Terathane™ 2900, 2000, 1800, 1400, 1000, 650, and 250 from Invista, Wichita, Kansas; Polymeg™ 2900, 2000, 1000, and 650 from Lyondell Chemicals, Limerick, Pennsylvania; and PolyTHF™ 650, 1000, and 2000 from BASF Corporation, Florham Park, New Jersey. Available examples of PPG-containing polyols include: Arcol™ PPG-425, 725, 1000, 1025, 2000, 2025, 3025, and 4000 manufactured by Covestro of Pittsburgh, Pennsylvania; Voranol™, Voralux™, and Specflex™ product lines manufactured by Dow of Midland, Michigan; and Multranol™, Ultracel™, Desmophen™, or Acclaim™ Polyol 12200, 8200, 6300, 4200, and 2200, respectively, manufactured by Covestro of Leverkusen, Germany.

[0043] The soft segment of the reaction mixture may contain, as the polymer polyol, one or more a) polyols having a polyether skeleton and 5 to 7, preferably 6, hydroxyl groups per molecule. Preferably, the soft segment of the reaction mixture contains, as the polymer polyol, a) a mixture of one or more polyols having a polyether skeleton and 5 to 7, preferably 6, hydroxyl groups per molecule with a bifunctional polyether polyol, more preferably a mixture in which the polyol having a polyether skeleton and 5 to 7, preferably 6, hydroxyl groups constitutes up to 20% by weight of the total liquid polyol component (ii).

[0044] Suitable polyols having a polyether backbone and 5 to 7 hydroxyl groups per molecule are available as VORANOL™ 202 polyol (Dow), which has 5 hydroxyl groups, a number average molecular weight of 590, and a hydroxyl number of 475 mg KOH / g; MULTRANOL™ 9185 polyol (Dow), which has 6 hydroxyl groups, a number average molecular weight of 3,366, and a hydroxyl number of 100 mg KOH / g; or VORANOL™ 4053 polyol (Dow), which has an average of 6.9 hydroxyl groups, a number average molecular weight of 12,420, and a hydroxyl number of 31 mg KOH / g.

[0045] The stoichiometry of the reaction mixture of the present invention is in the range of (NH + OH):NCO 0.85:1.0 to 1.15:1.0. If the stoichiometry exceeds the upper limit, the polyurethane product will suffer from a decrease in elongation at break. For purposes of this specification, stoichiometry refers to the molar ratio of amine or hydroxyl groups to isocyanate.

[0046] The curing agent mixture of the present invention is a liquid containing one or more liquid aromatic diamines and one or more short-chain difunctional polyols having 2 to 9 carbon atoms. Suitable short-chain difunctional polyols having 2 to 9 carbon atoms can be ethylene glycol, butanediol (BDO), dipropylene glycol (DPG), diethylene glycol (DEG), triethylene glycol (TEG), and mixtures thereof. However, the amount of one or more short-chain difunctional polyols having 2 to 9 carbon atoms in the curing agent mixture is in the range of at least 15 mol% of the curing agent mixture. If the amount of liquid aromatic diamine exceeds 85 mol%, the resulting CMP polishing layer or pad will be hard, but will not provide the desired improvement in PE and defectivity.

[0047] The hard segment of the reaction mixture of the present invention ranges from greater than 56.25 wt. % of the total reaction mixture, preferably at least greater than 60 wt. %, to retain adequate tensile properties, such as modulus and adequate hardness for use as a rigid top pad exhibiting high PE.

[0048] The liquid reaction mixture of the present invention allows for the production of CMP polishing pads by spraying the reaction mixture into an open mold and allowing the reaction mixture to harden. The two-component polyurethane-forming reaction mixture of the present invention is in liquid form and can be mixed in a static mixer or an impingement mixer and sprayed to form CMP polishing pads.

[0049] The chemical mechanical polishing pad of the present invention comprises a polishing layer that is a uniform dispersion of porous polyurethane. Homogeneity is important in achieving consistent polishing pad performance. Therefore, the reaction mixture of the present invention is selected so that the resulting pad morphology is stable and easily reproducible. For example, controlling additives such as antioxidants and impurities such as water is often important for consistent production. Because water reacts with isocyanate to form gaseous carbon dioxide and reaction products that are generally weaker than urethanes, the water concentration can affect the concentration of carbon dioxide bubbles that form pores in the polymer matrix and the overall uniformity of the polyurethane reaction product. In addition, accidental reaction of isocyanate with water reduces the amount of isocyanate available for reaction with chain extenders, which can alter the stoichiometry, including the level of crosslinking (if excess isocyanate groups are present), and tend to lower the molecular weight of the resulting polymer. To reduce the variability of water's effect on polyurethanes, the water content of the raw materials is monitored and adjusted to a specific value between 0 ppm and 1000 ppm, preferably between 50 ppm and 500 ppm.

[0050] Preferably, to maintain the stability of the pore structure in the reaction mixture and in the porous polyurethane comprising the CMP polishing layer or pad of the present invention, (ii) the liquid polyol component contains up to 2.0 wt. %, or preferably 0.1 to 1 wt. %, of a nonionic surfactant, preferably an organopolysiloxane-co-polyether surfactant, based on the total solids weight of the reaction mixture.

[0051] Preferably, (i) a catalyst can be used to improve the reactivity of the liquid polyol component with the liquid aromatic isocyanate component. Suitable catalysts include any catalyst known to those skilled in the art, such as oleic acid, azelaic acid, dibutyltin dilaurate, tin octoate, bismuth octoate, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), tertiary amine catalysts such as Dabco™ TMR catalyst (Air Products, Allentown, PA), triethylenediamine catalysts such as DABCO™ 33LV catalyst (Air Products), and mixtures thereof.

[0052] The reaction mixture of the present invention is substantially free of water and free of added organic solvents.

[0053] The resulting CMP polishing pad preferably has a specific gravity in the range of 0.9 to 0.5. As porosity increases, the bulk properties of the CMP polishing pad decrease and the removal rate (RR) increases. However, for hard porous CMP polishing pads, the planarization efficiency (PE) and defectivity characteristics are not expected to improve with increasing hardness or weight fraction of hard segment material.

[0054] Porosity is introduced into the pad by the spraying process, and the resulting pad's tensile modulus is a function of both the intrinsic polymer tensile modulus and the porosity, with increased porosity acting to decrease the bulk modulus. Typical densities achieved with the two-component spray manufacturing platform range from 0.5 g / mL to 0.9 g / mL, more typically from 0.6 g / mL to 0.8 g / mL.

[0055] Polishing pad density is measured according to ASTM D1622-08(2008). Density is the same as specific gravity.

[0056] The CMP polishing pads of the present invention are formed by a spray application method, which allows for higher throughput and lower costs. Preferably, the target or substrate in the method of the present invention is a mold having a groove pattern directly incorporated into the mold from which the CMP polishing pad is fabricated.

[0057] The CMP polishing pads of the present invention are effective for polishing interlayer dielectrics (ILDs) and inorganic oxides. For purposes of this specification, removal rate refers to the removal rate expressed in Å / min.

[0058] The chemical mechanical polishing pad of the present invention can simply comprise a polishing layer of the polyurethane reaction product, or a polishing layer laminated onto a subpad or sublayer. The polishing pad of the present invention, or in the case of a laminated pad, the polishing layer of the polishing pad of the present invention, is useful in both porous and non-porous (or unfilled) configurations.

[0059] Preferably, the CMP polishing layer used in the chemical mechanical polishing pad of the present invention has an average thickness of 500 to 3750 microns (20 to 150 mils), more preferably 750 to 3150 microns (30 to 125 mils), even more preferably 1000 to 3000 microns (40 to 120 mils), and most preferably 1250 to 2500 microns (50 to 100 mils).

[0060] The chemical mechanical polishing pad of the present invention optionally further comprises at least one additional layer in contact with the polishing layer. Preferably, the chemical mechanical polishing pad optionally further comprises a compressible subpad or base layer attached to the polishing layer. The compressible base layer preferably improves the conformability of the polishing layer to the surface of the substrate being polished.

[0061] The CMP polishing layer of the chemical mechanical polishing pad of the present invention has a polishing surface adapted for polishing a substrate. Preferably, the polishing surface has a macrotexture selected from at least one of perforations and grooves. The perforations can extend partially from the polishing surface or through the entire thickness of the polishing layer.

[0062] Preferably, the grooves are arranged in the polishing surface such that upon rotation of the chemical mechanical polishing pad during polishing, at least one groove sweeps over the surface of the substrate being polished.

[0063] Preferably, the CMP polishing layer of the chemical mechanical polishing pad of the present invention has a polishing surface adapted for polishing a substrate, the polishing surface having a macrotexture formed thereon, the macrotexture comprising a groove pattern selected from curved grooves, linear grooves, perforations, and combinations thereof. Preferably, the groove pattern comprises a plurality of grooves. More preferably, the groove pattern is selected from groove designs such as concentric grooves (which may be circular or spiral), curved grooves, linear grooves, crosshatch grooves (e.g., arranged as an XY grid across the pad surface), other regular designs (e.g., hexagonal, triangular), tire tread patterns, radial irregular designs (e.g., fractal patterns), and combinations thereof. More preferably, the groove design is selected from the group consisting of random grooves, concentric grooves, spiral grooves, crosshatch grooves, XY grid grooves, hexagonal grooves, triangular grooves, fractal grooves, and combinations thereof. The groove profile is preferably selected from a rectangular shape with flat sidewalls, or the groove cross section may be "V" shaped, "U" shaped, sawtooth and combinations thereof.

[0064] The method for making a CMP polishing pad according to the present invention allows for the creation of a macro-texture or groove pattern in the polishing surface of a chemical mechanical polishing pad to promote slurry flow and removal of polishing debris from the pad-wafer interface. Such grooves may be formed in the polishing surface of the polishing pad from the shape of a mold surface, i.e., the mold has a negative shaped version of the macro-texture.

[0065] The chemical mechanical polishing pad of the present invention can be used to polish a substrate selected from at least one of a magnetic substrate, an optical substrate, and a semiconductor substrate.

[0066] Preferably, the method of polishing a substrate of the present invention comprises the steps of providing a substrate selected from at least one of a magnetic substrate, an optical substrate, and a semiconductor substrate (preferably a semiconductor substrate, e.g., a semiconductor wafer), providing a chemical mechanical polishing pad according to the present invention, generating dynamic contact between the polishing surface of the polishing layer and the substrate to polish the surface of the substrate, and conditioning the polishing surface with an abrasive conditioner.

[0067] Conditioning a polishing pad involves contacting a conditioning disk with the polishing surface during intermittent interruptions of the CMP process when polishing is paused ("ex situ"), or while the CMP process is ongoing ("in situ"). The conditioning disk typically has a rough conditioning surface consisting of embedded diamond points that cut fine grooves into the pad surface, both abrading and digging into the pad material, renewing the polishing texture. Typically, the conditioning disk rotates in a fixed position relative to the axis of rotation of the polishing pad, sweeping an annular conditioning area as the polishing pad rotates.

[0068] EXAMPLES: The invention will now be described in detail in the following non-limiting examples. Unless otherwise stated, all temperatures are at room temperature (21-23°C) and all pressures are atmospheric (approximately 760 mmHg or 101 kPa).

[0069] Notwithstanding other ingredients disclosed below, the following ingredients were used in the examples: Ethacure™ 300 Curing Agent: Dimethylthiotoluenediamine (DMTDA), an aromatic diamine (Albemarle, Charlotte, NC).

[0070] Voranol™ V 5055 HH Polyol: Multifunctional polyether polyol (OH equivalent weight 2000), functionality = 6, number average molecular weight M of 12,000 NA high molecular weight ethylene oxide-capped propylene oxide polyol having the formula:

[0071] MDI Prepolymer: A linear isocyanate-terminated urethane prepolymer derived from MDI and low molecular weight dipropylene glycol (DPG) and tripropylene glycol (TPG), with an NCO content of approximately 23 wt% and an equivalent weight of 182. 100 wt% of this MDI prepolymer is considered to be the hard segment.

[0072] Niax™ L5345 surfactant: a nonionic organosilicon surfactant (Momentive, Columbus, OH).

[0073] DABCO 33 LV: An amine catalyst made from diazobicyclononane (triethylenediamine), DABCO 33 LV (Air Products, Allentown, PA) is a blend of 33 wt% triethylenediamine and 67 wt% dipropylene glycol.

[0074] Unilink™ 4200 hardener: N,N′-dialkylamino-diphenylmethane (Dorf Ketal, Stafford, TX)

[0075] PTMEG####: Poly(THF) or polytetramethylene glycol, made via ring-opening polymerization of tetrahydrofuran (THF) and sold as PolyTHF™ polyol (BASF, Leverkusen, Germany). The number following PTMEG is the average molecular weight as reported by the manufacturer. DPG: Dipropylene glycol BDO: 1,4-butanediol

[0076] PG: Monopropylene glycol (a product of Dow).

[0077] AOX 1: Benzofuranone compound, antioxidant (Milliken's product Milliguard AOX-1).

[0078] INT1940: Fatty acid surfactant (Mold Wiz INT-1940 RTM product from Axel Plastics). The characteristics of the CMP polishing pad were evaluated according to the following methods.

[0079] All tensile properties were measured in accordance with ASTM D412-06a, "Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers—Tension." Samples were cut to dog-bone C-shape dimensions. Unless otherwise noted, five specimens were measured, and the average of all specimens was reported for each specimen sample.

[0080] Tensile elongation at break: refers to the ratio of the changed length of the test specimen after break to its original length, and is tested in accordance with ASTM D412-06a(2006),"Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers - Tension."

[0081] In all of the following examples, the indicated two-component reaction mixture was mixed and sprayed onto an open mold using an impingement-type mixing air spray system with two tanks (an isotank and a polytank) to feed the mixing system. The two tanks were set at given material flow rates, allowing the relative amounts of each of the two components to be readily determined. The flows from the two tanks were started and stopped simultaneously. CMP polishing pads according to both the present invention and the comparative examples were formed as follows.

[0082] Comparative Example 1: Plate and Pad: In a mixing cup, 39 parts (97.50 g, 0.0513 equivalent moles) of ethylene oxide-capped propylene oxide polyol with functionality = 6 and equivalent weight = 1900 (Dow's Voranol™ 5055HH product) were combined with 1 part (2.50 g) of Niax™ L 5345 surfactant, 15.47 parts (38.68 g, 0.3615 moles) of Ethacure™ 300 liquid aromatic diamine, and 1.92 parts (4.80 g, 0.155 equivalent moles) of monoethylene glycol. To this degassed mixture, 42.608 parts (106.52 g, 0.5852 equivalent moles) of MDI prepolymer was added. The mixture was then vortex mixed for 30 seconds, then poured into a mold to form a slab, and cured at 100°C for 16 hours. The reaction mixture had a hard segment weight fraction of 60%, a stoichiometry of 95% (0.95:1), and contained 15.47% liquid aromatic diamine. The molar ratio of the liquid aromatic diamine to the total moles of diamine and polyol in the curing agent mixture was 70%. After curing, a plaque with a density of 1.16 g / mL exhibited a tensile modulus of 579 MPa (84,000 psi), a tensile strength of 40.7 MPa (5,900 psi), and a tensile elongation at break of 175%.

[0083] The reaction mixture was sprayed into an open mold using a two-component impingement-type air atomization system. The isotank was charged with MDI prepolymer, while a poly tank was charged with 67.60 parts (47.32 lbs) of Voranol™ 5055HH, 3.33 parts (2.33 lbs) of monoethylene glycol, 1.73 parts (1.21 lbs) of Niax™ L5345, and 26.81 parts (18.77 lbs) of Ethacure™ 300 in the same ratios used in the slab processing described above. The flow rates during spraying were 9.49 g / sec on the polyol side and 7.01 g / sec on the iso side. The air injected into the nozzle was set at a nominal rate of 100 L / min. The sprayed polyurethane formulation was directed into a mold with a channel shape. The sprayed pads were cured in a 100°C oven for 15 minutes, then removed from the mold and cured in a 100°C oven for 16 hours. The resulting pads contained both radial and concentric grooves. The resulting pads produced exhibited an average density of 0.762 g / mL, a bulk tensile modulus of 251.6 MPa (36,500 psi), a tensile strength of 15.2 MPa (2,200 psi), and a tensile elongation of 65%.

[0084] Example 2: Plates and Pads In a mixing cup, 39.6 parts (99.0 g, 0.0521 equivalent moles) of ethylene oxide-capped propylene oxide polyol with functionality = 6 and equivalent weight = 1900 (Dow's Voranol™ 5055HH product) were combined with 1 part (2.50 g) of Niax™ L5345 surfactant, 8.33 parts (20.82 g, 0.1946 equivalent moles) of Ethacure™ 300, and 4.48 parts (11.20 g, 0.3613 equivalent moles) of monoethylene glycol. To this degassed mixture, 46.59 parts (116.48 g, 0.640 equivalent moles) of MDI prepolymer was added. The mixture was then vortex mixed for 20 seconds, poured into molds to form slabs, and cured at 100°C for 16 hours. The formulation is described as having a hard segment weight fraction of 60%, a stoichiometry of 95%, and containing 8.33% Ethacure™ 300. The molar ratio of the liquid aromatic diamine to the total moles of diamine and polyol in the curing agent mixture is 35%. After curing, a plaque with a density of 1.16 g / mL exhibited a tensile modulus of 411 MPa (59,600 psi), a tensile strength of 29.0 MPa (4200 psi), and a tensile elongation of 169%.

[0085] The reaction mixture was sprayed into an open mold using a two-component impingement-type air atomization system. The isotank was charged with MDI prepolymer, while a poly tank was charged with 73.75 parts (58.26 lbs) of Voranol™ 5055HH, 8.34 parts (6.59 lbs) of monoethylene glycol, 1.84 parts (1.461 lbs) of Niax™ L5345, and 15.51 parts (12.25 lbs) of Ethacure™ 300 in the same ratios used in the slab processing described above. The flow rates during spraying were 9.10 g / sec on the polyol side and 7.90 g / sec on the iso side. The air injected into the nozzle was set at a nominal rate of 100 L / min. The sprayed polyurethane formulation was directed into a mold with a channel shape. The sprayed pads were cured in a 100°C oven for 15 minutes, then removed from the mold and cured in a 100°C oven for 16 hours. The resulting pads contained both radial and concentric grooves. The resulting pads produced exhibited an average density of 0.813 g / mL, a 15-second Shore D hardness of 57, a bulk tensile modulus of 291.0 MPa (42,200 psi), a tensile strength of 17.9 MPa (2,600 psi), and a tensile elongation of 116%.

[0086] Comparative Example 3: Plate and Pad A blend of equal parts by weight of poly(tetramethylene glycol) (PTMEG) 650, PTMEG 1000, and PTMEG 2000 was prepared. 34.65 parts (86.63 g, 0.1754 equivalent moles) of this blend was combined in a mixing cup with 1 part (2.50 g) of Niax™ L5345 surfactant and 18.24 parts (45.60 g, 0.4262 equivalent moles) of Ethacure™ 300. 46.11 parts (115.27 g, 0.6334 equivalent moles) of MDI prepolymer was added to the degassed mixture. The mixture was then vortex mixed for 20 seconds and then poured into molds to form slabs and cured at 100°C for 16 hours. The formulation is described as having a hard segment weight fraction of 65%, a stoichiometry of 95%, and containing 18.24 wt% Ethacure™ 300. The molar ratio of the liquid aromatic diamine to the total moles of diamine and polyol in the curing agent mixture is 100%. After curing, a plaque with a density of 1.16 g / mL exhibited a 15-second Shore D hardness of 71, a tensile modulus of 554.3 MPa (80,400 psi), a tensile strength of 46.88 MPa (6,800 psi), and a tensile elongation of 220%.

[0087] The reaction mixture was sprayed into an open mold using a two-component impingement-type air atomization system. The isotank was charged with MDI prepolymer, while a poly tank was charged with 20.457 parts (12.60 lbs) of PTMEG 650, 20.457 parts (12.60 lbs) of PTMEG 1000, 20.457 parts (12.60 lbs) of PTMEG 2000, 1.548 parts (0.954 lbs) of Niax L5345, and 36.616 parts (22.55 lbs) of Ethacure 300 in the same ratios used in the slab processing described above. The flow rates during spraying were 9.59 g / sec on the polyol side and 7.41 g / sec on the iso side. The air injected into the nozzle was set at a nominal rate of 100 L / min. The sprayed polyurethane formulation was directed into a mold with a channel shape. The sprayed pads were cured in an oven at 100°C for 16 hours. The resulting pads contained both radial and concentric grooves. The resulting pads exhibited an average density of 0.791 g / mL, a 15-second Shore D hardness of 56, a bulk tensile modulus of 277 MPa (40,200 psi), a tensile strength of 17.9 MPa (2,600 psi), and a tensile elongation of 112%.

[0088] Comparative Example 4: Plate and Pad A blend of equal parts by weight of poly(tetramethylene glycol) (PTMEG) 650, PTMEG 1000, and PTMEG 2000 was prepared. In a mixing cup, 34.65 parts (86.63 g, 0.1754 equivalent moles) of this blend were combined with 1 part (2.50 g) of Niax™ L5345 surfactant, 10.45 parts (26.128 g, 0.2442 equivalent moles) of Ethacure™ 300, and 3.02 parts (7.57 g, 0.2442 equivalent moles) of monoethylene glycol. To this degassed mixture, 50.87 parts (127.18 g, 0.6988 equivalent moles) of MDI prepolymer was added. The mixture was then vortex mixed for 20 seconds and then poured into molds to form slabs and cured at 100°C for 16 hours. The formulation is described as having a hard segment weight fraction of 65%, a stoichiometry of 95%, and containing 10.45 wt% Ethacure™ 300. The molar ratio of the liquid aromatic diamine to the total moles of diamine and polyol in the curing agent mixture is 50%. After curing, plaques with a density of 1.16 g / mL exhibited a 15-second Shore D hardness of 67, a tensile modulus of 467.5 MPa (67,800 psi), a tensile strength of 40.0 MPa (5,800 psi), and a tensile elongation of 230%.

[0089] The reaction mixture was sprayed into an open mold using a two-component impingement-type air atomization system. The isotank was charged with MDI prepolymer, while a poly tank was charged with 22.62 parts (16.92 lbs) of PTMEG 650, 22.62 parts (16.92 lbs) of PTMEG 1000, 22.62 parts (16.92 lbs) of PTMEG 2000, 1.712 parts (1.281 lbs) of Niax™ L5345, 6.72 parts (5.025 lbs) of monoethylene glycol, and 23.195 parts (17.35 lbs) of Ethacure™ 300 in the same ratios used in the slab processing described above. The flow rates during spraying were 8.67 g / sec on the polyol side and 8.33 g / sec on the iso side. The air injected into the nozzle was set at a nominal rate of 100 L / min. The sprayed polyurethane formulation was introduced into a mold containing grooves. The sprayed pads were cured in an oven at 100°C for 16 hours. The resulting pads contained both radial and concentric grooves. The resulting pads produced exhibited an average density of 0.848 g / mL, a 15-second Shore D hardness of 58, a bulk tensile modulus of 324.0 MPa (47,000 psi), a tensile strength of 19.3 MPa (2,800 psi), and a tensile elongation of 197%.

[0090] Example 5: Plates and Pads A blend of equal parts by weight of poly(tetramethylene glycol) (PTMEG) 650, PTMEG 1000, and PTMEG 2000 was prepared. 34.65 parts (86.63 g, 0.1754 equivalent moles) of this blend was combined in a mixing cup with 1 part (2.50 g) of Niax™ L5345 surfactant, 7.65 parts (19.13 g, 0.179 equivalent moles) of Ethacure™ 300, and 4.11 parts (10.29 g, 0.332 equivalent moles) of monoethylene glycol. 52.58 parts (131.46 g, 0.722 equivalent moles) of MDI prepolymer was added to the degassed mixture. The mixture was then vortex mixed for 20 seconds and then poured into molds to form slabs and cured at 100°C for 16 hours. The formulation is described as having a hard segment weight fraction of 65%, a stoichiometry of 95%, and containing 7.65 wt% Ethacure™ 300. The molar ratio of the liquid aromatic diamine to the total moles of diamine and polyol in the curing agent mixture is 35%. After curing, plaques with a density of 1.16 g / mL exhibited a 15-second Shore D hardness of 66, a tensile modulus of 411.6 MPa (59,700 psi), a tensile strength of 39.3 MPa (5,700 psi), and a tensile elongation of 290%.

[0091] The reaction mixture was sprayed into an open mold using a two-component impingement-type air atomization system. An isotank was charged with MDI prepolymer, and a poly tank was simultaneously charged with 24.22 parts (13.92 pounds) of PTMEG 650, 24.22 parts (13.92 pounds) of PTMEG 1000, 24.22 parts (13.92 pounds) of PTMEG 2000, 2.10 parts (1.20 pounds) of Niax™ L5345, 8.63 parts (4.96 pounds) of monoethylene glycol, 16.05 parts (9.225 pounds) of Ethacure™ 300, 0.43 parts (0.246 pounds) of DABCO™ 33-LV catalyst, and 0.142 parts (0.082 pounds) of bismuth neodecanoate catalyst in the same ratios used in the plaque formation process. The flow rates during spraying were 8.98 g / sec on the polyol side and 10.02 g / sec on the iso side. Air injected into the nozzle was set at a nominal rate of 100 L / min. The sprayed polyurethane formulation was directed into a mold containing grooves. The sprayed pads were cured in an oven at 100°C for 16 hours. The resulting pads contained both radial and concentric grooves. The resulting pads produced exhibited an average density of 0.650 g / mL, a 15-second Shore D hardness of 47.6, a bulk tensile modulus of 226.8 MPa (32,900 psi), a tensile strength of 18.6 MPa (2,700 psi), and a tensile elongation of 190%.

[0092] Example 6: Pad The reaction mixture was sprayed into an open mold using a two-component impingement-type air atomization system. The MDI prepolymer was charged to an isotank, and simultaneously, a poly tank was charged with 25.13 parts (17.97 lbs) of PTMEG 650, 25.13 parts (17.97 lbs) of PTMEG 1000, 25.13 parts (17.97 lbs) of PTMEG 2000, 1.90 parts (1.36 lbs) of Niax™ L5345, 4.988 parts (3.57 lbs) of monoethylene glycol, 17.21 parts (12.31 lbs) of Ethacure™ 300, 0.381 parts (0.273 lbs) of DABCO™ 33-LV catalyst, and 0.127 parts (0.091 lbs) of bismuth neodecanoate catalyst. The flow rates during spraying were 9.90 g / sec on the polyol side and 9.10 g / sec on the iso side. The formulation was described as having a 60% hard segment weight fraction, a 95% stoichiometry, and containing 9.02 wt% Ethacure™ 300. The molar ratio of the liquid aromatic diamine to the total moles of diamine and polyol in the curing agent mixture was 50%. The air injected into the nozzle was set at a nominal rate of 100 L / min. The sprayed polyurethane formulation was directed into a mold with a grooved shape. The sprayed pad was cured in an oven at 100°C for 16 hours. The resulting pad contained both radial and concentric grooves. The resulting pads produced exhibited an average density of 0.704 g / mL, a 15-second Shore D hardness of 40, a bulk tensile modulus of 137.2 MPa (19,900 psi), a tensile strength of 17.9 MPa (2,600 psi), and a tensile elongation of 260%.

[0093] Example 7: Pad The reaction mixture was sprayed into an open mold using a two-component impingement-type air atomization system. The MDI prepolymer was charged into an isotank, and simultaneously, a polyethylene tank was charged with 26.13 parts (21.20 lbs) of PTMEG 650, 26.13 parts (21.20 lbs) of PTMEG 1000, 26.13 parts (21.20 lbs) of PTMEG 2000, 1.98 parts (1.60 lbs) of Niax™ L5345, 7.70 parts (6.25 lbs) of monoethylene glycol, 11.40 parts (9.25 lbs) of Ethacure™ 300, 0.397 parts (0.322 lbs) of DABCO™ 33-LV catalyst, and 0.132 parts (0.107 lbs) of bismuth neodecanoate catalyst. The flow rates during spraying were 9.52 g / sec on the polyol side and 9.48 g / sec on the iso side. The formulation was described as having a 60% hard segment weight fraction, a 95% stoichiometry, and containing 5.75 wt% Ethacure™ 300. The molar ratio of the liquid aromatic diamine to the total moles of diamine and polyol in the curing agent mixture was 30%. The air injected into the nozzle was set at a nominal rate of 100 L / min. The sprayed polyurethane formulation was directed into a mold with a grooved shape. The sprayed pad was cured in an oven at 100°C for 16 hours. The resulting pad contained both radial and concentric grooves. The resulting pads produced exhibited an average density of 0.711 g / mL, a 15-second Shore D hardness of 39, a bulk tensile modulus of 117.9 MPa (17,100 psi), a tensile strength of 16.5 MPa (2,400 psi), and a tensile elongation of 260%.

[0094] Comparative Example 8: Pad The reaction mixture was sprayed into an open mold using a two-component impingement-type air atomization system. The isotank was charged with MDI prepolymer, while a poly tank was charged with 87.99 parts (61.593 lbs) of PolyTHF650, 0.88 parts (0.616 lbs) of Niax™ L5345 nonionic surfactant, 0.088 parts (0.062 lbs) of Niax™ T-9 catalyst, 0.2642 parts (0.185 lbs) of DABCO™ 33LV, and 0.22 parts (0.154 lbs) of water and 10.557 parts (7.39 lbs) of dipropylene glycol. The flow rates during spraying were 9.10 g / sec on the polyol side and 9.90 g / sec on the isoside side. The air injected into the nozzle was set at a nominal rate of 100 L / min. The sprayed polyurethane formulation was directed onto a Teflon-coated aluminum plate. The sprayed pads were cured in an oven at 100° C. for 16 hours. The resulting pads were described as having a 52.5% hard segment weight fraction at 95% stoichiometry, and the addition of 2500 ppm water produced pads with a bulk density of 0.53 g / mL, a bulk tensile modulus of 1.2 MPa (170 psi), a tensile strength of 6.0 MPa (870 psi), and a tensile elongation of 535%, with a 15-second Shore A hardness of 27.

[0095] Comparative Example 9: A commercially available IC1000 polishing pad (Dow) with the same K7R32 groove pattern and the same SUBA™ IV subpad (Dow) used in other polishing experiments. The density was 0.77 g / mL and the tensile modulus was 260 MPa (37,700 psi).

[0096] Example 10: Pad The reaction mixture was sprayed into an open mold using a two-component impingement-type air atomization system. The isotank was charged with MDI prepolymer, while a poly tank was charged with 84.85 parts PTMEG1000, 3.48 parts INT1940, 0.24 parts AOX1, 4.46 parts monoethylene glycol, 6.59 parts Ethacure™ 300, and 0.38 parts bismuth octoate catalyst. The flow rates during spraying were 4.6 g / sec on the polyol side and 3.4 g / sec on the isoside side. The formulation is described as having a 50% hard segment weight fraction, a 95% stoichiometry, and containing 3.79 wt% Ethacure™ 300. The molar ratio of liquid aromatic diamine to total moles of diamine and polyol in the curing agent mixture was 30%. The air injected into the nozzle was set at a nominal rate of 100 L / min. The sprayed polyurethane formulation was introduced into a mold containing grooves. The sprayed pads were cured in an oven at 100°C for 16 hours. The resulting pads contained both radial and concentric grooves. The resulting pads produced exhibited an average density of 0.68 g / mL, a 15-second Shore hardness DO of 32, a bulk tensile modulus of 4 MPa (600 psi), a tensile strength of 11 MPa (1500 psi), and a tensile elongation of 550%.

[0097] Example 11: Pad The reaction mixture was sprayed into an open mold using a two-component impingement-type air atomization system. The isotank was charged with MDI prepolymer, while a poly tank was charged with 81.96 parts PTMEG1000, 3.65 parts INT1940, 0.26 parts AOX1, 5.54 parts monoethylene glycol, 8.2 parts Ethacure™ 300, and 0.4 parts bismuth octoate catalyst. The flow rates during spraying were 4.6 g / sec on the polyol side and 3.8 g / sec on the isoside side. The formulation is described as having a 54% hard segment weight fraction, a 95% stoichiometry, and containing 4.49 wt% Ethacure™ 300. The molar ratio of liquid aromatic diamine to total moles of diamine and polyol in the curing agent mixture was 30%. The air injected into the nozzle was set at a nominal rate of 100 L / min. The sprayed polyurethane formulation was introduced into a mold containing grooves. The sprayed pads were cured in an oven at 100°C for 16 hours. The resulting pads contained both radial and concentric grooves. The resulting pads produced exhibited an average density of 0.70 g / mL, a 15-second Shore hardness DO of 49, a bulk tensile modulus of 12 MPa (1700 psi), a tensile strength of 15 MPa (2100 psi), and a tensile elongation of 500%.

[0098] Example 12: Pad The reaction mixture was sprayed into an open mold using a two-component impingement-type air atomization system. The isotank was charged with MDI prepolymer, while a poly tank was charged with 79.8 parts PTMEG1000, 3.55 parts INT1940, 0.25 parts AOX1, 6.46 parts monoethylene glycol, 9.55 parts Ethacure™ 300, and 0.39 parts bismuth octoate catalyst. The flow rates during spraying were 4.6 g / sec on the polyol side and 3.6 g / sec on the isoside side. The formulation is described as having a 54% hard segment weight fraction, a 110% stoichiometry, and containing 5.38 wt% Ethacure™ 300. The molar ratio of liquid aromatic diamine to total moles of diamine and polyol in the curing agent mixture was 30%. The air injected into the nozzle was set at a nominal rate of 100 L / min. The sprayed polyurethane formulation was introduced into a mold containing grooves. The sprayed pads were cured in an oven at 100°C for 16 hours. The resulting pads contained both radial and concentric grooves. The resulting pads produced exhibited an average density of 0.73 g / mL, a 15-second Shore hardness DO of 43, a bulk tensile modulus of 8 MPa (1200 psi), a tensile strength of 8 MPa (1200 psi), and a tensile elongation of 530%.

[0099] Example 13: Pad The reaction mixture was sprayed into an open mold using a two-component impingement-type air atomization system. The isotank was charged with MDI prepolymer, while a poly tank was charged with 77.32 parts PTMEG1000, 3.68 parts INT1940, 0.26 parts AOX1, 7.39 parts monoethylene glycol, 10.94 parts Ethacure™ 300, and 0.41 parts bismuth octoate catalyst. The flow rates during spraying were 4.6 g / sec on the polyol side and 3.9 g / sec on the isoside side. The formulation is described as having a 57% hard segment weight fraction, a 110% stoichiometry, and containing 5.94 wt% Ethacure™ 300. The molar ratio of liquid aromatic diamine to total moles of diamine and polyol in the curing agent mixture was 30%. The air injected into the nozzle was set at a nominal rate of 100 L / min. The sprayed polyurethane formulation was introduced into a mold containing grooves. The sprayed pads were cured in an oven at 100°C for 16 hours. The resulting pads contained both radial and concentric grooves. The resulting pads produced exhibited an average density of 0.74 g / mL, a 15-second Shore hardness DO of 56, a bulk tensile modulus of 21 MPa (3100 psi), a tensile strength of 3 MPa (500 psi), and a tensile elongation of 85%.

[0100] Example 14: Pad The reaction mixture was sprayed into an open mold using a two-component impingement-type air spray system. The isotank was charged with MDI prepolymer, while a poly tank was charged with 24.6 parts PTMEG 650, 24.6 parts PTMEG 1000, 24.6 parts PTMEG 2000, 1.87 parts Niax™ L5345, 14.23 parts dipropylene glycol, 9.73 parts Ethacure™ 300, and 0.37 parts bismuth neodecanoate catalyst. The flow rates during spraying were 10.4 g / s on the polyol side and 9.1 g / s on the isoside side. The formulation is described as having a 60% hard segment weight fraction, a 95% stoichiometry, and containing 5.21 wt% Ethacure™ 300. The molar ratio of the liquid aromatic diamine to the total moles of diamine and polyol in the curing agent mixture was 30%. The air injected into the nozzle was set at a nominal rate of 100 L / min. The sprayed polyurethane formulation was directed into a mold containing a groove pattern. The sprayed pad was cured in a 100°C oven for 16 hours. The resulting pad contained both radial and concentric grooves. The resulting pad produced exhibited an average density of 0.45 g / mL, a 15-second Shore D hardness of 14, a bulk tensile modulus of 27 MPa (3900 psi), a tensile strength of 7 MPa (1100 psi), and a tensile elongation of 300%.

[0101] Example 15: Pad The reaction mixture was sprayed into an open mold using a two-component impingement-type air spray system. The isotank was charged with MDI prepolymer, while a poly tank was charged with 25.49 parts PTMEG 650, 25.49 parts PTMEG 1000, 25.49 parts PTMEG 2000, 1.94 parts Niax™ L5345, 10.51 parts 1,4-butanediol, 10.7 parts Ethacure™ 300, and 0.39 parts bismuth neodecanoate catalyst. The flow rates during spraying were 10.1 g / s on the polyol side and 9.4 g / s on the iso side. The formulation is described as having a 60% hard segment weight fraction, a 95% stoichiometry, and containing 5.53 wt% Ethacure™ 300. The molar ratio of the liquid aromatic diamine to the total moles of diamine and polyol in the curing agent mixture was 30%. The air injected into the nozzle was set at a nominal rate of 100 L / min. The sprayed polyurethane formulation was directed into a mold with a grooved shape. The sprayed pad was cured in an oven at 100°C for 16 hours. The resulting pad contained both radial and concentric grooves. The resulting pad produced exhibited an average density of 0.66 g / mL, a 15-second Shore D hardness of 29, a bulk tensile modulus of 64 MPa (9300 psi), a tensile strength of 13 MPa (1900 psi), and a tensile elongation of 260%.

[0102] Example 16: Pad The reaction mixture was sprayed into an open mold using a two-component impingement-type air atomization system. The isotank was charged with the MDI prepolymer, while a poly tank was charged with 80.26 parts PTMEG 1000, 1.91 parts Niax™ L5345, 8.01 parts propylene glycol, 9.54 parts Ethacure™ 300, and 0.28 parts bismuth neodecanoate catalyst. The flow rates during spraying were 11.1 g / sec on the polyol side and 9.9 g / sec on the isoside side. The formulation is described as having a 57% hard segment weight fraction, a 95% stoichiometry, and containing 5.05 wt% Ethacure™ 300. The molar ratio of the liquid aromatic diamine to the total moles of diamine and polyol in the curing agent mixture was 30%. The air injected into the nozzle was set at a nominal rate of 100 L / min. The sprayed polyurethane formulation was introduced into a mold containing grooves. The sprayed pads were cured in an oven at 100°C for 16 hours. The resulting pads contained both radial and concentric grooves. The resulting pads produced exhibited an average density of 0.69 g / mL, a 15-second Shore D hardness of 36, a bulk tensile modulus of 81 MPa (11,700 psi), a tensile strength of 16 MPa (2,300 psi), and a tensile elongation of 280%.

[0103] The material and pad properties of the above examples are reported below in Table 1. The pads made in the above examples were tested for abrasion as described in the test methods below, and the results are reported below in Tables 1 and 2, respectively.

[0104] The CMP polishing pad was manufactured by lathe-machining the backside of the polishing layer indicated in the above example flat to provide a flat polishing pad. The polishing pad was then bonded to a SUBA™ IV subpad (Dow) via a pressure-sensitive adhesive. The final laminated pad had a diameter of 0.508 meters (20 inches), a polishing layer nominally 2.03 mm (80 mil) thick, and a groove pattern in which the grooves had a width of 0.508 mm (20 mil), a depth of 0.762 mm (30 mil), and a pitch of 1.78 mm (70 mil). The groove pattern included a concentric groove pattern with 32 radial grooves and 20 mil wide grooves. Polishing experiments were performed on 200 mm wafers on an Applied Mirra polisher (Applied Materials, Santa Clara, CA) using carrier downforces of 0.014, 0.016, 0.021, and 0.026 MPa (2.0, 2.3, 3.0, and 3.8 psi), a slurry flow rate of 200 mL / min, and Klebosol™ II 1730 colloidal silica slurry (Dow, 16 wt.% solids), a table rotation speed of 93 rpm, and a carrier rotation speed of 87 rpm. The polishing pads of Examples 1-9, 14, and 15 were conditioned and textured using a 3M™ Diamond Pad Conditioner A 153 L, 4.25 inch diameter, with an aggressiveness rating of 6-9 (The 3M Company, Minneapolis, MN). The polishing pads of Example 16 were conditioned and textured using Saesol Diamond Pad Conditioner AK 45 (Saesol™ AM 02 BSL 8031 ​​C 1). The polishing pads of Examples 10-13 were conditioned and textured using Saesol Diamond Pad Conditioner AD45 (Saesol™ AM02BSL8031E7). Each polishing pad was run in the conditioner and DI water for 30 minutes using only a typical downforce, e.g., 22.2 N or 31.1 N.The polishing pad was further conditioned in situ at 100% while polishing from 1.7 to 9.2 inches from the center of the pad at 22.2 N downforce at 10 sweeps / min. The wafer was cleaned with an OnTrack DSS-200 Synergy Post CMP. To further highlight the shallow scratches, an HF etch was performed in an SSEC single-wafer etch system, resulting in 200 Å of TEOS being etched from the wafer. Step height measurements for planarization were performed with a Bruker Dynamic Atomic Force Profiler (Bruker, Billerica, MA). The substrate was a tetraethoxysilicate (TEOS) wafer substrate. Removal rates were determined by measuring film thickness before and after polishing with a 3 mm edge exclusion zone using a KLA-Tencor FX200™ metrology tool (KLA Tencor, Milpitas, CA) using a 49-point spiral scan. The removal rate, in Å / min, was calculated by the change in thickness at each point for a specified polishing time. The non-uniformity rate (%NUR) was calculated by the % standard deviation of the removal rate.

[0105] [Table 1]

[0106] [Table 2]

[0107] As shown in Tables 1 and 2 above, the CMP polishing pad of the present invention exhibits improved planarization efficiency, even when compared to the commercially available CMP polishing pad of Comparative Example 10. At the same time, the removal rate and % non-uniformity were the same or similar to those produced by the IC 1000 pad (Dow) of Comparative Example 10. Furthermore, the performance of the CMP polishing pad of the present invention was significantly better than the pad from the liquid aromatic diamine curing agent of Comparative Example 3 and the pad from the 70% liquid aromatic diamine in the curing agent mixture as in Comparative Example 1.

Claims

1. 1. A chemical mechanical polishing (CMP) pad for polishing a substrate selected from at least one of a magnetic substrate, an optical substrate, and a semiconductor substrate, comprising: the CMP polishing pad comprises a polishing layer adapted for polishing the substrate; the polishing layer is polyurethane; The polyurethane is (i) a liquid aromatic isocyanate component comprising one or more aromatic diisocyanates or linear aromatic isocyanate-terminated urethane prepolymers having an unreacted isocyanate (NCO) concentration of 20 to 40 weight percent based on the total solids weight of the liquid aromatic isocyanate component; (ii) A liquid polyol component comprising: a) one or more polymer polyols; b) 12 to 40 wt. % based on the total weight of the liquid polyol component; one or more short chain difunctional polyols having 2 to 9 carbon atoms, and a curing agent mixture of a liquid aromatic diamine that is liquid under ambient conditions; a liquid polyol component comprising: and the molar ratio of the liquid aromatic diamine to the total number of moles of the short-chain difunctional polyol and the liquid aromatic diamine is in the range of 15:85 to 40:60; the reaction mixture comprises 48 to 68 wt. % of a hard segment material based on the total weight of the reaction mixture; Furthermore, the CMP polishing pad, wherein the polishing layer has a hardness of 50 Shore A (15 seconds) or more, a hardness of 68 Shore D (15 seconds) or less, and a density of 0.45 to 0.9 g / mL.

2. 2. The CMP polishing pad of claim 1, wherein the (i) liquid aromatic isocyanate component comprises a linear methylene diphenyl diisocyanate (MDI) prepolymer or MDI, and the one or more short-chain difunctional polyols having 2 to 9 carbon atoms in the b) curing agent mixture of the (ii) liquid polyol component are selected from the group consisting of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, tripropylene glycol, and mixtures thereof.

3. 2. The CMP polishing pad according to claim 1, wherein in the b) curing agent mixture, the molar ratio of the liquid aromatic diamine to the total number of moles of the short-chain difunctional polyol and the liquid aromatic diamine is in the range of 23:77 to 35:65.

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