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

Abstract

A CMP polishing pad or layer made from the polyurethane reaction product of a reaction mixture comprising: (i) a liquid aromatic isocyanate component comprising one or more aromatic diisocyanates or linear aromatic isocyanate-terminated urethane prepolymers, and (ii) a liquid polyol component comprising a) one or more polymer polyols, b) 12 wt.% to 40 wt.% of a curing agent mixture of one or more small-chain difunctional polyols having 2 to 9 carbon atoms, liquid aromatic diamines, based on the total weight of the liquid polyol component, wherein the molar ratio of the liquid aromatic diamine to the total molar number of the small-chain difunctional polyols and the liquid aromatic diamines is 15:85 to 40:60, wherein the reaction mixture comprises 48 wt.% to 68 wt.% of a hard segment material.

Description

[0001] The present invention relates to chemical mechanical planarization polishing (CMP polishing) pads and methods for making the same. More particularly, the present invention relates to CMP polishing pads that are polyurethane reaction products of a two-component reaction mixture comprising a liquid aromatic diisocyanate component and a liquid polyol component, the liquid polyol component comprising a monoalkylene glycol such as ethylene glycol and a liquid aromatic diamine curing agent.

[0002] In the CMP process, the 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 in a manner that flattens or maintains flatness of a semiconductor, optical or magnetic substrate. There is a continuous need for a CMP polishing pad with increased layer uniformity or flattening performance combined with an acceptable removal rate. However, there is still a performance tradeoff between flattening efficiency (PE) and defect rate in the industry, where a larger PE leads to more defects. Known CMP polishing pads are formed from a reaction mixture containing an aromatic diamine as a curing agent. A higher concentration of aromatic diamines imparts faster reaction times and better mechanical properties, like high tensile strength and high tensile modulus. However, although such CMP polishing pads with high tensile modulus and hardness can give good flattening efficiency, there is still a tradeoff of increased defects caused in polishing.

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

[0004] Barton et al., U.S. Patent Publication No. 20180148537, discloses a CMP polishing pad made by reacting a liquid aromatic isocyanate compound with a liquid polyol using a curing agent of one or more polyamines or diamines. However, this reference fails to recognize the critical extent to which blending a short-chain polyol with a diamine affects the resulting polishing pad in terms of planarization efficiency.

[0005] The present inventors have sought to solve the problem of providing a more flexible formulation window for making chemical mechanical polishing layers or pads that can be used to polish dielectric and silicon oxide substrates, and maintain good removal rate and planarization efficiency (PE) performance without undesirably increasing defectivity and hardness. Summary of the invention

[0006] 1. According to 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 to polish the substrate, the substrate comprising a polyurethane reaction product of a two-component reaction mixture substantially free of water and free of organic solvents, the two-component reaction mixture comprising (i) a liquid aromatic isocyanate component comprising one or more aromatic diisocyanates or linear aromatic isocyanate-terminated urethane prepolymers, preferably linear methylene diphenyl diisocyanate (MDI) prepolymers, having a solid weight of 20 wt.% to 40 wt.%, or preferably 18 wt.% to 34 wt.%, based on the total solid weight of the liquid aromatic isocyanate component. % unreacted isocyanate (NCO) concentration, and (ii) a liquid polyol component comprising a) one or more polymer polyols such as polytetramethylene glycol (PTMEG), polypropylene glycol (PPG), a polyol having 5 to 7 hydroxyl groups such as a hexafunctional polyol, or a mixture thereof, b) 12 wt. % to 40 wt. %, or preferably 15 wt. % to 25 wt. % of one or more small-chain difunctional polyols having 2 to 9 carbon atoms (such as, for example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2-methyl-1,3-propanediol, 1,4-butylene glycol, neopentyl glycol, 1 , 5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, tripropylene glycol and mixtures thereof, or preferably ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol and triethylene glycol), a curing agent mixture of a liquid aromatic diamine, which is liquid under ambient conditions, for example any one selected from the group consisting of dimethylthiotoluenediamine; diethyltoluenediamine; tert-butyltoluenediamine, such as 5-tert-butyl-2,4-toluenediamine or 3-tert-butyl-2,6-toluenediamine; chlorotoluenediamine; and N,N'-dialkylaminodiphenylmethane and mixtures thereof, or preferably aminotoluenediamine or dimethylthiotoluenediamine, diethyltoluenediamine (DETDA) and N , N'-dialkylaminodiphenylmethane, wherein the molar ratio of the liquid aromatic diamine to the total moles of the small chain difunctional polyol and the liquid aromatic diamine is 15:85 to 40:60, or preferably 23:77 to 35:65, and further wherein, based on the total weight of the reaction mixture, the reaction mixture contains 48 wt.% to 68 wt.%, or preferably 58 wt.% to 63 wt.% of hard segment material, and further wherein the CMP polishing layer has a hardness of 50 Shore A (15 seconds) to 68 Shore D (15 seconds), or preferably 55 Shore A (15 seconds) to 50 Shore D (15 seconds), and 0.45 to 0.9 g / mL, or preferably 0.60 to 0.85 g / mL density; preferably, even further wherein the CMP polishing layer contains no trace elements other than those formed by gas, water or CO2-amine adducts. .

[0007] 2. According to the present invention, the organic solvent-free reaction mixture for forming a chemical mechanical polishing (CMP polishing) layer as in item 1 above, wherein (i) the liquid aromatic isocyanate component comprises a liquid aromatic isocyanate component selected from the group consisting of methylene diphenyl diisocyanate (MDI); toluene diisocyanate (TDI); naphthalene diisocyanate (NDI); p-phenylene diisocyanate (PPDI); or o-toluidine diisocyanate (TODI); modified diphenylmethane diisocyanate, such as carbodiimide-modified diphenylmethane diisocyanate, allophanate-modified diphenylmethane diisocyanate, biuret-modified diphenylmethane diisocyanate; having 84 wt.% to 1.5 wt.% of the isocyanate; 100 wt.%, or preferably 90 wt.% to 100 wt.% of a linear isocyanate-terminated urethane prepolymer with a hard segment weight fraction, or more preferably MDI, or a linear isocyanate-terminated urethane prepolymer of MDI or MDI dimer and one or more isocyanate extenders selected from the following items: 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, the organic solvent-free reaction mixture for forming a chemical mechanical polishing (CMP polishing) layer as in any one of the above items 1 or 2, wherein ii) b) the curing agent mixture comprises one or more small-chain difunctional polyols having 2 to 9 carbon atoms and a liquid aromatic diamine selected from the group consisting of dimethylthiotoluenediamine, a mixture of isomers of 2,4-diamino-3,5-dimethylthiotoluene and 3,5-dimethylthio-2,4-toluenediamine; diethyltoluene diamine; tert-butyltoluenediamine, such as 5-tert-butyl-2,4-toluenediamine or 3-tert-butyl-2,6-toluenediamine; chlorotoluenediamine; and N,N'-dialkylaminodiphenylmethane and mixtures thereof, or preferably chlorotoluenediamine or dimethylthiotoluenediamine, a 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, a reaction mixture free of organic solvent for forming a chemical mechanical polishing (CMP polishing) layer as in any one of items 1, 2 or 3 above, wherein 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 0.85:1.0 to 1.15:1.0, or preferably 0.9:1.0 to 1.1:1.0.

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

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

[0012] 7. In yet another aspect, the present invention provides a method for making a chemical mechanical (CMP) polishing pad having a polishing layer adapted to polish a substrate, the method comprising providing a two-component reaction mixture as in any one of items 1, 2, 3, 4, 5 or 6 above, which comprises in ii) a liquid polyol component c) water or a CO2-amine adduct (such as a CO2-alkanolamine) sufficient to produce a density of the CMP polishing pad or layer, such as 250 to 3000 ppm, or preferably 500 to 2,000 ppm of water, or 0.05 wt.% to 2 wt.%, or preferably 0.1 wt.% to 1.5 wt.%, based on the total weight of the two-component reaction mixture, such as, for example, in a static mixer or an impingement mixer. The (i) liquid aromatic isocyanate component and the (ii) liquid polyol component are mixed in a mixer, and the reaction mixture is applied as one component to an open mold surface, preferably having a positive topography forming a negative groove pattern in the top surface of a CMP polishing pad or layer, the reaction mixture is cured at ambient temperature to 130° C. to form a molded polyurethane reaction product, for example, initially cured at ambient temperature to 130° C. for a period of 1 to 30 minutes, or preferably 30 seconds to 5 minutes, the polyurethane reaction product is removed from the mold, and then, finally cured at a temperature of 60° C. to 130° C. for a period of 1 minute to 18 hours, or preferably 5 minutes to 60 minutes to form the CMP polishing pad or layer.

[0013] 8. According to the method of the present invention as in item 7 above, the formation of the polishing pad further includes stacking or spraying a subpad layer such as a polymer-impregnated nonwoven, 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 method according to the present invention as in any one of items 7 or 8 above, wherein the method forms the surface of the CMP polishing pad directly in the mold.

[0015] 10. A method according to the present invention as in any one of items 7, 8 or 9 above, wherein applying the reaction mixture as a component comprises overspraying 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. In yet another aspect, the present invention provides a method for polishing a substrate, which comprises: providing a substrate selected from at least one of a magnetic substrate, an optical substrate and a semiconductor substrate, such as a dielectric-containing or silicon oxide-containing substrate; providing a chemical mechanical (CMP) polishing pad according to any one of items 1 to 6 above; generating dynamic contact between the polishing surface of the polishing layer of the CMP polishing pad and the substrate to polish the surface of the substrate; and adjusting the polishing surface of the polishing pad with an abrasive conditioner.

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

[0018] Unless otherwise indicated, any term containing brackets refers alternatively to the entire term as if no brackets were present and to the term without brackets, and to each alternative combination. Thus, the term "(poly)isocyanate" refers to an isocyanate, a polyisocyanate, or a mixture thereof.

[0019] For the purpose of this specification, reaction mixtures are expressed in wt. %, unless specifically stated otherwise.

[0020] All ranges are inclusive and combinable. For example, the term "50 cPs to 3000 cPs, or 100 cPs or more" would include each of 50 cPs to 100 cPs, 50 cPs to 3000 cPs, and 100 cPs to 3000 cPs.

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

[0022] As used herein, the term "average number of isocyanate groups" means the weighted average of the number of isocyanate groups in a mixture of aromatic isocyanate compounds. For example, a 50:50 wt.% mixture of MDI (2 NCO groups) and 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 the polyurethane reaction product or raw material from (ii) a liquid polyol component and (i) a liquid aromatic isocyanate component refers to the portion of the specified reaction mixture containing any diol, glycol, diglycol, diamine or triamine, diisocyanate, triisocyanate, or reaction product thereof. Thus, the "hard segment" does not include polyethers or polyglycols such as polyethylene glycol or polypropylene glycol, or polyoxyethylenes having three or more ether groups.

[0024] As used herein, the term "trace elements other than those formed by gas, water or CO2-amine adducts" means trace elements selected from hollow core polymer materials such as polymer microspheres, liquid-filled hollow core polymer materials such as fluid-filled polymer microspheres, and fillers such as boron nitride. Pores formed in the CMP polishing layer by gas or foaming agents such as CO2-amine adducts that only form gas are not considered trace elements.

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

[0026] As used herein, the term "polyurethane" refers to polymerization products derived from difunctional or polyfunctional isocyanates, such as polyether ureas, polyisocyanurates, polyurethanes, polyureas, polyurethane ureas, 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 the 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 rectangle cut from a polishing pad or layer according to the present invention.

[0030] As used herein, the term "Shore D Hardness" is the 15-second hardness of a given CMP polishing pad as measured in accordance with ASTM D2240-15 (2015), "Standard Test Method for Rubber Property—Durometer Hardness." Hardness is measured on a Rex Hybrid hardness tester (Rex Gauge Company, Inc., Buffalo Grove, IL) equipped with a D probe. For each hardness measurement, six samples were stacked and shuffled; and each pad tested was conditioned by placing it at 23° C. in 50% relative humidity for five days prior to testing and using the methods outlined in ASTM D2240-15 (2015) to improve the repeatability of the hardness test. In the present invention, the Shore D hardness of the polyurethane reaction product of the polishing layer or pad includes the Shore D hardness of the reaction, which reaction includes any additives to increase the hardness. The term "Shore A" hardness refers to the same 15 second hardness measured with a larger A probe for a softer material.

[0031] As used herein, the term "solids" refers to any material that remains 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 indicated, the term "substantially free of water" means that a given composition has no added water and that the materials entering the composition have no added water. A "substantially free of water" reaction mixture may contain 50 to 2000 ppm or preferably 50 to 1000 ppm of water present in the raw materials, or may contain water of reaction formed in the condensation reaction or water vapor from the ambient humidity in which the reaction mixture is used.

[0033] As used herein, unless otherwise indicated, the term "organic solvent-free" means that the composition does not contain any added organic solvents, and preferably does not contain any organic solvents.

[0034] As used herein, unless otherwise indicated, the term "viscosity" refers to the viscosity of a given material in pure form (100%) at a given temperature as measured using a rheometer set in an oscillatory shear rate sweep of 0.1-100 radians / second (in a 50 mm parallel plate geometry with a 100 μm gap).

[0035] As used herein, unless otherwise indicated, 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 weight percent.

[0037] According to the present invention, the inventors of the present invention have found that CMP polishing pads from a reaction mixture containing one or more small chain difunctional polyols having 2 to 9 carbon atoms in a liquid polyol component as part of a curing agent mixture provide porous CMP polishing layers having a Shore D (15 seconds) hardness of >30 that give attractive removal rate curves and enable polishing with low defectivity. In particular, reducing the content of liquid aromatic diamines and replacing a portion of the diamines with short chain diols results in an unexpected increase in planarization efficiency despite reduced tensile properties and hardness. The increase in planarization efficiency (PE) with reduced tensile properties and hardness is unexpected.

[0038] The reaction mixture of the present invention may comprise a very fast curing composition wherein the (i) liquid aromatic isocyanate component and (ii) liquid polyol component may 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 the gel time is that the reaction mixture must react slowly enough so as not to clog the mixing head in which it is mixed and to properly fill the mold when it is applied to the mold surface.

[0039] The hard segments of the reaction mixture ensure good mechanical properties.The hard segments may be 56.25 wt.% to 68 wt.% of the reaction mixture and may constitute part 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 may comprise a linear isocyanate-terminated urethane prepolymer formed from short chain diols like glycol and diethylene glycol or preferably monoethylene glycol (MEG), dipropylene glycol (DPG) or tripropylene glycol (TPG).

[0041] Preferably, the (i) liquid aromatic isocyanate component of the present invention contains only at most 5 wt.% of aliphatic isocyanate, or more preferably at most 1 wt.% of aliphatic isocyanate, based on the total weight of the liquid aromatic isocyanate.

[0042] The soft segment of the reaction mixture may comprise (ii) one or more difunctional polyether polyols as polymer polyols in an amount of up to 88 wt.% of the liquid polyol component. Suitable soft polyols are PTMEG and PPG. Useful examples of polyols containing PTMEG are as follows: Terathane from Invista, Wichita, KS. TM 2900, 2000, 1800, 1400, 1000, 650, and 250; Polymeg from Lyondell Chemicals, Limerick, PA TM 2900, 2000, 1000, 650; PolyTHF from BASF Corporation, Florham Park, NJ TM 650, 1000, 2000. Useful examples of PPG-containing polyols are as follows: Arcol from Covestro, Pittsburgh, PA; TM PPG-425, 725, 1000, 1025, 2000, 2025, 3025, and 4000; Voranol from Dow, Midland, MI TM 、Voralux TM , and Specflex TM Product line; each from Covestro (Leverkusen, DE) Multranol TM 、Ultracel TM 、Desmophen TM or Acclaim TM Polyol 12200, 8200, 6300, 4200, 2200.

[0043] The soft segment of the reaction mixture may comprise as polymer polyol a) one or more polyols having a polyether backbone and 5 to 7, preferably 6 hydroxyl groups per molecule. Preferably, the soft segment of the reaction mixture comprises as polymer polyol a) a mixture of one or more polyols having a polyether backbone and 5 to 7, preferably 6 hydroxyl groups per molecule and a difunctional polyether polyol, or more preferably a mixture in which the polyol having a polyether backbone and 5 to 7, preferably 6 hydroxyl groups accounts for up to 20 wt.% 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 having 5 hydroxyl groups, a number average molecular weight of 590 and a hydroxyl value of 475 mg KOH / g TM 202 polyol (Dow), MULTRANOL with 6 hydroxyl groups, number average molecular weight of 3,366 and hydroxyl value of 100 mg KOH / g TM 9185 polyol (Dow), or VORANOL having an average of 6.9 hydroxyl groups, a number average molecular weight of 12,420, and a hydroxyl value of 31 mg KOH / g TM 4053 polyol (Dow).

[0045] The stoichiometric range of the reaction mixture of the present invention is (NH+OH): NCO 0.85: 1.0 to 1.15: 1.0. If the stoichiometric range is above the upper limit, the elongation at break of the polyurethane product decreases. For the purpose of this specification, stoichiometry refers to the molar ratio of amine and hydroxyl to isocyanate.

[0046] The curing agent mixture of the present invention is a liquid comprising one or more liquid aromatic diamines and one or more small chain bifunctional polyols having 2 to 9 carbon atoms. Suitable small chain bifunctional 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 small chain bifunctional polyols having 2 to 9 carbon atoms in the curing agent mixture is at least 15 mol% of the curing agent mixture. If the amount of the liquid aromatic diamine exceeds 85 mol%, the resulting CMP polishing layer or pad will be hard, but will not provide the desired PE and defect improvements.

[0047] The hard segment range of the reaction mixture of the present invention is above 56.25 wt.%, or preferably at least 60 wt.% of the total reaction mixture to maintain sufficient tensile properties such as modulus and sufficient hardness for use as a hard top pad exhibiting high PE.

[0048] The liquid reaction mixture of the present invention can provide a CMP polishing pad from a process of spraying the reaction mixture onto an open mold and allowing it to cure. The two-component polyurethane forming reaction mixture of the present invention is a liquid and can be mixed in a static mixer or an impingement mixer and sprayed to form a CMP polishing pad.

[0049] The chemical mechanical polishing pad of the present invention comprises a polishing layer, which is a uniform dispersion of porous polyurethane. Uniformity is important for obtaining 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 generally important for consistent manufacturing. Because water reacts with isocyanates to form gaseous carbon dioxide and generally weak reaction products relative to urethanes, the water concentration can affect the concentration of carbon dioxide bubbles that form pores in the polymer matrix and the overall consistency of the polyurethane reaction product. The isocyanate reaction with exogenous water also reduces the available isocyanate for reaction with the chain extender, thereby changing the stoichiometry and the crosslinking level (if there are excess isocyanate groups) and tends to reduce the resulting polymer molecular weight. In order to reduce the variability of the effect of water on the polyurethane, the water content in the raw material is monitored and adjusted to a specific value of 0 ppm to 1000 ppm, preferably 50 ppm to 500 ppm.

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

[0051] Preferably, in order to increase the reactivity of (i) the liquid polyol component with the liquid aromatic isocyanate component, a catalyst may be used. 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 TM TMR catalyst (Air Products, Allentown, PA), triethylenediamine such as DABCO TM 33LV catalyst (Air Products), and mixtures thereof.

[0052] The reaction mixture of the present invention is substantially free of water and contains no added organic solvents.

[0053] The specific gravity of the resulting CMP polishing pad is preferably 0.9 to 0.5. As the porosity increases, the bulk properties of the CMP polishing pad weaken and the removal rate (RR) increases; however, in a hard and porous CMP polishing pad, it is not expected that the planarization efficiency (PE) and defect characteristics will improve with increasing hardness or hard segment material weight fraction.

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

[0055] Polishing pad density is measured as per 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 process which allows for higher yields and lower costs. Preferably, the target or substrate in the process of the present invention is a mold, wherein the produced CMP polishing pad will have a groove pattern incorporated directly into the mold.

[0057] The CMP polishing pads of the present invention are effective for interlayer dielectric (ILD) and inorganic oxide polishing. For the purposes of this specification, removal rate is defined as Represents the removal rate.

[0058] The chemical mechanical polishing pad of the present invention may comprise only a polishing layer of a polyurethane reaction product or a polishing layer stacked on a subpad or sublayer. The polishing pad, or in the case of a stacked pad, the polishing layer of the polishing pad of the present invention may be used in 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), or more preferably 750 to 3150 microns (30 to 125 mils), or still more preferably 1000 to 3000 microns (40 to 120 mils), or 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 interfacing with the polishing layer. Preferably, the chemical mechanical polishing pad optionally further comprises a compressible subpad or foundation layer adhered to the polishing layer. The compressible foundation layer preferably improves the conformity 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 to a polishing substrate. Preferably, the polishing surface has a macro texture selected from at least one of holes and grooves. The holes can extend partially from the polishing surface or extend all the way through the thickness of the polishing layer.

[0062] Preferably, the grooves are arranged on the polishing surface such that when the chemical mechanical polishing pad is rotated during polishing, at least one groove sweeps across 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 to a polishing substrate, wherein the polishing surface has a macro texture comprising a groove pattern formed therein and selected from curved grooves, linear grooves, holes and combinations thereof. Preferably, the groove pattern comprises a plurality of grooves. More preferably, the groove pattern is selected from a groove design, such as a groove design selected from the group consisting of concentric grooves (which may be circular or spiral), curved grooves, linear grooves, mesh grooves (e.g., arranged as an XY grid on the pad surface), other regular designs (e.g., hexagonal, triangular), tire tread type 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, mesh grooves, XY grid grooves, hexagonal grooves, triangular grooves, fractal grooves, and combinations thereof. The groove profile is preferably selected from a rectangle with straight sidewalls, or the groove cross section may be "V", "U", serrated, and combinations thereof.

[0064] According to the method of making a CMP polishing pad according to the present invention, the chemical mechanical polishing pad can be molded with a macrotexture or groove pattern in its polishing surface to promote slurry flow and remove polishing debris from the pad-wafer interface. Such grooves can be formed in the polishing surface of the polishing pad by the shape of the mold surface, that is, where the mold has a negative topographical form of the macrotexture.

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

[0066] Preferably, the method for polishing a substrate of the present invention comprises: providing a substrate selected from at least one of a magnetic substrate, an optical substrate and a semiconductor substrate (preferably a semiconductor substrate, such as 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 the polishing pad includes bringing a conditioning disk into contact with the polishing surface when polishing is paused ("ex-situ") or during intermittent breaks in the CMP process while the CMP process is ongoing ("in-situ"). The conditioning disk has a rough conditioning surface that typically includes embedded diamond points that cut microscopic grooves in the pad surface, grinding and scoring the pad material and renewing the polishing texture. Typically, the conditioning disk rotates in a fixed position relative to the rotational axis of the polishing pad and sweeps over an annular conditioning area as the polishing pad rotates.

[0068] Examples: The present invention will now be described in detail in the following non-limiting examples:

[0069] Unless otherwise indicated, all temperatures are room temperature (21-23° C.) and all pressures are atmospheric pressure (approximately 760 mm Hg or 101 kPa).

[0070] The following raw materials were used in the examples, although there are other raw materials disclosed below:

[0071] Ethacure TM 300 Curing Agent: dimethylthiotoluenediamine (DMTDA), an aromatic diamine (Albemarle, Charlotte, NC).

[0072] Voranol TM V5055HH polyol: multifunctional polyether polyol (OH equivalent weight 2000), functionality = 6, with a number average molecular weight M of 12,000 N High molecular weight ethylene oxide terminated propylene oxide polyol (The Dow Chemical Company, Midland, MI (Dow)) was used.

[0073] MDI prepolymer: a linear isocyanate-terminated urethane prepolymer from MDI and small molecule dipropylene glycol (DPG) and tripropylene glycol (TPG), having an NCO content of about 23 wt.% and an equivalent weight of 182. 100 wt.% of this MDI prepolymer was regarded as a hard segment.

[0074] Niax TM L5345 surfactant: nonionic silicone surfactant (Momentive, Columbus, OH).

[0075] DABCO 33LV: An amine catalyst prepared from diazobicyclononane (triethylenediamine), DABCO 33LV (Air Products, Allentown, PA) is a blend of 33 wt.% triethylenediamine and 67 wt.% dipropylene glycol.

[0076] Unilink TM 4200 Curing Agent: N,N'-dialkylamino-diphenylmethane (Dorf Ketal, Stafford, TX).

[0077] PTMEG####: Poly(THF) or polytetramethylene glycol, prepared by ring-opening polymerization of tetrahydrofuran (THF) and used as PolyTHF TM Polyols are sold by BASF, Leverkusen, DE. The number following PTMEG is the average molecular weight as reported by the manufacturer.

[0078] DPG: Dipropylene glycol

[0079] BDO: 1,4-Butanediol

[0080] PG: monopropylene glycol (product of Dow).

[0081] AOX1: benzofuranone compound, antioxidant (Milliguard AOX-1, product of Milliken).

[0082] INT1940: fatty acid surfactant (Axel Plastics product Mold Wiz INT-1940RTM).

[0083] CMP pad properties were evaluated according to the following methods:

[0084] All tensile properties were measured according to ASTM D412-06a, "Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers—Tension." Samples were cut into dog bone C dimensions. Unless otherwise specified, five test specimens were measured and the average of all test specimens for each analyte sample was reported.

[0085] Tensile elongation at break: It means the ratio between the changed length after the test specimen breaks and the initial length, and is tested according to ASTM D412-06a (2006), "Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers - Tension".

[0086] In all of the following examples, the specified two-component reaction mixture was mixed and sprayed onto an open mold using an impingement mixing and air spraying system with two tanks (isocyanate (iso) tank and polyol (poly) tank) to feed the mixing system. The two tanks were set at a given material flow rate, thereby easily determining the relative amount of each of the two components. The flow from the two tanks was started and stopped simultaneously. CMP polishing pads according to the present invention and comparative examples were formed as follows:

[0087] Comparative Example 1: Plate and Pad:

[0088] In a mixing cup, 39 parts (97.50 g, 0.0513 equivalent mol) of ethylene oxide-terminated propylene oxide polyol (Dow Voranol TM 5055HH) and 1 part (2.50 g) Niax TM L5345 surfactant and 15.47 parts (38.68 g, 0.3615 mol) of Ethacure TM 300 parts of liquid aromatic diamine and 1.92 parts (4.80 g, 0.155 equivalent mol) of monoethylene glycol are combined. 42.608 parts (106.52 g, 0.5852 equivalent mol) of MDI prepolymer are added to the mixed and degassed liquid. The cup is then mixed with a vortex mixer for 30 seconds, and then poured into a mold to cast a plate and cured at 100°C for 16 hours. The reaction mixture has a 60% hard segment weight fraction (at 95% (0.95: 1) stoichiometry) and contains 15.47% liquid aromatic diamine. The molar ratio of liquid aromatic diamine / diamine to the total moles of polyol in the curing agent mixture is 70%. After curing, the plaque with a density of 1.16 g / mL showed 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%.

[0089] The above reaction mixture was sprayed into an open mold using a two-component impingement mixing and air spray system. MDI prepolymer was loaded into the isocyanate (iso) tank, and 67.60 parts of Voranol (Voranol) were loaded into the polyol (poly) tank. TM 5055HH (47.32 lbs), 3.33 parts monoethylene glycol (2.33 lbs), 1.73 parts Niax TM L5345 (1.21 lbs), 26.81 parts Ethacure TM 300 (18.77 lbs); the same ratio as used in the above panel work. The flow rate on the polyol side during spraying was 9.49 g / s, and the flow rate on the isocyanate (iso) side was 7.01 g / s. The air injected into the nozzle was set to a nominal rate of 100 L / min. The sprayed polyurethane formulation was introduced into a mold with groove features. The sprayed pad was cured in a 100°C oven for 15 min, then removed from the mold and cured in a 100°C oven for 16 hours. The resulting pad contained both radial and concentric circular grooves. The resulting pad produced showed 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%.

[0090] Example 2: Plate and pad:

[0091] In a mixing cup, 39.6 parts (99.0 g, 0.0521 equivalent mol) of ethylene oxide-terminated propylene oxide polyol (Dow Voranol TM 5055HH) and 1 part (2.50 g) Niax TM L5345 surfactant and 8.33 parts (20.82 g, 0.1946 mol) of Ethacure TM 300 and 4.48 parts (11.20 g, 0.3613 equivalent mol) of monoethylene glycol were combined. To the mixed and degassed liquid was added 46.59 parts (116.48 g, 0.640 equivalent mol) of MDI prepolymer. The cup was then mixed with a vortex mixer for 20 seconds and then poured into a mold to cast a plaque and cured at 100°C for 16 hours. The formulation is described as having a 60% hard segment weight fraction (at 95% stoichiometry), containing 8.33% Ethacure TM 300. The molar ratio of liquid aromatic diamine / diamine to the total moles of polyol in the curing agent mixture is 35%. After curing, the plate with a density of 1.16 g / mL showed a tensile modulus of 411 MPa (59,600 psi), a tensile strength of 29.0 MPa (4200 psi) and a tensile elongation of 169%.

[0092] The above reaction mixture was sprayed into an open mold using a two-component impingement mixing and air spray system. MDI prepolymer was loaded into the isocyanate (iso) tank, and 73.75 parts of Voranol (poly) were loaded into the polyol (poly) tank. TM 5055HH (58.26 lbs), 8.34 parts monoethylene glycol (6.59 lbs), 1.84 parts Niax TM L5345 (1.461 lbs), 15.51 parts Ethacure TM300 (12.25lbs); the same ratio as used in the above board work. The flow rate on the polyol side during spraying is 9.10g / s, and the flow rate on the isocyanate (iso) side is 7.90g / s. The air injected into the nozzle is set to a nominal rate of 100L / min. The sprayed polyurethane formulation is introduced into a mold with groove features. The sprayed pad is cured in a 100°C oven for 15min, then removed from the mold and cured in a 100°C oven for 16 hours. The resulting pad contains both radial and concentric circular grooves. The resulting pad produced shows an average density of 0.813g / mL, and shows a 15-second hardness Shore D of 57, a bulk tensile modulus of 291.0MPa (42,200psi), a tensile strength of 17.9MPa (2,600psi), and a tensile elongation of 116%.

[0093] Comparative Example 3: Plate and Pad

[0094] A blend was prepared from equal parts by weight of poly(tetramethylene glycol) (PTMEG) 650, PTMEG 1000, and PTMEG 2000. In a mixing cup, 34.65 parts (86.63 g, 0.1754 equivalent mol) of this blend was mixed with 1 part (2.50 g) of Niax TM L5345 surfactant and 18.24 parts (45.60 g, 0.4262 equivalent mol) of Ethacure TM 300 is combined. To the mixed and degassed liquid, 46.11 parts (115.27 g, 0.6334 equivalent mol) of MDI prepolymer is added. The cup is then mixed with a vortex mixer for 20 seconds and then poured into a mold to cast a plaque and cured at 100°C for 16 hours. The formulation is described as having a 65% hard segment weight fraction (at 95% stoichiometry), containing 18.24 wt.% Ethacure TM 300. The molar ratio of the total moles of liquid aromatic diamine / diamine to polyol in the curing agent mixture is 100%. After curing, the plate with a density of 1.16 g / mL showed 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%.

[0095] Adopt two-component impingement type mixing and air spraying system to spray above reaction mixture into open mold.In isocyanate (iso) tank, load MDI prepolymer, and in polyol (poly) tank, load 20.457 parts of PTMEG650 (12.60lbs), 20.457 parts of PTMEG1000 (12.60lbs), 20.457PTMEG2000 (12.60lbs), 1.548 parts of NiaxL5345 (0.954lbs), 36.616 parts of Ethacure 300 (22.55lbs); The same ratio used in the above board work. The flow rate of the polyol side during spraying is 9.59g / s, and the flow rate of the isocyanate (iso) side is 7.41g / s. The air injected into the nozzle is set to a nominal rate of 100L / min. The sprayed polyurethane formulation is introduced into a mold with groove features. The sprayed pad was cured in an oven at 100°C for 16 hours. The resulting pad contained both radial and concentric circular grooves. The resulting pad produced exhibited an average density of 0.791 g / mL and exhibited a 15 second hardness Shore D 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%.

[0096] Example 4: Plate and pad:

[0097] A blend was prepared from equal parts by weight of poly(tetramethylene glycol) (PTMEG) 650, PTMEG 1000, and PTMEG 2000. In a mixing cup, 34.65 parts (86.63 g, 0.1754 equivalent mol) of this blend was mixed with 1 part (2.50 g) of Niax TM L5345 surfactant and 10.45 parts (26.128 g, 0.2442 equivalent mol) Ethacure TM 300 and 3.02 parts (7.57 g, 0.2442 equivalent mol) of monoethylene glycol were combined. To the mixed and degassed liquid was added 50.87 parts (127.18 g, 0.6988 equivalent mol) of MDI prepolymer. The cup was then mixed with a vortex mixer for 20 seconds and then poured into a mold to cast a plaque and cured at 100°C for 16 hours. The formulation is described as having a 65% hard segment weight fraction (at 95% stoichiometry), containing 10.45wt.% Ethacure TM300. The molar ratio of liquid aromatic diamine / diamine to the total moles of polyol in the curing agent mixture is 50%. After curing, the plate with a density of 1.16 g / mL showed 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%.

[0098] The above reaction mixture was sprayed into an open mold using a two-component impingement mixing and air spraying system. MDI prepolymer was loaded into the isocyanate (iso) tank, and 22.62 parts of PTMEG650 (16.92 lbs), 22.62 parts of PTMEG1000 (16.92 lbs), 22.62 parts of PTMEG2000 (16.92 lbs), 1.712 parts of Niax TM L5345 (1.281 lbs), 6.72 parts of monoethylene glycol (5.025 lbs), 23.195 parts of Ethacure TM 300 (17.35 lbs); the same ratio as used in the above panel work. The flow rate on the polyol side during spraying is 8.67 g / s, and the flow rate on the isocyanate (iso) side is 8.33 g / s. The air injected into the nozzle is set to a nominal rate of 100 L / min. The sprayed polyurethane formulation is introduced into a mold with groove features. The sprayed pad is cured in a 100°C oven for 16 hours. The resulting pad contains both radial and concentric circular grooves. The resulting pad produced shows an average density of 0.848 g / mL, and shows a 15-second hardness Shore D 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%.

[0099] Example 5: Plate and pad:

[0100] A blend was prepared from equal parts by weight of poly(tetramethylene glycol) (PTMEG) 650, PTMEG 1000, and PTMEG 2000. In a mixing cup, 34.65 parts (86.63 g, 0.1754 equivalent mol) of this blend was mixed with 1 part (2.50 g) of Niax TM L5345 surfactant and 7.65 parts (19.13 g, 0.179 equivalent mol) of Ethacure TM300 and 4.11 parts (10.29 g, 0.332 equivalent mol) of monoethylene glycol were combined. To the mixed and degassed liquid was added 52.58 parts (131.46 g, 0.722 equivalent mol) of MDI prepolymer. The cup was then mixed with a vortex mixer for 20 seconds and then poured into a mold to cast a plaque and cured at 100°C for 16 hours. The formulation is described as having a 65% hard segment weight fraction (at 95% stoichiometry), containing 7.65wt.% Ethacure TM 300. The molar ratio of liquid aromatic diamine / diamine to the total moles of polyol in the curing agent mixture is 35%. After curing, the plate with a density of 1.16 g / mL showed 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%.

[0101] The above reaction mixture was sprayed into an open mold using a two-component impingement mixing and air spraying system. MDI prepolymer was loaded into the isocyanate (iso) tank, and 24.22 parts of PTMEG650 (13.92 lbs), 24.22 parts of PTMEG1000 (13.92 lbs), 24.22 parts of PTMEG2000 (13.92 lbs), 2.10 parts of Niax TM L5345 (1.20 lbs), 8.63 parts of monoethylene glycol (4.96 lbs), 16.05 parts of Ethacure TM 300 (9.225 lbs), 0.43 (0.246 lbs) DABCO TM 33-LV catalyst and .142 parts (0.082lbs) of bismuth neodecanoate catalyst; the same ratio used in the above plate work. The flow rate on the polyol side during spraying is 8.98g / s, and the flow rate on the isocyanate (iso) side is 10.02g / s. The air injected into the nozzle is set to a nominal rate of 100L / min. The sprayed polyurethane formulation is introduced into a mold with groove features. The sprayed pad is cured in a 100°C oven for 16 hours. The resulting pad contains both radial and concentric circular grooves. The resulting pad produced shows an average density of 0.650g / mL, and shows a 15-second hardness Shore D of 47.6, a bulk tensile modulus of 226.8MPa (32,900psi), a tensile strength of 18.6MPa (2,700psi), and a tensile elongation of 190%.

[0102] Example 6: Pad:

[0103] The reaction mixture was sprayed into an open mold using a two-component impingement mixing and air spraying system. The isocyanate (iso) tank was filled with MDI prepolymer, while the polyol (poly) tank was filled with 25.13 parts of PTMEG650 (17.97 lbs), 25.13 parts of PTMEG1000 (17.97 lbs), 25.13 parts of PTMEG2000 (17.97 lbs), 1.90 parts of Niax TM L5345 (1.36 lbs), 4.988 parts of monoethylene glycol (3.57 lbs), 17.21 parts of Ethacure TM 300 (12.31 lbs), 0.381 parts DABCO TM 33-LV catalyst (0.273 lbs) and 0.127 parts of bismuth neodecanoate catalyst (0.091 lbs). The flow rate on the polyol side during spraying was 9.90 g / s and the flow rate on the isocyanate (iso) side was 9.10 g / s. The formulation is described as having a 60% hard segment weight fraction (at 95% stoichiometric), containing 9.02 wt.% Ethacure TM 300. The molar ratio of the total moles of liquid aromatic diamine / diamine to polyol in the curing agent mixture is 50%. The air injected into the nozzle is set to a nominal rate of 100L / min. The sprayed polyurethane formulation is introduced into a mold with groove features. The sprayed pad is cured in a 100°C oven for 16 hours. The resulting pad contains both radial and concentric circular grooves. The resulting pad shows an average density of 0.704g / mL, and shows a 15-second hardness Shore D of 40, a bulk tensile modulus of 137.2MPa (19,900psi), a tensile strength of 17.9MPa (2,600psi) and a tensile elongation of 260%.

[0104] Example 7: Pad:

[0105] The reaction mixture was sprayed into an open mold using a two-component impingement mixing and air spraying system. The isocyanate (iso) tank was filled with MDI prepolymer, while the polyol (poly) tank was filled with 26.13 parts of PTMEG650 (21.20 lbs), 26.13 parts of PTMEG1000 (21.20 lbs), 26.13 parts of PTMEG2000 (21.20 lbs), 1.98 parts of Niax TM L5345 (1.60 lbs), 7.70 parts of monoethylene glycol (6.25 lbs), 11.40 parts of Ethacure TM 300 (9.25 lbs), 0.397 parts DABCO TM33-LV catalyst (0.322 lbs) and 0.132 parts of bismuth neodecanoate catalyst (0.107 lbs). The flow rate on the polyol side during spraying was 9.52 g / s and the flow rate on the isocyanate (iso) side was 9.48 g / s. The formulation is described as having a 60% hard segment weight fraction (at 95% stoichiometric), containing 5.75 wt.% Ethacure TM 300. The molar ratio of the total moles of liquid aromatic diamine / diamine to polyol in the curing agent mixture is 30%. The air injected into the nozzle is set to a nominal rate of 100L / min. The sprayed polyurethane formulation is introduced into a mold with groove features. The sprayed pad is cured in a 100°C oven for 16 hours. The resulting pad contains both radial and concentric circular grooves. The resulting pad produced shows an average density of 0.711g / mL, and shows a 15-second hardness Shore D of 39, a bulk tensile modulus of 117.9MPa (17,100psi), a tensile strength of 16.5MPa (2,400psi) and a tensile elongation of 260%.

[0106] Comparative Example 8: Pad:

[0107] The reaction mixture was sprayed into an open mold using a two-component impingement mixing and air spray system. The isocyanate (iso) tank was filled with MDI prepolymer, while the polyol (poly) tank was filled with 87.99 parts of PolyTHF650 (61.593 lbs), 0.88 parts of Niax TM L5345 (0.616 lbs) nonionic surfactant, 0.088 parts Niax TM T-9 catalyst (0.062 lbs), 0.2642 parts DABCO TM 33LV (0.185 lbs) and 0.22 parts of water (0.154 lbs) and 10.557 parts of dipropylene glycol (7.39 lbs). The flow rate on the polyol side during spraying was 9.10 g / s and the flow rate on the isocyanate (iso) side was 9.90 g / s. The air injected into the nozzle was set to a nominal rate of 100 L / min. The sprayed polyurethane formulation was directed onto a Teflon coated aluminum plate. The sprayed pad was cured in a 100°C oven for 16 hours. The resulting pad is described as 52.5% hard segment weight fraction at 95% stoichiometry, and 2500 ppm water added produces a pad with a bulk density of 0.53 g / mL and exhibits 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.

[0108] Comparative Example 9:As used in other polishing experiments with the same K7R32 groove pattern and the same SUBA TM A commercial IC1000 polishing pad (Dow) with an IV subpad (Dow). The density is 0.77 g / mL and the tensile modulus is 260 MPa (37,700 psi).

[0109] Example 10: Pad:

[0110] The reaction mixture was sprayed into an open mold using a two-component impingement mixing and air spraying system. MDI prepolymer was placed in the isocyanate (iso) tank, while 84.85 parts of PTMEG1000, 3.48 parts of INT1940, 0.24 parts of AOX1, 4.46 parts of monoethylene glycol, 6.59 parts of Ethacure TM 300, 0.38 parts of bismuth octoate catalyst. The flow rate on the polyol side during spraying was 4.6 g / s, and the flow rate on the isocyanate (iso) side was 3.4 g / s. The formulation is described as having a 50% hard segment weight fraction (at 95% stoichiometry), containing 3.79 wt.% Ethacure TM 300. The molar ratio of the total moles of liquid aromatic diamine / diamine to polyol in the curing agent mixture is 30%. The air injected into the nozzle is set to a nominal rate of 100L / min. The sprayed polyurethane formulation is introduced into a mold with groove features. The sprayed pad is cured in a 100°C oven for 16 hours. The resulting pad contains both radial and concentric circular grooves. The resulting pad produced shows an average density of 0.68g / mL, and shows a 15-second hardness Shore DO of 32, a bulk tensile modulus of 4MPa (600psi), a tensile strength of 11MPa (1500psi) and a tensile elongation of 550%.

[0111] Example 11: Pad:

[0112] The reaction mixture was sprayed into an open mold using a two-component impingement mixing and air spraying system. MDI prepolymer was placed in the isocyanate (iso) tank, while 81.96 parts of PTMEG1000, 3.65 parts of INT1940, 0.26 parts of AOX1, 5.54 parts of monoethylene glycol, 8.2 parts of Ethacure TM 300, 0.4 parts of bismuth octoate catalyst. The flow rate on the polyol side during spraying was 4.6 g / s, and the flow rate on the isocyanate (iso) side was 3.8 g / s. The formulation is described as having a 54% hard segment weight fraction (at 95% stoichiometry), containing 4.49 wt.% Ethacure TM300. The molar ratio of the total moles of liquid aromatic diamine / diamine to polyol in the curing agent mixture is 30%. The air injected into the nozzle is set to a nominal rate of 100L / min. The sprayed polyurethane formulation is introduced into a mold with groove features. The sprayed pad is cured in a 100°C oven for 16 hours. The resulting pad contains both radial and concentric circular grooves. The resulting pad shows an average density of 0.70g / mL, and shows a 15-second hardness Shore DO of 49, a bulk tensile modulus of 12MPa (1700psi), a tensile strength of 15MPa (2100psi), and a tensile elongation of 500%.

[0113] Example 12: Pad:

[0114] The reaction mixture was sprayed into an open mold using a two-component impingement mixing and air spraying system. MDI prepolymer was placed in the isocyanate (iso) tank, while 79.8 parts of PTMEG1000, 3.55 parts of INT1940, 0.25 parts of AOX1, 6.46 parts of monoethylene glycol, 9.55 parts of Ethacure TM 300, 0.39 parts of bismuth octoate catalyst. The flow rate on the polyol side during spraying was 4.6 g / s, and the flow rate on the isocyanate (iso) side was 3.6 g / s. The formulation is described as having a 54% hard segment weight fraction (at 110% stoichiometry), containing 5.38 wt.% Ethacure TM 300. The molar ratio of the total moles of liquid aromatic diamine / diamine to polyol in the curing agent mixture is 30%. The air injected into the nozzle is set to a nominal rate of 100L / min. The sprayed polyurethane formulation is introduced into a mold with groove features. The sprayed pad is cured in a 100°C oven for 16 hours. The resulting pad contains both radial and concentric circular grooves. The resulting pad shows an average density of 0.73g / mL, and shows a 15-second hardness Shore DO of 43, a bulk tensile modulus of 8MPa (1200psi), a tensile strength of 8MPa (1200psi) and a tensile elongation of 530%.

[0115] Example 13: Pad:

[0116] The reaction mixture was sprayed into an open mold using a two-component impingement mixing and air spraying system. MDI prepolymer was placed in the isocyanate (iso) tank, while 77.32 parts of PTMEG1000, 3.68 parts of INT1940, 0.26 parts of AOX1, 7.39 parts of monoethylene glycol, 10.94 parts of Ethacure TM300, 0.41 parts of bismuth octoate catalyst. The flow rate on the polyol side during spraying was 4.6 g / s, and the flow rate on the isocyanate (iso) side was 3.9 g / s. The formulation is described as having a 57% hard segment weight fraction (at 110% stoichiometry), containing 5.94 wt.% Ethacure TM 300. The molar ratio of the total moles of liquid aromatic diamine / diamine to polyol in the curing agent mixture is 30%. The air injected into the nozzle is set to a nominal rate of 100L / min. The sprayed polyurethane formulation is introduced into a mold with groove features. The sprayed pad is cured in a 100°C oven for 16 hours. The resulting pad contains both radial and concentric circular grooves. The resulting pad produced shows an average density of 0.74g / mL, and shows a 15-second hardness Shore DO of 56, a bulk tensile modulus of 21MPa (3100psi), a tensile strength of 3MPa (500psi) and a tensile elongation of 85%.

[0117] Example 14: Pad:

[0118] The reaction mixture was sprayed into an open mold using a two-component impingement mixing and air spraying system. MDI prepolymer was loaded into the isocyanate (iso) tank, while 24.6 parts of PTMEG650, 24.6 parts of PTMEG1000, 24.6 parts of PTMEG2000, 1.87 parts of Niax were loaded into the polyol (poly) tank. TM L5345, 14.23 parts of dipropylene glycol, 9.73 parts of Ethacure TM 300, 0.37 parts of bismuth neodecanoate catalyst. The flow rate on the polyol side during spraying was 10.4 g / s, and the flow rate on the isocyanate (iso) side was 9.1 g / s. The formulation is described as having a 60% hard segment weight fraction (at 95% stoichiometry), containing 5.21 wt.% Ethacure TM 300. The molar ratio of the total moles of liquid aromatic diamine / diamine to polyol in the curing agent mixture is 30%. The air injected into the nozzle is set to a nominal rate of 100 L / min. The sprayed polyurethane formulation is introduced into a mold with groove features. The sprayed pad is cured in a 100° C. oven for 16 hours. The resulting pad contains both radial and concentric circular grooves. The resulting pad shows an average density of 0.45 g / mL, and shows a 15-second hardness Shore D 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%.

[0119] Example 15: Pad:

[0120] The reaction mixture was sprayed into an open mold using a two-component impingement mixing and air spraying system. MDI prepolymer was loaded into the isocyanate (iso) tank, while 25.49 parts of PTMEG650, 25.49 parts of PTMEG1000, 25.49 parts of PTMEG2000, 1.94 parts of Niax were loaded into the polyol (poly) tank. TM L5345, 10.51 parts 1,4-butanediol, 10.7 parts Ethacure TM 300, 0.39 parts of bismuth neodecanoate catalyst. The flow rate on the polyol side during spraying was 10.1 g / s, and the flow rate on the isocyanate (iso) side was 9.4 g / s. The formulation is described as having a 60% hard segment weight fraction (at 95% stoichiometry), containing 5.53 wt.% Ethacure TM 300. The molar ratio of the total moles of liquid aromatic diamine / diamine to polyol in the curing agent mixture is 30%. The air injected into the nozzle is set to a nominal rate of 100 L / min. The sprayed polyurethane formulation is introduced into a mold with groove features. The sprayed pad is cured in a 100° C. oven for 16 hours. The resulting pad contains both radial and concentric circular grooves. The resulting pad shows an average density of 0.66 g / mL, and shows a 15-second hardness Shore D 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%.

[0121] Example 16: Pad:

[0122] The reaction mixture was sprayed into an open mold using a two-component impingement mixing and air spraying system. MDI prepolymer was loaded into the isocyanate (iso) tank, while 80.26 parts of PTMEG1000, 1.91 parts of Niax were loaded into the polyol (poly) tank. TM L5345, 8.01 parts propylene glycol, 9.54 parts Ethacure TM 300, 0.28 parts of bismuth neodecanoate catalyst. The flow rate on the polyol side during spraying was 11.1 g / s, and the flow rate on the isocyanate (iso) side was 9.9 g / s. The formulation is described as having a 57% hard segment weight fraction (at 95% stoichiometry), containing 5.05 wt.% Ethacure TM300. The molar ratio of the total moles of liquid aromatic diamine / diamine to polyol in the curing agent mixture is 30%. The air injected into the nozzle is set to a nominal rate of 100L / min. The sprayed polyurethane formulation is introduced into a mold with groove features. The sprayed pad is cured in a 100°C oven for 16 hours. The resulting pad contains both radial and concentric circular grooves. The resulting pad produced shows an average density of 0.69g / mL, and shows a 15-second hardness Shore D of 36, a bulk tensile modulus of 81MPa (11700psi), a tensile strength of 16MPa (2300psi) and a tensile elongation of 280%.

[0123] The properties of the materials and pads in the above examples are reported below in Table 1. The polishing of the pads prepared in the above examples was tested as described in the Test Methods below, and the results are reported in each of Tables 1 and 2 below.

[0124] The CMP polishing pad was produced by machining the back side of the designated polishing layer prepared in the above example into a flat surface on a lathe to provide a flat polishing pad. The polishing pad was then bonded to the SUBA TM IV subpad (Dow). The final stack pad had a diameter of 0.508 meters (20"), with the polishing layer nominally 2.03 mm (80 mils) thick and featuring a groove pattern, wherein the plurality of grooves featured a concentric circular groove pattern having a width of 0.508 mm (20 mils), a depth of 0.762 mm (30 mils), a pitch of 1.78 mm (70 mils), and 32 radial grooves. Polishing experiments were conducted on 200 mm wafers on an Applied Mirra polisher (Applied Materials, Santa Clara, CA) with 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 TM II1730 colloidal silica slurry (Dow, 16 wt.% solids), the table rotation speed was 93 rpm, and the carrier rotation speed was 87 rpm. For Examples 1 to 9, 14 and 15, 3M TM Diamond Pad Conditioner A153L, 4.25 inch diameter, 3M Aggression Grade 6-9 (The 3M Company, Minneapolis, MN) was used to condition and texture the polishing pad. For Example 16, a Saesol Diamond Pad Conditioner AK45 (Saesol TMAM02BSL8031C1) to condition and texture the polishing pad. For Examples 10 to 13, a Saesol Diamond Pad Conditioner AD45 (Saesol TM AM02BSL8031E7) to condition and texture the polishing pad. Only typical downforce (e.g., 22.2N or 31.1N) was used to break the polishing pad with a conditioner and DI water for 30 minutes each. The polishing pad was further 100% in-situ conditioned at a downforce of 22.2N from 1.7 to 9.2 from the center of the polishing pad at 10 scans / min during polishing. The wafer was cleaned on an OnTrack DSS-200Synergy post-CMP cleaner. To further highlight shallow scratches, HF etching was performed on a SSEC single wafer etching system, thereby etching 200Ang of TEOS from the wafer. Flattened step height measurements were performed on a Bruker dynamic atomic force profiler (Bruker, Billerica, MA). The substrate is a tetraethoxysilicate (TEOS) wafer substrate. The KLA-Tencor FX200 was used to measure the step height of the flattened surface. TM The metrology tool (KLA Tencor, Milpitas, CA) used a 49-point spiral scan to measure the film thickness before and after polishing at 3 mm edge exclusion to determine Removal rate The removal rate is calculated from the change in thickness at each point during a specified polishing time in angstroms per minute. Inhomogeneity ratio The (%NUR) is calculated by the % standard deviation of the removal rate.

[0125] Table 1: Pad properties and characteristics

[0126]

[0127] *Defined as (number of moles of diamine) / (number of moles of diamine+small chain polyol); 1. PD: pattern density.

[0128] Table 2: Pad performance characteristics

[0129]

[0130] *Defined as (moles of diamine) / (moles of diamine+small chain polyol).

[0131] As shown in Tables 1 and 2 above, the CMP polishing pads of the present invention exhibit improved planarization efficiency even when compared to the commercial CMP polishing pad of Comparative Example 10. At the same time, the removal rate and % non-uniformity are the same or similar to the values ​​produced by the IC1000 pad (Dow) of Comparative Example 10. In addition, the performance of the CMP polishing pads of the present invention is significantly better than the pads from the liquid aromatic diamine curing agent in Comparative Example 3 and the pads from 70% liquid aromatic diamine in the curing agent mixture as in Comparative Example 1.

Claims

1. A chemical mechanical (CMP) polishing pad for polishing a substrate selected from at least one of a magnetic substrate, an optical substrate and a semiconductor substrate, the CMP polishing pad comprising a polishing layer adapted to polish the substrate, the polishing layer being a polyurethane, the polyurethane being the product of a reaction mixture comprising: The reaction mixture comprises: (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 wt.% to 40 wt.%, based on the total solid weight of the liquid aromatic isocyanate component, and (ii) a liquid polyol component comprising a) one or more polymer polyols, and b) 12 wt.% to 40 wt.% of one or more polyols having 2 to 9 carbon atoms, based on the total weight of the liquid polyol component. A curing agent mixture of a small chain difunctional polyol and a liquid aromatic diamine that is liquid under ambient conditions, wherein the molar ratio of the liquid aromatic diamine to the total moles of the small chain difunctional polyol and the liquid aromatic diamine is 15:85 to 40:60, based on the total weight of the reaction mixture, the reaction mixture contains 48 wt.% to 68 wt.% of hard segment material, and further wherein the CMP polishing layer has a 15 second Shore A hardness of 50 to a 15 second Shore D hardness of 68 and a density of 0.45 g / mL to 0.9 g / mL.

2. The CMP polishing pad according to claim 1, wherein The (i) liquid aromatic isocyanate component comprises a linear methylene diphenyl diisocyanate (MDI) prepolymer or MDI.

3. The CMP polishing pad according to claim 1, wherein The (ii) liquid polyol component comprises a) one or more polymer polyols selected from the group consisting of polytetramethylene glycol (PTMEG), polypropylene glycol (PPG), hexafunctional polyols, and mixtures thereof.

4. The CMP polishing pad according to claim 1, wherein In the b) curing agent mixture of the (ii) liquid polyol component, the one or more small-chain difunctional polyols having 2 to 9 carbon atoms are selected from the group consisting of ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2-methyl-1,3-propylene glycol, 1,4-butylene glycol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, tripropylene glycol, and mixtures thereof.

5. The CMP polishing pad according to claim 1, wherein In the b) curing agent mixture, the liquid aromatic diamine is selected from the group consisting of dimethylthiotoluenediamine, diethyltoluenediamine, tert-butyltoluenediamine, chlorotoluenediamine, N,N′-dialkylaminodiphenylmethane, and mixtures thereof.

6. 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 moles of the small-chain difunctional polyol and the liquid aromatic diamine is 23:77 to 35:

65.

7. The CMP polishing pad according to claim 1, wherein: The reaction mixture comprises 58 wt.% to 63 wt.% of hard segment material based on the total weight of the reaction mixture.

8. The CMP polishing pad according to claim 1, wherein The CMP polishing pad contains no trace elements other than those formed from gases, water or CO2-amine adducts.

9. A method for preparing a chemical mechanical (CMP) polishing pad according to claim 1, wherein the chemical mechanical (CMP) polishing pad has a polishing layer adapted to a polishing substrate, the method comprising: Providing a two-component reaction mixture including c) water or a CO2-amine adduct in ii) a liquid polyol component sufficient to produce the density of the CMP polishing pad or layer, mixing the (i) liquid aromatic isocyanate component and the (ii) liquid polyol component, and applying the reaction mixture as one component to an open mold surface; curing the reaction mixture at ambient temperature to 130°C to form a molded polyurethane reaction product; removing the polyurethane reaction product from the mold; and then, finally curing at a temperature of 60°C to 130°C for a period of 1 minute to 18 hours to form the polishing layer.

10. The method of claim 9, wherein: The mold surface has a positive topography that forms a negative groove pattern in the top surface of the CMP polishing layer.

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