Formulation for a high-hardness and highly porous chemical mechanical polishing pad and a CMP pad manufactured thereby

Abstract

To provide chemical mechanical polishing layers or pads that are improved in hardness and removal rate performance without an undesirable increase in defectivity.SOLUTION: The invention provides polishing pads for polyurethane polishing layers with a Shore DO (15 second) hardness of 40 to 80 made from a two-component reaction mixture [a two-component mixture of (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, b) 15 to 36 wt.%, based on the total weight of the liquid polyol component, of one or more small-chain difunctional polyols having 2 to 6 carbon atoms, c) 0 to 25 wt.%, based on the total weight of the liquid polyol component, of a liquid aromatic diamine which is a liquid at standard pressure and at 40°C, and d) an amount of water or CO2-amine adduct sufficient to reduce the density of a CMP polishing pad to 0.2 to 0.5 g / mL].SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a two-component polyurethane composition for manufacturing a chemical mechanical planarization (CMP polishing) pad having a Shore DO hardness (15 seconds) of 40 or more and a specific gravity (SG) of 0.5 or less, a CMP polishing pad manufactured therefrom, and a method for manufacturing the same. More specifically, the present invention relates to a CPM polishing pad comprising a polyurethane foam reaction product of a two-component reaction mixture of a liquid aromatic diisocyanate component and a liquid polyol component containing a short-chain diol and a liquid aromatic diamine curing agent, where the liquid polyol component contains water in an amount of 1000 to 8500 ppm based on the total weight of the two-component reaction mixture, for example.

Background Art

[0002] In the CMP process, the polishing pad, in combination with a polishing liquid (such as an abrasive-containing polishing slurry and / or a reactive liquid without abrasives), removes excess material so as to planarize or maintain the flatness of a semiconductor substrate, an optical substrate, or a magnetic substrate. There is a continuous need for a CMP polishing pad that improves the layer uniformity or planarization performance in combination with an acceptable removal rate. However, in the industry, there remains a performance trade-off between the removal rate or hardness and the defect rate, and the greater the removal rate or hardness, the more defects there are.

[0003] U.S. Patent Publication No. US 2014 / 0038503A1 by Itoyma et al. has a density of 0.30 to 0.60 g / cm 3and discloses a method for manufacturing a molded CMP polishing pad of polyurethane-urea foam having a type D hardness (JIS K 6253-1997 / ISO 7619) of 5 to 35 degrees. The formulation for the CMP polishing pad includes a mixture of an isocyanate compound, a polyisocyanate compound, a polyamine compound, and an aqueous dispersion mixture containing water, a foam stabilizer, a reaction catalyst, and a non-reactive gas. The composition further includes a polyol disclosed as having a number average molecular weight of 500 to 5000. The Itoyama pad includes pores generated by the reaction of water and isocyanate; however, the disclosed pad is soft because if the hardness is too high, scratches or defects are formed on the polished substrate. See

[0076] .

[0004] The present inventors have endeavored to solve the problem of providing a more flexible formulation window for manufacturing a chemical mechanical polishing layer or pad with improved hardness and removal rate performance without an inconvenient increase in the defect rate.

[0005] Statement of the Invention 1. According to the present invention, a reaction mixture free of organic solvents for forming a chemical mechanical polishing (CMP polishing) layer comprises: (i) a liquid aromatic isocyanate component containing one or more aromatic diisocyanates or linear aromatic isocyanate-terminated urethane prepolymers (the unreacted isocyanate (NCO) concentration is 18 to 40% by weight, or preferably 18 to 34% by weight based on the total solid content weight of the liquid aromatic isocyanate component), preferably a linear methylene diphenyl diisocyanate (MDI) prepolymer, and (ii) a liquid polyol component, including a) one or more high molecular weight polyols such as polytetramethylene glycol (PTMEG), polypropylene glycol (PPG), hexafunctional polyol, or mixtures thereof; b) one or more small chain bifunctional polyols having 2 to 6 carbon atoms, such as 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, or preferably ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol and / or triethylene glycol, etc., and further c) a liquid aromatic diamine that is liquid at standard atmospheric pressure and 40 °C in an amount of 0 to 25% by weight based on the total weight of the liquid polyol component, and d) an amount of water or a CO2-amine adduct such as CO2-alkanolamine sufficient to reduce the density of the CMP polishing pad produced from the two-component reaction mixture to 0.2 to 0.50 g / mL, or preferably 0.35 to 0.495 g / mL, for example, 1000 to 8500 ppm, or preferably 1000 to 5000 ppm of water, or 0.25 to 4% by weight, or preferably 0.4 to 2...A liquid polyol component containing, for example, 5% by weight of a CO2-amine adduct (an amount based on the total weight of the two-component reaction mixture), where the reaction mixture contains 60 to 75% by weight, or preferably more than 63 to 75% by weight of a hard segment material, based on the total weight of the reaction mixture. The two-component reaction mixture contains no trace elements other than those formed by water or the CO2-amine adduct.

[0006] 2. A reaction mixture according to the present invention, which is free of organic solvents for forming a chemical mechanical polishing (CMP polishing) layer similar to that of item 1 above, and has a gelation time at 65°C of 15 seconds to 3 minutes, or preferably 15 seconds to 2 minutes.

[0007] 3. 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 according to another aspect of the present invention, the polishing pad including a polishing layer adapted for polishing the substrate, the polishing layer being a two-component reaction mixture free of organic solvents [(i) one or more aromatic diisocyanates or linear aromatic isocyanate-terminated urethane prepolymers (unreacted isocyanate (NCO) concentration is 18 to 40% by weight, or preferably 18 to 34% by weight based on the total solid content weight of the aromatic isocyanate component), preferably including a linear methylene diphenyl diisocyanate (MDI) prepolymer, a liquid aromatic isocyanate component, and (ii) a liquid polyol component, which is a) one or more high molecular weight polyols such as polytetramethylene glycol (PTMEG), polypropylene glycol (PPG), a hexa-functional polyol, or a mixture thereof, b) one or more small chain bifunctional polyols having 2 to 6 carbon atoms, which is 15 to 36% by weight based on the total weight of the liquid polyol component, for example, 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, or preferably, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, and / or triethylene glycol, etc., and further c) a liquid aromatic diamine that is liquid under ambient conditions, which is 0 to 25% by weight based on the total weight of the liquid polyol component, for example, dimethylthio-toluenediamine, toluenediamine, tert-butyltoluenediamine, for example, 5-tert-butyl-2,4- or 3-tert-butyl-2,6-toluenediamine, chlorotoluenediamine, and N,N'-dialkylaminodiphenylmethane, and mixtures thereof, or preferably, chlorotoluenediamine, dimethylthio-toluenediamine, and mixtures thereof;Any diamine selected from diethyltoluenediamine (DETDA) and N,N'-dialkylaminodiphenylmethane, and d) a liquid polyol component containing an amount of water or a CO2-amine adduct such as CO2-alkanolamine sufficient to reduce the density of the CMP polishing pad to 0.2 to 0.50 g / mL, or preferably to 0.35 to 0.495 g / mL, for example, 1000 to 8500 ppm, or preferably 1000 to 5,000 ppm of water, or 0.25 to 4.0 wt%, or preferably 0.4 to 2.5 wt% of a CO2-amine adduct such as CO2-alkanolamine (amount based on the total weight of the two-component reaction mixture), a polishing pad comprising a polyurethane reaction product, wherein the reaction mixture comprises 60 to 75 wt%, or preferably more than 63 to 75 wt% of a hard segment material based on the total weight of the reaction mixture, the CMP polishing layer has a Shore D 0 (15 seconds) hardness of 40 to 80, or preferably at least 43, or 43 to 80, and a density of 0.2 to 0.55 g / mL, or preferably 0.35 to 0.50 g / mL, or more preferably 0.35 to 0.495 g / mL; preferably further, the CMP polishing layer does not contain trace elements other than those formed by water or CO2-amine adducts.,

[0008] 4. A CMP polishing pad or reaction mixture of the present invention similar to any one of items 1, 2, or 3 above, wherein the stoichiometric ratio of the total number of moles of amine (NH2) groups and the total number of moles of hydroxyl (OH) groups in the reaction mixture for producing the CMP polishing layer to the total number of 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.,

[0009] 5. A CMP polishing pad of the present invention similar to any one of the above items 3 or 4, wherein (i) the liquid aromatic isocyanate component is methylene diphenyl diisocyanate (MDI); toluene diisocyanate (TDI); naphthalene diisocyanate (NDI); para-phenylene diisocyanate (PPDI); or o-toluidine diisocyanate (TODI); a mixture thereof; a linear isocyanate-terminated urethane prepolymer [a hard segment material content of 84 to 100% by weight, or preferably 90 to 100% by weight, of MDI, TDI, NDI, PPDI, TODI, or a mixture thereof extended with any one of one or more chain extender compounds, 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 a linear isocyanate-terminated urethane prepolymer of MDI, which is MDI extended with one or more chain extender compounds or an MDI dimer, and includes one or more diisocyanate or isocyanate-terminated linear urethane prepolymer compounds selected therefrom, and the polishing pad.

[0010] 6. A CMP polishing pad of the present invention similar to any one of items 3, 4, or 5 above, wherein the liquid aromatic diamine curing agent is dimethylthio - toluenediamine, a mixture of isomers 2,4 - diamino - 3,5 - dimethylthiotoluene and 3,5 - dimethylthio - 2,4 - toluenediamine; diethyltoluenediamine; tert - butyltoluenediamine such as 5 - tert - butyl - 2,4 - or 3 - tert - butyl - 2,6 - toluenediamine; chlorotoluenediamine; and N,N’ - dialkylaminodiphenylmethane and mixtures thereof, or preferably chlorotoluenediamine or dimethylthio - toluenediamine, a mixture of isomers 2,4 - diamino - 3,5 - dimethylthiotoluene and 3,5 - dimethylthio - 2,4 - toluenediamine, diethyltoluenediamine (DETDA) and N,N’ - dialkylaminodiphenylmethane, and is liquid under ambient conditions, the polishing pad.

[0011] 7. A chemical mechanical polishing pad of the present invention similar to any one of items 1, 2, 3, 4, 5, or 6 above, comprising a CMP polishing layer, and further comprising a sub - pad or a backing layer such as a polymer - impregnated non - woven sheet or a polymer sheet on the bottom side of the polishing layer so that the polishing layer forms the uppermost part of the polishing pad, the polishing pad.

[0012] 8. In yet another aspect, the present invention is a method for manufacturing a chemical mechanical (CMP) polishing pad having a polishing layer adapted for polishing a substrate, the method comprising providing a two-component reaction mixture similar to any one of items 1, 2, 3, 4, 5, or 6 above, mixing (i) a liquid aromatic isocyanate component and (ii) a liquid polyol component, for example, with a static mixer or an impingement mixer, and applying the reaction mixture as one component to an open molding surface having a male topography that preferably forms a groove pattern of a female mold on the uppermost surface of the CMP polishing pad, curing the reaction mixture at ambient temperature to 130°C to form a molded polyurethane reaction product, for example, first curing at ambient temperature to 130°C for 1 to 30 minutes, or preferably for 30 seconds to 5 minutes, removing the polyurethane reaction product from the mold, and then finally curing at a temperature of 60 to 130°C for 1 minute to 16 hours, or preferably for 5 minutes to 15 minutes.

[0013] 9. A method of the present invention similar to item 8 above, wherein the formation of the polishing pad further comprises stacking a sub-pad layer, such as a polymer-impregnated nonwoven sheet, or a porous or non-porous polymer sheet, on the bottom side of the polishing layer such that the polishing layer forms the uppermost surface of the polishing pad.

[0014] 10. A method of the present invention similar to any one of items 8 or 9 above, wherein the surface of the CMP polishing pad is formed directly in the mold.

[0015] 11. A method of the present invention similar to any one of items 8, 9, or 10 above, wherein the application of the reaction mixture as one component comprises overspraying the mold and then curing to form a polyurethane reaction product, removing the polyurethane reaction product from the mold, and then trimming or cutting off the outer periphery of the polyurethane reaction product to the desired diameter of the CMP polishing pad.

[0016] 12. In yet another aspect, the present invention provides a method of polishing a substrate, the method comprising: providing a substrate selected from at least one of a magnetic substrate, an optical substrate, and a semiconductor substrate; providing a chemical mechanical (CMP) polishing pad according to any one of items 1 to 7 above; creating a 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 conditioning the polishing surface of the polishing pad using an abrasive conditioner.

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

[0018] Unless otherwise specified, any term containing parentheses refers to the term as a whole, optionally without the parentheses, the term without parentheses, and combinations of each alternative. Thus, the term "(poly) isocyanate" refers to isocyanate, polyisocyanate, or a mixture thereof.

[0019] All ranges are inclusive and combinable. For example, the term "in the range of 50 to 3000 cP, or 100 cP or more" would include 50 to 100 cP, 50 to 3000 cP, and 100 to 3000 cP respectively.

[0020] For the purposes of this specification, unless otherwise specifically stated, reaction mixtures are expressed in weight %.

[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 weight % mixture of MDI (2 NCO groups) and the isocyanurate of MDI (considered to have 3 NCO groups) has an average of 2.5 isocyanate groups.

[0023] As used herein, the term "gelation time" means the result obtained, for example, by mixing a given reaction mixture at about 65° C. for 30 seconds in a VM-2500 vortex laboratory mixer (StateMix Ltd., Winnipeg, Canada) set at 1000 rpm, setting the timer to zero and turning the timer on, pouring the mixture into an aluminum cup, placing the cup in the hot pot of a gelation timer (Gardco Hot Pot™ gelation timer, Paul N. Gardner Company, Inc., Pompano Beach, Fla.) set at 65° C., and stirring the reaction mixture at 20 RPM using a wire stirrer and recording the gelation time when the wire stirrer stops moving within the sample.

[0024] As used herein, the term "hard segment" of a polyurethane reaction product, or of raw materials from either a liquid polyol component or a liquid aromatic isocyanate component, refers to that portion of the indicated reaction mixture that includes any diol, glycol, diglycol, triglycol (having 6 or fewer carbon atoms), any diamine, triamine or polyamine, diisocyanate, triisocyanate, or reaction products thereof. Thus, "hard segment" excludes polyethers or polyglycols (such as polyethylene glycol or polypropylene glycol), or polyoxyethylene having 3 or more ether groups.

[0025] As used herein, the term "trace elements other than those formed by 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 foaming agents that form only gases or a gas, such as a CO2-amine adduct, are not considered trace elements.

[0026] As used herein, the term "polyisocyanate" means any isocyanate group-containing molecule containing two or more isocyanate groups.

[0027] As used herein, the term "polyisocyanate prepolymer" means any isocyanate group-containing molecule that is a reaction product of an excess of diisocyanate or polyisocyanate with an active hydrogen-containing compound containing two or more active hydrogen groups (such as diamines, diols, triols, and polyols).

[0028] As used herein, the term "polyurethane" refers to polymerization products from bifunctional or polyfunctional isocyanates, such as polyether ureas, polyisocyanurates, polyurethanes, polyureas, polyurethane ureas, their copolymers, and mixtures thereof.

[0029] As used herein, the term "reaction mixture" includes any non-reactive additives such as trace elements, and any additives for reducing the hardness of the polyurethane reaction product in the CMP polishing pad according to ASTM D2240-15 (2015).

[0030] As used herein, the term "stoichiometry" of the reaction mixture refers to the ratio of the molar equivalents of (free OH + free NH2 groups) to free NCO groups in the reaction mixture.

[0031] As used herein, the term "SG" or "specific gravity" refers to the weight / volume ratio of a rectangle cut from the polishing pad or polishing layer of the present invention.

[0032] As used herein, the term "Shore DO hardness" is the 15 - second hardness of a given CMP polish measured by ASTM D2240 - 15(2015) "Standard Test Method for Rubber Properties - Durometer Hardness". The hardness was measured with a Rex Hybrid hardness tester (Rex Gauge Company, Inc., Buffalo Grove, IL) equipped with an O - probe. Six samples were stacked and shuffled for each hardness measurement; and each pad to be tested was conditioned at 23°C and 50% relative humidity for 5 days before testing and using the method outlined in ASTM D2240 - 15(2015) to improve the reproducibility of the hardness test. In the present invention, the Shore D hardness of the polyurethane reaction product of the polishing layer or polishing pad includes the Shore D hardness of the reactant including any additives for increasing hardness. The term "Shore A" hardness refers to the same 15 - second hardness measurement using a larger A - probe for softer materials.

[0033] As used herein, the term "solids content" refers to any material remaining in the polyurethane reaction product of the present invention; thus, the solids content includes reactive and non - volatile liquids and additives that do not volatilize upon curing. The solids content excludes water and volatile solvents.

[0034] As used herein, unless otherwise specified, the term "viscosity" refers to the viscosity of a given material in neat form (100%) at a given temperature, measured using a rheometer set to a vibration shear rate sweep of 0.1 - 100 rad / sec in a 50 mm parallel plate geometry with a gap of 100 μm.

[0035] As used herein, unless otherwise specified, the term "weight % 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 "weight %" represents weight percent.

[0037] According to the present invention, the inventors have discovered that a CMP polishing pad having a highly porous CMP polishing layer with a Shore D0 (15 seconds) hardness > 40 is a useful hard pad with an attractive removal rate profile and can be polished with a low defect rate. In particular, a CMP polishing layer formed by spraying a reaction mixture having a hard segment weight fraction of 60 wt% to 68 wt%, or preferably higher than 60 wt%, provides a hardness having a Shore D0 (15 seconds) value exceeding 40, or preferably at least 43, and has a density of less than 0.50 g / mL. CMP polishing pads with hardness and porosity in this range were not previously achievable from other CMP manufacturing methods. Furthermore, the defect rate obtained by using the CMP polishing pad of the present invention was surprisingly good. Although an improvement in the tensile modulus of the CMP polishing pad is recognized as an important driving force for improving the planarization efficiency (PE), the same tensile modulus increases the defects formed during CMP polishing.

[0038] The CMP polishing pad of the present invention is formed from a two-component reaction mixture having a liquid aromatic diisocyanate component and a liquid polyol component that further contains the liquid aromatic diisocyanate component. The liquid aromatic diisocyanate component includes one or more liquid aromatic diisocyanates or linear aromatic isocyanate-terminated urethane prepolymers. Suitable linear urethane prepolymers may be methylene diphenyl diisocyanate (MDI) prepolymers having an NCO content exceeding 18% by weight; an example of such a linear aromatic isocyanate-terminated urethane prepolymer includes a prepolymer formed from MDI and (di)ethylene glycol having an NCO content of 23.0% by weight and an equivalent weight of 182 g / mol. A suitable reaction mixture further contains 0 to 25% by weight of a liquid aromatic diamine as a curing agent based on the total weight of the reaction mixture. The liquid aromatic diamine curing agent helps to provide a fast reaction time and good mechanical properties such as high tensile strength and high tensile modulus.

[0039] The hard segment of the reaction mixture ensures good mechanical properties. The hard segment can be 60 to 68% by weight of the reaction mixture and can be composed of a part of both the polyol component and the aromatic isocyanate component.

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

[0041] Preferably, the liquid aromatic diisocyanate component contains only aliphatic isocyanates at impurity levels.

[0042] The soft segments of the reaction mixture can include a polymeric polyol such as a difunctional polyether in the polyol component (ii). Suitable soft polyols are PTMEG and PPG. Available examples of PTMEG-containing polyols are as follows: Terathane™ 2900, 2000, 1800, 1400, 1000, 650 and 250 from Invista, Wichita, KS; Polymeg™ 2900, 2000, 1000, 650 from Lyondell Chemicals, Limerick, PA; PolyTHF™ 650, 1000, 2000 from BASF Corporation, Florham Park, NJ. Available examples of PPG-containing polyols are as follows: Arcol™ PPG-425, 725, 1000, 1025, 2000, 2025, 3025 and 4000 from Covestro, Pittsburgh, PA; Voranol™, Voralux™, and Specflex™ product lines from Dow, Midland, MI; Multranol™, Ultracel™, Desmophen™ or Acclaim™ Polyol 12200, 8200, 6300, 4200, 2200 from Covestro (Leverkusen, DE) respectively.

[0043] The soft segments of the reaction mixture can also include one or more polyols having a polyether backbone and having 5 to 7 hydroxyl groups per molecule.

[0044] Suitable polyols having a polyether backbone and having from 5 to 7 hydroxyl groups per molecule are available as VORANOL™ 202 polyol (Dow) having 5 hydroxyl groups, a number average molecular weight of 590 and a hydroxyl number of 475 mg KOH / g, MULTRANOL™ 9185 polyol (Dow) having 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) having 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 amount of (ii)a) the high molecular weight polyol in the liquid polyol component may range from up to 85% by weight of the liquid polyol component.

[0046] The liquid aromatic diamine curing agent of the present invention may constitute from 0 to 25% by weight, or preferably from 0 to 20% by weight, based on the total solids weight of the reaction mixture.

[0047] Suitable curing agents are aromatic diamines that are liquid at standard atmospheric pressure and 40 °C. However, the curing agent must be sufficiently slow so that the two-component reaction mixture can be mixed. The curing agent, when combined with the aromatic isocyanate component and the polyol component, must cause gelation (and the reactive mixture no longer flows) in at least 15 seconds, or preferably at least 20 seconds. Thus, the curing agents of the present invention do not contain more than 5% by weight as solids of N,N-primary alkylaryldiamines, or N,N-secondary or tertiary alkyldiamines.

[0048] To enhance the reactivity between the polyol component and the diisocyanate or polyisocyanate, a catalyst can be used. Suitable catalysts include any catalysts 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, triethylenediamine such as DABCO™ 33 LV, and mixtures thereof. The amine catalyst can promote the foaming reaction.

[0049] The reaction mixture of the present invention substantially does not contain an added organic solvent.

[0050] The specific gravity of the resulting CMP polishing pad ranges from 0.2 to 0.5, preferably from 0.35 to 0.495. As the porosity increases, the bulk properties of the CMP polishing pad decrease and the removal rate (RR) increases. However, when the CMP polishing pad or the polishing layer shows an increase in porosity and is a hard polishing layer or polishing pad, it cannot be expected that the defect rate and the planarization efficiency will be improved.

[0051] The CMP polishing pad or polishing layer of the present invention contains a porous material having a large number average pore diameter (X 50 ) in the range of 75 to 200 microns, or preferably 80 to 140 microns, as measured by a scanning electron microscope (SEM). The stoichiometry of the reaction mixture of the present invention is in the range of (NH+OH):NCO of 0.85:1.0 to 1.15:1.0.

[0052] The chemical mechanical polishing layer or polishing pad of the present invention includes a polishing layer that is a uniform dispersion of porous polyurethane. Uniformity is important to achieve consistent polishing pad performance. Therefore, the reaction mixture of the present invention is selected such that the morphology of the resulting pad is stable and easily reproducible. For example, for consistent production, it is often important to control additives such as antioxidants and impurities such as water.

[0053] According to the present invention, the CMP polishing layer can be produced by spraying a reaction mixture into an open mold and curing it. Since the two-component reaction mixture of the present invention can be sprayed or deposited as a fluid for producing the CMP polishing layer, the reaction mixture of the present invention can react much faster than when such a layer is formed in a closed mold. The gelling time of a suitable reaction mixture ranges from 10 seconds or more at 65°C, or preferably from 15 seconds to 2 minutes.

[0054] The liquid reaction mixture of the present invention is a very rapidly curable composition, which can include a composition in which (i) a liquid aromatic isocyanate component and (ii) a liquid polyol component can gel with a short gelling time of 15 seconds. The reaction must be slow enough so that after combining the two components, the reaction mixture can be mixed with a static or impinging mixer. The only limitation on the gelling time is that the reaction mixture must react slowly enough so that it does not clog the mixing head where it is mixed and so that it can properly fill the mold when applied to the mold surface.

[0055] Preferably, the target or substrate in the method of the present invention is an open mold in which a groove pattern is directly incorporated into the produced pad.

[0056] The CMP polishing layer of the present invention can be produced via impinging mixing or static mixing of a reaction mixture combined with a blowing agent (water or CO2 amine (carbamate), such as a CO2 - alkanolamine blowing reagent, etc.). After impinging or static mixing, the reaction mixture is sprayed from a spray nozzle towards the target by air spraying or airless spraying. In this way, a polyurethane or polyurethane - urea CMP polishing layer with variable porosity in the range of 0.1 g / mL to 0.5 g / mL can be obtained in a controlled process, with well - uniform and approximately spherical pores throughout the pad.

[0057] The fast gelation time of the reaction mixture of the present invention means that the pores formed by spraying or deposition remain in the cured CMP polishing layer. Thus, surfactants such as nonionic surfactants such as polyethoxylated siloxanes are not necessary in the reaction mixture of the present invention to produce stable foamed products therefrom.

[0058] Furthermore, since the CMP polishing pad of the present invention is formed by spraying or foaming in the presence of a foaming agent to create foam, trace elements such as hollow microspheres are not necessary and preferably do not exist.

[0059] Porosity is introduced into the pad or polishing layer by spraying, and the resulting tensile modulus of the pad is a function of both the inherent polymer tensile modulus and the porosity, and an increase in porosity acts to decrease the density or specific gravity. Thus, to supply an acceptable tensile modulus for a two-component spray-produced pad or polishing layer, the tensile modulus of the polymer matrix needs to be acceptably high, preferably exceeding 344 MPa, and more preferably exceeding 482 MPa.

[0060] The density of the polishing layer or polishing pad is that measured by ASTM D1622-08 (2008). Density is the same as specific gravity.

[0061] The CMP polishing layer or polishing pad of the present invention is effective for polishing interlayer dielectric films (ILDs) and inorganic oxides. For the purposes of this specification, the removal rate refers to the removal rate expressed in Å / min.

[0062] The chemical mechanical polishing pad of the present invention can include only a polishing layer of a polyurethane reaction product, or a polishing layer stacked on a sub-pad or sub-layer. The polishing layer of the polishing pad of the present invention, or in the case of a stacked pad, the polishing layer of the pad, is useful in both porous and non-porous or non-filled configurations.

[0063] Preferably, the 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 even more preferably 1000 to 3000 microns (40 to 120 mils), or most preferably 1250 to 2500 microns (50 to 100 mils).

[0064] The chemical mechanical polishing pad of the present invention may further include at least one additional layer connected to the polishing layer. Preferably, the chemical mechanical polishing pad may further include a compressible sub-pad or a base layer adhered to the polishing layer. The compressible base layer preferably improves the compatibility of the polishing layer with the surface of the substrate to be polished.

[0065] The polishing layer of the chemical mechanical polishing pad of the present invention has a polishing surface adapted for polishing the substrate. Preferably, the polishing surface has a macrotexture selected from at least one of perforations and grooves. The perforations may extend from the polishing surface partway or throughout the thickness of the polishing layer.

[0066] Preferably, the grooves are arranged on the polishing surface such that when the chemical mechanical polishing pad rotates during polishing, at least one groove sweeps across the surface of the substrate to be polished.

[0067] Preferably, the polishing layer of the chemical mechanical polishing pad of the present invention has a polishing surface adapted for polishing a substrate, where the polishing surface is a macrotexture including a groove pattern formed therein, and has a macrotexture selected from curved grooves, linear grooves, perforations, and combinations thereof. Preferably, the groove pattern includes a plurality of grooves. More preferably, the groove pattern is selected from groove designs such as concentric grooves (which can be circular or spiral), curved grooves, cross-hatch grooves (e.g., arranged as an XY grid across the pad surface), other regular designs (e.g., hexagons, triangles), tire groove-type patterns, irregular designs (e.g., fractal patterns), and combinations thereof. Even more preferably, the groove design is selected from the group consisting of random grooves, concentric grooves, spiral grooves, cross-hatch grooves, XY grid grooves, hexagonal grooves, triangular grooves, fractal grooves, and combinations thereof. Most preferably, the polishing surface has a spiral groove pattern formed therein. The contour of the groove is preferably selected from a rectangle with straight sidewalls, or the cross-section of the groove can be "V"-shaped, "U"-shaped, serrated, and combinations thereof.

[0068] According to the method for manufacturing the polishing pad of the present invention, the chemical mechanical polishing pad can be formed with a macrotexture or groove pattern on its polishing surface to promote the flow of the slurry and remove polishing debris from the pad-wafer interface. Such grooves can be formed on the polishing surface of the polishing pad from the shape of the mold surface, i.e., when the mold has a female topographic mold of the macrotexture.

[0069] The chemical mechanical polishing pad of the present invention can be used for polishing a substrate selected from at least one of a magnetic substrate, an optical substrate, and a semiconductor substrate.

[0070] Preferably, the method for polishing a substrate of the present invention includes the following: 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 of the present invention; creating a 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.

[0071] Conditioning of the polishing pad includes contacting a conditioning disk with the polishing surface either during intermittent interruptions of a CMP process when polishing is temporarily stopped ("ex situ"), or during the progress of the CMP process ("in situ"). The conditioning disk typically has a rough conditioning surface composed of embedded diamond points that cut fine grooves in the pad surface, performing both polishing and grooving of the pad material to update the polishing texture. Typically, the conditioning disk rotates at a position fixed relative to the axis of rotation of the polishing pad, and as the polishing pad rotates, it sweeps an annular conditioning region.

Example

[0072] Next, the present invention will be described in detail with the following non-limiting examples:

[0073] Unless otherwise specified, all temperatures are room temperature (21 - 23 °C) and all pressures are atmospheric pressure (about 760 mmHg or 101 kPa).

[0074] Regardless of other raw materials disclosed below, the following raw materials were used in the examples:

[0075] Ethacure (trademark) 300 curing agent: Dimethylthiotoluenediamine (DMTDA), an aromatic diamine (Albemarle, Charlotte, N.C.).

[0076] Voranol™ V5055HH polyol: A polyfunctional polyether polyol (OH equivalent 2000), a high molecular weight propylene oxide polyol capped with ethylene oxide having a number average molecular weight M N 12,000 and a functionality number = 6 (The Dow Chemical Company, Midland, MI (Dow)).

[0077] 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 of 182. 100 wt% of this MDI prepolymer is treated as a hard segment.

[0078] Niax™ L5345 surfactant: A nonionic organosilicon surfactant (Momentive, Columbus, OH).

[0079] DABCO™ 33 LV amine catalyst manufactured from diazabicyclononane (triethylenediamine) (Air Products, Allentown, PA), DABCO 33 LV is a blend of 33 wt% triethylenediamine and 67 wt% dipropylene glycol.

[0080] PTMEG#: Poly(THF) or polytetramethylene glycol, manufactured by ring-opening polymerization of tetrahydrofuran (THF), and sold as PolyTHF™ polyol (BASF, Leverkusen, DE). The number following PTMEG is the average molecular weight reported by the manufacturer. This polyol is sold by BASF as PolyTHF™ and is available in three different grades with molecular weights 650, 1000, or 2000 (PolyTHF 650, PolyTHF 1000, PolyTHF2000).

[0081] Niax™ T-9 catalyst: Tin octoate (Momentive).

[0082] The properties of the CMP polishing pad were evaluated by the following method:

[0083] All tensile properties were measured in accordance with ASTM D412-06a, "Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers - Tension". The specimens were cut to the dimensions of Type C dogbone. Unless otherwise specified, five specimens were measured and the average of all specimens for each analytical sample was reported.

[0084] Tensile break elongation: It means the ratio of the length changed after the specimen breaks to the original length, and was tested in accordance with ASTM D412-06a (2006), "Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers - Tension".

[0085] In all of the following examples, the two-component reaction mixture shown was mixed and sprayed into an open mold using a collision-type mixing and air atomization system having two tanks (an isotank and a polytank) for feeding into the mixing system. The two tanks were set to the flow rate of a given material, from which the relative amounts of the two components could be easily determined. The flows from the two tanks were started and stopped simultaneously.

[0086] Comparative Example 1 Using a two-component impingement mixing and air spraying system, the reaction mixture was sprayed into an open mold. The MDI prepolymer was charged into the isocyanate tank, while 98.62 parts of PolyTHF650, 0.9857 part of Niax™ L5345 nonionic surfactant, 0.09857 part of Niax™ T-9 catalyst, and 0.2957 part of DABCO 33LV catalyst were charged into the polyol tank. The flow rate during spraying was 10.11 g / sec on the polyol side and 5.89 g / sec on the isocyanate 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 polytetrafluoroethylene (PTFE)-coated aluminum plate. The sprayed pad was cured in an oven at 100 °C for 16 hours. The resulting polishing pad was a single-layer pad having a hard segment weight fraction of 37 wt% at 95% stoichiometry without the addition of water, a bulk density of 0.88 g / mL, showing a bulk tensile modulus of 1.37 MPa, a tensile strength of 3.10 MPa, a tensile elongation of 1300%, and a 15-second Shore A hardness of 35.

[0087] Comparative Example 2 Using a two-component impingement mixing and air spraying system, the reaction mixture was sprayed into an open mold. The MDI prepolymer was charged into the isocyanate tank, while 98.62 parts of PolyTHF650, 0.9857 part of Niax™ L5345 nonionic surfactant, 0.09857 part of Niax™ T-9 catalyst, and 0.2957 part of DABCO 33LV catalyst were charged into the polyol tank. The flow rate during spraying was 10.11 g / sec on the polyol side and 5.89 g / sec on the isocyanate side. The air injected into the nozzle was set at a nominal rate of 20 L / min. The sprayed polyurethane formulation was directed onto a PTFE-coated aluminum plate. The sprayed pad was cured in an oven at 100 °C for 16 hours. The resulting pad was formulated to have a hard segment weight fraction of 37 wt% at 95% stoichiometry without the addition of water, resulting in a pad with a bulk density of 0.97 g / mL, showing a bulk tensile modulus of 1.65 MPa, a tensile strength of 3.65 MPa, and a tensile elongation of 1200%, and a 15-second Shore A hardness of 36.

[0088] Comparative Example 3 Using a two-component impingement mixing and air spray system, the reaction mixture was sprayed into an open mold. The MDI prepolymer was charged into the isocyanate tank, while 98.52 parts of PolyTHF650, 0.9847 part of Niax™ L5345 nonionic surfactant, 0.09847 part of Niax™ T-9 catalyst, 0.2954 part of DABCO 33LV catalyst, and 0.098 part of water were charged into the polyol tank. The flow rate during spraying was 9.99 g / sec on the polyol side and 6.01 g / sec on the isocyanate 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 pad was cured in an oven at 100 °C for 16 hours. The resulting pad had a hard segment weight fraction of 38 wt% at 95% stoichiometry with 1000 ppm of water added, resulting in a pad with a bulk density of 0.73 g / mL, a bulk tensile modulus of 1.03 MPa (150 psi), a tensile strength of 3.65 MPa (530 psi), and a tensile elongation of 1200%, and a 15 second Shore A hardness of 32.

[0089] Comparative Example 4 A reaction mixture was sprayed into an open mold using a two-component impinging mixing and air atomization system. MDI prepolymer was charged into the isotank, while 98.52 parts of PolyTHF650, 0.9847 part of Niax™ L5345 nonionic surfactant, 0.09847 part of Niax™ T-9 catalyst, 0.2954 part of DABCO 33LV catalyst and 0.098 part of water were charged into the polyol tank. The flow rate during spraying was 9.99 g / sec on the polyol side and 6.01 g / sec on the iso side. The air injected into the nozzle was set at a nominal rate of 20 L / min. The sprayed polyurethane formulation was directed onto a Teflon-coated aluminum plate. The sprayed pad was cured in an oven at 100 °C for 16 hours. The resulting pad had a hard segment weight fraction of 38 wt% at 95% stoichiometry with 1000 ppm of water added, resulting in a pad with a bulk density of 0.80 g / mL, showing a bulk tensile modulus of 1.31 MPa (190 psi), a tensile strength of 3.72 MPa (540 psi), and a tensile elongation of 1200%, and a 15-second Shore A hardness of 33.

[0090] Comparative Example 5 Using a two-component reactive mixing and air spraying system, the reaction mixture was sprayed into an open mold. The MDI prepolymer was charged into the isotank, while 98.18 parts of PolyTHF650, 0.9814 parts of Niax L5345 nonionic surfactant, 0.0986 parts of Niax T-9 catalyst, 0.2942 parts of DABCO 33LV and 0.441 parts of water were charged into the polyol tank. The flow rate during spraying was 9.56 g / sec on the polyol side and 6.44 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 onto a Teflon-coated aluminum plate. The sprayed pad was cured in an oven at 100 °C for 16 hours. The resulting pad had a hard segment weight fraction of 40.7 wt% at 95% stoichiometry with 4500 ppm of water added, resulting in a pad with a bulk density of 0.39 g / mL, a bulk tensile modulus of 0.455 MPa (66 psi), a tensile strength of 1.93 MPa (280 psi), and an elongation at break of 890%, and a Shore A hardness of 15 for 15 seconds.

[0091] Comparative Example 6 A reaction mixture was sprayed into an open mold using a two-component impinging mixing and air atomization system. The MDI prepolymer was charged into the isotank, while 87.99 parts of PolyTHF650, 0.88 part of Niax L5345 nonionic surfactant, 0.0886 part of Niax T-9 catalyst, 0.264 part of DABCO 33LV, 0.220 part of water, and 10.557 parts of dipropylene glycol were charged into the polyol tank. The flow rate during spraying was 8.57 g / sec on the polyol side and 7.43 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 onto a Teflon-coated aluminum plate. The sprayed pad was cured in an oven at 100 °C for 16 hours. The resulting pad had a hard segment weight fraction of 52.5 wt% at 95% stoichiometry with 2500 ppm of water added, resulting in a pad with a bulk density of 0.53 g / mL, showing a bulk tensile modulus of 1.17 MPa (170 psi), a tensile strength of 6.00 MPa (870 psi), and a tensile elongation of 535%, and a 15-sec Shore A hardness of 27.

[0092] Example 7 Using a two-component impingement mixing and air spray system, the reaction mixture was sprayed into an open mold. The MDI prepolymer was charged into the isotank, while the polytank was charged with 73.179 parts of PolyTHF650, 0.7316 part of Niax L5345 nonionic surfactant, 0.0734 part of Niax T-9 catalyst, 0.2189 part of DABCO 33LV, 0.183 part of water, and 25.6126 parts of dipropylene glycol. The flow rate during spraying was 7.26 g / sec on the polyol side and 8.74 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 onto a Teflon-coated aluminum plate. The sprayed pad was cured in an oven at 100 °C for 16 hours. The resulting single-layer pad had a bulk density of 0.49 g / mL with a hard segment weight fraction of 66 wt% at 95% stoichiometry with 2500 ppm of water added, showing a bulk tensile modulus of 207 MPa (30,100 psi), a tensile strength of 7.58 MPa (1,100 psi), and a tensile elongation of 66%. The Shore A hardness (15 seconds) was 82 and the Shore D0 (15 seconds) hardness was 60.

[0093] The polishing experiments were performed on 200 mm wafers using an Applied Mirra polisher (Applied Materials, Santa Clara, CA) at carrier down forces 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. A 3M™ Diamond Pad Conditioner A153L (The 3M Company, Minneapolis, MN) with an aggressiveness rating of 6 - 9 from 3M and a diameter of 108 mm (4.25 inches) was used to condition and texture the polishing pads. The polishing pads were each broken in using only conditioner and DI water with a down force of 22.2 N for 30 minutes. The polishing pads were further conditioned at a down force of 22.2 N from 43 - 234 mm (1.7 - 9.2 inches) from the center of the polishing pad and at 100% in position during polishing at 10 sweeps / min. The wafers were cleaned using a Lam OnTrack DSS-200 Synergy™ CMP post-cleaner (Lam Research, Fremont, CA). To further accentuate shallow scratches, hydrogen fluoride (HF) etching was performed using an SSEC single wafer etching system (Veeco, Horsham, PA), thereby etching 200 Å of TEOS from the wafers. The step height measurements for planarization were performed using a Bruker Dynamic Atomic Force Profiler (Bruker, Billerica, MA). The substrate was a tetraethyl orthosilicate (TEOS) wafer substrate. The removal rate was determined by measuring the film thickness before and after polishing using a KLA-Tencor FX200™ metrology tool (KLA Tencor, Milpitas, CA) using a 49-point spiral scan excluding a 3 mm edge. The removal rate was calculated by the change in thickness (in angstroms / min) at individual points for a specified polish time.

[0094] The non-uniformity rate (%NUR) was calculated by the standard deviation % of the removal rate.

[0095] The defect rate was determined using an SP2 XP (trademark) and eDR5210 (trademark) scanning electron microscope wafer defect review system (KLA-Tencor). The classification of defect types was performed manually from a randomly selected set of 100 defects using Klarity Defect (trademark) software. Defects were classified as follows: A - All that the computer deems before A-HF etching; and, B - All that the computer deems after B-HF etching; and C - Chatter marks scratches identified by visual inspection by an expert. The polishing results are shown in Table 1 below.

[0096]

Table 1

[0097] The removal rate profile is shown in Table 1 above, which shows a removal rate 7% higher compared to the IC1000 (trademark) pad. The wafer was imaged immediately after polishing after rinsing and drying with DI water. The average number of defects after polishing with the IC1000 (trademark) pad was 405, while an average of 302 defects occurred in Example 7. Thus, the pad of the present invention in Example 7 shows a slight improvement in removal rate and higher pad hardness, but the defects in polishing are substantially reduced. A pad with a lower density and higher porosity of less than 0.49 g / mL is expected to be less hard and provide even better defect rate performance.

Claims

Claim 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 polishing pad including a polishing layer adapted for polishing the substrate, the polishing layer being polyurethane, and the polyurethane being a two-component reaction mixture free of organic solvents [(i) a liquid aromatic isocyanate component containing one or more aromatic diisocyanates or linear aromatic isocyanate-terminated urethane prepolymers (the unreacted isocyanate (NCO) concentration being 18 to 40% by weight based on the total solid content weight of the aromatic isocyanate component), and (ii) a liquid polyol component, a) one or more polymeric polyols, b) one or more small-chain difunctional polyols having 2 to 6 carbon atoms and being 15 to 36% by weight based on the total weight of the liquid polyol component, c) a liquid aromatic diamine that is liquid at standard atmospheric pressure and 40 °C and is 0 to 25% by weight based on the total weight of the liquid polyol component, and d) an amount of water or CO ２ -amine adducts sufficient to reduce the density of the CMP polishing pad produced from the two-component reaction mixture to 0.2 to 0.50 g / mL], the polishing pad being a product of a reaction mixture containing 60 to 75% by weight of a hard segment material based on the total weight of the reaction mixture, the CMP polishing layer having a Shore D0 (15 seconds) hardness of 40 to 80, and a density of 0.2 to 0.55 g / mL. Claim 2 (i) The liquid aromatic isocyanate component is selected from methylene diphenyl diisocyanate (MDI), toluene diisocyanate (TDI), naphthalene diisocyanate (NDI), para-phenylene diisocyanate (PPDI), or o-toluidine diisocyanate (TODI); a linear isocyanate-terminated urethane prepolymer [any of MDI, TDI, NDI, PPDI, TODI or a mixture thereof extended with one or more chain extender compounds]; or one or more diisocyanate or isocyanate-terminated linear urethane prepolymer compounds selected from mixtures thereof, the CMP polishing pad according to claim 1. Claim 3 (i) The liquid aromatic isocyanate component is selected from methylene diphenyl diisocyanate (MDI) or a linear isocyanate-terminated urethane prepolymer of MDI [MDI, or a MDI dimer extended with any 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], the CMP polishing pad according to claim 2. Claim 4 (ii) In the liquid polyol component, one or more high molecular weight polyols are selected from polytetramethylene glycol (PTMEG), polypropylene glycol (PPG), a hexafunctional polyol, and mixtures thereof, the CMP polishing pad according to claim 1. Claim 5 (ii)In the liquid polyol component, the one or more short-chain difunctional polyols having 2 to 6 carbon atoms are 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, triethylene glycol, tripropylene glycol, and mixtures thereof, the CMP polishing pad according to claim 1.

6. (ii)In the liquid polyol component, the one or more short-chain difunctional polyols having 2 to 6 carbon atoms are selected from ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, and mixtures thereof, the CMP polishing pad according to claim 5.

7. The CMP polishing pad according to claim 1, wherein the reaction mixture contains 63% to 75% by weight of the hard segment material.

8. The total number of moles of amine (NH ２ ), the total number of moles of hydroxyl (OH) groups, and the total number of moles of unreacted isocyanate (NCO) groups in the reaction mixture for producing the CMP polishing layer, and the stoichiometric ratio is in the range of 0.85:1.0 to 1.15:1.

0. The CMP polishing pad according to claim 1.

9. The CMP polishing pad contains no trace elements other than those formed by water or CO ２ - The CMP polishing pad according to claim 1, which does not contain amine adducts.

10. The CMP polishing pad according to claim 1, wherein d) is water in an amount of 1,000 to 8,500 ppm based on the total weight of the two-component reaction mixture.

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