Polishing pad formed from dual curative

Abstract

To provide a polishing pad formed from dual curative.SOLUTION: A chemical mechanical polishing pad is provided, comprising a polishing layer which comprises a reaction product of an isocyanate terminated urethane prepolymer; and a curative system comprising a sulfur containing diamine curative, and a high molecular weight polyol curative. The high molecular weight polyol curative can have reduced polishing defects. The high molecular weight polyol curative has a number average molecular weight of 2,500 to 100,000 g; and an average of 3 to 10 hydroxyl groups per molecule. The weight ratio of the high molecular weight polyol curative to the sulfur containing diamine curative is in the range of 3:10 to 7:10.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a polishing pad useful for chemical mechanical polishing. [Background technology]

[0002] In the manufacture of integrated circuits and other electronic devices, multiple layers of conductive, semiconductive, and dielectric materials are deposited on and removed from the surface of a semiconductor wafer. Thin layers of conductive, semiconductive, and dielectric materials can be deposited using a number of deposition techniques. Common deposition techniques in current wafer processing include physical vapor deposition (PVD), also known as sputtering, chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), and electrochemical plating, among others. Common removal techniques include wet and dry isotropic and anisotropic etching, among others.

[0003] As layers of material are successively deposited and removed, the top surface of the wafer becomes uneven. Subsequent semiconductor processing (e.g., metallization) requires that the wafer have a flat surface, so the wafer must be planarized. Planarization is useful for removing undesirable surface features and surface defects, such as rough surfaces, agglomerated materials, crystal lattice damage, scratches, and contaminated layers or materials.

[0004] Chemical mechanical planarization, or chemical mechanical polishing (CMP), is a common technique used to planarize or polish workpieces such as semiconductor wafers. In conventional CMP, a wafer carrier, or polishing head, is mounted on a carrier assembly. The polishing head holds the wafer and positions it in contact with a polishing layer of a polishing pad that is mounted on a table or platen in the CMP apparatus. The carrier assembly provides a controllable pressure between the wafer and the polishing pad. At the same time, a polishing medium (e.g., a slurry) is dispensed onto the polishing pad and drawn into the gap between the wafer and the polishing layer. To perform the polishing, the polishing pad and wafer typically rotate relative to one another. As the polishing pad rotates under the wafer, the wafer typically sweeps a circular polishing track, or polishing area, where the surface of the wafer is directly opposed to the polishing layer. The wafer surface is polished and planarized by the chemical and mechanical action of the polishing layer and the polishing medium on the surface.

[0005] During the polishing process, defects such as scratches and chatter marks may form on the substrate being polished.

[0006] It would be desirable to have a pad that reduces polishing defects while maintaining or improving other important properties such as removal rate. Summary of the Invention [Means for solving the problem]

[0007] Disclosed herein is a chemical mechanical polishing pad including a polishing layer having a polishing surface, the polishing layer comprising a reaction product of an isocyanate-terminated urethane prepolymer and a curing agent system including a sulfur-containing diamine curing agent and a high molecular weight polyol curing agent, the high molecular weight polyol curing agent having a number average molecular weight Mn of 2,500 to 100,000, the high molecular weight polyol curing agent having an average of 3 to 10 hydroxyl groups per molecule, and a weight ratio of the high molecular weight polyol curing agent to the sulfur-containing diamine curing agent in the range of 3:10 to 7:10. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Isocyanate-terminated urethane prepolymer The isocyanate-terminated urethane prepolymer used in forming the polishing layer of the chemical mechanical polishing pad of the present invention can comprise the reaction product of components including a polyfunctional isocyanate and a prepolymer polyol.

[0009] The polyfunctional isocyanate may be selected from the group consisting of aliphatic polyfunctional isocyanates, aromatic polyfunctional isocyanates, and mixtures thereof. The polyfunctional isocyanate may be a diisocyanate selected from the group consisting of 2,4 toluene diisocyanate, 2,6 toluene diisocyanate, 2,2' diphenylmethane diisocyanate, 2,4' diphenylmethane diisocyanate, 4,4' diphenylmethane diisocyanate, naphthalene 1,5 diisocyanate, toluidine diisocyanate, paraphenylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, 4,4' dicyclohexylmethane diisocyanate, cyclohexane diisocyanate, and mixtures thereof.

[0010] The prepolymer polyol can be selected from the group consisting of diols, polyols, polyol diols, copolymers thereof, and mixtures thereof. The prepolymer polyol can be selected from the group consisting of polyether polyols (e.g., poly(oxytetramethylene) glycol, poly(oxypropylene) glycol, poly(oxyethylene) glycol, poly(oxypropylene)-co-poly(oxyethylene) glycol), polycarbonate polyols, polyester polyols, polycaprolactone polyols, mixtures thereof, and mixtures thereof with one or more low molecular weight polyols selected from the group consisting of ethylene glycol, 1,2 propylene glycol, 1,3 propylene glycol, 1,2 butanediol, 1,3 butanediol, 2 methyl 1,3 propanediol, 1,4 butanediol, neopentyl glycol, 1,5 pentanediol, 3 methyl 1,5 pentanediol, 1,6 hexanediol, diethylene glycol, dipropylene glycol, and tripropylene glycol. For example, the prepolymer polyol may be selected from the group consisting of at least one of polytetramethylene ether glycol (PTMEG), polypropylene ether glycol (PPG), polyethylene ether glycol (PEG), and polyethylene ether glycol-co-polypropylene ether glycol (PEG-PPG copolymer); optionally mixed with at least one low molecular weight polyol selected from the group consisting of ethylene glycol, 1,2 propylene glycol, 1,3 propylene glycol, 1,2 butanediol, 1,3 butanediol, 2 methyl 1,3 propanediol, 1,4 butanediol, neopentyl glycol, 1,5 pentanediol, 3 methyl 1,5 pentanediol, 1,6 hexanediol, diethylene glycol, dipropylene glycol, and tripropylene glycol. The prepolymer polyol may be predominantly (i.e., 90% by weight or more) PTMEG.

[0011] The isocyanate-terminated urethane prepolymer can have an unreacted isocyanate (NCO) concentration of 7 to 11.4, 8 to 10, 8.3 to 9.8, 8.5 to 9.5, 8.6 to 9.3, 8.7 to 9.25, or 8.9 to 9.25 weight percent, based on the total weight of the isocyanate-terminated urethane prepolymer. Examples of commercially available isocyanate terminated urethane prepolymers include Imuthane® prepolymers (available from COIM USA, Inc., e.g., PET80A, PET85A, PET90A, PET93A, PET95A, PET60D, PET70D, PET75D); Adiprene® prepolymers (available from LANXESS Urethane Systems, e.g., LF800A, LF900A, LF910A, LF930A, LF931A, LF939A, LF950A, LF952A, LF600D, LF601D, LF650D, LF667, LF700D, LF750D, LF751D, LF752D, LF753D, L325); Andur® prepolymers (available from Anderson Development Available from the Company, for example, 70APLF, 80APLF, 85APLF, 90APLF, 95APLF, 60DPLF, 70APLF, 75APLF).

[0012] The isocyanate-terminated urethane prepolymer may be a low free isocyanate-terminated urethane prepolymer having a free toluene diisocyanate (TDI) monomer content of less than 0.1% by weight.

[0013] Hardener Curing agents include sulfur-containing diamine curing agents and high molecular weight polyol curing agents.

[0014] The sulfur-containing diamine curing agent can include a diamine-functional aromatic compound having one or more alkylthio groups pendant from the aromatic ring. For example, the sulfur-containing diamine curing agent can include, consist essentially of, or consist of dialkylthiotoluenediamine, monoalkylthiotoluenediamine, or both, in each case the alkyl group contains 1, 2, or 3 carbon atoms. For example, the sulfur curing agent can include, consist essentially of, or consist of monomethylthiotoluenediamine, dimethylthiotoluenediamine, or combinations thereof. For example, the sulfur curing agent can include 95 to 97 weight percent dimethylthiotoluenediamine, based on the total weight of the sulfur-containing diamine curing agent. For example, the sulfur curing agent can include 2 to 3% monomethylthiotoluenediamine, based on the total weight of the sulfur-containing diamine curing agent. For example, the sulfur-containing diamine curing agent can include 3,5-dimethylthio-2,4-toluenediamine, an isomer of 3,5-dimethylthio-2,4-toluenediamine (such as 3,5-dimethylthio-2,6-toluenediamine), or a combination thereof.

[0015] The high molecular weight polyol curing agent may have a number average molecular weight Mn of 2,500 to 100,000 g. For example, the high molecular weight polyol curing agent used may have a number average molecular weight Mn of 5,000 to 50,000, 7,500 to 25,000, or 10,000 to 12,000. The number average molecular weight may be determined by gel permeation chromatography against a polystyrene standard.

[0016] The high molecular weight polyol curing agent can have an average of 3 to 10, 4 to 8, 5 to 7, or 6 hydroxyl groups per molecule.

[0017] Examples of commercially available high molecular weight polyol curing agents include Specflex® Polyols, Voranol® Polyols, and Voralux® Polyols (available from The Dow Chemical Company), Multranol® Specialty Polyols and Ultracel® Flexible Polyols (available from Covestro AG), and Pluracol® Polyols (available from BASF).

[0018] The inventors have found that the use of a combination of a sulfur-containing diamine curing agent and a high molecular weight polyol curing agent in forming a polishing pad results in a surprising reduction in defects during polishing, compared to the use of either of these curing agents alone, or compared to the combination of a high molecular weight polyol with a non-sulfur-containing curing agent such as 4,4' methylene bis (2 chloroaniline) (MBOCA).

[0019] Stoichiometry of reactive groups The total reactive hydrogen groups (i.e., the total of amine (NH2) groups and hydroxyl (OH) groups) contained in the components of the curing agent system (i.e., the high molecular weight polyol curing agent and the difunctional curing agent) used to form the polishing layer of the chemical mechanical polishing pad of the present invention divided by the unreacted isocyanate (NCO) groups in the isocyanate-terminated urethane prepolymer (i.e., the stoichiometric ratio) can be from 0.85 to a maximum of 1.15, or a maximum of 1.05, or a maximum of 1.0.

[0020] Pad structure and composition The polishing surface of the polishing layer of the chemical mechanical polishing pad of the present invention is adapted to polish a substrate. For example, the polishing surface can be adapted to polish a substrate selected from at least one of a magnetic substrate, an optical substrate, and a semiconductor substrate. Preferably, the polishing surface is adapted to polish a semiconductor substrate. For example, the polishing surface can be adapted to polish a silicon oxide (e.g., tetraethyl orthosilicate (TEOS)) surface or a silicon nitride (SiN) surface of a semiconductor substrate.

[0021] The polishing surface can have a macrotexture selected from at least one of holes and grooves. The holes can extend from the polishing surface through or throughout the thickness of the polishing layer. The grooves can be arranged on the polishing surface such that at least one groove sweeps the surface of the substrate being polished as the chemical mechanical polishing pad rotates during polishing. For example, the polishing surface can have a macrotexture including at least one groove selected from the group consisting of curved grooves, straight grooves, and combinations thereof.

[0022] For example, the groove design can be selected from the group consisting of concentric grooves (which may be circular or spiral), curved grooves, radial grooves, cross-hatch grooves (e.g., arranged as an XY grid across the pad surface), other regular designs (e.g., hexagonal, triangular), tire tread-type patterns, irregular designs (e.g., fractal patterns), and combinations thereof. For example, the groove design can be selected from the group consisting of random grooves, concentric grooves, spiral grooves, radial grooves, cross-hatch grooves, XY grid grooves, hexagonal grooves, triangular grooves, fractal grooves, and combinations thereof. As a specific example, the polishing surface can have a concentric groove pattern, or a combination of a concentric groove pattern and radial grooves formed therein. The shape of the groove can be selected from a rectangle with straight sidewalls, or the cross section of the groove can be a "V" shape, a "U" shape, a sawtooth shape, and combinations thereof.

[0023] The polishing layer of the chemical mechanical polishing pad of the present invention optionally further comprises a plurality of microelements. The plurality of microelements can be uniformly distributed throughout the polishing layer. The plurality of microelements can be selected from trapped air bubbles, hollow core polymer-based materials, liquid-filled hollow core polymer-based materials, water-soluble materials, and insoluble phase materials (e.g., mineral oil). The plurality of microelements has a volume average diameter of less than 150 μm (more preferably less than 50 μm, most preferably 10-50 μm). The plurality of microelements comprises polymeric microballoons. The microballoons can have a shell wall comprising, for example, polyacrylonitrile or polyacrylonitrile copolymer (e.g., Nouryon's Expancel® microspheres). The plurality of microelements is incorporated into the polishing layer to provide a porosity of 0-50, 5-35, or 10-25 volume percent.

[0024] The polishing layer of the chemical mechanical polishing pad of the present invention can be provided in both porous and non-porous configurations (i.e., unfilled). The polishing layer of the chemical mechanical polishing pad of the present invention has a surface roughness of 0.6 g / cm as measured according to ASTM D1622. 3 For example, 0.7 to 1.2, 0.75 to 1.0, or 0.75 to 0.95 g / cm 3 The density of is shown.

[0025] The polishing layer of the chemical mechanical polishing pad of the present invention can have a Shore D hardness of 40 to 70, 45 to 55, or 50 to 55 as measured according to ASTM D2240. These hardnesses were measured using a Hoto Instruments Asker P2 durometer equipped with a D probe by stacking four 3.81 cm square samples having a thickness of 80 mils (2.032 mm) to eliminate errors in measuring the support surface.

[0026] The polishing layer of the chemical mechanical polishing pad of the present invention exhibits an elongation at break of 125-350, 140-300, or 150-200% as measured according to test method A of ASTM D412-98a (reapproved 2002). The test used an MTS Criterion C43 tester equipped with an Instron 2712-02 load cell with a maximum load of 1000 Newtons and Instron pneumatic side action grips clamping at approximately 30 psi (207 kPa). The specimens were based on the dimensions of a standard dumbbell die C in U.S. customary units with a thickness of 80 mils (2.032 mm) and the test temperature was 23° C. + / - 2° C. The specimens were deformed by the grips at 20 inches (50.8 cm) + / - 2 inches per minute (5.08 cm / min). Five replicates were measured for each sample and the median was reported.

[0027] The polishing layer of the chemical mechanical polishing pad of the present invention can have a shear modulus (30°C) G'30 of 50-300, 75-250, or 100-200 MPa measured according to ASTM D5279-13 with a sample size of 20.00 mm x 6.53 mm x 2.02 mm. The heating rate is set at 3°C / min, and a TA Instruments ARES-G2 torsional rheometer and torsional rectangular sample clamp are used, with a dynamic torsional displacement of 0.2% and a frequency of 10.0 rad / sec.

[0028] The polishing layer of the chemical mechanical polishing pad of the present invention can have a shear modulus (40° C.) G′40 of 45 to 275 MPa, measured according to ASTM D5279-13.

[0029] The polishing layer of the chemical mechanical polishing pad of the present invention can have a shear loss modulus (40° C.) G′40 of 3 to 20 MPa, measured according to ASTM D5279-13.

[0030] The polishing layer of the chemical mechanical polishing pad of this invention can have a G'30 / 90 ratio of from 1.5 or 2 to 4 as measured according to ASTM D5279-13.

[0031] The polishing layer of the chemical mechanical polishing pad of the present invention can have a toughness of from 20 MPa, or from 25 MPa, to 80 MPa, or from 70 MPa, or from 60 MPa, or from 50 MPa, or from 40 MPa, calculated from a stress-strain curve measured according to Test Method A of ASTM D412-98a (reapproved in 2002) mentioned above.

[0032] The polishing layer of the chemical mechanical polishing pad of the present invention can have a tensile strength of from 10 MPa or 15 MPa to 35 MPa or 30 MPa or 25 MPa, measured according to Test Method A of ASTM D412-98a (reapproved 2002) mentioned above.

[0033] Abrasive layer materials that exhibit high elongation at break values ​​tend to deform reversibly when subjected to machining operations, resulting in unacceptably poor groove formation and insufficient texturing during diamond conditioning. The unique hardener systems used in forming the abrasive layers of the chemical mechanical polishing pads of the present invention provide both a Shore D hardness of 40-70, 45-55, or 50-55, and an elongation at break of 125-300, 140-300, 150-250, or 150-200%, as measured according to Test Method A of ASTM D412-98a (reapproved 2002) previously described.

[0034] The abrasive layer can have an average thickness of 20 to 150 mils, 30 to 125 mils, 40 to 120 mils, or 50 to 100 mils (0.5 to 3.8 mm, 0.8 to 3.2 mm, 1.0 to 3.0 mm, or 1.3 to 2.5 mm).

[0035] The chemical mechanical polishing pad of the present invention can be adapted to be interfaced with a platen of a polisher. For example, the chemical mechanical polishing pad can be adapted to be affixed to the platen of a polisher. For example, the affixing can be achieved using at least one of a pressure sensitive adhesive and a vacuum.

[0036] The chemical mechanical polishing pad of the present invention optionally further comprises at least one additional layer bonded to the polishing layer at an interface. For example, the chemical mechanical polishing pad optionally further comprises a compressible base layer bonded to the polishing layer. The compressible base layer can improve the conformability of the polishing layer to the surface of the substrate being polished.

[0037] An important step in a substrate polishing operation is to determine the end point of the process. One common in situ method for detecting the end point includes providing a polishing pad with one or more windows transparent to light of a selected wavelength. During polishing, a light beam is irradiated onto the substrate surface through the window, where it is reflected back through the window and into a detector (e.g., a spectrophotometer). Based on the return signal, the characteristics of the substrate surface (e.g., the film thickness thereon) can be determined for the purpose of end point detection. To facilitate such light-based end point methods, the chemical mechanical polishing pad of the present invention optionally further includes an end point detection window. The end point detection window can be selected from an integral window incorporated into the polishing layer and a plug-in place end point detection window block incorporated into the chemical mechanical polishing pad. Those skilled in the art will understand how to select the appropriate construction material of the end point detection window for use in the intended polishing process.

[0038] Pad manufacturing method The method of making a chemical mechanical polishing pad of the present invention can include combining an isocyanate-terminated urethane prepolymer with a curing agent system to form a combination; reacting the combination to form a product; forming a polishing layer from the product; and forming a chemical mechanical polishing pad with the polishing layer. The combination of the isocyanate-terminated urethane prepolymer and the curing agent system can further include microelements, such as, for example, expandable polymeric microballoons.

[0039] The method can include providing a mold; pouring the combination into the mold; and reacting the combination in the mold to form a hardened cake in a heated oven; from which an abrasive layer is obtained. For example, the hardened cake is skived (sliced ​​or cut) to obtain multiple abrasive layers from a single hardened cake. Optionally, the method further includes heating the hardened cake to facilitate the skiving operation. Optionally, the hardened cake can be heated using infrared heat lamps during the skiving operation in which the hardened cake is skived into multiple abrasive layers.

[0040] The method of making a chemical mechanical polishing pad of the present invention optionally further includes providing at least one additional layer (e.g., a base layer or a subpad layer); and interfacially bonding the at least one additional layer with the polishing layer to form a chemical mechanical polishing pad; The at least one additional layer can be attached to the polishing layer by known techniques, such as by using an adhesive (e.g., a pressure sensitive adhesive, a hot melt adhesive, a contact adhesive).

[0041] The method of manufacturing a chemical mechanical polishing pad of the present invention optionally further includes providing an endpoint detection window; and incorporating the endpoint detection window into the chemical mechanical polishing pad.

[0042] Polishing method The method of the present invention for chemical mechanical polishing a substrate preferably includes: preparing a chemical mechanical polishing apparatus having a platen; preparing at least one substrate to be polished (e.g., the substrate is selected from the group consisting of at least one of a magnetic substrate, an optical substrate, and a semiconductor substrate, and preferably the substrate is a semiconductor substrate); preparing a chemical mechanical polishing pad of the present invention; mounting the chemical mechanical polishing pad on the platen; optionally providing a polishing medium (e.g., an abrasive slurry or a non-abrasive-containing reactive liquid formulation) at the interface between the polishing surface of the chemical mechanical polishing pad and the substrate, forming dynamic contact between the polishing surface and the substrate and removing at least some material from the substrate; and optionally conditioning the polishing surface with an abrasive conditioner. The polishing slurry can, for example, include a cerium oxide abrasive with or without chemical additives. Optionally, the chemical mechanical polishing apparatus prepared in the method of the present invention further includes a light source and a light sensor (preferably a multi-sensor spectrometer), and the chemical mechanical polishing pad prepared further includes an endpoint detection window; the method further includes determining a polishing endpoint by transmitting light from the light source through the endpoint detection window; and analyzing light reflected from the surface of the substrate and returned through the endpoint detection window and incident on the light sensor. EXAMPLES

[0043] Formation of abrasive layer The isocyanate-terminated urethane prepolymer was mixed with the curing agent system and expandable polymer microspheres according to the formulations shown in Table 1. In each formulation, the isocyanate-terminated urethane prepolymer has an NCO% of about 9.1%. The sulfur-containing curing agent, designated SC1, contains 95-98% by weight dimethylthiotoluenediamine and 2-3% by weight monomethylthiotoluenediamine. The high molecular weight polyol curing agent, designated HMWC2, has an average molecular weight of about 11,400 grams / mole and a nominal functionality of 6 OH groups. The expandable polymer microspheres were added to the mixture in an amount to obtain the specific gravity listed in Table 1. The amounts of isocyanate-terminated urethane prepolymer and curing agent system are selected such that the stoichiometric ratio of reactive hydrogen groups in the curing agent system to unreacted NCO groups in the isocyanate-terminated urethane prepolymer is as shown in the table. The mixture is fed into a mold and heated to form a cured composition. The density or specific gravity is determined by the actual weight and volume of the scraped pad using the polymer density. The cured composition is cast to a thickness to be used as the polishing layer and applied to a subpad.

[0044] [Table 1]

[0045] Testing pads having an abrasive layer for defects. Pads were manufactured having a polishing layer with the formulation shown in Table 1. These were used to polish three wafers with a ceria slurry.

[0046] A first set of wafers polished with pads having a polishing layer with the formulation shown in Table 2 were inspected for scratch and chatter mark defects by scanning electron microscope. The data, normalized to pads containing the Comparative 1 formulation shown in Table 2, shows that the inventive formulations show significant improvement in defectivity.

[0047] A second set of wafers polished with pads having a polishing layer with the formulation shown in Table 3 were examined by scanning electron microscope for scratch and chatter mark defects, and for TEOS and SiN removal rates. The data normalized to pads with the formulation of Comparative 1 shown in Table 3 shows that the formulations of the present invention have significantly improved defectivity and improved SiN removal rates.

[0048] A third set of wafers polished with pads having a polishing layer with the formulation shown in Table 4 were examined by scanning electron microscope for scratch and chatter mark defects, and for TEOS and SiN removal rates. The data normalized to pads with the formulation of Comparative 1 shown in Table 4 shows that the inventive formulations significantly improved defectivity and improved SiN removal rates with little or no degradation in TEOS removal rates.

[0049] [Table 2]

[0050] [Table 3]

[0051] [Table 4]

[0052] Accordingly, the following non-limiting aspects are disclosed herein:

[0053] Aspect 1. A chemical mechanical polishing pad comprising a polishing layer having a polishing surface, the polishing layer comprising a reaction product of an isocyanate-terminated urethane prepolymer and a curing agent system comprising (a) a sulfur-containing diamine curing agent and (b) a high molecular weight polyol curing agent, the high molecular weight polyol curing agent having a number average molecular weight Mn of 2,500 to 100,000, the high molecular weight polyol curing agent having an average of 3 to 10 hydroxyl groups per molecule, and a weight ratio of the high molecular weight polyol curing agent to the sulfur-containing diamine curing agent in the range of 3:10 to 7:10.

[0054] Embodiment 2. The chemical mechanical polishing pad of embodiment 1, wherein the sulfur-containing diamine curing agent comprises a diamine-functional aromatic compound having one or more alkylthio groups pendant from the aromatic ring.

[0055] Aspect 3. The chemical mechanical polishing pad of aspect 1 or 2, wherein the sulfur-containing diamine curing agent comprises a dialkylthiotoluene diamine, a monoalkylthiotoluene diamine, or both, in each case, the alkyl group contains 1, 2, or 3 carbon atoms.

[0056] Embodiment 4. The chemical polishing pad according to any one of embodiments 1 to 3, wherein the sulfur-containing diamine curing agent comprises at least 95 weight percent dimethylthiotoluenediamine, based on the total weight of the diamine curing agent.

[0057] Aspect 5. The chemical polishing pad according to any one of Aspects 1 to 4, wherein the weight ratio of the high molecular weight polyol curing agent to the sulfur-containing diamine ranges from 4:10 to 5:10.

[0058] Aspect 6. The chemical polishing pad according to any one of Aspects 1 to 5, wherein the isocyanate-terminated urethane prepolymer has 8.3 to 9.8 weight percent unreacted NCO groups.

[0059] Aspect 7. The chemical polishing pad according to any one of aspects 1 to 6, wherein the curing agent system has a plurality of reactive hydrogen groups, the isocyanate-terminated urethane prepolymer has a plurality of unreacted NCO groups, and the stoichiometric ratio of reactive hydrogen groups to unreacted NCO groups is 0.85 to 1.15.

[0060] Aspect 8. The chemical polishing pad according to any one of aspects 1 to 7, wherein the polishing layer has a density of 0.7 to 1.1 g / cubic centimeter, as determined by dividing the actual weight by the actual volume.

[0061] Embodiment 9. The chemical polishing pad of any one of embodiments 1 to 8, wherein the polishing layer comprises expanded polymeric microspheres.

[0062] Aspect 10. The chemical polishing pad of any one of aspects 1 to 9, wherein the polishing surface comprises grooves in a concentric, radial, or combination thereof pattern.

[0063] Aspect 11. The chemical polishing pad according to any one of Aspects 1 to 10, wherein the high molecular weight polyol curing agent has a number average molecular weight of 5,000 to 50,000, preferably 7,500 to 25,000, or more preferably 10,000 to 12,000.

[0064] Aspect 12. The chemical polishing pad according to any one of aspects 1 to 11, wherein the high molecular weight polyol curing agent has an average of 4 to 8, preferably 5 to 7, or more preferably 6 hydroxyl groups per molecule.

[0065] All ranges disclosed herein are inclusive of the endpoints, and the endpoints can be independently combined with each other (e.g., the range "up to 25% by weight, more specifically 5% to 20% by weight" includes the endpoints and all intermediate values ​​in the range "5% to 25% by weight", etc.). Additionally, the upper and lower limits listed can be combined to form ranges (e.g., "at least 1% by weight or at least 2% by weight" and "up to 10% or 5% by weight" can be combined to form the ranges "1 to 10% by weight" or "1 to 5% by weight" or "2 to 10% by weight" or "2 to 5% by weight").

[0066] The present disclosure can either comprise, consist of, or consist essentially of any suitable components disclosed herein. The present disclosure can additionally or alternatively be formulated to be free or substantially free of any components, materials, ingredients, adjuvants, or species used in prior art compositions or that are not necessary to achieve the function and / or purpose of the present disclosure.

[0067] All cited patents, patent applications, and other references are incorporated herein by reference in their entirety, except that if a term from an incorporated reference conflicts or conflicts with a term in this application, the term in this application takes precedence over the conflicting term in the incorporated reference.

[0068] Unless otherwise specified herein, all test standards are the latest standards in effect as of the filing date of this application or, if priority is claimed, as of the filing date of the earliest priority application in which the test standard appears.

Claims

1. 1. A chemical mechanical polishing pad comprising a polishing layer having a polishing surface, the polishing layer comprising an isocyanate-terminated urethane prepolymer and (a) a sulfur-containing diamine curing agent; and (b) a curing agent system including a high molecular weight polyol curing agent, said high molecular weight polyol curing agent having a number average molecular weight Mn of 2,500 to 100,000, said high molecular weight polyol curing agent having an average of 3 to 10 hydroxyl groups per molecule; The chemical mechanical polishing pad has a weight ratio of the high molecular weight polyol curing agent to the sulfur-containing diamine curing agent in the range of 3:10 to 7:

10.

2. 10. The chemical mechanical polishing pad of claim 1, wherein the sulfur-containing diamine curing agent comprises a diamine-functional aromatic compound having one or more alkylthio groups pendant from an aromatic ring.

3. 3. The chemical mechanical polishing pad of claim 2, wherein the sulfur-containing diamine curing agent comprises a dialkylthiotoluene diamine, a monoalkylthiotoluene diamine, or both, in each case where the alkyl group contains 1, 2, or 3 carbon atoms.

4. 2. The chemical mechanical polishing pad of claim 1, wherein the sulfur-containing diamine curing agent comprises at least 95 weight percent dimethylthiotoluenediamine, based on the total weight of the diamine curing agent.

5. 2. The chemical mechanical polishing pad of claim 1, wherein the weight ratio of the high molecular weight polyol curing agent to the sulfur-containing diamine ranges from 4:10 to 5:

10.

6. 2. The chemical mechanical polishing pad of claim 1, wherein the isocyanate-terminated urethane prepolymer has 8.3 to 9.8 weight percent unreacted NCO groups.

7. 2. The chemical mechanical polishing pad of claim 1, wherein the curing agent system has a plurality of reactive hydrogen groups, the isocyanate-terminated urethane prepolymer has a plurality of unreacted NCO groups, and the stoichiometric ratio of the reactive hydrogen groups to the unreacted NCO groups is from 0.85 to 1.

15.

8. 10. The chemical mechanical polishing pad of claim 1, wherein the polishing layer has a density of 0.7 to 1.1 g / cubic centimeter as determined by dividing the actual weight by the actual volume.

9. The chemical mechanical polishing pad of claim 1 , wherein the polishing layer comprises expanded polymeric microspheres.

10. 10. The chemical mechanical polishing pad of claim 1, wherein the polishing surface comprises grooves in a concentric, radial, or combination pattern.

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