Pad for chemical mechanical polishing

Abstract

To provide a pad that can be used at high pressures and optionally paired with ceria slurries to achieve higher removal rate without introducing any negative effects.SOLUTION: A polishing pad suitable for polishing at least one of semiconductor, optical, magnetic or electromechanical substrates comprises a polishing layer including a polyurea having a soft phase and a hard phase. The soft phase is a copolymer of aliphatic fluorine-free species and a fluorinated aliphatic species. The polyurea is cured with a curative agent. The hard phase includes crystallinity. The polyurea is characterized by a melting point of at least 230°C and ΔHf of at least 3 J / g as determined by dynamic scanning calorimetry of the polyurea.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The field of this invention is chemical mechanical polishing and pads useful for chemical mechanical polishing. [Background technology]

[0002] Chemical mechanical planarization (CMP) is a type of polishing technique widely used to flatten, or planarize, layers of integrated circuit structures in order to accurately construct multilayer three-dimensional circuits. The layer being polished is typically a thin film (less than 10,000 angstroms) deposited on the underlying substrate. The purpose of CMP is to remove excess material from the wafer surface to produce an extremely flat layer of uniform thickness that extends across the entire wafer area. Controlling the removal rate and ensuring uniformity of removal are of paramount importance.

[0003] CMP utilizes a liquid, often called a slurry, containing nano-sized particles. The slurry is supplied to the surface of a rotating multilayer polymer sheet, or pad, mounted on a rotating platen. The wafer is mounted in a separate fixture, or carrier, with a separate rotating mechanism, and pressed against the surface of the pad under a controlled load. This creates high-speed relative motion between the wafer and the polishing pad (i.e., high-speed shear occurs on both the substrate and the pad surface). The slurry particles trapped at the pad / wafer junction abrade the wafer surface to achieve removal. Various types of textures are incorporated into the top surface of the polishing pad to control the speed, prevent hydroplaning, and efficiently transport the slurry under the wafer. Fine-scale textures are produced by abrading the pad with an array of micro-diamonds. This is done to control and increase the removal speed and is commonly called conditioning. Also, grooves of various patterns and dimensions (e.g., XY, circular, radial) on a larger scale are incorporated to regulate fluid dynamics and slurry transport.

[0004] It is widely accepted that the removal rate during CMP follows Preston's equation: rate = Kp * P * V (where P is the pressure of the pad on the substrate, V is the velocity of the pad on the substrate, and Kp is the so-called Preston coefficient). The Preston coefficient is a lumped sum constant characteristic of the set of consumables used. Some of the most important influences contributing to Kp are: (a) the pad contact area (which largely depends on the pad texture and the mechanical properties of the surface); (b) the concentration of slurry particles on the contact area surface available for working; and (c) the reaction rate between the surface particles and the surface of the layer being polished. Influence (a) is determined primarily by the pad properties and the conditioning process. Influence (b) is determined by both the pad and the slurry, and influence (c) is determined primarily by the properties of the slurry.

[0005] The emergence of high-capacity multilayer memory devices (such as 3D NAND flash memory) has necessitated a further increase in removal speed. A key part of the 3D NAND manufacturing process involves stacking multilayer layers of SiO2 and Si3N4 films alternately in a pyramidal, stepped structure. Once completed, the stack is capped with a thick SiO2 overlayer, which must then be planarized before the device structure is finalized. This thick film is commonly called a pre-metallic diode (PMD). Device capacity is proportional to the number of layers in the stack. Current commercial devices use 32 and 64 layers, but the industry is rapidly moving towards 128 layers. The thickness of each oxide / nitride pair in the stack is approximately 125 nm. Therefore, the stack thickness increases in direct proportion to the number of layers (32=4,000 nm, 64=8,000 nm, 128=16,000 nm). In the case of a PMD step, the total amount of capping insulator removed is approximately equal to about 1.5 times the stack thickness, assuming shape-conforming deposition of the PMD.

[0006] Conventional insulator CMP slurries have a removal rate of approximately 250 nm / min. This results in undesirably long CMP processing times for the PMD step, which is now the main bottleneck in the 3D NAND manufacturing process. As a result, considerable effort has been devoted to developing faster CMP processes. Most improvements have focused on processing conditions (higher P and V), changes to the pad conditioning process, and slurry design, particularly improvements to ceria-based slurries.

[0007] Certain pads exhibit a benefit in removal rate from higher downforces up to a certain pressure (or downforce), but beyond that pressure, the removal rate may plateau or even decrease. Improved pads that can be used at higher pressures and, optionally, combined with cerias slurry to achieve higher removal rates without negative effects would represent a significant improvement in CMP technology. [Overview of the Initiative] [Means for solving the problem]

[0008] Disclosed herein is a polishing pad adapted for polishing at least one of semiconductor, optical, magnetic, or electromechanical substrates, comprising a polishing layer containing a polyurea having a soft phase and a hard phase, wherein the soft phase is a copolymer of an aliphatic fluorine-free species and a fluorinated aliphatic species, the polyurea is cured with a curing agent, the hard phase contains a degree of crystallinity, and the polyurea has a melting temperature of at least 230°C and a ΔH of at least 3 joules / gram, as determined by dynamic scanning calorimetry of the polyurea. f This is a polishing pad characterized by the following features.

[0009] Here, we refer to the drawings, which represent exemplary embodiments. In the drawings, similar elements are denoted by similar reference numerals. [Brief explanation of the drawing]

[0010] [Figure 1]Figure 1 is a DSC thermograph showing the performance of various fluorinated polyureas. [Figure 2] Figure 2 is a graph showing the removal rate against downforce pressure at a platen speed of 90 revolutions per minute (rpm) for both a comparative pad and the pad of the present invention. [Figure 3] Figure 3 is a graph showing the removal rate against downforce pressure at a platen speed of 120 revolutions per minute (rpm) for both a comparative pad and the pad of the present invention. [Modes for carrying out the invention]

[0011] Detailed explanation The polishing pads disclosed herein are suitable for polishing at least one of semiconductor, optical, magnetic, or electromechanical substrates. The polishing layer of the polishing pad comprises a polyurea having a soft phase and a hard phase. The soft phase comprises segments formed using a relatively low concentration of fluorine-containing aliphatic polymer (about 1 to 20% by weight (wt%) based on the total weight of the soft segments) and a non-fluorinated aliphatic polymer. The hard phase has a melting temperature (Tm) of at least 230°C and an enthalpy of formation (ΔH) of at least 3 joules / gram, at least 3.5 joules / gram, or at least 4 joules / gram, as determined by dynamic scanning calorimetry. f ) includes the degree of crystallinity indicated by ΔH. Tm can be a temperature lower than the decomposition temperature of the polymer, for example, 300°C or less, 280°C or less, 275°C or less, or 270°C or less. f The tangency can be 35 joules / gram or less, 30 joules / gram or less, or 25 joules / gram or less. More specifically, the melting temperature Tm can be determined by dynamic scanning calorimetry (DSC) by placing a sample of the polymer in a pan, equilibrating it at room temperature, and then raising the temperature to 300°C at a rate of 10°C / min. The melting temperature is recorded as the lowest point on the curve where endothermic activity indicating melting appears. ΔH f This can be determined from the DSC curve by integrating the area from where the endothermic reaction begins to where it ends.

[0012] The pad can produce an improved removal rate during polishing and can withstand higher polishing pressure and polishing speed. Furthermore, the polishing pad can achieve improved performance by being hydrophilic during polishing. Achieving a hydrophilic polishing pad during polishing facilitates the achievement of a thin and efficient pad / wafer gap for efficient polishing. The addition of a fluorine-containing copolymer reduces the electronegativity or zeta potential of the pad, which makes the pad surface highly hydrophilic during polishing.

[0013] The hard phase contains rigid, rigid segments that provide stiffness. The hard phase can be partially crystalline and partially amorphous. The amorphous portion has a relatively higher glass transition temperature (Tg) compared to the soft phase (soft segments). The Tg of the hard phase can be, for example, in the range of 100 to 170°C. Furthermore, thanks to the partial crystalline structure of the hard phase, a melting temperature Tm is observed in the hard phase. The melting temperature of polyurea can be at least 230°C. Tg can be determined by dynamic mechanical analysis (DMA).

[0014] The soft phase contains segments that are more flexible at room temperature and generally have a lower Tg compared to the hard phase segments. Phase separation occurs due to immismiability between the hard and soft segments. The Tg of the soft phase can be in the range of, for example, -40 to 130°C.

[0015] The rigid and flexible segments are crosslinked with a polyamine (e.g., a diamine). The amine group reacts with the isocyanate groups of the rigid segment components (e.g., prepolymer) and the flexible segments (e.g., prepolymer) to form the urea bond of the polyurea.

[0016] The soft phase can be formed from soft segments having one or more aliphatic fluorine-free species (e.g., monomers, dimers, trimers, or higher-order oligomers), each having two reactive end groups, and at least one fluorinated species (e.g., polymers such as monomers or oligomers). The fluorinated species may have at least 6, at least 8, and a length of 20 or 16 carbon atoms or less. For example, the fluorinated species may include polymers (e.g., oligomers) of fluorinated alkylene oxides and non-fluorinated alkylene oxides. The aliphatic fluorine-free polymer group is bonded to the reactive end group of at least one fluorinated species. The bond may be nitrogen-containing. Examples of nitrogen-containing bonds include urea groups and urethane groups. One end of the aliphatic fluorine-free polymer group is bonded to at least one nitrogen-containing bond of a fluorinated species. An isocyanate group can cap the reactive end of the aliphatic fluorine-free polymer group. Typically, the reacting aliphatic fluorine-free polymer species can have a number-average molecular weight of 200-7500 or 250-5000, as measured, for example, by gel permeation chromatography (GPC), or as specified in the product documentation. For clarity, the number-average molecular weight of the aliphatic fluorine-free polymer group ends does not include any of the following: isocyanate end groups, nitrogen-containing bonds, or amine curing agents. The soft segments form a soft phase within the polyurea matrix. The aliphatic fluorine-free polymer group can be a polytetramethylene ether bonded to the fluorinated species. The fluorinated species may contain at least one fluorinated ether. The fluorinated species may contain reaction products of fluorinated ethylene oxide, fluorinated oxymethylene, and ethylene oxide. The atomic ratio of the fluorinated ether group, e.g., fluorinated ethylene oxide and fluorinated oxymethylene, to ethylene oxide may be less than 3.

[0017] The hard phase can be formed from a fluorine-free diisocyanate-containing hard segment and an amine-containing curing agent. The hard segment may include urea groups formed from isocyanate groups that cap the outer ends of aliphatic fluorine-free polymer groups reacted with the amine-containing curing agent. The hard segment can aggregate as a hard phase within the soft phase. This configuration provides a fluorine-rich phase (which can improve ceria interactions) and a hard phase to reinforce the soft phase, improving polishing asperity integrity for enhanced pad life and stability when polishing multiple wafers. The hard segment (e.g., isocyanate or urea portion) and the soft segment can form a prepolymer, which then reacts with the amine-containing curing agent to form a polyurea matrix. The presence of a fluorine-containing portion in the soft segment increases the soft-segment glass transition temperature (Tg) of the soft phase. This unexpected increase in glass transition temperature enhances the thermal stability of the polymer.

[0018] During polishing, concentration of fluorinated soft segment components can occur on the uppermost surface of the polymer in the air. The in situ and continuous generation of this fluorine-rich phase on the surface further enhances the beneficial effects of small amounts of fluoropolymer. At relatively low concentrations of fluorinated soft segment (e.g., less than 20% by weight of the total soft segment content), the amount of fluorinated species is insufficient to prevent dipole rearrangement of water molecules when the polymer is subsequently exposed to water, particularly under shear. This results in complex wetting behavior when droplets are exposed to shear. Specifically, it is thought that the water surface rearranges, leading to increased water interaction with the hydrophilic portion of the polymer. This, in turn, results in a decrease in the receding contact angle of the droplets and a corresponding increase in surface energy during polishing. As a result, under shear, the polishing pads disclosed herein can become more hydrophilic than their fluorine-free analogues.

[0019] The polyurethane used in the polishing layer of the polishing pad disclosed in this specification is a block copolymer. The terminally isocyanate-modified urethane prepolymer that can be used in the formation of the polishing layer of the chemical mechanical polishing pad disclosed in this specification can include a reaction product of components including a polyfunctional isocyanate and a prepolymer mixture containing two or more components, one of which is fluorinated.

[0020] The isocyanate is polyfunctional and is, for example, a diisocyanate. Examples of diisocyanates include 2,4-toluene diisocyanate; 2,6-toluene diisocyanate; 4,4'-diphenylmethane diisocyanate; naphthalene-1,5-diisocyanate; toluidine diisocyanate; para-phenylene diisocyanate; xylylene diisocyanate; isophorone diisocyanate; hexamethylene diisocyanate; 4,4'-dicyclohexylmethane diisocyanate; cyclohexane diisocyanate; and mixtures thereof. The diisocyanate can be toluene diisocyanate.

[0021] Aliphatic fluorine-free polymer groups can be reacted from the group consisting of diols, polyols, polyoldiols, copolymers thereof, and mixtures thereof. For example, it is possible to react an aliphatic fluorine-free polymer group with a diisocyanate and then bond a fluorinated species to the diisocyanate. The prepolymer polyol can be selected from the group consisting of polyether polyols (for example, polyalkylene glycols containing 2 to 5 carbon atoms in the alkylene, such as poly(oxytetramethylene) glycol, poly(oxypropylene) glycol, poly(oxyethylene) glycol); polycarbonate polyols; polyester polyols; polycaprolactone polyols; mixtures thereof; and mixtures of one or more of these 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. The prepolymer polyol may be polytetramethylene ether glycol (PTMEG); polypropylene ether glycol (PPG); polyethylene ether glycol (PEG); or a mixture of one or more selected low molecular weight polyols, 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; and tripropylene glycol, or a mixture thereof, which can be optionally mixed with these. The prepolymer polyol may be primarily (e.g., ≥90% by weight) polytetramethylene ether. Fluorinated polyols can be produced by adding fluorine by substitution from any of the above non-fluorinated polyols.This minimizes the variation in the final mechanical properties.

[0022] The terminal isocyanate-modified urethane prepolymer can have an unreacted isocyanate (NCO) concentration of 8.5 to 9.5% by weight. Examples of commercially available terminal isocyanate-modified urethane prepolymers include Imuthane™ prepolymers (commercially available from COIM USA, Inc., such as PET-80A, PET-85A, PET-90A, PET-93A, PET-95A, PET-60D, PET-70D, PET-75D); Adiprene™ prepolymers (commercially available from Chemtura, such as LF-800A, LF-900A, LF-910A, LF-930A, LF-931A, LF-939A, LF-950A, LF-952A, LF-600D, LF-601D, LF-650D, LF-667, LF-70D, LF-750D, LF-751D, LF-752D, LF-753D and L325); Andur™ prepolymers (commercially available from Anderson Development Company, such as 70APLF, 80APLF, 85APLF, 90APLF, 95APLF, 60DPLF, 70APLF, 75APLF).

[0023] The terminal isocyanate-modified urethane prepolymer can be a low-free isocyanate-terminated urethane prepolymer having a free toluene diisocyanate (TDI) monomer content of less than 0.1% by weight.

[0024] The inventors have found that the selection of the curing agent used in the formation of the polishing layer enables the formation of crystallinity in the hard phase and can increase the melting temperature Tm. In particular, the curing agent has the formula I

Chemical formula

[0025] For example, the curing agent can be bis(4-amino-2-chloro-3,5-diethylphenyl)methane ("MCDEA").

[0026] A curing agent of formula I, such as MCDEA, can be used in amounts of 30, 40, 45-100, 95, 90, or 80 mol% based on the total amount of curing agent, and the desired thermal stability can be achieved.

[0027] In addition to the curing agent of formula I, for example MCDEA, the curing agent may contain one or more further polyfunctional aromatic amines. Examples of such further polyfunctional aromatic amines include diethyltoluenediamine (DETDA); 3,5-dimethylthio-2,4-toluenediamine and its isomers; 3,5-diethyltoluene-2,4-diamine and its isomers (e.g., 3,5-diethyltoluene-2,6-diamine); 4,4′-bis-(sec-butylamino)diphenylmethane; 1,4-bis-(sec-butylamino)-benzene; 4,4′-methylene-bis-(2-chloroaniline)polytetramethyleneoxide-di-p-aminobenzoate; N,N-dialkyldiaminodi Phenylmethane; p,p′-methylenedianiline (MDA); m-phenylenediamine (MPDA); 4,4′-methylene-bis-(2-chloroaniline) (MBOCA); 4,4′-methylene-bis-(2,6-diethylaniline) (MDEA); 4,4′-methylene-bis-(2,3-dichloroaniline) (MDCA); 4,4′-diamino-3,3′-diethyl-5,5′-dimethyldiphenylmethane; 2,2′,3,3-tetrachlorodiaminodiphenylmethane; trimethylene glycol di-p-aminobenzoate; and mixtures thereof.

[0028] The polishing pads disclosed herein can be manufactured by a method comprising the steps of: providing a terminal isocyanate-modified urethane prepolymer; separately, providing a curing agent component; combining the terminal isocyanate-modified urethane prepolymer and the curing agent component to form a mixture; reacting the mixture to form a product; forming an abrasive layer from the product, for example by skiving the product to form an abrasive layer of a desired thickness; and creating grooves in the abrasive layer, for example by machining; and forming a chemical mechanical polishing pad having the abrasive layer.

[0029] The polishing layer of the chemical mechanical polishing pad disclosed herein may further include a plurality of microelements. The microelements may be uniformly dispersed throughout the polishing layer or dispersed according to a gradient from top to bottom of the polishing layer. The microelements may be, for example, trapped bubbles, hollow core polymer materials, liquid-filled hollow core polymer materials, water-soluble materials and insoluble phase materials (e.g., mineral oil). More specifically, the plurality of microelements may be selected from trapped bubbles and hollow core polymer materials uniformly dispersed throughout the polishing layer. The plurality of microelements may have a diameter of less than 150 μm or 50 μm or less; and a weight-average diameter of at least 1 μm or at least 10 μm. For example, the plurality of microelements may be polymer microballoons having shell walls of polyacrylonitrile or vinylidene chloride-polyacrylonitrile copolymer (e.g., Akzo Nobel's ExpanseL® microspheres). Multiple microelements that provide pores can be incorporated into the polishing layer to produce a porosity of 0-50 volume% or 10-35 volume%. The volume% of pores can be determined by dividing the difference between the specific gravity of the unfilled polishing layer and the specific gravity of the microelement-containing polishing layer by the specific gravity of the unfilled polishing layer.

[0030] The abrasive layers of the polishing pads disclosed herein may be provided in a porous or non-porous (i.e., unfilled) form. The abrasive layers of the chemical mechanical polishing pads disclosed herein have a density of 0.4 to 1.15 g / cm³ as measured according to ASTM D1622 (2014). 3 Or 0.70-1.0 g / cm³ 3 It can have a density of .

[0031] The abrasive layer of the chemical mechanical polishing pads disclosed herein may have a Shore D hardness of 28 to 75 as measured according to ASTM D2240 (2015).

[0032] The abrasive layer can have an average thickness of 20-150 mils (0.05-0.4 cm), 30-125 mils (0.08-0.3 cm), 40-120 mils (0.1-0.3 cm), or 50-100 mils (0.13-0.25 cm).

[0033] The polishing pads disclosed herein can be adapted to interface with the platen of a polishing machine. For example, a CMP polishing pad can be adapted to be attached to the platen of a polishing machine (for example, using at least one of a pressure-sensitive adhesive and a vacuum).

[0034] The polishing pads disclosed in the present invention further optionally include at least one further layer interfaced with the polishing layer. For example, a CMP polishing pad may further optionally include a compressible base layer bonded to the polishing layer. The compressible base layer can improve the shape conformity of the polishing layer to the surface of the substrate being polished. This shape conformity can improve the polishing removal rate and broad-area uniformity.

[0035] The polishing pads disclosed herein may, in their final form, include textures of one or more dimensions on their surface. Such textures can be classified by size into macrotextures or microtextures. Macrotextures can facilitate hydrodynamic response and control of slurry transport. Macrotextures can, in no particular way, include grooves of many forms and designs, such as annular, radial, asymmetric radial, and crosshatch grooves, and protrusions arranged in regular, accidental, or annular or radial patterns (e.g., columnar objects of various shapes, pyramidal objects). These can be formed directly on the pad by molding or on a thin, uniform sheet by machining. Microtextures include finer-scale features that form a collection of surface asperities, which are contact points with the substrate wafer being polished. For example, microtextures can, in no particular way, include textures formed by abrasion with an array of hard particles such as diamond before, during, or after use (often called pad conditioning), and microtextures formed during the pad manufacturing process.

[0036] Unlike porous pads, non-porous pads have increased rigidity for improved planarization efficiency, reduced dishing, and lower wear rates. Because non-porous pads polish differently from porous pads, both types of pads typically require different groove patterns and different diamond conditioners to produce a viable CMP pad. Without a proper groove pattern and microtexture, these pads are susceptible to hydroplaning and glazing of the polishing pad surface. Glazing is where the pad wears or deforms, reducing its texture. For example, severe glazing is where the pad loses all of its microtexture.

[0037] As described in the "Background Art" section of this specification, CMP polishing pads are used with polishing slurries. The polishing pads disclosed herein can be used in particular with such slurries, especially those having a pH below the isoelectric point pH of the particles used. For example, ceria has an isoelectric point pH of about 6.6. Below this pH, the particle surface has a net positive charge. Above this pH, the particles have a net negative charge. Since the pads disclosed herein can exhibit a high negative charge at their pH, velocity enhancement is achieved when the particles are below their isoelectric point.

[0038] The polishing pads disclosed herein can be manufactured by a variety of methods compatible with thermosetting urethane. Such methods include mixing the above components, pouring them into a mold, annealing, and slicing them into sheets of the desired thickness. Alternatively, they can also be manufactured in a more precise net form. For example, the following methods can be used: 1. Injection molding of thermosetting resins (often called “reaction injection molding” or “RIM”); 2. Injection blow molding of thermoplastic or thermosetting resins; 3. Compression molding; or 4. Any similar type of method of placing a fluid material and allowing it to solidify, thereby forming at least a portion of the macro-texture or micro-texture of the pad. In one example of molding: 1. Extrude the fluid material into or onto a structure or substrate; 2. As the material solidifies, the structure or substrate imparts a surface texture to the material; 3. Then separate the structure or substrate from the solidified material. [Examples]

[0039] material PTMEG was a blend of various PTMEGs with molecular weights ranging from 250 to 2000.

[0040] 4,4′-Dicyclohexylmethane diisocyanate (H12MDI).

[0041] Toluene diisocyanate (TDI).

[0042] Toluene diisocyanate ("H12MDI / TDI") PTMEG was a prepolymer containing 8.95–9.25% by weight of NCO.

[0043] The polymer microspheres were vinylidene chloride-polyacrylonitrile copolymer microspheres with an average particle size of approximately 20 μm.

[0044] The fluoropolymer was an ethoxylated perfluoroether. The fluoropolymer had a linear structure of fluorinated ethylene oxide-ethylene oxide-capped fluorinated oxymethylene. The atomic ratio "R" of fluorinated ether to ethylene oxide was 1.9 or 5.3.

[0045] MCDEA was bis(4-amino-2-chloro-3,5-diethylphenyl)methane.

[0046] MBOCA was 4,4′-methylene-bis(2-chloroaniline).

[0047] Prepolymer synthesis procedure The prepolymer was synthesized in batches ranging from approximately 200 to 1000 grams. Ethoxylated perfluoroether and PTMEG were mixed to produce polytetramethyl ether with the desired fluorination level. TDI and H12MDI were mixed in a weight ratio of 80:20 and then added to the mixture. Next, a sufficient isocyanate mixture to achieve the desired NCO% by weight was added to the mixture of ethoxylated perfluoroether and PTMEG. After mixing the entire mixture again, it was placed in a preheated oven at 65°C for 4 hours before use.

[0048] Pad manufacturing procedure The synthesized prepolymer and the ("H12MDI / TDI")PTMEG prepolymer were heated to 65°C. The curing agent was pre-weighed and melted in an oven at 110°C. After 4 hours of reaction, the polymer microspheres were added to the prepolymer, or heated once and degassed under vacuum along with the polymer microspheres in the polymer. All filled samples contained a sufficient distribution of polymer microspheres to reach specific gravity or final density. After degassing, once both components had reached the desired temperature, the curing agent was added to the prepolymer and mixed. After mixing, the sample was poured onto a heating plate and stretched using a Teflon®-coated bar with a spacer set to 175 mil (4.4 mm). The plate was then transferred to an oven and heated to 104°C, where it was held for 16 hours. The drawdown was then released, punched down to 22 inches (55.9 cm), and used to prepare a laminated pad for polishing. All pads were 30 inches (76 cm) in diameter and had an 80 mil (2.0 mm) top pad, 1010 circular grooves with widths, depths, and pitches of 20 mil, 30 mil, and 120 mil (0.51 mm, 0.76 mm, and 3.05 mm) respectively, a pressure-sensitive adhesive film for the sub-pads, Suba IV® polyurethane-impregnated polyester felt sub-pads, and a pressure-sensitive platen adhesive. Plaques from each material set were also used for physical property testing, both with and without polymer microsphere fillers.

[0049] Example 1 The polymer prepared from the prepolymer (or, in the case of the control, the non-fluorinated (“H12MDI / TDI”) PTMEG prepolymer) was tested by dynamic scanning calorimetry (DSC) with various curing agents (shown in Table 1) by placing a 30-milligram sample in an aluminum pan and raising the temperature from room temperature to 280 °C or 300 °C at a rate of 10 °C / min. The DSC thermographs are shown in Figure 1. Note that the curves for each polymer in Figure 1 show the relative heat flow during the process (i.e., the y-axis shows the relative heat flow), and the curves for each polymer are offset for clarity. In other words, for example, the control polymer does not have a higher heat flow overall than the other polymers, but the curve is offset so that it can be seen without overlapping the other curves. The melting temperature in Table 1 is the lowest point on the DSC curve where a decrease (i.e., endotherm) indicating melting can be observed. The integral of the endotherm from where the endotherm starts to where it ends on the curve gives delta H f (ΔH f , i.e., the enthalpy of formation) was determined.

[0050]

Table 1

[0051] As can be seen, with 25% MCDEA and 75% MBOCA, the thermograph curve of Sample 3 shows no melting temperature, suggesting an amorphous polymer (especially an amorphous hard phase). Samples 4 and 5 demonstrate that a larger amount of MCDEA produces a polymer with some degree of crystallinity and a higher melting temperature compared to polymers having 75% or more of MBOCA. When the amount of MCDEA exceeds 25 mol%, the amount of crystallinity indicated by ΔH f increases.

[0052] <Pads were manufactured as described above using the following curing agents: Sample 1 (100% MBOCA), Sample 4 (50 mol% MBOCA / 50 mol% MCDEA), and Sample 5 (100% MCDEA). A commercially available pad (DuPont IK4150) was also tested as a control. The pads were tested by polishing silicon oxide substrates at various platen speeds and pressures using an AMAT Reflexion polishing machine with HS-0220 (Hitachi) slurry and AK45 (Saesol) conditioner. As shown in Figure 2, at 90 RPM, samples 4 and 5 of the present invention pads do not show a flat region of removal rate like the control pad and Sample 1 at downforce pressures exceeding approximately 275 hPa (hectopascals). Similarly, in Figure 3, at a 120 RPM platen, samples 4 and 5 begin to level off in removal rate, while sample 1 and the control pad actually show a decrease in removal rate at pressures above approximately 275 hPa. The improved performance of samples 4 and 5 of the present invention may be due to the improved thermal stability of the polymer (e.g., a higher melting temperature), which allows the polymer to withstand higher processing temperatures during polishing at higher pressures and speeds.

[0053] This disclosure further includes the following aspects:

[0054] Embodiment 1: A polishing pad adapted for polishing at least one of semiconductor, optical, magnetic, or electromechanical substrates, comprising a polishing layer containing a polyurea having a soft phase and a hard phase, wherein the soft phase is a copolymer of an aliphatic fluorine-free species and a fluorinated aliphatic species, the polyurea is cured with a curing agent, the hard phase contains a degree of crystallinity, and the polyurea has a melting temperature of at least 230°C and a ΔH of at least 3 joules / gram, preferably at least 3.5 joules / gram, more preferably at least 4 joules / gram, and even more preferably at least 4.5 joules / gram, as determined by dynamic scanning calorimetry of the polyurea. f A polishing pad characterized by [features].

[0055] Embodiment 2: The polishing pad according to Embodiment 1, wherein the melting temperature is less than 280°C.

[0056] Appearance 3: ΔH f A polishing pad according to embodiment 1 or 2, wherein the joules per gram are 35 joules / gram or less, preferably 30 joules / gram or less, and more preferably 25 joules / gram or less.

[0057] Embodiment 4: A polishing pad according to any of the embodiments, wherein the polyurea in the polishing layer forms a matrix, and the polishing layer further comprises gas or liquid-filled polymer microelements dispersed in the matrix.

[0058] Embodiment 5: The hardening agent is of formula I

[0059] [ka]

[0060] (In the formula, R1, R2, and R3 are selected from H, a halogen (preferably fluorine or chlorine, more preferably chlorine), and an alkyl group with 1 to 3 carbon atoms, preferably 2 atoms. However, at least one of R1, R2, and R3, preferably R1 and R2, is an alkyl group with 1 to 3 carbon atoms, preferably 2 atoms, and there is one or fewer halogens per aromatic ring.) A polishing pad according to any of the above embodiments, comprising a hardening agent.

[0061] Embodiment 6: A polishing pad according to any of the above embodiments, wherein the curing agent of formula I is 4,4'-methylene-bis-(3-chloro-2,6-diethylaniline).

[0062] Embodiment 7: An abrasive pad according to any of the above embodiments, wherein the amount of the curing agent of formula I in the curing agent is 30 mol%, preferably 35 mol%, more preferably 40 mol%, even more preferably 45 mol% to 100 mol%, preferably 95 mol%, more preferably 90 mol%, and even more preferably 80 mol% of the total curing agent.

[0063] Embodiment 8: The curing agent further comprises diethyltoluenediamine (DETDA); 3,5-dimethylthio-2,4-toluenediamine and its isomers; 3,5-diethyltoluene-2,4-diamine and its isomers (e.g., 3,5-diethyltoluene-2,6-diamine); 4,4′-bis-(sec-butylamino)diphenylmethane; 1,4-bis-(sec-butylamino)-benzene, 4,4′-methylene-bis-(2-chloroaniline)polytetramethylene oxide-di-p-aminobenzoate; N,N-dialkyldiaminodiphenylmethane; p,p′-methylene A polishing pad according to any embodiment of the above, comprising one or more further curing agents selected from dianiline (MDA); m-phenylenediamine (MPDA); 4,4′-methylene-bis(2-chloroaniline) (MBOCA); 4,4′-methylene-bis-(2,6-diethylaniline) (MDEA); 4,4′-methylene-bis-(2,3-dichloroaniline) (MDCA); 4,4′-diamino-3,3′-diethyl-5,5′-dimethyldiphenylmethane; 2,2′,3,3-tetrachlorodiaminodiphenylmethane; trimethylene glycol di-p-aminobenzoate.

[0064] Embodiment 9: An abrasive pad according to any of the embodiments, wherein the copolymer of the soft phase has a structure comprising fluorinated alkylene oxide and non-fluorinated alkylene oxide.

[0065] Embodiment 10: The polishing pad according to Embodiment 9, wherein the molar ratio of fluorinated alkylene oxide to non-fluorinated alkylene oxide is less than 3.

[0066] Embodiment 11: An abrasive pad according to any of the embodiments, wherein the aliphatic fluorine-free species is polytetramethylene ether.

[0067] Embodiment 12: A polishing pad according to any of the embodiments, wherein the hard phase comprises a reaction product of a diisocyanate hard segment and a hardening agent.

[0068] Embodiment 13: A polishing pad according to any of the embodiments, wherein the polishing layer has a polishing surface including a macrotexture.

[0069] Embodiment 14: An abrasive pad according to any of the embodiments, wherein the removal rate at a pressure of 345 hPa is equal to or greater than the removal rate at 275 hPa when rotating at 120 revolutions per minute (RPM).

[0070] Embodiment 15: A polishing pad according to any of the embodiments, wherein the polishing layer remains hydrophilic under shear conditions during polishing.

[0071] Embodiment 16: A method comprising the steps of providing a substrate to be polished and polishing the substrate using one of the polishing pads from Embodiments 1 to 15.

[0072] Embodiment 17: The method of Embodiment 16, further comprising the step of applying a slurry between a substrate and an abrasive pad.

[0073] Embodiment 18: The method of Embodiment 17, wherein the slurry contains ceria.

[0074] Embodiment 19: Any one of Embodiments 16 to 18, wherein the substrate contains silicon dioxide on its surface.

[0075] All ranges disclosed herein include endpoints, which are independently and combinable with each other (for example, the range “25% by weight or less, or more specifically 5% to 20% by weight” includes the endpoint and all intermediate values ​​of the range “5% to 25% by weight”). Furthermore, the upper and lower limits stated can also be combined to form ranges (for example, “at least 1% by weight or at least 2% by weight” and “10% or 5% by weight or less” can be combined to form ranges of “1 to 10% by weight,” “1 to 5% by weight,” “2 to 10% by weight,” or “2 to 5% by weight”).

[0076] This disclosure may optionally include, consist of, or essentially consist of any suitable components disclosed herein. This disclosure may also be formulated to exclude, or substantially exclude, any components, materials, ingredients, auxiliaries, or species used in prior art compositions or otherwise not necessary for achieving the function or purpose of this disclosure.

[0077] All cited patents, patent applications, and other references are incorporated herein by reference as a whole. However, if any term in this application is inconsistent with or incompatible with a term in one of the incorporated references, the term from this application shall prevail over the incompatible term from the incorporated reference.

[0078] Unless otherwise specified herein, all test standards are the most current 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 on which the test standard is stated.

Claims

1. A polishing pad adapted for polishing at least one of semiconductor, optical, magnetic, or electromechanical substrates, comprising a polishing layer containing a polyurea having a soft phase and a hard phase, wherein the soft phase is a copolymer of an aliphatic fluorine-free species and a fluorinated aliphatic species, the polyurea is cured with a curing agent, the hard phase contains a degree of crystallinity, and the polyurea has a melting temperature of at least 230°C and a ΔH of at least 3 joules / gram, as determined by dynamic scanning calorimetry of the polyurea. f A polishing pad characterized by [features].

2. The polishing pad according to claim 1, wherein the polyurea in the polishing layer forms a matrix, and the polishing layer further comprises gas or liquid-filled polymer microelements dispersed in the matrix.

3. The hardening agent is, Formula I 【Transformation 3】 (In the formula, R 1 , R 2 and R 3 R is selected from H, halogens, and alkyl groups with 1 to 3 carbon atoms. 1 , R 2 and R 3 At least one of these is an alkyl group with 1 to 3 carbon atoms, and there is one or fewer halogens per aromatic ring. The polishing pad according to claim 1, comprising 30 mol% or more of the hardening agent based on the total moles of the hardening agent.

4. The polishing pad according to claim 3, wherein the curing agent of formula I is 4,4'-methylene-bis-(3-chloro-2,6-diethylaniline).

5. The curing agent may further include diethyltoluenediamine (DETDA); 3,5-dimethylthio-2,4-toluenediamine and its isomers; 3,5-diethyltoluene-2,4-diamine and its isomers (e.g., 3,5-diethyltoluene-2,6-diamine); 4,4'-bis-(sec-butylamino)diphenylmethane; 1,4-bis-(sec-butylamino)benzene; 4,4'-methylene-bis-(2-chloroaniline)polytetramethylene oxide-di-p-aminobenzoate; N,N-dialkyldiaminodiphenylmethane; p,p'-methylene The polishing pad according to claim 3, comprising one or more further curing agents selected from dianiline (MDA); m-phenylenediamine (MPDA); 4,4'-methylene-bis(2-chloroaniline) (MBOCA); 4,4'-methylene-bis-(2,6-diethylaniline) (MDEA); 4,4'-methylene-bis-(2,3-dichloroaniline) (MDCA); 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane; 2,2',3,3-tetrachlorodiaminodiphenylmethane; trimethylene glycol di-p-aminobenzoate.

6. The copolymer of the soft phase has a structure comprising fluorinated alkylene oxide and non-fluorinated alkylene oxide, The polishing pad according to claim 1, wherein the molar ratio of fluorinated alkylene oxide to non-fluorinated alkylene oxide is less than 3.

7. The polishing pad according to claim 1, wherein the aliphatic fluorine-free polymer group is polytetramethylene ether, and the hard phase comprises a reaction product of a diisocyanate hard segment and a curing agent.

8. The polishing pad according to claim 1, wherein the polishing layer has a polishing surface including a macro texture.

9. The polishing pad according to claim 1, wherein at 120 revolutions per minute, the removal rate at a pressure of 345 hectopascals is equal to or greater than the removal rate at 275 hectopascals.

10. The polishing pad according to claim 1, wherein the polishing layer remains hydrophilic under shear conditions during polishing.

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