Additives for improving particle dispersion in CMP slurries

Abstract

The present invention provides a chemical-mechanical polishing composition comprising (a) about 0.05 to about 10 weight% of an abrasive; (b) a dispersant which is a linear or branched C2-C10 alkylenediol; and (c) water, wherein the chemical-mechanical polishing composition has a pH of about 2 to about 6. The present invention also provides a method for chemical-mechanical polishing of a substrate by contacting the substrate with the chemical-mechanical polishing composition of the present invention.

Description

Background Technology

[0001] Compositions and methods for planarizing or polishing the surface of a substrate are well known in the art. A polishing composition (also known as a polishing slurry) typically contains an abrasive material in a liquid carrier and is applied to a surface by bringing the surface into contact with a polishing pad wet with the polishing composition. Typical abrasive materials include silicon dioxide, cerium oxide, aluminum oxide, zirconium oxide, and tin oxide. The polishing composition is typically used with a polishing pad (e.g., a polishing cloth or disc). Instead of being suspended in the polishing composition, or in addition thereto, the abrasive material may be incorporated into the polishing pad.

[0002] In many cases, it is desirable for the abrasive material to have a narrow particle size distribution. When the abrasive is suspended in an abrasive composition, it may aggregate or merge upon standing to form particles with a particle size significantly larger than the average particle size of the abrasive material. An increased proportion of abrasive particles with large particle sizes is thought to contribute to an increase in micro-scratches on the surface of a substrate polished by an abrasive composition containing such particles. Micro-scratches result in a failure to meet stringent quality requirements.

[0003] Therefore, there remains a need in the field for abrasive compositions having enhanced abrasive particle size stability.

[0004] The present invention comprises (a) about 0.05 to about 10 weight percent of an abrasive; (b) linear or branched C2-C 10 A chemical-mechanical polishing composition comprising (c) a dispersant which is an alkylenediol; and water, wherein the chemical-mechanical polishing composition has a pH of about 2 to about 6.

[0005] In addition, the present invention comprises: (i) providing a substrate; (ii) providing a polishing pad; (iii) (a) about 0.05 to about 10 weight percent of an abrasive, (b) linear or branched C2-C10 A method for chemically mechanical polishing of a substrate is provided, comprising the steps of: (c) providing a chemically mechanical polishing composition having a pH of about 2 to about 6, comprising a dispersant which is an alkylenediol; (iv) bringing the substrate into contact with the polishing pad and the chemically mechanical polishing composition; and (v) polishing the substrate by moving the polishing pad and the chemically mechanical polishing composition against the substrate to abrade at least a portion of the surface of the substrate. Brief explanation of the drawing

[0006] Figure 1 shows the average particle size of an abrasive composition containing colloidal silica and 0 wt%, 2 wt%, or 10 wt% of 1,4-butanediol at pH values ​​of 3, 4, or 5 during storage at 45°C for 0, 1, 2, and 3 weeks. Figure 2 shows the average particle size of an abrasive composition comprising alumina surface-treated with a sulfonic acid-containing polymer and 0 wt%, 0.5 wt%, 2 wt%, or 10 wt% of 1,4-butanediol at a pH value of 2 or 4 during storage at 45°C for 0, 1, 2, 3, 4, and 5 weeks. Specific details for implementing the invention

[0007] The present invention comprises (a) about 0.05 to about 10 weight percent of an abrasive; (b) linear or branched C2-C 10 A dispersant that is an alkylenediol; and (c) a chemical-mechanical polishing composition comprising, or consisting of, or essentially consisting of, water, wherein the chemical-mechanical polishing composition has a pH of about 2 to about 6.

[0008] The abrasive may be any suitable abrasive. The abrasive particles may include, consist of, or essentially consist of any suitable particulate material, said material being typically metal oxides and / or metalloid oxides (hereinafter collectively referred to as “metal oxides”). Examples of suitable materials include alumina, treated alumina (e.g., surface-treated alumina), colloidal silica, fumed silica, surface-modified silica, and combinations thereof.

[0009] The alumina may be any suitable alumina, for example, α-alumina, γ-alumina, or fumed alumina. The alumina may be treated alumina, wherein the alumina particles may be surface-treated with anionic polymers, such as polysulfonic acid, polystyrenesulfonic acid, copolymers containing sulfonic acid monomer units, such as poly(2-acrylamido-2-methyl-1-propanesulfonic acid), etc.

[0010] The silica may be unmodified silica or surface-modified silica, many of which are known in the art. For example, surface-modified silica may be surface-modified by doping with aluminum ions or by treating with a surface-modifying agent, such as a silane, such as an amino-containing silane, an alkyl silane, etc. In a preferred embodiment, the silica may be colloidal silica (e.g., unmodified colloidal silica).

[0011] When the silica is colloidal silica, the colloidal silica may be any suitable colloidal silica. For example, the colloidal silica may be wet silica, such as condensation polymerized silica. Condensation polymerized silica is typically prepared by condensing Si(OH)4 to form colloidal particles, wherein colloidality is defined as having an average particle size of about 1 to about 1000 nm. These abrasive particles may be manufactured in accordance with US 5,230,833 or may be obtained as any of the various commercially available products, such as Akzo-Nobel Bindzil (trademark) 50 / 80, 30 / 360, 159 / 500, 40 / 220, 40 / 130, and CJ2-2 products and Nalco 1050, 1060, 2327, and 2329 products, as well as any of the other similar products available from DuPont, Bayer, Applied Research, Nissan Chemical, Fuso, and Clariant.

[0012] The abrasive composition may contain any suitable amount of abrasive. Typically, the abrasive composition contains at least about 1 weight percent, for example, at least about 1.5 weight percent, at least about 2 weight percent, or at least about 2.5 weight percent of abrasive. Alternatively or additionally, the abrasive composition contains at least about 5 weight percent, for example, at least about 4.5 weight percent, at least about 4 weight percent, or at least about 3.5 weight percent of abrasive. Thus, the abrasive composition may contain an amount of abrasive limited by any two of the aforementioned endpoints. For example, the abrasive composition may comprise about 1 to about 5 weight%, for example, about 1 to about 4.5 weight%, about 1 to about 4 weight%, about 1 to about 3.5 weight%, about 1.5 to about 5 weight%, about 1.5 to about 4.5 weight%, about 1.5 to about 4 weight%, about 1.5 to about 3.5 weight%, about 2 to about 5 weight%, about 2 to about 4.5 weight%, about 2 to about 4 weight%, about 2 to about 3.5 weight%, about 2.5 to about 5 weight%, about 2.5 to about 4.5 weight%, about 2.5 to about 4 weight%, or about 2.5 to about 3.5 weight% of an abrasive.

[0013] The abrasive is preferably colloidally stable. The term colloid refers to a suspension of abrasive particles in a liquid carrier. Colloidal stability refers to the retention of the suspension over time. In the present invention, when an abrasive is placed in a 100 ml graduated cylinder and left unstirred for 2 hours, the abrasive is considered colloidally stable if the difference between the concentration of particles in the lower 50 ml of the graduated cylinder ([B], unit: g / ml) divided by the initial concentration of particles in the abrasive composition ([C], unit: g / ml) and the concentration of particles in the upper 50 ml of the graduated cylinder ([T], unit: g / ml) is 0.5 or less (i.e., {[B] - [T]} / [C] ≤ 0.5). More preferably, the value of [B]-[T] / [C] is 0.3 or less, and most preferably 0.1 or less.

[0014] The abrasive may have any suitable average particle size (i.e., average particle diameter). The particle size of the abrasive particle is the diameter of the smallest sphere containing the abrasive particle. The abrasive may have an average particle size of about 5 nm or more, e.g., about 10 nm or more, about 15 nm or more, about 20 nm or more, about 25 nm or more, about 30 nm or more, about 35 nm or more, about 40 nm or more, about 45 nm or more, about 50 nm or more, about 55 nm or more, about 60 nm or more, about 65 nm or more, about 70 nm or more, about 75 nm or more, about 80 nm or more, about 85 nm or more, about 90 nm or more, about 95 nm or more, or about 100 nm or more. Alternatively or additionally, the abrasive may have an average particle size of about 200 nm or less, e.g., about 190 nm or less, about 180 nm or less, about 170 nm or less, about 160 nm or less, about 150 nm or less, about 140 nm or less, about 130 nm or less, about 120 nm or less, about 110 nm or less, about 100 nm or less, about 95 nm or less, about 90 nm or less, about 85 nm or less, about 80 nm or less, about 75 nm or less, or about 70 nm or less. Thus, the abrasive may have an average particle size limited by any two of the aforementioned endpoints.For example, the abrasive may have an average particle size of about 10 to about 200 nm, e.g., about 10 to about 190 nm, about 10 to about 180 nm, about 15 to about 170 nm, about 20 to about 160 nm, about 20 to about 150 nm, about 20 to about 140 nm, about 20 to about 130 nm, about 20 to about 120 nm, about 20 to about 110 nm, about 100 to about 200 nm, about 100 to about 190 nm, about 100 to about 180 nm, about 100 to about 170 nm, about 100 to about 160 nm, about 100 to about 150 nm, about 10 to about 100 nm, about 25 to about 80 nm, or about 30 to about 70 nm. there is.

[0015] The abrasive composition is linear or branched C2-C 10 It includes a dispersant that is an alkylenediol. In certain embodiments, the dispersant is a linear or branched C2-C7 alkylenediol. In certain preferred embodiments, the dispersant is a linear or branched C4-C7 alkylenediol. In certain embodiments, C2-C 10 Alkylenediols are linear C2-C 10 It is an alkylenediol (e.g., a linear C2-C7 alkylenediol or a linear C4-C7 alkylenediol). As understood by those skilled in the art, alkylenediols comprise an aliphatic carbon chain containing two attached hydroxyl groups, wherein the hydroxyl groups are typically attached to different carbon atoms of the alkylenediol. As further understood by those skilled in the art, C2 alkylenediols cannot be branched because only two carbon atoms exist in the C2 alkylenediol, whereas C3-C 10The alkylenediol may be linear or branched, wherein the branch comprises one or more carbon atoms attached to the main chain of the alkylenediol. The alkylenediol may contain 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. In an embodiment, the dispersant is selected from 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, and combinations thereof. In a preferred embodiment, the dispersant is 1,4-butanediol.

[0016] The abrasive composition may contain any suitable amount of dispersant. For example, the polishing composition may contain about 0.5 wt% or more, for example, about 0.6 wt% or more, about 0.7 wt% or more, about 0.8 wt% or more, about 0.9 wt% or more, about 1 wt% or more, about 1.1 wt% or more, about 1.2 wt% or more, about 1.3 wt% or more, about 1.4 wt% or more, about 1.5 wt% or more, about 1.6 wt% or more, about 1.7 wt% or more, about 1.8 wt% or more, about 1.9 wt% or more, about 2 wt% or more, about 2.1 wt% or more, about 2.2 wt% or more, about 2.3 wt% or more, about 2.4 wt% or more, about 2.5 wt% or more, about 2.6 wt% or more, about 2.7 wt% or more, about 2.8 wt% or more, about 2.9 wt% or more, or about 3 wt% or more of a dispersant. Alternatively or additionally, the abrasive composition may contain about 20 wt% or less of a dispersant, for example, about 19.5 wt% or less, about 19 wt% or less, about 18.5 wt% or less, about 18 wt% or less, about 17.5 wt% or less, about 17 wt% or less, about 16.5 wt% or less, about 16 wt% or less, about 15.5 wt% or less, about 15 wt% or less, about 14.5 wt% or less, about 14 wt% or less, about 13.5 wt% or less, about 13 wt% or less, about 12.5 wt% or less, about 12 wt% or less, about 11.5 wt% or less, about 11 wt% or less, about 10.5 wt% or less, or about 10 wt% or less of a dispersant. Accordingly, the abrasive composition may contain the dispersant in an amount limited by any two of the aforementioned endpoints. For example, the abrasive composition is about 0.5 to about 20 wt%, for example about 0.5 to about 19 wt%, about 0.5 to about 18 wt%, about 0.5 to about 17 wt%, about 0.5 to about 16 wt%, about 0.5 to about 15 wt%, about 0.5 to about 14 wt%, about 0.5 to about 13 wt%, about 0.5 to about 12 wt%, about 0.5 to about 11 wt%, about 0.5 to about 10 wt%, about 1 to about 15 wt%, about 1 to about 14 wt%, about 1 to about 13 wt%, about 1 to about 12 wt%, about 1 to about 11 wt%, about 1 to about 10 wt%, about 2 to about 15 wt%, about 2 to about 14 wt%, about 2 to about 13 wt%, about 2 to about 12 wt%, about 2 to about 11 wt%, about 2 to about 10 wt%, about 3 to about 15 wt%, about 3 to about 14 wt%, about 3 to about 12 wt%, about 3 to about 11 wt%, or about 3 to about 10 It may contain a weight percent of dispersant.

[0017] The abrasive composition comprises water. The water may be any suitable water, deionized water, or distilled water. In some embodiments, the abrasive composition may further comprise one or more organic solvents combined with water. For example, the abrasive composition may further comprise hydroxy solvents, such as methanol or ethanol, ketone solvents, amide solvents, sulfoxide solvents, etc. Preferably, the abrasive composition comprises pure water.

[0018] The abrasive composition may have any suitable pH, for example, a pH of about 1 to about 7. Typically, the abrasive composition may have a pH of about 2 or higher, for example, about 2.2 or higher, about 2.4 or higher, about 2.6 or higher, about 2.8 or higher, or about 3 or higher. Alternatively or additionally, the abrasive composition may have a pH of about 6 or lower, for example, about 5 or lower, about 4.5 or lower, about 4 or lower, about 3.5 or lower, or about 3 or lower. Thus, the abrasive composition may have a pH limited by any two of the aforementioned endpoints. For example, the abrasive composition may have a pH of about 2 to about 6, for example, about 2 to about 5, about 2 to about 4, about 2.5 to about 5, about 2.5 to about 4.5, about 2.5 to about 4, or about 2 to about 4.5.

[0019] The abrasive composition optionally contains an inorganic acid. Non-limiting examples of suitable inorganic acids include nitric acid, sulfuric acid, and phosphoric acid.

[0020] The abrasive composition may additionally contain a base to adjust the pH of the abrasive composition. Non-limiting examples of suitable bases include sodium hydroxide, potassium hydroxide, and ammonium hydroxide.

[0021] The polishing composition optionally further comprises an oxidizing agent. The oxidizing agent may be any suitable oxidizing agent. In certain embodiments, the oxidizing agent comprises ferric ions. The ferric ions may be provided by any suitable source of ferric ions. In some embodiments, the oxidizing agent may comprise a salt of a metal. For example, the ferric ions may be provided by a ferric salt comprising an inorganic anion, such as a nitrate ion (e.g., ferric nitrate), a cyanide ion (e.g., ferric cyanide anion), etc. Additionally, the oxidizing agent may comprise a ferric organic iron(III) compound, such as, but not limited to, acetate, acetylacetone, citrate, gluconate, oxalate, phthalate, succinate, and mixtures thereof. In other embodiments, the oxidizing agent may be an oxy-containing oxidizing agent. Non-limiting examples of suitable oxy-containing oxidizing agents include hydrogen peroxide, persulfate salts, bromate persulfate salts, iodate persulfate salts, perbromate persulfate salts, periodate persulfate salts, organic peroxy compounds, such as peracetic acid, oxone, etc.

[0022] The abrasive composition may contain any suitable amount of an oxidizing agent. For example, the abrasive composition may contain an oxidizing agent of about 1 ppm or more, e.g., about 5 ppm or more, about 25 ppm or more, about 50 ppm or more, about 75 ppm or more, or about 100 ppm or more. Alternatively or additionally, the abrasive composition may contain an oxidizing agent of about 2500 ppm (about 2.5 wt%) or less, e.g., about 2000 ppm or less, about 1500 ppm or less, about 1000 ppm or less, about 500 ppm or less, or about 250 ppm or less. Unless otherwise noted, the term ppm is intended to reflect parts per million based on weight. For example, 1000 ppm corresponds to 1 wt%.

[0023] If an optional oxidizing agent includes hydrogen peroxide, hydrogen peroxide may be present in the polishing composition in any suitable amount. For example, the polishing composition may contain hydrogen peroxide in an amount of about 0.1 to about 10 weight%, for example, about 0.5 to about 10 weight%, or about 0.5 to about 5 weight%.

[0024] The polishing composition optionally further comprises amino acids. The amino acids may be any suitable amino acids. Non-limiting examples of suitable amino acids include glycine, alanine, lysine, and arginine. The polishing composition may contain any suitable amount of amino acids. For example, the polishing composition may contain about 0.1 to about 5 weight% (about 100 to about 5000 ppm), for example about 0.1 to about 4 weight%, about 0.1 to about 3 weight%, about 0.1 to about 2 weight%, or about 0.1 to about 1 weight% of amino acids.

[0025] If the polishing composition contains ferric ions (i.e., Fe(III) ions), the polishing composition optionally further comprises a stabilizer for ferric ions. The stabilizer for ferric ions may be any suitable stabilizer for ferric ions. A non-limiting example of a stabilizer for ferric ions is malonic acid. The polishing composition may contain any suitable amount of a stabilizer for ferric ions. For example, the polishing composition may contain about 0.1 to about 2 weight%, for example about 0.1 to about 1.8 weight%, about 0.1 to about 1.6 weight%, about 0.1 to about 1.4 weight%, about 0.1 to about 1.2 weight%, or about 0.1 to about 1 weight% of a stabilizer for ferric ions.

[0026] Abrasive compositions can be manufactured by any suitable technique, many of which are known to those skilled in the art. Abrasive compositions can be manufactured by batch or continuous processes. Generally, abrasive compositions can be manufactured by combining their components in any order. As used herein, the term "component" includes individual components (e.g., abrasives, dispersants, optional oxidizers, optional amino acids, etc.) and any combination of components (e.g., abrasives, dispersants, optional oxidizers, optional amino acids, etc.).

[0027] For example, the abrasive may be dispersed in water. Subsequently, a dispersant may be added and the components may be mixed by any method capable of incorporating them into the abrasive composition. An optional oxidizing agent and an optional amino acid may be added at any time during the preparation of the abrasive composition. The abrasive composition may be prepared before use by adding one or more components, such as an oxidizing agent, such as hydrogen peroxide, to the abrasive composition immediately before use (e.g., within about 1 minute before use, within about 1 hour before use, or within about 7 days before use). Additionally, the abrasive composition may be prepared by mixing the components on the surface of the substrate during the abrasive operation.

[0028] The polishing composition may be supplied as a one-package system comprising an abrasive, a dispersant, an optional oxidizing agent, an optional amino acid, and water. Alternatively, the abrasive may be supplied as an aqueous dispersion in a first container, and the dispersant, the optional oxidizing agent, and the optional amino acid may be supplied in a second container in a dry form, or as an aqueous solution or dispersion. If the oxidizing agent includes hydrogen peroxide, the hydrogen peroxide is preferably supplied separately from the other components of the polishing composition and is combined with the other components of the polishing composition, for example, immediately before use by the end user (e.g., within one week, within one day, within one hour, within ten minutes, or within one minute before use). The components of the first and second containers may be in a dry form, whereas the components of the other container may be in the form of an aqueous dispersion. Additionally, it is suitable for the components of the first and second containers to have different pH values, or alternatively, substantially similar or even identical pH values. Other combinations of components of the abrasive composition, such as 2-vessels or 3 or more-vessels, are within the knowledge of those skilled in the art.

[0029] Additionally, the polishing composition of the present invention may be provided as a concentrate intended to be diluted with an appropriate amount of water before use. In such an embodiment, the polishing composition concentrate may contain an abrasive, a dispersant, an optional oxidizing agent, an optional amino acid, and water with or without optional hydrogen peroxide, in an amount such that when the concentrate is diluted with an appropriate amount of water, and when optional hydrogen peroxide is added (if not yet present in an appropriate amount), each component of the polishing composition is present in the polishing composition in an amount within the appropriate range mentioned above for each component. For example, the abrasive, dispersant, optional oxidizing agent, and optional amino acid may each be present in an amount of about twice (e.g., about three times, about four times, or about five times) greater than the concentration mentioned above for each component, so that when the concentrate is diluted with an appropriate amount of optional hydrogen peroxide in an equal volume of water (e.g., two times the equal volume of water, three times the equal volume of water, or four times the equal volume of water, respectively), each component is present in the abrasive composition in an amount within the range presented above for each component. Additionally, as understood by those skilled in the art, the concentrate may contain an appropriate fraction of water present in the final abrasive composition to ensure that other components are at least partially or completely dissolved in the concentrate.

[0030] In addition, the present invention provides a method for chemically mechanical polishing of a substrate, comprising the steps of: (i) providing a substrate; (ii) providing a polishing pad; (iii) providing a chemically mechanical polishing composition as described herein; (iv) bringing the substrate into contact with the polishing pad and the chemically mechanical polishing composition; and (v) moving the polishing pad and the chemically mechanical polishing composition against the substrate to abrade at least a portion of the surface of the substrate to polish the substrate.

[0031] More specifically, the present invention also comprises: (i) providing a substrate; (ii) providing a polishing pad; (iii) (a) about 0.05 to about 10 weight percent of an abrasive, (b) linear or branched C2-C 10 A method for chemically mechanical polishing of a substrate is provided, comprising the steps of: (c) providing a chemically mechanical polishing composition comprising a dispersant which is an alkylenediol and water (wherein the chemically mechanical polishing composition has a pH of about 2 to about 6); (iv) bringing the substrate into contact with the polishing pad and the chemically mechanical polishing composition; and (v) polishing the substrate by moving the polishing pad and the chemically mechanical polishing composition against the substrate to abrade at least a portion of the surface of the substrate.

[0032] A substrate that can be polished using the method of the present invention may be any suitable substrate, in particular a substrate comprising one or more metal layers. The metal may be any suitable metal, for example, the metal may comprise, consist of, or essentially consist of a metal selected from the group consisting of tungsten, aluminum, nickel-phosphorus, copper, ruthenium, cobalt, and combinations thereof. In a preferred embodiment, the metal is tungsten. A preferred substrate comprises one or more layers on the surface of a substrate comprising, consisting of, or essentially consisting of a metal, in particular a layer exposed to polishing, so that at least a portion of the metal on the surface of the substrate is worn away (i.e. removed) to polish the substrate. In some embodiments, the substrate comprises one or more layers of metal and one or more layers of silicon oxide. In some preferred embodiments, the substrate comprises one or more layers of tungsten and one or more layers of silicon oxide. The polishing composition and method of the present invention are suitable for use in a so-called damascene polishing method in which circuit lines are formed on a suitable substrate, e.g., silicon oxide, by forming circuit lines by etching the silicon oxide surface and then overcoating the substrate with a layer of tungsten to fill the circuit lines. A substrate comprising tungsten circuit lines isolated on a silicon oxide substrate is formed by exposing the surface of the silicon oxide substrate by chemical-mechanical polishing of at least the tungsten overcoat and thereby creating isolated tungsten lines on the substrate. In some embodiments, one or more subsequent polishing and / or washing steps may be applied to the substrate thus formed to produce a finished substrate.

[0033] Accordingly, in a preferred embodiment, the substrate comprises a tungsten layer on the surface of the substrate, wherein at least a portion of the tungsten layer is worn away to polish the substrate. In another preferred embodiment, the substrate comprises a silicon-oxygen layer on the surface of the substrate, wherein at least a portion of the silicon oxide layer is worn away to polish the substrate. In another preferred embodiment, the substrate comprises a silicon-nitrogen layer on the surface of the substrate, wherein at least a portion of the silicon nitride layer is worn away to polish the substrate. The substrate may comprise one or more of a tungsten layer on the surface of the substrate, a silicon-oxygen layer on the surface of the substrate, and a silicon nitride layer on the surface of the substrate, wherein at least a portion of the tungsten layer, the silicon-oxygen layer, and the silicon nitride layer is worn away to polish the substrate.

[0034] The abrasive composition of the present invention preferably exhibits reduced growth in average particle size over time. Growth in average particle size is thought to be caused by an abrasive particle aggregation that increases the population of particles having a relatively large particle size. Particles having a relatively large particle size are thought to contribute to the increased generation of micro-scratches on the substrate being abraded, and micro-scratches can lead to increased substrate defects. The abrasive composition of the present invention provides enhanced abrasive performance regarding substrate surface quality, particularly in the reduced generation of micro-scratches on the substrate being abraded, and additionally preferably exhibits a sufficient removal ratio when used to abrade substrates, particularly those comprising tungsten and silicon oxide.

[0035] The polishing method of the present invention is particularly suitable for use with a chemical-mechanical polishing (CMP) machine. Typically, the machine comprises a platen (which moves when used and has a velocity resulting from orbital, linear, or circular motion), a polishing pad in contact with the platen (which moves together with the platen when moving), and a carrier (which holds a substrate to be polished by contacting the surface of the polishing pad and moving against it). Polishing of the substrate occurs by placing the substrate in contact with the polishing pad and the polishing composition of the present invention, and then moving the polishing pad against the substrate to abrade at least a portion of the substrate, thereby polishing the substrate.

[0036] The substrate is flattened or polished by a chemical-mechanical polishing composition and any suitable polishing pad (e.g., a polishing surface). Suitable polishing pads include, for example, woven and non-woven polishing pads. Additionally, suitable polishing pads may include any suitable polymer of various densities, hardness, thickness, compressibility, recovery under compression, and compression ratios. Suitable polymers include, for example, polyvinyl chloride, polyvinyl fluoride, nylon, fluorocarbon, polycarbonate, polyester, polyacrylate, polyether, polyethylene, polyamide, polyurethane, polystyrene, polypropylene, copolymerized products thereof, and mixtures thereof.

[0037] Preferably, the CMP machine further comprises a polishing endpoint detection system of the same reaction system, many of which are known in the art. Techniques for inspecting and monitoring the polishing process by analyzing light or other radiation reflected from the surface of a workpiece are known in the art. Such methods are described, for example, in US 5,196,353, US 5,433,651, US 5,609,511, US 5,643,046, US 5,658,183, US 5,730,642, US 5,838,447, US 5,872,633, US 5,893,796, US 5,949,927, and US 5,964,643. Preferably, inspection or monitoring of the progress of the polishing process for a workpiece to be polished enables the determination of the polishing endpoint, that is, the determination of the time to terminate the polishing process for a specific workpiece.

[0038] Preferably, the abrasive composition of the present invention exhibits reduced fine scratches on a substrate polished thereby. In addition, the abrasive composition of the present invention preferably exhibits enhanced storage stability.

[0039] The present invention may be characterized by the following embodiments.

[0040] Mode of implementation

[0041] (1) In embodiment (1), (a) about 0.05 to about 10 weight percent of abrasive;

[0042] (b) Linear or branched C2-C 10 A dispersant that is an alkylenediol; and

[0043] (c) water

[0044] A chemical-mechanical polishing composition having a pH of about 1 to about 7, comprising... is presented.

[0045] (2) In embodiment (2), the chemical-mechanical polishing composition of embodiment (1) is presented, wherein the composition comprises about 1 to about 5 weight percent of abrasive.

[0046] (3) In embodiment (3), the chemical-mechanical polishing composition of embodiment (1) or embodiment (2) is presented, wherein the composition comprises about 2.5 to about 3.5 weight percent of abrasive.

[0047] (4) In embodiment (4), any one of embodiments (1) to (3) is provided as a chemical-mechanical polishing composition, wherein the polishing agent is selected from treated alumina, colloidal silica, fumed silica, surface-modified silica and combinations thereof.

[0048] (5) In embodiment (5), any one of embodiments (1) to (4) is provided as a chemical-mechanical polishing composition, wherein the polishing agent is colloidal silica.

[0049] (6) In embodiment (6), the chemical-mechanical polishing composition of embodiment (5) is presented, wherein the colloidal silica has an average particle size of about 10 to about 100 nm.

[0050] (7) In embodiment (7), the chemical-mechanical polishing composition of embodiment (6) is presented, wherein the colloidal silica has an average particle size of about 30 to about 70 nm.

[0051] (8) In embodiment (8), any one of embodiments (1) to (7) of a chemical-mechanical polishing composition is presented, wherein the composition comprises about 0.5 to about 20 weight percent of a dispersant.

[0052] (9) In embodiment (9), any one of embodiments (1) to (8) of a chemical-mechanical polishing composition is presented, wherein the composition comprises about 1 to about 15 weight percent of a dispersant.

[0053] (10) In embodiment (10), any one of embodiments (1) to (9) of a chemical-mechanical polishing composition is presented, wherein the composition comprises about 3 to about 10 weight percent of a dispersant.

[0054] (11) In embodiment (11), any one of embodiments (1) to (10) of a chemical-mechanical polishing composition is presented, wherein the chemical-mechanical polishing composition has a pH of about 2 to about 5.

[0055] (12) In embodiment (12), any one of embodiments (1) to (11) is provided with a chemical-mechanical polishing composition, wherein the chemical-mechanical polishing composition has a pH of about 2 to about 4.

[0056] (13) In embodiment (13), any one of embodiments (1) to (12) of a chemical-mechanical polishing composition is presented, wherein the dispersant is a linear or branched C2-C7 alkylenediol.

[0057] (14) In embodiment (14), any one of embodiments (1) to (13) of a chemical-mechanical polishing composition is presented, wherein the dispersant is a linear or branched C4-C7 alkylenediol.

[0058] (15) In embodiment (15), any one of embodiments (1) to (14) of a chemical-mechanical polishing composition is provided, wherein the dispersant is 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol or a combination thereof.

[0059] (16) In embodiment (16), any one of embodiments (1) to (15) of chemical-mechanical polishing composition is presented, wherein the dispersant is 1,4-butanediol.

[0060] (17) In embodiment (17), the chemical-mechanical polishing composition of embodiment (1) is presented, wherein the dispersant is linear C2-C 10 It is an alkylenediol.

[0061] (18) In an embodiment (18), (i) a step of providing a record;

[0062] (ii) Step of providing a polishing pad;

[0063] (iii) (a) about 0.05 to about 10 weight percent of abrasive,

[0064] (b) Linear or branched C2-C 10 A dispersant that is an alkylenediol, and

[0065] (c) water

[0066] A step of providing a chemical-mechanical polishing composition having a pH of about 2 to about 6, comprising

[0067] (iv) a step of contacting the above substrate with the polishing pad and the chemical-mechanical polishing composition; and

[0068] (v) a step of polishing the substrate by moving the polishing pad and the chemical-mechanical polishing composition against the substrate to abrade at least a portion of the surface of the substrate.

[0069] A chemical-mechanical polishing method for a substrate including is presented.

[0070] (19) In embodiment (19), the method of embodiment (18) is presented, and the composition contains about 1 to about 5 weight percent of abrasive.

[0071] (20) In embodiment (20), the method of embodiment (18) or embodiment (19) is presented, wherein the composition comprises about 2.5 to about 3.5 weight percent of abrasive.

[0072] (21) In embodiment (21), any one of embodiments (18) to (20) is presented, wherein the abrasive is selected from treated alumina, colloidal silica, fumed silica, surface-modified silica and combinations thereof.

[0073] (22) In embodiment (22), any one of embodiments (18) to (21) is presented, wherein the abrasive is colloidal silica.

[0074] (23) In embodiment (23), the method of embodiment (22) is presented, wherein the colloidal silica has an average particle size of about 10 to about 100 nm.

[0075] (24) In embodiment (24), the method of embodiment (23) is presented, wherein the colloidal silica has an average particle size of about 30 to about 70 nm.

[0076] (25) In embodiment (25), any one of embodiments (18) to (24) is presented, wherein the composition comprises about 0.5 to about 20 weight percent of a dispersant.

[0077] (26) In embodiment (26), any one of embodiments (18) to (25) is presented, wherein the composition comprises about 1 to about 15 weight percent of a dispersant.

[0078] (27) In embodiment (27), any one of embodiments (18) to (26) is presented, wherein the composition comprises about 3 to about 10 weight percent of a dispersant.

[0079] (28) In embodiment (28), any one of embodiments (18) to (27) is presented, wherein the chemical-mechanical polishing composition has a pH of about 2 to about 5.

[0080] (29) In embodiment (29), any one of embodiments (18) to (28) is presented, wherein the chemical-mechanical polishing composition has a pH of about 2 to about 4.

[0081] (30) In embodiment (30), any one of embodiments (18) to (29) is presented, wherein the dispersant is a linear or branched C2-C7 alkylenediol.

[0082] (31) In embodiment (31), any one of embodiments (18) to (30) is presented, wherein the dispersant is a linear or branched C4-C7 alkylenediol.

[0083] (32) In embodiment (32), any one of embodiments (18) to (31) is presented, wherein the dispersant is 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol or a combination thereof.

[0084] (33) In embodiment (33), any one of embodiments (18) to (32) is presented, wherein the dispersant is 1,4-butanediol.

[0085] (34) In embodiment (34), the method of embodiment (18) is presented, wherein the dispersant is linear C2-C 10 It is an alkylenediol.

[0086] (35) In embodiment (35), any one of embodiments (18) to (34) is presented, wherein the substrate comprises a tungsten layer on the surface of the substrate, and at least a portion of the tungsten layer is worn away to polish the substrate.

[0087] (36) In embodiment (36), any one of embodiments (18) to (35) is presented, wherein the substrate additionally comprises a silicon-oxygen layer on the surface of the substrate, and at least a portion of the silicon-oxygen layer is worn away to polish the substrate.

[0088] (37) In embodiment (37), any one of embodiments (18) to (36) is presented, wherein the substrate additionally comprises a silicon nitrogen layer on the surface of the substrate, and at least a portion of the silicon nitrogen layer is worn away to polish the substrate.

[0089] The following examples further illustrate the invention, but should not be interpreted as limiting its scope in any way.

[0090] Example 1

[0091] This embodiment demonstrates the stability of a polishing composition comprising colloidal silica and a dispersant according to an embodiment of the present invention.

[0092] Polishing compositions 1A to 1G contained 3 wt% colloidal silica (Akzo Nobel CJ2-2), 1335 ppm malonic acid, 500 ppm glycine, 618 ppm 10% ferric nitrate solution, 2.5 wt% hydrogen peroxide, Kathlon (trademark), and varying amounts of 1,4-butanediol (i.e., dispersant) at pH 3, 4, or 5 as presented in Table 1. The average particle size was determined using a particle size measuring instrument available from Malvern Panalytical (Malvern, UK) immediately after preparation of the polishing compositions and after storing the polishing compositions at 45°C for 1, 2, and 3 weeks. The results are graphed in Figure 1.

[0093] Amount of dispersant and pH of abrasive compositions 1A to 1G Abrasive composition Dispersant (weight%) pH Initial average particle size (nm) 1A (for comparison) 0 3 80 1B (for comparison) 0 4 80 1C (for comparison) 0 5 80 1D (The present invention) 2 3 120 1E (The present invention) 2 5 120 1F (The present invention) 10 3 120 1G (The present invention) 10 5 120

[0094] As is evident from the results shown in Figure 1, the particles present in polishing compositions 1A to 1C, which contain colloidal silica but no dispersant and have an initial average particle size of about 80 nm, showed an increase in average particle size to about 120 nm (polishing composition 1A), about 160 nm (polishing composition 1B), and about 200 nm (polishing composition 1C) after storing the polishing compositions at 45°C for 3 weeks. These increases in particle size occurred at pH 3 (polishing composition 1A), pH 4 (polishing composition 1B), and pH 5 (polishing composition 1C), respectively.

[0095] Polishing compositions 1F and 1G, containing 10 wt% of a dispersant at pH values ​​of 3 and 5, respectively, and having an initial average particle size of approximately 120 nm, showed an increase in average particle size to approximately 130 nm (Polishing Composition 1F) and approximately 150 nm (Polishing Composition 1G) after storage at 45°C for 3 weeks. The minimum increase in average particle size (approximately 8%) after storage at 45°C for 3 weeks was observed in polishing composition 1F, containing colloidal silica and 10 wt% of a dispersant, at pH 3. As demonstrated by these results, the presence of the dispersant inhibited aggregation and consequently prevented an increase in average particle size. For example, polishing composition 1A, having pH 3 and no dispersant, showed an increase in particle size of approximately 50%, whereas polishing composition 1F, having pH 3 and 10 wt% of a dispersant, showed an increase in particle size of approximately 8%.

[0096] Example 2

[0097] This embodiment demonstrates the stability of a polishing composition comprising alumina surface-treated with a sulfonic acid-containing polymer and a dispersant according to an embodiment of the present invention.

[0098] Polishing compositions 2A to 2G contained 250 ppm of alumina surface-treated with a sulfonic acid-containing polymer at a pH of 2 or 4 as presented in Table 2, 1080 ppm of malonic acid, 1000 ppm of lysine, 1000 ppm of arginine, 500 ppm of ferric nitrate, 0.5 wt% of hydrogen peroxide, Kathlon (trademark), and varying amounts of 1,4-butanediol (i.e., dispersant). The average particle size was determined using a particle size measuring instrument available from Malvern Panalytical (Malvern, UK) immediately after preparation of the polishing compositions and after storage at 45°C for 1, 2, and 3 weeks. The results are graphed in Figure 2.

[0099] Amount of dispersant and pH of abrasive compositions 2A to 2G Abrasive composition Dispersant (weight%) pH 2A (for comparison) 0 2 2B (for comparison) 0 4 2C (The present invention) 0.5 2 2D (The present invention) 2 2 2E (The present invention) 2 4 2F (The present invention) 10 2 2G (The present invention) 10 4

[0100] As is evident from the results shown in Figure 2, particles present in polishing compositions 2A and 2B, which contain alumina surface-treated with a sulfonic acid-containing polymer but no dispersant and have an initial average particle size of about 150 nm, showed an increase in average particle size to about 950 nm (polishing composition 2A) and about 800 nm (polishing composition 2B) after storage at 45°C for 3 weeks. These increases in particle size occurred at pH 2 (polishing composition 2A) and pH 4 (polishing composition 2B), respectively. The increase in average particle size of polishing compositions 2A and 2B was about 630% and 530%, respectively.

[0101] Polishing compositions 2C to 2G containing 0.5 to 10 weight percent of a dispersant at a pH value of 2 or 4 did not substantially show an increase in particle size after being stored at 45°C for 3 weeks. As demonstrated by these results, the presence of a dispersant in polishing compositions containing alumina surface-treated with a sulfonic acid-containing polymer substantially and completely inhibited aggregation and prevented an increase in average particle size.

[0102] Example 3

[0103] This embodiment demonstrates the removal ratio of tungsten and silicon oxide provided by a polishing composition comprising an abrasive and a dispersant according to an embodiment of the present invention.

[0104] Polishing compositions 3A to 3E contained 3 wt% colloidal silica (average particle size: 75 nm) at pH 4.0, 1500 ppm of 10 wt% ferric nitrate solution, 3240 ppm of malonic acid, 2000 ppm of lysine, and 15 ppm of Kathlon (trademark). Polishing composition 3A (for comparison) did not contain a dispersant. Polishing compositions 3B to 3E (the present invention) additionally contained 1 wt%, 3 wt%, 7 wt%, and 9 wt% of 1,4-butanediol (i.e., a dispersant), respectively. Separate substrates comprising a blanket layer of tungsten or silicon oxide were polished with the five polishing compositions (polishing compositions 3A to 3E). After polishing, the removal ratios of tungsten and silicon oxide were determined, and the results are shown in Table 3.

[0105] Tungsten (W) and silicon oxide (SiO) removal ratio as a function of dispersant Abrasive composition Dispersant (weight%) W Removal Ratio (Å) SiO removal ratio (Å) 3A (for comparison) 0 184 394 3B (The present invention) 1 175 367 3C (The present invention) 3 182 343 3D (The present invention) 7 167 318 3E (The present invention) 9 162 310

[0106] As is evident from the results presented in Table 3, the presence of a dispersant significantly inhibits particle size growth as demonstrated in Example 1 of the present invention, whereas an increase in the amount of 1,4-butanediol dispersant from 0 wt% (Abrasive Composition 3A) to 9 wt% (Abrasive Composition 3E) was useful, with a slight decrease in the removal ratio of tungsten and silicon oxide.

[0107] All references cited herein, including publications, patent applications, and patents, are incorporated by reference in the same sense as they are incorporated individually and specifically as they are incorporated herein in their entirety.

[0108] The use of singular expressions and the use of "at least one" and similar indicators in the context describing the invention (particularly in the context of the following claims) includes both singular and plural expressions unless indicated herein or the context clearly indicates otherwise. The use of the term "at least one" following a list of one or more items (e.g., "at least one of A and B") should be interpreted to mean one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B), unless otherwise specified herein or clearly contradictory in the context. The terms "comprising," "having," "including," and "containing" should be interpreted as open-ended terms unless otherwise stated (i.e., meaning "comprising but not limited thereto"). References to ranges of values ​​in this specification are intended merely to function as a shorthand method for individually referring to each individual value within the range, unless otherwise indicated, and each individual value is incorporated into the specification as if it were individually cited in this specification. All methods described herein may be performed in any suitable order unless otherwise indicated herein or clearly contradictory in the context. Any use of any examples or exemplary language provided herein (e.g., “e.g., for example”) is merely intended to better illustrate the invention and does not limit the scope of the invention unless otherwise claimed. No language in this specification shall be interpreted as representing an element not claimed to be essential to the practice of the invention.

[0109] Preferred embodiments of the present invention, including the best mode known to the inventors for carrying out the present invention, are described herein. Variations of these preferred embodiments may become apparent to those skilled in the art upon reading the description above. The inventors expect that those skilled in the art will appropriately adopt such variations, and the inventors intend for the present invention to be practiced differently from as specifically described herein. Accordingly, the present invention includes all modifications and equivalents of the subject matter cited in the claims appended herein as permitted by applicable law. Furthermore, any combination of the elements described above in all possible variations is included in the present invention, unless otherwise indicated in the present specification or clearly contradictory in the context.

Claims

Claim 1 (a) 0.05 to 10 weight% of abrasive; (b) a dispersant selected from 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol and combinations thereof; and (c) water, comprising a chemical-mechanical polishing composition having a pH of 1 to 7, wherein the abrasive is alumina surface-treated with an anionic polymer, chemical-mechanical polishing composition. Claim 2 A chemical-mechanical polishing composition according to claim 1, wherein the composition comprises 2 to 5 weight percent of an abrasive. Claim 3 A chemical-mechanical polishing composition according to claim 1, wherein the composition comprises 0.5 to 20 weight percent of a dispersant. Claim 4 A chemical-mechanical polishing composition according to claim 1, wherein the chemical-mechanical polishing composition has a pH of 2 to 5. Claim 5 A chemical-mechanical polishing composition according to claim 1, wherein the dispersant is 1,4-butanediol. Claim 6 delete Claim 7 delete Claim 8 delete Claim 9 delete Claim 10 delete Claim 11 delete Claim 12 delete Claim 13 delete Claim 14 delete Claim 15 delete Claim 16 delete Claim 17 delete Claim 18 delete Claim 19 delete Claim 20 delete Claim 21 delete Claim 22 delete

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