Additives for improving particle dispersion in CMP slurry

Abstract

To provide polishing compositions having enhanced abrasive particle size stability.SOLUTION: The present invention provides a chemical-mechanical polishing composition comprising: (a) about 0.05 wt.% to about 10 wt.% of an abrasive; (b) a dispersant that is a linear or branched C2-C10 alkylene diol; and (c) water; where 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.SELECTED DRAWING: Figure 1

Description

[Background technology]

[0001] Compositions and methods for planarizing or polishing the surface of a substrate are well known in the art. Polishing compositions (also known as polishing slurries) generally contain an abrasive in a liquid carrier and are applied to a surface by bringing the surface into contact with a polishing pad saturated with the polishing composition. Common abrasives include silicon dioxide, cerium oxide, aluminum oxide, zirconium oxide, and tin oxide. Polishing compositions are generally used in combination with a polishing pad (e.g., abrasive cloth or disc). Instead of being suspended in the polishing composition, or in addition to that, the abrasive material may be incorporated into the polishing pad.

[0002] In many cases, it is desirable for abrasive materials to have a narrow particle size distribution. When abrasives are suspended in an abrasive composition, they may aggregate or clump together if left standing, thereby forming particles with a particle size significantly larger than the average particle size of the abrasive material. An increase in the proportion of abrasive particles with larger particle sizes is thought to lead to an increase in microscratches on the surface of the substrate being polished with the abrasive composition containing them. Microscratches can lead to substrate defects that do not meet stringent quality requirements.

[0003] Therefore, in this technical field, there remains a need for abrasive compositions having improved stability of abrasive particle size. [Overview of the project]

[0004] The present invention relates to a chemical mechanical polishing composition comprising (a) about 0.05% to about 10% by weight of an abrasive, and (b) a dispersant comprising linear or branched C2-C2. 10 The present invention provides a chemical mechanical polishing composition comprising (c) an alkylenediol as a dispersant and water, and having a pH of about 2 to about 6.

[0005] The present invention also relates to a method for chemically and mechanically polishing a substrate, comprising: (i) preparing a substrate; (ii) preparing a polishing pad; and (iii) a chemical mechanical polishing composition comprising: (a) about 0.05% to about 10% by weight of an abrasive; and (b) a dispersant, which is linear or branched C2-C2. 10 The present invention also provides a method comprising: (c) preparing a chemical mechanical polishing composition comprising an alkylenediol dispersant and water, and having a pH of about 2 to about 6; (iv) bringing a substrate into contact with a polishing pad and the chemical mechanical polishing composition; and (v) moving the polishing pad and the chemical mechanical polishing composition against the substrate to polish the substrate by grinding at least a portion of the surface of the substrate. [Brief explanation of the drawing]

[0006] [Figure 1] This graph shows the average particle size of abrasive compositions containing colloidal silica at 0 wt%, 2 wt%, or 10 wt% 1,4-butanediol concentrations at pH values ​​of 3, 4, or 5, after storage at 45°C for 0, 1, 2, and 3 weeks. [Figure 2] This graph shows the average particle size of abrasive compositions containing alumina surface-treated with a sulfonic acid-containing polymer, at 0 wt%, 0.5 wt%, 2 wt%, or 10 wt% 1,4-butanediol concentrations at pH 2 or 4, after storage at 45°C for 0, 1, 2, 3, 4, and 5 weeks. [Modes for carrying out the invention]

[0007] The present invention relates to a chemical mechanical polishing composition comprising (a) about 0.05% to about 10% by weight of an abrasive, and (b) a dispersant comprising linear or branched C2-C2. 10 The present invention provides a chemical mechanical polishing composition having a pH of about 2 to about 6, comprising (c) an alkylenediol as a dispersant and (c) water, and essentially consisting of or comprising the same.

[0008] The abrasive can be any suitable abrasive. The abrasive particles may contain, be essentially, or be made of any suitable particulate material, which is typically a metal oxide and / or metalloid oxide (hereinafter collectively referred to as "metal oxide"). 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 can be any suitable alumina, for example, α-alumina, γ-alumina, or fumed alumina. The alumina can be treated alumina, and the alumina particles can be surface-treated with anionic polymers such as copolymers containing sulfonic acid monomer units, such as polysulfonic acid, polystyrene sulfonic acid, and poly(2-acrylamido-2-methyl-1-propanesulfonic acid).

[0010] Silica can be unmodified silica or surface-modified silica, many of which are known in the art. For example, surface-modified silica can be surface-modified by doping with aluminum ions or by treatment with a surface modifier such as a silane containing amino silanes, alkylsilanes, etc. In a preferred embodiment, silica may be colloidal silica (e.g., unmodified colloidal silica).

[0011] If the silica is colloidal silica, then the colloidal silica can be any suitable colloidal silica. For example, colloidal silica can be a wet-process silica such as condensed silica. Condensed silica is typically prepared by condensing Si(OH)4 to form colloidal particles, which are defined as having an average particle size of about 1 nm to about 1000 nm. Such grinding particles can be prepared in accordance with U.S. Patent No. 5,230,833 or obtained as one of a variety of commercially available products such as Akzo-Nobel Bindzil® products 50 / 80, 30 / 360, 159 / 500, 40 / 220, and 40 / 130, CJ2-2, Nalco products 1050, 1060, 2327, and 2329, as well as 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 about 1% by weight or more, for example, about 1.5% by weight or more, about 2% by weight or more, or about 2.5% by weight or more of abrasive. Alternatively, or in addition, the abrasive composition may contain about 5% by weight or less, for example, about 4.5% by weight or less, about 4% by weight or less, or about 3.5% by weight or less of abrasive. Thus, the abrasive composition may contain abrasive in an amount bounded by any two of the aforementioned endpoints. For example, the abrasive composition may contain about 1% to about 5% by weight of abrasive, for example, about 1% to about 4.5% by weight, about 1% to about 4% by weight, about 1% to about 3.5% by weight, about 1.5% to about 5% by weight, about 1.5% to about 4.5% by weight, about 1.5% to about 4% by weight, about 1.5% to about 3.5% by weight, about 2% to about 5% by weight, about 2% to about 4.5% by weight, about 2% to about 4% by weight, about 2% to about 3.5% by weight, about 2.5% to about 5% by weight, about 2.5% to about 4.5% by weight, about 2% to about 4% by weight, or about 2.5% to about 3.5% by weight of abrasive.

[0013] The abrasive is preferably colloidally stable. The term colloid refers to the suspension of abrasive particles in a liquid carrier. Colloidal stability refers to the maintenance of the suspension over time. In the context of the present invention, when the abrasive is placed in a 100 ml graduated cylinder and left undisturbed for 2 hours, the abrasive is considered colloidally stable if the difference between the particle concentration in the bottom 50 ml of the graduated cylinder ([B], in units of g / ml) and the particle concentration in the top 50 ml of the graduated cylinder ([T], in units of g / ml) is divided by the initial particle concentration in the abrasive composition ([C], in units of g / ml) and the result 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 (e.g., average particle diameter). The particle size of the abrasive particles is the diameter of the smallest sphere containing the abrasive particles. The abrasive may have an average particle size of about 5 nm or more, for example, 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 in addition, the abrasive may have an average particle size of approximately 200 nm or less, for example, approximately 190 nm or less, approximately 180 nm or less, approximately 170 nm or less, approximately 160 nm or less, approximately 150 nm or less, approximately 140 nm or less, approximately 130 nm or less, approximately 120 nm or less, approximately 110 nm or less, approximately 100 nm or less, approximately 95 nm or less, approximately 90 nm or less, approximately 85 nm or less, approximately 80 nm or less, approximately 75 nm or less, or approximately 70 nm or less. Thus, the abrasive may have an average particle size bounded by any two of the aforementioned endpoints. For example, the abrasive material may have an average particle size of approximately 10 nm to approximately 200 nm, such as approximately 10 nm to approximately 190 nm, approximately 10 nm to approximately 180 nm, approximately 15 nm to approximately 170 nm, approximately 20 nm to approximately 160 nm, approximately 20 nm to approximately 150 nm, approximately 20 nm to approximately 140 nm, approximately 20 nm to approximately 130 nm, approximately 20 nm to approximately 120 nm, approximately 20 nm to approximately 110 nm, approximately 100 nm to approximately 200 nm, approximately 100 nm to approximately 190 nm, approximately 100 nm to approximately 180 nm, approximately 100 nm to approximately 170 nm, approximately 100 nm to approximately 160 nm, approximately 100 nm to approximately 150 nm, approximately 10 nm to approximately 100 nm, approximately 25 nm to approximately 80 nm, or approximately 30 nm to approximately 70 nm.

[0015] The abrasive composition contains a dispersant, which is a linear or branched C2-C2 compound. 10 It 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-C2 molecules. 10These are alkylenediols (e.g., linear C2-C7 alkylenediols or linear C4-C7 alkylenediols). As will be understood by those skilled in the art, alkylenediols contain an aliphatic carbon chain with two hydroxyl groups bonded to it, and the hydroxyl groups are typically bonded to different carbon atoms of the alkylenediol. As will be further understood by those skilled in the art, C2 alkylenediols cannot branch because there are only two carbon atoms in the C2 alkylenediol, and on the other hand, C3-C 10 Alkylenediols can be linear or branched, with branching containing one or more carbon atoms bonded to the alkylenediol skeleton. Alkylenediols may contain 2, 3, 4, 5, 6, 7, 8, 9, or 10 carbon atoms. In one 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 abrasive composition may contain about 0.5% by weight or more, for example, about 0.6% by weight or more, about 0.7% by weight or more, about 0.8% by weight or more, about 0.9% by weight or more, about 1% by weight or more, about 1.1% by weight or more, about 1.2% by weight or more, about 1.3% by weight or more, about 1.4% by weight or more, about 1.5% by weight or more, about 1.6% by weight or more, about 1.7% by weight or more, about 1.8% by weight or more, about 1.9% by weight or more, about 2% by weight or more, about 2.1% by weight or more, about 2.2% by weight or more, about 2.3% by weight or more, about 2.4% by weight or more, about 2.5% by weight or more, about 2.6% by weight or more, about 2.7% by weight or more, about 2.8% by weight, about 2.9% by weight or more, or about 3% by weight or more of dispersant. Alternatively, or in addition, the abrasive composition may contain a dispersant in an amount of about 20% by weight or less, for example, about 19.5% by weight or less, about 19% by weight or less, about 18.5% by weight or less, about 18% by weight or less, about 17.5% by weight or less, about 17% by weight or less, about 16.5% by weight or less, about 16% by weight or less, about 15.5% by weight or less, about 15% by weight or less, about 14.5% by weight or less, about 14% by weight or less, about 13.5% by weight or less, about 13% by weight or less, about 12.5% ​​by weight or less, about 12% by weight or less, about 11.5% by weight or less, about 11% by weight or less, about 10.5% by weight or less, or about 10% by weight or less. Thus, the abrasive composition may contain a dispersant in an amount bounded by any two of the aforementioned endpoints.For example, the abrasive composition contains approximately 0.5% to 20% by weight, for example, approximately 0.5% to 19% by weight, approximately 0.5% to 18% by weight, approximately 0.5% to 17% by weight, approximately 0.5% to 16% by weight, approximately 0.5% to 15% by weight, approximately 0.5% to 14% by weight, approximately 0.5% to 13% by weight, approximately 0.5% to 12% by weight, approximately 0.5% to 11% by weight, approximately 0.5% to 10% by weight, approximately 1% to 15% by weight, approximately 1% to 14% by weight, approximately 1% to approx It may contain 13% by weight, approximately 1% to approximately 12% by weight, approximately 1% to approximately 11% by weight, approximately 1% to approximately 10% by weight, approximately 2% to approximately 15% by weight, approximately 2% to approximately 14% by weight, approximately 2% to approximately 13% by weight, approximately 2% to approximately 12% by weight, approximately 2% to approximately 11% by weight, approximately 2% to approximately 10% by weight, approximately 3% to approximately 15% by weight, approximately 3% to approximately 14% by weight, approximately 3% to approximately 13% by weight, approximately 3% to approximately 12% by weight, approximately 3% to approximately 11% by weight, or approximately 3% to approximately 10% by weight of a dispersant.

[0017] The polishing composition contains water. The water can be any suitable water, for example, deionized water or distilled water. In some embodiments, the polishing composition may further contain one or more organic solvents in combination with water. For example, the polishing composition may further contain a hydroxyl solvent, such as methanol or ethanol, a ketone solvent, an amide solvent, a sulfoxide solvent, and the like. Preferably, the polishing composition contains pure water.

[0018] The polishing composition can have any suitable pH, for example, a pH of from about 1 to about 7. Typically, the polishing composition can have a pH of about 2 or more, for example, about 2.2 or more, about 2.4 or more, about 2.6 or more, about 2.8 or more, or about 3 or more. Alternatively, or in addition, the polishing composition can have a pH of about 6 or less, for example, about 5 or less, about 4.5 or less, about 4 or less, about 3.5 or less, or about 3 or less. Thus, the polishing composition can have a pH within a range bounded by any two of the aforementioned endpoints. For example, the polishing composition can have a pH of from about 2 to about 6, for example, from about 2 to about 5, from about 2 to about 4, from about 2.5 to about 5, from about 2.5 to about 4.5, from about 2.5 to about 4, or from about 2 to about 4.5.

[0019] The polishing composition optionally contains a mineral acid. Non-limiting examples of suitable mineral acids include nitric acid, sulfuric acid, and phosphoric acid.

[0020] The polishing composition can further contain a base for adjusting the pH of the polishing composition. Non-limiting examples of suitable bases include sodium hydroxide, potassium hydroxide, and ammonium hydroxide.

[0021] The polishing composition optionally further contains an oxidizing agent. The oxidizing agent can be any suitable oxidizing agent. In certain embodiments, the oxidizing agent contains ferric ions. The ferric ions can be provided by any suitable ferric ion source. In some embodiments, the oxidizing agent can contain a metal salt. For example, the ferric ions can be provided by a ferric salt containing inorganic anions such as nitrate ions (e.g., ferric nitrate), cyanide ions (e.g., ferric anion), etc. The oxidizing agent can also contain organic iron (III) compounds such as acetates, acetylacetonates, citrates, gluconates, oxalates, phthalates, and succinates, and mixtures thereof, but is not limited thereto. In other embodiments, the oxidizing agent can be an oxygen-containing oxidizing agent. Non-limiting examples of suitable oxygen-containing oxidizing agents include organic peroxide compounds such as hydrogen peroxide, persulfates, bromate persulfates, iodate persulfates, perbromate persulfates, periodate persulfates, peracetic acid, and oxone.

[0022] The polishing composition can contain any suitable amount of an oxidizing agent. For example, the polishing composition can contain an oxidizing agent of about 1 ppm or more, such as 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 in addition, the polishing composition can contain an oxidizing agent of about 2500 ppm (about 2.5 wt%) or less, such as 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 specified, the term ppm is meant to reflect one part per million based on weight. For example, 1000 ppm corresponds to 1 wt%.

[0023] If any oxidizing agent contains hydrogen peroxide, the hydrogen peroxide can be present in any suitable amount in the polishing composition. For example, the polishing composition can contain about 0.1 wt% to about 10 wt% of hydrogen peroxide, such as about 0.5 wt% to about 10 wt%, or about 0.5 wt% to about 5 wt%.

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

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

[0026] Abrasive compositions can be prepared by any suitable technique, many of which are known to those skilled in the art. Abrasive compositions can be prepared by batch or continuous processes. Generally, abrasive compositions can be prepared by combining their components in any order. As used herein, the term “components” includes individual components (e.g., abrasives, dispersants, any oxidizing agents, any amino acids, etc.) as well as any combination of components (e.g., abrasives, dispersants, any oxidizing agents, any amino acids, etc.).

[0027] For example, abrasive materials can be dispersed in water. A dispersant can then be added and mixed in any way that incorporates the components into the polishing composition. Any oxidizing agent and any amino acids can be added at any point during the preparation of the polishing composition. The polishing composition can be prepared before use by adding one or more components, such as an oxidizing agent, hydrogen peroxide, to the polishing composition immediately before use (e.g., within about 1 minute before use, or within about 1 hour before use, or within about 7 days before use). The polishing composition can also be prepared by mixing the components on the surface of the substrate during the polishing process.

[0028] The abrasive composition may be supplied as a single 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, optional oxidizing agent, and optional amino acid may be supplied in a second container, either in dry form or in aqueous solution or aqueous dispersion. If the oxidizing agent includes hydrogen peroxide, the hydrogen peroxide is preferably supplied separately from the other components of the abrasive composition and combined with the other components by the end user immediately before use (e.g., within one week, one day, one hour, ten minutes, or one minute before use). The components in the first or second container may be in dry form, and the components in the other container may be in aqueous dispersion form. Furthermore, it is preferable that the components in the first and second containers have different pH values, or substantially similar or equal pH values. The combination of the other two containers, or three or more containers, of the components of the abrasive composition is within the scope of the knowledge of those skilled in the art.

[0029] The abrasive composition of the present invention may also be provided as a concentrate intended to be diluted with an appropriate amount of water before use. In such embodiments, the concentrate of the abrasive composition may contain, with or without hydrogen peroxide, an abrasive, a dispersant, an optional oxidizing agent, an optional amino acid, and water in amounts such that, upon dilution of the concentrate with an appropriate amount of water, and upon addition of hydrogen peroxide if an appropriate amount is not already present, each component of the abrasive composition will be present in the abrasive composition in amounts within the appropriate ranges listed above for each component. For example, the abrasive, dispersant, optional oxidizing agent, and optional amino acid may each be present at a concentration about twice (e.g., about three times, about four times, or about five times) higher than the concentrations listed above for each component, and as a result, when the concentrate is diluted with an appropriate amount of any hydrogen peroxide and an equal amount of water (e.g., two equal parts of water, three equal parts of water, or four equal parts of water, respectively), each component will be present in the abrasive composition in amounts within the above ranges for each component. Furthermore, as will be understood by those skilled in the art, the concentrate may contain water present in the final polishing composition in a suitable proportion to ensure that the other components dissolve in the concentrate at least partially or completely.

[0030] The present invention also provides a method for chemically and mechanically polishing a substrate, comprising: (i) preparing a substrate; (ii) preparing a polishing pad; (iii) preparing a chemical mechanical polishing composition as described herein; (iv) bringing the substrate into contact with the polishing pad and the chemical mechanical polishing composition; and (v) moving the polishing pad and the chemical mechanical polishing composition against the substrate to grind at least a portion of the surface of the substrate, thereby polishing the substrate.

[0031] More specifically, the present invention also relates to a method for chemically and mechanically polishing a substrate, comprising: (i) preparing a substrate; (ii) preparing a polishing pad; and (iii) a chemically and mechanically polishing composition comprising: (a) about 0.05% to about 10% by weight of an abrasive; and (b) a dispersant, which is linear or branched C2-C2. 10The present invention also provides a method comprising: (c) preparing a chemical mechanical polishing composition comprising an alkylenediol dispersant and water, and having a pH of about 2 to about 6; (iv) bringing a substrate into contact with a polishing pad and the chemical mechanical polishing composition; and (v) moving the polishing pad and the chemical mechanical polishing composition against the substrate to polish the substrate by grinding at least a portion of the surface of the substrate.

[0032] A substrate polished using the method of the present invention may be any suitable substrate, in particular a substrate comprising at least one metal layer. The metal may be any suitable metal, for example, the metal may include, be essentially composed of, or be composed of, a metal selected from tungsten, aluminum, nickel-phosphorus, copper, ruthenium, cobalt, and combinations thereof. In a preferred embodiment, the metal is tungsten. A preferred substrate includes at least one layer on the surface of the substrate for polishing, in particular an exposed layer, which comprises, is essentially composed of, or consists of a metal, so that at least a portion of the metal on the surface of the substrate is ground (i.e., removed) to polish the substrate. In some embodiments, the substrate comprises at least one layer of metal and at least one layer of silicon oxide. In some preferred embodiments, the substrate comprises at least one layer of tungsten and at least one layer of silicon oxide. The polishing compositions and methods of the present invention are suitable for use in so-called damascene polishing methods for forming circuit lines on a suitable substrate, such as silicon oxide, by etching the silicon oxide surface to form circuit lines, and then overcoating the substrate with a layer of tungsten to fill the circuit lines. A substrate containing tungsten circuit lines insulated on a silicon oxide substrate is formed by at least chemically and mechanically polishing the tungsten overcoat to expose the silicon oxide substrate surface, and thus generating insulated tungsten lines on the substrate. In some embodiments, the substrate thus formed can be subjected to one or more subsequent polishing and / or cleaning steps to produce a finished substrate.

[0033] Therefore, in a preferred embodiment, the substrate includes a tungsten layer on its surface, and the substrate is polished by grinding at least a portion of the tungsten layer. In another preferred embodiment, the substrate includes a silicon-oxygen layer on its surface, and the substrate is polished by grinding at least a portion of the silicon oxide layer. In yet another preferred embodiment, the substrate includes a silicon-nitrogen layer on its surface, and the substrate is polished by grinding at least a portion of the silicon nitride layer. The substrate may include one or more of the tungsten layer, the silicon-oxygen layer, and the silicon nitride layer on its surface, and the substrate is polished by grinding at least a portion of one or more of the tungsten layer, the silicon-oxygen layer, and the silicon nitride layer.

[0034] The polishing compositions of the present invention preferably exhibit a reduction in the growth of average particle size over time. The growth of average particle size is thought to be caused by the aggregation of abrasive particles, which increases the total number of particles having relatively large particle sizes. Particles having relatively large particle sizes are thought to lead to an increase in the generation of microscratches on the substrate being polished, and these microscratches can lead to an increase in defects on the substrate. When the polishing compositions of the present invention are used to polish substrates, particularly substrates containing tungsten and silicon oxide, they provide improved polishing performance with respect to substrate surface quality, particularly in reducing the generation of microscratches on the substrate being polished, while also more preferably exhibiting a satisfactory removal rate.

[0035] The polishing method of the present invention is particularly suitable for use with a chemical mechanical polishing (CMP) apparatus. Typically, a CMP apparatus includes a platen that moves during use and has a velocity resulting from orbital, linear, or circular motion; a polishing pad that contacts the platen and moves with the platen during operation; and a carrier that contacts and moves against the surface of the polishing pad to hold the substrate so that it can be polished. Polishing of the substrate is performed by positioning the substrate in contact with the polishing pad and the polishing composition of the present invention, and then the polishing pad moves against the substrate to polish the substrate by grinding at least a portion of it.

[0036] The substrate can be planarized or polished with a chemical mechanical polishing composition along with any suitable polishing pad (e.g., polishing surface). Suitable polishing pads include, for example, woven and nonwoven polishing pads. Furthermore, suitable polishing pads may contain any suitable polymer having a variety of densities, hardness, thickness, compressibility, ability to rebound upon compression, and compressive modulus. Suitable polymers include, for example, polyvinyl chloride, polyvinyl fluoride, nylon, fluorocarbon, polycarbonate, polyester, polyacrylate, polyether, polyethylene, polyamide, polyurethane, polystyrene, polypropylene, their co-formation products, and mixtures thereof.

[0037] Preferably, the CMP apparatus further includes an in-situ polishing endpoint detection 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 disclosed, for example, in U.S. Patents 5,196,353, 5,433,651, 5,609,511, 5,643,046, 5,658,183, 5,730,642, 5,838,447, 5,872,633, 5,893,796, 5,949,927, and 5,964,643. It is desirable that inspection or monitoring of the progress of the polishing process with respect to the workpiece being polished enables the determination of the polishing endpoint, i.e., when to terminate the polishing process with respect to a particular workpiece.

[0038] Preferably, the polishing composition of the present invention exhibits reduced micro-scratch on the substrate polished with it. Preferably, the polishing composition of the present invention also exhibits improved storage stability.

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

[0040] Embodiment (1) In Embodiment (1), a chemical mechanical polishing composition is provided, which (a) contains about 0.05 wt% to about 10 wt% of an abrasive, and (b) a dispersant which is a linear or branched C2 - C 10 alkylene diol, and (c) water, and has a pH of about 1 to about 7. A chemical mechanical polishing composition is presented.

[0041] (2) In Embodiment (2), a chemical mechanical polishing composition according to Embodiment (1) is provided, wherein the composition contains about 1 wt% to about 5 wt% of an abrasive.

[0042] (3) In Embodiment (3), a chemical mechanical polishing composition according to Embodiment (1) or (2) is provided, wherein the composition contains about 2.5 wt% to about 3.5 wt% of an abrasive.

[0043] (4) In Embodiment (4), a chemical mechanical polishing composition according to any one of Embodiments (1) to (3) is provided, wherein the abrasive is selected from treated alumina, colloidal silica, fumed silica, surface - modified silica, and combinations thereof.

[0044] (5) In Embodiment (5), a chemical mechanical polishing composition according to any one of Embodiments (1) to (4) is provided, wherein the abrasive is colloidal silica.

[0045] (6) In Embodiment (6), a chemical mechanical polishing composition according to Embodiment (5) is provided, wherein the colloidal silica has an average particle size of about 10 nm to about 100 nm.

[0046] (7) In Embodiment (7), a chemical mechanical polishing composition according to Embodiment (6) is provided, wherein the colloidal silica has an average particle size of about 30 nm to about 70 nm.

[0047] (8) Embodiment (8) presents a chemical mechanical polishing composition according to any one of Embodiments (1) to (7), wherein the composition comprises about 0.5% to about 20% by weight of a dispersant.

[0048] (9) Embodiment (9) presents a chemical mechanical polishing composition according to any one of Embodiments (1) to (8), wherein the composition comprises about 1% to about 15% by weight of a dispersant.

[0049] (10) Embodiment (10) presents a chemical mechanical polishing composition according to any one of Embodiments (1) to (9), wherein the composition comprises about 3% to about 10% by weight of a dispersant.

[0050] (11) Embodiment (11) presents a chemical mechanical polishing composition according to any one of Embodiments (1) to (10), wherein the chemical mechanical polishing composition has a pH of about 2 to about 5.

[0051] (12) Embodiment (12) presents a chemical mechanical polishing composition according to any one of Embodiments (1) to (11), wherein the chemical mechanical polishing composition has a pH of about 2 to about 4.

[0052] (13) Embodiment (13) presents a chemical mechanical polishing composition according to any one of Embodiments (1) to (12), wherein the dispersant is a linear or branched C2-C7 alkylenediol.

[0053] (14) Embodiment (14) presents a chemical mechanical polishing composition according to any one of Embodiments (1) to (13), wherein the dispersant is a linear or branched C4-C7 alkylenediol.

[0054] (15) Embodiment (15) presents a chemical mechanical polishing composition according to any one of Embodiments (1) to (14), wherein the dispersant is 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, or a combination thereof.

[0055] (16) Embodiment (16) presents a chemical mechanical polishing composition according to any one of Embodiments (1) to (15), wherein the abrasive is 1,4-butanediol.

[0056] (17) In embodiment (17), the dispersant is a linear C2-C 10 A chemical mechanical polishing composition described in embodiment (1), which is an alkylenediol, is presented.

[0057] (18) Embodiment (18) is a method for chemically and mechanically polishing a substrate, (i) Prepare the circuit board, (ii) Prepare a polishing pad, (iii) A chemical mechanical polishing composition, (a) an abrasive in an amount of approximately 0.05% to approximately 10% by weight, (b) Dispersant, which is linear or branched C2-C 10 Alkylenediol is a dispersant, (c) Water and, Prepare a chemical mechanical polishing composition having a pH of approximately 2 to 6, (iv) bringing the substrate into contact with the polishing pad and the chemical mechanical polishing composition, (v) A method is presented which includes moving a polishing pad and a chemical mechanical polishing composition against a substrate to grind at least a portion of the surface of the substrate.

[0058] (19) Embodiment (19) presents the method according to Embodiment (18), wherein the composition comprises about 1% to about 5% by weight of an abrasive.

[0059] (20) Embodiment (20) presents the method according to Embodiment (18) or Embodiment (19), wherein the composition comprises about 2.5% to about 3.5% by weight of an abrasive.

[0060] (21) Embodiment (21) presents a method according to any one of Embodiments (18) to (20), wherein the abrasive is selected from treated alumina, colloidal silica, fumed silica, surface-modified silica, and combinations thereof.

[0061] (22) Embodiment (22) presents a method according to any one of embodiments (18) to (21), wherein the abrasive is colloidal silica.

[0062] (23) Embodiment (23) presents the method according to Embodiment (22), wherein the colloidal silica has an average particle size of about 10 nm to about 100 nm.

[0063] (24) Embodiment (24) presents the method according to Embodiment (23) in which the colloidal silica has an average particle size of about 30 nm to about 70 nm.

[0064] (25) Embodiment (25) presents a method according to any one of Embodiments (18) to (24), wherein the composition comprises about 0.5% to about 20% by weight of a dispersant.

[0065] (26) Embodiment (26) presents a method according to any one of Embodiments (18) to (25), wherein the composition comprises about 1% to about 15% by weight of a dispersant.

[0066] (27) Embodiment (27) presents a method according to any one of Embodiments (18) to (26), wherein the composition comprises about 3% to about 10% by weight of a dispersant.

[0067] (28) Embodiment (28) presents a method according to any one of Embodiments (18) to (27), wherein the chemical mechanical polishing composition has a pH of about 2 to about 5.

[0068] (29) Embodiment (29) presents a method according to any one of Embodiments (18) to (28), wherein the chemical mechanical polishing composition has a pH of about 2 to about 4.

[0069] (30) Embodiment (30) presents a method according to any one of Embodiments (18) to (29), wherein the dispersant is a linear or branched C2-C7 alkylenediol.

[0070] (31) Embodiment (31) presents a method according to any one of Embodiments (18) to (30), wherein the dispersant is a linear or branched C4-C7 alkylenediol.

[0071] (32) Embodiment (32) presents a method according to any one of Embodiments (18) to (31), wherein the dispersant is 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, or a combination thereof.

[0072] (33) Embodiment (33) presents a method according to any one of Embodiments (18) to (32), wherein the dispersant is 1,4-butanediol.

[0073] (34) In embodiment (34), the dispersant is a linear C2-C 10 A method described in Embodiment (18) is presented, which is an alkylenediol.

[0074] (35) Embodiment (35) presents a method according to any one of embodiments (18) to (34), wherein the substrate includes a tungsten layer on the surface of the substrate, and the substrate is polished by grinding at least a portion of the tungsten layer.

[0075] (36) Embodiment (36) presents a method according to any one of embodiments (18) to (35), wherein the substrate further includes a silicon-oxygen layer on the surface of the substrate, and the substrate is polished by grinding at least a portion of the silicon-oxygen layer.

[0076] (37) Embodiment (37) presents a method according to any one of embodiments (18) to (36), wherein the substrate further includes a silicon nitrogen layer on the surface of the substrate, and the substrate is polished by grinding at least a portion of the silicon nitrogen layer. [Examples]

[0077] The following embodiments further illustrate the present invention, but should of course not be construed as limiting its scope.

[0078] Example 1 This example demonstrates the stability of an abrasive composition containing colloidal silica and a dispersant according to an embodiment of the present invention.

[0079] Polishing compositions 1A to 1G, as shown in Table 1, contained 3% by weight of colloidal silica (Akzo Nobel CJ2-2), 1335 ppm of malonic acid, 500 ppm of glycine, 618 ppm of a 10% ferric nitrate solution, 2.5% by weight of hydrogen peroxide Kathlon®, and varying amounts of 1,4-butanediol (i.e., dispersant) at pH 3, 4, or 5. Average particle size was determined immediately after preparation of the polishing compositions and after storage at 45°C for 1, 2, and 3 weeks, using a particle size analyzer available from Malvern Panalytical (Malvern, UK). The results are shown graphically in Figure 1. [Table 1]

[0080] As is clear from the results shown in Figure 1, the particles present in polishing compositions 1A to 1C, which contain colloidal silica, do not contain a dispersant, and have an initial average particle size of approximately 80 nm, showed an increase in average particle size to approximately 120 nm (polishing composition 1A), approximately 160 nm (polishing composition 1B), and approximately 200 nm (polishing composition 1C) after 3 weeks of storage at 45°C. These increases in particle size occurred at pH 3 (polishing composition 1A), pH 4 (polishing composition 1B), and pH 5 (polishing composition 1C), respectively.

[0081] Polishing compositions 1F and 1G, each containing 10% by weight 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 3 weeks of storage at 45°C. The minimum increase in average particle size (approximately 8%) after 3 weeks of storage at 45°C was observed in polishing composition 1F, which contained colloidal silica and 10% by weight of a dispersant at pH 3. As demonstrated by these results, the presence of a dispersant significantly suppresses aggregation and therefore prevents 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%, while polishing composition 1F, having pH 3 and 10% by weight of a dispersant, showed an increase in particle size of approximately 8%.

[0082] Example 2 This example demonstrates the stability of an abrasive composition comprising alumina surface-treated with a sulfonic acid-containing polymer and a dispersant, according to an embodiment of the present invention.

[0083] Polishing compositions 2A-2G, as described in Table 2, contained 250 ppm of alumina surface-treated with a sulfonic acid-containing polymer, 1080 ppm of malonic acid, 1000 ppm of lysine, 1000 ppm of arginine, 500 ppm of ferric nitrate, 0.5% by weight of hydrogen peroxide Kathlon®, and varying amounts of 1,4-butanediol (i.e., dispersant) at pH 2 or 4. Average particle size was determined immediately after preparation of the polishing compositions and after storage at 45°C for 1, 2, and 3 weeks, using a particle size analyzer available from Malvern Panalytical (Malvern, UK). The results are shown graphically in Figure 2. [Table 2]

[0084] As is clear 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 and do not contain a dispersant, and have an initial average particle size of approximately 150 nm, showed an increase in average particle size to approximately 950 nm (polishing composition 2A) and approximately 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 increases in average particle size for polishing compositions 2A and 2B were approximately 630% and 530%, respectively.

[0085] Polishing compositions 2C to 2G, containing 0.5 to 10% by weight of a dispersant at a pH of 2 or 4, showed virtually no increase in particle size after 3 weeks of storage at 45°C. 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 suppresses aggregation and thus prevents an increase in average particle size.

[0086] Example 3 This embodiment demonstrates the removal rates of tungsten and silicon dioxide provided by an abrasive composition comprising an abrasive and a dispersant according to an embodiment of the present invention.

[0087] Polishing compositions 3A to 3E contained 3% by weight of colloidal silica (average particle size of 75 nm), 1500 ppm of a 10% by weight ferric nitrate solution, 3240 ppm of malonic acid, 2000 ppm of lysine, and 15 ppm of Kathlon® at a pH of 4.0. Polishing composition 3A (comparative) did not contain a dispersant. Polishing compositions 3B to 3E (inventive) further contained 1% by weight, 3% by weight, 7% by weight, and 9% by weight of 1,4-butanediol (i.e., a dispersant), respectively. Separate substrates containing a tungsten or silicon dioxide blanket layer were polished with the five polishing compositions (polishing compositions 3A to 3E). After polishing, the removal rates of tungsten and silicon dioxide were determined. The results are shown in Table 3. [Table 3]

[0088] As is evident from the results shown in Table 3, increasing the amount of 1,4-butanediol dispersant from 0% by weight in abrasive composition 3A to 9% by weight in abrasive composition 3E provides a useful effect, slightly reducing the removal rate of tungsten and silicon dioxide, while the presence of the dispersant significantly suppresses particle size growth, as demonstrated in Example 1 of this specification.

[0089] All references cited herein, including publications, patent applications, and patents, are incorporated herein by reference to the same extent as they are incorporated herein by reference, with each reference being shown to be incorporated individually and specifically.

[0090] In the context describing the present invention (particularly in the context of the following claims), the use of the terms “a,” “an,” “the,” and “at least one” and similar demonstrative pronouns should be interpreted as encompassing both singular and plural forms, unless otherwise indicated herein or unless clearly contradicted by the context. The use of the term “at least one” following an enumeration of one or more items (e.g., “at least one of A and B”) should be interpreted as meaning one item selected from the enumerated items (A or B), or any combination of two or more enumerated items (A and B), unless otherwise indicated herein or unless clearly contradicted by the context. The terms “equip,” “have,” “include,” and “contain” should be interpreted as non-restrictive terms unless otherwise stated (i.e., “include, but not limited to”). The enumeration of value ranges herein is intended solely as a convenient way to refer individually to each distinct value within the range, unless otherwise indicated herein, and each distinct value is incorporated herein as if it were individually enumerated herein. All methods described herein may be performed in any preferred order, unless otherwise indicated herein or unless it is clearly inconsistent with the context. Any embodiments or exemplary words (e.g., "etc.") provided herein are intended solely to further illustrate the invention and, unless otherwise claimed, do not limit the scope of the invention. Nothing herein should be construed as indicating any unclaimed element essential to the practice of the invention.

[0091] Preferred embodiments of the Invention, including the best mode known to the inventors for carrying out the Invention, are described herein. Variations of these preferred embodiments may become apparent to those skilled in the art by reading the preceding description. The inventors expect that those skilled in the art will use such variations appropriately, and the inventors intend that the Invention may be carried out in a manner other than as specifically described herein. Accordingly, the Invention includes all variations and equivalents of the subject matter enumerated in the claims appended herein, as permitted by applicable law. Furthermore, unless otherwise indicated herein, or unless it is clearly inconsistent in context, any combination of the above in all possible variations is incorporated into the Invention. This disclosure also includes the following: <Aspect 1> A chemical mechanical abrasive composition, (a) an abrasive in an amount of approximately 0.05% to approximately 10% by weight, (b) Dispersant, which is linear or branched C 2 ~C 10 Alkylenediol is a dispersant, (c) Water and, A chemical mechanical abrasive composition having a pH of approximately 1 to 7. <Aspect 2> The chemical mechanical polishing composition according to embodiment 1, wherein the composition comprises about 2% to about 5% by weight of the abrasive. <Aspect 3> The chemical mechanical polishing composition according to embodiment 1, wherein the abrasive is selected from treated alumina, colloidal silica, fumed silica, surface-modified silica, and combinations thereof. <Aspect 4> The chemical mechanical polishing composition according to embodiment 1, wherein the abrasive is colloidal silica. <Aspect 5> The chemical mechanical polishing composition according to embodiment 4, wherein the colloidal silica has an average particle size of about 10 nm to about 100 nm. <Aspect 6> The chemical mechanical polishing composition according to embodiment 1, wherein the composition comprises about 0.5% to about 20% by weight of the dispersant. <Aspect 7> The chemical mechanical polishing composition according to embodiment 1, wherein the chemical mechanical polishing composition has a pH of about 2 to about 5. <Aspect 8> The dispersant is linear or branched C 2 ~C 7 The chemical mechanical polishing composition according to embodiment 1 above, wherein the component is alkylenediol. <Pattern 9> The chemical mechanical polishing composition according to embodiment 1, wherein the dispersant is selected from 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, and combinations thereof. <Aspect 10> The chemical mechanical polishing composition according to embodiment 1, wherein the dispersant is 1,4-butanediol. <Aspect 11> The dispersant is a linear C 2 ~C 10 The chemical mechanical polishing composition according to embodiment 1 above, wherein the component is alkylenediol. <Aspect 12> A method for chemically and mechanically polishing a substrate, (i) Prepare the circuit board, (ii) Prepare a polishing pad, (iii) A chemical mechanical polishing composition, (a) an abrasive in an amount of approximately 0.05% to approximately 10% by weight, (b) Dispersant, which is linear or branched C 2 ~C 10 Alkylenediol is a dispersant, (c) Water and, Prepare a chemical mechanical polishing composition having a pH of approximately 2 to 6, (iv) bringing the substrate into contact with the polishing pad and the chemical mechanical polishing composition, (v) A method comprising moving the polishing pad and the chemical mechanical polishing composition against the substrate to grind at least a portion of the surface of the substrate and polish the substrate. <Aspect 13> The method according to embodiment 12, wherein the composition contains about 1% to about 5% by weight of the abrasive. <Aspect 14> The method according to embodiment 12, wherein the abrasive is selected from treated alumina, colloidal silica, fumed silica, surface-modified silica, and combinations thereof. <Aspect 15> The method according to embodiment 12, wherein the abrasive is colloidal silica. <Aspect 16> The method according to embodiment 15, wherein the colloidal silica has an average particle size of about 10 nm to about 100 nm. <Aspect 17> The method according to embodiment 12, wherein the composition comprises about 0.5% to about 20% by weight of the dispersant. <Aspect 18> The method according to embodiment 12, wherein the chemical mechanical polishing composition has a pH of about 2 to about 5. <Aspect 19> The dispersant is linear or branched C 2 ~C 7 The method according to embodiment 12 above, wherein the material is alkylenediol. <Aspect 20> The method according to embodiment 12, wherein the dispersant is selected from 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, and combinations thereof. <Aspect 21> The method according to embodiment 12, wherein the dispersant is 1,4-butanediol. <Aspect 22> The method according to embodiment 12, wherein the substrate includes a tungsten layer on its surface, and the substrate is polished by grinding at least a portion of the tungsten layer.

Claims

1. A method for chemically and mechanically polishing a substrate, (i) to prepare a substrate, wherein the substrate includes a tungsten layer on its surface, (ii) Prepare a polishing pad, (iii) A chemical mechanical abrasive composition, (a) an abrasive in an amount of 0.05% to 10% by weight, wherein the abrasive is alumina surface-treated with an anionic polymer, (b) A dispersant comprising linear or branched C ２ ~C １０ Alkylenediol is a dispersant, (c) Ferric ions and, (d) Water and, Prepare a chemical mechanical polishing composition having a pH of 2 to 4, (iv) bringing the substrate into contact with the polishing pad and the chemical mechanical polishing composition, (v) polishing the substrate by moving the polishing pad and the chemical mechanical polishing composition against the substrate to grind at least a portion of the surface of the substrate, A method wherein the dispersant is selected from 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, and combinations thereof.

2. The method according to claim 1, wherein the composition comprises 1% to 5% by weight of the abrasive.

3. The method according to claim 1, wherein the composition comprises 0.5% to 20% by weight of the dispersant.

4. The method according to claim 1, wherein the dispersant is 1,4-butanediol.

5. The method according to claim 1, wherein at least a portion of the tungsten layer is ground to polish the substrate.

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