Silica based slurry for selective polishing of carbon based film

Abstract

To provide a silica based slurry for selective polishing of carbon based films.SOLUTION: The present invention provides a chemical mechanical polishing composition containing (a) silica abrasive; (b) surfactant; (c) iron cation; (d) ligand optionally; and (e) water, wherein the silica abrasive has negative zeta potential in the chemical mechanical polishing composition. The present invention provides a method for chemical mechanical polishing substrates, especially those containing carbon based films, using the composition.SELECTED DRAWING: None

Description

Technical Field

[0001] In the manufacture of integrated circuits and other electronic devices, multiple layers of conductive, semiconductive, and dielectric materials are deposited or removed relative to the substrate surface. As the layers of material are successively deposited and removed relative to the substrate, the uppermost surface of the substrate becomes non-planarized and planarization may be required. Planarizing the surface, or "polishing" the surface, is a process of removing material from the surface of the substrate to generally form a uniform surface. Planarization is useful for removing undesirable surface geometries and surface defects such as rough surfaces, agglomerated materials, damage to the crystal lattice, scratches, contaminated layers or materials. Also, planarization is useful for removing excess deposited material used to fill features on the substrate and for providing a uniform surface for subsequent metallization and processing.

Background Art

[0002] Compositions and methods for planarizing or polishing the surface of a substrate are well known in the art. Chemical mechanical planarization or chemical mechanical polishing (CMP) is a common technique used to planarize a substrate. CMP utilizes a chemical composition known as a CMP composition or more simply a polishing composition (also called a polishing slurry) to selectively remove material from the substrate. The polishing composition is typically applied to the substrate by contacting a polishing pad (e.g., a polishing cloth or a polishing disk) saturated with the polishing composition to the surface of the substrate. Polishing of the substrate is typically further assisted by the chemical activity of the polishing composition and / or the mechanical activity of an abrasive suspended in the polishing composition or incorporated into the polishing pad (e.g., a non-volatile abrasive polishing pad).

[0003] As the miniaturization of integrated circuits and the increase in the number of integrated circuits on a chip progress, in order to fit into the limited space on a general chip, it is necessary to arrange the components constituting the circuit closer together. To maximize the performance of the semiconductor, it is important to effectively insulate between circuits. For this purpose, shallow grooves are etched in the semiconductor substrate, filled with an insulating material, and the active regions of the integrated circuit are separated. Specifically, STI (Shallow Trench Isolation) is a process in which a silicon nitride layer or a titanium nitride layer is formed on a silicon substrate, shallow trenches are formed by etching and photolithography, and a dielectric layer is deposited to fill the trenches. Since there is variation in the depth of the trenches formed by this method, it is usually necessary to deposit an excessive amount of dielectric material on the substrate in order to completely fill all the trenches. The dielectric material (for example, a carbon-based film) conforms to the geometry under the substrate. The excessive dielectric material is usually removed by a CMP process, and further provides a flat surface for further processing.

[0004] A polishing composition can be characterized by its polishing rate (i.e., removal rate) and its planarization efficiency. The polishing rate refers to the rate at which material is removed from the surface of the substrate and is usually expressed in units of length (thickness) per unit time (for example, angstroms (Å) / minute). The planarization efficiency is related to the reduction in step height with respect to the amount of material removed from the substrate. Specifically, a polishing surface, for example, a polishing pad, first contacts the "high points" on the surface and it is necessary to remove material to form a flat surface. A process that achieves a flat surface with less material removal is considered to be more efficient than a process that requires more material removal to achieve flatness.

[0005] In many cases, since the removal rate of the carbon-based film can be the rate-limiting step in the dielectric polishing step in the STI process, a high removal rate of the carbon-based film is desired to increase the throughput of the device. However, if the blanket removal rate is too fast, the oxide of the exposed grooves is polished excessively and groove erosion occurs, increasing the defects of the device.

[0006] There remains a need for compositions and methods for chemical mechanical polishing of carbon-based membranes that provide useful removal rates while also providing improved planarization efficiency. The present invention provides such polishing compositions and methods. These and other advantages of the present invention, as well as additional inventive features, will become apparent from the description of the invention provided herein. SUMMARY OF THE INVENTION

[0007] The present invention provides a chemical mechanical polishing composition comprising, consisting essentially of, or consisting of: (a) a silica abrasive; (b) a surfactant; (c) an iron cation; (d) optionally a ligand; and (e) water, wherein the silica abrasive has a negative zeta potential in the chemical mechanical polishing composition.

[0008] The present invention further provides a method of chemically mechanically polishing a substrate, comprising: (i) providing a substrate; (ii) providing a polishing pad; (iii) providing a chemical mechanical polishing composition comprising: (a) a silica abrasive; (b) a surfactant; (c) an iron cation; (d) optionally a ligand; and (e) water, wherein the silica abrasive has a negative zeta potential in the chemical mechanical polishing composition; (iv) contacting the substrate with the polishing pad and the chemical mechanical polishing composition; and (v) relatively moving the polishing pad and the chemical mechanical polishing composition with respect to the substrate to abrade at least a portion of the substrate to polish the substrate.

[0009] The present invention provides a chemical mechanical polishing composition comprising: (a) a silica abrasive; (b) a surfactant; (c) an iron cation; (d) optionally a ligand; and (e) water, wherein the silica abrasive has a negative zeta potential in the chemical mechanical polishing composition.

[0010] The polishing composition contains a silica abrasive. As used herein, the terms "silica abrasive", "silica abrasive particles", "silica particles", and "abrasive particles" can be used interchangeably and can refer to any silica particles (e.g., colloidal silica particles). The silica particles (e.g., colloidal silica particles) can be modified (e.g., surface modified) or unmodified and have a negative native zeta potential or a positive native zeta potential. As used herein, the term "native zeta potential" means the zeta potential of the silica abrasive before it is added to the polishing composition. For example, the native zeta potential can mean the zeta potential of the silica abrasive measured in a storage solution or aqueous solution before the silica abrasive is added to the polishing composition. One of ordinary skill in the art will be able to determine whether the silica abrasive before it is added to the polishing composition has a negative native zeta potential or a positive native zeta potential. The charge on dispersed particles such as silica abrasives (e.g., colloidal silica particles) is generally referred to as the zeta potential (or electrokinetic potential). The zeta potential of a particle means the potential difference between the charge of the ions surrounding the particle and the charge of the bulk solution of the composition in which the particle is measured (e.g., the liquid carrier and other components dissolved therein). The zeta potential typically depends on the pH of the aqueous medium. For a given polishing composition, the isoelectric point of the particles is defined as the pH at which the zeta potential is zero. As the pH increases or decreases away from the isoelectric point, the surface charge (and thus the zeta potential) decreases or increases accordingly (to a negative or positive zeta potential value). The native zeta potential and the zeta potential of the polishing composition can be obtained using a DT-1202 type acoustic-electroacoustic spectrometer available from Dispersion Technologies, Inc. (Bedford Hills, New York). As used herein, the term "negative zeta potential" refers to a silica abrasive that exhibits a negative surface charge when measured in the polishing composition. As used herein, the term "positive zeta potential" means a silica abrasive that exhibits a positive surface charge when measured in the polishing composition.

[0011] The silica abrasive has a negative zeta potential in the chemical mechanical polishing composition. Without wishing to be bound by a particular theory, the negative zeta potential of the silica abrasive in the chemical mechanical polishing composition is thought to have a favorable interaction with the cationicity of the surface of the carbon-based film and to help produce the favorable polishing characteristics described herein. In some embodiments, the silica abrasive has a zeta potential of less than 0 mV when measured in the polishing composition, i.e., the silica abrasive has a negative zeta potential when measured in the polishing composition. For example, the silica abrasive can have a zeta potential of -10 mV or less, -20 mV or less, -30 mV or less, or -40 mV or less in the chemical mechanical polishing composition. In some embodiments, the silica abrasive has a negative zeta potential of from about -10 mV to about -60 mV, from about -10 mV to about -50 mV, from about -10 mV to about -40 mV, from about -20 mV to about -60 mV, from about -20 mV to about -50 mV, from about -20 mV to about -40 mV, from about -30 mV to about -40 mV, or from about -20 mV to about -30 mV, of from about 0 mV to about -60 mV.

[0012] Silica abrasives (e.g., colloidal silica particles) can be modified (e.g., surface-modified) or unmodified and have a negative native zeta potential or a positive native zeta potential. Thus, silica abrasives (e.g., colloidal silica particles) can have a positive or negative zeta potential before being added to a chemical mechanical polishing composition. For example, silica particles (e.g., colloidal silica particles) can have a native zeta potential of less than 0 mV (e.g., -5 mV or less) before being added to a chemical mechanical polishing composition. Alternatively, silica particles (e.g., colloidal silica particles) can have a native zeta potential of 0 mV or more (e.g., 5 mV or more) before being added to a chemical mechanical polishing composition. When added to the chemical mechanical polishing composition of the present invention described herein, a silica abrasive having a negative native zeta potential maintains a negative zeta potential (e.g., by (i) using a cationic surfactant that cannot convert the negative zeta potential to a positive zeta potential, or (ii) using an anionic surfactant that maintains the negative zeta potential). Alternatively, when added to the chemical mechanical polishing composition of the present invention described herein, desirably, a silica abrasive having a positive native zeta potential is converted to a silica abrasive having a negative zeta potential (e.g., by using an anionic surfactant that can convert the positive zeta potential to a negative zeta potential).

[0013] Silica particles (e.g., colloidal silica particles) and charged silica particles (e.g., colloidal silica particles) can be prepared by various methods, some of which are commercially used and known. Useful silica particles include precipitated silica or condensed polymerized silica, which can be prepared using known methods such as the method called the "sol-gel" method or the method by ion exchange of silicic acid. Condensed polymerized silica particles are often prepared by condensing Si(OH)4 to form substantially spherical (e.g., spherical, oval, or oblong) particles. The precursor Si(OH)4 can be obtained, for example, by hydrolysis of high-purity alkoxysilane or acidification of an aqueous silicate solution. U.S. Patent No. 5,230,833 describes a method for preparing colloidal silica particles in solution.

[0014] In some embodiments, the silica abrasive is colloidal silica. As is known to those skilled in the art, colloidal silica is a suspension of fine amorphous, porous, and typically spherical particles in a liquid phase. Colloidal silica can take the form of condensed polymerized or precipitated silica particles. In some embodiments, the silica is in the form of wet-process type silica particles. The particles, such as colloidal silica, can have any suitable average size (i.e., average particle diameter). If the average abrasive particle size is too small, the polishing composition may not exhibit a sufficient removal rate. In contrast, if the average abrasive particle size is too large, the polishing composition may exhibit undesirable polishing performance such as poor substrate defectivity.

[0015] Accordingly, the silica abrasive (e.g., silica particles or colloidal silica particles) can have an average particle size of about 10 nm or more, e.g., 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, or about 50 nm or more. Alternatively, or additionally, the silica abrasive can have an average particle size of about 200 nm or less, e.g., about 175 nm or less, about 150 nm or less, about 125 nm or less, about 100 nm or less, about 75 nm or less, about 50 nm or less, or about 40 nm or less. Accordingly, the silica abrasive can have an average particle size bounded by any two of the foregoing endpoints.

[0016] For example, the silica abrasive (e.g., silica particles or colloidal silica particles) can have an average particle size of from about 10 nm to about 200 nm, from about 20 nm to about 200 nm, from about 20 nm to about 175 nm, from about 20 nm to about 150 nm, from about 25 nm to about 125 nm, from about 25 nm to about 100 nm, from about 30 nm to about 100 nm, from about 30 nm to about 75 nm, from about 30 nm to about 40 nm, or from about 50 nm to about 100 nm. In the case of non-spherical silica abrasive particles, the size of the particle is the diameter of the smallest sphere that encloses the particle. The particle size of the abrasive can be measured using any suitable technique, e.g., laser diffraction technique. Suitable particle size measuring devices are available, for example, from Malvern Instruments (Malvern, UK).

[0017] Silica abrasive agents (e.g., silica particles or colloidal silica particles) are preferably colloidal stable in the polishing composition. The term "colloid" means a suspension of particles in a liquid carrier (e.g., water). Colloidal stability refers to the suspension being maintained over time. In the context of the present invention, an abrasive agent is considered to be colloidal stable when the abrasive agent is placed in a 100 mL graduated cylinder and left without stirring for 2 hours, and the difference between the concentration of particles (in g / mL conversion, [B]) contained in the lower 50 mL of the graduated cylinder and the concentration of particles (in g / mL conversion, [T]) contained in the upper 50 mL of the graduated cylinder is divided by the initial concentration of particles (in g / mL conversion, [C]) of the polishing composition 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.

[0018] The silica abrasive agent can be present in the polishing composition in any suitable amount. If the polishing composition of the present invention contains too little abrasive agent, the composition may not exhibit a sufficient removal rate. In contrast, if the polishing composition contains too much abrasive agent, the polishing composition may exhibit undesirable polishing performance and / or may not be cost-effective and / or may not be stable. The polishing composition can contain the silica abrasive agent in an amount of about 10 wt% or less, such as 9 wt% or less, 8 wt% or less, 7 wt% or less, 6 wt% or less, 5 wt% or less, 4 wt% or less, 3 wt% or less, 2 wt% or less, 1 wt% or less, 0.9 wt% or less, 0.8 wt% or less, 0.7 wt% or less, 0.6 wt% or less, or 0.5 wt% or less. Alternatively, or additionally, the polishing composition can contain the silica abrasive agent in an amount of 0.001 wt% or more, such as 0.005 wt% or more, 0.01 wt% or more, 0.05 wt% or more, 0.1 wt% or more, 0.2 wt% or more, 0.3 wt% or more, 0.4 wt% or more, 0.5 wt% or more, or 1 wt% or more. Accordingly, the polishing composition can appropriately contain the silica abrasive agent in an amount enclosed by any two of the aforementioned endpoints.

[0019] For example, in some embodiments, the silica abrasive is present in the polishing composition in an amount of from about 0.001 wt% to about 10 wt%, such as from about 0.001 wt% to about 8 wt%, from about 0.001 wt% to about 6 wt%, from about 0.001 wt% to about 5 wt%, from about 0.001 wt% to about 4 wt%, from about 0.001 wt% to about 2 wt%, from about 0.001 wt% to about 1 wt%, from about 0.01 wt% to about 10 wt%, from about 0.01 wt% to about 8 wt%, from about 0.01 wt% to about 6 wt%, from about 0.01 wt% to about 5 wt%, from about 0.01 wt% to about 4 wt%, from about 0.01 wt% to about 2 wt%, from about 0.01 wt% to about 1 wt%, from about 0.05 wt% to about 10 wt%, from about 0.05 wt% to about 8 wt%, from about 0.05 wt% to about 6 wt%, from about 0.05 wt% to about 5 wt%, from about 0.05 wt% to about 4 wt%, from about 0.05 wt% to about 2 wt%, from about 0.05 wt% to about 1 wt%, from about 0.1 wt% to about 10 wt%, from about 0.1 wt% to about 8 wt%, from about 0.1 wt% to about 6 wt%, from about 0.1 wt% to about 5 wt%, from about 0.1 wt% to about 4 wt%, from about 0.1 wt% to about 2 wt%, from about 0.1 wt% to about 1 wt%, from about 0.5 wt% to about 10 wt%, from about 0.5 wt% to about 8 wt%, from about 0.5 wt% to about 5 wt%, from about 0.5 wt% to about 4 wt%, from about 0.5 wt% to about 2 wt%, from about 0.5 wt% to about 1 wt%, from about 1 wt% to about 10 wt%, from about 1 wt% to about 8 wt%, from about 1 wt% to about 6 wt%, from about 1 wt% to about 5 wt%, from about 1 wt% to about 4 wt%, or from about 1 wt% to about 2 wt%.

[0020] The polishing composition contains iron cations. The iron cations can be present as ferric (i.e., iron III) or ferrous (i.e., iron II), and can be added to the composition as any suitable iron-containing salt. For example, the iron cations can be generated by adding to the polishing composition iron nitrate, iron sulfate, iron halides (including fluorides, chlorides, bromides, and iodides, as well as perchlorates, perbromates, and periodates), and organic iron compounds such as iron acetate, iron acetylacetonate, iron citrate, iron gluconate, iron malonate, iron oxalate, iron phthalate, iron succinate and combinations thereof.

[0021] The polishing composition can include any suitable amount of iron cations. The polishing composition can include about 0.01 ppm or more of iron cations, for example, 0.1 ppm or more, about 0.5 ppm or more, about 1 ppm or more, about 5 ppm or more, about 10 ppm or more, or about 20 ppm or more of iron cations. Alternatively, or in addition, the polishing composition can include about 100 ppm or less of iron cations, for example, about 80 ppm or less, about 60 ppm or less, or about 40 ppm or less of iron cations. Thus, the polishing composition can include an amount of iron cations bounded by any two of the aforementioned endpoints. For example, the polishing composition may contain about 0.01 ppm to about 100 ppm, for example, about 0.01 ppm to about 80 ppm, about 0.01 ppm to about 60 ppm, about 0.01 ppm to about 40 ppm, about 0.1 ppm to about 100 ppm, about 0.1 ppm to about 80 ppm, about 0.1 ppm to about 60 ppm, about 0.1 ppm to about 40 ppm, about 1 ppm to about 100 ppm, about 1 ppm to about 80 ppm, about 1 ppm to about 60 ppm, about 1 ppm to about 40 ppm, about 10 ppm to about 100 ppm, about 10 ppm to about 80 ppm, about 10 ppm to about 60 ppm, or about 10 ppm to about 40 ppm of iron cations. Without wishing to be bound by any particular theory, it is believed that increasing the iron concentration results in a higher carbon-based film removal rate. However, it is also believed that higher iron concentrations may correlate with defectivity issues when polishing commercial carbon-based films.

[0022] The polishing composition contains a surfactant. The surfactant can be a cationic surfactant or an anionic surfactant. Generally, when the silica abrasive has a negative native zeta potential, the surfactant is a cationic surfactant or an anionic surfactant, and when the silica abrasive has a positive native zeta potential, the surfactant is an anionic surfactant. As described herein, the silica abrasive has a negative zeta potential in the chemical mechanical polishing composition (i.e., when measured in the chemical mechanical polishing composition). Thus, any suitable combination of silica particles and surfactant can be used as long as the resulting composition has a silica abrasive with a negative zeta potential. In certain embodiments, when the silica abrasive has a negative native zeta potential, the surfactant is a cationic surfactant, and when the silica abrasive has a positive native zeta potential, the surfactant is an anionic surfactant such that the resulting composition has a silica abrasive with a negative zeta potential. In a preferred embodiment, the silica abrasive has a positive native zeta potential, and the surfactant is an anionic surfactant such that the silica abrasive has a negative zeta potential when measured in the chemical mechanical polishing composition.

[0023] In some embodiments, the chemical mechanical polishing composition includes a silica abrasive having a negative native zeta potential and a cationic surfactant such that the silica abrasive has a negative zeta potential when measured in the chemical mechanical polishing composition.

[0024] In some embodiments, the chemical mechanical polishing composition includes a silica abrasive having a negative native zeta potential and an anionic surfactant such that the silica abrasive has a negative zeta potential when measured in the chemical mechanical polishing composition.

[0025] In some embodiments, the chemical mechanical polishing composition includes a silica abrasive having a positive native zeta potential and an anionic surfactant such that the silica abrasive has a negative zeta potential when measured in the chemical mechanical polishing composition.

[0026] In certain embodiments, the chemical mechanical polishing composition comprises a silica abrasive having a native zeta potential opposite in charge to the surfactant, i.e., a silica abrasive having a positive native zeta potential and an anionic surfactant or a silica abrasive having a negative native zeta potential and a cationic surfactant.

[0027] In some embodiments, the surfactant is a cationic surfactant. The cationic surfactant can be any suitable cationic surfactant, many of which are known in the art. In some embodiments, the cationic surfactant comprises a quaternary ammonium salt. Exemplary cationic surfactants include, but are not limited to, N,N,N’,N’,N’-pentamethyl-N-tallowalkyl-1,3-propanediammonium dichloride, (oxydi-2,1-ethanediyl)bis(cocoalkyl)dimethylammonium dichloride, 3-methacrylamidopropyltrimethylammonium chloride (“MAPTAC”), 3-acrylamidopropyltrimethylammonium chloride (“APTAC”), diallyldimethylammonium chloride (“DADMAC”), 2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEA.MCQ”), 2-(methacryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEM.MCQ”), N,N-dimethylaminoethyl acrylate benzyl chloride (“DMAEA.BCQ”), N,N-dimethylaminoethyl methacrylate benzyl chloride (“DMAEM.BCQ”), and combinations thereof.

[0028] In some embodiments, the surfactant is an anionic surfactant. The anionic surfactant can be any suitable anionic surfactant, many of which are known in the art. In some embodiments, the anionic surfactant is selected from alkyl sulfonic acids, alkyl sulfonates, aryl sulfonic acids, aryl sulfonates, alkyl aryl sulfonic acids, alkyl aryl sulfonates, and combinations thereof. In certain embodiments, the anionic surfactant is saturated or unsaturated C6-C 40 alkyl sulfonate, saturated or unsaturated C6-C 40 alkyl sulfonic acid, saturated or unsaturated C6-C 40 alkyl benzene sulfonate, saturated or unsaturated C6-C 40 alkyl benzene sulfonic acid and combinations thereof. Exemplary anionic surfactants include, but are not limited to, the CALSOFTTM surfactants (e.g., CALSOFTTM LPS-99 - dodecylbenzene sulfonic acid) commercially available from Pilot Chemical Corporation, West, West Chester, Ohio or the ZETASPERSE® surfactants (e.g., ZETASPERSE® Z2300 - ethoxylated C6-C 12 alcohol (CAS 68439-45-2) and C 10 -C 14 alkyl aryl sulfonate mixture) commercially available from Air Products, Allentown, Pennsylvania.

[0029] In some embodiments, the cationic surfactant and / or anionic surfactant comprises an alkyl chain having about 6 or more carbon atoms. For example, the cationic surfactant and / or anionic surfactant can consist of an alkyl chain having about 8 or more carbons, such as about 10 or more carbons, about 12 or more carbons, about 14 carbons, or about 16 or more carbons. Without wishing to be bound by any particular theory, surfactants having an alkyl chain with about 6 or more carbons (e.g., about 12 or more carbons) are thought to provide a desirable amount of wettability (i.e., lubricity) to the chemical mechanical polishing composition.

[0030] The polishing composition can include any suitable amount of surfactant. The polishing composition can include about 10 ppm or more of surfactant, such as about 20 ppm or more, about 50 ppm or more, about 100 ppm or more, about 200 ppm or more, about 300 ppm or more, or about 500 ppm or more. Alternatively, or additionally, the polishing composition can include about 10,000 ppm or less of surfactant, such as about 8,000 ppm or less, about 6,000 ppm or less, about 5,000 ppm or less, about 4,000 ppm or less, or about 3,000 ppm or less. Thus, the polishing composition can include an amount of surfactant bounded by any two of the foregoing endpoints. For example, the polishing composition can include from about 10 ppm to about 10,000 ppm of surfactant, such as from about 10 ppm to about 8,000 ppm, from about 10 ppm to about 6,000 ppm, from about 10 ppm to about 5,000 ppm, from about 10 ppm to about 4,000 ppm, from about 10 ppm to about 3,000 ppm, from about 50 ppm to about 10,000 ppm, from about 50 ppm to about 8,000 ppm, from about 50 ppm to about 6,000 ppm, from about 50 ppm to about 5,000 ppm, from about 50 ppm to about 4,000 ppm, from about 50 ppm to about 3,000 ppm, from about 10 ppm to about 10,000 ppm, from about 100 ppm to about 8,000 ppm, from about 100 ppm to about 6,000 ppm, from about 100 ppm to about 5,000 ppm, from about 100 ppm to about 4,000 ppm, or from about 100 ppm to about 3,000 ppm of surfactant.

[0031] The polishing composition optionally includes a ligand (e.g., a ligand for an iron cation). Thus, in some embodiments, the polishing composition includes a ligand, and in other embodiments, the composition does not include a ligand. In preferred embodiments, the polishing composition includes a ligand (e.g., a ligand for an iron cation). The ligand can be any suitable ligand, many of which are known in the art. In some embodiments, the ligand includes an alkene moiety, an alkyne moiety, a diacid moiety, an alcohol moiety, or a combination thereof. For example, the ligand can be an alkene moiety; an alkyne moiety; a diacid moiety; an alcohol moiety; an alkene moiety and a diacid moiety, an alkene moiety and an alcohol moiety; an alkene moiety, a diacid moiety and an alcohol moiety; an alkyne moiety and a diacid moiety; an alkyne moiety and an alcohol moiety; an alkyne moiety, a diacid moiety and an alcohol moiety; or an alkene moiety, an alkyne moiety, a diacid moiety and an alcohol moiety; or any compound (e.g., an organic compound) including an alkyne moiety, a diacid moiety and an alcohol moiety. In some embodiments, the ligand includes an alkene moiety and a diacid moiety; or an alkyne moiety and an alcohol moiety. Exemplary ligands include, but are not limited to, succinic acid, maleic acid, malonic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, oxalic acid, tartaric acid, 3,5-dimethyl-1-hexyn-3-ol, 2,4,7,9-tetramethyl-5-decyn-4,7-diol, 2,4,7,9-tetramethyl-5-decyn-4,7-diol ethoxylate, 2,5-dimethyl-3-hexyn-2,5-diol, 3-methyl-1-pentyn-3-ol, and combinations thereof.

[0032] When a ligand is present, the polishing composition can contain any suitable amount of the ligand. When a ligand is present, the polishing composition can contain at least about 10 ppm of the ligand, such as at least about 15 ppm, at least about 20 ppm, at least about 25 ppm, at least about 30 ppm, at least about 35 ppm, or at least about 40 ppm. Alternatively, or additionally, the polishing composition can contain up to about 1000 ppm of the ligand, such as up to about 800 ppm, up to about 600 ppm, up to about 400 ppm, up to about 200 ppm, up to about 100 ppm, up to about 80 ppm, up to about 60 ppm, or up to about 40 ppm. Thus, the polishing composition can contain an amount of the ligand bounded by any two of the aforementioned endpoints. For example, the polishing composition can contain from about 10 ppm to about 1000 ppm of the ligand, such as from about 10 ppm to about 800 ppm, from about 10 ppm to about 600 ppm, from about 10 ppm to about 400 ppm, from about 10 ppm to about 200 ppm, from about 10 ppm to about 100 ppm, from about 10 ppm to about 80 ppm, from about 10 ppm to about 60 ppm, from about 10 ppm to about 40 ppm, from about 20 ppm to about 1000 ppm, from about 20 ppm to about 800 ppm, from about 20 ppm to about 600 ppm, from about 20 ppm to about 400 ppm, from about 20 ppm to about 200 ppm, from about 20 ppm to about 100 ppm, from about 20 ppm to about 80 ppm, from about 20 ppm to about 60 ppm, or from about 20 ppm to about 40 ppm.

[0033] The chemical mechanical polishing composition can contain one or more compounds (i.e., pH adjusting compounds) that can adjust (i.e., regulate) the pH of the polishing composition. The pH of the polishing composition can be adjusted using any suitable compound that can adjust the pH of the polishing composition. The pH adjusting compound is desirably water-soluble and compatible with the other components of the polishing composition. Typically, the chemical mechanical polishing composition has a pH of from about 1 to about 7 (such as a pH of from about 1 to about 6, from about 1 to about 5, from about 2 to about 7, from about 2 to about 6, from about 2 to about 5, from about 3 to about 6, or from about 1 to about 4) at the time of use. Preferably, the chemical mechanical polishing composition has a pH of from about 1 to about 4 at the time of use.

[0034] Compounds that can adjust and buffer pH can be selected from the group consisting of ammonium salts, alkali metal salts, carboxylic acids, alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates, borates, and mixtures thereof.

[0035] The chemical mechanical polishing composition may optionally further contain one or more additives. Exemplary additives include conditioners, acids (e.g., sulfonic acids), complexing agents, chelating agents, biocides, scale inhibitors, and dispersants.

[0036] The biocide, when present, can be any suitable biocide and can be present in the polishing composition in any suitable amount. Suitable biocides are isothiazolinone biocides. Typically, the polishing composition contains from about 1 ppm to about 50 ppm of biocide, preferably from about 10 ppm to about 20 ppm of biocide.

[0037] The polishing composition can be manufactured by any suitable technique, many of which are known to those skilled in the art. The polishing composition can be prepared by a batch process or a continuous process. Generally, the polishing composition is prepared by combining the components of the polishing composition. As used herein, the term "component" includes individual components (e.g., silica abrasive, surfactant, iron cation, any ligand, any pH adjuster, and / or any additive), and any combination of components (e.g., silica abrasive, surfactant, iron cation, any ligand, any pH adjuster, and / or any additive, etc.).

[0038] For example, the polishing composition can be prepared by (i) providing all or part of the liquid carrier, (ii) dispersing the silica abrasive, surfactant, iron cation, any ligand, any pH adjuster, and / or any additive using any suitable means for preparing such a dispersion, (iii) adjusting the pH of the dispersion as appropriate, and (iv) optionally adding any other optional components and / or additives to the mixture in appropriate amounts.

[0039] Alternatively, the polishing composition can be adjusted by: (i) adding one or more components (e.g., surfactant, iron cation, optional ligand, optional pH adjuster, and / or optional additive) into the silica abrasive slurry; (ii) adding one or more components into an additive solution (e.g., liquid carrier, surfactant, iron cation, optional ligand, optional pH adjuster, and / or optional additive); (iii) combining the silica abrasive slurry and the additive solution to form a mixture; (iv) optionally adding an appropriate amount of any other optional additive to the mixture; and (v) appropriately adjusting the pH of the mixture.

[0040] The polishing composition can be supplied as a one-package system containing silica abrasive, surfactant, iron cation, optional ligand, optional pH adjuster, and / or optional additive, and water. Alternatively, the polishing composition of the present invention can be supplied as a two-package system containing a silica abrasive slurry in a first package and an additive solution in a second package, where the silica abrasive slurry consists essentially of, or consists of, silica abrasive and water, and the additive solution consists essentially of, or consists of, surfactant, iron cation, optional ligand, optional pH adjuster, and / or optional additive. The two-package system can adjust the properties of the polishing composition by varying the blending ratio of the two packages of the silica abrasive slurry and the additive solution.

[0041] To utilize such a two-package polishing system, various methods can be employed. For example, the silica abrasive slurry and the additive solution can be supplied to the polishing table through different pipes joined and connected at the outlet of the supply pipe. Also, the silica abrasive slurry and the additive solution can be mixed shortly before or immediately before polishing, or can be supplied simultaneously on the polishing table. Furthermore, when mixing the two packages, deionized water can be added as desired to adjust the polishing properties of the polishing composition and the resulting substrate.

[0042] Similarly, three, four, or more package systems can be utilized in connection with the present invention, and each of the plurality of containers contains different components of the chemical mechanical polishing composition of the present invention, one or more optional components, and / or one or more identical components at different concentrations.

[0043] To mix the components contained in two or more storage devices to produce the polishing composition at or near the point of use, the storage devices are typically provided with one or more flow paths leading from each storage device to the point of use of the polishing composition (e.g., a platen, a polishing pad, or a substrate surface). As used herein, the term "point of use" means the location where the polishing composition is applied to the substrate surface (e.g., a polishing pad or the substrate surface itself). The term "flow path" means the path of flow from an individual storage container to the point of use of the component stored therein. Each flow path can lead directly to the point of use, or two or more of the flow paths can be combined at any point to lead to the point of use as a single flow path. Further, any of the flow paths (e.g., individual flow paths or combined flow paths) can first be connected to one or more other devices (e.g., a pumping device, a measuring device, a mixing device, etc.) before reaching the point of use of the component(s).

[0044] The components of the polishing composition can be delivered independently to the point of use (e.g., the components are delivered to the substrate surface where they are mixed during the polishing process), or one or more of the components can be combined, for example, shortly before or immediately before being delivered to the point of use. When the components are combined after about 5 minutes, for example about 4 minutes or less, about 3 minutes or less, about 2 minutes or less, about 1 minute or less, about 45 seconds or less, about 30 seconds or less, about 10 seconds or less after being added in a mixed state on the platen, or when the components are combined simultaneously with the delivery of the components at the point of use (e.g., the components are joined by a dispenser), the components are combined "shortly before being delivered to the point of use". Also, when the components are combined within 5 m of the point of use, for example within 1 m of the point of use, or within 10 cm of the point of use (e.g., within 1 cm of the point of use), the components are combined "shortly before being delivered to the point of use".

[0045] If two or more components of the polishing composition are combined before reaching the point of use, the components can be combined in the flow path and sent to the point of use without using a mixing device. Alternatively, one or more of the flow paths can lead to a mixing device to facilitate the combination of two or more of the components. Any suitable mixing device can be used. For example, the mixing device can be a nozzle or jet (e.g., a high-pressure nozzle or jet) through which two or more components flow. Alternatively, the mixing device can be a container-type mixing device that includes one or more inlets through which two or more components of the polishing slurry are introduced into the mixer, and at least one outlet through which the mixed components exit the mixer and are sent to the point of use directly or via other elements of the device (e.g., through one or more flow paths). Further, the mixing device can include two or more chambers, each chamber having at least one inlet and at least one outlet, and two or more components being combined in each chamber. When a container-type mixing device is used, the mixing device preferably comprises a mixing mechanism to further facilitate the combination of the components. Mixing mechanisms are generally known in the art and include stirrers, blenders, agitators, baffles with paddles, gas sparger systems, vibrators, etc.

[0046] The polishing composition can also be provided as a concentrate intended to be diluted with an appropriate amount of water before use. In such embodiments, the polishing composition concentrate contains the components of the polishing composition such that when the concentrate is diluted with an appropriate amount of water, 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 silica abrasive, surfactant, iron cation, any ligand, any pH adjuster, and / or any additive are each present in the concentrate in an amount approximately 2 times (e.g., about 3 times, about 4 times, or about 5 times) greater than the concentration described above for each component such that when the concentrate is diluted with an equal volume of water (e.g., 2 volumes of water, 3 volumes of water, or 4 volumes of water respectively), each component is present in the polishing composition in an amount within the range described above for each component. Further, as will be understood by those skilled in the art, the concentrate can contain an appropriate proportion of the water present in the final polishing composition such that the silica abrasive, surfactant, iron cation, any ligand, any pH adjuster, and / or any additive dissolve at least partially or completely in the concentrate.

[0047] The present invention further provides a method of chemically-mechanically polishing a substrate, comprising: (i) providing a substrate; (ii) providing a polishing pad; (iii) providing a chemical-mechanical polishing composition comprising (a) a silica abrasive; (b) a surfactant; (c) an iron cation; (d) optionally a ligand; and (e) water, wherein the silica abrasive has a negative zeta potential in the chemical-mechanical polishing composition; (iv) contacting the substrate with the polishing pad and the chemical-mechanical polishing composition; and (v) relatively moving the polishing pad and the chemical-mechanical polishing composition with respect to the substrate to wear at least a part of the substrate and polish the substrate.

[0048] The chemical mechanical polishing composition can be used to polish any suitable substrate, and is particularly useful for polishing a substrate including at least one layer (typically a surface layer) made of a low dielectric constant material. Suitable substrates include wafers used in the semiconductor industry. The wafer typically includes or consists of, for example, a metal, metal oxide, metal nitride, metal composite, metal alloy, low dielectric constant material, or a combination thereof. The method of the present invention is particularly useful for polishing a substrate made of a carbon-based film (e.g., a carbon hard mask material). In some embodiments, the substrate includes a carbon-based film, and at least a part of the carbon-based film is worn at a certain removal rate (Å / min) to polish the substrate.

[0049] In certain embodiments, the substrate includes a carbon-based film. The carbon-based film can be any suitable material containing carbon (e.g., a low dielectric constant material), many of which are known in the art. In some embodiments, the carbon-based film contains more than about 50 wt% carbon, such as more than about 60 wt% carbon, more than about 70 wt% carbon, more than about 80 wt% carbon, more than about 90 wt% carbon, or more than about 95 wt% carbon. The carbon-based film can have any suitable phase. For example, the carbon-based film can be amorphous, crystalline, or a combination thereof. In certain embodiments, the carbon-based film is amorphous. Exemplary carbon-based films are described in Weigand et al. ("Evaluating spin-on carbon materials at low temperatures for high wiggling resistance", Advanced Etch Technology for Nanopatterning II. Vol. 8685. International Society for Optics and Photonics, 2013), and Kim et al. ("Study on the etching characteristics of amorphous carbon layer in oxygen plasma with carbonyl sulfide", Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films (2013), 31:2:021301, pp. 1-7).

[0050] In some embodiments, the substrate includes a carbon-based film, and at least a portion of the carbon-based film is worn away at a removal rate (Å / min) to polish the substrate. The chemical mechanical polishing composition of the present invention desirably exhibits a high removal rate when polishing a substrate including a carbon-based film according to the method of the present invention. For example, when polishing a substrate including a carbon-based film according to an embodiment of the present invention, the polishing composition desirably has a removal rate of the carbon-based film of about 400 Å / min or more, such as about 500 Å / min or more, about 600 Å / min or more, about 700 Å / min or more, about 800 Å / min or more, about 900 Å / min or more, about 1,000 Å / min or more, about 1,100 Å / min or more, about 1,200 Å / min or more, about 1,500 Å / min or more, about 2,000 Å / min or more, about 3,000 Å / min or more, or about 4,000 Å / min or more.

[0051] In some embodiments, the substrate further includes silicon oxide, silicon nitride, polysilicon, titanium nitride, or a combination thereof, and at least a portion of the silicon oxide, silicon nitride, polysilicon, or titanium nitride is worn away at a removal rate (Å / min) to polish the substrate. In embodiments where the substrate further includes silicon oxide, silicon nitride, polysilicon, titanium nitride, or a combination thereof, the removal rate (Å / min) of the carbon-based film is greater than the removal rate (Å / min) of the silicon oxide, silicon nitride, polysilicon, or titanium nitride. For example, the removal rate (Å / min) of the carbon-based film is at least 10 times greater than the removal rate (Å / min) of the silicon oxide, silicon nitride, polysilicon, or titanium nitride, at least 20 times greater than the removal rate (Å / min) of the silicon oxide, silicon nitride, polysilicon, or titanium nitride, or at least 40 times greater than the removal rate (Å / min) of the silicon oxide, silicon nitride, polysilicon, or titanium nitride.

[0052] In embodiments where the substrate further comprises silicon oxide, the silicon oxide can be any suitable silicon oxide, many of which are known in the art. Suitable types of silicon oxide include, but are not limited to, borophosphosilicate glass (BPSG), tetraethyl orthosilicate (TEOS), plasma enhanced tetraethyl orthosilicate (PETEOS), thermal oxide, undoped silicate glass, and high density plasma (HDP) oxide. The chemical mechanical polishing composition of the present invention preferably exhibits a low removal rate when polishing a substrate containing silicon oxide according to the method of the present invention. For example, when polishing a substrate made of silicon oxide according to an embodiment of the present invention, the polishing composition preferably exhibits a silicon oxide removal rate of about 500 Å / min or less, such as about 250 Å / min or less, about 200 Å / min or less, about 150 Å / min or less, about 100 Å / min or less, about 50 Å / min or less, about 25 Å / min or less, about 10 Å / min or less, or about 5 Å / min or less. In some embodiments, the polishing composition exhibits a silicon oxide removal rate that is too low to be detected.

[0053] In embodiments where the substrate further comprises polysilicon, the polysilicon can be any suitable polysilicon, many of which are known in the art. The polysilicon can have any suitable phase and can be amorphous, crystalline, or a combination thereof. The chemical mechanical polishing composition of the present invention preferably exhibits a low removal rate when polishing a substrate made of polysilicon according to the method of the present invention. For example, when polishing a substrate made of polysilicon according to an embodiment of the present invention, the polishing composition preferably exhibits a polysilicon removal rate of about 500 Å / min or less, such as about 250 Å / min or less, about 200 Å / min or less, about 150 Å / min or less, about 100 Å / min or less, about 50 Å / min or less, about 25 Å / min or less, about 10 Å / min or less, or about 5 Å / min or less. In some embodiments, the polishing composition exhibits a polysilicon removal rate that is too low to be detected.

[0054] In embodiments where the substrate further comprises silicon nitride, the silicon nitride can be any suitable silicon nitride, many of which are known in the art. The chemical mechanical polishing composition of the present invention preferably exhibits a low removal rate when polishing a substrate comprising silicon nitride according to the method of the present invention. For example, when polishing a substrate comprising silicon nitride according to an embodiment of the present invention, the polishing composition preferably exhibits a silicon nitride removal rate of about 500 Å / min or less, such as about 250 Å / min, about 200 Å / min, about 150 Å / min, about 100 Å / min, about 50 Å / min, about 25 Å / min, about 10 Å / min, or about 5 Å / min. In some embodiments, the polishing composition exhibits a silicon nitride removal rate that is too low to detect.

[0055] In embodiments where the substrate further comprises titanium nitride, the titanium nitride can be any suitable titanium nitride, many of which are known in the art. The chemical mechanical polishing composition of the present invention preferably exhibits a low removal rate when polishing a substrate comprising titanium nitride according to the method of the present invention. The polishing composition preferably exhibits a titanium nitride removal rate of about 500 Å / min or less, such as about 250 Å / min, about 200 Å / min, about 150 Å / min, about 100 Å / min, about 50 Å / min, about 25 Å / min, about 10 Å / min, or about 5 Å / min. In some embodiments, the polishing composition exhibits a titanium nitride removal rate that is too low to detect.

[0056] The polishing composition of the present invention preferably exhibits low particle defects when polishing the substrate, as determined by suitable techniques. The particle defects on the substrate polished with the polishing composition of the present invention can be determined by any suitable technique. For example, laser light scattering techniques such as dark field normal beam synthesis (DCN) and dark field oblique beam synthesis (DCO) can be used to determine particle defects on the polished substrate. Suitable apparatus for evaluating the defectiveness of particles is available, for example, from KLA-Tencor (e.g., SURFSCAN® SPI apparatus operating at a threshold of 120 nm or 160 nm).

[0057] The chemical mechanical polishing composition and method of the present invention are particularly suitable for use in combination with a chemical mechanical polishing apparatus. Typically, the apparatus includes a platen that moves during use and has a speed resulting from orbital, linear, or circular motion, a polishing pad that contacts the platen and moves with the platen during movement, and a carrier that holds the substrate to be polished and contacts and moves the substrate relative to the surface of the polishing pad. Polishing of the substrate is performed by contacting the substrate with the polishing pad and the polishing composition of the present invention and then wearing at least a portion of the substrate by relative movement of the polishing pad with respect to the substrate to polish the substrate.

[0058] The substrate can be polished with the chemical mechanical polishing composition using any suitable polishing pad (e.g., a polishing surface). Suitable polishing pads include, for example, woven and non-woven polishing pads. Further, suitable polishing pads can include any suitable polymer having various densities, hardnesses, thicknesses, compressibilities, the ability to rebound upon compression, and compression elastic moduli. Suitable polymers include, for example, polyvinyl chloride, polyvinyl fluoride, nylon, fluorocarbon, polycarbonate, polyester, polyacrylate, polyether, polyethylene, polyamide, polyurethane, polystyrene, polypropylene, copolymers thereof, and mixtures thereof. Soft polyurethane polishing pads are particularly useful in combination with the polishing method of the present invention. Representative pads include, but are not limited to, SURFIN® 000, SURFIN® SSW1, SPM3100 (e.g., commercially available from Eminess Technologies), POLITEX®, EPIC® D100 pad (commercially available from Cabot Microelectronics), IC1010 pad (commercially available from Dow, Inc), and Fujibo POLYPAS® 27, etc.

[0059] Desirably, the chemical mechanical polishing apparatus further comprises 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 the substrate being polished are known in the art. Such methods are described, for example, in U.S. Patent Nos. 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. Desirably, inspection or monitoring of the progress of the polishing process for the substrate being polished enables determination of the polishing endpoint, i.e., determination of when to end the polishing process for a particular substrate.

[0060] Aspects including embodiments of the invention described herein may be beneficial alone or in combination with one or more other aspects or embodiments. Without limiting the foregoing description, specific non-limiting embodiments 1 to 46 of the present disclosure are provided below. As will be apparent to those skilled in the art upon reading the present disclosure, each of the individually numbered embodiments can be used or combined with any of the preceding or subsequent individually numbered embodiments. This is intended to provide support for all combinations of such embodiments and is not limited to the combinations of embodiments explicitly provided below.

[0061] [Embodiment] (1) In Embodiment (1), a chemical mechanical polishing composition is presented comprising: (a) a silica abrasive; (b) a surfactant; (c) an iron cation; (d) optionally a ligand; and (e) water, Here, the silica abrasive has a negative zeta potential in the chemical mechanical polishing composition.

[0062] (2) In Embodiment (2), there is provided the polishing composition according to Embodiment 1, wherein the polishing composition contains about 0.001 wt% to about 10 wt% of the silica abrasive.

[0063] (3) In Embodiment (3), there is provided the polishing composition according to Embodiment 1 or 2, wherein the polishing composition contains about 0.05 wt% to about 5 wt% of the silica abrasive.

[0064] (4) In Embodiment (4), there is provided the polishing composition according to any one of Embodiments (1) to (3), wherein the silica abrasive is colloidal silica.

[0065] (5) In Embodiment (5), there is provided the polishing composition according to any one of Embodiments (1) to (4), wherein the polishing composition has a pH of about 1 to about 7.

[0066] (6) In Embodiment (6), there is provided the polishing composition according to any one of Embodiments (1) to (5), wherein the polishing composition has a pH of about 1 to about 4.

[0067] (7) In Embodiment (7), there is provided the polishing composition according to any one of Embodiments (1) to (6), wherein the surfactant is a cationic surfactant.

[0068] (8) In Embodiment (8), there is provided the polishing composition according to Embodiment (7), wherein the cationic surfactant contains a quaternary ammonium salt.

[0069] (9) In Embodiment (9), the cationic surfactant is selected from N,N,N’,N’,N’-pentamethyl-N-tallow alkyl-1,3-propanediammonium dichloride, (oxydi-2,1-ethanediyl)bis(coco alkyl)dimethylammonium dichloride, 3-methacrylamidopropyltrimethylammonium chloride (“MAPTAC”), 3-acrylamidopropyltrimethylammonium chloride (“APTAC”), diallyldimethylammonium chloride (“DADMAC”), 2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEA.MCQ”), 2-(methacryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEM.MCQ”), N,N-dimethylaminoethyl acrylate benzyl chloride (“DMAEA.BCQ”), N,N-dimethylaminoethyl methacrylate benzyl chloride (“DMAEM.BCQ”), and combinations thereof, presenting the polishing composition according to Embodiment (7).

[0070] (10) In Embodiment (10), presenting the polishing composition according to any one of Embodiments (1) to (6), wherein the surfactant is an anionic surfactant.

[0071] (11) In Embodiment (11), presenting the polishing composition according to Embodiment (10), wherein the anionic surfactant is selected from alkyl sulfonic acid, alkyl sulfonate, aryl sulfonic acid, aryl sulfonate, alkylaryl sulfonic acid, alkylaryl sulfonate, and combinations thereof.

[0072] (12) In Embodiment (12), the anionic surfactant is saturated or unsaturated C6-C 40 alkyl sulfonate, saturated or unsaturated C6-C 40 alkyl sulfonic acid, saturated or unsaturated C6-C 40 alkylbenzene sulfonate, saturated or unsaturated C6-C 40Present a polishing composition according to embodiment (10), selected from alkylbenzene sulfonic acids and combinations thereof.

[0073] (13) In embodiment (13), present a polishing composition according to any one of embodiments (1)-(12), wherein the iron cation is present in the polishing composition in an amount of about 1 ppm to about 100 ppm.

[0074] (14) In embodiment (14), present a polishing composition according to any one of embodiments (1)-(13), wherein the iron cation is present in the polishing composition in an amount of about 10 ppm to about 80 ppm.

[0075] (15) In embodiment (15), present a polishing composition according to any one of embodiments (1)-(14), wherein the polishing composition contains a ligand.

[0076] (16) In embodiment (16), present a polishing composition according to embodiment (15), wherein the ligand contains an alkene moiety, an alkyne moiety, a diacid moiety, an alcohol moiety, or a combination thereof.

[0077] (17) In embodiment (17), provide a polishing composition according to embodiment (15) or embodiment (16), wherein the ligand contains an alkene moiety and a diacid moiety.

[0078] (18) In embodiment (18), present a polishing composition according to embodiment (15) or embodiment (16), wherein the ligand contains an alkyne moiety.

[0079] (19) In embodiment (19), present a polishing composition according to embodiment (18), wherein the ligand further contains an alcohol moiety.

[0080] (20) In the embodiment (20), the ligand is selected from succinic acid, maleic acid, malonic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, oxalic acid, tartaric acid, 3,5-dimethyl-1-hexyne-3-ol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol ethoxylate, 2,5-dimethyl-3-hexyne-2,5-diol, 3-methyl-1-pentyne-3-ol, and combinations thereof, presenting the polishing composition according to embodiment (15) or (16).

[0081] (21) In the embodiment (21), in the chemical mechanical polishing composition, presenting the polishing composition according to any one of embodiments (1) to (20), wherein the zeta potential of the silica abrasive is -10 mV or less.

[0082] (22) In the embodiment (22), in the chemical mechanical polishing composition, presenting the polishing composition according to any one of embodiments (1) to (21), wherein the zeta potential of the silica abrasive is -20 mV or less.

[0083] (23) In the embodiment (23), in the chemical mechanical polishing composition, presenting the polishing composition according to any one of embodiments (1) to (22), wherein the zeta potential of the silica abrasive is -30 mV or less.

[0084] (24) A method for chemically mechanically polishing a substrate, comprising: (i) providing a substrate; (ii) providing a polishing pad; (iii) (a) a silica abrasive; (b) a surfactant; (c) an iron cation; (d) optionally a ligand; and (e) providing a chemical mechanical polishing composition containing water, wherein the silica abrasive has a negative zeta potential in the chemical mechanical polishing composition. (iv) contacting the substrate with the polishing pad and the chemical mechanical polishing composition, and (v) presenting a method comprising relatively moving the polishing pad and the chemical mechanical polishing composition with respect to the substrate to wear at least a part of the substrate and polish the substrate.

[0085] (25) In embodiment (25), presenting the method according to embodiment (24), wherein the polishing composition comprises about 0.001 wt% to about 10 wt% of the silica abrasive.

[0086] (26) In embodiment (26), presenting the method according to embodiment (24) or (25), wherein the polishing composition comprises about 0.05 wt% to about 5 wt% of the silica abrasive.

[0087] (27) In embodiment (27), presenting the method according to any one of embodiments (24) to (26), wherein the silica abrasive is colloidal silica.

[0088] (28) In embodiment (28), presenting the method according to any one of embodiments (24) to (27), wherein the polishing composition has a pH of about 1 to about 7.

[0089] (29) In embodiment (29), presenting the method according to any one of embodiments (24) to (28), wherein the polishing composition has a pH of about 1 to about 4.

[0090] (30) In embodiment (30), presenting the method according to any one of embodiments (24) to (29), wherein the surfactant is a cationic surfactant.

[0091] (31) In embodiment (31), presenting the method according to embodiment (30), wherein the cationic surfactant comprises a quaternary ammonium salt.

[0092] (32) In embodiment (32), the cationic surfactant includes, but is not limited to, N,N,N’,N’,N’-pentamethyl-N-tallowalkyl-1,3-propanediammonium dichloride, (oxydi-2,1-ethanediyl)bis(cocoalkyl)dimethylammonium dichloride, 3-methacrylamidopropyltrimethylammonium chloride (“MAPTAC”), 3-acrylamidopropyltrimethylammonium chloride (“APTAC”), diallyldimethylammonium chloride (“DADMAC”), 2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEA.MCQ”), 2-(methacryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEM.MCQ”), N,N-dimethylaminoethyl acrylate benzyl chloride (“DMAEA.BCQ”), N,N-dimethylaminoethyl methacrylate benzyl chloride (“DMAEM.BCQ”), and combinations thereof, and presents the method according to embodiment (30).

[0093] (33) In embodiment (33), presenting the method according to any one of embodiments (24) to (29), where the surfactant is an anionic surfactant.

[0094] (34) In embodiment (34), the anionic surfactant includes, but is not limited to, alkyl sulfonic acid, alkyl sulfonate, aryl sulfonic acid, aryl sulfonate, alkyl aryl sulfonic acid, alkyl aryl sulfonate, and combinations thereof, and presents the method according to embodiment (33).

[0095] (35) In embodiment (35), the anionic surfactant is a saturated or unsaturated C6-C 40 alkyl sulfonate, a saturated or unsaturated C6-C 40 alkyl sulfonic acid, a saturated or unsaturated C6-C 40 alkyl benzene sulfonate, a saturated or unsaturated C6-C 40Present a method according to embodiment (33), selected from alkylbenzenesulfonic acids and combinations thereof.

[0096] (36) In embodiment (36), present a method according to any one of embodiments (24) to (35), wherein the iron cation is present in the polishing composition in an amount of about 1 ppm to about 100 ppm.

[0097] (37) In embodiment (37), present a method according to any one of embodiments (24) to (36), wherein the iron cation is present in the polishing composition in an amount of about 10 ppm to about 80 ppm.

[0098] (38) In embodiment (38), present a method according to any one of embodiments (24) to (37), wherein the polishing composition contains a ligand.

[0099] (39) In embodiment (39), present a method according to embodiment (38), wherein the ligand contains an alkene moiety, an alkyne moiety, a diacid moiety, an alcohol moiety, or a combination thereof.

[0100] (40) In embodiment (40), present a method according to embodiment (39), wherein the ligand contains an alkene moiety and a diacid moiety.

[0101] (41) In embodiment (41), present a method according to embodiment (39), wherein the ligand contains an alkyne moiety.

[0102] (42) In embodiment (42), present a method according to embodiment (41), wherein the ligand further contains an alcohol moiety.

[0103] (43) In embodiment (43), the ligand is selected from succinic acid, maleic acid, malonic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, oxalic acid, tartaric acid, 3,5-dimethyl-1-hexyne-3-ol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol ethoxylate, 2,5-dimethyl-3-hexyne-2,5-diol, 3-methyl-1-pentyne-3-ol, and combinations thereof, presenting the method according to embodiment (38) or (39).

[0104] (44) In embodiment (44), in the chemical mechanical polishing composition, presenting the polishing composition according to any one of embodiments (24) to (43), wherein the zeta potential of the silica abrasive is -10 mV or less.

[0105] (45) In embodiment (45), in the chemical mechanical polishing composition, presenting the polishing composition according to any one of embodiments (24) to (44), wherein the zeta potential of the silica abrasive is -20 mV or less.

[0106] (46) In embodiment (46), in the chemical mechanical polishing composition, presenting the polishing composition according to any one of embodiments (24) to (45), wherein the zeta potential of the silica abrasive is -30 mV or less.

[0107] (47) In embodiment (47), the substrate is made of a carbon-based film, and at least a part of the carbon-based film is worn at a certain removal rate (Å / min) to polish the substrate, presenting the method according to any one of embodiments (24) to (46).

[0108] (48) In embodiment (48), the substrate further includes silicon oxide, silicon nitride, polysilicon, titanium nitride, or a combination thereof, and at least a part of silicon oxide, silicon nitride, polysilicon, or titanium nitride is worn at a removal rate (Å / min) to polish the substrate, presenting the method according to embodiment (47).

[0109] (49) In embodiment (49), the method of embodiment (48) is provided, wherein the removal rate (Å / min) of the carbon-based film is greater than the removal rate (Å / min) of silicon oxide, silicon nitride, polysilicon, or titanium nitride.

[0110] (50) In embodiment (50), the method of embodiment (49) is provided, wherein the removal rate (Å / min) of the carbon-based film is at least 10 times greater than the removal rate (Å / min) of silicon oxide, silicon nitride, polysilicon, or titanium nitride.

[0111] (51) In embodiment (51), the method of embodiment (50) is provided, wherein the removal rate (Å / min) of the carbon-based film is at least 20 times greater than the removal rate (Å / min) of silicon oxide, silicon nitride, polysilicon, or titanium nitride.

[0112] (52) In embodiment (52), the method of embodiment (51) is provided, wherein the removal rate (Å / min) of the carbon-based film is at least 40 times greater than the removal rate (Å / min) of silicon oxide, silicon nitride, polysilicon, or titanium nitride. EXAMPLES

[0113] These following examples further illustrate the invention but, of course, should not be construed as in any way limiting its scope.

[0114] The following abbreviations are used throughout the examples: removal rate (RR); carbon film (CF); carbon-containing spin-on dielectric (SOD); tetraethylorthosilicate (TEOS); polysilicon (polySi); silicon nitride (SiN); and molecular weight (MW).

[0115] In the following examples, SOD, TEOS, polysilicon, or SiN was coated on silicon, and the resulting patterned substrate was polished on a Logitech 2 tabletop polisher with a 2 PSI (13.7 kPa) downforce using a Fujibo pad conditioned with a product commercially available as A82 (3M, St. Paul, Minnesota). The polishing parameters of Logitec were head speed = 93 rpm, platen speed = 87 rpm, and total flow rate = 150 mL / min. The removal rate was calculated by measuring the film thickness using spectroscopic ellipsometry and subtracting the final thickness from the initial thickness.

[0116] Example 1 This example demonstrates the preparation of a polishing composition according to the invention, comprising a silica abrasive, a surfactant, an iron cation, and optionally a ligand. Polishing compositions 1A - 1F according to the invention and polishing compositions 1G and 1H as comparative controls were used in the following Examples 2 - 6 to demonstrate the efficiency of the polishing method according to the claims.

[0117] For each composition according to the invention used in Examples 2 - 6, a combination of silica particles having a positive native zeta potential (Particle A: spherical silica particles cationized over a wide pH range with a dynamic light scattering particle size of 150 nM) or a negative native zeta potential (Particle B: oval silica particles anionized over a wide pH range with a dynamic light scattering particle size of 75 - 80 nm) and an anionic surfactant or a cationic surfactant was shown. For the purposes of the compositions according to the invention used in Examples 2 - 6, the anionic surfactant was CALSOFTTM LPS - 99 (dodecylbenzenesulfonic acid; commercially available from Pilot Chemical Corporation, West Chester, Ohio) or ZETASPERSE® Z2300 (ethoxylated C6 - C 12 alcohol (CAS 68439 - 45 - 2) and C 10 -C 14A mixture of alkyl aryl sulfonates; commercially available from Air Products, Allentown, Pennsylvania), and the cationic surfactant was diallyldimethylammonium chloride ("DADMAC"). Iron cations (i.e., as the iron compounds described herein), ligands, and / or potassium nitrate (KNO₃) were added to each of the polishing compositions according to the present invention in the amounts specified in Table 1, and the pH of each polishing composition according to the present invention was adjusted to 2.5. Each of the polishing compositions A - F according to the present invention had a zeta potential of less than 0 mV, i.e., a negative zeta potential, for the resulting silica particles.

[0118] The polishing composition 1G, which is a comparative object, is different from the polishing compositions A - F according to the present invention in that the polishing composition 1G, which is a comparative object, does not contain a surfactant or iron cations, and the zeta potential of the resulting silica particles is 0 mV or more, i.e., it has a positive zeta potential. The silica particles used in the polishing composition 1G, which is a comparative object, are particle C, which are oval silica particles having a dynamic light scattering particle size of 45 - 55 nm and treated to be cationized in a wide pH range, and have a positive native zeta potential.

[0119] The polishing composition 1H, which is a comparative object, was the same as the polishing composition 1A according to the present invention except that it did not contain iron cations.

[0120] The obtained compositions were summarized in Table 1.

Table 1

[0121] Example 2 This example demonstrates the beneficial polishing performance provided by the polishing compositions prepared according to the present invention.

[0122] A patterned substrate containing SOD, TEOS, SiN, or polysilicon was polished under the same conditions using the polishing compositions 1A - 1G defined in Table 1 of Example 1. In this particular example, the SOD patterned substrate was used as a substitute for measuring the carbon removal rate of a commercially available carbon film material. After polishing, the RR for SOD, TEOS, SiN, and polysilicon was determined, and the results are shown in Table 2.

Table 2

[0123] As is clear from Table 2, the polishing compositions 1A and 1C - 1F according to the present invention provided a removal rate of SOD that was consistent with the SOD removal rate of the polishing composition 1G, which was the comparative object. However, each of the polishing compositions 1A - 1F according to the present invention was found to have significantly higher polishing selectivity for SOD than the polishing composition 1G, which was the comparative object, as can be seen from the fact that the removal rates of TEOS and polysilicon of the polishing composition 1G, which was the comparative object, were high. Thus, from Table 2, it was found that a silica polishing agent having a negative zeta potential and a polishing composition having an iron cation provided a higher SOD RR and an improved removal selectivity of the carbon film system with respect to the silicon film system compared to a polishing composition having a silica polishing agent with a negative zeta potential and no iron cation.

[0124] Example 3 This example shows the effect of ligand and iron cation concentration on the polishing performance provided by the polishing composition prepared according to the present invention.

[0125] A patterned substrate containing SOD was polished under the same conditions using the polishing compositions 1B - 1E as defined in Table 1 of Example 1. In this particular example, the patterned substrate of SOD was used as a substitute for measuring the carbon film removal rate of a commercially available carbon film material. After polishing, the RR of SOD was determined, and the results are shown in Table 3.

Table 3

[0126] As is clear from Table 3, polishing compositions 1C to 1E containing a combination of a ligand having an olefin or alkyne and a diacid or alcohol produced a relatively high SOD removal rate, even though they had a lower iron cation concentration than polishing composition 1B containing a ligand having only a diacid.

[0127] Therefore, Table 3 shows that polishing compositions containing ligands having an alkene moiety, an alkyne moiety, a diacid moiety, an alcohol moiety, or combinations thereof, preferably combinations of an alkene moiety or an alkyne moiety and a diacid or alcohol, require fewer iron cations and can provide a high carbon removal rate, as can be seen from the SOD removal rate.

[0128] Example 4 This example demonstrates the effect of ligand and iron cation concentration on the polishing performance provided by the polishing composition prepared according to the present invention.

[0129] The patterned substrate includes a carbon film as described by Weigand et al. ("Evaluating spin-on carbon materials at low temperatures for high wiggling resistance", Advanced Etch Technology for Nanopatterning II, Vol. 8685, International Society for Optics and Photonics, 2013) and Kim et al. ("Study on the etching characteristics of amorphous carbon layer in oxygen plasma with carbonyl sulfide", Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films (2013), 31:2:021301, pp. 1-7), and was polished under the same conditions using polishing compositions 1B - 1E as defined in Table 1 of Example 1. After polishing, the CF RR was determined and the predicted results are shown in Table 4 as the estimated percentage of the removal rate value of the SOD provided in Table 3.

Table 4

[0130] As is apparent from the predicted results shown in Table 4, polishing compositions 1C - 1E, which contain a combination of a ligand having an olefin or alkyne and a diacid or alcohol, are considered to achieve a higher carbon removal rate than polishing composition 1B, even though they have a lower iron cation concentration than polishing composition 1B, which contains a ligand having only a diacid (see Table 3 of Example 3).

[0131] Also, as is apparent from Table 4, the CF RR caused by polishing compositions 1B - 1E is considered to be lower than the removal rate of the SOD, which was used as a substitute for measuring the carbon film removal rate of commercially available carbon film materials, as described in Examples 2 and 3. Also, polishing composition 1E is considered to have the highest CF RR among polishing compositions 1B - 1E.

[0132] Example 5 This example demonstrates the effect of iron cation concentration on the polishing performance provided by the polishing composition prepared according to the present invention.

[0133] The patterned substrate containing SOD was polished under the same conditions using the polishing composition 1A according to the present invention or the polishing composition 1H as a comparison target, as defined in Table 1 of Example 1. In this particular example, the SOD patterned substrate was used as a substitute for measuring the carbon film removal rate of a commercially available carbon film material. After polishing, the RR of SOD was determined, and the results are shown in Table 5. [Table 5]

[0134] As is clear from Table 5, the polishing composition 1A according to the present invention containing iron cations produced an SOD removal rate that was consistent with the SOD removal rate produced by the polishing composition 1H as a comparison target. While not wishing to be bound by any particular theory, it is believed that a polishing composition containing a silica abrasive having a negative zeta potential is very efficient at removing SOD, and the patterned substrate of SOD may not be a suitable substitute for measuring the effect of iron cation concentration on polishing performance. That is, it is suitable for judging the selectivity of the carbon film for TEOS, SiN, and poly-Si of the composition according to the present invention, but the SOD substrate may not be suitable for judging the maximum carbon film removal rate of the polishing composition according to the present invention.

[0135] As further described in Example 6, it is considered that when iron cations are completely absent from the polishing composition, the carbon film removal rate of a commercially available carbon film material may be significantly reduced.

[0136] Example 6 This example demonstrates the effect of iron cation concentration on the polishing performance provided by the polishing composition prepared according to the present invention.

[0137] The patterned substrate includes a carbon film described, for example, in Weigand et al. ("Evaluating spin-on carbon materials at low temperatures for high wiggling resistance", Advanced Etch Technology for Nanopatterning II. Vol. 8685. International Society for Optics and Photonics, 2013), and Kim et al. ("Study on the etching characteristics of amorphous carbon layer in oxygen plasma with carbonyl sulfide", Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films (2013), 31:2:021301, pp. 1-7), and was polished under the same conditions using polishing composition 1A according to the present invention defined in Table 1 of Example 1 or polishing composition 1H as a comparative target. After polishing, the CF RR was determined, and the predicted results are shown in Table 6 as the estimated percentage of the SOD removal rate value provided in Example 5.

Table 6

[0138] As is apparent from the predicted results described in Table 6, iron cations are believed to play an important role in maintaining a high CF RR. More specifically, it is considered that when iron cations are removed from polishing composition 1A, the CF RR may decrease by as much as 15%.

[0139] When the iron cation concentration increases, it is considered that a higher carbon film removal rate can be obtained. However, when the iron cation concentration increases, it is also considered that there may be a correlation with a plurality of defect problems when polishing commercially available carbon film materials. Therefore, it is important to use an ideal iron cation concentration in order to maintain a high carbon film removal rate, high selectivity, and minimal defects. The invention described in this specification provides a means of avoiding the problem of defects while maintaining a high carbon film removal rate.

[0140] In this regard, Examples 3 to 6 show that iron cations are components necessary to achieve an optimal carbon film removal rate, and by adding a ligand having an alkene moiety, an alkyne moiety, a diacid moiety, an alcohol moiety, or a combination thereof, the level of iron cations necessary to maintain these optimal carbon film removal rates can be reduced, thereby avoiding the defect problem during polishing of the carbon film.

[0141] All documents, including publications, patent applications, and patents, cited in this specification are hereby incorporated by reference in their entirety to the same extent as if each document were individually and expressly indicated to be incorporated by reference.

[0142] The use of the terms "a", "an", "the", "at least one" and similar references in the context of describing the present invention (particularly in the context of the following claims) is to be construed as including both the singular and the plural unless specifically indicated otherwise herein or clearly contradicted by the context. The use of the term "at least one" following a listing of one or more items (e.g., "at least one of A and B") is to be construed to mean either 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 indicated herein or clearly contradicted by the context. The terms "comprising", "having", "including", "containing" are to be construed as open-ended terms (i.e., meaning "including but not limited to") unless specifically stated otherwise. The recitation of ranges of values herein is merely intended to serve as a shorthand for referring individually to each separate value falling within the range and each separate value is incorporated herein as if it were individually recited herein. All methods described herein can be performed in any suitable order unless specifically indicated otherwise herein or clearly contradicted by the context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein is merely intended to better clarify the invention and does not pose a limitation to the scope of the invention unless otherwise claimed. No language in this specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0143] Preferred embodiments of the invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments will become apparent to those skilled in the art upon reading the foregoing description. The inventors expect those skilled in the art to adopt such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, the invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Further, any combination of the above-described elements in all possible variations thereof is included in the invention unless otherwise specifically indicated herein or otherwise clearly contradicted by context.

Claims

1. (a) a silica abrasive; (b) a surfactant; (c) an iron cation; (d) optionally a ligand; and (e) water A chemical mechanical polishing composition comprising the above, wherein the silica abrasive has a negative zeta potential in the chemical mechanical polishing composition.

2. The polishing composition according to claim 1, wherein the polishing composition contains about 0.001 wt% to about 10 wt% of the silica abrasive.

3. The polishing composition according to claim 1 or 2, wherein the polishing composition contains about 0.05 wt% to about 5 wt% of the silica abrasive.

4. The polishing composition according to any one of claims 1 to 3, wherein the silica abrasive is colloidal silica.

5. The polishing composition according to any one of claims 1 to 4, wherein the polishing composition has a pH of about 1 to about 7.

6. The polishing composition according to any one of claims 1 to 5, wherein the polishing composition has a pH of about 1 to about 4.

7. The polishing composition according to any one of claims 1 to 6, wherein the surfactant is a cationic surfactant.

8. The polishing composition according to claim 7, wherein the cationic surfactant contains a quaternary ammonium salt.

9. The cationic surfactant is N,N,N′,N′,N′-pentamethyl-N-tallowalkyl-1,3-propanediammonium dichloride, (oxydi-2,1-ethanediyl)bis(cocoalkyl)dimethylammonium dichloride, 3-methacrylamidopropyltrimethylammonium chloride (“MAPTAC”), 3-acrylamidopropyltrimethylammonium chloride (“APTOC”), diallyldimethylammonium chloride (“DADMAC”), 2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEA.MCQ”), 2-(methacryloyloxy)-N,N,N-trimethylethanaminium chloride (“DMAEM.MCQ”), N,N-dimethylaminoethyl acrylate benzyl chloride (“DMAEA.BCQ”), N,N-dimethylaminoethyl methacrylate benzyl chloride (“DMAEM.BCQ”) and combinations thereof. The polishing composition according to claim 7.

10. The polishing composition according to any one of claims 1 to 6, wherein the surfactant is an anionic surfactant.

11. The polishing composition according to claim 10, wherein the anionic surfactant is selected from alkylsulfonic acids, alkylsulfonates, arylsulfonic acids, arylsulfonates, alkylarylsulfonic acids, alkylarylsulfonates, and combinations thereof.

12. The anionic surfactant is a saturated or unsaturated C 6 -C 40 alkyl sulfonate, saturated or unsaturated C 6 -C 40 alkyl sulfonic acid, saturated or unsaturated C 6 -C 40 alkylbenzene sulfonate, saturated or unsaturated C 6 -C 40 The polishing composition according to claim 10, selected from alkylbenzene sulfonic acid and combinations thereof.

13. The polishing composition according to any one of claims 1 to 12, wherein the iron cation is present in the polishing composition in an amount of about 1 ppm to about 100 ppm.

14. The polishing composition according to any one of claims 1 to 13, wherein the iron cation is present in the polishing composition in an amount of about 10 ppm to about 80 ppm.

15. The polishing composition according to any one of claims 1 to 14, wherein the polishing composition contains a ligand.

16. The polishing composition according to claim 15, wherein the ligand contains an alkene moiety, an alkyne moiety, a diacid moiety, an alcohol moiety, or a combination thereof.

17. The polishing composition according to claim 15 or 16, wherein the ligand contains an alkene moiety and a diacid moiety.

18. The polishing composition according to claim 15 or 16, wherein the ligand contains an alkyne moiety.

19. The polishing composition according to claim 18, wherein the ligand further contains an alcohol moiety.

20. The polishing composition according to claim 15 or 16, wherein the ligand is selected from succinic acid, maleic acid, malonic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, oxalic acid, tartaric acid, 3,5-dimethyl-1-hexyne-3-ol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol ethoxylate, 2,5-dimethyl-3-hexyne-2,5-diol, 3-methyl-1-pentyne-3-ol, and combinations thereof.

21. The polishing composition according to any one of claims 1 to 20, wherein in the chemical mechanical polishing composition, the zeta potential of the silica abrasive is -10 mV or less.

22. The polishing composition according to any one of claims 1 to 21, wherein in the chemical mechanical polishing composition, the zeta potential of the silica abrasive is -20 mV or less.

23. The polishing composition according to any one of claims 1 to 22, wherein in the chemical mechanical polishing composition, the zeta potential of the silica abrasive is -30 mV or less.

24. A method of chemically-mechanically polishing a substrate, comprising: (i) providing a substrate; (ii) providing a polishing pad; (iii) (a) a silica abrasive; (b) a surfactant; (c) an iron cation; (d) optionally a ligand; and (e) water providing a chemical-mechanical polishing composition comprising the same, (wherein the silica abrasive has a negative zeta potential in the chemical-mechanical polishing composition); (iv) contacting the substrate with the polishing pad and the chemical-mechanical polishing composition; and (v) relatively moving the polishing pad and the chemical-mechanical polishing composition with respect to the substrate to wear at least a part of the substrate to polish the substrate.

25. The method according to claim 24, wherein the polishing composition comprises from about 0.001 wt% to about 10 wt% of the silica abrasive.

26. The method according to claim 24 or 25, wherein the polishing composition comprises from about 0.05 wt% to about 5 wt% of the silica abrasive.

27. The method according to any one of claims 24 to 26, wherein the silica abrasive is colloidal silica.

28. The method according to any one of claims 24 to 27, wherein the polishing composition has a pH of from about 1 to about 7.

29. The method according to any one of claims 24 to 28, wherein the polishing composition has a pH of from about 1 to about 4.

30. The method according to any one of claims 24 to 29, wherein the surfactant is a cationic surfactant.

31. The method according to claim 30, wherein the cationic surfactant comprises a quaternary ammonium salt.

32. The method according to claim 30, wherein the cationic surfactant is selected from N,N,N',N',N'-pentamethyl-N-tallow alkyl-1,3-propanediammonium dichloride, (oxydi-2,1-ethanediyl)bis(cocoalkyl)dimethylammonium dichloride, 3-methacrylamidopropyltrimethylammonium chloride ("MAPTAC"), 3-acrylamidopropyltrimethylammonium chloride ("APTAC"), diallyldimethylammonium chloride ("DADMAC"), 2-(acryloyloxy)-N,N,N-trimethylethanaminium chloride ("DMAEA.MCQ"), 2-(methacryloyloxy)-N,N,N-trimethylethanaminium chloride ("DMAEM.MCQ"), N,N-dimethylaminoethyl acrylate benzyl chloride ("DMAEA.BCQ"), N,N-dimethylaminoethyl methacrylate benzyl chloride ("DMAEM.BCQ"), and combinations thereof.

33. The method according to any one of claims 24 to 29, wherein the surfactant is an anionic surfactant.

34. The method according to claim 33, wherein the anionic surfactant is selected from alkyl sulfonic acids, alkyl sulfonates, aryl sulfonic acids, aryl sulfonates, alkylaryl sulfonic acids, alkylaryl sulfonates, and combinations thereof.

35. The anionic surfactant is a saturated or unsaturated C 6 -C 40 alkyl sulfonate, a saturated or unsaturated C 6 -C 40 alkyl sulfonic acid, a saturated or unsaturated C 6 -C 40 alkylbenzene sulfonate, a saturated or unsaturated C 6 -C 40 alkylbenzene sulfonic acid, and a combination thereof, the method according to claim 33.

36. The method according to any one of claims 24 to 35, wherein the iron cation is present in the polishing composition in an amount of about 1 ppm to about 100 ppm.

37. The method according to any one of claims 24 to 36, wherein the iron cation is present in the polishing composition in an amount of about 10 ppm to about 80 ppm.

38. The method according to any one of claims 24 to 37, wherein the polishing composition contains a ligand.

39. The method according to claim 38, wherein the ligand contains an alkene moiety, an alkyne moiety, a diacid moiety, an alcohol moiety, or combinations thereof.

40. The method according to claim 38 or 39, wherein the ligand contains an alkene moiety and a diacid moiety.

41. The method according to claim 38 or 39, wherein the ligand contains an alkyne moiety.

42. The method according to claim 41, wherein the ligand further contains an alcohol moiety.

43. The method according to claim 38 or 39, wherein the ligand is selected from succinic acid, maleic acid, malonic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, oxalic acid, tartaric acid, 3,5-dimethyl-1-hexyne-3-ol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol ethoxylate, 2,5-dimethyl-3-hexyne-2,5-diol, 3-methyl-1-pentyne-3-ol, and combinations thereof.

44. The method according to any one of claims 24 to 43, wherein in the chemical mechanical polishing composition, the zeta potential of the silica abrasive is -10 mV or less.

45. The method according to any one of claims 24 to 44, wherein in the chemical mechanical polishing composition, the zeta potential of the silica abrasive is -20 mV or less.

46. The method according to any one of claims 24 to 45, wherein in the chemical mechanical polishing composition, the zeta potential of the silica abrasive is -30 mV or less.

47. The method according to any one of claims 24 to 46, wherein the substrate includes a carbon-based film, and at least a part of the carbon-based film is worn at a certain removal rate (Å / min) to polish the substrate.

48. The method according to claim 47, wherein the substrate further includes silicon oxide, silicon nitride, polysilicon, titanium nitride, or a combination thereof, and at least a part of the silicon oxide, silicon nitride, polysilicon, or titanium nitride is worn at a certain removal rate (Å / min) to polish the substrate.

49. The method according to claim 48, wherein the removal rate (Å / min) of the carbon-based film is greater than the removal rate (Å / min) of the silicon oxide, silicon nitride, polysilicon, or titanium nitride.

50. The method according to claim 49, wherein the removal rate (Å / min) of the carbon-based film is at least 10 times greater than the removal rate (Å / min) of the silicon oxide, silicon nitride, polysilicon, or titanium nitride.

51. The method according to claim 50, wherein the removal rate (Å / min) of the carbon-based film is at least 20 times greater than the removal rate (Å / min) of the silicon oxide, silicon nitride, polysilicon, or titanium nitride.

52. 52. The method of claim 51 , wherein the removal rate (Å / min) of the carbon-based film is at least 40 times greater than the removal rate (Å / min) of the silicon oxide, silicon nitride, polysilicon, or titanium nitride.

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