Chemical mechanical polishing compositions and methods of using the same

Abstract

The present invention relates to a chemical mechanical polishing composition and methods of using the same. The present invention relates to a polishing composition comprising: at least one abrasive, at least one organic acid, at least one anionic surfactant comprising at least a phosphate, at least one phosphonic acid compound having a molecular weight of less than 500 g / mol, at least one azole-containing compound, at least one alkyl amine compound having an alkyl chain of 6 to 24 carbons, and an aqueous solvent, and optionally, a pH adjuster.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 128,412, filed December 21, 2020, pursuant to 35 USC §119, which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to chemical mechanical polishing compositions. In particular, this disclosure relates to polishing compositions that balance the desired polishing performance characteristics of cobalt and other substances used in the art. Background Technology

[0004] The semiconductor industry is continuously driven by process, material, and integration innovations to further miniaturize devices and improve chip performance. Early material innovations included the introduction of copper instead of aluminum as the conductive material in interconnect structures, and the use of tantalum (Ta) / tantalum nitride (TaN) (or titanium (Ti) / titanium nitride (TiN)) as diffusion barrier layers to separate the Cu conductive material from the non-conductive / insulating dielectric material. Copper (Cu) was chosen as the interconnect material due to its low resistivity and excellent electromigration resistance.

[0005] However, as the feature size of next-generation chips shrinks, multilayer copper / barrier / dielectric stacks must be thinner and more conformal to maintain effective interconnect resistivity in back-end-of-line (BEOL) processes. Thinner Cu and Ta / TaN barrier film solutions present challenges in resistivity and flexibility during deposition. For example, resistivity is deteriorating exponentially with smaller dimensions and advanced manufacturing nodes, and the speed improvements of transistor circuits (at the front-end-of-line (FEOL)) are halved due to delays caused by conductive Cu / barrier layer wiring (BEOL). Cobalt (Co) has emerged as a leading candidate material for padding, barrier, and conductive layers. Furthermore, cobalt is being investigated as a substitute for tungsten (W) in various applications such as W metal contacts, plugs, vias, and gate materials.

[0006] Many currently available CMP pastes are specifically designed to remove materials more common in older chip designs, such as the aforementioned copper and tungsten. Certain components in these older CMP pastes can cause harmful and unacceptable defects in cobalt because cobalt is more susceptible to chemical corrosion. Therefore, when copper polishing pastes are used on cobalt layers, unacceptable corrosion, wafer morphology, and removal rate selectivity often occur.

[0007] Although cobalt is still used in combination with other metals (such as Cu and / or W), as cobalt (Co) is increasingly used as a metal component in semiconductor manufacturing, there is a market demand for CMP slurries that can effectively polish dielectric or barrier components on Co-containing surfaces without significant metal corrosion. Summary of the Invention

[0008] This summary is provided to introduce selected concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to help limit the scope of the claimed subject matter.

[0009] As defined herein, unless otherwise stated, all percentages shown should be understood as weight percentages relative to the total weight of the chemical mechanical polishing composition. Furthermore, all ranges shown include the disclosed ranges and any subranges thereof. For example, the range “0.1% to 1% by weight” includes the range 0.1 to 1 and any subranges thereof, such as 0.2 to 0.9, 0.5 to 1, 0.1 to 0.5, etc. The range “6 to 24 carbons” includes 6 to 24 carbons, 8 to 20 carbons, 6 to 12 carbons, 10 to 24 carbons, etc.

[0010] In one aspect, this disclosure provides a polishing composition comprising: at least one abrasive, at least one organic acid, at least one anionic surfactant containing at least a phosphate / ester, at least one phosphonic acid compound with a molecular weight of less than 500 g / mol, at least one azole compound, at least one alkylamine compound having a 6 to 24 carbon alkyl chain, and an aqueous solvent, and optionally, a pH adjuster.

[0011] In another aspect, this disclosure provides a polishing composition comprising: at least one abrasive in an amount of about 0.01% to about 25% by weight of the composition; at least two organic acids in an amount of about 0.001% to about 2.5% by weight of the composition, wherein at least one organic acid is an amino acid; and at least one anionic surfactant containing at least a phosphate / ester and containing at least one of a hydrophobic 6- to 24-carbon alkyl chain and 2 to 16 ethylene oxide groups, wherein the anionic surfactant... The composition comprises, by weight, about 0.001% to about 0.5% of an active agent; about 0.01% to about 1.5% of a phosphonic acid compound having a molecular weight of less than 500 g / mol; about 0.001% to about 0.5% of an azole compound; about 0.0005% to about 0.5% of an alkylamine compound having a 6 to 24 carbon alkyl chain; and an aqueous solvent, wherein the pH of the composition is about 7 to about 12.

[0012] In another aspect, the embodiments disclosed herein relate to a method of polishing a substrate using the polishing composition described herein.

[0013] Other aspects and advantages of the claimed subject matter will become apparent from the following description and the appended claims. Detailed Implementation

[0014] The embodiments disclosed herein generally relate to compositions and methods for polishing a substrate comprising at least a cobalt portion and a tungsten portion using said compositions. Furthermore, the embodiments disclosed herein relate to compositions and methods for polishing a substrate comprising at least a cobalt portion, a tungsten portion, and a dielectric (TEOS, SiN, low-k, etc.) portion using said compositions.

[0015] This disclosure provides compositions that offer desired and improved cobalt and tungsten corrosion resistance. Furthermore, compared to currently available slurries, the compositions of this disclosure offer the ability to regulate the removal rates of cobalt, tungsten, TEOS, and dielectrics. The removal rates of cobalt and tungsten can be controlled to be higher or lower than the TEOS and dielectric removal rates as needed. The compositions comprise an advantageous combination of: at least one anionic surfactant containing at least a phosphate / ester, at least one phosphonic acid compound with a molecular weight of less than 500 g / mol, and at least one alkylamine compound having a 6- to 24-carbon alkyl chain, and other components. As discussed in more detail below, the combination of these three components provides polishing-related results for cobalt and tungsten that would not be expected based on the performance of each component alone.

[0016] With the introduction of cobalt (Co) as a barrier layer, conductive layer, and / or W substitute, the market demands CMP slurries that can polish Co at an efficient material removal rate without significant Co corrosion (i.e., with a moderate Co removal rate) and exhibit a range of selectivity in polishing rates for other metals and metal nitrides or oxides (Cu, W, Ti, TiN, Ta, TaN, Ta2O5, TiO2, Ru, ZrO2, HfO2, etc.) and dielectric films (SiN, silicon oxide, polycrystalline Si, low-k dielectrics (e.g., carbon-doped silicon oxide)). For example, after an aggressive bulk polishing step that removes a significant amount of material, a buffing polishing step is often desired to achieve the desired surface morphology. In some embodiments, the composition used for buffing polishing will remove dielectric materials and metals (e.g., TEOS, SiN, and Co) at a lower rate than that occurring during the bulk polishing step or at approximately the same removal rate for each component (e.g., within 10% or 5%) to achieve the desired surface morphology. Because Co is more chemically reactive than Cu and other noble metals, Co corrosion prevention is particularly challenging in the design of advanced node polishing compositions. Current metal polishing slurries are inadequate for polishing Co-containing surfaces because they suffer from Co corrosion problems during the CMP process. Furthermore, it is often desirable to remove a certain amount of Co during polishing to form a smooth surface in the patterned semiconductor substrate for subsequent manufacturing processes.

[0017] Furthermore, advanced nodes typically use substrates containing multiple metals (e.g., Co and W), therefore, the prevention of excessive corrosion of each metal must be considered when formulating polishing compositions. Different metals corrode to varying degrees when placed in the same chemical environment. For example, cobalt is generally more easily corroded than tungsten under low pH conditions, and vice versa under high pH conditions. Similar considerations apply to chemical additives (i.e., some chemical additives may potentially corrode or prevent the corrosion of a metal compared to different metals).

[0018] In one or more embodiments, the polishing composition of this disclosure comprises: at least one abrasive; at least one organic acid; at least one anionic surfactant containing at least a phosphate / ester; at least one phosphonic acid compound with a molecular weight of less than 500 g / mol; at least one azole compound; at least one alkylamine compound having a 6 to 24 carbon alkyl chain; an aqueous solvent; and optionally, a pH adjuster.

[0019] In one or more embodiments, the polishing composition according to this disclosure may comprise: about 0.1% to about 25% by weight of an abrasive; about 0.001% to about 2.5% by weight of an organic acid; about 0.001% to about 0.5% by weight of an anionic surfactant containing at least a phosphate / ester; about 0.01% to about 1.5% by weight of a phosphonic acid compound with a molecular weight of less than 500 g / mol; about 0.001% to about 0.5% by weight of an azole-containing compound; about 0.0005% to about 0.5% by weight of an alkylamine compound having a 6 to 24 carbon alkyl chain; and the remaining percentage (e.g., about 70% to 99% by weight) of an aqueous solvent.

[0020] In one or more embodiments, this disclosure provides a concentrated polishing composition that can be diluted with water by up to two, three, four, six, eight, or ten times prior to use. In other embodiments, this disclosure provides a point-of-use (POU) polishing composition for use on a cobalt- and tungsten-containing substrate, comprising the above-described polishing composition; water; and optionally, an oxidizing agent.

[0021] In one or more embodiments, the POU polishing composition according to this disclosure may comprise: about 0.1% to about 12% by weight of an abrasive; about 0.001% to about 1% by weight of an organic acid; about 0.001% to about 0.1% by weight of an anionic surfactant containing at least a phosphate / ester; about 0.01% to about 0.5% by weight of a phosphonic acid compound with a molecular weight of less than 500 g / mol; about 0.001% to about 0.1% by weight of an azole-containing compound; about 0.0005% to about 0.05% by weight of an alkylamine compound having a 6 to 24 carbon alkyl chain; and the remaining percentage (e.g., about 70% to 99% by weight) of an aqueous solvent.

[0022] In one or more embodiments, the concentrated polishing composition according to this disclosure may comprise: about 1% to about 25% by weight of abrasive; about 0.01% to about 2.5% by weight of organic acid; about 0.01% to about 0.5% by weight of anionic surfactant containing at least phosphate / ester; about 0.1% to about 1.5% by weight of phosphonic acid compound with a molecular weight of less than 500 g / mol; about 0.01% to about 0.5% by weight of azole compound; about 0.005% to about 0.5% by weight of alkylamine compound having a 6 to 24 carbon alkyl chain; and the remaining percentage (e.g., about 70% to 99% by weight) of aqueous solvent.

[0023] In one or more embodiments, at least one (e.g., two or three) abrasive is selected from cationic abrasives, substantially neutral abrasives, and anionic abrasives. In one or more embodiments, at least one abrasive is selected from alumina, silica, titanium dioxide, cerium dioxide, zirconium oxide, co-formed products thereof (i.e., co-formed products of alumina, silica, titanium dioxide, cerium dioxide, or zirconium oxide), coated abrasives, surface-modified abrasives, and mixtures thereof. In some embodiments, at least one abrasive does not include cerium dioxide. In some embodiments, at least one abrasive is of high purity and may have less than about 100 ppm of alcohol, less than about 100 ppm of ammonia, and less than about 100 parts per billion (ppb) of alkali metal cations such as sodium cations. Based on the total weight of the POU polishing composition, the abrasive may be present in an amount from about 0.1% to about 12% (e.g., from about 0.5% to about 10%) or any subrange thereof. Wafer

[0024] In one or more embodiments, the abrasive is a silica-based abrasive, such as an abrasive selected from colloidal silica, pyrolytic silica, and mixtures thereof. In one or more embodiments, the abrasive may be surface-modified with organic groups and / or non-silica inorganic groups. For example, a cationic abrasive may contain end groups of formula (I):

[0025] -O m -X-(CH2) n -Y (I),

[0026] Where m is an integer from 1 to 3; n is an integer from 1 to 10; X is Al, Si, Ti, Ce, or Zr; and Y is a cationic amino or thiol group. As another example, anionic abrasives may contain end groups of formula (I):

[0027] -O m -X-(CH2) n -Y (I),

[0028] Where m is an integer from 1 to 3; n is an integer from 1 to 10; X is Al, Si, Ti, Ce or Zr; and Y is an acidic group.

[0029] In one or more embodiments, the average particle size of the abrasive described herein can be from at least about 1 nm (e.g., at least about 5 nm, at least about 10 nm, at least about 20 nm, at least about 40 nm, at least about 50 nm, at least about 60 nm, at least about 80 nm, or at least about 100 nm) to at most about 1000 nm (e.g., at most about 800 nm, at most about 600 nm, at most about 500 nm, at most about 400 nm, or at most about 200 nm). As used herein, the mean particle size (MPS) is determined by dynamic light scattering techniques.

[0030] In some embodiments, at least one abrasive is present in an amount of at least about 0.1% (e.g., at least about 0.5%, at least about 1%, at least about 2%, at least about 4%, at least about 5%, at least about 10%, at least about 12%, at least about 15%, or at least about 20%) to at most about 25% (e.g., at most about 20%, at most about 18%, at most about 15%, at most about 12%, at most about 10%, or at most about 5%) by weight of the polishing composition described herein.

[0031] In one or more embodiments, the polishing composition comprises at least one organic acid. In one or more embodiments, the organic acid (or a salt thereof) may be selected from carboxylic acids, amino acids, sulfonic acids, phosphonic acids, or mixtures thereof. In some embodiments, the organic acid may be a carboxylic acid containing one or more (e.g., two, three, or four) carboxylic acid groups, such as dicarboxylic acids or tricarboxylic acids. In some embodiments, the organic acid may be an amino acid containing carboxylic acid groups. In one or more embodiments, the organic acid is selected from gluconic acid, lactic acid, citric acid, tartaric acid, malic acid, glycolic acid, malonic acid, formic acid, oxalic acid, acetic acid, propionic acid, peracetic acid, succinic acid, lactic acid, glycine, phenoxyacetic acid, N-di(hydroxyethyl)glycine, diethylene glycolic acid, glyceric acid, N-tris(hydroxymethyl)methylglycine (tricine), maleic acid, hypozoxytriacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, alanine, histidine, valine, phenylalanine, proline, glutamine, aspartic acid, glutamic acid, arginine, lysine, tyrosine, glycine, serine, asparagine, cysteine, leucine, isoleucine, methionine, threonine, tryptophan, benzoic acid, and mixtures thereof. In one or more embodiments, the polishing composition comprises at least two organic acids, one of which is an amino acid. Unwilling to be bound by theory, it is surprising that organic acids or amino acids (such as those mentioned above) can be used as effective barrier layers and / or cobalt removal rate enhancers in the polishing compositions described herein to improve the removal rate of barrier films and / or cobalt films in semiconductor substrates.

[0032] In some embodiments, the amount of at least one organic acid is from at least about 0.001% (e.g., at least about 0.003%, at least about 0.005%, at least about 0.01%, at least about 0.03%, at least about 0.05%, at least about 0.1%, at least about 0.3%, at least about 0.5%, at least about 1%, at least about 1.3%, or at least about 1.5%) to at most about 2.5% (e.g., at most about 2.2%, at most about 2%, at most about 1.7%, at most about 1.5%, at most about 1.2%, at most about 1%, at most about 0.7%, at most about 0.5%, at most about 0.2%, at most about 0.15%, at most about 0.1%, at most about 0.07%, or at most about 0.05%) of the polishing composition described herein by weight. In embodiments where the composition contains more than one organic acid, the above range may apply independently to each organic acid, or to the combined amount of organic acids in the polishing composition.

[0033] In one or more embodiments, the anionic surfactant comprises one or more phosphate / ester groups and one or more of the following groups: a six- to twenty-four-carbon alkyl chain, zero to eighteen ethylene oxide groups, or combinations thereof. In one or more embodiments, the alkyl chain may have at least eight, at least ten, at least twelve, or at least fourteen carbons. In one or more embodiments, the alkyl chain may have up to 22, at most 20, or at most 18 carbons. Unwilling to be bound by theory, it is surprising that anionic surfactants (such as those described above) can act as cobalt corrosion inhibitors in the polishing compositions described herein to reduce or minimize the removal rate of cobalt in semiconductor substrates.

[0034] In some embodiments, the amount of anionic surfactant is from at least about 0.001% (e.g., at least about 0.002%, at least about 0.005%, at least about 0.01%, at least about 0.02%, at least about 0.05%, at least about 0.1%, or at least about 0.2%) to at most about 0.5% (e.g., at most about 0.4%, at most about 0.2%, at most about 0.1%, at most about 0.08%, at most about 0.05%, at most about 0.02%, at most about 0.0075%, or at most about 0.005%) of the polishing composition described herein by weight.

[0035] In one or more embodiments, the phosphonic acid is selected from phenylphosphonic acid, butylphosphonic acid, hexylphosphonic acid, octylphosphonic acid, decylphosphonic acid, dodecylphosphonic acid, tetradecylphosphonic acid, hexadecylphosphonic acid, octadecylphosphonic acid, benzylphosphonic acid, phenylethylphosphonic acid, phenylpropylphosphonic acid, phenylbutylphosphonic acid, and mixtures thereof. Unexpectedly, without being bound by theory, the aforementioned phosphonic acids can reduce or minimize the corrosion of cobalt in semiconductor substrates. Furthermore, unexpectedly, when using the polishing composition according to this disclosure to polish patterned wafers, the anionic surfactant and phosphonic acid exhibit a synergistic benefit in reducing TEOS edge erosion (EoE). This synergistic effect is illustrated in more detail in the examples provided at the end of this disclosure. In one or more embodiments, the weight percentage between the phosphonic acid and the anionic surfactant (i.e., wt% phosphonic acid: wt% anionic surfactant) should be from about 5:1 to 100:1. For example, the ratio can be at least 10:1, at least 15:1, at least 20:1, at least 25:1, at least 30:1, at least 35:1, at least 40:1, at least 45:1 or at least 50:1 up to at most 95:1, at most 90:1, at most 85:1, at most 80:1, at most 75:1, at most 70:1, at most 65:1, at most 60:1 or at most 55:1.

[0036] In some embodiments, the amount of phosphonic acid is from at least about 0.01% (e.g., at least about 0.05%, at least about 0.075%, at least about 0.1%, at least about 0.25%, at least about 0.5%, at least about 0.75%, or at least about 1%) by weight of the polishing composition described herein to at most about 1.5% (e.g., at most about 1.25%, at most about 1%, at most about 0.75%, at most about 0.5%, at most about 0.25%, at most about 0.1%, or at most 0.075%) by weight.

[0037] In one or more embodiments, at least one azole is selected from tetrazolium, benzotriazole, adenine, benzimidazole, thibendazole, tolyltriazole, 1,2,3-triazole, 1,2,4-triazole, 1-hydroxybenzotriazole, 2-methylbenzothiazole, 2-aminobenzimidazole, 2-amino-5-ethyl-1,3,4-thiadiazole, 3,5-diamino-1,2,4-triazole, 3-amino-5-methyl Pyrazoles, 4-amino-4H-1,2,4-triazoles, 5-methylbenzotriazoles, 5-chlorobenzotriazoles, 5-fluorobenzotriazoles, 5-bromobenzotriazoles, 5-iodobenzotriazoles, 5-aminotetrazoles, 5-ethylbenzotriazoles, 5-butylbenzotriazoles, dimethylbenzotriazoles, dichlorobenzotriazoles, chloromethylbenzotriazoles, phenylbenzotriazoles, benzylbenzotriazoles, nitrobenzotriazoles, imidazoles, and combinations thereof. Unexpectedly, azole-containing corrosion inhibitors (such as those mentioned above) can significantly reduce or minimize the removal rate of copper (or other metals) from semiconductor substrates.

[0038] In some embodiments, the amount of at least one azole is from at least about 0.001% (e.g., at least about 0.002%, at least about 0.005%, at least about 0.01%, at least about 0.02%, at least about 0.05%, at least about 0.1%, or at least about 0.2%) to at most about 0.5% (e.g., at most about 0.4%, at most about 0.2%, at most about 0.1%, at most about 0.08%, at most about 0.05%, at most about 0.02%, at most about 0.0075%, or at most about 0.005%) of the polishing composition described herein by weight.

[0039] In some embodiments, at least one alkylamine compound has at least one (e.g., two or three) alkyl chains comprising 6 to 24 (i.e., 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, or 24) carbons. In one or more embodiments, the alkyl chains may be linear, branched, or cyclic alkyl groups. In one or more embodiments, the alkylamine compound may be a primary, secondary, tertiary, or cyclic compound. In one or more embodiments, the alkylamine compound may be an alkoxylated amine (e.g., comprising ethoxylated and / or propoxylated groups). In one or more embodiments, the alkoxylated amine may comprise 2 to 100 ethoxylated and / or propoxylated groups. In some embodiments, at least one alkylamine compound has an alkyl chain comprising 6 to 18 carbons. In some embodiments, the alkylamine is selected from selfamine, octylamine, decylamine, dodecylamine, tetradecylamine, pentadecylamine, hexadecylamine, octadecylamine, cyclohexylamine, dicyclohexylamine, dipropylamine, or mixtures thereof. Unexpectedly, rather than being bound by theory, the aforementioned alkylamine compounds can significantly reduce or minimize the corrosion of tungsten in semiconductor substrates.

[0040] In some embodiments, the amount of at least one alkylamine compound is from at least about 0.0005% (e.g., at least about 0.001%, at least about 0.002%, at least about 0.005%, at least about 0.01%, at least about 0.02%, at least about 0.05%, at least about 0.1%, or at least about 0.2%) to at most about 0.5% (e.g., at most about 0.4%, at most about 0.2%, at most about 0.1%, at most about 0.08%, at most about 0.05%, at most about 0.02%, at most about 0.0075%, or at most about 0.005%) of the polishing composition described herein by weight.

[0041] In some embodiments, the polishing composition may optionally contain an amine compound other than the aforementioned alkylamine compounds or amino acids. For example, the polishing composition may optionally contain an amine compound selected from: monoethanolamine, 2-(2-aminoethoxy)ethanol, 3-methoxypropylamine, tris(hydroxymethyl)aminomethane, diethanolamine, 1-(2-hydroxyethyl)piperazine, 2,2,6,6-tetramethylpiperidine, 1-(o-tolyl)biguanidine, 1,3-di-o-tolylguanidine, N-methylethanolamine, pentamethyldiethylenetriamine, aminopropylmethylethanolamine, morpholine, piperazine, morpholinopropylamine, cyclohexylamine, dicyclohexylamine, aminoethylpiperazine, or mixtures thereof. Unexpectedly, rather than being bound by theory, the aforementioned optional amine compounds can significantly reduce or minimize the corrosion of tungsten in semiconductor substrates.

[0042] In some embodiments, the optional amine compound is included in the polishing composition in amounts ranging from at least about 0.005% (e.g., at least about 0.0075%, at least about 0.01%, at least about 0.025%, at least about 0.05%, at least about 0.1%, or at least about 0.25%) to at most about 0.5% (e.g., at most about 0.4%, at most about 0.2%, at most about 0.1%, at most about 0.08%, at most about 0.05%, at most about 0.02%, or at most about 0.0075%) of the polishing composition described herein by weight.

[0043] In one or more embodiments, the polishing composition may further comprise a pH adjuster. In one or more embodiments, the pH adjuster is selected from ammonium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide, monoethanolamine, diethanolamine, triethanolamine, methylethanolamine, methyldiethanolamine, tetrabutylammonium hydroxide, tetrapropylammonium hydroxide, tetraethylammonium hydroxide, tetramethylammonium hydroxide, ethyltrimethylammonium hydroxide, diethyldimethylammonium hydroxide, dimethyldipropylammonium hydroxide, benzyltrimethylammonium hydroxide, tris(2-hydroxyethyl)methylammonium hydroxide, choline hydroxide, and any combination thereof.

[0044] In some embodiments, when included in the composition, the amount of at least one pH adjuster is from at least about 0.01% (e.g., at least about 0.05%, at least about 0.1%, at least about 0.5%, at least about 1%, at least about 1.5%, at least about 2%, at least about 2.5%, at least about 4%, or at least about 4.5%) to at most about 5% (e.g., at most about 4.5%, at most about 4%, at most about 3.5%, at most about 3%, at most about 2.5%, at most about 2%, at most about 1.5%, at most about 1%, at most about 0.5%, at most about 0.2%, or at most about 0.1%) of the polishing composition described herein by weight.

[0045] In some embodiments, the pH of the polishing composition can be at least about 7 (e.g., at least about 7.5, at least about 8, at least about 8.5, at least about 9, at least about 9.5, at least about 10, at least about 10.5, at least about 11, at least about 11.5, or at least about 12) to at most about 14 (e.g., at most about 13.5, at most about 13, at most about 12.5, at most about 12, at most about 11.5, at most about 11, at least about 10.5, at most about 10, at most about 9.5, or at most about 9). It is not intended to be theoretically correct, but it is believed that polishing compositions with a pH below 7 significantly increase cobalt removal rates and corrosion, while polishing compositions with a pH above 14 may affect the stability of suspended abrasives and significantly increase the roughness of films polished with such compositions, and reduce the overall quality of films polished with such compositions. To obtain the desired pH, the relative concentrations of the components in the polishing compositions described herein can be adjusted.

[0046] When diluting the concentrated polishing composition to form the POU polishing composition, an optional oxidizing agent may be added. The oxidizing agent may be selected from hydrogen peroxide, ammonium persulfate, silver nitrate (AgNO3), ferric nitrate or ferric chloride, peracids or peracids, ozone water, potassium ferricyanide, potassium dichromate, potassium iodate, potassium bromate, potassium periodate, periodic acid, vanadium trioxide, hypochlorous acid, sodium hypochlorite, potassium hypochlorite, calcium hypochlorite, magnesium hypochlorite, ferric nitrate, potassium permanganate, other inorganic or organic peroxides, and mixtures thereof. In one embodiment, the oxidizing agent is hydrogen peroxide.

[0047] In some embodiments, the amount of oxidant is at least about 0.01% (e.g., at least about 0.05%, at least about 0.1%, at least about 0.2%, at least about 0.4%, at least about 0.5%, at least about 1%, at least about 1.5%, at least about 2%, at least about 2.5%, at least about 3%, at least about 3.5%, at least about 4%, or at least about 4.5%) by weight to at most about 5% (e.g., at most about 4.5%, at most about 4%, at most about 3.5%, at most about 3%, at most about 2.5%, at most about 2%, at most about 1.5%, at most about 1%, at most about 0.5%, or at most about 0.1%) of the polishing composition described herein. In some embodiments, the oxidant may reduce the shelf life of the polishing composition. In such embodiments, the oxidant may be added to the polishing composition at the point of use (e.g., just before polishing).

[0048] In some embodiments, the polishing composition described herein may contain a solvent (e.g., a first solvent) such as water. In some embodiments, the amount of solvent (e.g., water) is from at least about 20% by weight (e.g., at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 92%, at least about 94%, at least about 95%, or at least about 97%) to at most about 99% by weight (e.g., at most about 98%, at most about 96%, at most about 94%, at most about 92%, at most about 90%, at most about 85%, at most about 80%, at most about 75%, at most about 70%, or at most about 65%) of the polishing composition described herein.

[0049] In one or more embodiments, an optional second solvent (e.g., an organic solvent) may be used in the polishing composition of this disclosure (e.g., a POU polishing composition or a concentrated polishing composition) to facilitate the dissolution of the azole-containing corrosion inhibitor. In one or more embodiments, the second solvent may be one or more alcohols, alkylene glycols, or alkylene glycol ethers. In one or more embodiments, the second solvent comprises one or more solvents selected from: ethanol, 1-propanol, 2-propanol, n-butanol, propylene glycol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol propyl ether, and ethylene glycol.

[0050] In some embodiments, the amount of the second solvent is at least about 0.005% (e.g., at least about 0.01%, at least about 0.02%, at least about 0.05%, at least about 0.1%, at least about 0.2%, at least about 0.4%, at least about 0.6%, at least about 0.8%, at least about 1%, at least about 3%, at least about 5%, or at least about 10%) of the polishing composition described herein, to at most about 15% (e.g., at most about 12%, at most about 10%, at most about 5%, at most about 3%, at most about 2%, at most about 1%, at most about 0.8%, at most about 0.6%, at most about 0.5%, or at most about 0.1%) of the polishing composition described herein.

[0051] In one or more embodiments, the polishing compositions described herein may be substantially free of one or more of certain components, such as organic solvents, pH adjusters (e.g., dicarboxylic or tricarboxylic acids), quaternary ammonium compounds (e.g., salts or hydroxides), amines, alkali metal bases (e.g., alkali metal hydroxides), fluorinated compounds (e.g., fluorinated compounds or fluorinated compounds (e.g., polymers / surfactants)), silicon-containing compounds such as silanes (e.g., alkoxysilanes), imines (e.g., amidines such as 1,8-diazabicyclo[5.4.0]-7-undecene (DBU) and 1,5-dioxane), etc. The polishing composition may contain: azabicyclo[4.3.0]non-5-ene (DBN), salts (e.g., halide salts or metal salts), polymers (e.g., cationic or anionic polymers), surfactants (e.g., cationic, anionic, or nonionic surfactants), plasticizers, oxidants (e.g., H₂O₂ or periodic acid), corrosion inhibitors (e.g., azole or nonazole corrosion inhibitors), electrolytes (e.g., polyelectrolytes), and / or certain abrasives (e.g., cerium dioxide abrasives, nonionic abrasives, surface-modified abrasives, or negatively / positively charged abrasives). Halide salts that may be excluded from the polishing composition include alkali metal halides (e.g., sodium or potassium halides) or ammonium halides (e.g., ammonium chloride), and may be fluorides, chlorides, bromides, or iodides. As used herein, a component “substantially free” in the polishing composition means a component that is not intentionally added to the polishing composition. In some embodiments, the polishing compositions described herein may contain up to about 1000 ppm (e.g., up to about 500 ppm, up to about 250 ppm, up to about 100 ppm, up to about 50 ppm, up to about 10 ppm, or up to about 1 ppm) of one or more of the aforementioned components that are substantially absent from the polishing compositions. In some embodiments, the polishing compositions described herein may be completely free of one or more of the aforementioned components.

[0052] This disclosure also contemplates methods using either the above-described concentrate or POU slurry. For the concentrate, the method may include the steps of: diluting the concentrate to form a POU polishing composition, then contacting a substrate surface at least partially containing cobalt with the POU polishing composition, and contacting a pad (e.g., a polishing pad) with a surface of the substrate and moving the pad relative to the substrate. For the POU polishing composition, the method includes the steps of: contacting a substrate surface at least partially containing cobalt with the polishing composition, and contacting a pad (e.g., a polishing pad) with a surface of the substrate and moving the pad relative to the substrate. In one or more embodiments, the surface in contact with the polishing composition may also contain tungsten.

[0053] In one or more embodiments, this disclosure features a polishing method that may include applying a polishing composition according to this disclosure to a substrate (e.g., a wafer) having at least cobalt on its surface; and contacting a pad with the surface of the substrate and moving the pad relative to the substrate. In some embodiments, when the substrate comprises at least one or more of silicon oxides (e.g., TEOS), silicon nitrides (e.g., SiN), and / or barrier materials (e.g., Ta, TaN, Ti, or TiN), the above method may remove at least a portion of these materials at a rate approximately the same as or faster than that used to remove cobalt. For example, in one or more embodiments, the polishing rate difference between the TEOS / SiN and Co in the polishing composition of this disclosure is less than about 20%, less than about 15%, less than about 10%, or less than about 5%. In one or more embodiments, the polishing selectivity (i.e., the ratio of polishing rates) of the polishing composition to cobalt for silicon oxide (e.g., TEOS), silicon nitride (e.g., SiN), and / or barrier materials (e.g., Ta, TaN, Ti, or TiN) may not exceed about 1:1, about 2:1, about 3:1, or about 4:1. It should be noted that the term "silicon oxide" described herein is explicitly intended to include both undoped and doped forms of silicon oxide. For example, in one or more embodiments, the silicon oxide may be doped with at least one dopant selected from carbon, nitrogen (for silicon oxide), oxygen, hydrogen, or any other known silicon oxide dopant. Some examples of silicon oxide film types include TEOS (tetraethyl orthosilicate), SiOC, SiOCN, SiOCH, SiOH, and SiON. In one or more embodiments, when polishing patterned or blanket wafers, the cobalt removal rate provided by the polishing composition according to this disclosure may be from about 50 Å / min to 500 Å / min. In one or more embodiments, when polishing patterned or unpatterned wafers, the tungsten removal rate provided by the polishing composition according to this disclosure can be from about 0 Å / min to 100 Å / min. In one or more embodiments, when a cobalt sample is incubated in the polishing composition at 60°C for 5 minutes, the static etch rate (SER) of the polishing composition for cobalt is approximately / minutes to / minute. In one or more embodiments, when a tungsten sample is incubated in the polishing composition at 60°C for 5 minutes, the static etching rate (SER) of the polishing composition on the tungsten is approximately / minutes to / minute.

[0054] In some embodiments, the method using the polishing composition described herein may also include producing a semiconductor device from a substrate treated with the polishing composition through one or more steps. For example, photolithography, ion implantation, dry / wet etching, plasma etching, deposition (e.g., PVD, CVD, ALD, ECD), wafer mounting, die dicing, packaging, and testing can be used to produce semiconductor devices from a substrate treated with the polishing composition described herein.

[0055] The specific embodiments described below should be interpreted as illustrative only and do not limit the remainder of this disclosure in any way. It is understood that those skilled in the art can utilize this disclosure to the fullest extent based on the description herein, without further explanation.

[0056] Example

[0057] Polishing was performed under the following conditions: AMAT Mirra CMP polisher, Fujibo H804 pad, 1.5 psi downforce, 120 / 114 rpm platen / head speed, and 175 mL / min polishing composition flow rate.

[0058] The general compositions used in the following examples are shown in Table 1 below. Specific details regarding the differences in the compositions tested will be described in more detail when discussing the various examples.

[0059] Table 1

[0060]

[0061]

[0062] Example 1

[0063] Table 2 below shows the results of static etching rate (SER) tests comparing compositions containing alkylamines having 6 to 24 carbon alkyl chains, conforming to Table 1 above, with compositions not containing alkylamines. All other components of the compositions are identical except for the amount of water.

[0064] In the test, a cobalt or tungsten metal sample was immersed in the polishing composition at 60°C for five minutes. The sample was then rinsed with deionized water and dried under nitrogen. The static etching rate was determined by measuring the sample thickness before and after the test using a four-point probe metrology tool.

[0065] The results showed that the addition of alkylamines significantly reduced the corrosion rate (SER) of tungsten without significantly affecting the SER of cobalt. Therefore, alkylamines are effective inhibitors of tungsten corrosion or removal rate.

[0066] Table 2

[0067]

[0068] Example 2

[0069] Table 3 below shows the results of static etching rate (SER) tests comparing a composition containing only an anionic surfactant as a cobalt corrosion inhibitor with a composition containing an anionic surfactant and a phosphonic acid compound with a molecular weight of less than 500 g / mol as a second cobalt corrosion inhibitor. Both compositions contain the alkylamine compound used in Example 1. All other components of the compositions are identical.

[0070] The results showed that the addition of a second cobalt corrosion inhibitor (phosphonic acid) did not significantly affect the cobalt SER, indicating that both compositions should protect cobalt and tungsten from corrosion in approximately the same way. Indeed, Table 3 shows that the cobalt removal rates of each of Examples 3 and Comparative Examples 3 were approximately the same. However, the addition of the second cobalt corrosion inhibitor significantly reduced the Co contact angle of the composition of Example 3, indicating that the composition of Example 3 was more capable of wetting the cobalt surface compared to the composition of Comparative Example 3. After the addition of the second cobalt corrosion inhibitor, the tungsten SER and tungsten contact angle measurements remained approximately the same, indicating that the second cobalt corrosion inhibitor did not significantly interact with the tungsten surface. Comparative Example 4 showed that the combination of a small amount of the first cobalt corrosion inhibitor with no second cobalt corrosion inhibitor resulted in an unacceptably high cobalt removal rate due to insufficient cobalt protection. Comparative Example 5 showed an extremely high cobalt removal rate, indicating that the second cobalt corrosion inhibitor alone was not sufficient to protect cobalt.

[0071] Table 3

[0072]

[0073] RR = Removal Rate

[0074] Example 3

[0075] Table 4 below shows the edge corrosion (EoE) measurements after polishing a patterned wafer including a cobalt portion adjacent to the TEOS portion of the wafer. The EoE measurements represent the degree of corrosion of the TEOS portion adjacent to the cobalt portion of the wafer and are measured using atomic force microscopy (AFM). In this embodiment, the patterned wafer was polished using the first two polishing compositions detailed in Example 2, instead of the latter two, because the latter two polishing compositions have too high a cobalt removal rate (see Table 3), which would understandably lead to unacceptably high cobalt corrosion.

[0076] The results showed that Example 3 (the composition containing the second cobalt corrosion inhibitor) unexpectedly exhibited a significantly reduced EoE compared to Comparative Example 3. Not bound by theory, the inventors believe that the unique synergistic effect of the cobalt corrosion inhibitor in Example 3 allows for the improved EoE due to the significantly smaller molecular size of the phosphonic acid-based cobalt corrosion inhibitor compared to the anionic surfactant. Since both molecules have an affinity for the cobalt surface, they determine the surface chemistry of the cobalt portion of the wafer surface adjacent to the TEOS portion. The contact angle changes shown in Table 3 demonstrate this synergistic effect. As in Comparative Example 3, when only a larger anionic surfactant is used, abrasive particles may accumulate at the edges where the cobalt and TEOS meet during polishing due to the large surfactant coverage, reducing the wetting of the cobalt portion rather than the TEOS portion. This accumulation causes edge corrosion of the TEOS due to the increased residence time of the abrasive particles at the edges. However, when the composition contains a smaller phosphonic acid-based cobalt corrosion inhibitor, the polishing composition can more effectively wet the cobalt surface in addition to the TEOS surface, preventing significant accumulation of abrasive particles at the cobalt and TEOS interface. Therefore, Example 3 exhibited significantly less corrosion than the composition containing only anionic surfactant as a cobalt corrosion inhibitor.

[0077] Table 4

[0078]

[0079] While only a few exemplary embodiments have been described in detail above, those skilled in the art will readily understand that many modifications can be made to the exemplary embodiments without substantially departing from the scope of this disclosure. Therefore, all such modifications are intended to be included within the scope of this disclosure as defined in the foregoing claims.

Claims

1. A polishing composition comprising: At least one abrasive; At least one organic acid; At least one anionic surfactant containing at least a phosphate / ester; At least one phosphonic acid compound with a molecular weight of less than 500 g / mol, wherein the at least one phosphonic acid compound is selected from phenylphosphonic acid, butylphosphonic acid, hexylphosphonic acid, octylphosphonic acid, benzylphosphonic acid, phenylethylphosphonic acid, phenylpropylphosphonic acid, phenylbutylphosphonic acid, and mixtures thereof; At least one azole-containing compound; At least one alkylamine compound having a 6- to 24-carbon alkyl chain; and Aqueous solvents; Optionally, pH adjuster The weight percentage of the phosphonic acid compound to the anionic surfactant is from 5:1 to 100:

1. The cobalt removal rate provided by the composition is from 50 Å / min to 500 Å / min. The static etching rate (SER) for cobalt provided by the composition is from 0 Å / min to 10 Å / min, and The at least one azole-containing compound is selected from benzotriazole, adenine, benzimidazole, thiabendazole, toluenetriazole, 1,2,3-triazole, 1,2,4-triazole, 1-hydroxybenzotriazole, 2-methylbenzothiazole, 2-aminobenzimidazole, 2-amino-5-ethyl-1,3,4-thiadiazole, 3,5-diamino-1,2,4-triazole, 3-amino-5-methylpyrazole, 4-amino-4H-1,2,4-triazole, 5-methylbenzotriazole, 5-chlorobenzotriazole, 5-fluorobenzotriazole, 5-bromobenzotriazole, 5-iodobenzotriazole, 5-aminotetrazole, 5-ethylbenzotriazole, 5-butylbenzotriazole, dimethylbenzotriazole, dichlorobenzotriazole, chloromethylbenzotriazole, phenylbenzotriazole, benzylbenzotriazole, nitrobenzotriazole, imidazole, and combinations thereof.

2. The polishing composition according to claim 1, wherein the at least one abrasive is selected from alumina; silicon dioxide; titanium dioxide; cerium dioxide; zirconium oxide; a co-formation of alumina, silicon dioxide, titanium dioxide, cerium dioxide, or zirconium oxide; coated abrasive; surface-modified abrasive; and mixtures thereof.

3. The polishing composition according to claim 1, wherein the amount of the at least one abrasive is from 0.01% to 25% by weight of the composition.

4. The polishing composition according to claim 1, wherein the at least one organic acid is selected from gluconic acid, lactic acid, citric acid, tartaric acid, malic acid, glycolic acid, malonic acid, formic acid, oxalic acid, acetic acid, propionic acid, peracetic acid, succinic acid, aminoacetic acid, phenoxyacetic acid, N-di(hydroxyethyl)glycine, diethylene glycol, glyceric acid, N-tris(hydroxymethyl)methylglycine, maleic acid, hypozoxytriacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, alanine, histidine, valine, phenylalanine, proline, glutamine, aspartic acid, glutamic acid, arginine, lysine, tyrosine, glycine, serine, asparagine, cysteine, leucine, isoleucine, methionine, threonine, tryptophan, benzoic acid, and mixtures thereof.

5. The polishing composition according to claim 1, wherein at least two organic acids are present, and one of them is an amino acid.

6. The polishing composition according to claim 1, wherein the amount of the at least one organic acid is from 0.001% to 2.5% by weight of the composition.

7. The polishing composition according to claim 1, wherein the at least one anionic surfactant is selected from alkyl phosphates / esters, polyoxyethylene alkyl ether phosphates / esters, polyoxyethylene aryl alkyl ether phosphates / esters, and mixtures thereof.

8. The polishing composition according to claim 1, wherein the at least one anionic surfactant is selected from alkyl phosphates / esters, polyoxyethylene alkyl ether phosphates / esters, polyoxyethylene nonyl aryl ether phosphates / esters, and mixtures thereof.

9. The polishing composition according to claim 1, wherein the at least one anionic surfactant is selected from alkyl phosphates / esters, polyoxyethylene alkyl ether phosphates / esters, polyoxyethylene nonylphenyl ether phosphates / esters, and mixtures thereof.

10. The polishing composition according to claim 1, wherein the at least one anionic surfactant further comprises at least one of a hydrophobic 6 to 24 carbon alkyl chain and 2 to 16 epoxy alkyl groups.

11. The polishing composition according to claim 1, wherein the amount of the anionic surfactant is 0.001% to 0.5% by weight of the composition.

12. The polishing composition according to claim 1, wherein the amount of the at least one phosphonic acid compound is from 0.01% to 1.5% by weight of the composition.

13. The polishing composition according to claim 1, wherein the amount of the at least one azole compound is from 0.001% to 0.5% by weight of the composition.

14. The polishing composition according to claim 1, wherein the at least one alkylamine compound has a 6- to 20-carbon alkyl chain.

15. The polishing composition according to claim 1, wherein the amount of the at least one alkylamine compound is 0.0005% to 0.5% by weight of the composition.

16. The polishing composition according to claim 1, wherein the pH of the composition is 7 to 12.

17. The polishing composition according to claim 1, further comprising: An organic solvent, wherein the amount of said organic solvent is 0.01% to 5% by weight of the composition.

18. The polishing composition according to claim 17, wherein the organic solvent is selected from ethanol, 1-propanol, 2-propanol, n-butanol, propylene glycol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol propyl ether, ethylene glycol, and any combination thereof.

19. A polishing composition comprising: At least one abrasive, wherein the amount of said at least one abrasive is from 0.01% to 25% by weight of the composition; The composition contains at least two organic acids, wherein the amount of the at least two organic acids is from 0.001% to 2.5% by weight, and wherein at least one of the organic acids is an amino acid; At least one anionic surfactant, said at least one anionic surfactant comprising at least a phosphate / ester and comprising at least one of a hydrophobic 6 to 24 carbon alkyl chain and 2 to 16 epoxy ethylene groups, wherein said anionic surfactant is present in an amount of 0.001% to 0.5% by weight of the composition; At least one phosphonic acid compound with a molecular weight of less than 500 g / mol, wherein the amount of the at least one phosphonic acid compound with a molecular weight of less than 500 g / mol is 0.01% to 1.5% by weight of the composition, wherein the at least one phosphonic acid compound is selected from phenylphosphonic acid, butylphosphonic acid, hexylphosphonic acid, octylphosphonic acid, benzylphosphonic acid, phenylethylphosphonic acid, phenylpropylphosphonic acid, phenylbutylphosphonic acid, and mixtures thereof; At least one azole-containing compound, wherein the amount of said at least one azole-containing compound is 0.001% to 0.5% by weight of the composition; At least one alkylamine compound having a 6- to 24-carbon alkyl chain, wherein the amount of said at least one alkylamine compound having a 6- to 24-carbon alkyl chain is 0.0005% to 0.5% by weight of the composition; and Aqueous solvents; The pH of the composition is said to be 7 to 12. The weight percentage of the phosphonic acid compound to the anionic surfactant is from 5:1 to 100:

1. The cobalt removal rate provided by the composition is from 50 Å / min to 500 Å / min. The static etching rate (SER) for cobalt provided by the composition is from 0 Å / min to 10 Å / min, and The at least one azole-containing compound is selected from benzotriazole, adenine, benzimidazole, thiabendazole, toluenetriazole, 1,2,3-triazole, 1,2,4-triazole, 1-hydroxybenzotriazole, 2-methylbenzothiazole, 2-aminobenzimidazole, 2-amino-5-ethyl-1,3,4-thiadiazole, 3,5-diamino-1,2,4-triazole, 3-amino-5-methylpyrazole, 4-amino-4H-1,2,4-triazole, 5-methylbenzotriazole, 5-chlorobenzotriazole, 5-fluorobenzotriazole, 5-bromobenzotriazole, 5-iodobenzotriazole, 5-aminotetrazole, 5-ethylbenzotriazole, 5-butylbenzotriazole, dimethylbenzotriazole, dichlorobenzotriazole, chloromethylbenzotriazole, phenylbenzotriazole, benzylbenzotriazole, nitrobenzotriazole, imidazole, and combinations thereof.

20. A method for polishing a cobalt-containing substrate, comprising: The polishing composition according to any one of claims 1 to 18 is applied to a substrate, wherein the substrate contains cobalt on its surface; and The pad is brought into contact with the surface of the substrate and the pad is moved relative to the substrate.

21. The method of claim 20, further comprising forming a semiconductor device from the substrate.

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