Polishing composition and method for using the same

Abstract

To realize the market need for CMP slurries that can efficiently polish dielectric or barrier components on Co-containing surfaces without significant Co corrosion.SOLUTION: The polishing compositions contain abrasives; pH adjusters; barrier film removal rate enhancers; a first low-k removal rate inhibitor; a second low-k removal rate inhibitor; an azole-containing corrosion inhibitor; and a cobalt corrosion inhibitor. The present disclosure also relates to a method for polishing a substrate containing cobalt using the polishing compositions described in the present disclosure.SELECTED DRAWING: None

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims priority from U.S. Provisional Application No. 62 / 904,857, filed on September 24, 2019, the content of which is hereby incorporated by reference in its entirety.

Background Art

[0002] The semiconductor industry is constantly driven to improve chip performance through further miniaturization of devices through innovations in processes, materials, and integration. Previous material innovations include the introduction of copper, the replacement of aluminum as a conductive material in interconnect structures, and the use of tantalum (Ta) / tantalum nitride (TaN) as a diffusion barrier to isolate Cu conductive material from non - conductive / insulating dielectric materials. Copper (Cu) was selected as an interconnect material due to its low resistivity and good resistance to electron migration.

[0003] However, to maintain effective interconnect resistance in the Back End of Line (BEOL), as the features of newer - generation chips shrink, the multi - layer Cu / barrier / dielectric stack must be thinner and more conformal. Schemes to make the Cu and Ta / TaN barrier films thinner cause problems with resistivity and deposition flexibility. For example, as dimensions get smaller and manufacturing nodes become more advanced, the resistivity has been deteriorating exponentially, and the improvement in transistor circuit speed (in the Front End of Line (FEOL)) has been halved due to the delay resulting from the conductive Cu / barrier wiring (BEOL). Cobalt (Co) has emerged as a major candidate for use as a liner material, barrier layer, and conductive layer. Furthermore, cobalt is also currently being studied as a replacement for tungsten (W) in various applications such as W metal contacts, plugs, vias, and gate materials.

[0004] Many currently available CMP slurries were specifically designed to remove materials that were more common in older chip designs, such as the aforementioned copper and tungsten. Due to the greater chemical corrosiveness of cobalt, certain components in these older CMP slurries can cause harmful and unacceptable defects in cobalt. As a result, using a copper polishing slurry on a cobalt layer often results in unacceptable corrosion, wafer topography, and removal rate selectivity.

[0005] As the use of cobalt (Co) as a metal component in semiconductor manufacturing increases, there is a market need for a CMP slurry that can efficiently polish dielectric or barrier components on Co-containing surfaces without significant Co corrosion.

Summary of the Invention

Means for Solving the Problems

[0006] This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the subject matter claimed, nor is it intended to be used as an aid in limiting the scope of the subject matter claimed.

[0007] In the definitions of the present disclosure, unless otherwise specified, all percentage values described should be understood to be weight percentages based on the total weight of the chemical mechanical polishing composition.

[0008] In one aspect, embodiments described in the present disclosure relate to a polishing composition comprising an abrasive; a pH adjuster; an agent for increasing the barrier film removal rate; a first low-k removal rate inhibitor; a second low-k removal rate inhibitor different from the first low-k removal rate inhibitor; an azole-containing rust inhibitor; and a cobalt rust inhibitor.

[0009] In another aspect, embodiments described in the present disclosure relate to a polishing composition comprising an abrasive; a pH adjuster; an organic acid or a salt thereof; a nonionic surfactant; an amphiphilic copolymer; an azole-containing rust inhibitor; and an anionic surfactant.

[0010] In yet another aspect, embodiments described in the present disclosure relate to a method of polishing a substrate, comprising applying the polishing composition according to claim 1 to a surface of the substrate, wherein the surface contains cobalt; and contacting a pad with the surface of the substrate and moving the pad relative to the substrate.

[0011] Other aspects and advantages of the subject matter claimed will be apparent from the following description and the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

[0012] Embodiments described in the present disclosure generally relate to a composition and a method of using the composition to polish a substrate comprising at least a cobalt portion, and more specifically a substrate that may comprise at least a cobalt portion and a copper portion. The compositions described in the present disclosure can effectively suppress the low-k removal rate, minimize the loss of cobalt liners, and reduce defects observed on the copper surface after polishing, while still effectively removing a barrier film (e.g., a Ta film or a TaN film). For example, the compositions described in the present disclosure can be particularly useful for polishing advanced node films comprising copper, cobalt liners, barriers (Ta, TaN), and dielectric materials (TEOS, low-k, ultra low-k, etc.).

[0013] Cobalt (Co) is introduced as a barrier layer, as a conductive layer, and / or as a replacement for W, and it is possible to polish Co at an effective material removal rate without significant Co corrosion, and other metals and metal oxides (Cu, Ti, Ta 2 O 5 TiO 2 RuO 2, etc.) and dielectric films (SiN, silicon oxide, polysilicon, low k dielectrics (e.g., carbon-doped silicon oxide), etc.) There is a market need for CMP slurries with a range of choices for polishing rates. Since Co is more chemically reactive than Cu and other noble metals, Co corrosion prevention is very challenging in advanced node slurry design. Current metal polishing slurries are ill-equipped to polish surfaces containing Co because they suffer from the problem of Co corrosion in the CMP process. In addition, it is generally desirable to remove a certain amount of Co during polishing so as to form a smooth surface on the patterned semiconductor substrate for subsequent manufacturing processes. For example, in some fabrication processes, significant amounts of dishing often exist in the copper and cobalt portions after removing excess copper deposition. For this reason, in the subsequent barrier polishing step, the polishing composition of the present disclosure can be formulated to polish the barrier material (Ta or TaN) at a faster rate than removing copper metal and removing cobalt from the liner so as to correct the previous dishing so that the polished film can have a smooth topography. Thus, one of the goals of the polishing composition in the present disclosure is to have an appropriate Co removal rate while effectively removing a specific target material (e.g., Ta or TaN).

[0014] In one or more embodiments, the polishing composition comprises an abrasive; a pH adjuster; a barrier film removal rate enhancer; a first low-k removal rate inhibitor; a second low-k removal rate inhibitor; an azole-containing rust inhibitor; and a cobalt rust inhibitor. In one or more embodiments, the polishing composition may further comprise a chelating agent. In one or more embodiments, the polishing composition according to the present disclosure comprises from about 0.1 wt% to about 50 wt% of an abrasive, from about 0.05 wt% to about 10 wt% of a pH adjuster, from about 0.02 wt% to about 4 wt% of a barrier film removal rate enhancer, from about 0.005 wt% to about 5 wt% of a first low-k removal rate inhibitor, from about 0.005 wt% to about 5 wt% of a second low-k removal rate inhibitor, from about 0.0001 wt% to about 1 wt% of an azole-containing rust inhibitor, from about 0.0001 wt% to about 1 wt% of a cobalt rust inhibitor, and the balance by weight (e.g., from about 20 wt% to about 99 wt%) of a solvent (e.g., deionized water). In one or more embodiments, the polishing composition may further comprise from about 0.001 wt% to about 1 wt% of a chelating agent.

[0015] In one or more embodiments, the present disclosure provides a concentrated polishing composition that can be diluted up to 2-fold, or 4-fold, or 6-fold, or 8-fold, or 10-fold with water before use. In other embodiments, the present disclosure provides a point-of-use (POU) polishing composition for use on a cobalt substrate, comprising the polishing composition, water, and optionally an oxidizing agent.

[0016] In one or more embodiments, the POU polishing composition may include from about 0.1 wt% to about 12 wt% abrasive, from about 0.05 wt% to about 5 wt% pH adjuster, from about 0.02 wt% to about 2 wt% barrier film removal rate enhancer, from about 0.005 wt% to about 0.5 wt% first low-k removal rate inhibitor, from about 0.005 wt% to about 0.5 wt% second low-k removal rate inhibitor, from about 0.0001 wt% to about 0.1 wt% azole-containing rust inhibitor, from about 0.0001 wt% to about 0.1 wt% cobalt rust inhibitor, optionally from about 0.1 wt% to about 5 wt% oxidizing agent, and from about 80 wt% to about 99 wt% solvent (e.g., deionized water). In one or more embodiments, the POU polishing composition may further include from about 0.001 wt% to about 0.1 wt% chelating agent.

[0017] In one or more embodiments, the concentrated polishing composition may include from about 1 wt% to about 50 wt% abrasive, from about 0.5 wt% to about 10 wt% pH adjuster, from about 0.2 wt% to about 4 wt% barrier film removal rate enhancer, from about 0.05 wt% to about 5 wt% first low-k removal rate inhibitor, from about 0.05 wt% to about 5 wt% second low-k removal rate inhibitor, from about 0.001 wt% to about 1 wt% azole-containing rust inhibitor, from about 0.001 wt% to about 1 wt% cobalt rust inhibitor, and the balance by weight (e.g., from about 20 wt% to about 98.5 wt%) solvent (e.g., deionized water). In one or more embodiments, the concentrated polishing composition may further include from about 0.01 wt% to about 1 wt% chelating agent.

[0018] In one or more embodiments, the polishing composition described in the present disclosure may include at least one (e.g., two or three) polishing agents. In some embodiments, the at least one polishing agent is selected from the group consisting of cationic polishing agents, substantially neutral polishing agents, and anionic polishing agents. In one or more embodiments, the at least one polishing agent is selected from the group consisting of alumina, silica, titania, ceria, zirconia, its co-formed product (i.e., a co-formed product of alumina, silica, titania, ceria, or zirconia), coated polishing agents, surface-modified polishing agents, and mixtures thereof. In some embodiments, the at least one polishing agent does not include ceria. In some embodiments, the at least one polishing agent is of high purity, with alcohol being less than about 100 ppm, ammonia being less than about 100 ppm, and alkali cations such as sodium cations being less than about 100 parts per billion (ppb). The polishing agent may be present in an amount of about 0.1% to about 12% (e.g., about 0.5% to about 10%), or any subrange thereof, based on the total weight of the POU polishing composition.

[0019] In some embodiments, the at least one polishing agent is present in an amount of about 0.1 wt% or more (e.g., about 0.5 wt% or more, about 1 wt% or more, about 2 wt% or more, about 4 wt% or more, about 5 wt% or more, about 10 wt% or more, about 12 wt% or more, about 15 wt% or more, or about 20 wt% or more) to about 50 wt% or less (e.g., about 45 wt% or less, about 40 wt% or less, about 35 wt% or less, about 30 wt% or less, about 25 wt% or less, about 20 wt% or less, about 15 wt% or less, about 12 wt% or less, about 10 wt% or less, or about 5 wt% or less) with respect to the polishing composition described in the present disclosure.

[0020] In one or more embodiments, the polishing composition described in the present disclosure may include at least one (e.g., two or three) pH adjuster. In some embodiments, the at least one pH adjuster is selected from the group consisting of ammonium hydroxide, sodium hydroxide, potassium hydroxide, cerium 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.

[0021] In some embodiments, the at least one pH adjuster is present in an amount of about 0.05 wt% or more (e.g., about 0.1 wt% or more, about 0.2 wt% or more, about 0.4 wt% or more, about 0.5 wt% or more, about 0.8 wt% or more, about 1 wt% or more, about 2 wt% or more, about 5 wt% or more, or about 7 wt% or more) to about 10 wt% or less (e.g., about 9 wt% or less, about 8 wt% or less, about 7 wt% or less, about 6 wt% or less, about 5 wt% or less, about 4 wt% or less, about 3 wt% or less, about 2 wt% or less, about 1 wt% or less, about 0.5 wt% or less, about 0.2 wt% or less, or about 0.1 wt% or less) based on the polishing composition described in the present disclosure.

[0022] In some embodiments, the pH value of the polishing composition may be in the range of about 7 or higher (e.g., about 7.5 or higher, about 8 or higher, about 8.5 or higher, about 9 or higher, about 9.5 or higher, about 10 or higher, about 10.5 or higher, about 11 or higher, about 11.5 or higher, or about 12 or higher) to about 14 or lower (e.g., about 13.5 or lower, about 13 or lower, about 12.5 or lower, about 12 or lower, about 11.5 or lower, about 11 or lower, about 10.5 or lower, about 10 or lower, about 9.5 or lower, or about 9 or lower). Without wishing to be bound by theory, a polishing composition having a pH lower than 7 will significantly increase the cobalt removal rate and corrosion, and a polishing composition having a pH higher than 14 may affect the stability of the suspended abrasive, significantly increase the roughness, and degrade the overall quality of the film polished by the composition. To obtain the desired pH, the relative concentrations of the components in the polishing composition described in the present disclosure may be adjusted.

[0023] In one or more embodiments, the polishing composition described in the present disclosure may include at least one (e.g., two or three) barrier film removal rate enhancer. In some embodiments, the at least one barrier film removal rate enhancer is an organic acid (e.g., carboxylic acid, amino acid, sulfonic acid, or phosphonic acid) or a salt thereof. In some embodiments, the barrier film removal rate enhancer is 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, aminoacetic acid, phenoxyacetic acid, bicine, diglycolic acid, glyceric acid, tricine, alanine, histidine, valine, phenylalanine, proline, glutamine, aspartic acid, glutamic acid, arginine, lysine, tyrosine, benzoic acid, 1,2-ethanedisulfonic acid, 4-amino-3-hydroxy-1-naphthalenesulfonic acid, 8-hydroxyquinoline-5-sulfonic acid, aminomethanesulfonic acid, benzenesulfonic acid, hydroxylamine O-sulfonic acid, methanesulfonic acid, m-xylene-4-sulfonic acid, poly(4-styrenesulfonic acid), polyanetholesulfonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, ethylphosphoric acid, cyanoethylphosphoric acid, phenylphosphoric acid, vinylphosphoric acid, poly(vinylphosphonic acid), 1-hydroxyethane-1,1-diphosphonic acid, nitrilotri(methylphosphonic acid), diethylenetriaminepentaakis(methylphosphonic acid), N,N,N’,N’-ethylenediaminetetrakis(methylenephosphonic acid), n-hexylphosphonic acid, benzylphosphonic acid, phenylphosphonic acid, salts thereof, and mixtures thereof, and is an organic acid or a salt thereof selected from the group consisting of. Without wishing to be bound by theory, it is surprising that an organic acid or a salt thereof (such as those described above) can be used as an effective barrier film removal rate enhancer in the polishing composition described in the present disclosure to improve the removal rate of a barrier film (e.g., a Ta film or a TaN film) in a semiconductor substrate.

[0024] In some embodiments, the barrier film removal rate enhancer is present in an amount of about 0.02 wt% or more (e.g., about 0.05 wt% or more, about 0.1 wt% or more, about 0.2 wt% or more, about 0.4 wt% or more, about 0.5 wt% or more, about 0.6 wt% or more, about 0.8 wt% or more, about 1 wt% or more, about 1.5 wt% or more, about 2 wt% or more) to about 4 wt% or less (e.g., about 3.5 wt% or less, about 3 wt% or less, about 2.5 wt% or less, about 2 wt% or less, about 1.5 wt% or less, or about 1 wt% or less) based on the polishing composition described in the present disclosure.

[0025] In one or more embodiments, the polishing composition described in the present disclosure may include at least one (e.g., two or three) first low-k removal rate inhibitor. In some embodiments, the at least one first low-k removal rate inhibitor is a nonionic surfactant. In one or more embodiments, the nonionic surfactant is selected from the group consisting of alcohol alkoxylates, alkylphenol alkoxylates, tristyrylphenol alkoxylates, sorbitan ester alkoxylates, polyalkoxylates, polyalkylene oxide block copolymers, tetrahydroxy oligomers, alkoxylated diamines, and mixtures thereof. In one or more embodiments, the nonionic surfactant is a polymer having a number average molecular weight of about 1,000 g / mol or more, or about 2,500 g / mol or more, or about 5,000 g / mol or more, or about 7,500 g / mol or more, or about 10,000 g / mol or more. In one or more embodiments, the nonionic surfactant is a polymer having a number average molecular weight of about 1,000,000 g / mol or less, or about 750,000 g / mol or less, or about 500,000 g / mol or less, or about 250,000 g / mol or less, or about 100,000 g / mol or less. In one or more embodiments, the alkoxylate groups of the alkoxylated nonionic surfactant are ethoxylate, propoxylate, or a combination of an ethoxylate group and a propoxylate group. Without wishing to be bound by theory, it is surprising that nonionic surfactants (such as those described above) can be used as low-k removal rate inhibitors in the polishing compositions described in the present disclosure to reduce or minimize the removal rate of low-k films (e.g., carbon-doped silicon oxide films) in semiconductor substrates.

[0026] In some embodiments, the first low-k removal rate inhibitor is present in an amount of about 0.005 wt% or more (e.g., about 0.01 wt% or more, about 0.05 wt% or more, about 0.1 wt% or more, about 0.5 wt% or more, about 1 wt% or more, about 1.5 wt% or more, about 2 wt% or more, or about 3 wt% or more) to about 5 wt% or less (e.g., about 4.5 wt% or less, about 4 wt% or less, about 3.5 wt% or less, about 3 wt% or less, about 2.5 wt% or less, about 2 wt% or less, about 1.5 wt% or less, about 1 wt% or less, about 0.5 wt% or less, or about 0.1 wt% or less) with respect to the polishing composition described in the present disclosure.

[0027] In one or more embodiments, the polishing composition described in the present disclosure may include at least one (e.g., two or three) second low-k removal rate inhibitors. In some embodiments, the at least one second low-k removal rate inhibitor is an amphiphilic copolymer. In one or more embodiments, the amphiphilic copolymer is a styrene-maleic anhydride copolymer. In one or more embodiments, the amphiphilic copolymer has a number average molecular weight of about 1,000 g / mol or more (e.g., about 2,500 g / mol or more, about 5,000 g / mol or more, about 7,500 g / mol or more, about 10,000 g / mol or more) to about 200,000 g / mol or less (e.g., about 150,000 g / mol or less, about 100,000 g / mol or less, about 50,000 g / mol or less, or about 25,000 g / mol or less). Without wishing to be bound by theory, it is surprising that an amphiphilic copolymer (such as those described above) can be used as a low-k removal rate inhibitor in the polishing composition described in the present disclosure to reduce or minimize the removal rate of a low-k film (e.g., a carbon-doped silicon oxide film) in a semiconductor substrate.

[0028] In some embodiments, the second low-k removal rate inhibitor is present in an amount of about 0.005 wt% or more (e.g., about 0.01 wt% or more, about 0.05 wt% or more, about 0.1 wt% or more, about 0.5 wt% or more, about 1 wt% or more, about 1.5 wt% or more, about 2 wt% or more, or about 3 wt% or more) to about 5 wt% or less (e.g., about 4.5 wt% or less, about 4 wt% or less, about 3.5 wt% or less, about 3 wt% or less, about 2.5 wt% or less, about 2 wt% or less, about 1.5 wt% or less, about 1 wt% or less, about 0.5 wt% or less, or about 0.1 wt% or less) relative to the polishing composition described in the present disclosure.

[0029] Without wishing to be bound by theory, it has surprisingly been found that by including both a nonionic surfactant (i.e., the first low-k removal rate inhibitor) and an amphiphilic copolymer (i.e., the second low-k removal rate inhibitor) in the polishing composition described in the present disclosure, a synergistic effect can occur and the removal rate of a low-k film (e.g., a carbon-doped silicon oxide film) can be decreased relative to the sum of the removal rate decreases by each component when each component is used individually.

[0030] In one or more embodiments, the polishing composition described in the present disclosure may include at least one (e.g., two or three) azole-containing rust inhibitor. In some embodiments, the at least one azole-containing rust inhibitor is selected from the group consisting of substituted or unsubstituted triazole, substituted or unsubstituted tetrazole, substituted or unsubstituted benzotriazole, substituted or unsubstituted pyrazole, and substituted or unsubstituted imidazole. In one or more embodiments, the azole-containing rust inhibitor is selected from the group consisting of triazole, 1,2,4-triazole, tetrazole, benzotriazole, tolyltriazole, ethylbenzotriazole, propylbenzotriazole, butylbenzotriazole, pentylbenzotriazole, hexylbenzotriazole, dimethylbenzotriazole, chlorobenzotriazole, dichlorobenzotriazole, chloromethylbenzotriazole, chloroethylbenzotriazole, phenylbenzotriazole, benzylbenzotriazole, aminotriazole, aminobenzimidazole, aminotetrazole, and mixtures thereof. Without wishing to be bound by theory, it is believed that azole-containing rust inhibitors (such as those described above) can significantly reduce or minimize the removal rate of copper in a semiconductor substrate.

[0031] In some embodiments, the azole-containing rust inhibitor is present in an amount of about 0.0001 wt% or more (e.g., about 0.0002 wt% or more, about 0.0005 wt% or more, about 0.001 wt% or more, about 0.002 wt% or more, about 0.005 wt% or more, about 0.01 wt% or more, about 0.02 wt% or more, about 0.05 wt% or more, about 0.1 wt% or more, about 0.2 wt% or more, or about 0.5 wt% or more) to about 1 wt% or less (e.g., about 0.8 wt% or less, about 0.6 wt% or less, about 0.5 wt% or less, about 0.4 wt% or less, about 0.2 wt% or less, about 0.1 wt% or less, about 0.05 wt% or less, about 0.02 wt% or less, about 0.01 wt% or less, or about 0.005 wt% or less) based on the polishing composition described in the present disclosure.

[0032] In one or more embodiments, the polishing composition described in the present disclosure may include at least one (e.g., two or three) cobalt rust inhibitor. In some embodiments, the at least one cobalt rust inhibitor is an anionic surfactant. In one or more embodiments, the anionic surfactant includes one or more phosphate groups and one or more of the following groups, namely, an alkyl chain having 6 to 24 carbon atoms, 0 to 18 ethylene oxide groups, or a combination thereof. In one or more embodiments, the alkyl chain may have 8 or more carbon atoms, 10 or more carbon atoms, 12 or more carbon atoms, or 14 or more carbon atoms. In one or more embodiments, the alkyl chain may have 22 or fewer carbon atoms, 20 or fewer carbon atoms, or 18 or fewer carbon atoms. Without wishing to be bound by theory, it is surprising that an anionic surfactant (such as those described above) can be used as a cobalt rust inhibitor in the polishing composition described in the present disclosure so as to reduce or minimize the removal rate of cobalt in the semiconductor substrate.

[0033] In some embodiments, the cobalt rust inhibitor is present in an amount of about 0.0001 wt% or more (e.g., about 0.0002 wt% or more, about 0.0005 wt% or more, about 0.001 wt% or more, about 0.002 wt% or more, about 0.005 wt% or more, about 0.01 wt% or more, about 0.02 wt% or more, about 0.05 wt% or more, about 0.1 wt% or more, about 0.2 wt% or more, or about 0.5 wt% or more) to about 1 wt% or less (e.g., about 0.8 wt% or less, about 0.6 wt% or less, about 0.5 wt% or less, about 0.4 wt% or less, about 0.2 wt% or less, about 0.1 wt% or less, about 0.05 wt% or less, about 0.02 wt% or less, about 0.01 wt% or less, or about 0.005 wt% or less) with respect to the polishing composition described in the present disclosure.

[0034] In one or more embodiments, the polishing composition described in the present disclosure may include at least one (e.g., two or three) optional chelating agents. In some embodiments, the at least one optional chelating agent may be an amino-containing carboxylic acid (e.g., a polyaminopolycarboxylic acid) or a phosphonic acid. In some embodiments, the chelating agent is selected from the group consisting of ethylenediaminetetraacetic acid, iminodiacetic acid, N-hydroxyethyl-ethylenediaminetriacetic acid, nitrilotriacetic acid, diethylenetriaminepentaacetic acid, hydroxyethylethylenediaminetriacetic acid, triethylenetetraminehexaacetic acid, diaminocyclohexanetetraacetic acid, nitrilotrimethylphosphonic acid, ethylenediaminetetra(methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, diethylenetriaminepenta(methylenephosphonic acid), and combinations thereof. Without wishing to be bound by theory, it is believed to be surprising that including a chelating agent (e.g., those described above) in the polishing composition described in the present disclosure can significantly reduce or minimize defects observed on a semiconductor substrate (e.g., a copper wafer).

[0035] In some embodiments, the chelating agent is present in an amount of about 0.001 wt% or more (e.g., about 0.002 wt% or more, about 0.005 wt% or more, about 0.01 wt% or more, about 0.02 wt% or more, about 0.05 wt% or more, about 0.1 wt% or more, about 0.2 wt% or more, or about 0.5 wt% or more) to about 1 wt% or less (e.g., about 0.8 wt% or less, about 0.6 wt% or less, about 0.5 wt% or less, about 0.4 wt% or less, about 0.2 wt% or less, about 0.1 wt% or less, about 0.05 wt% or less, about 0.02 wt% or less, about 0.01 wt% or less, or about 0.005 wt% or less) based on the polishing composition described in the present disclosure.

[0036] The optional oxidizing agent may be added when diluting the concentrated slurry to form a POU slurry. The oxidizing agent is hydrogen peroxide, ammonium persulfate, silver nitrate (AgNO 3) Iron(III) nitrate or iron(III) chloride, peracid or per salt, 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, iron(III) nitrate, potassium permanganate, other inorganic or organic peroxides, and mixtures thereof may be selected. In one embodiment, the oxidizing agent is hydrogen peroxide.

[0037] In some embodiments, the oxidizing agent is present in an amount of about 0.05 wt% or more (e.g., about 0.1 wt% or more, about 0.2 wt% or more, about 0.4 wt% or more, about 0.5 wt% or more, about 1 wt% or more, about 1.5 wt% or more, about 2 wt% or more, about 2.5 wt% or more, about 3 wt% or more, about 3.5 wt% or more, about 4 wt% or more, or about 4.5 wt% or more) to about 5 wt% or less (e.g., about 4.5 wt% or less, about 4 wt% or less, about 3.5 wt% or less, about 3 wt% or less, about 2.5 wt% or less, about 2 wt% or less, about 1.5 wt% or less, about 1 wt% or less, about 0.5 wt% or less, or about 0.1 wt% or less) based on the polishing composition described in the present disclosure. In some embodiments, without wishing to be bound by theory, it is believed that the oxidizing agent can assist in the removal of the metal film by forming a metal complex with a chelating agent so as to be able to remove the metal in the CMP process. In some embodiments, without wishing to be bound by theory, it is believed that the metal complex formed between the metal film and the oxidizing agent can form a passive layer, and this passive layer can protect the metal from corrosion. In some embodiments, the oxidizing agent may reduce the shelf life of the polishing composition. In such embodiments, the oxidizing agent may be added to the polishing composition at the point-of-use immediately before polishing.

[0038] In some embodiments, the polishing composition described in the present disclosure may contain a solvent such as water (e.g., a primary solvent). In some embodiments, the solvent (e.g., water) may be present in an amount of about 20 wt% or more (e.g., about 25 wt% or more, about 30 wt% or more, about 35 wt% or more, about 40 wt% or more, about 45 wt% or more, about 50 wt% or more, about 55 wt% or more, about 60 wt% or more, about 65 wt% or more, about 70 wt% or more, about 75 wt% or more, about 80 wt% or more, about 85 wt% or more, about 90 wt% or more, about 92 wt% or more, about 94 wt% or more, about 95 wt% or more, or about 97 wt% or more) to about 99 wt% or less (e.g., about 98 wt% or less, about 96 wt% or less, about 94 wt% or less, about 92 wt% or less, about 90 wt% or less, about 85 wt% or less, about 80 wt% or less, about 75 wt% or less, about 70 wt% or less, or about 65 wt% or less) based on the polishing composition described in the present disclosure.

[0039] In one or more embodiments, an optional secondary solvent (e.g., an organic solvent) can be used in the polishing composition of the present disclosure (e.g., a POU polishing composition or a concentrated polishing composition), and the use of the secondary solvent can assist in dissolving the azole-containing rust inhibitor. In one or more embodiments, the secondary solvent can be one or more alcohols, alkylene glycols, or alkylene glycol ethers. In one or more embodiments, the secondary solvent includes one or more solvents selected from the group consisting of ethanol, 1-propanol, 2-propanol, n-butanol, propylene glycol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol propyl ether, and ethylene glycol.

[0040] In some embodiments, the secondary solvent may be present in an amount of about 0.0025 wt% or more (e.g., about 0.005 wt% or more, about 0.01 wt% or more, about 0.02 wt% or more, about 0.05 wt% or more, about 0.1 wt% or more, about 0.2 wt% or more, about 0.4 wt% or more, about 0.6 wt% or more, about 0.8 wt% or more, or about 1 wt% or more) to about 2 wt% or less (e.g., about 1.8 wt% or less, about 1.6 wt% or less, about 1.5 wt% or less, about 1.4 wt% or less, about 1.2 wt% or less, about 1 wt% or less, about 0.8 wt% or less, about 0.6 wt% or less, about 0.5 wt% or less, or about 0.1 wt% or less) based on the polishing composition described in the present disclosure.

[0041] In one or more embodiments, the polishing composition of the present disclosure comprises an organic solvent, a pH adjuster, a quaternary ammonium compound (e.g., a salt or hydroxide), an amine, an alkali base (e.g., an alkali hydroxide), a fluorine-containing compound, a silane (e.g., an alkoxysilane), an imine (e.g., an amidine such as 1,8-diazabicyclo[5.4.0]-7-undecene (DBU) and 1,5-diazabicyclo[4.3.0]nona-5-ene (DBN)), a salt (e.g., a halide salt or a metal salt), a polymer (e.g., a cationic or anionic polymer), a surfactant (e.g., a cationic surfactant, an anionic surfactant, or a nonionic surfactant), a plasticizer, an oxidizing agent (e.g., H 2 O 2) It may also be substantially free of one or more specific components such as a rust inhibitor (e.g., an azole rust inhibitor or a non-azole rust inhibitor), and / or a specific abrasive (e.g., a ceria abrasive, a nonionic abrasive, a surface-modified abrasive, or a negatively / positively charged abrasive). Examples of the halide salts that may be excluded from the polishing composition include alkali metal halides (e.g., sodium halide or potassium halide) or ammonium halides (e.g., ammonium chloride), which may be chlorides, bromides, or iodides. As used in the present disclosure, a component that is "substantially absent" from the polishing composition refers to a component that is not intentionally added to the polishing composition. In some embodiments, the polishing composition described in the present disclosure may have one or more of the above components that are substantially absent from the polishing composition at about 1000 ppm or less (e.g., about 500 ppm or less, about 250 ppm or less, about 100 ppm or less, about 50 ppm or less, about 10 ppm or less, or about 1 ppm or less). In some embodiments, the polishing composition described in the present disclosure may not contain any of one or more of the above components at all.

[0042] In one or more embodiments, the polishing composition described in the present disclosure has a ratio of the removal rate of silicon oxide (e.g., TEOS) to the removal rate of a barrier material (e.g., Ta, TaN) with respect to the removal rate of Cu, Co, or a low-k dielectric material (i.e., the removal rate selectivity) of about 3:1 or more (e.g., about 4:1 or more, about 5:1 or more, about 10:1 or more, about 25:1 or more, about 50:1 or more, about 60:1 or more, about 75:1 or more, about 100:1 or more, about 150:1 or more, about 200:1 or more, about 250:1 or more, or about 300:1 or more) to about 1000:1 or less (e.g., about 500:1 or less). In one or more embodiments, the above ratio may be applied when measuring the removal rate for polishing a blanket wafer or when measuring the removal rate for polishing a patterned wafer (e.g., a wafer including a conductive layer, a barrier layer, and / or dielectric layers).

[0043] In one or more embodiments, when a wafer is polished using the polishing composition according to the present disclosure, the total defect count on a wafer having a diameter of 12 inches (i.e., about 300 mm) (e.g., on the copper surface of the wafer) is 800 or less (e.g., 700 or less, 600 or less, 500 or less, 400 or less, 300 or less, 250 or less, 200 or less, 150 or less, 100 or less, or 50 or less). In one or more embodiments, the defects can result from scratching, organic residues, particle contamination (e.g., abrasive), and combinations thereof. Generally, the defects are counted using a laser scattering inspection system and analyzed and classified by examining an image of the polished wafer taken using a scanning electron microscope (SEM). In one or more embodiments, the defects to be counted are those having a size of about 100 nm or more.

[0044] The present disclosure also contemplates methods of using any of the above polishing compositions (e.g., concentrates or POU slurries). In the case of a concentrate, the method may include diluting the concentrate (e.g., by a factor of 2 or more) to form a POU slurry, and then contacting a surface that at least partially includes cobalt with the POU slurry. In some embodiments, an oxidizing agent may be added to the slurry before or after the dilution. In the case of a POU slurry, the method includes contacting a surface that at least partially includes cobalt with the slurry.

[0045] In one or more embodiments, the present disclosure features a polishing method that may include applying a polishing composition according to the present disclosure to a substrate (e.g., a wafer) having at least cobalt on its surface; and moving a pad in contact with the surface of the substrate relative to the substrate. In some embodiments, when the substrate includes at least one of silicon oxide and / or a barrier material (e.g., Ta, TaN), the method can remove at least a portion of these materials without substantially removing cobalt. The term "silicon oxide" as described in the present disclosure is expressly intended to include both undoped and doped silicon oxides. For example, in one or more embodiments, the silicon oxide may be doped with at least one dopant selected from carbon, nitrogen, oxygen, hydrogen, and any other known dopant for silicon oxide. Some examples of types of silicon oxide films include TEOS (tetraethyl orthosilicate), SiOC, SiOCN, SiOCH, SiOH, and SiON.

[0046] In some embodiments, the method of using the polishing composition described in the present disclosure may further include manufacturing a semiconductor device from the substrate treated with the polishing composition in one or more steps. For example, photolithography, ion implantation, dry / wet etching, plasma ashing, deposition (e.g., PVD, CVD, ALD, ECD), wafer mounting, dicing, packaging, and testing may be used to manufacture a semiconductor device from the substrate treated with the polishing composition described in the present disclosure.

[0047] The following specific examples should be construed as merely illustrative and not limiting in any way to the remainder of the present disclosure. Without further elaboration, it is believed that one skilled in the art can, based on the description herein, utilize the present invention to its fullest extent.

Examples

[0048] In these examples, polishing was performed on 200 mm wafers using an AMAT Mirra CMP polisher, a Fuji Spinning H804 pad, a downforce pressure of 1.5 psi, a platen head speed of 120 / 114 rpm, and a slurry flow rate of 175 mL / min.

[0049] The general compositions used in the following examples are shown in Table 1 below. Details of the differences between the tested compositions will be described in more detail when explaining each example.

[0050]

Table 1

[0051] Example 1 Table 2 below shows the removal rates for TEOS blanket wafers, Ta blanket wafers, Black Diamond 1 (BD-1) blanket wafers, and Black Diamond 2 (BD-2) blanket wafers when polished using Compositions 1-6. Compositions 1-6 contained the same components at the same concentrations except for the differences described below and the differences shown in Table 2. Composition 1 contained one type of polyalkoxylate low-k removal rate inhibitor (LK RRI; nonionic surfactant) and functioned as a control. As shown in Table 2, Compositions 2-6 each contained combinations of two different LK RRIs (i.e., alkoxylated diamine nonionic surfactant (LK RRI-1) and amphiphilic copolymer (LK RRI-2)) at various concentrations. The BD-1 and BD-2 blanket wafers are low-k dielectric materials (i.e., carbon-doped silicon oxide) coated on silicon wafers.

[0052] Surprisingly, the nonionic surfactant and the amphiphilic copolymer can be used as low-k removal rate inhibitors, and the combination of these two inhibitors (i.e., LK RRI-1 and LK RRI-2) showed more effectively suppressing the polishing rate than the LK RRI of the comparison target. Furthermore, as the concentration of LK RRI-1 in the combination of LK RRI-1 and LK RRI-2 increased, the data showed that the removal rate of the low-k dielectric material in the BD-1 blanket wafer and the BD-2 blanket wafer decreased much more significantly than the TEOS removal rate and the Ta removal rate, which indicates the influence of LK RRI-1 and LK RRI-2 on the low-k removal rate.

[0053]

Table 2

[0054] Example 2 Table 3 below shows the removal rates for Cu blanket wafers, TEOS blanket wafers, Ta blanket wafers, and BD-1 blanket wafers when polished using polishing compositions 7 - 14. Compositions 7 - 14 contained the same components at the same concentrations except for the differences described below and the differences shown in Table 3. Composition 7 used LK RRI and benzotriazole as copper rust inhibitors (CI-1) and functioned as a control. Compositions 8 - 14 contained a combination of two separate LK RRIs (LK RRI-1 and LK RRI-2) and a copper rust inhibitor selected from CI-1 (benzotriazole) and CI-3 - CI-5 (substituted benzotriazoles). Furthermore, in Compositions 8 - 14, as shown in Table 3, the concentration of the rust inhibitor was varied from 6× to 25×.

[0055] The combination of two separate LK RRIs (LK RRI-1 and LK RRI-2) and a copper corrosion inhibitor selected from CI-1 and CI-3 to CI-5 showed a TEOS polishing rate and a Ta polishing rate comparable to those achieved by Composition 7, as well as excellent Cu removal rate inhibition performance (see Compositions 8 to 14). That is, this result indicated that the low-k removal rate inhibitor and the copper corrosion inhibitor did not substantially affect the TEOS removal rate and the Ta removal rate. On the other hand, this result indicated that the copper removal rate could be significantly reduced by including substituted benzotriazole (see Compositions 10 to 14).

[0056]

Table 3

[0057] Example 3 Table 4 below shows the removal rates for Cu blanket wafers, Co blanket wafers, and BD blanket wafers and the count of defects on the Cu wafers when polished using polishing compositions 15 to 21. Compositions 15 to 21 contained the same components at the same concentrations except for the differences described below and the differences shown in Table 4. Composition 15 contained a combination of two separate LK RRIs (LK RRI-1 and LK RRI-2) and benzotriazole (CI-1) as a copper corrosion inhibitor. Composition 16 was compositionally the same as Composition 15, but the copper corrosion inhibitor used was alkylbenzotriazole (CI-5) instead of benzotriazole (CI-1). As a result of this change, the defects observed on the Cu wafers were significantly reduced.

[0058] Composition 17 contained a phosphoric acid-based anionic surfactant as a cobalt corrosion inhibitor (Co-CI) in addition to the copper corrosion inhibitor (CI-5). This addition significantly reduced the cobalt polishing rate, and surprisingly, significantly reduced the defects observed on the Cu wafers even though the amount of CI-5 used was half the amount used in Composition 16.

[0059] Compositions 18 - 21 surprisingly showed that the addition of a chelating agent (CA) can reduce the cobalt removal rate and the defects observed on the copper wafer. In particular, as a result of using a high concentration of an aminopolycarboxylic acid - based chelating agent CA - 1 in Composition 19, a very low cobalt removal rate and a better reduction of defects on the copper wafer were achieved. Compositions 20 and 21 are analogous to Compositions 18 and 19, but used a different, comparative chelating agent (CA - 2). CA - 2 is a sulfonic acid - based chelating agent and did not show the same ability to reduce defects on the Cu wafer at high concentrations as CA - 1 used in Composition 19.

[0060]

Table 4

[0061] Example 4 In this example, patterned copper coupons with cobalt liners were immersed in each of polishing compositions 22 - 24 at 60 °C for 5 minutes. Compositions 22 - 24 contained the same components (i.e., all of the components shown in Table 1) at the same concentration except for the differences described below and the differences shown in Table 5. After immersion, the resulting slurry was analyzed by ICP - MS to measure the concentration of cobalt ions etched away from the patterned coupons.

[0062] Table 5 below shows that the cobalt ion concentration in the polishing slurry decreased with the addition of the Co corrosion inhibitor (CoCI), indicating the protective ability of the Co corrosion inhibitor during polishing. Refer to the column "60°C SER Co ion concentration". Table 5 shows the electrochemical test data obtained by testing Cu or Co blanket coupons in a polishing slurry containing all of the components shown in Table 1 (except that Composition 22 did not contain a cobalt corrosion inhibitor), comparing the corrosion potential (Ecorr) and the current corresponding to the corrosion potential (Icorr) for cobalt and copper. Generally, a higher value of Ecorr or a lower value of Icorr indicates that the material of interest is better protected / passivated. Thus, it can be seen that Composition 24, which contains the highest amount of Co corrosion inhibitor, had the highest protection / passivation for cobalt. Furthermore, it has been shown that the addition of the Co corrosion inhibitor does not have much effect on the corrosion potential of copper.

[0063]

Table 5

[0064] Example 5 Table 6 below shows the removal rates for Cu blanket wafers, TEOS blanket wafers, TaN blanket wafers, Black Diamond 1 (BD-1) blanket wafers, and ultra low-k (ULK) blanket wafers when polished using Compositions 25 - 29. Compositions 25 - 29 contained the same components at the same concentrations except for the differences described below and the differences shown in Table 4. Specifically, Composition 25 did not contain a low-k removal rate inhibitor, Composition 26 contained one type of polyalkoxylate low-k removal rate inhibitor (LK RRI), Compositions 27 and 28 contained only one of LK RRI-1 and LK RRI-2, and Composition 29 contained a combination of two separate LK RRIs (i.e., an alkoxylated diamine nonionic surfactant (LK RRI-1) and an amphiphilic copolymer (LK RRI-2)).

[0065] Surprisingly, these results show that the nonionic surfactants (LK RRI and LK RRI-1) and the amphiphilic copolymer (LK RRI-2) can be used as low-k removal rate inhibitors, and that a combination of both LK RRI-1 and LK RRI-2 more effectively suppresses the polishing rate of BD-1 than the comparative LK RRI or LK RRI-1 and LK RRI-2 used individually.

[0066] [Table 6]

[0067] Although only a few exemplary embodiments have been described in detail above, those skilled in the art will readily understand that many modifications are possible in these exemplary embodiments without departing substantially from the present invention. Accordingly, all such modifications are also intended to be included within the scope of the present disclosure as defined by the following claims. [1] A polishing agent; A pH adjuster; An agent for increasing the barrier film removal rate; A first low-k removal rate inhibitor; A second low-k removal rate inhibitor different from the first low-k removal rate inhibitor; An azole-containing rust inhibitor; and A cobalt rust inhibitor A polishing composition comprising the same. [2] The polishing composition according to [1] above, wherein the polishing agent is selected from the group consisting of alumina; silica; titania; ceria; zirconia; co-formed products of alumina, silica, titania, ceria, or zirconia; coated polishing agents; surface-modified polishing agents; and mixtures thereof. [3] The polishing composition according to [1] above, wherein the polishing agent is present in the composition in an amount of about 0.1 wt% to about 50 wt%. [4] The polishing composition according to [1] above, wherein the barrier film removal rate increasing agent is an organic acid or a salt thereof selected from the group consisting of 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, potassium acetate, potassium citrate, aminoacetic acid, phenoxyacetic acid, bicine, diglycolic acid, glyceric acid, tricine, alanine, histidine, valine, phenylalanine, proline, glutamine, aspartic acid, glutamic acid, arginine, lysine, tyrosine, benzoic acid, 1,2-ethanedisulfonic acid, 4-amino-3-hydroxy-1-naphthalenesulfonic acid, 8-hydroxyquinoline-5-sulfonic acid, aminomethanesulfonic acid, benzenesulfonic acid, hydroxylamine O-sulfonic acid, methanesulfonic acid, m-xylene-4-sulfonic acid, poly(4-styrenesulfonic acid), polyanetholesulfonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, ethylphosphoric acid, cyanoethylphosphoric acid, phenylphosphoric acid, vinylphosphoric acid, poly(vinylphosphonic acid), 1-hydroxyethane-1,1-diphosphonic acid, nitrilotri(methylphosphonic acid), diethylenetriamine pentakis(methylphosphonic acid), N,N,N',N'-ethylenediaminetetrakis(methylenephosphonic acid), n-hexylphosphonic acid, benzylphosphonic acid, phenylphosphonic acid, salts thereof, and mixtures thereof. [5] The polishing composition according to [1] above, wherein the barrier film removal rate increasing agent is present in an amount of about 0.02 wt% to about 4 wt% based on the composition. [6] The polishing composition according to [1] above, wherein the first low-k removal rate inhibitor is a nonionic surfactant. [7] The composition according to [6] above, wherein the nonionic surfactant is selected from the group consisting of alcohol alkoxylates, alkylphenol alkoxylates, tristyrylphenol alkoxylates, sorbitan ester alkoxylates, polyalkoxylates, polyalkylene oxide block copolymers, tetrahydroxy oligomers, alkoxylated diamines, and mixtures thereof. [8] The polishing composition according to [1], wherein the first low-k removal rate inhibitor is present in an amount of about 0.005 wt% to about 5 wt% based on the composition. [9] The polishing composition according to [1], wherein the second low-k removal rate inhibitor is an amphiphilic copolymer.

[10] The polishing composition according to [1], wherein the amphiphilic copolymer is a styrene-maleic anhydride copolymer.

[11] The polishing composition according to [1], wherein the second low-k removal rate inhibitor is present in an amount of about 0.005 wt% to about 5 wt% based on the composition.

[12] The polishing composition according to [1], wherein the azole-containing rust inhibitor is selected from the group consisting of triazole, tetrazole, benzotriazole, tolyltriazole, ethylbenzotriazole, propylbenzotriazole, butylbenzotriazole, pentylbenzotriazole, hexylbenzotriazole, dimethylbenzotriazole, chlorobenzotriazole, dichlorobenzotriazole, chloromethylbenzotriazole, chloroethylbenzotriazole, phenylbenzotriazole, benzylbenzotriazole, aminotriazole, aminobenzimidazole, pyrazole, imidazole, aminotetrazole, and mixtures thereof.

[13] The polishing composition according to [1], wherein the azole-containing rust inhibitor is present in an amount of about 0.0001 wt% to about 1 wt% based on the composition.

[14] The polishing composition according to [1], wherein the cobalt rust inhibitor is an anionic surfactant.

[15] The anionic surfactant is one or more phosphate groups and one or more of the following groups: an alkyl chain having 6 to 24 carbon atoms, 0 to 18 ethylene oxide groups, or combinations thereof, The polishing composition according to

[14] .

[16] The polishing composition according to [1], wherein the cobalt rust inhibitor is present in an amount of about 0.0001 wt% to about 1 wt% based on the composition.

[17] The polishing composition according to [1], wherein the pH adjuster is selected from the group consisting of ammonium hydroxide, sodium hydroxide, potassium hydroxide, cerium 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.

[18] The polishing composition according to [1], wherein the pH adjuster is present in an amount of about 0.05 wt% to about 10 wt% based on the composition.

[19] The polishing composition according to [1], further comprising a chelating agent selected from the group consisting of ethylenediaminetetraacetic acid, iminodiacetic acid, N-hydroxyethyl-ethylenediaminetriacetic acid, nitrilotriacetic acid, diethylenetriaminepentaacetic acid, hydroxyethylethylenediaminetriacetic acid, triethylenetetraminehexaacetic acid, diaminocyclohexanetetraacetic acid, nitrilotrimethylphosphonic acid, ethylenediaminetetra(methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, diethylenetriaminepenta(methylenephosphonic acid), and combinations thereof.

[20] The polishing composition according to

[19] , wherein the chelating agent is present in an amount of about 0.001 wt% to about 1 wt% based on the composition.

[21] The composition is the abrasive in an amount of about 0.1 wt% to about 50 wt% based on the composition; The pH adjuster in an amount of about 0.05 wt% to about 10 wt% based on the composition; The barrier film removal rate enhancer in an amount of about 0.02 wt% to about 4 wt% based on the composition; The first low-k removal rate inhibitor in an amount of about 0.005 wt% to about 5 wt% based on the composition; The second low-k removal rate inhibitor in an amount of about 0.005 wt% to about 5 wt% based on the composition; The azole-containing rust inhibitor in an amount of about 0.0001 wt% to about 1 wt% based on the composition; and The cobalt rust inhibitor in an amount of about 0.0001 wt% to about 1 wt% based on the composition; The polishing composition according to [1], comprising the above.

[22] The polishing composition according to [1], wherein the pH of the composition is about 7 to about 14.

[23] A polishing agent; A pH adjuster; An organic acid or its salt; A nonionic surfactant; An amphiphilic copolymer; An azole-containing rust inhibitor; and An anionic surfactant A polishing composition comprising the above.

[24] A step of applying the polishing composition according to [1] to the surface of a substrate, wherein the surface contains cobalt; and, A step of moving the pad relative to the substrate by bringing the pad into contact with the surface of the substrate, A method for polishing a substrate, comprising the above.

Claims

1. Abrasives; pH adjuster; Barrier film removal rate enhancer; A first low-k removal rate inhibitor; a second low-k removal rate inhibitor different from the first low-k removal rate inhibitor; An azole-containing rust inhibitor; and Cobalt Rust Inhibitor Including, the first low-k removal rate inhibitor is a nonionic surfactant; the second low-k removal rate inhibitor is an amphiphilic copolymer; Polishing composition.

2. 2. The polishing composition of claim 1, wherein the abrasive is selected from the group consisting of alumina; silica; titania; ceria; zirconia; co-formed products of alumina, silica, titania, ceria, or zirconia; coated abrasives; surface-modified abrasives; and mixtures thereof.

3. 10. The polishing composition of claim 1, wherein the abrasive is present in an amount of 0.1% to 50% by weight of the composition.

4. The barrier film removal rate increasing agent is selected from the group consisting of 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, potassium acetate, potassium citrate, aminoacetic acid, phenoxyacetic acid, bicine, diglycolic acid, glyceric acid, tricine, alanine, histidine, valine, phenylalanine, proline, glutamine, aspartic acid, glutamic acid, arginine, lysine, tyrosine, benzoic acid, 1,2-ethanedisulfonic acid, 4-amino-3-hydroxy-1-naphthalenesulfonic acid, 8-hydroxyquinoline-5-sulfonic acid, aminomethanesulfonic acid, benzenesulfonic acid, hydroxylamine O-sulfonic acid, methanesulfonic acid, benzoic ...

2. The polishing composition of claim 1, wherein the organic acid or salt thereof is selected from the group consisting of: sulfonic acid, m-xylene-4-sulfonic acid, poly(4-styrenesulfonic acid), polyanetholesulfonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, ethyl phosphate, cyanoethyl phosphate, phenyl phosphate, vinyl phosphate, poly(vinyl phosphonic acid), 1-hydroxyethane-1,1-diphosphonic acid, nitrile tri(methylphosphonic acid), diethylenetriaminepentakis(methylphosphonic acid), N,N,N',N'-ethylenediaminetetrakis(methylenephosphonic acid), n-hexylphosphonic acid, benzylphosphonic acid, phenylphosphonic acid, salts thereof, and mixtures thereof.

5. 2. The polishing composition of claim 1, wherein the barrier film removal rate enhancing agent is present in an amount of 0.02% to 4% by weight of the composition.

6. 2. The polishing composition of claim 1, wherein the nonionic surfactant is selected from the group consisting of alcohol alkoxylates, alkylphenol alkoxylates, tristyrylphenol alkoxylates, sorbitan ester alkoxylates, polyalkoxylates, polyalkylene oxide block copolymers, tetrahydroxy oligomers, alkoxylated diamines, and mixtures thereof.

7. 2. The polishing composition of claim 1, wherein the first low-k removal rate inhibitor is present in an amount of 0.005% to 5% by weight of the composition.

8. 2. The polishing composition of claim 1, wherein the amphiphilic copolymer is a styrene-maleic anhydride copolymer.

9. 2. The polishing composition of claim 1, wherein the second low-k removal rate inhibitor is present in an amount of 0.005% to 5% by weight of the composition.

10. 2. The polishing composition of claim 1, wherein the azole-containing rust inhibitor is selected from the group consisting of triazole, tetrazole, benzotriazole, tolyltriazole, ethylbenzotriazole, propylbenzotriazole, butylbenzotriazole, pentylbenzotriazole, hexylbenzotriazole, dimethylbenzotriazole, chlorobenzotriazole, dichlorobenzotriazole, chloromethylbenzotriazole, chloroethylbenzotriazole, phenylbenzotriazole, benzylbenzotriazole, aminotriazole, aminobenzimidazole, pyrazole, imidazole, aminotetrazole, and mixtures thereof.

11. 2. The polishing composition of claim 1, wherein the azole-containing rust inhibitor is present in an amount of 0.0001% to 1% by weight of the composition.

12. The polishing composition of claim 1 , wherein the cobalt rust inhibitor is an anionic surfactant.

13. The anionic surfactant is one or more phosphate groups and one or more of the following groups: an alkyl chain containing 6 to 24 carbon atoms, 0 to 18 ethylene oxide groups, or a combination thereof; The polishing composition of claim 12 , comprising:

14. 2. The polishing composition of claim 1, wherein the cobalt rust inhibitor is present in an amount of 0.0001% to 1% by weight of the composition.

15. 2. The polishing composition of claim 1, wherein the pH adjuster is selected from the group consisting of ammonium hydroxide, sodium hydroxide, potassium hydroxide, cerium 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.

16. 2. The polishing composition of claim 1, wherein the pH adjuster is present in an amount of 0.05% to 10% by weight of the composition.

17. 2. The polishing composition of claim 1, further comprising a chelating agent selected from the group consisting of ethylenediaminetetraacetic acid, iminodiacetic acid, N-hydroxyethyl-ethylenediaminetriacetic acid, nitrilotriacetic acid, diethylenetriaminepentaacetic acid, hydroxyethylethylenediaminetriacetic acid, triethylenetetraminehexaacetic acid, diaminocyclohexanetetraacetic acid, nitrilotrimethylphosphonic acid, ethylenediaminetetra(methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, diethylenetriaminepenta(methylenephosphonic acid), and combinations thereof.

18. 18. The polishing composition of claim 17, wherein the chelating agent is present in an amount of 0.001% to 1% by weight of the composition.

19. The composition, said abrasive in an amount of 0.1% to 50% by weight of said composition; said pH adjuster in an amount of 0.05% to 10% by weight of said composition; said barrier film removal rate enhancing agent in an amount of 0.02% to 4% by weight of said composition; the first low-k removal rate inhibitor in an amount of 0.005% to 5% by weight of the composition; the second low-k removal rate inhibitor in an amount of 0.005% to 5% by weight of the composition; the azole-containing rust inhibitor in an amount of 0.0001% to 1% by weight of the composition; and said cobalt rust inhibitor in an amount of 0.0001% to 1% by weight of said composition; The polishing composition of claim 1 , comprising:

20. 2. The polishing composition of claim 1, wherein the pH of the composition is from 7 to 14.

21. Abrasives; pH adjuster; Organic acids or their salts; Nonionic surfactants; Amphiphilic copolymers; An azole-containing rust inhibitor; and Anionic Surfactants Including, The polishing composition, wherein the amphiphilic copolymer is present in an amount of 0.1% to 5% by weight of the polishing composition.

22. applying the polishing composition of claim 1 to a surface of a substrate, the surface comprising cobalt; and contacting a pad with the surface of the substrate and moving the pad relative to the substrate; 16. A method for polishing a substrate, comprising:

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