A polishing composition and its application

Abstract

The present application belongs to the field of chemical mechanical polishing technology, and specifically relates to a polishing composition and its application. The present application can significantly improve the polishing effect by coordinating the components in the polishing composition, especially the coordination of the thiopyridine compound and the anionic polymer, and effectively avoid the occurrence of dishing while achieving high-speed removal of copper. In the present application, the polishing composition can oxidize copper into CuO / Cu2O, and the "nitrogen and sulfur" elements carried by the thiopyridine compound can form a strong coordination with copper and be adsorbed on the surface of the oxidized copper film. The anionic polymer can be adsorbed on the surface of the copper film through the action of electric charge. The above two substances are adsorbed on the surface of the copper film by different mechanisms, respectively, to produce a reinforcement effect, which can resist the destructive force of the mechanical force on the copper film during the polishing process, thereby achieving the effect of suppressing the occurrence of dishing.

Description

Technical Field

[0001] The present application belongs to the technical field of chemical mechanical polishing, and specifically relates to a polishing composition and its application. Background Art

[0002] The demand for smaller chips and higher computing / storage capabilities can be achieved by reducing line width and increasing the number of stacked layers, which requires good flatness between chip layers. Currently, the only technology that can achieve good interlayer flatness in chip manufacturing is chemical mechanical polishing (CMP).

[0003] Copper has been widely used as a wiring metal in integrated circuit manufacturing, replacing aluminum. This is primarily due to the advantages of Cu wiring, such as lower resistivity and RC delay, as well as better resistance to electromigration. The copper wiring layer is produced using a dual damascene process. The general steps are as follows: trenches are etched in the dielectric layer; the trenches are then filled with a copper barrier layer, such as Ta / TaN. To improve adhesion between the copper and the trenches, a copper seed layer is deposited; finally, the trenches are filled with copper using electroplating; and finally, the copper wiring layer is subjected to CMP.

[0004] The CMP process for copper wiring layers consists of three main steps: the first involves using a copper polishing slurry at high polishing pressure to quickly remove a large amount of copper; the second step involves using a copper polishing slurry at low polishing pressure to remove the remaining copper and stop at the barrier layer; and the third step involves using a barrier polishing slurry to remove the barrier metal, dielectric layer, and a small amount of copper. The second polishing step must stop at the barrier layer while minimizing the depth of the copper wiring within the dielectric trench. This requires the copper polishing slurry to have a low removal rate for the dielectric layer—in other words, a high selectivity for the dielectric layer over copper. This characteristic of the copper polishing slurry can cause depressions in the surface between the dielectric and copper layers after the second polishing step. Another type of depression arises from over-polishing of the dielectric layer between the wiring metal layers by CMP. The resulting depressions reduce the width of the copper wiring and increase its resistivity.

[0005] To prevent dishing, existing patents disclose chemical mechanical polishing compositions that achieve high-speed copper removal, low surface dishing, and good intra-wafer non-uniformity after polishing. However, the ability to suppress dishing remains to be further improved. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present application is to overcome the defects of the polishing liquid in the prior art, such as the need to further improve the polishing effect, thereby providing a polishing composition and its application.

[0007] To this end, this application provides the following technical solutions:

[0008] According to one aspect of the present application, a polishing composition is provided, comprising abrasive particles, an oxidizing agent, a complexing agent, a corrosion inhibitor, a thiopyridine compound, a pH adjuster, an anionic polymer, and deionized water, wherein, based on the total mass of the polishing composition, the mass percentage of the thiopyridine compound is 0.001 wt%-0.1 wt%; the mass percentage of the anionic polymer is 0.001%-0.1 wt%.

[0009] As an example, the amount of the thiopyridine compound added can be 0.001 wt%, 0.003 wt%, 0.005 wt%, 0.008 wt%, 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, 0.1 wt% of the mass of the polishing composition, or any range thereof. As an example, the amount of the anionic polymer added can be 0.001 wt%, 0.003 wt%, 0.005 wt%, 0.008 wt%, 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, 0.1 wt% of the mass of the polishing composition, or any range thereof.

[0010] In the present application, by the coordination between the components in the polishing composition, especially the coordination between the thiopyridine compound and the anionic polymer, the polishing effect can be significantly improved, while ensuring the removal rate of copper, the occurrence of depression can be avoided to the greatest extent. In the present application, the polishing composition can oxidize copper into CuO / Cu2O, and the "nitrogen and sulfur" elements carried by the thiopyridine compound can form a strong coordination with copper and be adsorbed on the surface of the oxidized copper film. The anionic polymer can be adsorbed on the surface of the copper film through the action of charge. The above two substances are adsorbed on the surface of the copper film by different mechanisms, respectively, to produce a reinforcing effect, which can resist the destructive force of the mechanical force on the copper film during the polishing process, thereby achieving the effect of significantly suppressing the occurrence of dishing depression. Due to the solubility of this type of substance, the content of the thiopyridine compound should not be too high, and if the addition amount is too low, the effect described in the present application cannot be achieved. The content of the anionic polymer should not be too high, and if the addition amount is too high, the copper removal rate will be too low, and if the addition amount is too low, the effect described in the present application cannot be achieved.

[0011] In some optional embodiments, the polishing composition includes the following components in percentage by weight: 0.01 wt%-0.5 wt% of abrasive particles, 0.1 wt%-5 wt% of an oxidizing agent, 0.1 wt%-5 wt% of a complexing agent, 0.01 wt%-0.5 wt% of a corrosion inhibitor, 0.001 wt%-0.1 wt% of a thiopyridine compound, 0.01 wt%-1 wt% of a pH adjuster, 0.001%-0.1 wt% of an anionic polymer, and the balance is deionized water.

[0012] In some optional embodiments, the thiopyridine compound includes at least one of (4-thiopyridine)acetic acid, 3-(2-pyridyldithio)propionic acid, pyridine-2-thioamide, 4-pyridinethioacetic acid hydrochloride, pyridine-3-thioamide, 2,6-dichloropyridine-4-thioamide, 2-pyridinedithiocarbamate, 2-ethylpyridine-4-thioformamide, 2,2'-dithiodipyridine, 3-(methylthio)pyridine (CAS: 18794-33-7), 2-methylthiopyridine, and 4,4'-dithiobipyridine; optionally, the thiopyridine compound includes (4-thiopyridine)acetic acid and 3-(methylthio)pyridine.

[0013] In some optional embodiments, the anionic polymer includes at least one of polyacrylic acid, acrylic acid-acrylate copolymer, anionic polyacrylamide, alkyl sulfonic acid and salts thereof, alkylbenzenesulfonic acid and salts thereof, alkyl sulfuric acid and salts thereof, alkylphenol polyoxyethylene ether sulfuric acid and salts thereof, alkyl ether polyoxyethylene ether sulfuric acid and salts thereof, alkylphenol polyoxyethylene ether phosphoric acid and salts thereof, and alkyl ether polyoxyethylene ether phosphoric acid and salts thereof;

[0014] In some alternative embodiments, the number average molecular weight of the anionic polymer is 200-1,000,000, alternatively 200-100,000. As an example, the number average molecular weight of the anionic polymer can be 200, 1,000, 5,000, 8,000, 10,000, 13,000, 15,000, 20,000, 30,000, 50,000, 70,000, 90,000, 100,000, 150,000, 200,000, 250,000, 300,000, 350,000, 400,000, 450,000, 500,000, 1,000,000, or within the range of any of the above values. If the molecular weight of the anionic polymer is too low, the ability of the polymer to suppress depressions weakens, and if the molecular weight is too high, it is difficult to disperse well in water.

[0015] In some optional embodiments, the abrasive particles include at least one of silicon oxide particles, zirconium oxide particles, cerium oxide particles, aluminum oxide particles, and silicon carbide particles; optionally, the abrasive particles include silicon oxide particles; further optionally, the silicon oxide particles are silica sols prepared by any one of the elemental silicon method, ion exchange method, and sol-gel method, and are optionally ion exchange silica sols.

[0016] In this application, silicon oxide particles are softer than aluminum oxide particles, have fewer polishing defects, and are more stable than cerium oxide and silicon carbide particles. The silica sol prepared by the ion exchange method is softer and free of silicon impurities than the elemental silicon method, and has a cost advantage over the sol-gel method. There are no specific restrictions on the specific preparation method of the abrasive particles. The specific preparation method can refer to existing technologies, or the corresponding abrasive can be purchased directly from the market.

[0017] In some optional embodiments, the silicon oxide particles are spherical particles, or non-spherical particles with an association degree of 2-4, optionally spherical particles.

[0018] In this application, the term "association" refers to the physical bonding of multiple abrasive particles during the preparation process, and "association degree" refers to the number of physically bonded abrasive particles. The degree of association can be determined by taking TEM images of the abrasive particle morphology. Compared to highly associated particles, spherical particles tend to achieve higher polishing rates.

[0019] In some optional embodiments, the D50 size of the abrasive particles is 10-300 nm, optionally 40-120 nm. In the present application, the D50 size of the abrasive particles can be obtained by dynamic light scattering.

[0020] As an example, the mass percentage of the abrasive particles in the polishing composition can be 0.01 wt%, 0.05 wt%, 0.1 wt%, 0.15 wt%, 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.35 wt%, 0.4 wt%, 0.45 wt%, 0.5 wt%, or any range thereof; the D50 size of the abrasive particles can be: 20 nm, 50 nm, 75 nm, 100 nm, 120 nm, 150 nm, 180 nm, 200 nm, 230 nm, 250 nm, 270 nm, 285 nm, 300 nm, preferably 40-120 nm. In the present application, if the size of the abrasive particles is too small, the polishing rate will be affected and it will be difficult to clean after polishing. If the size is too large, polishing defects will easily occur.

[0021] In some optional embodiments, the oxidizing agent includes hydrogen peroxide. As an example, the mass percentage of the oxidizing agent in the polishing composition can be 0.1wt%, 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, or within a range consisting of any of the above values; in the present application, the oxidizing agent hydrogen peroxide can first oxidize copper into CuO / Cu2O, forming a softened copper oxide film, which can be removed by subsequent mechanical action and complexation with a complexing agent. If too little hydrogen peroxide is added, the copper removal rate will be affected, and the surface roughness of the copper after polishing will increase. If the amount added is too high, the oxide film formed on the copper surface will be too dense, which is not conducive to polishing and will also inhibit the copper removal rate.

[0022] In some optional embodiments, the complexing agent includes at least one of glycine, malonic acid, citric acid, oxalic acid, valine, alanine, threonine, ethylenediaminetetraacetic acid, disodium ethylenediaminetetraacetic acid, dipotassium ethylenediaminetetraacetic acid, cyanoacetic acid, ethylenediaminetetramethylenephosphonic acid, sodium ethylenediaminetetramethylenephosphate, and aminotrimethylenephosphonic acid; optionally, the complexing agent includes at least one of glycine, valine or ethylenediaminetetraacetic acid, more optionally, the complexing agent includes valine or glycine.

[0023] As an example, the mass percentage of the complexing agent in the polishing composition can be 0.1wt%, 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, 5wt%, or within the range of any of the above values. The addition of a complexing agent to the polishing composition is beneficial for complexing free copper ions in the polishing solution and promoting the removal of copper, but excessive addition of a complexing agent will increase the roughness of the polished surface, while excessive addition will affect the removal rate of copper. In the present application, the removal rate of copper can be further improved by optimizing the complexing agent.

[0024] In some optional embodiments, the corrosion inhibitor includes at least one of aspartic acid, glutamic acid, cysteine, tetrazole, 2-aminopyrrole, pyrazole, imidazole, 1,2,4-triazole, 3-amino-1,2,4-triazole, benzotriazole, cytosine, uracil, 2-methyl-4-isothiazolinetrione (CAS: 2682-20-4, methylisothiazolinone) and 3,5-diaminotriazole; optionally, the corrosion inhibitor includes at least one of aspartic acid, 1,2,4-triazole and 2-methyl-4-isothiazolinetrione.

[0025] As an example, the mass percentage of the corrosion inhibitor in the polishing composition can be 0.01 wt%, 0.02 wt%, 0.04 wt%, 0.06 wt%, 0.08 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, or any range thereof. The addition of the corrosion inhibitor to the polishing composition can form a protective film on the copper surface, reducing the roughness of the copper surface after polishing. Excessive addition can reduce the copper removal rate, while too little addition cannot effectively protect the copper surface from chemical corrosion.

[0026] In some optional embodiments, the pH adjuster includes at least one of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, ethanolamine, diethanolamine, triethanolamine, aniline, potassium hydroxide, sodium hydroxide, guanidine compounds, and alkali metal alkoxides; alternatively, the pH adjuster includes at least one of tetramethylammonium hydroxide, ethanolamine, potassium hydroxide, and guanidine carbonate, and more alternatively, includes at least one of tetramethylammonium hydroxide, ethanolamine, and potassium hydroxide;

[0027] In some alternative embodiments, the pH of the polishing composition is 5-9.

[0028] In the present application, the amount of the pH regulator added is associated with the pH of the polishing composition. As an example, the mass percentage of the pH regulator in the polishing composition can be 0.01wt%, 0.03wt%, 0.05wt%, 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, or within the range of any of the above values, as long as the pH of the polishing composition is within the above-mentioned limited range. In the present application, a pH regulator that has no effect on the copper removal rate is preferred. If the system pH is too low, copper corrosion will be aggravated, and if it is too high, the copper removal rate will be reduced.

[0029] In the present application, the preparation method of the polishing composition is conventional in the field. For example, the abrasive particles, the complexing agent, the corrosion inhibitor, the thiopyridine compound, the anionic polymer and water can be mixed first, the pH of the system can be adjusted using a pH adjuster (the pH of the system can also be adjusted after adding an oxidizing agent), and then the oxidizing agent can be added to obtain the polishing composition.

[0030] It should be noted that in order to reduce the experimental error caused by the decomposition of the oxidant (hydrogen peroxide) over time, the samples were used within 8 hours after preparation.

[0031] According to another aspect of the present application, there is provided a use of the polishing composition described above in chemical mechanical polishing, optionally, in chemical mechanical polishing of copper interconnect structures in integrated circuit manufacturing.

[0032] In the present application, the specific application method and operating parameters of the polishing composition in the chemical mechanical polishing of copper interconnect structures in integrated circuit manufacturing are conventional in the field and are not specifically limited in the present application.

[0033] The technical solution of this application has the following advantages:

[0034] The polishing composition provided by the present application includes abrasive particles, an oxidant, a complexing agent, a corrosion inhibitor, a thiopyridine compound, a pH regulator, an anionic polymer and deionized water, wherein the mass percentage of the thiopyridine compound is 0.001wt%-0.1wt% based on the total mass of the polishing composition; the mass percentage of the anionic polymer is 0.001%-0.1wt%. The present application can significantly improve the polishing effect by coordinating the components in the polishing composition, especially the thiopyridine compound and the anionic polymer, while achieving high-speed removal of copper and effectively avoiding the occurrence of dishing. The polishing composition of the present application can oxidize copper into CuO / Cu2O, and the "nitrogen and sulfur" elements carried by the thiopyridine compound can form strong coordination with copper and be adsorbed on the surface of the oxidized copper film. The anionic polymer can be adsorbed on the surface of the copper film by charge action. The above two substances are adsorbed on the surface of the copper film by different mechanisms, respectively, to produce a reinforcing effect, which can resist the destructive force of the mechanical force on the copper film during the polishing process, thereby achieving the effect of suppressing the occurrence of dishing.

[0035] The application of the polishing composition provided in this application has the same advantages as the above-mentioned polishing composition due to the use of the polishing composition provided in this application, which will not be described in detail here.

[0036] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. DETAILED DESCRIPTION

[0037] The following examples are provided to further better understand the present application, but are not limited to the best implementation mode described herein, and do not limit the content and protection scope of the present application. Any product identical or similar to the present application obtained by anyone under the inspiration of the present application or by combining the features of the present application with other prior arts shall fall within the scope of protection of the present application.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "including" and "having" and any variations thereof in this application text are intended to cover non-exclusive inclusions.

[0039] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0040] The "range" disclosed in this application is defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The range defined in this way can be inclusive or exclusive of the end values ​​and can be arbitrarily combined, i.e., any lower limit can be combined with any upper limit to form a range. In this application, unless otherwise specified, the numerical range "ab" represents an abbreviation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed herein, and "0-5" is just an abbreviation of these numerical combinations. In addition, when stating that a certain parameter is an integer ≥2, it is equivalent to disclosing that the parameter can be, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0041] In the description of the embodiments of the present application, the term "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0042] In the description of the embodiments of the present application, the term "at least one" refers to one or more than two (including two).

[0043] Unless otherwise specified, all steps of the present application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), indicating that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0044] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in this field can be used. If the manufacturer of the reagents or instruments is not specified, they are all commercially available conventional reagents.

[0045] The present application is described below with reference to specific embodiments. It should be noted that these embodiments are merely illustrative and do not limit the present application in any way.

[0046] Example 1-Example 10

[0047] This embodiment provides a polishing composition. The composition and amount of each component in the formula are shown in Table 1. The oxidizing agent is hydrogen peroxide, and the balance is deionized water. The preparation method is as follows: first, abrasive particles, a complexing agent, a corrosion inhibitor, a thiopyridine compound, an anionic polymer and water are mixed, the oxidizing agent is added, and the pH of the system is adjusted to 7.2 using potassium hydroxide as a pH adjuster;

[0048] The silicon dioxide abrasive particles in this embodiment are spherical particles and are commercially available.

[0049] Example 11

[0050] This embodiment provides a polishing composition. Compared with Example 1, the polishing composition has the following difference: the abrasive particles are non-spherical silicon oxide particles with an association degree of 3.

[0051] Example 12

[0052] This embodiment provides a polishing composition, which is different from that of Example 1 in that the size of the abrasive particles is 200 nm.

[0053] Example 13

[0054] This embodiment provides a polishing composition, which is different from Example 1 in that the pH value of the final product is 5.

[0055] Example 14

[0056] This embodiment provides a polishing composition, which is different from Example 1 in that the pH value of the final product is 9.

[0057] Comparative Example 1-Comparative Example 3

[0058] This comparative example provides a polishing composition, which is different from Example 1 in that the specific composition is different, as shown in Table 1.

[0059] Comparative Example 4

[0060] This comparative example provides a polishing composition that does not contain an oxidizing agent compared to Example 1.

[0061] Comparative Example 5

[0062] This comparative example provides a polishing composition having the following composition: based on the total mass of the polishing composition, the composition comprises 0.3 wt % of silica abrasive particles, 0.005 wt % of polymer 8 arm-PEG-OH, and the structural formula of the polymer is: , R2 is , p=50, n=4, the content of the complexing agent alanine is 1wt%, the content of the corrosion inhibitor 1,2,4-triazole is 0.08wt%, the components are mixed evenly, the balance in the formula is supplemented with deionized water, and potassium hydroxide is used to adjust the pH to 7.

[0063] Table 1

[0064]

[0065] Note: “ / ” in the table means that the component is not included.

[0066] Test Case

[0067] 1. Evaluation of polishing rate

[0068] During the polishing rate test, the instruments and parameters used for copper polishing are as follows:

[0069] Table 2

[0070]

[0071] The copper wafer used for polishing consists of a 50,000Å copper film electroplated on a 500µm single-crystal silicon substrate. The copper wafer measures 12 inches in size. Starting from zero, a four-probe conductivity meter is used to measure the conductivity of selected points on the copper wafer every 1cm in the positive and negative directions, for a total of 28 points. The thickness of the copper wafer is then calculated. The difference in thickness before and after polishing, divided by the polishing time, is the copper polishing rate.

[0072] 2. Evaluation of polishing depressions

[0073] Preparation of polishing wafers: First, trenches are etched in the silicon oxide layer with a width of 100μm, a depth of 500nm, and a spacing of 100μm. A 30nm thick TaN film is deposited on the patterned wafer by sputtering, followed by a 50nm thick copper film by sputtering, and finally a 10,000Å thick copper film is deposited by electroplating. A test pattern is designed with a copper line width of 100μm, a silicon oxide line width of 100μm, and a line density of 50% (100 / 100). Similarly, a (10 / 90) test pattern is produced. Polishing wafers can be manufactured by CMP consumables manufacturers.

[0074] Polishing conditions: Polishing pressure is 2.7 psi, rotation speed is 77 / 71 rpm. When there is 2500Å copper film remaining on the wafer (the polishing machine has its own endpoint detection), the polishing pressure is changed to 1.2 psi, and the rotation speed is maintained at 77 / 71 rpm. When no copper film is detected on the wafer, over-polishing is performed for 10 seconds, and polishing is completed.

[0075] The test method for pattern wafer concavity is to use a step profiler to measure in the order of dielectric layer-copper line concavity-dielectric layer. The height difference between the dielectric layer surface and the lowest point of the concavity is the concavity.

[0076] The specific test results are shown in the table below:

[0077] Table 3

[0078]

[0079] As can be seen from the data in the table above, when comparing Comparative Example 1 with Example 1, the dishing level of Example 1, which incorporates both anionic polymer and thiopyridine compound, is significantly lower, demonstrating that this combination significantly reduces dishing. Comparative Examples 2 and 3, when compared with Example 1, demonstrate that Example 1, which incorporates both anionic polymer and thiopyridine compound, exhibits significantly lower dishing levels than Comparative Examples 2 and 3, which incorporate only the aforementioned substances. This demonstrates that combining anionic polymer and thiopyridine compound can achieve a better dishing reduction effect. Comparative Example 4, when compared with Example 1, demonstrates that the copper polishing rate of Comparative Example 1, which lacks hydrogen peroxide, is extremely low, making it impractical for practical application. Comparative Example 5 exhibits a weaker dishing reduction capability than the examples.

[0080] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A polishing composition, characterized in that The polishing composition comprises abrasive particles, an oxidizing agent, a complexing agent, a corrosion inhibitor, a thiopyridine compound, a pH adjuster, an anionic polymer, and deionized water, wherein, based on the total mass of the polishing composition, the mass percentage of the thiopyridine compound is 0.001 wt%-0.1 wt%; the mass percentage of the anionic polymer is 0.001 wt%-0.1 wt%; The thiopyridine compound includes at least one of (4-thiopyridine)acetic acid, 3-(2-pyridyldithio)propionic acid, pyridine-2-thioamide, 4-pyridinethioacetic acid hydrochloride, pyridine-3-thioamide, 2,6-dichloropyridine-4-thioamide, 2-pyridinedithiocarbamate, 2-ethylpyridine-4-thioformamide, 2,2'-dithiodipyridine, 3-(methylthio)pyridine, 2-methylthiopyridine, and 4,4'-dithiobipyridine.

2. The polishing composition according to claim 1, wherein The invention comprises the following components in percentage by weight: 0.01wt%-0.5wt% of abrasive particles, 0.1wt%-5wt% of an oxidizing agent, 0.1wt%-5wt% of a complexing agent, 0.01wt%-0.5wt% of a corrosion inhibitor, 0.001wt%-0.1wt% of a thiopyridine compound, 0.01wt%-1wt% of a pH regulator, 0.001%-0.1wt% of an anionic polymer, and the balance is deionized water.

3. The polishing composition according to claim 1 or 2, characterized in that The anionic polymer includes at least one of polyacrylic acid, acrylic acid-acrylate copolymer, anionic polyacrylamide, alkyl sulfonic acid and its salts, alkylbenzene sulfonic acid and its salts, alkyl sulfuric acid and its salts, alkylphenol polyoxyethylene ether sulfuric acid and its salts, alkyl ether polyoxyethylene ether sulfuric acid and its salts, alkylphenol polyoxyethylene ether phosphoric acid and its salts, and alkyl ether polyoxyethylene ether phosphoric acid and its salts.

4. The polishing composition according to claim 1 or 2, characterized in that The number average molecular weight of the anionic polymer is 200-1,000,000.

5. The polishing composition according to claim 1 or 2, wherein The abrasive particles include at least one of silicon oxide particles, zirconium oxide particles, cerium oxide particles, aluminum oxide particles, and silicon carbide particles; And / or, the D50 size of the abrasive particles is 10-300 nm.

6. The polishing composition according to claim 1 or 2, characterized in that The oxidizing agent includes hydrogen peroxide.

7. The polishing composition according to claim 1 or 2, wherein The complexing agent includes at least one of glycine, malonic acid, citric acid, oxalic acid, valine, alanine, threonine, ethylenediaminetetraacetic acid, disodium ethylenediaminetetraacetate, dipotassium ethylenediaminetetraacetate, cyanoacetic acid, ethylenediaminetetramethylenephosphonic acid, sodium ethylenediaminetetramethylenephosphate, and aminotrimethylenephosphonic acid.

8. The polishing composition according to claim 1 or 2, characterized in that The corrosion inhibitor includes at least one of aspartic acid, glutamic acid, cysteine, tetrazole, 2-aminopyrrole, pyrazole, imidazole, 1,2,4-triazole, 3-amino-1,2,4-triazole, benzotriazole, cytosine, uracil, 2-methyl-4-isothiazolinetrione, and 3,5-diaminotriazole.

9. The polishing composition according to claim 1 or 2, characterized in that The pH regulator includes at least one of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, ethanolamine, diethanolamine, triethanolamine, aniline, potassium hydroxide, sodium hydroxide, guanidine compounds, and alkali metal alkoxides; And / or, the pH of the polishing composition is 5-9.

10. Use of a polishing composition in chemical mechanical polishing, characterized in that: The polishing composition is the polishing composition according to any one of claims 1 to 9.

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