Compound agent, chemical mechanical polishing composition for copper and polishing method

Abstract

The invention discloses a compound for inhibiting copper corrosion, which comprises a nitrogen-containing compound a, a nitrogen-containing compound b and a surfactant, the structures of the nitrogen-containing compound a and the nitrogen-containing compound b are as follows: # imgabs0 #; the surfactant comprises one or a combination of more of methoxypolyethylene glycol, polyamine ether, polyoxyethylene alkylamine and polyvinylpyrrolidone, and the HLB (Hydrophile-Lipophile Balance) value of the surfactant is 18-20; the molar ratio of the nitrogen-containing compound a to the nitrogen-containing compound b is (1: 1)-(1: 5), and the molar ratio of the nitrogen-containing compound a to the surfactant is (1: 1)-(1: 3). The complex agent can effectively inhibit corrosion of copper, the polishing composition containing the complex agent can also inhibit corrosion of copper, the low copper removal rate is guaranteed, meanwhile, the polishing rate of a barrier layer is increased, the occurrence of dish-shaped defects is reduced, copper and the surrounding barrier layer are completely flattened, and the corrosion resistance of copper is improved. And improvement of device contact interconnection performance and improvement of integrated circuit density are facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of chemical mechanical polishing, and particularly relates to a compounding agent, a chemical mechanical polishing composition for copper containing the same, and a polishing method. Background Art

[0002] In recent years, with the continuous development of semiconductor technology, the geometric dimensions of devices in integrated circuits (ICs) have been continuously reduced, and more components have been integrated on smaller chips. Due to the advantages of low resistivity, high electromigration resistance, and short RC delay time of Cu wiring, the wiring of very large scale integrated circuits is being transformed from aluminum wiring process to copper wiring process. However, copper is prone to diffuse through the dielectric layer, leading to the failure of device characteristics. Therefore, a barrier layer needs to be deposited before the deposition of copper. The barrier layer can prevent the migration or diffusion between layers in the wafer, and most of the barrier layers are resistant to acid and alkali corrosion.

[0003] Chemical mechanical polishing is still the most effective process method for copper wiring planarization. In the CMP process, multiple barrier layers are involved in the back-end process of metallic copper, such as Ta, TaN, Ti, TiN, or TiW, etc. Due to the inconsistent polishing rates of copper and the barrier layer, and the concentrated distribution of mechanical stress in the edge region of copper interconnects, copper is over-polished, resulting in the formation of the dishing phenomenon. The chemical mechanical planarization (CMP) of the barrier layer is a key step in the wafer damascene process. Therefore, a polishing liquid with high selectivity for polishing copper and its barrier layer, inhibiting the polishing rate and corrosion rate of copper, and increasing the polishing rate of the barrier layer is required.

[0004] There is an urgent need to explore a new type of chemical mechanical polishing liquid for copper to solve the problems existing in the prior art. Summary of the Invention

[0005] In view of the problems existing in the prior art, in a first aspect, the present invention provides a compounding agent for inhibiting copper corrosion, the compounding agent comprising a nitrogen-containing compound a, a nitrogen-containing compound b, and a surfactant;

[0006] The structures of the nitrogen-containing compound a and the nitrogen-containing compound b are as follows:

[0007]

[0008] Wherein, R1, R2, and R3 each independently include one or more combinations of a hydrogen atom, a methyl group, an ethyl group, an amino group, and an acetic acid group;

[0009] The surfactant includes one or more combinations of polyethylene glycol monomethyl ether, polyamine ether, polyoxyethylene alkylamine, and polyvinylpyrrolidone, and the HLB value of the surfactant is 18-20;

[0010] The molar ratio of the nitrogen-containing compound a to the nitrogen-containing compound b is 1:1 to 1:5;

[0011] The molar ratio of the nitrogen-containing compound a to the surfactant is 1:1 to 1:3;

[0012] Furthermore, the nitrogen-containing compound a includes one or a combination of both of 1,2,3-benzotriazole and 5-methylbenzotriazole;

[0013] Preferably, the nitrogen-containing compound a is 1,2,3-benzotriazole;

[0014] The nitrogen-containing compound b includes one or a combination of more of 5-amino-tetrazole, 5-ethyl-1-methyl-tetrazole, tetrazole, 1-acetic acid-tetrazole, 1-methyl-tetrazole, and 5-methyl-tetrazole;

[0015] Preferably, the nitrogen-containing compound b is 5-amino-tetrazole;

[0016] Furthermore, the surfactant is polyethylene glycol monomethyl ether;

[0017] In a second aspect of the present invention, a chemical mechanical polishing composition for copper is provided. The chemical mechanical polishing composition for copper includes 0.5 wt% to 10.0 wt% of abrasive particles, a complexing agent, 0.02 wt% to 0.03 wt% of the compounding agent as described in the first aspect of the present invention, a pH adjuster, a bactericide, and an oxidizing agent;

[0018] The pH of the chemical mechanical polishing composition for copper is 9 to 10;

[0019] Furthermore, the chemical mechanical polishing composition for copper includes 5.0 wt% to 10.0 wt% of abrasive particles, a complexing agent, 0.025 wt% to 0.03 wt% of the compounding agent as described in the first aspect of the present invention, a pH adjuster, a bactericide, and an oxidizing agent;

[0020] Furthermore, the abrasive particles include one or a combination of more of diamond, alumina, zirconia, ceria, and colloidal silica;

[0021] Furthermore, the abrasive particles are colloidal silica;

[0022] Furthermore, the complexing agent is a compound including one or a combination of both of amino and carboxyl groups and its salts, and the complexing agent includes one or a combination of more of malonic acid, citric acid, glycine, arginine, alanine, valine, glutamic acid, cysteine, histidine, serine, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, and triethylenetetraminehexaacetic acid;

[0023] The oxidizing agent includes one or a combination of more than one of hydrogen peroxide, potassium periodate, nitric acid, iodate, perchlorate, and persulfate;

[0024] The pH regulator includes one or a combination of more than one of potassium hydroxide, nitric acid, sulfuric acid, phosphoric acid, hydrochloric acid, acetic acid, ammonium hydroxide, potassium carbonate, and ammonia water;

[0025] The fungicide includes one or a combination of more than one of 2-methyl-4-isothiazolin-3-one (MIT), 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT), and 1,2-benzisothiazolin-3-one (BIT);

[0026] Furthermore, the complexing agent includes one or a combination of more than one of citric acid, glycine, and histidine;

[0027] The oxidizing agent includes one or a combination of more than one of hydrogen peroxide, nitric acid, and persulfate;

[0028] The pH regulator includes one or a combination of more than one of potassium hydroxide, ammonium hydroxide, nitric acid, and phosphoric acid;

[0029] The fungicide includes one or a combination of both 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one.

[0030] The third aspect of the present invention provides a method for polishing a substrate, which is characterized by including:

[0031] (i) Providing a substrate;

[0032] (ii) Providing a polishing pad;

[0033] (iii) Providing the chemical mechanical polishing composition as described in the second aspect of the present invention;

[0034] (iv) Bringing the substrate into contact with the polishing pad and the chemical mechanical polishing composition; and

[0035] (v) Moving the polishing pad and the chemical mechanical polishing composition relative to the substrate to grind at least a part of the substrate to polish the substrate.

[0036] Beneficial effects:

[0037] (1) The present invention proposes a compounding agent, which contains two corrosion inhibitors and a surfactant and can control the corrosion of copper.

[0038] (2) The present invention provides a polishing composition. In this polishing composition, in addition to the above-mentioned compounding agent, it further contains abrasive particles, complexing agent, pH regulator, fungicide and oxidant, which effectively inhibits the corrosion of copper. While ensuring a low copper removal rate, it improves the polishing rate of the barrier layer, reduces the occurrence of dishing defects, makes the copper and the surrounding barrier layer completely planar, which is beneficial to improving the device contact interconnection performance and increasing the integrated circuit density. Detailed Embodiments

[0039] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0040] <Compound Agent>

[0041] In the first aspect of the present invention, a compounding agent for inhibiting copper corrosion is provided. The compounding agent includes nitrogen-containing compound a, nitrogen-containing compound b and surfactant.

[0042] Nitrogen-containing compound a

[0043] In the present invention, the structure of the nitrogen-containing compound a is shown as follows:

[0044]

[0045] Among them, R1 includes one or more combinations of a hydrogen atom, methyl group, ethyl group, amino group, and acetic acid group.

[0046] Exemplarily, the nitrogen-containing compound a includes one or both combinations of 1,2,3-benzotriazole and 5-methylbenzotriazole. Preferably, the nitrogen-containing compound a is 1,2,3-benzotriazole.

[0047] In the present invention, the nitrogen-containing compound a is a water-soluble compound. Due to the presence of a benzene ring, it has a certain hydrophobicity, which enhances its ability to interact with the copper surface during the polishing process. It can adsorb on the copper surface to form a protective film, effectively preventing corrosive media (such as oxidants, acids, and alkalis) from contacting the copper, thereby inhibiting the corrosion of copper and reducing the number of dishing depressions.

[0048] Nitrogen-containing compound b

[0049] In the present invention, the structure of the nitrogen-containing compound b is shown as follows:

[0050]

[0051] Among them, each of R2 and R3 independently includes one or more combinations of a hydrogen atom, a methyl group, an ethyl group, an amino group, and an acetic acid group.

[0052] Exemplarily, the nitrogen-containing compound b includes one or more combinations of 5-amino-tetrazole, 5-ethyl-1-methyl-tetrazole, tetrazole, 1-acetic acid-tetrazole, 1-methyl-tetrazole, and 5-methyl-tetrazole. Preferably, the nitrogen-containing compound b is 5-amino-tetrazole.

[0053] In the present invention, the nitrogen-containing compound b belongs to a water-soluble compound. Compared with the nitrogen-containing compound a, the nitrogen-containing compound b has stronger hydrophilicity. The nitrogen-containing compound b will also form a protective film on the copper surface, inhibit the occurrence of the corrosion reaction, ensure the stability of the copper during the polishing process, and reduce the occurrence probability of dish-shaped defects.

[0054] In the present invention, exemplarily, the combinations of the nitrogen-containing compound a and the nitrogen-containing compound b include 1,2,3-benzotriazole and 5-amino-tetrazole, 1,2,3-benzotriazole and 5-ethyl-1-methyl-tetrazole, 1,2,3-benzotriazole and tetrazole, 1,2,3-benzotriazole and 1-acetic acid-tetrazole, 1,2,3-benzotriazole and 1-methyl-tetrazole, 1,2,3-benzotriazole and 5-methyl-tetrazole; 5-methylbenzotriazole and 5-amino-tetrazole, 5-methylbenzotriazole and 5-ethyl-1-methyl-tetrazole, 5-methylbenzotriazole and tetrazole, 5-methylbenzotriazole and 1-acetic acid-tetrazole, 5-methylbenzotriazole and 1-methyl-tetrazole, 5-methylbenzotriazole and 5-methyl-tetrazole.

[0055] In the present invention, in this compounding agent, due to the different abilities of the nitrogen-containing compound a and the nitrogen-containing compound b to complex with Cu, and both of these nitrogen-containing compounds can independently form a protective film, a multi-layer protective film can be constructed. Compared with a single nitrogen-containing compound, the nitrogen-containing compound a and the nitrogen-containing compound b act synergistically. The construction of the multi-layer protective film can effectively reduce the contact between the copper and the corrosive medium, inhibit the corrosion of the copper, improve the selectivity during the polishing process, thereby adjusting the polishing rates of the copper and the barrier layer during the subsequent polishing process, while maintaining good flatness and surface uniformity, and reducing dish-shaped depressions.

[0056] Surfactant

[0057] In the present invention, the surfactant includes one or more combinations of polyethylene glycol monomethyl ether, polyamine ether, polyoxyethylene alkylamine, and polyvinylpyrrolidone. Exemplarily, polyethylene glycol monomethyl ether surfactants include but are not limited to mPEG 350, mPEG 2000, mPEG 3000, mPEG 5000, etc.; polyamine ether surfactants include but are not limited to poloxamer 188, poloxamer 407, Tetronic 904, etc.; polyoxyethylene alkylamine surfactants include but are not limited to Brij 35, Brij 58, Ethomeen T / 25; and polyvinylpyrrolidone surfactants include but are not limited to PVP K-12, K-17, PVP K-30, S-630, etc.

[0058] The HLB value is a value used to represent the hydrophilic or lipophilic ability of a surfactant. The higher the HLB value, the stronger the hydrophilicity. In the present invention, the HLB value of the surfactant is 18 - 20. Therefore, preferably, the surfactant includes polyethylene glycol monomethyl ether (e.g., mPEG 2000, mPEG 3000, mPEG 5000, etc.), polyamine ether (e.g., poloxamer 407, Tetronic 904, etc.), polyoxyethylene alkylamine (e.g., Brij 58, Ethomeen T / 25, etc.), and polyvinylpyrrolidone (e.g., PVP K-12, K-17, S-630, etc.). Further preferably, the surfactant does not contain nitrogen. Most preferably, the surfactant is polyethylene glycol monomethyl ether.

[0059] In the present invention, in addition to the functions of dispersion and wetting, when the surfactant is compounded with nitrogen-containing compounds a and b, due to its unique chemical structure and good interfacial activity, the surfactant can improve the dispersibility, adsorbability, and film-forming property of nitrogen-containing compounds a and b. Nitrogen-containing compounds a and b are more uniformly dispersed in the polishing composition, are more likely to be adsorbed on the surface of copper, and are more likely to form a protective film. Therefore, the corrosion of copper can be further inhibited.

[0060] Ratio of the compounding agent

[0061] In the present invention, the molar ratio of nitrogen-containing compound a to nitrogen-containing compound b is 1:1 - 1:5, and the molar ratio of nitrogen-containing compound a to the surfactant is 1:1 - 1:3.

[0062] In the present invention, when the proportion of nitrogen-containing compound a and nitrogen-containing compound b is too low, the formed protective film may be insufficient and unable to effectively inhibit the corrosion of copper, resulting in the copper surface being vulnerable to corrosion. During the polishing process, a relatively high corrosion rate of copper may occur, which in turn affects the polishing effect and surface uniformity. When the proportion of nitrogen-containing compound a and nitrogen-containing compound b is too high, excessive inhibition may be triggered, resulting in an overly thick protective film on the copper surface, thereby affecting the polishing rate of copper and leading to poor selectivity. When the proportion of the surfactant is too low, it may not be able to effectively improve the dispersibility and adsorption of nitrogen-containing compound a and nitrogen-containing compound b, resulting in uneven dispersion of the two nitrogen-containing compounds in the polishing composition, incomplete formation of the protective film, reduced protective effect on the copper surface, and thus may lead to non-uniformity during the polishing process, affecting flatness and surface uniformity. When the proportion of the surfactant is too high, it may cause overly strong interfacial activity, overly affecting the surface properties of the polishing liquid, possibly resulting in changes in surface tension and affecting the flatness during the polishing process.

[0063] <Chemical Mechanical Polishing Composition for Copper>

[0064] In the second aspect of the present invention, there is provided a chemical mechanical polishing composition for copper, comprising abrasive particles, a complexing agent, a compounding agent as described in the first aspect of the present invention, a pH regulator, a bactericide, and an oxidizing agent.

[0065] Abrasive particles

[0066] In the present invention, the abrasive particles include one or more combinations of diamond, alumina, zirconia, cerium oxide, and silica. Preferably, the abrasive particles are colloidal silica.

[0067] Diamond, alumina, zirconia, cerium oxide, and silica are common abrasive particles in polishing compositions. Each particle has unique properties, advantages, and disadvantages and is suitable for different polishing requirements. Diamond can polish materials with relatively high hardness (such as cemented carbide, ceramics, sapphire, etc.), quickly removing irregular parts on the material surface to achieve an efficient polishing effect, but it is expensive and has a worse effect on soft materials than other abrasive particles; alumina has good hardness and relatively high mechanical strength, but its particles are relatively sharp and prone to generating scratches during polishing; the hardness and strength of zirconia are between those of diamond and alumina, and it has good toughness and anti-cracking properties, thus reducing fine particle contamination caused by particle breakage, but the price of zirconia is relatively high; cerium oxide has relatively low hardness and strong chemical stability, and can effectively remove minute defects on the material surface during the polishing process, generating relatively small scratches; silica has a lower hardness than cerium oxide, higher uniformity, good chemical stability, can effectively balance the polishing speed and surface flatness, reduce scratches, and is relatively inexpensive.

[0068] Hydrosol silica has a high degree of dispersibility, fluidity and stability, which can provide a uniform polishing effect, avoid surface defects caused by uneven particle distribution, and will not cause excessive wear or scratches.

[0069] Complexing agent

[0070] In the present invention, the complexing agent is a compound and its salt including one or both of amino group and carboxyl group, and the complexing agent includes one or more combinations of malonic acid, citric acid, glycine, arginine, alanine, valine, glutamic acid, cysteine, histidine, serine, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid and triethylenetetraminehexaacetic acid. Preferably, the complexing agent includes one or more combinations of citric acid, glycine and histidine.

[0071] The complexing agent forms a stable complex by coordinating with metal ions (such as Ta ions, Ti ions, etc.), thereby controlling the dissolution rate of metal ions and preventing uneven wear or damage on the surface. The complexing agent can also effectively inhibit the precipitation of metal ions. If the metal ions in the polishing solution are deposited on the polishing surface, it will cause surface defects or uneven polishing. The complexing agent forms soluble complexes with these metal ions, reducing the redeposition of metals and ensuring the flatness and smoothness of the polishing surface. During the polishing process, an oxidant (such as hydrogen peroxide) may cause oxidation of the metal surface, while the complexing agent can form a complex with metal ions to prevent over-oxidation, thereby obtaining a more uniform and high-quality surface. Between the copper barrier layer and the copper layer, the complexing agent can selectively remove the barrier layer metal without damaging the copper layer, ensuring precise polishing in a complex multi-layer structure.

[0072] Oxidizing agent

[0073] In the present invention, the oxidant includes one or more combinations of hydrogen peroxide, potassium periodate, nitric acid, iodate, perchlorate and persulfate. Preferably, the oxidant includes one or more combinations of hydrogen peroxide, nitric acid and persulfate.

[0074] When the oxidant contacts the surface of a metal (such as Ta, Ti, etc.), an oxide film will be formed. The oxide layer can react with other components in the polishing solution (such as the complexing agent, etc.) to help remove the metal material, making the removal of the metal more uniform and controllable. The oxide film can also reduce the redeposition on the metal surface, avoid the reattachment of metal particles, and reduce the occurrence of surface defects. The introduction of the oxidant can also accelerate the dissolution of the metal, making it easier for metal ions to dissolve into the polishing solution and improving the removal rate. At the same time, in the polishing of the copper barrier layer, the oxidant can also improve the surface quality after polishing.

[0075] pH regulator

[0076] In the present invention, the pH regulator includes one or more combinations of potassium hydroxide, nitric acid, sulfuric acid, phosphoric acid, hydrochloric acid, acetic acid, ammonium hydroxide, potassium carbonate, and ammonia water. Preferably, the pH regulator includes one or more combinations of potassium hydroxide, ammonium hydroxide, nitric acid, and phosphoric acid.

[0077] The pH regulator affects the efficiency of the polishing process, the removal rate of the metal, and the surface quality after polishing. The pH regulator helps to optimize the entire polishing process by regulating the acidity and alkalinity of the polishing liquid.

[0078] In the polishing liquid composition, the role of the pH regulator is to maintain an appropriate pH value, which affects the corrosion rate and polishing rate of copper and the barrier layer. By keeping the pH value of the polishing composition within a reasonable range, the corrosion rate of copper can be reduced, the removal rate of the barrier layer can be increased, the occurrence of dish-shaped defects can be reduced, and the best removal effect can be ensured. The pH regulator can also control the dissolution behavior of metal ions, avoiding excessive corrosion or uneven removal. In addition, the pH regulator can also help to control the redox reaction in the polishing liquid, enabling a stable oxide film to form on the metal surface, thereby improving the polishing quality of the metal surface.

[0079] Bactericide

[0080] In the present invention, the bactericide includes one or more combinations of MIT, CMIT, and BIT. Preferably, the bactericide includes one or both combinations of MIT and CMIT.

[0081] During the use of the polishing liquid, especially in high-humidity and high-temperature environments, it is prone to microbial growth. If these microorganisms multiply in large numbers, they may not only contaminate the polishing liquid, reducing the polishing effect, but also cause uneven corrosion or other adverse reactions to the metal surface, thereby affecting the final polishing quality. The bactericide ensures that the polishing liquid remains clean and stable throughout the production process by inhibiting or killing the microorganisms in the polishing liquid. This can effectively reduce the chemical reaction changes caused by microorganisms and avoid the destruction or contamination of the components of the polishing liquid. In addition, the bactericide can also reduce the spoilage of the polishing liquid, extend its service life, thereby reducing production costs and improving the reliability of the process.

[0082] pH of the chemical mechanical polishing composition

[0083] In the present invention, the pH of the chemical mechanical polishing composition for copper is 9 to 10.

[0084] In the present invention, if the pH of the chemical mechanical polishing composition for copper is < 9, it may increase the acidic corrosion rate of copper, resulting in easier corrosion of the copper surface, formation of corrosive substances on the copper surface, and affecting the surface smoothness after polishing. If the pH of the chemical mechanical polishing composition for copper is > 10, copper is prone to form oxides (such as copper oxide), making the reaction between the copper surface and the abrasive and corrosion inhibitor in the polishing liquid insufficient, which may lead to poor surface finish and reduce the efficiency of the polishing process.

[0085] Ratio of the chemical mechanical polishing composition

[0086] A chemical mechanical polishing composition for copper comprises 0.5 wt% - 10.0 wt% of abrasive particles, a complexing agent, 0.02 wt% - 0.03 wt% of the compounding agent as described in any one of claims 1 - 3, a pH regulator, a fungicide, and an oxidizing agent.

[0087] More preferably, the chemical mechanical polishing composition for copper comprises 5.0 wt% - 10.0 wt% of abrasive particles, a complexing agent, 0.025 wt% - 0.03 wt% of the compounding agent as described in any one of claims 1 - 3, a pH regulator, a fungicide, and an oxidizing agent.

[0088] In the present invention, setting the content of the abrasive particles in the range of 0.5 wt% - 10.0 wt% can ensure that while providing sufficient mechanical grinding force, the risk of increasing scratches and other surface damages due to excessive concentration of the abrasive particles is avoided. If the content of the compounding agent is less than 0.02 wt%, it may lead to weakened corrosion inhibition and poor dispersibility, increasing the risk of non-uniformity and dishing on the copper surface; if the content is higher than 0.03 wt%, it may form an overly thick protective film, resulting in insufficient contact between the copper and the polishing medium, thereby reducing the polishing rate, affecting the polishing selectivity, and possibly reducing the surface flatness. Maintaining an appropriate concentration of the compounding agent is crucial for ensuring the polishing effect, the quality of the copper surface, and improving the processing efficiency.

[0089] <Method for polishing a substrate>

[0090] Providing a substrate, a polishing pad, and the above chemical mechanical polishing composition, bringing the substrate into contact with the polishing pad and the chemical mechanical polishing composition, and moving the polishing pad and the chemical mechanical polishing composition relative to the substrate to grind at least a part of the substrate to polish the substrate.

[0091] The above and other advantages of the present invention can be better understood through the following examples, but the following examples are not intended to limit the scope of the present invention.

[0092] Examples

[0093] The following examples are given to illustrate the present invention, but the present invention is not limited by the following examples.

[0094] Table 1 shows the components and contents of the copper polishing composition in the embodiments and comparative examples of the present invention. The formulations shown in Table 1, 8.5 wt% of colloidal silica abrasive particles with a particle size of 30 nm, 0.005 wt% of citric acid complexing agent, and 0.002 wt% of MIT fungicide are mixed by simple stirring to prepare a chemical mechanical polishing liquid. After mixing evenly, the pH value is adjusted with nitric acid or potassium hydroxide. 1.0 wt% of hydrogen peroxide is added before use, and the mixture is stirred evenly. The balance is made up with water to 100%. The polishing liquids of each embodiment and comparative example of the present invention are obtained according to the components and ratios shown in Table 1:

[0095] Table 1

[0096]

[0097]

[0098] The HLB values of the surfactants mPEG 2000, poloxamer 407, Brij 58, and PVPK-12 used in the above embodiments and comparative examples are all in the range of 18-20, while the HLB value of mPEG 350 is about 13.

[0099] The polishing compositions in the above embodiments and comparative examples are subjected to electrochemical experiments and polishing experiments to obtain corrosion rate (ER), polishing rate, and dishing defect data.

[0100] Electrochemical experiment: The instrument used is an electrochemical workstation (AMETEK PARSTAT MC). The test process is as follows:

[0101] 1. Cut the Cu wafer into slices of 2.5 cm × 5.0 cm and soak them in a 3.0 wt% citric acid solution for 10 min. These slices are all from the same 12-inch wafer, and try to avoid using slices with obvious scratches.

[0102] 2. Wash and dry the slices with ultrapure water to ensure that there is no dust or particulate matter on the slices.

[0103] 3. Try to dry the mold and insert the slices into the mold. Pour the polishing compositions in the above embodiments and comparative examples, install the corresponding electrodes. The reference electrode and the counter electrode are preferably perpendicular to the liquid surface, and the platinum wire of the counter electrode extends about 5 mm below the liquid surface.

[0104] 4. After installing the electrodes, let it stand for 10 min, then measure the open circuit potential (OCP), and measure repeatedly until it is stable. Measure in the order of the three test methods of OCP-EIS-Tafel. Each group of experiments is measured in parallel three times and the average value is taken.

[0105] Polishing experiment: The Cu blank and Cu 754 wafers were polished using an LK (CMP machine), a DH3000W polishing pad (purchased from DINGLONG Co., Ltd.), with a pressure of 1.8 psi, a polishing base / polishing head rotation speed of 93 / 87 rpm, and a polishing liquid flow rate of 300 mL / min.

[0106] The results of the electrochemical experiment and the polishing experiment are shown in Table 2.

[0107] Table 2

[0108]

[0109]

[0110] It should be noted that, based on the explanations and elaborations in the above specification, those skilled in the art to which the present invention pertains can also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some equivalent modifications and changes to the present invention should also be within the scope of protection of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for convenience of description and do not constitute any limitation to the invention.

Claims

1. A compounding agent for inhibiting copper corrosion, characterized in that, The compounding agent includes a nitrogen-containing compound a, a nitrogen-containing compound b, and a surfactant; The structures of the nitrogen-containing compound a and the nitrogen-containing compound b are shown as follows: Wherein, R1, R2, and R3 each independently include one or more combinations of a hydrogen atom, a methyl group, an ethyl group, an amino group, and an acetic acid group; The surfactant includes one or more combinations of polyethylene glycol monomethyl ether, polyamine ether, polyoxyethylene alkylamine, and polyvinylpyrrolidone, and the HLB value of the surfactant is 18-20; The molar ratio of the nitrogen-containing compound a to the nitrogen-containing compound b is 1:1 to 1:5; The molar ratio of the nitrogen-containing compound a to the surfactant is 1:1 to 1:

3.

2. The compounding agent according to claim 1, characterized in that The nitrogen-containing compound a includes one or both combinations of 1,2,3-benzotriazole and 5-methylbenzotriazole, and preferably the nitrogen-containing compound a is 1,2,3-benzotriazole; The nitrogen-containing compound b includes one or more combinations of 5-amino-tetrazole, 5-ethyl-1-methyl-tetrazole, tetrazole, 1-acetic acid-tetrazole, 1-methyl-tetrazole, and 5-methyl-tetrazole, and preferably the nitrogen-containing compound b is 5-amino-tetrazole.

3. The compounding agent according to claim 1, characterized in that, The surfactant is polyethylene glycol monomethyl ether.

4. A chemical mechanical polishing composition for copper, characterized in that, The chemical mechanical polishing composition for copper includes 0.5 wt% to 10.0 wt% of abrasive particles, a complexing agent, 0.02 wt% to 0.03 wt% of the compounding agent according to any one of claims 1 to 3, a pH regulator, a bactericide, and an oxidizing agent; The pH of the chemical mechanical polishing composition for copper is 9 to 10.

5. The chemical mechanical polishing composition for copper according to claim 4, wherein The chemical mechanical polishing composition for copper includes 5.0 wt% to 10.0 wt% of abrasive particles, a complexing agent, 0.025 wt% to 0.03 wt% of the compounding agent according to any one of claims 1 to 3, a pH regulator, a bactericide, and an oxidizing agent.

6. The chemical mechanical polishing composition for copper according to claim 4 or 5, characterized in that, The abrasive particles include one or more combinations of diamond, alumina, zirconia, cerium oxide, and colloidal silica.

7. The chemical mechanical polishing composition for copper according to claim 6, characterized in that, The abrasive particles are colloidal silica.

8. The chemical mechanical polishing composition for copper according to claim 4 or 5, characterized in that, The complexing agent is a compound and its salt including one or both combinations of an amino group and a carboxyl group, and the complexing agent includes one or more combinations of malonic acid, citric acid, glycine, arginine, alanine, valine, glutamic acid, cysteine, histidine, serine, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, and triethylenetetraminehexaacetic acid; The oxidizing agent includes one or more combinations of hydrogen peroxide, potassium periodate, nitric acid, iodate, perchlorate, and persulfate; The pH regulator includes one or more combinations of potassium hydroxide, nitric acid, sulfuric acid, phosphoric acid, hydrochloric acid, acetic acid, ammonium hydroxide, potassium carbonate, and ammonia water; The bactericide includes one or more combinations of 2-methyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, and 1,2-benzisothiazolin-3-one.

9. The chemical mechanical polishing composition for copper according to claim 8, wherein The complexing agent includes one or more combinations of citric acid, glycine, and histidine; The oxidizing agent includes one or more combinations of hydrogen peroxide, nitric acid, and persulfate; The pH regulator includes one or more combinations of potassium hydroxide, ammonium hydroxide, nitric acid, and phosphoric acid; The fungicide includes one or a combination of both of 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one.

10. A method for polishing a substrate, characterized in that, Comprising: (i) providing a substrate; (ii) providing a polishing pad; (iii) providing the chemical mechanical polishing composition as claimed in claim 4; (iv) bringing the substrate into contact with the polishing pad and the chemical mechanical polishing composition; and (v) moving the polishing pad and the chemical mechanical polishing composition relative to the substrate to grind at least a part of the substrate to polish the substrate.

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