Chemical mechanical polishing slurry and chemical mechanical polishing device and method

Abstract

The invention provides chemical mechanical polishing slurry and a chemical mechanical polishing device and method. In the first aspect, the chemical mechanical polishing slurry is provided and comprises an abrasive, a dispersing agent, a pH regulator and a liquid carrier, and the pH regulator is a polymer capable of regulating the pH of the slurry to be 3-10; the content of a compound with the molecular weight not greater than 100 in the chemical mechanical polishing slurry is not higher than 1000ppm. According to the polishing slurry, a high-molecular polymer is used for replacing a small-molecular pH regulator, the problem that a double-electrode-layer structure on the surface of an abrasive is thinned due to small-molecular ions is solved, the pressure sensitivity of the polishing slurry is improved, butterfly defects in the polishing process are relieved, and the flatness of a polished plane is improved.

Description

Technical Field

[0001] The present application relates to the technical field of chemical mechanical polishing, and in particular to a chemical mechanical polishing slurry and a chemical mechanical polishing device and method. Background Art

[0002] Chemical Mechanical Polishing (CMP) is a technology used in the semiconductor device manufacturing process to obtain a flat, scratch-free and impurity-free surface. The basic principle is to place the workpiece to be polished on a polishing pad and apply a polishing slurry to the surface of the polishing pad. The polishing slurry includes an abrasive. When the workpiece to be polished rotates relative to the polishing pad, the material to be removed on the surface of the workpiece to be polished is removed under the mechanical grinding action of the abrasive to obtain a flat, scratch-free and impurity-free surface.

[0003] Shallow trench isolation (STI) is an important process for isolating adjacent devices and preventing leakage. The formation of the STI structure is usually to first deposit a polysilicon layer and a barrier layer on a semiconductor substrate in sequence, then form the STI structure on the above structure, and fill the STI structure with insulating material. Finally, the insulating material is polished using CMP technology to remove the insulating material and expose the barrier layer.

[0004] Ideally, the polishing plane should be flush with the barrier layer plane, but in the actual polishing process, butterfly defects will be formed. Such butterfly defects need to be avoided as much as possible during the polishing process, otherwise they will affect the quality of subsequent processes and semiconductor devices. Therefore, the requirements for chemical mechanical polishing technology (STI-CMP) for shallow trench isolation structures are very high. Summary of the invention

[0005] The present application provides a chemical mechanical polishing slurry for alleviating butterfly defects occurring in the STI-CMP technology to obtain a flat polishing surface.

[0006] The present application also provides a chemical mechanical polishing device including the chemical mechanical polishing slurry, and a chemical mechanical polishing method using the device.

[0007] The first aspect of the present application provides a chemical mechanical polishing slurry, comprising: an abrasive, a dispersant, a pH regulator and a liquid carrier, wherein:

[0008] The pH adjuster is a polymer capable of adjusting the pH of the polishing slurry to 3-10;

[0009] The content of the compound with a molecular weight not greater than 100 in the chemical mechanical polishing slurry is not higher than 1000 ppm, and the molecular structure of the compound with a molecular weight not greater than 100 includes an acidic group and / or a basic group.

[0010] In a possible implementation, the weight average molecular weight of the polymer is 100-50,000.

[0011] In a possible implementation, the molecular structure of the polymer includes at least two repeating units, and the repeating units include one or both of an acidic functional group and a basic functional group.

[0012] In a possible implementation, the acidic functional group includes one or more of a sulfonic acid group, a phosphoric acid group, a carboxylic acid group, a boric acid group, and a hydroxyl group;

[0013] And / or, the basic functional group includes one or more of primary amine, secondary amine, tertiary amine, quaternary ammonium, quaternary phosphonium, and cyclic amine.

[0014] In a possible implementation, the pH adjuster is selected from one or more of polyacrylic acid, polymaleic acid, polystyrene sulfonic acid, poly(2-acrylamido-2-methylpropane sulfonic acid), and polyphosphoric acid.

[0015] In a possible implementation, based on 100 g of the liquid carrier, the solubility of the pH adjuster is not less than 0.01 g.

[0016] In a possible implementation, the polishing slurry further includes a surfactant.

[0017] In a possible implementation, the surfactant is selected from one or both of an ionic surfactant and a non-ionic surfactant.

[0018] In a possible implementation, the mass of the surfactant is 0.001%-2% of the total mass of the polishing slurry.

[0019] In a possible implementation, the abrasive is selected from one or more of metal oxides, metal oxides coated with organic materials or inorganic materials, and metal oxides in a colloidal state;

[0020] The metal oxide is selected from one or more of silicon dioxide, aluminum oxide, cerium oxide, titanium dioxide and zirconium dioxide.

[0021] In a possible implementation, the D50 of the abrasive is 3-300 nm.

[0022] In a possible implementation, the mass of the abrasive is 0.05%-5% of the total mass of the polishing slurry.

[0023] In one possible implementation, the dispersant is selected from one or more of picolinic acid, nicotinic acid, toluic acid, salicylic acid, nitrobenzoic acid, benzoic acid, phenylacetic acid, naphthoic acid, mandelic acid, pyridinedicarboxylic acid, nicotinic acid, isonicotinic acid, quinolinic acid, anthranilic acid, fusaric acid, phthalic acid, isophthalic acid, terephthalic acid, pyridinecarboxylic acid, anionic polymers, cationic polymers, and nonionic polymers.

[0024] In a possible implementation, the mass of the dispersant is 0.001%-2% of the total mass of the polishing slurry.

[0025] In a possible implementation, the polishing slurry is suitable for a workpiece to be polished having a shallow groove isolation structure.

[0026] The second aspect of the present application provides a chemical mechanical polishing device, including a polishing table, a polishing pad, a slurry storage device, and a polishing head, wherein:

[0027] The polishing pad is laid on the surface of the polishing table;

[0028] The polishing head is arranged above the polishing pad and is used to fix the workpiece to be polished so that the surface to be polished of the workpiece to be polished contacts the polishing pad;

[0029] The slurry storage is used to store any of the chemical mechanical polishing slurries described above and apply the chemical mechanical polishing slurry to the surface of the polishing pad.

[0030] The third aspect of the present application provides a chemical mechanical polishing method, which is performed using the above-mentioned chemical mechanical polishing device, comprising the following steps:

[0031] Fixing the workpiece to be polished on the polishing head, and arranging the surface to be polished of the workpiece to be polished close to the polishing pad;

[0032] applying the chemical mechanical polishing slurry to the surface of the polishing pad;

[0033] The rotation speeds of the polishing table and the polishing head are controlled to perform chemical mechanical polishing on the surface to be polished of the workpiece to be polished.

[0034] In the chemical mechanical polishing slurry provided in the present application, a high molecular polymer is used instead of a small molecule pH regulator, thereby avoiding the problem of thinning of the double electric layer structure on the abrasive surface caused by small molecule ions, improving the pressure sensitivity of the polishing slurry, alleviating the formation of butterfly defects during the polishing process, and helping to obtain a relatively flat polishing surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0036] Figure 1 A schematic diagram of a structure before shallow trench isolation is formed according to an embodiment of the present application;

[0037] Figure 2 A schematic diagram of a structure after shallow trench isolation is formed according to an embodiment of the present application;

[0038] Figure 3 A schematic diagram of filling an insulating material provided in an embodiment of the present application;

[0039] Figure 4 A schematic diagram of polishing under ideal conditions provided by an embodiment of the present application;

[0040] Figure 5 A schematic diagram of polishing in actual state provided by an embodiment of the present application;

[0041] Figure 6 A schematic diagram of the structure of a chemical mechanical polishing device provided in one embodiment of the present application;

[0042] Figure 7 A schematic diagram of a process flow of a chemical mechanical polishing method provided in one embodiment of the present application.

[0043] Description of reference numerals:

[0044] 100-substrate;

[0045] 200-polysilicon layer;

[0046] 300-barrier layer;

[0047] 400- shallow trench isolation structure;

[0048] 500-insulating material;

[0049] 600-butterfly-shaped depression;

[0050] 701-Polishing table;

[0051] 702- polishing pad;

[0052] 703-Polishing head;

[0053] 704-workpiece to be polished;

[0054] 705- slurry storage;

[0055] 706-Chemical Mechanical Polishing Slurry;

[0056] 707-Collator. DETAILED DESCRIPTION

[0057] The terms used in the implementation section of this application are only used to explain the specific embodiments of this application and are not intended to limit this application.

[0058] Shallow trench isolation (STI) is an important process for isolating adjacent devices and preventing leakage. The formation of the STI structure is usually to first deposit a polysilicon layer and a barrier layer on a semiconductor substrate in sequence, then form the STI structure on the above structure, and fill the STI structure with insulating material. Finally, the insulating material is polished using CMP technology to remove the insulating material and expose the barrier layer.

[0059] In a specific embodiment, Figure 1-5 As shown, the formation process of the shallow trench isolation (STI) structure generally includes the following steps: first, a polysilicon layer 200 and a barrier layer 300 are sequentially deposited on a semiconductor substrate 100 to form a Figure 1 Then, conventional processes in the art (such as photolithography) are used to Figure 1 The structure shown is formed as Figure 2 Then, the insulating material 500 is filled into the shallow trench isolation structure 400. The insulating material 500 is usually silicon oxide. Since silicon oxide has poor fluidity, when it is filled into the shallow trench isolation structure 400, the corresponding position of the silicon oxide surface also appears as shown in FIG. Figure 3 As shown in the recess, therefore, in general, it is necessary to ensure that the height of the insulating material 500 is higher than the barrier layer 300 to ensure that the shallow trench isolation structure 400 is completely filled with the insulating material; finally, the insulating material needs to be polished using CMP technology to remove the insulating material 500 to expose the barrier layer 300 and perform subsequent manufacturing processes.

[0060] Ideally, the plane formed by polishing should be flush with the plane of the barrier layer 300, that is, the device after polishing has a Figure 4 The structure shown in the figure, but in the actual polishing process, the Figure 5 The butterfly defect 600 is shown, and this type of butterfly defect 600 needs to be avoided as much as possible during the polishing process, otherwise it will affect the subsequent processes.

[0061] The polishing slurry used in CMP technology mostly includes an abrasive, a dispersant, a pH adjuster and a liquid carrier. For example, the Chinese invention patent with publication number CN104250816A discloses a chemical mechanical polishing (CMP) slurry composition, comprising: a. 0.0 wt % to 25 wt % of an abrasive; b. 0.01 wt % to 22 wt % of an integrator; c. 0.001 wt % to 0.15 wt % of a corrosion inhibitor; d. 0.0001 wt % to 0.50 wt % of a choline salt; e. 0.0001 wt % to 0.20 wt % of a choline salt; % by weight of an organic amine; f. 0.01 wt % to 10 wt % of an oxidizing agent; g. 0.0001 wt % to 0.05 wt % of a biocide; h. optionally, one selected from the following: 0.01 wt % to 0.5 wt % of a pH adjuster containing an inorganic or organic acid; 0.00 wt % to 1.0 wt % of a surfactant; and combinations thereof; i. the remainder is essentially a liquid carrier; wherein the polishing slurry composition has a pH of 5.0 to 8.0, wherein the pH adjuster containing an inorganic or organic acid is selected from nitric acid, sulfuric acid, phosphoric acid, and mixtures thereof.

[0062] Chinese invention patent publication number CN107109136A discloses a polishing composition comprising composite particles, additives, a pH adjuster and water, wherein the pH adjuster is selected from sodium hydroxide, potassium hydroxide, cesium hydroxide, ammonium hydroxide, organic quaternary ammonium hydroxide and combinations thereof, and the pH of the polishing composition is about 2 to about 12.

[0063] A Chinese invention patent with publication number CN114958207A discloses a CMP slurry composition for polishing a silicon oxide film, comprising: abrasive (A); a dispersant (B); an auxiliary dispersant (C); a non-ionic additive (D); a pH adjuster (E); and residual ultrapure water (F), wherein: the pH adjuster (E) comprises an organic compound containing one or more hydroxyl groups (-OH) and a carboxyl group (-COOH), specifically, wherein the pH adjuster (E) comprises at least one selected from lactic acid, glycolic acid and hydroxybutyric acid.

[0064] According to the above content, the existing chemical mechanical polishing slurries all include small molecule pH adjusters, most of which have a molecular weight of no more than 100. These conventional pH adjusters are small molecule ions. The addition of these small molecule ions will compress the double electric layer structure on the abrasive surface, making the material coated on the abrasive surface thinner, thereby reducing the pressure sensitivity of the slurry, resulting in more butterfly defects during polishing. High pressure-sensitive slurries form fewer butterfly defects and have better flattening effects.

[0065] Based on the above research, the first aspect of the present application provides a chemical mechanical polishing slurry to improve the pressure sensitivity of the slurry, reduce the formation of butterfly defects, and obtain a relatively flat polishing surface. Specifically, the chemical mechanical polishing slurry includes: an abrasive, a dispersant, a pH adjuster and a liquid carrier, wherein:

[0066] The pH adjuster is a polymer capable of adjusting the pH of the polishing slurry to 3-10;

[0067] The content of the compound with a molecular weight not greater than 100 in the chemical mechanical polishing slurry is not higher than 1000 ppm, and the molecular structure of the compound with a molecular weight not greater than 100 includes an acidic group and / or a basic group.

[0068] In the present application, the compound with a molecular weight not greater than 100 specifically refers to a small molecule pH regulator, which can be an inorganic small molecule pH regulator or an organic small molecule pH regulator, and its molecular structure includes an acidic group and / or a basic group; further, the molecular weight of the small molecule compound is not greater than 200; further, the molecular weight of the small molecule compound is not greater than 1000.

[0069] For example, small molecule pH adjusters include, but are not limited to, nitric acid, hydrochloric acid, phosphoric acid, sulfuric acid, hydrofluoric acid, hydrobromic acid, hydroiodic acid, formic acid, acetic acid, malonic acid, adipic acid, maleic acid, oxalic acid, citric acid, phthalic acid, propionic acid, fumaric acid, lactic acid, salicylic acid, pimelic acid, benzoic acid, succinic acid, phthalic acid, butyric acid, glutaric acid, glutamic acid, glycolic acid, lactic acid, aspartic acid, tartaric acid, ammonia, aminomethylpropanol, triethanolamine, sodium hydroxide, potassium hydroxide, magnesium hydroxide, cesium hydroxide, ammonium hydroxide, sodium bicarbonate, sodium carbonate, and one or more of imidazole compounds.

[0070] The present application uses a high molecular weight polymer instead of a small molecule pH regulator, thereby avoiding the problem of thinning of the double electric layer structure on the abrasive surface caused by small molecule ions, improving the pressure sensitivity of the polishing slurry, alleviating the formation of butterfly defects, and helping to obtain a relatively flat polishing surface.

[0071] In a possible implementation, based on the total mass of the polishing slurry, the content of the above-mentioned small molecule compound is not higher than 1000ppm, for example, the content of the small molecule compound is 0ppm, 1ppm, 5ppm, 10ppm, 20ppm, 50ppm, 80ppm, 100ppm, 150ppm, 200ppm, 250ppm, 300ppm, 350ppm, 400ppm, 450ppm, 500ppm, 550ppm, 600ppm, 650ppm, 700ppm, 750ppm, 800ppm, 850ppm, 900ppm, 950ppm, 1000ppm. By controlling the content of the small molecule compound, the compression of the double electric layer structure on the surface of the abrasive by the small molecule ions can be reduced, the pressure sensitivity of the polishing slurry can be improved, and the butterfly defects occurring during polishing can be alleviated.

[0072] Furthermore, the content of the small molecule compound is not higher than 10ppm, for example, the content of the small molecule compound is 0ppm, 0.1ppm, 0.2ppm, 0.3ppm, 0.5ppm, 0.8ppm, 1.0ppm, 1.2ppm, 1.3ppm, 1.5ppm, 1.8ppm, 2.0ppm, 2.1ppm, 2.2ppm, 2.5ppm, 2.8ppm, 3.0ppm, 3.1ppm, 3.2ppm, 3.3ppm, 3.5ppm, 3.8ppm, 4.0ppm, 4.1ppm, 4.2ppm, 4.3ppm, 4.5ppm, 4.6ppm, 4.8ppm, 4.9ppm, 5.1ppm, 5.2ppm, 5.3ppm, 5.4ppm, 5.5ppm, 5.6ppm, 5.7ppm, 5.8ppm, 5.9ppm, 5.1ppm, 5.2ppm, 5.3ppm, 5.5ppm, 5.6ppm, 5.7ppm, 5.8ppm, 5.9ppm, .8ppm, 5.0ppm, 5.1ppm, 5.2ppm, 5.3ppm, 5.5ppm, 5.8ppm, 6.0ppm, 6.1ppm, 6.2ppm, 6.3ppm, 6.5ppm, 6.8ppm, 7.0ppm, 7.1ppm, 7.2ppm, 7 .3ppm, 7.5ppm, 7.8ppm, 8.0ppm, 8.1ppm, 8.2ppm, 8.3ppm, 8.5ppm, 8.8ppm, 9.0ppm, 9.1ppm, 9.2ppm, 9.3ppm, 9.5ppm, 9.8ppm, 10.0ppm.

[0073] Furthermore, the content of small molecule compounds is not higher than 1ppm, for example, the content of small molecule compounds is 0ppm, 0.01ppm, 0.02ppm, 0.03ppm, 0.05ppm, 0.08ppm, 0.10ppm, 0.11ppm, 0.12ppm, 0.15ppm, 0.18ppm, 0.20ppm, 0.21ppm, 0.22ppm, 0.23ppm, 0.25ppm, 0.28ppm, 0.30ppm, 0.31ppm, 0.32ppm, 0.33ppm, 0.35ppm, 0.38ppm, 0.40ppm, 0.41ppm, 0.42ppm, 0.43ppm, 0.45ppm ppm, 0.90ppm, 0.91ppm, 0.92ppm, 0.93ppm, 0.95ppm, 0.98ppm, 1.0ppm. The content of small molecule compound can be tested according to conventional technical means in this area.

[0074] In the present application, a high molecular weight polymer is used instead of a small molecular weight compound to adjust the pH of the polishing slurry. Specifically, the molecular structure of the polymer includes an acidic group and / or a basic group, which can adjust the pH of the polishing slurry to be controlled within 3-10.

[0075] It can be understood that the molecular weight of the polymer provided in the present application should be at least greater than or equal to 100. In one possible implementation, the weight average molecular weight of the polymer is 100-50,000. For example, the weight average molecular weight of the polymer is 100, 200, 300, 500, 800, 1000, 2000, 3000, 5000, 8000, 10000, 11000, 12000, 13000, 15000, 18000, 20000, 21000, 22000, 23000, 25000, 28000, 30000, 31000, 32000, 33000, 35000, 38000, 40000, 41000, 42000, 43000, 45000, 48000, and 50000. Increasing the molecular weight of the polymer can help further improve the pressure sensitivity of the slurry and alleviate the formation of butterfly defects to obtain a flatter polishing surface.

[0076] Further, the weight average molecular weight of the polymer is 500-10,000, for example, the weight average molecular weight of the polymer is 500, 600, 700, 800, 900, 1000, 1100, 1200, 1500, 1800, 2000, 2100, 2200, 2500, 2800, 3000, 3100, 3200, 3500, 3800, 4000, 4100, 420 0, 4500, 4800, 5000, 5100, 5200, 5500, 5800, 6000, 6100, 6200, 6500, 6800, 7000, 7100, 7200, 7500, 7800, 8000, 8100, 8200, 8500, 8800, 9000, 9100, 9200, 9500, 9800, 10000.

[0077] Furthermore, the weight average molecular weight of the polymer is 1000-3000, for example, the weight average molecular weight of the polymer is 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000.

[0078] The weight average molecular weight of the polymer can be measured by conventional techniques in the art, for example, by aqueous phase GPC testing.

[0079] In a possible implementation, the molecular structure of the polymer is formed by a plurality of repeating units interconnected by covalent bonds, and the repeating units include one or both of an acidic functional group and a basic functional group.

[0080] In a possible implementation, the acidic functional group includes one or more of a sulfonic acid group, a phosphoric acid group, a carboxylic acid group, a boric acid group, and a hydroxyl group;

[0081] And / or, the basic functional group includes one or more of primary amine, secondary amine, tertiary amine, quaternary ammonium, quaternary phosphonium, and cyclic amine.

[0082] In a possible implementation, in the molecular structure of the polymer, the number of repeating units is at least two.

[0083] Furthermore, the number of repeating units is not less than 5, further, the number of repeating units is not less than 10; further, the number of repeating units is 10-50. By controlling the number of repeating units, the molecular weight of the polymer is controlled, the pressure sensitivity of the polishing slurry is increased, and the formation of butterfly defects is alleviated to obtain a relatively flat polishing surface.

[0084] In one possible implementation, based on 100g of the liquid carrier, the solubility of the pH adjuster is not less than 0.01g, and the solubility can be tested according to the GBT 21845-2008 method. By increasing the solubility of the macromolecular pH adjuster in the liquid carrier, it helps to improve its dispersibility in the liquid carrier, thereby facilitating the preparation of the polishing slurry and the polishing effect.

[0085] In a possible implementation, the pH adjuster is selected from one or more of polyacrylic acid, polymaleic acid, polystyrene sulfonic acid, poly(2-acrylamido-2-methylpropane sulfonic acid), and polyphosphoric acid.

[0086] In one possible implementation, the content of the pH adjuster in the polishing slurry can be determined according to the pH of the slurry. For example, the pH of the polishing slurry is 3-10. For example, the pH of the polishing slurry is 3, 3.1, 3.2, 3.5, 3.8, 4, 4.1, 4.2, 4.5, 4.8, 5, 5.1, 5.2, 5.5, 5.8, 6, 6.1, 6.2, 6.3, 6.5, 6.8, 7, 7.1, 7.2, 7.5, 7.8, 8, 8.1, 8.2, 8.5, 8.8, 9, 9.1, 9.2, 9.5, 9.8, 10.

[0087] Further, the pH of the polishing slurry is 4-9, for example, the pH of the polishing slurry is 4, 4.1, 4.2, 4.3, 4.5, 4.6, 4.7, 4.8, 4.9, 5, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8, 8.1, 8.2, 8.3, 8.4, 8.5, 8.6, 8.7, 8.8, 8.9, 9.

[0088] Furthermore, the pH of the polishing slurry is 5-8, for example, the pH of the polishing slurry is 5, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8. The pH of the slurry can be determined according to the type of workpiece to be polished.

[0089] In the present application, the liquid carrier is generally water. In order to improve the dispersibility of the polymer in water, the polishing slurry also includes a surfactant; specifically, the surfactant includes one or more of ionic and non-ionic surfactants, including but not limited to sodium dodecyl sulfate, sodium lauryl sulfate, ammonium dodecyl sulfate, secondary alkane sulfonates, polyvinyl alcohol, polyethylene oxide, and one or more of EO-PO. Those skilled in the art can select a suitable surfactant according to their needs.

[0090] In one possible implementation, based on the total mass of the polishing slurry, the mass of the surfactant is 0.001%-2%, for example, selected from 0.001%, 0.002%, 0.005%, 0.008%, 0.010%, 0.020%, 0.050%, 0.080%, 0.10%, 0.20%, 0.50%, 0.80%, 1.00%, 1.10%, 1.20%, 1.50%, 1.80%, 2.00% or a range consisting of any two of them.

[0091] In the present application, the abrasive may be a conventional material in the art, for example, one or more selected from metal oxides, metal oxides coated with organic materials or inorganic materials, and metal oxides in a colloidal state.

[0092] Furthermore, the metal oxide is selected from one or more of silicon dioxide, aluminum oxide, cerium oxide, titanium dioxide and zirconium dioxide.

[0093] Compared with silicon dioxide, cerium dioxide has high reactivity, which helps to increase the removal rate of oxides on the surface of the workpiece to be polished. Therefore, in a possible implementation, the abrasive is preferably cerium dioxide.

[0094] In a possible implementation, the D50 of the abrasive is 3-300nm, and D50 refers to the particle size corresponding to the cumulative particle size distribution percentage in the abrasive sample reaching 50%. When the D50 of the abrasive is less than 3nm, the polishing speed is reduced, resulting in low efficiency in terms of productivity. When the D50 of the abrasive is greater than 300nm, it is not conducive to its dispersibility in the liquid carrier; for example, it is selected from 3nm, 5nm, 10nm, 20nm, 30nm, 50nm, 80nm, 100nm, 120nm, 150nm, 180nm, 200nm, 210nm, 220nm, 250nm, 280nm, 300nm or any two thereof. The D50 of the abrasive can be obtained according to the particle size analyzer test.

[0095] Further, the D50 of the abrasive is 10-200nm, for example, the D50 of the abrasive is 10nm, 11nm, 12nm, 15nm, 18nm, 20nm, 21nm, 22nm, 25nm, 28nm, 30nm, 31nm, 32nm, 35nm, 38nm, 40nm, 41nm, 42nm, 45nm, 48nm, 50nm, 51nm, 55nm, 58nm, 60nm, 61nm, 62nm, 65nm, 68nm, 70nm, 71nm, 72nm, 75nm, 78nm, 80nm, 81nm, 82nm, 85nm, 88nm, 90nm, 91nm, 92nm, 95nm, 98nm, 100nm, 110nm, 120nm, 150nm, 180nm, 200nm.

[0096] Further, the D50 of the abrasive is 30-150nm, for example, the D50 of the abrasive is 30nm, 31nm, 32nm, 35nm, 38nm, 40nm, 41nm, 42nm, 45nm, 48nm, 50nm, 51nm, 55nm, 58nm, 60nm, 61nm, 62nm, 65nm, 68nm, 70nm, 71nm, 72nm, 75nm, 78nm, 80nm, 81nm, 82nm, 85nm, 88nm, 90nm, 91nm, 92nm, 95nm, 98nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm.

[0097] Furthermore, the D50 of the abrasive is 80-120nm, for example, the D50 of the abrasive is 80nm, 81nm, 82nm, 83nm, 84nm, 85nm, 88nm, 89nm, 90nm, 91nm, 92nm, 93nm, 94nm, 95nm, 96nm, 97nm, 98nm, 99nm, 100nm, 110nm, 120nm.

[0098] In a possible implementation, based on the total mass of the polishing slurry, the mass of the abrasive is 0.05%-5.0%. When the content of the abrasive is less than 0.05%, the polishing slurry may not be able to exhibit sufficient polishing performance, and when it is greater than 5.0%, due to the increase in the amount of abrasive, the amount of abrasive retained on the surface to be polished increases, which may cause scratches on the surface to be polished. For example, the range is selected from 0.05%, 0.08%, 0.10%, 0.20%, 0.50%, 0.80%, 1.0%, 1.10%, 1.20%, 1.50%, 1.80%, 2.0%, 2.1%, 2.2%, 2.5%, 2.8%, 3.0%, 3.1%, 3.2%, 3.5%, 3.8%, 4.0%, 4.1%, 4.2%, 4.5%, 4.8%, 5.0% or any two thereof.

[0099] Further, the mass of the abrasive is 0.2%-2.0% of the total mass of the polishing slurry, for example, selected from 0.20%, 0.21%, 0.22%, 0.25%, 0.28%, 0.30%, 0.31%, 0.32%, 0.35%, 0.38%, 0.40%, 0.41%, 0.42%, 0.45%, 0.48%, 0.50%, 0.51%, 0.52%, 0.55%, 0.58%, 0.60%, 0.61%, %, 0.62%, 0.65%, 0.68%, 0.70%, 0.71%, 0.72%, 0.75%, 0.78%, 0.80%, 0.81%, 0.82%, 0.83%, 0.85%, 0.88%, 0.90%, 0.91%, 0.92%, 0.95%, 0.98%, 1.00%, 1.10%, 1.20%, 1.50%, 1.80%, 2.0% or a range consisting of any two of them.

[0100] In the present application, the dispersant is used to control the dispersion stability of the components contained in the slurry. The specific materials can be based on conventional materials in the art. For example, the dispersant includes but is not limited to one or more of picolinic acid, nicotinic acid, toluic acid, salicylic acid, nitrobenzoic acid, benzoic acid, phenylacetic acid, naphthoic acid, mandelic acid, pyridinedicarboxylic acid, nicotinic acid, isonicotinic acid, quinolinic acid, anthranilic acid, fusaric acid, phthalic acid, isophthalic acid, terephthalic acid, pyridinecarboxylic acid, anionic polymers, cationic polymers, and nonionic polymers.

[0101] In one possible implementation, based on the total mass of the polishing slurry, the mass of the dispersant is 0.001%-2%, for example, selected from 0.001%, 0.002%, 0.005%, 0.008%, 0.010%, 0.011%, 0.012%, 0.015%, 0.018%, 0.020%, 0.021%, 0.022%, 0.025%, 0.028%, 0.030%, 0.031%, 0.032%, 0.035%, 0.038%, 0.040%, 0.041%, 0.042%, 0.045%, 0.048%, 0.050%, 0.051%, 0.052%, 0.055%, 0.056%, 0.057%, 0.058%, 0.060%, 0.061%, 0.062%, 0.065%, 0.066%, 0.067%, 0.068%, 0.070%, 0.071%, 0.072%, 0.073%, 0.074%, 0.075%, 0.076%, 0.077%, 0.078%, 0.079%, 0.080%, 0.081%, 0.082%, 0.083%, 0.084%, 0.085%, 0.086%, 0.087%, 0.088%, 0.089%, 0.090%, 0.091%, 0.092%, 0.095%, 0.096%, 0.097%, 0.098%, 0.099%, 0.010 0.052%, 0.055%, 0.058%, 0.060%, 0.061%, 0.062%, 0.065%, 0.068%, 0.070%, 0.071%, 0.072%, 0.075%, 0.078%, 0.080%, 0.081%, 0.082%, 0.085%, 0.088%, 0.090%, 0.091%, 0.092%, 0.095%, 0.098%, 0.10%, 0.20%, 0.50%, 0.80%, 1.0%, 1.1%, 1.2%, 1.5%, 1.8%, 2.0% or a range consisting of any two thereof.

[0102] Further, the mass of the dispersant is 0.01%-1%, for example, can be selected from 0.01%, 0.011%, 0.012%, 0.015%, 0.018%, 0.020%, 0.021%, 0.022%, 0.025%, 0.028%, 0.030%, 0.031%, 0.032%, 0.035%, 0.038%, 0.040%, 0.041%, 0.042%, 0.045%, 0.048%, 0.050%, 0.051%, 0.052%, 0.055 %, 0.058%, 0.060%, 0.061%, 0.062%, 0.065%, 0.068%, 0.070%, 0.071%, 0.072%, 0.075%, 0.078%, 0.080%, 0.081%, 0.082%, 0.085%, 0.088%, 0.090%, 0.091%, 0.092%, 0.095%, 0.098%, 0.10%, 0.20%, 0.50%, 0.80%, 1.0% or a range consisting of any two thereof.

[0103] The polishing slurry provided in the present application is suitable for use in a workpiece to be polished having an STI structure.

[0104] When preparing the slurry provided in the present application, the abrasive, dispersant and liquid carrier are firstly mixed thoroughly and uniformly in a certain proportion, and then a pH adjuster is added to adjust the pH of the mixture to a preset value, and the polishing slurry can be prepared.

[0105] In summary, the present application uses a high molecular weight polymer instead of a small molecule pH regulator, thereby avoiding the problem of thinning of the double electric layer structure on the abrasive surface caused by small molecule ions, improving the pressure sensitivity of the polishing slurry, alleviating the formation of butterfly defects, and helping to obtain a relatively flat polishing surface.

[0106] The second aspect of the present application provides a chemical mechanical polishing device, comprising: a polishing table, a polishing pad, a slurry storage device, and a polishing head, wherein:

[0107] The polishing pad is laid on the surface of the polishing table;

[0108] The polishing head is arranged above the polishing pad and is used to fix the workpiece to be polished so that the surface to be polished of the workpiece to be polished contacts the polishing pad;

[0109] The slurry storage is used to store any of the chemical mechanical polishing slurries described above and apply the chemical mechanical polishing slurry to the surface of the polishing pad.

[0110] Furthermore, the device also includes a finisher for cleaning the surface of the polishing pad to ensure the flatness of the surface of the polishing pad.

[0111] Furthermore, the device also includes a pressure controller for controlling the pressure of the polishing head.

[0112] Furthermore, the device also includes a rotation speed controller for controlling the rotation speeds of the polishing table and the polishing head.

[0113] In one possible implementation, Figure 6 A schematic diagram of a chemical mechanical polishing device provided in an embodiment of the present application is shown in FIG. Figure 6 As shown, the device includes a polishing table 701, a polishing pad 702, a polishing head 703 and a slurry storage 705, wherein:

[0114] The polishing pad 702 is laid on the surface of the polishing table 701, and a polishing head 703 is arranged above the polishing pad 702. The workpiece 704 to be polished is fixed under the polishing head 703, and the surface to be polished is arranged on the side close to the polishing pad 702, so that the surface to be polished of the workpiece 704 to be polished can contact the polishing pad 702.

[0115] A slurry storage 705 is disposed above the polishing pad 702 , in which chemical mechanical polishing slurry 706 is stored. When polishing starts, the chemical mechanical polishing slurry 706 stored therein is applied to the surface of the polishing pad 702 .

[0116] The polishing device further includes a pressure controller (not shown in the figure) for controlling the pressure of the polishing head 703 .

[0117] The polishing device also includes a speed controller (not shown in the figure) for controlling the speed of the polishing table and the polishing head, which can be specifically set according to the polishing needs.

[0118] The polishing device further includes a finisher 707 , which rotates at a certain speed under the control of a controller to finish the surface of the polishing pad 702 and remove impurities.

[0119] In summary, based on the chemical mechanical polishing slurry provided in the first aspect of the present application, using a chemical mechanical polishing device including the polishing slurry for chemical mechanical polishing can help avoid the problem of thinning of the double electric layer structure on the abrasive surface caused by small molecule ions, improve the pressure sensitivity of the polishing slurry, alleviate the formation of butterfly defects, and help obtain a relatively flat polishing surface.

[0120] The third aspect of the present application provides a chemical mechanical polishing method, which is performed using the above-mentioned chemical mechanical polishing device, comprising the following steps:

[0121] Fixing the workpiece to be polished on the polishing head, and arranging the surface to be polished of the workpiece to be polished close to the polishing pad;

[0122] applying the chemical mechanical polishing slurry to the surface of the polishing pad;

[0123] The rotation speeds of the polishing table and the polishing head are controlled to perform chemical mechanical polishing on the surface to be polished of the workpiece to be polished.

[0124] In one possible implementation, Figure 7 A schematic diagram of a chemical mechanical polishing method according to an embodiment of the present application is shown in FIG. Figure 7 As shown, the following steps are included:

[0125] Step 1, fixing the workpiece to be polished on the polishing head, and setting the surface to be polished of the workpiece to be polished close to the polishing pad;

[0126] First, the workpiece to be polished 704 is fixed on the polishing head 703, and the surface to be polished of the workpiece to be polished faces downward and is located close to the polishing pad.

[0127] Specifically, the workpiece 704 to be polished has a shallow groove isolation structure. In a possible implementation, it has the following Figure 3The structure shown includes a substrate 100, a polysilicon layer 200, a barrier layer 300 and an insulating material 500 filled in a shallow trench isolation structure. The above materials are all conventional materials in the art. For example, the substrate 100 is a silicon substrate; the barrier layer 300 includes one or more of silicon nitride, silicon oxynitride (SiON), and silicon carbide (SiC); and the insulating material 500 includes silicon oxide.

[0128] Step 2, applying the chemical mechanical polishing slurry to the surface of the polishing pad;

[0129] The slurry storage is opened, and the stored chemical mechanical polishing slurry is applied to the surface of the polishing pad 702 . The amount of application can be determined according to conventional technical means in the art.

[0130] Step 3: Control the rotation speed of the polishing table and the polishing head to perform chemical mechanical polishing on the surface to be polished of the workpiece to be polished.

[0131] Turn on the speed controller to make the polishing table 701 and the polishing head 703 rotate at a certain speed. The polishing table 701 drives the polishing pad 702 to rotate, and the polishing head 703 drives the workpiece 704 to be polished to rotate; and as the polishing pad 702 rotates, the polishing slurry 706 is spread onto the surface of the polishing pad 702 under the action of centrifugal force, so that it contacts the surface to be polished of the workpiece 704 to be polished; at the same time, the pressure of the polishing head 703 is controlled by the pressure controller, so that the surface of the workpiece 704 to be polished is polished. The specific polishing process and parameter control can be set according to actual needs.

[0132] In summary, the present application uses a high molecular polymer instead of a small molecule pH regulator, thereby avoiding the problem of thinning of the double electric layer structure on the abrasive surface caused by small molecule ions, improving the pressure sensitivity of the slurry, alleviating the formation of butterfly defects, and helping to obtain a relatively flat polishing surface.

[0133] The chemical mechanical polishing slurry provided in this application is described in detail below in conjunction with specific embodiments:

[0134] Example 1

[0135] This embodiment provides a chemical mechanical polishing slurry, the pH value of the polishing slurry is 5, and specifically comprises:

[0136] Abrasive nano cerium oxide, the mass of the abrasive is 1% of the total mass of the polishing slurry, and the D50 of the nano cerium oxide is 160nm;

[0137] Dispersant, the mass of the dispersant is 0.5% of the total mass of the polishing slurry;

[0138] pH adjuster polyacrylic acid, the weight average molecular weight of polyacrylic acid is 2000;

[0139] The remainder is water.

[0140] The preparation method of the chemical mechanical polishing slurry provided in this embodiment comprises the following steps:

[0141] Abrasives and dispersants are added into water according to a certain mass, and after being evenly dispersed, a pH adjuster, polyacrylic acid, is added to adjust the pH of the slurry to 5, thereby obtaining the chemical mechanical polishing slurry.

[0142] Example 2

[0143] This embodiment provides a chemical mechanical polishing slurry, the pH value of the polishing slurry is 5, and specifically comprises:

[0144] Abrasive nano cerium oxide, the mass of the abrasive is 1% of the total mass of the polishing slurry, and the D50 of the nano cerium oxide is 160nm;

[0145] Dispersant, the mass of the dispersant is 0.5% of the total mass of the polishing slurry;

[0146] pH adjuster polymaleic acid;

[0147] The remainder is water.

[0148] The preparation method of the chemical mechanical polishing slurry provided in this embodiment comprises the following steps:

[0149] Abrasives and dispersants are added into water according to a certain mass, and after being evenly dispersed, polymaleic acid, a pH regulator, is added to adjust the pH of the slurry to 5, thereby obtaining the chemical mechanical polishing slurry.

[0150] Example 3

[0151] This embodiment provides a chemical mechanical polishing slurry, the pH value of the polishing slurry is 5, and specifically comprises:

[0152] Abrasive nano cerium oxide, the mass of the abrasive is 1% of the total mass of the polishing slurry, and the D50 of the nano cerium oxide is 160nm;

[0153] Dispersant, the mass of the dispersant is 0.5% of the total mass of the polishing slurry;

[0154] pH adjuster polymethacrylic acid;

[0155] The remainder is water.

[0156] The preparation method of the chemical mechanical polishing slurry provided in this embodiment comprises the following steps:

[0157] Abrasives and dispersants are added into water according to a certain mass, and after being evenly dispersed, a pH adjuster, polymethacrylic acid, is added to adjust the pH of the slurry to 5, thereby obtaining the chemical mechanical polishing slurry.

[0158] Example 4

[0159] This embodiment provides a chemical mechanical polishing slurry, the pH value of the polishing slurry is 4, and specifically comprises:

[0160] Abrasive nano cerium oxide, the mass of the abrasive is 1% of the total mass of the polishing slurry, and the D50 of the nano cerium oxide is 160nm;

[0161] Dispersant, the mass of the dispersant is 0.5% of the total mass of the polishing slurry;

[0162] pH adjuster polyacrylic acid, the weight average molecular weight of polyacrylic acid is 2000;

[0163] The remainder is water.

[0164] The preparation method of the chemical mechanical polishing slurry provided in this embodiment comprises the following steps:

[0165] Abrasives and dispersants are added into water according to certain mass, and after being evenly dispersed, a pH adjuster, polyacrylic acid, is added to adjust the pH of the slurry to 4, thereby obtaining the chemical mechanical polishing slurry.

[0166] Comparative Example 1

[0167] This comparative example provides a chemical mechanical polishing slurry, the pH value of the polishing slurry is 5, and specifically comprises:

[0168] Abrasive nano cerium oxide, the mass of the abrasive is 1% of the total mass of the polishing slurry, and the D50 of the nano cerium oxide is 160nm;

[0169] Dispersant, the mass of the dispersant is 0.5% of the total mass of the polishing slurry;

[0170] pH adjuster nitric acid;

[0171] The remainder is water.

[0172] The preparation method of the chemical mechanical polishing slurry provided in this comparative example comprises the following steps:

[0173] Abrasives and dispersants are added into water according to a certain mass, and after being evenly dispersed, nitric acid, a pH adjuster, is added to adjust the pH of the slurry to 5, thereby obtaining the chemical mechanical polishing slurry.

[0174] Comparative Example 2

[0175] This comparative example provides a chemical mechanical polishing slurry, the pH value of the polishing slurry is 5, and specifically comprises:

[0176] Abrasive nano cerium oxide, the mass of the abrasive is 1% of the total mass of the polishing slurry, and the D50 of the nano cerium oxide is 160nm;

[0177] Dispersant, the mass of the dispersant is 0.5% of the total mass of the polishing slurry;

[0178] pH adjuster phosphoric acid;

[0179] The remainder is water.

[0180] The preparation method of the chemical mechanical polishing slurry provided in this comparative example comprises the following steps:

[0181] Abrasives and dispersants are added into water according to certain mass, and after being evenly dispersed, phosphoric acid as a pH adjuster is added to adjust the pH of the slurry to 5, thereby obtaining the chemical mechanical polishing slurry.

[0182] Comparative Example 3

[0183] This comparative example provides a chemical mechanical polishing slurry, the pH value of the polishing slurry is 5, and specifically comprises:

[0184] Abrasive nano cerium oxide, the mass of the abrasive is 1% of the total mass of the polishing slurry, and the D50 of the nano cerium oxide is 160nm;

[0185] Dispersant, the mass of the dispersant is 0.5% of the total mass of the polishing slurry;

[0186] pH adjuster sulfuric acid;

[0187] The remainder is water.

[0188] The preparation method of the chemical mechanical polishing slurry provided in this comparative example comprises the following steps:

[0189] Abrasives and dispersants are added into water according to a certain mass, and after being evenly dispersed, sulfuric acid as a pH adjuster is added to adjust the pH of the slurry to 5, thereby obtaining the chemical mechanical polishing slurry.

[0190] Comparative Example 4

[0191] This comparative example provides a chemical mechanical polishing slurry, the pH value of the polishing slurry is 5, and specifically comprises:

[0192] Abrasive nano cerium oxide, the mass of the abrasive is 1% of the total mass of the polishing slurry, and the D50 of the nano cerium oxide is 160nm;

[0193] Dispersant, the mass of the dispersant is 0.5% of the total mass of the polishing slurry;

[0194] pH adjuster L-ascorbic acid;

[0195] The remainder is water.

[0196] The preparation method of the chemical mechanical polishing slurry provided in this comparative example comprises the following steps:

[0197] Abrasives and dispersants are added into water according to a certain mass, and after being evenly dispersed, a pH adjuster L-ascorbic acid is added to adjust the pH of the slurry to 5, thereby obtaining the chemical mechanical polishing slurry.

[0198] Table 1 lists the compositions of the polishing slurries provided in Examples 1-4 and Comparative Examples 1-4 to make the differences between the polishing slurries provided in Examples 1-4 and Comparative Examples 1-4 more intuitive.

[0199] Table 1 Composition and pH of polishing slurry provided in Examples 1-4 and Comparative Examples 1-4

[0200] Abrasive pH Adjusters pH Example 1 Nano Cerium Oxide Polyacrylic acid 5 Example 2 Nano Cerium Oxide Polymaleic acid 5 Example 3 Nano Cerium Oxide Polymethacrylic acid 5 Example 4 Nano Cerium Oxide Polyacrylic acid 4 Comparative Example 1 Nano Cerium Oxide Nitric acid 5 Comparative Example 2 Nano Cerium Oxide Phosphoric acid 5 Comparative Example 3 Nano Cerium Oxide sulfuric acid 5 Comparative Example 4 Nano Cerium Oxide L-Ascorbic Acid 5

[0201] according to Figure 6 The chemical mechanical polishing device shown uses the polishing slurry provided in Examples 1-4 and Comparative Examples 1-4 to perform chemical mechanical polishing on the silicon oxide on the surface of the workpiece, and tests the removal rate of the silicon oxide under different back pressures, wherein the back pressures are 2 psi (low pressure) and 3 psi (high pressure), respectively. The pressure sensitivity of the polishing slurry is calculated based on (high pressure removal rate - low pressure removal rate). The test and calculation results are shown in Table 2.

[0202] Table 2 Removal rate and pressure sensitivity of polishing slurries provided in Examples 1-4 and Comparative Examples 1-4 to silicon oxide

[0203]

[0204] According to Table 2, compared with the small molecule pH regulator provided in Comparative Examples 1-4, the addition of high molecular weight polymer as pH regulator in Examples 1-4 helps to improve the pressure sensitivity of the polishing slurry. Therefore, the polishing slurry provided in the present application helps to alleviate the formation of butterfly depressions and obtain a flat polishing surface.

[0205] In the description of the embodiments of the present application, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0206] In the description of the embodiments of the present application, it should be noted that the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0207] In the description of the embodiments of the present application, it should be noted that the term "plurality" refers to two or more than two.

[0208] In the description of the embodiments of the present application, it should be noted that the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the previous and next associated objects are in an "or" relationship; in a formula, the character " / " indicates that the previous and next associated objects are in a "division" relationship.

[0209] In the description of the embodiments of the present application, it should be noted that the various digital numbers involved in the embodiments of the present application are only used for the convenience of description and are not used to limit the scope of the embodiments of the present application.

[0210] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, rather than to limit them. Although the embodiments of the present application have been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A chemical mechanical polishing slurry, characterized in that: include: Abrasive, dispersant, pH adjuster and liquid carrier, wherein: The pH adjuster is a polymer capable of adjusting the pH of the polishing slurry to 3-10; The content of the compound with a molecular weight not greater than 100 in the chemical mechanical polishing slurry is not higher than 1000 ppm, and the molecular structure of the compound with a molecular weight not greater than 100 includes an acidic group and / or a basic group.

2. The polishing slurry according to claim 1, characterized in that The weight average molecular weight of the polymer is 100-50,000.

3. The polishing slurry according to claim 1, characterized in that The molecular structure of the polymer includes at least two repeating units, and the repeating units include one or both of an acidic functional group and a basic functional group.

4. The polishing slurry according to claim 3, characterized in that The acidic functional group includes one or more of a sulfonic acid group, a phosphoric acid group, a carboxylic acid group, a boric acid group, and a hydroxyl group; And / or, the basic functional group includes one or more of primary amine, secondary amine, tertiary amine, quaternary ammonium, quaternary phosphonium, and cyclic amine.

5. The polishing slurry according to any one of claims 1 to 4, characterized in that: The pH adjuster is selected from one or more of polyacrylic acid, polymaleic acid, polystyrene sulfonic acid, poly(2-acrylamide-2-methylpropane sulfonic acid), and polyphosphoric acid.

6. The polishing slurry according to claim 1, characterized in that The solubility of the pH adjuster is not less than 0.01 g based on 100 g of the liquid carrier.

7. The polishing slurry according to any one of claims 1 to 6, characterized in that: The polishing slurry also includes a surfactant.

8. The polishing slurry according to claim 7, characterized in that The surfactant is selected from one or both of ionic surfactants and non-ionic surfactants.

9. The polishing slurry according to claim 7, characterized in that: The mass of the surfactant is 0.001%-2% of the total mass of the polishing slurry.

10. The polishing slurry according to any one of claims 1 to 9, characterized in that: The abrasive is selected from one or more of metal oxides, metal oxides coated with organic or inorganic materials, and metal oxides in a colloidal state; The metal oxide is selected from one or more of silicon dioxide, aluminum oxide, cerium oxide, titanium dioxide and zirconium dioxide.

11. The polishing slurry according to claim 1 or 10, characterized in that: The D50 of the abrasive is 3-300 nm.

12. The polishing slurry according to claim 1 or 10, characterized in that: The mass of the abrasive is 0.05%-5% of the total mass of the polishing slurry.

13. The polishing slurry according to any one of claims 1 to 12, characterized in that: The dispersant is selected from one or more of picolinic acid, nicotinic acid, toluic acid, salicylic acid, nitrobenzoic acid, benzoic acid, phenylacetic acid, naphthoic acid, mandelic acid, pyridinedicarboxylic acid, nicotinic acid, isonicotinic acid, quinolinic acid, anthranilic acid, fusaric acid, phthalic acid, isophthalic acid, terephthalic acid, pyridinecarboxylic acid, anionic polymers, cationic polymers, and nonionic polymers.

14. The polishing slurry according to claim 1 or 13, characterized in that: The mass of the dispersant is 0.001%-2% of the total mass of the polishing slurry.

15. The polishing slurry according to any one of claims 1 to 14, characterized in that: The polishing slurry is suitable for a workpiece to be polished having a shallow groove isolation structure.

16. A chemical mechanical polishing device, characterized in that: It includes a polishing table, a polishing pad, a slurry storage device, and a polishing head, wherein: The polishing pad is laid on the surface of the polishing table; The polishing head is arranged above the polishing pad and is used to fix the workpiece to be polished so that the surface to be polished of the workpiece to be polished contacts the polishing pad; The slurry storage is used to store the chemical mechanical polishing slurry according to any one of claims 1 to 15, and apply the chemical mechanical polishing slurry to the surface of the polishing pad.

17. A chemical mechanical polishing method, characterized in that: The method is carried out using the chemical mechanical polishing device according to claim 16, comprising the following steps: Fixing the workpiece to be polished on the polishing head, and arranging the surface to be polished of the workpiece to be polished close to the polishing pad; applying the chemical mechanical polishing slurry to the surface of the polishing pad; The rotation speeds of the polishing table and the polishing head are controlled to perform chemical mechanical polishing on the surface to be polished of the workpiece to be polished.

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