Silicon wafer chemical mechanical polishing liquid, preparation method and application thereof

Abstract

The application provides a silicon wafer chemical mechanical polishing liquid, a use method and application thereof, and a mass percentage composition of the silicon wafer chemical mechanical polishing liquid comprises 10-30% of high-purity silicon sol, 0.1-0.5% of a pH regulator, 0.1-1% of a vinyl pyrrolidone-quaternary ammonium salt copolymer, and the balance of water. The polishing liquid can be applied to polishing in a silicon wafer after being diluted by 20-39 times, the wafer surface is not hydrophilic after polishing, and surface micro scratches can be repaired; the polishing liquid can be applied to fine polishing of the silicon wafer after being diluted by 1-19 times, the wafer surface is strongly hydrophilic after polishing, contamination of abrasive particles and air impurities is avoided, and thus low surface defects are obtained.

Description

Technical Field

[0001] This invention relates to the field of chemical mechanical polishing (CMP) technology, specifically to a silicon wafer chemical mechanical polishing slurry, its preparation method, and its application. Background Technology

[0002] Semiconductor devices typically require nanometer-level flatness; otherwise, uneven resistance and inaccurate photolithography will occur. Currently, the best process combines chemical (liquid) and mechanical (pad) methods. In chemical mechanical polishing (CMP), the two most important materials are the polishing slurry and the polishing pad. Polishing accounts for approximately 7% of the cost, yet it is the most frequently repeated step in semiconductor manufacturing. A 28nm chip requires 12 polishing cycles. As chips become smaller, at the 10nm process, polishing is repeated 30 times, using over 30 different polishing slurries.

[0003] CMP polishing slurry is a mixture of abrasives and chemical additives used in planarization processes. Slurry primarily consists of abrasives, surfactants, pH buffers, oxidants, and corrosion inhibitors. The abrasives typically include nano-sized silica (SiO2), nano-sized aluminum oxide (Al2O3), and nano-sized cerium oxide (CeO2). Other additives are combined to create different types of polishing slurries depending on the material being polished, thus classifying them into non-metallic polishing slurries, metallic polishing slurries, and other special polishing slurries.

[0004] Silicon wafer polishing slurries are non-metallic polishing slurries. The silicon wafer polishing process is divided into edge polishing, rough polishing, intermediate polishing, and fine polishing. Patents on silicon wafer polishing slurries mainly focus on rough polishing and fine polishing, and currently no patent mentions a polishing slurry that can handle both processes. Existing technologies require a wide variety of polishing slurries, causing problems for storage and transportation. Developing a polishing slurry that can handle two or more polishing processes would greatly simplify the storage, transportation, and use of polishing slurries. Summary of the Invention

[0005] To address the aforementioned problems in the existing technology, the purpose of this invention is to design a chemical mechanical polishing slurry for silicon wafers that can be applied to intermediate and fine polishing. This slurry, diluted 20 to 39 times, can be applied to intermediate polishing of silicon wafers, resulting in a non-hydrophilic wafer surface that can repair micro-scratches. When diluted 1 to 19 times, the slurry can be applied to fine polishing of silicon wafers, resulting in a highly hydrophilic wafer surface that avoids contamination of abrasive particles with air impurities, thereby achieving low surface defects.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned chemical mechanical polishing slurry for silicon wafers.

[0007] Another object of the present invention is to provide the application of this silicon wafer chemical mechanical polishing slurry.

[0008] To achieve the above technical effects, the present invention adopts the following technical solution:

[0009] A chemical mechanical polishing slurry for silicon wafers comprises, by weight percentage: 10%–30% high-purity silica sol, 0.5%–1% pH adjuster, 0.1%–1% vinylpyrrolidone-quaternary ammonium salt copolymer, and the balance being water.

[0010] In a preferred embodiment, the product comprises, by weight percentage: 15%–25% high-purity silica sol, 0.5%–1% pH adjuster, 0.3% vinylpyrrolidone-quaternary ammonium salt copolymer, and the balance being water.

[0011] In one specific implementation, the high-purity silica sol has a metal ion content of less than 0.1 ppm and a primary particle size of 10–50 nm.

[0012] In one specific embodiment, the vinylpyrrolidone-quaternary ammonium salt copolymer is selected from any one of vinylpyrrolidone-dimethylaminoethyl methacrylate quaternary ammonium salt copolymer, vinylpyrrolidone-vinylimidazolium quaternary ammonium salt copolymer, and vinylpyrrolidone-methacrylamidopropyltrimethylammonium chloride copolymer, preferably vinylpyrrolidone-methacrylamidopropyltrimethylammonium chloride copolymer.

[0013] In one specific implementation, the pH adjuster is selected from any one of potassium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide, and tetraethylammonium hydroxide, preferably tetramethylammonium hydroxide.

[0014] In one specific implementation, the pH value of the silicon wafer chemical mechanical polishing slurry is 10-12.

[0015] On the other hand, the present invention also provides a method for preparing the above-mentioned chemical mechanical polishing slurry for silicon wafers, comprising the following steps:

[0016] 1) Mix the vinylpyrrolidone-quaternary ammonium salt copolymer, pH adjuster and water evenly to obtain a dispersion;

[0017] 2) Add high-purity silica sol to the dispersion in step 1), mix thoroughly and evenly to obtain a silicon wafer chemical mechanical polishing slurry.

[0018] Furthermore, the present invention also provides the application of the above-mentioned silicon wafer chemical mechanical polishing slurry in chemical mechanical polishing.

[0019] In one specific implementation, the silicon wafer chemical mechanical polishing slurry is suitable for wafers with silicon as the substrate.

[0020] In one specific implementation, the silicon wafer chemical mechanical polishing slurry can be diluted 1 to 19 times for fine polishing of silicon wafers, and diluted 20 to 39 times for polishing of silicon wafers; preferably, the pH value after dilution is 8 to 10. The polishing slurry can be diluted 1 to 19 times with water (preferably ultrapure water) for fine polishing of silicon wafers, and can also be diluted 20 to 39 times with water (preferably ultrapure water) for polishing of silicon wafers.

[0021] In one specific implementation, the polishing conditions for the silicon wafer are as follows: polishing machine type HWATSING or EBARA, silicon wafer diameter 200 or 300 mm, polishing pad SUBA series, polishing pressure 200 g / cm. 2 The polishing temperature is 25-30℃, the polishing head and polishing disc rotation speed is 87 / 93 rpm, and the polishing fluid flow rate is 300 mL / min.

[0022] In one specific implementation, the conditions for silicon wafer fine polishing are as follows: polishing machine type HWATSING or EBARA, silicon wafer diameter 200 or 300 mm, polishing pad POLYPAS 27NX series, polishing pressure 150 g / cm. 2 The polishing temperature is 25-30℃, the polishing head and polishing disc rotation speed is 87 / 93 rpm, and the polishing fluid flow rate is 250 mL / min.

[0023] Compared with the prior art, the beneficial effects of the technical solution of the present invention are as follows:

[0024] 1) The silicon wafer chemical mechanical polishing slurry of the present invention can be applied to both medium and fine polishing by adjusting the dilution ratio. It is easy to operate, convenient to store and transport, avoids wafer contamination, and saves costs.

[0025] 2) The silicon wafer chemical mechanical polishing slurry of the present invention, after being diluted 20 to 39 times during the polishing process, has a vinylpyrrolidone-quaternary ammonium salt copolymer content of less than 150 ppm, the wafer surface is non-hydrophilic, and it has a certain removal rate. Simultaneously, it utilizes lactam and N... + The structure adheres to the depressions on the wafer surface, which can repair surface micro-scratches.

[0026] 3) In the silicon wafer chemical mechanical polishing slurry of the present invention, after dilution by 1 to 19 times during the fine polishing process, the content of vinylpyrrolidone-quaternary ammonium salt copolymer is greater than 150 ppm, which is achieved through hydrogen bonding and N + The structure integrates with the wafer surface to form a transparent and flexible film. The exposed C=O structure gives the polished wafer surface strong hydrophilicity, preventing contamination by abrasive particles and air impurities, thereby achieving low surface defects. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the hydrophilicity effect on the wafer surface after polishing in Example 3.

[0028] Figure 2 This is a schematic diagram of the hydrophilicity effect on the wafer surface after polishing in Example 7. Detailed Implementation

[0029] To better understand the technical solution of the present invention, the following embodiments will further illustrate the method provided by the present invention. However, the present invention is not limited to the listed embodiments, but should also include any other known modifications within the scope of the claims of the present invention.

[0030] A chemical mechanical polishing slurry for silicon wafers comprises, by weight percentage: 10%–30% high-purity silica sol, 0.5%–1% pH adjuster, 0.1%–1% vinylpyrrolidone-quaternary ammonium salt copolymer, and the balance being water.

[0031] The preparation method of the high-purity silica sol is not particularly limited and can employ any known method in the prior art. Preferably, the high-purity silica sol has a metal ion content of less than 0.1 ppm, a primary particle size of 10–50 nm, and a secondary particle size of 20–120 nm. Based on the total mass of the polishing slurry, the amount of high-purity silica sol added is 10%, 12%, 15%, 18%, 20%, 25%, 27%, 30%, etc., preferably 15%–25%.

[0032] The vinylpyrrolidone-quaternary ammonium salt copolymer is selected from any one of vinylpyrrolidone-dimethylaminoethyl methacrylate quaternary ammonium salt copolymer, vinylpyrrolidone-vinylimidazolium quaternary ammonium salt copolymer, and vinylpyrrolidone-methacrylamide propyltrimethylammonium chloride copolymer, preferably vinylpyrrolidone-methacrylamide propyltrimethylammonium chloride copolymer, such as polyquaternium-11, polyquaternium-16, polyquaternium-28, etc. The amount of the vinylpyrrolidone-quaternary ammonium salt copolymer added, based on the total mass of the polishing fluid, is 0.1% to 1%, for example, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, etc., but is not limited thereto, and preferably 0.3%.

[0033] The pH adjuster is selected from potassium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide, and tetraethylammonium hydroxide, preferably tetramethylammonium hydroxide. The pH of the silicon wafer chemical mechanical polishing slurry is adjusted to 10-12 using the pH adjuster.

[0034] The preparation method of the silicon wafer chemical mechanical polishing slurry of the present invention is not particularly limited, and for example includes the following steps:

[0035] 1) Mix the vinylpyrrolidone-quaternary ammonium salt copolymer, pH adjuster and water evenly to obtain a dispersion;

[0036] 2) Add high-purity silica sol to the dispersion in step 1), mix thoroughly and evenly to obtain a silicon wafer chemical mechanical polishing slurry.

[0037] The silicon wafer chemical mechanical polishing slurry of the present invention is suitable for chemical mechanical polishing of wafers with silicon as the substrate.

[0038] Specifically, the silicon wafer chemical mechanical polishing slurry of the present invention can be applied to fine polishing and mid-polishing of silicon wafers. Before use, the polishing slurry can be diluted with ultrapure water to the appropriate ratio. For example, diluting the silicon wafer chemical mechanical polishing slurry by 1 to 19 times can be used for fine polishing of silicon wafers, including but not limited to 1x, 2x, 3x, 4x, 5x, 6x, 7x, 8x, 9x, 10x, 11x, 12x, 13x, 14x, 15x, and 16x. The chemical mechanical polishing slurry for silicon wafers can be diluted 20 to 39 times to polish silicon wafers, including but not limited to 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, and 39 times. Preferably, the pH value of the diluted polishing slurry is 8 to 10.

[0039] In a preferred embodiment, the polishing conditions for the silicon wafer are: polishing machine type HWATSING or EBARA, silicon wafer diameter 200 or 300 mm, polishing pad SUBA series, and polishing pressure 200 g / cm. 2 The polishing temperature is 25-30℃, the polishing head and polishing disc rotation speed is 87 / 93 rpm, and the polishing fluid flow rate is 300 mL / min.

[0040] In a preferred embodiment, the conditions for fine polishing of the silicon wafer are: polishing machine type HWATSING or EBARA, silicon wafer diameter 200 or 300 mm, polishing pad POLYPAS 27NX series, and polishing pressure 150 g / cm. 2 The polishing temperature is 25-30℃, the polishing head and polishing disc rotation speed is 87 / 93 rpm, and the polishing fluid flow rate is 250 mL / min.

[0041] The present invention will be further explained and illustrated below through more specific embodiments, but these do not constitute any limitation.

[0042] The main raw material sources used in the embodiments of this invention are as follows:

[0043] High-purity silica sol: primary particle size 10-50 nm;

[0044] Vinylpyrrolidone-quaternary ammonium salt copolymers: all purchased from Beijing Innocare Technology Co., Ltd., including vinylpyrrolidone-dimethylaminoethyl methacrylate quaternary ammonium salt copolymer polyquaternary ammonium salt-11, vinylpyrrolidone-vinylimidazolium quaternary ammonium salt copolymer polyquaternary ammonium salt-16, and vinylpyrrolidone-methacrylamidopropyltrimethylammonium chloride copolymer polyquaternary ammonium salt-28.

[0045] Unless otherwise specified, all other reagents are ordinary raw materials purchased from the market.

[0046] Examples 1-8

[0047] A chemical mechanical polishing slurry for silicon wafers containing a vinylpyrrolidone-quaternary ammonium salt copolymer was prepared. The composition and mass percentage of the raw materials, excluding water, are shown in Table 1. The balance is ultrapure water, and the sum of the mass percentages of all components is 100%. The steps are as follows:

[0048] 1) Mix the vinylpyrrolidone-quaternary ammonium salt copolymer, pH adjuster and water evenly to obtain a dispersion;

[0049] 2) Add high-purity silica sol to the dispersion in step 1), mix thoroughly and evenly to obtain a silicon wafer chemical mechanical polishing slurry.

[0050] Table 1. Composition of raw materials for silicon wafer chemical mechanical polishing slurry in the examples.

[0051]

[0052]

[0053]

[0054] Note: The POU content in the table above refers to the content after dilution according to the corresponding dilution factor.

[0055] Comparative Example 1

[0056] Referring to the formulation and preparation method of Example 3, the only difference is that polyquaternium-28 is not added to the formulation, while other operating conditions and parameters remain unchanged, and a polishing solution with a pH of 9.5 is obtained.

[0057] Comparative Example 2

[0058] Referring to the formulation and preparation method of Example 3, the only difference is that the polyquaternium-28 in the formulation is replaced with an equal mass of vinylpyrrolidone-vinyl acetate copolymer, while other operating conditions and parameters remain unchanged, to obtain a polishing solution with a pH of 9.5.

[0059] Comparative Example 3

[0060] Referring to the formulation and preparation method of Example 7, the only difference is that polyquaternium-28 is not added to the formulation, while other operating conditions and parameters remain unchanged, and a polishing solution with a pH of 8.5 is obtained.

[0061] Comparative Example 4

[0062] Referring to the formulation and preparation method of Example 7, the only difference is that the polyquaternium-28 in the formulation is replaced with an equal mass of vinylpyrrolidone-vinyl acetate copolymer, while other operating conditions and parameters remain unchanged, to obtain a polishing solution with a pH of 8.5.

[0063] Applications of polishing slurries prepared in Examples 1-8 and Comparative Examples 1-4:

[0064] The silicon wafers used were 300mm in diameter and were provided by Shandong Yuanjing Electronics Technology Co., Ltd.

[0065] Polishing conditions are as follows: Polishing machine: HWATSING-300B. Rough polishing conditions: SUBA800 polishing pad, polishing pressure: 300g / cm. 2 The polishing temperature was 25–30℃, the polishing head and disc rotation speed was 87 / 93 rpm, the polishing time was 60 seconds, and the polishing fluid flow rate was 300 mL / min. For intermediate polishing, the polishing pad was SUBA400, and the polishing pressure was 200 g / cm³. 2 The polishing temperature was 25–30℃, the polishing head and disc rotation speed was 87 / 93 rpm, the polishing time was 60 seconds, and the polishing fluid flow rate was 300 mL / min. Fine polishing conditions included a POLYPAS 275NX polishing pad and a polishing pressure of 150 g / cm². 2 The polishing pad temperature was 25℃, the polishing head and polishing disc rotation speed was 83 / 97 rpm, the polishing time was 120s, and the polishing fluid flow rate was 250mL / min.

[0066] Table 2 shows the statistics of the number of surface defects and water contact angle of silicon wafers after fine polishing of Comparative Examples 1-2 and Examples 1-4 using the polishing solution of the present invention.

[0067] Table 3 shows the statistics of the number of scratches and water contact angles on the silicon wafer surface after polishing in Comparative Examples 3-4 and Examples 5-8 of the present invention.

[0068] Silicon wafer surface defect count: Using the Skyverse SP3 defect detection device, defects larger than 40nm on the wafer surface were detected along with their coordinates. Then, the defects in the detected defect coordinates were observed using a scanning electron microscope (SEM), and the defect count was recorded.

[0069] Water contact angle on silicon wafer surface: Using a Dataphysics OCA25 video optical contact angle meter, 2μL of water was dropped onto the wafer surface, and the contact angle value was calculated using a five-point fitting method.

[0070] Number of scratches on silicon wafer surface: Before and after polishing, the number of scratches on the silicon wafer surface was observed using an optical microscope at 1000x magnification.

[0071] Table 2. Number of surface defects and water contact angle of silicon wafers after fine polishing in Comparative Examples 1-2 and Examples 1-4.

[0072]

[0073]

[0074] Table 3 shows the number of scratches and water contact angles on the polished silicon wafer surface in Comparative Examples 3-4 and Examples 5-8.

[0075] Serial Number Number of scratches after rough polishing Number of scratches after polishing Water contact angle (°) Comparative Example 3 15 15 81.8 Comparative Example 4 16 10 62.6 Example 5 18 5 57.7 Example 6 15 3 55.4 Example 7 14 0 52.6 Example 8 15 1 53.7

[0076] Compared to Example 3, Comparative Example 1 did not contain the vinylpyrrolidone-quaternary ammonium salt copolymer, while Comparative Example 2 contained the vinylpyrrolidone-vinyl acetate copolymer. Table 2 shows that the polymer can reduce the number of surface defects to some extent during the fine polishing process. The reason for this is that Comparative Example 1 lacked a polymer, and the alkaline additives and high-purity silica sol directly contacted the wafer. Due to chemical corrosion and particle residue, the surface defects were the most numerous. After polishing, the surface had a high water contact angle, forming a hydrophobic surface. The polymer in Comparative Example 2 lacked a quaternary ammonium salt structure and failed to provide comprehensive protection for the wafer surface or high-purity silica sol. The surface defects were only partially improved, and while the water contact angle decreased, the optimal effect was not achieved. In Examples 1-4, the addition of the vinylpyrrolidone-quaternary ammonium salt copolymer further reduced the number of wafer surface defects and the water contact angle, forming a strongly hydrophilic surface. The reason for this is that the vinylpyrrolidone-quaternary ammonium salt copolymer simultaneously possesses lactam and N... + The structure can be wrapped around the silica sol to prevent direct contact between the silica sol and the wafer surface. During polishing, the vinylpyrrolidone-quaternary ammonium salt copolymer forms bonds through hydrogen bonds and N... + The structure integrates with the wafer surface, forming a transparent, flexible thin film. The exposed C=O structure endows the wafer surface with strong hydrophilicity, preventing contamination by abrasive particles and airborne impurities, thereby achieving low surface defects and a low water contact angle. For example... Figure 1 As shown, after polishing the wafer using Example 3, the surface exhibits strong hydrophilicity. Table 2 data shows that the number of defects above 40nm on the wafer surface in Examples 1-4 is below 80, and the water contact angle is below 10°, meeting the requirements of most customers.

[0077] Compared to Example 7, Comparative Example 3 did not contain the vinylpyrrolidone-quaternary ammonium salt copolymer, while Comparative Example 4 contained the vinylpyrrolidone-vinyl acetate copolymer. Table 3 shows that the polymer can reduce the number of surface scratches to some extent during the polishing process. The reason for this is that Comparative Example 3 did not contain a polymer, so the alkaline additive directly contacted the wafer surface, resulting in a uniform removal rate at each location, thus failing to eliminate surface scratches. The vinylpyrrolidone-vinyl acetate copolymer in Comparative Example 4 had a lower molecular weight than polyquaternary ammonium salt-28, resulting in less tight adsorption at the scratches on the wafer surface, thus only providing some improvement. In Examples 5-8, the addition of the vinylpyrrolidone-quaternary ammonium salt copolymer further reduced the number of surface scratches on the wafer after polishing. The reason for this is... Figure 2 To demonstrate the hydrophilicity effect of the wafer surface after polishing in Example 7, compared to Examples 1-4, the polishing solution has a lower polyquaternium salt content and a higher water contact angle; the polyquaternium salt is produced through lactam and N... + The structure adheres to the depressions on the wafer surface, resulting in a low removal rate in the depressions and a high removal rate around them. Polishing can make the surface smooth and repair micro-scratches.

[0078] In summary, the polishing slurry of this invention, diluted 1-19 times, can be applied to the fine polishing of silicon wafers. By controlling the content of vinylpyrrolidone-quaternary ammonium copolymer, the number of defects above 40nm on the wafer surface after fine polishing is reduced to below 50, the number of defects above 60nm to below 10, and the number of defects above 90nm to 0. Simultaneously, the water contact angle on the wafer surface after polishing is below 10°, and the wafer surface exhibits strong hydrophilicity, preventing contamination by abrasive particles and airborne impurities. The polishing slurry of this invention, diluted 20-39 times, can be applied to the polishing of silicon wafers. By controlling the content of vinylpyrrolidone-quaternary ammonium copolymer, the number of scratches on the wafer surface after intermediate polishing is reduced to below 5.

[0079] Although the present invention has been described in detail through the preferred embodiments described above, it should be understood that the above description should not be considered as limiting the present invention. Those skilled in the art will understand that modifications or adjustments can be made to the present invention under the guidance of this specification. These modifications or adjustments should also be within the scope defined by the claims of the present invention.

Claims

1. A chemical mechanical polishing slurry for silicon wafers, characterized in that, It consists of the following components by mass percentage: 10%–30% high-purity silica sol, 0.5%–1% pH adjuster, 0.1%–1% vinylpyrrolidone-quaternary ammonium salt copolymer, and the balance being water; The chemical mechanical polishing slurry for silicon wafers has a pH value of 10-12, and by adjusting the dilution ratio, it can be applied to both medium and fine polishing. During the polishing process, the content of vinylpyrrolidone-quaternary ammonium salt copolymer after dilution by 20 to 39 times is less than 150 ppm; During the fine polishing process, the content of vinylpyrrolidone-quaternary ammonium salt copolymer after dilution of 1 to 19 times is greater than 150 ppm; The vinylpyrrolidone-quaternary ammonium salt copolymer is selected from any one of vinylpyrrolidone-dimethylaminoethyl methacrylate quaternary ammonium salt copolymer, vinylpyrrolidone-vinylimidazolium quaternary ammonium salt copolymer, and vinylpyrrolidone-methacrylamidopropyltrimethylammonium chloride copolymer.

2. The silicon wafer chemical mechanical polishing slurry according to claim 1, characterized in that, It consists of the following components: 15%–25% high-purity silica sol, 0.5%–1% pH adjuster, 0.3% vinylpyrrolidone-quaternary ammonium salt copolymer, and the balance being water.

3. The silicon wafer chemical mechanical polishing slurry according to claim 1 or 2, characterized in that, The high-purity silica sol has a metal ion content of less than 0.1 ppm and a primary particle size of 10–50 nm.

4. The silicon wafer chemical mechanical polishing slurry according to claim 1, characterized in that, The vinylpyrrolidone-quaternary ammonium salt copolymer is a vinylpyrrolidone-methacrylamide-propyltrimethylammonium chloride copolymer.

5. The silicon wafer chemical mechanical polishing slurry according to claim 1 or 2, characterized in that, The pH adjuster is selected from any one of potassium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide, and tetraethylammonium hydroxide.

6. The silicon wafer chemical mechanical polishing slurry according to claim 5, characterized in that, The pH adjuster is tetramethylammonium hydroxide.

7. A method for preparing a chemical mechanical polishing slurry for silicon wafers according to any one of claims 1-6, characterized in that, Includes the following steps: 1) Mix the vinylpyrrolidone-quaternary ammonium salt copolymer, pH adjuster and water evenly to obtain a dispersion; 2) Add high-purity silica sol to the dispersion in step 1), mix thoroughly and evenly to obtain a silicon wafer chemical mechanical polishing slurry.

8. The application of the silicon wafer chemical mechanical polishing slurry according to any one of claims 1-6 in chemical mechanical polishing.

9. The application of the silicon wafer chemical mechanical polishing slurry according to claim 8 in chemical mechanical polishing, characterized in that, Applicable to wafer types with silicon as the substrate.

10. The application of the silicon wafer chemical mechanical polishing slurry according to claim 8 or 9 in chemical mechanical polishing, characterized in that, The silicon wafer chemical mechanical polishing slurry can be diluted 1 to 19 times for fine polishing of silicon wafers, and diluted 20 to 39 times for polishing of silicon wafers.

11. The application of the silicon wafer chemical mechanical polishing slurry according to claim 10 in chemical mechanical polishing, characterized in that, The diluted pH value is 8-10.

12. The application of the silicon wafer chemical mechanical polishing slurry according to claim 10 in chemical mechanical polishing, characterized in that, The conditions for polishing silicon wafers are as follows: polishing machine type HWATSING or EBARA, silicon wafer diameter 200 or 300 mm, polishing pad SUBA series, polishing pressure 200 g / cm. 2 The polishing temperature is 25-30℃, the polishing head and polishing disc rotation speed is 87 / 93 rpm, and the polishing fluid flow rate is 300 mL / min.

13. The application of the silicon wafer chemical mechanical polishing slurry according to claim 12 in chemical mechanical polishing, characterized in that, The conditions for fine polishing of silicon wafers are: polishing machine type HWATSING or EBARA, silicon wafer diameter 200 or 300 mm, polishing pad POLYPAS27NX series, and polishing pressure 150 g / cm. 2 The polishing temperature is 25-30℃, the polishing head and polishing disc rotation speed is 87 / 93 rpm, and the polishing fluid flow rate is 250 mL / min.

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