A high-suspension polishing liquid suitable for large-size silicon wafers, preparation method and use

Abstract

The present invention relates to a high suspension grinding liquid suitable for large-size silicon wafers, which comprises 5-10 parts of catalyst auxiliary agent, 10-20 parts of catalyst precursor, 5-15 parts of oxidant, 5-20 parts of dispersant, 5-20 parts of pH regulator, 0.2-5 parts of surfactant and 15-45 parts of deionized water according to parts by weight. The present invention also discloses a preparation method and use of the above-mentioned grinding liquid. The catalyst auxiliary agent of the present invention contains a pyridine group and a carboxyl group at the same time, which has the effect of accelerating the gelation process, reducing the activation energy of the reaction and improving the suspension. The oxidant anthraquinone-2-sodium sulfonate has a light-excited oxidation effect, which can significantly improve the photocatalytic efficiency, and the methylene dinaphthalene sodium sulfonate dispersant can improve the dispersion and suspension. Octadecanol polyoxyethylene ether as a surfactant can produce an electrostatic repulsion effect with a catalyst auxiliary agent, a dispersant, etc., and enhance its suspension to abrasive. The present invention improves the suspension of the grinding liquid by synergistically combining multiple components.

Description

Technical Field

[0001] The invention belongs to the field of semiconductor manufacturing technology, and in particular relates to a high-suspension polishing liquid suitable for large-size silicon wafers, a preparation method and use thereof. Background Art

[0002] With the development of semiconductor material technology, higher requirements are placed on the specifications and quality of silicon wafers. The market demand for large-diameter silicon wafers suitable for micro-processing will increase day by day.

[0003] In the manufacturing process of large-size single-crystal silicon wafers for semiconductors, the grinding technical indicators of silicon wafers are more stringent, requiring the silicon wafers to have a higher removal rate, smaller thickness difference and lower damage layer depth, etc. The grinding process is a key step in maintaining the quality of silicon wafers, and the grinding fluid used in this step is one of the core technologies that affect the grinding indicators. The dispersion and suspension of the grinding fluid play a decisive role in the grinding effect. At the same time, the grinding fluid also poses new technical challenges to the grinding rate and surface quality of silicon wafers.

[0004] CN114751438B provides an aluminum oxide abrasive, a preparation method, a use, a silicon wafer grinding liquid containing the same, and a grinding method. The aluminum oxide abrasive is a two-dimensional flaky circular aluminum oxide abrasive, and its surface morphology is porous and smooth without sharp edges and corners, and the particle size is uniform and the particle size distribution is narrow. The silicon wafer grinding liquid comprises: 0.1-5 parts of a dispersant, 0.1-10 parts of a polyol, 1-10 parts of a pH regulator, 0.1-5 parts of a suspending agent, 0.05-0.1 parts of a surfactant, 0.001-0.05 parts of a rust inhibitor, 0.05-0.5 parts of a defoaming agent, 10-20 parts of an aluminum oxide abrasive, 5-20 parts of α-phase aluminum oxide, and 60-80 parts of water. The silicon wafer grinding liquid of the present invention has the advantages of good abrasive suspension, not easy to scratch, and high grinding efficiency. Summary of the invention

[0005] The technical problem solved by the present invention is that the current silicon wafer grinding liquid has poor suspension, the surface quality of the silicon wafer after grinding with the grinding liquid is not high, and there are many scratches.

[0006] In view of the technical problems existing in the prior art, the present invention designs a preparation method and use of a highly suspended polishing liquid suitable for large-size silicon wafers.

[0007] In order to solve the above-mentioned technical problems, the present invention adopts the following solutions:

[0008] A high-suspension polishing liquid suitable for large-size silicon wafers, characterized in that it comprises the following components calculated by weight:

[0009]

[0010] Wherein, the catalyst promoter is one of 2-methylpyridine-4-carboxylic acid, 6-carboxypyridine-2-methanol, 2-carboxypyridine-5-boric acid, 5-carboxy-2,3-diaminopyridine, and 5,6-dimethyl-3-carboxy-2-pyridone;

[0011] The catalyst precursor is one of tetrabutyl titanate and ethyl orthosilicate;

[0012] The mass ratio of the catalyst promoter to the catalyst precursor is 1-2:2-4;

[0013] The oxidant is one of sodium pyridine-4-acetate, sodium anthraquinone-2-sulfonate, cyanoethylene, and 2,4,6-triphenylpyridinium tetrafluoroborate.

[0014] The dispersant is one or more of sodium methylene dinaphthalene sulfonate, sodium dodecylbenzene sulfonate, sodium dodecyl succinate, sodium dodecyl sulfate, sodium polyacrylate, sodium hexametaphosphate, sodium α-olefin sulfonate and sodium secondary alkyl sulfonate.

[0015] Furthermore, the pH regulator is one or more of sodium hydroxide, potassium hydroxide, monoethanolamine, and triethanolamine.

[0016] Furthermore, the surfactant is one or more of C12-C16 fatty alcohol polyoxyethylene ether, C18 fatty alcohol polyoxyethylene ether, octylphenol polyoxyethylene ether, and acetylene glycol polyoxyethylene ether.

[0017] Further, the catalyst promoter is 2-methylpyridine-4-carboxylic acid;

[0018] The catalyst precursor is tetrabutyl titanate;

[0019] The oxidant is sodium anthraquinone-2-sulfonate.

[0020] Furthermore, the dispersant is sodium methylene dinaphthalene sulfonate;

[0021] The pH regulator is monoethanolamine or triethanolamine;

[0022] The surfactant is stearyl alcohol polyoxyethylene ether.

[0023] The present invention also discloses a method for preparing a high-suspension polishing liquid suitable for large-size silicon wafers, which is characterized by comprising the following steps:

[0024] Step 1: Stir deionized water and a pH regulator evenly at room temperature at 100-300 rpm for 5-10 minutes to obtain a pH regulator system;

[0025] Step 2: adding the catalyst precursor to the pH regulator system obtained in step 1 to hydrolyze it into titanium dioxide, wherein the conditions are a rotation speed of 300-1000 rpm, a temperature of 30-60° C., and a time of 5-15 min to obtain a solution system A;

[0026] Step 3: adding a catalyst promoter to the above solution system A, wherein the conditions are a rotation speed of 300-1000 rpm, a temperature of 30-60° C., and a time of 5-15 min to obtain a solution system B;

[0027] Step 4: Add the oxidant, dispersant and surfactant to the above solution system B respectively, wherein the conditions are rotation speed 300-1000rpm, temperature 30-60°C, time 10-30min, to obtain a high suspension polishing liquid suitable for large-size silicon wafers.

[0028] The present invention also discloses a grinding process for a high-suspension grinding liquid suitable for large-size silicon wafers, which is characterized by comprising the following steps:

[0029] Step 1: dilute the prepared high-suspension polishing liquid suitable for large-size silicon wafers by 15-35 times to obtain a diluted high-suspension polishing liquid for standby use;

[0030] Step 2: setting ultraviolet light to irradiate the surface of the silicon wafer, the ultraviolet light wavelength is 100-400nm;

[0031] Step 3: Add the grinding abrasive at a mass fraction of 10%-30% to the diluted high-suspension grinding liquid obtained in step 1 and stir for 8-15 minutes at a speed of 30-200 rpm to obtain a high-suspension grinding liquid with the grinding abrasive;

[0032] Step 4: Use the high suspension grinding liquid added with grinding abrasive obtained in step 3 to grind the substrate, which is an 8 / 12 inch silicon wafer, wherein the grinding conditions are a grinding machine speed of 50-100r / min, a pressure of 60-100kg, a flow rate of 5-200mL / min, and a grinding time of 10-30min.

[0033] Furthermore, the grinding abrasive in step 3 is one of silicon dioxide, cerium oxide, diamond, boron nitride, zirconium oxide, and aluminum oxide;

[0034] The particle size of the aluminum oxide grinding abrasive is in the range of 1-20 μm;

[0035] In the present invention, the grinding abrasive may further preferably be aluminum oxide;

[0036] In the present invention, the particle size range of the aluminum oxide grinding abrasive may further preferably be 5-15 μm.

[0037] The invention also discloses a use of a high-suspension polishing liquid suitable for large-size silicon wafers in the field of silicon wafer polishing.

[0038] In some specific embodiments of the present invention, the catalyst additive may preferably be 8-10 parts; the catalyst precursor 15-20 parts; the oxidant 10-15 parts; the dispersant 5-15 parts; the pH adjuster 5-15 parts; the surfactant 0.2-3 parts; and the deionized water 20-35 parts.

[0039] In the present invention, the catalyst adjuvant and the catalyst precursor tetrabutyl titanate can promote the gelation of titanium dioxide. The titanium dioxide gel not only has an excellent photocatalytic effect, but also can be evenly dispersed in water, improves suspension, and thus improves grinding quality.

[0040] In the present invention, the oxidant can have an electrostatic repulsion effect with the catalyst additive and the hydroxyl groups on the titanium dioxide, thereby improving the suspension of the polishing liquid.

[0041] In some practical applications, the high suspension polishing liquid of the present invention is also applicable to semiconductor materials such as gallium nitride and sapphire.

[0042] It should be noted that, in the present invention, unless otherwise specified, the specific meaning of "including" in relation to composition limitations and descriptions includes both open-ended "including", "comprising" and similar meanings, and closed-ended "consisting of..." and similar meanings.

[0043] The present invention provides a high-suspension polishing liquid suitable for large-size silicon wafers, a preparation method and use thereof, which have the following beneficial effects:

[0044] (1) The catalyst auxiliary agent 2-methylpyridine-4-carboxylic acid used in the present invention contains both a pyridine group and a carboxyl group, which have an electrostatic repulsion effect with the sulfonic acid group contained in the catalyst precursor sodium anthraquinone-2-sulfonate, thereby improving the suspension of the polishing liquid.

[0045] (2) The oxidant anthraquinone-2-sodium sulfonate used in the present invention has the following advantages:

[0046] First, sodium anthraquinone-2-sulfonate has a photo-excited oxidation effect, which can significantly improve the photocatalytic efficiency.

[0047] Secondly, the two polar groups, phenolic group and sulfonic acid group, contained in sodium anthraquinone-2-sulfonate can act as buffers to stabilize the pH value of the grinding liquid and ensure the smooth progress of the reaction.

[0048] Thirdly, since sodium anthraquinone-2-sulfonate contains sulfonic acid groups, it can have an electrostatic repulsion effect with the catalyst additive and the hydroxyl groups on titanium dioxide, thereby improving the suspension of the polishing liquid.

[0049] (3) The sodium methylene dinaphthalene sulfonate dispersant in the present invention has the following advantages:

[0050] First, sodium methylene dinaphthalene sulfonate can be adsorbed on the surface of solid particles to produce a sufficiently high potential barrier to disperse the particles and achieve the characteristics of dispersion and suspension.

[0051] Secondly, sodium methylene dinaphthalene sulfonate and the carboxyl group of the catalyst additive can achieve the effect of electrostatic repulsion, synergistically improve the dispersibility of the grinding abrasive, reduce agglomeration, and improve the grinding quality.

[0052] (4) The octadecyl alcohol polyoxyethylene ether in the present invention has the following advantages as a surfactant:

[0053] First, the alcohol hydroxyl group contained in octadecyl alcohol polyoxyethylene ether can produce an electrostatic repulsion effect with catalyst additives, dispersants, etc., which can enhance its suspension of abrasives.

[0054] Secondly, the octadecyl alcohol polyoxyethylene ether surfactant can also synergize with the phenoloxy group in the oxidant, utilizing the characteristic of the phenoloxy group to enhance the molecular polarity, thereby jointly enhancing the solubility of dispersants, catalyst additives and other substances, avoiding the agglomeration of abrasives, that is, enhancing their dispersion and suspension properties.

[0055] (5) The present invention designs a special catalytic system with unique advantages:

[0056] The present invention is different from other titanium dioxide nanoparticle catalytic systems in that the catalyst used in the present invention is titanium dioxide gel prepared from the catalyst precursor tetrabutyl titanate.

[0057] The main reason is that although titanium dioxide has hydrophilic groups, its water solubility is not ideal. It is very likely to agglomerate during the grinding process, affecting the grinding effect. Titanium dioxide gel not only has an excellent photocatalytic effect, but can also be evenly dispersed in water, thereby improving the grinding quality. In addition, titanium dioxide gel also has a certain viscosity, which helps to improve the suspension of the grinding liquid.

[0058] Therefore, the high-suspension polishing liquid suitable for large-size silicon wafers of the present invention has very good application prospects and large-scale industrial promotion potential in the field of large-size silicon wafer polishing. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a diagram showing the suspension effect of the high-suspension polishing liquid of Example 1 of the present invention after being left to stand for 5 days;

[0060] Figure 2 This is a diagram showing the suspension effect of the grinding liquid of Comparative Example 2 of the present invention after being left to stand for 5 days;

[0061] Figure 3This is a diagram showing the suspension effect of the grinding liquid of Comparative Example 4 of the present invention after being left to stand for 5 days. DETAILED DESCRIPTION

[0062] The present invention will be further described below in conjunction with specific embodiments and accompanying drawings:

[0063] Table 1: Example 1-Example 8

[0064]

[0065] Table 2: Comparative Examples 1-6

[0066]

[0067] Preparation method of high suspension polishing liquid suitable for large size silicon wafers

[0068] The preparation method of Embodiment 1-3 comprises the following steps:

[0069] Step 1: Stir deionized water and a pH regulator evenly at room temperature at 200 rpm for 8 minutes to obtain a pH regulator system;

[0070] Step 2: adding the catalyst precursor to the pH regulator system obtained in step 1 to hydrolyze it into titanium dioxide, wherein the conditions are a rotation speed of 800 rpm, a temperature of 50° C., and a time of 10 min to obtain a solution system A;

[0071] Step 3: adding a catalyst promoter to the above solution system A, wherein the conditions are a rotation speed of 800 rpm, a temperature of 50° C., and a time of 10 min to obtain a solution system B;

[0072] Step 4: Add the oxidant, dispersant and surfactant to the above solution system B respectively, wherein the conditions are a rotation speed of 800 rpm, a temperature of 50° C., and a time of 20 min to obtain a high suspension polishing liquid suitable for large-size silicon wafers.

[0073] Wherein, the preparation method of embodiment 4-6 comprises the following steps:

[0074] Step 1: Stir deionized water and a pH regulator evenly at room temperature at 100 rpm for 10 minutes to obtain a pH regulator system;

[0075] Step 2: adding the catalyst precursor to the pH regulator system obtained in step 1 to hydrolyze it into titanium dioxide, wherein the conditions are a rotation speed of 300 rpm, a temperature of 60° C., and a time of 15 min to obtain a solution system A;

[0076] Step 3: adding a catalyst promoter to the above solution system A, wherein the conditions are a rotation speed of 300 rpm, a temperature of 60° C., and a time of 15 min to obtain a solution system B;

[0077] Step 4: Add the oxidant, dispersant and surfactant to the above solution system B respectively, wherein the conditions are a rotation speed of 300 rpm, a temperature of 60° C., and a time of 30 min to obtain a high suspension polishing liquid suitable for large-size silicon wafers.

[0078] Wherein, the preparation method of embodiment 7-8 comprises the following steps:

[0079] Step 1: Stir deionized water and pH regulator at 300 rpm at room temperature for 5 minutes to obtain p H regulator system;

[0080] Step 2: adding the catalyst precursor to the pH regulator system obtained in step 1 to hydrolyze it into titanium dioxide, wherein the conditions are a rotation speed of 1000 rpm, a temperature of 30° C., and a time of 5 min to obtain a solution system A;

[0081] Step 3: adding a catalyst promoter to the above solution system A, wherein the conditions are a rotation speed of 1000 rpm, a temperature of 30° C., and a time of 5 min to obtain a solution system B;

[0082] Step 4: Add the oxidant, dispersant and surfactant to the above solution system B respectively, wherein the conditions are a rotation speed of 1000 rpm, a temperature of 30° C., and a time of 10 min to obtain a high suspension polishing liquid suitable for large-size silicon wafers.

[0083] The preparation methods of the comparative examples of the present invention are all the same as those of Example 1.

[0084] About the polishing process of high suspension polishing slurry suitable for large size silicon wafers

[0085] The following steps are involved:

[0086] Step 1: dilute the prepared high-suspension polishing liquid suitable for large-size silicon wafers by 25 times to obtain a diluted high-suspension polishing liquid for standby use;

[0087] Step 2: setting ultraviolet light to irradiate the silicon wafer surface, the ultraviolet light wavelength is 250nm;

[0088] Step 3: Add 20% aluminum oxide grinding abrasive at a mass fraction to the diluted high-suspension grinding liquid obtained in step 1 and stir for 10 minutes at a speed of 150 rpm to obtain a high-suspension grinding liquid with the addition of grinding abrasive; wherein the particle size of the aluminum oxide grinding abrasive is 10 μm.

[0089] Step 4: Use the high suspension grinding liquid with grinding abrasive added obtained in step 3 to grind the substrate, which is an 8 / 12 inch silicon wafer, wherein the grinding conditions are a grinding machine speed of 100 r / min, a pressure of 80 kg, a flow rate of 100 mL / min, and a grinding time of 20 min.

[0090] About performance testing and description:

[0091] Suspension time test method:

[0092] After stirring the grinding liquid and water at a ratio of 1:25 for 5-15 minutes, add 20% of the grinding abrasive by mass into the above system, stir for 5-15 minutes, let it stand, and observe and record the suspension time of the grinding abrasive.

[0093] Table 3: Test results

[0094] Example Suspension time Example Suspension time Example 1 12 days Example 8 10 days Example 2 8 days Comparative Example 1 6 days Example 3 11 days Comparative Example 2 5 days Example 4 9 days Comparative Example 3 4 days Example 5 10 days Comparative Example 4 3 days Example 6 9.5 days Comparative Example 5 7 days Example 7 10 days Comparative Example 6 5 days

[0095] Analysis of the test results:

[0096] It can be seen from the test results in Table 3 that the suspension effect of the high suspension polishing liquids of Examples 1-8 of the present invention is better than that of the polishing liquids of Comparative Examples 1-6.

[0097] It can be seen from comparative examples 1 and 3 that Example 1 can significantly increase the suspension time of the grinding liquid due to the catalyst auxiliary agent and oxidant containing special groups, and the carboxyl group and sulfonic acid group can have a good synergistic effect with other components.

[0098] It can be seen from Comparative Example 2 that although titanium dioxide is used as a catalyst, the titanium dioxide gel has excellent dispersibility and certain viscosity, so it can better play the role of other functional components and significantly improve the suspension of the grinding liquid.

[0099] It can be seen from Comparative Examples 4 and 5 that the addition of cationic dispersants and surfactants not only fails to achieve a dispersing effect, but also causes agglomeration due to electrostatic effects, thereby reducing the suspension time of the grinding liquid.

[0100] Although no catalyst additive and catalyst precursor were added to Comparative Example 6, the suspension time of the prepared grinding liquid was still better than that of Comparative Examples 3 and 4 due to the synergistic effect between the oxidant, dispersant and surfactant, and no titanium dioxide nanoparticles with poor water solubility were added.

[0101] Further comparison is made through the attached drawings in the specification:

[0102] Figure 1 This is a diagram showing the suspension effect of the high-suspension polishing liquid of Example 1 of the present invention after being left to stand for 5 days; Figure 2 This is a diagram showing the suspension effect of the grinding liquid of Comparative Example 2 of the present invention after being left to stand for 5 days; Figure 3 This is a diagram showing the suspension effect of the grinding liquid of Comparative Example 4 of the present invention after being left to stand for 5 days.

[0103] from Figure 1 , 2 It can be seen from Figures 3 and 4 that the high suspension polishing liquid of Example 1 of the present invention still has good suspension properties after being left to stand for 5 days.

[0104] After 5 days, the abrasive in Comparative Example 2 has settled a lot, and the abrasive in Comparative Example 4 has almost completely sunk to the bottom.

[0105] The high suspension polishing liquid suitable for large-size silicon wafers, the preparation method and the use of the present invention have the following advantages compared with the prior art:

[0106] In the present invention, the suspension of the system is improved by using sodium methylene dinaphthalene sulfonate as a dispersant, further, the suspension of the system is improved by using sodium anthraquinone-2-sulfonate as an oxidant, further, the suspension of the system is improved by using 2-methylpyridine-4-carboxylic acid as a catalyst adjuvant and tetrabutyl titanate as a catalyst precursor, and further, octadecyl alcohol polyoxyethylene ether is used as a surfactant to assist in improving the suspension of the system. The polishing liquid prepared by the superposition of multiple effects has extremely excellent suspension performance and can significantly improve the polishing effect.

[0107] The present invention is described exemplarily above in conjunction with the embodiments and drawings. It is obvious that the implementation of the present invention is not limited to the above-mentioned methods. As long as various improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A high suspension polishing liquid suitable for large-size silicon wafers, characterized in that: Calculated by weight, it includes the following components: Catalyst additive 5-10 parts; 10-20 parts of catalyst precursor; 5-15 parts of oxidant; Dispersant 5-20 parts; 5-20 parts of pH regulator; Surfactant 0.2-5 parts; 15-45 parts of deionized water; Wherein, the catalyst promoter is one of 2-methylpyridine-4-carboxylic acid, 6-carboxypyridine-2-methanol, 2-carboxypyridine-5-boric acid, 5-carboxy-2,3-diaminopyridine, and 5,6-dimethyl-3-carboxy-2-pyridone; The catalyst precursor is one of tetrabutyl titanate and ethyl orthosilicate; The oxidant is one of sodium pyridine-4-acetate, sodium anthraquinone-2-sulfonate, cyanoethylene, and 2,4,6-triphenylpyridinium tetrafluoroborate; The dispersant is one or more of sodium methylene dinaphthalene sulfonate, sodium dodecylbenzene sulfonate, sodium dodecyl succinate, sodium dodecyl sulfate, sodium polyacrylate, sodium hexametaphosphate, sodium α-olefin sulfonate, and sodium secondary alkyl sulfonate; The surfactant is one or more of C12-C16 fatty alcohol polyoxyethylene ether, C18 fatty alcohol polyoxyethylene ether, octylphenol polyoxyethylene ether, and acetylene glycol polyoxyethylene ether.

2. The high suspension polishing liquid suitable for large-size silicon wafers according to claim 1, characterized in that: The pH regulator is one or more of sodium hydroxide, potassium hydroxide, monoethanolamine and triethanolamine.

3. The high suspension polishing liquid suitable for large-size silicon wafers according to claim 1, characterized in that: The catalyst promoter is 2-methylpyridine-4-carboxylic acid; The catalyst precursor is tetrabutyl titanate; The oxidant is sodium anthraquinone-2-sulfonate.

4. The high suspension polishing liquid suitable for large-size silicon wafers according to claim 2, characterized in that: The dispersant is sodium methylene dinaphthalene sulfonate; The pH regulator is monoethanolamine or triethanolamine; The surfactant is C18 fatty alcohol polyoxyethylene ether.

5. A method for preparing a high suspension polishing liquid suitable for large-size silicon wafers according to any one of claims 1 to 4, characterized in that: The steps include: Step 1: Stir deionized water and a pH regulator evenly at room temperature at 100-300 rpm for 5-10 minutes to obtain a pH regulator system; Step 2: adding the catalyst precursor tetrabutyl titanate to the pH regulator system obtained in step 1 to hydrolyze it into titanium dioxide, wherein the conditions are a rotation speed of 300-1000 rpm, a temperature of 30-60° C., and a time of 5-15 min to obtain a solution system A; Step 3: adding a catalyst promoter to the above solution system A, wherein the conditions are a rotation speed of 300-1000 rpm, a temperature of 30-60° C., and a time of 5-15 min to obtain a solution system B; Step 4: Add the oxidant, dispersant and surfactant to the above solution system B respectively, wherein the conditions are rotation speed 300-1000rpm, temperature 30-60°C, time 10-30min, to obtain a high suspension polishing liquid suitable for large-size silicon wafers.

6. A grinding process for a high-suspension grinding liquid suitable for large-size silicon wafers according to any one of claims 1 to 4, characterized in that The following steps are involved: Step 1: dilute the prepared high-suspension polishing liquid suitable for large-size silicon wafers by 15-35 times to obtain a diluted high-suspension polishing liquid for standby use; Step 2: setting ultraviolet light to irradiate the surface of the silicon wafer, the ultraviolet light wavelength is 100-400nm; Step 3: Add the grinding abrasive at a mass fraction of 10%-30% to the diluted high-suspension grinding liquid obtained in step 1 and stir for 8-15 minutes at a speed of 30-200 rpm to obtain a high-suspension grinding liquid with the grinding abrasive added; Step 4: Use the high suspension grinding liquid added with grinding abrasive obtained in step 3 to grind the substrate, which is an 8 / 12 inch silicon wafer, wherein the grinding conditions are a grinding machine speed of 50-100r / min, a pressure of 60-100kg, a flow rate of 5-200mL / min, and a grinding time of 10-30min.

7. The polishing process of the high-suspension polishing liquid suitable for large-size silicon wafers according to claim 6, characterized in that: The grinding abrasive in step 3 is one of silicon dioxide, cerium oxide, diamond, boron nitride, zirconium oxide, and aluminum oxide; The particle size of the aluminum oxide grinding abrasive is in the range of 1-20 μm.

8. Use of the high suspension polishing liquid suitable for large-size silicon wafers as claimed in any one of claims 1 to 4 in the field of silicon wafer polishing.

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