Preparation method and application of high-purity silicon dioxide sol

Abstract

The invention discloses a preparation method and application of high-purity silicon dioxide sol, and belongs to the technical field of functional inorganic nano-material manufacturing, and the method comprises the following steps: firstly, carrying out dilute acid preliminary impurity removal treatment on monatomic silicon powder, washing with water, drying, forming a reaction system by the monatomic silicon powder, water, a catalyst and a recoverable solid defoaming agent, and carrying out solid-liquid separation to obtain high-purity silicon dioxide sol; carrying out two-stage gradient heating reaction to obtain a silica sol primary product; recovering the solid defoaming agent in the silica sol primary product, filtering, carrying out oxidation treatment on the filtered silica sol by adding hydrogen peroxide to carry out two-stage heating oxidation treatment or ultraviolet ozone combined oxidation treatment, and then further removing impurities and concentrating by using mixed bed ion exchange resin and an ultrafiltration process to obtain the silica sol. The silicon dioxide sol is low in conductivity and good in polishing effect, and has a good application prospect in the field of electronic polishing.

Description

Technical Field

[0001] The present invention belongs to the technical field of manufacturing functional inorganic nanomaterials, and particularly relates to a preparation method and application of high-purity silica sol. Background Art

[0002] Silica sol is in a milky white or white liquid state, which is a dispersion of nanoscale silicon dioxide particles in water or a solvent, and has a high specific surface area, good adsorption and stability. As an important inorganic functional material, silica sol plays an irreplaceable role in fields such as semiconductor polishing, catalyst carriers, and electronic coatings. Silica sol can be prepared by methods such as hydrolysis of orthosilicic acid esters (such as the Chinese patent document with publication number CN109665531A), polymerization growth after ion exchange of water glass (such as the Chinese patent document with publication number CN110980745A), hydrolysis and condensation of silicon powder (such as the Chinese patent document with publication number CN108716005A), etc. Among them, the hydrolysis method of elemental silicon has attracted much attention due to the easy availability of raw materials and simple process, but its industrialization still faces the following technical bottlenecks:

[0003] (1) Problem of residual elemental silicon: Incomplete reaction of silicon powder will cause extremely hard elemental silicon nanoparticles to remain in the silica sol, which is likely to cause scratches on the surface of the wafer when used as a polishing liquid, seriously affecting the performance of semiconductor devices;

[0004] (2) Low reaction efficiency and yield: Hydrogen bubbles in the reaction process hinder the contact between silicon powder and the solution, and traditional defoamers (such as silicone-based ones) are prone to residue and difficult to recycle, resulting in a yield of less than 80%;

[0005] (3) Insufficient purity: Alkali metal ions (Na + , K + ) introduced by alkaline catalysts (such as NaOH) are difficult to completely remove, and the conductivity is often higher than 50 μS / cm, which cannot meet the requirements of electronic-grade silica sol.

[0006] The Chinese patent document with publication number CN108716005A discloses a method for preparing silica sol by electrolyzing silicon micro-powder slurry. In this method, silicon micro-powder is mixed and slurried with an alkaline solution, and a bipolar membrane electrolytic cell is used to separate the mixed slurry; the silicate ions in the mixed slurry pass through the anion exchange membrane and enter the anode chamber, where they combine with the hydrogen ions electrolyzed at the anode to be converted into silicic acid solution; the cations in the mixed slurry pass through the cation exchange membrane and enter the cathode chamber, where they are mixed with the hydroxide ions electrolyzed at the cathode to obtain an alkaline solution; as the concentration of the silicic acid solution in the anode chamber increases, silica sol is obtained, but there may be problems such as membrane fouling and high purity requirements for silicon micro-powder.

[0007] The Chinese patent document with the publication number CN118495542A discloses a method for preparing narrow-distribution spherical silica sol using silicon powder. The method includes: dispersing silicon powder in water, heating to 55 - 75 °C to activate the silicon powder; adding an alkali catalyst to the activated silicon powder dispersion, and carrying out a high-temperature and high-pressure reaction under closed conditions, with a reaction pressure of 0.1 - 5 MPa, a reaction temperature of 130 - 200 °C, and a reaction time of 5 - 10 h; the mass ratio of silicon powder, water, and alkali catalyst is 50 - 300:500 - 3000:0.5 - 5. Although this invention simplifies the technological process of preparing silica sol by the hydrolysis method of silicon powder under normal pressure, there are still problems of high equipment requirements and high water consumption.

[0008] The Chinese patent document with the publication number CN101857236A discloses a method for preparing high-concentration silica sol from ultrafine silicon powder. The method includes: taking 20 - 25 parts by mass of silicon powder with a purity of 97% - 99% and a particle size of 500 - 2000 mesh, adding 100 - 200 parts by mass of deionized water, and heating at 50 - 60 °C for 10 - 30 minutes; then, at a temperature of 70 - 90 °C and with stirring, adding an aqueous sodium hydroxide solution with a mass percentage concentration of 0.16% - 0.96% to the mixture of silicon powder and water in portions and controlling the pH value of the reaction solution to be 8.5 - 10.0, and the total stirring reaction time is 6 - 8 hours; then standing at room temperature for 8 - 12 hours and then carrying out vacuum filtration, thus obtaining the high-concentration silica sol. This method has the problem of high purity requirements for silicon fine powder.

[0009] Therefore, research on the preparation of silica sol by the hydrolysis method of elemental silicon is needed to solve the above bottlenecks. Summary of the Invention

[0010] To overcome the problems of difficult removal of a small amount of elemental silicon particle impurities and insufficient purity of silica sol during the preparation of silica sol from elemental silicon, the present invention provides a method for preparing high-purity silica sol, and the prepared silica sol has low conductivity and good polishing effect.

[0011] The specific technical solution adopted is as follows:

[0012] A method for preparing high-purity silica sol includes the following steps:

[0013] (1) After performing preliminary impurity removal treatment of elemental silicon powder with dilute acid, washing with water, and drying, the pretreated silicon powder is obtained; wherein the particle size of the elemental silicon powder is 50 - 500 mesh, and the purity ≥ 95%.

[0014] (2) Carry out a two-stage gradient temperature rise reaction on the reaction system composed of pretreated silicon powder, water, catalyst and recyclable solid defoaming agent. The parameters of the first stage are to maintain at 55-65 °C for 50-70 min, and the parameters of the second stage are to react at 85-95 °C for 4-8 h to obtain the initial product of silica sol;

[0015] (3) Let the initial product of silica sol stand still, recover the solid defoaming agent, then filter, and carry out oxidation treatment on the filtered silica sol. The oxidation treatment method is to add hydrogen peroxide for two-stage temperature rise oxidation treatment or ultraviolet ozone combined oxidation treatment;

[0016] (4) Treat the silica sol obtained in step (3) with a mixed bed ion exchange resin to make the conductivity of the silica sol < 10 μS / cm (alkali metal ion content < 1 ppm);

[0017] (5) Ultrafilter and concentrate the silica sol treated in step (4). During the concentration process, adjust the pH to 9.5-10.0 and add a stabilizer to obtain a silica sol with a silica content ≥ 30 wt% and an average silica particle size of 10-50 nm.

[0018] Specifically, the silica sol prepared by the method of the present invention has high purity, extremely low content of elemental silicon particle impurities therein (the surface roughness Ra < 0.2 nm after wafer polishing), and low content of impurity ions (such as alkali metal ions) (conductivity < 10 μS / cm), and good storage stability.

[0019] Preferably, in step (1), after the preliminary impurity removal treatment of elemental silicon powder with dilute acid, the acid solution is sedimented and separated, and the silicon powder is washed with deionized water until the conductivity ≤ 50 μS / cm to ensure that the acid residue meets the standard.

[0020] Optionally, in step (1), the dilute acid is selected from at least one of dilute hydrochloric acid, dilute sulfuric acid, dilute nitric acid or hydrofluoric acid.

[0021] Specifically, the preliminary impurity removal treatment with dilute acid can remove impurities such as iron, aluminum and calcium, and the concentration and number of acid washes can be appropriately changed according to the purity of the silicon powder. For elemental silicon powder with a particle size ≤ 200 mesh, on the basis of washing with 2%-6% dilute hydrochloric acid, dilute sulfuric acid or dilute nitric acid, 1%-5% hydrofluoric acid is added to break the surface oxide layer, and the washing time is 5-15 min; during the acid washing process, ultrasonic assisted washing with a frequency of 30-50 kHz and a power of 500-800 W is applied to improve the washing efficiency and reduce the acid consumption.

[0022] Specifically, in step (2), the catalyst is selected from tetramethylammonium hydroxide, or a mixture of tetramethylammonium hydroxide and tetrapropylammonium hydroxide. The selection of the above catalyst can avoid the introduction of impurity ions.

[0023] Further, when the catalyst is tetra - methyl ammonium hydroxide, the mass of the catalyst added is 0.1% - 3% of the mass of the elemental silicon powder; when the catalyst is a mixture of tetra - methyl ammonium hydroxide and tetra - propyl ammonium hydroxide, the mass of tetra - methyl ammonium hydroxide added is 0.1% - 0.5% of the mass of the elemental silicon powder, and the mass of tetra - propyl ammonium hydroxide added is 0.05% - 0.1% of the mass of the elemental silicon powder.

[0024] Preferably, the dosage ratio of the elemental silicon powder to water is 1 kg: 4 - 6 L, and the mass of the solid defoamer is 0.1% - 5% of the mass of the elemental silicon powder.

[0025] Specifically, the solid defoamer is a hydrophobic and water - insoluble defoaming particle with a particle size of 10 nm - 500 mm, selected from hydrophobic modified silica, alumina, calcium carbonate, titanium dioxide or barium sulfate.

[0026] Preferably, the parameters of the two - stage temperature - rising oxidation treatment are: the first stage is at 90 - 100 °C and maintained for 50 - 70 min under a pressure of 0.5 - 1 MPa, and the second stage is at 150 - 200 °C and 1 - 2 MPa and maintained for 30 min - 5 h.

[0027] More preferably, when adding hydrogen peroxide, the mass of the active ingredient hydrogen peroxide in the hydrogen peroxide is 0.5% - 5% of the mass of SiO2 in the filtered silica sol, and the hydrogen peroxide is added in three portions according to a mass ratio of 1:0.4 - 0.6:0.4 - 0.6.

[0028] Preferably, the parameters of the ultraviolet - ozone combined treatment are: ozone concentration 40 - 60 ppm, ultraviolet wavelength 254 nm, the reaction temperature is maintained at 80 - 120 °C and treated under normal pressure for 1 - 3 h.

[0029] Preferably, the ultrafiltration process is carried out in a way of connecting multiple ultrafiltration membranes in series for concentration. The molecular weight cut - off of the ultrafiltration membranes is all ≥ 10 kDa, and the concentration rate is maintained ≤ 5 L / h.

[0030] Preferably, the stabilizer is selected from polyvinyl alcohol or hydroxypropyl methylcellulose, and the mass of the stabilizer is 0.1% - 0.5% of the mass of SiO2 in the silica sol.

[0031] The present invention also provides a polishing liquid, the components of which include the silica sol prepared by the preparation method of the high - purity silica sol described above.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] (1) In the process of preparing high-purity silica sol in the present invention, through the oxidation treatment of silica sol, the elemental silicon particle impurities in the silica sol are effectively reduced, the application prospect as a semiconductor polishing liquid is increased, the polishing defects generated on the polished plane are reduced, and the surface roughness Ra < 0.2 nm after wafer polishing using this silica sol.

[0034] (2) The silica sol prepared by the method of the present invention has good stability, a long storage period, low impurity ion content, uniform particle size of silica particles and good dispersibility.

[0035] (3) The present invention uses elemental silicon as a raw material to prepare silica sol, with a simple production process, a short production cycle, high efficiency, and good application prospects in the field of electronic polishing. Description of the Drawings

[0036] Figure 1 It is the scanning electron microscope image of the silica sol prepared in Example 1.

[0037] Figure 2 It is the scanning electron microscope image of the silica sol prepared in Example 2.

[0038] Figure 3 It is the scanning electron microscope image of the silica sol prepared in Example 3.

[0039] Figure 4 It is the scanning electron microscope image of the silica sol prepared in Comparative Example 1.

[0040] Figure 5 It is the scanning electron microscope image of the silica sol prepared in Comparative Example 2. Detailed Embodiments

[0041] To make the objectives, features, and advantages of the present invention more obvious and understandable, detailed descriptions are provided below through specific embodiments. Many specific details are set forth in the following description to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below. The technical features in each embodiment of the present invention can be combined correspondingly without conflict.

[0042] The operation methods without specific conditions noted in the following examples are usually carried out under conventional conditions or according to the conditions recommended by the manufacturer. The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art. The experimental materials used in the following examples can be obtained from conventional biochemical reagent companies without special instructions.

[0043] Example 1

[0044] Step 1: Pretreatment of silicon powder

[0045] Take 1 kg of elemental silicon powder with a particle size of 200 mesh and a purity of ≥95%, add 5% dilute hydrochloric acid and wash for 30 min to remove impurities such as iron and aluminum. Then supplement 3% hydrofluoric acid and wash for 10 min. During the pickling process, apply ultrasonic-assisted cleaning with a frequency of 40 kHz and a power of 500 W. During the pickling process, adopt a multi-stage countercurrent pickling process, connect multiple pickling tanks in series, and configure an acid-resistant ceramic membrane (pore size 0.1 μm) to circulate the acid solution, with an acid reuse rate of ≥85%; after preliminary acid impurity removal treatment, settle and separate the acid solution, and wash the silicon powder with deionized water until the conductivity is 45 μS / cm, and further dry it under vacuum for standby.

[0046] Step 2: Preparation of silica sol

[0047] Add the silicon powder pretreated in Step 1 and 5 L of deionized water to the reaction kettle, stir at a rotation speed of 300 rpm, then add the catalyst tetramethylammonium hydroxide (the addition amount is 0.5% of the mass of the elemental silicon powder) and the defoaming agent hydrophobic silica (average particle size 0.1 μm, the addition amount is 0.3% of the mass of the elemental silicon powder). Then carry out a two-stage gradient temperature rise reaction on the above reaction system. The parameters of the first stage are to maintain at 60°C for 60 min, and the parameters of the second stage are to react at 90°C for 6 h to obtain the primary silica sol.

[0048] Step 3: Purification and oxidation treatment

[0049] Let the primary silica sol obtained in Step 2 stand for 8 min to recover the defoaming agent, then filter the silica sol with a 0.1 μm ceramic membrane to remove unreacted silicon powder with a larger particle size. Carry out oxidation treatment on the filtered silica sol. The oxidation treatment method is to add hydrogen peroxide for two-stage temperature rise oxidation treatment. The total addition amount of hydrogen peroxide is calculated based on the mass of hydrogen peroxide being 2% of the mass of SiO2 in the filtered silica sol. Hydrogen peroxide is added in three portions according to a mass ratio of 1:0.5:0.5. Stir for 10 min after the first addition and stir for 30 min after the second addition. The two-stage temperature rise oxidation treatment is as follows: the parameters of the first stage are to maintain at 95°C and 1 MPa pressure for 60 min, and the second stage is to maintain at 180°C and 1.8 MPa pressure for 3 h.

[0050] Step 4: Ion exchange and concentration

[0051] Treat the silica sol after the oxidation treatment in Step 3 with a mixed-bed ion exchange resin to make the conductivity of the silica sol 8 μS / cm. Subsequently, concentrate it in a way that three ultrafiltration membranes are connected in series (cut-off molecular weight 50 kDa → 30 kDa → 10 kDa), maintain the concentration rate at 4 L / h, adjust the pH to 9.8 during the concentration process and add the stabilizer polyvinyl alcohol. The mass of polyvinyl alcohol is 0.3% of the mass of SiO2 in the silica sol. After concentration, a high-purity silica sol with a silica content of 32 wt% and an average silica particle size of 40 nm is obtained (SEM images are as shown in Figure 1 ), and there is no gelation after storage for 6 months.

[0052] Performance test: Use this high-purity silica sol as a polishing liquid to polish a wafer, and the measured surface roughness Ra of the polished wafer is 0.18 nm (AFM).

[0053] Example 2

[0054] The difference between this example and Example 1 is as follows:

[0055] (1) The particle size of the elemental silicon powder is 100 mesh, and the silicon powder is washed with deionized water until the conductivity is 35 μS / cm;

[0056] (2) The catalyst is a mixture of tetramethylammonium hydroxide (the addition amount is 0.3% of the mass of the elemental silicon powder) and tetrapropylammonium hydroxide (the addition amount is 0.08% of the mass of the elemental silicon powder).

[0057] (3) Treat the oxidized silica sol with a mixed-bed ion exchange resin to make the conductivity of the silica sol 7 μS / cm.

[0058] The remaining steps and parameters are the same as those in Example 1.

[0059] After concentration in this example, a high-purity silica sol with a silica content of 30 wt% and an average silica particle size of 30 nm is obtained (SEM images are as shown in Figure 2 ).

[0060] Performance test: Use this high-purity silica sol as a polishing liquid to polish a wafer, and the measured surface roughness Ra of the polished wafer is 0.15 nm (AFM).

[0061] Example 3

[0062] The difference between this example and Example 1 is as follows:

[0063] (1) The oxidation treatment method is to add hydrogen peroxide, and the total addition amount of hydrogen peroxide is calculated based on the mass of hydrogen peroxide being 3% of the mass of SiO2 in the filtered silica sol.

[0064] (2) After adding hydrogen peroxide, two-stage temperature-rising oxidation treatment is carried out: the parameters of the first stage are 95 °C and 1 MPa pressure for 60 min, and the second stage is 200 °C and 2 MPa pressure for 2 h.

[0065] (3) Use a mixed-bed ion exchange resin to treat the oxidized silica sol, so that the conductivity of the silica sol is 6 μS / cm.

[0066] The remaining steps and parameters are the same as those in Example 1.

[0067] In this example, a high-purity silica sol with a silica content of 31 wt% and an average silica particle size of 35 nm is obtained after concentration (the SEM image is as Figure 3 shown).

[0068] Performance test: Use this high-purity silica sol as a polishing liquid to polish a wafer, and the surface roughness Ra of the polished wafer is measured to be 0.14 nm (AFM).

[0069] Comparative Example 1

[0070] The difference between this comparative example and Example 1 is only that no oxidation treatment is carried out, and the remaining steps and parameters are the same as those in Example 1.

[0071] In this comparative example, a silica sol with a silica content of 31 wt% and an average silica particle size of 40 nm is obtained after concentration (the SEM image is as Figure 4 shown).

[0072] Performance test: Use this silica sol as a polishing liquid to polish a wafer, and the surface roughness Ra of the polished wafer is measured to be 0.7 nm (AFM).

[0073] Comparative Example 2

[0074] The differences between this comparative example and Example 1 are as follows:

[0075] (1) Hydrofluoric acid cleaning is not supplemented and ultrasonic-assisted cleaning is not applied during pickling.

[0076] (2) A recyclable solid defoamer is not added.

[0077] (3) No oxidation treatment is carried out.

[0078] (4) An ordinary ultrafiltration system is used, the concentration rate is not controlled, the pH is not adjusted during concentration, and no stabilizer is added.

[0079] The remaining steps and parameters are the same as those in Example 1.

[0080] This comparative example was concentrated to obtain a silica sol with a silica content of 35 wt% and an average silica particle size of 55 nm (SEM images are as shown in Figure 5 ).

[0081] Performance test: Using this silica sol as a polishing liquid to polish a wafer, the surface roughness Ra of the polished wafer was measured to be 1.3 nm (AFM).

[0082] Sample analysis

[0083] Table 1 Comparison of the performance of the silica sols obtained in the examples and the comparative example

[0084] Index Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Conductivity (μS / cm) 8 7 6 8 10 Polishing Roughness Ra (nm) 0.18 0.15 0.14 0.7 1.3 <![CDATA[SiO2 content (wt%)]]> 32 30 31 31 35

[0085] As shown in Table 1, the results of Examples 1-3 illustrate the significant advantages of the present invention in terms of controlling the residual impurities of elemental silicon particles, improving purity, and process efficiency. Among them, the oxidation treatment, especially the two-stage temperature-raising oxidation treatment with the addition of hydrogen peroxide, is crucial for the deep removal of impurities in elemental silicon particles; specific types of catalysts, mixed-bed ion exchange resins, and the control of the process synergistically reduce the content of impurity ions, especially the content of alkali metal ions.

[0086] The above-described embodiments have detailed the technical solutions of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, supplements, or substitutions in a similar manner within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing high-purity silica sol, characterized in that: The following steps are involved: (1) subjecting elemental silicon powder to preliminary impurity removal treatment with dilute acid, washing with water, and drying to obtain pretreated silicon powder; wherein the particle size of the elemental silicon powder is 50 to 500 meshes, and the purity is ≥95%; (2) subjecting the reaction system consisting of the pretreated silicon powder, water, catalyst and recyclable solid defoaming agent to a two-stage gradient temperature reaction, wherein the first stage parameter is 55-65° C. for 50-70 min, and the second stage parameter is 85-95° C. for 4-8 h to obtain a primary silica sol; (3) allowing the silica sol to stand, recovering the solid defoamer, and then filtering, and subjecting the filtered silica sol to oxidation treatment, wherein the oxidation treatment method is to add hydrogen peroxide to perform a two-stage temperature-raising oxidation treatment or a UV-ozone combined oxidation treatment; (4) treating the silica sol obtained in step (3) with a mixed bed ion exchange resin to make the conductivity of the silica sol less than 10 μS / cm; (5) The silica sol treated in step (4) is concentrated by ultrafiltration, and the pH value is adjusted to 9.5-10.0 during the concentration process and a stabilizer is added to obtain a silica sol having a silica content of ≥30 wt % and an average silica particle size of 10-50 nm.

2. The method for preparing high-purity silica sol according to claim 1, characterized in that: In step (1), the elemental silicon powder is subjected to a preliminary impurity removal treatment with dilute acid, the acid solution is separated by sedimentation, and the silicon powder is washed with deionized water until the conductivity is ≤50 μS / cm.

3. The method for preparing high-purity silica sol according to claim 1, characterized in that: In step (1), the dilute acid is at least one of dilute hydrochloric acid, dilute sulfuric acid, dilute nitric acid or hydrofluoric acid.

4. The method for preparing high-purity silica sol according to claim 1, characterized in that: The catalyst is tetramethylammonium hydroxide, or a mixture of tetramethylammonium hydroxide and tetrapropylammonium hydroxide; And / or, when tetramethylammonium hydroxide is used as the catalyst, the mass of the catalyst added is 0.1% to 3% of the mass of the elemental silicon powder; when the catalyst is a mixture of tetramethylammonium hydroxide and tetrapropylammonium hydroxide, the mass of the tetramethylammonium hydroxide added is 0.1% to 0.5% of the mass of the elemental silicon powder, and the mass of the tetrapropylammonium hydroxide added is 0.05% to 0.1% of the mass of the elemental silicon powder.

5. The method for preparing high-purity silica sol according to claim 1, characterized in that: The solid defoamer is a hydrophobic and water-insoluble defoamer particle with a particle size of 10 nm to 500 mm, selected from hydrophobically modified silicon dioxide, aluminum oxide, calcium carbonate, titanium dioxide or barium sulfate.

6. The method for preparing high-purity silica sol according to claim 1, characterized in that: The parameters of the two-stage temperature-raising oxidation treatment are: the first stage is 90-100°C and maintained at a pressure of 0.5-1 MPa for 50-70 minutes, and the second stage is 150-200°C and maintained at a pressure of 1-2 MPa for 30 minutes to 5 hours.

7. The method for preparing high-purity silica sol according to claim 1, characterized in that: When adding hydrogen peroxide, the mass of hydrogen peroxide, an active ingredient in the hydrogen peroxide, is 0.5% to 5% of the mass of SiO2 in the filtered silica sol, and the hydrogen peroxide is added three times at a mass ratio of 1:0.4 to 0.6:0.4 to 0.

6.

8. The method for preparing high-purity silica sol according to claim 1, characterized in that: The ultrafiltration process uses a multi-stage ultrafiltration membrane in series for concentration. The molecular weight cutoff of the ultrafiltration membrane is ≥10kDa, and the concentration rate is maintained at ≤5L / h.

9. The method for preparing high-purity silica sol according to claim 1, characterized in that: The stabilizer is polyvinyl alcohol or hydroxypropyl methylcellulose, and the mass of the stabilizer is 0.1% to 0.5% of the mass of SiO2 in the silica sol.

10. A polishing liquid, characterized in that: The components include the silica sol prepared by the preparation method of high-purity silica sol according to any one of claims 1-9.

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