Silicon carbide CMP fine polishing liquid and preparation method thereof

Abstract

The present invention relates to a silicon carbide CMP fine polishing liquid and a preparation method thereof. The polishing liquid comprises silicon oxide abrasive, a catalyst, a catalyst activator, a dispersant, an oxidant, a pH regulator, and deionized water, wherein the pH value is 8.5 to 11.0. The components are as follows by weight percentage: silicon oxide abrasive: 5 wt.% to 20 wt.%, catalyst: 1 wt.% to 5 wt.%, catalyst activator: 0.1 wt.% to 2 wt.%, dispersant: 0.1 wt.% to 1 wt.%, oxidant: 0.5 wt.% to 5 wt.%, pH regulator: 0.1 wt.% to 0.5 wt.%, and the remainder is deionized water. The polishing liquid prepared by the present invention has higher processing efficiency and better surface quality. The polishing liquid has simple components and is easy to prepare. It is not easy to crystallize or foam during the polishing process. It has no corrosive effect on the machine. It has good economic benefits, is easy to store and recycle, and is easy to clean after use. It has good process performance and is suitable for sub-nanometer polishing of silicon carbide wafer substrate surfaces.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor wafer polishing, and in particular to a silicon carbide CMP fine polishing liquid and a preparation method thereof. Background Art

[0002] Single-crystal SiC is a typical material for third-generation semiconductors, widely used in defense sectors such as military, aerospace, and energy, as well as consumer applications such as computers, home appliances, and digital electronics. Compared to previous semiconductor materials, SiC offers advantages such as a wide bandgap, high breakdown electric field, high thermal conductivity, high electron saturation drift rate, and strong radiation resistance.

[0003] Single crystal SiC has high hardness and great brittleness, and is prone to defects such as cracks and scratches during processing. In addition, SiC has stable chemical properties and is difficult to react with other substances. This leads to widespread problems such as low processing efficiency and poor processing quality, which greatly limits its large-scale application and development in the field of electronic information manufacturing.

[0004] Chemical mechanical polishing (CMP) is the only effective way to achieve ultra-smooth, damage-free processing of SiC wafer surfaces. The polishing slurry is a key factor influencing the effectiveness of SiC CMP. Existing SiC CMP polishing slurries mostly use strong oxidants such as periodates, perchlorates, hypochlorites, and permanganates as oxidants. However, due to their strong oxidizing properties, these oxidants often cause chemical corrosion defects such as orange peel and pitting on the polished SiC wafer surface, severely impacting the surface quality of the wafer. Furthermore, reduced products such as manganese dioxide adhere to the equipment and wafer surfaces, making them difficult to clean. In contrast, hydrogen peroxide is a more suitable oxidant for SiC CMP polishing slurries. Furthermore, hydrogen peroxide's oxidizing effect can be significantly enhanced in the presence of an appropriate catalyst, thereby helping to improve the CMP material removal rate of SiC wafers. For example, using potassium permanganate as an example, existing catalysts include Pt, Fe, and KMnO4. The removal rate and roughness of the final product achieved with existing technologies no longer meet the requirements for higher precision. Summary of the Invention

[0005] In view of this, the present invention proposes a silicon carbide CMP fine polishing liquid and a preparation method thereof. The present invention adopts a high-efficiency catalyst to effectively catalyze hydrogen peroxide, significantly improve the oxidation ability of hydrogen peroxide, thereby improving the material removal rate of the polishing liquid and reducing the surface roughness of the polished wafer. At the same time, the raw materials used in the polishing liquid are pollution-free to the environment, the waste liquid is easy to handle, and there is no damage to the equipment, thereby achieving ultra-smooth and damage-free processing of silicon carbide.

[0006] The technical means adopted in the present invention are as follows:

[0007] A silicon carbide CMP fine polishing liquid comprises silicon oxide abrasive, a catalyst, a catalyst activator, a dispersant, an oxidant, a pH adjuster, and deionized water. The pH is 8.5 to 11.0. The components, in percentage by weight, are as follows: silicon oxide abrasive: 5 to 20 wt.%, catalyst: 1 to 5 wt.%, catalyst activator: 0.1 to 2 wt.%, dispersant: 0.1 to 1 wt.%, oxidant: 0.5 to 5 wt.%, pH adjuster: 0.1 to 0.5 wt.%, and the remainder is deionized water. The pH is preferably 9.5.

[0008] Furthermore, the silicon oxide abrasive is silicon dioxide particles, and the particle size of the silicon oxide abrasive is 30 to 100 nanometers.

[0009] Furthermore, the catalyst is vanadate.

[0010] Furthermore, the catalyst is one or a mixture of calcium vanadate, ammonium vanadate, sodium metavanadate, tripotassium vanadate, sodium ammonium vanadate, sodium orthovanadate, lithium vanadate, lead vanadate, and manganese vanadate, preferably sodium orthovanadate and sodium metavanadate, more preferably sodium metavanadate.

[0011] Furthermore, the catalyst activator is a niobium salt.

[0012] Furthermore, the catalyst activator is one or a mixture of niobium pentoxide, niobium dioxide, niobium oxalate, sodium niobate, potassium niobate, niobium pentachloride, niobium hydroxide, ammonium niobate oxalate hydrate, niobium bromide, copper niobate, and lithium niobate. The niobium salt is preferably niobium pentoxide and niobium hydroxide, and more preferably niobium hydroxide.

[0013] Furthermore, the dispersant is an organic solvent, specifically a mixture of one or more of ethanol, sodium hexametaphosphate, fructose molecules, hexadecyl methyl ammonium bromide, citric acid, polyvinyl pyrrolidone (PVP), ammonium polyacrylate, and polyethyleneimine (PEI). The dispersant is preferably hexadecyl methyl ammonium bromide and polyvinyl pyrrolidone (PVP), more preferably polyvinyl pyrrolidone (PVP).

[0014] Furthermore, the oxidant is hydrogen peroxide.

[0015] Furthermore, the pH adjuster is one or a mixture of hydrochloric acid, phosphoric acid, oxalic acid, sodium hydroxide, ammonia water and potassium hydroxide, preferably sodium hydroxide and potassium hydroxide, more preferably potassium hydroxide.

[0016] The present invention also discloses a method for preparing the silicon carbide CMP fine polishing liquid, comprising the following steps:

[0017] Step 1, weighing 40 wt.% to 60 wt.% of deionized water accounting for the total mass fraction of the polishing liquid, adding 1 wt.% to 5 wt.% of the catalyst accounting for the total mass fraction of the polishing liquid, and uniformly stirring to obtain a catalyst aqueous solution;

[0018] Step 2, weighing deionized water with a total mass fraction of 1 wt.% to 10 wt.% of the polishing liquid, adding an appropriate amount of a pH adjuster to make the solution alkaline, and then adding a catalyst activator with a total mass fraction of 0.1 wt.% to 2 wt.% of the polishing liquid, stirring uniformly to dissolve, to obtain a catalyst activator aqueous solution;

[0019] Step 3, weighing 1 wt.% to 5 wt.% of deionized water accounting for the total mass fraction of the polishing liquid, adding 0.1 wt.% to 1 wt.% of a dispersant accounting for the total mass fraction of the polishing liquid, and stirring uniformly to obtain a dispersant aqueous solution;

[0020] Step 4, weighing 5 wt.% to 20 wt.% of silica particles accounting for the total mass fraction of the polishing liquid, and uniformly dispersing the silica particles in 10 wt.% to 20 wt.% of deionized water accounting for the total mass fraction of the polishing liquid to obtain a colloidal silica slurry;

[0021] Step 5: fully mixing the catalyst aqueous solution prepared in step 1, the catalyst activator aqueous solution prepared in step 2, and the dispersant aqueous solution prepared in step 3, and uniformly stirring to obtain a mixed solution;

[0022] Step 6: slowly add the colloidal silica slurry prepared in step 4 to the mixed solution prepared in step 5, and stir thoroughly to obtain a polishing solution;

[0023] Step 7: Add 1 wt.% to 5 wt.% of hydrogen peroxide to the polishing liquid obtained in step 6, stir evenly, add 0.1 wt.% to 0.5 wt.% of potassium hydroxide to the polishing liquid, adjust to the corresponding pH value, and obtain the silicon carbide CMP fine polishing liquid.

[0024] The working principle of the present invention is that hydrogen peroxide, under the combined action of a catalyst and a catalyst activator, generates a large number of hydroxyl radicals (OH·) in the polishing liquid. The hydroxyl radicals have stronger oxidizing properties and can quickly oxidize the surface of the silicon carbide wafer, forming a layer of oxide layer with lower hardness on the wafer surface. Subsequently, the oxide layer is removed by the mechanical action of the abrasive in the polishing liquid under a certain polishing pressure, thereby achieving a fine polishing effect. The reaction process involved can be expressed as follows: SiC+4 OH · →SiO2+CO2+2H2O.

[0025] Compared with the prior art, the present invention has the following advantages: the polishing liquid prepared by the present invention has higher processing efficiency and better surface quality, its components are simple, it is easy to prepare, it is not easy to crystallize or foam during the polishing process, it has no corrosive effect on the machine, it has good economic benefits, is easy to store, can be recycled, is easy to clean after use, has good process performance, and is suitable for sub-nanometer polishing of the surface of silicon carbide wafer substrates. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces 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 invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0027] Figure 1 This is a surface roughness diagram of silicon carbide sample 1# in Example 1 of the present invention;

[0028] Figure 2 This is a surface roughness diagram of silicon carbide sample 2# in Example 2 of the present invention;

[0029] Figure 3 This is a surface roughness diagram of silicon carbide sample 3# in Example 3 of the present invention;

[0030] Figure 4 This is a surface roughness diagram of silicon carbide sample 4# in Example 4 of the present invention;

[0031] Figure 5 This is a surface roughness diagram of silicon carbide sample 5# in Example 5 of the present invention;

[0032] Figure 6 This is a surface roughness diagram of silicon carbide sample 6# in Comparative Example 1 of the present invention;

[0033] Figure 7 This is a surface roughness diagram of silicon carbide sample 7# in Comparative Example 2 of the present invention;

[0034] Figure 8 This is a surface roughness diagram of silicon carbide sample 8# in comparative example 3 of the present invention. DETAILED DESCRIPTION

[0035] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0036] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0037] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0038] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0039] The silicon carbide wafer substrate used in the experiment is a 6-inch Si-surface silicon carbide wafer substrate.

[0040] The machine model used in the experiment is a CP-610R2-SVI chemical mechanical polishing equipment, a polishing nap damping cloth polishing pad, a polishing disc diameter of 610mm, a polishing pressure of 3-6psi, a polishing disc speed of 35-80rpm, a pressure plate speed of 35-80rpm, a polishing liquid flow rate of 300mL / min, and a polishing time of 4 hours. The polishing experiment is carried out at room temperature. After polishing, the silicon carbide wafer substrate is first cleaned with an ultrasonic cleaner, then blown dry with dry air, and then weighed on an electronic balance. The removal rate (nm / h) of the silicon carbide wafer substrate is obtained by the weight difference before and after polishing.

[0041] Example 1

[0042] Step 1, weighing 60 wt.% of deionized water accounting for the total mass fraction of the polishing liquid, adding 1 wt.% of sodium orthovanadate accounting for the total mass fraction of the polishing liquid, and stirring uniformly to obtain a catalyst aqueous solution;

[0043] Step 2: Weigh 10 wt.% of deionized water based on the total mass fraction of the polishing liquid, add an appropriate amount of a pH adjuster to make the solution alkaline, then add 0.1 wt.% of niobium pentoxide based on the total mass fraction of the polishing liquid, and stir evenly to dissolve it to obtain a catalyst activator aqueous solution;

[0044] Step 3, weighing 5 wt.% of deionized water accounting for the total mass fraction of the polishing liquid, adding 0.1 wt.% of hexadecylmethylammonium bromide accounting for the total mass fraction of the polishing liquid, and stirring uniformly to obtain a dispersant aqueous solution;

[0045] Step 4: Weighing silica particles with a particle size of 30 nm and accounting for 5 wt.% of the total mass fraction of the polishing liquid, and uniformly dispersing them in deionized water accounting for 20 wt.% of the total mass fraction of the polishing liquid to obtain a colloidal silica slurry;

[0046] Step 5: fully mix the catalyst aqueous solution prepared in step 1, the catalyst activator aqueous solution prepared in step 2, the dispersant aqueous solution prepared in step 3, and the remaining amount of deionized water, and stir uniformly to obtain a mixed solution;

[0047] Step 6: slowly add the colloidal silica slurry prepared in step 4 to the mixed solution prepared in step 5, and stir thoroughly to obtain a polishing solution;

[0048] Step 7: Add 5 wt.% of hydrogen peroxide to the polishing liquid obtained in step 6, stir evenly, and adjust the pH value to 8 with potassium hydroxide to obtain the silicon carbide CMP fine polishing liquid of Example 1.

[0049] Example 2

[0050] Step 1, weighing 55 wt.% of deionized water accounting for the total mass fraction of the polishing liquid, adding 3 wt.% of sodium ammonium vanadate accounting for the total mass fraction of the polishing liquid, and stirring uniformly to obtain a catalyst aqueous solution;

[0051] Step 2: Weigh 8 wt.% of deionized water to make the polishing solution alkaline by adding an appropriate amount of a pH adjuster, then add 0.5 wt.% of niobium hydroxide to make the solution alkaline by adding the niobium hydroxide to make the solution alkaline, and stir evenly to dissolve the niobium hydroxide to obtain a catalyst activator aqueous solution;

[0052] Step 3, weighing 5 wt.% of deionized water accounting for the total mass fraction of the polishing liquid, adding 1 wt.% of polyvinylpyrrolidone (PVP) accounting for the total mass fraction of the polishing liquid, and stirring uniformly to obtain a dispersant aqueous solution;

[0053] Step 4: Weigh silica particles with a particle size of 50 nm and a total mass fraction of 10 wt.% of the polishing liquid, and evenly disperse them in deionized water with a total mass fraction of 15 wt.% of the polishing liquid to obtain a colloidal silica slurry;

[0054] Step 5: fully mix the catalyst aqueous solution prepared in step 1, the catalyst activator aqueous solution prepared in step 2, the dispersant aqueous solution prepared in step 3, and the remaining amount of deionized water, and stir uniformly to obtain a mixed solution;

[0055] Step 6: slowly add the colloidal silica slurry prepared in step 4 to the mixed solution prepared in step 5, and stir thoroughly to obtain a polishing solution;

[0056] Step 7: Add 2 wt.% of hydrogen peroxide to the polishing liquid obtained in step 6, stir evenly, and adjust the pH value to 9.5 with potassium hydroxide to obtain the silicon carbide CMP fine polishing liquid of Example 2.

[0057] Example 3

[0058] Step 1, weighing 50 wt.% of deionized water accounting for the total mass fraction of the polishing liquid, adding 2 wt.% of tripotassium vanadate accounting for the total mass fraction of the polishing liquid, and stirring uniformly to obtain a catalyst aqueous solution;

[0059] Step 2: Weigh 6 wt.% of deionized water to make the polishing solution alkaline by adding an appropriate amount of a pH adjuster, then add 0.7 wt.% of niobium dioxide to the polishing solution, and stir evenly to dissolve the niobium dioxide to obtain a catalyst activator aqueous solution;

[0060] Step 3, weighing 2 wt.% of deionized water accounting for the total mass fraction of the polishing liquid, adding 0.3 wt.% of ethanol accounting for the total mass fraction of the polishing liquid, and stirring evenly to obtain a dispersant aqueous solution;

[0061] Step 4: Weigh silica particles with a particle size of 50 nm and a total mass fraction of 12 wt.% of the polishing liquid, and evenly disperse them in deionized water with a total mass fraction of 12 wt.% of the polishing liquid to obtain a colloidal silica slurry;

[0062] Step 5: fully mix the catalyst aqueous solution prepared in step 1, the catalyst activator aqueous solution prepared in step 2, the dispersant aqueous solution prepared in step 3, and the remaining amount of deionized water, and stir uniformly to obtain a mixed solution;

[0063] Step 6: slowly add the colloidal silica slurry prepared in step 4 to the mixed solution prepared in step 5, and stir thoroughly to obtain a polishing solution;

[0064] Step 7: Add 3 wt.% of hydrogen peroxide to the polishing liquid obtained in step 6, stir evenly, and adjust the pH value to 8.5 with potassium hydroxide to obtain the silicon carbide CMP fine polishing liquid of Example 3.

[0065] Example 4

[0066] Step 1, weighing 45 wt.% of deionized water accounting for the total mass fraction of the polishing liquid, adding 4 wt.% of lithium vanadate accounting for the total mass fraction of the polishing liquid, and stirring uniformly to obtain a catalyst aqueous solution;

[0067] Step 2: Weigh 4 wt.% of deionized water to make the polishing solution alkaline, add an appropriate amount of a pH adjuster to make the solution alkaline, then add 1.5 wt.% of niobium bromide to the polishing solution, and stir evenly to dissolve it to obtain a catalyst activator aqueous solution;

[0068] Step 3, weighing 3 wt.% of deionized water accounting for the total mass fraction of the polishing liquid, adding 0.8 wt.% of citric acid accounting for the total mass fraction of the polishing liquid, and stirring uniformly to obtain a dispersant aqueous solution;

[0069] Step 4: Weigh silica particles with a particle size of 70 nanometers and a total mass fraction of 13 wt.% of the polishing liquid, and evenly disperse them in deionized water with a total mass fraction of 16 wt.% of the polishing liquid to obtain a colloidal silica slurry;

[0070] Step 5: fully mix the catalyst aqueous solution prepared in step 1, the catalyst activator aqueous solution prepared in step 2, the dispersant aqueous solution prepared in step 3, and the remaining amount of deionized water, and stir uniformly to obtain a mixed solution;

[0071] Step 6: slowly add the colloidal silica slurry prepared in step 4 to the mixed solution prepared in step 5, and stir thoroughly to obtain a polishing solution;

[0072] Step 7: Add 3.5 wt.% of hydrogen peroxide to the polishing liquid obtained in step 6, stir evenly, and adjust the pH value to 9.5 with sodium hydroxide to obtain the silicon carbide CMP fine polishing liquid of Example 4.

[0073] Example 5

[0074] Step 1, weighing 40 wt.% of deionized water accounting for the total mass fraction of the polishing liquid, adding 5 wt.% of sodium metavanadate accounting for the total mass fraction of the polishing liquid, and stirring evenly to obtain a catalyst aqueous solution;

[0075] Step 2: Weigh 1 wt.% of deionized water to make the polishing solution alkaline by adding an appropriate amount of a pH adjuster, then add 0.5 wt.% of niobium hydroxide to make the solution alkaline by adding the niobium hydroxide to make the solution alkaline, and stir evenly to dissolve the niobium hydroxide to obtain a catalyst activator aqueous solution;

[0076] Step 3, weighing 1 wt.% of deionized water accounting for the total mass fraction of the polishing liquid, adding 1 wt.% of polyvinylpyrrolidone (PVP) accounting for the total mass fraction of the polishing liquid, and stirring uniformly to obtain a dispersant aqueous solution;

[0077] Step 4: Weigh silica particles with a particle size of 100 nm and a total mass fraction of 20 wt.% of the polishing liquid, and evenly disperse them in deionized water with a mass fraction of 10 wt.% to obtain a colloidal silica slurry;

[0078] Step 5: fully mix the catalyst aqueous solution prepared in step 1, the catalyst activator aqueous solution prepared in step 2, the dispersant aqueous solution prepared in step 3, and the remaining amount of deionized water, and stir uniformly to obtain a mixed solution;

[0079] Step 6: slowly add the colloidal silica slurry prepared in step 4 to the mixed solution prepared in step 5, and stir thoroughly to obtain a polishing solution;

[0080] Step 7: Add 5 wt.% of hydrogen peroxide to the polishing liquid obtained in step 6, stir evenly, and adjust the pH value to 9.5 with potassium hydroxide to obtain the silicon carbide CMP fine polishing liquid of Example 5.

[0081] The experimental results of Examples 1-5 are shown in Table 1.

[0082] Serial number Removal rate (nm / h) Roughness (nm) Surface quality Example 1 156 0.15 No obvious scratches Example 2 177 0.12 No obvious scratches Example 3 186 0.11 No obvious scratches Example 4 203 0.09 No obvious scratches Example 5 221 0.08 No obvious scratches

[0083] Table 1

[0084] It can be seen from the above five groups of embodiments that, by using the fine polishing liquid and the preparation method thereof proposed in the present invention, the surface quality of the wafer obtained after polishing is good, without obvious scratches, and the material removal rate is also high.

[0085] In order to verify the necessity of catalyst, catalyst activator and dispersant for good polishing performance of polishing liquid, the following three groups of comparative examples were implemented.

[0086] Comparative Example 1

[0087] The preparation method used is the same as that of Example 1, except that no catalyst, catalyst activator, or dispersant is added to the polishing liquid;

[0088] Comparative Example 2

[0089] The preparation method used is the same as that of Example 1, except that no catalyst activator or dispersant is added to the polishing liquid;

[0090] Comparative Example 3

[0091] The preparation method used is the same as that of Example 1, except that no dispersant is added to the polishing liquid;

[0092]

[0093] Table 2

[0094] From the above three groups of comparative experiments, it can be seen that under the same process parameters, if no catalyst is added, hydrogen peroxide will not be able to decompose quickly to produce hydroxyl radicals, which will in turn weaken the oxidizing effect of the polishing liquid, resulting in a decrease in the polishing material removal rate and an increase in scratches on the surface of the polished silicon carbide wafer. The effect is significantly improved after the catalyst is added. In addition, it can be seen from the comparison that the addition of catalyst activators and dispersants can further enhance the polishing effect.

[0095] In summary, the polishing efficiency of the polishing liquid with the addition of catalyst is much better than that without the addition of catalyst. In addition, the addition of catalyst activator can further improve the removal rate. The appropriate addition of dispersant can improve the dispersibility of the abrasive, thereby further improving the quality of the processed surface without having much impact on the polishing rate.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, 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 invention.

Claims

1. A silicon carbide CMP fine polishing liquid, characterized in that: The composition includes silica abrasive, catalyst, catalyst activator, dispersant, oxidant, pH regulator and deionized water, and the pH value is 8.5-11.0; the weight percentage of each component is as follows: silica abrasive: 5 wt.%-20 wt.%, catalyst: 1 wt.%-5 wt.%, catalyst activator: 0.1 wt.%-2 wt.%, dispersant: 0.1 wt.%-1 wt.%, oxidant: 0.5 wt.%-5 wt.%, pH regulator: 0.1 wt.%-0.5 wt.%, and the rest is deionized water; The catalyst is one or a mixture of calcium vanadate, ammonium vanadate, sodium metavanadate, tripotassium vanadate, sodium ammonium vanadate, sodium orthovanadate, lithium vanadate, lead vanadate, and manganese vanadate; The catalyst activator is one or a mixture of niobium pentoxide, niobium dioxide, niobium oxalate, sodium niobate, potassium niobate, niobium pentachloride, niobium hydroxide, ammonium niobate oxalate hydrate, niobium bromide, copper niobate, and lithium niobate; The dispersant is one or a mixture of ethanol, sodium hexametaphosphate, fructose molecules, hexadecylmethylammonium bromide, citric acid, polyvinylpyrrolidone PVP, ammonium polyacrylate and polyethyleneimine PEI; The oxidant is hydrogen peroxide.

2. The silicon carbide CMP fine polishing liquid according to claim 1, characterized in that The particle size of the silica abrasive is 30 to 100 nanometers.

3. The silicon carbide CMP fine polishing liquid according to claim 1, characterized in that The pH regulator is one or a mixture of hydrochloric acid, phosphoric acid, oxalic acid, sodium hydroxide, ammonia water and potassium hydroxide.

4. A method for preparing a silicon carbide CMP fine polishing liquid, characterized in that: The steps include: Step 1, weighing 40 wt.% to 60 wt.% of deionized water accounting for the total mass fraction of the polishing liquid, adding 1 wt.% to 5 wt.% of the catalyst accounting for the total mass fraction of the polishing liquid, and uniformly stirring to obtain a catalyst aqueous solution; Step 2, weighing 1 wt.% to 10 wt.% of deionized water accounting for the total mass fraction of the polishing liquid, adding an appropriate amount of a pH adjuster to make the solution alkaline, and then adding 0.1 wt.% to 2 wt.% of a catalyst activator accounting for the total mass fraction of the polishing liquid, stirring uniformly to dissolve it, to obtain a catalyst activator aqueous solution; Step 3, weighing 1 wt.% to 5 wt.% of deionized water accounting for the total mass fraction of the polishing liquid, adding 0.1 wt.% to 1 wt.% of a dispersant accounting for the total mass fraction of the polishing liquid, and stirring uniformly to obtain a dispersant aqueous solution; Step 4, weighing 5 wt.% to 20 wt.% of silica particles accounting for the total mass fraction of the polishing liquid, and uniformly dispersing the silica particles in 10 wt.% to 20 wt.% of deionized water accounting for the total mass fraction of the polishing liquid to obtain a colloidal silica slurry; Step 5: fully mixing the catalyst aqueous solution prepared in step 1, the catalyst activator aqueous solution prepared in step 2, and the dispersant aqueous solution prepared in step 3, and uniformly stirring to obtain a mixed solution; Step 6: slowly add the colloidal silica slurry prepared in step 4 to the mixed solution prepared in step 5, and stir thoroughly to obtain a polishing solution; Step 7, adding 1 wt.% to 5 wt.% of hydrogen peroxide to the polishing liquid obtained in step 6, stirring evenly, adding 0.1 wt.% to 0.5 wt.% of potassium hydroxide to the polishing liquid, adjusting the pH to 8.5 to 11.0, to obtain the silicon carbide CMP fine polishing liquid; The catalyst is one or a mixture of calcium vanadate, ammonium vanadate, sodium metavanadate, tripotassium vanadate, sodium ammonium vanadate, sodium orthovanadate, lithium vanadate, lead vanadate, and manganese vanadate; The catalyst activator is one or a mixture of niobium pentoxide, niobium dioxide, niobium oxalate, sodium niobate, potassium niobate, niobium pentachloride, niobium hydroxide, ammonium niobate oxalate hydrate, niobium bromide, copper niobate, and lithium niobate; The dispersant is one or a mixture of ethanol, sodium hexametaphosphate, fructose molecules, hexadecylmethylammonium bromide, citric acid, polyvinylpyrrolidone PVP, ammonium polyacrylate and polyethyleneimine PEI.

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