An acidic chemical mechanical polishing slurry for gallium arsenide substrates and its application

Abstract

This invention provides an acidic chemical mechanical polishing slurry for gallium arsenide substrates and its application, belonging to the field of chemical mechanical polishing technology. The polishing slurry comprises, by weight percentage, 0.5–5 wt% modified cerium oxide abrasive, 0.1–3 wt% peracetic acid, 0.05–2 wt% urea peroxide, and the balance deionized water, with a pH value of 3.0–5.0; wherein the modified cerium oxide abrasive is nano-cerium oxide particles with surface-grafted organic acid functional groups, with an average particle size of 20–80 nm. The acidic chemical mechanical polishing slurry for fine polishing of gallium arsenide substrates provided by this invention, by employing a dual oxidant system composed of peracetic acid and urea peroxide, combined with modified cerium oxide abrasive with surface-grafted organic acid functional groups, balances surface reaction stability, abrasive dispersibility, and low-load mechanical removal requirements under acidic conditions, thereby helping to reduce surface scratches, particle residue, and subsurface damage depth, and improving the surface integrity of gallium arsenide substrates after fine polishing.

Description

Technical Field

[0001] This invention relates to the field of chemical mechanical polishing technology, and in particular to an acidic chemical mechanical polishing slurry for gallium arsenide substrates and its application. Background Technology

[0002] Gallium arsenide (GaAs), a typical III-V compound semiconductor material, possesses characteristics such as high electron mobility, a distinct direct bandgap structure, and excellent optoelectronic properties, making it widely used in radio frequency devices, optoelectronic devices, and high-speed digital circuits. As devices evolve towards higher frequencies, higher integration, and miniaturization, GaAs substrates face increasingly stringent requirements for surface flatness, surface defect density, and subsurface damage. Chemical mechanical polishing (CMP) is a crucial process for achieving global wafer surface flatness, with the fine polishing step directly impacting the quality of subsequent epitaxy, growth, photolithography, and device manufacturing.

[0003] In typical gallium arsenide (GaAs) substrate polishing, the goal is not simply to increase the material removal rate, but to achieve atomic-level surface smoothness, controlled scratches, reduced corrosion defects, decreased particle residue, and reduced subsurface damage with a relatively small removal amount. Because gallium arsenide itself has high chemical reactivity, the polishing process requires both stable control of the surface reaction and gentle mechanical removal; otherwise, problems such as localized over-corrosion, surface scratches, particle adhesion, and deepening of the damaged layer can easily occur.

[0004] However, existing gallium arsenide polishing solutions still have the following shortcomings: although alkaline systems are beneficial for the dispersion of some abrasives, they are not conducive to the formation of a uniform and dense surface reaction layer, resulting in limited improvement in surface quality; although acidic systems are more suitable for surface reactions, hydrogen peroxide commonly used decomposes quickly in acidic environments, which can easily cause polishing rate drift. At the same time, traditional silica abrasives or unmodified cerium oxide abrasives are prone to agglomeration under acidic conditions, which can lead to surface scratches and particle residue.

[0005] To this end, an acidic chemical mechanical polishing slurry for gallium arsenide substrates and its application are proposed. Summary of the Invention

[0006] This invention provides an acidic chemical mechanical polishing slurry for fine polishing of gallium arsenide substrates, comprising, by weight percentage, 0.5–5 wt% modified cerium oxide abrasive, 0.1–3 wt% peracetic acid, 0.05–2 wt% urea peroxide, and the balance being deionized water, wherein the pH value of the polishing slurry is 3.0–5.0; wherein the modified cerium oxide abrasive is nano-cerium oxide particles with surface grafted organic acid functional groups, and the average particle size is 20–80 nm.

[0007] In this invention, peracetic acid and urea peroxide together constitute the dual oxidant components in the acidic polishing system. Peracetic acid provides the primary oxidizing power required for gallium arsenide surface oxidation, while urea peroxide regulates the oxidation process, ensuring good reaction continuity and stability of the polishing slurry under acidic conditions. Modified cerium oxide abrasive, acting as a mechanical removal medium, works in conjunction with the surface reaction layer formed by the dual oxidants to synergistically remove arsenide from the gallium arsenide substrate surface, thereby facilitating fine polishing under lower mechanical load conditions.

[0008] Further, the content of the modified cerium oxide abrasive is 1-3 wt%, the content of the peracetic acid is 0.2-1.5 wt%, the content of the urea peroxide is 0.1-0.5 wt%, the mass ratio of the peracetic acid to the urea peroxide is 3:1-10:1, and the pH value of the polishing solution is 3.5-4.2.

[0009] In the aforementioned preferred range, when the content of modified cerium oxide abrasive is controlled at 1–3 wt%, it ensures sufficient mechanical removal capability of the polishing slurry while controlling the risk of scratches caused by high solid content; when peracetic acid is controlled at 0.2–1.5 wt%, it meets the oxidation reaction intensity required for fine polishing of gallium arsenide surfaces; when urea peroxide is controlled at 0.1–0.5 wt%, it helps to stabilize the oxidation environment; when the mass ratio of the two is controlled at 3:1–10:1, it helps to balance the surface reaction rate and the stability of the polishing process. Controlling the pH value at 3.5–4.2 helps to balance surface quality and polishing slurry stability under acidic reaction conditions.

[0010] Furthermore, the modified cerium oxide abrasive is prepared by first modifying the surface of nano-cerium oxide with a silane coupling agent, and then grafting it with a short-chain organic acid.

[0011] Specifically, the preparation of the modified cerium oxide abrasive may include the following process: first, pre-treating nano-cerium oxide by dehydration, then dispersing it in an organic solvent and adding a silane coupling agent for surface modification to introduce the active groups required for subsequent grafting onto the cerium oxide surface; then, dispersing the silane-modified cerium oxide in an aqueous system and adding a short-chain organic acid for grafting, so that the organic acid functional groups are fixed on the surface of the cerium oxide particles; finally, washing and drying to obtain the modified cerium oxide abrasive. This surface modification treatment helps to improve the dispersion stability of cerium oxide abrasive in acidic media and reduces the adverse effects of agglomerated particles on the surface quality of fine polishing.

[0012] Furthermore, the silane coupling agent is γ-aminopropyltriethoxysilane or γ-mercaptopropyltrimethoxysilane, and the short-chain organic acid is at least one of citric acid, tartaric acid, or adipic acid.

[0013] In this process, silane coupling agents are used to form a reactive interface on the surface of nano-cerium oxide, while short-chain organic acids are used to introduce organic acid functional groups onto the particle surface. The combination of these silane coupling agents and short-chain organic acids not only maintains the polishing activity of cerium oxide abrasives but also improves their suspension and dispersion in acidic polishing solutions.

[0014] Furthermore, the acidic chemical mechanical polishing slurry also includes 0.01 to 0.3 wt% of a nonionic surfactant, wherein the nonionic surfactant is a fatty alcohol polyoxyethylene ether or an alkylphenol polyoxyethylene ether.

[0015] The nonionic surfactant is used to improve the wettability of the polishing slurry on the wafer surface and helps reduce the adhesion and residue of particles and reaction products on the surface during the polishing process, thereby improving the surface cleanliness after polishing. Because a nonionic surfactant is used, it does not introduce additional risks of metal ion contamination, making it suitable for use in semiconductor substrate fine polishing systems.

[0016] Furthermore, the acidic chemical mechanical polishing slurry also includes 0.05–0.5 wt% of an amino acid complexing agent, wherein the amino acid complexing agent is glycine or L-proline.

[0017] The amino acid-based complexing agent is used to form soluble complexes with the relevant ions generated during the reaction of gallium arsenide surface, promotes the transfer of polishing products to the liquid phase, reduces the risk of surface deposition and secondary scratches, and thus helps to further improve the surface quality after fine polishing.

[0018] Furthermore, the acidic chemical mechanical polishing fluid also includes 0.001–0.05 wt% of isothiazolinone bactericide.

[0019] The isothiazolinone bactericide is used to inhibit microbial contamination of the polishing solution during storage and use, which helps to extend the shelf life of the polishing solution and improve batch stability.

[0020] Further, the acidic chemical mechanical polishing slurry is prepared by the following method: first, modified cerium oxide abrasive is added to deionized water for pre-dispersion to obtain an abrasive slurry; then, peracetic acid, urea peroxide and other components are added to deionized water to dissolve to obtain a functional component solution; then, the functional component solution is added to the abrasive slurry and the pH value is adjusted to 3.0-5.0, and finally, the acidic chemical mechanical polishing slurry is obtained by filtration.

[0021] In the above preparation process, it is preferable to first pre-disperse the modified cerium oxide abrasive separately to improve the uniformity of the abrasive in the liquid phase; after pre-dissolving peracetic acid, urea peroxide and optional additives, they are mixed with the abrasive slurry, which helps to avoid uneven composition or aggravated decomposition caused by excessively high local concentrations; after mixing, the pH of the system is adjusted to the target range to obtain an acidic polishing slurry suitable for fine polishing of gallium arsenide substrates.

[0022] Furthermore, the pre-dispersion is carried out using a high-shear dispersion method, and the filtration is performed using a 0.5 μm filter cartridge for circulating filtration.

[0023] The high-shear dispersion method is beneficial for uniformly dispersing the modified cerium oxide abrasive in the aqueous phase; the use of a 0.5 μm filter cartridge for circulating filtration is beneficial for removing any large particles or agglomerates that may be present in the system, further reducing the probability of surface scratches during polishing and improving the consistency of the finished polishing solution.

[0024] This invention also provides the application of the above-mentioned acidic chemical mechanical polishing slurry in the fine polishing of gallium arsenide substrates. In this application, the fine polishing conditions are: polishing pressure 0.5–2.5 psi, polishing disc rotation speed 20–60 rpm, polishing head rotation speed 20–60 rpm, polishing slurry flow rate 30–150 mL / min, and polishing time 2–8 min.

[0025] The embodiments of the present invention have the following advantages due to the adoption of the above technical solutions: I. The acidic chemical mechanical polishing slurry for fine polishing of gallium arsenide substrates provided by the present invention uses peracetic acid and urea peroxide to form a dual oxidant system, and combines it with modified cerium oxide abrasive with surface grafted organic acid functional groups. Under acidic conditions, it takes into account the surface reaction stability, abrasive dispersibility and low load mechanical removal requirements, thereby helping to reduce surface scratches, particle residue and subsurface damage depth, and improve the surface integrity of gallium arsenide substrates after fine polishing.

[0026] Second, the acidic chemical mechanical polishing slurry provided by the present invention maintains high surface quality while having good storage stability and process consistency. It can balance removal rate and surface quality during the fine polishing of gallium arsenide substrates, reduce polishing performance fluctuations, and is more conducive to meeting the requirements of stability and batch consistency in the precision processing of semiconductor substrates.

[0027] The above overview is for illustrative purposes only and is not intended to be limiting in any way. Further aspects, embodiments, and features of the invention will become readily apparent from the following detailed description, in addition to the illustrative aspects, embodiments, and features described above. Detailed Implementation

[0028] This invention provides an acidic chemical mechanical polishing slurry for fine polishing of gallium arsenide substrates. The slurry, by weight percentage, comprises modified cerium oxide abrasive, peracetic acid, urea peroxide, and deionized water, with the pH value controlled between 3.0 and 5.0. The modified cerium oxide abrasive consists of nano-cerium oxide particles with surface-grafted organic acid functional groups, having an average particle size of 20–80 nm. In some embodiments, the slurry may further contain nonionic surfactants, amino acid complexing agents, and isothiazolinone bactericides to further improve surface cleanliness, reaction product migration ability, and storage stability.

[0029] The modified cerium oxide abrasive of the present invention can be prepared by the following method: first, the surface of nano-cerium oxide is modified with a silane coupling agent, and then grafted with a short-chain organic acid.

[0030] Specifically, nano-cerium oxide undergoes dehydration pretreatment, then disperses in anhydrous ethanol, and a silane coupling agent is added for reaction. After silanization, it is redispersed in an aqueous system, and a short-chain organic acid is added for grafting reaction. Finally, the mixture is washed and dried to obtain modified cerium oxide abrasive. This surface modification improves the dispersion of cerium oxide abrasive in acidic polishing solutions and reduces the risk of surface scratches caused by agglomerated particles. The silane coupling agent can be γ-aminopropyltriethoxysilane or γ-mercaptopropyltrimethoxysilane, and the short-chain organic acid can be at least one of citric acid, tartaric acid, or adipic acid.

[0031] The acidic chemical mechanical polishing slurry of this invention can be prepared by the following method: First, modified cerium oxide abrasive is added to deionized water for pre-dispersion to form a uniform abrasive slurry; then, peracetic acid, urea peroxide, and other functional components are added to another portion of deionized water to fully dissolve them, obtaining a functional component solution; then, the functional component solution is slowly added to the abrasive slurry, and the pH of the system is adjusted to 3.0–5.0 under stirring conditions; finally, the solution is filtered through a filter cartridge to obtain the finished acidic chemical mechanical polishing slurry. In some embodiments, the pre-dispersion is carried out using a high-shear dispersion method, and the filtration is performed using a 0.5 μm filter cartridge for circulating filtration to reduce the content of larger particles or agglomerates in the system.

[0032] The acidic chemical mechanical polishing slurry of this invention can be applied to the fine polishing of gallium arsenide substrates. In application, the coarsely polished gallium arsenide wafer is fixed to the polishing head of a polishing machine. The polishing slurry is delivered to the surface of the polishing pad, and fine polishing is performed under the following conditions: polishing pressure 0.5–2.5 psi, polishing disc rotation speed 20–60 rpm, polishing head rotation speed 20–60 rpm, polishing slurry flow rate 30–150 mL / min, and polishing time 2–8 min. Further, the polishing pressure can be controlled to 1.0–1.5 psi, the polishing disc rotation speed can be controlled to 30–50 rpm, the polishing head rotation speed can be controlled to 30–50 rpm, and the polishing slurry flow rate can be controlled to 50–100 mL / min; the polishing pad can be a soft foamed polyurethane polishing pad or a non-woven fabric polishing pad. After polishing, the wafer can be sequentially rinsed with deionized water, cleaned with SC-1 solution, rinsed with deionized water, and then spin-dried.

[0033] Example 1 This embodiment provides an acidic chemical mechanical polishing slurry for fine polishing of gallium arsenide substrates. By weight percentage, its composition is: 2.5 wt% modified cerium oxide abrasive with an average particle size of 40 nm; 0.8 wt% peracetic acid; 0.2 wt% urea peroxide; 0.1 wt% glycine; 0.02 wt% fatty alcohol polyoxyethylene ether AEO-9; 0.005 wt% isothiazolinone bactericide; the balance being deionized water. Acetic acid is used to adjust the pH of the polishing slurry to 4.0.

[0034] In this embodiment, the modified cerium oxide abrasive is prepared as follows: 50 g of nano-cerium oxide with an average particle size of 40 nm is dispersed in 500 mL of anhydrous ethanol, and 2.5 g of γ-aminopropyltriethoxysilane is added. The mixture is reacted at 70 °C for 5 h. After centrifugation and washing, the mixture is redispersed in deionized water, and 5 g of citric acid is added. The mixture is then reacted at 50 °C for another 2 h. After washing and drying, the modified cerium oxide abrasive is obtained. Subsequently, the modified cerium oxide abrasive is added to a portion of deionized water and pre-dispersed using a high-shear dispersion method to form an abrasive slurry. Peracetic acid, urea peroxide, glycine, AEO-9, and isothiazolinone bactericide are added to another portion of deionized water and stirred to dissolve, forming a functional component solution. The functional component solution is then slowly added to the abrasive slurry, and the pH is adjusted to 4.0 with acetic acid under stirring conditions. Finally, the mixture is filtered through a 0.5 μm filter cartridge to obtain the polishing solution product of this embodiment.

[0035] Example 2 This embodiment provides an acidic chemical mechanical polishing slurry for fine polishing of gallium arsenide substrates. By weight percentage, its composition is: 3.0 wt% modified cerium oxide abrasive with an average particle size of 50 nm; 1.2 wt% peracetic acid; 0.3 wt% urea peroxide; 0.15 wt% L-proline; 0.03 wt% alkylphenol polyoxyethylene ether OP-10; 0.005 wt% isothiazolinone bactericide; and the balance is deionized water. Acetic acid is used to adjust the pH of the polishing slurry to 3.8.

[0036] In this embodiment, the preparation method of the modified cerium oxide abrasive is basically the same as that in Example 1, except that the grafting organic acid is replaced by an equal amount of tartaric acid instead of citric acid. In this embodiment, the content of modified cerium oxide abrasive, peracetic acid, urea peroxide, and pH value all fall within the preferred range of this invention. Furthermore, the use of another amino acid complexing agent and another nonionic surfactant further demonstrates the stability of the formulation system of this invention.

[0037] Example 3 This embodiment provides an acidic chemical mechanical polishing slurry for fine polishing of gallium arsenide substrates. By weight percentage, its composition is: 1.5 wt% modified cerium oxide abrasive with an average particle size of 30 nm; 0.5 wt% peracetic acid; 0.15 wt% urea peroxide; 0.08 wt% glycine; and the balance being deionized water. The pH of the polishing slurry is adjusted to 4.2 using acetic acid.

[0038] This embodiment does not include nonionic surfactants and bactericides, and is mainly used to verify that under simplified formulation conditions, the dual oxidant system of the present invention and the modified cerium oxide abrasive can still achieve good fine polishing effect.

[0039] Comparative Example 1 Compared to Example 1, this comparative example only replaces peracetic acid and urea peroxide with an equal amount of hydrogen peroxide, with the amount of hydrogen peroxide added being 1.0 wt%. The remaining components and pH value remain consistent with Example 1. This comparative example is used to illustrate the impact on polishing efficiency and surface quality when the acidic polishing solution does not use the peracetic acid and urea peroxide dual oxidant system described in this invention, but instead uses a traditional single hydrogen peroxide system.

[0040] Comparative Example 2 Compared to Example 1, this comparative example differs only in that the modified cerium oxide abrasive in Example 1 is replaced with unmodified commercially available nano-cerium oxide with an average particle size of 40 nm. The remaining components and pH value remain consistent with Example 1. This comparative example illustrates the effect of the modified cerium oxide abrasive formed by grafting organic acid functional groups according to the present invention on reducing agglomeration and improving surface quality in acidic systems.

[0041] Comparative Example 3 Compared to Example 1, this comparative example uses only 1.0 wt% peracetic acid, without the addition of urea peroxide, while maintaining the same components and pH value as in Example 1. This comparative example illustrates the effect of using only peracetic acid without introducing urea peroxide on the removal rate, surface roughness, and system stability in an acidic polishing system.

[0042] Fine polishing performance test The polishing solutions of Examples 1-3 and Comparative Examples 1-3 were used to perform fine polishing tests on 2-inch gallium arsenide wafers that had undergone rough polishing, with the crystal orientation as follows: <100> The fine polishing conditions were uniformly set as follows: polishing pressure 1.5 psi, polishing disc rotation speed 45 rpm, polishing head rotation speed 45 rpm, polishing fluid flow rate 80 mL / min, and polishing time 5 min. The test results are shown in Table 1. Table 1: Results of Fine Polishing Performance Test

[0043] As can be seen from Table 1, the polishing solutions of Examples 1 to 3 of the present invention can still achieve a removal rate of 195 to 305 nm / min under a low pressure of 1.5 psi, which is significantly higher than the 108 nm / min of Comparative Example 1. At the same time, the surface roughness Ra of Examples 1 to 3 is all less than 0.25 nm, with Example 3 reaching 0.15 nm, while Comparative Example 1 and Comparative Example 2 are 0.55 nm and 0.78 nm, respectively.

[0044] The scratch density and particle residue results further illustrate that the combination of the dual-oxidant system and the modified cerium oxide abrasive of this invention is beneficial for balancing removal rate and surface quality; among them, the scratch density of Comparative Example 2 reached 22-28 scratches / cm. 2 This indicates that the aggregation of unmodified cerium oxide in an acidic system is more likely to cause surface defects. On the other hand, the subsurface damage layer depth of Examples 1-3 is less than 8 nm, while that of the comparative examples is 13-42 nm, indicating that the present invention is suitable for fine polishing of gallium arsenide substrates. Considering the indicators listed in Table 1, Example 1 achieves a better balance between removal rate, surface roughness, scratch density, particle residue, and subsurface damage depth, and is a preferred embodiment.

[0045] 30-day storage stability test The polishing solutions of Examples 1-3 and Comparative Examples 1-3 were sealed in HDPE containers and stored in the dark at room temperature (25±2℃) for 30 days. Samples were taken on days 0, 10, 20, and 30, and gallium arsenide wafers were polished under the same process conditions as the aforementioned fine polishing performance test to examine the removal rate retention, surface roughness change, and pH stability. The test results of Examples 1-3 are shown in Table 2. Table 2: Results of 30-day storage stability test.

[0046]

[0047] As shown in Table 2, after 30 days of storage at room temperature in the dark, the removal rate retention rate of Examples 1-3 was all above 91%, the surface roughness Ra only increased slightly, and the pH value change within 30 days was less than 0.1, indicating that the dual oxidant system of the present invention has good storage stability. The stability results of the comparative examples: the removal rate retention rate of Comparative Example 1 was only 51.9%, and the removal rate decreased from 108 nm / min to 56 nm / min after 30 days; the removal rate retention rates of Comparative Examples 2 and 3 were 80.2% and 78.5%, respectively, both significantly lower than those of the examples of the present invention. Therefore, the polishing solution of the present invention can maintain good polishing performance and surface quality consistency even after long-term storage.

[0048] In summary, this invention introduces peracetic acid and urea peroxide into an acidic system to form a dual oxidant component, and combines it with modified cerium oxide abrasive with surface-grafted organic acid functional groups, which can still achieve good fine polishing effect on gallium arsenide substrates under low polishing pressure conditions. At the same time, by combining optional components such as nonionic surfactants, amino acid complexing agents and bactericides, the surface cleanliness and storage stability can also be improved.

[0049] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various variations or substitutions within the technical scope disclosed in the present invention, and these should all be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An acidic chemical mechanical polishing slurry for fine polishing of gallium arsenide substrates, characterized in that, The polishing solution comprises, by weight percentage, 0.5–5 wt% modified cerium oxide abrasive, 0.1–3 wt% peracetic acid, 0.05–2 wt% urea peroxide, and the balance being deionized water. The pH value of the polishing solution is 3.0–5.

0. The modified cerium oxide abrasive is nano-cerium oxide particles with surface grafted organic acid functional groups, and the average particle size is 20–80 nm.

2. The acidic chemical mechanical polishing slurry according to claim 1, characterized in that, The modified cerium oxide abrasive has a content of 1-3 wt%, the peracetic acid has a content of 0.2-1.5 wt%, the urea peroxide has a content of 0.1-0.5 wt%, the mass ratio of the peracetic acid to the urea peroxide is 3:1-10:1, and the pH value of the polishing solution is 3.5-4.

2.

3. The acidic chemical mechanical polishing slurry according to claim 1, characterized in that, The modified cerium oxide abrasive is prepared by first modifying the surface of nano-cerium oxide with a silane coupling agent, and then grafting it with a short-chain organic acid.

4. The acidic chemical mechanical polishing slurry according to claim 3, characterized in that, The silane coupling agent is γ-aminopropyltriethoxysilane or γ-mercaptopropyltrimethoxysilane, and the short-chain organic acid is at least one of citric acid, tartaric acid or adipic acid.

5. The acidic chemical mechanical polishing slurry according to claim 1, characterized in that, It also includes 0.01 to 0.3 wt% of a nonionic surfactant, wherein the nonionic surfactant is a fatty alcohol polyoxyethylene ether or an alkylphenol polyoxyethylene ether.

6. The acidic chemical mechanical polishing slurry according to claim 1, characterized in that, It also includes 0.05 to 0.5 wt% of an amino acid complexing agent, wherein the amino acid complexing agent is glycine or L-proline.

7. The acidic chemical mechanical polishing slurry according to claim 1, characterized in that, It also includes 0.001 to 0.05 wt% of isothiazolinone bactericides.

8. The acidic chemical mechanical polishing slurry according to claim 1, characterized in that, The acidic chemical mechanical polishing slurry is prepared by the following method: first, modified cerium oxide abrasive is added to deionized water for pre-dispersion to obtain an abrasive slurry; then, peracetic acid, urea peroxide and other components are added to deionized water to dissolve to obtain a functional component solution; then, the functional component solution is added to the abrasive slurry and the pH value is adjusted to 3.0-5.0; finally, the slurry is filtered to obtain the acidic chemical mechanical polishing slurry.

9. The acidic chemical mechanical polishing slurry according to claim 8, characterized in that, The pre-dispersion is carried out using a high-shear dispersion method, and the filtration is performed using a 0.5μm filter cartridge for circulating filtration.

10. The application of the acidic chemical mechanical polishing slurry according to any one of claims 1 to 9 in the fine polishing of gallium arsenide substrates, characterized in that, The fine polishing conditions are as follows: polishing pressure 0.5-2.5 psi, polishing disc speed 20-60 rpm, polishing head speed 20-60 rpm, polishing fluid flow rate 30-150 mL / min, and polishing time 2-8 min.

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