Silicon oxide / silicon nitride acidic polishing solution based on cerium oxide abrasive and preparation method of silicon oxide / silicon nitride acidic polishing solution

Abstract

The invention relates to a silicon oxide / silicon nitride acidic polishing solution based on a cerium oxide grinding material and a preparation method of the silicon oxide / silicon nitride acidic polishing solution. According to the polishing solution, a quaternary ammonium salt compound is used as an ionic active auxiliary agent, and the polishing rate of silicon oxide is improved and the polishing rate of silicon nitride is inhibited under the combined action of a small-particle-size cerium oxide abrasive, amino acid, a surfactant and the ionic active auxiliary agent under the acidic condition; and relatively low silicon oxide / silicon nitride surface roughness is obtained. According to the invention, the polishing rate of silicon oxide is more than # imgabs0 # imgabs1 #, the polishing rate of silicon nitride is less than # imgabs2 #, and the surface roughness of both silicon oxide and silicon nitride is less than 0.1 nm.

Description

Technical Field

[0001] The invention belongs to the field of polishing liquid, and in particular relates to a highly selective silicon oxide / silicon nitride acidic polishing liquid based on cerium oxide abrasive and a preparation method thereof. Background Art

[0002] With the continuous development of integrated circuit technology, some leading semiconductor manufacturers have begun mass production or are developing 3nm process technology. These advanced process nodes have further reduced the size of transistors. Higher integration and performance requirements have also placed higher requirements on chemical mechanical polishing (CMP) in the shallow trench isolation (STI) process. CMP is a technology that combines mechanical and chemical actions to achieve global planarization. The STI process often uses silicon oxide as the filling material for the trench and silicon nitride as the lining material for the trench sidewalls. During the production process, the silicon oxide layer needs to be polished and stopped on the silicon nitride layer.

[0003] For STI silicon oxide / silicon nitride CMP, in order to improve production efficiency and ensure that low surface roughness can be achieved immediately during the production process, the silicon oxide removal rate should be controlled within In order to maintain the structural integrity of silicon nitride, the removal rate of silicon nitride should be controlled at This is because a lower polishing rate can avoid damage and excessive removal of silicon nitride. At the same time, the surface quality of silicon oxide / silicon nitride will have a great impact on the next process, so a silicon oxide / silicon nitride film with low surface roughness is crucial.

[0004] Since cerium oxide abrasive has a high selectivity for silicon oxide and silicon nitride, it is often used in the second step of STI CMP process. Currently, large-particle-size (100-300nm) cerium oxide abrasives are more commonly used in the industry, but large-particle-size abrasives are prone to cause surface defects of silicon oxide / silicon nitride. For example, CN118048109A discloses a method for preparing a cerium oxide polishing liquid containing cerium oxide slurry, organic acid additives, pH regulators, dispersants, and bactericides, but the average particle size of cerium oxide used in this technology is 170-200nm, and large-particle-size cerium oxide particles are more likely to cause defects in the actual production process. Therefore, small-particle-size (20-80nm) cerium oxide abrasives are more likely to be used in the STI CMP process. However, in these small particle size solutions (such as Oh M-H, Singh RK, Gupta S, et al. Polishing behaviors of single crystalline ceria abrasives on silicon dioxide and silicon nitride CMP [J]. Microelectronic Engineering, 2010, 87 (12): 2633-2637. and Sampurno Y, Sudargho F, Zhuang Y, et al. Effect of Cerium Oxide Particle Sizes in Oxide Chemical Mechanical Planning [J]. Electrochemical and Solid-State Letters, 2009, 12 (6): H191.), due to the large specific surface area of ​​small particle size cerium oxide abrasives, there are certain limitations in physical, chemical and mechanical effects compared with large particle size abrasives. During the polishing process, it is more difficult for small particle size cerium oxide abrasives to achieve a high silicon oxide polishing rate and a higher silicon oxide / silicon nitride selectivity than large particle size cerium oxide abrasives. Therefore, using small-grained cerium oxide abrasives to achieve a higher silicon oxide polishing rate while obtaining a higher silicon oxide / silicon nitride rate selectivity and a lower silicon oxide / silicon nitride surface roughness is a problem that needs to be solved urgently. Summary of the invention

[0005] The purpose of the present invention is to address the limitations of the current technology and propose a silicon oxide / silicon nitride acidic polishing liquid based on cerium oxide abrasive and a preparation method thereof. The polishing liquid uses a quaternary ammonium salt compound as an ionic active auxiliary agent, and under acidic conditions, through the combined action of small-particle cerium oxide abrasives, amino acids, surfactants and ionic active auxiliary agents, it can improve the polishing rate of silicon oxide and suppress the polishing rate of silicon nitride, and obtain a lower silicon oxide / silicon nitride surface roughness. The present invention achieves a silicon oxide polishing rate of Above, silicon nitride polishing rate At the same time, the surface roughness of both silicon oxide and silicon nitride reached less than 0.1nm.

[0006] The solution of the present invention is:

[0007] A silicon oxide / silicon nitride acidic polishing liquid based on cerium oxide abrasive, the polishing liquid comprises: the mass percentage concentration of cerium oxide in the cerium oxide abrasive is 0.1-1%, the molar concentration of amino acid is 0.001-0.1 mol / L, the molar concentration of surfactant is 0.001-0.1 mol / L, the molar concentration of ionic active additive is 0.001-0.1 mol / L, the balance is water, and the pH value of the polishing system is 3-7;

[0008] The particle size of the cerium oxide abrasive is 30-80 nm.

[0009] The amino acid is one or more of DL-aspartic acid (DL-Asp), arginine (Arg), glutamic acid (Glu), lysine (Lys), and proline (Pro).

[0010] The surfactant is one or more of fatty alcohol ether sodium sulfate (AES), ammonium dodecyl sulfate (ADS), sodium α-olefin sulfonate (AOS), fatty alcohol polyoxyethylene ether (AEO-9), polyethylene glycol (PEG), sodium dodecylbenzene sulfonate (SDBS), and alkylphenol polyoxyethylene ether (APEO).

[0011] The ionic active auxiliary agent is one or more of tetrapropylammonium hydroxide (TPAOH), TEAOH, and 1-adamantyltrimethylammonium hydroxide (ADAOH).

[0012] Preferably, the mass percentage concentration of cerium oxide in the cerium oxide abrasive is 0.4 to 0.6%;

[0013] Preferably, the molar concentration of the amino acid is 0.01 to 0.03 mol / L, and the molar concentration of the surfactant is 0.001 to 0.005 mol / L;

[0014] Preferably, the pH value of the polishing liquid system is 4.5-5.5.

[0015] The method for preparing the silicon oxide / silicon nitride acidic polishing liquid based on cerium oxide abrasive is characterized by comprising the following steps:

[0016] (1) Weighing the required amount of amino acid and adding it to the first portion of deionized water, stirring until completely dissolved, to prepare a first premix solution;

[0017] (2) Weighing the required amount of surfactant and ionic active agent and adding them to the second portion of deionized water, stirring until completely dissolved, to prepare a second premix;

[0018] (3) adding the cerium oxide abrasive into the third portion of deionized water and stirring to obtain a third premixed solution;

[0019] (4) Pour the first premixed liquid and the second premixed liquid into the third premixed liquid while stirring, and add a pH adjuster to adjust the pH value of the solution to 3-7. After stirring evenly, dilute with deionized water to obtain a cerium oxide polishing liquid.

[0020] The pH adjuster is one or more of sodium hydroxide, potassium hydroxide, ammonia water, phosphoric acid, hydrochloric acid and nitric acid.

[0021] The first portion of deionized water, the second portion of deionized water and the third portion of deionized water may have the same or different masses, and are all 10% to 45% of the mass of the total deionized water.

[0022] The essential features of the present invention are:

[0023] The use of small particle size (30-80nm) cerium oxide abrasives in combination with amino acid additives, ionic active agents, and surfactants achieved a higher silicon oxide polishing rate and a high silicon oxide / silicon nitride rate selectivity, and obtained a lower surface roughness. Carboxyl-rich amino acids carry cerium oxide particles to the silicon oxide surface through electrostatic and hydrogen bonding forces, which improves the utilization rate of cerium oxide abrasives and thereby improves the silicon oxide polishing rate. Amino acid-rich amino acids adsorb on the silicon nitride surface through hydrogen bonding to form an adsorption layer, which reduces the contact between the polishing liquid and the silicon nitride surface, thereby inhibiting the silicon nitride polishing rate. Therefore, different types of amino acids are compounded to increase the silicon oxide polishing rate while also reducing the silicon nitride polishing rate. The ionic active agent TEAOH can form complexes with Ce(Ⅲ) and Ce(Ⅳ) under acidic conditions. These complexes have higher reactivity and increase the Ce in cerium oxide. 3+ The utilization rate of TEAOH can more effectively react with the silicon oxide surface and promote the polishing rate of silicon oxide. At the same time, TEAOH can also be adsorbed on the silicon oxide surface, reducing the surface tension of silicon oxide and improving polishing efficiency.

[0024] The beneficial effects of the present invention are:

[0025] (1) The amino groups of DL-Asp and Arg are protonated at a pH of 3 to 7. The protonated amino groups can form an adsorption layer on the surface of silicon nitride through hydrogen bonding, thereby reducing the contact between the polishing liquid and the silicon nitride surface and inhibiting the polishing rate of silicon nitride. At the same time, amino acids can also increase the activity of cerium oxide, promote the adsorption of cerium oxide on the surface of silicon oxide, increase the formation of Ce-O-Si bonds, thereby increasing the chemical force of the cerium oxide polishing liquid on the surface of silicon oxide and increasing the polishing rate of silicon oxide. When the ratio of the two is 3:2 (Comparative Example 5), the polishing rate of silicon oxide can reach At this time, the polishing rate of silicon nitride is Compared with the case without addition, the polishing rate of silicon oxide increased by 19.6%, while the polishing rate of silicon nitride decreased by 68.0%.

[0026] (2) The addition of surfactant improves the dispersibility of cerium oxide particles and improves the wettability of the polishing liquid to a certain extent, thereby reducing the surface roughness of silicon oxide and silicon nitride. As in Example 1, the surface roughness of silicon oxide and silicon nitride are 0.062nm and 0.046nm, respectively. Compared with the comparative example, the surface roughness of the two is reduced by 82.8% and 75.5%, respectively.

[0027] (3) The addition of ionic active additives improves the utilization rate of Ce(III) in cerium oxide, increases the chemical interaction between cerium oxide and the surface of silicon oxide, and further improves the polishing rate of silicon oxide. As in Example 1, the polishing rates of silicon oxide and silicon nitride are and At this time, the polishing rate of silicon oxide is increased by 41.6% compared with the comparative example, while the polishing rate of silicon nitride is reduced by 90.1%.

[0028] (4) The polishing liquid of the present invention has a low solid content (0.1-1%), which saves costs, controls particle contamination, and facilitates subsequent cleaning.

[0029] (5) Finally, the present invention achieves a high removal rate of silicon oxide (higher than ) and low surface roughness (less than 0.1nm), low removal rate of silicon nitride (less than ) and low surface roughness (less than 0.1nm). It meets the CMP process requirements in the STI process of low technology nodes. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the AFM image of the silicon oxide surface after being treated with the polishing liquid of Comparative Example 1.

[0031] Figure 2This is an AFM image of the silicon nitride surface after being treated with the polishing liquid of Comparative Example 1.

[0032] Figure 3 This is an AFM image of the silicon oxide surface after being treated with the polishing liquid of Example 1.

[0033] Figure 4 This is an AFM image of the silicon nitride surface after being treated with the polishing liquid of Example 1.

[0034] Figure 5 This is the SEM image of the silicon oxide surface after being treated with the polishing liquid of Example 2.

[0035] Figure 6 This is a SEM image of the silicon nitride surface after being treated with the polishing liquid of Example 2. DETAILED DESCRIPTION

[0036] The present invention is further explained below in conjunction with specific embodiments. The embodiments listed here are only used to explain the present invention, but do not limit the scope of the present invention.

[0037] The model of the chemical mechanical polisher used in this application is POLI-500 produced by South Korea's G&P Technology, equipped with a Gas_Pad_20in_GP polishing pad. The process conditions are: polishing liquid flow rate is 250ml / min, polishing head speed is 87r / min, polishing disc speed is 93r / min, polishing head pressure is 3.5psi, and retaining ring pressure is 4.5psi; the cerium oxide dispersion used in the experiment is VK-Ce02W from Xuancheng Jingrui New Materials Co., Ltd.

[0038] The thickness of silicon oxide and silicon nitride films before and after polishing was measured using an F50-UV dielectric film thickness tester (F50, Filmetrics, USA). The surface roughness was detected by atomic force microscopy (AFM, Agilent 5600LS, USA). Three areas were randomly selected on a 4-inch coated sheet for imaging and roughness measurement. The scanning range was 5μm×5μm, and the scanning rate was 0.5 lines per second. The surface particle residue and the surface state after polishing were detected by scanning electron microscopy (SEM, Sigma 500, Zeiss, Germany).

[0039] Example 1

[0040] The present embodiment provides a cerium oxide polishing liquid, in which the mass fraction of cerium oxide is 0.5% (the particle size of the cerium oxide abrasive is 30-80 nm, and the average particle size is 50 nm), the concentration of DL-Asp is 0.02 mol / L, the concentration of Arg is 0.02 mol / L, the concentration of ADS is 0.003 mol / L, the concentration of TEAOH is 0.003 mol / L, the pH value is adjusted to 4.5-5.5 using a pH adjuster, and the balance is deionized water.

[0041] This embodiment also provides a method for preparing 1L of the above cerium oxide polishing liquid, the preparation method comprising the following steps:

[0042] (1) Weigh 0.02 mol of amino acid DL-Asp and 0.02 mol of amino acid Arg and add them to deionized water, stirring until completely dissolved to prepare premix 1;

[0043] (2) weighing 0.003 mol of surfactant ADS and 0.003 mol of ionic active agent TEAOH and adding them into deionized water, stirring evenly to prepare premix 2;

[0044] (3) Add 25 ml of 20% cerium oxide dispersion into another portion of deionized water and stir evenly;

[0045] (4) Pour premix 1 and premix 2 into the mixture while stirring, and add potassium hydroxide / phosphoric acid to adjust the pH value of the solution to 4.5-5.5. After stirring evenly, dilute to 1 L with deionized water to obtain a cerium oxide polishing solution.

[0046] Example 2

[0047] The present embodiment provides a cerium oxide polishing liquid, in which the mass fraction of cerium oxide in the cerium oxide polishing liquid is 0.5% (the particle size of the cerium oxide abrasive is 30-80 nm, and the average particle size is 50 nm), the concentration of DL-Asp is 0.02 mol / L, the concentration of Arg is 0.02 mol / L, the concentration of AEO-9 is 0.004 mol / L, the concentration of TEAOH is 0.002 mol / L, the pH value is adjusted to 4.5-5.5 using a pH adjuster, and the balance is deionized water.

[0048] This embodiment also provides a method for preparing 1L of the above cerium oxide polishing liquid, the preparation method comprising the following steps:

[0049] (1) Weigh 0.02 mol of amino acid DL-Asp and 0.02 mol of amino acid Arg and add them to deionized water, stirring until completely dissolved to prepare premix 1;

[0050] (2) weighing 0.004 mol of surfactant AEO-9 and 0.002 mol of ionic active agent TEAOH and adding them into deionized water, stirring until completely dissolved, to prepare premix 2;

[0051] (3) Add 25 ml of 20% cerium oxide dispersion into another portion of deionized water and stir evenly;

[0052] (4) Pour premix 1 and premix 2 into the mixture while stirring, and add potassium hydroxide / phosphoric acid to adjust the pH value of the solution to 4.5-5.5. After stirring evenly, dilute to 1 L with deionized water to obtain a cerium oxide polishing solution.

[0053] Example 3

[0054] The present embodiment provides a cerium oxide polishing liquid, in which the mass fraction of cerium oxide is 0.5% (the particle size of the cerium oxide abrasive is 30-80 nm, and the average particle size is 50 nm), the concentration of DL-Asp is 0.02 mol / L, the concentration of Arg is 0.02 mol / L, the concentration of PEG is 0.002 mol / L, the concentration of TEAOH is 0.004 mol / L, the pH value is adjusted to 4.5-5.5 using a pH adjuster, and the balance is deionized water.

[0055] This embodiment also provides a method for preparing 1L of the above cerium oxide polishing liquid, the preparation method comprising the following steps:

[0056] (1) Weigh 0.02 mol of amino acid DL-Asp and 0.02 mol of amino acid Arg and add them to deionized water, stirring until completely dissolved to prepare premix 1;

[0057] (2) weighing 0.002 mol of a surfactant PEG and 0.004 mol of an ionic active agent TEAOH and adding them to deionized water, stirring until completely dissolved, to prepare a premix 2;

[0058] (3) Add 25 ml of 20% cerium oxide dispersion into another portion of deionized water and stir evenly;

[0059] (4) Pour premix 1 and premix 2 into the mixture while stirring, and add potassium hydroxide / phosphoric acid to adjust the pH value of the solution to 4.5-5.5. After stirring evenly, dilute to 1 L with deionized water to obtain a cerium oxide polishing solution.

[0060] Comparative Example 1

[0061] This comparative example provides a cerium oxide polishing liquid, in which the mass fraction of cerium oxide is 0.5% (the particle size of the cerium oxide abrasive is 30-80 nm, and the average particle size is 50 nm), the pH value is adjusted to 4.5-5.5 using a pH regulator, and the balance is deionized water.

[0062] Comparative Example 2

[0063] This comparative example provides a cerium oxide polishing liquid, in which the mass fraction of cerium oxide is 0.5% (the particle size of the cerium oxide abrasive is 30-80 nm, and the average particle size is 50 nm), the concentration of DL-Asp is 0.008 mol / L, the concentration of Arg is 0.032 mol / L, the pH value is adjusted to 4.5-5.5 using a pH adjuster, and the balance is deionized water.

[0064] This comparative example also provides a method for preparing 1L of the above-mentioned cerium oxide polishing liquid, and the preparation method comprises the following steps:

[0065] (1) Weigh 0.008 mol of amino acid DL-Asp and 0.032 mol of amino acid Arg and add them to deionized water, stirring until completely dissolved to prepare a premix solution;

[0066] (2) Add 25 ml of 20% cerium oxide dispersion into another portion of deionized water and stir evenly;

[0067] (3) Pour the premixed solution into the mixture while stirring, and add potassium hydroxide / phosphoric acid to adjust the pH value of the solution to 4.5-5.5. After stirring evenly, dilute the volume to 1 L with deionized water to obtain a cerium oxide polishing solution.

[0068] Comparative Example 3

[0069] The other steps were the same as those in Comparative Example 2, except that the concentration of DL-Asp was 0.016 mol / L, and the concentration of Arg was 0.024 mol / L.

[0070] Comparative Example 4

[0071] The other steps were the same as those in Comparative Example 2, except that the concentration of DL-Asp was 0.02 mol / L and the concentration of Arg was 0.02 mol / L.

[0072] Comparative Example 5

[0073] The other steps were the same as those in Comparative Example 2, except that the concentration of DL-Asp was 0.024 mol / L, and the concentration of Arg was 0.016 mol / L.

[0074] Comparative Example 6

[0075] The other steps were the same as those in Comparative Example 2, except that the concentration of DL-Asp was 0.032 mol / L, and the concentration of Arg was 0.008 mol / L.

[0076] The cerium oxide polishing liquid prepared in Examples 1-3 and Comparative Examples 1-6 was used for STI polishing. The polishing rates of silicon oxide and silicon nitride and the rate selection ratio of silicon oxide / silicon nitride obtained by CMP of 4-inch silicon oxide and silicon nitride coated wafers were shown in Table 1.

[0077] Table 1

[0078]

[0079] From the data in Table 1, we can see the following points:

[0080] (1) A comprehensive comparison of the data of Comparative Examples 2-6 shows that by adjusting the ratio of different types of amino acids, the polishing rate of silicon oxide can be improved to varying degrees, and the polishing rate of silicon nitride can be suppressed to varying degrees, thereby regulating the rate selectivity of silicon oxide / silicon nitride. Under optimal conditions, the polishing rate of silicon oxide can reach above.

[0081] (2) Comprehensively comparing the data of Examples 1-3 and Comparative Examples 1-6, it can be seen that the addition of surfactants and ionic active additives can increase the polishing rate of silicon oxide to a certain extent while reducing the polishing rate of silicon nitride. The silicon oxide / silicon nitride selectivity can reach more than 16, achieving a good polishing effect.

[0082] By comparison Figure 1 and Figure 3 , Figure 2 and Figure 4 It can be concluded that the present invention can reduce the surface roughness of silicon oxide from 0.360nm to 0.062nm and the surface roughness of silicon nitride from 0.188nm to 0.046nm by controlling the ratio of different types of amino acids and combining the synergistic effect of surfactants and ionic active additives, thereby achieving good polishing effect.

[0083] pass Figure 5 and Figure 6 It can be concluded that the cerium oxide polishing liquid provided by the present invention can achieve only a few surface particles remaining on the surfaces of silicon oxide and silicon nitride after polishing, while satisfying the polishing rate and selectivity, thereby achieving a good polishing effect.

[0084] In summary, the cerium oxide polishing liquid provided by the present invention has a higher silicon oxide polishing rate, a lower silicon nitride polishing rate and a higher silicon oxide / silicon nitride rate selection ratio. The surface roughness of the polished silicon oxide and silicon nitride is relatively low, and there are very few surface particles remaining after polishing, which can achieve a good polishing effect.

[0085] The applicant declares that the above detailed description of the preparation method of the cerium oxide polishing liquid for the STI process with reference to the specific embodiment is only for illustration and not for limitation. Any changes or modifications that can be easily conceived through the present invention are within the protection scope of the present invention.

[0086] Matters not covered by the present invention are known technologies.

Claims

1. A silicon oxide / silicon nitride acidic polishing liquid based on cerium oxide abrasive, characterized by The polishing liquid comprises: the mass percentage concentration of cerium oxide in cerium oxide abrasive is 0.1-1%, the molar concentration of amino acid is 0.001-0.1 mol / L, the molar concentration of surfactant is 0.001-0.1 mol / L, the molar concentration of ionic active auxiliary agent is 0.001-0.1 mol / L, the balance is water, and the pH value of the polishing system is 3-7; The surfactant is one or more of fatty alcohol ether sodium sulfate (AES), ammonium dodecyl sulfate (ADS), sodium α-olefin sulfonate (AOS), fatty alcohol polyoxyethylene ether (AEO-9), polyethylene glycol (PEG), sodium dodecylbenzene sulfonate (SDBS), and alkylphenol polyoxyethylene ether (APEO); The ionic active auxiliary agent is one or more of tetrapropylammonium hydroxide (TPAOH), TEAOH, and 1-adamantyltrimethylammonium hydroxide (ADAOH).

2. The silicon oxide / silicon nitride acidic polishing liquid based on cerium oxide abrasive according to claim 1, characterized in that: The amino acid is one or more of DL-aspartic acid (DL-Asp), arginine (Arg), glutamic acid (Glu), lysine (Lys), and proline (Pro).

3. The silicon oxide / silicon nitride acidic polishing liquid based on cerium oxide abrasive according to claim 1, characterized in that: The cerium oxide abrasive particle size is 30 to 80 nm.

4. The silicon oxide / silicon nitride acidic polishing liquid based on cerium oxide abrasive according to claim 1, characterized in that: The molar concentration of the amino acid is 0.01-0.03 mol / L, and the molar concentration of the surfactant is 0.001-0.005 mol / L.

5. The silicon oxide / silicon nitride acidic polishing liquid based on cerium oxide abrasive according to claim 1, characterized in that: The pH value of the polishing liquid system is 4.5-5.

5.

6. The method for preparing a silicon oxide / silicon nitride acidic polishing liquid based on cerium oxide abrasive according to claim 1, characterized in that: The following steps are involved: (1) Weighing the required amount of amino acid and adding it to the first portion of deionized water, stirring until completely dissolved, to prepare a first premix solution; (2) Weighing the required amount of surfactant and ionic active agent and adding them to the second portion of deionized water, stirring until completely dissolved, to prepare a second premix; (3) adding the cerium oxide abrasive into the third portion of deionized water and stirring to obtain a third premixed solution; (4) Pour the first premixed liquid and the second premixed liquid into the third premixed liquid while stirring, and add a pH adjuster to adjust the pH value of the solution to 3-7. After stirring evenly, dilute with deionized water to obtain a cerium oxide polishing liquid.

7. The method for preparing a silicon oxide / silicon nitride acidic polishing liquid based on cerium oxide abrasive according to claim 6, characterized in that: The pH adjuster is one or more of sodium hydroxide, potassium hydroxide, ammonia water, phosphoric acid, hydrochloric acid and nitric acid.

8. The method for preparing a silicon oxide / silicon nitride acidic polishing liquid based on cerium oxide abrasive according to claim 1, characterized in that: The first portion of deionized water, the second portion of deionized water and the third portion of deionized water may have the same or different masses, and are all 10% to 45% of the mass of the total deionized water.

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