Polishing solution for improving removal rate of oxide layer

Abstract

The invention relates to the technical field of chemical mechanical polishing, in particular to a polishing solution for improving the removal rate of an oxide layer, which comprises the following components in parts by weight: 75-85 parts of sol-type silicon dioxide; 0.01 to 20 parts of a rate accelerator; 0.01 to 0.5 part of a surfactant; 0.01 to 0.5 part of a dispersant; 15 to 25 parts of water; the particle size range of the sol type silicon dioxide is 100 to 200 nm. The polishing solution for improving the removal rate of the oxide layer, provided by the invention, shows remarkable advantages in the aspects of removal rate, surface roughness, surface particle control and the like when being used as an OXIDE polishing solution by virtue of unique component combination and excellent performance of the polishing solution. The polishing solution not only can improve the polishing efficiency and quality, but also can reduce the production cost and environmental pollution, and has wide application prospects and market value.

Description

Technical Field

[0001] The invention relates to the technical field of chemical mechanical polishing, and in particular to a polishing liquid capable of improving the removal rate of an oxide layer. Background Art

[0002] With the rapid development of semiconductors, optoelectronic displays, and microelectronic packaging, the surface quality requirements for chips, glass substrates, and other materials are becoming increasingly stringent. In particular, efficient removal of the oxide layer has become one of the key processes.

[0003] OXIDE polishing fluid is mainly used in the chemical mechanical polishing (CMP) process of oxide layer materials. Through the CMP process, materials such as silicon oxide layers on the wafer surface or other substrates can be precisely polished to achieve the required surface flatness and thickness control. This polishing fluid is widely used in the semiconductor industry, especially in the wafer manufacturing process, and is crucial to improving device performance and reliability. With the rapid development of the semiconductor industry, the demand for OXIDE polishing fluid continues to grow.

[0004] The existing OXIDE polishing liquid has the problem of low polishing rate during the polishing process, which seriously restricts the production efficiency. Summary of the invention

[0005] The purpose of the present invention is to provide a polishing liquid for improving the oxide layer removal rate, and to improve the oxide polishing rate through the synergistic effect of various components.

[0006] The technical solution adopted by the present invention to solve its technical problem is:

[0007] A polishing liquid for improving the removal rate of an oxide layer, comprising the following components in parts by weight:

[0008]

[0009] The particle size of the sol-type silica is in the range of 100-200 nm.

[0010] Optionally, the mass concentration of silica colloidal particles in the sol-type silica is 20%-50%.

[0011] Optionally, the mass concentration of silica colloidal particles in the sol-type silica is 40%.

[0012] Optionally, the rate accelerator is selected from at least one of alkali metal hydroxides and alkali metal carbonates.

[0013] Optionally, the rate accelerator is selected from at least one of sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate.

[0014] Optionally, the rate accelerator is selected from at least one of potassium hydroxide and potassium carbonate.

[0015] Optionally, the surfactant is selected from at least one of a nonionic surfactant, an amphoteric surfactant, and a polyol surfactant.

[0016] Optionally, the surfactant is selected from at least one of long-chain fatty alcohol polyoxyethylene ether, alkylphenol polyoxyethylene ether, fatty acid polyoxyethylene ester, polyoxyethylene alkylamine, polyoxyethylene alkylamide, and polyether compounds.

[0017] Optionally, the dispersant is selected from at least one of a polyester dispersant, a polyether dispersant, a polyurethane dispersant, a multi-block copolymer dispersant, a nonionic polymer dispersant, and a high molecular weight dispersant.

[0018] Optionally, the dispersant is polyethylene glycol.

[0019] The beneficial effects of the present invention are:

[0020] The polishing liquid for improving the removal rate of the oxide layer provided by the present invention, by virtue of its unique combination of ingredients and excellent performance, when used as an OXIDE polishing liquid, shows significant advantages in terms of removal rate, surface roughness, surface particle control, etc. The polishing liquid can not only improve the polishing efficiency and quality, but also reduce production costs and environmental pollution, and has broad application prospects and market value. DETAILED DESCRIPTION

[0021] The present invention is now further described in detail. The embodiments described below are exemplary and intended to be used to explain the present invention, but cannot be understood as limiting the present invention. All other embodiments obtained by ordinary technicians in this field without creative work based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0022] In order to solve the problem of low polishing rate of the existing OXIDE polishing liquid during the polishing process, the present application provides a polishing liquid for improving the oxide layer removal rate. The polishing liquid comprises the following components in parts by weight:

[0023]

[0024] The particle size of the sol-type silica is in the range of 100-200 nm.

[0025] The polishing liquid provided in the present application has unique advantages through the synergistic effect of various components, so that the polishing liquid exhibits excellent performance in the fields of semiconductor manufacturing, optical component processing and precision machinery surface treatment.

[0026] The polishing liquid provided in this application, by virtue of its unique composition and excellent performance, when used as an OXIDE polishing liquid, shows significant advantages in removal rate, surface roughness, surface particle control, etc. The polishing liquid can not only improve polishing efficiency and quality, but also reduce production costs and environmental pollution, and has broad application prospects and market value.

[0027] As the key abrasive in the polishing liquid, the present application adopts sol-type silica with nanometer-scale particle size distribution, high surface energy, good dispersibility, and can provide uniform and delicate grinding effect during the polishing process. Its unique sol morphology enables the abrasive particles to penetrate into the microstructure of the surface to be polished more effectively, especially for hard materials such as oxide layers (OXIDE), showing faster removal rate and lower surface roughness. Based on the characteristics of the oxide layer, the present application prefers that the particle size of the sol-type silica is preferably 100-200nmnm. It is further preferred that the concentration of silica colloidal particles in the sol-type silica is preferably 20%-50%, and more preferably 40%; the percentage is mass percentage.

[0028] This high concentration of sol-type silica not only provides strong grinding ability, but also ensures stability and uniformity during polishing. The nano-scale size of the colloidal particles allows them to easily penetrate into the microstructure of the workpiece surface, effectively removing oxide layers, scratches and other surface defects while maintaining extremely low surface roughness.

[0029] Polishing liquid rate accelerator is a chemical additive that can accelerate the chemical reaction and physical grinding action during the polishing process. It works synergistically with other components in the polishing liquid to optimize the polishing environment and improve polishing efficiency and quality.

[0030] There are many types of polishing liquid rate accelerators, the most common of which include organic acids, fluorides, ammonia water, inorganic bases, organic bases, and isocyanate silane compounds. Different types of rate accelerators have different chemical structures and properties, and are suitable for different polishing systems and process conditions. In order to ensure the polishing rate, the preferred rate accelerator of the present application is selected from at least one of alkali metal hydroxides and alkali metal carbonates. These rate accelerators can play multiple roles in the polishing process, such as adjusting the pH value of the polishing liquid to promote chemical reactions, increasing the activity of abrasives, and improving the interaction between the polishing liquid and the workpiece surface, thereby significantly improving the polishing rate and optimizing the polishing quality.

[0031] To further increase the polishing rate, the present application preferably selects the rate accelerator from at least one of sodium hydroxide, potassium hydroxide, sodium carbonate, and potassium carbonate; and further preferably selects the rate accelerator from at least one of potassium hydroxide and potassium carbonate.

[0032] In order to improve the wettability and dispersibility of the polishing liquid and ensure the uniform distribution of abrasive particles in the polishing liquid, the present application also adds high-quality surfactants. Such surfactants can significantly reduce the interfacial tension between the polishing liquid and the workpiece surface, promote the polishing liquid to better penetrate into the tiny gaps and depressions on the workpiece surface, and prevent the aggregation and precipitation of abrasive particles, thereby ensuring the continuity and stability of the polishing process.

[0033] The surfactant is preferably a nonionic surfactant, an amphoteric surfactant, or a polyol surfactant. In the present application, the surfactant is preferably selected from at least one of a nonionic surfactant, an amphoteric surfactant, and a polyol surfactant. It is further preferred that the surfactant is a series of compounds with special chemical structures and properties, and the surfactant is preferably selected from at least one of long-chain fatty alcohol polyoxyethylene ethers, alkylphenol polyoxyethylene ethers, fatty acid polyoxyethylene esters, polyoxyethylene alkylamines, polyoxyethylene alkylamides, and polyether compounds.

[0034] The present invention also specifically adds a dispersant to enhance the dispersion effect between the components in the polishing liquid. The dispersant forms a stable dispersion system by physically or chemically reacting with the surface of the sol-type silica particles, preventing agglomeration and precipitation between the particles, thereby improving the stability and service life of the polishing liquid. The preferred dispersant of the present application is selected from at least one of a polyester dispersant, a polyether dispersant, a polyurethane dispersant, a multi-block copolymer dispersant, a nonionic polymer dispersant, and a high molecular weight dispersant, and the dispersant is further preferably polyethylene glycol (PEG).

[0035] The preferred water in this application is deionized water.

[0036] The polishing liquid provided in this application is effective for SIO 2 The film has a higher polishing rate, and a higher removal rate is obtained by screening the rate-enhancing agent.

[0037] The present invention also includes a method for removing SIO 2 The chemical mechanical planarization method of the film comprises the following polishing steps:

[0038] First, Huahai Qingke U300 polishing machine was used, and the polishing pad was: IC1010;

[0039] Polishing pad: 12 inch SIO2;

[0040] Pressure: 3.4 / 3.3 / 3.45 / 3.55 / 7.25 / 8.0;

[0041] Speed: 110 / 108;

[0042] Flow rate: 200ml / min;

[0043] Time: 60s;

[0044] Polishing dilution ratio: stock solution: DIW = 1:1.

[0045] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below.

[0046] Example 1

[0047] Preparation of 1LOXIDE film polishing liquid:

[0048] According to the weight percentage, 0.20 parts of potassium hydroxide, 0.04 parts of PEG400, and 0.10 parts of fatty acid polyoxyethylene ester are dissolved in 19 parts of DIW to prepare a premixed liquid; then the premixed liquid is added to 80 parts of colloidal silica with a particle size of 100nm and a mass concentration of 40% under stirring to obtain edge polishing liquid No. 1, whose pH is about 11.

[0049] First, take the prepared No. 1 edge polishing liquid, use Huahai Qingke U300 polishing machine, polishing pad: IC1010, polishing pressure: pressure: 3.4 / 3.3 / 3.45 / 3.55 / 7.25 / 8.0, polishing head / disc speed: 110 / 108rpm, flow rate is 200ml / min. The polishing disk temperature is controlled at 30±5℃, and the liquid dilution ratio is 1:1; the results after polishing are shown in Table 1.

[0050] Example 2

[0051] Preparation of 1LOXIDE film polishing liquid:

[0052] According to the weight percentage, 0.20 parts of sodium hydroxide, 0.04 parts of PEG400, and 0.10 parts of fatty acid polyoxyethylene ester are dissolved in 19 parts of DIW to prepare a premixed liquid; then the premixed liquid is added to 80 parts of colloidal silica with a particle size of 100nm and a concentration of 40% under stirring to obtain a No. 2 edge polishing liquid with a pH of about 11.

[0053] First, take the prepared No. 2 edge polishing liquid, use Huahai Qingke U300 polishing machine, polishing pad: IC1010, polishing pressure: pressure: 3.4 / 3.3 / 3.45 / 3.55 / 7.25 / 8.0, polishing head / disc speed: 110 / 108rpm, flow rate is 200ml / min. The polishing disk temperature is controlled at 30±5℃, and the liquid dilution ratio is 1:1; the results after polishing are shown in Table 1.

[0054] Example 3

[0055] Preparation of 1LOXIDE film polishing liquid:

[0056] According to the weight percentage, 0.11 parts of sodium carbonate, 0.04 parts of PEG400, and 0.10 parts of fatty acid polyoxyethylene ester are dissolved in 19 parts of DIW to prepare a premixed liquid; then the premixed liquid is added to 80 parts of colloidal silica with a particle size of 100nm and a concentration of 40% under stirring to obtain No. 3 edge polishing liquid, whose pH is about 11.

[0057] First, take the prepared No. 3 edge polishing liquid, use Huahai Qingke U300 polishing machine, polishing pad: IC1010, polishing pressure: pressure: 3.4 / 3.3 / 3.45 / 3.55 / 7.25 / 8.0, polishing head / disc speed: 110 / 108rpm, flow rate is 200ml / min. The polishing disk temperature is controlled at 30±5℃, and the liquid dilution ratio is 1:1; the results after polishing are shown in Table 1.

[0058] Example 4

[0059] Preparation of 1LOXIDE film polishing liquid:

[0060] According to the weight percentage, 0.11 parts of potassium carbonate, 0.04 parts of PEG400, and 0.10 parts of fatty acid polyoxyethylene ester are dissolved in 19 parts of DIW to prepare a premixed liquid; then the premixed liquid is added to 80 parts of colloidal silica with a particle size of 100nm and a concentration of 40% under stirring to obtain No. 4 edge polishing liquid, whose pH is about 11.

[0061] First, take the prepared No. 4 edge polishing liquid, use Huahai Qingke U300 polishing machine, polishing pad: IC1010, polishing pressure: pressure: 3.4 / 3.3 / 3.45 / 3.55 / 7.25 / 8.0, polishing head / disc speed: 110 / 108rpm, flow rate is 200ml / min. The polishing disk temperature is controlled at 30±5℃, and the liquid dilution ratio is 1:1; the results after polishing are shown in Table 1.

[0062] Comparative Example 1

[0063] Preparation of 1LOXIDE film polishing liquid:

[0064] According to the weight percentage, 0.04 parts of PEG400 and 0.10 parts of fatty acid polyoxyethylene ester are dissolved in 19 parts of DIW to prepare a premixed liquid; then the premixed liquid is added to 80 parts of colloidal silica with a particle size of 100nm and a concentration of 40% under stirring to obtain D1 edge polishing liquid with a pH of about 10.

[0065] First, take the prepared D1 edge polishing liquid, use Huahai Qingke U300 polishing machine, polishing pad: IC1010, polishing pressure: pressure: 3.4 / 3.3 / 3.45 / 3.55 / 7.25 / 8.0, polishing head / disc speed: 110 / 108rpm, flow rate is 200ml / min. The polishing disk temperature is controlled at 30±5℃, and the liquid dilution ratio is 1:1; the results after polishing are shown in Table 1.

[0066] Comparative Example 2

[0067] Preparation of 1LOXIDE film polishing liquid:

[0068] According to the weight percentage, 0.20 parts of potassium hydroxide and 0.10 parts of fatty acid polyoxyethylene ester are dissolved in 19 parts of DIW to prepare a premixed liquid; then the premixed liquid is added to 80 parts of colloidal silica with a particle size of 100nm and a concentration of 40% under stirring to obtain D2 edge polishing liquid with a pH of about 11.

[0069] First, take the prepared D2 edge polishing liquid, use Huahai Qingke U300 polishing machine, polishing pad: IC1010, polishing pressure: pressure: 3.4 / 3.3 / 3.45 / 3.55 / 7.25 / 8.0, polishing head / disc speed: 110 / 108rpm, flow rate is 200ml / min. The polishing disk temperature is controlled at 30±5℃, and the liquid dilution ratio is 1:1; the results after polishing are shown in Table 1.

[0070] Comparative Example 3

[0071] Preparation of 1LOXIDE film polishing liquid:

[0072] According to the weight percentage, 0.20 parts of potassium hydroxide and 0.04 parts of PEG400 are dissolved in 19 parts of DIW to prepare a premixed liquid; then the premixed liquid is added to 80 parts of colloidal silica with a particle size of 100nm and a concentration of 40% under stirring to obtain D3 edge polishing liquid, whose pH is about 11.

[0073] First, take the prepared D3 edge polishing liquid, use Huahai Qingke U300 polishing machine, polishing pad: IC1010, polishing pressure: pressure: 3.4 / 3.3 / 3.45 / 3.55 / 7.25 / 8.0, polishing head / disc speed: 110 / 108rpm, flow rate is 200ml / min. The polishing disk temperature is controlled at 30±5℃, and the liquid dilution ratio is 1:1; the results after polishing are shown in Table 1.

[0074] Comparative Example 4

[0075] Preparation of 1LOXIDE film polishing liquid:

[0076] According to the weight percentage, 0.29 parts of tetramethylammonium hydroxide, 0.04 parts of PEG400, and 0.10 parts of fatty acid polyoxyethylene ester are dissolved in 19 parts of DIW to prepare a premixed liquid; then the premixed liquid is added to 80 parts of colloidal silica with a particle size of 100nm and a concentration of 40% under stirring to obtain D4 edge polishing liquid, whose pH is about 11.

[0077] First, take the prepared D4 edge polishing liquid, use Huahai Qingke U300 polishing machine, polishing pad: IC1010, polishing pressure: pressure: 3.4 / 3.3 / 3.45 / 3.55 / 7.25 / 8.0, polishing head / disc speed: 110 / 108rpm, flow rate is 200ml / min. The polishing disk temperature is controlled at 30±5℃, and the liquid dilution ratio is 1:1; the results after polishing are shown in Table 1.

[0078] Comparative Example 5

[0079] Preparation of 1LOXIDE film polishing liquid:

[0080] According to the weight percentage, 0.29 parts of ethylenediamine, 0.04 parts of PEG400, and 0.10 parts of fatty acid polyoxyethylene ester are dissolved in 19 parts of DIW to prepare a premixed liquid; then the premixed liquid is added to 80 parts of colloidal silica with a particle size of 100 nm and a concentration of 40% under stirring to obtain D5 edge polishing liquid, whose pH is about 11.

[0081] First, take the prepared D5 edge polishing liquid, use Huahai Qingke U300 polishing machine, polishing pad: IC1010, polishing pressure: pressure: 3.4 / 3.3 / 3.45 / 3.55 / 7.25 / 8.0, polishing head / disc speed: 110 / 108rpm, flow rate is 200ml / min. The polishing disk temperature is controlled at 30±5℃, and the liquid dilution ratio is 1:1; the results after polishing are shown in Table 1.

[0082] Table 1

[0083]

[0084] Comparing Comparative Examples 1-3 with Example 1, it can be seen that removing any one of the rate accelerator, surfactant, and dispersant in the system will lead to a decrease in the polishing rate.

[0085] By comparing Examples 1-2, it can be seen that the rate of adding KOH is higher than the rate of adding NaOH; by comparing Examples 3-4, it can be seen that the rate of adding potassium carbonate is higher than the rate of adding sodium carbonate; by comparing Comparative Examples 4 and 5 with Comparative Example 1, it can be seen that adding organic bases will reduce the rate to varying degrees; by adding inorganic bases and K salts, the removal rate of the polishing liquid can be quickly increased. Therefore, in order to achieve the requirement of increasing the removal rate of OXIDE film during production and processing, it is recommended to give priority to inorganic bases and carbonates as rate accelerators, and further give priority to potassium hydroxide or potassium carbonate as rate accelerators.

[0086] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A polishing liquid for improving the removal rate of an oxide layer, characterized in that: According to parts by weight, it includes the following components: The particle size of the sol-type silica is in the range of 100-200 nm.

2. The polishing liquid for improving the oxide layer removal rate according to claim 1, characterized in that: The mass concentration of silica colloidal particles in the sol-type silica is 20%-50%.

3. The polishing liquid for improving the oxide layer removal rate according to claim 2, characterized in that: The mass concentration of silica colloidal particles in the sol-type silica is 40%.

4. The polishing liquid for improving the oxide layer removal rate according to claim 1, characterized in that: The rate accelerator is selected from at least one of alkali metal hydroxides and alkali metal carbonates.

5. The polishing liquid for improving the oxide layer removal rate according to claim 4, characterized in that: The rate accelerator is selected from at least one of sodium hydroxide, potassium hydroxide, sodium carbonate and potassium carbonate.

6. The polishing liquid for improving the oxide layer removal rate according to claim 5, characterized in that: The rate accelerator is selected from at least one of potassium hydroxide and potassium carbonate.

7. The polishing liquid for improving the oxide layer removal rate according to claim 1, characterized in that: The surfactant is selected from at least one of a nonionic surfactant, an amphoteric surfactant, and a polyol surfactant.

8. The polishing liquid for improving the oxide layer removal rate according to claim 7, characterized in that: The surfactant is selected from at least one of long-chain fatty alcohol polyoxyethylene ethers, alkylphenol polyoxyethylene ethers, fatty acid polyoxyethylene esters, polyoxyethylene alkylamines, polyoxyethylene alkylamides, and polyether compounds.

9. The polishing liquid for improving the oxide layer removal rate according to claim 1, characterized in that: The dispersant is selected from at least one of polyester dispersants, polyether dispersants, polyurethane dispersants, multi-block copolymer dispersants, non-ionic polymer dispersants, and high molecular weight dispersants.

10. The polishing liquid for improving the oxide layer removal rate according to claim 1, characterized in that: The dispersant is polyethylene glycol.

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