Aluminum alloy material and manufacturing method thereof

Abstract

The invention provides an aluminum alloy material and a manufacturing method thereof, the aluminum alloy material is used for semiconductor equipment, the aluminum alloy material contains Al and inevitable impurities, and further contains the following chemical elements in percentage by mass: 0.5-0.7% of Si, 0.05-0.15% of Fe, 0.2-0.3% of Cu, less than or equal to 0.15% of Mn, 0.8-1.2% of Mg, 0.15-0.35% of Cr, and the balance of Al and inevitable impurities. Fe / Si is greater than or equal to 0.08 and less than or equal to 0.28, and Mg / Si is greater than 1.73 and less than 1.83. According to the aluminum alloy material, the mass percentage content of Fe is limited to be 0.05-0.15%, and Fe / Si is larger than or equal to 0.08 and smaller than or equal to 0.28, so that the Fe content and the Fe / Si ratio are controlled within a proper range, and the precipitation number of an AlFeSi phase in the casting process can be reduced on the basis of ensuring that the mechanical property is not lost.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing, and more specifically, to an aluminum alloy material and its manufacturing method. Background Technology

[0002] With the rapid development of the semiconductor equipment industry in China, the requirements for key supporting components are becoming increasingly stringent. Among them, 6061 aluminum alloy is a material widely used by mainstream international semiconductor equipment manufacturers, especially in physical vapor deposition (PVD) equipment, where more than 30% of the key components are made of 6061 aluminum alloy.

[0003] However, during the deposition process, 6061 aluminum alloy is subjected to high-density plasma bombardment corrosion. In addition, after a certain process cycle, key components need to be regenerated and cleaned. During the regeneration and cleaning process, since most of the contaminants are metal films and are relatively thick, they need to be cleaned with strong corrosive media such as nitric acid and hydrofluoric acid. Therefore, 6061 aluminum alloy components are subject to corrosion by strong corrosive media such as nitric acid and hydrofluoric acid, which affects the stability and lifespan of key components. Summary of the Invention

[0004] The present invention aims to at least solve the problem that 6061 aluminum alloy parts are susceptible to corrosion by strong corrosive media such as nitric acid and hydrofluoric acid in the prior art, thereby affecting the stability and lifespan of key components. The present invention proposes an aluminum alloy material and its manufacturing method.

[0005] To achieve the objective of this invention, a method for manufacturing an aluminum alloy material is provided. The aluminum alloy material is used in semiconductor devices. The manufacturing method includes the following steps: S10: Melting, mixing and melting pure aluminum ingots and intermediate alloys in a specific ratio, satisfying the following elemental requirements: Si: 0.5-0.7%, Cu: 0.2-0.3%, Mn: ≤0.15%, Mg: 0.8-1.2%, Cr: 0.15-0.35%; it also satisfies Fe: 0.05-0.15%, 0.08≤Fe / Si≤0.28, 1.73<Mg / Si<1.83; S20: Casting; S30: One-stage homogenization treatment; S40: Hot deformation treatment; S50: Solution heat treatment.

[0006] In some embodiments, step S30 specifically includes the following steps: S31: entering the homogenizing furnace at room temperature; S32: heating the furnace to 520-560°C; S33: holding the temperature for 10-15 hours after reaching the preset temperature; S34: air cooling the ingot after reaching the preset holding time.

[0007] In some embodiments, in step S33, the temperature difference between various locations within the homogenizing furnace does not exceed 10°C.

[0008] In some embodiments, in step S40, the hot deformation treatment specifically includes: S41: preheating the ingot after peeling; S42: after reaching the hot deformation temperature, deforming the ingot so that the deformation amount of the ingot is greater than 80%.

[0009] In some embodiments, in step S42, the ingot is deformed by hot rolling, and the hot rolling deformation amount R of the ingot is R=(H0-H) / H0×100%, where H0 is the height of the ingot before deformation and H is the height of the ingot after deformation; or the ingot is deformed by forging, and the forging deformation amount is the ratio of the size of the ingot before deformation to the size of the ingot after deformation.

[0010] In some embodiments, after step S50, the microstructure of the aluminum alloy sheet material has a Mg2Si phase that is dispersed in a granular manner.

[0011] In some embodiments, after step S50, the phase size of the Mg2Si phase is less than 50 μm.

[0012] In some embodiments, after step S50, the microstructure of the aluminum alloy material has a plate-like discontinuous distribution of AlFeSi phase or a granular discontinuous distribution of AlFeSi phase.

[0013] In some embodiments, after step S50, the phase size of the AlFeSi phase is less than 100 μm.

[0014] In some embodiments, after step S50, the grain size of the aluminum alloy material is less than 500 μm.

[0015] The method for manufacturing aluminum alloy materials of the present invention reduces the amount of AlFeSi phase precipitation during the casting process by maintaining Fe, Si, and Mg in a specific ratio, without compromising mechanical properties. On this basis, a one-stage homogenization process is combined to achieve a discontinuous fine distribution with a size <100µm, without the presence of coarse triangular AlFeSi phase, while ensuring that the grain size is less than 500µm through deformation and solution treatment processes. Attached Figure Description

[0016] Figure 1 These are microstructure images of Examples 1 and 2 and Comparative Examples 1 and 2 before corrosion of the present invention;

[0017] Figure 2 (a) Figure 2 (b) and Figure 2 (c) is a microstructure image of Comparative Example 1 after 90 min of corrosion;

[0018] Figure 3 (a) Figure 3 (b) and Figure 3 (c) is a microstructure image of Comparative Example 2 after 90 min of corrosion;

[0019] Figure 4 (a) Figure 4 (b) and Figure 4 (c) is a microstructure image of Example 1 after 90 min of corrosion;

[0020] Figure 5 (a) Figure 5 (b) and Figure 5 (c) is a microstructure image of Example 2 after 90 min of corrosion.

[0021] Figure 6 (a) is a diagram of the surface condition of the sample of Comparative Example 1 after it has been immersed in nitric acid for 20 cycles of cyclic corrosion;

[0022] Figure 6 (b) is a diagram of the surface condition of the sample of Comparative Example 2 after it has been immersed in nitric acid for 20 cycles of cyclic corrosion;

[0023] Figure 6 (c) is a diagram of the surface condition of the sample from Example 1 after it has been immersed in nitric acid for 20 cycles of cyclic corrosion;

[0024] Figure 6 (d) is a diagram of the surface state of the sample of Example 2 after it has been immersed in nitric acid for 20 cycles of corrosion.

[0025] like Figure 7 Microstructure images of Examples 3 and 4 and Comparative Examples 3 and 4 before corrosion are shown;

[0026] Figure 8 (a) Figure 8 (b) and Figure 8 (c) is a microstructure image of Comparative Example 3 after 90 min of corrosion;

[0027] Figure 9 (a) Figure 9 (b) and Figure 9 (c) is a microstructure image of Comparative Example 4 after 90 min of corrosion;

[0028] Figure 10 (a) Figure 10 (b) and Figure 10 (c) is a microstructure image of Example 3 after 90 min of corrosion;

[0029] Figure 11 (a) Figure 11 (b) and Figure 11(c) is a microstructure image of Example 4 after 90 min of corrosion.

[0030] Figure 12 (a) is a diagram of the surface condition of the sample of Comparative Example 3 after it has been immersed in nitric acid for 20 cycles of cyclic corrosion;

[0031] Figure 12 (b) is a diagram of the surface condition of the sample of Comparative Example 4 after it has been immersed in nitric acid for 20 cycles of cyclic corrosion.

[0032] Figure 12 (c) is a diagram of the surface condition of the sample in Example 3 after it has been immersed in nitric acid for 20 cycles of cyclic corrosion;

[0033] Figure 12 (d) is a diagram of the surface state of the sample in Example 4 after it has been immersed in nitric acid for 20 cycles of cyclic corrosion.

[0034] Figure 13 (a) is a high-magnification grain image of the sample in Comparative Example 5;

[0035] Figure 13 (b) is a high-magnification grain image of the sample in Comparative Example 3;

[0036] Figure 13 (c) is a high-magnification grain image of the sample from Example 3.

[0037] Figure 14 (a) is a diagram of the surface condition of the sample of Comparative Example 5 after it has been immersed in nitric acid for 20 cycles of cyclic corrosion;

[0038] Figure 14 (b) is a diagram of the surface condition of the sample of Comparative Example 3 after it has been immersed in nitric acid for 20 cycles of cyclic corrosion;

[0039] Figure 14 (c) is a diagram of the surface state of the sample of Example 3 after it has been immersed in nitric acid for 20 cycles of corrosion. Detailed Implementation

[0040] To enable those skilled in the art to better understand the technical solution of the present invention, the aluminum alloy material and its manufacturing method provided by the present invention will be described in detail below with reference to the accompanying drawings.

[0041] Components made of 6061 aluminum alloy, when used as key components, will exhibit severe corrosion phenomena such as large-area corrosion pits and thinning after several regeneration and cleaning processes. This will affect the performance of the coating process and may even render the components unusable.

[0042] The reason is that the main alloying elements of 6061 aluminum alloy are Mg, Si, Fe, Cu and Mn. During the casting and cooling process, due to the different solubilities of these alloying elements in solid aluminum, the alloying elements usually accumulate at the grain boundaries in the form of intermetallic compounds, generally Mg2Si phase and AlFeSi phase. These second phases distributed at the grain boundaries are prone to electrochemical reactions in electrolyte solutions because their electrochemical potentials are different from those of the aluminum matrix.

[0043] To improve the corrosion resistance of aluminum alloy surfaces, a common technique in the field is to form a dense anodic oxide film through surface treatment. This film protects the surface of critical components, reducing contact between the component surface and the electrolyte solution, thereby improving corrosion resistance. Compared to natural oxide films with a thickness of 1-5 nm, anodic oxide films can reach a thickness of 20-200 μm, thus exhibiting superior wear resistance and corrosion resistance.

[0044] Therefore, in the manufacturing process of aluminum alloy materials, the proportion of alloying elements, process steps or process parameters are usually changed to enable the aluminum alloy material to form a better anodic oxide film, thereby improving the density, uniformity and hardness of the anodic oxide film.

[0045] However, anodized aluminum alloys still have many defects. Firstly, the surface porosity of anodized aluminum alloys is relatively high, which is problematic when the PVD machine requires a vacuum level of 10... -8 When the temperature reaches approximately 100°C, the aluminum alloy undergoing anodizing treatment cannot achieve the required vacuum level due to its high surface porosity. Secondly, while existing technologies can anodize 50-250mm rolled plates and produce uniform and dense anodized films, the aluminum alloy raw materials used in most internal components of the process chamber are thicker than 250mm. Using rolled plates would result in incomplete core deformation and coarse second phases, severely impacting the localized corrosion resistance of these components.

[0046] It can be seen that while using anodizing to improve the corrosion resistance of key components in aluminum alloys is feasible, it is still limited by the operating environment and component size. The applicant believes that the reason is that existing improvements to aluminum alloys focus on improving the anodized film, while neglecting research on the corrosion resistance of the aluminum alloy material itself. Therefore, it is not suitable for harsh working conditions that require high corrosion resistance of the aluminum alloy substrate, resulting in the ineffective resolution of problems such as thinning and localized corrosion of key components in PVD machines after multiple regeneration cleanings.

[0047] The applicant's research revealed that during the cleaning of critical components, highly corrosive media such as nitric acid and hydrofluoric acid form electrolyte solutions. When these critical components come into contact with the electrolyte solution, the Mg₂Si and AlFeSi phases in the aluminum alloy readily undergo electrochemical reactions. The Mg₂Si phase has a more negative electrochemical potential compared to the aluminum matrix, thus acting as the anode and undergoing corrosion and dissolution. Conversely, the AlFeSi phase has a more positive electrochemical potential compared to the aluminum matrix, thus acting as the cathode and being protected. However, the aluminum matrix surrounding the AlFeSi phase acts as the anode and is corroded and dissolved, leading to severe corrosion phenomena such as large-area pitting and thinning in the critical components. The distribution, size, and quantity of the Mg₂Si and AlFeSi phases are key factors influencing the localized corrosion behavior of the aluminum alloy. In addition, the grain size of aluminum alloy is also one of the factors affecting its surface corrosion resistance. Therefore, changing the distribution, size and quantity of Mg2Si phase and AlFeSi phase, as well as the grain size of aluminum alloy, can reduce the corrosion rate and improve the corrosion resistance of aluminum alloy material itself from the level of electrochemical reaction. Therefore, the corrosion resistance requirements can be met without anodizing treatment.

[0048] Based on this, a method for manufacturing an aluminum alloy material for use in semiconductor devices is also disclosed. The manufacturing method includes the following steps:

[0049] S10: Smelting, which involves mixing and smelting pure aluminum ingots and intermediate alloys in a specific ratio, and meeting the following elemental requirements: Si: 0.5-0.7%, Fe: 0.05-0.15%, Cu: 0.2-0.3%, Mn≤0.15%, Mg: 0.8-1.2%, Cr: 0.15-0.35%; it also meets the following requirements: Fe: 0.05-0.15%, 0.08≤Fe / Si≤0.28, 1.73<Mg / Si<1.83;

[0050] S20: Casting;

[0051] S30: One-stage homogenization process;

[0052] S40: Heat deformation treatment;

[0053] S50: Solution heat treatment.

[0054] The method for manufacturing aluminum alloy materials of the present invention reduces the amount of AlFeSi phase precipitation during the casting process by maintaining Fe, Si, and Mg in a specific ratio, without compromising mechanical properties. On this basis, a one-stage homogenization process is combined to achieve a discontinuous fine distribution with a size <100um, without the presence of coarse triangular AlFeSi phase, while the grain size is ensured to be less than 500um through deformation and solution treatment processes.

[0055] In related technologies, a two-stage homogenization process is usually adopted. However, during the two-stage homogenization process, the temperature is easily too high, which can lead to over-burning of the Mg2Si phase, and the holding time is too long, which can cause the β-AlFeSi phase to grow again. The present invention adopts a one-stage homogenization process, which can avoid high temperature and excessive holding time, thereby avoiding over-burning of the Mg2Si phase and β-AlFeSi phase growth again, thus resulting in better uniformity of the final aluminum alloy structure.

[0056] Specifically, in step S10, pure aluminum ingots and intermediate alloys are mixed and smelted in a specific ratio. Slag is skimmed and the mixture is stirred during the smelting process. A direct-reading spectrometer is used to analyze the chemical composition of the liquid aluminum, ensuring the following elemental requirements are met: Fe: 0.05-0.15%, 0.08≤Fe / Si≤0.28, 1.73<Mg / Si<1.83. By controlling the Fe content and Fe / Si within appropriate ranges, the amount of AlFeSi phase precipitated during casting can be reduced without compromising mechanical properties. Limiting Mg / Si to greater than 1.73 ensures sufficient Mg to form the Mg2Si phase, preventing free Si from precipitating at grain boundaries and forming continuous anodic corrosion channels with the Mg2Si phase, thereby improving the intergranular corrosion resistance of the aluminum alloy. Conversely, controlling Mg / Si to less than 1.83 prevents excess Mg from reducing the solubility of the Mg2Si phase in solid aluminum, avoiding the growth and coarsening of excessive Mg2Si phase precipitates at grain boundaries, and reducing the corrosion tendency of the aluminum alloy. Subsequently, the molten aluminum was degassed and slag removed in the refining furnace, while an online hydrogen measurement system was used to detect the hydrogen content of the molten aluminum.

[0057] The manufacturing method of the present invention limits the Fe mass percentage to 0.05-0.15% and 0.08≤Fe / Si≤0.28, thereby controlling the Fe content and Fe / Si ratio within a suitable range, which can reduce the amount of AlFeSi phase precipitated during the casting process without compromising mechanical properties.

[0058] The aluminum alloy material of this invention has a Mg / Si ratio greater than 1.73, which is equivalent to adding excess Mg. It also ensures that enough Mg and Si form the Mg2Si phase, thereby preventing free Si from precipitating at the grain boundaries and forming continuously distributed anodic corrosion channels with Mg2Si, thus improving the intergranular corrosion resistance of the aluminum alloy. At the same time, limiting the Mg / Si ratio to less than 1.83 can prevent excess Mg from inhibiting the solid solution of the Mg2Si phase during the subsequent homogenization process, avoiding the precipitation of coarse Mg2Si phases in the intergranular space, thereby reducing the corrosion tendency of the aluminum alloy and improving the corrosion resistance of the aluminum alloy material.

[0059] For example, the mass percentage of each chemical element in the aluminum alloy material is as follows: Si: 0.5-0.7%, Fe: 0.05-0.15%, Cu: 0.2-0.3%, Mn: ≤0.15%, Mg: 0.8-1.2%, Cr: 0.15-0.35%; the balance is Al and other unavoidable impurities; it also satisfies 0.08≤Fe / Si≤0.28, 1.73<Mg / Si<1.83.

[0060] In step S20, during casting, a semi-continuous casting process is used, and a grain refiner is added to refine the grains.

[0061] In some embodiments, step S30 specifically includes:

[0062] S31: Enter the homogenizing furnace at room temperature;

[0063] S32: Heat the furnace to 520-560℃;

[0064] S33: After reaching the preset temperature, maintain the temperature for 10-15 hours, and the temperature difference between different locations in the homogenizing furnace shall not exceed 10℃.

[0065] S34: After the preset holding time is reached, the ingot is removed from the furnace and cooled by air.

[0066] The homogenization process can ensure the complete dissolution of coarse Mg2Si phase and promote the transformation of some coarse β-AlFeSi phase into acicular α-AlFeSi phase. Furthermore, while related technologies typically employ a two-stage homogenization process, the manufacturing method of this invention uses a single-stage process. This ensures that the chemical composition meets the above requirements, and by controlling the appropriate homogenization temperature and time, dendritic segregation within the ingot is eliminated. Simultaneously, the Mg2Si phase dissolution process and the AlFeSi phase transformation process occur concurrently. Compared to two-stage homogenization, this avoids problems such as excessively high temperatures leading to Mg2Si phase overheating and excessively long holding times causing β-AlFeSi phase re-growth. This results in a more uniform aluminum alloy microstructure with dispersed Mg2Si distribution and a size less than 50 μm. In addition, it significantly improves the production efficiency of the aluminum alloy and reduces manufacturing costs.

[0067] In some embodiments, step S40 specifically includes:

[0068] S41: Preheat the ingot after removing the skin;

[0069] S42: After reaching the hot deformation temperature, the ingot is deformed to make the deformation amount of the ingot greater than 80%.

[0070] For example, hot rolling can be used to deform the ingot. The hot rolling deformation amount of the ingot is R=(H0-H) / H0×100%, where H0 is the height of the ingot before deformation and H is the height of the ingot after deformation.

[0071] However, this is not limiting; in other embodiments, the ingot can also be deformed by forging. When forging is used to deform the ingot, the forging deformation amount is the ratio of the ingot's dimensions before deformation to its dimensions after deformation.

[0072] Taking upsetting forging as an example, Y N =H N1 / H N0 ×100%, where H N0 H represents the vertical height of the ingot before the Nth forging deformation. N1 Let Y be the vertical height of the ingot after the Nth forging deformation, where N is a positive integer. In other words, the forging process can be a single forging or multiple forgings. When multiple forgings are performed, the total forging deformation Y... 总 =Y1×Y2×Y3×……×Y N .

[0073] For example: when the total number of forgings is 1, N=1, Y 总 =Y1=H 11 / H 10 ×100%, where H 10 H represents the vertical height of the ingot before its first forging deformation. 11 The vertical height of the ingot after the first forging deformation.

[0074] For example: when the total number of forgings is 3, N=3, Y 总 =Y1×Y2×Y3=H 11 / H 10 ×H 21 / H 20 ×H 31 / H 30 ×100%, similarly, where H 10 H represents the vertical height of the ingot before its first forging deformation. 11 H is the vertical height of the ingot after the first forging deformation. 20 H represents the vertical height of the ingot before the second forging deformation. 21 H is the vertical height of the ingot after the second forging deformation. 30 H represents the vertical height of the ingot before the third forging deformation. 31 The vertical height of the ingot after the third forging deformation.

[0075] It should be noted that during multiple forging processes, each forging can be carried out continuously, that is, after this forging, the next forging can be carried out directly; other forging processes can also be added between each forging, which is not limited in this embodiment.

[0076] When forging is performed continuously, the vertical height of the ingot after each forging deformation is basically equal to the vertical height of the ingot before the next forging deformation. Therefore, Y 总 It can be equivalent to H N1 / H 10 ×100%, which is the vertical height of the ingot before the first forging deformation and the vertical height of the ingot after the Nth forging deformation.

[0077] The method for manufacturing aluminum alloy material of the present invention uses hot deformation treatment to make the deformation of the ingot greater than 80%, thereby refining the grains in the alloy plate and completely breaking the β-AlFeSi phase, ultimately ensuring that the AlFeSi phase is discontinuously distributed and the phase size is less than 100 μm, and can also make the grain size less than 500 μm.

[0078] S50: Solution heat treatment, heating the ingot to 450℃~550℃ for 60~120min to recrystallize the deformed structure, ultimately ensuring that the grain size is less than 500um.

[0079] The aluminum alloy material and its guiding method of the present invention will be further described below with reference to specific embodiments 1-5 and comparative examples 1-4.

[0080] Among them, Comparative Examples 1, 3, 5 and Examples 1, 2, 4 all used rolled plates with a diameter of less than 130 mm, while Comparative Examples 2, 4, 6 and Example 3 used forgings with a diameter of more than 200 mm. The microstructure and size of the Mg2Si phase and AlFeSi phase were controlled by chemical composition and homogenization process, and the size and grain size of the second phase were further optimized by hot deformation treatment to form a three-variable comparative test sample.

[0081] Table 1 lists the mass percentage of each chemical element and the specific process parameters in the homogenization process of the aluminum alloy materials for semiconductor devices in Examples 1 to 4 and the comparative aluminum alloy materials in Comparative Examples 1 to 5, as well as the size of the second phase.

[0082] Table 1

[0083]

[0084] As shown in Table 1, Examples 1 to 4 all satisfy the following parameters: Fe: 0.05-0.15%, 0.08≤Fe / Si≤0.28, 1.73<Mg / Si<1.83. Furthermore, they meet the process parameter requirements for the homogenization treatment. Therefore, the corresponding Mg2Si phase is less than 50 μm, and the AlFeSi phase is less than 100 μm.

[0085] In Comparative Example 1, the mass percentage of Fe does not meet the requirements, while the values ​​of Fe / Si and Mg / Si meet the requirements. The process parameters of homogenization treatment also do not meet the requirements. According to Table 1, the Mg2Si phase in Comparative Example 1 is greater than 50 μm, and the AlFeSi phase is less than 100 μm.

[0086] In Comparative Example 2, the mass percentage of Fe, the Fe / Si ratio, and the Mg / Si ratio all did not meet the above requirements, and the process parameters for homogenization treatment also did not meet the requirements. According to Table 1, the Mg2Si phase in Comparative Example 2 is greater than 50 μm, and the AlFeSi phase is less than 100 μm.

[0087] In Comparative Example 3, the mass percentage of Fe, the Fe / Si ratio, and the Mg / Si ratio all did not meet the above requirements, and the process parameters for homogenization treatment also did not meet the requirements. According to Table 1, the Mg2Si phase in Comparative Example 3 was less than 50 μm, and the AlFeSi phase was less than 250 μm.

[0088] In Comparative Example 4, the mass percentage of Fe meets the requirements, while the values ​​of Fe / Si and Mg / Si do not. The process parameters for homogenization treatment also do not meet the requirements. Therefore, according to Table 1, the Mg2Si phase in Comparative Example 4 is less than 50 μm and the AlFeSi phase is less than 150 μm.

[0089] In Comparative Example 5, the mass percentage of Fe and the Fe / Si ratio meet the requirements, while the Mg / Si ratio does not. The process parameters for homogenization treatment meet the requirements. According to Table 1, the Mg2Si phase in Comparative Example 5 is less than 50 μm, and the AlFeSi phase is less than 100 μm.

[0090] In Comparative Example 6, the mass percentage of Fe, the Fe / Si ratio, and the Mg / Si ratio all meet the above requirements. However, the process parameters for homogenization treatment do not meet the requirements. As can be seen from Table 1, the Mg2Si phase in Comparative Example 6 is greater than 50 μm, and the AlFeSi phase is greater than 100 μm.

[0091] This shows that only when the following conditions are met simultaneously: Fe: 0.05-0.15%, 0.08≤Fe / Si≤0.28, 1.73<Mg / Si<1.83, and the process parameters of the homogenization treatment, can the corresponding Mg2Si phase be less than 50µm and the AlFeSi phase less than 100µm. This is because, by controlling the Fe content and Fe / Si within appropriate ranges, the amount of AlFeSi phase precipitated during the casting process can be reduced without compromising mechanical properties. Limiting Mg / Si to greater than 1.73 ensures sufficient Mg to form the Mg2Si phase with Si, preventing free Si from precipitating at grain boundaries and forming continuously distributed anodic corrosion channels with the Mg2Si phase, thereby improving the intergranular corrosion resistance of the aluminum alloy. Controlling Mg / Si to less than 1.83 prevents excess Mg from reducing the solubility of the Mg2Si phase in solid aluminum, avoiding the growth and coarsening of excessive Mg2Si phase precipitated at grain boundaries, and reducing the corrosion tendency of the aluminum alloy. A one-stage homogenization process is then adopted. While ensuring that the chemical composition meets the above requirements, the dendritic segregation phenomenon inside the ingot is removed by controlling the appropriate homogenization temperature and time. At the same time, the Mg2Si phase re-dissolution process and the AlFeSi phase transformation process are carried out simultaneously, so that the final aluminum alloy has better uniformity.

[0092] Table 2 lists the specific process parameters and grain size of the aluminum alloy materials for semiconductor devices in Examples 1 to 4 and the comparative aluminum alloy materials in Comparative Examples 1 to 5 during the hot deformation step.

[0093] Table 2

[0094]

[0095] As can be seen from Table 2, the process parameters required for the hot deformation process in Examples 1 to 4 are such that the grain size is less than 500 μm.

[0096] In Comparative Example 1, the hot deformation treatment was performed by rolling, and the deformation amount was >80%, which met the above requirements. Therefore, the grain size in Comparative Example 1 was less than 500 μm.

[0097] In Comparative Example 2, the hot deformation treatment was carried out by forging, and the deformation amount was >80%, which met the above requirements. Therefore, the grain size in Comparative Example 2 was less than 500 μm.

[0098] In Comparative Example 3, the hot deformation treatment was performed by rolling, and the deformation amount was <60%, which did not meet the above requirements. Therefore, the grain size in Comparative Example 3 was greater than 500 μm.

[0099] In Comparative Example 4, the hot deformation treatment was carried out by forging, and the deformation amount was >80%, which met the above requirements. Therefore, the grain size in Comparative Example 4 was less than 500um.

[0100] In Comparative Example 5, the hot deformation treatment was performed by rolling, and the deformation amount was <60%, which did not meet the above requirements. Therefore, the grain size was greater than 1000um.

[0101] In Comparative Example 6, the hot deformation treatment was carried out by forging, and the deformation amount was greater than 80%, which met the above requirements. Therefore, the grain size was less than 500 μm.

[0102] This demonstrates that by controlling appropriate homogenization temperature and time, the homogenization process can ensure complete re-dissolution of the coarse Mg2Si phase, forming a dispersed distribution with a size less than 50 μm. Simultaneously, it promotes the transformation of some coarse β-AlFeSi phases into acicular α-AlFeSi phases, resulting in better uniformity of the aluminum alloy microstructure. Furthermore, by using hot deformation treatment to achieve a deformation of over 80% in the ingot, the grains in the alloy sheet are refined, and the β-AlFeSi phase is completely broken down. This ultimately ensures that the AlFeSi phase is discontinuously distributed with a size less than 100 μm, and also promotes a flattened grain distribution with a grain size less than 500 μm.

[0103] After the process was completed, samples of the aluminum alloy materials from Examples 1 to 4 and Comparative Examples 1 to 6 were taken, and each sample was degreased, cleaned, and washed with water to remove surface contaminants. Then, each sample underwent pre-blasting treatment, requiring Ra 6~8 μm to simulate the surface roughness of actual key components. Next, each sample was suspended and immersed in a 35% HNO3 solution using a special fixture, with each immersion lasting 90 minutes. After immersion, the mass and thickness of the samples were measured, and the surface condition was observed for corrosion pits, flow marks, etc. This corrosion test was repeated 20 times. Finally, the corrosion resistance was evaluated based on the average corrosion rate W(%)=(m0-m1) / S, the thinning amount Δt=t0-t1, and the surface corrosion state. Finally, each sample was polished to a mirror finish, and the distribution and quantity of the second phase were observed under a metallographic microscope at 50x and 100x magnification. Qualitative analysis of the second phase was performed using scanning electron microscopy (SEM) combined with energy dispersive spectroscopy (EDS), and the size of the second phase was determined. After etching the sample surface with Keller's reagent for 90 seconds, the grain boundaries and grain size were observed under a metallographic microscope. Table 3 lists the microstructure characteristics and corrosion resistance of the aluminum alloy plates in Examples 1 to 5 and Comparative Examples 1 to 4.

[0104] Table 3

[0105]

[0106] As can be seen from Table 3, the average corrosion rate and thinning amount of the samples are strongly correlated with the size of the second phase and the grain size.

[0107] In Examples 1 to 4, the Mg₂Si phase was less than 50 μm, the AlFeSi phase was less than 100 μm, and the grain size was less than 500 μm. Therefore, the corrosion rate was consistently around 0.9 mg / cm². 2 With a thickness of less than h and a thinning amount of less than 0.4 mm, it has strong corrosion resistance.

[0108] In Comparative Examples 1 to 6, at least one of the following—Mg2Si phase, AlFeSi phase, or grain size—did not meet the requirements; therefore, the corrosion rates were all below 1 mg / cm³. 2 With a thickness of over h and a reduction of over 0.4 mm, its corrosion resistance is relatively weak.

[0109] like Figure 1 The images show the microstructure of Examples 1 and 2 and Comparative Examples 1 and 2 before corrosion. Among them, from... Figure 1 (a) The sample of Implementation Case 1 shown and Figure 1 (b) As can be seen from the samples of Example 2, the Mg2Si phase in both samples is continuously distributed in strip-like patterns along the grain boundaries, with a size of 50~150 μm. From Figure 1 (c) It can be seen that the Mg2Si phase in Implementation Case 3 is dispersed in a granular manner, with a Mg2Si phase size of less than 50 μm. From Figure 1 (d) It can be seen that the Mg2Si phase in Implementation Case 4 is mainly distributed in small, spherical shapes, with a size of less than 20 μm.

[0110] Please combine Figures 2 to 5 ,in, Figure 2 (a) Figure 2 (b) and Figure 2 (c) is a microstructure image of Comparative Example 1 after 90 min of corrosion; Figure 3 (a) Figure 3 (b) and Figure 3 (c) is a microstructure image of Comparative Example 2 after 90 min of corrosion; Figure 4 (a) Figure 4 (b) and Figure 4 (c) is a microstructure image of Example 1 after 90 min of corrosion; Figure 5 (a) Figure 5 (b) and Figure 5 (c) is a microstructure image of Example 2 after 90 min of corrosion.

[0111] After immersing the sample in a 35% HNO3 solution, the potential difference between the second phase and the aluminum matrix acts as a driving force for the electrochemical reaction, causing the anodic phase to corrode and dissolve. The greater the potential difference, the greater the corrosion rate. The potential difference between the Mg2Si phase and the surrounding aluminum matrix is ​​greater than that between the AlFeSi phase, so it preferentially undergoes electrochemical corrosion and dissolution as the anode in the electrolyte environment.

[0112] As the size of the Mg2Si phase increases, continuous dissolution channels form at the grain boundaries, leading to more severe electrochemical corrosion and larger corrosion pits. When the Mg2Si phase is continuously distributed along the grain boundaries in strip-like form and its size is greater than 50 μm, the larger Mg2Si phases form continuous corrosion channels at the grain boundaries, promoting continuous corrosion propagation along the grain boundaries and ultimately causing the entire grain to detach and form corrosion pits. Because the Mg2Si phase is dispersed in granular form, it is less likely to form continuous dissolution channels within the grain boundaries, thus mitigating electrochemical corrosion. When the Mg2Si phase is dispersed in granular form and its size is less than 50 μm, the Mg2Si phase does not act as a preferential dissolution phase, resulting in lower corrosion levels and less likelihood of forming continuous corrosion channels. This prevents corrosion from continuously propagating along the grain boundaries and forming corrosion pits, thus reducing the likelihood of large corrosion pits.

[0113] like Figure 6 As shown, Figure 6 (a) is a diagram of the surface condition of the sample of Comparative Example 1 after it has been immersed in nitric acid for 20 cycles of cyclic corrosion; Figure 6 (b) is a diagram of the surface condition of the sample of Comparative Example 2 after it has been immersed in nitric acid for 20 cycles of cyclic corrosion; Figure 6 (c) is a diagram of the surface condition of the sample from Example 1 after it has been immersed in nitric acid for 20 cycles of cyclic corrosion; Figure 6 (d) is a diagram of the surface state of the sample of Example 2 after it has been immersed in nitric acid for 20 cycles of corrosion.

[0114] according to Figure 6 As shown, both Comparative Example 1 and Comparative Example 2 showed obvious corrosion pits on the surface, while Example 1 and Example 2 had good surface conditions without corrosion pits or a large number of pits. Therefore, it can be verified that the corrosion resistance is better when the phase size of the Mg2Si phase is less than 50 μm.

[0115] like Figure 7 The images show the microstructure of Examples 3 and 4 and Comparative Examples 3 and 4 before corrosion. Among them, from... Figure 7 (a) The sample of Comparative Example 3 shown and Figure 7 (b) As shown in Comparative Example 4, the AlFeSi phase in both samples is continuously distributed along the grain boundaries in coarse, elongated strips, with a size ranging from 150 to 250 μm. Figure 7 (c) The sample of Example 3 shown and Figure 7 As can be seen from the sample of Example 4 shown in (d), the AlFeSi phase was processed and deformed and broken relatively completely, and was distributed intermittently in plate or granular form with a size of less than 100 μm.

[0116] Please combine Figures 8 to 11 ,in, Figure 8 (a) Figure 8 (b) and Figure 8 (c) is a microstructure image of Comparative Example 3 after 90 min of corrosion; Figure 9 (a) Figure 9 (b) and Figure 9 (c) is a microstructure image of Comparative Example 4 after 90 min of corrosion; Figure 10 (a) Figure 10 (b) and Figure 10 (c) is a microstructure image of Example 3 after 90 min of corrosion; Figure 11 (a) Figure 11 (b) and Figure 11 (c) is a microstructure image of Example 4 after 90 min of corrosion.

[0117] After immersing the sample in a 35% HNO3 solution for 90 minutes, the AlFeSi phase, acting as the cathode, was retained, while the surrounding aluminum matrix, acting as the anode, was corroded and dissolved.

[0118] As the size of the AlFeSi phase increases, the degree of corrosion on the sample surface increases. When the AlFeSi phase is continuously distributed along the grain boundaries in a strip-like shape (i.e., coarse triangular AlFeSi phase) and the phase size is greater than 100 μm, the coarse strip-like or coarse triangular AlFeSi phase causes the surrounding aluminum matrix to form continuous corrosion channels along the grain boundaries, promoting continuous corrosion expansion and eventually leading to large corrosion pits or numerous pits. When the microstructure of the sample has a discontinuously distributed AlFeSi phase in a plate-like or granular form and the phase size is less than 100 μm, the degree of surface corrosion decreases significantly. This indicates that the corrosion expansion effect is reduced after the second phase size is smaller than the critical reaction size. Therefore, corrosion pits and numerous pits do not appear on the sample surface, and the local corrosion resistance is good.

[0119] like Figure 12 As shown, Figure 12 (a) is a diagram of the surface condition of the sample of Comparative Example 3 after it has been immersed in nitric acid for 20 cycles of cyclic corrosion; Figure 12 (b) is a diagram of the surface condition of the sample of Comparative Example 4 after it has been immersed in nitric acid for 20 cycles of cyclic corrosion. Figure 12 (c) is a diagram of the surface condition of the sample in Example 3 after it has been immersed in nitric acid for 20 cycles of cyclic corrosion; Figure 12 (d) is a diagram of the surface state of the sample in Example 4 after it has been immersed in nitric acid for 20 cycles of cyclic corrosion.

[0120] according to Figure 12As shown, Comparative Examples 3 and 4 both exhibited obvious corrosion pits on their surfaces, while Examples 3 and 4 showed good surface condition with no corrosion pits or numerous pits. This verifies that the corrosion resistance is better when the AlFeSi phase size is less than 100 μm. In other words, when the AlFeSi phase size is less than 100 μm, the corrosion propagation effect is reduced, and the surface corrosion degree is significantly decreased. Therefore, corrosion pits and numerous pits do not appear on the surface of key components, resulting in improved local corrosion resistance.

[0121] The aluminum alloy material of this invention achieves homogenization by confining Fe, Si, and Mg to specific bonds in a single-stage process. Therefore, the microstructure lacks coarse triangular AlFeSi phases, preventing the formation of continuous corrosion channels along grain boundaries in the surrounding aluminum matrix. This avoids the continuous expansion of corrosion, significantly reducing the degree of localized corrosion, and preventing large-sized corrosion pits from appearing on the surface after prolonged cyclic cleaning. In some embodiments, the microstructure of the aluminum alloy material lacks coarse triangular AlFeSi phases and instead features either a plate-like discontinuous distribution of AlFeSi phases or a granular discontinuous distribution of AlFeSi phases.

[0122] Figure 13 (a) is a high-magnification grain image of the sample in Comparative Example 5; Figure 13 (b) is a high-magnification grain image of the sample in Comparative Example 3; Figure 13 (c) is a high-magnification grain image of the sample from Example 3.

[0123] like Figure 13 As shown in (a), Comparative Example 5 exhibits significant intragranular segregation within its grains, with a grain size reaching 1000 μm, similar to the as-cast microstructure; Figure 13 As shown in (b), the grains of Comparative Example 3 are irregularly shaped and exhibit partial intragranular segregation, with a grain size > 500 μm; Figure 13 As shown in (c), the samples of Example 3 underwent significant processing deformation, resulting in a flattened grain distribution with a grain size of less than 500 μm. This grain refinement causes the second phase / metal compound particles to decompose, reducing their size to below certain critical dimensions. This effectively inhibits the cathodic / anodic reaction of the second phase, thus improving the corrosion resistance of the aluminum alloy.

[0124] like Figure 14 As shown, Figure 14 (a) is a diagram of the surface condition of the sample of Comparative Example 5 after it has been immersed in nitric acid for 20 cycles of cyclic corrosion; Figure 14 (b) is a diagram of the surface condition of the sample of Comparative Example 3 after it has been immersed in nitric acid for 20 cycles of cyclic corrosion; Figure 14 (c) is a diagram of the surface state of the sample of Example 3 after it has been immersed in nitric acid for 20 cycles of corrosion.

[0125] according to Figure 14 As shown, when the grain size exceeds 500 μm, black and white spots appear on the sample surface after immersion in 35% HNO3 solution for 90 min. If the AlFeSi phase is continuously distributed along the grain boundaries, large-sized corrosion pits will be formed. However, when the grain size is less than 500 μm, no black and white spots or large corrosion pits appear on the surface after HNO3 corrosion, and the local corrosion resistance is improved.

[0126] In other words, the method for manufacturing aluminum alloy materials of the present invention can make the grain size of the aluminum alloy material less than 500 μm. When the grain size of the aluminum alloy material is less than 500 μm, the cathodic reaction of the AlFeSi phase or the anodic reaction of the Mg2Si phase can be effectively prevented, which is beneficial to improving the corrosion resistance of the aluminum alloy.

[0127] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for manufacturing an aluminum alloy material, said aluminum alloy material being used in semiconductor equipment, characterized in that, The manufacturing method includes the following steps: S10: Smelting, which involves mixing and smelting pure aluminum ingots and master alloys in a specific ratio, and meeting the following elemental requirements: Si: 0.5-0.7%, Cu: 0.2-0.3%, Mn: ≤0.15%, Mg: 0.8-1.2%, Cr: 0.15-0.35%; it also meets the following requirements: Fe: 0.05-0.15%, 0.08≤Fe / Si≤0.28, 1.73<Mg / Si<1.83; S20: Casting; S30: One-stage homogenization process; S40: Heat deformation treatment; S50: Solution heat treatment.

2. The manufacturing method according to claim 1, characterized in that, In step S30, the one-stage homogenization process specifically includes: S31: Enter the homogenizing furnace at room temperature; S32: Heat the furnace to 520-560℃; S33: After reaching the preset temperature, maintain the temperature for 10-15 hours; S34: After the preset holding time is reached, the ingot is removed from the furnace and cooled by air.

3. The manufacturing method according to claim 2, characterized in that, In step S33, The temperature difference between different locations within the homogenizing furnace does not exceed 10°C.

4. The manufacturing method according to claim 1, characterized in that, In step S40, the heat deformation treatment specifically includes: S41: Preheat the ingot after removing the skin; S42: After reaching the heat deformation temperature, the ingot is subjected to deformation treatment so that the deformation amount of the ingot is greater than 80%.

5. The manufacturing method according to claim 4, characterized in that, In step S42, The ingot is deformed by hot rolling, and the hot rolling deformation amount R of the ingot is R=(H0-H) / H0×100%, where H0 is the height of the ingot before deformation and H is the height of the ingot after deformation; or The ingot is deformed by forging, and the forging deformation amount is the ratio of the size of the ingot before deformation to the size of the ingot after deformation.

6. The manufacturing method according to claim 4, characterized in that, After step S50, The microstructure of the aluminum alloy material has a Mg2Si phase that is dispersed in granular form.

7. The manufacturing method according to claim 4, characterized in that, After step S50, The phase size of the Mg2Si phase is less than 50 μm.

8. The manufacturing method according to claim 4, characterized in that, After step S50, The microstructure of the aluminum alloy material has a plate-like discontinuous distribution of AlFeSi phase or a granular discontinuous distribution of AlFeSi phase.

9. The manufacturing method according to claim 4, characterized in that, After step S50, The phase size of the AlFeSi phase is less than 100 μm.

10. The manufacturing method according to claim 4, characterized in that, After step S50, The grain size of the aluminum alloy material is less than 500 μm.

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