6-series aluminum alloy for semiconductor equipment and preparation method of 6-series aluminum alloy

Abstract

The invention provides a 6-series aluminum alloy for semiconductor equipment and a preparation method of the 6-series aluminum alloy, and aims to improve the mechanical property and the stability of the aluminum alloy in a high-temperature and high-corrosion environment. The aluminum alloy is prepared from magnesium, silicon, copper, manganese, chromium, zinc, iron, titanium and aluminum through the steps of smelting, refining, casting, homogenizing annealing, hot rolling, cold rolling, heat treatment and the like. By optimizing the alloy components and the heat treatment process, the prepared aluminum alloy has excellent high temperature resistance and corrosion resistance and low thermal expansion coefficient, and high precision and reliability can be kept in the complex working environment of semiconductor equipment. In addition, the surface is subjected to chemical polishing and anodic oxidation treatment, the surface hardness and corrosion resistance of the material are further improved, and the material is suitable for key structural parts in semiconductor equipment.

Description

Technical Field

[0001] The present invention relates to the field of preparation of aluminum alloys, and more specifically to a 6 series aluminum alloy for semiconductor equipment and a preparation method thereof. Background Art

[0002] With the rapid development of the semiconductor industry, the requirements for materials in semiconductor equipment are increasing. In high-precision fields such as integrated circuits and chip manufacturing, equipment materials not only need to have good electrical conductivity and mechanical strength, but also need to meet multiple performance requirements such as lightweight, corrosion resistance, and thermal fatigue resistance. 6 series aluminum alloy, as the most commonly used material in the aluminum alloy series, has been widely used in many fields due to its excellent comprehensive performance.

[0003] At present, the existing 6 series aluminum alloy materials have limitations in the following aspects:

[0004] (1) Insufficient high temperature resistance: During the semiconductor manufacturing process, equipment is often in a high temperature environment. Traditional 6 series aluminum alloys are prone to softening or loss of strength under long-term high temperatures, affecting the stability and life of the equipment.

[0005] (2) Limited corrosion resistance: Although 6 series aluminum alloys have good corrosion resistance in conventional environments, in semiconductor processing, equipment is often exposed to corrosive gases or liquids, such as etching solutions. Existing aluminum alloy materials are easily corroded in such environments, which in turn affects the accuracy and reliability of the equipment.

[0006] (3) High thermal expansion coefficient: In semiconductor equipment, the thermal expansion coefficient of the material will affect the dimensional stability of the equipment, especially in an environment with large temperature fluctuations. The high thermal expansion coefficient of aluminum alloy can easily cause structural deformation, affecting the accuracy and working efficiency of the equipment.

[0007] (4) Uneven mechanical properties: Due to the precision of semiconductor equipment, higher requirements are placed on the mechanical properties of materials. However, the mechanical properties (such as tensile strength, hardness, etc.) of traditional 6 series aluminum alloys fluctuate greatly under different process conditions, making it difficult to ensure the stability and consistency of the product.

[0008] Therefore, developing a special 6 series aluminum alloy for semiconductor equipment that can maintain excellent mechanical properties and dimensional stability in high temperature and high corrosion environments, and has good machinability and fatigue resistance, is an urgent problem to be solved in the current materials field. Summary of the invention

[0009] In order to solve the problems existing in the prior art, the present invention provides a 6 series aluminum alloy for semiconductor equipment and a preparation method thereof, and the specific scheme is as follows:

[0010] A method for preparing a 6 series aluminum alloy for semiconductor equipment. The preparation method comprises the following steps:

[0011] S1: Aluminum alloy composition design: The aluminum alloy composition includes the following elements: Mg; Si; Cu; Mn; Cr; Zn; Fe; Ti; Al;

[0012] S2: Melting and refining: Weigh high-purity aluminum ingots and alloy elements according to the formula ratio, put the raw materials into a medium-frequency induction furnace for melting, the melting temperature is controlled at 720℃~750℃, and the melting time is 1 hour; add 0.1%~0.2% refining agent, the refining temperature is controlled at 740℃~760℃, the refining time is 15 minutes, and after the refining is completed, let it stand for 10 minutes and carry out slag removal;

[0013] S3: Casting: pouring the molten aluminum alloy into a mold preheated to 200°C to 250°C, casting an ingot by semi-continuous casting, and controlling the cooling rate at 50°C / min to 80°C / min;

[0014] S4: Billet homogenization annealing: The cast aluminum alloy ingot is placed in an annealing furnace for homogenization treatment;

[0015] S5: hot rolling: heating the annealed ingot to 400°C to 450°C and performing hot rolling;

[0016] S6: cold rolling: cold rolling the hot rolled sheet;

[0017] S7: Heat treatment: Heat treatment of the plate includes solution treatment and aging treatment;

[0018] S8: Surface treatment: chemical polishing and anodizing of the plate.

[0019] Furthermore, the mass percentage of each element in S1 is as follows: Mg: 0.8%~1.2%; Si: 0.7%~1.1%; Cu: 0.2%~0.4%; Mn: 0.1%~0.3%; Cr: 0.05%~0.15%; Zn: 0.2%~0.4%; Fe: ≤0.15%; Ti: 0.05%~0.1%; and the balance is Al.

[0020] Furthermore, in S4, the annealing temperature is 480°C to 520°C, and the holding time is 10 to 12 hours; after the annealing is completed, the ingot is slowly cooled to room temperature at a speed of 10°C / h to 20°C / h.

[0021] Furthermore, the parameters of the solution treatment in S7 are: heating the cold-rolled aluminum alloy plate to 530° C. to 550° C. and keeping the temperature for 1 to 2 hours.

[0022] Furthermore, the parameters of the aging treatment in S7 are: the aging temperature is controlled at 160° C. to 180° C., and the insulation time is 10 to 12 hours.

[0023] Furthermore, the parameters of chemical polishing in S8 are to immerse the aluminum alloy plate after aging treatment in a chemical polishing liquid, the composition of the polishing liquid is 20% to 25% sulfuric acid, 10% to 15% phosphoric acid, and 5% to 10% nitric acid, the polishing time is 3 to 5 minutes, and the temperature is controlled at 25°C to 35°C.

[0024] Furthermore, the parameters of anodizing in S8 are that the polished plate is anodized in an electrolyte containing 3% to 5% sulfuric acid, the oxidation voltage is 15V to 20V, and the time is 20 minutes to 30 minutes.

[0025] An aluminum alloy obtained by a preparation method of a 6-series aluminum alloy for semiconductor equipment.

[0026] Beneficial effects:

[0027] The present invention provides a 6 series aluminum alloy specially used for semiconductor equipment and a preparation method thereof. Compared with the existing aluminum alloy materials, the present invention has the following beneficial effects:

[0028] (1) By optimizing the alloy composition and heat treatment process, the 6 series aluminum alloy of the present invention can still maintain good mechanical properties and structural stability in a high temperature environment of 150°C to 250°C, avoiding the problem of softening and strength loss of existing aluminum alloys in a high temperature environment, and greatly extending the service life of semiconductor equipment.

[0029] (2) The present invention significantly improves the corrosion resistance of the material by adding appropriate amounts of alloy elements such as copper, zinc, and chromium, especially in the corrosive gas and chemical solution environments commonly found in semiconductor equipment, showing excellent corrosion resistance and effectively reducing equipment failures and precision losses caused by corrosion.

[0030] (3) The aluminum alloy of the present invention reduces the thermal expansion coefficient of the material by regulating its composition, significantly improves the dimensional stability of the equipment in a working environment with large temperature changes, reduces structural deformation caused by thermal expansion, and thus improves the accuracy and reliability of semiconductor manufacturing equipment.

[0031] (4) Through strict smelting, casting, heat treatment and surface treatment processes, the aluminum alloy of the present invention has highly consistent mechanical properties, ensuring the performance stability of the material in different production batches. The tensile strength, hardness and ductility of the material have been greatly improved, meeting the requirements of semiconductor equipment for high-precision structural parts.

[0032] (5) The present invention not only improves the surface corrosion resistance of the aluminum alloy through chemical polishing and anodizing treatment, but also gives the material a better decorative appearance, while improving the surface hardness and wear resistance, making it more suitable for the harsh working conditions of semiconductor equipment. DETAILED DESCRIPTION

[0033] In order to deepen the understanding of the present invention, the present invention will be further described in detail below in conjunction with examples. The examples are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.

[0034] Based on your claims, I have written three specific implementation examples for you, with each step detailed and specific to parameters, so as to clearly demonstrate the technical solution of this patent.

[0035] Embodiment 1:

[0036] (1) Aluminum alloy composition design

[0037] The composition of aluminum alloy is as follows (mass percentage):

[0038] Magnesium (Mg): 1.0%

[0039] Silicon (Si): 1.0%

[0040] Copper (Cu): 0.3%

[0041] Manganese (Mn): 0.2%

[0042] Chromium (Cr): 0.1%

[0043] Zinc (Zn): 0.3%

[0044] Iron (Fe): ≤0.15%

[0045] Titanium (Ti): 0.08%

[0046] Aluminum (Al): Balance

[0047] (2) Melting and refining

[0048] The high-purity aluminum ingot and alloy elements of the above formula ratio are put into a medium frequency induction furnace, and the melting temperature is controlled at 740°C for 1 hour. During the melting process, 0.15% of refining agent is added, the refining temperature is controlled at 750°C, the refining time is 15 minutes, and after the refining is completed, it is left to stand for 10 minutes for slag removal.

[0049] (3) Casting

[0050] The molten aluminum alloy liquid is poured into a mold preheated to 230°C, and the ingot is cast using a semi-continuous casting method, with the cooling rate controlled at 70°C / min.

[0051] (4) Billet homogenization annealing

[0052] The ingot was placed in an annealing furnace at a temperature of 500°C for 11 hours, and then slowly cooled to room temperature at a rate of 15°C / h.

[0053] (5) Hot rolling

[0054] The annealed ingot was heated to 430°C and hot rolled with a hot rolling reduction of 75% to obtain a plate with a thickness of 7 mm.

[0055] (6) Cold rolling

[0056] The hot-rolled sheet was cold-rolled with a cold-rolling reduction rate of 40% and a final sheet thickness of 2 mm.

[0057] (7) Heat treatment

[0058] Solution treatment: Heat the cold rolled plate to 540°C, keep it warm for 1.5 hours, and then quickly quench it into room temperature water.

[0059] Aging treatment: The plate after solution treatment is subjected to aging treatment, the aging temperature is 170°C, and the insulation time is 11 hours.

[0060] (8) Surface treatment

[0061] Chemical polishing: The aluminum alloy plate after aging treatment is immersed in a chemical polishing solution (23% sulfuric acid, 12% phosphoric acid, 7% nitric acid) for 4 minutes and the temperature is controlled at 30°C.

[0062] Anodizing: The polished plate was anodized in an electrolyte containing 4% sulfuric acid at an oxidation voltage of 18 V for 25 minutes.

[0063] Example 2

[0064] (1) Aluminum alloy composition design

[0065] The composition of aluminum alloy is as follows (mass percentage):

[0066] Magnesium (Mg): 0.9%

[0067] Silicon (Si): 0.8%

[0068] Copper (Cu): 0.2%

[0069] Manganese (Mn): 0.1%

[0070] Chromium (Cr): 0.05%

[0071] Zinc (Zn): 0.2%

[0072] Iron (Fe): ≤0.10%

[0073] Titanium (Ti): 0.05%

[0074] Aluminum (Al): Balance

[0075] (2) Melting and refining

[0076] The smelting temperature is controlled at 730°C, the smelting time is 1 hour, 0.12% refining agent is added, the refining temperature is controlled at 745°C, the refining time is 15 minutes, and the slag is removed after standing for 10 minutes.

[0077] (3) Casting

[0078] The mold was preheated to 220°C and the cooling rate was controlled at 60°C / min.

[0079] (4) Billet homogenization annealing

[0080] The annealing temperature is 490°C, the holding time is 10 hours, and the cooling rate is 12°C / h.

[0081] (5) Hot rolling

[0082] The hot rolling temperature was 420°C, the hot rolling reduction ratio was 70%, and the final thickness was 8 mm.

[0083] (6) Cold rolling

[0084] The cold rolling reduction ratio was 35% and the final thickness was 1.5 mm.

[0085] (7) Heat treatment

[0086] Solution treatment: heat to 535℃, keep warm for 1 hour, and quickly quench in water.

[0087] Aging treatment: Aging temperature is 165℃, keep warm for 10 hours.

[0088] (8) Surface treatment

[0089] Chemical polishing: The polishing liquid consists of 20% sulfuric acid, 10% phosphoric acid, and 5% nitric acid. The polishing time is 3 minutes and the temperature is controlled at 28°C.

[0090] Anodizing: voltage is 16V, time is 22 minutes.

[0091] Example 3

[0092] (1) Aluminum alloy composition design

[0093] The composition of aluminum alloy is as follows (mass percentage):

[0094] Magnesium (Mg): 1.1%

[0095] Silicon (Si): 1.1%

[0096] Copper (Cu): 0.4%

[0097] Manganese (Mn): 0.3%

[0098] Chromium (Cr): 0.15%

[0099] Zinc (Zn): 0.4%

[0100] Iron (Fe): ≤0.15%

[0101] Titanium (Ti): 0.1%

[0102] Aluminum (Al): Balance

[0103] (2) Melting and refining

[0104] The smelting temperature is controlled at 745°C, the smelting time is 1 hour, 0.18% refining agent is added, the refining temperature is controlled at 755°C, the refining time is 15 minutes, and the slag is removed after standing for 10 minutes.

[0105] (3) Casting

[0106] The mold was preheated to 240°C and the cooling rate was controlled at 75°C / min.

[0107] (4) Billet homogenization annealing

[0108] The annealing temperature is 510°C, the holding time is 12 hours, and the cooling rate is 18°C / h.

[0109] (5) Hot rolling

[0110] The hot rolling temperature was 440°C, the hot rolling reduction ratio was 80%, and the final thickness was 6 mm.

[0111] (6) Cold rolling

[0112] The cold rolling reduction ratio was 50% and the final thickness was 1 mm.

[0113] (7) Heat treatment

[0114] Solution treatment: heat to 550℃, keep warm for 2 hours, and quickly quench in water.

[0115] Aging treatment: The aging temperature is 180℃ and the insulation time is 12 hours.

[0116] (8) Surface treatment

[0117] Chemical polishing: The polishing liquid consists of 25% sulfuric acid, 15% phosphoric acid, and 10% nitric acid. The polishing time is 5 minutes and the temperature is controlled at 35°C.

[0118] Anodizing: voltage is 20V, time is 30 minutes.

[0119] The performance test data of Examples 1 to 3 and the traditional 6 series aluminum alloy are as follows:

[0120]

[0121] It can be seen from the data in the above table that the 6 series aluminum alloy obtained by optimizing the embodiment has enhanced mechanical properties and chemical properties.

[0122] As a further improvement, the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a 6-series aluminum alloy for semiconductor equipment, characterized in that: The preparation method comprises the following steps: S1: Aluminum alloy composition design: The aluminum alloy composition includes the following elements: Mg; Si; Cu; Mn; Cr; Zn; Fe; Ti; Al; S2: Melting and refining: Weigh high-purity aluminum ingots and alloy elements according to the formula ratio, put the raw materials into a medium-frequency induction furnace for melting, the melting temperature is controlled at 720℃~750℃, and the melting time is 1 hour; add 0.1%~0.2% refining agent, the refining temperature is controlled at 740℃~760℃, the refining time is 15 minutes, and after the refining is completed, let it stand for 10 minutes and carry out slag removal; S3: Casting: pouring the molten aluminum alloy into a mold preheated to 200°C to 250°C, casting an ingot by semi-continuous casting, and controlling the cooling rate at 50°C / min to 80°C / min; S4: Billet homogenization annealing: The cast aluminum alloy ingot is placed in an annealing furnace for homogenization treatment; S5: hot rolling: heating the annealed ingot to 400°C to 450°C and performing hot rolling; S6: cold rolling: cold rolling the hot rolled sheet; S7: Heat treatment: Heat treatment of the plate includes solution treatment and aging treatment; S8: Surface treatment: chemical polishing and anodizing of the plate.

2. The method for preparing a 6 series aluminum alloy for semiconductor devices according to claim 1, characterized in that: The mass percentages of the elements in S1 are as follows: Mg: 0.8% to 1.2%; Si: 0.7% to 1.1%; Cu: 0.2% to 0.4%; Mn: 0.1% to 0.3%; Cr: 0.05% to 0.15%; Zn: 0.2% to 0.4%; Fe: ≤0.15%; Ti: 0.05%~0.1%; the balance is Al.

3. The method for preparing a 6 series aluminum alloy for semiconductor devices according to claim 1, characterized in that: In S4, the annealing temperature is 480°C to 520°C, and the holding time is 10 to 12 hours. After the annealing is completed, the ingot is slowly cooled to room temperature at a speed of 10°C / h-20°C / h.

4. The method for preparing a 6-series aluminum alloy for semiconductor devices according to claim 1, characterized in that: The parameters of the solution treatment in S7 are: heating the cold-rolled aluminum alloy plate to 530° C. to 550° C. and keeping the temperature for 1 to 2 hours.

5. The method for preparing a 6 series aluminum alloy for semiconductor devices according to claim 1, characterized in that: The parameters of the aging treatment in S7 are: the aging temperature is controlled at 160°C to 180°C, and the insulation time is 10 to 12 hours.

6. The method for preparing a 6 series aluminum alloy for semiconductor devices according to claim 1, characterized in that: The parameters of chemical polishing in S8 are to immerse the aluminum alloy plate after aging treatment in a chemical polishing liquid, the composition of the polishing liquid is 20% to 25% sulfuric acid, 10% to 15% phosphoric acid, and 5% to 10% nitric acid, the polishing time is 3 to 5 minutes, and the temperature is controlled at 25°C to 35°C.

7. The method for preparing a 6-series aluminum alloy for semiconductor devices according to claim 1, characterized in that: The parameters of anodizing in S8 are that the polished plate is anodized in an electrolyte containing 3% to 5% sulfuric acid, the oxidation voltage is 15V to 20V, and the time is 20 minutes to 30 minutes.

8. The aluminum alloy obtained by the method for preparing a 6-series aluminum alloy for semiconductor devices as claimed in any one of claims 1 to 7.

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