Vacuum diffusion welding method of three-layer gas distribution disc body for semiconductor

Abstract

The invention provides a vacuum diffusion welding method of a three-layer gas distribution disc body for a semiconductor, which comprises the following steps of: cleaning to remove an oxidation film on the surface of an aluminum disc body, stacking aluminum 3003 in the middle and aluminum 1060 on the upper side and the lower side respectively to obtain the three-layer gas distribution disc body for the semiconductor, and finally performing vacuum diffusion welding treatment. The problems of low welding binding rate and large deformation during vacuum diffusion welding of large-area aluminum 1060 disc bodies and large-area aluminum 3003 disc bodies are effectively solved, and the prepared three-layer gas distribution disc body for the semiconductor is good in quality and meets use requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of metal welding, in particular to a vacuum diffusion welding method for a three-layer gas distribution disc for semiconductors. Background Art

[0002] Vacuum diffusion welding is a welding method that uses heat and pressure in a vacuum environment to achieve a metallurgical bond through prolonged diffusion of atoms at the intimate welding interface. The entire process relies on solid-state diffusion, without a molten state. Vacuum diffusion welding offers excellent weld quality, low residual stress, and high surface cleanliness requirements, making it suitable for use in precision semiconductor manufacturing.

[0003] Existing vacuum diffusion welding of dissimilar aluminum alloys will produce pores and cracks, and cannot meet the needs of large-area welding, and has problems such as low welding bonding rate.

[0004] CN112589251A discloses a non-vacuum diffusion welding method for aluminum alloy and dissimilar metals. A copper film is chemically deposited on the surface of the aluminum alloy to be welded. The copper film can effectively prevent the surface of the aluminum alloy to be welded from being secondary oxidized, thereby avoiding the oxide layer on the surface of the aluminum alloy from reducing the performance of the welded joint. At the same time, it can improve the diffusion coefficient of the surface of the aluminum alloy to be welded, promote diffusion efficiency, and enhance the comprehensive mechanical properties of the welded joint between the aluminum alloy and the dissimilar metal.

[0005] CN101920393A discloses a low-temperature diffusion welding method for magnesium alloy and aluminum alloy, which comprises the following steps: (1) a workpiece surface cleaning step: processing the magnesium alloy sheet and the aluminum alloy sheet to a specified size and removing the oxide layer on their surfaces to be welded; (2) a workpiece assembly step: placing an intermediate layer, tin-zinc alloy foil, between the aluminum alloy sheet and the magnesium alloy sheet, and placing a solder resist layer on each of the upper and lower layers to construct the welded workpiece; (3) a workpiece clamping and furnace welding step: placing the welded workpiece into a vacuum diffusion welding furnace, heating and keeping it warm, applying axial pressure to the welded workpiece when the insulation starts, and releasing the pressure after the insulation ends.

[0006] CN113770500A discloses a method for welding magnesium / magnesium alloy and aluminum / aluminum alloy. The magnesium / magnesium alloy, aluminum / aluminum alloy, pure tin and pure zinc materials are ground, polished, ultrasonically cleaned and then blown dry. The above materials are then assembled and fixed in the order of magnesium / magnesium alloy, pure zinc, pure tin and aluminum / aluminum alloy. The temperature is then increased in stages and vacuum diffusion welding is performed to obtain the product.

[0007] However, the above welding method may cause low welding bonding rate and large deformation when welding aluminum 1060 and aluminum 3003. Summary of the Invention

[0008] To solve the above technical problems, the present invention provides a vacuum diffusion welding method for a three-layer gas distribution plate for semiconductors. First, the oxide film on the surface of the aluminum plate is cleaned and removed. Then, aluminum 3003 is stacked in the middle and aluminum 1060 is stacked on the upper and lower sides to obtain a three-layer gas distribution plate for semiconductors. Finally, vacuum diffusion welding with specific process parameters is used to effectively solve the problems of low welding bonding rate and large deformation caused by vacuum diffusion welding of large-area aluminum 1060 and aluminum 3003 alloys. The prepared three-layer gas distribution plate for semiconductors is of high quality and meets the use requirements.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] The present invention provides a vacuum diffusion welding method for a three-layer gas distribution plate for semiconductors, the vacuum diffusion welding method comprising the following steps:

[0011] (1) cleaning and removing the oxide film on the surface of the first aluminum plate and the second aluminum plate to obtain a cleaned first aluminum plate and a cleaned second aluminum plate;

[0012] The first aluminum plate comprises aluminum 1060; the second aluminum plate comprises aluminum 3003;

[0013] (2) stacking the cleaned first aluminum tray, the cleaned second aluminum tray, and the cleaned first aluminum tray in sequence from bottom to top to obtain a three-layer gas distribution tray for the semiconductor to be processed;

[0014] (3) performing vacuum diffusion welding on the three-layer gas distribution plate for semiconductors to obtain a welded three-layer gas distribution plate for semiconductors;

[0015] The temperature of the vacuum diffusion welding process is 500-600° C., and the pressure is 1-10 MPa.

[0016] The vacuum diffusion welding method for a three-layer semiconductor gas distribution plate, described herein, first cleans and removes the aluminum oxide film on the surfaces of the first and second aluminum plates, leaving active aluminum on the surfaces, thereby improving bonding during the subsequent vacuum diffusion welding process. The cleaned first aluminum plate, the cleaned second aluminum plate, and the cleaned first aluminum plate are then stacked in order from bottom to top. The first aluminum plate, made of 1060 aluminum with high thermal conductivity and corrosion resistance, serves as the outer layer of the three-layer semiconductor gas distribution plate. The second aluminum plate, made of 3003 aluminum with high strength, serves as the middle layer. This stacked arrangement of dissimilar aluminum plates meets the functional layering requirements of the gas distribution plate. Finally, vacuum diffusion welding is performed at a temperature of 500-600°C and a pressure of 1-10 MPa, achieving a secure welding of the dissimilar aluminum plates with minimal deformation. The vacuum diffusion welding method for a three-layer semiconductor gas distribution plate, described herein, eliminates the need for additional coating, simplifies the welding process, and reduces welding costs.

[0017] The temperature of the vacuum diffusion welding process of the present invention is 500-600°C, for example, 500°C, 510°C, 520°C, 550°C, 560°C, 580°C or 600°C, but is not limited to the listed values. Other values ​​not listed within this range are also applicable.

[0018] The pressure is 1 to 10 MPa, for example, 1 MPa, 2 MPa, 3 MPa, 5 MPa, 7 MPa, 9 MPa or 10 MPa, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0019] The present invention preferably uses a vacuum diffusion welding process at a temperature of 500-600°C. This process achieves secure welding of large-area aluminum plates, with a welding bond rate of ≥99%. Lower temperatures or pressures during vacuum diffusion welding can reduce the welding bond rate, affecting the proper function of the three-layer gas distribution plate for semiconductors. Higher temperatures or pressures can significantly deform the aluminum plate.

[0020] Preferably, the cleaning in step (1) includes pickling, alkali washing and water washing in sequence. Pickling and alkali washing can effectively remove the aluminum oxide film on the surface of the aluminum plate. The water washing step is to clean and remove the residual alkali washing solution to facilitate subsequent vacuum diffusion welding processing.

[0021] Preferably, the pickling is carried out using a nitric acid solution with a volume fraction of 15% to 40%, for example, it can be 15%, 20%, 25%, 30%, 32%, 34%, 35%, 37%, 39% or 40%, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0022] Preferably, the alkali washing is carried out using a sodium hydroxide solution with a mass concentration of 5% to 10%, for example, 5%, 6%, 6.5%, 7%, 8%, 9% or 10%, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0023] Preferably, the washing is carried out using ultrapure water.

[0024] Preferably, the cleaning temperature in step (1) is 30-60°C, for example, it can be 30°C, 32°C, 35°C, 40°C, 45°C, 50°C or 60°C, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0025] Preferably, the cleaning in step (1) is followed by vacuum drying.

[0026] Preferably, the vacuum degree of the vacuum drying treatment is <1Pa, for example, it can be 0.9Pa, 0.8Pa, 0.5Pa, 0.4Pa, 0.3Pa, 0.2Pa or 0.1Pa, etc., but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0027] The present invention preferably has a vacuum degree of less than 1 Pa in the vacuum drying process to avoid volatilization of residual water vapor leading to oxidation. Insufficient vacuum degree will prolong the drying time or lead to incomplete drying.

[0028] Preferably, the temperature of the vacuum drying treatment is 50-100° C., for example, 50° C., 60° C., 70° C., 80° C., 85° C., 90° C. or 100° C., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0029] The time is 1 to 5 hours, for example, it can be 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 4 hours or 5 hours, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0030] Preferably, in step (1), the thickness of the first aluminum plate is 5 to 40 mm.

[0031] Diameter is 300-500mm;

[0032] Preferably, the second aluminum plate has a thickness of 5 to 40 mm and a diameter of 300 to 500 mm.

[0033] Preferably, the time for the vacuum diffusion welding treatment in step (3) is 30 to 80 minutes, for example, it can be 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 60 minutes or 80 minutes, etc., but is not limited to the listed values, and other unlisted values ​​within this numerical range are also applicable.

[0034] As a preferred technical solution of the present invention, the vacuum diffusion welding method includes the following steps:

[0035] (1) removing oxide films from the surfaces of the first aluminum tray and the second aluminum tray by sequentially performing acid washing, alkaline washing, and water washing, and then performing vacuum drying to obtain a cleaned first aluminum tray and a cleaned second aluminum tray;

[0036] The acid wash is performed using a nitric acid solution with a volume fraction of 15% to 40%; the alkaline wash is performed using a sodium hydroxide solution with a mass concentration of 5% to 10%; the water wash is performed using ultrapure water; the washing temperature is 30 to 60°C; the vacuum degree of the vacuum drying process is <1Pa; the vacuum drying process temperature is 50 to 100°C, and the time is 1 to 5 hours;

[0037] The first aluminum plate comprises aluminum 1060; the thickness of the first aluminum plate is 5 to 40 mm, and the diameter is 300 to 500 mm; the second aluminum plate comprises aluminum 3003; the thickness of the second aluminum plate is 5 to 40 mm, and the diameter is 300 to 500 mm;

[0038] (2) stacking the cleaned first aluminum tray, the cleaned second aluminum tray, and the cleaned first aluminum tray in sequence from bottom to top to obtain a three-layer gas distribution tray for the semiconductor to be processed;

[0039] (3) The three-layer gas distribution plate for semiconductor is subjected to vacuum diffusion welding at a temperature of 500-600° C. and a pressure of 1-10 MPa for 30-80 minutes to obtain a welded three-layer gas distribution plate for semiconductor.

[0040] Compared with the prior art, the present invention has at least the following beneficial effects:

[0041] The vacuum diffusion welding method for a three-layer gas distribution plate for semiconductors provided by the present invention is simple to operate, does not require additional solder, and adopts a vacuum diffusion welding process with specific process parameters. This solves the problems of low welding bonding rate and large deformation that occur during the vacuum diffusion welding process of large-area aluminum 1060 and aluminum 3003. A high-quality three-layer gas distribution plate for semiconductors that meets usage requirements is prepared, which is suitable for large-scale promotion and application. DETAILED DESCRIPTION

[0042] For the convenience of understanding the present invention, the present invention is given below with examples. It should be understood by those skilled in the art that the examples are only for the purpose of helping to understand the present invention and should not be regarded as specific limitations of the present invention.

[0043] The present invention is further described in detail below. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0044] The following are typical but non-limiting examples of the present invention:

[0045] Example 1

[0046] This embodiment provides a vacuum diffusion welding method for a three-layer gas distribution plate for semiconductors, the vacuum diffusion welding method comprising the following steps:

[0047] (1) removing oxide films from the surfaces of the first aluminum tray and the second aluminum tray by sequentially performing acid washing, alkaline washing, and water washing, and then performing vacuum drying to obtain a cleaned first aluminum tray and a cleaned second aluminum tray;

[0048] The acid wash is performed using a 35% volume fraction nitric acid solution; the alkaline wash is performed using an 8% mass concentration sodium hydroxide solution; the water wash is performed using ultrapure water; the washing temperature is 50° C.; the vacuum degree of the vacuum drying process is 0.8 Pa; the vacuum drying process is performed at a temperature of 80° C. for 3 hours;

[0049] The first aluminum plate is made of aluminum 1060; the thickness of the first aluminum plate is 20 mm and the diameter is 400 mm; the second aluminum plate is made of aluminum 3003; the thickness of the second aluminum plate is 20 mm and the diameter is 400 mm;

[0050] (2) stacking the cleaned first aluminum tray, the cleaned second aluminum tray, and the cleaned first aluminum tray in sequence from bottom to top to obtain a three-layer gas distribution tray for the semiconductor to be processed;

[0051] (3) The three-layer gas distribution plate for semiconductors was subjected to vacuum diffusion welding at a temperature of 560° C. and a pressure of 5 MPa for 60 minutes to obtain a welded three-layer gas distribution plate for semiconductors.

[0052] Example 2

[0053] This embodiment provides a vacuum diffusion welding method for a three-layer gas distribution plate for semiconductors, the vacuum diffusion welding method comprising the following steps:

[0054] (1) removing oxide films from the surfaces of the first aluminum tray and the second aluminum tray by sequentially performing acid washing, alkaline washing, and water washing, and then performing vacuum drying to obtain a cleaned first aluminum tray and a cleaned second aluminum tray;

[0055] The acid wash is performed using a nitric acid solution with a volume fraction of 15%; the alkaline wash is performed using a sodium hydroxide solution with a mass concentration of 10%; the water wash is performed using ultrapure water; the washing temperature is 60°C; the vacuum degree of the vacuum drying process is 0.5 Pa; the vacuum drying process temperature is 50°C and the time is 5 hours;

[0056] The first aluminum plate is made of aluminum 1060; the thickness of the first aluminum plate is 5 mm and the diameter is 300 mm; the second aluminum plate is made of aluminum 3003; the thickness of the second aluminum plate is 10 mm and the diameter is 300 mm;

[0057] (2) stacking the cleaned first aluminum tray, the cleaned second aluminum tray, and the cleaned first aluminum tray in sequence from bottom to top to obtain a three-layer gas distribution tray for the semiconductor to be processed;

[0058] (3) The three-layer gas distribution plate for semiconductors was subjected to vacuum diffusion welding at a temperature of 600° C. and a pressure of 1 MPa for 80 minutes to obtain a welded three-layer gas distribution plate for semiconductors.

[0059] Example 3

[0060] This embodiment provides a vacuum diffusion welding method for a three-layer gas distribution plate for semiconductors, the vacuum diffusion welding method comprising the following steps:

[0061] (1) removing oxide films from the surfaces of the first aluminum tray and the second aluminum tray by sequentially performing acid washing, alkaline washing, and water washing, and then performing vacuum drying to obtain a cleaned first aluminum tray and a cleaned second aluminum tray;

[0062] The acid wash is performed using a nitric acid solution with a volume fraction of 40%; the alkaline wash is performed using a sodium hydroxide solution with a mass concentration of 5%; the water wash is performed using ultrapure water; the washing temperature is 60°C; the vacuum degree of the vacuum drying process is 0.3 Pa; the vacuum drying process temperature is 100°C and the time is 1 hour;

[0063] The first aluminum plate is made of aluminum 1060; the thickness of the first aluminum plate is 40 mm and the diameter is 500 mm; the second aluminum plate is made of aluminum 3003; the thickness of the second aluminum plate is 30 mm and the diameter is 500 mm;

[0064] (2) stacking the cleaned first aluminum tray, the cleaned second aluminum tray, and the cleaned first aluminum tray in sequence from bottom to top to obtain a three-layer gas distribution tray for the semiconductor to be processed;

[0065] (3) The three-layer gas distribution plate for semiconductors was subjected to vacuum diffusion welding at a temperature of 500° C. and a pressure of 10 MPa for 30 minutes to obtain a welded three-layer gas distribution plate for semiconductors.

[0066] Example 4

[0067] This embodiment provides a vacuum diffusion welding method for a three-layer gas distribution plate for semiconductors, the vacuum diffusion welding method comprising the following steps:

[0068] (1) removing oxide films from the surfaces of the first aluminum tray and the second aluminum tray by sequentially performing acid washing, alkaline washing, and water washing, and then performing vacuum drying to obtain a cleaned first aluminum tray and a cleaned second aluminum tray;

[0069] The acid wash was performed using a nitric acid solution with a volume fraction of 30.5%; the alkaline wash was performed using a sodium hydroxide solution with a mass concentration of 6.8%; the water wash was performed using ultrapure water; the washing temperature was 42° C.; the vacuum degree of the vacuum drying process was 0.33 Pa; the vacuum drying process temperature was 52° C., and the time was 1.8 h;

[0070] The first aluminum plate is made of aluminum 1060; the thickness of the first aluminum plate is 25 mm and the diameter is 420 mm; the second aluminum plate is made of aluminum 3003; the thickness of the second aluminum plate is 25 mm and the diameter is 420 mm;

[0071] (2) stacking the cleaned first aluminum tray, the cleaned second aluminum tray, and the cleaned first aluminum tray in sequence from bottom to top to obtain a three-layer gas distribution tray for the semiconductor to be processed;

[0072] (3) The three-layer gas distribution plate for semiconductors was subjected to vacuum diffusion welding at a temperature of 507° C. and a pressure of 3.6 MPa for 55 minutes to obtain a welded three-layer gas distribution plate for semiconductors.

[0073] It can be seen from Examples 1 to 4 that the vacuum diffusion welding method for a three-layer gas distribution plate for semiconductors provided by the present invention is simple to operate. First, the oxide film on the surface of the aluminum plate is cleaned and removed, and then a vacuum diffusion welding process is performed at a temperature of 500-600°C and a pressure of 1-10 MPa. This solves the problems of low welding bonding rate and large deformation during the vacuum diffusion welding process of aluminum 1060 and aluminum 3003. The welding bonding rate of the prepared three-layer gas distribution plate for semiconductors is ≥99%.

[0074] Example 5

[0075] This embodiment provides a vacuum diffusion welding method for a three-layer gas distribution plate for semiconductors. The vacuum diffusion welding method is the same as that of embodiment 1 except that the cleaning temperature is 20°C.

[0076] Example 6

[0077] This embodiment provides a vacuum diffusion welding method for a three-layer gas distribution plate for semiconductors. The vacuum diffusion welding method is the same as that of embodiment 1 except that the cleaning temperature is 60°C.

[0078] From Example 1 and Examples 5 to 6, it can be seen that the cleaning temperature in Example 5 is relatively low, which will lead to a poor cleaning effect and fail to effectively clean and remove the oxide film on the surface of the aluminum disk; the cleaning temperature in Example 6 is relatively high, which will lead to over-corrosion, which is not conducive to the subsequent vacuum diffusion welding process and will result in a lower welding bonding rate of the final three-layer gas distribution disk for semiconductors.

[0079] Example 7

[0080] This embodiment provides a vacuum diffusion welding method for a three-layer gas distribution plate for semiconductors. The vacuum diffusion welding method is the same as that of embodiment 1 except that acid washing is not performed in step (1).

[0081] In this embodiment, since the aluminum plate is not pickled but only alkaline washed, the surface of the aluminum plate may be excessively corroded, and the welding bonding rate of the three-layer gas distribution plate for semiconductors obtained by welding is reduced.

[0082] Example 8

[0083] This embodiment provides a vacuum diffusion welding method for a three-layer gas distribution plate for semiconductors. The vacuum diffusion welding method is the same as that of embodiment 1 except that alkaline cleaning is not performed in step (1).

[0084] In this embodiment, since alkaline washing is not performed, that is, only acid washing is performed on the aluminum plate, the oxide film is not completely removed, and the welding bonding rate of the three-layer gas distribution plate for semiconductors obtained by welding is reduced.

[0085] Comparative Example 1

[0086] This comparative example provides a vacuum diffusion welding method for a three-layer gas distribution plate for semiconductors. The vacuum diffusion welding method is the same as Example 1 except that step (1) of cleaning and removing the oxide film on the surface of the first aluminum plate and the second aluminum plate is not performed.

[0087] In this comparative example, since the oxide film on the surface of the aluminum disc is not removed before the vacuum diffusion welding process, the diffusion effect of aluminum atoms is deteriorated, and the welding bonding rate of the aluminum disc after diffusion welding is significantly reduced, which cannot meet the use requirements.

[0088] Comparative Example 2

[0089] This comparative example provides a vacuum diffusion welding method for a three-layer gas distribution plate for semiconductors. The vacuum diffusion welding method is the same as Example 1 except that in step (2), the cleaned second aluminum plate, the cleaned first aluminum plate and the cleaned second aluminum plate are stacked in sequence from bottom to top.

[0090] In this comparative example, the stacking order of the aluminum discs from bottom to top is aluminum 3003, aluminum 1060 and aluminum 3003. On the one hand, this will cause large deformation during the vacuum diffusion welding process. On the other hand, the thermal conductivity and corrosion resistance of aluminum 3003 are worse than those of aluminum 1060, and the service life of the prepared three-layer gas distribution disc for semiconductors will be reduced.

[0091] Comparative Example 3

[0092] This comparative example provides a vacuum diffusion welding method for a three-layer gas distribution plate for semiconductors. The vacuum diffusion welding method is the same as Example 1 except that the temperature of the vacuum diffusion welding treatment in step (3) is 400°C.

[0093] Comparative Example 4

[0094] This comparative example provides a vacuum diffusion welding method for a three-layer gas distribution plate for semiconductors. The vacuum diffusion welding method is the same as Example 1 except that the temperature of the vacuum diffusion welding treatment in step (3) is 700°C.

[0095] From Example 1 and Comparative Examples 3 to 4, it can be seen that in Comparative Example 3, due to the low temperature of the vacuum diffusion welding process, the welding bonding rate is reduced, affecting the normal use of the three-layer gas distribution disk for semiconductors; in Comparative Example 4, due to the high temperature of the vacuum diffusion welding process, the aluminum disk is deformed to a large extent and cannot meet the use requirements.

[0096] In summary, the vacuum diffusion welding method for the three-layer gas distribution plate for semiconductors provided by the present invention cleans and removes the oxide film on the surface of the aluminum plate, and then stacks aluminum 3003 in the middle and aluminum 1060 on the upper and lower sides to obtain the three-layer gas distribution plate for semiconductors. Finally, vacuum diffusion welding with specific process parameters is used to effectively solve the problems of low welding bonding rate and large deformation when vacuum diffusion welding of large-area aluminum 1060 and aluminum 3003 alloys is performed. The prepared three-layer gas distribution plate for semiconductors is of good quality and meets the use requirements.

[0097] The applicant declares that the above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. A vacuum diffusion welding method for a three-layer gas distribution plate for semiconductors, characterized in that: The vacuum diffusion welding method comprises the following steps: (1) cleaning and removing the oxide film on the surface of the first aluminum plate and the second aluminum plate to obtain a cleaned first aluminum plate and a cleaned second aluminum plate; The first aluminum plate comprises aluminum 1060; the second aluminum plate comprises aluminum 3003; (2) stacking the cleaned first aluminum tray, the cleaned second aluminum tray, and the cleaned first aluminum tray in sequence from bottom to top to obtain a three-layer gas distribution tray for the semiconductor to be processed; (3) performing vacuum diffusion welding on the three-layer gas distribution plate for semiconductors to obtain a welded three-layer gas distribution plate for semiconductors; The temperature of the vacuum diffusion welding process is 500-600° C., and the pressure is 1-10 MPa.

2. The vacuum diffusion welding method according to claim 1, wherein: The cleaning in step (1) includes acid cleaning, alkali cleaning and water cleaning performed in sequence.

3. The vacuum diffusion welding method according to claim 2, wherein: The pickling is carried out using a nitric acid solution with a volume fraction of 15% to 40%.

4. The vacuum diffusion welding method according to claim 2, wherein: The alkali washing is carried out using a sodium hydroxide solution with a mass concentration of 5% to 10%.

5. The vacuum diffusion welding method according to claim 2, wherein: The water washing is carried out using ultrapure water.

6. The vacuum diffusion welding method according to any one of claims 1 to 5, characterized in that: The cleaning temperature in step (1) is 30-60°C.

7. The vacuum diffusion welding method according to any one of claims 1 to 6, characterized in that: After the cleaning in step (1), vacuum drying is also performed; Preferably, the vacuum degree of the vacuum drying process is less than 1 Pa; Preferably, the vacuum drying treatment is carried out at a temperature of 50 to 100° C. and for a time of 1 to 5 hours.

8. The vacuum diffusion welding method according to any one of claims 1 to 7, characterized in that: Step (1) The thickness of the first aluminum plate is 5 to 40 mm and the diameter is 300 to 500 mm; Preferably, the second aluminum plate has a thickness of 5 to 40 mm and a diameter of 300 to 500 mm.

9. The vacuum diffusion welding method according to any one of claims 1 to 8, characterized in that: The time for the vacuum diffusion welding treatment in step (3) is 30 to 80 minutes.

10. The vacuum diffusion welding method according to any one of claims 1 to 9, characterized in that: The vacuum diffusion welding method comprises the following steps: (1) removing oxide films from the surfaces of the first aluminum tray and the second aluminum tray by sequentially performing acid washing, alkaline washing, and water washing, and then performing vacuum drying to obtain a cleaned first aluminum tray and a cleaned second aluminum tray; The acid wash is performed using a nitric acid solution with a volume fraction of 15% to 40%; the alkaline wash is performed using a sodium hydroxide solution with a mass concentration of 5% to 10%; the water wash is performed using ultrapure water; the washing temperature is 30 to 60°C; the vacuum degree of the vacuum drying process is <1Pa; the vacuum drying process temperature is 50 to 100°C, and the time is 1 to 5 hours; The first aluminum plate comprises aluminum 1060; the thickness of the first aluminum plate is 5 to 40 mm, and the diameter is 300 to 500 mm; the second aluminum plate comprises aluminum 3003; the thickness of the second aluminum plate is 5 to 40 mm, and the diameter is 300 to 500 mm; (2) stacking the cleaned first aluminum tray, the cleaned second aluminum tray, and the cleaned first aluminum tray in sequence from bottom to top to obtain a three-layer gas distribution tray for the semiconductor to be processed; (3) The three-layer gas distribution plate for semiconductor is subjected to vacuum diffusion welding at a temperature of 500-600° C. and a pressure of 1-10 MPa for 30-80 minutes to obtain a welded three-layer gas distribution plate for semiconductor.