A hot isostatic pressing welding method for a complex structure gas distribution plate for a semiconductor

Abstract

The application belongs to the technical field of semiconductor processing, and relates to a hot isostatic pressing welding method for a complex structure gas distribution plate for semiconductors, comprising the following steps: (1) first machining and composite cleaning are performed on each layer component of the gas distribution plate to obtain a semi-finished product of the gas distribution plate to be welded; second machining and ultrasonic cleaning are performed on a stainless steel mold to obtain a mold to be assembled; (2) the semi-finished product of the gas distribution plate to be welded obtained in step (1) and the mold to be assembled are assembled, and the obtained assembly component is sequentially subjected to sleeving sealing, degassing and hot isostatic pressing welding to obtain a complex structure gas distribution plate product for semiconductors. The hot isostatic pressing welding method provided by the application realizes low deformation, high dimensional precision and high strength welding of the complex structure gas distribution plate, and significantly improves the service life and process stability of the gas distribution plate.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor processing technology and relates to a hot isostatic pressing welding method for a complex structure gas distribution plate for semiconductors. Background Technology

[0002] Gas distribution disks are critical consumable components in core semiconductor equipment such as etching machines and CVD (Continuous Chemical Vapor Deposition) systems. Currently, traditional single-layer drilled gas distribution disks are insufficient for complex process requirements, leading researchers to develop multi-layer composite gas distribution disks. These disks integrate multiple independent gas channels, cooling water channels, mixing chambers, pressure stabilizing chambers, and micro-pore arrays, enabling multi-stage gas buffering, uniform flow distribution, and precise temperature control, thus creating a highly consistent airflow and temperature field above the wafer. However, due to their dense internal channels, thin walls, complex structure, and poor overall rigidity, they are prone to thermal deformation, dimensional deviations in flatness, channel collapse and blockage, insufficient welding bonding, internal leakage, and inadequate airtightness during the welding process. These issues severely restrict their performance and reliability, becoming a key technological bottleneck in the manufacturing of core semiconductor components.

[0003] Existing welding processes for gas distribution discs include vacuum brazing, vacuum diffusion welding, and conventional clamping welding. Vacuum brazing involves heating filler metal in a vacuum furnace to melt and fill the weld seam. However, in traditional vacuum brazing for multi-layered complex gas distribution discs, the molten filler metal easily flows into the channels, causing blockages in the water and gas channels, narrowing the flow channels, and affecting the uniformity of airflow. Furthermore, vacuum brazing also suffers from uneven temperature fields, significant post-weld warping, and severe dimensional deviations in products. Vacuum diffusion welding is a method of welding gas distribution discs by applying axial pressure and heating, causing atomic diffusion between the components of each layer. Because vacuum diffusion welding uses axial pressure, it easily leads to a large pressure difference between the center and the edge of the workpiece, resulting in a welded center but over-pressure deformation. Moreover, since complex gas distribution discs are multi-layered, the axial pressure in vacuum diffusion welding easily causes uneven stress on the multi-layered disc structure, resulting in poor consistency, making it impossible to guarantee uniform pressure and deformation in each layer, leading to large quality fluctuations within the same batch of products.

[0004] CN119347086A discloses a low-deformation diffusion welding method for a multi-layer complex flow channel aluminum alloy uniform gas structure, comprising the following steps: processing pre-welding blanks of upper, middle, and lower layer plates; pickling the processed pre-welding blanks; selecting a multi-stage welding scheme or a single-stage welding scheme based on the welding area ratio between the upper and middle layer plates and between the middle and lower layer plates; and finally, precision machining the post-welding blank of the uniform gas structure according to the adjusted processing datum to obtain a multi-layer complex flow channel aluminum alloy uniform gas structure product. However, this welding method is complex to operate and is not suitable for welding multi-layer complex aluminum alloy products with high bonding rates and high strength.

[0005] CN109175660A discloses an aluminum alloy diffusion welding device and method, which achieves large-area welding between aluminum alloy components by utilizing the pressure generated by the difference in linear expansion coefficients between different materials. However, the invention has the problem that the pressure generated by the linear expansion coefficients between aluminum alloy and other materials is relatively small, which makes it impossible to achieve high bonding rate and high strength welding of products. In addition, the fixture structure designed by this invention is complex and the operation is cumbersome, which is not conducive to large-scale industrial promotion.

[0006] In summary, there is an urgent need to develop a method for achieving low-deformation, high-precision, and high-strength welding of large-size, multi-layered, complex gas distribution discs. Summary of the Invention

[0007] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a hot isostatic pressing welding method for complex structure gas distribution disks for semiconductors, which realizes low deformation, high cleanliness, high precision and high strength welding of complex structure gas distribution disks.

[0008] To achieve this objective, the present invention adopts the following technical solution: This invention provides a hot isostatic pressing method for bonding complex structure gas-equalizing disks for semiconductors, comprising the following steps: (1) Perform the first machining and composite cleaning on each layer of the gas equalization plate to obtain the semi-finished gas equalization plate to be welded; perform the second machining and ultrasonic cleaning on the stainless steel mold to obtain the mold to be assembled. (2) Assemble the semi-finished gas equalization plate obtained in step (1) with the mold to be assembled. The resulting assembly components are sequentially encapsulated, degassed and hot isostatically welded to obtain a complex structure gas equalization plate product for semiconductors.

[0009] The hot isostatic pressing (HIP) welding method for complex gas distribution disks used in semiconductors provided by this invention introduces precision stainless steel mold positioning and isotropic pressure forming during HIP welding, based on traditional diffusion welding. This effectively solves the technical problems that easily occur in traditional welding processes, such as deformation and warping of gas distribution disk structures, flow channel collapse, solder contamination, and low weld bonding rate. Through strict pre-welding cleaning and processing and control of parameters within a specific range during welding, this invention achieves low deformation, high cleanliness, high precision, and high strength welding of large-size, multi-layer, complex gas distribution disks.

[0010] Preferably, in step (1), the flatness of each layer of the first machined gas distribution plate is ≤0.125mm, for example, it can be 0.125mm, 0.12mm, 0.115mm, 0.11mm or 0.1mm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0011] The surface finish of each layer of the first machined air distribution plate should be mirror-like and free of irregular patterns.

[0012] Preferably, the material of each layer of the gas distribution plate in step (1) includes any one of A6061 aluminum alloy, A6061-T6 aluminum alloy, A2024 aluminum alloy or A5083 aluminum alloy.

[0013] The aforementioned materials have advantages such as good thermal conductivity, matching coefficient of thermal expansion, and high chemical stability, which can meet the requirements of semiconductor operating conditions.

[0014] Preferably, the composite cleaning in step (1) includes high-pressure water washing, acid washing and hot water washing performed in sequence.

[0015] The composite cleaning process ensures the cleanliness of the welding surfaces of each layer of the gas distribution plate, removes oil, metal particles, dust and other contaminants, and helps to improve the further diffusion efficiency between metal atoms during welding, making it easier to obtain products with high strength and high bonding rate.

[0016] Preferably, the water pressure of the high-pressure water wash is 2-4 MPa, for example, it can be 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa or 4 MPa, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0017] Preferably, the acid solution used for pickling is a mixture of hydrofluoric acid, nitric acid, sulfuric acid and water, wherein the mass percentage concentration of hydrofluoric acid is 40%, the mass percentage concentration of nitric acid is 68%, and the mass percentage concentration of sulfuric acid is 98%; and the volume fraction of hydrofluoric acid, nitric acid, sulfuric acid and water is 1:5:4:75.

[0018] Preferably, the pickling time is 1-8 minutes, for example, it can be 1 minute, 3 minutes, 5 minutes, 6 minutes or 8 minutes, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0019] Preferably, the temperature of the hot water wash is 40-90℃, and the time is 1-5 minutes.

[0020] The temperature of the hot water wash is 40-90℃, for example, it can be 40℃, 50℃, 60℃, 80℃ or 90℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0021] The hot water washing time is 1-5 minutes, for example, it can be 1 minute, 2 minutes, 3 minutes, 4 minutes or 5 minutes, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0022] Preferably, after the composite cleaning in step (1), a vacuum drying step at 80-100℃ for 0.5-1.5h is also included.

[0023] The vacuum drying temperature is 80-100℃, for example, it can be 80℃, 85℃, 90℃, 95℃ or 100℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0024] The vacuum drying time is 0.5-1.5h, for example, it can be 0.5h, 0.8h, 1h, 1.2h or 1.5h, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0025] Preferably, the stainless steel mold in step (1) is of any one of 304, 304L, 309, 310S or 316.

[0026] Preferably, in step (1), the second machining process makes the assembly gap between the upper mold and the side mold of the mold to be assembled after the assembly in step (2) 0.5-2mm, and the assembly gap between the inner wall of the side mold and the semi-finished gas equalization plate to be welded 0.5-5mm.

[0027] It should be noted that the dimensions of the stainless steel mold after the second machining need to be determined based on the actual assembled dimensions of each layer of the gas distribution plate components. This invention does not impose specific limitations on the dimensions of the stainless steel mold after the second machining. The aforementioned gap design allows for thermal expansion space between the semi-finished gas distribution plate to be welded and the stainless steel material, preventing jamming.

[0028] The assembly gap between the upper mold and the side mold of the mold to be assembled is 0.5-2mm, for example, it can be 0.5mm, 0.8mm, 1mm, 1.5mm or 2mm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0029] The assembly gap between the inner wall of the side mold and the semi-finished gas equalization plate to be welded is 0.5-5mm, for example, it can be 0.5mm, 1mm, 2mm, 3mm or 5mm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0030] Preferably, the ultrasonic cleaning in step (1) includes sequential cleaning with a surfactant solution for 4-6 minutes, cleaning with deionized water for 4-6 minutes, and cleaning with isopropanol solution for 4-6 minutes.

[0031] The surfactant solution may be a detergent solution, but is not limited thereto. Those skilled in the art can select a suitable surfactant solution according to the actual application scenario.

[0032] The cleaning time for the surfactant solution is 4-6 minutes, for example, 4 minutes, 4.5 minutes, 5 minutes, 5.5 minutes or 6 minutes, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0033] The deionized water rinsing time is 4-6 minutes, for example, it can be 4 minutes, 4.5 minutes, 5 minutes, 5.5 minutes or 6 minutes, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0034] The washing time with the isopropanol solution is 4-6 minutes, for example, 4 minutes, 4.5 minutes, 5 minutes, 5.5 minutes or 6 minutes, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0035] Preferably, the ultrasonic cleaning step (1) is followed by a vacuum packaging step.

[0036] Preferably, in the assembly described in step (2), graphite paper with a thickness of 0.2-1mm is placed on the contact surfaces of the upper mold, the lower mold of the mold to be assembled and the semi-finished gas equalizing plate to be welded. For example, it can be 0.2mm, 0.5mm, 0.6mm, 0.8mm or 1mm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0037] The graphite paper prevents the mold to be assembled from the semi-finished gas equalizer plate to be welded from sticking together after welding and becoming impossible to remove.

[0038] It should be noted that the cleaned semi-finished gas equalization plate to be welded and the assembly mold must be put into the furnace for welding within 5 days. If the time limit is exceeded, they must be cleaned and repackaged. During the assembly, the semi-finished gas equalization plate to be welded is designed with anti-foolproof positioning pins between each layer of components to strictly control the position between each layer and prevent misalignment.

[0039] Preferably, before the sheath sealing welding in step (2), the assembly component is placed inside the alkaline-washed aluminum sheath. The alkaline washing solution can be a 4% NaOH solution.

[0040] Preferably, the sheath sealing welding in step (2) is performed using argon arc welding.

[0041] Preferably, after the sheath sealing and before degassing in step (2), the process further includes evacuating to a vacuum level ≤ 1×10⁻⁶. - 3 Pa, for example, could be 1×10 -3 Pa, 0.8×10 -3 Pa, 0.5×10 -3 Pa, 0.3×10 -3Pa or 1×10 -4 Pa, but not limited to the listed values, applies to other unlisted values ​​within the range as well.

[0042] Preferably, the degassing temperature in step (2) is 200-400℃ and the time is 1-5h.

[0043] The degassing process removes gases adsorbed inside the workpiece and the casing, ensuring a pore-free welding interface and guaranteeing the welding effect.

[0044] The degassing temperature is 200-400℃, for example, it can be 200℃, 250℃, 300℃, 350℃ or 400℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0045] The degassing time is 1-5 hours, for example, it can be 1 hour, 2 hours, 3 hours, 4 hours or 5 hours, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0046] Preferably, in the hot isostatic pressing welding described in step (2), pads are placed between the stacked components of the gas equalization plate semi-finished product to be welded, so that there is a gap of 5-10mm between adjacent components. For example, it can be 5mm, 6mm, 8mm, 9mm or 10mm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0047] The hot isostatic pressing welding method sets a certain gap between adjacent layers of components, which allows the workpieces to be subjected to isostatic pressure with uniformity.

[0048] Preferably, the heating rate of the hot isostatic pressing welding in step (2) is 2-8℃ / min, the heating endpoint is 400-600℃, and the holding time is 3-6h.

[0049] The heating rate for hot isostatic pressing welding is 2-8℃ / min, for example, it can be 2℃ / min, 3℃ / min, 5℃ / min, 6℃ / min or 8℃ / min, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0050] The heating endpoint for hot isostatic pressing welding is 400-600℃, for example, it can be 400℃, 450℃, 500℃, 550℃ or 600℃, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0051] The holding time for hot isostatic pressing welding is 3-6 hours, for example, it can be 3 hours, 3.5 hours, 4 hours, 5 hours or 6 hours, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0052] Preferably, the welding pressure of hot isostatic pressing in step (2) is 2-20 MPa, for example, it can be 2 MPa, 5 MPa, 10 MPa, 15 MPa or 20 MPa, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0053] Preferably, after hot isostatic pressing welding in step (2), the temperature is naturally cooled and the temperature at the furnace outlet is controlled to be 50-150℃, for example, 50℃, 80℃, 100℃, 120℃ or 150℃, but not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0054] Preferably, after hot isostatic pressing welding in step (2), the product is removed from the furnace, the cladding and the mold to be assembled are removed in sequence, and the complex structure gas distribution plate product for semiconductors is taken out. The complex structure gas distribution plate product for semiconductors is then subjected to dimensional inspection, ultrasonic welding bonding rate inspection and helium inspection in sequence.

[0055] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0056] Compared with the prior art, the present invention has the following beneficial effects: The hot isostatic pressing (HIP) welding method for complex structure gas distribution disks used in semiconductors provided by this invention introduces precision stainless steel mold positioning and isotropic pressure forming during HIP welding, based on traditional diffusion welding. This effectively solves the technical problems that easily occur in the gas distribution disk structure in traditional welding processes, such as deformation and warping, flow channel collapse, solder contamination, and low welding bonding rate. Through strict pre-welding cleaning and processing and control of welding parameters, this invention achieves low deformation, high cleanliness, high precision, and high strength welding of large-size, multi-layer, complex structure gas distribution disks. The diameter deformation is as low as 0.2 mm, the thickness deformation is as low as 0.2 mm, the ultrasonic welding bonding rate can reach 100%, the welding strength can reach 120 MPa, and the deformation of the channel width and depth is as low as 3%, significantly improving the service life and process stability of the gas distribution disk. Detailed Implementation

[0057] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0058] Example 1 This embodiment provides a hot isostatic pressing method for welding complex structure gas-equalizing disks for semiconductors, including the following steps: (1) The components of each layer of the A6061 aluminum alloy gas equalization plate are first machined to a flatness of 0.1 mm, and then subjected to 3MPa high-pressure water washing, acid washing for 5 min and hot water washing at 60℃ for 3 min in sequence. The acid solution used for acid washing is a mixture of hydrofluoric acid, nitric acid, sulfuric acid and water, wherein the mass percentage concentration of hydrofluoric acid is 40%, the mass percentage concentration of nitric acid is 68%, and the mass percentage concentration of sulfuric acid is 98%. The ratio of hydrofluoric acid, nitric acid, sulfuric acid and water by volume fraction is 1:5:4:75. Then, vacuum drying at 90℃ for 1 h is performed to obtain the semi-finished gas equalization plate to be welded. The 304 stainless steel mold is second machined so that after the assembly in step (2), the assembly gap between the upper mold and the side mold of the mold to be assembled is 1 mm, and the assembly gap between the inner wall of the side mold and the semi-finished gas equalization plate to be welded is 2 mm. Then, ultrasonic cleaning with detergent solution for 5 min, ultrasonic cleaning with deionized water for 5 min and ultrasonic cleaning with isopropanol solution for 5 min are performed in sequence to obtain the mold to be assembled.

[0059] (2) Assemble the semi-finished gas equalization plate obtained in step (1) with the mold to be assembled. Place graphite paper with a thickness of 0.5 mm on the contact surfaces of the upper and lower molds of the mold to be assembled with the semi-finished gas equalization plate to be welded. Place the resulting assembly into an aluminum sleeve that has been alkaline washed with a 4% NaOH solution. Seal the sleeve using argon arc welding and evacuate to a vacuum degree of 1×10. -4 The gas is degassed at 300℃ for 3 hours; then hot isostatic pressing is performed, in which spacers are placed between the stacked gas distribution plate semi-finished products to be welded, so that there is an 8mm gap between adjacent two layers of components. Then the temperature is raised to 500℃ at a heating rate of 5℃ / min, and the holding time is 5 hours. The welding pressure is 10MPa; then it is naturally cooled, and the furnace exit temperature is controlled at 100℃. The cladding and the mold to be assembled are removed in sequence to obtain the complex structure gas distribution plate product for semiconductors.

[0060] Example 2 This embodiment provides a hot isostatic pressing method for welding complex structure gas-equalizing disks for semiconductors, including the following steps: (1) The components of each layer of the A6061-T6 aluminum alloy gas distribution plate are first machined to a flatness of 0.11 mm, and then subjected to 2 MPa high-pressure water washing, pickling for 1 min, and hot water washing at 40°C for 5 min in sequence. The acid solution used for pickling is a mixture of hydrofluoric acid, nitric acid, sulfuric acid and water, wherein the mass percentage concentration of hydrofluoric acid is 40%, the mass percentage concentration of nitric acid is 68%, and the mass percentage concentration of sulfuric acid is 98%; the volume fraction of hydrofluoric acid, nitric acid, sulfuric acid and water is 1:1. :5:4:75;; Then, vacuum dry at 80℃ for 1.5h to obtain the semi-finished gas equalizer plate to be welded; perform a second machining on the 304L stainless steel mold so that after the assembly described in step (2), the assembly gap between the upper mold and the side mold of the mold to be assembled is 0.5mm, and the assembly gap between the inner wall of the side mold and the semi-finished gas equalizer plate to be welded is 0.5mm; then, perform ultrasonic cleaning with detergent solution for 4min, ultrasonic cleaning with deionized water for 4min, and ultrasonic cleaning with isopropanol solution for 4min in sequence to obtain the mold to be assembled.

[0061] (2) Assemble the semi-finished gas equalization plate obtained in step (1) with the mold to be assembled. Place graphite paper with a thickness of 0.2 mm on the contact surfaces of the upper and lower molds of the mold to be assembled with the semi-finished gas equalization plate to be welded. Place the resulting assembly into an aluminum sleeve that has been alkaline washed with a 4% NaOH solution. Seal the sleeve using argon arc welding and evacuate to a vacuum degree of 0.5 × 10⁻⁶. -3 The gas is degassed at 200℃ for 5 hours; then hot isostatic pressing is performed, in which spacers are placed between the stacked gas distribution plate semi-finished products to be welded, so that there is a 5mm gap between adjacent two layers of components. Then the temperature is raised to 400℃ at a heating rate of 2℃ / min, and the holding time is 6 hours. The welding pressure is 20MPa; then it is naturally cooled, and the furnace exit temperature is controlled at 50℃. The cladding and the mold to be assembled are removed in sequence to obtain the complex structure gas distribution plate product for semiconductors.

[0062] Example 3 This embodiment provides a hot isostatic pressing method for welding complex structure gas-equalizing disks for semiconductors, including the following steps: (1) The components of each layer of the A2024 aluminum alloy gas equalization plate are first machined to a flatness of 0.125 mm, and then subjected to 4 MPa high-pressure water washing, acid washing for 8 min and hot water washing at 90℃ for 1 min in sequence. The acid solution used for acid washing is a mixture of hydrofluoric acid, nitric acid, sulfuric acid and water, wherein the mass percentage concentration of hydrofluoric acid is 40%, the mass percentage concentration of nitric acid is 68%, and the mass percentage concentration of sulfuric acid is 98%; the volume fraction of hydrofluoric acid, nitric acid, sulfuric acid and water is 1:5:4:75; then vacuum drying at 100℃ for 0.5 h to obtain the semi-finished gas equalization plate to be welded; the 316 stainless steel mold is second machined so that after the assembly in step (2), the assembly gap between the upper mold and the side mold of the mold to be assembled is 2 mm, and the assembly gap between the inner wall of the side mold and the semi-finished gas equalization plate to be welded is 5 mm; then ultrasonic cleaning with detergent solution for 6 min, ultrasonic cleaning with deionized water for 6 min and ultrasonic cleaning with isopropanol solution for 6 min are performed in sequence to obtain the mold to be assembled.

[0063] (2) Assemble the semi-finished gas equalization plate obtained in step (1) with the mold to be assembled. Place graphite paper with a thickness of 1 mm on the contact surfaces of the upper and lower molds of the mold to be assembled with the semi-finished gas equalization plate to be welded. Place the resulting assembly into an aluminum sleeve that has been alkaline washed with a 4% NaOH solution. Seal the sleeve using argon arc welding. Evacuate to a vacuum degree of 1×10 -3 The gas is degassed at 400℃ for 1 hour; then hot isostatic pressing is performed, in which spacers are placed between the stacked semi-finished gas distribution plate components to be welded, so that there is a 10mm gap between adjacent two layers of components. Then the temperature is raised to 600℃ at a heating rate of 8℃ / min, and the holding time is 3 hours. The welding pressure is 2MPa; then it is naturally cooled, and the furnace exit temperature is controlled at 150℃. The cladding and the mold to be assembled are removed in sequence to obtain the complex structure gas distribution plate product for semiconductors.

[0064] Example 4 This embodiment provides a hot isostatic pressing welding method for a complex structure gas distribution plate for semiconductors. The difference from Embodiment 1 is that the hot water washing at 60°C for 3 minutes in step (1) is changed to a room temperature water washing at 20°C for 3 minutes. All other steps are the same as in Embodiment 1.

[0065] Example 5 This embodiment provides a hot isostatic pressing welding method for a complex structure gas equalization plate for semiconductors. The difference from Embodiment 1 is that graphite paper is not placed on the contact surface between the upper and lower molds of the mold to be assembled and the semi-finished gas equalization plate to be welded in step (2). All other aspects are the same as in Embodiment 1.

[0066] Example 6 This embodiment provides a hot isostatic pressing welding method for a complex structure gas equalization plate for semiconductors. The difference from Embodiment 1 is that no pads are placed between the layers of the stacked gas equalization plate semi-finished products to be welded in step (2). The rest is the same as in Embodiment 1.

[0067] Comparative Example 1 This comparative example provides a hot isostatic pressing welding method for a complex structure gas distribution plate for semiconductors. The difference from Example 1 is that a stainless steel mold is not introduced in step (1), while the rest is the same as Example 1.

[0068] Comparative Example 2 This comparative example provides a hot isostatic pressing welding method for a complex structure gas distribution plate for semiconductors. The difference from Example 1 is that the high-pressure water washing, acid washing and hot water washing in step (1) are changed to a single high-pressure water washing. The rest are the same as in Example 1.

[0069] The semiconductor complex structure gas distribution plate products were prepared by hot isostatic pressing welding method provided in Examples 1-6 and Comparative Examples 1 and 2. The products were inspected for size, ultrasonic welding bonding rate and helium content using a coordinate measuring machine. The results are shown in Table 1.

[0070] Table 1 As can be seen from Table 1, the hot isostatic pressing welding method for complex structure gas distribution disks for semiconductors provided by the present invention can achieve low deformation, high dimensional accuracy, and high strength welding of complex structure gas distribution disk products for semiconductors, significantly improving the service life and process stability of the gas distribution disk.

[0071] A comparison between Examples 1 and 4 shows that using room temperature water for composite washing reduces the cleaning effect compared to hot water washing, thus affecting the welding effect. A comparison between Examples 1 and 5 shows that not placing graphite paper on the contact surfaces of the upper and lower molds of the mold to be assembled and the semi-finished gas equalizing plate to be welded will cause the mold and the product to stick together, affecting the demolding effect and product quality. A comparison between Examples 1 and 6 shows that not placing pads between the stacked semi-finished gas equalizing plates to be welded will prevent the isotropic pressure forming from being achieved effectively, thus reducing the welding effect.

[0072] As can be seen from the comparison between Example 1 and Comparative Example 1, the absence of a stainless steel mold for limiting the position leads to a significant increase in product deformation. As can be seen from the comparison between Example 1 and Comparative Example 2, the use of a single water washing step for the air distribution plate significantly reduces the cleaning effect, thereby significantly reducing the welding bonding rate and welding strength.

[0073] In summary, the hot isostatic pressing (HIP) welding method for complex structure gas distribution disks for semiconductors provided by this invention introduces precision stainless steel mold positioning and isotropic pressure forming during HIP welding, based on traditional diffusion welding. This effectively solves the technical problems that easily occur in traditional welding processes, such as deformation and warping of gas distribution disk structures, flow channel collapse, solder contamination, and low welding bonding rate. Through strict pre-welding cleaning and processing and control of welding parameters, this invention achieves low deformation, high cleanliness, high precision, and high strength welding of large-size, multi-layer, complex structure gas distribution disks. The diameter deformation is as low as 0.2 mm, the thickness deformation is as low as 0.2 mm, the ultrasonic welding bonding rate can reach 100%, the welding strength can reach 120 MPa, and the deformation of the channel width and depth is as low as 3%, significantly improving the service life and process stability of the gas distribution disk.

[0074] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A hot isostatic pressing method for bonding complex-structured gas-equalizing disks for semiconductors, characterized in that, Includes the following steps: (1) Perform the first machining and composite cleaning on each layer of the gas equalization plate to obtain the semi-finished gas equalization plate to be welded; perform the second machining and ultrasonic cleaning on the stainless steel mold to obtain the mold to be assembled. (2) Assemble the semi-finished gas equalization plate obtained in step (1) with the mold to be assembled. The resulting assembly components are sequentially encapsulated, degassed and hot isostatically welded to obtain a complex structure gas equalization plate product for semiconductors.

2. The hot isostatic pressing welding method according to claim 1, characterized in that, Step (1) The flatness of each layer of the first machined gas distribution plate is ≤0.125mm; Preferably, the material of each layer of the gas distribution plate in step (1) includes any one of A6061 aluminum alloy, A6061-T6 aluminum alloy, A2024 aluminum alloy or A5083 aluminum alloy.

3. The hot isostatic pressing welding method according to claim 1 or 2, characterized in that, The composite cleaning in step (1) includes high-pressure water washing, acid washing, and hot water washing performed sequentially; Preferably, the water pressure for the high-pressure water washing is 2-4 MPa; Preferably, the acid solution used for pickling is a mixture of hydrofluoric acid, nitric acid, sulfuric acid and water, wherein the mass percentage concentration of hydrofluoric acid is 40%, the mass percentage concentration of nitric acid is 68%, and the mass percentage concentration of sulfuric acid is 98%; and the volume fraction of hydrofluoric acid, nitric acid, sulfuric acid and water is 1:5:4:

75. Preferably, the pickling time is 1-8 minutes; Preferably, the temperature of the hot water wash is 40-90℃, and the time is 1-5 minutes; Preferably, after the composite cleaning in step (1), a vacuum drying step at 80-100℃ for 0.5-1.5h is also included.

4. The hot isostatic pressing welding method according to any one of claims 1-3, characterized in that, The stainless steel mold used in step (1) includes any one of 304, 304L, 309, 310S or 316. Preferably, in step (1), the second machining process makes the assembly gap between the upper mold and the side mold of the mold to be assembled after the assembly in step (2) 0.5-2mm, and the assembly gap between the inner wall of the side mold and the semi-finished gas equalization plate to be welded 0.5-5mm.

5. The hot isostatic pressing welding method according to any one of claims 1-4, characterized in that, The ultrasonic cleaning in step (1) includes sequential cleaning with surfactant solution for 4-6 minutes, cleaning with deionized water for 4-6 minutes, and cleaning with isopropanol solution for 4-6 minutes.

6. The hot isostatic pressing welding method according to any one of claims 1-5, characterized in that, In step (2), graphite paper with a thickness of 0.2-1mm is placed on the contact surfaces of the upper and lower molds of the mold to be assembled and the semi-finished gas equalization plate to be welded.

7. The hot isostatic pressing welding method according to any one of claims 1-6, characterized in that, The sheath sealing welding in step (2) is performed using argon arc welding; Preferably, after the sheath sealing and before degassing in step (2), the process further includes evacuating to a vacuum level ≤ 1×10⁻⁶. -3 Pa; Preferably, the degassing temperature in step (2) is 200-400℃ and the time is 1-5h.

8. The hot isostatic pressing welding method according to any one of claims 1-7, characterized in that, In the hot isostatic pressing welding described in step (2), pads are placed between the layers of the stacked gas equalization plate semi-finished products to be welded, so that there is a gap of 5-10mm between adjacent layers.

9. The hot isostatic pressing welding method according to any one of claims 1-8, characterized in that, The heating rate of the hot isostatic pressing welding in step (2) is 2-8℃ / min, the heating endpoint is 400-600℃, and the holding time is 3-6h; Preferably, the welding pressure of the hot isostatic pressing in step (2) is 2-20 MPa.

10. The hot isostatic pressing welding method according to any one of claims 1-9, characterized in that, After hot isostatic pressing welding in step (2), the furnace is cooled naturally, and the furnace exit temperature is controlled at 50-150℃.

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