Collimator for physical vapor deposition and method of manufacturing thereof

Abstract

The present application relates to the technical field of semiconductor, in particular to a collimator for physical vapor deposition and a manufacturing method thereof. The collimator for physical vapor deposition is integrally formed by metal additive manufacturing technology, comprising a filter body, the filter body has a plurality of collimating holes arranged in a honeycomb shape, the collimating holes penetrate through the filter body and are used for controlling the transmission direction of sputtering particles, wherein the collimating holes have a gradient aspect ratio distribution, the aspect ratio gradually decreases from the center region to the edge region of the filter body, the collimator for physical vapor deposition effectively solves the technical problem that the existing uniform aspect ratio collimator cannot meet the deposition requirements of different regions, and significantly improves the radial uniformity of the film thickness.

Description

Technical Field

[0001] This invention relates to the field of semiconductor technology, and more particularly to a collimator for physical vapor deposition and its manufacturing method. Background Technology

[0002] Physical vapor deposition (PVD) is one of the core processes in semiconductor manufacturing, widely used in the preparation of critical thin films such as metal interconnect layers, barrier layers, and seed layers. In PVD, sputtered particles are generated by bombarding a target with ions; these particles are transported to the substrate surface and deposited to form a thin film. With the continuous shrinking of semiconductor device feature sizes and the increasing integration density, the requirements for thin film deposition quality, especially thickness uniformity, are becoming increasingly stringent.

[0003] Collimators are widely used in PVD equipment to improve the directionality and uniformity of thin film deposition. Currently, the collimators used in PVD equipment mainly employ the following technical solution: Multiple layers of thin metal sheets (usually copper, stainless steel, or aluminum alloy) are processed with regularly arranged through-holes using a stamping process. Then, the multiple sheets are assembled into a collimator structure of a certain thickness using brazing or diffusion welding processes. The aspect ratio of the collimating holes is typically designed to be a fixed value between 8:1 and 15:1, maintaining a uniform distribution across the entire collimator surface. The working principle of this design is to utilize the geometric constraints of the collimating holes, causing sputtered particles with incident angles exceeding the critical angle to collide with and be adsorbed by the hole walls, allowing only particles with near-perpendicular incident angles to pass through and reach the substrate surface, thereby improving the directionality of the thin film.

[0004] However, the aforementioned existing technologies have limitations: the uniform aspect ratio design of the collimating aperture does not match the objective law of uneven radial distribution of sputtered particles in PVD processes. In typical magnetron sputtering processes, due to the influence of magnetic field confinement and target erosion mechanisms, the radial distribution of sputtered particles exhibits significant non-uniformity. The sputtered particle flux density generated in the central region of the target is relatively low but has good directionality, with most particles being nearly perpendicularly incident; while the particle flux density generated in the edge region of the target is higher but has greater angular dispersion, with more particles incident at large angles. Collimators with a uniform aspect ratio design cannot adaptively adjust to this radial distribution difference. In the central region, over-collimation may occur, leading to a further reduction in the deposition rate; in the edge region, insufficient collimation may occur, affecting the film directionality, ultimately resulting in the radial uniformity of the film thickness on the substrate surface failing to meet the requirements of advanced processes.

[0005] Furthermore, existing technologies have shortcomings in manufacturing processes. Traditional multilayer thin-plate welding and assembly processes have limitations in manufacturing precision, making it difficult to guarantee the alignment accuracy between each layer, and stress concentration and deformation are prone to occur at the welding interface. The weld area can also become a source of particulate contamination, affecting the semiconductor manufacturing environment with stringent cleanliness requirements. At the same time, traditional manufacturing methods are limited by tool accessibility and clamping methods, making it difficult to achieve complex functional integration, such as advanced functions like embedded cooling channels, thus limiting further improvements in product performance. Summary of the Invention

[0006] This invention provides a collimator for physical vapor deposition and its manufacturing method. The collimator effectively solves the technical problem that existing collimators with uniform aspect ratio cannot meet the deposition requirements of different regions, and significantly improves the radial uniformity of film thickness.

[0007] This invention provides a collimator for physical vapor deposition, which is integrally formed by metal additive manufacturing technology and includes: a filter body having a plurality of collimating holes arranged in a honeycomb pattern, the collimating holes penetrating the filter body and used to control the transport direction of sputtered particles; wherein, the collimating holes have a gradient aspect ratio distribution, the aspect ratio gradually decreasing from the central region to the edge region of the filter body.

[0008] According to the present invention, a collimator has a collimation hole with a depth-to-width ratio greater than or equal to 10:1.

[0009] According to a collimator provided by the present invention, the aspect ratio of the collimating hole located in the central region of the filter body is 12:1 to 18:1, and the aspect ratio of the collimating hole located in the edge region of the filter body is 10:1 to 15:1.

[0010] According to a collimator provided by the present invention, the axis of the collimating hole and the normal of the collimator form an angle α, wherein the angle α satisfies: 0°≤a≤5°.

[0011] According to the collimator provided by the present invention, the roughness b of the inner wall surface of the collimation hole satisfies: 1μm≤b≤10μm.

[0012] According to a collimator provided by the present invention, a partition wall is provided between two adjacent collimating holes, and a conformal cooling channel is integrally formed in the partition wall.

[0013] According to the collimator provided by the present invention, the wall thickness c of the partition wall satisfies: 2mm≤c≤5mm, and the width d of the conformal cooling channel satisfies: 0.5mm≤d≤1.5mm.

[0014] According to a collimator provided by the present invention, the conformal cooling channel includes a vertical section arranged along the axial direction of the collimator and a horizontal section parallel to the vertical section, the horizontal section being connected to the vertical section.

[0015] According to the present invention, a collimator has a conformal cooling channel that is at least one of a three-dimensional coil type and a serpentine type.

[0016] According to the collimator provided by the present invention, a flange is further provided at one axial end of the filter body, the flange being used for a sealed connection with the chamber of a physical vapor deposition apparatus.

[0017] According to the present invention, a collimator is made of titanium alloy, tantalum, niobium or molybdenum.

[0018] The present invention also provides a method for manufacturing the above-mentioned collimator, comprising the following steps: S1: constructing a three-dimensional digital model of the collimator according to the deposition rate and deposition uniformity requirements of the physical vapor deposition (PVD) process, the model including honeycomb collimating holes with gradient aspect ratio distribution; S2: selecting metal or alloy powder suitable for high vacuum and high temperature environments as printing raw materials; S3: using powder bed melting technology, melting metal or alloy powder layer by layer through high energy source, and integrally forming the collimator blank; S4: performing heat treatment on the collimator blank to eliminate internal stress and increase density to obtain the collimator.

[0019] According to a manufacturing method provided by the present invention, the particle size of the metal or alloy powder ranges from 10 μm to 100 μm, and the sphericity is greater than 0.9.

[0020] According to a manufacturing method provided by the present invention, the metal or alloy powder is at least one selected from aluminum alloy, titanium alloy, tantalum, niobium, molybdenum, stainless steel and high-temperature nickel-based alloy.

[0021] According to a manufacturing method provided by the present invention, the powder bed melting technology is selective laser melting or electron beam melting, the laser power is 200-3000W, the scanning speed is 300-2000mm / s, the powder bed thickness is 10-60μm, and the scanning strategy adopts rotational scanning or partitioned scanning.

[0022] According to a manufacturing method provided by the present invention, the heat treatment includes vacuum heat treatment, inert gas protected heat treatment, or hot isostatic pressing.

[0023] According to a manufacturing method provided by the present invention, the hot isostatic pressing treatment temperature is 400-1200℃, the pressure is 100-150MPa, and the heat and pressure holding time is 2-4 hours.

[0024] This invention provides a collimator for physical vapor deposition (PVD). The collimator is integrally manufactured using metal additive manufacturing technology and employs a gradient aspect ratio collimator aperture design, solving the technical problem of existing collimators being unable to adapt to the uneven radial distribution of sputtered particles in PVD processes. In magnetron sputtering, the magnetic field distribution and erosion mode on the target surface cause radial differences in particle flux and angular distribution. The central region has a lower particle flux density but better directionality, while the edge region has a higher particle flux density but greater angular dispersion. Existing collimators with uniform aspect ratios use the same collimation standard for all regions, failing to optimize for radial differences, resulting in insufficient deposition rate in the central region or poor film directionality in the edge region. This invention achieves differentiated collimation control by gradually decreasing the aspect ratio from the center to the edge. The higher aspect ratio in the central region allows more qualified particles to pass through, improving the local deposition rate, while the lower aspect ratio in the edge region rigorously filters angularly dispersed particles to ensure deposition quality, thereby achieving a balanced global deposition rate distribution and significantly improving the radial uniformity of film thickness. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a top view schematic diagram of a collimator for physical vapor deposition provided by the present invention.

[0027] Figure 2 This is a schematic diagram of the collimator structure from below, provided by the present invention.

[0028] Figure 3 This is a three-dimensional structural diagram of a filter body provided by the present invention.

[0029] Figure 4 This is a cross-sectional structural diagram of a collimator provided by the present invention.

[0030] Figure 5 This is a cross-sectional structural diagram of another collimator provided by the present invention.

[0031] Figure 6 This is a partially enlarged structural schematic diagram of a collimation hole provided by the present invention.

[0032] Figure 7 This is a cross-sectional structural diagram of another collimator provided by the present invention.

[0033] Figure 8This is a schematic flowchart of a collimator manufacturing method provided by the present invention.

[0034] Figure label: 1. Filter body; 11. Collimation orifice; 12. Spacer wall; 13. Conformal cooling channel; 131. Vertical section; 132. Horizontal section; 2. Flange. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0036] The following is combined with Figures 1 to 7 The present invention describes a collimator for physical vapor deposition, which is integrally formed by metal additive manufacturing technology and includes: a filter body 1 having a plurality of collimating holes 11 arranged in a honeycomb pattern, the collimating holes 11 penetrating the filter body 1 and used to control the transport direction of sputtered particles; wherein the collimating holes 11 have a gradient aspect ratio distribution, the aspect ratio gradually decreasing from the central region to the edge region of the filter body 1.

[0037] In this invention, a collimator is integrally manufactured using metal additive manufacturing technology. A collimating aperture 11 with a gradient aspect ratio distribution is employed, solving the technical problem that existing collimators cannot adapt to the uneven radial distribution of sputtered particles in PVD processes. In magnetron sputtering, the magnetic field distribution and erosion mode on the target surface cause radial differences in particle flux and angular distribution. The central region has a lower particle flux density but better directionality, while the edge region has a higher particle flux density but greater angular dispersion. Existing collimators with uniform aspect ratios use the same collimation standard for all regions, failing to optimize for radial differences, resulting in insufficient deposition rate in the central region or poor film directionality in the edge region. This invention achieves differentiated collimation control by gradually decreasing the aspect ratio from the center to the edge. The higher aspect ratio in the central region allows more qualified particles to pass through, improving the local deposition rate, while the lower aspect ratio in the edge region rigorously filters angularly dispersed particles to ensure deposition quality. This achieves a balanced distribution of the global deposition rate and significantly improves the radial uniformity of the film thickness.

[0038] The integrated molding process of metal additive manufacturing eliminates the inherent limitations of traditional manufacturing methods. Traditional collimators employ a multi-layer thin-plate stamping and welding assembly method, which suffers from technical defects such as limited alignment accuracy between layers, residual stress deformation in the weld heat-affected zone, and weld seams easily becoming sources of particle detachment. The integrated molding structure of this invention fundamentally eliminates the welding interface, resulting in high overall structural dimensional accuracy and significantly improved mechanical strength and thermal stability. The arrangement of the honeycomb collimating holes 11 further optimizes collimation performance, exhibiting higher filling density and more uniform hole spacing distribution compared to traditional arrangements, improving particle transmittance while ensuring collimation effectiveness. The design flexibility of additive manufacturing technology allows for precise control of the geometric parameters of each collimating hole 11, truly achieving accurate manufacturing of gradient aspect ratios. In practical applications, compared to traditional uniform aspect ratio collimators, the radial uniformity of the film thickness on the substrate surface is significantly improved by using a gradient aspect ratio design, providing a more precise and reliable technical means for film quality control in PVD processes.

[0039] Specifically, the filter body 1 adopts a honeycomb structure, with collimating holes 11 arranged in a hexagonal pattern to form a dense array of collimating channels. The collimating holes 11 in the central region have a high depth-to-width ratio, allowing for more precise control over the angle of incident particles; the collimating holes 11 in the edge regions have a moderate depth-to-width ratio, ensuring sufficient particle flux. This gradient distribution is achieved by controlling the geometric parameters of the collimating holes 11 in each region, with the depth and width of the collimating holes 11 at different locations varying according to a preset functional relationship.

[0040] In one specific embodiment, when applied to the PVD process of tungsten thin films on 12-inch silicon wafers, conventional uniform aspect ratio collimators result in a lower deposition rate in the wafer's central region and a higher deposition rate in the edge region, causing radial non-uniformity in film thickness. By employing the gradient aspect ratio collimator of this invention, the higher aspect ratio in the central region reduces obstruction of vertically incident particles, while the moderate aspect ratio in the edge region controls the flux of high-angle particles, significantly improving the uniformity of film thickness across the entire wafer surface.

[0041] In related technologies, traditional collimators are typically constructed by stacking and welding machined metal sheets. The weld seams are prone to particle contamination, and residual stress in the heat-affected zone can lead to deformation under high-temperature operating conditions. Existing collimators maintain a uniform aspect ratio (depth-to-width ratio) across the entire filter surface, which is insufficient to accommodate the uneven radial distribution of sputtered particles in PVD processes. In this invention, the one-piece molding structure completely eliminates the welding process and weld contamination problems, improving the overall strength and stability of the collimator. The gradient aspect ratio design actively compensates for differences in the radial distribution of sputtered particles, enabling precise control of deposition rates in different regions and solving the technical challenge of traditional uniform designs failing to achieve uniform deposition in both the center and edge regions.

[0042] like Figure 7 As shown, in some embodiments, the aspect ratio of the collimating hole 11 is greater than or equal to 10:1.

[0043] In this invention, the aspect ratio of the collimating aperture 11 is set to be greater than or equal to 10:1, ensuring that the collimating aperture 11 has sufficient length to effectively control the direction of sputtered particle motion. When the aspect ratio reaches 10:1, particles with a near-vertical motion direction can smoothly pass through the collimating aperture 11 and reach the substrate surface, while particles with an incident angle deviating from the normal by more than a certain angle will collide with the aperture wall and be captured by the wall surface.

[0044] Specifically, the physical significance of the aspect ratio of the collimating aperture 11 lies in limiting the maximum incident angle of particles that can pass through it. According to the principles of geometrical optics, when the incident angle of a particle exceeds the geometrically permissible critical angle of the collimating aperture 11, the particle will collide with the aperture wall. A critical angle corresponding to an aspect ratio of 10:1 is approximately 5.7°, which can control most deflected particles and ensure the directionality of the deposited particles.

[0045] In this embodiment of the invention, the aspect ratio ≥ 10:1 ensures good collimation while also taking into account reasonable transmittance. This design is particularly suitable for applications requiring high film orientation and step coverage, and can significantly improve deposition quality in high aspect ratio structures.

[0046] like Figure 2-3 As shown, in some embodiments, the aspect ratio of the collimation hole 11 located in the central region of the filter body 1 is 12:1 to 18:1, and the aspect ratio of the collimation hole 11 located in the edge region of the filter body 1 is 10:1 to 15:1.

[0047] In this invention, the aspect ratio of the collimating aperture 11 in the central region is set to 12:1 to 18:1, and the aspect ratio of the collimating aperture 11 in the edge region is set to 10:1 to 15:1. This specific numerical range allows for precise control of the gradient distribution. The higher aspect ratio in the central region enables more stringent control of the particle angle, compensating for the relatively low sputtering flux in this region; the moderate aspect ratio in the edge region ensures sufficient particle flux, avoiding excessive restriction on the deposition rate in the edge region.

[0048] Specifically, the critical angle range for the central region's aspect ratio of 12:1 to 18:1 is 3.2° to 4.8°, primarily allowing near-vertical incident particles to pass through, while most off-center particles are captured and attached to the wall. The critical angle range for the edge region's aspect ratio of 10:1 to 15:1 is 3.8° to 5.7°, allowing particles at slightly larger angles to pass through compared to the central region, thus balancing the collimation effect with transmittance.

[0049] In one specific embodiment, in the tungsten thin film sputtering deposition process, the particle flux density in the region directly opposite the center of the target is low but has good directionality, while the particle flux density in the region corresponding to the edge of the target is high but has a large angular dispersion. By adopting a gradient design with a depth-to-width ratio of 15:1 in the central region and a depth-to-width ratio of 12:1 in the edge region, more vertically incident particles can be obtained in the central region, while high-angle particles can be moderately controlled in the edge region, ultimately achieving a uniform distribution of the thin film thickness on the wafer surface.

[0050] In this embodiment of the invention, differentiated control of the collimation degree in different regions is achieved by setting specific aspect ratio ranges. The high aspect ratio design in the central region fully utilizes the advantage of good particle directionality in this region, while the moderate aspect ratio design in the edge region balances the collimation effect and particle flux requirements, overcoming the limitations of traditional uniform design.

[0051] like Figure 6 As shown, in some embodiments, the axis of the collimating hole 11 forms an angle α with the normal of the collimator, and the angle α satisfies: 0°≤a≤5°.

[0052] In this invention, the angle between the axis of the collimating hole 11 and the collimator normal is set to 0°≤a≤5°. By introducing a small tilt angle, the particle path and wall adhesion effect are optimized. A completely vertical collimating hole 11 (angle of 0°) can achieve the most stringent direction control, while a moderate tilt (angle within 5°) can make it easier for angular particles to collide effectively with the tilted wall and be captured while maintaining a good collimation effect.

[0053] Specifically, the tilt direction of the collimation hole 11 axis can be designed according to specific application requirements, and can be radial tilt, tangential tilt, or a combination of both. The selection of the tilt angle needs to consider the geometric characteristics of the target substrate and the deposition requirements. For planar substrates, a vertical collimation hole 11 is most effective; for substrates with stepped or grooved structures, a moderate tilt can improve the sidewall coverage effect.

[0054] In one specific embodiment, during the metallization process applied to MEMS devices, the device surface has complex three-dimensional microstructures. When using a fully vertical collimating aperture 11, insufficient deposition occurs at the bottom of the sidewalls of some deep trench structures due to a shading effect. By designing the axis of the collimating aperture 11 to be slightly tilted at a 3° angle to the normal, particles in the tilted direction can reach the previously shaded areas, improving the deposition integrity of complex structures.

[0055] In this embodiment of the invention, the allowance of an angle range of 0° to 5° provides design flexibility. Vertical designs are suitable for planar deposition, while slightly tilted designs are suitable for three-dimensional structure deposition. At the same time, the upper limit of 5° ensures that the tilt angle is not too large and affects the basic collimation effect.

[0056] In some embodiments, the roughness b of the inner wall surface of the collimation hole 11 satisfies: 1μm≤b≤10μm.

[0057] In this invention, the surface roughness of the inner wall of the collimating aperture 11 is controlled within the range of 1μm≤b≤10μm. This moderate surface roughness enhances the ability to capture incident particles and prevents secondary particle slippage. When sputtered particles impact the inner wall of the collimating aperture 11 at a certain angle, the microscopic uneven structure of the rough surface effectively adheres to these particles, preventing particle slippage and secondary ejection from the smooth surface.

[0058] Specifically, the surface roughness of 1 μm to 10 μm creates numerous microscopic pits and protrusions, which provide physical anchoring points for incident particles. When high-energy sputtered particles impact the wall, they embed themselves in these microscopic depressions and are firmly attached by van der Waals forces and surface adhesion. The rough surface increases the effective contact area, improves the bonding strength between the particles and the wall, and prevents the particles from being released again under thermal disturbance or vibration.

[0059] In one specific embodiment, during the copper thin film sputtering process, when using a smooth collimating hole 11 with a surface roughness of 0.1 μm, copper atoms incident at an off-angle are prone to slippage after impacting the wall surface, and some particles will re-enter the deposition path, forming irregular deposition patterns on the substrate. Increasing the wall roughness to 5 μm effectively traps and adheres the copper atoms to the microstructure of the wall surface, eliminating secondary slippage and significantly improving the uniformity of the thin film on the substrate.

[0060] In this embodiment of the invention, by controlling the surface roughness within a specific range, the particle trapping effect of the surface microstructure is actively utilized to improve collimation performance. Additive manufacturing processes inherently possess a certain degree of surface roughness; by rationally controlling process parameters, the target roughness can be directly obtained, achieving effective trapping of angular particles and fundamentally eliminating the secondary slippage problem.

[0061] like Figure 7 As shown, in some embodiments, a partition wall 12 is provided between two adjacent collimating holes 11, and a conformal cooling channel 13 is integrally formed in the partition wall 12.

[0062] In this invention, an integrally formed conformal cooling channel 13 within the partition wall 12 enables active thermal management of the collimator. High-energy particle bombardment and radiative heating during the PVD process raise the collimator temperature, and the resulting geometric deformation due to thermal expansion affects collimation accuracy. The embedded cooling channel removes heat through a circulating cooling medium, keeping the collimator temperature within a reasonable range and ensuring geometric stability.

[0063] Specifically, the conformal cooling channel 13 is designed according to the heat load distribution, increasing the density of cooling channels in areas of concentrated heat and reducing the number of cooling channels in areas of lower temperature. The cross-sectional shape and orientation of the channel are optimized according to heat transfer requirements to maximize heat exchange efficiency. The one-piece molding process ensures a perfect fit between the channel and the structure, eliminating the contact thermal resistance of traditional cartridge-type cooling pipes.

[0064] In one specific embodiment, the target power density can reach 30 W / cm² in a high-power tantalum thin film sputtering process. 2 The collimator is subjected to thermal radiation and particle bombardment, causing its temperature to rise above 300°C. Appropriate temperature control not only ensures structural stability but also facilitates effective adhesion of sputtered particles to the wall surface; excessively high temperatures may cause the already adhered particles to re-evaporate. By employing an embedded conformal cooling channel 13, the temperature is controlled below 80°C through circulating cooling water, maintaining the geometric stability of the collimation hole 11.

[0065] In this embodiment of the invention, the one-piece embedded cooling system completely eliminates the risk of leakage from external piping, while the conformal design enables higher cooling efficiency. It is particularly suitable for high-power-density PVD processes, significantly improving equipment reliability and lifespan.

[0066] In some embodiments, the wall thickness c of the partition wall 12 satisfies: 2mm≤c≤5mm, and the width d of the conformal cooling channel 13 satisfies: 0.5mm≤d≤1.5mm.

[0067] In this invention, the partition wall 12 is designed with a thickness of 2-5 mm and a cooling channel width of 0.5-1.5 mm. A reasonable dimensional ratio achieves a balance between structural strength and cooling efficiency. The partition wall 12 needs to withstand vacuum pressure differential loads; insufficient thickness will lead to structural deformation, while excessive thickness will affect the arrangement of the cooling channels and heat transfer efficiency. The cooling channel width affects the fluid velocity and heat transfer coefficient, requiring a balance between heat transfer effect and flow resistance.

[0068] Specifically, a wall thickness of 2-5 mm can withstand pressure differential loads in a vacuum environment (typically 1 atmosphere) while providing sufficient space for the internal flow channels. A flow channel width of 0.5-1.5 mm corresponds to a moderate Reynolds number range, ensuring effective turbulent heat transfer while avoiding the problem of easy clogging due to excessively small flow channels. The ratio of flow channel width to wall thickness ensures sufficient wall thickness to maintain structural strength.

[0069] like Figure 7 As shown, in some embodiments, the conformal cooling channel 13 includes a vertical section 131 arranged along the axial direction of the collimator and a horizontal section 132 parallel to the vertical section 131, the horizontal section 132 being connected to the vertical section 131.

[0070] In this invention, the cooling channel includes an axial vertical section 131 and a horizontal section 132, which are interconnected to form a complete cooling circulation network. The vertical section 131 is arranged axially along the collimation hole 11, directly cooling the main area subjected to particle bombardment and radiative heating; the horizontal section 132 connects each vertical section 131, realizing the uniform distribution and recovery of the cooling medium. The two-section interconnection design ensures the circulation continuity of the cooling system.

[0071] Specifically, the arrangement density of the axial vertical sections 131 is optimized according to the heat load distribution, increasing the number of vertical cooling channels in areas of concentrated heat. The horizontal sections 132 serve as distribution and collection points, distributing the cooling medium from the inlet to each vertical section 131, and then collecting it from each vertical section 131 to the outlet. The interconnected design avoids dead zones and bubble accumulation, ensuring smooth fluid circulation.

[0072] In one specific embodiment, for a collimator with a thickness of 50 mm, eight axial vertical cooling channels are designed, connected by horizontal distribution sections at the top and bottom. Cooling water enters from one side horizontal section 132, flows downward through four vertical channels, changes direction after passing through the bottom horizontal section 132, flows upward through another four vertical channels, and finally flows out from the other side horizontal section 132, achieving uniform cooling of the collimator.

[0073] In this embodiment of the invention, the three-dimensional flow channel network combining axial and horizontal directions enables uniform cooling of the entire collimator. The interconnected design ensures flow balance between each channel, avoiding the problem of insufficient local cooling, and significantly improving the overall cooling effect.

[0074] In some embodiments, the conformal cooling channel 13 is at least one of a three-dimensional coil type and a serpentine type.

[0075] In this invention, the conformal cooling channel 13 adopts at least one structural form, either a three-dimensional coil or a serpentine shape, and the cooling effect is optimized by selecting a suitable channel geometry. The three-dimensional coil channel increases the path length of the cooling medium per unit volume through a spiral path, thereby increasing the heat exchange area; the serpentine channel achieves uniform distribution of the cooling medium through a reversing path, making it suitable for large-area cooling needs.

[0076] Specifically, the conformal cooling channel 13 has an inlet and an outlet. The coolant enters through the inlet, flows meanderingly within the conformal cooling channel 13, and is finally discharged through the outlet. The three-dimensional coil-type channel is arranged in a spiral form along the axial direction of the collimating hole 11, with the spiral radius and pitch designed according to heat transfer requirements. The spiral structure increases the channel length and surface area, while the centrifugal force generated by the spiral flow enhances the heat transfer effect. The serpentine channel is arranged in a meandering path in the horizontal plane, achieving coverage of a large area through multiple turns, and the channel spacing design ensures the uniformity of temperature distribution.

[0077] Optionally, the conformal cooling channel 13 is modeled after the complex geometry of the collimated hole array 11.

[0078] In some embodiments, a flange 2 is also provided at one axial end of the filter body 1, the flange 2 being used for a sealed connection with the chamber of the physical vapor deposition apparatus.

[0079] In this invention, the collimator includes a flange 2 for a sealed connection with the PVD equipment chamber. The flange 2 and the filter body 1 are integrally molded to form a single structure, eliminating the connection interface of traditional multi-part assemblies and improving sealing reliability. The design of the flange 2 follows standard specifications, facilitating matching and installation with existing PVD equipment.

[0080] Specifically, flange 2 adopts standard vacuum flange specifications, including features such as sealing grooves and bolt holes. The one-piece molding process ensures that there are no welded joints or mechanical connections between flange 2 and filter body 1, avoiding potential leakage problems at these connection points. The flatness and roughness of the flange surface meet vacuum sealing requirements, achieving a reliable seal when used with O-rings or metal gaskets.

[0081] In some embodiments, the collimator is made of titanium alloy, tantalum, niobium or molybdenum.

[0082] In this invention, the collimator material is selected from high-performance metals such as titanium alloys, tantalum, niobium, or molybdenum. These materials possess excellent high-temperature performance and chemical stability, enabling them to withstand the harsh working environment of the PVD process. Material selection requires consideration of multiple factors, including operating temperature, chemical compatibility, mechanical strength, and vacuum suitability.

[0083] Specifically, titanium alloys offer a good strength-to-weight ratio and corrosion resistance, making them suitable for medium-temperature PVD processes. Tantalum possesses excellent chemical inertness and high-temperature stability, making it suitable for processes requiring high purity. Niobium has similar chemical properties to tantalum but is less expensive, making it suitable for cost-sensitive applications. Molybdenum has a high melting point and good thermal conductivity, making it suitable for high-temperature, high-power processes. These materials have extremely low vapor pressures under high vacuum conditions, preventing gaseous contamination.

[0084] like Figure 8 As shown, the present invention also provides a method for manufacturing the above-mentioned collimator, comprising the following steps: S1: Construct a three-dimensional digital model of the collimator based on the deposition rate and deposition uniformity requirements of the physical vapor deposition (PVD) process. The model includes honeycomb collimating holes 11 with gradient aspect ratio distribution. S2: Select metal or alloy powders suitable for high vacuum and high temperature environments as printing raw materials; S3: Using powder bed melting technology, metal or alloy powder is melted layer by layer by a high-energy source and the collimator green blank is manufactured in one piece; S4: Heat treatment is performed on the collimator blank to eliminate internal stress and increase density, thus obtaining the collimator.

[0085] In this invention, the manufacturing process includes a complete flow of 3D modeling, material preparation, additive manufacturing, and heat treatment, achieving integrated manufacturing from design to finished product. Each process step is optimized for the specific requirements of the collimator, ensuring the quality and performance of the final product. The complete process flow avoids the quality transfer problems in traditional multi-stage manufacturing.

[0086] Specifically, the 3D modeling stage establishes a complete digital model of the collimator, including its shape, internal flow channels, collimation orifice 11, and all other features. Material preparation includes pretreatment processes such as powder screening, drying, and mixing. Additive manufacturing employs suitable process parameters for layer-by-layer fabrication. Heat treatment eliminates manufacturing stress and optimizes material properties. Parameter matching between each process ensures process continuity.

[0087] In related technologies, traditional manufacturing methods require multiple processes, including machining, welding, and assembly, each of which may introduce errors and defects. Quality transfer between processes can easily lead to cumulative errors, affecting the accuracy of the final product. Manufacturing complex internal structures requires specialized tooling, increasing manufacturing costs and time. However, in this invention, the integrated manufacturing process directly produces the finished product from the digital model, avoiding the cumulative errors of multiple processes. The near-net-shape characteristic reduces subsequent processing requirements, especially for complex internal structures, where geometric features difficult to achieve with traditional processes can be directly manufactured.

[0088] In some embodiments, the particle size of the metal or alloy powder ranges from 10 μm to 100 μm, and the sphericity is greater than 0.9.

[0089] In this invention, the particle size of the metal powder is controlled within the range of 10-100 μm, and the sphericity is greater than 0.9. These parameters ensure that the powder has good flowability and formability. Particle size distribution affects the powder's bulk density and flow characteristics, while sphericity affects the powder's flowability and laser absorption characteristics. Reasonable powder characteristics are the foundation of high-quality additive manufacturing.

[0090] Specifically, a particle size range of 10-100 μm avoids the problems of excessively fine powder agglomeration and excessively coarse powder being difficult to melt. The particle size distribution adopts a normal distribution, with the average particle size controlled within the range of 40-60 μm. A sphericity greater than 0.9 means that the particles are close to perfect spheres, with smooth surfaces and good flowability. High sphericity also facilitates uniform absorption of laser energy, improving melting quality.

[0091] In one specific embodiment, the titanium alloy powder prepared by gas atomization had an average particle size of 50 μm, a particle size distribution of D10 = 25 μm, D90 = 75 μm, and a sphericity of 0.93. Powder flowability testing showed a Hall flow rate of 28 s / 50 g and a loose packing density of 2.1 g / cm³. 3 Tap density 2.5 g / cm³ 3 All indicators meet the requirements of the SLM process.

[0092] In this embodiment of the invention, the particle size and sphericity parameters of the powder are strictly controlled to ensure stable additive manufacturing quality. Although high-quality powder is more expensive, it can significantly improve forming accuracy and surface quality, reduce post-processing workload, and achieve better overall cost-effectiveness.

[0093] In some embodiments, the metal or alloy powder is at least one of aluminum alloy, titanium alloy, tantalum, niobium, molybdenum, stainless steel, and high-temperature nickel-based alloy.

[0094] In this invention, the powder material includes at least one of aluminum alloy, titanium alloy, tantalum, niobium, molybdenum, stainless steel, and high-temperature nickel-based alloys, providing a wide range of material choices to meet different application requirements. Different materials have different performance characteristics and cost levels, allowing users to select the appropriate material based on specific process requirements and economic considerations.

[0095] Specifically, aluminum alloys have low density and low cost, making them suitable for weight-sensitive applications. Titanium alloys have high strength and corrosion resistance, making them suitable for high-performance applications. Tantalum has excellent chemical inertness, making it suitable for high-purity processes. Niobium has properties similar to tantalum but at a lower cost. Molybdenum has a high melting point and good thermal conductivity, making it suitable for high-temperature applications. Stainless steel has moderate cost and good machinability, making it suitable for general industrial applications. High-temperature nickel-based alloys are suitable for extreme high-temperature environments.

[0096] In some embodiments, the powder bed melting technology is selective laser melting or electron beam melting, with a laser power of 200-3000W, a scanning speed of 300-2000mm / s, a powder layer thickness of 10-60μm, and a scanning strategy of rotational scanning or partitioned scanning.

[0097] In this invention, the additive manufacturing process employs selective laser melting or electron beam melting, both of which are currently the mainstream methods for metal additive manufacturing, possessing mature technological foundations and equipment support. The process parameters need to be optimized based on material properties and product requirements to ensure a balance between forming quality and efficiency.

[0098] Specifically, selective laser melting uses a laser as the heat source, is suitable for most metal materials, and offers high forming precision. Electron beam melting uses an electron beam as the heat source, is suitable for high-melting-point materials, and offers high forming efficiency. Laser power ranges from 200-3000W, covering needs from small precision parts to large structural components. Parameters such as scanning speed, layer thickness, and scanning spacing are matched according to the material and geometric characteristics.

[0099] In this embodiment of the invention, additive manufacturing technology can directly produce complex three-dimensional structures, including features that cannot be processed by traditional methods, such as internal cooling channels. The choice between two process technologies provides flexibility for different materials and requirements, and parameter optimization ensures stable and reliable manufacturing quality.

[0100] In some embodiments, heat treatment includes vacuum heat treatment, inert gas protected heat treatment, or hot isostatic pressing.

[0101] In this invention, the heat treatment process includes vacuum heat treatment, inert gas protected heat treatment, or hot isostatic pressing. By selecting a suitable heat treatment method, material properties are optimized and manufacturing defects are eliminated. The rapid cooling characteristics of additive manufacturing can generate residual stress and non-equilibrium structures, which heat treatment can effectively improve.

[0102] Specifically, vacuum heat treatment is performed in a vacuum environment, avoiding oxidation contamination of reactive metals, and is suitable for highly reactive materials such as titanium and tantalum. Inert gas protected heat treatment has lower costs and is suitable for mass production. Hot isostatic pressing eliminates internal porosity through a high-temperature and high-pressure environment, significantly improving density. Different heat treatment methods are suitable for different materials and performance requirements.

[0103] Furthermore, the hot isostatic pressing treatment is carried out at a temperature of 400-1200℃, a pressure of 100-150MPa, and a holding time of 2-4 hours.

[0104] In this invention, hot isostatic pressing (HIP) is performed at a temperature of 400-1200℃ and a pressure of 100-150MPa for 2-4 hours. This high-temperature, high-pressure environment achieves material densification and performance optimization. The isotropic pressure of HIP effectively eliminates micropores and directional differences in additive manufacturing, enabling the material to achieve performance levels approaching those of forgings.

[0105] Specifically, the temperature range of 400-1200℃ covers the recrystallization temperature of different materials, enabling thorough homogenization of the microstructure. A pressure of 100-150 MPa is sufficient to close micropores without causing excessive deformation. A holding time of 2-4 hours ensures the full effect of temperature and pressure. The plastic deformation and diffusion of the material during processing eliminate interlayer interfaces and anisotropy inherent in additive manufacturing.

[0106] In one specific embodiment, the titanium alloy collimator underwent hot isostatic pressing (HIP) treatment at 920°C and 120 MPa for 3 hours. The material density before treatment was 96.5%, and after treatment it reached 99.8%, close to the theoretical density. The tensile strength increased from 880 MPa to 950 MPa, and the elongation increased from 12% to 18%, demonstrating significant improvement in material properties.

[0107] In this embodiment of the invention, hot isostatic pressing effectively eliminates internal porosity in the material through a high-temperature and high-pressure environment, enabling the performance of the additively manufactured part to reach or even exceed that of traditional forgings. This treatment is particularly important for collimators operating under high-temperature and high-stress environments, ensuring their long-term stable performance.

[0108] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A collimator for physical vapor deposition, characterized in that, The collimator is integrally formed using metal additive manufacturing technology, including: The filter body (1) has a plurality of collimating holes (11) arranged in a honeycomb pattern, the collimating holes (11) penetrating the filter body (1) and used to control the transport direction of sputtered particles; The collimating hole (11) has a gradient aspect ratio distribution, and the aspect ratio gradually decreases from the center region to the edge region of the filter body (1).

2. The collimator for physical vapor deposition according to claim 1, characterized in that, The aspect ratio of the collimating hole (11) is greater than or equal to 10:

1.

3. The collimator for physical vapor deposition according to claim 2, characterized in that, The aspect ratio of the collimating hole (11) located in the central region of the filter body (1) is 12:1 to 18:1, and the aspect ratio of the collimating hole (11) located in the edge region of the filter body (1) is 10:1 to 15:

1.

4. The collimator for physical vapor deposition according to claim 1, characterized in that, The axis of the collimation hole (11) forms an angle α with the normal of the collimator, and the angle α satisfies: 0°≤a≤5°.

5. The collimator for physical vapor deposition according to claim 1, characterized in that, The roughness b of the inner wall surface of the collimation hole (11) satisfies: 1μm≤b≤10μm.

6. The collimator for physical vapor deposition according to claim 1, characterized in that, A partition wall (12) is provided between two adjacent collimating holes (11), and a conformal cooling channel (13) is integrally formed in the partition wall (12).

7. The collimator for physical vapor deposition according to claim 6, characterized in that, The wall thickness c of the partition wall (12) satisfies: 2mm≤c≤5mm, and the width d of the conformal cooling channel (13) satisfies: 0.5mm≤d≤1.5mm.

8. The collimator for physical vapor deposition according to claim 6, characterized in that, The conformal cooling channel (13) includes a vertical section (131) arranged along the axial direction of the collimator and a horizontal section (132) parallel to the vertical section (131), the horizontal section (132) being connected to the vertical section (131).

9. The collimator for physical vapor deposition according to any one of claims 1-8, characterized in that, It also includes a flange (2) disposed at one axial end of the filter body (1), the flange (2) being used for a sealed connection with the chamber of the physical vapor deposition equipment.

10. A method for manufacturing a collimator for physical vapor deposition as described in any one of claims 1-9, characterized in that, Includes the following steps: S1: Construct a three-dimensional digital model of the collimator according to the deposition rate and deposition uniformity requirements of the physical vapor deposition process. The model includes honeycomb collimating holes with gradient aspect ratio distribution (11). S2: Select metal or alloy powders suitable for high vacuum and high temperature environments as printing raw materials; S3: Using powder bed melting technology, the metal or alloy powder is melted layer by layer by a high-energy source, and the collimator green blank is manufactured in one piece; S4: The collimator green blank is subjected to heat treatment to eliminate internal stress and increase density to obtain the collimator.

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