Magnetron sputtering device with particle guidance and multi-layer shielding functions

Abstract

This application discloses a magnetron sputtering apparatus with particle guidance and multi-layer shielding functions, including a process cavity, a target material, and a lifting stage, as well as a first shield, a second shield, and a third shield. During magnetron sputtering, the lifting stage rises to the process position, causing the second shield and the first shield to enclose and form an inner space that can limit the deposition area of ​​sputtered particles. The stage and the target surface are constrained in the inner space. The third shield forms an outer space around the inner space. The sieve holes of the first shield create a directional particle guidance path, which allows sputtered particles to enter the outer space from the inner space and finally deposit on the third shield, thereby significantly reducing the adhesion and accumulation of particles on the inner wall of the inner space. Particles deposited on the outer space are physically blocked and cannot flow back to the inner space, thereby improving the coating environment and ensuring the wafer preparation yield.

Description

Technical Field

[0001] This application relates to the field of magnetron sputtering technology, and in particular to a magnetron sputtering device with particle guidance and multi-layer shielding functions. Background Technology

[0002] Magnetron sputtering is widely used in semiconductors, optical coating, and flat panel displays. During the sputtering process, to prevent thin films from depositing on the inner wall of the chamber and non-target areas, shields are usually placed around the stage and on the inner wall of the chamber. In the prior art, the most commonly used shield is a single-layer metal structure, which mainly serves as a physical barrier.

[0003] However, existing single-layer shielding components have the following technical problems: First, there is the issue of particulate contamination. As the process accumulates, sputtered materials continuously deposit on the surface of the substrate, forming a thick film. Due to factors such as internal stress within the film, differences in thermal expansion coefficients, and physical collisions, the deposited film is prone to cracking and peeling, forming micron-sized particles. Once these particles fall onto the wafer surface, they can directly cause defects such as short circuits and open circuits, severely impacting product yield.

[0004] Second, there is the issue of secondary sputtering contamination. When high-energy particles sputtered from the target reach the surface of the substrate, not all of them are adsorbed. Some particles collide with the substrate surface, "bounced" or "re-sputtered" the atoms or matrix material already deposited on the substrate surface, forming a secondary particle stream. These secondary particles have lower energy and are prone to drifting in the chamber and redepositing on the wafer surface, becoming an additional source of contamination.

[0005] Third, there is the problem of abnormal discharge caused by poor electrical contact. In magnetron sputtering systems, the shield is usually part of the grounding loop. After long-term use, the contact resistance of a single-layer shield may increase due to thermal deformation or surface deposits, resulting in potential floating, charge accumulation, and micro-arc discharge. This can not only damage the shield surface, but also cause material splashing, generate additional particles, and even trigger process alarms and wafer scrap. Summary of the Invention

[0006] The purpose of this application is to overcome the shortcomings of the existing technology and provide a magnetron sputtering device with particle guidance and multi-layer shielding functions.

[0007] This application provides a magnetron sputtering apparatus with particle guidance and multi-layer shielding functions, including a process chamber, a target, and a lifting platform, and further comprising: a first shielding member disposed on the upper part of the process chamber and surrounding the target, the first shielding member having multiple sieve holes; a second shielding member disposed on the lifting platform and capable of moving up and down with the lifting platform to approach or move away from the first shielding member, the second shielding member including a skirt extending outward from the outer periphery of the lifting platform; and a third shielding member circumferentially disposed within the process chamber and at least surrounding the portion of the first shielding member with sieve holes. Inside; when the lifting stage rises to the process position, the skirt can abut against the first shield, and the first and second shields can cooperate to form an inner ring space. At least the stage portion of the lifting stage used to support the wafer and the target surface of the target material are in the inner ring space. The inner ring space can limit the deposition area of ​​sputtered particles; the third shield is located outside the inner ring space and forms an outer ring space surrounding the inner ring space; the sieve connects the inner ring space and the outer ring space. The sieve can guide sputtered particles from the inner ring space into the outer ring space and deposit them on the third shield.

[0008] Furthermore, the sieve holes on the first shield are oblique holes, with the hole axis inclined towards the target material to guide sputtered particles into and through the sieve holes; and / or, the incident side of the sieve holes on the first shield has a flared chamfer or a flared mouth structure to increase the capture aperture for sputtered particles; and / or, the hole walls on the first shield are smooth surfaces; and / or, the inner wall surface of the first shield is a rough surface with a roughness Ra of 1.6 μm to 3.2 μm, used to mechanically anchor the sputtered particles attached thereto; and / or, the inner wall surface of the first shield is coated with a coating of the same material as the target material to enhance the adhesion of the sputtered particles attached thereto; and / or, the inner wall surface of the third shield is a rough surface with a roughness Ra ≥ 6. 0.3μm; and / or, the inner wall of the third shield is provided with circumferential grooves or fin structures to increase the specific surface area and firmly lock the sputtered particles; and / or, only the middle and lower part of the first shield has sieve holes, the overall opening ratio of the first shield is 20%~60%, and the sieve holes on the first shield are evenly distributed along its circumference and staggered along its axial direction; and / or, the air inlet of the process cavity is directly connected to the inner ring space, and the air outlet of the process cavity is located on the outside of the third shield to form an airflow from the inner ring space, through the sieve holes, to the outer ring space; and / or, the first shield and the third shield are electrically insulated from each other, and the first shield is grounded and the third shield is connected to a positive bias power supply to form an electric field pointing towards the outer ring space between the two, thereby guiding the charged particles to move towards the sieve holes.

[0009] Furthermore, the bottom end face of the first shield and / or the upper surface of the skirt are coated with a low-adhesion coating to reduce the adhesion of sputtered particles at the connection between the first shield and the second shield; and / or, at least the part of the first shield that contacts the skirt and the part of the skirt that contacts the first shield are made of different metal materials, so that the adhesion of sputtered particles to the two is different, so that the sputtered particles deposited at the connection will preferentially detach from the side with weaker adhesion; and / or, the first shield or the second shield is provided with a purge air hole, which is connected to an external air source to form an airflow barrier at the connection, thereby preventing sputtered particles from depositing there; and / or, when the lifting platform rises to the process position, there is a preset gap between the first shield and the skirt, which forms an annular channel, allowing sputtered particles to pass through the preset gap and enter the outer ring space, thereby preventing particles from depositing at the connection.

[0010] Furthermore, the skirt edge is also provided with sieve holes; at least when the second cover is raised to the process position with the lifting platform, the third cover can surround the part of the skirt edge with sieve holes.

[0011] Furthermore, the second shield also includes a sleeve portion and a hanging edge disposed on the top of the sleeve portion, the hanging edge extending inward to cover the edge of the lifting stage, so as to form a groove on the lifting stage for accommodating the wafer.

[0012] Furthermore, the top surface of the hanging edge is inclined downward toward the center of the lifting platform, making the groove have a wide opening and a narrow bottom; and / or, one of the second cover and the lifting platform is provided with a limiting groove, and the other is provided with a limiting block. The limiting groove includes an axially extending entry part and a circumferential locking part communicating with the entry part. During installation, the limiting block enters the limiting groove along the entry part, and then the second cover is rotated to make the limiting block enter the circumferential locking part, thereby realizing the circumferential locking and axial anti-disengagement of the second cover.

[0013] Furthermore, the third shield is cylindrical, with an open top for inserting the first shield, and openings on its sides corresponding to the wafer inlet and outlet of the process cavity. A clearance hole is located at the center of its bottom. The connecting part of the lifting platform passes through the clearance hole and is connected to an external lifting drive. At least the portion of the first shield with sieve holes, the platform of the lifting platform, and the second shield are located within the outer ring space formed by the third shield. The bottom wall of the third shield is annular, with its skirt facing the bottom wall. The inner diameter of the clearance hole is larger than the outer diameter of the platform of the lifting platform, and the inner circumference of the bottom wall is provided with an annular dust barrier to prevent particles deposited in the outer ring space from escaping through the clearance hole.

[0014] Furthermore, the top of the third shield is provided with an outwardly extending mounting strip, and the outer periphery of the first shield is provided with a hanging strip. The first shield can be detachably hung in the third shield through the hanging strip and the mounting strip. The inner wall of the process cavity is provided with a ring of supporting steps, and the third shield can be detachably hung in the process cavity through the mounting strip and the supporting steps. The lower outer periphery of the first shield is also provided with a ring of reinforcing edge, and a gap is left between the reinforcing edge and the inner wall of the third shield to increase the structural strength of the first shield and form an airflow buffer gap.

[0015] Furthermore, the magnetron sputtering device with particle guidance and multi-layer shielding functions also includes an elastic conductive element, which is disposed on the skirt and located directly below the first shield; the first shield is grounded; when the second shield rises to the process position with the lifting platform, the first shield can press against the elastic conductive element, thereby achieving low-resistance grounding of the second shield.

[0016] Furthermore, the magnetron sputtering device with particle guidance and multi-layer shielding functions also includes: a fourth shielding element for shielding the wafer inlet and outlet on the third shielding element; and a shielding drive element for driving the fourth shielding element to move closer to or away from the wafer inlet and outlet.

[0017] This application provides a magnetron sputtering apparatus with particle guidance and multi-layer shielding functions, including a process chamber, a target, and a lifting stage, as well as a first shield, a second shield, and a third shield. The first shield has multiple sieve holes, the second shield can move up and down with the lifting stage, and the third shield at least surrounds the portion of the first shield with sieve holes. During magnetron sputtering, the lifting stage rises to the process position, causing the second shield and the first shield to surround and form an inner space that can define the sputtered particle deposition area. The stage and the target surface are constrained within the inner space. The third shield forms an outer space around the inner space. The sieve holes of the first shield create a directional particle guidance path, allowing sputtered particles to enter from the inner space. The particles enter the outer ring and are ultimately deposited on the third shielding element, thereby significantly reducing the adhesion and accumulation of particles on the inner wall of the inner ring space. This prevents the formation of a thick film on the surface of the inner ring shielding element due to continuous particle deposition, thus eliminating the problem of micron-sized particles contaminating the wafer due to film layer cracking and peeling caused by internal stress and thermal cycling deformation. At the same time, the particles deposited on the outer ring are physically blocked and cannot flow back to the inner ring. Therefore, even if a small number of secondary sputtered particles are generated on the outer ring, they will be confined to the outer ring space and cannot drift to the wafer surface to cause secondary contamination. The magnetron sputtering device with particle guiding and multi-layer shielding functions provided in this application improves the coating environment from three aspects: particle constraint, deposition partitioning, and physical barrier, which can effectively ensure the wafer preparation yield. Attached Figure Description

[0018] Figure 1 A schematic diagram of a magnetron sputtering device with particle guidance and multi-layer shielding functions provided in this application; Figure 2 A schematic diagram of another magnetron sputtering device with particle guidance and multi-layer shielding functions provided in this application; Figure 3 for Figure 2 A schematic diagram of the magnetron sputtering device with particle guidance and multi-layer shielding functions from another perspective; Figure 4 for Figure 2 The diagram shows the structure of the first shielding element, the second shielding element, and the third shielding element in the magnetron sputtering device with particle guidance and multi-layer shielding functions. Detailed Implementation

[0019] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0020] This application provides a magnetron sputtering apparatus with particle guidance and multi-layer shielding functions, including a process cavity 1, a target 2, and a lifting stage 3 for supporting wafers. It further includes: a first shield 10, disposed on the upper part of the process cavity 1 and surrounding the target 2, the first shield 10 having multiple sieve holes; a second shield 20, disposed on the lifting stage 3 and capable of moving up and down with the lifting stage 3 to approach or move away from the first shield 10, the second shield 20 including a skirt 21 extending outward from the outer periphery of the lifting stage 3; and a third shield 30, arranged around the process cavity 1 and at least surrounding the portion of the first shield 10 with sieve holes. When the lifting stage 3 rises to the process position, the skirt 21 can interact with the first shield... The first shield 10 and the second shield 20 can cooperate to form an inner ring space. At least the platform 3 used to support the wafer and the target surface of the target 2 are located in the inner ring space. The inner ring space can limit the deposition area of ​​sputtered particles. The third shield 30 is located outside the inner ring space and forms an outer ring space surrounding the inner ring space. The sieve holes connect the inner ring space and the outer ring space. The sieve holes can guide sputtered particles from the inner ring space into the outer ring space and deposit them on the third shield 30. During operation, the first shield 10, the second shield 20 and the third shield 30 together constitute a particle guiding path so that the particles sputtered from the target 2 can pass through the sieve holes, enter the outer ring space and be received by the third shield 30.

[0021] Specifically, the magnetron sputtering process is carried out within a sealed process chamber 1, which provides a stable vacuum environment for the coating operation. The target material 2, serving as the raw material source for thin film deposition, is fixedly positioned within the process chamber 1, while the lifting platform 3 is located directly below the target material 2 and serves to support the wafer. During process operation, the process gas within the chamber is ionized into plasma under the influence of an electromagnetic field. The high-energy plasma continuously bombards the surface of the target material 2, causing atoms or molecules of the target material 2 to be ejected and form sputtered particles. These sputtered particles move downwards in a directional manner and are uniformly deposited on the surface of the wafer supported by the lifting platform 3, ultimately forming a thin film layer on the wafer that meets the process requirements.

[0022] During actual sputtering, a large number of sputtered particles cannot be precisely deposited on the wafer surface. Some drift randomly to non-process areas such as the inner wall of the cavity and the edge of the stage. These particles accumulate in non-target areas and are prone to cracking and peeling due to internal stress and thermal cycling, forming micron-sized particles that contaminate the wafer. Furthermore, collisions and bounces of particles in non-target areas can generate secondary sputtering, further deteriorating the wafer's processing environment. Therefore, a shielding element needs to be installed inside the process cavity 1 to constrain and block sputtered particles, preventing contamination of non-process areas and ensuring the stability of the coating process and wafer yield.

[0023] For details, please refer to Figure 1 or Figure 2 In the illustrated embodiment, the first shielding member 10 is disposed on the upper part of the process cavity 1 and surrounds the target material 2, with at least the target surface of the target material 2 exposed within the circle formed by the first shielding member 10. Multiple rows and columns of sieve holes are formed at the lower part of the first shielding member 10. The first shielding member 10 serves as an upper shielding component, providing a channel foundation for particle guidance.

[0024] Continue to refer to Figure 1 or Figure 2 The second cover 20 is installed on the lifting platform 3 and can move up and down synchronously with the platform. The second cover 20 may only include a skirt 21, which is detachably set on the outer peripheral wall of the lifting platform 3 and extends outward, or the skirt 21 is integrally formed with the lifting platform 3; the second cover 20 may also be configured to include a skirt 21 and be easy to assemble and disassemble with the lifting platform 3 (e.g., Figure 2-4 The second shielding member 20, as a lower shielding component, can work with the first shielding member 10 to construct an inner ring space. By enclosing the target surface of the target material 2 and the platform of the lifting stage 3, it effectively limits the process space of magnetron sputtering and the activity space of sputtered particles.

[0025] Continue to refer to Figure 1 or Figure 2The third shielding member 30 is arranged in a ring shape inside the process cavity 1, and completely surrounds the part of the first shielding member 10 with the sieve holes. The third shielding member 30, as an outer shielding component, constructs an external receiving space.

[0026] It is important to note that Figure 1 In the embodiment shown, the sieve hole is only provided in the lower middle part of the first shield 10, so the third shield 30 only covers the lower middle part of the first shield 10. Figure 2 In the illustrated embodiment, the skirt 21 is also provided with sieve holes, so the third shield 30 is designed to also enclose the second shield 20. The third shield 30 claimed in this application needs to be constructed to fully shield the sieve holes, so as to ensure that sputtered particles passing through the sieve holes are captured by the outer ring space and do not fall into the process cavity 1 without shielding.

[0027] Continue to refer to Figure 1 or Figure 2 The third shield 30 has an opening on one side, which faces the wafer inlet and outlet of the process cavity 1 to facilitate wafer entry and exit. The first shield 10 is positioned slightly higher than the wafer inlet and outlet. In non-process states, the second shield 20 is away from the first shield 10; at this time, neither the first shield 10 nor the second shield 20 will obstruct the wafer inlet and outlet.

[0028] In one specific embodiment, when the lifting platform 3 rises to the process position, the skirt 21 and the first shield 10 approach each other (they can be directly and tightly fitted, or a certain preset gap can be left, as detailed below), forming an inner ring space between the first shield 10 and the second shield 20. This inner ring space confines the platform portion of the lifting platform 3 and the target surface of the target material 2, achieving precise restriction of the sputtered particle deposition area. The third shield 30 forms an outer ring space around the inner ring space. The sieve holes on the first shield 10 connect the inner ring space and the outer ring space. The three shields work together to form a particle guiding path. During magnetron sputtering, particles sputtered from the target 2 pass through the sieve holes along this path, enter the outer space from the inner space, and are finally received by the third shielding element 30. In this way, the normal coating of the wafer in the inner space can be guaranteed, and excess sputtered particles can be guided to the outer space for deposition. This avoids the large amount of particles adhering and accumulating on the inner wall of the inner space, thereby effectively reducing the contamination of the wafer caused by particle shedding and secondary sputtering, and improving the stability of the coating process.

[0029] In summary, the magnetron sputtering apparatus with particle guidance and multi-layer shielding functions provided in this application effectively solves the problems of particle contamination and secondary sputtering contamination caused by single-layer shielding through the cooperation of the first shielding member 10, the second shielding member 20, and the third shielding member 30. During magnetron sputtering, the lifting stage 3 is raised to the process position, causing the second shielding member 20 and the first shielding member 10 to enclose and form an inner space that can limit the sputtered particle deposition area. The stage and the target surface are constrained within the inner space. The third shielding member 30 forms an outer space around the inner space. The sieve holes of the first shielding member 10 construct a directional particle guidance path, which allows sputtered particles to enter the outer circle from the inner circle and finally deposit on the third shielding member. On component 30, the adhesion and accumulation of particles on the inner wall of the inner space are greatly reduced, avoiding the formation of a thick film on the surface of the inner shielding component due to continuous particle deposition. This eliminates the problem of micron-sized particles contaminating the wafer due to the cracking and peeling of the film layer caused by internal stress and thermal cycling deformation. At the same time, the particles deposited on the outer ring are physically blocked and cannot flow back to the inner ring. Therefore, even if a small number of secondary sputtered particles are generated on the outer ring, they will be confined to the outer ring space and cannot drift to the wafer surface and cause secondary contamination. The magnetron sputtering device with particle guiding and multi-layer shielding functions provided in this application improves the coating environment from three aspects: particle constraint, deposition partitioning, and physical barrier, which can effectively ensure the wafer preparation yield.

[0030] To achieve directional confinement and stable deposition of sputtered particles, it is preferable to allow the sputtered particles to enter the sieve holes and pass smoothly through and into the outer ring space, and finally attach and deposit on the third shield 30, rather than drifting randomly in the outer ring space. At the same time, for the small number of sputtered particles that cannot be avoided to adhere to the surfaces of the first shield 10 and the second shield 20, they need to be firmly bonded to reduce the risk of secondary sputtering and film fragmentation and detachment.

[0031] Based on this, this application features targeted design from four dimensions: First, it optimizes the internal structure of the sieve holes to guide particles smoothly through and reach the outer ring; second, it optimizes the inner wall of the first shield 10 to ensure that most particles enter the sieve holes first, while firmly adhering any particles that inevitably adhere, preventing them from falling off due to vibration, thermal stress, or subsequent particle impact; third, it optimizes the third shield 30 to effectively receive and firmly lock particles passing through the sieve holes, trapping fragments in the outer ring space even if the film cracks and peels off, thus preventing contaminants from returning to the inner ring space as much as possible; fourth, it rationally sets the specific position and opening ratio of the sieve holes to balance the particle passage efficiency with the outer ring's receiving effect, avoiding excessively large apertures that reduce the outer ring's receiving efficiency or excessively small apertures that cause sieve blockage.

[0032] Optionally, the sieve holes on the first shield 10 are oblique holes, with the hole axis inclined toward the target material 2, so as to guide sputtered particles into and through the sieve holes.

[0033] Specifically, the sieve holes are not radially horizontal holes with their axes perpendicular to the inner wall of the inner ring, but rather oblique holes with their axes inclined upwards toward the target material 2. Compared to radially horizontal holes, oblique openings better match the natural trajectory of sputtered particles as they disperse outwards from the target material 2, allowing particles to enter the sieve holes smoothly at a smaller incident angle. This increases the throughput of sputtered particles passing through the sieve holes and flowing into the outer ring space, and reduces the probability of particles bouncing back after directly impacting the hole wall.

[0034] Optionally, the axis of the sieve hole forms an angle of 30° to 60° with the normal of the inner wall of the first shield 10.

[0035] This angle range can avoid the problems of a large number of particles bouncing back due to a small angle, and the problem of a large angle disrupting the overall particle flow layout. While ensuring the efficiency of particle flow, it does not damage the original shielding and protection function of the first shielding component 10.

[0036] Optionally, the incident side of the sieve aperture on the first shield 10 is provided with a flared chamfer or is configured as a flared mouth structure to increase the capture aperture for sputtered particles.

[0037] It should be explained that the incident side of the sieve aperture refers to the side of the sieve aperture that connects to the inner ring space, which is also the side where sputtered particles enter the sieve aperture.

[0038] It should also be explained that the flaring and chamfering is performed on the side of the screen hole that is the incident point. The chamfering depth is generally 1 / 3 to 1 / 2 of the thickness of the first shielding plate, and the flaring angle is generally 45° to 60°.

[0039] The funnel-shaped structure is formed by machining the inlet side of the sieve hole into an enlarged shape similar to a funnel (the diameter gradually decreases from the inlet to the inside).

[0040] Both methods can effectively increase the capture aperture of sputtered particles through the sieve holes, so as to guide particles that would otherwise easily brush past the edge of the sieve holes into the holes smoothly, and prevent particles from bouncing off the outer wall of the sieve holes, thus helping to increase the probability of sputtered particles passing through the sieve holes and entering the outer space.

[0041] Optionally, the walls of the sieve holes on the first shield 10 are smooth surfaces.

[0042] Specifically, the surface roughness Ra of the sieve hole wall is ≤0.4μm.

[0043] By forming a smooth and flat contact surface on the inner wall of the sieve holes, the probability of sputtered particles adhering to the hole wall can be reduced, and particles can be prevented from adhering and accumulating inside the holes. This reduces the risk of sieve hole blockage and ensures that sputtered particles can pass smoothly through the sieve holes and enter the outer ring space, ensuring the long-term stability and smoothness of the particle guidance path.

[0044] Optionally, the inner wall surface of the first shield 10 is a rough surface with a roughness Ra of 1.6 μm to 3.2 μm, which is used to mechanically anchor the sputtered particles attached thereto.

[0045] Specifically, the inner wall of the first shield 10 can be surface-processed by sandblasting to precisely control its roughness to Ra1.6μm~3.2μm.

[0046] This roughness range provides microscopic anchor points for sputtered particles, allowing a small number of particles adhering to the inner wall to form a stable mechanical anchor after embedding in the pits, making them less likely to detach. It also maintains a moderate anchoring force, avoiding problems such as insufficient particle adhesion and susceptibility to vibration or thermal stress detachment when the roughness is below Ra1.6μm. At the same time, it prevents particles from being over-captured and unable to enter the sieve holes smoothly when the roughness is above Ra3.2μm. This ensures that the vast majority of sputtered particles can preferentially enter the sieve holes to complete the flow, while guaranteeing the firm adhesion of the small number of adhering particles.

[0047] Optionally, the inner wall surface of the first shield 10 is coated with the same material as the target 2 to enhance the adhesion of sputtered particles attached thereto.

[0048] Coating the inner wall surface of the first shield 10 with a coating of the same material as the target 2 allows the sputtered particles to form a homogeneous bond with the coating substrate, thereby enhancing the adhesion of the particles by relying on the strong affinity between the materials.

[0049] Specifically, the substrate of the first shielding element 10 is preferably made of stainless steel 304 / 316L or titanium alloy. These substrates have a natural affinity with common sputtering materials such as Al, Ti, and Cu. When combined with a homogeneous coating, the adhesion effect can be further enhanced.

[0050] For example, when the target material 2 is aluminum, an aluminum coating with a thickness of 5~20μm is constructed on the inner wall surface of the first shield 10 by pre-sputtering deposition or plasma spraying, so that the sputtered aluminum particles and the inner wall coating form a completely homogeneous bond, allowing the particles attached to the inner wall to have extremely strong adhesion and not fall off due to process vibration, thermal stress changes or subsequent particle impacts, while not hindering the majority of sputtered particles from preferentially entering the sieve holes and achieving directional flow.

[0051] Optionally, the inner wall surface of the third shield 30 is a rough surface with a roughness Ra≥6.3μm.

[0052] Specifically, an extremely rough surface with a roughness Ra≥6.3μm can be formed on the inner wall of the third shield 30 by deep sandblasting or shot peening. Furthermore, a circumferential V-groove can be machined on the inner wall of the third shield 30 to form a labyrinth-type anchoring structure.

[0053] This provides a larger specific surface area and stronger retention capacity for sputtered particles that pass through the sieve holes and enter the outer space, allowing the particles to embed into the rough microstructure or the circumferential groove and be mechanically locked after impacting the inner wall of the third shield 30. At this point, even if the attached particles are continuously bombarded by subsequent particles, they are difficult to release again, thus preventing the particles from rebounding back into the inner space and causing secondary pollution.

[0054] Optionally, the inner wall of the third shield 30 is provided with an circumferential groove or fin structure to increase the specific surface area and firmly lock the sputtered particles.

[0055] Specifically, the circumferential groove is a groove structure machined circumferentially on the inner wall of the third shield 30, while the fin structure is a sheet-like protrusion structure integrally formed or assembled on the inner wall.

[0056] By adding this type of structure, the inner wall morphology can be optimized, making the surface area of ​​the inner wall of the third shield 30 2 to 5 times that of a smooth cylinder of the same size. The larger specific surface area can effectively increase the total capacity of the device to receive sputtered particles, reduce the probability of rapid particle accumulation and overload, thereby extending the cleaning and maintenance cycle of the shield. At the same time, in conjunction with the roughening treatment of the inner wall, it can more firmly lock the sputtered particles passing through the sieve holes, preventing particles from rebounding or falling off.

[0057] Optionally, only the lower middle part of the first shielding member 10 is provided with sieve holes, the overall opening rate of the first shielding member 10 is 20%~60%, and the sieve holes on the first shielding member 10 are evenly distributed along its circumference and staggered along its axial direction.

[0058] For details, please refer to Figure 1 or Figure 2 In the illustrated embodiment, the first shielding member 10 has sieve holes only in its lower middle part, while its upper part (the area near the target material 2) has no sieve holes or maintains an extremely low opening ratio. In this way, high-energy particles can be initially shielded, preventing particles from flying directly out of the inner space and affecting the particle concentration in the sputtering process area.

[0059] Setting the overall open area ratio of the first shielding member 10 to 20%~60% can avoid the problem of insufficient particle guidance effect and most particles still adhering to the inner wall when the open area ratio is less than 20%, and can also prevent the structural strength of the first shielding member 10 from decreasing due to the open area ratio being greater than 60%.

[0060] Furthermore, the sieve holes are evenly distributed circumferentially to ensure the uniformity of particle guidance in all directions. At the same time, the honeycomb-shaped staggered arrangement of the sieve holes can avoid the formation of axial or circumferential straight gaps.

[0061] In one specific embodiment, the starting position of the sieve holes is set 30mm below the lower edge of the target material 2, and the ending position is set 5mm above the upper edge of the wafer inlet and outlet. The overall aperture ratio is controlled at 30%. Each row of sieve holes is evenly distributed equidistantly along the circumference, but multiple rows of sieve holes are arranged in a honeycomb pattern in the axial direction. In this way, sputtered particles can enter the outer ring space efficiently along the trajectory, while maintaining the structural strength of the first shielding member 10.

[0062] Optionally, the air inlet of the process chamber 1 is directly connected to the inner ring space, and the air outlet of the process chamber 1 is located outside the third shield 30, so that the air pressure in the outer ring space is lower than that in the inner ring space during magnetron sputtering, so as to form an airflow from the inner ring space, through the sieve holes, to the outer ring space.

[0063] Specifically, the air inlet of the process chamber is connected to the inner space (air can flow downwards from the top or inwards from the side, the specific air inlet position is not limited), while the air outlet is arranged at the lower part or bottom of the process chamber 1. To facilitate the flow of gas through the third shield 30 to the air outlet, an air outlet can be provided at the lower part or bottom of the third shield 30, or the third shield 30 can be configured as a partially sealed structure (such as providing a clearance hole, see below for details) to achieve airflow.

[0064] During magnetron sputtering, by adjusting the opening of the extraction valve and the air flow rate, the pressure in the outer space can be controlled to be 1 to 10 Pa lower than that in the inner space. Thus, the process gas flows into the inner space from the inlet, then enters the outer space through the sieve holes, and finally flows out of the outer space through the outlet or clearance holes, towards the extraction port, and is ultimately extracted, forming a directional micro-flow from the inner space, through the sieve holes, to the outer space. This airflow path actively carries suspended particles and secondary sputtered particles towards the outer space to improve the sieve hole capture efficiency, and also removes detached film fragments from the inner space, thereby reducing the risk of wafer contamination. Furthermore, the reasonable pressure differential control does not interfere with the stability of the plasma discharge.

[0065] Optionally, the first shield 10 and the third shield 30 are electrically insulated from each other, and the first shield 10 is grounded and the third shield 30 is connected to a positive bias power supply to form an electric field pointing towards the outer space between them, thereby guiding charged particles to move towards the sieve holes.

[0066] Specifically, the first shield 10 and the third shield 30 are physically isolated and electrically insulated from each other by insulating pads and insulating support components. The electrical insulation design can block the conductive path between the two and ensure that their potentials are independent of each other.

[0067] To create a directional electric field pointing towards the outer space and guide charged particles toward the sieve apertures, the third shield 30 needs to be at a positive potential relative to the first shield 10. Therefore, the third shield 30 is connected to a weak positive bias power supply with an output of +5V to +10V (or an auxiliary electrode ring is placed between the outer wall of the third shield 30 and the inner wall of the cavity, and a weak positive bias voltage (+5V to +10V) is applied to the auxiliary electrode ring. The auxiliary electrode ring does not contact the plasma, but will induce a small potential difference on the inner wall of the third shield 30 through capacitive coupling). This low-amplitude bias voltage will not interfere with the plasma discharge of magnetron sputtering, will not adversely affect the normal process of magnetron sputtering, and can achieve directional guidance of charged particles.

[0068] In one embodiment, when the second cover 20 rises to the process position with the lifting platform 3, the skirt 21 directly contacts the first cover 10, so that the first cover 10 and the second cover 20 are tightly connected.

[0069] By ensuring a tight connection between the first shielding element 10 and the second shielding element 20, the inner space can remain relatively completely sealed, preventing sputtered particles from entering the gap between them and depositing and sticking. Especially... Figure 1 In the illustrated embodiment, when the third shield 30 only surrounds the outside of the first shield 10, the tight connection between the first shield 10 and the second shield 20 prevents sputtered particles from escaping the inner and outer ring spaces through the gap at their connection point. Furthermore, the tight connection ensures a stable and reliable electrical connection between the first shield 10 and the second shield 20, effectively eliminating the micro-arc discharge problem caused by charge accumulation. It also precisely limits the flow and deposition path of the sputtered particles, forcing them to enter the outer ring space only through the sieve holes, maximizing the particle guidance effect.

[0070] However, since the annular contact connection between the first shield 10 and the second shield 20 is directly exposed to the sputtering environment, the tight fit will cause sputtering particles to continuously deposit at the contact interface. As the deposited layer grows and thickens, it will firmly stick the two shields together. In some cases, when the lifting stage 3 descends and causes the second shield 20 to separate from the first shield 10, the stuck deposited layer will be directly torn apart, resulting in a large number of micron-sized contamination particles. These particles are very easy to fall onto the wafer surface and cause wafer defects.

[0071] Optionally, the bottom end face of the first shield 10 and / or the upper surface of the skirt 21 are coated with a low-adhesion coating to reduce the adhesion of sputtered particles at the junction of the first shield 10 and the second shield 20.

[0072] It should be explained that the low-adhesion coating is a low surface energy coating applied to the bottom end face of the first shield 10 and the upper surface of the skirt 21. Specifically, materials such as diamond-like carbon and titanium nitride, which are vacuum-compatible and suitable for the process temperature, can be selected. The coating thickness is controlled between 1 and 3 μm. If conductivity needs to be maintained at the connection between the two shields, the coating can be locally removed by laser to form exposed metal points, or an elastic conductive element 4 can be provided (details below), thus avoiding the coating from affecting the electrical contact effect.

[0073] Setting a low-adhesion coating can significantly reduce the adhesion of sputtered particles at the contact interface, making it difficult for the deposit to form a continuous film. Even if a deposit is formed, it can be peeled off in one piece rather than torn, thus effectively preventing the first shielding member 10 and the second shielding member 20 from sticking together due to the deposit. When the two are separated, there will be no tearing of the deposit layer or generation of micron-sized particles, thus avoiding the pollution problem caused by adhesion at the connection point from the root.

[0074] Optionally, at least the portion of the first shield 10 that contacts the skirt 21 and the portion of the skirt 21 that contacts the first shield 10 are made of different metal materials, so that the sputtered particles have different adhesion to the two, so that the sputtered particles deposited at the junction preferentially detach from the side with weaker adhesion.

[0075] Specifically, at least the bottom of the first shield 10 and the upper surface of the skirt 21 are made of dissimilar metal materials. For example, the first shield 10 can be made of stainless steel 304 and the skirt 21 of aluminum alloy 6061; or, the first shield 10 can be made of titanium alloy Ti-6Al-4V and the skirt 21 of stainless steel; or, the first shield 10 can be made of molybdenum and the skirt 21 of stainless steel. This application does not limit the specific material of the shield, and the material can be selected according to the actual process requirements.

[0076] Because sputtered particles exhibit significant differences in adhesion to different metal substrates, the deposited film preferentially and firmly adheres to one of the surfaces, thus forming a natural weak interface at the contact point between the two surfaces. When the lifting platform 3 descends, causing the second shield 20 to separate from the first shield 10, the deposited film will crack completely directly at the weak interface, rather than tearing in the middle of the film. This also avoids contamination problems caused by adhesion at the connection point from the outset.

[0077] Optionally, the first shield 10 or the second shield 20 is provided with a purge air hole, which is connected to an external air source to form an airflow barrier at the connection point, thereby preventing sputtered particles from depositing there.

[0078] Specifically, the purge vents can be located at the lower part or bottom of the first shield 10, or inside the skirt 21 of the second shield 20, close to the connection point of the two shields. Multiple purge vents can be evenly distributed along the axial direction, or arranged in an annular vent structure to ensure complete coverage of the connection point by the purge gas. The purge vents are connected to an external gas source; argon can be used as the purge gas, or process gas if necessary.

[0079] During the magnetron sputtering process, a micro-flow rate of 1-10 sccm of purge gas is continuously introduced through purge vents and directed towards the junction of the first shield 10 and the second shield 20, forming a stable gas curtain barrier. The micro-flow purge gas supply can actively remove sputtered particles and prevent particle deposition at the contact interface without interfering with the plasma discharge of magnetron sputtering.

[0080] In another embodiment, when the lifting platform 3 rises to the process position, there is a preset gap between the first shield 10 and the skirt 21. The preset gap forms an annular channel, allowing sputtered particles to pass through the preset gap and enter the outer ring space, thereby preventing particles from depositing at the connection between the first shield 10 and the second shield 20.

[0081] To maintain a preset gap, it can be achieved by controlling the rising range of the lifting platform 3, or by placing limiting pads (such as elastic conductive parts 4) at the bottom of the first cover 10 or at the corresponding position of the skirt 21, and providing limiting support for both when the lifting platform 3 rises to the process position.

[0082] The reserved annular pre-set gap can serve as an independent passageway, allowing sputtered particles in the inner space to flow directly into the outer space along the passageway, thereby completely avoiding the docking contact position of the first shield 10 and the second shield 20. This eliminates the root cause of sputtered particles adhering and depositing at this location, and also completely eliminates the problem of the deposition layer tearing and impurity particles being generated during subsequent structural separation.

[0083] Optionally, the height of the preset gap is 0.1mm to 2.0mm.

[0084] If the gap value is too small (<0.1mm), it will still easily cause particles to accumulate and stagnate. If the value is too large (greater than 2.0mm), it will disrupt the particle movement trajectory in the inner space and affect the normal flow guidance effect. A reasonable gap can balance the flowability and the spatial enclosure effect.

[0085] It should be noted that when leaving the preset gap, it is necessary to ensure that the second shield 20 is also wrapped by the third shield 30 and that the gap is blocked by the outer ring space, so as to prevent sputtering particles from escaping through the gap and contaminating the process cavity 1 (see below for details).

[0086] In one embodiment, the skirt 21 is also provided with sieve holes; at least when the second shield 20 rises with the lifting platform 3 to the process position, the third shield 30 can surround the part of the skirt 21 with sieve holes.

[0087] Creating a sieve hole on the skirt 21 can add a particle flow channel to guide excess sputtering particles in the lower part of the inner space, near the wafer and the lifting stage 3, relieve the particle flow pressure of the first shield 10, accelerate the speed at which excess particles in the inner circle are discharged outward, reduce the accumulation and adhesion of particles in the lower part of the inner circle, further improve the effect of particle diversion and guidance in the whole area, and allow excess sputtering particles in different positions to flow outward smoothly.

[0088] For details, please refer to Figures 2 to 4 In the illustrated embodiment, the second shield 20 and the platform of the lifting platform 3 are always enclosed within the third shield 30. The bottom of the third shield 30 is an annular baffle extending inward to below the skirt 21, which can effectively catch sputtered particles falling from the sieve holes on the skirt 21.

[0089] In one embodiment, the second shield 20 further includes a sleeve portion 22 and a hanging edge 23 provided on the top of the sleeve portion 22. The hanging edge 23 extends inward and can cover the edge of the lifting platform 3 to form a groove on the lifting platform 3 for accommodating the wafer.

[0090] For details, please refer to Figure 1 or Figure 2 In the illustrated embodiment, the sleeve portion 22 is a hollow cylindrical structure that can be fitted onto the outside of the platform of the lifting platform 3. The hanging edge 23 is integrally set at the top of the sleeve portion 22 and extends horizontally inward. The skirt edge 21 extends outward from the bottom of the sleeve portion 22. The three are integrally formed to constitute a complete second cover structure.

[0091] During assembly, the skirt 21 is inserted into the sleeve 22 at the bottom of the platform. After the platform surface abuts against the hanging edge 23, it overlaps with the edge of the platform surface, thus completing the positioning and installation of the second shield 20 and the lifting platform 3 through a hanging and overlapping method. At this time, the hanging edge 23 forms a receiving groove on the platform surface that can stably place the wafer. The receiving groove can realize the limited placement of the wafer, preventing the wafer from shifting position, and also protecting the main body of the platform, preventing sputtering particles from depositing in areas not covered by the wafer and causing contamination. This hanging structure also simplifies the disassembly and assembly process, and facilitates the cleaning of the shield on a regular or as-needed basis.

[0092] Optionally, the top surface of the hanging edge 23 is inclined downward toward the center of the lifting platform 3, so that the groove has a wide opening and a narrow bottom.

[0093] For details, please refer to Figure 1In the illustrated embodiment, the top surface of the hanging edge 23 extends inward and slopes downward toward the center of the lifting platform 3. Due to this slope, the wafer receiving groove formed by the hanging edge 23 and the platform surface has a wide opening and gradually narrows at the bottom. This inclined configuration provides a natural guiding effect when placing the wafer, reducing the difficulty of wafer placement and alignment. Simultaneously, the inclined top surface can also prevent scattered sputtering particles from entering the groove and adhering to the sides and edges of the wafer, further optimizing the anti-sputtering effect.

[0094] Optionally, one of the second cover 20 and the lifting platform 3 is provided with a limiting groove, and the other is provided with a limiting block. The limiting groove includes an axially extending entry part and a circumferential locking part communicating with the entry part. During installation, the limiting block enters the limiting groove along the entry part, and then the second cover 20 is rotated to make the limiting block enter the circumferential locking part, thereby realizing the circumferential locking and axial anti-disengagement of the second cover 20.

[0095] Specifically, at least two sets of limiting grooves can be provided on the inner wall of the sleeve portion 22, and corresponding limiting blocks can be provided on the outer peripheral wall of the lifting platform 3; for convenient rotation, the at least two sets of limiting grooves are distributed in a centrally symmetrical manner. Alternatively, at least two sets of limiting grooves can be provided on the outer peripheral wall of the lifting platform 3, and corresponding limiting blocks can be provided on the inner wall of the sleeve portion 22. This application does not limit the specific installation position and quantity of the limiting grooves and limiting blocks, as long as they can correspond to each other and allow for optional assembly and disassembly.

[0096] More specifically, the limiting groove includes an axially extending straight entry portion and a circumferential locking portion communicating with it. The limiting groove is L-shaped and is a one-piece groove structure. The limiting block is a raised block structure adapted to the size of the groove.

[0097] During assembly, first let the limiting block slide into the limiting groove along the entry part. After it is in place, the limiting block is facing the circumferential locking part. Then rotate the second cover 20 so that the limiting block can slide into the circumferential locking part and complete the locking.

[0098] This mating structure not only provides axial anti-fall-off limiting but also locks and secures the circumferential position. It effectively prevents the second shielding component 20 from circumferential deflection or axial loosening and displacement when it moves with the lifting platform 3, thus maintaining the stability of the shielding component's position and ensuring the stability of the spatial structure and particle flow channel formed by the shielding components. Furthermore, the assembly and disassembly process required by this structure is simple, facilitating future inspection and replacement of the second shielding component 20.

[0099] Optionally, the end of the circumferential locking part is provided with an elastic anti-reverse protrusion or a recessed groove to prevent accidental loosening due to vibration or during the process.

[0100] Specifically, the elastic locking protrusion is located on the groove wall at the end of the circumferential locking part. It can be made of a metal stamping structure, a combination of an internal spring and a positioning ball, or an elastic material such as polyurethane. When the limit block enters the locking position, external force needs to be applied to overcome the elastic resistance of the protrusion to smoothly pass over the protrusion. After reaching the position, the elastic protrusion automatically springs back to complete the locking, thus restricting the limit block within a fixed area. In this way, the elastic locking action effectively prevents the limit block from rotating back and loosening during daily use. When disassembling, only a slightly larger reverse rotational force needs to be applied to overcome the elastic resistance again to complete the unlocking. This structure provides a clear locking feel and audible indication during installation, has strong adaptability to manufacturing tolerances, can meet the needs of multiple disassembly and assembly, and effectively resists displacement caused by slight vibrations of the equipment.

[0101] The recessed groove is a shallow pit structure formed directly at the bottom of the groove at the end of the circumferential locking part. It can be circular, elliptical, or elongated. After the limiting block rotates into the end of the circumferential locking part, it will naturally fall into the recess under its own weight or the pushing action of the matching elastic washer. To disengage it, the limiting block needs to be lifted to overcome gravity or auxiliary elastic force. The sidewall of the recess further restricts the reverse circumferential rotation of the shielding part, ensuring the positional stability of the shielding part after installation. This structure requires no additional moving parts, is not prone to wear and damage after machining, and has a simple and reliable overall structure. Utilizing the low vibration environment under magnetron sputtering conditions, it can stably lock the assembly position, preventing accidental loosening of the second shielding part 20 during process operation.

[0102] In one embodiment, the third shield 30 is cylindrical, with an open top for inserting the first shield 10, and openings on its sides corresponding to the wafer inlet and outlet of the process cavity 1. A clearance hole is provided at the center of its bottom. The connecting part of the lifting platform 3 passes through the clearance hole and is connected to an external lifting drive. At least the portion of the first shield 10 with sieve holes, the platform portion of the lifting platform 3, and the second shield 20 are located within the outer ring space formed by the third shield 30. The bottom wall of the third shield 30 is annular, and the skirt 21 is directly opposite the bottom wall of the third shield 30.

[0103] For details, please refer to Figure 4 In the illustrated embodiment, the third shield 30 is a cylindrical structure with an open top that allows the first shield 10 to be inserted vertically from above; the side of the cylinder has an opening aligned with the wafer inlet and outlet of the process cavity 1; a circular clearance hole is reserved at the center of the bottom, and the bottom wall has an annular structure.

[0104] During assembly, the transmission connection part of the lifting platform 3 can extend out of the cavity through the bottom clearance hole and connect with the external lifting drive structure (such as a cylinder, electric cylinder, etc.). The main body section of the first cover 10 with the screen hole is inserted and positioned inward from the top opening of the third cover 30, so that the opening section of the first cover 10, the platform of the lifting platform 3, and the entire second cover 20 are inside the cylinder of the third cover 30. At the same time, the skirt 21 extending from the outside of the second cover 20 is exactly aligned with the annular bottom wall of the third cover 30.

[0105] This nested assembly layout does not obstruct the normal lifting and lowering movement of the lifting platform. The reserved openings on the side facilitate wafer loading and unloading operations. The side walls can receive sputtered particles flowing out of the sieve holes of the first shield 10, and the annular bottom wall can receive sputtered particles flowing out of the sieve holes of the second shield 20. The cylindrical enclosure forms a complete and independent outer ring space, which can constrain all outwardly directed particles inside the cylinder, thereby effectively preventing particles from flowing back to the inner coating operation area.

[0106] Optionally, the inner diameter of the clearance hole is larger than the outer diameter of the platform 3, and the inner circumference of the bottom wall is provided with an annular dust barrier to prevent particles deposited in the outer space from escaping from the clearance hole.

[0107] The inner diameter of the clearance hole is designed to be larger than the outer diameter of the lifting platform 3 to allow sufficient room for disassembly and assembly, so that various shielding parts can be removed from the process cavity 1 later.

[0108] However, this design also has drawbacks. The reserved annular gap allows sputtered particles in the outer space to scatter outwards along the gap, causing pollution.

[0109] Adding an annular dust-blocking component can create a shield at the clearance hole, preventing deposited particles in the outer space from escaping outward through the clearance hole.

[0110] In one embodiment, the annular dust baffle is a telescopic bellows. The upper end of the bellows is sealed to the bottom surface of the skirt 21 of the second baffle 20, and the lower end is sealed to the front surface of the bottom wall of the third baffle 30. The connecting part of the lifting platform 3 passes through the bellows.

[0111] Relying on the bellows' ability to freely expand and contract, it not only achieves full-circumference sealing of the clearance holes to prevent dust and particle leakage, but also moves with the lifting platform 3 and the second shield 20 without restricting the normal operation of the equipment. When disassembling and cleaning the shields, the second shield 20, the third shield 30, and the bellows can be removed simultaneously, and all three can be disassembled or processed together as needed.

[0112] In another embodiment, a vacuum-adapted high-density flexible felt ring is selected as an annular dust-blocking component. The felt ring is embedded in the inner ring of the clearance hole, so that the inner side of the felt tightly fits the outer wall of the lifting platform 3 connection part, and the sputtered particles can be intercepted by the dense fiber structure.

[0113] This application does not limit the specific configuration of the annular dust baffle, as long as it can prevent sputtered particles in the outer ring space from escaping through the clearance hole.

[0114] In one embodiment, the top of the third cover 30 is provided with an outwardly extending mounting strip 31, and the outer periphery of the first cover 10 is provided with a hanging strip 11. The first cover 10 can be detachably hung in the third cover 30 through the hanging strip 11 and the mounting strip 31. The inner wall of the process cavity 1 is provided with a ring of supporting steps, and the third cover 30 can be detachably hung in the process cavity 1 through the mounting strip 31 and the supporting steps.

[0115] For details, please refer to Figures 2 to 4 In the illustrated embodiment, the mounting strip 31 is an annular outward-extending flange structure integrally formed on the top of the third cover 30; the hanging strip 11 is an annular protrusion surrounding the outer wall of the first cover 10; and the supporting step is an annular receiving platform surrounding the inner wall of the process cavity 1 and protruding inward.

[0116] In use, first, place the third cover 30 into the process cavity 1 from top to bottom, so that the mounting strip 31 rests on the support step, thus suspending the third cover 30 inside the process cavity 1. Then, mount the second cover 20 onto the lifting platform 3. Next, place the first cover 10 into the third cover 30 from top to bottom, so that the hanging strip 11 rests on the mounting strip 31, completing the arrangement of the three covers inside the cavity. For disassembly, simply lift upwards to remove each cover in sequence.

[0117] This hanging assembly structure eliminates a large number of fastening parts, making it easy to disassemble and clean the shielding components. At the same time, the hanging and limiting method can ensure that each shielding component is coaxially aligned, accurately maintaining the shape of the inner and outer ring spaces and the particle flow path, and adapting to the routine use and maintenance needs of magnetron sputtering equipment.

[0118] To improve the stability of the mounting connection, after the first cover 10 is mounted on the third cover 30, the mounting strip 11 and the installation strip 31 can be locked together with screws. Similarly, after the third cover 30 is mounted in the process cavity 1, the installation strip 31 and the support step can be locked together with screws.

[0119] Specifically, aligned mounting holes (at least the mounting holes on the support step should be screw holes) can be evenly drilled in advance at the corresponding positions of the hanging strip 11, mounting strip 31 and support step. After the two cover parts are installed in place, ensure that the holes correspond and overlap one by one, insert the appropriate screws and tighten them to complete the locking and fixing.

[0120] It is easy to understand that simply relying on hanging placement can easily lead to positional displacement and slight shaking under the vibration of equipment operation and the impact of airflow inside the cavity. Adding screws for locking can further compact and fit the connection parts, firmly lock the relative positions of each component, effectively maintain the coaxiality and preset position between the shielding parts, stably maintain the airflow direction, electric field distribution and particle guide channel shape inside the cavity, avoid component misalignment affecting the sputtering process effect, and at the same time prevent components from bumping and wearing each other. While retaining the advantages of convenient assembly and disassembly of the hanging structure, it improves the overall assembly firmness and equipment operation stability.

[0121] Optionally, a reinforcing edge 12 is provided on the lower outer periphery of the first shield 10, and a gap is left between the reinforcing edge 12 and the inner wall of the third shield 30 to increase the structural strength of the first shield 10 and form an airflow buffer gap.

[0122] For details, please refer to Figure 4 In the illustrated embodiment, the lower outer periphery of the first shield 10 is provided with a ring-shaped reinforcing edge 12, which is integrally formed with the first shield 10 and is located in the area where the sieve holes are provided.

[0123] The reinforcing edge 12 can thicken and reinforce the lower area of ​​the first shield 10 with sieve holes, thereby improving the overall structural rigidity of the first shield 10 to resist the deformation stress caused by temperature fluctuations and airflow impact in the cavity, prevent the shield from bending and warping, and stabilize the arrangement of sieve holes and the overall shape.

[0124] Meanwhile, a gap is reserved between the reinforcing edge 12 and the inner wall of the third shield 30, which can form a natural airflow buffer space, smooth the process airflow passing through this place, reduce the generation of turbulence, and also buffer the impact force brought by the airflow carrying particles, reduce the wear of the inner wall, and will not occupy the particle flow space, nor interfere with the normal flow direction of particles passing through the sieve holes, thus taking into account the dual functions of structural reinforcement and smooth airflow.

[0125] Optionally, the magnetron sputtering device with particle guidance and multi-layer shielding functions provided in this application further includes an elastic conductive element 4, which is disposed on the skirt 21 and located directly below the first shield 10; the first shield 10 is grounded; when the second shield 20 rises to the process position with the lifting platform 3, the first shield 10 can press against the elastic conductive element 4, thereby achieving low-resistance grounding of the second shield 20.

[0126] For details, please refer to Figure 2 and Figure 3 In the illustrated embodiment, the elastic conductive element 4 is a conductive elastic component (such as a sheet or spring made of conductive material) with good conductivity and elastic compressibility, which is fixedly arranged on the upper surface of the skirt 21 and located directly below the first shield 10.

[0127] When the second shield 20 rises to the process position along with the lifting platform 3, the bottom of the first shield 10 presses down against the elastic conductive element 4, thereby achieving a tight fit and conduction through the elasticity of the conductive element 4 itself. Since the first shield 10 is in a grounded state, the second shield 20 can form a low-resistance conductive loop through the elastic conductive element 4, completing reliable grounding. In this way, the static electricity and excess charge accumulated on the surface of the second shield 20 under sputtering conditions can be discharged in a timely manner, effectively preventing charge accumulation, abnormal arcing and random discharge phenomena in the cavity, and ensuring stable and orderly discharge of magnetron sputtering plasma. At the same time, the elastic structure can also adapt to assembly deviations and contact gaps, always maintaining a stable conductive contact effect without interfering with the spatial layout between shields and the normal passage of particles.

[0128] In one embodiment, the upper surface of the skirt 21 of the second cover member 20 is provided with an inner groove, the elastic conductive member 4 is disposed in the inner groove, and its height in the free state is higher than the depth of the groove; or, the bottom surface of the first cover member 10 is provided with an inner groove; when the first cover member 10 abuts against the second cover member 20, the elastic conductive member 4 is compressed and accommodated in the inner groove.

[0129] Specifically, the recessed groove is used to embed the elastic conductive element 4, which can be hidden and stored by relying on the space of the groove. Since the height of the elastic conductive element 4 is higher than the depth of the groove in its natural state, when the first shield 10 and the second shield 20 abut against each other, the elastic conductive element 4 will inevitably be squeezed and incorporated into the recessed groove after shrinking.

[0130] By concealing the elastic conductive element 4 with an indentation, it is possible to prevent the elastic conductive element 4 from protruding outward and obstructing the mating surface, so that the first and second shielding elements can fit tightly together. At the same time, the indentation can form a circumferential limit on the elastic conductive element 4, preventing the conductive element from shifting or slipping during the lifting and vibration of the equipment. It can also limit its compression stroke, preventing excessive pressure from causing elastic failure. In addition, it can prevent splashed dust and fine debris from accumulating at the conductive contact position, keeping the contact point clean and unobstructed at all times, and maintaining a stable low-resistance grounding conductivity.

[0131] Optionally, the magnetron sputtering apparatus with particle guidance and multi-layer shielding functions provided in this application further includes: a fourth shield 40 for shielding the wafer inlet and outlet on the third shield 30; and a shielding drive 40a for driving the fourth shield 40 closer to or further away from the wafer inlet and outlet.

[0132] For details, please refer to Figure 2 and Figure 3In the illustrated embodiment, the fourth shield 40 is a sealing plate whose shape is adapted to the wafer inlet and outlet, and its overall size can completely cover the wafer passage opening (i.e., the aforementioned passage opening) on ​​the side of the third shield 30. The shielding drive 40a can be a lifting drive such as a cylinder or electric cylinder. The fixed end of the shielding drive 40a is installed on the outside of the process cavity 1 near the wafer inlet and outlet, and the output end extends into the cavity and is connected to the fourth shield 40. The fourth shield 40 is directly opposite the wafer inlet and outlet of the third shield 30. During operation, the shielding drive 40a drives the fourth shield 40 to perform reciprocating lifting and lowering movements, thereby achieving the sealing and separation of the fourth shield 40 from the inlet and outlet.

[0133] In other embodiments, the wafer inlet and outlet of the third shield 30 can also be blocked by translating or oscillating the fourth shield 40. This application does not limit the specific configuration of the fourth shield 40 and the shielding drive 40a, as long as the two can cooperate to achieve the blocking and opening of the wafer inlet and outlet.

[0134] More specifically, during the wafer loading and unloading stage, the shielding drive 40a drives the fourth shield 40 away from the opening, leaving a clear passage for the wafer to enter and exit; after entering the sputtering coating process, the shielding drive 40a drives the fourth shield 40 to approach or even adhere to the wafer inlet and outlet, which can prevent sputtering particles in the outer aperture from escaping outward from the opening, so as to maintain the pressure difference and particle flow direction between the inner and outer spaces.

[0135] Optionally, the fourth shield 40 is grounded via a flexible conductive wire or an elastic contact piece.

[0136] It should be explained that the fourth shielding element 40 is constantly exposed to the cavity sputtering environment, making it highly susceptible to contact with plasma and various charged particles. Static charges easily accumulate on its surface. This charge buildup not only disrupts the predetermined electric field distribution within the cavity and affects the normal guiding trajectory of particles, but also easily induces localized abnormal discharges. Grounding can quickly dissipate the accumulated charge, stabilizing the process environment within the cavity and mitigating potential discharge hazards.

[0137] In one embodiment, a flexible conductive wire is laid, with one end of the cable connected to the fourth shield 40 and the other end connected to the unified grounding circuit of the device. The flexible wire can adapt to the reciprocating movement of the fourth shield 40 without being pulled or stuck.

[0138] In another embodiment, an elastic contact piece is assembled and fixed to the grounded cavity sidewall or the third shield 30. The elastic contact piece continuously adheres to the fourth shield in the active state by its own elasticity, thereby maintaining conductive connection.

[0139] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A magnetron sputtering apparatus with particle guidance and multi-layer shielding functions, comprising a process chamber (1), a target (2), and a lifting platform (3), characterized in that, Also includes: A first shield (10) is disposed on the upper part of the process cavity (1) and surrounds the target material (2). The first shield (10) has multiple sieve holes. The second cover (20) is disposed on the lifting platform (3) and can move up and down with the lifting platform (3) to move closer to or away from the first cover (10). The second cover (20) includes a skirt (21) extending outward from the outer periphery of the lifting platform (3). The third shield (30) is arranged in a ring within the process cavity (1) and at least surrounds the portion of the first shield (10) with the sieve holes. When the lifting platform (3) rises to the process position, the skirt (21) can abut against the first shield (10), and the first shield (10) and the second shield (20) can cooperate to form an inner circle space. At least the platform portion of the lifting platform (3) used to support the wafer and the target surface of the target material (2) are in the inner circle space, and the inner circle space can limit the deposition area of ​​sputtered particles. The third shielding element (30) is disposed around the inner ring space and forms an outer ring space surrounding the inner ring space; The sieve holes connect the inner ring space and the outer ring space. The sieve holes can guide sputtered particles from the inner ring space into the outer ring space and deposit them on the third shield (30). The air inlet of the process cavity (1) is directly connected to the inner ring space, and the air outlet of the process cavity (1) is located outside the third shield (30) to form an airflow from the inner ring space, through the sieve holes, to the outer ring space; The skirt edge (21) is also provided with sieve holes; At least when the second shield (20) rises to the process position with the lifting platform (3), the third shield (30) is able to surround the portion of the skirt (21) with sieve holes.

2. The magnetron sputtering apparatus with particle guidance and multi-layer shielding functions according to claim 1, characterized in that, The sieve holes on the first shield (10) are oblique holes, and the hole axis of the sieve holes is inclined toward the target material (2) so as to guide sputtered particles into and through the sieve holes; And / or, the incident side of the sieve hole on the first shield (10) is provided with a flared chamfer or is provided with a flared mouth structure to increase the capture aperture of sputtered particles; And / or, the sieve hole walls on the first shield (10) have a smooth surface; And / or, the inner wall surface of the first shield (10) is a rough surface with a roughness Ra of 1.6 μm to 3.2 μm, which is used to make the sputtered particles attached thereto form a mechanical anchor; And / or, the inner wall surface of the first shield (10) is coated with the same material as the target (2) to enhance the adhesion of sputtered particles attached thereto; And / or, the inner wall surface of the third shield (30) is a rough surface with a roughness Ra≥6.3μm; And / or, the inner wall of the third shield (30) is provided with circumferential grooves or fin structures to increase the specific surface area and firmly lock the sputtered particles; And / or, only the lower middle part of the first shield (10) is provided with sieve holes, the overall opening rate of the first shield (10) is 20%~60%, and the sieve holes on the first shield (10) are evenly distributed along its circumference and staggered along its axial direction. And / or, the first shield (10) and the third shield (30) are electrically insulated from each other, and the first shield (10) is grounded and the third shield (30) is connected to a positive bias power supply to form an electric field between them pointing toward the outer ring space, thereby guiding charged particles toward the sieve holes.

3. The magnetron sputtering apparatus with particle guidance and multi-layer shielding functions according to claim 1, characterized in that, The bottom end face of the first shield (10) and / or the upper surface of the skirt (21) are coated with a low-adhesion coating to reduce the adhesion of sputtered particles at the junction of the first shield (10) and the second shield (20); And / or, at least the portion of the first shield (10) that contacts the skirt (21) and the portion of the skirt (21) that contacts the first shield (10) are made of different metal materials, so that the sputtered particles have different adhesion to the two, so that the sputtered particles deposited at the junction preferentially detach from the side with weaker adhesion. And / or, the first shield (10) or the second shield (20) is provided with a purge air hole, which is connected to an external air source to form an airflow barrier at the connection point, thereby preventing sputtered particles from depositing there; And / or, when the lifting platform (3) rises to the process position, there is a preset gap between the first shield (10) and the skirt (21), the preset gap forms an annular channel, and the sputtered particles can pass through the preset gap and enter the outer ring space, thereby avoiding particle deposition at the connection.

4. The magnetron sputtering apparatus with particle guidance and multi-layer shielding functions according to claim 1, characterized in that, The second shield (20) also includes a sleeve portion (22) and a hanging edge (23) provided on the top of the sleeve portion (22), the hanging edge (23) extending inward and able to cover the edge of the platform of the lifting platform (3) to form a groove for accommodating the wafer on the lifting platform (3).

5. The magnetron sputtering apparatus with particle guidance and multi-layer shielding functions according to claim 4, characterized in that, The top surface of the hanging edge (23) is inclined downward toward the center of the lifting platform (3), so that the groove has a wide opening and a narrow bottom. And / or, one of the second cover (20) and the lifting platform (3) is provided with a limiting groove, and the other is provided with a limiting block. The limiting groove includes an axially extending entry part and a circumferential locking part communicating with the entry part. During installation, the limiting block enters the limiting groove along the entry part, and then the second cover (20) is rotated so that the limiting block enters the circumferential locking part, thereby realizing circumferential locking and axial anti-dislodgement of the second cover (20).

6. The magnetron sputtering apparatus with particle guidance and multi-layer shielding functions according to claim 1, characterized in that, The third shield (30) is cylindrical, with an open top for inserting the first shield (10), and an opening on its side corresponding to the wafer inlet and outlet of the process cavity (1), and a clearance hole at the center of its bottom. The connecting part of the lifting platform (3) passes through the clearance hole and is connected to the external lifting drive; At least the portion of the first shield (10) with the sieve hole, the platform portion of the lifting platform (3), and the second shield (20) are located within the outer ring space formed by the third shield (30); The bottom wall of the third cover (30) is annular, and the skirt (21) is directly opposite the bottom wall of the third cover (30); The inner diameter of the clearance hole is larger than the outer diameter of the platform of the lifting platform (3), and the inner circumference of the bottom wall is provided with an annular dust-blocking component, which is used to prevent particles deposited in the outer ring space from escaping from the clearance hole.

7. The magnetron sputtering apparatus with particle guidance and multi-layer shielding functions according to claim 6, characterized in that, The top of the third cover (30) is provided with an outwardly extending mounting strip (31), and the outer periphery of the first cover (10) is provided with a hanging strip (11). The first cover (10) can be detachably hung in the third cover (30) through the hanging strip (11) and the mounting strip (31). The inner wall of the process cavity (1) is provided with a ring of supporting steps, and the third cover (30) can be detachably hung in the process cavity (1) through the mounting strip (31) and the supporting steps; The lower outer periphery of the first shield (10) is also provided with a reinforcing edge (12), and there is a gap between the reinforcing edge (12) and the inner wall of the third shield (30) to increase the structural strength of the first shield (10) and form an airflow buffer gap.

8. The magnetron sputtering apparatus with particle guidance and multi-layer shielding functions according to claim 1, characterized in that, It also includes an elastic conductive element (4), which is disposed on the skirt (21) and located directly below the first shield (10); The first shield (10) is grounded; When the second shield (20) rises to the process position with the lifting platform (3), the first shield (10) can press against the elastic conductive element (4), thereby achieving low resistance grounding of the second shield (20).

9. The magnetron sputtering apparatus with particle guidance and multi-layer shielding functions according to claim 1, characterized in that, Also includes: The fourth shield (40) is used to shield the wafer inlet and outlet on the third shield (30); A shielding drive (40a) is used to drive the fourth shield (40) closer to or further away from the wafer inlet / outlet.

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