Particle deposition shield for a coating apparatus

Abstract

This application discloses an anti-particle deposition mask for coating equipment, disposed within the coating cavity, comprising an annular upper plate and a lower plate, with a labyrinthine airflow channel formed between the upper and lower plates by staggered and spaced baffles; a 0-2mm gap exists between the outer edge of the mask and the inner wall of the coating cavity, the cavity wall of the coating cavity is grounded, and the gap is constructed into an electron depletion region dominated by positive charge; by intercepting inadvertently entering particles through the labyrinthine channel and blocking particles escaping along the gap through the electron depletion region, the contamination frequency of the lower cavity can be significantly reduced, thereby reducing equipment downtime and maintenance costs; both the labyrinthine airflow channel and the electron depletion region are non-blocking designs, the labyrinthine channel does not obstruct the normal transport of reactive gases, and the electron depletion region does not affect the lifting and lowering of the wafer and the mask, achieving the anti-contamination function while being fully compatible with the process rhythm of existing coating equipment without requiring modification to the main structure of the equipment.

Description

Technical Field

[0001] This application relates to the field of wafer coating equipment technology, and in particular to a particle deposition shielding device for coating equipment. Background Technology

[0002] In plasma coating processes, the shielding element is a key component that separates the reaction area from the lower cavity. Its core function is to block particles (including plasma charged ions, metal particles, etc.) generated during the reaction process, preventing them from falling downwards and contaminating the stage and lower cavity components.

[0003] Existing coating equipment typically uses simple annular thin-plate structures as masking elements, which are only used to shield the wafer edges. To house the masking element, the inner wall of the reaction chamber has a hook-shaped structure. The inner sidewall of this hook-shaped structure supports the masking element, and the bottom of the groove in the hook-shaped structure has an inlet hole through which reactive gases enter and exit the reaction area. During operation, the masking element is lifted away from the hook-shaped structure by the stage and the wafer, allowing deposited particles to escape into the lower chamber through the gap between them. This results in a high frequency of contamination of the lower chamber components, requiring frequent disassembly and cleaning, significantly increasing equipment maintenance costs and process downtime. Summary of the Invention

[0004] The purpose of this application is to overcome the shortcomings of the prior art and provide a particle deposition shielding element for coating equipment.

[0005] This application provides a particle deposition shielding device for a coating equipment, disposed within a coating cavity, comprising an annular upper plate and a lower plate connected to each other, forming a closed space between them; staggered and spaced baffles are provided within the closed space, which complicate the gas flow path within the closed space, constructing the closed space as a labyrinthine airflow channel; a 0-2mm gap exists between the outer edge of the shielding device and the inner wall of the coating cavity, the cavity wall of the coating cavity is grounded, constructing the gap as an electron depletion region dominated by positive charges; an air inlet is provided on the lower plate, and an air outlet is provided on the upper plate; when the coating equipment is operating, the stage... The wafer rises and lifts the shielding device. The reactive gas enters the labyrinth-shaped airflow channel through the inlet, then flows out through the outlet and into the reaction area. Particles entering the labyrinth-shaped airflow channel through the outlet will collide with the baffle due to the tortuous channel and eventually deplete their kinetic energy and settle in the labyrinth-shaped airflow channel. Particles entering the electron depletion region will eventually lose their activity or be unable to break through the gap due to the strong electric field and the separation characteristics of the charge. The labyrinth-shaped airflow channel and the electron depletion region work together to limit the movement range of particles and prevent them from contaminating the stage or the cavity below, thereby ensuring the stability of the coating process and the yield of the thin film.

[0006] Furthermore, the inner wall of the coating cavity is provided with a hanging wall extending towards the center of the cavity, which is used to support the shielding component; the hanging wall is provided with multiple elastic conductive components, which are evenly distributed along the circumference. When the shielding component is placed on the hanging wall, the elastic conductive components are compressed and electrically connected to the shielding component and the cavity wall of the coating cavity, so that the shielding component and the cavity wall form an electrical equipotential connection.

[0007] Furthermore, a groove is provided around the outer edge of the lower surface of the lower plate. When the shield is placed on the wall, the wall is inserted into the groove. In the labyrinth-type airflow channel, a stepped structure is provided in the inner area corresponding to the groove. The stepped structure extends in a stepped shape to form at least one raised step to increase the tortuosity of the labyrinth-type airflow channel. The horizontal step surface is directly opposite the air outlet. The distance between the horizontal step surface and the air outlet is less than the channel width of the main section of the labyrinth-type airflow channel to reduce the activity space of the stray particles and accelerate their kinetic energy depletion.

[0008] Furthermore, the shield is made of titanium or titanium alloy; or, the shield is made of aluminum alloy, and the indirect grounding connection part of the shield is provided with a conductive coating.

[0009] Furthermore, the upper plate and the lower plate are detachably connected; the edges of the upper plate and the lower plate are provided with corresponding positioning holes and positioning pins; the upper surface of the lower plate is provided with a groove, and the inner edge of the upper plate can be inserted into the groove; a sealing ring is provided between the upper plate and the lower plate to prevent gas or particles from escaping from the connection between the two; a conductive ring is also provided between the upper plate and the lower plate to realize the electrical connection between the upper plate and the lower plate.

[0010] Furthermore, the conductive ring is an elastic metal spring made of beryllium copper alloy or silver-plated copper alloy; the cross-sectional shape of the conductive ring is C-shaped, U-shaped or Ω-shaped; the lower surface of the upper plate and / or the upper surface of the lower plate are provided with an annular groove for accommodating the conductive ring, and the conductive ring is fixed in the annular groove by interference fit and is pressed between the upper plate and the lower plate; the conductive ring can provide continuous contact pressure by elastic deformation in order to resist the surface oxidation, micro-unevenness and thermal deformation of the plate, thereby maintaining the electrical connection between the upper plate and the lower plate.

[0011] Furthermore, the baffle includes an upper baffle on the lower surface of the upper plate and a lower baffle on the upper surface of the lower plate. Both the upper and lower baffles are annular structures coaxial with the shielding member. The upper and lower baffles are staggered and spaced apart along the radial direction of the shielding member. The number of baffles is at least 3. The distance between any two adjacent baffles is 2-8 mm. In the enclosed space, the vertical distance between the upper and lower plate surfaces is H1, and the vertical distance between the lower baffle and the lower surface of the upper plate is H2. The values ​​of H1 and H2 are both in the range of 0.5-2 mm, and H1 < H2.

[0012] Furthermore, the inner wall of the labyrinth-shaped airflow channel is coated with a polytetrafluoroethylene (PTFE) anti-stick coating. The PTFE anti-stick coating can change the adhesion state of particles in the labyrinth-shaped airflow channel, transforming it from solid scale to loose accumulation. And / or, the bottom of the labyrinth-shaped airflow channel is provided with an arc-shaped groove, which is located on the downstream side of the baffle or on the outside of the airflow bend, which can maximize the settling efficiency in the low-speed zone and guide and concentrate particles in a designated area.

[0013] Furthermore, the inner edge of the shield is stepped, including a first inclined surface formed by the inner edge of the upper plate, a second inclined surface formed by the inner edge of the lower plate, and a horizontal connecting surface formed by the upper surface of the lower plate between the first and second inclined surfaces. The second inclined surface can capture particles that are incident at a large angle and might otherwise be deposited in the edge region of the wafer. The first inclined surface and the horizontal connecting surface can tighten the opening exposed to the target material, ensuring that the central area of ​​the wafer that needs to be coated is exposed in the particle stream. The end of the inner edge of the shield that abuts against the wafer is provided with a rounded chamfer with a radius of 0.5-1.5 mm, which is used to reduce the contact area between the lower plate and the wafer and prevent them from sticking together.

[0014] Furthermore, the upper plate is provided with multiple air outlets, which are evenly distributed along the circumference. The lower plate is provided with multiple air inlets, which are also evenly distributed along the circumference. The number of air inlets is greater than the number of air outlets, and the total flow area of ​​the air inlets is greater than the total flow area of ​​the air outlets. This is to establish a uniform and stable back pressure in the labyrinth-type airflow channel, ensuring the uniformity of the reaction gas flow and avoiding high-speed airflow from disturbing the plasma stability of the reaction region. And / or, the air inlets are arranged in a trumpet shape, with the diameter of the air inlets increasing the further away from the upper plate. The expansion angle of the air inlets is 45°-60°, so as to guide the reaction gas into the labyrinth-type airflow channel uniformly.

[0015] This application also provides a particle deposition shielding device for coating equipment, disposed within the coating cavity, comprising an annular upper plate and a lower plate, wherein a labyrinthine airflow channel is formed between the upper and lower plates by staggered and spaced baffles; a 0-2mm gap exists between the outer edge of the shielding device and the inner wall of the coating cavity, the cavity wall of the coating cavity is grounded, and the gap is constructed into an electron depletion region dominated by positive charge; by intercepting inadvertently entering particles through the labyrinthine channel and blocking particles escaping along the gap through the electron depletion region, the contamination frequency of the lower cavity can be significantly reduced, thereby reducing equipment downtime and maintenance costs; both the labyrinthine airflow channel and the electron depletion region are non-blocking designs, the labyrinthine channel will not obstruct the normal transport of reactive gases, and the electron depletion region will not affect the lifting and lowering of the wafer and the shielding device, while achieving the anti-contamination function, it is fully compatible with the process rhythm of existing coating equipment without requiring modification to the main structure of the equipment. Attached Figure Description

[0016] Figure 1 A schematic diagram of the structure of a particle deposition shielding element for coating equipment provided in this application within the coating cavity;

[0017] Figure 2 for Figure 1 The diagram shows a cross-sectional view of the anti-particle deposition mask used in a coating equipment within the coating chamber.

[0018] Figure 3 for Figure 1 The diagram shows a cross-sectional view of the anti-particle deposition mask used in coating equipment.

[0019] Figure 4 for Figure 3 The diagram shows a partial structural schematic of a particle deposition shielding component used in coating equipment.

[0020] Figure 5 for Figure 3 The diagram shown is an exploded view of the structure of a particle deposition shielding component used in coating equipment. Detailed Implementation

[0021] 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.

[0022] This application provides a particle deposition shielding device for a coating equipment, disposed within a coating cavity 10. It includes an annular upper plate 1 and a lower plate 2, connected to form a closed space between them. The closed space contains staggered and spaced baffles 3, which complicate the gas flow path within the closed space, creating a labyrinthine airflow channel. A 0-2mm gap exists between the outer edge of the shielding device and the inner wall of the coating cavity 10. The cavity wall of the coating cavity 10 is grounded, creating an electron depletion region dominated by positive charges. The lower plate 2 has an air inlet 2a, and the upper plate 1 has an air outlet 1a. During operation of the coating equipment… The stage 20 carries the wafer upward and lifts the shield. The reaction gas enters the labyrinth-shaped airflow channel through the inlet 2a, then flows out through the outlet 1a and enters the reaction area. Particles entering the labyrinth-shaped airflow channel through the outlet 1a will collide with the baffle 3 due to the tortuous channel and eventually deplete their kinetic energy and settle in the labyrinth-shaped airflow channel. Particles entering the electron depletion region will eventually lose their activity or be unable to break through the gap due to the strong electric field force and the separation characteristics of the charge. The labyrinth-shaped airflow channel and the electron depletion region work together to limit the movement range of the particles and prevent them from contaminating the stage 20 or the cavity below, thereby ensuring the stability of the coating process and the yield of the thin film.

[0023] For details, please refer to Figure 1 and Figure 2 In the illustrated embodiment, the coating cavity 10 is a sealed vacuum cavity, serving as the core space for thin film deposition. The coating cavity 10 is divided into an upper cavity and a lower cavity (the illustration shows only a portion of the coating cavity 10, not the complete cavity). The target material is located at the top of the upper cavity, and a stage 20 is located at the bottom of the lower cavity. A shielding element is located between the target material and the stage 20, typically suspended within the coating cavity 10 via a platform or sliding mechanism (such as a slide rail or groove). The cavity walls of the coating cavity 10 are grounded to provide a stable zero-potential reference and to form the electric field loop required for plasma deposition, thereby ensuring effective transfer of radio frequency energy and the integrity of the current loop.

[0024] The stage 20, located below the shield, is the wafer carrier and lifting component, capable of moving the wafer vertically. During operation, the stage 20 lifts the wafer, raises the shield, and allows the wafer to enter the reaction area below the target.

[0025] The target material is located above the shield and serves as the "particle source" for thin film deposition (such as a vanadium target in vanadium oxide coating). After being energized, it generates the metal atoms to be deposited through plasma sputtering.

[0026] Combined with reference Figures 3 to 5 The shielding component is a ring-shaped structure located between the target and the stage 20. It is a key component that separates the reaction area from the lower cavity and prevents the deposited particles from escaping further downward.

[0027] Continue to refer to Figures 1 to 4The shielding component consists of an upper plate 1 and a lower plate 2 that are sealed together, with a closed space between the upper plate 1 and the lower plate 2 for gas flow. The closed space is equipped with an upper baffle (fixed to the lower surface of the upper plate 1 and spaced apart from the upper surface of the lower plate 2) and a lower baffle (fixed to the upper surface of the lower plate 2 and spaced apart from the lower surface of the upper plate 1). Both are annular structures coaxial with the shielding component and are arranged alternately and intermittently along the radial direction of the shielding component, constructing the closed space into a labyrinthine channel with multiple bends.

[0028] Continue to refer to Figure 4 The lower plate 2 has an air inlet 2a, and the upper plate 1 has an air outlet 1a. The coating chamber 10 has an air inlet that is connected to the external reaction gas supply equipment; the air inlet is located below the shielding component. During the coating process, the reaction gas enters the lower chamber through the air inlet, and then enters the labyrinthine airflow channel inside the shielding component through the air inlet 2a. The gas entering the enclosed space cannot flow in a straight line, but must flow along a tortuous path of "upward-right-downward-right-upward", and finally enters the reaction area through the air outlet 1a to participate in the ionization reaction.

[0029] When particles (such as metal atoms and plasma) in the reaction zone deposit downwards and enter the labyrinth-shaped airflow channel through the air outlet 1a in the opposite direction, the tortuous path will force the particles to hit the baffle 3 multiple times. Each impact will consume the kinetic energy of the particles. After 2 to 4 impacts, the kinetic energy of the particles is completely exhausted. Under the action of gravity, they sink to the bottom of the channel and can no longer move through the air inlet 2a, so they cannot enter the lower cavity.

[0030] In addition, the tortuous structure of the labyrinth-shaped airflow channel can slow down the airflow speed and prevent high-speed airflow from disturbing the plasma in the reaction area, thereby ensuring uniform gas distribution on the wafer surface and helping to improve coating uniformity.

[0031] Continue to refer to Figure 1 and Figure 2 The inner wall of the coating cavity 10 is provided with a hanging wall 11 extending towards the center of the cavity. The shielding element is placed on the hanging wall 11, supported by the hanging wall 11, and suspended above the stage 20. A 0-2mm annular gap is reserved between the outer edge of the shielding element and the inner wall of the coating cavity 10. The width of this gap is much smaller than that of the prior art (conventional >5mm), and the width of the gap is uniform along the circumferential direction (error ≤ ±0.1mm), providing space for charge concentration.

[0032] Since the cavity wall of the coating cavity 10 is connected to the ground through a grounding terminal (usually located on the outer wall of the cavity), the potential of the cavity wall is 0; at the same time, the shield is indirectly grounded through the wall hanging 11 or the platform 20, and the potential of the shield also approaches 0.

[0033] After the gap is formed, the free electrons near the gap and in the reaction area will preferentially move towards the grounded shield or cavity wall due to their extremely small mass and fast speed, and will be quickly guided away through the grounding circuit. Positive ions (such as argon ions and metal ions) are large in mass and move slowly, and cannot migrate synchronously. They will remain in the gap, eventually forming an electron depletion region that is "dominated by positive charge and has scarce electrons".

[0034] The electron depletion region serves to prevent particles from entering the lower cavity through the gap between the outer edge of the shield and the cavity wall. Specifically, for charged particles (electrons and positive ions), electrons are quickly conducted away by the grounded surface and cannot accumulate in the gap; while positive ions are repelled by the "positive charge region" within the gap (the direction of the electric field is opposite to the direction of the positive ion's movement), their kinetic energy gradually decays, and they are eventually "pushed back" to the reaction area, unable to break through the gap. For neutral particles (such as unionized metal atoms), although they are not affected by the electric field, the narrow gap of 0-2 mm itself increases the diffusion resistance of neutral particles, and the labyrinthine airflow channel has already intercepted most neutral particles through sedimentation, making it difficult for the remaining few neutral particles to enter the lower cavity through the gap.

[0035] The electron depletion region acts like an invisible wall, completely cutting off the path for particles to leak along the gaps.

[0036] The design incorporates a labyrinthine airflow channel and an electron depletion region. These two elements work synergistically. On one hand, the labyrinthine channel intercepts stray particles, while the electron depletion region blocks particles escaping along the gaps. This dual protection significantly reduces the contamination frequency of the lower cavity, thereby minimizing equipment downtime and maintenance costs. On the other hand, the labyrinthine channel guides the uniform flow of the reactive gas and prevents airflow disturbances to the plasma, helping to ensure a stable coating process and effectively improving the compositional uniformity and yield of the thin film.

[0037] In addition, both the labyrinth-shaped airflow channel and the electron depletion region are non-blocking designs. The labyrinth-shaped channel will not obstruct the normal transport of the reactive gas, and the electron depletion region will not affect the lifting and lowering of the wafer and the mask. While achieving the anti-contamination function, it is fully compatible with the process rhythm of existing coating equipment without the need to modify the main structure of the equipment.

[0038] The particle deposition shielding device for coating equipment provided in this application forms a labyrinthine airflow channel through the enclosed space between the annular upper plate 1 and the lower plate 2, and the staggered baffles 3 inside the enclosed space. This causes particles that accidentally enter through the air outlet 1a to settle due to the tortuous channel, impact with the baffles 3, and depletion of kinetic energy, thus preventing the particles from diffusing downwards. Furthermore, the 0-2mm gap between the outer edge of the shielding device and the inner wall of the coating cavity 10, combined with the electron depletion area formed by the grounding of the cavity wall, uses strong electric field force and charge separation characteristics to restrict particles from breaking through the gap, thereby cutting off the path of particle leakage along the gap. The two work together to restrict particles and prevent them from contaminating non-coating areas downwards. This reduces the frequency of equipment cleaning and maintenance, lowers maintenance costs and the risk of process interruption, while ensuring the uniform flow of reaction gases, thereby ensuring the stability of the coating process and the yield of thin film preparation.

[0039] In one embodiment, the inner wall of the coating cavity 10 is provided with a hanging wall 11 extending toward the center of the cavity, and the hanging wall 11 is used to support the shielding component.

[0040] For details, please refer to Figure 1 and Figure 2 In the illustrated embodiment, the mounting wall 11 is an annular support platform that protrudes towards the center of the cavity from the inner side of the cavity wall. It is adapted to the annular shape of the shield and can provide a uniform support contact surface for the shield. When the stage 20 is not carrying a wafer, the shield can be stably placed on this mounting wall 11, thereby maintaining its state of being suspended in a specific position above the stage 20. In this way, the structural and positional stability of the shield in the non-working state can be ensured, and the structure is also prepared for the subsequent lifting of the shield by the stage 20 carrying the wafer and entering the working state, ensuring the positional accuracy of the shield when switching between working and non-working states.

[0041] Optionally, the wall 11 is provided with multiple elastic conductive elements, which are evenly distributed along the circumferential direction. When the shield is placed on the wall, the elastic conductive elements are compressed and electrically connected to the shield and the cavity wall of the coating cavity 10, so that the shield and the cavity wall form an electrical equipotential connection.

[0042] It needs to be explained that the electron depletion zone still needs to be maintained after the coating is completed. This is because during the process of coating, stage 20 descending and wafer transfer, there will still be particles in the reaction area that have not been completely settled. If the mask cannot immediately form an electrical equipotential connection with the cavity wall of the coating cavity 10 after leaving the wafer and stage 20, thus causing the electron depletion zone to fail, the residual particles are very likely to leak into the lower cavity along the gap between the mask and the cavity wall.

[0043] The addition of elastic conductive components (such as springs or sheet metal made of conductive materials) is to utilize the elastic deformation characteristics of the elastic conductive components to achieve potential conduction in advance before the shielding component descends with the platform 20 and completely falls back to the hanging wall 11. This ensures that the equipotential connection between the shielding component and the grounded cavity wall is never interrupted (only when the shielding component and the cavity wall are at the same potential can electrons in the gap be quickly conducted away while positive ions can remain effectively, thereby forming a stable strong electric field to confine the particles and prevent the particles from leaking down the cavity along the gap), thus maintaining the stable function of the electron depletion region throughout the process.

[0044] Specifically, during the coating process, the mask is lifted by the wafer and the stage 20, the physical contact with the wall mount 11 is broken, and the electrical connection is cut off. However, the lower plate 2 of the mask will directly contact the edge of the wafer or the stage 20. Since the stage 20 is grounded and the wafer is firmly attracted by the grounded stage 20 (usually an electrostatic chuck), the mask can maintain a potential close to the ground potential through the direct path of "mask-stage" or the indirect path of "mask-wafer-stage". This grounding path is sufficient to maintain the electric field in the narrow gap area and ensure the existence of the electron depletion region.

[0045] After one coating cycle, the stage 20 descends, and the masking element, losing its support, falls, first contacting the elastic conductive element (which, at this point, is in an extended state due to the lack of pressure, and is positioned relatively high, may even remain attached to the masking element), continuously compressing it until it finally falls back onto the hanging wall 11. Because the elastic conductive element is connected to the cavity wall of the coating chamber 10 and is in a grounded state, the masking element can establish a low-resistance, high-reliability permanent path through the elastic conductive element during its descent, achieving equipotential connection with the grounded cavity wall in advance, thereby ensuring the continuity of the electron depletion region.

[0046] Alternatively, the flexible conductive element may be a crescent-shaped or finger-shaped spring made of beryllium copper. Beryllium copper combines excellent conductivity and elasticity, making it better suited for grounding requirements.

[0047] Optionally, the elastic conductive element is made of stainless steel spring sheet.

[0048] Optionally, the wall-mounted component 11 is provided with multiple elastic conductive elements, which are evenly distributed along the circumference. Each elastic conductive element is connected to the cavity wall of the coating cavity 10 via a metal braided strip. When the shielding component falls back onto the wall-mounted component 11, its outer edge or back surface will press precisely onto the elastic conductive element. With the help of the weight of the shielding component itself and the elastic force of the elastic conductive element, multiple evenly distributed and reliable electrical connection points are formed.

[0049] Using elastic conductive components allows for electrical connection in advance when the shielding component falls back down. Furthermore, its elastic design compensates for thermal expansion and contraction and machining tolerances during equipment operation, ensuring stable contact pressure between the shielding component and the cavity wall, thereby maintaining a reliable electrical connection.

[0050] Optionally, a groove 2b is provided around the outer edge of the lower surface of the lower plate 2. When the cover is placed on the wall hanging 11, the wall hanging 11 is inserted into the groove 2b.

[0051] For details, please refer to Figures 1 to 4 In the illustrated embodiment, the groove 2b is formed on the outer edge of the lower surface of the lower plate 2, and is a ring structure extending along the circumference of the lower plate 2. The shape and size of the groove are adapted to the wall hanging 11, and can just accommodate the wall hanging 11.

[0052] When the shield is placed on the hanging wall 11, the hanging wall 11 is inserted into the groove 2b. The two work together to position and fix the suspension position of the shield. This helps to ensure that the shield returns to the preset position above the stage 20 after lifting and lowering. This lays the foundation for the shield to accurately fit with the edge of the wafer, the stability of the airflow path of the labyrinth-type airflow channel, and the uniformity of the gap between the outer edge of the shield and the cavity wall when the stage 20 lifts the wafer and raises the shield.

[0053] Optionally, in the labyrinth-type airflow channel, a step structure 2c is provided in the inner region corresponding to the groove 2b. The step structure 2c extends in a stepped manner and forms at least one raised step to increase the tortuosity of the labyrinth-type airflow channel.

[0054] For details, please refer to Figure 3 and Figure 4 In the illustrated embodiment, the stepped structure 2c is disposed inside the labyrinth-shaped airflow channel and corresponds to the groove 2b (the inwardly recessed part of the groove 2b protrudes within the labyrinth-shaped airflow channel, forming a stepped structure 2c). Its overall shape is a stepped form extending along the circumference of the shield. The contour of this step adapts to the inner wall of the labyrinth-shaped airflow channel, naturally integrating into the overall structure of the channel. It does not obstruct the basic flow of the reactant gas within the channel, and the stepped protrusion alters the local path of the channel.

[0055] The stepped structure 2c can increase the tortuosity of the labyrinth-type airflow channel. Its stepped extension and raised step design can further change the trajectory of airflow and stray particles on the basis of the original tortuous path of the channel. The airflow must bypass the raised steps to continue flowing towards the air outlet 1a, and the particles that stray into the enclosed space also need to hit the steps and baffles 3 more times, providing more opportunities for the consumption of particle kinetic energy.

[0056] Optionally, the horizontal step surface of the step faces the air outlet 1a, and the distance between the horizontal step surface and the air outlet 1a is less than the channel width of the main section of the labyrinth-type airflow channel, so as to reduce the activity space of the stray particles and accelerate their kinetic energy depletion.

[0057] For details, please refer to Figure 4In the illustrated embodiment, the horizontal step surface of the step corresponding to the groove 2b faces the air outlet 1a. Its function is to accurately intercept particles that mistakenly enter the labyrinth-shaped airflow channel from the air outlet 1a. Specifically, if particles in the reaction area enter the air outlet 1a, they can contact the step surface without undergoing complex diffusion, thereby causing most particles to quickly dissipate their kinetic energy, creating the preconditions for the subsequent depletion of kinetic energy and sedimentation of particles.

[0058] It needs to be explained that the "maze-shaped airflow channel main section" refers to the basic tortuous channel section within the enclosed space, composed of staggered baffles 3, which is not disturbed by the stepped structure 2c. This channel section maintains a relatively uniform width and is the main path for the reaction gas to flow within the channel. (See attached diagram for details.) Figure 4 The section between the middle baffles 3 has a relatively regular channel outline.

[0059] Making the distance between the horizontal step and the air outlet 1a smaller than the width of the main section of the labyrinth-shaped airflow channel further reduces the activity space of stray particles. It's easy to understand that compared to the wider main section, the narrower distance causes particles entering through the air outlet 1a to be blocked by the horizontal step within a very short distance. This compresses the particle's path, increases the frequency of impacts with the step or baffle 3, and allows kinetic energy to be depleted more quickly.

[0060] In one embodiment, the distance between the horizontal stepped surface and the air outlet 1a is strictly controlled within the range of 0.5-2mm.

[0061] This spacing design can significantly reduce the activity space of particles that accidentally enter the labyrinth-shaped airflow channel from the air outlet 1a. After entering from the air outlet 1a, the particles only need to travel a short distance to contact the horizontal step surface and cannot diffuse over a large area in the channel, thereby further accelerating the depletion of kinetic energy of the particles.

[0062] At the same time, the spacing of 0.5-2mm is neither too small to hinder the normal diffusion of the reactant gas, nor too large to give the particles enough space to change their direction of motion and avoid the step surface. This ensures the uniform flow of the reactant gas while promoting particle sedimentation.

[0063] Alternatively, the shield may be made of titanium or a titanium alloy.

[0064] Titanium possesses excellent high-temperature resistance, maintaining its structural stability during the coating process (often accompanied by the high-temperature plasma environment). It is not easily deformed by high temperatures, helping to ensure that the gap between the shielding element and the coating cavity wall, as well as the dimensions of the labyrinth-shaped airflow channel, always meet design requirements, preventing structural deformation from affecting the particle-blocking effect. Simultaneously, titanium has good electrical conductivity, ensuring stable electrical connections between the shielding element, the cavity wall, and the stage 20, contributing to the formation of a uniform and effective electron depletion region. Furthermore, titanium exhibits excellent corrosion resistance, resisting the erosion of reactive gases during coating, reducing material loss, and extending its service life.

[0065] Titanium alloys, while inheriting titanium's core advantages such as high temperature resistance, electrical conductivity, and corrosion resistance, further enhance the material's mechanical strength and structural rigidity. This makes the shielding components less prone to bending and deformation during long-term use, ensuring that the tortuosity and uniformity of the gaps in the labyrinthine airflow channels remain intact. Furthermore, the comprehensive properties of titanium alloys make the shielding components more durable when dealing with frequent process cycles, further reducing the frequency of replacement.

[0066] Optionally, the shield is made of aluminum alloy, and the indirect grounding connection part of the shield is provided with a conductive coating.

[0067] The density of aluminum alloy is approximately 2.7 g / cm³. 3 Compared to titanium (approximately 4.51 g / cm³), 3 It is lighter, which minimizes the weight of the shield and reduces the load when the platform 20 lifts the shield, making it easier to pick up, put down, and maintain. At the same time, aluminum alloy has excellent conductivity, which is better than that of titanium. It has a good foundation for ensuring a smooth grounding path and maintaining the stability of the electron depletion region, and can meet the conductivity requirements of the shield.

[0068] However, a non-conductive aluminum oxide insulating layer naturally forms on the surface of aluminum alloys, which can easily lead to grounding failure.

[0069] Conductive coatings specifically refer to coatings applied to the grounding connection points of shielding components to enhance conductivity. These mainly include localized nickel-plated or gold-plated coatings, or coatings formed through special conductive sealing processes (such as nickel salt sealing processes).

[0070] The “indirect grounding connection part” of the shielding part specifically refers to the key area on the shielding part used to realize the transmission of grounding current, including the area where the outer edge of the shielding part contacts the cavity wall of the coating cavity 10 (the part that contacts it when it is attached to the wall 11), the area where the inner edge of the shielding part contacts the wafer or stage 20, and the grounding connection point preset on the shielding part (the part used to make conductive connection with the wall 11 and other structures).

[0071] By setting a conductive coating at the key part of indirect grounding, the barrier of the aluminum oxide insulation layer can be overcome, ensuring that the shielding component establishes a stable conductive path with the wall 11 or carrier 20 through the coating, so as to always maintain the potential of the shielding component close to the ground and ensure the stable existence of the electron depletion region.

[0072] Optionally, the upper plate 1 and the lower plate 2 are detachably connected.

[0073] After long-term use, a large number of particles will accumulate in the labyrinth-shaped airflow channel. The detachable design allows staff to easily disassemble the upper and lower plates to clean the inner walls of the channel, baffles 3, and other parts, preventing particles from clogging the channel, affecting the flow of the reaction gas, and causing accidental particles to settle.

[0074] Meanwhile, if the shielding component is partially damaged, the detachable design eliminates the need to replace the entire shielding component; only the damaged panel needs to be replaced, which can significantly reduce usage costs.

[0075] In addition, the upper plate 1, lower plate 2, baffle 3, air inlet and outlet holes and other structures can be precision machined separately during processing and then assembled. Compared with the complex enclosed space and internal structure of one-piece processing, it is easier to ensure the accuracy of each component.

[0076] This application does not limit the specific detachable connection form of the upper plate 1 and the lower plate 2.

[0077] In one embodiment, bolt holes are evenly spaced along the circumference of the inner and / or outer edges of the upper plate 1 and the lower plate 2. After aligning the upper and lower plates, bolts are inserted into the bolt holes and tightened to achieve a stable connection between the two. Disassembly is achieved by simply unscrewing the bolts with a tool to separate the upper and lower plates.

[0078] In another embodiment, one of the upper plate 1 and the lower plate 2 has a buckle on its inner and / or outer peripheral surface, and the other has a hook on its inner and / or outer peripheral surface. After the two plates are closed together, the buckle and hook are fastened together to secure the upper and lower plates. To disassemble, the buckle can be released to separate the upper and lower plates.

[0079] Optionally, the edges of the upper plate 1 and the lower plate 2 are provided with corresponding positioning holes and positioning pins.

[0080] For details, please refer to Figure 5 In the illustrated embodiment, at least two positioning holes are provided on the edge of the upper surface of the lower plate 2, and at least two positioning pins are provided on the edge of the lower surface of the upper plate 1. The positioning pins correspond one-to-one with the positioning holes. The diameter of the positioning pins is precisely matched with the diameter of the positioning holes, so that the positioning pins can be precisely inserted into the positioning holes during assembly.

[0081] The positioning holes and positioning pins serve two purposes. First, they effectively prevent misalignment during the assembly of the upper plate 1 and the lower plate 2, ensuring that the labyrinth-shaped airflow channel between them has the designed shape to maintain the preset labyrinth interception effect. Second, after each disassembly, cleaning, or maintenance of the shielding component, the precise fit of the positioning holes and positioning pins allows the upper plate 1 and the lower plate 3 to be quickly restored to their assembled state upon reassembly, ensuring that the geometry of the labyrinth-shaped airflow channel (such as channel width and tortuosity) remains consistent.

[0082] Optionally, the upper surface of the lower plate 2 is provided with a groove, and the inner edge of the upper plate 1 can be inserted into the groove.

[0083] For details, please refer to Figure 4 In the illustrated embodiment, the width of the upper plate 1 is smaller than the width of the lower plate 2 along the left-right direction, and the inner edge of the right side of the upper plate 1 rests on the top of the lower plate 2. The part of the lower plate 2 that contacts the inner edge of the right side of the upper plate 1 is provided with a groove. After the inner edge of the upper plate 1 is inserted, it can form a close connection with the inner wall of the groove, and this part will form one side wall of the labyrinth-shaped airflow channel.

[0084] By inserting the inner edge of the upper plate 1 into the groove, the sealing connection between the two plates can be strengthened, preventing reactive gases or accidentally introduced particles from escaping from the gap between the two plates. This close fit can also maintain the integrity and continuity of the labyrinth-type airflow channel, preventing gaps from appearing due to loose connection between the inner edges of the upper and lower plates, which could lead to channel structure breakage and affect the movement trajectory and sedimentation effect of particles in the channel.

[0085] Optionally, a sealing ring is provided between the upper plate 1 and the lower plate 2 to prevent gas or particles from escaping from the connection between the two.

[0086] For details, please refer to Figure 4 In the illustrated embodiment, a first sealing ring is provided at the outer edge connection position (left side) of the upper plate 1 and the lower plate 2, and a second sealing ring is provided at the position where the inner edge of the upper plate 1 connects with the groove of the lower plate 2. To facilitate the placement of the sealing ring, an annular sealing ring groove is also provided between the upper and lower plates. The sealing ring is made of perfluoroelastomer rubber or fluororubber. After being embedded in the sealing ring groove, when the upper plate 1 covers the lower plate 2, the sealing ring is compressed and forms a tight sealing structure between the two plates, which can prevent gas and particles from escaping or accidentally entering from the connection position of the upper and lower plates.

[0087] Optionally, a conductive ring is provided between the upper plate 1 and the lower plate 2 to realize the electrical connection between the upper plate 1 and the lower plate 2.

[0088] The conductive ring is located inside the sealing ring and is made of conductive material (such as copper alloy, silver-plated copper alloy, etc.). When the upper plate 1 covers the lower plate 2, the two plates together press the conductive ring tightly against it, thus forming a stable connection structure between the upper and lower plates to achieve electrical conduction.

[0089] The conductive ring can establish a low-resistance electrical path between the upper and lower plates, ensuring a reliable electrical connection between the upper plate 1 and the lower plate 2. Even if the shielding component is disassembled and reassembled multiple times, the conductive ring can still maintain a good electrical connection state due to its own material properties (such as the excellent elasticity of beryllium copper alloy and the good conductivity of silver-plated copper alloy).

[0090] This application does not limit the specific configuration of the conductive ring, as long as it can fit the upper and lower plates and achieve electrical connection.

[0091] In one embodiment, the conductive ring is made of beryllium copper alloy and has a C-shaped annular structure. An annular conductive ring mounting groove is provided between the upper and lower plates. After the upper and lower plates are closed, the conductive ring in the mounting groove is compressed and undergoes elastic deformation. The deformed C-shaped conductive ring will fit tightly against the upper plate 1 and the lower plate 2, and a low-resistance and durable electrical connection between the upper and lower plates is achieved by relying on the high conductivity and elastic recovery force of the beryllium copper alloy.

[0092] In another embodiment, the conductive ring is made of silver-plated copper alloy and has a U-shaped annular structure. After the upper and lower plates are closed, the upper plate 1 presses against the top crossbar of the U-shaped conductive ring, causing slight outward expansion deformation of the two side walls of the U-shape, further enhancing its tight contact with the conductive ring mounting groove and the lower surface of the upper plate 1. The silver plating layer effectively reduces contact resistance, while the copper alloy ensures structural strength and basic conductivity, thereby achieving a stable electrical connection between the upper and lower plates.

[0093] The design of the upper and lower plates, which are detachably connected, includes positioning holes and pins, grooves, sealing rings, and conductive rings. While ensuring the detachability of the upper and lower plates (facilitating subsequent cleaning, maintenance, and component replacement), it solves problems that may arise from the detachable connection, such as assembly misalignment (the positioning holes and pins prevent misalignment of the upper and lower plates, ensuring precise alignment of the internal structure and maintaining the design state), sealing failure (the inner edge of the upper plate 1 is inserted into the groove of the lower plate 2, and with the sealing ring, it completely blocks the escape of gas or particles from the connection gap between the two plates), and conductivity interruption (the conductive ring establishes a low-resistance, high-reliability electrical connection between the upper and lower plates, which remains stable even after multiple disassemblies and reassemblies, ensuring that the potential of the upper plate 1 and the lower plate 2 is consistent, thereby stabilizing the overall grounding potential of the shield and ensuring the continuous effectiveness of the electron depletion zone). This ensures that the core structural function of the shield can be fully restored after the upper and lower plates are assembled—maintaining the design integrity and stability of the labyrinth-type airflow channel, ensuring the reliability of the electrical connection required for the grounding of the shield, and preventing gas or particles from leaking from the connection point.

[0094] In one specific embodiment, the conductive ring is an elastic metal spring made of beryllium copper alloy or silver-plated copper alloy; the cross-sectional shape of the conductive ring is C-shaped, U-shaped or Ω-shaped; the lower surface of the upper plate 1 and / or the upper surface of the lower plate 2 are provided with an annular groove for accommodating the conductive ring, and the conductive ring is fixed in the annular groove by interference fit and is pressed between the upper plate 1 and the lower plate 2; the conductive ring can provide continuous contact pressure by elastic deformation in order to resist the surface oxidation, micro-unevenness and thermal deformation of the plate, thereby maintaining the electrical path between the upper plate 1 and the lower plate 2.

[0095] Specifically, the conductive ring is made of beryllium copper alloy or silver-plated copper alloy, and the cross-sectional shape can be C-shaped, U-shaped or Ω-shaped. At the same time, an annular groove adapted to the conductive ring is provided on the lower surface of the upper plate 1 and / or the upper surface of the lower plate 2. The annular groove is used to accommodate the conductive ring, ensuring that the conductive ring can be stably placed in the preset position and maintain contact and matching with the upper and lower plates.

[0096] More specifically, the conductive ring is fixed in the annular groove by an interference fit. The interference fit allows the conductive ring to be initially fixed in the annular groove, preventing displacement before assembly. When the upper plate 1 covers the lower plate 2, the conductive ring will be pressed between the upper plate 1 and the lower plate 2, causing the elastic metal spring to undergo slight elastic deformation.

[0097] The elastic metal spring can provide continuous contact pressure through elastic deformation. This continuous contact pressure can effectively resist surface oxidation and micro-unevenness that may occur on the contact surfaces of the upper and lower plates during long-term use, as well as thermal deformation caused by temperature changes during the operation of the coating equipment. This prevents these factors from causing gaps, increased contact resistance, or even connection interruption in the electrical connection between the upper and lower plates, so as to always maintain the electrical path between the upper plate 1 and the lower plate 2, and ensure that the entire shielding component has a long-term stable ground potential, providing the necessary electrical basis for the stable maintenance of the electron depletion region.

[0098] In one embodiment, the baffle 3 includes an upper baffle disposed on the lower surface of the upper plate 1 and a lower baffle disposed on the upper surface of the lower plate 2. Both the upper baffle and the lower baffle are annular structures coaxial with the shield. The upper baffle and the lower baffle are staggered and spaced apart along the radial direction of the shield. The number of baffles 3 is at least 3. The distance between any two adjacent baffles 3 is 2-8 mm.

[0099] For details, please refer to Figure 3 and Figure 4 In the illustrated embodiment, the baffle 3 includes an upper baffle and a lower baffle. The upper baffle is fixedly disposed on the lower surface of the upper plate 1, and the lower baffle is fixedly disposed on the upper surface of the lower plate 2. Both the upper baffle and the lower baffle are annular structures coaxial with the overall annular structure of the shielding member, adapting to the circumferential shape of the shielding member.

[0100] Continue to refer to Figure 3 and Figure 4The upper and lower baffles are staggered (left and right in the figure) and spaced apart along the radial direction of the shield. They are offset from each other and not aligned in the radial direction of the shield. At the same time, any two adjacent baffles 3 (i.e., an adjacent upper baffle and a lower baffle) maintain an orderly interval. The two baffles together build a tortuous structural foundation for the labyrinth-shaped airflow channel in the enclosed space.

[0101] It should be explained that the requirement of "at least three baffles 3" is to ensure the formation of a maze-like airflow channel with sufficient tortuosity within the enclosed space. If there are fewer than three baffles, the channel has too few bends and the path is relatively simple. Particles that accidentally enter from the air outlet 1a may pass through the channel with only a few impacts, making it difficult to fully exhaust their kinetic energy and effectively achieve sedimentation and interception. At least three baffles 3, through their staggered distribution, can form multiple bends, allowing particles to repeatedly change direction and impact the baffles 3 within the channel, gradually dissipating their kinetic energy and eventually settling within the channel.

[0102] It's also important to explain that the requirement of "the distance between any two adjacent baffles 3 being 2-8 mm" is to ensure both smooth flow of the reactant gas and the effective particle interception by the labyrinthine airflow channel. If the distance is too small (<2 mm), the flow resistance within the channel will significantly increase, affecting the uniform delivery and flow rate stability of the reactant gas, and may even cause channel blockage. If the distance is too large (>8 mm), the particles will have too long a distance between adjacent baffles 3, providing sufficient space to maintain kinetic energy or change direction to avoid collisions, making it difficult to ensure sufficient kinetic energy consumption. A distance range of 2-8 mm allows for smooth passage of the reactant gas while ensuring that particles easily collide with each other during their movement between adjacent baffles 3, gradually depleting their kinetic energy, thus achieving a balance between airflow and particle interception.

[0103] Optionally, in the enclosed space, the vertical distance between the upper baffle and the upper surface of the lower plate 2 is H1, and the vertical distance between the lower baffle and the lower surface of the upper plate 1 is H2. The values ​​of H1 and H2 are both in the range of 0.5-2mm, and H1 < H2.

[0104] The values ​​of H1 and H2 are both in the range of 0.5-2mm. This is based on a trade-off between particle blocking efficiency and gas flow resistance, and is determined by a combination of actual process requirements, processing feasibility, and synergy with other structures of the shielding component.

[0105] Specifically, the lower limit is set at 0.5mm because this size can be stably achieved and the tolerance can be precisely controlled in machining. It is small enough to form an effective physical barrier for nano- to submicron-sized particles (such as sputtered metal atoms / ion clusters, whose movement is Brownian motion), making it easy for particles to collide with the channel wall and be captured. It can also use the high-speed airflow in the narrow channel to form a "sweeping" effect to prevent particles from settling on the side of the baffle 3. At the same time, it reserves a safety margin for the thermal expansion of the material during the process heating, avoiding thermal deformation that could cause the upper baffle to jam or be damaged by contact between the lower baffle 2 and the lower baffle to the upper baffle 1.

[0106] The reason for setting the upper limit to 2mm is twofold. First, it is to maintain design logic consistency with the 0-2mm gap upper limit between the outer edge of the shield and the coating cavity wall, jointly creating a physical environment that is difficult for particles to pass through. Second, it is to avoid increasing the risk of particle escape due to excessive spacing (when the spacing exceeds 2mm, particles with greater kinetic energy or strong directionality are prone to pass through the channel without sufficient collision). At the same time, it can balance airflow resistance, avoid excessive pressure drop that puts too high a demand on the air pump and sealing system, reduce the parallelism of the upper and lower plates, reduce the processing difficulty of baffle 3, improve the assembly fault tolerance, and better adapt to the flow state of gas between viscous flow and molecular flow in PVD vacuum environment, ensuring frequent collisions between particles and gas molecules and channel walls.

[0107] The reason for setting H1 < H2 is to combine the movement trend of deposited particles to further optimize the interception effect and airflow. Since most particles that mistakenly enter the maze-shaped airflow channel move from top to bottom, H1, as the vertical distance between the upper baffle and the upper surface of the lower plate 2, is the first "threshold" after the particles enter the channel. A smaller H1 can intercept most of the top-down particles near the entrance with a more stringent gap, reducing the amount of particles that need to be processed later from the source. A slightly larger H2 can avoid the total resistance of the channel from increasing dramatically due to both gaps being too small, which would affect the smooth flow of the reactant gas. This ensures efficient particle interception while also taking into account the stability of the airflow.

[0108] Optionally, the inner wall of the labyrinth-shaped airflow channel is coated with a polytetrafluoroethylene (PTFE) anti-stick coating, which can change the adhesion state of particles in the labyrinth-shaped airflow channel, transforming it from solid scale to loose deposits.

[0109] The PTFE non-stick coating covers all the walls within the labyrinthine airflow channel that may come into contact with the reactive gases and particles, ensuring that the coating forms a continuous and complete non-stick layer without any missed areas, thus covering the entire path of particle impact and sedimentation.

[0110] Leveraging the extremely low surface energy of polytetrafluoroethylene (PTFE), the adhesion state of particles within the channel can be altered. Specifically, after particles exhaust their kinetic energy by impacting baffle 3 within the channel, they will still settle, but unlike on exposed metal walls, they will not form hard scale that is firmly bonded to the substrate or pre-deposited particles. Instead, they will remain loosely piled or physically placed at the bottom or corners of the channel. This alteration ensures that particles are effectively trapped within the channel, preventing them from entering the reaction area through the vent 1a and contaminating the wafer. Furthermore, it avoids hard scale altering the channel geometry (e.g., reducing critical gaps), affecting the airflow field and particle interception efficiency, and greatly simplifies subsequent maintenance and cleaning procedures (after disassembling the upper and lower plates, loosely piled particles can be easily removed using a vacuum cleaner, high-pressure airflow, or a lint-free cloth, while eliminating the risk of secondary particle contamination due to thermal stress or vibration causing the hard scale layer to peel off). Ultimately, this maintains the reliability of the shielding component's performance during long-term use.

[0111] Optionally, the thickness of the polytetrafluoroethylene anti-stick coating is 10-20 μm.

[0112] Setting the thickness of the polytetrafluoroethylene anti-stick coating to 10-20μm is a result of comprehensively ensuring the anti-stick effect, adapting to the labyrinth-type airflow channel structure, and taking into account both process feasibility and long-term stability.

[0113] 10μm is the lower limit for forming a continuous and complete non-stick layer. Below this thickness, defects such as micropores and missed coatings are likely to occur due to uneven spraying process, causing local areas of the channel wall to lose their non-stick properties, and particles may still form solid scale in these areas.

[0114] The upper limit of 20μm is to avoid reducing the effective cross-sectional area of ​​the labyrinth-type airflow channel due to excessive coating thickness, especially the critical narrow gaps in the channel (such as H1 and H2 with a thickness of 0.5-2mm). If the coating is too thick, it will change the original geometry of the channel, affect the flow resistance and flow velocity stability of the reactant gas, and may even cause local blockage of the channel, interfering with the design effect of particle impact interception.

[0115] Meanwhile, this thickness range can adapt to temperature fluctuations in the coating process. Although polytetrafluoroethylene has a high coefficient of thermal expansion, a thickness of 10-20μm can compensate for the difference in thermal expansion between the coating and the metal substrate (such as titanium alloy and aluminum alloy) through its own elastic deformation, avoiding the coating cracking or peeling caused by stress due to temperature changes. It is also sufficient to cope with the kinetic energy of particle impacts, so it will not be easily damaged by particle wear due to being too thin, nor will it increase the risk of adhesion between the coating and the substrate due to being too thick.

[0116] Furthermore, the 10-20μm thickness meets the process precision of conventional electrostatic spraying or suspension spraying, ensuring uniform coverage of the inner wall and corners of the channel. The thickness tolerance is easily controlled within a reasonable range, ensuring the overall consistency of the coating. During later maintenance, the surface of the coating at this thickness is smooth, and loosely accumulated particles can be easily removed with a vacuum cleaner or high-pressure airflow. It does not cause deep pits due to excessive coating thickness, which would make the particles embedded and difficult to clean. Ultimately, a balance is achieved between anti-stick performance, structural adaptability, process implementation, and ease of maintenance, ensuring that the labyrinth-type airflow channel can stably perform its particle interception function for a long time.

[0117] Optionally, the bottom of the labyrinth-shaped airflow channel is provided with an arc-shaped groove, which is located on the downstream side of the baffle 3 or on the outside of the airflow bend, so as to maximize the settling efficiency in the low-speed zone and guide and concentrate the particles in the designated area.

[0118] It should be explained that the labyrinth-shaped airflow channel serves both as an intake and exhaust channel. The coating chamber 10 is equipped with an intake port and an exhaust port, with the exhaust port connected to a negative pressure device for regulating the internal air pressure. Both the intake and exhaust ports are located below the baffle plate. During the coating process, newly introduced reactive gases enter the reaction zone through the labyrinth-shaped airflow channel. Simultaneously, unreacted gases and byproducts can also leave the reaction zone through the labyrinth-shaped airflow channel and be extracted by the negative pressure device.

[0119] The tortuous path of the labyrinth-shaped airflow channel and the spaced baffles 3 naturally form a spatial stratification. The reacting gas enters through the inlet 2a under the supply pressure, flows upward along the main path of the labyrinth-shaped airflow channel, and finally enters the reaction area evenly through the outlet 1a. The gas that does not participate in the reaction flows downward along the gaps of the baffles 3 in the channel or in areas that are offset from the inlet path under the negative pressure of the negative pressure device, and is finally discharged.

[0120] In this design, the upward driving force of the intake and the downward suction force of the exhaust form a clear pressure gradient. Combined with the damping effect of the labyrinth structure, the two airflows can flow in layers within the channel without interfering with each other. This ensures both a uniform supply of the reactant gas and efficient exhaust of the waste gas. At the same time, the tortuous nature of the channel allows any stray deposited particles to collide and settle fully in the stable environment of the bidirectional airflow, without being disturbed by different airflow directions. Therefore, it is fully capable of performing both intake and exhaust functions simultaneously.

[0121] It should also be explained that the downstream side of baffle 3 specifically refers to the area on the side where particles continue to flow along the airflow direction after passing through baffle 3 and colliding with it in the maze-shaped airflow channel. That is, the area behind baffle 3 where particles arrive after colliding with baffle 3 and having their kinetic energy initially consumed.

[0122] The outer side of the airflow turning point refers to the area on the side away from the turning center along the airflow turning trajectory when the airflow changes direction (such as from horizontal to vertical, or turning along the annular channel) in a labyrinthine airflow channel. In other words, it is the outer space formed by the curvature of the path when the airflow turns.

[0123] The reason for placing the arc-shaped grooves at these two locations is that these are the areas where particles are most likely to lose kinetic energy and aggregate. After colliding with baffle 3, the particles' kinetic energy is significantly reduced, making it difficult for them to continue moving downstream, and they are very likely to fall due to gravity. However, when the airflow turns, the particles, due to inertia, will maintain their original straight-line motion tendency, thus being thrown to the outside of the turn, detached from the mainstream airflow, and able to fall into the arc-shaped grooves on the outside. The placement of these two locations maximizes the particle capture efficiency of the arc-shaped grooves.

[0124] Furthermore, because the arc-shaped groove deviates from the main airflow path of the labyrinth-type airflow channel, the airflow diffusion or obstruction occurs, resulting in a gas velocity inside the arc-shaped groove that is much lower than in the main flow area. This provides an ideal low-speed environment for particle settling, preventing particles from being re-entrained by the airflow and guiding and concentrating dispersed particles in the channel into these designated areas, preventing particles from randomly scattering at the bottom of the channel. The tapering structure at the edge of the arc-shaped groove further prevents settled particles from escaping the groove, helping particles to remain stably in the designated area without interfering with the normal airflow path and particle interception function of the labyrinth-type airflow channel.

[0125] In one embodiment, the inner edge of the shield is stepped, including a first inclined surface 1b formed by the inner edge of the upper plate 1, a second inclined surface 2d formed by the inner edge of the lower plate 2, and a horizontal connecting surface 2e formed by the upper surface of the lower plate 2 between the first inclined surface 1b and the second inclined surface 2d; the second inclined surface 2d can capture particles that are incident at a large angle and might otherwise be deposited in the edge region of the wafer; the first inclined surface 1b and the horizontal connecting surface 2e can tighten the opening exposed to the target material, ensuring that the central region of the wafer that needs to be coated is exposed to the particle flow.

[0126] For details, please refer to Figure 4 In the illustrated embodiment, the stepped inner edge of the mask consists of three interconnected structures. The first part is a first inclined surface 1b integrally formed from the inner edge of the upper plate 1, the second part is a second inclined surface 2d integrally formed from the inner edge of the lower plate 2, and the third part is a horizontal connecting surface 2e located between the first inclined surface 1b and the second inclined surface 2d and extended from the upper surface of the lower plate 2. Together, the three constitute a stepped structure that gradually transitions from the mask to the wafer from top to bottom.

[0127] Among them, the second inclined plane 2d can accurately capture particles that are incident at a large angle. These particles may originally be deposited in the edge area of ​​the wafer. By capturing them, unnecessary thin films can be avoided on the wafer edge and back side. This is crucial for the smooth progress of subsequent photolithography and etching processes and the stability of chip performance.

[0128] The first inclined surface 1b and the horizontal connecting surface 2e work together to tighten the opening exposed below the target material, precisely defining a stable "deposition window" to ensure that the central area of ​​the wafer that needs to be coated is exactly exposed in the particle flow of the deposition window, while creating a wider "shade area" for the wafer edge, further eliminating invalid deposition.

[0129] Meanwhile, the stepped inner edge of the shielding device serves as the final threshold for the reactant gas to enter the deposition window after flowing out through the labyrinth-shaped gas flow channel and the gas outlet 1a. The gradually expanding slope shape allows the gas to turn and diffuse more smoothly over the wafer, thereby avoiding the generation of eddies near the wafer edge (eddies can cause uneven film thickness and may roll up deposited particles, causing secondary contamination).

[0130] Furthermore, by carefully designing the bevel angle, the flow rate and distribution of gas on the wafer surface can be adjusted, promoting the uniformity of thin film deposition.

[0131] Furthermore, compared to a thick vertical inner wall, the sloping structure significantly reduces the weight of the shielding component while ensuring sufficient structural strength, aligning with its design goals of lightweight construction, easy lifting, and minimal risk of wafer damage. This geometry also further enhances the shielding component's resistance to thermal deformation, ensuring its structural stability during long-term use and guaranteeing that the stepped shape and function of the shielding component's inner edge are not easily compromised by temperature changes.

[0132] Optionally, the inner edge of the shielding member has a rounded chamfer at the end that abuts against the wafer. The radius of the rounded chamfer is 0.5-1.5mm, which is used to reduce the contact area between the lower plate 2 and the wafer and prevent them from sticking together.

[0133] For details, please refer to Figure 4 In the illustrated embodiment, the end of the lower plate 2 used to abut against the wafer (i.e., the lower right corner of the lower plate 2) is rounded, and the chamfer is a smooth and continuous arc shape. Its radius is strictly controlled within the range of 0.5-1.5mm, which allows the end of the shield used to abut against the wafer to transition from a possible sharp edge or right angle to a rounded arc structure, ensuring a smooth contact interface when in contact with the wafer, rather than a rigid sharp contact.

[0134] The rounded chamfer can reduce the contact area between the lower plate 2 and the wafer, and can even shield the edge of the wafer without contacting it. In this way, even if a few deposited particles adhere to the area where the two are close to each other, it is difficult to form a force strong enough to make them stick together. This can effectively prevent the mask and the wafer from sticking together after the process is completed, and ensure that the mask can be smoothly separated from the wafer after the coating is completed.

[0135] The stepped inner edge and rounded chamfer of the masking element work together to precisely control the particle deposition area, ensure wafer coating quality, and guarantee smooth process operation and wafer structural safety. The stepped inner edge captures particles incident at large angles via the second inclined surface 2d, preventing them from depositing on the wafer's edge areas and forming ineffective films. Simultaneously, the first inclined surface 1b and the horizontal connecting surface 2e together tighten the opening of the deposition window, strictly limiting the deposition range and ensuring that the central area of ​​the wafer requiring coating is precisely exposed to the particle stream, achieving precise coating and edge protection. The rounded chamfer at the end of the masking element that abuts against the wafer effectively prevents adhesion between the two due to deposited particles by reducing the contact area between the lower plate 2 and the wafer, facilitating separation of the masking element from the wafer. Furthermore, the smooth, rounded shape prevents sharp ends from scratching the wafer edges, helping to ensure the integrity of the wafer structure. The two work together to achieve precise control of particle deposition through the stepped inner edge, and solve the problems of adhesion and damage at the contact points through the rounded chamfer. This allows the mask to play a precise coating auxiliary function while taking into account the convenience of process operation and the safety of the wafer.

[0136] Optionally, the upper plate 1 is provided with multiple air outlets 1a, which are equally spaced along the circumference. The lower plate 2 is provided with multiple air inlets 2a, which are also equally spaced along the circumference. The number of air inlets 2a is greater than the number of air outlets 1a, and the total flow area of ​​the air inlets 2a is greater than the total flow area of ​​the air outlets 1a. This is to establish a uniform and stable back pressure in the labyrinth-shaped airflow channel, ensuring the uniformity of the reaction gas flow and avoiding high-speed airflow from disturbing the plasma stability of the reaction region.

[0137] The reason for limiting "the number of air inlets 2a to be greater than the number of air outlets 1a, and the total flow area of ​​air inlets 2a to be greater than the total flow area of ​​air outlets 1a" is to achieve uniform gas distribution, stable back pressure establishment and enhanced particle sedimentation through structural optimization of the airflow path.

[0138] Specifically, more air inlets 2a allow the reactant gas to have more dispersed inlets when entering the labyrinth-shaped airflow channel, which can reduce the initial flow distance of the gas in the channel, allowing it to quickly and evenly fill the entire annular channel. Moreover, the flow velocity of each air inlet 2a is lower under the same total flow rate, which can prevent high-speed airflow from generating eddies in the channel and stirring up settled particles.

[0139] The smaller total flow area of ​​the vent 1a will form a "bottleneck" for gas outflow, so that the gas can establish a uniform and stable back pressure inside the labyrinth-shaped airflow channel. This back pressure can drive the gas to flow out uniformly from each vent 1a, avoiding the gas from flowing out from some vent 1a in a concentrated manner, which would cause uneven airflow above the wafer. At the same time, it reduces the flow rate of gas entering the reaction area, preventing high-speed airflow from impacting the wafer surface or disturbing the plasma.

[0140] In addition, this structure can work in conjunction with the tortuous path of the labyrinthine airflow channel to prolong the residence time of the gas in the channel, reduce the drag force of the gas on the particles, and give the particles more opportunities to collide with the baffle 3 and settle under the action of gravity.

[0141] Optionally, the air inlet 2a is configured in a trumpet shape, with the diameter of the air inlet 2a increasing the further away from the upper plate 1. The expansion angle of the air inlet 2a is 45°-60°, so as to guide the reaction gas into the labyrinth-type airflow channel evenly.

[0142] The air inlet 2a is shaped like a trumpet to allow the reactant gas to have a smoother and more diffused flow path when it enters the labyrinth-shaped airflow channel from outside the shield. This prevents the gas from directly impacting the inside of the channel in a concentrated columnar flow, thereby guiding the gas to diffuse evenly in all directions in the early stage of entering the channel. This reduces local velocity differences or eddies caused by concentrated airflow, ensuring that the gas can quickly and evenly fill the entire labyrinth-shaped airflow channel.

[0143] The expansion angle of the air inlet 2a is limited to 45°-60° because this range allows for uniform airflow diffusion, avoids airflow turbulence, and also considers manufacturing feasibility. Specifically, if the expansion angle is less than 45°, the divergence of the flared opening is insufficient, the airflow guidance effect is limited, and the gas may still enter the channel in a relatively concentrated form, making it difficult to achieve uniform diffusion. It may even generate local high-speed flow due to the excessive constraint of the hole wall on the airflow. If the expansion angle is greater than 60°, the divergence of the flared opening is too large. On the one hand, this increases the manufacturing difficulty of the air inlet (especially the hole wall forming accuracy in the thickness direction of the lower plate). On the other hand, an excessively wide opening can easily cause the airflow to backflow or diffuse disorderly within the hole, which in turn disrupts the stability of the airflow entering the channel and may even stir up particles that have settled at the bottom of the channel, affecting the particle interception effect of the labyrinth-type airflow channel. An expansion angle of 45°-60° can effectively guide the airflow to diffuse smoothly in all directions, ensuring the uniformity of gas entry, while avoiding processing difficulties and airflow turbulence problems, ensuring that the air inlet can stably guide the gas to enter the labyrinth-type airflow channel evenly.

[0144] 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 particle deposition shielding element for a coating equipment, disposed within a coating cavity (10), characterized in that, It includes an upper plate (1) and a lower plate (2) arranged in a ring shape, wherein the upper plate (1) and the lower plate (2) are connected and a closed space is formed between them; The enclosed space is provided with staggered and spaced baffles (3), which can complicate the flow path of gas in the enclosed space and construct the enclosed space into a maze-shaped airflow channel. There is a 0-2mm gap between the outer edge of the shielding element and the inner wall of the coating cavity (10). The cavity wall of the coating cavity (10) is grounded, and the gap is constructed into an electron depletion region dominated by positive charge. The lower plate (2) is provided with an air inlet (2a), and the upper plate (1) is provided with an air outlet (1a). When the coating equipment is working, the stage (20) carries the wafer up and lifts the shield. The reaction gas enters the labyrinth-shaped airflow channel through the air inlet (2a), and then flows out from the air outlet (1a) and enters the reaction area. Particles entering the labyrinth-shaped airflow channel through the air outlet (1a) will collide with the baffle (3) due to the tortuous passage, eventually exhausting their kinetic energy and settling in the labyrinth-shaped airflow channel; Particles entering the electron depletion region will eventually lose their activity or be unable to break through the gap due to the strong electric field and the separation characteristics of the charge. The labyrinth-shaped airflow channel and the electron depletion region work together to limit the movement range of particles and prevent them from contaminating the stage (20) or the cavity below, thereby ensuring the stability of the coating process and the yield of the thin film.

2. The particle deposition shielding component for coating equipment according to claim 1, characterized in that, The inner wall of the coating cavity (10) is provided with a hanging wall (11) extending toward the center of the cavity, and the hanging wall (11) is used to support the shielding component; The wall (11) is provided with a plurality of elastic conductive elements, which are distributed at equal intervals along the circumferential direction. When the shield is placed on the wall, the elastic conductive elements are compressed and electrically connected to the shield and the cavity wall of the coating cavity (10), so that the shield and the cavity wall form an electrical equipotential connection.

3. The particle deposition shielding component for coating equipment according to claim 2, characterized in that, The lower plate (2) has a groove (2b) around its outer edge on its lower surface. When the cover is placed on the hanging wall (11), the hanging wall (11) is inserted into the groove (2b). In the labyrinth-type airflow channel, a step structure (2c) is provided in the inner area corresponding to the groove (2b). The step structure (2c) extends in a stepped shape and forms at least one raised step to increase the tortuosity of the labyrinth-type airflow channel. The horizontal step surface of the step is directly opposite the air outlet (1a). The distance between the horizontal step surface and the air outlet (1a) is less than the channel width of the main body of the labyrinth-shaped airflow channel, so as to reduce the activity space of the stray particles and accelerate their kinetic energy depletion.

4. The particle deposition shielding member for coating equipment according to claim 1, wherein the shielding member is made of titanium or titanium alloy; Alternatively, the shield may be made of aluminum alloy, and the indirect grounding connection portion of the shield may be provided with a conductive coating.

5. The particle deposition shielding element for coating equipment according to claim 1 or 4, characterized in that, The upper plate (1) and the lower plate (2) are detachably connected; The upper plate (1) and the lower plate (2) are provided with corresponding positioning holes and positioning pins at their edges; The upper surface of the lower plate (2) is provided with a groove, and the inner edge of the upper plate (1) can be inserted into the groove; A sealing ring is provided between the upper plate (1) and the lower plate (2) to prevent gas or particles from escaping from the connection between the two. A conductive ring is also provided between the upper plate (1) and the lower plate (2) to realize the electrical connection between the upper plate (1) and the lower plate (2).

6. The particle deposition shielding member for coating equipment according to claim 5, characterized in that, The conductive coil is an elastic metal spring, made of beryllium copper alloy or silver-plated copper alloy; The cross-sectional shape of the conductive coil is C-shaped, U-shaped, or Ω-shaped; The lower surface of the upper plate (1) and / or the upper surface of the lower plate (2) are provided with an annular groove for accommodating the conductive ring. The conductive ring is fixed in the annular groove by an interference fit and is pressed between the upper plate (1) and the lower plate (2). The conductive ring can provide continuous contact pressure by using elastic deformation to resist surface oxidation, micro-irregularities and thermal deformation of the plate, thereby maintaining the electrical connection between the upper plate (1) and the lower plate (2).

7. The particle deposition shielding element for coating equipment according to claim 1, characterized in that, The baffle (3) includes an upper baffle disposed on the lower surface of the upper plate (1) and a lower baffle disposed on the upper surface of the lower plate (2). Both the upper baffle and the lower baffle are annular structures coaxial with the shield. The upper baffle and the lower baffle are staggered and spaced apart along the radial direction of the shield; The number of baffles (3) is at least 3; The distance between any two adjacent baffles (3) is 2-8 mm; In the enclosed space, the vertical distance between the upper baffle and the upper surface of the lower plate (2) is H1, and the vertical distance between the lower baffle and the lower surface of the upper plate (1) is H2. The values ​​of H1 and H2 are both 0.5-2mm, and H1 < H2.

8. The particle deposition shielding element for coating equipment according to claim 1, characterized in that, The inner wall of the labyrinth-shaped airflow channel is coated with a polytetrafluoroethylene (PTFE) anti-stick coating. The PTFE anti-stick coating can change the adhesion state of particles in the labyrinth-shaped airflow channel, transforming it from a solid scale into a loose accumulation. And / or, the bottom of the labyrinth-shaped airflow channel is provided with an arc-shaped groove, which is located on the downstream side of the baffle (3) or on the outside of the airflow bend, so as to maximize the settling efficiency in the low-speed zone and guide and concentrate the particles in the designated area.

9. The particle deposition shielding element for coating equipment according to claim 1, characterized in that, The inner edge of the shield is stepped, including a first inclined surface (1b) formed by the inner edge of the upper plate (1), a second inclined surface (2d) formed by the inner edge of the lower plate (2), and a horizontal connecting surface (2e) formed by the upper surface of the lower plate (2) between the first inclined surface (1b) and the second inclined surface (2d). The second slope (2d) can capture particles that would otherwise be deposited in the wafer edge region when incident at a large angle; The first inclined surface (1b) and the horizontal connecting surface (2e) can tighten the opening exposed to the target material, ensuring that the central area of ​​the wafer that needs to be coated is exposed to the particle flow; The inner edge of the shielding member is provided with a rounded chamfer at the end that abuts against the wafer. The radius of the rounded chamfer is 0.5-1.5mm, which is used to reduce the contact area between the lower plate (2) and the wafer and prevent them from sticking together.

10. The particle deposition shielding element for coating equipment according to claim 1, characterized in that, The upper plate (1) is provided with a plurality of air outlets (1a), which are equally spaced along the circumferential direction. The lower plate (2) is provided with a plurality of air inlets (2a), which are also equally spaced along the circumferential direction. The number of air inlets (2a) is greater than the number of air outlets (1a), and the total flow area of ​​the air inlets (2a) is greater than the total flow area of ​​the air outlets (1a). This is to establish a uniform and stable back pressure in the labyrinth-shaped airflow channel, ensure the uniformity of the reaction gas flow, and avoid high-speed airflow disturbing the plasma stability of the reaction region. And / or, the air inlet (2a) is arranged in a trumpet shape, and the diameter of the air inlet (2a) is larger the further away from the upper plate (1). The expansion angle of the air inlet (2a) is 45°-60° so as to guide the reaction gas into the labyrinth-shaped airflow channel evenly.

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