Microwave plasma source for plasma uniform treatment and microwave treatment system

Abstract

The invention discloses a microwave plasma source and a microwave processing system for plasma uniform processing, and relates to the technical field of microwave plasmas. The solid-state microwave source is used for generating a microwave signal; the microwave radiator is electrically connected with the solid-state microwave source through a coaxial line and is used for receiving and radiating a microwave signal; the mobile platform is used for bearing the microwave radiator and driving the microwave radiator to move along the plane outside the vacuum cavity; the gradient refractive index dielectric plate is arranged in the window area of the vacuum cavity in a sealing manner; and microwaves radiated by the microwave radiator penetrate through the gradient refractive index dielectric plate and then form a surface wave-like mode in the vacuum cavity, so that low-ionization plasma excitation is realized. According to the invention, the microwave radiator is separated from the vacuum insulation ceramic piece, and the high-directivity microwave antenna is matched with the XY double-axis sliding bracket, so that the dynamic adjustment of the microwave incident position in the cavity can be realized.

Description

Technical Field

[0001] This invention relates to the field of microwave plasma technology, and more specifically, to a microwave plasma source and microwave processing system for plasma homogenization. Background Technology

[0002] Currently, microwave plasma technology is widely used in industrial processing fields such as material surface cleaning, etching, deposition, and coating, and is considered one of the key dry processing technologies. However, existing technologies have significant shortcomings in terms of the uniformity of plasma generation, which directly limits the application effect of microwave plasma technology in large-area, precision processing.

[0003] In existing microwave plasma devices, microwave radiation sources (such as microwave antennas or waveguide ports) are typically fixedly mounted on one side or top of the cavity and are usually integrated with a ceramic window / isolator to isolate the vacuum zone. For example, a fixed incident microwave source is formed on a heat treatment / plasma generation cavity, and microwaves are coupled into the cavity through a ceramic window to excite the gas and form plasma.

[0004] This structure has the following characteristics: (1) Fixed microwave point source: The microwave radiation structure is fixed on one side of the cavity and integrated with the ceramic window, so the entire microwave radiation direction is fixed. (2) Limited energy mode in the cavity: The combination of the fixed microwave incident position and the cavity boundary conditions will form a fixed field distribution mode, which will cause the microwave energy to generate a standing wave field distribution inside the cavity, resulting in non-uniform plasma density in space. (3) Unable to adjust the energy distribution in the cavity: Since the microwave source and the ceramic isolator are immovable, the microwave field cannot be adjusted in position or energy distribution in the cavity, and it is impossible to achieve precise coverage of plasma at different positions according to process requirements.

[0005] While the above design can generate plasma to some extent, the fixed layout of the microwave field within the cavity often results in peak and trough regions in the plasma density, failing to meet the requirement of achieving uniform plasma processing on large-area, complex workpieces. Therefore, researching and designing a microwave plasma source and microwave processing system that can overcome these shortcomings for uniform plasma processing is an urgent problem we need to solve. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a microwave plasma source and microwave processing system for uniform plasma processing. By separating the microwave radiator from the vacuum-sealed ceramic component and employing a highly directional microwave antenna in conjunction with an XY dual-axis sliding bracket, the microwave incident position can be dynamically adjusted within the cavity.

[0007] The above-mentioned technical objective of the present invention is achieved through the following technical solution: In a first aspect, a microwave plasma source for plasma homogenization is provided, comprising: Vacuum chambers are used to provide a sealed chamber to maintain the low-pressure environment required for plasma processing. Solid-state microwave sources are used to generate microwave signals; A microwave radiator, electrically connected to the solid-state microwave source via a coaxial line, is used to receive and radiate the microwave signal; A mobile platform carries the microwave radiator and drives the microwave radiator to move along a plane outside the vacuum cavity; A gradient refractive index dielectric plate is sealed in the window area of ​​the vacuum cavity and located on the microwave radiation path of the microwave radiator; The microwaves radiated by the microwave radiator penetrate the gradient refractive index dielectric plate and form a surface wave-like mode in the vacuum cavity to achieve low-ionization plasma excitation.

[0008] Furthermore, the gradient refractive index dielectric plate is formed by stacking multiple layers of dielectric materials sequentially along the microwave propagation direction, and the dielectric constant of the multiple layers of dielectric materials increases sequentially from the atmospheric pressure side to the vacuum side of the vacuum cavity.

[0009] Furthermore, the gradient refractive index dielectric plate is composed of a quartz ceramic layer, a boron nitride ceramic layer, and an alumina ceramic layer.

[0010] Furthermore, the dielectric constant of the quartz ceramic layer is 3.8-4.2, the dielectric constant of the boron nitride ceramic layer is 4.5-5.0, and the dielectric constant of the alumina ceramic layer is 9.5-10.0.

[0011] Furthermore, the thickness of the quartz ceramic layer is 3-5 mm, the thickness of the boron nitride ceramic layer is 2-4 mm, and the thickness of the alumina ceramic layer is 2-5 mm.

[0012] Furthermore, the microwave radiator includes: The antenna feed point is connected to the coaxial line. The main body is an all-metal rectangular plate, which is mounted on the moving platform and spaced apart from the gradient refractive index medium plate. A double-slit structure is provided on the side of the all-metal rectangular plate body facing away from the gradient refractive index medium plate; Two grounding copper posts are positioned on both sides of the double-slot structure; The grounding copper pillars on both sides form a constrained electromagnetic boundary with the metal reflective surface of the all-metal rectangular plate body to achieve main lobe concentration and side lobe suppression.

[0013] Furthermore, the gap length of the double-slit structure is 18-22mm, the width is 0.5-1.0mm, and the spacing is 2-15mm.

[0014] Furthermore, the mounting height between the metal reflective surface and the antenna feed point is 15-25mm; the diameter of the grounding copper pillar is 5-8mm, and the spacing between the two grounding copper pillars is 30-35mm.

[0015] In a second aspect, a microwave processing system is provided, including a control module and a microwave plasma source for plasma homogenization processing as described in any one of the first aspects. The control module is electrically connected to the mobile platform and drives the mobile platform to move along the planned path according to the received or generated control signals.

[0016] Furthermore, the control module is also configured to: Acquire luminescence images of plasma within a vacuum chamber; The YOLO algorithm is used to identify the plasma region in the luminescent image and calculate the average brightness intensity. The average brightness intensity is then compared with the experimentally calibrated intensity level threshold to determine the plasma strength level. Based on the preset target position in the load scanning area, calculate the position error of the plasma's current position; The vector velocity of the moving platform is dynamically adjusted based on the position error and the plasma intensity level. The mobile platform is controlled to move along the plane according to the vector velocity, and the path is adjusted preferentially to areas with insufficient plasma intensity.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention separates the microwave radiator from the vacuum-sealed ceramic component and employs a highly directional microwave antenna in conjunction with an XY dual-axis sliding bracket, enabling dynamic adjustment of the microwave incident position within the cavity. Compared to existing fixed point source structures, this invention can change the plasma excitation region in real time according to process requirements, avoiding "hot spots" and "dark areas" that occur in traditional cavities, and providing infrastructure for improving the spatial uniformity of plasma in the processing area; 2. This invention employs a low-Q broadband matching design and a three-layer gradient refractive index dielectric plate to achieve gradual microwave impedance matching and surface wave-like conversion, thereby concentrating microwave energy in the vacuum region on the back of the ceramic. This design reduces energy loss in fixed point sources and cavity reflections, improves the ionization efficiency of local gases, thereby improving the coupling efficiency between microwaves and plasma, reducing energy consumption, and improving the overall energy conversion efficiency. 3. Through a double-slit design, metal pillar constraint, and reflector surface optimization, the antenna achieves high-directional radiation with concentrated main lobe and suppressed side lobes. After the directionality is enhanced, microwave energy can be applied more precisely to the target process area, reducing energy waste in non-processing areas and improving plasma utilization efficiency and process controllability. 4. The present invention achieves uniform scanning of the load by a smart control method that senses the spatial distribution of plasma in real time and dynamically adjusts the position of the plasma source based on the sensing results. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the microwave plasma source in this invention; Figure 2 This is a schematic diagram of the microwave radiator in this invention; Figure 3 The simulation results are shown using traditional ceramic window panels. Figure 4 This is a simulation result diagram of the gradient refractive index dielectric plate at the center position in this invention; Figure 5 This is a simulation result diagram of the gradient refractive index dielectric plate used in this invention at the lower left corner position; Figure 6 This is a simulation result diagram of the gradient refractive index dielectric plate used in this invention, located at the lower right corner.

[0019] The attached diagram shows the markings and corresponding component names: 1. Solid-state microwave source; 2. Coaxial cable; 3. Microwave radiator; 4. Antenna feed point; 5. Moving platform; 6. Quartz ceramic layer; 7. Boron nitride ceramic layer; 8. Alumina ceramic layer; 9. Vacuum cavity; 10. Material tray to be processed; 11. All-metal rectangular plate body; 12. Double-slit structure; 13. Grounding copper column. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0021] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly or indirectly attached to that other component. When a component is referred to as being "connected to" another component, it can be directly or indirectly connected to that other component.

[0022] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] In existing technologies, systems using microwaves to generate plasma primarily focus on how to effectively couple microwave energy into a vacuum cavity to excite plasma for processes such as cleaning, etching, or deposition. Microwave energy input is typically achieved through a fixed microwave radiation structure, waveguide, or antenna integrated with a vacuum isolator. For example, a prior art microwave plasma applicator with improved power uniformity uses a waveguide and helical coil structure to introduce microwaves into a dielectric tube and attempts to improve the power absorption distribution within the discharge tube by adjusting the electric field direction. While this approach improves local energy absorption uniformity to some extent, the microwave source and ceramic window remain in a fixed configuration, preventing dynamic changes to the microwave incident position. The plasma field is still affected by the fixed cavity and energy input mode.

[0025] Similarly, existing technologies have proposed techniques to improve plasma density distribution by forming a ring-shaped plasma from the top surface of a cavity through ring microwave radiation. This technique attempts to form a more uniform plasma cloud through a specific antenna structure, but the position and radiation structure of the microwave source are also fixed, and the plasma density is mainly adjusted by the distribution of the reflection field inside the cavity, rather than by dynamically controlling the microwave incident position in space.

[0026] In addition, there are methods to improve plasma uniformity by adding multiple microwave introduction points inside the cavity, such as multi-branch waveguide structures. These structures distribute microwaves to multiple antenna or waveguide ports to introduce them into the cavity, attempting to improve the overall field uniformity within the cavity. While these methods are structurally complex, each incident end remains stationary, and the spatial distribution of microwave energy is still limited by a fixed geometric layout, preventing adjustments to the energy distribution path within the processing area according to process requirements.

[0027] Some existing technologies attempt to improve plasma density distribution by smoothing the distribution of the microwave electric field within the cavity through modal adjustments to the microwave field, such as mode switching within the waveguide and microwave absorbing / diffusion elements. These technologies emphasize the "static homogenization" of the electric field mode, that is, altering the shape of the existing standing wave field through cavity design and passive structures to make it spatially closer to an equilibrium distribution, aiming to improve the consistency of etching or coating processes. Although these technologies can reduce local peak electric fields to some extent, their core remains a passive optimization of an existing fixed energy distribution, failing to fundamentally address the homogenization limitations caused by the unchanged microwave incident position.

[0028] Compared with the aforementioned existing patented technologies, the technical solution of this invention differs significantly in its structural design concept. Traditional solutions generally employ an integrated fixed approach where the microwave source and vacuum isolation structure are fixed together. This means the direction and position of microwave radiation are entirely limited by the cavity geometry, making it impossible to adjust the spatial coverage of the microwave in the processing area. Consequently, "hot spots" and "dark areas" appear in the plasma density inside the cavity. While there have been numerous attempts to improve this fixed point source implementation, its dynamic controllability is insufficient, making it difficult to adjust the plasma position, size, and coverage trajectory according to process requirements.

[0029] To address the problems of low energy utilization, insufficient directionality, limited local power concentration, and insufficient cavity scanning flexibility in traditional microwave plasma devices, the present invention proposes the following technical solution.

[0030] Example 1: A microwave plasma source for plasma homogenization, such as... Figure 1 As shown, it includes a vacuum cavity 9, a solid-state microwave source 1, a microwave radiator 3, a moving platform 5, and a gradient refractive index dielectric plate.

[0031] The vacuum chamber 9 primarily provides a sealed chamber to maintain the low-pressure environment required for plasma processing. The solid-state microwave source 1 generates microwave signals. The microwave radiator 3 is electrically connected to the solid-state microwave source 1 via a coaxial line 2 and is used to receive and radiate microwave signals. The moving platform 5 carries the microwave radiator 3 and drives it to move along a plane outside the vacuum chamber 9. The gradient refractive index dielectric plate is sealed in the window area of ​​the vacuum chamber 9 and located on the microwave radiation path of the microwave radiator 3. The microwaves radiated by the microwave radiator 3 penetrate the gradient refractive index dielectric plate and form a surface wave-like mode inside the vacuum chamber 9 to achieve low-ionization plasma excitation.

[0032] In some optional examples, the vacuum chamber 9 is equipped with a material tray 10, a gas input interface, and a gas output interface. The material tray 10 is used to hold the workpiece, and the gas input interface and gas output interface are mainly used for the introduction of process gas and the discharge of exhaust gas.

[0033] Vacuum chamber 9 can be made of stainless steel with a polished inner wall. The interior of the chamber is evacuated to a low-pressure environment, such as 10, using mechanical and molecular pumps. -3 -10 3 The specific pressure (Pa) can be flexibly adjusted according to specific process requirements.

[0034] Although some existing technologies describe devices with adjustable microwave point sources within a cavity, these require electromagnetic shielding design for the control system placed inside the cavity, and also present problems such as inconvenience in the installation and maintenance of the control system. Furthermore, if the microwave radiation point is placed directly outside the vacuum cavity 9, the microwaves radiated by the microwave radiator 3 will penetrate the window plate, which previously only served as a seal, making it difficult to achieve low-ionization plasma excitation within the vacuum cavity 9.

[0035] To address this, the present invention replaces the conventional window plate with a gradient refractive index dielectric plate in the window region of the vacuum cavity 9. Furthermore, the design of separating the microwave radiator 3 from the vacuum-sealed ceramic component allows the microwave source to be no longer fixed within the cavity. Simultaneously, the highly directional microwave radiator 3, in conjunction with a motion control mechanism, moves along a predetermined path outside the ceramic plate, enabling dynamic adjustment of the microwave incident position in space. This approach not only overcomes the constraints of fixed radiation points in existing technologies but also allows for real-time changes in the plasma excitation position based on different process stages and target areas, providing more flexible and uniform plasma coverage for processes such as etching, deposition, and cleaning.

[0036] In some optional examples, the gradient refractive index dielectric plate is composed of multiple dielectric materials stacked sequentially along the microwave propagation direction, and the dielectric constant of the multiple dielectric materials increases sequentially from the atmospheric pressure side to the vacuum side of the vacuum cavity 9.

[0037] The gradient refractive index dielectric plate consists of a quartz ceramic layer 6, a boron nitride ceramic layer 7, and an alumina ceramic layer 8. Quartz ceramic layer 6 serves as the first layer, providing a low dielectric constant and structural support; boron nitride ceramic layer 7 serves as the second layer, improving dielectric uniformity and adjusting the refractive index gradient; and alumina ceramic layer 8 serves as the third layer, providing high-temperature resistance and enhancing impedance matching. The three layers form a gradient refractive index structure, achieving gradual microwave impedance matching and phase velocity compression. After penetrating the medium, the microwave is converted into a surface wave-like wave, with wavelength compression and a highly concentrated electric field in the vacuum region on the back of the ceramic, thereby exciting low-ionization plasma within a confined space. The refractive index gradient along the propagation direction causes wavefront bending, localizing the microwave along the medium interface. The refractive index gradient leads to the refraction and localization of electromagnetic waves along the medium interface, forming a surface wave mode with an electric field enhancement factor. , The local electric field strength on the surface. Using the free-space reference electric field strength can improve the local gas ionization efficiency.

[0038] Generally, the dielectric constant of the quartz ceramic layer 6 is 3.8-4.2, the dielectric constant of the boron nitride ceramic layer 7 is 4.5-5.0, and the dielectric constant of the alumina ceramic layer 8 is 9.5-10.0. For example, the dielectric constant of the quartz ceramic layer 6 is 3.8, the dielectric constant of the boron nitride ceramic layer 7 is 4.5, and the dielectric constant of the alumina ceramic layer 8 is 9.5.

[0039] The thickness of the gradient dielectric layer can be parametrically designed: the thickness of the quartz ceramic layer 6 is 3-5 mm, the thickness of the boron nitride ceramic layer 7 is 2-4 mm, and the thickness of the alumina ceramic layer 8 is 2-5 mm. The thickness ratio can be optimized according to the microwave frequency band and power density to improve the local gas ionization efficiency.

[0040] In some optional examples, such as Figure 2 As shown, the microwave radiator 3 includes an antenna feed point 4, an all-metal rectangular plate body 11, a double-slot structure 12, and two grounding copper pillars 13.

[0041] Specifically, the antenna feed point 4 is connected to the coaxial line 2; the all-metal rectangular plate body 11 is mounted on the moving platform 5 and is spaced apart from the gradient refractive index dielectric plate; the double-slit structure 12 is disposed on the side of the all-metal rectangular plate body 11 facing away from the gradient refractive index dielectric plate; and two grounding copper pillars 13 are disposed on both sides of the double-slit structure 12. The grounding copper pillars 13 on both sides and the metal reflective surface of the all-metal rectangular plate body 11 form a constrained electromagnetic boundary to achieve main lobe concentration and side lobe suppression.

[0042] The microwave radiator is erected at a certain height, and together with the grounded copper pillars 13 on both sides and the metal reflector, it forms a constrained electromagnetic boundary, achieving main lobe concentration and side lobe suppression. The metal pillars act as boundary conditions to regulate the antenna radiation mode (mode superposition and interferometry control), enhancing the directional gain according to beamforming and array theory. Furthermore, the field strength distribution is optimized. The double slots in the middle form a dual-mode coupling between microstrip resonance and current distribution, which can generate two approximately independent resonance peaks, thus broadening the antenna's operating bandwidth.

[0043] Each gap acts as a local capacitive load, changing the equivalent resonant frequency of the plate. By adjusting the gap width and spacing, dual-mode coupling is achieved, reducing the quality factor Q, improving impedance matching, and enhancing broadband performance.

[0044] The microwave radiator 3 adopts an all-metal structure (copper, aluminum or stainless steel) and can withstand a maximum input power of 300W. Combined with heat dissipation optimization (natural / air cooling / water cooling), it can avoid local overheating or dielectric breakdown.

[0045] In some optional examples, the moving platform 5 includes an X-axis slide rail, a Y-axis slide rail, a drive motor, and a transmission mechanism. The X-axis and Y-axis slide rails constitute a two-dimensional moving mechanism; the drive motor and transmission mechanism enable the microwave radiator 3 to perform reciprocating linear motion or trajectory planning motion within the working area of ​​the vacuum cavity 9; the scanning speed ranges from 0.1 to 10 mm / s, and the scanning trajectory covers the surface of the material to be processed.

[0046] The microwave radiator 3 is fixed on the XY dual-axis sliding bracket and can move arbitrarily in the XY plane to achieve microwave scanning or local coverage, making the plasma region dynamically adjustable. This provides the infrastructure to meet the strict requirements of spatial uniformity in processes such as deposition, etching, and cleaning.

[0047] The antenna of this invention adopts an all-metal rectangular plate body 11 (5mm thick, 45mm long and wide), with two precision slits in the middle. These slits achieve dual-mode coupling by changing the local capacitance and current path of the plate, causing the antenna to generate two approximately independent resonant peaks and reducing the antenna's quality factor. Expand half-power bandwidth , The center frequency of the antenna is given. Based on the transmission line model and cavity resonator theory, the gap width, length, and spacing can be optimized to match the impedance under different load conditions, ensuring stable coupling of microwaves over a wide frequency band.

[0048] In some optional examples, the presence of the double-slot structure 12 introduces microstrip resonance coupling with the plate resonance, forming two approximately independent resonance peaks and achieving low-Q broadband characteristics. Each slot acts as a local capacitive load, changing the plate's equivalent resonant frequency. , At the speed of light, The geometric length of the structure, To achieve effective refractive index, two-mode coupling is realized by adjusting the slit length, width, and spacing. Parametric optimization yields optimal impedance matching and bandwidth. For example, a 0.1 mm increase or decrease in slit width can alter the resonant frequency by approximately 10-15 MHz, and adjusting the slit spacing can affect the bimodal resonant interval, enabling customized bandwidth design.

[0049] Specific parameter optimization example: The gap length of the double-slit structure 12 is 18-22mm, the width is 0.5-1.0mm, and the spacing is 2-15mm. This can be adjusted according to the load dielectric constant. Adjustments were made to optimize the dual-peak resonance. The feed point 4 and the slot position of the bottom-fed N-type antenna were optimized through simulation to achieve a VSWR of <1.5 and ensure a power transmission efficiency of over 90%.

[0050] In some optional examples, the mounting height between the metal reflector and the antenna feed point 4 is 15-25 mm; the diameter of the grounding copper pillar 13 is 5-8 mm, and the spacing between two grounding copper pillars 13 is 30-35 mm. According to beamforming theory, the grounding copper pillar 13 serves as a boundary condition to constrain the electromagnetic field distribution, achieving main lobe concentration through mode superposition and suppressing sidelobe radiation, thereby improving directional gain. dBi. This structure can optimize the radiation pattern by adjusting the height and spacing parameters of the copper pillars, adapting to the uniformity requirements of different process areas.

[0051] This invention uses simulation comparison experiments, employing simulation results of traditional ceramic window panels, as shown below. Figure 3 As shown, the simulation results using a gradient refractive index dielectric plate at the center position are as follows: Figure 4 As shown, the simulation results using a gradient refractive index dielectric plate at the lower left corner are as follows: Figure 5 As shown, the simulation results using a gradient refractive index dielectric plate at the lower right corner are as follows: Figure 6 As shown in the figure. The comparison shows that when using a multi-layered gradient refractive index dielectric plate, the energy can be concentrated directly below the antenna, while without a multi-layered gradient refractive index dielectric plate, the energy cannot be concentrated, and the plasma will be scattered randomly.

[0052] Example 2: A microwave processing system includes a control module and a microwave plasma source for plasma homogenization processing as described in Example 1. The control module is electrically connected to a mobile platform 5, and the control module drives the mobile platform 5 to move along a planned path according to received or generated control signals.

[0053] For example, the planned path could be a strategy of uniform movement within the vacuum chamber 9, such as the moving platform 5 traversing the entire plane at a constant speed. Furthermore, timed movement strategies can be designed for different locations based on process requirements, and the planned path can be flexibly set as needed without restriction.

[0054] Considering that traditional open-loop or simple closed-loop control methods cannot sense the plasma distribution in real time, which can easily lead to local over-processing or under-processing, this invention proposes an intelligent control method that senses the spatial distribution of plasma in real time and dynamically adjusts the position of the plasma source based on the sensing results, thereby achieving uniform scanning of the load by the plasma.

[0055] In some optional examples, an optical monitoring device is also installed inside the vacuum chamber 9 to collect plasma distribution data in real time and feed it back to the control module or host computer.

[0056] The control module is also configured to perform the following steps: (1) Acquire the luminescence image of the plasma inside the vacuum chamber 9.

[0057] (2) The YOLO algorithm is used to identify the plasma region in the luminescent image and calculate the average brightness intensity. The average brightness intensity is then compared with the intensity level threshold calibrated in the experiment to determine the strength level of the plasma.

[0058] Average brightness intensity The calculation expression is: ,in, For plasma region, coordinates The pixel grayscale value at that location.

[0059] The specific classification of plasma intensity levels is as follows: If The plasma strength level is then classified as weak. This is the lower limit threshold for the intensity level; if The plasma strength level is then medium. This is the upper limit threshold for the intensity level; if If the plasma intensity level is strong, then the plasma intensity level is strong.

[0060] (3) Calculate the position error of the plasma at the current position by combining the preset target position of the load scanning area.

[0061] For example, setting the center of the load scan area as but: ,in The current position is represented by two-dimensional coordinates. This represents the positional error on the X-axis. This represents the positional error on the Y-axis.

[0062] (4) The vector velocity of the moving platform 5 is dynamically adjusted according to the position error and the intensity level of the plasma.

[0063] For example, if The plasma source moves in the negative X direction; if The plasma source moves in the positive X direction.

[0064] like The plasma source moves in the negative Y direction; if The plasma source moves in the positive Y direction.

[0065] (5) Control the moving platform 5 to move along the plane according to the vector velocity, and prioritize adjusting the path to the area with insufficient plasma intensity.

[0066] For example, the speed of movement is inversely proportional to the plasma intensity: , ; in, The speed of movement along the X-axis. The speed of movement on the Y-axis. These are the scaling factors on the X and Y axes, respectively; To prevent small constants from being divided by zero.

[0067] Record information such as the cumulative plasma exposure time of each region on the load surface, and prioritize guiding the plasma source to move to the under-processed area to achieve adaptive uniform scanning.

[0068] Working Principle: This invention overcomes the limitations of existing fixed microwave source plasma devices in terms of spatial uniformity, energy utilization, and process flexibility through a comprehensive technical solution that integrates highly directional microwave radiation, movable scanning, gradient medium matching, and dual-slit broadband design. This achieves efficient, uniform, and controllable industrial microwave plasma processing. This technology not only improves processing quality and process consistency but also reduces energy consumption, providing a practical solution for microwave plasma applications in large-area precision machining.

[0069] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0070] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0071] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0072] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0073] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A microwave plasma source for plasma homogenization, characterized in that, include: A vacuum chamber (9) is provided to provide a sealed chamber to maintain the low-pressure environment required for plasma processing; Solid-state microwave source (1) is used to generate microwave signals; A microwave radiator (3) is electrically connected to the solid-state microwave source (1) via a coaxial line (2) and is used to receive and radiate the microwave signal. The mobile platform (5) carries the microwave radiator (3) and drives the microwave radiator (3) to move along a plane outside the vacuum cavity (9); A gradient refractive index dielectric plate is sealed in the window area of ​​the vacuum cavity (9) and located on the microwave radiation path of the microwave radiator (3); The microwaves radiated by the microwave radiator (3) penetrate the gradient refractive index medium plate and form a surface wave-like mode in the vacuum cavity (9) to achieve low-ionization plasma excitation.

2. The microwave plasma source for plasma homogenization processing according to claim 1, characterized in that, The gradient refractive index dielectric plate is formed by stacking multiple dielectric materials sequentially along the microwave propagation direction, and the dielectric constant of the multiple dielectric materials increases sequentially from the atmospheric pressure side to the vacuum side of the vacuum cavity (9).

3. The microwave plasma source for plasma homogenization processing according to claim 2, characterized in that, The gradient refractive index dielectric plate is composed of a quartz ceramic layer (6), a boron nitride ceramic layer (7), and an alumina ceramic layer (8).

4. A microwave plasma source for plasma homogenization processing according to claim 3, characterized in that, The dielectric constant of the quartz ceramic layer (6) is 3.8-4.2, the dielectric constant of the boron nitride ceramic layer (7) is 4.5-5.0, and the dielectric constant of the alumina ceramic layer (8) is 9.5-10.

0.

5. A microwave plasma source for plasma homogenization processing according to claim 3, characterized in that, The thickness of the quartz ceramic layer (6) is 3-5 mm, the thickness of the boron nitride ceramic layer (7) is 2-4 mm, and the thickness of the alumina ceramic layer (8) is 2-5 mm.

6. A microwave plasma source for plasma homogenization processing according to any one of claims 1-5, characterized in that, The microwave radiator (3) includes: The antenna feed point (4) is connected to the coaxial line (2); The all-metal rectangular plate body (11) is mounted on the moving platform (5) and is spaced apart from the gradient refractive index medium plate; A double-slit structure (12) is disposed on the side of the all-metal rectangular plate body (11) facing away from the gradient refractive index medium plate; Two grounding copper pillars (13) are disposed on both sides of the double-slot structure (12); The grounding copper pillars (13) on both sides and the metal reflective surface of the all-metal rectangular plate body (11) form a constrained electromagnetic boundary to achieve main lobe concentration and side lobe suppression.

7. A microwave plasma source for plasma homogenization processing according to claim 6, characterized in that, The double-slit structure (12) has a slit length of 18-22 mm, a slit width of 0.5-1.0 mm, and a slit spacing of 2-15 mm.

8. A microwave plasma source for plasma homogenization processing according to claim 6, characterized in that, The mounting height between the metal reflector and the antenna feed point (4) is 15-25mm; the diameter of the grounding copper pillar (13) is 5-8mm, and the distance between the two grounding copper pillars (13) is 30-35mm.

9. A microwave processing system, characterized in that, Includes a control module and a microwave plasma source for plasma homogenization as described in any one of claims 1-8; The control module is electrically connected to the mobile platform (5) and drives the mobile platform (5) to move along the planned path according to the received or generated control signals.

10. A microwave processing system according to claim 9, characterized in that, The control module is also configured to: Acquire luminescence images of the plasma inside the vacuum cavity (9); The YOLO algorithm is used to identify the plasma region in the luminescent image and calculate the average brightness intensity. The average brightness intensity is then compared with the experimentally calibrated intensity level threshold to determine the plasma strength level. Based on the preset target position in the load scanning area, calculate the position error of the plasma's current position; The vector velocity of the moving platform (5) is dynamically adjusted according to the position error and the plasma intensity level. The moving platform (5) is controlled to move along the plane according to the vector velocity, and the path is adjusted preferentially to the area with insufficient plasma intensity.

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