A laser window anti-pollution device and method based on micro-transport mechanism

Abstract

The application relates to a laser window anti-pollution device and method based on a micro-transport mechanism, and the device comprises an anode cylinder, a cathode cylinder, a workpiece base, a diffusion trapping pipe, a laser window and a vacuum deposition chamber, wherein the laser window is arranged at the outermost layer and is provided with the vacuum deposition chambers on both sides; the anode cylinder and the cathode cylinder are placed on the same axis and are coaxial opposed electrodes; the central axis of the anode cylinder is designed with a through hole with a large length-diameter ratio, the diffusion trapping pipe with a large length-diameter ratio and a large space diffusion area; and the anode cylinder and the cathode cylinder are provided with the workpiece base on both sides. The application utilizes a three-stage series connection method of a small hole, the diffusion trapping pipe and the space diffusion area, realizes the non-attenuation of a laser beam, greatly attenuates the deposition jet directed to the laser window in the vacuum coating process, reduces the pollution of the laser window to be negligible, and has scientific and industrial practical potential.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of vacuum arc thin film deposition technology, and more particularly, the present application relates to a laser window anti-pollution device and method based on micro-transport mechanism. BACKGROUND

[0002] Vacuum arc deposition is a widely used thin film preparation technology in industry, and laser arc deposition technology using pulsed laser ignition is a new development direction. The characteristic of the laser arc deposition technology is that one laser pulse ignites a pulsed arc. Therefore, under the control of the program, the selective and alternate ignition of multiple targets can be easily realized, and the arc pulse energy, ignition times and repetition frequency of each target can be precisely controlled, so that the deposition of multi-layer, multi-component and gradient thin films and other important and urgent advanced functions can be realized. Compared with the continuous vacuum arc plating film using mechanical contact ignition, pulsed vacuum arc can produce a pulsed plasma with a temperature and density much higher than that of continuous arc. Laser ignition technology has excellent controllability, and the combination of the two has important significance for the industrial application of vacuum arc deposition technology and the scientific research of functional thin films.

[0003] The principle of laser arc deposition is that an external pulsed laser source converges on the cathode (target) surface through a laser window to ignite a pulsed vacuum arc discharge. The high temperature of the arc causes the cathode material to evaporate and ionize, forming an expanding plasma jet and depositing on the workpiece surface to form a thin film. There are three main methods for igniting the vacuum arc in the thin film deposition chamber: mechanical contact arc, high voltage breakdown discharge and pulsed laser ignition. Due to the high directionality and controllability of laser, it is used as a novel arc ignition method. This technology focuses high peak power pulsed laser on the cathode (target) surface to generate a small plasma, which in turn ignites the main pulsed arc. Compared with mechanical contact, high voltage pulsed breakdown and other methods, laser ignition has many advantages.

[0004] The laser ignition of the arc first needs to introduce the laser beam generated by the external laser source into the vacuum deposition chamber. However, the window used to introduce the laser into the vacuum chamber will also be deposited with thin films during the coating process and will soon lose high transparency, and the arc can no longer be reliably ignited. In a more serious case, the laser window absorbs too much heat and explodes, causing serious accidents. For industrial equipment, due to the requirement of production capacity, the deposition speed is much higher than that of research equipment, and the pollution of the laser window is much more serious. Unlike general coating observation windows, the method of using a baffle can prevent the observation window from being polluted, but it cannot be applied in the case of laser ignition because the laser beam is also blocked, and the laser energy cannot be introduced into the vacuum chamber. Therefore, the difficulty lies in preventing the window from being polluted by not shielding the window. If the deposition jet is shielded by a baffle, the thin film can be prevented from depositing on the window, but the laser beam is also blocked. The laser beam must be directly irradiated on the target, and there cannot be any opaque barrier between the window and the target. In this way, the introduction of the laser beam and the prevention of the pollution of the window are contradictory. So far, several methods have been tried to solve this problem, including in-situ laser cleaning, renewable transparent film walking mechanism, reflective light path, magnetic field and electric field deflection of plasma, pulsed gas flow protection window, etc., but the performance and industrial practical value are poor.

[0005] The core of the present application is to propose a new mechanism-based laser window anti-pollution method for laser arc thin film deposition chamber, which has better performance and industrial practical value to solve the pollution problem of the laser window. SUMMARY

[0006] The embodiments of the present application provide a laser window anti-pollution device and method based on micro-transport mechanism. In order to have a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This part is not a general review, nor does it determine the key / important elements or delineate the protection scope of these embodiments. Its only purpose is to present some concepts in a simple form as a prelude to the detailed description that follows.

[0007] In a first aspect, the embodiments of the present application provide a laser window anti-pollution device based on micro-transport mechanism, which comprises: an anode cylinder, a cathode cylinder, a workpiece pedestal, a diffusion trapping tube, a laser window, and a vacuum deposition chamber, wherein:

[0008] The laser window is arranged at the outermost layer, and the vacuum deposition chamber is arranged on both sides of the laser window;

[0009] The anode cylinder and the cathode cylinder are placed on the same axis and are coaxial opposed electrodes;

[0010] The central axis of the anode cylinder is designed with a large-aspect-ratio through hole, a large-aspect-ratio diffusion trapping tube, and a large space diffusion area;

[0011] The anode cylinder and cathode cylinder are provided with workpiece bases on both sides.

[0012] According to a preferred embodiment, the large aspect ratio hole on the axis of the anode cylinder has a diameter of ≤1mm near the outlet, and the anode small hole has an aspect ratio of 2-5mm.

[0013] According to a preferred embodiment, the large aspect ratio diffusion trapping tube has a diameter of ≤6mm and a length of about 50-100mm, and an aspect ratio of not less than 10.

[0014] According to a preferred embodiment, the length of the spatial diffusion zone is ≤350mm.

[0015] According to a preferred embodiment, a particle flow limiting structure is further provided between the spatial diffusion zone and the laser window, which limits the plasma.

[0016] According to a preferred embodiment, a scanning galvanometer is further provided, which cooperates with the control software to accurately adjust the position of the laser spot, ensuring that the laser beam is aligned with the small hole and does not irradiate on the hole wall.

[0017] According to a preferred embodiment, a lens is provided in the scanning galvanometer, which can play a focusing role.

[0018] According to another aspect of a preferred embodiment, the application provides a laser window anti-pollution method based on micro-transport mechanism, which comprises:

[0019] Step 1, converging an external pulsed laser source on the surface of the cathode cylinder through the laser window;

[0020] Step 2, igniting the vacuum arc discharge between the anode and cathode by the external pulsed laser source and forming a plasma;

[0021] Step 3, the plasma mostly expands radially to form a radial deposition jet pointing to the workpiece base;

[0022] Step 4, a small part of the plasma that does not expand radially passes through the anode small hole on the axis of the anode cylinder, and part of it will rub against the hole wall and cannot continue to escape through the anode small hole;

[0023] Step 5, a part of the plasma escaping from the anode small hole will be trapped by the diffusion trapping tube;

[0024] Step 6, the residual plasma that is not trapped by the diffusion trapping tube will randomly expand and fly away in space.

[0025] According to a preferred embodiment, the converging of the external pulsed laser source on the cathode cylinder surface through the laser window comprises:

[0026] The external pulsed laser source is introduced into the vacuum deposition chamber through the laser window;

[0027] The external pulsed laser source is converged on the cathode cylinder surface through the long-diameter ratio hole on the central axis of the anode cylinder.

[0028] According to a preferred embodiment, the external pulsed laser source ignites the vacuum arc discharge between the cathode and the anode and forms a plasma, comprising:

[0029] The external pulsed laser source converged on the cathode cylinder surface ignites the vacuum arc discharge between the cathode and the anode;

[0030] The high temperature of the vacuum arc makes the cathode material evaporate and ionize, forming a high-density plasma that expands rapidly.

[0031] The technical scheme provided by the embodiments of the present application can include the following beneficial effects:

[0032] In the embodiment of the present application, the laser window anti-pollution device based on micro-transport mechanism comprises an anode cylinder, a cathode cylinder, a workpiece base, a diffusion trapping tube, a laser window and a vacuum deposition chamber, wherein the laser window is arranged at the outermost layer and is provided with the vacuum deposition chamber on both sides; the anode cylinder and the cathode cylinder are arranged on the same axis and are coaxial opposed electrodes; the central axis of the anode cylinder is designed with a large-length-diameter ratio through hole, a large-length-diameter ratio diffusion trapping tube and a large space diffusion area; and the anode cylinder and the cathode cylinder are provided with the workpiece base on both sides. The laser window anti-pollution method based on micro-transport mechanism comprises the following steps: 1, converging an external pulsed laser source on the surface of the cathode cylinder through the laser window; 2, igniting vacuum arc discharge between the anode and the cathode by the external pulsed laser source and forming plasma; 3, most of the plasma expands in the radial direction to form a radial deposition jet pointing to the workpiece base; 4, a small part of the plasma that does not expand in the radial direction passes through the anode small hole in the central axis of the anode cylinder, part of which rubs against the hole wall and cannot continue to escape through the anode small hole; 5, a part of the plasma escaping from the anode small hole is trapped by the diffusion trapping tube; and 6, the residual plasma that is not trapped by the diffusion trapping tube randomly expands and scatters in space. The laser window anti-pollution device and method based on micro-transport mechanism provided in the present application use a three-stage series method of small hole, diffusion trapping tube and space diffusion area, which can allow the laser beam to pass through without attenuation, effectively guide the laser energy into the vacuum deposition chamber, effectively block the deposition jet pointing to the laser window in the laser path, thereby preventing the laser window from being polluted, making the laser arc ignition process continue and stabilize, and integrating the three-stage attenuation design and the anode design, the structure is simple, there is no moving part and no side effects on the deposition process environment. The technology is simple, stable and reliable, can be used for high-load industrial production equipment, and provides a more complete and practical method for solving the long-standing window pollution problem in laser arc deposition technology, which has scientific and industrial potential.

[0033] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0034] The drawings incorporated into the specification and forming part of the specification, show embodiments consistent with the present application, and together with the specification, serve to explain the principles of the present application.

[0035] Figure 1 is a basic structure schematic diagram of a laser arc deposition equipment of a laser window anti-pollution device based on micro-transport mechanism provided in the embodiment of the present application;

[0036] Figure 2 is a flowchart of a laser window anti-pollution method based on micro-transport mechanism provided by an embodiment of the present application;

[0037] Figure 3 is an engineering prototype schematic diagram of a laser window anti-pollution device and method based on micro-transport mechanism provided by an embodiment of the present application;

[0038] Figure 4 is a schematic diagram of a facing anode and cathode assembly of a laser window anti-pollution device and method based on micro-transport mechanism provided by an embodiment of the present application.

[0039] Reference signs: 1-target (cathode), laser ignition arc site, 2-dense plasma region generated between anode and cathode by laser ignition, 3-workpiece pedestal, 4-radial deposition jet formed after plasma expansion, 5-anode small hole, 6-diffusion trapping tube, 7-anode cylinder, 8-space diffusion zone, 9-particle flow restriction structure, 10-laser window, 11-converging laser beam, focused on the surface of the cathode, 12-vacuum deposition chamber. DETAILED DESCRIPTION

[0040] The following description and drawings are illustrative of specific embodiments of the present application and are not intended to limit the scope of the present application.

[0041] It should be clear that the described embodiments are only some of the embodiments of the present application, not all the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0042] The following description refers to the accompanying drawings. Unless otherwise indicated, same numbers in different drawings indicate same or similar elements. The implementations described in the following example embodiments are not meant to represent all implementations consistent with the present application. Rather, they are merely examples of systems and methods consistent with some aspects of the present application as detailed in the appended claims.

[0043] In the description of the present application, it should be understood that the terms "first", "second", etc. are used only for the purpose of description, and cannot be understood as indicating or implying relative importance. For a person of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. In addition, in the description of the present application, "multiple" means two or more, unless otherwise specified. "And / or", which describes the association between the associated objects, means that there can be three relationships, for example, A and / or B can mean that there are three cases of A alone, A and B together, and B alone. The character " / " generally represents that the associated objects before and after are in an "or" relationship.

[0044] The application will be described below in conjunction with the accompanying drawings Figure 1 - the drawings Figure 4 A laser window anti-pollution device and method based on micro-transport mechanism are provided in the embodiments of the application.

[0045] The innovation of the application is to propose a new mechanism and its technical implementation method, which can allow the laser beam to pass through without attenuation and effectively block the deposition jet directed to the window on the laser path, thereby preventing the laser window from being polluted and allowing the laser arc ignition process to continue stably. The new technology is simple, stable and reliable, and provides a more complete and practical solution to the long-standing window pollution problem in laser arc deposition technology. The embodiments of the application are implemented on a self-developed laser arc coating equipment engineering prototype, as shown in Figure 2 The overall scheme adopts a facing electrode design.

[0046] Please refer to Figure 1 A laser arc deposition equipment basic architecture schematic diagram is provided in the embodiments of the application based on the micro-transport mechanism of the laser window anti-pollution device. As shown in Figure 1 The laser window anti-pollution device based on the micro-transport mechanism described in the embodiments of the application can include an anode cylinder 7, a cathode cylinder 1, a workpiece base 3, a diffusion trapping tube 6, a laser window 10, and a vacuum deposition chamber 12, wherein:

[0047] The laser window 10 is arranged at the outermost layer, and the vacuum deposition chamber 12 is arranged on both sides of the laser window 10;

[0048] The anode cylinder 7 and the cathode cylinder 1 are placed on the same axis, and are coaxial facing electrodes;

[0049] The anode cylinder 7 has a large-length-diameter ratio through hole, a large-length-diameter ratio diffusion trapping tube 6, and a large space diffusion area 8 in the center axis;

[0050] The anode cylinder 7 and the cathode cylinder 1 are provided with the workpiece base 3 on both sides.

[0051] Specifically, the facing electrode is composed of the anode cylinder 7 and the cathode cylinder 1 which are coaxial, and the cathode cylinder in the embodiments of the application is a Figure 1The target in the anode cylinder 7 is machined with the large aspect ratio through hole and the large aspect ratio diffusion trapping tube 6. The large aspect ratio through hole on the axis of the anode cylinder 7 is designed with an anode small hole 5 with a diameter ≤1mm and an aspect ratio of 2-5mm near the outlet. The large aspect ratio diffusion trapping tube 6 is designed with a diameter ≤6mm and a length of about 50-100mm, with an aspect ratio not less than 10, and is water-cooled with the anode cylinder 7. The spatial diffusion zone 8 is designed with a length ≤350mm. The particle flow limiting structure 9 is further arranged between the spatial diffusion zone 8 and the laser window 10. The particle flow limiting structure 9 is provided with an opening on the laser path, and the opening is covered with a thin film. The thin film is a laser high-transmission film and does not affect the transmission of laser, but can limit the diffusion of plasma. The area of the thin film is larger than the laser window 10, and the particle flow limiting structure 9 is tightly attached to the laser window 10, so as to limit the diffusion of the little plasma in the spatial diffusion zone 8 and prevent the plasma from polluting the laser window 10. The laser window 10 plays a role of introducing laser and vacuum sealing. In addition, the device further comprises a scanning galvanometer, and the scanning galvanometer is provided with a lens and can play a role of focusing. When working, the lens in the scanning galvanometer converges the external pulsed laser source, and the scanning galvanometer cooperates with other control software to accurately adjust the position of the converged laser spot, so as to ensure that the laser beam is aligned with the small hole and does not irradiate on the hole wall. Therefore, the laser beam passes through the anode small hole 5 and is focused on the surface of the cathode cylinder 1 without attenuation.

[0052] Please refer to Figure 2 A flowchart of a laser window anti-pollution method based on micro-transport mechanism is provided for the embodiments of the present application. As shown in the figure, Figure 2 The method of the embodiments of the present application can include the following steps:

[0053] Step 1: converging the external pulsed laser source on the surface of the cathode cylinder 1 through the laser window 10;

[0054] Step 2: igniting the vacuum arc discharge between the anode and the cathode and forming plasma by the external pulsed laser source;

[0055] Step 3: most of the plasma expands along the radial direction to form a radial deposition jet 4 pointing to the workpiece pedestal 3;

[0056] Step 4: a small part of the plasma that does not expand along the radial direction passes through the anode small hole 5 on the axis of the anode cylinder 7, and part of it will rub against the hole wall and cannot continue to escape through the anode small hole 5;

[0057] Step 5: a part of the plasma escaping from the anode small hole 5 will be trapped by the diffusion trapping tube 6;

[0058] Step 6: The residual plasma that is not captured by the diffusion trapping tube 6 will randomly expand and disperse into space.

[0059] Specifically, firstly, an external pulsed laser source is focused through a lens within the scanning galvanometer and introduced into the vacuum deposition chamber 12 through the laser window 10. The laser beam focused by the lens is then focused onto the surface of the cathode cylinder 1 through a large aspect ratio through-hole on the anode cylinder 7, initially forming a laser ablation plasma. This small plasma serves as a seed source, subsequently igniting a pulsed arc between the anode and cathode, which is then subjected to a DC voltage, forming a high-temperature, high-density plasma (coaxial laser ignition; currently, all publicly reported and products use oblique incidence ignition). This high-density plasma exhibits properties defined by the vacuum technology term "viscous flow." A crucial feature of this application's embodiments is that, due to frequent collisions and changes in direction between particles, the microscopic particles (electrons, ions) in the plasma do not form ray-like flight trajectories when expanding in a vacuum; instead, they undergo a superposition of random thermal motion and overall flow. When such plasma passes through a pipe, the frequent collisions between ions and the pipe wall, as well as between ions themselves, generate significant frictional resistance, much like the resistance a person experiences when trying to quickly pass through a crowded narrow passage. This is the physical basis of this application.

[0060] The three attenuation mechanisms in this application embodiment are as follows:

[0061] (1) The blocking effect of the anode orifice 5 on the plasma;

[0062] Depend on Figure 1 It can be seen that the dense plasma between the opposing electrodes expands radially without hindrance, thereby forming a radial deposition jet 4 pointing towards the workpiece base 3. However, most of the plasma expanding axially is obstructed by the surface of the anode cylinder 7 and redirects to radial expansion, also forming a radial deposition jet 4 pointing towards the workpiece base 3. At the anode orifice 5 at the center of the anode cylinder 7, since there is no solid surface obstruction, an escape channel for the plasma exists. A small portion of the plasma escapes through the anode orifice 5; however, the viscous plasma experiences friction with the orifice wall as it passes through, encountering significant resistance, and consequently, the amount escaping is very small. The physical mechanism is as follows:

[0063] The flow rate of a viscous gas (such as high-density plasma) through a circular pipe in laminar flow conditions is:

[0064]

[0065] Where P1 and P0 are the pressures at the high-pressure and low-pressure ends of the pipeline, respectively, d is the pipeline diameter, l is the pipeline length, and η is the viscosity coefficient of the fluid. From equation (1), it can be seen that the flow rate increases with d.4 When the diameter of the pipe is reduced, the resistance of the small hole increases rapidly, the flow rate decreases rapidly, and the plasma is in a congested state. In this state, most of the plasma easily expands radially along the small resistance to form a radial deposition jet 4, and the plasma flowing through the anode small hole 5 is strongly blocked. In addition, it is worth noting that according to the analysis of the state of the plasma in the anode small hole 5, the characteristic quantity reflecting the flow state, the Reynolds number, is much larger than 2000, that is, the plasma is in a turbulent state defined in fluid mechanics. The resistance of the flow in this state is much larger than the value obtained by formula (1). Therefore, in the design of the present application, the first attenuation mechanism is that the plasma is blocked by the anode small hole 5. Figure 1 In the opposite electrode structure shown in the figure, the plasma deposition jet 4 is mainly sprayed radially, and only a small part passes through the anode small hole 5. Although it is difficult to know the viscosity coefficient of the plasma at a high temperature of ~30000K, as a conservative estimate, the plasma escaping from the anode small hole 5 is not more than 1 / 1000 of the total plasma. It can be seen that the plasma flow through the anode small hole 5 is greatly blocked. This is the first attenuation mechanism in the design.

[0066] (2) The large aspect ratio diffusion trapping pipe 6 traps the plasma;

[0067] Although the anode small hole 5 blocks most of the plasma, a small amount of it will still escape. In the design, most of the small amount of escape in the design will be trapped by the large aspect ratio diffusion trapping pipe 6 behind the anode small hole 5 during transmission. This is because the small amount of plasma escaping from the anode small hole 5 will spread away after leaving the anode small hole 5 due to its own thermal motion to hit the wall of the diffusion trapping pipe 6. The vapor of the general solid target material, that is, the plasma in the embodiment of the present application, will condense and deposit on the relatively cold diffusion pipe wall when it hits the wall, so the plasma can no longer continue to pass through the diffusion trapping pipe 6. This is the second attenuation mechanism in the design.

[0068] (3) The spatial diffusion zone 8 disperses the plasma;

[0069] After being limited by the anode small hole 5 and trapped by the diffusion trapping pipe 6, the remaining plasma is even more rare. When it reaches the outlet of the diffusion trapping pipe 6, it no longer flows directionally but expands and scatters into space according to the random thermal motion of microscopic particles, and its angular distribution obeys the Knudsen cosine law. From the Knudsen cosine law, it can be seen that the angle of the plasma is evenly distributed in all directions, and the plasma is dispersed in the spatial diffusion zone 8. Figure 1It can be seen that only a small part of the divergent and expanded plasma can reach the laser window 10, and a particle flow limiting structure 9 is further arranged between the spatial diffusion zone 8 and the laser window 10. The particle flow limiting structure 9 is provided with an opening on the laser passage, and a film is covered on the opening. The film is a laser high-transmission film and does not affect the transmission of laser, but can limit the diffusion of plasma. The area of the film is larger than the laser window 10, and the particle flow limiting structure 9 is tightly attached to the laser window 10 together, so as to limit the diffusion of the little plasma in the spatial diffusion zone 8 and prevent the plasma from polluting the laser window 10. This is the third attenuation mechanism in the design.

[0070] The three attenuation mechanisms described above are in a relationship of series connection, and therefore the total attenuation coefficient is the product of the attenuation coefficients. Due to this multiplication relationship instead of addition relationship, the total attenuation coefficient is very large, which is the desired result. Conservatively, the total attenuation coefficient is greater than 10 6 In contrast, the converged laser beam is very thin and has high directivity, and can pass through the small hole without attenuation after adjustment and alignment.

[0071] After the test of the embodiment of the present application, the finally achieved results include: the stable introduction of laser power into the vacuum chamber, the arc ignition rate of 100%, and the stable arc discharge parameter; the laser window 10 is not visibly polluted (cumulative 100,000 pulses), and the prevention of laser introduction window pollution is simpler and more thorough; the three-stage attenuation design is integrated with the anode design, the structure is simple, there is no moving part, and it is fully compatible with the film coating machine structure; it does not bring any side effects to the deposition process environment; it has potential for heavy-duty industrial equipment; the requirements for the laser are reduced, the cost is significantly reduced, and the reliability is increased.

[0072] The above implementation results show that after the three-stage series connection of the laser outlet through the small hole, the capture through the large-length-ratio diffusion pipeline, and the unconstrained spatial diffusion, the plasma that can pollute the window is already very small. After the film deposition process with a cumulative pulse number > 10 5 times, the laser window 10 is not visibly deposited and polluted. This result confirms the proposed mechanism, achieves both transmission of laser and prevention of plasma passing through, and solves the problem of laser introduction window pollution. It is proved that the method of using a properly designed hole instead of a baffle can achieve a method of transmitting laser beam without attenuation and greatly attenuating deposition jet on the laser passage. The method has a large attenuation ratio for the deposition jet, is simple and reliable, and has no moving parts. At the same time, according to its mechanism, this design idea can also be used for other shapes of electrode structures. For example, in the case of laser beam line scanning, a slit can be used instead of a small hole. For the case of laser oblique incidence, the effect and mechanism are similar.

[0073] The above embodiment numbers of the present application are only for description, and do not represent the advantages and disadvantages of the embodiments.

[0074] The above disclosure is merely the preferred embodiments of the present application and is not intended to limit the scope of the present application. Any equivalent changes made according to the claims of the present application are still within the scope of the present application.

Claims

1. A laser window anti-contamination device based on microscopic transport mechanism, characterized in that, include: The components include an anode cylinder, a cathode cylinder, a workpiece base, a diffusion trap, a laser window, and a vacuum deposition chamber, among which: The laser window is located on the outermost layer, and the vacuum deposition chambers are located on both sides; The anode cylinder and the cathode cylinder are placed on the same axis, forming coaxial opposing electrodes; The central axis of the anode cylinder is designed with a through hole with a large aspect ratio, a diffusion trap with a large aspect ratio, and a spatial diffusion zone. Workpiece bases are provided on both sides of the anode cylinder and the cathode cylinder; The through hole with a large aspect ratio on the central axis of the anode cylinder has a section of anode small hole with a diameter ≤1mm and an aspect ratio of 2 to 5mm near the outlet. The diameter of the high aspect ratio diffusion trap is ≤6mm, the length is 50mm~100mm, and the aspect ratio is not less than 12; The length of the spatial diffusion zone is ≤350mm; A particle flow confinement structure is also provided between the spatial diffusion region and the laser window, which confines the plasma.

2. The laser window anti-contamination device based on microscopic transport mechanism according to claim 1, characterized in that, It also includes a scanning galvanometer, which, in conjunction with control software, can precisely adjust the position of the laser spot to ensure that the laser beam is aligned with the small hole and does not irradiate the hole wall.

3. The laser window anti-contamination device based on microscopic transport mechanism according to claim 2, characterized in that, The scanning galvanometer is equipped with a lens, which can perform focusing.

4. A laser window anti-contamination method based on microscopic transport mechanism, characterized in that, The laser window anti-contamination device based on microscopic transport mechanism according to any one of claims 1-3 comprises: Step 1: Focus an external pulsed laser source onto the surface of the cathode cylinder through the laser window; Step 2: The external pulsed laser source ignites a vacuum arc discharge between the anode and cathode to form plasma; Step 3: Most of the plasma expands radially to form a radial deposition jet pointing towards the workpiece base; Step 4: A small portion of the plasma that does not expand radially passes through the anode hole along the central axis of the anode cylinder. Some of it will rub against the hole wall and will not be able to escape through the anode hole. Step 5: A portion of the plasma escaping from the anode orifice will be captured by the diffusion trapping tube; Step 6: The residual plasma that is not captured by the diffusion trap will randomly expand and disperse into space.

5. The laser window anti-contamination method based on microscopic transport mechanism according to claim 4, characterized in that, The step of focusing an external pulsed laser source onto the surface of a cathode cylinder through a laser window includes: The external pulsed laser source is introduced into the vacuum deposition chamber using the laser window; The external pulsed laser source converges onto the surface of the cathode cylinder through the large aspect ratio through hole on the central axis of the anode cylinder.

6. The laser window anti-contamination method based on microscopic transport mechanism according to claim 4, characterized in that, The external pulsed laser source ignites a vacuum arc discharge between the anode and cathode to form plasma, including: The external pulsed laser source, focused on the surface of the cathode cylinder, ignites the vacuum arc discharge between the anode and cathode; The high temperature of the vacuum arc causes the cathode material to evaporate and ionize, forming a rapidly expanding, high-density plasma.

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