Argon gas cluster ion polishing machine and polishing method of diamond crystal workpiece

Abstract

The invention provides an argon gas cluster ion polishing machine and a diamond crystal workpiece polishing method. The polishing machine comprises a pulse control valve used for generating pulse type airflow beams, and a nozzle device, a beam splitter, an ionizer, an absorption electrode, an accelerator and a permanent magnet which are sequentially arranged in the spraying direction of the pulse type airflow beams. The nozzle device is used for spraying pulse type airflow beams; wherein the pulse type airflow beam comprises divergent argon atom airflow and neutral cluster particle flow concentrated on a central shaft; the beam splitter is used for screening and separating neutral cluster particles and argon atoms in the pulse type airflow beam; the ionizer is used for ionizing the neutral cluster particles into cluster ions; the suction electrode is used for guiding the ionized ionomer clusters to form an initially converged conical airflow beam; the accelerator is used for focusing and accelerating the conical airflow beam; the permanent magnet is used for separating ions with different masses to form a pure cluster ion beam; and high-quality polishing of the surface of the diamond crystal workpiece can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of material surface treatment, and particularly relates to an argon gas cluster ion polishing machine and a polishing method for diamond crystal workpieces. Background Art

[0002] Ion implantation technology is a semiconductor doping and surface modification technology developed in the last century. By changing the surface composition and structure of materials, the surface properties of materials can be optimized, and even some new excellent properties can be obtained. That is, a material is bombarded with an ion beam having a certain energy and dose. Due to the impact of atoms and molecules in the material or other physical and chemical effects, the ion beam gradually loses energy, reduces its speed, and finally stops at a position not far from the material surface.

[0003] The excellent physical and chemical properties of diamond make it widely used in many fields. Diamond is an indirect bandgap semiconductor material with a bandgap width of about 5.2 eV, a thermal conductivity as high as 22 W / (cm•K), and room temperature electron and hole mobilities as high as 4500 cm 2 / (V.s) and 3380 cm 2 / (V.s), which are much higher than those of the third-generation semiconductor materials GaN and SiC. Therefore, diamond has broad application prospects in high-power power electronic devices operating at high temperatures and high-frequency high-power microwave devices.

[0004] However, during the processing of diamond crystal workpieces, processing marks, microcracks and a certain degree of roughness often remain on their surfaces. These defects not only affect the appearance quality of diamond crystal workpieces, but also have a negative impact on their service performance. For example, in the electronic field, it may affect the stability of electrical signal transmission, and in die applications, it may reduce the demolding performance, etc.

[0005] Traditional polishing methods, such as mechanical polishing and chemical polishing, have many limitations when dealing with diamond crystal workpieces. Mechanical polishing is prone to cause surface scratches and subsurface damage, and it is difficult to achieve uniform polishing for diamond crystal workpieces with complex shapes; chemical polishing may introduce chemical impurities, corrode the workpiece substrate, and at the same time face environmental protection pressure. Therefore, it is urgent to develop a high-efficiency, precise and non-destructive surface polishing technology for diamond crystal workpieces. In the surface treatment of materials, especially under the high-precision polishing requirements of materials such as diamond crystals, the argon gas cluster ion source polishing technology has gradually emerged. However, there are many deficiencies in the structural design and performance of existing nozzle devices. Common nozzles are difficult to accurately control the injection direction, flow rate, and energy distribution of the argon gas cluster ion beam, resulting in problems such as uneven polishing and low efficiency during the polishing process. Moreover, traditional nozzles lack flexibility and adaptability when facing workpieces of different shapes and sizes, and cannot meet diverse processing requirements. In addition, during long-term use, the nozzle is easily eroded and corroded by the ion beam, resulting in a short service life and high maintenance costs.

[0006] Therefore, it is urgent to develop a nozzle device for argon gas cluster ion source polishing that is efficient, accurate, and durable. Summary of the Invention

[0007] Based on the above description, the present invention provides an argon gas cluster ion polishing machine and a polishing method for diamond crystal workpieces, which can be used to generate and accelerate hot electrons. Under the action of sufficient ionization of neutral cluster particles and acceleration voltage, cluster ions are obtained and a cluster ion beam is formed to achieve high-quality polishing of the surface of diamond crystal workpieces, improve their surface finish and flatness, reduce surface roughness, and at the same time avoid the damage and pollution problems brought by traditional polishing methods.

[0008] The technical solutions of the present invention to solve the above technical problems are as follows: In a first aspect, the present invention provides an argon gas cluster ion polishing machine, including a pulse control valve for generating a pulsed gas flow beam, and a nozzle device, a beam splitter, an ionizer, an extractor, an accelerator, and a permanent magnet arranged in sequence along the direction of the pulsed gas flow beam ejection; The nozzle device is used to eject the pulsed gas flow beam; wherein, the pulsed gas flow beam includes a divergent argon atom gas flow and a neutral cluster particle flow concentrated on the central axis; The beam splitter is used to screen and separate the gas flow beam in the pulsed gas flow beam in a cluster state; The ionizer is used to ionize the particles in the gas flow beam into cluster ions; The extractor is used to guide the ionized cluster ions to form an initially converging conical gas flow beam; The accelerator is composed of three-stage electrostatic lenses and is used to focus and accelerate the conical gas flow beam; The permanent magnet is used to separate ions of different masses to form a pure cluster ion beam; It further includes a displacement platform, and the displacement platform is used to carry the diamond crystal workpiece to be polished.

[0009] On the basis of the above technical solutions, the present invention can also be improved as follows.

[0010] Further, it further includes a vacuum chamber; the vacuum chamber is provided with a vacuum pump group for maintaining the internal vacuum degree of the device between 1×10⁻³ and 1×10⁻ 4 Pa.

[0011] Further, the minimum aperture of the beam splitter is 1.4 - 2 mm.

[0012] Further, the ionizer includes a grid screen housing, two cathodes and an anode; wherein, the shape of the grid screen housing is cylindrical and the material is stainless steel; The cathode is prepared from tungsten wire; The anode is prepared from molybdenum material.

[0013] Further, the nozzle device includes an ultrasonic nozzle and a positioning and collimating assembly arranged in sequence along the direction of the pulsed gas flow beam; The head of the ultrasonic nozzle is a double - layer conical nozzle structure. The outer conical nozzle is used to eject a divergent argon atom gas flow, and the inner conical nozzle is used to eject a neutral cluster particle flow concentrated on the central axis; The positioning and collimating assembly is used to perform positioning and collimating processing on the argon atom gas flow and the neutral cluster particle flow.

[0014] In a second aspect, the present invention provides a polishing method for polishing a diamond crystal workpiece by using the argon gas cluster ion polishing machine described in the first aspect, including the following steps: S1. Generate a pulsed gas flow beam through a pulse control valve. The gas flow beam includes a divergent argon atom gas flow and a neutral cluster particle flow concentrated on the central axis; S2. Use the nozzle device to eject the pulsed gas flow beam along a preset direction; S3. Use the beam splitter to screen and separate the neutral cluster particles and argon atoms in the pulsed gas flow beam; S4. Ionize the neutral cluster particles into cluster ions and ionize the argon atoms into single - atom ions in the ionizer; S5. Guide the ionized ions through the attracting electrode to form an initially converging conical gas flow beam; S6. Use the accelerator to focus and accelerate the conical gas flow beam; S7. Separate ions of different masses through a permanent magnet to form a pure cluster ion beam; S8. Act on the surface of the diamond crystal workpiece with the cluster ion beam for polishing treatment.

[0015] Based on the above - mentioned technical solutions, the present invention can also be improved as follows.

[0016] Further, before step S1, it also includes: introducing high-purity argon gas into the vacuum chamber.

[0017] Further, in step S8, the process parameters of the polishing treatment include: Ion energy: 1 - 10 keV; Ion beam current density: 10 - 100 μA / cm²; Polishing time: 10 - 60 minutes.

[0018] Further, after step S8, it also includes: Inspecting and post-processing the polished diamond crystal workpiece.

[0019] Further, the inspection includes surface roughness measurement, surface flatness detection, and electrical property testing; The post-processing includes ultrasonic cleaning and drying treatment.

[0020] Compared with the prior art, the argon gas cluster ion polishing machine and the corresponding polishing method for polishing diamond crystal workpieces provided by the present invention have the following beneficial technical effects: (1) The gas cluster ion source generation method provided by the present invention can achieve that at standard temperature and a certain air pressure, the neutral clusters passing through the conical nozzle are ionized during the collision with electrons to form gas cluster ions, and then under the action of the extraction electrode, accelerator, and permanent magnet, they converge into a cluster ion beam. This generation mechanism is not only efficient and stable, but also can precisely control the formation process of the ion beam, ensuring the quality and performance of the ion beam. Compared with the traditional ion source generation method, the method of the present invention can work under a wider range of environmental conditions, has stronger adaptability, and the energy distribution of the generated ion beam is more uniform, providing a stable and high-quality ion source for the subsequent polishing process. (2) In the argon gas cluster ion polishing machine of the present invention, a pulsed control valve is used to control the ejection of a pulsed gas flow beam, which includes two different conical gas flows. One is composed of divergent argon atoms, and the other is composed of neutral cluster particles concentrated on the central axis. The pulsed gas flow beam passes through the beam splitter, and the beam splitting ratio can be adjusted as needed. This design can accurately control the particle flow acting on the surface of the diamond crystal workpiece, realizing precise processing of different regions and different processing requirements. The divergent argon atom gas flow can perform a large-area preliminary cleaning on the workpiece surface to remove loose attachments, while the concentrated neutral cluster particle flow can perform fine polishing on key regions, greatly improving the polishing efficiency and quality. (3) In the argon gas cluster ion polishing machine of the present invention, a permanent magnet (preferably an E-shaped permanent magnet) is provided, which consists of an iron core and two Co-Sm magnetic poles. The magnetic field strength at the center of the E-shaped permanent magnet is about 150 mT. According to the Lorentz force principle, in the magnetic field environment generated by it, single-atom ions and light cluster ions will deviate from their original paths due to the action of Lorentz forces to varying degrees, while heavy cluster ions, due to their large mass, are relatively less affected by the Lorentz force on their motion trajectories and almost maintain their original paths through the magnetic field. Finally, the separation and screening of ions with different masses are realized, enabling the heavy cluster ions to converge into a cluster ion beam, effectively improving the purity and stability of the ion beam, and providing a high-quality ion beam current for the subsequent polishing process of diamond crystal workpieces.

[0021] (4) In the argon gas cluster ion polishing machine of the present invention, a high-precision displacement platform is used to carry the diamond crystal workpiece. Its positioning accuracy can reach ±0.001 mm, the repeat positioning accuracy is ±0.0005 mm, and the motion speed range is 1 - 100 mm / s, realizing precise motion control of the workpiece relative to the ion beam, ensuring that the ion beam evenly covers the entire surface of the workpiece. For workpieces with complex shapes, multi-axis linkage can also be achieved through programming, enabling the ion beam to accurately scan along the contour of the workpiece. At the same time, an optical microscope, a scanning electron microscope, and an energy dispersive X-ray spectrometer (EDS) are used to observe the surface state of the workpiece in real time and detect changes in elemental composition. Once abnormalities are found, such as new damage or impurity contamination on the surface, the polishing is immediately stopped and the process parameters are adjusted, ensuring the stability and reliability of the entire polishing process, greatly reducing the defective rate, and improving production efficiency.

[0022] In summary, the argon gas cluster ion polishing machine and the polishing method for diamond crystal workpieces provided by the present invention can be used to generate and accelerate hot electrons. Under the action of sufficient ionization of neutral cluster particles and acceleration voltage, cluster ions are obtained and a cluster ion beam is formed to achieve high-quality polishing of the surface of diamond crystal workpieces, improve their surface finish and flatness, reduce the surface roughness, and at the same time avoid the damage and contamination problems brought by traditional polishing methods. BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0023] Figure 1 It is a schematic structural diagram of the argon gas cluster ion polishing machine provided in Embodiment 1 of the present invention; Figure 2A polishing method for polishing a diamond crystal workpiece using the argon gas cluster ion polishing machine provided in Embodiment 2 of the present invention; In the attached drawings, the list of components represented by each reference numeral is as follows: 1. Pulse control valve; 2. Nozzle device; 21. Ultrasonic nozzle; 22. Alignment and collimation assembly; 3. Beam splitter; 4. Ionizer; 41. Grid screen housing; 42. Cathode; 43. Anode; 5. Attractor; 6. Accelerator; 7. Permanent magnet; 8. Boron nitride insulating disc; A. Cluster gas flow; B. Pulsed gas flow beam passing through the ionizer. Detailed implementation manners

[0024] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without making creative efforts based on the embodiments in the present invention belong to the scope of protection of the present invention.

[0025] The following combines the attached Figure 1 and Figure 2 and embodiments to further describe the implementation manners of the present invention in detail. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0026] Embodiment 1 The embodiment of the present invention provides an argon gas cluster ion polishing machine, as Figure 1 shown, including a pulse control valve 1 for generating a pulsed gas flow beam, and a nozzle device 2, a beam splitter 3, an ionizer 4, an attractor 5, an accelerator 6 and a permanent magnet 7 arranged in sequence along the ejection direction of the pulsed gas flow beam.

[0027] The pulse control valve 1 is used to generate a pulsed gas flow beam, and the nozzle device 2 is used to eject the pulsed gas flow beam; wherein, the pulsed gas flow beam contains a divergent argon atom gas flow and a neutral cluster particle flow concentrated on the central axis - the cluster gas flow A.

[0028] The beam splitter 3 is used to screen and separate the neutral cluster particles and argon atoms in the pulsed gas flow beam. Preferably, the minimum aperture of the beam splitter 3 is 1.4 - 2 mm.

[0029] Specifically, when the gas flow enters from the smallest aperture, only the clusters with concentrated distribution can pass through smoothly, thereby excluding part of the argon atoms, so that the neutral cluster particles and another part of the argon atoms can pass through the beam splitter. The passed clusters still maintain a conical shape and coincide with the central axis of the subsequent ionizer.

[0030] The beam splitter 3 is made of pure aluminum material. To further improve its performance and durability, a layer of nickel is plated on the surface of the beam splitter 3. The nozzle equipped with the beam splitter 3 has its diameter range precisely controlled within 0.15 - 0.25 mm, ensuring a stable and precise material ejection effect.

[0031] The ionizer 4 is used to ionize neutral cluster particles into cluster ions.

[0032] The collector 5 is used to guide the ionized cluster ions to form an initially converging conical air flow beam.

[0033] The accelerator 6 is composed of three - stage electrostatic lenses and is used to focus and accelerate the conical air flow beam.

[0034] The middle electrostatic lens of the three - stage electrostatic lenses of the accelerator 6 is applied with a negative voltage of - 7 ~ 12 kV, and the other two electrostatic lenses are grounded. This configuration can achieve precise focusing and acceleration of the ion beam. The middle negative - voltage lens attracts ions, causing them to converge towards the central axis and accelerate; the two grounded lenses play a role in defining the electric - field boundary and can assist in focusing to meet the requirements of different polishing processes for ion energy and beam shape.

[0035] The permanent magnet 7 is used to separate ions of different masses to form a pure cluster ion beam.

[0036] Preferably, it is an E - type permanent magnet 7. Correspondingly, in this embodiment, the E - type permanent magnet 7 is 50 mm long, consists of an iron core and two magnetic poles, and has a relatively strong central magnetic force, reaching about 150 mT.

[0037] It also includes a displacement platform, which is used to carry the diamond crystal workpiece to be polished.

[0038] In an alternative example, it also includes a vacuum chamber; the vacuum chamber is equipped with a vacuum pump group to maintain the internal vacuum degree of the device between 1×10⁻³ and 1×10⁻ 4 Pa.

[0039] Specifically, high - purity argon gas (purity ≥99.999%) is selected as the working gas and introduced into the vacuum chamber through a precision gas flow controller. The vacuum chamber is equipped with a high - efficiency vacuum pump group to maintain the internal vacuum degree between 1×10⁻³ and 1×10⁻ 4 Pa, ensuring that argon can form stable clusters in the chamber.

[0040] The ion source uses electron cyclotron resonance to excite argon gas. The pulsed control valve 1 controls the ejection of a pulsed gas flow beam, ionizes it and aggregates it into cluster ions, and focuses and shapes the ion beam through an electromagnetic focusing system to ensure the energy distribution uniformity and directivity of the ion beam.

[0041] The argon gas cluster ion source has significant advantages compared with traditional ion sources. On the one hand, the energy dispersion of the ion beam generated by it is extremely low, enabling precise removal of atoms on the surface of diamond crystal workpieces at the atomic level, avoiding over-etching or damage to the surrounding areas, and maximizing the preservation of the original structural integrity of the workpieces. On the other hand, the large size of the cluster ions makes the energy transfer more gentle and uniform when they interact with the workpiece surface. Compared with single-atom ions, the probability of surface defects caused by concentrated energy is greatly reduced, effectively reducing the formation of microcracks, pits and other defects, laying a foundation for obtaining a super-smooth surface.

[0042] Argon is excited by the electron cyclotron resonance method. The pulsed gas flow beam passes through the ionizer 4. Thermoelectrons are generated in the ionizer 4. The neutral cluster particles in the pulsed gas flow beam are ionized into cluster ions, and argon atoms are ionized into single-atom ions.

[0043] In a specific example, the ionizer 4 includes a grid screen housing 41, two cathodes 42 and an anode 43.

[0044] The grid screen housing 41 is cylindrical in shape and made of stainless steel; the cathode 42 is prepared from tungsten wire; the anode 43 is prepared from molybdenum material.

[0045] Specifically, the cathode 42 material of the ionizer 4 is tungsten wire, which is used to emit thermoelectrons. During the process of thermoelectrons reaching the anode 43 from the cathode 42, they collide with cluster particles, ionizing them into cluster ions. The entire ionizer 4 is wrapped by a cylindrical stainless steel grid screen, which can prevent thermoelectrons from escaping and enable them to fully contact the clusters, greatly improving the ionization efficiency. Both ends of the ionizer 4 are connected to the grounded aperture through boron nitride insulating disks 8. The boron nitride insulating disks 8 are used to isolate the ionizer 4 and the aperture, and can also support the anode 43, the cathode 42 and the stainless steel grid screen. This structural design not only ensures a stable electric field environment inside the ionizer 4, but also enhances the mechanical stability and electrical insulation of the entire device, effectively extending the service life of the equipment and reducing the maintenance cost.

[0046] Furthermore, the conical gas flow beam continues to be accelerated by the accelerator 6 and then passes through the E-shaped permanent magnet 7. When passing through the magnetic field of the E-shaped permanent magnet 7, the single-atom ions and cluster ions with an atomic number less than or equal to 100 in the conical gas flow beam deviate under the action of the Lorentz force, and the cluster ions with an atomic number greater than 100 maintain the original path and pass through the magnetic field, forming a cluster ion beam.

[0047] In an alternative example, the nozzle device 2 includes an ultrasonic nozzle 21 and a positioning and collimation assembly 22 arranged in sequence along the direction of the pulsed gas flow beam ejection.

[0048] The head of the ultrasonic nozzle 21 has a double-layer conical nozzle structure. The outer conical nozzle is used to eject a divergent argon atom gas flow, and the inner conical nozzle is used to eject a neutral cluster particle flow concentrated on the central axis.

[0049] The positioning and collimating assembly 22 is used to perform positioning and collimating processing on the argon atom gas flow and the neutral cluster particle flow.

[0050] Embodiment 2 This embodiment provides a polishing method for polishing a diamond crystal workpiece using the argon gas cluster ion polishing machine described in Embodiment 1, including the following steps: S1. Generate a pulsed gas flow beam through a pulse control valve. The gas flow beam includes a divergent argon atom gas flow and a neutral cluster particle flow concentrated on the central axis.

[0051] Before step S1, it further includes: introducing high-purity argon gas into the vacuum chamber.

[0052] S2. Use the nozzle device to eject the pulsed gas flow beam along a preset direction.

[0053] S3. Use a beam splitter to screen and separate the neutral clusters and argon atoms in the pulsed gas flow beam.

[0054] S4. Ionize the neutral cluster particles into cluster ions and the argon atoms into single atom ions in an ionizer.

[0055] S5. Guide the ionized ions through a collector to form an initially converging conical gas flow beam.

[0056] S6. Use an accelerator to focus and accelerate the conical gas flow beam.

[0057] S7. Separate ions of different masses through a permanent magnet to form a pure cluster ion beam.

[0058] S8. Apply the cluster ion beam to the surface of the diamond crystal workpiece for polishing treatment.

[0059] Specifically, the process parameters of the polishing treatment include: Ion energy: 1 - 10 keV; Ion beam current density: 10 - 100 μA / cm²; Polishing time: 10 - 60 minutes.

[0060] Corresponding effects: In this embodiment, comprehensive process parameter optimization is achieved. By precisely setting process parameters such as ion energy, ion beam current density, and polishing time, personalized adjustment can be made according to the material properties, initial surface roughness, and required polishing effect of the diamond crystal workpiece. For example, the ion energy can be precisely adjusted between 1 - 10 keV, the ion beam current density is controlled within the range of 10 - 100 μA / cm², and the polishing time is set between 10 - 60 minutes according to the actual situation of the workpiece. At the same time, combined with real-time monitoring technologies, such as using a laser interferometer to monitor the change in surface flatness and an atomic force microscope for on-line detection of surface roughness, the polishing time is dynamically adjusted to ensure that the best effect can be achieved for each polishing, meeting the strict requirements for the surface quality of diamond crystal workpieces in different application scenarios.

[0061] S9. Inspect and post-process the polished diamond crystal workpiece.

[0062] Specifically, the inspection includes surface roughness measurement, surface flatness detection, and electrical property testing; the post-processing includes ultrasonic cleaning and drying treatment.

[0063] After polishing, the possible residual ion implantation layer or loose particles on the surface are removed by mild ultrasonic cleaning, and then drying treatment is carried out. A variety of detection means are used to comprehensively evaluate the quality of the polished workpiece. The surface roughness Ra value is measured by a surface roughness measuring instrument with an accuracy of up to ±0.001 μm to ensure that it is reduced below a predetermined standard (such as Ra ≤ 0.1μm); the surface flatness is detected by a profiler with an accuracy of ±0.001 mm to ensure that the flatness deviation is within the range of ±0.005 mm; the electrical property indexes such as conductivity are detected by an electrical property testing device to verify that the polishing process has not had a negative impact on the electrical properties of the diamond crystal. This perfect post-processing and quality inspection system ensures the high quality of the final product and provides a strong guarantee for the application of diamond crystal workpieces in fields with extremely high surface quality requirements such as aerospace and electronics.

[0064] In a specific example, the specific working process of the argon gas cluster ion polishing machine is introduced: 1. Generation of pulsed gas flow beam: Under the gas pressure environment of standard temperature 293K (20℃) and 101.325kPa, the pulsed control valve precisely regulates and sprays a pulsed high-pressure gas flow beam. This gas flow beam is conical and can be clearly divided into two parts. Among them, the single-atom conical gas flow B is mainly composed of argon atoms and is widely distributed; while the cluster gas flow is composed of neutral cluster particles concentrated on the central axis of the pulsed gas flow beam, with a relatively concentrated distribution and closer to the central axis. 2. Beam splitter screening: The pulsed gas flow enters the beam splitter. When the gas flow enters from the location with the smallest aperture, only the clusters with concentrated distribution can pass through smoothly, thereby excluding some argon atoms, enabling neutral cluster particles and some other argon atoms to pass through the beam splitter. The clusters passing through still maintain a conical shape and coincide with the central axis of the subsequent ionizer.

[0065] 3. Ionization process: The pulsed gas flow enters the ionizer. The cathode of the ionizer is made of tungsten wire, and its function is to emit thermoelectrons. The voltage difference between the anode and the cathode is set between 60 and 200 V, and this voltage difference is used to accelerate the thermoelectrons until the energy of the thermoelectrons reaches the ionization energy of the cluster particles. During the movement of the thermoelectrons from the cathode to the anode, they collide with the cluster particles, thereby ionizing the cluster particles into cluster ions. At this time, the anode current is about 40 mA, and the cathode current is about 1.4 A.

[0066] The entire ionizer is wrapped by a cylindrical stainless steel grid screen, which can effectively prevent the escape of thermoelectrons and ensure sufficient contact between the thermoelectrons and the clusters. Both ends of the ionizer are connected to the grounded diaphragm through boron nitride insulating disks. The boron nitride insulating disks not only play a role in isolating the ionizer and the diaphragm but also support the anode, cathode, and stainless steel grid screen. After passing through the ionizer, the neutral cluster particles in the pulsed gas flow are ionized into cluster ions, and the argon atoms are also ionized into single-atom ions.

[0067] 4. Accelerating and converging by the collector: The pulsed gas flow passing through the ionizer enters the collector. Under the action of the collector, the gas flow obtains an initial acceleration and gradually converges to form a converging conical gas flow, preparing for further acceleration and screening in the subsequent process.

[0068] 5. Screening and separation by the E-shaped permanent magnet: The conical gas flow continues to be further accelerated through the accelerator and then enters the magnetic field region of the E-shaped permanent magnet. In the magnetic field, according to the Lorentz force principle, the single-atom ions and the cluster ions with the number of atoms less than or equal to 100 (heavy clusters) in the conical gas flow will be affected by the Lorentz force and deviate from the original path, while the cluster ions with the number of atoms greater than 100 (light clusters) are hardly affected by the Lorentz force on their movement trajectories and almost maintain the original path through the magnetic field, finally successfully forming a pure cluster ion beam, providing a high-quality ion source for the subsequent polishing process of diamond crystal workpieces.

[0069] In summary, the argon gas cluster ion polishing machine and the polishing method for diamond crystal workpieces provided by the embodiments of the present invention can be used to generate and accelerate thermoelectrons. Under the action of sufficient ionization of neutral cluster particles and accelerating voltage, cluster ions are obtained and a cluster ion beam is formed to achieve high-quality polishing of the surface of diamond crystal workpieces, improve their surface finish and flatness, reduce the surface roughness, and at the same time avoid the damage and pollution problems brought by traditional polishing methods. In the description of this specification, the description referring to terms such as "specific example" or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An argon gas cluster ion polisher, characterized in that: It includes a pulse control valve for generating a pulsed gas flow beam, and a nozzle device, a beam splitter, an ionizer, an anode, an accelerator and a permanent magnet which are sequentially arranged along the ejection direction of the pulsed gas flow beam; The nozzle device is used to spray the pulsed gas flow beam; wherein the pulsed gas flow beam comprises a divergent argon atomic gas flow and a neutral cluster particle flow concentrated on a central axis; The beam splitter is used to screen and separate the airflow beam in a cluster state from the pulsed airflow beam; The ionizer is used to ionize particles in the gas flow beam into cluster ions; The absorber is used to guide the ionized de-clustered clusters to form an initially converging conical airflow beam; The accelerator is composed of three-stage electrostatic lenses for focusing and accelerating the conical airflow beam; The permanent magnet is used to separate ions of different masses to form a pure cluster ion beam; It also includes a displacement platform, which is used to carry the diamond crystal workpiece to be polished.

2. The argon gas cluster ion polishing machine according to claim 1, characterized in that: It also includes a vacuum chamber; the vacuum chamber is provided with a vacuum pump group for maintaining the vacuum degree inside the device at 1×10⁻³~1×10⁻ 4 Between Pa.

3. The argon gas cluster ion polishing machine according to claim 1, characterized in that: The minimum aperture of the beam splitter is 1.4~2mm.

4. The argon gas cluster ion polishing machine according to claim 1, characterized in that: The ionizer includes a screen housing, two cathodes and an anode; Wherein, the shape of the grille screen shell is cylindrical and the material is stainless steel; The cathode is prepared by using tungsten wire; The anode is made of molybdenum material.

5. The argon gas cluster ion polishing machine according to claim 1, characterized in that: The nozzle device comprises an ultrasonic nozzle and a positioning collimation assembly which are sequentially arranged along the ejection direction of the pulsed air flow beam; The head of the ultrasonic nozzle is a double-layer conical nozzle structure, the outer conical nozzle is used to spray a divergent argon atomic gas flow, and the inner conical nozzle is used to spray a neutral cluster particle flow concentrated on the central axis; The positioning and collimation component is used to perform positioning and collimation processing on the argon atomic gas flow and the neutral cluster particle flow.

6. A polishing method for polishing a diamond crystal workpiece using the argon gas cluster ion polisher according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. Generate a pulsed gas flow beam through a pulse control valve, wherein the gas flow beam comprises a divergent argon atomic gas flow and a neutral cluster particle flow concentrated on a central axis; S2, using a nozzle device to spray the pulsed air flow along a preset direction; S3, screening and separating the neutral cluster particles and argon atoms in the pulsed gas flow beam by using a beam splitter; S4, ionizing neutral cluster particles into cluster ions and ionizing argon atoms into monatomic ions in an ionizer; S5, guiding the ionized ions through the anode to form an initial converging conical airflow beam; S6, focusing and accelerating the conical airflow beam by using an accelerator; S7, separate ions of different masses by permanent magnets to form a pure cluster ion beam; S8, applying the cluster ion beam to the surface of the diamond crystal workpiece for polishing.

7. The polishing method according to claim 6, characterized in that: Before step S1, the method further includes: introducing high-purity argon gas into the vacuum chamber.

8. The polishing method according to claim 7, characterized in that: In step S8, the process parameters of the polishing process include: Ion energy: 1~10 keV; Ion beam current density: 10~100 μA / cm²; Polishing time: 10~60 minutes.

9. The polishing method according to claim 7, characterized in that: After step S8, the method further includes: Inspection and post-processing of polished diamond crystal workpieces.

10. The polishing method according to claim 9, characterized in that: The detection includes surface roughness measurement, surface flatness detection and electrical performance test; The post-treatment includes ultrasonic cleaning and drying.

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