Ion beam diameter adjusting device for ion beam processing

Abstract

The invention relates to the technical field of ion beam ultra-precision machining, in particular to an ion beam diameter adjusting device for ion beam machining, which comprises an adjusting main body, a graphite base, a graphite disc, a cover plate and a heat dissipation structure, and is characterized in that the adjusting main body is provided with a first central through hole; the graphite base is arranged at the other end of the adjusting main body, a graphite disc is mounted on the graphite base, a second central through hole for the ion beam to pass through is formed in the graphite disc, and the second central through hole is communicated with the first central through hole; the cover plate covers the graphite base; the heat dissipation structure comprises a heat conduction ring and a water cooling coil pipe, the heat conduction ring is arranged on the adjusting body, and the water cooling coil pipe surrounds the outer side of the heat conduction ring. According to the invention, the graphite disc is easy to replace, so that modification requirements of different spatial frequency errors are met; and an efficient heat dissipation system is integrated, absorbed heat can be conducted out in time, and thermal deformation is effectively restrained.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ion beam ultra-precision machining, and particularly relates to an ion beam diameter adjusting device for ion beam machining. BACKGROUND

[0002] Since the development of ion beam machining technology in the 1980s, it has become one of the means for ultra-precision optical surface shaping. Its physical basis is ion sputtering effect: in a vacuum environment, high-energy inert gas ions generated by an ion source are accelerated and bombard the surface of an optical element, and through momentum transfer, the atoms or molecules on the surface of the workpiece are physically "sputtered" and removed. The whole process is a non-contact machining process, which avoids the problems of surface / subsurface damage, tool wear, abrasive residue and edge effect caused by traditional mechanical polishing, and is suitable for machining aspherical surfaces and optical elements with extremely high precision requirements, such as extreme ultraviolet lithography projection objectives, large astronomical telescope primary mirrors, and mirrors in high-energy laser devices.

[0003] The ion source is the core component of the IBF system, and its performance directly determines the stability, symmetry, half-width and peak removal rate of the removal function. Among the many types of ion sources, Kaufman-type ion sources are widely used due to their mature technology, uniform beam density and stable operation. Its typical working principle is: in the discharge chamber, plasma is generated through gas discharge between the cathode and the anode, and ions are then extracted and accelerated by the multipole grid to form a directional ion beam.

[0004] However, the traditional IBF process faces a core contradiction: the error spectrum of the surface of an optical element usually contains various spatial frequencies from low frequency, medium frequency to high frequency. For the correction of large-scale low-frequency errors, a larger beam diameter is needed to achieve high-efficiency material removal; while for the control of medium-frequency errors, a smaller beam diameter is needed to obtain higher spatial resolution and prevent the introduction of new high-frequency disturbances. Most existing commercial ion sources have relatively fixed beam diameter size and energy distribution patterns after the mechanical structure and electrical parameters are determined, and lack online rapid adjustment capability. If the shaping requirements of different frequency bands are to be considered in the same machining process, the operator can only adopt a compromise beam diameter parameter or aperture assembly. At the same time, the aperture used to adjust the ion beam diameter is mostly made of metal blades, such as aluminum, copper or stainless steel; when intercepting the ion beam, its sputtering yield is relatively high, and metal particle contaminants are easily produced, which pollutes the vacuum environment and the work surface; at the same time, it lacks an efficient and uniform active heat dissipation structure, making it difficult to ensure thermal stability under long-time and high-power machining. SUMMARY

[0005] Therefore, the application aims to provide an ion beam diameter adjusting device for ion beam processing, which can quickly switch different ion beam constraint sizes without changing the main body structure, adapt to the shaping requirements of different spatial frequency errors, and integrate an efficient heat dissipation system to timely discharge the absorbed heat, effectively inhibit thermal deformation, and ensure the shape stability of the removal function during long-time processing.

[0006] To achieve the above-mentioned purposes, the technical scheme of the application is as follows: An ion beam diameter adjusting device for ion beam processing is used to adjust the diameter of the ion beam emitted from the outlet of an ion source, comprising: An adjusting main body, one end of the adjusting main body is connected with the flange of the outlet of the ion source, and the adjusting main body is provided with a first central through hole for the ion beam to pass through; A hollow graphite base, the graphite base is arranged at the other end of the adjusting main body, Two graphite discs, one graphite disc is arranged in the graphite base, the graphite disc is provided with a second central through hole for the ion beam to pass through, the second central through hole is in communication with the first central through hole and the hollow graphite base, the diameter of the second central through hole is smaller than the hole diameter of the hollow graphite base and the diameter of the first central through hole, and the diameter of the ion beam is limited by the second central through hole; A hollow cover plate, the cover plate covers the graphite base and presses the graphite disc in the graphite base, the second central through hole is in communication with the hollow cover plate, and the hole diameter of the cover plate is greater than the diameter of the second central through hole; A heat dissipation structure, the heat dissipation structure comprises a heat conduction ring and a water-cooled coil pipe, the heat conduction ring is arranged on the adjusting main body, the outer side of the heat conduction ring is surrounded by the water-cooled coil pipe, and the heat generated by the adjusting main body is transmitted by the heat conduction ring and the water-cooled coil pipe in sequence.

[0007] Further, the top surface of the graphite base is inwardly recessed to form a containing groove, and the graphite disc is arranged in the containing groove; eight first stepped holes are arranged on the bottom wall of the containing groove and close to the side wall; eight first positioning holes are arranged on the top surface of the graphite base and close to the edge; the first stepped holes and the first positioning holes are annularly distributed around the axis of the third central through hole; the bottom surface of the graphite base is outwardly protruded to form a second annular protrusion, the second annular protrusion is embedded in the second central through hole; the middle part of the groove bottom of the containing groove is inwardly recessed to form a third central through hole, the third central through hole is in communication with the through hole of the second annular protrusion, the third central through hole is in communication with the second central through hole and the first central through hole, the third central through hole is larger than the hole diameter of the second central through hole, and the diameters of the second central through holes are adjusted to adjust the diameter of the ion beam.

[0008] Further, the number of graphite discs is at least two, the aperture of the second central through hole of the at least two graphite discs is different, the beam diameter of the ion beam is adjusted by replacing the second central through hole with different aperture, eight second stepped holes are arranged on the top surface of the graphite disc near the edge, the bottom surface of the graphite disc is outwardly protruded to form a first annular protrusion near the second central through hole, the first annular protrusion is embedded in the third central through hole, the second stepped hole is connected with the corresponding first stepped hole through the first screw, and the graphite disc is fixed in the accommodating groove of the graphite base.

[0009] Further, the top surface of the cover plate is inwardly recessed to form a fourth central through hole, the top surface of the cover plate is outwardly protruded to form a third annular protrusion near the fourth central through hole, the first annular protrusion is embedded in the fourth central through hole, the fourth central through hole is communicated with the second central through hole, the aperture of the fourth central through hole is larger than that of the second central through hole, the beam diameter of the ion beam is limited by the second central through hole, the outer circumferential surface of the third annular protrusion is outwardly protruded to form four positioning blocks, the positioning blocks extend to the outer wall of the cover plate, the top surface of the positioning block is provided with a second positioning hole in the middle, the second positioning hole and the corresponding first positioning hole are connected through the second screw, the cover plate is fixed on the graphite base, and the graphite disc is pressed in the accommodating groove.

[0010] Further, the bottom end of the adjusting body is outwardly protruded to form a connecting ring, the outer diameter of the connecting ring is larger than the outer diameter of the adjusting body, the connecting ring is connected with the flange through the bolt, the top end of the adjusting body has a frustum, the top end of the frustum has a positioning ring, the first central through hole penetrates the frustum, the adjusting body, the connecting ring and the positioning ring, and is used for the ion beam to pass through; the top surface of the frustum is provided with eight third positioning holes in the inside of the positioning ring, the third positioning hole, the corresponding second positioning hole and the corresponding first positioning hole are connected through the second screw, and the graphite base is fixed on the frustum and in the positioning ring.

[0011] Further, the side wall of the frustum is provided with a heat dissipation hole, the heat dissipation hole is arranged in a ring shape along the axis of the frustum, and the heat dissipation area of the frustum is increased.

[0012] Further, the heat dissipation structure further comprises two female connectors, two male connectors and two cooling water hoses, one end of the two female connectors is communicated with two ends of the water cooling coil, the heat conduction ring is arranged on the positioning ring and is in interference fit with the positioning ring, the other end of the two female connectors is inserted with one end of the corresponding male connector, and the other end of the two male connectors is communicated with the corresponding cooling water hose, so that cold water is added into the water cooling coil to cool the heat conduction ring and the positioning ring.

[0013] Further, it further comprises a support frame and a support plate, the two female connectors are installed on the support frame, the two ends of the support frame are connected with the adjusting body through the support plate, and the cooling water hose is away from the adjusting body and the frustum.

[0014] Further, the support frame comprises a horizontal arc-shaped plate, a vertical arc-shaped plate and a first connecting plate, the vertical arc-shaped plate is fixed on the horizontal arc-shaped plate near one end of the adjusting body, the two ends of the horizontal arc-shaped plate and the two ends of the vertical arc-shaped plate are connected by the first connecting plate respectively, the first connecting plate is connected with one end of the support plate, two female connectors are installed on the horizontal arc-shaped plate and are close to the first connecting plate respectively; the ends of the horizontal arc-shaped plate and the vertical arc-shaped plate away from each other are recessed inward to form grooves, the vertical arc-shaped plate is arranged on the outer side of the connecting ring for the cooling water hose to be away from the adjusting body.

[0015] Further, the support plate comprises an L-shaped connecting plate, an inclined plate, a square connecting plate and a second connecting plate, the two ends of the L-shaped connecting plate are connected with the square connecting plate and the inclined plate respectively, the square connecting plate is installed on the outer wall of the adjusting body by a third screw, the inclined plate is connected with the second connecting plate, and the second connecting plate is installed on the outer side of the first connecting plate by a fourth screw, for supporting the horizontal arc-shaped plate, the vertical arc-shaped plate and the first connecting plate.

[0016] Compared with the prior art, the application can achieve the following beneficial effects: (1) The graphite disc has a second central through hole with different hole diameters to realize discrete but precise beam diameter control. The complex motion mechanism is avoided, and the precision depends on the machining precision of the graphite disc, which is usually within ±0.05mm, much higher than the repeat positioning precision of the adjustable diaphragm, and the switching operation is quick and simple; (2) The adjusting body is welded with the heat conducting ring, and the water cooling coil is integrated, forming a high-efficiency three-dimensional heat dissipation system. The heat absorbed by the graphite passes through the adjusting body, the heat conducting ring, the water cooling coil and the cooling water in turn, the heat conduction efficiency of the above-mentioned heat path is high, the thermal resistance is small, and the stability and repeatability of long-time and high-power processing are guaranteed; (3) The graphite disc and the graphite base of the application are both made of graphite material, the graphite material has high resistance to ions, and the sputtering product has less pollution to most optical workpieces, and the pollution of carbon as the sputtering product is relatively easy to handle, which is conducive to maintaining the cleanliness of the vacuum chamber and protecting the expensive optical workpiece; the graphite disc can be made into a thin structure, reducing the blocking area of the useless beam, and the effective beam density reaching the workpiece is higher, thereby improving the peak removal rate and overall processing efficiency; (4) The modular design of the application makes the replacement and maintenance of the graphite disc and the graphite disc base, the adjusting body, the heat dissipation structure, the support frame and the support plate very intuitive and simple, reducing the maintenance cost and downtime. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 An exploded view of the ion beam diameter adjustment device for ion beam processing described in the embodiments of the present invention; Figure 2 A schematic diagram of the ion beam diameter adjustment device for ion beam processing as described in the embodiments of the present invention; Figure 3 for Figure 1 A schematic diagram of the structure with the cover plate removed. Figure 4 for Figure 1 A schematic diagram of the connection structure of the main body, connecting ring, frustum, and positioning ring; Figure 5 for Figure 1 Schematic diagram of the central heat-conducting ring; Figure 6 for Figure 1 Schematic diagram of the structure of the water-cooled coil; Figure 7 for Figure 1 Schematic diagram of the graphite base; Figure 8 for Figure 1 Schematic diagram of the graphite disk structure; Figure 9 for Figure 1 Schematic diagram of the middle cover plate; Figure 10 for Figure 1 Schematic diagram of the middle support frame; Figure 11 for Figure 1 Schematic diagram of the middle support plate; Figure 12 A surface view of the ion beam diameter adjustment device for ion beam processing described in the embodiments of the present invention before processing; Figure 13 The surface shape diagram of the ion beam diameter adjustment device after processing according to the embodiment of the present invention.

[0018] Explanation of reference numerals in the attached figures: 10. Adjustment body; 11. First central through hole; 12. Connecting ring; 13. Frustum; 14. Positioning ring; 15. Third positioning hole; 16. Heat dissipation hole; 20. Graphite base; 21. Receiving groove; 22. Third central through hole; 23. First stepped hole; 24. First positioning hole; 25. Second annular protrusion; 30. Graphite disk; 31. Second central through hole; 32. Second stepped hole; 33. First annular protrusion; 40. Cover plate; 41. Third annular protrusion; 42. Fourth central through hole; 43. Positioning block; 44. Second positioning hole; 50. Heat-conducting ring; 51. Water-cooled coil; 52. Cooling water hose; 53. Female connector; 54. Male connector; 60. Support frame; 61. Horizontal arc plate; 62. Vertical arc plate; 63. First connecting plate; 64. Groove; 70. Support plate; 71. L-shaped connecting plate; 72. Inclined plate; 73. Square connecting plate; 74. Second connecting plate. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0020] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0021] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this 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, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] like Figures 1 to 3 As shown, an ion beam diameter adjustment device for ion beam processing is used to adjust the diameter of the ion beam emitted from the ion source outlet, comprising: The main body 10 is adjusted, and one end of the main body 10 is connected to the flange of the ion source outlet. The main body 10 has a first central through hole 11 for the ion beam to pass through. The main body 10 serves as the installation platform for the entire device and is made of lightweight and high-strength aluminum alloy 2A12. This material belongs to high-strength hard aluminum and has the characteristics of low density, high specific stiffness, and excellent machinability, making it very suitable as a structural component in a vacuum environment. A hollow graphite base 20 is located at the other end of the adjustment body 10. Two graphite disks 30 are provided, one of which is installed inside a graphite base 20. A second central through hole 31 for the ion beam to pass through is provided on the graphite disk 30. The second central through hole 31 is connected to the first central through hole 11 and the hollow graphite base 20. The diameter of the second central through hole 31 is smaller than the diameter of the hole in the hollow graphite base 20 and the diameter of the first central through hole 11. The diameters of the second central through holes 31 on at least the two graphite disks 30 are different. The beam diameter of the ion beam can be adjusted by replacing the second central through holes 31 with different diameters. A hollow cover plate 40 is placed on the graphite base 20 and presses the graphite disk 30 into the graphite base 20. The second central through hole 31 is connected to the hollow cover plate 40, and the diameter of the hole in the cover plate 40 is larger than the diameter of the second central through hole 31. The heat dissipation structure includes a heat-conducting ring 50 and a water-cooling coil 51. The heat-conducting ring 50 is vacuum brazed onto the adjustment body 10, thereby rapidly and with low resistance, conducting heat away from the adjustment body 10. Its large heat capacity also helps to buffer instantaneous thermal shocks. The water-cooling coil 51 surrounds the outside of the heat-conducting ring 50, conducting heat to the adjustment body 10 through the heat-conducting ring 50 and carrying away the heat dissipated by the heat-conducting ring 50 through the water-cooling coil 51. The heat-conducting ring 50 is mechanically fixed to the adjustment body 10 with two M5×20 screws and washers, which aims to improve structural reliability and prevent weld failure due to thermal stress or vibration in extreme cases. The contact surface between the water-cooling coil 51 and the heat-conducting ring 50 is welded using argon arc welding to ensure that the thermal contact resistance between the two is extremely low.

[0025] Specifically, the initial ion beam drawn from the ion source passes through the graphite base 20 and the second central through-hole 31 on the graphite disk 30. The second central through-hole 31 laterally confines the ion beam, determining the basic diameter of the ion velocity. During this process, some ions with higher energy or larger angular deviations collide with the walls of the second central through-hole 31 on the graphite disk 30 and graphite base 20, converting their kinetic energy into heat energy. This heat is conducted through the graphite material of the graphite base 20 and graphite disk 30 and transferred to the adjustment body 10 through the contact interface. The heat-conducting ring 50 welded to the adjustment body 10 acts as a highly efficient heat conductor, rapidly transferring the collected heat to the water-cooling coil 51 welded to it. Cooling water flows within the water-cooling coil 51, continuously carrying away heat, thereby maintaining the entire cutoff device in a relatively stable low-temperature operating state. The cover plate 40 is used to press the graphite disk 30, ensuring accurate positioning and good contact.

[0026] By replacing different graphite disks 30, the constraint size of the ion beam can be quickly switched to achieve different aperture sizes of the second central through-hole 31, adapting to the correction requirements of different spatial frequency errors. At the same time, an efficient heat dissipation structure is integrated, which can promptly dissipate the heat absorbed by the device in this application, effectively suppressing thermal deformation and ensuring the morphological stability of the removal function during long-term processing.

[0027] The graphite disk 30, as a replaceable component, is fixed inside the graphite base 20 with screws. The diameter of the second central through hole 31 is precisely designed according to the target ion beam diameter. Users can select to install graphite disks 30 with different central apertures according to the processing requirements, thereby achieving flexible and precise control over the half-width of the emitted ion beam.

[0028] The graphite disk 30 of this application is made of graphite material. Graphite material has excellent properties such as high temperature resistance, small coefficient of thermal expansion, good thermal conductivity, high absorption rate of ion beam and low sputtering yield. A second central through hole 31 is opened at the center of the graphite disk 30. While realizing ion beam shaping, unnecessary obstruction of useful ion beam is minimized, thereby improving processing efficiency and consistency.

[0029] The graphite disk 30 can also be made of refractory metals such as high-purity tungsten, molybdenum or tantalum, or high-performance ceramic materials such as alumina and aluminum nitride, so that the graphite disk 30 has excellent high temperature resistance and anti-sputtering properties.

[0030] The heat dissipation structure is an active cooling system. The heat-conducting ring 50 acts as a heat-conducting bridge, rapidly transferring the heat absorbed by the adjustment body 10 to the water-cooling coil 51. The continuously flowing cooling water in the water-cooling coil 51 carries away the heat, forming a highly efficient forced convection cooling circuit, ensuring that the operating temperature of the adjustment body 10, graphite base 20, and graphite disk 30 remains stable within the allowable range.

[0031] The heat-conducting ring 50 and the water-cooling coil 51 can be made of molybdenum-copper alloy or high thermal conductivity carbon material (such as pyrolytic graphite) and have their surfaces metallized for welding. In space-constrained applications, the water-cooling coil 51 can be placed inside the heat-conducting ring 50, with the cooling channels directly machined in.

[0032] The heat-conducting ring 50 and the adjustment body 10 can be designed as a whole, and are made by casting (such as vacuum die casting) and then machining. The internal cooling channels are pre-embedded, which can completely eliminate the welding process.

[0033] like Figures 1 to 3 , Figures 5 to 7 As shown, the top surface of the graphite base 20 is recessed inward to form a receiving groove 21, and the graphite disk 30 is disposed in the receiving groove 21; eight first stepped holes 23 are formed on the bottom wall of the receiving groove 21 near the side wall; eight first positioning holes 24 are formed on the top surface of the graphite base 20 near the edge, and the first positioning holes 24 are m5x25 countersunk screw holes. The first stepped holes 23 and the first positioning holes 24 are all arranged in a ring around the axis of the third central through hole 22. The graphite base 20 The bottom surface protrudes outward to form a second annular protrusion 25, which is embedded in the second central through hole 31. The bottom center of the receiving groove 21 is recessed inward to form a third central through hole 22, which is connected to the through hole of the second annular protrusion 25. The third central through hole 22 is connected to the second central through hole 31 and the first central through hole 11. The diameter of the third central through hole 22 is larger than that of the second central through hole 31. The beam diameter of the ion beam is adjusted by the second central through hole 31 with different diameters.

[0034] The graphite base 20 can conduct part of the heat received by the graphite disk 30 to the third central through hole 22 of the adjustment body 10, which is usually slightly larger than the second central through hole 31, and plays the role of assisting the beam to pass through and secondary interception.

[0035] like Figures 1 to 3 , Figure 8 As shown, eight second step holes 32 are provided on the top surface of the graphite disk 30 near the edge. The bottom surface of the graphite disk 30 and the position near the second central through hole 31 protrude outward to form a first annular protrusion 33. Four second step holes 32 arranged at intervals can be connected to the corresponding first step holes 23 through holes with first screws for fixing the graphite disk 30 in the receiving groove 21 of the graphite base 20.

[0036] The graphite disk 30 directly faces the ion beam and is the component that performs the main beam cutoff and shaping functions. The second central through-hole 31 restricts the boundary and half-width of the emitted ion beam. By changing the graphite disk 30 with different aperture sizes, the ion beam diameter can be quickly switched, greatly improving process flexibility.

[0037] The main body 10 can be made of stainless steel (such as 304SS) or Invar alloy to suit applications requiring higher strength or lower thermal expansion.

[0038] like Figures 1 to 3 , Figure 9 As shown, the top surface of the cover plate 40 is recessed inward to form a fourth central through hole 42. The top surface of the cover plate 40, near the fourth central through hole 42, protrudes outward to form a third annular protrusion 41. The first annular protrusion 33 is embedded in the fourth central through hole 42. The fourth central through hole 42 is connected to the second central through hole 31. The diameter of the fourth central through hole 42 is larger than the diameter of the second central through hole 31. The diameter of the ion beam is limited by the second central through hole 31. The outer circumference of the third annular protrusion 41 protrudes outward to form four positioning blocks 43. The positioning blocks 43 extend to the outer wall of the cover plate 40. The top surface of the positioning blocks 43 is provided with a second positioning hole 44. The four second positioning holes 44, which are spaced apart, are connected to the corresponding first positioning holes 24 by second screws for fixing the cover plate 40 to the graphite base 20 and pressing the graphite disk 30 into the receiving groove 21.

[0039] The cover plate ensures that the graphite disk 30 is in close contact with the mounting surface of the graphite base 20, thereby establishing a good heat conduction path and preventing the graphite disk 30 from vibrating or shifting under the impact of the ion beam.

[0040] like Figures 1 to 4As shown, the bottom end of the adjusting body 10 protrudes outward to form a connecting ring 12. The outer diameter of the connecting ring 12 is larger than the outer diameter of the adjusting body 10. Eight M6 through holes are evenly distributed on the connecting ring 12, and it is connected to the flange by bolts to fix the entire device. The top end of the adjusting body 10 has a cone 13, and the top end of the cone 13 has a positioning ring 14. The first central through hole 11 passes through the cone 13, the adjusting body 10, the connecting ring 12 and the positioning ring 14 for the ion beam to pass through. Eight third positioning holes 15 are opened on the top surface of the cone 13 and inside the positioning ring 14. The third positioning holes 15 are M5x25 threaded holes. The third positioning holes 15, the corresponding second positioning holes 44 and the corresponding first positioning holes 24 are connected by second screws for fixing the graphite base 20 on the cone 13 and inside the positioning ring 14. The setting of the positioning ring 14 ensures the accuracy of the axial position of the graphite base 20.

[0041] The main body 10 is adjusted to precisely position the graphite base 20 through the positioning ring 14, and precisely connects with the flange of the ion source outlet through the connecting ring 12, effectively ensuring the accurate installation and replacement of the graphite disk 30.

[0042] At least eight heat dissipation holes 16 are provided on the side wall of the cone 13. The at least eight heat dissipation holes 16 are arranged in a ring along the axis of the cone 13 to increase the heat dissipation area of ​​the cone 13.

[0043] At least eight heat dissipation holes 16 can form a multi-row heat dissipation hole array to increase the heat dissipation area and utilize the residual gas in the vacuum chamber for limited convective heat dissipation, which helps air convection and assists in heat dissipation. At the same time, it provides an escape channel for ions whose energy and direction have deviated from the main beam after multiple scattering, preventing them from accumulating inside the adjustment body 10 and causing discharge or unnecessary heating. That is, it allows a small number of scattered ions that are not completely absorbed by the graphite component to escape, avoiding the accumulation of charge in the cavity.

[0044] The heat dissipation structure also includes two female connectors 53, two male connectors 54, and two cooling water hoses 52. One end of each of the two female connectors 53 is connected to both ends of the water-cooling coil 51. The heat-conducting ring 50 is fitted onto the positioning ring 14 with an interference fit to ensure the pre-tightening force before welding and the contact area after welding. The other end of each of the two female connectors 53 is inserted into one end of the corresponding male connector 54. The other end of each of the two male connectors 54 is connected to the corresponding cooling water hose 52 for adding cold water into the water-cooling coil 51 to cool the heat-conducting ring 50 and the positioning ring 14.

[0045] like Figures 1 to 3 , Figure 10As shown, it also includes a support frame 60 and a support plate 70. Two plug-in female heads 53 are installed on the support frame 60. The two ends of the support frame 60 are connected to the adjustment body 10 through the support plate 70, so that the cooling water hose 52 is away from the adjustment body 10 and the cone 13.

[0046] The function of the support frame 60 and the support plate 70 is to provide a stable mounting base for the external female connector 53 and male connector 54, and to prevent stress interference to the core heat dissipation components caused by the gravity or vibration of the cooling water hose 52.

[0047] The female connector 53 and male connector 54 can be Swagelok brand plug-in connectors, which have the advantages of reliable connection, good sealing, and allowing quick insertion and removal. The female connector 53 connects to the water cooling coil 51 and is installed on the support plate 70, while the male connector 54 connects to the cooling water hose 52. By inserting the female connector 53 and male connector 54, a convenient connection between the water cooling pipeline and the adjustment body 10 is achieved. At the same time, the support plate 70 separates the water cooling pipeline from the adjustment body 10, greatly facilitating the installation and maintenance of the device.

[0048] like Figures 1 to 3 , Figure 11 As shown, the support frame 60 includes a horizontal arc plate 61, a vertical arc plate 62, and a first connecting plate 63. The vertical arc plate 62 is fixed on the horizontal arc plate 61 at one end near the adjusting body 10. The two ends of the horizontal arc plate 61 and the two ends of the vertical arc plate 62 are respectively connected by the first connecting plate 63. The first connecting plate 63 is connected to one end of the support plate 70. Two plug-in female heads 53 are installed on the horizontal arc plate 61 and are respectively positioned close to the first connecting plate 63. The ends of the horizontal arc plate 61 and the vertical arc plate 62 that are far apart are recessed inward to form a groove 64. The vertical arc plate 62 is located on the outside of the connecting ring 12, so that the cooling water hose 52 is away from the adjusting body 10.

[0049] The support plate 70 includes an L-shaped connecting plate 71, an inclined plate 72, a square connecting plate 73, and a second connecting plate 74. The two ends of the L-shaped connecting plate 71 are connected to the square connecting plate 73 and the inclined plate 72, respectively. The square connecting plate 73 is installed on the outer wall of the adjusting body 10 by a third screw. The inclined plate 72 is connected to the second connecting plate 74. The second connecting plate 74 is installed on the outer side of the first connecting plate 63 by a fourth screw, and is used to support the horizontal arc plate 61, the vertical arc plate 62, and the first connecting plate 63.

[0050] The specific assembly process is as follows: Step 1: Fit the heat-conducting ring 50 onto the outer wall of the positioning ring 14 and weld the connection; Step 2: Pass the plug-in female 53 through the mounting hole on the horizontal arc plate 61, and fix it to the horizontal arc plate 61 with the nut that matches the plug-in female 53; Step 3: Weld the water-cooling coil 51 to the outside of the heat-conducting ring 50, ensuring that the water-cooling coil 51 is in close contact with the outer surface of the heat-conducting ring 50; connect the two ends of the water-cooling coil 51 to the plug-in female 53 using a compression fitting method and tighten them. Argon arc welding can be used to weld the contact points between the water-cooled coil 51 and the heat-conducting ring 50 firmly point by point; Step 4: Connect the two square connecting plates 73 symmetrically to the threaded holes on the outer wall of the adjusting body 10 using two M5×20 screws and washers; install the second connecting plate 74 onto the corresponding first connecting plate 63 using four M6×12 screws and washers. Step 5: Place the graphite base 20 on the truncated cone 13 and position it inside the positioning ring 14, and connect the third positioning hole 15 and the first step hole 23 by four M5×25 countersunk screws. Step 6: Select a graphite disk 30 with a suitable aperture and place it on the mounting surface of the graphite base 20. Align the second step hole 32 and the first step hole 23, and use four M5×16 countersunk screws to connect the corresponding second step hole 32 and first step hole 23 respectively to press and fix the graphite disk 30.

[0051] Step 7: Cover the graphite disk 30 with the cover plate 40, and use four M5×25 screws to pass through the second positioning hole 44 and the corresponding first positioning hole 24 and the corresponding third positioning hole 15, and tighten them evenly so that the cover plate 40 presses the graphite disk 30, completing the final encapsulation.

[0052] At this point, the entire ion source cutoff device is assembled. Before being installed in the vacuum chamber, its water-cooling circuit must be pressure tested to ensure there are no leaks.

[0053] The various components of this application are mechanically connected, including screw connections and welding, to form a whole and work together to achieve precise, stable, and controllable cut-off and shaping of the ion beam.

[0054] This application adopts a reasonable split structure and assembly process, which makes the device structure compact, easy to install, debug, maintain and replace components, and improves the reliability and ease of use of the entire ion beam processing system.

[0055] The manufacturing, assembly, and experimental verification of the prototype have been completed in this application.

[0056] Experimental platform: The experiment was conducted on a self-developed Φ4000mm ion beam processing machine, and the ion source was a Kaufman type ion source.

[0057] Testing: The above process was used to assemble a prototype of the device of this application, and graphite disks 30 with second central through holes 31 having diameters of D80mm, D40mm and D20mm were installed for testing.

[0058] result: 1. Beam diameter and shape: The beam current density distribution was measured using a Faraday cup. The results showed that after changing to different graphite disks, the obtained ion beam diameters were 40.5 mm, 23.4 mm, and 15.5 mm, respectively, which were in good agreement with the design values. The beam current distribution was symmetrical and there was no significant distortion.

[0059] 2. Heat dissipation performance: After 10 hours of continuous operation at maximum beam current power, no ACC short circuit or excessive RF feedback power occurred due to overheating, indicating that the heat dissipation system works efficiently.

[0060] 3. Removal Function Stability: During the 8-hour processing, silicon carbide samples were sputter-etched every 60 minutes, and the Faraday cup scan results were statistically analyzed. The measurement results showed that the volumetric removal rate of the removal function fluctuated by less than 2.5%, and the half-width variation was less than 0.1 mm, demonstrating the excellent thermal stability and process repeatability of the device.

[0061] 4. Functional processing verification: Successfully applied to the surface shape error correction of a 1500mm diameter silicon carbide aspherical mirror. By switching between D80mm and Φ40mm graphite disks 30 for roughing and fine finishing respectively, the final surface shape accuracy (RMS) converged from the initial 52.899nm to 7.936nm. Figures 12 to 13 As shown.

[0062] Experimental conclusion: The device of the present invention fully met the design expectations and is superior to the traditional adjustable aperture solution in terms of beam shaping flexibility, thermal stability and processing performance.

[0063] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. An ion beam diameter adjustment device for ion beam processing, used to adjust the diameter of the ion beam emitted from the ion source outlet, characterized in that, include: An adjustment body, one end of which is connected to the flange of the ion source outlet, has a first central through hole for the ion beam to pass through; A hollow graphite base is disposed at the other end of the adjustment body; A graphite disk is installed inside a graphite base. The graphite disk has a second central through hole for the ion beam to pass through. The second central through hole communicates with the first central through hole and the hollow graphite base. The diameter of the second central through hole is smaller than the diameter of the hole in the hollow graphite base and the diameter of the first central through hole. The beam diameter of the ion beam is limited by the second central through hole. A hollow cover plate is placed on the graphite base and presses the graphite disk into the graphite base. The second central through hole communicates with the hollow cover plate, and the diameter of the hole in the cover plate is larger than the diameter of the second central through hole. The heat dissipation structure includes a heat-conducting ring and a water-cooling coil. The heat-conducting ring is disposed on the adjustment body, and the water-cooling coil is surrounded on the outside of the heat-conducting ring. The heat generated by the adjustment body is transferred sequentially through the heat-conducting ring and the water-cooling coil.

2. The ion beam diameter adjustment device for ion beam processing according to claim 1, characterized in that: The top surface of the graphite base is recessed inward to form a receiving groove, and the graphite disk is disposed in the receiving groove. A first stepped hole is formed on the bottom wall of the receiving groove near the side wall. A first positioning hole is formed on the top surface of the graphite base near the edge. The first stepped hole and the first positioning hole are both distributed in a ring around the axis of the receiving groove. The bottom surface of the graphite base protrudes outward to form a second annular protrusion. The second annular protrusion is embedded in the second central through hole. The bottom of the receiving groove is recessed inward to form a third central through hole. The third central through hole communicates with the through hole in the middle of the second annular protrusion, the second central through hole, and the first central through hole. The diameter of the third central through hole is larger than that of the second central through hole. The beam diameter of the ion beam is adjusted by using the second central through holes of different diameters.

3. The ion beam diameter adjustment device for ion beam processing according to claim 2, characterized in that: The number of graphite disks is at least two, and the diameter of the second central through hole of the at least two graphite disks is different. The beam diameter of the ion beam is adjusted by changing the second central through hole with different diameters. A second stepped hole is opened on the top surface of the graphite disk near the edge. The bottom surface of the graphite disk protrudes outward near the second central through hole to form a first annular protrusion. The second stepped hole and the corresponding first stepped hole are connected by a first screw for fixing the graphite disk in the receiving groove of the graphite base.

4. The ion beam diameter adjustment device for ion beam processing according to claim 3, characterized in that: The top surface of the cover plate is recessed inward to form a fourth central through hole. The top surface of the cover plate, near the fourth central through hole, protrudes outward to form a third annular protrusion. The first annular protrusion is embedded in the fourth central through hole, which is connected to the second central through hole. The outer circumference of the third annular protrusion protrudes outward to form a positioning block. The positioning block extends to the outer wall of the cover plate. The top surface of the positioning block has a second positioning hole. The second positioning hole and the corresponding first positioning hole are connected by a second screw for fixing the cover plate to the graphite base and pressing the graphite disk into the receiving groove.

5. The ion beam diameter adjustment device for ion beam processing according to claim 4, characterized in that: The bottom end of the adjustment body protrudes outward to form a connecting ring. The outer diameter of the connecting ring is larger than the outer diameter of the adjustment body. The connecting ring is connected to the flange by bolts. The top end of the adjustment body has a truncated cone. The top end of the truncated cone has a positioning ring. The first central through hole passes through the truncated cone, the adjustment body, the connecting ring, and the positioning ring, and is used for the passage of the ion beam. A third positioning hole is opened on the top surface of the truncated cone and inside the positioning ring. The third positioning hole, the corresponding second positioning hole, and the corresponding first positioning hole are connected by the second screw, which is used to fix the graphite base on the truncated cone and inside the positioning ring.

6. The ion beam diameter adjustment device for ion beam processing according to claim 5, characterized in that: The side wall of the cone has heat dissipation holes arranged in a ring along the axis of the cone to increase the heat dissipation area of ​​the cone.

7. The ion beam diameter adjustment device for ion beam processing according to claim 5, characterized in that: The heat dissipation structure also includes two female connectors, two male connectors, and two cooling water hoses. One end of each of the two female connectors is connected to both ends of the water-cooling coil. The heat-conducting ring is fitted onto the positioning ring with an interference fit. The other end of each of the two female connectors is connected to one end of the corresponding male connector. The other end of each of the two male connectors is connected to the corresponding cooling water hose, which is used to add cold water into the water-cooling coil to cool the heat-conducting ring.

8. The ion beam diameter adjustment device for ion beam processing according to claim 7, characterized in that: It also includes a support frame and a support plate. Both of the aforementioned plug-in female heads are mounted on the support frame. The two ends of the support frame are respectively connected to the adjustment body through the support plate, so that the cooling water hose is away from the adjustment body and the cone.

9. The ion beam diameter adjustment device for ion beam processing according to claim 8, characterized in that: The support frame includes a horizontal arc plate, a vertical arc plate, and a first connecting plate. The vertical arc plate is fixed to one end of the horizontal arc plate near the adjusting body. The two ends of the horizontal arc plate and the two ends of the vertical arc plate are respectively connected by the first connecting plate. The first connecting plate is connected to one end of the support plate. Two plug-in females are installed on the horizontal arc plate and are respectively positioned close to the first connecting plate. The ends of the horizontal and vertical arc plates that are far apart are recessed inward to form grooves. The vertical arc plate is located outside the connecting ring so that the cooling water hose is away from the adjusting body.

10. The ion beam diameter adjustment device for ion beam processing according to claim 9, characterized in that: The support plate includes an L-shaped connecting plate, an inclined plate, a square connecting plate, and a second connecting plate. The two ends of the L-shaped connecting plate are connected to the square connecting plate and the inclined plate, respectively. The square connecting plate is installed on the outer wall of the adjustment body by a third screw. The inclined plate is connected to the second connecting plate. The second connecting plate is installed on the outer side of the first connecting plate by a fourth screw, and is used to support the horizontal arc plate, the vertical arc plate, and the first connecting plate.

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