An ion beam diameter dynamic confinement adjustment device and parameter optimization method thereof

Abstract

The present invention discloses a device for dynamically confining and adjusting the diameter of an ion beam, comprising a mounting frame, and a first ion beam channel, a second ion beam channel, and a third ion beam channel sequentially and coaxially arranged on the mounting frame, wherein the first ion beam channel and the third ion beam channel are both cylindrical, and the second ion beam channel is conical. The mounting frame is provided with a first electric lens assembly on the circumference of the first ion beam channel, and a second electric lens assembly on the circumference of the third ion beam channel. A method for optimizing parameters of the device for dynamically confining and adjusting the diameter of an ion beam is also disclosed. The device for dynamically confining and adjusting the diameter of an ion beam can meet the requirements for producing a small-diameter ion beam and has good adaptability, which not only enables continuous adjustment of the beam diameter but also reduces the energy loss of the ion beam current. The method for optimizing parameters of the device for dynamically confining and adjusting the diameter of an ion beam facilitates the determination of relevant parameters of the device for dynamically confining and adjusting the diameter of an ion beam and the verification and preparation of the most reasonable device for dynamically confining and adjusting the diameter of an ion beam.

Description

Technical Field

[0001] The present invention relates to the technical field of ion beam ultra-precision machining, and in particular to an ion beam diameter dynamic constraint adjustment device and a parameter optimization method thereof. Background Art

[0002] The precision of optical components is a key parameter in the overall performance of optical systems. With the continuous advancement of science and technology, observation systems, laser systems, photolithography, and projection techniques have placed stringent demands on the manufacturing accuracy of optical components. Ultra-precision ion beam polishing is an advanced optical component processing technology based on ion sputtering theory. It uses a particle stream of a certain energy to bombard the surface of the optical component. When the bombarded surface atoms gain sufficient energy, they can break free from the constraints of surface energy and detach from the workpiece surface, thereby achieving atomic-scale material removal with a Gaussian profile. Ion beam polishing is currently a highly deterministic, highly stable, and non-contact ultra-precision processing method.

[0003] To correct for a certain spatial frequency error, the theoretical full width at half maximum of the ion beam should be less than half the error wavelength. Therefore, for some currently lightweight, compact, and high-steepness optical components, generating a small-diameter ion beam (intense millimeter- or submillimeter-level ion beam) is a key factor in successfully correcting these component shape errors.

[0004] Currently, the common method for generating small ion beams is to place an appropriately sized aperture at the ion source exit, replacing it before each reshaping process based on processing requirements. Because the ion source operates in a high vacuum, replacing the aperture inevitably requires disrupting the vacuum environment, extending the manufacturing cycle. A small number of ion beam polishing systems are equipped with automated aperture mechanisms to avoid disrupting the vacuum environment, but this solution requires complex transmission design and is costly. Furthermore, for some specialized component processing techniques, such as conical mirror processing, the ion beam must be adjusted to a very small size as the processing area transitions from the side to the cone tip. Using the traditional aperture replacement method reduces processing consistency and prevents continuous adjustment of the ion beam diameter within the millimeter to submillimeter range. Furthermore, the aperture arrangement blocks a significant portion of the beam energy, resulting in extremely low beam energy utilization. Consequently, these ion beam polishing systems lack continuous adjustment of the ion beam diameter within the millimeter to submillimeter range, making them difficult to meet the requirements for generating small ion beams (intense millimeter or submillimeter ion beams).

[0005] Existing application number 202311212077.0 discloses an ion beam diameter adjustment device and an ion beam generating device, comprising an insulating mounting base provided with an inner hole for the ion beam to pass through. An electromagnetic lens is provided on the insulating mounting base, located around the inner hole, for changing the ion trajectory to achieve beam diameter adjustment. The electromagnetic lens comprises a deceleration pole, a bunching pole, and an accelerating pole, arranged in sequence along the direction of ion beam input to output from the inner hole. The deceleration pole, bunching pole, and accelerating pole are all annular in structure. Applying different voltages to the deceleration pole, bunching pole, and accelerating pole can respectively decelerate, bunch, and accelerate the electron beam. This device is designed to achieve dynamic adjustment of the ion beam diameter, avoiding the residual error at the cutoff frequency and the high requirements for machine tool dynamic performance caused by the fixed beam diameter of traditional ion beam machining, as well as the preparation time required to replace the aperture of traditional variable beam diameter ion beams. This ion beam diameter adjustment device can dynamically adjust the ion beam diameter using only a single electric lens, which only allows for continuous adjustment of the ion beam diameter within a range of millimeters or more. This makes it difficult to meet the requirements for producing small-diameter ion beams (intense millimeter- or submillimeter-level ion beams) and presents poor adaptability. Using multiple electric lenses in series to adjust the ion beam diameter presents challenges, firstly, in achieving continuous adjustment of the ion beam diameter; secondly, in reducing energy loss between the ion beam lenses; and thirdly, in determining the diameters and spacing of the deceleration, focusing, and accelerating electrodes of each electric lens, as well as the parameters of the connectors between the lenses. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the existing technology and provide an ion beam diameter dynamic confinement adjustment device that can meet the requirements of generating a small beam diameter ion beam, has good adaptability, and can continuously adjust the beam diameter of the ion beam during the entire process while reducing the energy loss of the ion beam current between each electric lens component; and also provides a parameter optimization method for the ion beam beam diameter dynamic confinement adjustment device that is convenient for determining the relevant parameters of the ion beam beam diameter dynamic confinement adjustment device and verifying and preparing the most reasonable ion beam beam diameter dynamic confinement adjustment device.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A device for dynamically confining and adjusting the diameter of an ion beam comprises a mounting frame, and a first ion beam channel, a second ion beam channel and a third ion beam channel which are sequentially and coaxially arranged on the mounting frame, wherein the first ion beam channel and the third ion beam channel are both cylindrical, and the diameter of the first ion beam channel is larger than that of the third ion beam channel, the second ion beam channel is conical, and the large-aperture end of the second ion beam channel is connected to the outlet end of the first ion beam channel, and the small-aperture end is connected to the inlet end of the third ion beam channel, the inner diameter of the large-aperture end of the second ion beam channel is smaller than that of the first ion beam channel, and the inner diameter of the small-aperture end is smaller than that of the third ion beam channel, the mounting frame is provided with a first electric lens assembly on the circumference of the first ion beam channel for changing the ion trajectory to achieve beam diameter adjustment, and a second electric lens assembly on the circumference of the third ion beam channel for changing the ion trajectory to achieve beam diameter adjustment.

[0009] As a further improvement of the above technical solution:

[0010] The cone angle of the second ion beam channel is 20°.

[0011] The inner diameter of the large-aperture end of the second ion beam channel is 14 mm, and the inner diameter of the small-aperture end is 2 mm.

[0012] The first electric lens assembly includes a first deceleration ring, a first focusing ring and a first acceleration ring which are arranged in sequence along the direction from ion beam input to output of the first ion beam channel. The second electric lens assembly includes a second deceleration ring, a second focusing ring and a second acceleration ring which are arranged in sequence along the direction from ion beam input to output of the third ion beam channel.

[0013] The mounting frame includes a first mounting seat, a second mounting seat and a third mounting seat that are detachably connected. The first ion beam channel is arranged on the first mounting seat, the second ion beam channel is arranged on the second mounting seat, and the third ion beam channel is arranged on the third mounting seat. The first deceleration ring, the first focusing ring and the first acceleration ring are movably mounted on the first mounting seat, and the second deceleration ring, the second focusing ring and the second acceleration ring are movably mounted on the third mounting seat.

[0014] The first mounting seat is provided with a first insulating shell outside the first electric lens assembly, and the first insulating shell is provided with a first locking piece for locking the first deceleration ring, a second locking piece for locking the first focusing ring, and a third locking piece for locking the first acceleration ring. The third mounting seat is provided with a second insulating shell outside the second electric lens assembly, and the second insulating shell is provided with a fourth locking piece for locking the second deceleration ring, a fifth locking piece for locking the second focusing ring, and a sixth locking piece for locking the second acceleration ring.

[0015] The first mounting seat is threadedly connected to the second mounting seat, and the third mounting seat is threadedly connected to the first insulating shell.

[0016] The first insulating shell is provided with a first visual port for observing the positions of the first deceleration ring, the first focusing ring and the first acceleration ring. The second insulating shell is provided with a second visual port for observing the positions of the second deceleration ring, the second focusing ring and the second acceleration ring.

[0017] The inner diameters of the first deceleration ring, the first focusing ring and the first acceleration ring are all 60 mm, and the spacing is 5 mm. The inner diameters of the second deceleration ring, the second focusing ring and the second acceleration ring are all 14 mm, and the spacing is 4 mm.

[0018] A parameter optimization method for the above-mentioned ion beam diameter dynamic confinement adjustment device includes taking the voltage, length and spacing of the first deceleration ring, the first focusing ring and the first acceleration ring of the ion beam diameter dynamic confinement adjustment device, the cone angle and the inner diameter of the two ends of the second ion beam channel, and the voltage, length and spacing of the second deceleration ring, the second focusing ring and the second acceleration ring as parameters to be optimized, performing finite element analysis on the ion beam diameter dynamic confinement adjustment device under different combinations of parameters to be optimized to obtain the corresponding ion beam diameters, and taking the combination of parameters to be optimized corresponding to the optimal ion beam diameter as the optimized optimal structural parameters for each ion beam diameter within the given ion beam diameter range obtained by optimization for preparing the ion beam diameter dynamic confinement adjustment device.

[0019] Compared with the prior art, the advantages of the present invention are:

[0020] The present invention's dynamic ion beam diameter confinement and adjustment device allows the ion beam to first pass through a first ion beam channel, where it is decelerated, focused, and then accelerated by a first electric lens assembly. It then passes through a second ion beam channel for concentration, allowing the ion beam to be focused to a submillimeter diameter after exiting the second channel. It then passes through a third ion beam channel, where the second electric lens assembly allows the ion beam to be focused to a submillimeter diameter after exiting the third channel. The initial plasma, under the action of the first and second electric lens assemblies, can be focused to a submillimeter diameter within a short stroke. Combined with the second electric lens assembly, this allows dynamic adjustment of the ion beam diameter within the millimeter to submillimeter range. The present ion beam diameter dynamic confinement and adjustment device, on the one hand, can satisfy the requirement of continuously adjusting the ion beam diameter within a range of more than a millimeter through the combined action of the first ion beam channel provided with a first electric lens assembly on the circumferential side, the second ion beam channel and the third ion beam channel provided with a second electric lens assembly on the circumferential side, and can generate a small beam diameter ion beam (strong millimeter or submillimeter ion beam). On the other hand, through the connecting action of the conical second ion beam channel, the beam diameter of the ion beam can be continuously adjusted during the entire process, and the energy loss of the ion beam flow between the electric lens assemblies is reduced.

[0021] The parameter optimization method of the beam diameter dynamic constraint adjustment device of the present invention, on the one hand, facilitates the determination of the diameters, spacings, and related parameters of the connecting parts between the deceleration poles, focusing poles, and accelerating poles of each electric lens assembly; on the other hand, facilitates the verification and preparation of the most reasonable ion beam diameter dynamic constraint adjustment device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the three-dimensional structure of the ion beam diameter dynamic confinement adjustment device of the present invention.

[0023] Figure 2 It is a schematic diagram of the main cross-sectional structure of the ion beam diameter dynamic confinement adjustment device of the present invention.

[0024] Figure 3 It is a schematic diagram of beam diameter adjustment of the ion beam diameter dynamic confinement adjustment device of the present invention.

[0025] Figure 4 It is a schematic diagram of the internal potential and electric field distribution of the ion beam diameter dynamic confinement adjustment device of the present invention.

[0026] Figure 5 This is a relationship diagram between the voltage and focusing radius of the first bunching ring of the ion beam diameter dynamic confinement adjustment device of the present invention.

[0027] Figure 6This is a relationship diagram between the target distance and the beam radius of the first focusing ring of the ion beam diameter dynamic confinement adjustment device of the present invention under different voltages, wherein the target distance is the distance from the outlet of the third ion beam channel to the workpiece.

[0028] Figure 7 It is a schematic diagram of the ion trajectory of the ion beam diameter dynamic confinement adjustment device of the present invention at different time periods, wherein a is a schematic diagram of the ion trajectory of the ion 2.2041E-6s after emission or after entering the first ion beam channel, and b is a schematic diagram of the ion trajectory of the ion 6E-6s after emission or after entering the first ion beam channel.

[0029] The numbers in the figure represent:

[0030] 1. Mounting frame; 11. First mounting seat; 12. Second mounting seat; 13. Third mounting seat; 14. First insulating shell; 141. First locking member; 142. Second locking member; 143. Third locking member; 15. Second insulating shell; 151. Fourth locking member; 152. Fifth locking member; 153. Sixth locking member; 2. First ion beam channel; 3. Second ion beam channel; 4. Third ion beam channel; 5. First electric lens assembly; 51. First deceleration ring; 52. First focusing ring; 53. First acceleration ring; 6. Second electric lens assembly; 61. Second deceleration ring; 62. Second focusing ring; 63. Second acceleration ring; 7. First visual port; 8. Second visual port. DETAILED DESCRIPTION

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0033] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0034] In the present invention, unless otherwise expressly specified or limited, terms such as "assemble," "connect," "connect," and "fix" should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0035] Example 1:

[0036] Figure 1 and Figure 2 An embodiment of the ion beam diameter dynamic confinement adjustment device of the present invention is shown. The ion beam diameter dynamic confinement adjustment device of this embodiment includes a mounting frame 1, and a first ion beam channel 2, a second ion beam channel 3 and a third ion beam channel 4 arranged in sequence and coaxially on the mounting frame 1. The first ion beam channel 2 and the third ion beam channel 4 are both cylindrical, and the diameter of the first ion beam channel 2 is larger than that of the third ion beam channel 4. The second ion beam channel 3 is conical, and the large-aperture end of the second ion beam channel 3 is connected to the outlet end of the first ion beam channel 2, and the small-aperture end is connected to the inlet end of the third ion beam channel 4. The inner diameter of the large-aperture end of the second ion beam channel 3 is smaller than that of the first ion beam channel 2, and the inner diameter of the small-aperture end is smaller than that of the third ion beam channel 4. The mounting frame 1 is provided with a first electric lens assembly 5 on the peripheral side of the first ion beam channel 2 for changing the ion trajectory to achieve beam diameter adjustment, and a second electric lens assembly 6 on the peripheral side of the third ion beam channel 4 for changing the ion trajectory to achieve beam diameter adjustment.

[0037] Mounting bracket 1 serves as a carrier for the ion beam diameter dynamic confinement and adjustment device, used to mount the device on the ion source. In this embodiment, it is made of ceramic. During operation, the first and second electric lens assemblies 5 and 6 are each connected to an external power source to create a potential difference, converting the plasma's kinetic energy into potential energy and then into kinetic energy. Ions collectively pass through the electric lens assemblies, sequentially experiencing deceleration, focusing, and acceleration. By adjusting the external voltage, ion beams of varying sizes can be controlled and the focused beam diameter adjusted. The entrance aperture (inner diameter at the large aperture end) of the second ion beam channel 3 can be adjusted based on the initial beam diameter of the ion source, the dimensional parameters of the first electric lens assembly 5, and the voltage parameters. The second ion beam channel 3 is tapered, and its basic principle is to continuously shrink the ion beam by continuously narrowing the sidewalls. The present ion beam diameter dynamic confinement and adjustment device allows the ion beam to first pass through the first ion beam channel 2, and achieve the effects of deceleration, focusing, and then acceleration under the action of the first electric lens component 5; then it passes through the second ion beam channel 3 for concentration, so that the beam diameter of the ion beam is focused to a submillimeter range after it is emitted from the second ion beam channel 3; then it passes through the third ion beam channel 4, and under the action of the second electric lens component 6, the beam diameter of the ion beam can be maintained in the millimeter to submillimeter range after it is emitted from the third ion beam channel 4. Under the action of the first electric lens component 5 and the second ion beam channel 3, the initial plasma can focus the plasma beam diameter to a submillimeter range within a short stroke. Combined with the second electric lens component 6, dynamic adjustment of the ion beam diameter within the millimeter to submillimeter range can be achieved. The beam diameter adjustment process is as follows: Figure 3 As shown. The present ion beam diameter dynamic confinement and adjustment device, on the one hand, can achieve continuous adjustment of the ion beam diameter within a range exceeding millimeters through the combined action of the first ion beam channel 2, second ion beam channel 3, and third ion beam channel 4, which is provided with a second electric lens assembly 6 on its circumference. This satisfies the requirement for generating a small-diameter ion beam (strong millimeter-level or submillimeter-level ion beam). Furthermore, through the connection of the tapered (conical) second ion beam channel 3, the ion beam diameter can be continuously adjusted throughout the entire process while reducing energy loss of the ion beam between the electric lens assemblies.

[0038] Furthermore, in this embodiment, the cone angle of the second ion beam channel 3 is 20°. That is, the inclination angle of the inner wall of the second ion beam channel 3 is 10°. After ions enter the second ion beam channel 3, they collide with the inner wall surface of the second ion beam channel 3, resulting in low energy loss of the ion beam flow.

[0039] Furthermore, in this embodiment, the inner diameter of the large-aperture end of the second ion beam channel 3 is 14 mm, and the inner diameter of the small-aperture end is 2 mm. This facilitates continuous adjustment of the ion beam diameter between 8 mm and 0.5 mm. The inner diameter (entrance diameter) of the large-aperture end of the second ion beam channel 3 can be adjusted based on the initial beam diameter of the ion source, the size parameters of the first electric lens assembly 5, and the voltage parameters. The basic principle is to continuously shrink the ion beam by continuously narrowing the sidewalls. The inner diameter of the large-aperture end of the second ion beam channel 3 is preferably 14 mm. The overall structure and working principle of the second electric lens assembly 6 are similar to those of the first electric lens assembly 5. The outlet diameter of the second ion beam channel 3 (concentration channel) is 2 mm, i.e., the beam diameter of the ion beam at the outlet end.

[0040] Furthermore, in this embodiment, the first electric lens assembly 5 includes a first deceleration ring 51, a first focusing ring 52 and a first acceleration ring 53 which are arranged in sequence along the ion beam input to output direction of the first ion beam channel 2, and the second electric lens assembly 6 includes a second deceleration ring 61, a second focusing ring 62 and a second acceleration ring 63 which are arranged in sequence along the ion beam input to output direction of the third ion beam channel 4. The first deceleration ring 51, the first focusing ring 52 and the first acceleration ring 53 constitute the first electric lens assembly 5, and the first deceleration ring 51, the first focusing ring 52 and the first acceleration ring 53 are coaxially installed on the mounting frame 1 in sequence from the plasma entrance to the exit, and the second deceleration ring 61, the second focusing ring 62 and the second acceleration ring 63 constitute the second electric lens assembly 6, and the second deceleration ring 61, the second focusing ring 62 and the second acceleration ring 63 are coaxially installed on the mounting frame 1 in sequence from the plasma entrance to the exit. When in use, the first deceleration ring 51 and the first acceleration ring 53 are grounded, and high voltage is applied to the first focusing ring 52. Similarly, the second deceleration ring 61 and the second acceleration ring 63 are grounded, and voltage is applied to the second focusing ring 62. This arrangement can form a regular potential difference in the first ion beam channel 2, so as to realize the mutual conversion of ion beam flow energy and potential energy, so that the inside of the device is formed as follows Figure 4 For example, for an initial ion beam with an initial beam diameter of 40 mm and an Ar+ kinetic energy of 600 eV, the relationship between the voltage applied by the first focusing ring 52 and the focusing radius is as follows: Figure 5 As shown, the overall trend is that as the voltage increases, the ion bunching radius decreases. In other words, the voltage applied to the first focusing ring 52 should be relatively high, such as 760 to 780 V. Based on the beam diameter requirements of the workpiece during ion beam processing, the corresponding voltage is applied to the second focusing ring 62, which can meet the requirements for continuous adjustment of the ion beam diameter within the range of 8 mm to 0.5 mm.

[0041] In this embodiment, the first deceleration ring 51 , the first focusing ring 52 , the first acceleration ring 53 , and the second deceleration ring 61 , the second focusing ring 62 , and the second acceleration ring 63 are made of graphite, a conductive material.

[0042] Furthermore, in this embodiment, the working principle of the second electric lens assembly 6 can be referred to Figure 3 In the upper part, when no voltage or a lower voltage is applied to the second focusing ring 62, the ion beam profile will gradually diverge after leaving the exit end of the second ion beam channel 3, that is, the beam diameter increases, and the beam energy presents a Gaussian distribution symmetrical about the central axis; by dynamically adjusting the ion beam diameter by continuously increasing the voltage of the second focusing ring 62, the beam profile can be reduced to the submillimeter level; the dynamic adjustment of the ion beam diameter can improve the continuity and flexibility of the processing process, and improve the processing capability of the device for complex curved optical elements.

[0043] Furthermore, in this embodiment, the mounting frame 1 includes a first mounting seat 11, a second mounting seat 12, and a third mounting seat 13 that are detachably connected. The first ion beam channel 2 is disposed on the first mounting seat 11, the second ion beam channel 3 is disposed on the second mounting seat 12, and the third ion beam channel 4 is disposed on the third mounting seat 13. The first deceleration ring 51, the first focusing ring 52, and the first acceleration ring 53 are movably mounted on the first mounting seat 11, and the second deceleration ring 61, the second focusing ring 62, and the second acceleration ring 63 are movably mounted on the third mounting seat 13. The first mounting seat 11, the second mounting seat 12, and the third mounting seat 13 are detachably connected to facilitate assembly and disassembly. The first deceleration ring 51, the first focusing ring 52, and the first acceleration ring 53 are movably mounted on the first mounting seat 11 and can be adjusted in spacing along the axial direction of the first ion beam channel 2. The second deceleration ring 61, the second focusing ring 62, and the second acceleration ring 63 are movably mounted on the third mounting seat 13 and can be adjusted in spacing along the axial direction of the third ion beam channel 4. The first electric lens assembly 5 and the second electric lens assembly 6 can both adjust the spacing between the internal rings. In this way, on the one hand, the requirements for comparing the beam adjustment results at different spacings can be met. On the other hand, the spacing can be adjusted to a better one to meet the processing requirements of strong millimeter or submillimeter ion beams.

[0044] Furthermore, in this embodiment, the first mounting seat 11 and the third mounting seat 13 are both insulating mounting seats, such as made of insulating ceramics, and the second mounting seat 12 is a conductive mounting seat, such as made of conductive material graphite.

[0045] Furthermore, in this embodiment, the first mounting base 11 is provided with a first insulating housing 14 outside the first electric lens assembly 5. The first insulating housing 14 is provided with a first locking member 141 for locking the first deceleration ring 51, a second locking member 142 for locking the first focusing ring 52, and a third locking member 143 for locking the first acceleration ring 53. The third mounting base 13 is provided with a second insulating housing 15 outside the second electric lens assembly 6. The second insulating housing 15 is provided with a fourth locking member 151 for locking the second deceleration ring 61, a fifth locking member 152 for locking the second focusing ring 62, and a sixth locking member 153 for locking the second acceleration ring 63. After the spacing between the first deceleration ring 51, the first focusing ring 52, and the first acceleration ring 53 is adjusted, the first locking member 141, the second locking member 142, and the third locking member 143 are used to lock the first deceleration ring 51, the second focusing ring 62, and the second acceleration ring 63. Similarly, after the spacing between the second deceleration ring 61, the second focusing ring 62, and the second acceleration ring 63 is adjusted, the fourth locking member 151, the fifth locking member 152, and the sixth locking member 153 are used to lock the second deceleration ring 61, the second focusing ring 62, and the second acceleration ring 63.

[0046] Furthermore, in this embodiment, the first mounting seat 11 is threadedly connected to the second mounting seat 12, and the third mounting seat 13 is threadedly connected to the first insulating shell 14. The structure is simple and easy to assemble and disassemble.

[0047] Furthermore, in this embodiment, the first insulating housing 14 is provided with a first visual port 7 for observing the positions of the first deceleration ring 51, the first focusing ring 52, and the first acceleration ring 53, and the second insulating housing 15 is provided with a second visual port 8 for observing the positions of the second deceleration ring 61, the second focusing ring 62, and the second acceleration ring 63. Preferably, the first mounting seat 11 and the third mounting seat 13 are both sleeve-shaped, and the first insulating housing 14 and the second insulating housing 15 are both sleeve-shaped. The first mounting seat 11 and the first insulating housing 14 are coaxially sleeved and fixedly connected at the inlet end of the first ion beam channel 2 by a fixing ring. The third mounting seat 13 and the second insulating housing 15 are coaxially sleeved and fixedly connected at the inlet end of the third ion beam channel 4 by a fixing ring.

[0048] Furthermore, in this embodiment, the inner diameters of the first deceleration ring 51 , the first focusing ring 52 and the first acceleration ring 53 are all 60 mm, and the spacing is 5 mm; the inner diameters of the second deceleration ring 61 , the second focusing ring 62 and the second acceleration ring 63 are all 14 mm, and the spacing is 4 mm.

[0049] Research shows that the electrode ring size, axial spacing, and voltage configuration of the first deceleration ring 51, the first focusing ring 52, and the first acceleration ring 53 are all parameters to be optimized for the ion beam diameter dynamic confinement adjustment device, which have a significant impact on the plasma beam focusing effect.

[0050] The axial spacing between the first deceleration ring 51, the first focusing ring 52, and the first acceleration ring 53 on the first mounting seat 11 can be observed through the first viewing port 7 (through slot) and manually fine-tuned. The axial spacing between the second deceleration ring 61, the second focusing ring 62, and the second acceleration ring 63 on the third mounting seat 13 can be observed through the second viewing port 8 (through slot) and manually fine-tuned.

[0051] When the ion beam diameter dynamic confinement adjustment device is in use, its central axis is parallel to the horizontal plane. Therefore, the corresponding locking parts (setting screws) can be used to fix them based on the position adjustment of the first deceleration ring 51, the first focusing ring 52 and the first acceleration ring 53. According to the actual positions of the first deceleration ring 51, the first focusing ring 52 and the first acceleration ring 53, the locking parts can be selectively installed in the threaded hole 201 on the side wall of the first insulating shell 14.

[0052] like Figure 1 As shown, the power cables of the first deceleration ring 51, the first focusing ring 52, and the first acceleration ring 53 can be led out through the first visual port 7 on the first insulating housing 14. The power cables of the second deceleration ring 61, the second focusing ring 62, and the second acceleration ring 63 can be led out through the second visual port 8 on the second insulating housing 15.

[0053] For the initial plasma, it is inevitable that some Ar+ will directly bombard the side wall of the chamber. The first mounting seat 11 is set on the inner wall of the first electric lens assembly 5 to effectively prevent the positively charged Ar+ from accumulating on the surface of the three types of electrode rings (the first deceleration ring 51, the first focusing ring 52 and the first acceleration ring 53), thereby ensuring the stability of the confined electric field generated by the first electric lens assembly 5.

[0054] like Figure 5 As shown, for an initial plasma beam with an initial beam diameter of 40 mm and an Ar+ kinetic energy of 600 eV, different voltages have different effects on the focusing ability of the plasma beam. The overall rule is that as the voltage applied to the first focusing ring 52 increases, the focusing radius gradually decreases. In actual use, there is an upper limit to the applied voltage, and excessively high voltage makes the device more difficult to control and adjust.

[0055] Furthermore, if Figure 5 Research shows that for the plasma beam under the above conditions, the first electric lens assembly 5 can only constrain the beam diameter to 12 mm within the allowable applied voltage range. For some optical elements with complex surface shapes, the processing of micro-optical elements, and the sub-nanometer precision shaping of optical elements, this beam diameter cannot meet actual needs.

[0056] Furthermore, to achieve the goal of focusing the plasma beam to a beam diameter that meets the requirements of strong millimeter- or submillimeter-level ion beam processing, the initial plasma is confined by the first electric lens assembly 5. At this point, the plasma beam has a relatively ideal energy distribution, which is beneficial for the subsequent mechanical focusing of the plasma beam. Under the condition that the second ion beam channel 3 meets the conditions of plasma beam concentration, only a small amount of Ar+ strikes the wall of the second ion beam channel 3, resulting in beam energy loss. The majority of Ar+ is squeezed toward the central axis as the wall of the second ion beam channel 3 changes, resulting in an ion beam diameter close to submillimeter at the exit of the second ion beam channel 3 and extremely high beam energy.

[0057] Furthermore, the principle of the second electric lens assembly 6 is the same as that of the first electric lens assembly 5. The basic principle is still to set a bias on the second focusing ring 62. The difference between the two is that the main purpose of the second electric lens assembly 6 is to achieve continuous adjustment of the beam diameter of a high-energy, small-beam-diameter plasma beam at the outlet of the second ion beam channel 3. By setting the bias, the plasma beam diameter can be scaled.

[0058] In summary, this device achieves dynamic adjustment of the ion beam diameter in the millimeter to submillimeter range through the dynamic confinement of the ion beam by the two-stage electric lens and the mechanical compression of the ion beam by the second ion beam channel 3. Compared with the traditional processing method of destroying the vacuum environment and manually replacing the aperture piece to obtain a small beam diameter, this device can, on the one hand, flexibly adjust the ion beam diameter according to the actual processing needs of the actual optical components, ensure the continuity of the processing, extend the service life of the ion beam polishing machine, and has a simple structure; on the other hand, while obtaining a small beam diameter, less ion beam energy is lost, greatly improving the processing efficiency. This device is suitable for the processing of tiny optical components and complex curved surface components. The maturity of this technology is expected to provide important technical support for the sub-nanometer precision shaping of optical components.

[0059] Example 2:

[0060] A parameter optimization method for an ion beam diameter dynamic confinement adjustment device according to embodiment 1 includes taking the voltage, length, and spacing of the first deceleration ring 51, the first focusing ring 52, and the first acceleration ring 53 of the ion beam diameter dynamic confinement adjustment device, the cone angle and the inner diameter of the second ion beam channel 3, and the voltage, length, and spacing of the second deceleration ring 61, the second focusing ring 62, and the second acceleration ring 63 as parameters to be optimized, performing finite element analysis on the ion beam diameter dynamic confinement adjustment device under different combinations of parameters to be optimized to obtain the corresponding ion beam diameters, and using the optimized parameter combination corresponding to the optimal ion beam diameter as the optimized structural parameters for each ion beam diameter within a given ion beam diameter range to prepare the ion beam diameter dynamic confinement adjustment device. On the one hand, this method facilitates the determination of the diameters and spacings of the deceleration pole, focusing pole, and acceleration pole of each electric lens assembly, as well as the parameters related to the connecting parts between the electric lenses; on the other hand, it facilitates the verification and preparation of the most reasonable ion beam diameter dynamic confinement adjustment device.

[0061] Research has shown that the voltage, length, and spacing of the first deceleration ring 51, first focusing ring 52, and first acceleration ring 53; the cone angle and inner diameter of the second ion beam channel 3; and the voltage, length, and spacing of the second deceleration ring 61, second focusing ring 62, and second acceleration ring 63 are key parameters affecting plasma beam energy and beam diameter. Finite element analysis was used to determine the optimal combination of parameters corresponding to the ion beam diameter, facilitating the verification and development of the most appropriate dynamic ion beam confinement and adjustment device.

[0062] Furthermore, parametric modeling was adopted for the ion beam diameter dynamic confinement adjustment device under the charged particle tracking module and electrostatic module of the COMSOL finite element analysis software. Parametric scanning was used to analyze the plasma beam diameter confinement effect under various parameter combinations, and the optimal confinement effect was selected as the size parameter selection and physical quantity selection of the ion beam diameter dynamic confinement adjustment device.

[0063] For the initial plasma beam with an initial beam diameter of 40 mm and an Ar+ kinetic energy of 600 eV, through COMSOL finite element analysis, the optimal parameters are that the diameters of the three types of electrode rings (the first deceleration ring 51, the first focusing ring 52 and the first acceleration ring 53) of the first electric lens assembly 5 are all 60 mm, the spacing between adjacent electrode rings is 5 mm, the entrance diameter of the second ion beam channel 3 is 14 mm, the exit diameter is 2 mm, the cone angle of the second ion beam channel 3 is 20°, the diameters of the three types of electrode rings (the second deceleration ring 61, the second focusing ring 62 and the second acceleration ring 63) of the second electric lens assembly 6 are all 14 mm, and the spacing between adjacent electrode rings is 4 mm. Ultimately, the ion beam diameter can be continuously adjusted within the range of 8 mm-0.5 mm.

[0064] Under the optimal size parameters of the ion beam diameter dynamic confinement adjustment device, the first focusing ring 52 is connected to a voltage of 700V, the second focusing ring 62 is connected to a voltage of 300V, the first deceleration ring 51, the first acceleration ring 53, the second deceleration ring 61 and the second acceleration ring 63 are all grounded. Figure 4 Schematic diagram of internal potential and electric field distribution. Ar+ moves in the direction of the electric field to change its motion trajectory.

[0065] In order to further prove the feasibility of the ion beam diameter dynamic confinement adjustment device, the COMSOL simulation software is used to simulate the motion trajectory of the ion beam. Figure 7 As shown, the initial plasma enters the ion beam confinement device from the left end, and passes through the first electric lens assembly 5, the second ion beam channel 3 and the second electric lens assembly 6 in sequence. The movement trajectory of Ar+ is deflected accordingly under the action of the electric field and the wall surface. By adjusting the focusing ring voltage, the ion beam diameter can be dynamically adjusted in the millimeter to submillimeter range. While obtaining a small beam diameter, the plasma beam energy is also greatly improved, thereby improving the processing efficiency of the small beam diameter ion beam.

[0066] like Figure 7 As shown in the figure, there are a few cases where the trajectories of Ar+ diverge in the final simulation results. This is related to the fact that a few Ar+ collide with the wall of the concentration chamber at irregular incident angles. These Ar+ will hit the side wall of the insulating seat or move in the opposite direction. The energy of such Ar+ is low and the overall impact on the plasma beam energy is not significant. Figure 7 It is a schematic diagram of the ion trajectory of the ion beam diameter dynamic confinement adjustment device of the present invention at different time periods, wherein a is a schematic diagram of the ion trajectory of the ion 2.2041E-6s after emission or after entering the first ion beam channel 2, that is, the state diagram of the ion beam when passing through the second ion beam channel 3, and b is a schematic diagram of the ion trajectory of the ion 6E-6s after emission or after entering the first ion beam channel 2, that is, the state diagram of the ion beam after being ejected through the third ion beam channel 4. The overall process shows the continuous adjustment process of the ion beam diameter from large to small.

[0067] Example 3:

[0068] A parameter optimization method for the ion beam diameter dynamic confinement adjustment device according to the first embodiment is a method for determining the optimal target distance (the target distance is the distance from the workpiece to the exit of the third ion beam channel 4) for the parameters used in the existing ion beam diameter dynamic confinement adjustment device. Specifically, the method includes using COMSOL Multiphysics with MATLAB to perform batch simulations for multiple target distances, extracting and analyzing the argon ion distribution on each target surface (the side of the workpiece facing the exit of the third ion beam channel 4), determining the focusing radius under the target distance, and using the target distance corresponding to the optimal ion beam diameter as the focusing distance of the ion beam confinement device. The target distance can be used as a reference for the focusing distance in actual ion beam processing. Taking the determination of the optimal target distance of the first electric lens assembly 5 as an example, the size parameters of the ion beam confinement device have been selected as the optimal parameters according to the above method, and the voltage of the first focusing ring 52 is adjusted. The research results are as follows: Figure 6 As shown, when the voltage is 750V, the beam radius has the lowest value. Therefore, the voltage of 750V is better than 505V, 570V and 670V.

[0069] For the initial plasma beam with an initial beam diameter of 40 mm and an Ar+ kinetic energy of 600 eV, through COMSOL finite element analysis, the optimal parameters are that the diameters of the three types of electrode rings (the first deceleration ring 51, the first focusing ring 52 and the first acceleration ring 53) of the first electric lens assembly 5 are all 60 mm, the spacing between adjacent electrode rings is 5 mm, the entrance diameter of the second ion beam channel 3 is 14 mm, the exit diameter is 2 mm, the cone angle of the second ion beam channel 3 is 20°, the diameters of the three types of electrode rings (the second deceleration ring 61, the second focusing ring 62 and the second acceleration ring 63) of the second electric lens assembly 6 are all 14 mm, and the spacing between adjacent electrode rings is 4 mm. Ultimately, the ion beam diameter can be continuously adjusted within the range of 8 mm-0.5 mm.

[0070] Under the optimal size parameters of the ion beam diameter dynamic confinement adjustment device, the first focusing ring 52 is connected to a voltage of 700V, the second focusing ring 62 is connected to a voltage of 300V, the first deceleration ring 51, the first acceleration ring 53, the second deceleration ring 61 and the second acceleration ring 63 are all grounded. Figure 4 Schematic diagram of internal potential and electric field distribution. Ar+ moves in the direction of the electric field to change its motion trajectory.

[0071] Furthermore, parametric modeling was adopted for the ion beam diameter dynamic confinement adjustment device under the charged particle tracking module and electrostatic module of the COMSOL finite element analysis software. Parametric scanning was used to analyze the plasma beam diameter confinement effect under various parameter combinations, and the optimal confinement effect was selected as the size parameter selection and physical quantity selection of the ion beam diameter dynamic confinement adjustment device.

[0072] For the initial plasma beam with an initial beam diameter of 40 mm and an Ar+ kinetic energy of 600 eV, through COMSOL finite element analysis, the optimal parameters are that the diameters of the three types of electrode rings (the first deceleration ring 51, the first focusing ring 52 and the first acceleration ring 53) of the first electric lens assembly 5 are all 60 mm, the spacing between adjacent electrode rings is 5 mm, the entrance diameter of the second ion beam channel 3 is 14 mm, the exit diameter is 2 mm, the cone angle of the second ion beam channel 3 is 20°, the diameters of the three types of electrode rings (the second deceleration ring 61, the second focusing ring 62 and the second acceleration ring 63) of the second electric lens assembly 6 are all 14 mm, and the spacing between adjacent electrode rings is 4 mm. Ultimately, the ion beam diameter can be continuously adjusted within the range of 8 mm-0.5 mm.

[0073] Under the optimal size parameters of the ion beam diameter dynamic confinement adjustment device, the first focusing ring 52 is connected to a voltage of 700V, the second focusing ring 62 is connected to a voltage of 300V, the first deceleration ring 51, the first acceleration ring 53, the second deceleration ring 61 and the second acceleration ring 63 are all grounded. Figure 4 Schematic diagram of internal potential and electric field distribution. Ar+ moves in the direction of the electric field to change its motion trajectory.

[0074] In order to further prove the feasibility of the ion beam diameter dynamic confinement adjustment device, the COMSOL simulation software is used to simulate the motion trajectory of the ion beam. Figure 7 As shown, the initial plasma enters the ion beam confinement device from the left end, and passes through the first electric lens assembly 5 and the second electric lens assembly 6 in sequence. The movement trajectory of Ar+ is deflected accordingly under the action of the electric field and the wall surface. By adjusting the focusing ring voltage, the ion beam diameter can be dynamically adjusted in the millimeter to submillimeter range. While obtaining a small beam diameter, the plasma beam energy is also greatly improved, thereby improving the processing efficiency of the small beam diameter ion beam.

[0075] like Figure 7 As shown in the figure, there are a few cases where the trajectories of Ar+ diverge in the final simulation results. This is related to the fact that a few Ar+ collide with the wall of the concentration chamber at irregular incident angles. These Ar+ will hit the side wall of the insulating seat or move in the opposite direction. The energy of such Ar+ is low and the overall impact on the plasma beam energy is not significant. Figure 7 It is a schematic diagram of the ion trajectory of the ion beam diameter dynamic confinement adjustment device of the present invention at different time periods, wherein a is a schematic diagram of the ion trajectory of the ion 2.2041E-6s after emission or after entering the first ion beam channel 2, that is, the state diagram of the ion beam when passing through the second ion beam channel 3, and b is a schematic diagram of the ion trajectory of the ion 6E-6s after emission or after entering the first ion beam channel 2, that is, the state diagram of the ion beam after being ejected through the third ion beam channel 4. The overall process shows the continuous adjustment process of the ion beam diameter from large to small.

[0076] Although the present invention has been disclosed above with reference to preferred embodiments, this is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, utilize the technical content disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent embodiment with equivalent changes. Therefore, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the scope of protection of the technical solution of the present invention.

Claims

1. An ion beam diameter dynamic confinement adjustment device, characterized by: The invention comprises a mounting frame (1), and a first ion beam channel (2), a second ion beam channel (3) and a third ion beam channel (4) which are sequentially and coaxially arranged on the mounting frame (1), wherein the first ion beam channel (2) and the third ion beam channel (4) are both cylindrical, and the diameter of the first ion beam channel (2) is larger than that of the third ion beam channel (4), and the second ion beam channel (3) is conical, and the large-aperture end of the second ion beam channel (3) is connected to the outlet end of the first ion beam channel (2), and the small-aperture end is connected to the inlet end of the third ion beam channel (4), the inner diameter of the large-aperture end of the second ion beam channel (3) is smaller than that of the first ion beam channel (2), and the inner diameter of the small-aperture end is smaller than that of the third ion beam channel (4), and the mounting frame (1) is provided with a first electric lens assembly (5) for changing the ion trajectory to achieve beam diameter adjustment on the peripheral side of the first ion beam channel (2), and a second electric lens assembly (6) for changing the ion trajectory to achieve beam diameter adjustment on the peripheral side of the third ion beam channel (4).

2. The ion beam diameter dynamic confinement adjustment device according to claim 1, characterized in that: The cone angle of the second ion beam channel (3) is 20°.

3. The ion beam diameter dynamic confinement adjustment device according to claim 2, characterized in that: The inner diameter of the large-aperture end of the second ion beam channel (3) is 14 mm, and the inner diameter of the small-aperture end is 2 mm.

4. The ion beam diameter dynamic confinement adjustment device according to any one of claims 1 to 3, characterized in that: The first electric lens assembly (5) comprises a first deceleration ring (51), a first focusing ring (52) and a first acceleration ring (53) which are sequentially arranged at intervals along the direction from ion beam input to output of the first ion beam channel (2); the second electric lens assembly (6) comprises a second deceleration ring (61), a second focusing ring (62) and a second acceleration ring (63) which are sequentially arranged at intervals along the direction from ion beam input to output of the third ion beam channel (4).

5. The ion beam diameter dynamic confinement adjustment device according to claim 4, characterized in that: The mounting frame (1) comprises a first mounting seat (11), a second mounting seat (12) and a third mounting seat (13) which are detachably connected; the first ion beam channel (2) is arranged on the first mounting seat (11); the second ion beam channel (3) is arranged on the second mounting seat (12); the third ion beam channel (4) is arranged on the third mounting seat (13); the first deceleration ring (51), the first focusing ring (52) and the first acceleration ring (53) are movably mounted on the first mounting seat (11); and the second deceleration ring (61), the second focusing ring (62) and the second acceleration ring (63) are movably mounted on the third mounting seat (13).

6. The ion beam diameter dynamic confinement adjustment device according to claim 5, characterized in that: The first mounting seat (11) is provided with a first insulating shell (14) outside the first electric lens assembly (5); the first insulating shell (14) is provided with a first locking member (141) for locking the first deceleration ring (51), a second locking member (142) for locking the first focusing ring (52), and a third locking member (143) for locking the first acceleration ring (53); the third mounting seat (13) is provided with a second insulating shell (15) outside the second electric lens assembly (6); the second insulating shell (15) is provided with a fourth locking member (151) for locking the second deceleration ring (61), a fifth locking member (152) for locking the second focusing ring (62), and a sixth locking member (153) for locking the second acceleration ring (63).

7. The ion beam diameter dynamic confinement adjustment device according to claim 6, characterized in that: The first mounting seat (11) is threadedly connected to the second mounting seat (12), and the third mounting seat (13) is threadedly connected to the first insulating shell (14).

8. The ion beam diameter dynamic confinement adjustment device according to claim 6, characterized in that: The first insulating housing (14) is provided with a first visual port (7) for observing the positions of the first deceleration ring (51), the first focusing ring (52), and the first acceleration ring (53); and the second insulating housing (15) is provided with a second visual port (8) for observing the positions of the second deceleration ring (61), the second focusing ring (62), and the second acceleration ring (63).

9. The ion beam diameter dynamic confinement adjustment device according to claim 4, characterized in that: The inner diameters of the first deceleration ring (51), the first focusing ring (52) and the first acceleration ring (53) are all 60 mm, and the spacing is 5 mm; the inner diameters of the second deceleration ring (61), the second focusing ring (62) and the second acceleration ring (63) are all 14 mm, and the spacing is 4 mm.

10. A parameter optimization method for an ion beam diameter dynamic confinement adjustment device according to any one of claims 4 to 9, characterized in that: The invention includes the voltage, length and spacing of the first deceleration ring (51), the first focusing ring (52) and the first acceleration ring (53) of the ion beam diameter dynamic confinement adjustment device, the cone angle and the inner diameter of the two ends of the second ion beam channel (3), and the voltage, length and spacing of the second deceleration ring (61), the second focusing ring (62) and the second acceleration ring (63) as parameters to be optimized. Finite element analysis is performed on the ion beam diameter dynamic confinement adjustment device under different combinations of parameters to be optimized to obtain the corresponding ion beam diameters, and the combination of parameters to be optimized corresponding to the optimal ion beam diameter is used as the optimal structural parameters under each ion beam diameter within the given ion beam diameter range obtained by optimization to prepare the ion beam diameter dynamic confinement adjustment device.

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