Multi-angle adjustment ion beam impurity sputtering experiment device and method based on magnetic driving

Abstract

The invention discloses a multi-angle adjustment ion beam impurity sputtering experiment device and method based on magnetic driving. The multi-angle adjustment ion beam impurity sputtering experiment device comprises a vacuum cavity, a sample table assembly, a magnetic control angle isocentric adjustment mechanism and a multi-layer magnetic shielding mechanism. By adjusting the magnetic field direction and strength of an electromagnet in the magnetic driving angle isocentric adjusting mechanism, 0-90-degree non-contact angle adjustment of a sample in a vacuum environment is realized, and the vacuum sealing problem caused by a traditional shaft penetrating type transmission structure is avoided. The multilayer magnetic shielding mechanism can effectively inhibit interference of magnetic field leakage to ion beam transmission and sputtering processes. Due to the isocentric adjustment design, the sputtering point position of the sample is kept fixed in the rotating process, and the problems of ion flux deviation and sputtering point drift caused by incident angle change are solved. The device is compact in structure, reliable in sealing, small in magnetic interference and suitable for multi-angle impurity sputtering, incident angle dependence research and surface deposition experiments.

Description

Technical Field

[0001] This invention relates to the field of ion beam impurity sputtering experiments, and specifically to a magnetically driven multi-angle adjustable ion beam impurity sputtering experimental apparatus and method. Background Technology

[0002] In magnetic confinement fusion devices, plasma-facing (PFC) components (such as the first wall and limiters) are directly exposed to high-energy plasma and are subjected to long-term effects of ion bombardment, thermal load, and particle flux. Impurity sputtering during the interaction between the ion beam and the component surface is a key factor affecting component lifetime, plasma purity, and device operational reliability. The generation and escape of impurity atoms depend not only on the energy and type of the incident particles but also on the incident angle. Numerous experimental and simulation studies have shown that sputtering yield exhibits a significant nonlinear characteristic with respect to the incident angle, particularly showing a significant enhancement in the 60°–80° range. Therefore, accurately obtaining sputtering yield data at different incident angles is of significant reference value for material selection and lifetime assessment of PFC components in fusion reactors.

[0003] Therefore, research institutions both domestically and internationally widely employ ion beam sputtering experimental setups to simulate plasma-wall interactions. However, in existing publicly available technologies, typical ion beam / sputtering devices do not have a specifically designed layout for "multi-angle incident impurity sputtering." Traditional designs typically use mechanical through-shafts or motors to rotate the sample stage to tilt it, thereby adjusting the impurity sputtering incident angle. However, this often leads to a series of problems:

[0004] 1. When mechanical through-shaft transmission is used to achieve angle adjustment, the sealing structure of the vacuum through-shaft part is prone to wear and leakage under long-term operation and high-temperature cycling, resulting in vacuum fluctuations, which in turn changes the ion beam energy distribution and flux density, affecting the repeatability of sputtering experiments.

[0005] 2. In the impurity sputtering experimental setup, charged particles in the ion beam are very sensitive to magnetic fields. If there is a strong magnetic field in the angle adjustment mechanism and no good magnetic shielding design is carried out, the magnetic field may escape outward into the ion beam sputtering area, causing ion trajectory deviation and beam spot instability, which may seriously affect the impurity sputtering experiment.

[0006] 3. The design of most angle adjustment mechanisms may cause the sample surface to shift when the sample stage rotates, resulting in a deviation in the sputtering point position. This "sputtering point drift" will cause uneven changes in the incident ion flux, introducing systematic errors in impurity sputtering experiments and reducing the reliability of experimental results.

[0007] Therefore, there is an urgent need to propose a new magnetically driven multi-angle adjustable ion beam impurity sputtering experimental device to address the challenges in the design of current ion beam impurity sputtering experimental devices. Summary of the Invention

[0008] To address the problems in existing ion beam sputtering systems, such as reliance on mechanical transmission for sample angle adjustment, difficulties in vacuum sealing, severe magnetic field interference, and shifts in ion beam flux density and sputtering point position during sample rotation, this invention provides a magnetically driven, multi-angle adjustable ion beam impurity sputtering experimental device and method. This device enables continuous and controllable adjustment of the sample stage from 0° to 90° in a vacuum environment while maintaining a relatively fixed spatial position of the ion beam incident point. This allows for impurity sputtering experiments under different incident angle conditions, providing a highly stable and repeatable experimental platform for studying the impurity sputtering characteristics of PFC component materials in fusion reactors.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] An experimental apparatus for multi-angle adjustable ion beam impurity sputtering based on magnetic drive includes an ion source unit, a magnetically driven multi-angle isocentric adjustment mechanism, a vacuum chamber, and a control system. The ion source unit, along the ion beam path from top to bottom, includes a radio frequency power supply, a high-frequency heating coil, an air intake unit, an accelerating electrode system, a beam current limiting aperture, and an electron suppressor. The magnetically driven multi-angle isocentric adjustment mechanism includes a multi-angle magnetic drive device, a rocker arm, a sample stage rotation device, a sample stage drive shaft, and a sample stage. The rotation center axis of the multi-angle magnetic drive device is parallel to the upper surface of the sample on the sample stage and passes through the sample center point. The ion beam axis generated by the ion source unit intersects with the rotation center axis. The rocker arm is connected at both ends to the drive shaft of the multi-angle magnetic drive device and the sample stage rotation device, respectively. The sample stage rotation device drives the sample stage to rotate via the sample stage drive shaft. The control system adjusts the current of the electromagnet group to stop the rotor at the target angle and maintain torque balance.

[0011] Furthermore, the multi-angle magnetic drive device includes a drive shaft, an outer shielding layer, a vacuum gap, an inner shielding layer, a ceramic insulating layer, an electromagnet assembly, a permanent magnet assembly, a rotor, and an angle sensor. A vacuum gap is formed between the outer shielding layer and the inner shielding layer. The electromagnet assembly is circumferentially and uniformly arranged inside the inner shielding layer and isolated from the inner shielding layer by the ceramic insulating layer. The permanent magnet assembly is located outside the rotor and is circumferentially and uniformly arranged. The rotor is fixedly connected to the drive shaft. The angle sensor installed on the drive shaft is used to monitor the rotor rotation angle.

[0012] Furthermore, the outer shielding layer is made of permalloy, the inner shielding layer is made of soft iron, and the rotor and drive shaft are made of low-permeability metal materials.

[0013] Furthermore, the magnetic force between the electromagnet assembly and the permanent magnet assembly drives the rotor to rotate. The rotor transmits the rotational motion to the sample stage through the drive shaft, rocker arm, sample stage rotation device, and sample stage drive shaft, thereby achieving sample angle adjustment.

[0014] Furthermore, the sample stage rotation device has the same internal structure as the multi-angle magnetic drive device, and its rotation axis is perpendicular to the sample surface, so that the sample stage can achieve in-plane rotation while tilting.

[0015] Furthermore, the vacuum chamber is a sealed structure, and the magnetically driven multi-angle isocentric adjustment mechanism is entirely located inside the vacuum chamber. The ion beam generated by the ion source unit is adjusted to the required energy by the accelerating electrode system, collimated by the beam current limiting aperture, and modulated by the electron suppressor before bombarding the sample.

[0016] Furthermore, the vacuum gap serves as both a magnetic shielding gap and a thermal isolation gap, while the ceramic insulating layer provides electrical insulation and thermal isolation between the electromagnet assembly and the inner shielding layer.

[0017] Furthermore, the multi-angle magnetic drive device and the sample stage rotation device are linked by a rocker arm, so that the position of the ion beam bombardment point on the sample surface remains unchanged when the sample stage rotates around the rotation center axis.

[0018] Furthermore, it also includes a control system. When the electromagnet group is energized, it generates a directional magnetic field. Under the action of the magnetic field torque, the permanent magnet group drives the rotor to rotate. The angle sensor provides real-time feedback of the rotor angle signal. The control system adjusts the current of the electromagnet group according to the feedback signal, so that the rotor stops at the target angle and maintains torque balance.

[0019] This invention also provides an angle adjustment method for a magnetically driven multi-angle adjustable ion beam impurity sputtering experimental device, comprising: a control system supplying current to a portion of the electromagnets in the electromagnet group according to the target angle to generate a directional driving magnetic field; a permanent magnet group driving the rotor, drive shaft, rocker arm, sample stage rotation device, and sample stage to rotate under the action of the magnetic field torque; an angle sensor detecting the rotor angle in real time and feeding it back to the control system; the control system comparing the actual angle with the target angle, and when the actual angle reaches the target angle, adjusting the current of the electromagnet group to generate a holding magnetic field so that the sample stage is stably maintained at the target angle.

[0020] Beneficial effects:

[0021] 1. This invention employs magnetically controlled non-contact angle adjustment, replacing the traditional mechanical through-shaft transmission. This fundamentally avoids the leakage problems caused by long-term operation, wear, or high-temperature cycling of the vacuum through-shaft sealing structure, ensuring the long-term stability of the vacuum level inside the vacuum chamber;

[0022] 2. To address the potential magnetic field interference from the angle adjustment mechanism itself, this invention incorporates a multi-layer magnetic shielding mechanism. This mechanism effectively suppresses the outward escape of the magnetic field into the ion beam sputtering area, preventing stray magnetic fields from interfering with the trajectory of the charged ion beam.

[0023] 4. The present invention adopts an "isocentric adjustment design" to ensure that the position of the sputtering point on the sample surface remains unchanged during the continuous large-angle adjustment of the sample stage (0°~90°), which solves the problem of sputtering point drift and ion flux change caused by sample stage displacement during rotation in traditional mechanisms.

[0024] 5. This invention features a compact structure that effectively combines magnetic control adjustment, isocentric design, and magnetic shielding. It boasts high vacuum sealing reliability, minimal magnetic interference, and precise isocentric rotation characteristics, making it suitable for experiments requiring precise control of the incident angle, such as multi-angle impurity sputtering and incident angle-dependent experiments. Attached Figure Description

[0025] Figure 1 This is an overall schematic diagram of a magnetically driven, multi-angle adjustable ion beam impurity sputtering experimental device according to the present invention.

[0026] Figure 2 This is a schematic diagram of the internal structure of the multi-angle magnetic drive device in a magnetically driven multi-angle adjustable ion beam impurity sputtering experimental apparatus according to the present invention.

[0027] Figure 3 This is a top view of the internal structure of the multi-angle magnetic drive device in a magnetically driven multi-angle adjustable ion beam impurity sputtering experimental apparatus according to the present invention.

[0028] Figure 4 A comparison diagram of the magnetic shielding effects of different inner and outer magnetic shielding layer materials;

[0029] The reference numerals in the attached figures are as follows: 1-RF power supply; 2-High-frequency heating coil; 3-Inlet unit; 4-Accelerating electrode system; 5-Beam current limiting aperture; 6-Electron suppressor; 7-Multi-angle magnetic drive device; 8-Rock arm; 9-Sample stage rotation device; 10-Sample stage drive shaft; 11-Sample stage; 12-Sample; 13-Vacuum cavity; 71-Drive shaft; 72-Outer shielding layer; 73-Vacuum gap; 74-Inner shielding layer; 75-Electromagnet assembly; 76-Permanent magnet assembly; 77-Rotor; 78-Angle sensor; 79-Ceramic insulating layer. Detailed Implementation

[0030] 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 embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other. The following specific embodiments illustrate the implementation of this invention, and those skilled in the art can easily understand other advantages and effects of this invention based on the content of this specification.

[0031] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding and reading. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and objectives of the invention, should still fall within the scope of the invention's technical content. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0032] The present invention will now be described more clearly and completely with reference to the accompanying drawings in the embodiments of the present invention. It should be noted that these embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it.

[0033] like Figure 1 As shown, the magnetically driven, multi-angle adjustable ion beam impurity sputtering experimental apparatus of the present invention is constructed inside a vacuum chamber 13. It mainly comprises two functional systems: an ion source unit and a magnetically driven multi-angle isocentric adjustment mechanism.

[0034] In this embodiment, the ion source unit is used to generate and guide the ion beam. It is arranged along a central axis (ion beam path) and includes, from top to bottom, the following components along the same central axis: an inlet unit 3, a high-frequency heating coil 2, an accelerating electrode system 4, a beam current limiting aperture 5, and an electron suppressor 6. The radio frequency power supply 1 is connected to the high-frequency heating coil 2. The working process is as follows: the working gas is introduced through the inlet unit 3 and ionized under the excitation of the high-frequency heating coil 2 (powered by the radio frequency power supply 1) to form a plasma beam. This plasma beam is then extracted and accelerated by the accelerating electrode system 4, adjusted to the ion energy and flux required for the experiment. Finally, the ion beam is collimated by the beam current limiting aperture 5 and modulated by the electron suppressor 6 before bombarding the sample 12 on the sample stage 11.

[0035] The magnetically driven multi-angle isocentric adjustment mechanism is the core of this invention, used to achieve precise adjustment of the impurity sputtering angle of sample 12. It mainly includes: a multi-angle magnetic drive device 7, a rocker arm 8, a sample stage rotation device 9, a sample stage drive shaft 10, and a sample stage 11. The rotation center axis of the multi-angle magnetic drive device 7 is set parallel to the upper surface of sample 12 and passes through the center point of sample 12. Simultaneously, the ion beam axis of the ion source unit is adjusted to intersect with the rotation center axis of the multi-angle magnetic drive device 7 (the intersection point is the sputtering center point). The beneficial effect of this structure is that when the multi-angle magnetic drive device 7 drives the sample stage 11 and sample 12 to rotate around this rotation center axis (i.e., changing the ion beam incident angle), the bombardment point of the ion beam always remains at the original sputtering point of sample 12, and "sputtering point drift" does not occur. This fundamentally avoids changes in ion flux introduced by changes in the sputtering point position.

[0036] like Figure 2 and Figure 3 As shown, the multi-angle magnetic drive device 7 adopts a magnetic drive structure, avoiding the vacuum dynamic sealing problem caused by traditional mechanical through-shaft transmission. A vacuum gap 73 is formed between the outer shielding layer 72 and the inner shielding layer 74 in the multi-angle magnetic drive device 7. Electromagnetic magnets 75 are evenly arranged circumferentially inside the inner shielding layer 74 and isolated from it by a ceramic insulating layer 79. Permanent magnets 76 are located outside the rotor 77 and are evenly distributed circumferentially. The rotor 77 is fixedly connected to the drive shaft 71. An angle sensor 78 mounted on the drive shaft 71 is used to monitor the rotor rotation angle. In this embodiment, the electromagnets 75 are the driving components, evenly distributed circumferentially. The rotor 77 and the permanent magnets 76 fixed thereon are the driven components. The rotor 77 is connected to the drive shaft 71, which outputs power to the rocker arm 8, thereby adjusting the impurity sputtering angle of the sample 12.

[0037] To prevent the strong magnetic field of the multi-angle magnetic drive device 7 (mainly from the electromagnet group 75 and the permanent magnet group 76) from leaking into the ion beam path and interfering with ion movement, this invention provides a multi-layer magnetic shielding mechanism. For example... Figure 2 and Figure 3 As shown, the multi-layer magnetic shielding mechanism includes an outer shielding layer 72, an inner shielding layer 74, and a vacuum gap 73 between them. In a preferred embodiment, for optimal shielding effect, the outer shielding layer 72 is made of permalloy with high magnetic permeability, and the inner shielding layer 74 is made of soft iron with high saturation magnetic induction. The rotor 77 and the drive shaft 71 themselves are made of a low-permeability metallic material (such as austenitic stainless steel). Figure 4 The simulation results show that the double-layer shielding structure of "permalloy (outer) + soft iron (inner)" can better suppress magnetic field leakage compared to other material combinations.

[0038] To reduce the heat generated by the electromagnet assembly 75 during operation and its transfer into the vacuum cavity, thus affecting the experimental environment, this invention also incorporates a thermal isolation structure: the vacuum gap 73 between the outer shielding layer 72 and the inner shielding layer 74 serves both magnetic shielding and vacuum thermal insulation, reducing heat conduction. A ceramic insulating layer 79 is placed between the electromagnet assembly 75 and the inner shielding layer 74. This layer possesses high electrical insulation and low thermal conductivity, further reducing the diffusion of heat generated by the electromagnets during operation into the inner shielding layer 74 and the vacuum cavity.

[0039] The sample stage rotation device 9 has the same internal structure as the multi-angle magnetic drive device 7. Its rotation axis (i.e., the sample stage drive shaft 10) is perpendicular to the surface of the sample 12. This allows the sample stage 11 and the sample 12 to rotate in-plane while achieving multi-angle tilting. This rotation function allows the sample 12 to be sputtered more uniformly under ion beam bombardment.

[0040] Preferably, the permanent magnet assembly is uniformly embedded in the rotor along the circumferential direction.

[0041] Preferably, the rotation center axis of the multi-angle magnetic drive device is parallel to the upper surface of the sample and passes through the center point.

[0042] This invention also provides a method for controlling the angle adjustment of sample 12 using a magnetically driven multi-angle adjustable ion beam impurity sputtering experimental apparatus, comprising the following steps:

[0043] S1: The control system supplies a specific current to some of the electromagnets in the electromagnet group 75 according to the target angle set by the user, thereby generating a directional driving magnetic field.

[0044] S2: After being subjected to the force (or torque) of the driving magnetic field, the permanent magnet assembly 76 drives the rotor 77 and the transmission shaft 71 to rotate, and then rotates the sample stage 11 and the sample 12 toward the target angle through the rocker arm 8 and the sample stage rotation device 9.

[0045] S3: Angle sensor 78 detects the current angle of rotor 77 in real time and feeds this angle signal back to the control system.

[0046] S4: The control system compares the actual angle fed back with the set target angle. When the rotor 77 rotates to the preset angle, the control system adjusts the direction and intensity of the magnetic field of the electromagnet group 75 and the permanent magnet group 76 to achieve a torque balance state (i.e., generate a static "holding" magnetic field), so that the sample stage 11 and the sample 12 are accurately and stably held at the set angle.

[0047] In summary, this invention solves the problems of vacuum seal leakage and sputtering point drift through magnetic drive and isocentric adjustment design; through the optimized multi-layer magnetic shielding structure, it eliminates the interference of magnetic field on ion beam, and realizes high-precision, high-stability and high-repeatability multi-angle ion beam impurity sputtering experiments.

[0048] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made according to the technical solution of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A magnetically driven, multi-angle adjustable ion beam impurity sputtering experimental apparatus, characterized in that, The system includes an ion source unit, a magnetically driven multi-angle isocentric adjustment mechanism, a vacuum chamber, and a control system. The ion source unit, along the ion beam path from top to bottom, includes a radio frequency power supply, a high-frequency heating coil, an air intake unit, an accelerating electrode system, a beam current limiting aperture, and an electron suppressor. The magnetically driven multi-angle isocentric adjustment mechanism includes a multi-angle magnetic drive device, a rocker arm, a sample stage rotation device, a sample stage drive shaft, and a sample stage. The rotation center axis of the multi-angle magnetic drive device is parallel to the upper surface of the sample on the sample stage and passes through the sample center point. The ion beam axis generated by the ion source unit intersects with the rotation center axis. The rocker arm is connected at both ends to the drive shaft of the multi-angle magnetic drive device and the sample stage rotation device, respectively. The sample stage rotation device drives the sample stage to rotate via the sample stage drive shaft. The control system adjusts the current of the electromagnet group to stop the rotor at the target angle and maintain torque balance.

2. The magnetically driven, multi-angle adjustable ion beam impurity sputtering experimental apparatus according to claim 1, characterized in that, The multi-angle magnetic drive device includes a drive shaft, an outer shielding layer, a vacuum gap, an inner shielding layer, a ceramic insulating layer, an electromagnet assembly, a permanent magnet assembly, a rotor, and an angle sensor. A vacuum gap is formed between the outer shielding layer and the inner shielding layer. The electromagnet assembly is evenly arranged circumferentially inside the inner shielding layer and is isolated from the inner shielding layer by the ceramic insulating layer. The permanent magnet assembly is located outside the rotor and is evenly arranged circumferentially. The rotor is fixedly connected to the drive shaft. The angle sensor installed on the drive shaft is used to monitor the rotor rotation angle.

3. The magnetically driven, multi-angle adjustable ion beam impurity sputtering experimental apparatus according to claim 2, characterized in that, The outer shielding layer is made of permalloy, the inner shielding layer is made of soft iron, and the rotor and drive shaft are made of low-permeability metal materials.

4. The magnetically driven, multi-angle adjustable ion beam impurity sputtering experimental apparatus according to claim 2, characterized in that, The magnetic force between the electromagnet group and the permanent magnet group drives the rotor to rotate. The rotor transmits the rotational motion to the sample stage through the drive shaft, rocker arm, sample stage rotation device and sample stage drive shaft to realize the sample angle adjustment.

5. The magnetically driven, multi-angle adjustable ion beam impurity sputtering experimental apparatus according to claim 1, characterized in that, The sample stage rotation device has the same internal structure as the multi-angle magnetic drive device. Its rotation axis is perpendicular to the sample surface, so that the sample stage can rotate in the plane while tilting.

6. The magnetically driven, multi-angle adjustable ion beam impurity sputtering experimental apparatus according to claim 1, characterized in that, The vacuum chamber is a sealed structure, and the magnetically driven multi-angle isocentric adjustment mechanism is all located inside the vacuum chamber. The ion beam generated by the ion source unit is adjusted to the required energy by the accelerating electrode system, collimated by the beam current limiting aperture, and modulated by the electron suppressor before bombarding the sample.

7. The magnetically driven, multi-angle adjustable ion beam impurity sputtering experimental apparatus according to claim 2, characterized in that, The vacuum gap serves as both a magnetic shielding gap and a thermal isolation gap, while the ceramic insulating layer provides electrical insulation and thermal isolation between the electromagnet assembly and the inner shielding layer.

8. The magnetically driven, multi-angle adjustable ion beam impurity sputtering experimental apparatus according to claim 1, characterized in that, The multi-angle magnetic drive device and the sample stage rotation device are linked by a rocker arm, so that the position of the ion beam bombardment point on the sample surface remains unchanged when the sample stage rotates around the rotation center axis.

9. A magnetically driven, multi-angle adjustable ion beam impurity sputtering experimental apparatus according to any one of claims 1 to 8, characterized in that, It also includes a control system. When the electromagnet group is energized, it generates a directional magnetic field. Under the action of the magnetic field torque, the permanent magnet group drives the rotor to rotate. The angle sensor provides real-time feedback of the rotor angle signal. The control system adjusts the current of the electromagnet group according to the feedback signal, so that the rotor stops at the target angle and maintains torque balance.

10. The angle adjustment method of a magnetically driven multi-angle adjustable ion beam impurity sputtering experimental apparatus according to any one of claims 1-9, characterized in that, include: The control system supplies current to some of the electromagnets in the electromagnet group according to the target angle, thereby generating a directional driving magnetic field. Under the action of magnetic field torque, the permanent magnet assembly drives the rotor, drive shaft, rocker arm, sample stage rotation device and sample stage to rotate; the angle sensor detects the rotor angle in real time and feeds it back to the control system; the control system compares the actual angle with the target angle, and when the actual angle reaches the target angle, it adjusts the current of the electromagnet assembly to generate a holding magnetic field so that the sample stage is stably maintained at the target angle.

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