Target changing device for ion source and ion source

Abstract

Embodiments of the present invention provide a target changing device for an ion source and an ion source. The target changing device includes: a target disk having multiple target positions arranged along its circumference; a pulley and a connecting shaft, the pulley being connected to the target disk via the connecting shaft; a synchronous belt engaged with the pulley; and a motor configured to drive the synchronous belt, thereby causing the pulley to rotate the target disk.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of ion sources, and in particular to a target changing device for an ion source and an ion source. Background Art

[0002] An ion source generates ions by bombarding a sample target with a particle beam. For example, a cesium sputtering ion source is used to ionize cesium vapor into positive cesium ions and then use the cesium ion stream to bombard the sample target surface, thereby sputtering and generating negative ions.

[0003] An ion source typically includes a target plate with multiple target positions. Multiple sample targets are placed on the multiple target positions. Target replacement is achieved by rotating the target plate so that the corresponding target position is rotated to a working position, so that the sample target on the target position can be bombarded by the particle beam.

[0004] Prior art targets are rotated using compressed gas to rotate the target disk. However, this method suffers from slow target switching, limited positioning accuracy, and poor stability. Furthermore, it requires auxiliary equipment such as an air compressor and filter, which increases the overall size of the ion source system. Summary of the Invention

[0005] According to one aspect of the present invention, a target changing device for an ion source is provided, comprising: a target disk, the target disk being provided with a plurality of target positions along a circumferential direction; a pulley and a connecting shaft, the pulley being connected to the target disk via the connecting shaft; a synchronous belt cooperating with the pulley; and a motor configured to drive the synchronous belt to move, thereby causing the pulley to drive the target disk to rotate.

[0006] According to another aspect of the present invention, an ion source is provided, comprising: an ion source body, the ion source body comprising an ion source cavity; and the target changing device; wherein the target changing device is connected to the ion source body, and the target disk can enter the ion source cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Other objects and advantages of the present invention will become apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, which will help to provide a comprehensive understanding of the present invention.

[0008] Figure 1 A schematic diagram showing a target changing device for an ion source according to one embodiment of the present invention from one perspective;

[0009] Figure 2 Show Figure 1 A schematic diagram of the target changing device from another perspective;

[0010] Figure 3 A schematic diagram showing one perspective of an ion source according to one embodiment of the present invention;

[0011] Figure 4 Show Figure 3 Schematic diagram of another perspective of the ion source. DETAILED DESCRIPTION

[0012] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of this application. Obviously, the described embodiment is only one embodiment of this application, not all embodiments. Based on the described embodiments of this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0013] It should be noted that, unless otherwise defined, the technical or scientific terms used in this application should have the common meanings understood by persons having ordinary skills in the field to which this application belongs.

[0014] Figure 1 A schematic diagram showing a target changing device 100 for an ion source according to one embodiment of the present invention from one perspective; Figure 2 Show Figure 1 Schematic diagram of another perspective of the target changing device 100. Figure 1 and Figure 2 The target changing device 100 includes: a target plate 10, which is provided with a plurality of target positions along the circumference; a pulley 20 and a connecting shaft 22, wherein the pulley 20 is connected to the target plate 10 via the connecting shaft 22; a synchronous belt 24, which cooperates with the pulley 20; and a motor 26, which is configured to drive the synchronous belt 24 to move, thereby causing the pulley 20 to drive the target plate 10 to rotate.

[0015] In the target changing device 100 according to an embodiment of the present invention, the use of motor 26 for driving can improve control accuracy while also reducing operating noise. The use of a synchronous belt 24 and pulley 20 for transmission can ensure an accurate transmission ratio, eliminate slip during operation, and achieve a constant speed ratio, resulting in a precise and smooth transmission process. Overall, the positioning accuracy and smoothness of the target changing process can be improved, ensuring that the target changing device 100 has buffering and vibration reduction capabilities, reducing mechanical vibration, error accumulation, and response time during the target changing process. Furthermore, the device eliminates the need for additional auxiliary equipment, facilitating the miniaturization of the ion source design.

[0016] The synchronous belt 24 has a toothed structure, and the pulley 20 also has a toothed structure. The toothed structure of the synchronous belt 24 cooperates with the toothed structure of the pulley 20, so that the synchronous belt 24 moves, driving the pulley 20 to rotate. The rotating shaft of the motor 26 can have a toothed structure for cooperating with the toothed structure of the synchronous belt 24, so that the rotating shaft of the motor 26 rotates, driving the synchronous belt 24 to move. Alternatively, the rotating shaft of the motor 26 can be connected to another pulley, which in turn cooperates with the synchronous belt 24. The motor 26 drives the other pulley to rotate, and the other pulley drives the synchronous belt 24 to move. The pulley 20 is connected to the target disk 10 via a connecting shaft 22, so that the target disk 10 can rotate along with the pulley 20.

[0017] In some embodiments, the motor 26 is a servo motor, which can further improve the control accuracy and the target changing efficiency.

[0018] Specifically, a servo motor is equipped with an encoder and controlled by a controller. The encoder can detect the rotational position of the servo motor and feed the detected information back to the controller. The controller can then control the rotational position of the servo motor based on the information detected by the encoder, thereby adjusting the position deviation through closed-loop control and achieving high-precision positioning.

[0019] The rotation of the servo motor is controlled by a pulse signal. Multiple target positions on the target disk 10 can be coded, each with a corresponding target number. Each target number corresponds to a corresponding pulse number. By sending the corresponding pulse number to the servo motor, the servo motor drives the target disk 10 to rotate the corresponding angle, thereby moving the corresponding target position to the working position. For example, the number of target positions on the target disk 10 can be 48.

[0020] With this control method, you only need to select the corresponding target number to directly rotate the corresponding target position to the working position, making the target changing process efficient and fast. In comparison, the existing technology can only switch between adjacent target positions when changing targets, and the target changing process requires multiple button presses, which is relatively time-consuming.

[0021] The above control method can be achieved through a PLC controller, which sends pulses to the servo motor. The servo motor can be controlled by a control box equipped with a touch screen. The servo motor can also be remotely controlled using a computer.

[0022] In an embodiment of the present invention, the resolution of the servo motor is 0.04° / pulse, so that the rotation of the target disk 10 can be finely adjusted, so that the centering of the sample target is better, and the utilization rate of the sample target and the sputtering efficiency of the ion source are improved.

[0023] In some embodiments, the target changing device 100 further includes: a fixing portion 30 for being mounted to the ion source body 200; a mounting portion 40 connected to the fixing portion 30, with a pulley 20 disposed on the mounting portion 40, and the mounting portion 40 and the target plate 10 respectively located on both sides of the fixing portion 30; and a driving portion 42 for driving the mounting portion 40 to move relative to the fixing portion 30, so that the pulley 20 drives the target plate 10 to move, so that the target plate 10 approaches or moves away from the fixing portion 30.

[0024] Figure 3 and Figure 4 The ion source body 200 is shown. The ion source body 200 includes an ion source cavity 70. The particle beam for bombarding the sample target is formed in the ion source cavity 70. When the ion source is working, the target disk 10 needs to enter the ion source cavity 70. Figures 1 to 4 The fixing portion 30 is mounted to the ion source body 200. The target disk 10 located on one side of the fixing portion 30 is positioned within the ion source body 200, while the mounting portion 40 located on the other side of the fixing portion 30 is positioned outside the ion source body 200. The pulley 20 and the motor 26 can both be mounted on the mounting portion 40, and thus also positioned outside the ion source body 200. The fixing portion 30 can be connected to the ion source body 200 via threaded fasteners, and a sealing ring can be used to ensure a tight seal at the connection between the fixing portion 30 and the ion source body 200. The mounting portion 40 can be a flange.

[0025] Under the driving action of the driving portion 42, the target disk 10 can move closer to or farther from the fixing portion 30, so that the target disk 10 can be inserted into the ion source cavity 70 to be bombarded by the particle beam, or can be withdrawn from the ion source cavity 70 to replace the target disk 10 or replace the sample target on the target disk 10. When the target disk 10 moves closer to the fixing portion 30, the target disk 10 is away from the ion source cavity 70 and can be withdrawn from the ion source cavity 70; when the target disk 10 moves away from the fixing portion 30, the target disk 10 is closer to the ion source cavity 70 and can be inserted into the ion source cavity 70.

[0026] The driving portion 42 is used to drive the mounting portion 40 to move. Accordingly, the pulley 20 provided on the mounting portion 40 will move along with the mounting portion 40. Since the pulley 20 is connected to the target disk 10 via the connecting shaft 22, the target disk 10 will move along with the pulley 20. Since the mounting portion 40 and the target disk 10 are located on either side of the fixing portion 30, and the length of the connecting shaft 22 between the pulley 20 and the target disk 10 is fixed, when the mounting portion 40 moves away from the fixing portion 30, the target disk 10 will move closer to the fixing portion 30; when the mounting portion 40 moves closer to the fixing portion 30, the target disk 10 will move away from the fixing portion 30.

[0027] In an embodiment of the present invention, the driving portion 42 is a pneumatic cylinder. The cylinder body is mounted on the mounting portion 40, and the piston of the cylinder is connected to the fixed portion 30. When the piston extends or retracts relative to the cylinder body, the mounting portion 40 moves relative to the fixed portion 30. Specifically, when the piston extends, the mounting portion 40 moves away from the fixed portion 30; when the piston retracts, the mounting portion 40 moves toward the fixed portion 30. The number of cylinders can be multiple. In an embodiment of the present invention, three cylinders are provided, evenly distributed on the mounting portion 40, and move synchronously. This ensures balanced force on the target plate 10 during movement and ensures good positioning accuracy, facilitating the replacement of the target plate 10.

[0028] In other embodiments, the fixing portion 30 and the mounting portion 40 may be connected via a guide rod, the fixing portion 30 is fixed to one end of the guide rod, and the driving portion 42 is used to drive the mounting portion 40 to move along the guide rod.

[0029] In some embodiments, the target changing device 100 further includes: a bellows 50, the bellows 50 and the target plate 10 are located on the same side of the fixing portion 30, one end of the bellows 50 is connected to the fixing portion 30, and the connecting shaft 22 passes through the tube cavity of the bellows 50; and a rotating seal is arranged between the connecting shaft 22 and the tube wall of the bellows 50.

[0030] The interior of the ion source chamber 70 is a vacuum environment. When the target disk 10 extends into the ion source chamber 70, the vacuum condition of the ion source chamber 70 must be protected. The present invention achieves sealing by providing a bellows 50 and a rotary seal to maintain the vacuum level of the ion source chamber 70. The bellows 50 is used to provide a vacuum seal in the axial direction, while the rotary seal is used to provide a vacuum seal in the rotational direction. The rotary seal is mounted on the connecting shaft 22 and contacts the wall of the bellows 50 to seal the portion between the connecting shaft 22 and the wall of the bellows 50. The rotary seal may be a magnetic fluid seal.

[0031] The bellows 50 is elastic and can expand and contract, thereby not hindering the movement of the target plate 10. The bellows 50 is disposed between the fixing portion 30 and the target plate 10. When the target plate 10 moves toward the fixing portion 30, the bellows 50 can contract without hindering the movement of the target plate 10; when the target plate 10 moves away from the fixing portion 30, the bellows 50 can expand. The bellows 50 can also provide a buffer for the movement of the target plate 10, allowing the target plate 10 to move more smoothly.

[0032] The fixing portion 30 has a cavity into which one end of the bellows 50 is connected. The bellows 50 can be retracted into the cavity of the fixing portion 30 , allowing the target plate 10 to move more fully and to a position closer to the fixing portion 30 .

[0033] In some embodiments, the target changing device 100 further includes: a turntable 44, which is disposed on the mounting portion 40, and the turntable 44 is disposed on a side of the mounting portion 40 away from the fixing portion 30, and the turntable 44 rotates following the pulley 20, and the turntable 44 is provided with a mark, which is used to indicate the positions of the multiple target positions.

[0034] When the fixing portion 30 is mounted on the ion source body 200, the target disk 10 is inserted into the ion source body 200, making it difficult for the operator to see the target disk 10 and understand the positions of the multiple targets on the target disk 10. By providing a turntable 44 on the side of the mounting portion 40 facing away from the fixing portion 30, the operator can see the turntable 44 and understand the current target positions based on the markings on the turntable 44, facilitating operations such as target replacement. The markings on the turntable 44 can include scale lines and target numbers.

[0035] The turntable 44 can be connected to the pulley 20 via the connecting shaft 22. That is, the pulley 20, the turntable 44 and the target plate 10 are connected via the same connecting shaft 22, and the three can rotate synchronously. The turntable 44 can reflect the rotation of the target plate 10.

[0036] In some embodiments, the ion source body 200 includes a guide rail 60; the target changing device 100 further includes a bracket 32 ​​connected to the fixing portion 30, and the bracket 32 ​​is capable of sliding along the guide rail 60. The bracket 32 ​​may include a sliding portion that slides along the guide rail 60. The bracket 32 ​​may include an operating portion, and an operator operates the operating portion to pull or push the bracket 32 ​​to slide along the guide rail 60.

[0037] There can be two brackets 32, one on each side of the fixing portion 30. The bracket 32 ​​can be in an inverted F shape, comprising a vertically extending portion and two lateral extending portions connected to the vertically extending portion. One end of the vertically extending portion is connected to the fixing portion 30, and the other end and the middle of the vertically extending portion are respectively connected to the two lateral extending portions. One of the lateral extending portions is provided with the sliding portion, and the other lateral extending portion serves as the operating portion.

[0038] The target changing device 100 can be moved by the sliding of the bracket 32. The guide rail 60 provides guidance for the sliding of the bracket 32, and further provides guidance for the movement of the target changing device 100, so that the target changing device 100 can move relative to the ion source body 200 to approach or move away from the ion source body 200, which is conducive to the target changing device 100 being installed on the ion source body 200 or separated from the ion source body 200.

[0039] When the target plate 10 needs to be replaced or the sample target on the target plate 10 needs to be replaced, the fixing portion 30 can be disassembled from the ion source body 200, and then the bracket 32 ​​can be operated to move the target changing device 100 along the guide rail 60 away from the ion source body 200, so that the target plate 10 is exposed. At this time, the operator can replace the target plate 10 or replace the sample target.

[0040] According to another aspect of the present invention, an ion source is provided, comprising: an ion source body 200 , the ion source body 200 including an ion source cavity 70 ; a target changing device 100 ; wherein the target changing device 100 is connected to the ion source body 200 , and a target plate 10 can enter the ion source cavity 70 .

[0041] The ion source can be a cesium sputtering ion source, and the ion source body 200 includes a cesium container 74 for placing cesium and heating cesium to produce cesium vapor. The ion source body 200 also includes an ionizer and a focusing lens arranged in the ion source chamber 70, wherein the ionizer is used to ionize the cesium vapor into cesium positive ions, and the focusing lens is used to focus the cesium positive ions into a cesium ion beam, which is used to bombard the sample target to produce negative ions. The ion source body 200 also includes a gas supply assembly 76 connected to the ion source chamber 70 for conveying, for example, an inert gas into the ion source chamber 70.

[0042] In some embodiments, the ion source body 200 further includes: an isolation valve 72, which is connected between the target changing device 100 and the ion source chamber 70; when the isolation valve 72 is in an open state, the target disk 10 enters the ion source chamber 70; or when the isolation valve 72 is in a closed state, the target disk 10 is blocked outside the ion source chamber 70.

[0043] When the target disk 10 or the sample target needs to be replaced, the target disk 10 is withdrawn from the ion source chamber 70 . At this time, the isolation valve 72 is closed to seal the ion source chamber 70 and protect the vacuum environment in the ion source chamber 70 .

[0044] The ion source body 200 further includes a cooling flange connected between the isolation valve 72 and the ion source chamber 70 , for blocking or slowing down the transfer of heat from the ion source chamber 70 to the isolation valve 72 .

[0045] In some embodiments, when the isolation valve 72 is in a closed state, a temporary cavity is formed between the isolation valve 72 and the target changing device 100; the ion source body 200 also includes: a gas pumping port 71, which is connected to the temporary cavity, wherein the temporary cavity is pumped or supplied with gas through the gas pumping port 71.

[0046] When the target disk 10 or sample target needs to be replaced, the target disk 10 is withdrawn from the ion source chamber 70 and the isolation valve 72 is closed. At this time, the temporary chamber between the isolation valve 72 and the target changing device 100 is in a vacuum state. Due to the pressure difference between the internal and external pressures, the target changing device 100 cannot be separated from the ion source body 200. At this time, air is supplied to the temporary chamber through the air pump port 71 to balance the internal and external pressures. The fixing portion 30 is then disassembled from the ion source body 200. The target changing device 100 can then be moved away from the ion source body 200, leaving sufficient space between them and facilitating the replacement of the target disk 10 or sample target.

[0047] After the target disk 10 or sample target is replaced, the target changing device 100 is moved closer to the ion source body 200. After being moved to the appropriate position, the fixing portion 30 is installed on the ion source body 200. The temporary cavity can then be evacuated through the gas pumping port 71 to restore the temporary cavity to a vacuum state. At this time, the isolation valve 72 can be opened to allow the target disk 10 to extend into the ion source cavity 70.

[0048] The target changing device 100 of the present invention can improve the positioning accuracy, replacement speed and smoothness of the replacement process when changing the target position; and can realize the smooth exit of the target plate 10 from the ion source chamber 70, which is conducive to replacing the target plate 10 or replacing the sample target; at the same time, it can ensure that the vacuum environment in the ion source chamber 70 will not be destroyed when replacing the target plate 10 or the sample target.

[0049] Regarding the embodiments of the present invention, it should also be noted that, in the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to obtain new embodiments.

[0050] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A target changing device for an ion source, characterized in that: include: A target disc, wherein the target disc is provided with a plurality of target positions along the circumference; A pulley and a connecting shaft, wherein the pulley is connected to the target disc via the connecting shaft; a synchronous belt, cooperating with the pulley; A motor is configured to drive the synchronous belt to move, thereby causing the pulley to drive the target disc to rotate; A fixing portion, configured to be mounted to an ion source body; A mounting portion connected to the fixing portion, the pulley being arranged on the mounting portion, and the mounting portion and the target plate being respectively located on both sides of the fixing portion; a driving portion, configured to drive the mounting portion to move relative to the fixing portion, so that the pulley drives the target plate to move, so that the target plate moves closer to or farther from the fixing portion; a bellows, wherein the bellows and the target disk are located on the same side of the fixing portion, one end of the bellows is connected to the fixing portion, the connecting shaft passes through the lumen of the bellows, and the bellows is arranged between the fixing portion and the target disk; A rotary seal is provided between the connecting shaft and the wall of the bellows; The target plate located on one side of the fixing portion enters the interior of the ion source body, and the mounting portion located on the other side of the fixing portion is located outside the ion source body; The fixing portion has a chamber, and one end of the bellows is connected to the chamber.

2. The device according to claim 1, characterized in that The motor is a servo motor, and the resolution of the servo motor is 0.04° / pulse.

3. The device according to claim 1, characterized in that The rotary seal is a magnetic fluid seal.

4. The device according to claim 1, characterized in that Also includes: A turntable is arranged on a side of the mounting portion away from the fixing portion, the turntable rotates following the pulley, and the turntable is provided with a mark for marking the positions of the multiple target positions.

5. The device according to claim 1, characterized in that The ion source body includes a guide rail; The target changing device further includes a bracket connected to the fixing portion, and the bracket is capable of sliding along the guide rail.

6. An ion source, characterized in that include: an ion source body, the ion source body comprising an ion source cavity; The target changing device according to any one of claims 1 to 5; Wherein, the target changing device is connected to the ion source body, and the target plate can enter the ion source cavity.

7. The ion source according to claim 6, characterized in that The ion source body further comprises: an isolation valve connected between the target changing device and the ion source chamber; The isolation valve is in an open state, and the target disk enters the ion source chamber; or The isolation valve is in a closed state, and the target disk is blocked outside the ion source cavity.

8. The ion source according to claim 7, characterized in that When the isolation valve is in a closed state, a temporary cavity is formed between the isolation valve and the target changing device; The ion source body further includes a gas pumping port, which is in communication with the temporary cavity, wherein gas is pumped or supplied to the temporary cavity through the gas pumping port.

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