Hybrid magnet structure

Abstract

This invention proposes a hybrid magnet structure comprising two opposing diode magnet assemblies. Each diode magnet assembly includes a permanent magnet, two iron cores, and a movable magnetic field shunt element. This hybrid magnet structure can focus charged particle beams at different locations by applying an adjustable gradient magnetic field in the horizontal or vertical direction. This invention achieves the focusing of charged particle beams by allowing them to pass through the gradient magnetic field established between the two diode magnet assemblies. Furthermore, the magnitude of the gradient magnetic field can be changed by adjusting the gap between the movable magnetic field shunt element and the permanent magnet, thereby controlling the particle beam size along a certain axis for charged particle beams of different energies or masses.

Description

Technical Field

[0001] This invention relates to a hybrid magnet structure, and more particularly to a hybrid magnet structure suitable for the field of ion implantation technology. Background Technology

[0002] Currently, in the field of ion implantation technology, the method of winding coils around an iron core is used to manufacture dipole magnets and quadrupole magnets (composed of two dipole magnets). This creates a gradient magnetic field between the two dipole magnets, and then uses this gradient magnetic field to converge (focus) the charged particle beam (such as an ion beam) in a specific axis, as described in Taiwan patents TW I679669 and TW I640999.

[0003] The characteristic of this gradient magnetic field is that the magnetic field at the center is zero, and the magnitude of the magnetic field gradually increases with distance from the center along a certain axis (e.g., the Y-axis). During operation, the center of the charged particle beam is positioned through the center of this gradient magnetic field. This way, the charged particles at the center of the beam experience zero magnetic field, allowing them to maintain their original path. However, the charged particles deviating from the center of the beam along the Y-axis experience a non-zero magnetic field, and the magnetic force exerted on them causes them to move closer to the center of the beam (the center of the field), thereby achieving the goal of converging (focusing) the charged particle beam.

[0004] Traditional quadrupole magnets work by changing the magnitude of the gradient magnetic field by altering the current in the coil, thereby focusing a beam of charged particles passing through the magnetic field. This method of controlling the gradient magnetic field by changing the coil current has the following problems: (1) it consumes additional power, increasing the carbon footprint of the processed products and increasing processing costs; (2) the leakage magnetic field is relatively large, which can easily affect the magnetic field strength of nearby magnets; (3) the insulation material of the coil will release gas when overheated, affecting or contaminating the vacuum chamber; and (4) the degree of change in the magnetic field is limited. Summary of the Invention

[0005] The present invention proposes a hybrid magnet structure for focusing a beam of charged particles moving along the Z-axis. The hybrid magnet structure includes a first diode magnet assembly and a second diode magnet assembly arranged in a coplanar manner.

[0006] The first dipole magnet assembly includes a first permanent magnet, a first iron core, a second iron core, and a first magnetically conductive element. The first permanent magnet has a first N-pole, a first S-pole, a first inner surface, and a first outer surface opposite the first inner surface. The first N-pole and the first S-pole are arranged in a straight line parallel to the X-axis. The first inner surface and the first outer surface are located between the first N-pole and the first S-pole, and the first inner surface is arranged toward the path of motion of the charged particle beam. The first iron core includes a first covering section and a first extending section connected to each other, the first covering section covering the first N-pole, and the first extending section extending from the first covering section and protruding beyond the first inner surface. The second iron core includes a second covering section and a second extending section connected to each other, the second covering section covering the first S-pole, and the second extending section extending from the second covering section and protruding beyond the first inner surface. The first magnetically conductive element is movably disposed on the first outer surface of the first permanent magnet.

[0007] The second dipole magnet assembly includes a second permanent magnet, a third core, a fourth core, and a second magnetically conductive element. The second permanent magnet has a second N-pole, a second S-pole, a second inner surface, and a second outer surface opposite the second inner surface. The second N-pole and the second S-pole are arranged in a direction parallel to the X-axis. The second inner surface and the second outer surface are located between the second N-pole and the second S-pole, and the second inner surface is arranged toward the path of the charged particle beam and toward the first inner surface of the first permanent magnet. The third core includes a third covering section and a third extending section connected to each other. The third covering section covers the second S-pole, and the third extending section extends from the third covering section and protrudes beyond the second inner surface. The third extending section and the first extending section are arranged in a direction parallel to the Y-axis. The fourth core includes a fourth covering section and a fourth extending section connected to each other. The fourth covering section covers the second N-pole, and the fourth extending section extends from the fourth covering section and protrudes beyond the second inner surface. The fourth extending section and the second extending section are arranged in a direction parallel to the Y-axis. The second magnetically conductive element is movably disposed on the second outer surface of the second permanent magnet.

[0008] The hybrid magnet structure of the present invention establishes a gradient magnetic field between the first diode magnet assembly and the second diode magnet assembly. The movable first magnetic conductive element and the second magnetic conductive element serve as magnetic field shunt elements. By controlling the distance between the first magnetic conductive element and the first permanent magnet and the distance between the second magnetic conductive element and the second permanent magnet, it can be verified that the magnitude of the gradient magnetic field can be adjusted without the use of a high-energy-consuming coil. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of a first embodiment of the hybrid magnet structure of the present invention;

[0010] Figure 2AThis is a schematic diagram of the magnetic field lines distribution when the first magnetically conductive element of the first embodiment is close to the first permanent magnet.

[0011] Figure 2B This is a schematic diagram of the magnetic field lines distribution when the first magnetically conductive element is far away from the first permanent magnet in the first embodiment.

[0012] Figure 3A This is a schematic diagram of the magnetic field lines distribution when the second magnetically conductive element of the first embodiment is close to the second permanent magnet.

[0013] Figure 3B This is a schematic diagram of the magnetic field lines distribution when the second magnetically conductive element of the first embodiment is far away from the second permanent magnet.

[0014] Figure 4A This is a schematic diagram simulating the gradient magnetic field formed by the hybrid magnet structure of the first embodiment, wherein the coordinates of the center of the gradient magnetic field are (0,0), and the curve represents the trend of the magnetic field Bx changing with the Y axis when X=0;

[0015] Figure 4B This is a schematic diagram simulating the gradient magnetic field formed by the hybrid magnet structure of the first embodiment, wherein the coordinates of the center of the gradient magnetic field are (0,0), and the curve represents the trend of the magnetic field By changing with the X-axis when Y=0;

[0016] Figure 5 This is a schematic diagram of a second embodiment of the hybrid magnet structure of the present invention;

[0017] Figure 6 This is a schematic diagram of the magnetic field lines distribution when the first magnetically conductive element is close to the first permanent magnet and the second magnetically conductive element is close to the second permanent magnet in the second embodiment.

[0018] Figure 7 This is a schematic diagram of the magnetic field lines distribution when the first magnetically conductive element is far away from the first permanent magnet and the second magnetically conductive element is far away from the second permanent magnet in the second embodiment.

[0019] Figure 8A This is a schematic diagram simulating the gradient magnetic field formed by the hybrid magnet structure in the second embodiment. The coordinates of the center of the gradient magnetic field are (0,0). The curve represents the trend of the magnetic field Bx changing with the Y axis when X=0. P1 to P3 represent the curves obtained with different DX2 values, respectively.

[0020] Figure 8B This is a schematic diagram simulating the gradient magnetic field formed by the hybrid magnet structure in the second embodiment. The coordinates of the center of the gradient magnetic field are (0,0). The curve represents the trend of the magnetic field By changing with the X-axis when Y=0. P1 to P3 represent curves obtained with different DX2 values.

[0021] [Symbol Explanation]

[0022] 1,2: Hybrid magnet structure

[0023] 11,21: First Dipole Magnet Assembly

[0024] 111,211: First permanent magnet

[0025] 111A, 211A: First inner surface

[0026] 111B, 211B: First outer surface

[0027] 111N, 211N: The first N extreme

[0028] 111S, 211S: First S extreme

[0029] 112,212: First iron core

[0030] 1121,2121: First coverage segment

[0031] 1122, 2122: First extension section

[0032] 113,213: Second iron core

[0033] 1131, 2131: Second coverage segment

[0034] 1132, 2132: Second extension section

[0035] 114,214: First magnetic element

[0036] 114G, 214G: Spacing

[0037] 13,23: Second Dipole Magnet Assembly

[0038] 131,231: Second permanent magnet

[0039] 131A, 231A: Second inner surface

[0040] 131B, 231B: Second outer surface

[0041] 131N, 231N: The second N-extreme

[0042] 131S, 231S: Second S extreme

[0043] 132,232: Third iron core

[0044] 1321,2321: Third Coverage Segment

[0045] 1322, 2322: Third extension section

[0046] 133,233: Fourth iron core

[0047] 1331,2331: Fourth Coverage Segment

[0048] 1332, 2332: Fourth extension section

[0049] 134,234: Second magnetic element

[0050] 134G, 234G: Spacing

[0051] 90, 92: Charged particle beams

[0052] DX1, DX2: Spacing

[0053] DY1, DY2: Spacing

[0054] ML: Magnetic field lines

[0055] WX: Width Detailed Implementation

[0056] In the following embodiments, "upper," "lower," "front," or "rear" are merely used to indicate their orientation in the accompanying drawings or to facilitate the description of the relative relationship between the elements, and are not intended to limit their actual orientation.

[0057] For ease of explanation, the component relationships and physical quantities of the various embodiments in this specification are described using a Cartesian coordinate system, wherein the direction of motion of the charged particle beam is defined in the Z-axis direction, and the two oppositely arranged diodes are coplanar with their N and S ends located in the XY plane.

[0058] Unless otherwise defined, the term "spacing" in the following embodiments refers to the shortest distance between two elements or between specific parts of two elements. It should be specifically noted that... Figure 5 The spacing DX2 shown refers to the longest distance between the first extension segment 2122 and the second extension segment 2132.

[0059] A permanent magnet is a component made of magnetic materials that possesses a persistent magnetic field, unlike the magnetic field of an electromagnet, whose strength cannot be altered by controlling an electric current. Types of permanent magnets include ceramic, ferromagnetic, and rare-earth permanent magnets (such as SmCo).

[0060] The generation of charged particles generally involves introducing a source gas into a plasma reaction chamber to plasmaize it, and then extracting the desired charged particles (ions) by passing the plasma-plasma source gas through a slit-shaped extraction electrode. Therefore, the cross-sectional shape of the charged particle beam is generally flat, meaning it is longer along one axis (hereinafter referred to as the major axis) and flatter along another mutually orthogonal axis (hereinafter referred to as the minor axis). For ease of explanation, the major axis of the charged particle beam in this specification is defined as the Y-axis direction (or the vertical direction), and the minor axis of the charged particle beam is defined as the X-axis direction (or the horizontal direction).

[0061] Please refer to Figure 1 This is a schematic diagram of a first embodiment of the hybrid magnet structure of the present invention, illustrating a hybrid magnet structure 1. The hybrid magnet structure 1 is a quadrupole magnet, mainly comprising two secondary magnets arranged coplanarly in the XY plane, namely a first secondary magnet assembly 11 and a second secondary magnet assembly 13. The hybrid magnet structure 1 is used to focus a charged particle beam 90 moving along the Z-axis direction, the cross-section of which is approximately as shown below. Figure 1 The diagram is flat, with the major axis representing the Y-axis (vertical direction) and the minor axis representing the X-axis (horizontal direction). Figure 1 The hybrid magnet structure 1, configured in this manner, is used to focus the charged particle beam 90 along its long axis. That is, after passing through the hybrid magnet structure 1, the cross-sectional length of the charged particle beam 90 decreases along the Y-axis and slightly increases along the X-axis. The principle of focusing a charged particle beam using a quadrupole magnet has been described in many prior art documents and will not be repeated here. The focus of this invention is to propose a novel hybrid magnet structure to replace the traditional quadrupole magnet that uses coils to control the magnetic field.

[0062] like Figure 1 As shown, the first diode magnet assembly 11 includes a first permanent magnet 111, which has a first N-terminal 111N and a first S-terminal 111S, a first inner surface 111A, and a first outer surface 111B opposite to the first inner surface 111A. The first N-terminal 111N and the first S-terminal 111S are arranged in a straight line parallel to the X-axis. The first inner surface 111A and the first outer surface 111B are located between the first N-terminal 111N and the first S-terminal 111S, and the first inner surface 111A is configured toward the movement path of the charged particle beam 90.

[0063] The first diode magnet assembly 11 further includes a first iron core 112, which includes a first covering section 1121 and a first extension section 1122 connected to each other. The first covering section 1121 covers the end face of the first N-terminal 111N to guide the magnetic field lines ML emitted from the first N-terminal 111N to the first extension section 1122 as much as possible. The first extension section 1122 is connected to one end of the first covering section 1121, extends from the first covering section 1121, and protrudes from the first inner surface 111A. The magnetic field lines ML of the first permanent magnet 111 are emitted mainly from the first extension section 1122, thus the first extension section 1122 serves as one of the magnetic poles of the first diode magnet assembly 11.

[0064] The first diode magnet assembly 11 further includes a second core 113, which includes a second covering section 1131 and a second extension section 1132 connected to each other. The second covering section 1131 covers the end face of the first S-end 111S to guide the magnetic field lines ML emitted from the first extension section 1122 to the first S-end 111S as much as possible. The second extension section 1132 is connected to one end of the second covering section 1131 and extends from the second covering section 1131, protruding from the first inner surface 111A. After the magnetic field lines ML of the first permanent magnet 111 are emitted from the first extension section 1122, most of them return to the first permanent magnet 111 through the second extension section 1132. Therefore, the second extension section 1132 serves as another magnetic pole of the first diode magnet assembly 111.

[0065] Reference Figure 1 and Figure 2A , Figure 2B The first dipole magnet assembly 11 further includes a first magnetically conductive element 114, which is movably disposed on the first outer surface 111B of the first permanent magnet 111. In some embodiments, the first magnetically conductive element 114 is made of an iron core material, so a portion of the magnetic field lines ML of the first permanent magnet 111 will be diverted to the first magnetically conductive element 114. Figure 2A As shown, when the first magnetically conductive element 114 is closer to the first outer surface 111B, that is, when the distance 114G between the first magnetically conductive element 114 and the first outer surface 111B is small, the magnetic field lines ML shunted to the first magnetically conductive element 114 will be more numerous, which in turn results in a smaller magnetic flux emitted from the first extension section 1122 and returning to the first permanent magnet 111 through the second extension section 1132. Figure 2BAs shown, when the first magnetically conductive element 114 is farther away from the first outer surface 111B, that is, when the distance 114G between the first magnetically conductive element 114 and the first outer surface 111B is larger, the magnetic field lines ML shunted to the first magnetically conductive element 114 will be less, thereby increasing the magnetic flux emitted from the first extension section 1122 and returning to the first permanent magnet 111 through the second extension section 1132. In this way, engineers can control the magnitude of the magnetic field exerted by the first diode magnet assembly 11 on the charged particle beam 90 by adjusting the distance 114G between the first magnetically conductive element 114 and the first outer surface 111B of the first permanent magnet 111.

[0066] Reference Figure 1 The second diode magnet assembly 13 includes a second permanent magnet 131, which has a second N-terminal 131N and a second S-terminal 131S, a second inner surface 131A, and a second outer surface 131B opposite to the second inner surface 131A. The second N-terminal 131N and the second S-terminal 131S are arranged in a straight line parallel to the X-axis, and are 180 degrees different from the arrangement of the first N-terminal 111N and the first S-terminal 111S. The second inner surface 131A and the second outer surface 131B are located between the second N-terminal 131N and the second S-terminal 131S. The second inner surface 131A is arranged toward the movement path of the charged particle beam 90 and toward the first inner surface 111A of the first permanent magnet 111.

[0067] The second dipole magnet assembly 13 further includes a third core 132, which includes a third covering section 1321 and a third extending section 1322 connected to each other. The third covering section 1321 covers the end face of the second S-end 131S to guide the magnetic field lines ML emitted from the third extending section 1322 to the second S-end 131S as far as possible. The third extending section 1322 extends from the third covering section 1321 and protrudes from the second inner surface 131A. The third extending section 1322 and the first extending section 1122 are arranged in a straight line parallel to the Y-axis and are separated from each other by a distance DY1.

[0068] The second dipole magnet assembly 13 further includes a fourth core 133, which includes a fourth covering section 1331 and a fourth extending section 1332 connected to each other. The fourth covering section 1331 covers the end face of the second N-terminal 131N to guide the magnetic field lines ML emitted from the second N-terminal 131N to the fourth extending section 1332 as far as possible. The fourth extending section 1332 is connected to one end of the fourth covering section 1331 and extends from the fourth covering section 1331, protruding from the second inner surface 131A. The fourth extending section 1332 and the second extending section 1132 are arranged in a straight line parallel to the Y-axis and are separated from each other by a distance DY1. The magnetic field lines ML of the second permanent magnet 131 are mainly emitted from the fourth extension section 1332 and return to the second permanent magnet 131 via the third extension section 1322 and the third covering section 1321. Therefore, the third extension section 1322 and the fourth extension section 1332 are the two magnetic poles of the second dipole magnet assembly 13.

[0069] Reference Figure 1 and Figure 3A , Figure 3B The second diode magnet assembly 13 further includes a second magnetically conductive element 134, which is movably disposed on the second outer surface 131B of the second permanent magnet 131. The function of the second magnetically conductive element 134 is similar to that of the first magnetically conductive element 114. In some embodiments, the second magnetically conductive element 134 is made of an iron core material, so a portion of the magnetic field lines ML of the second permanent magnet 131 will be diverted to the second magnetically conductive element 134. Figure 3A As shown, when the second magnetic element 134 is closer to the second outer surface 131B, that is, when the distance 134G between the second magnetic element 134 and the second outer surface 131B is smaller, the magnetic field lines ML shunted to the second magnetic element 134 will be more numerous, which in turn will result in a smaller magnetic flux emitted from the fourth extension section 1332 and returning to the second permanent magnet 131 through the third extension section 1322. Figure 3B As shown, when the second magnetically conductive element 134 is farther away from the second outer surface 131B, that is, when the distance 134G between the second magnetically conductive element 134 and the second outer surface 131B is larger, the magnetic field lines ML shunted to the second magnetically conductive element 134 will be less, thereby increasing the magnetic flux emitted from the fourth extension section 1332 and returning to the second permanent magnet 131 through the third extension section 1322. In this way, engineers can control the magnitude of the magnetic field exerted by the second dipole magnet assembly 13 on the charged particle beam 90 by adjusting the distance 134G between the second magnetically conductive element 134 and the second outer surface 131B of the second permanent magnet 131.

[0070] In reality, some magnetic field lines emitted from the first extension section 1122 may also enter the third extension section 1322, and some magnetic field lines emitted from the fourth extension section 1332 may also enter the second extension section 1132. However, since the length of the major axis of the charged particle beam 90 is often much greater than the length of the minor axis, in actual operation, DY1 will also be much greater than DX1. Therefore, the proportion of magnetic field lines emitted from the first extension section 1122 entering the third extension section 1322 or the proportion of magnetic field lines emitted from the fourth extension section 1332 entering the second extension section 1132 is very limited.

[0071] Reference Figure 4A and Figure 4B This is a schematic diagram simulating the gradient magnetic field formed by the hybrid magnet structure 1, where the gradient magnetic field is located on the XY plane, and the coordinates of the center of the gradient magnetic field are (0,0). Figure 4A The graph shows the variation of the magnetic field Bx with the Y-axis when X = 0. Figure 4B This is a graph showing the magnetic field By as a function of the X-axis when Y=0. Figure 4A and Figure 4B It can be seen that the magnetic field at the center of the gradient magnetic field is 0, and the magnetic field will gradually increase as it moves away from the center of the gradient magnetic field.

[0072] Foreseeable, if Figure 1 If the cross-section of the charged particle beam is rotated 90 degrees, that is, the major axis is the X-axis (horizontal direction) and the minor axis is the Y-axis (vertical direction), then it is only necessary to... Figure 1 The hybrid magnet structure 1 is also rotated 90 degrees, which can also be used to focus it in the X-axis direction.

[0073] like Figure 1As shown, in some embodiments, the distance between the first extension segment 1122 of the first iron core 112 and the third extension segment 1322 of the third iron core 132 along the Y-axis is equal to the distance between the second extension segment 1132 of the second iron core 113 and the fourth extension segment 1332 of the fourth iron core 133 along the Y-axis, and both are DY1. Furthermore, the distance between the first extension segment 1122 of the first iron core 112 and the second extension segment 1132 of the second iron core 113 along the X-axis is equal to the distance between the third extension segment 1322 of the third iron core 132 and the fourth extension segment 1332 of the fourth iron core 133 along the X-axis, and both are DX1. Furthermore, the width of the first permanent magnet 111 along the X-axis is equal to the width of the second permanent magnet 131 along the X-axis, and both are WX. In this embodiment, the hybrid magnet structure 1 is used to converge (focus) the charged particle beam 90 with its major axis in the Y-axis direction; therefore, DY1 is greater than DX1. In addition, DX1 will be smaller than WX, that is, the first extension segment 1122 and the second extension segment 1132 extend inward, and the third extension segment 1322 and the fourth extension segment 1332 also extend inward.

[0074] As mentioned above, when the major axis of the charged particle beam is in the X-axis direction (horizontal direction), simply rotating the hybrid magnet structure 1 of the first embodiment by 90 degrees can be used to focus the charged particle beam in the X-axis direction. However, in some cases, due to space constraints or existing component configurations and wiring, it may be possible to install a quadrupole magnet only in a single axis (e.g., the vertical direction). Therefore, the present invention further proposes a second embodiment, which can achieve focusing of the charged particle beam in the X-axis direction while maintaining the relative spatial configuration of the two secondary magnet assemblies as shown in the first embodiment.

[0075] Reference Figure 5 This is a schematic diagram of a second embodiment of the hybrid magnet structure of the present invention, illustrating a hybrid magnet structure 2. The hybrid magnet structure 2 mainly comprises two secondary magnets arranged coplanarly in the XY plane, namely a first diode magnet assembly 21 and a second diode magnet assembly 23. The hybrid magnet structure 2 is used to focus a charged particle beam 92 moving along the Z-axis direction, the cross-section of which is approximately as shown below. Figure 5 The diagram is flat, with the major axis pointing to the X-axis (horizontal direction) and the minor axis pointing to the Y-axis (vertical direction). Figure 5 The hybrid magnet structure 2 configured in this way is used to focus the charged particle beam 92 in the horizontal axis direction. That is, after the charged particle beam 92 passes through the hybrid magnet structure 2, the length of its cross section along the X-axis direction will become shorter, and the length along the Y-axis direction will become slightly longer. Its structure is described in detail below.

[0076] like Figure 5As shown, the first diode magnet assembly 21 includes a first permanent magnet 211, which has a first N-terminal 211N and a first S-terminal 211S, a first inner surface 211A, and a first outer surface 211B opposite to the first inner surface 211A. The first N-terminal 211N and the first S-terminal 211S are arranged in a straight line parallel to the X-axis. The first inner surface 211A and the first outer surface 211B are located between the first N-terminal 211N and the first S-terminal 211S, and the first inner surface 211A is configured toward the movement path of the charged particle beam 92.

[0077] Continue to refer to Figure 5 The second diode magnet assembly 23 includes a second permanent magnet 231, which has a second N-pole 231N and a second S-pole 231S, a second inner surface 231A, and a second outer surface 231B opposite to the second inner surface 231A. The second N-pole 231N and the second S-pole 231S are arranged in a straight line parallel to the X-axis, and are 180 degrees different from the arrangement of the first N-pole 211N and the first S-pole 211S. The second inner surface 231A and the second outer surface 231B are located between the second N-pole 231N and the second S-pole 231S. The second inner surface 231A is arranged toward the movement path of the charged particle beam 92 and toward the first inner surface 211A of the first permanent magnet 211.

[0078] The first diode magnet assembly 21 further includes a first iron core 212, which includes a first covering section 2121 and a first extension section 2122 connected to each other. The first covering section 2121 covers the end face of the first N-terminal 211N to guide the magnetic field lines ML emitted from the first N-terminal 211N to the first extension section 2122 as much as possible. The first extension section 2122 is connected to one end of the first covering section 2121 and extends from the first covering section 2121 and protrudes from the first inner surface 211A. The magnetic field lines ML of the first permanent magnet 211 are mainly emitted from the first extension section 2122, thus the first extension section 2122 serves as one of the magnetic poles of the first diode magnet assembly 21. Unlike the first embodiment where the first extension section 1122 extends inward after protruding from the first inner surface 111A, the first extension section 2122 in this embodiment extends outward after protruding from the first inner surface 211A.

[0079] The second dipole magnet assembly 23 further includes a third core 232, which includes a third covering section 2321 and a third extending section 2322 connected to each other. The third covering section 2321 covers the end face of the second S-pole 231S to guide the magnetic field lines ML emitted from the first extending section 2122 to the third extending section 2322 as much as possible. The third extending section 2322 extends from the third covering section 2321 and protrudes from the second inner surface 231A. The third extending section 2322 and the first extending section 2122 are configured symmetrically with respect to the XZ plane and are separated from each other by a distance DY2. Unlike the first embodiment where the third extending section 1322 extends inward, in this embodiment, the third extending section 2322 extends outward after protruding from the second inner surface 231A.

[0080] Refer to Figure 5 and combined Figure 6 , 7 The first diode magnet assembly 21 further includes a second iron core 213, which includes a second covering section 2131 and a second extension section 2132 connected to each other. The second covering section 2131 covers the end face of the first S-end 211S to guide the magnetic field lines ML emitted from the second permanent magnet 231 of the second diode magnet assembly 23 to the second extension section 2132 as much as possible. The second extension section 2132 is connected to one end of the second covering section 2131 and extends from the second covering section 2131, protruding from the first inner surface 211A. Unlike the first embodiment where the second extension section 1132 extends inward after protruding from the first inner surface 111A, the second extension section 2132 in this embodiment extends outward after protruding from the first inner surface 211A. Furthermore, in this embodiment, the first permanent magnet 211 has a width WX along the X-axis direction, the first extension segment 2122 and the second extension segment 2132 have a distance DX2 along the X-axis direction, and DX2 is greater than WX and DX2.

[0081] The second dipole magnet assembly 23 further includes a fourth core 233, which comprises a fourth covering section 2331 and a fourth extending section 2332 connected to each other. The fourth covering section 2331 covers the end face of the second N-pole 231N to guide the magnetic field lines ML emitted from the second N-pole 231N to the fourth extending section 2332 as much as possible. The fourth extending section 2332 is connected to one end of the fourth covering section 2331 and extends from the fourth covering section 2331, protruding from the second inner surface 231A. The fourth extending section 2332 and the second extending section 2132 are configured symmetrically with respect to the XZ plane and are separated from each other by a distance DY2. The magnetic field lines ML of the second permanent magnet 231 are emitted mainly from the fourth extending section 2332 and enter the second extending section 2132 and the second covering section 2131. Unlike the first embodiment where the fourth extension segment 1332 extends inward, in this embodiment the fourth extension segment 2332 extends outward. Furthermore, in this embodiment, the second permanent magnet 231 has a width WX along the X-axis, and the third extension segment 2322 and the fourth extension segment 2332 have a distance DX2 along the X-axis, with DX2 being greater than WX and DX2.

[0082] Rereference Figures 5 to 7 The first dipole magnet assembly 21 includes a first magnetically conductive element 214, which is movably disposed on the first outer surface 211B of the first permanent magnet 211. In some embodiments, the first magnetically conductive element 214 is made of an iron core material, so a portion of the magnetic field lines ML of the first permanent magnet 211 will be diverted to the first magnetically conductive element 214. Figure 6 As shown, when the first magnetic element 214 is closer to the first outer surface 211B, that is, when the distance 214G between the first magnetic element 214 and the first outer surface 211B is small, the magnetic field lines ML shunted to the first magnetic element 214 will be more numerous, which in turn results in a smaller magnetic flux emitted from the first extension section 2122 and passing through the third extension section 2322. Figure 7 As shown, when the first magnetically conductive element 214 is farther away from the first outer surface 211B, that is, when the distance 214G between the first magnetically conductive element 214 and the first outer surface 211B is larger, the magnetic field lines ML shunted to the first magnetically conductive element 214 will be less, thereby increasing the magnetic flux emitted from the first extension section 2122 and passing through the third extension section 2322. In this way, engineers can control the magnitude of the magnetic field exerted by the first diode magnet assembly 21 on the charged particle beam 92 by adjusting the distance 214G between the first magnetically conductive element 214 and the first outer surface 211B of the first permanent magnet 211.

[0083] Rereference Figures 5 to 7The second dipole magnet assembly 23 further includes a second magnetically conductive element 234, which is movably disposed on the second outer surface 231B of the second permanent magnet 231. The function of the second magnetically conductive element 234 is similar to that of the first magnetically conductive element 214. In some embodiments, the second magnetically conductive element 234 is made of an iron core material, so a portion of the magnetic field lines ML of the second permanent magnet 231 will be diverted to the second magnetically conductive element 234. Figure 6 As shown, when the second magnetic element 234 is closer to the second outer surface 231B, that is, when the distance 234G between the second magnetic element 234 and the second outer surface 231B is smaller, the magnetic field lines ML shunted to the second magnetic element 234 will be more numerous, which in turn will result in a smaller magnetic flux emitted from the fourth extension section 2332 and passing through the second extension section 2132. Figure 7 As shown, when the second magnetically conductive element 234 is farther away from the second outer surface 231B, that is, when the distance 234G between the second magnetically conductive element 234 and the second outer surface 231B is larger, the magnetic field lines ML shunted to the second magnetically conductive element 234 will be less, thereby increasing the magnetic flux emitted from the fourth extension section 2332 and passing through the second extension section 2132. In this way, engineers can control the magnitude of the magnetic field exerted by the second dipole magnet assembly 13 on the charged particle beam 92 by adjusting the distance 234G between the second magnetically conductive element 234 and the second outer surface 231B of the second permanent magnet 231.

[0084] like Figure 6 and Figure 7 As shown, in reality, some of the magnetic field lines emitted from the first extension section 2122 may also enter the second extension section 2132, and some of the magnetic field lines emitted from the fourth extension section 2332 may also enter the third extension section 2322. However, since the length of the major axis (X-axis) of the charged particle beam 92 is often much greater than the length of the minor axis (Y-axis), in actual operation, DX2 will also be much greater than DY2. Therefore, the proportion of magnetic field lines emitted from the first extension section 2122 entering the second extension section 2132 or the proportion of magnetic field lines emitted from the fourth extension section 2332 entering the third extension section 2322 is very limited.

[0085] Reference Figure 8A and Figure 8B This is a schematic diagram simulating the gradient magnetic field formed by the hybrid magnet structure 2, where the gradient magnetic field is located on the XY plane, the coordinates of the center of the gradient magnetic field are (0,0), and DY2 = DY1. Figure 8A The graph shows the variation of the magnetic field Bx in the X direction with the Y axis when X = 0. Figure 8B This is a graph showing the magnetic field By in the Y direction as a function of the X-axis when Y=0. Figure 8A and Figure 8BIt can be seen that the magnetic field at the center of the gradient magnetic field is 0, and the magnetic field will gradually increase as it moves away from the center of the gradient magnetic field.

[0086] Figure 8A and Figure 8B The simulation includes three curves: P1, P2, and P3. These curves represent the magnetic field simulation results obtained by changing the distance DX2 while keeping the distance DY2 constant. The distance DX2 in curve P3 is greater than that in curve P2, and the distance DX2 in curve P2 is greater than that in curve P1. The simulation results show that when the distance between two adjacent diode magnet components is fixed (i.e., DY2 remains constant), increasing the distance DX2 along the X-axis does not significantly change the magnitude of the magnetic field By in the Y-direction, but the magnetic field Bx in the X-direction decreases as DX2 increases.

[0087] like Figure 5 As shown, in some embodiments, the distance between the first extension segment 2122 of the first iron core 212 and the third extension segment 2322 of the third iron core 232 along the Y-axis is equal to the distance between the second extension segment 2132 of the second iron core 213 and the fourth extension segment 2332 of the fourth iron core 233 along the Y-axis, and both are DY2. Furthermore, the distance between the first extension segment 2122 of the first iron core 212 and the second extension segment 2132 of the second iron core 213 along the X-axis is equal to the distance between the third extension segment 2322 of the third iron core 232 and the fourth extension segment 2332 of the fourth iron core 233 along the X-axis, and both are DX2. Furthermore, the width of the first permanent magnet 211 along the X-axis is equal to the width of the second permanent magnet 231 along the X-axis, and both are WX. The hybrid magnet structure 2 of this embodiment is used to converge (focus) the charged particle beam 92 with its major axis along the X-axis; therefore, DX2 will be greater than DY2, and DX2 will also be greater than WX.

[0088] In some embodiments, the outer surfaces of the first and second permanent magnets may be coated with a graphite layer approximately 5 mm thick to prevent them from being damaged by direct radiation, thereby extending their service life. Alternatively, a titanium nitride layer approximately 5 μm thick may be deposited on the surfaces of the first and second permanent magnets to prevent them from releasing gases that could damage or contaminate the vacuum chamber during operation due to high temperatures.

[0089] In some embodiments, the first and second magnetic elements can be disposed outside the vacuum chamber, which helps to miniaturize the ion implantation system.

[0090] Continuing from the above, the hybrid magnet structure of the present invention controls the magnetic field strength of the magnetic poles by shunting the current of two magnetic conductive elements. Compared with the traditional method of using high-energy-consuming coils, it has at least one of the following advantages: (1) the magnetic field control does not consume a lot of electricity, which has the function of energy saving and carbon reduction; (2) the magnetic flux leakage is small and does not affect the magnetic field strength of the adjacent magnets; (3) it is suitable for particle beams of different energy ranges; (4) it is suitable for vacuum environments, especially ultra-high vacuum; and (5) it provides a compact and miniaturized ion implantation machine system.

[0091] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make some modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the appended claims.

Claims

1. A hybrid magnet structure, characterized in that, The hybrid magnet structure, used to focus a beam of charged particles moving along the Z-axis, comprises: A first and second pole magnet assembly, disposed on the XY plane, includes: A first permanent magnet has a first N-end, a first S-end, a first inner side and a first outer side opposite to the first inner side, the first N-end and the first S-end are arranged in a straight line direction parallel to the X-axis, the first inner side and the first outer side are located between the first N-end and the first S-end, and the first inner side is arranged toward the movement path of the charged particle beam. A first iron core includes a first covering section and a first extending section connected to each other, the first covering section covering the first N-end, and the first extending section extending from the first covering section and protruding from the first inner side surface; A second iron core comprising a second covering section and a second extending section connected to each other, the second covering section covering the first S-end, and the second extending section extending from the second covering section and protruding from the first inner surface; and A first magnetic conductive element is movably disposed on the first outer surface of the first permanent magnet; and a second dipole magnet assembly is coplanar with the first dipole magnet assembly, comprising: A second permanent magnet has a second N-terminal, a second S-terminal, a second inner side and a second outer side opposite to the second inner side. The second N-terminal and the second S-terminal are arranged in another straight line direction parallel to the X-axis. The second inner side and the second outer side are located between the second N-terminal and the second S-terminal. The second inner side is arranged toward the movement path of the charged particle beam and toward the first inner side of the first permanent magnet. A third iron core includes a third covering section and a third extending section connected to each other. The third covering section covers the second S-end, and the third extending section extends from the third covering section and protrudes from the second inner side surface. The third extending section and the first extending section are arranged in a straight line direction parallel to the Y-axis. A fourth core includes a fourth covering section and a fourth extending section connected to each other. The fourth covering section covers the second N-end, and the fourth extending section extends from the fourth covering section and protrudes from the second inner surface. The fourth extending section and the second extending section are arranged in a straight line direction parallel to the Y-axis. A second magnetic conductive element is movably disposed on the second outer surface of the second permanent magnet.

2. The hybrid magnet structure according to claim 1, characterized in that, The distance between the first extension segment and the third extension segment along the Y-axis is equal to the distance between the second extension segment and the fourth extension segment along the Y-axis.

3. The hybrid magnet structure according to claim 2, characterized in that, The distance between the first extension segment and the second extension segment along the X-axis is equal to the distance between the third extension segment and the fourth extension segment along the X-axis.

4. The hybrid magnet structure according to claim 3, characterized in that, The first extension segment and the third extension segment have a distance DY1 along the Y-axis direction, the second extension segment and the fourth extension segment also have a distance DY1 along the Y-axis direction, the first extension segment and the second extension segment have a distance DX1 along the X-axis direction, and the third extension segment and the fourth extension segment also have a distance DX1 along the X-axis direction, and DY1 is greater than DX1.

5. The hybrid magnet structure according to claim 4, characterized in that, The first permanent magnet has a width WX along the X-axis, the second permanent magnet has a width WX along the X-axis, and DX1 is less than WX.

6. The hybrid magnet structure according to claim 1, characterized in that, The first extension segment and the third extension segment have a distance DY2 along the Y-axis direction, the second extension segment and the fourth extension segment have a distance DY2 along the Y-axis direction, the first extension segment and the second extension segment have a distance DX2 along the X-axis direction, and the third extension segment and the fourth extension segment have a distance DX2 along the X-axis direction, and DY2 is less than DX2.

7. The hybrid magnet structure according to claim 6, characterized in that, The first permanent magnet has a width WX along the X-axis, the second permanent magnet has a width WX along the X-axis, and DX2 is greater than WX.

8. The hybrid magnet structure according to any one of claims 1 to 7, characterized in that, The outer surfaces of the first permanent magnet and the second permanent magnet are coated with a graphite layer.

9. The hybrid magnet structure according to any one of claims 1 to 7, characterized in that, The outer surfaces of the first permanent magnet and the second permanent magnet are coated with a titanium nitride layer.

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