Electrostatic quadrupole lens and ion implanter

Abstract

The utility model discloses an electrostatic quadrupole lens and an ion implanter, and relates to the technical field of focusing lenses. The electrostatic quadrupole lens comprises a frame and a cover plate, the frame comprises a quadrilateral frame and a mounting plate arranged at the first end of the quadrilateral frame, a first round hole is formed in the mounting plate, the cover plate is detachably mounted at the second end of the quadrilateral frame, a second round hole is formed in the cover plate, and the first round hole and the second round hole are equal in size; through holes are formed in the graphite plates, the number of the graphite plates is two, and the two graphite plates are arranged on the mounting plate and the cover plate respectively; the quadrupole lens group comprises four lens assemblies, the four lens assemblies are located in the frame and installed on the installation plate, and two opposite lens assemblies in the four lens assemblies are connected through wires. The electrostatic quadrupole lens provided by the utility model is uniform in electric field bunching effect and stable and reliable in performance. The frame and the quadrupole lens group are simple in overall structure, convenient to install and maintain through screw installation, small in size and suitable for various application scenes.

Description

Technical Field

[0001] The utility model relates to the technical field of focusing lenses. More specifically, the utility model relates to an electrostatic quadrupole lens and an ion implanter. Background Art

[0002] Ion beams are an important technology in modern science. Especially in the process of implanting ions into semiconductor wafers, ion beams are often focused by quadrupole lenses. In the ion implantation process, beam current energy, implantation depth, implantation uniformity, implantation yield, etc. are important criteria for testing the maturity of ion implantation technology. To ensure that the beam current is accelerated to the required energy level and does not diverge due to the mutual interference of space charges during the transportation process, focusing is required during the transportation process. The quadrupole lens is a component that plays a focusing role. Most existing ion implanters use magnetic quadrupole lenses. However, due to the inherent volume of the magnetic induction coil, the magnetic quadrupole lens has a relatively large volume and a large weight, and its applicable range is limited. Summary of the Utility Model

[0003] Aiming at the deficiencies of the existing technology, the utility model innovatively provides an electrostatic quadrupole lens and an ion implanter, which can at least solve the above technical problems existing in the existing technology.

[0004] To achieve the above technical purpose, in the first aspect of the utility model, an electrostatic quadrupole lens is disclosed, including:

[0005] A frame, including a quadrilateral border and a mounting plate provided at the first end of the quadrilateral border, and a first round hole is formed on the mounting plate.

[0006] A cover plate, which is detachably mounted at the second end of the quadrilateral border. A second round hole is formed on the cover plate, and the first round hole and the second round hole are of equal size.

[0007] A graphite disk, on which a through hole is formed. There are two graphite disks, and the two graphite disks are respectively arranged on the mounting plate and the cover plate. The graphite disk is in a disk shape, and the outer diameter of the graphite disk is larger than the inner diameters of the first round hole and the second round hole.

[0008] A quadrupole lens group, including four lens components. The four lens components are located inside the frame and are mounted on the mounting plate. Two of the four lens components that are opposite to each other are connected by wires.

[0009] Further, the lens component includes a lens electrode and a mounting block, and the lens electrode is connected to the mounting block through an insulating magnetic column.

[0010] Further, the lens electrode is an arc-shaped electrode.

[0011] Further, the mounting block includes a first mounting surface and a second mounting surface that are perpendicular to each other. The first mounting surface is for mounting the lens electrode, and the second mounting surface is for connecting to the mounting plate.

[0012] Further, the mounting block is a hexahedron structure.

[0013] Further, four mounting positions are formed on the mounting plate around the circumference of the first circular hole. The four mounting positions are evenly distributed around the circumference of the first circular hole, and the four lens assemblies are respectively mounted on one of the mounting positions.

[0014] Further, the four mounting positions are symmetrically distributed on both sides of the first circular hole, and the axis of symmetry is a straight line perpendicular to the top and bottom walls of the quadrilateral frame and passing through the center of the first circular hole.

[0015] Further, two diagonally opposite lens electrodes are connected by the same wire.

[0016] Further, the wire is externally wrapped with a protective spring.

[0017] In a second aspect of the present invention, an ion implanter is disclosed, which includes the above-mentioned electrostatic quadrupole lens.

[0018] The beneficial effects of the present invention are as follows:

[0019] The electrostatic quadrupole lens provided by the present invention has a uniform electric field focusing effect and stable and reliable performance. The overall structure of the frame and the quadrupole lens group is simple, and it is installed by screws, which is convenient for installation and maintenance, and has a small volume and is suitable for various application scenarios. Description of the Drawings

[0020] Figure 1 Showing the internal structure schematic diagram of the electrostatic quadrupole lens according to the embodiment of the present invention;

[0021] Figure 2 Showing the structure schematic diagram of the electrostatic quadrupole lens according to the embodiment of the present invention;

[0022] Figure 3 Showing the disassembled state schematic diagram of the lens assembly according to the embodiment of the present invention.

[0023] In the figure,

[0024] 1. Frame; 12. Mounting plate; 121. First circular hole; 2. Cover plate; 3. Graphite disk; 4. Lens assembly; 41. Lens electrode; 42. Mounting block; 43. Insulating magnetic column; 5. Wire. Detailed Embodiments

[0025] The following will combine the accompanying drawings of the specification to provide a detailed explanation and description of the electrostatic quadrupole lens and ion implanter provided by the present utility model.

[0026] According to the first aspect of the present utility model, there is provided an electrostatic quadrupole lens that can be applied to an ion implanter to focus an ion beam. As Figure 1 、 Figure 2 shown, in some embodiments, the electrostatic quadrupole lens provided by the present utility model includes a frame 1 and a quadrupole lens group disposed within the frame 1. A graphite disk 3 is further provided on the frame 1 for protecting the quadrupole lens group and the internal structure of the frame 1.

[0027] In some embodiments, the frame 1 includes a quadrilateral border and a mounting plate 12 provided at the first end of the quadrilateral border. Optionally, the border and the mounting plate 12 can be connected by a connecting member such as a screw to form an integral structure. A first circular hole 121 is formed on the mounting plate 12. Optionally, the quadrilateral border is rectangular or square, and the center of the first circular hole 121 coincides on the plane where the mounting plate 12 is located. In this embodiment, four mounting positions are formed around the circumference of the first circular hole 121 on the mounting plate 12. The four mounting positions are evenly distributed around the circumference of the first circular hole 121. Optionally, the mounting positions are constituted by mounting holes. For example, each mounting position is constituted by two through holes for cooperating with the installation of components such as fixing screws and pins.

[0028] In some embodiments, a cover plate 2 is further provided on the frame 1. The cover plate 2 is detachably mounted at the second end of the quadrilateral border. A second circular hole is formed on the cover plate 2. The first circular hole 121 and the second circular hole are of equal size, and the second circular hole, the first circular hole 121, and the center of the quadrilateral border are located on the same straight line.

[0029] Through holes are formed on the graphite disk 3. Two graphite disks 3 are provided, and the two graphite disks 3 are respectively provided on the mounting plate 12 and the cover plate 2 and are located outside the frame 1. The graphite disk 3 is disk-shaped, and the outer diameter of the graphite disk 3 is greater than the inner diameters of the first circular hole 121 and the second circular hole, that is, the graphite disk 3 shields the first circular hole 121 and the second circular hole, and the centers of the through holes on the two graphite disks 3 are located on the same straight line as the centers of the first circular hole 121 and the second circular hole. The circular holes on the graphite disk 3 are for the passage of the example beam current. The graphite disk 3 can protect the quadrupole lens group inside the frame 1, reduce the probability of the lens group being struck by the beam, enhance the structural safety, and extend the service life of the structure. Optionally, the graphite disk 3 is fixedly connected to the cover plate 2 or the mounting plate 12 by a connecting member such as a screw.

[0030] In some embodiments, as Figure 1 、 Figure 3As shown in the figure, the quadrupole lens group includes four lens assemblies 4. The four lens assemblies 4 are located within the frame 1 and are mounted on the mounting plate 12. Each lens assembly 4 is mounted at a mounting position, and two of the four relatively positioned lens assemblies 4 are connected by a wire 5. In this embodiment, the lens assembly 4 includes a lens electrode 41 and a mounting block 42. The lens electrode 41 is insulated and connected to the mounting block 42, and the mounting block 42 is fixedly connected to the mounting plate 12. Optionally, the lens electrode 41 is connected to the mounting block 42 through an insulating magnetic column 43. Optionally, the lens electrode 41 is an arc-shaped electrode, with a uniform electric field bunching effect and stable and reliable performance.

[0031] Optionally, the mounting block 42 includes a first mounting surface and a second mounting surface that are perpendicular to each other. The first mounting surface is for mounting the lens electrode 41, and the second mounting surface is for connection to the mounting plate 12. After the four mounting blocks 42 are mounted on the mounting plate 12, the corresponding four lens electrodes 41 all face the center of the first circular hole 121. Optionally, the mounting block 42 has a hexahedron structure, or any structure with a perpendicular first mounting surface and second mounting surface.

[0032] In this embodiment, the four mounting positions are symmetrically distributed on both sides of the first circular hole 121. The axis of symmetry is a straight line perpendicular to the top and bottom walls of the quadrilateral frame and passing through the center of the first circular hole 121. When the frame is square, the four lens assemblies 4 are respectively located on the two diagonals of the frame, and two relatively arranged lens assemblies 4 are provided on each diagonal. The two obliquely opposite lens electrodes 41 are connected by the same wire 5. During operation, the two lens electrodes 41 connected by the same wire 5 exhibit the same polarity, such as both being positive or both being negative. The electric field in the central region of the four lens electrodes 41 is conjugate symmetrically distributed.

[0033] The two obliquely opposite lens electrodes 41 are connected by the same wire. Each of the two lens electrodes 41 located on the lower side is connected to an external device through a wire 5 as an output wire. The two output wires are in different planes and there is a spacing between the two output wires. Optionally, the distance between the planes where the two output wires are located is at least 28 mm, and the projected spacing between the two output wires on the mounting plate 12 is at least 38 mm. Further, any two adjacent wires 5 are not in the same plane, and the spacing between the planes where they are located is at least 28 mm. Such a layout of the wires 5 can effectively avoid breakdown and improve the withstand voltage.

[0034] When the accelerated ions pass through the central region of the four lens assemblies 4, the lens electrodes 41 exert a strong bunching effect on them, changing the direction of ion movement, but the energy of the ions remains unchanged. When the lower left and upper right lens electrodes 41 are positively charged and the upper left and lower right lens electrodes 41 are negatively charged, the electric ions (positively charged) passing through the lens electrodes 41 are bunched, moving away from the lower left and upper right lens electrodes 41 and approaching the upper left and lower right lens electrodes 41. When observing the beam from the axial direction, it can be found that the beam changes from a circular strip to an elliptical strip.

[0035] The force that the ions receive within the quadrupole lens group is attractive in one direction and repulsive in the other perpendicular direction, i.e., attractive in the x-direction and repulsive in the y-direction. Since the bunching effect is always greater than the divergence effect, by superimposing the quadrupole lens group in the beam movement direction and changing the polarity of the quadrupole lens group at intervals, the beam can be continuously bunched axially. By adjusting the voltage, the ideal beam shape can be finally achieved. Optionally, the wire 5 is wrapped with a protective spring, which can enhance the service life of the wire 5.

[0036] The electrostatic quadrupole lens provided by the present utility model adopts an arc-shaped lens electrode 41, with uniform electric field bunching effect, stable and reliable performance. Moreover, it has excellent voltage withstand performance. In the atmospheric environment, when the voltage reaches 8 kV, the resistance of each path can be > 1 GΩ; in the vacuum environment, when the voltage reaches 20 kV, the current can be less than 10 μA. The overall structure of the frame 1 and the quadrupole lens group is simple and is installed by screws, which is convenient for installation and maintenance.

[0037] According to the second aspect of the present utility model, an ion implanter is provided, including the above-mentioned electrostatic quadrupole lens.

[0038] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model.

[0039] In the present utility model, unless otherwise clearly defined and limited, terms such as "installation", "connection", "linkage", "fixation" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral one; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0040] In the description of this specification, the descriptions referring to terms such as "this embodiment", "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any at least one embodiment or example. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0041] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present utility model, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0042] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent replacements, and simple improvements made to the substantial content of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. An electrostatic quadrupole lens, characterized in that: include: The frame comprises a quadrilateral frame and a mounting plate arranged at a first end of the quadrilateral frame, wherein a first circular hole is formed on the mounting plate. A cover plate, the cover plate is detachably mounted on the second end of the quadrilateral frame, a second circular hole is formed on the cover plate, and the first circular hole and the second circular hole are equal in size; A graphite disk, wherein a through hole is formed on the graphite disk, two graphite disks are provided, and the two graphite disks are respectively provided on the mounting plate and the cover plate, and the graphite disk is in the shape of a disk, and the outer diameter of the graphite disk is larger than the inner diameter of the first circular hole and the second circular hole; The quadrupole lens group comprises four lens assemblies, wherein the four lens assemblies are located in the frame and mounted on the mounting plate, and two opposite ones of the four lens assemblies are connected by wires.

2. The electrostatic quadrupole lens according to claim 1, characterized in that: The lens assembly comprises a lens electrode and a mounting block, wherein the lens electrode is connected to the mounting block via an insulating magnetic column.

3. The electrostatic quadrupole lens according to claim 2, characterized in that: The lens electrode is an arc-shaped electrode.

4. The electrostatic quadrupole lens according to claim 3, characterized in that: The mounting block comprises a first mounting surface and a second mounting surface which are perpendicular to each other, the first mounting surface is used for mounting the lens electrode, and the second mounting surface is used for connecting with the mounting plate.

5. The electrostatic quadrupole lens according to claim 4, characterized in that: The mounting block is a hexahedral structure.

6. The electrostatic quadrupole lens according to claim 5, characterized in that: Four mounting positions are formed on the mounting plate around the circumference of the first circular hole. The four mounting positions are evenly distributed around the circumference of the first circular hole, and each of the four lens assemblies is mounted on one of the mounting positions.

7. The electrostatic quadrupole lens according to claim 6, characterized in that: The four mounting positions are symmetrically distributed on both sides of the first circular hole, and the axis of symmetry is a straight line that is perpendicular to the top wall and the bottom wall of the quadrilateral frame and passes through the center of the first circular hole.

8. The electrostatic quadrupole lens according to claim 7, characterized in that: The two lens electrodes which are diagonally opposite to each other are connected via a same wire.

9. The electrostatic quadrupole lens according to claim 8, characterized in that: The outside of the wire is wrapped with a protective spring.

10. An ion implanter, characterized in that: The invention comprises the electrostatic quadrupole lens as described in any one of claims 1 to 9.

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