Ion beam current accelerating tube with dual-suppression and focusing functions and ion implanter comprising ion beam current accelerating tube

Abstract

The invention discloses an ion beam current accelerating tube with double suppression and focusing functions and an ion implanter comprising the ion beam current accelerating tube, and the ion beam current accelerating tube comprises a high-voltage electrode assembly, a middle electrode assembly, a suppression electrode assembly and a ground electrode assembly which are sequentially arranged along the movement direction of an ion beam current, insulating rings are arranged between the middle electrode assembly and the high-voltage electrode assembly and between the middle electrode assembly and the ground electrode assembly, the suppression electrode assembly is connected to the center of the ground electrode assembly, and the suppression electrode assembly comprises a suppression electrode ring and a suppression permanent magnet which are arranged in sequence; the high-voltage electrode assembly, the intermediate electrode assembly, the suppression electrode assembly, the ground electrode assembly and the insulating ring are in sealed connection, so that a vacuum environment is formed in the ion beam current accelerating tube. The device has the advantages of being compact in structure, high in stability, beneficial to improving the production efficiency of SiC devices and the like, and ion beam focusing and secondary electron suppression can be well achieved.

Description

Technical Field

[0001] The invention relates to the field of semiconductor technology, and in particular to an ion beam accelerating tube with dual suppression and focusing functions and an ion implanter comprising the same. Background Art

[0002] Ion implantation is a very important technology in modern integrated circuit manufacturing that ionizes and accelerates doping elements and then injects them into the wafer. The ion implantation process can accurately control the doping accuracy and doping concentration, and has replaced the traditional diffusion process on a large scale, becoming the mainstream doping technology in semiconductor technology.

[0003] The function of the accelerating tube in the ion implanter is to accelerate the ion beam so that the ions can obtain a high enough momentum to be injected into the surface of the wafer to be doped. In order to ensure that the voltage can be applied accurately and reliably and the beam is transmitted efficiently, the suppression electrode and the focusing electrode need to be arranged reasonably in the accelerating tube. The suppression electrode plays a role in reducing secondary electrons, thereby reducing the generation of radiation by reverse acceleration and excitation of secondary electrons; the focusing electrode plays a role in focusing and constraining the ion beam entering the accelerating tube, preventing it from diverging and bombarding the inner wall of the accelerating tube, causing pollution and sparking discharge. In addition, the maintenance cycle of the accelerating tube is 3 to 6 months, and its maintainability is also an aspect that should be considered during design.

[0004] The existing ion beam accelerator tubes have the following problems: the beam diverges after entering the accelerator tube, and after the beam diverges, it touches the metal electrode to cause spark discharge. The beam excites secondary electrons at the exit of the accelerator tube and reversely accelerates to generate X-rays, so the structural design of the ion beam focusing electrode and the secondary electron suppression electrode is particularly important. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an ion beam accelerator tube with dual suppression and focusing functions and an ion implanter containing the same, which has a compact structure, high stability and is conducive to improving the production efficiency of SiC devices.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] An ion beam accelerator with dual suppression and focusing functions comprises a high-voltage electrode assembly, an intermediate electrode assembly, a suppression electrode assembly and a ground electrode assembly which are sequentially arranged along the direction of movement of the ion beam, an insulating ring is arranged between the intermediate electrode assembly and the high-voltage electrode assembly and the ground electrode assembly, the suppression electrode assembly is connected to the center of the ground electrode assembly, and the suppression electrode assembly comprises a suppression electrode ring and a suppression permanent magnet which are sequentially arranged; the high-voltage electrode assembly, the intermediate electrode assembly, the suppression electrode assembly, the ground electrode assembly and the insulating ring are sealed and connected, so that a vacuum environment is formed inside the ion beam accelerator.

[0008] As a further improvement of the present invention, the ground electrode assembly includes a ground electrode and an outlet flange, the ground electrode is installed on the outlet flange, the outlet flange is sealed and connected to an insulating ring, and the suppression electrode assembly is connected to the center of the outlet flange.

[0009] As a further improvement of the present invention, the suppression electrode assembly also includes an electric suppression introduction assembly and an insulating support, one end of the insulating support is connected and fixed to the limiting flange in the center of the outlet flange, the other end of the insulating support is connected to the suppression electrode ring, and the suppression permanent magnet is nested outside the limiting flange.

[0010] As a further improvement of the present invention, the suppression electrode assembly also includes an electric suppression introduction assembly, one end of which is connected to the suppression electrode ring, and the other end of which passes through the outlet flange and is connected to an external power supply.

[0011] As a further improvement of the present invention, the insulating support member includes an insulating magnetic column and a labyrinth protective cover, one end of the insulating magnetic column is fixed to the inner side of the labyrinth protective cover, and the other end of the insulating magnetic column extends to the inner side of the limiting flange; one end of the labyrinth protective cover is connected to the suppression electrode ring, and the other end of the labyrinth protective cover is connected to the limiting flange.

[0012] As a further improvement of the present invention, the intermediate electrode assembly includes a plurality of intermediate electrodes arranged in sequence, and two adjacent intermediate electrodes are sealed and connected by an insulating ring; the intermediate electrode closest to the high-voltage electrode assembly is connected to the focusing electrode introduction assembly to form a focusing electrode.

[0013] As a further improvement of the present invention, the high-voltage electrode assembly includes an inlet flange, a graphite aperture and a high-voltage electrode, which are sealed with an insulating ring. The graphite aperture and the high-voltage electrode are sequentially arranged at the center of the inlet flange, and the graphite aperture is located inside the ion beam acceleration tube.

[0014] As a further improvement of the present invention, the suppression electrode ring is made of graphite material, the electrical suppression is high voltage secondary voltage suppression, and the power supply voltage is preferably -10KV to 20KV.

[0015] As a further improvement of the present invention, the magnetization direction of the suppression permanent magnet is the ion beam transmission direction, and the magnetic field strength is preferably 100GS to 300GS.

[0016] As a general technical concept, the present invention also provides an ion implanter, including the above-mentioned ion beam accelerating tube with dual suppression and focusing functions.

[0017] Compared with the prior art, the advantages of the present invention are:

[0018] The ion beam accelerator with dual suppression and focusing functions of the present invention and the ion implanter including the same are characterized in that a high-voltage electrode assembly, an intermediate electrode assembly, a suppression electrode assembly and a ground electrode assembly are sequentially arranged along the direction of movement of the ion beam, and the intermediate electrode assembly has the functions of focusing and accelerating the ion beam, insulating rings are arranged between the intermediate electrode assembly and the high-voltage electrode assembly and the ground electrode assembly, and each component is sealed and connected, thus obtaining an ion beam accelerator with a vacuum environment formed inside; further, the suppression electrode assembly includes suppression electrode rings and suppression permanent magnets that are sequentially arranged, thereby enhancing the suppression effect of secondary electrons; and the suppression permanent magnets are cleverly arranged, thereby ensuring a safe distance between electrodes and facilitating assembly; and the intermediate electrode assembly is added after the high-voltage electrode assembly of the ion beam accelerator, thereby realizing ion beam acceleration and well focusing the beam, thereby avoiding the pollution and discharge caused by the beam bombarding the inner wall of the accelerator due to divergence, thereby improving the stability of beam transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structural principle of an ion beam accelerating tube in a specific embodiment of the present invention;

[0020] Figure 2 It is a schematic diagram of the layout of the permanent magnet in a specific embodiment of the present invention;

[0021] Figure 3 It is a schematic diagram of the structural principle of an insulating support member in a specific embodiment of the present invention;

[0022] Legend: 1. Ground electrode assembly; 2. Intermediate electrode assembly; 3. High-voltage electrode assembly; 4. Insulating ring; 10. Ground electrode; 11. Outlet flange; 12. Suppression electrode ring; 13. Suppression permanent magnet; 111. Electric suppression introduction assembly; 112. Insulating support; 1121. Insulating magnetic column; 1122. Labyrinth protection cover; 113. Limiting flange; 21. Adapter flange; 22. Intermediate electrode; 23. Focusing electrode introduction assembly; 31. Inlet flange; 32. Graphite aperture; 33. High-voltage electrode. DETAILED DESCRIPTION

[0023] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0024] In the description of the present invention, it should be understood that the terms "side", "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0025] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0026] Example

[0027] like Figure 1 , Figure 2 and Figure 3 As shown, the ion beam accelerator with dual suppression and focusing functions of the present invention comprises a high-voltage electrode assembly 3, an intermediate electrode assembly 2, a suppression electrode assembly and a ground electrode assembly 1 arranged in sequence along the direction of movement of the ion beam, an insulating ring 4 is arranged between the intermediate electrode assembly 2, the high-voltage electrode assembly 3 and the ground electrode assembly 1, the suppression electrode assembly is connected to the center of the ground electrode assembly 1, and the suppression electrode assembly comprises a suppression electrode ring 12 and a suppression permanent magnet 13 arranged in sequence. The high-voltage electrode assembly 3, the intermediate electrode assembly 2, the suppression electrode assembly, the ground electrode assembly 1 and the insulating ring 4 are sealed and connected, so that a high vacuum environment is formed inside the ion beam accelerator.

[0028] In this embodiment, the high-voltage electrode assembly 3, the intermediate electrode assembly 2, the suppression electrode assembly and the ground electrode assembly 1 are arranged in sequence along the direction of movement of the ion beam, and the intermediate electrode assembly 2 includes the functions of focusing and accelerating, and an insulating ring 4 is set between the intermediate electrode assembly 2 and the high-voltage electrode assembly 3 and the ground electrode assembly 1, and each component is sealed and connected, that is, an ion beam accelerator with a vacuum environment formed inside is obtained. Furthermore, the suppression electrode assembly includes a suppression electrode ring 12 and a suppression permanent magnet 13 arranged in sequence, which enhances the suppression effect of secondary electrons; and the suppression permanent magnet 13 is cleverly arranged to ensure a safe distance between electrodes and easy assembly. Adding the intermediate electrode assembly after the high-voltage electrode assembly 3 of the ion beam accelerator tube not only realizes ion beam acceleration, but also focuses the beam well, avoids the pollution and discharge caused by the beam bombarding the inner wall of the accelerator tube due to divergence, and improves the stability of beam transmission.

[0029] In this embodiment, the suppression permanent magnet 13 adopts a ring structure, the magnetization direction of the suppression permanent magnet 13 is the ion beam transmission direction, and the magnetic field strength is preferably 100GS to 300GS, which can well adapt to the beam size and beam energy.

[0030] like Figure 1 As shown, the ground electrode assembly 1 includes a ground electrode 10 and an outlet flange 11 . The ground electrode 10 is mounted on the outlet flange 11 . The outlet flange 11 is sealed and connected to the insulating ring 4 . The suppression electrode assembly is connected to the center of the outlet flange 11 .

[0031] like Figure 1 and Figure 2 As shown, the suppression electrode assembly also includes an electric suppression introduction assembly 111 and an insulating support 112, one end of the insulating support 112 is connected and fixed to a limiting flange 113 at the center of the outlet flange 11, and the other end of the insulating support 112 is connected to a suppression electrode ring 12, and a suppression permanent magnet 13 is nested outside the limiting flange 113, and a certain distance is spaced between the suppression electrode ring 12 and the suppression permanent magnet 13.

[0032] In this embodiment, the suppression electrode assembly also includes an electric suppression introduction assembly 111, one end of the electric suppression introduction assembly 111 is connected to the suppression electrode ring 12, and the other end of the electric suppression introduction assembly 111 is connected to an external power supply after passing through the outlet flange 11. Furthermore, the suppression electrode ring 12 adopts a graphite electrode ring, which has good conductivity and is resistant to high temperature and beam bombardment. The electric suppression is a high-voltage secondary voltage suppression, and the power supply voltage is preferably -10KV to 20KV. The electric suppression introduction assembly 111 adopts a ceramic sintered vacuum sealed electrode, one end of the electrode is connected to the power output line, and the other end of the electrode is connected to the suppression electrode ring 12 in the high vacuum environment inside the accelerating tube.

[0033] like Figure 3As shown, the insulating support member 112 includes an insulating magnetic column 1121 and a labyrinth protective cover 1122. One end of the insulating magnetic column 1121 is fixed to the inner side of the labyrinth protective cover 1122, and the other end of the insulating magnetic column 1121 extends to the inner side of the limiting flange 113. One end of the labyrinth protective cover 1122 is connected to the suppression electrode ring 12, and the other end of the labyrinth protective cover 1122 is connected to the limiting flange 113. The suppression electrode ring 12 and the limiting flange 113 are connected by insulating ceramics, and the insulating ceramics adopt the mode of insulating magnetic columns and labyrinth protective covers to prevent contamination.

[0034] like Figure 1 As shown, the intermediate electrode assembly 2 includes three intermediate electrodes 22 arranged in sequence, each intermediate electrode 22 is connected to the adapter flange, and two adjacent intermediate electrodes 22 are sealed and connected by an insulating ring 4 to improve the insulation performance. Among the three intermediate electrodes 22, the first intermediate electrode 22 closest to the high-voltage electrode assembly 3 is connected to the focusing electrode lead-in assembly 23 to form a focusing electrode.

[0035] Each stage of the intermediate electrode assembly 2 has an axial voltage, and there is a potential difference of tens of thousands of volts between the stages, which accelerates the charged ion beam. The difference between the focusing electrode and the intermediate electrode 22 mainly lies in whether the focusing power supply is connected. The intermediate electrode 22 at the first stage is connected to the focusing electrode introduction assembly 23, and the focusing electrode introduction assembly 23 is connected to the output end of the focusing power supply. The focusing voltage is loaded on the first-stage intermediate electrode 22 in the radial direction to form a focusing electrode to constrain the ion beam and prevent the ion beam from diverging.

[0036] like Figure 1 As shown, the high-voltage electrode assembly 3 includes an inlet flange 31, a graphite aperture 32 and a high-voltage electrode 33, which are sealed and connected to the insulating ring 4. The graphite aperture 32 and the high-voltage electrode 33 are sequentially arranged at the center of the inlet flange 31, and the graphite aperture 32 is located inside the ion beam accelerating tube. The high-voltage electrode 33 is equivalent to an accelerating electrode. After the beam is accelerated, it enters the accelerating tube through the graphite aperture 32 for focusing, passes through the suppression electrode ring 12 and the suppression permanent magnet 13 for secondary electron suppression, and then passes through the ground electrode 10 and is output.

[0037] In this embodiment, an ion implanter is also provided, including the above-mentioned ion beam accelerating tube with dual suppression and focusing functions.

[0038] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. An ion beam accelerator tube with dual suppression and focusing functions, characterized in that: The invention comprises a high-voltage electrode assembly (3), an intermediate electrode assembly (2), a suppression electrode assembly and a ground electrode assembly (1) which are sequentially arranged along the direction of movement of an ion beam, an insulating ring (4) is arranged between the intermediate electrode assembly (2), the high-voltage electrode assembly (3) and the ground electrode assembly (1), the suppression electrode assembly is connected to the center of the ground electrode assembly (1), and the suppression electrode assembly comprises a suppression electrode ring (12) and a suppression permanent magnet (13) which are sequentially arranged; the high-voltage electrode assembly (3), the intermediate electrode assembly (2), the suppression electrode assembly, the ground electrode assembly (1) and the insulating ring (4) are sealed and connected, so that a vacuum environment is formed inside the ion beam accelerator tube.

2. The ion beam accelerating tube with dual suppression and focusing functions according to claim 1, characterized in that: The ground electrode assembly (1) comprises a ground electrode (10) and an outlet flange (11), the ground electrode (10) is mounted on the outlet flange (11), the outlet flange (11) is sealedly connected to an insulating ring (4), and the suppression electrode assembly is connected to the center of the outlet flange (11).

3. The ion beam accelerating tube with dual suppression and focusing functions according to claim 2, characterized in that: The suppression electrode assembly also includes an electric suppression introduction assembly (111) and an insulating support (112), one end of the insulating support (112) is connected and fixed to a limiting flange (113) at the center of the outlet flange (11), the other end of the insulating support (112) is connected to the suppression electrode ring (12), and the suppression permanent magnet (13) is nested outside the limiting flange (113).

4. The ion beam accelerating tube with dual suppression and focusing functions according to claim 3, characterized in that: The suppression electrode assembly further comprises an electric suppression introduction assembly (111), one end of which is connected to the suppression electrode ring (12), and the other end of which passes through the outlet flange (11) and is connected to an external power source.

5. The ion beam accelerating tube with dual suppression and focusing functions according to claim 4, characterized in that: The insulating support member (112) comprises an insulating magnetic column (1121) and a labyrinth protective cover (1122); one end of the insulating magnetic column (1121) is fixed to the inner side of the labyrinth protective cover (1122), and the other end of the insulating magnetic column (1121) extends to the inner side of the limiting flange (113); one end of the labyrinth protective cover (1122) is connected to the suppression electrode ring (12), and the other end of the labyrinth protective cover (1122) is connected to the limiting flange (113).

6. The ion beam accelerating tube with dual suppression and focusing functions according to claim 4, characterized in that: The intermediate electrode assembly (2) comprises a plurality of intermediate electrodes (22) arranged in sequence, and two adjacent intermediate electrodes (22) are sealed and connected via an insulating ring (4); the first intermediate electrode (22) closest to the high-voltage electrode assembly (3) is connected to a focusing electrode introduction assembly (23) to form a focusing electrode.

7. The ion beam accelerating tube with dual suppression and focusing functions according to claim 6, characterized in that: The high-voltage electrode assembly (3) comprises an inlet flange (31), a graphite aperture (32) and a high-voltage electrode (33), which are sealed and connected to an insulating ring (4); the graphite aperture (32) and the high-voltage electrode (33) are sequentially arranged at the center of the inlet flange (31); and the graphite aperture (32) is located inside the ion beam accelerating tube.

8. The ion beam accelerating tube with dual suppression and focusing functions according to any one of claims 4 to 7, characterized in that: The suppression electrode ring (12) is made of graphite material, and the electrical suppression is high voltage secondary voltage suppression, and the power supply voltage is preferably -10KV to 20KV.

9. The ion beam accelerating tube with dual suppression and focusing functions according to any one of claims 1 to 7, characterized in that: The magnetization direction of the suppression permanent magnet (13) is the ion beam transmission direction, and the magnetic field strength is preferably 100 GS to 300 GS.

10. An ion implanter, characterized in that: An ion beam accelerating tube with dual suppression and focusing functions comprising any one of claims 1 to 9.

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