Segmented radio-frequency acceleration system, and ion implanter

Abstract

Disclosed in the present invention are a segmented radio-frequency acceleration system, and an ion implanter. The segmented radio-frequency acceleration system comprises a plurality of radio-frequency acceleration units and achromatic deflection magnet systems, wherein an achromatic deflection magnet system is arranged between every two adjacent radio-frequency acceleration units, and each of the achromatic deflection magnet systems comprises one or more achromatic deflection magnets having a non-uniform magnetic field distribution. The ion implanter comprises an ion source, an extraction apparatus, a mass analysis magnet, the segmented radio-frequency acceleration system, an energy analysis magnet, a focusing apparatus, a scanner and a parallelization magnet, which are sequentially arranged. In the present invention, achromatic deflection magnet systems are used in combination with a plurality of radio-frequency acceleration units to implement the segmented radio-frequency acceleration of ion beams; moreover, achromatization can be realized, and angular deflection is implemented, so as to ensure that the ion beams move according to a predetermined trajectory; and during usage, the overall shape of the segmented radio-frequency acceleration system can be flexibly adjusted, thereby reducing the occupied space, and thus reducing the footprint of an ion implanter.

Description

Segmented radio frequency acceleration system and ion implanter Technical Field

[0001] The present invention belongs to the field of semiconductor technology, and more specifically, the present invention relates to a segmented radio frequency acceleration system and an ion implanter. Background Art

[0002] Ion implanters are common equipment in semiconductor component manufacturing. Their primary function is to manipulate dopant ions through various electrical and magnetic devices, ultimately implanting them into substrate materials to achieve material modification. With the advancement of science and technology, the importance of ion implantation in the semiconductor field has become increasingly prominent. The requirements for implanted ion energy, dopant type, doping depth, and implantation angle have become more precise, and the design requirements for ion implantation components have become even greater challenges.

[0003] High-energy ion implanters typically use radio frequency (RF) acceleration units to accelerate ions. Because the RF acceleration voltage is a sinusoidal alternating voltage, the beam energy is modulated during the acceleration process, transforming a continuous beam into a cluster with a certain energy dispersion. Furthermore, the RF acceleration section is a straight line, resulting in a fixed shape and a large footprint for the ion implanter. Technical issues

[0004] An embodiment of the present invention provides a segmented radio frequency acceleration system and an ion implanter, which adopts an achromatic deflection magnet system in conjunction with multiple radio frequency acceleration units to achieve segmented radio frequency acceleration of the ion beam. At the same time, it can eliminate chromatic aberration and realize angular deflection to ensure that the ion beam moves along a predetermined trajectory. During use, the overall shape of the segmented radio frequency acceleration system can be flexibly adjusted to reduce the occupied space, thereby reducing the footprint of the ion implanter. At the same time, the layout of the ion implanter is made more flexible and diversified, solving the problems of beam energy dispersion after acceleration, fixed shape of the ion implanter and large footprint. Technical Solutions

[0005] To this end, the embodiments of the present invention provide the following technical solutions:

[0006] An embodiment of the present invention provides a segmented radio frequency acceleration system, comprising multiple radio frequency acceleration units and an achromatic deflection magnet system. The achromatic deflection magnet system is disposed between two adjacent radio frequency acceleration units. The achromatic deflection magnet system includes one or more achromatic deflection magnets with a non-uniform magnetic field distribution.

[0007] Furthermore, the angle of the achromatic deflection magnet system is 45° to 360°.

[0008] Furthermore, the angles of the multiple achromatic deflection magnets in the achromatic deflection magnet system are the same or different.

[0009] Furthermore, the number of RF acceleration buckets of the multiple RF acceleration units is the same or different.

[0010] An embodiment of the present invention further provides an ion implanter, comprising an ion source, an extraction device, a mass analysis magnet, the segmented radio frequency acceleration system described in the above embodiment, an energy analysis magnet, a focusing device, a scanner, and a parallelization magnet.

[0011] The ion source is used to generate an ion beam;

[0012] The extraction device is arranged downstream of the ion source and is used to extract the ion beam;

[0013] The mass analysis magnet is arranged downstream of the extraction device and is used to perform mass analysis on the extracted ion beam and screen out the ion species required for injection;

[0014] The segmented radio frequency acceleration system is arranged downstream of the mass analysis magnet and is used to perform radio frequency acceleration and achromatic deflection on the screened ion beam;

[0015] The energy analysis magnet is arranged downstream of the segmented radio frequency acceleration system and is used to perform energy analysis on the ion beam after radio frequency acceleration and achromatic deflection;

[0016] The focusing device is arranged downstream of the energy analysis magnet and is used to focus the ion beam after energy analysis;

[0017] The scanner is arranged downstream of the focusing device and is used to scan the focused ion beam along a preset direction at a preset scanning frequency;

[0018] The parallelizing magnet is arranged downstream of the scanner and is used to parallelize the scanned ion beam.

[0019] Furthermore, the angle of the mass analysis magnet is 30° to 180°.

[0020] Furthermore, the angle of the energy analysis magnet is 30° to 180°.

[0021] Furthermore, the angle of the parallelizing magnet is 30° to 180°. Beneficial effects

[0022] The beneficial effects of the present invention are: using an achromatic deflection magnet system in conjunction with multiple radio frequency acceleration units to achieve segmented radio frequency acceleration of the ion beam, while being able to eliminate chromatic aberration and achieve angular deflection to ensure that the ion beam moves along a predetermined trajectory; during use, the overall shape of the segmented radio frequency acceleration system can be flexibly adjusted to reduce occupied space, thereby reducing the footprint of the ion implanter, and making the layout of the ion implanter more flexible and diversified. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of each embodiment. Obviously, the drawings described below are only some embodiments of the embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings in the specific description below of the embodiments of the present invention without paying any creative work.

[0024] FIG1 is a schematic structural diagram of an ion implanter according to an embodiment of the present invention.

[0025] FIG. 2 is a schematic structural diagram of an ion implanter according to another embodiment of the present invention.

[0026] FIG3 is a schematic structural diagram of an ion implanter according to another embodiment of the present invention.

[0027] FIG4 is a schematic structural diagram of an ion implanter according to another embodiment of the present invention.

[0028] FIG5 is a simulation diagram of ion beam deflection of the achromatic deflection magnet system according to an embodiment of the present invention.

[0029] FIG6 is a simulation diagram of ion beam deflection of an achromatic deflection magnet system according to another embodiment of the present invention.

[0030] In the figure, 1. Segmented RF acceleration system; 11. RF acceleration unit; 12. Achromatic deflection magnet system; 13. Achromatic deflection magnet; 2. Ion source; 3. Extraction device; 4. Mass analysis magnet; 5. Energy analysis magnet; 6. Focusing device; 7. Scanner; 8. Parallelization magnet; 9. Target chamber; 10. Quadrupole. Modes for Carrying Out the Invention

[0031] The following, in conjunction with the accompanying drawings, provides a clear and complete description of the technical solutions for a segmented radio frequency acceleration system and ion implanter provided by various embodiments of the present invention. Obviously, the described embodiments represent only a portion of the present invention, not all of it. All other embodiments derived by those skilled in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0032] In the description of the embodiments of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, so they cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", "third" and the like are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", and "third" may explicitly or implicitly include one or more features. In the description of the embodiments of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0033] In the embodiments of the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connected," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0034] In the embodiments of the present invention, the word "exemplary" is used to mean "serving as an example, illustration or description". Any embodiment described as "exemplary" in the embodiments of the present invention is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is given to enable any person skilled in the art to implement and use the embodiments of the present invention. In the following description, the embodiments of the present invention are listed in detail for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the embodiments of the present invention can be implemented even without using these specific details. In other examples, well-known structures and processes are not elaborated in detail to avoid obscuring the description of the embodiments of the present invention with unnecessary details. Therefore, the embodiments of the present invention are not intended to be limited to the embodiments shown, but should be consistent with the widest scope consistent with the principles and features disclosed in the embodiments of the present invention.

[0035] Example 1:

[0036] Referring to Figures 1-4, this embodiment specifically discloses a segmented RF acceleration system comprising multiple RF acceleration units 11 and an achromatic deflection magnet system 12, with an achromatic deflection magnet system 12 positioned between two adjacent RF acceleration units 11. Multiple RF acceleration units 11 inevitably generate energy dispersion. The achromatic deflection magnet system 12 positioned between each pair of RF acceleration units 11 can deflect the ion beam trajectory while reducing energy dispersion and lateral beam loss. The deflection of the achromatic deflection magnet system eliminates the need for a linear RF acceleration system, enabling deflection. This allows for flexible adjustment of the RF acceleration system's shape and reduces space requirements. As shown in Figures 1-3, each segmented RF acceleration system is equipped with two RF acceleration units 11, with an achromatic deflection magnet system 12 positioned between the two RF acceleration units 11. As shown in Figure 4, the segmented RF acceleration system is equipped with three RF acceleration units 11 and two achromatic deflection magnet systems 12, with an achromatic deflection magnet system 12 positioned between each pair of RF acceleration units 11.

[0037] In this embodiment, the achromatic deflection magnet system 12 includes one or more achromatic deflection magnets 13 with a non-uniform magnetic field distribution. Specifically, the achromatic deflection magnet system 12 can be a single magnet system or a multi-magnet system, depending on the deflection and achromatic requirements. The achromatic deflection magnet system 12 shown in FIG5 includes a single 110° achromatic deflection magnet 13. The achromatic deflection magnet system 12 shown in FIG6 includes two 55° achromatic deflection magnets 13, creating a composite field dual-magnet system. Two 55° achromatic deflection magnets 13 are connected in series, with two quadrupoles 10 positioned between them. This also achieves 110° deflection. Alternatively, a 40°+40°+30° combination or other angle combinations can be used to achieve different deflection configurations. In this embodiment, deflection at a specific angle can be achieved using a single deflection magnet at that angle, or using multiple series-connected deflection magnets whose total deflection angle equals that angle.

[0038] The achromatic deflection magnet 13 is a magnet with a non-uniform magnetic field distribution. Because multiple RF acceleration units 11 inevitably generate energy dispersion, beams of different energies will have different deflection trajectories within the magnetic field of a typical deflection magnet. Using a conventional uniform dipole magnetic field to deflect the ion beam trajectory results in significant beam loss due to energy dispersion. The achromatic deflection magnet system 12 of this embodiment utilizes a single magnet system or a composite field multi-magnet system with a non-uniform magnetic field distribution to further reduce energy dispersion and ensure minimal transverse beam loss during deflection.

[0039] The magnetic pole shape of the magnet with non-uniform magnetic field distribution in the embodiment of the present application is a quadratic surface, preferably a hyperbola, and the magnetic field is divided into three sections, each occupying 1 / 3, and the change gradient of the magnetic field in the middle section is opposite to the change gradient of the magnetic fields in the front and rear sections.

[0040] In this embodiment, the angle of the achromatic deflection magnet system 12 ranges from 45° to 360°. Different deflection angles result in different bending angles and, consequently, different overall shapes of the achromatic deflection magnet system 12. The specific deflection angle can be flexibly adjusted based on actual production requirements and the size of the worksite. The angle of the achromatic deflection magnet system 12 shown in Figure 1 is 110°, the angle of the achromatic deflection magnet system 12 shown in Figures 2 and 3 is 90°, and the angles of both achromatic deflection magnet systems 12 shown in Figure 4 are 55°. Each achromatic deflection magnet system can be a single-magnet system or a composite-field, multi-magnet system.

[0041] The angles of the multiple achromatic deflection magnets 13 in the achromatic deflection magnet system 12 can be the same or different. For example, the achromatic deflection magnet system 12 can use two 45° achromatic deflection magnets 13 to achieve a 90° deflection. Other combinations are also possible, such as three 30° achromatic deflection magnets 13, or one 30° achromatic deflection magnet 13 plus one 60° achromatic deflection magnet 13. As long as the total deflection angle is 90°, any combination will suffice. This increases setup flexibility and allows for flexible selection based on actual production needs and the size of the workspace.

[0042] The energy of a typical radio frequency accelerated beam is not uniform but rather chromatic. Using existing magnet deflection methods, the beam would split into multiple beams, making subsequent radio frequency acceleration impossible. The achromatic deflection magnet system of this embodiment, with its number of achromatic deflection magnets and its non-uniform magnetic field distribution, creates a composite magnetic field that allows the chromatic beams to be combined into a single beam after deflection, enabling the next stage of radio frequency acceleration.

[0043] Ion beams of different energies can become spatially dispersed during the latter stages of transmission under existing deflection magnetic fields, preventing subsequent second-stage RF acceleration. However, the achromatic deflection magnet system of this embodiment effectively resolves this problem and ensures that the widths of the ion beams before and after deflection by the achromatic deflection magnet system are close and nearly identical. As shown in FIG5 , which illustrates an ion beam deflection simulation, the achromatic deflection magnet system includes an achromatic deflection magnet with a non-uniform magnetic field distribution. The magnetic field in FIG5 is divided into three sections. As shown in FIG5 , the beam transmission efficiency for a ±5% energy dispersion is 92%. In the third magnetic field section, three beams of different energies (1000keV, 1050keV, and 950keV) disperse within the magnetic field but ultimately merge into a single beam after deflection. Furthermore, the widths of the ion beams before and after deflection by the achromatic deflection magnet are nearly identical, allowing RF acceleration to continue after this deflection. As shown in the ion beam deflection simulation diagram in Figure 6, the achromatic deflection magnet system includes two achromatic deflection magnets, and the beam transmission efficiency of ±5% energy dispersion is 96%. After being deflected by the first achromatic deflection magnet, three beams of different energies 1000keV, 1050keV, and 950keV are dispersed, but are combined into one beam after being deflected by the second achromatic deflection magnet, and the width of the ion beam before and after being deflected by the achromatic deflection magnet is almost the same, so that RF acceleration can still be performed after this deflection.

[0044] The number of RF acceleration units 11 in the segmented RF acceleration system can be flexibly adjusted based on actual production requirements and the area of ​​the work site. In this embodiment, the number of RF acceleration barrels in multiple RF acceleration units 11 can be the same or different. Due to the number of RF acceleration units 11 and the achromatic and deflection functions of the achromatic deflection magnet system 12, the number of RF acceleration barrels in each RF acceleration unit 11 can also be flexibly distributed, as long as the required RF acceleration requirements are met. In this embodiment, the number of RF acceleration barrels in each RF acceleration unit does not exceed 10. As shown in Figure 1, the first RF acceleration unit 11 has 8 RF acceleration barrels, and the second RF acceleration unit 11 has 6 RF acceleration barrels. As shown in Figure 2, the first RF acceleration unit 11 has 10 RF acceleration barrels, and the second RF acceleration unit 11 has 5 RF acceleration barrels. As shown in Figure 3, the first RF acceleration unit 11 has 8 RF acceleration barrels, and the second RF acceleration unit 11 has 6 RF acceleration barrels. As shown in Figure 4, the first RF acceleration unit 11 has five RF acceleration barrels, the second RF acceleration unit 11 has five RF acceleration barrels, and the third RF acceleration unit 11 has six RF acceleration barrels. By adjusting the number of RF acceleration barrels in each RF acceleration unit 11, the overall operating beam current and beamline layout of the ion implanter can be further optimized.

[0045] The design of the achromatic deflection magnet system can reduce the number of RF acceleration barrels in the RF acceleration unit. RF acceleration energy is not unique, and the fewer RF acceleration barrels there are, the greater the energy dispersion. For beam deflection with large energy dispersion, the back-end transmission is more difficult. If the number of RF acceleration barrels is large (more than 12), the energy dispersion generated by the beam is also small (1%), and the corresponding deflection magnet design requirements are lower. For the transmission of a beam with large energy dispersion (5%) accelerated by 5-10 RF acceleration barrels, the back-end transmission is more difficult, and the existing deflection magnets cannot meet the requirements. This embodiment effectively solves the above problems through the design of the achromatic deflection magnet system, so that the number of RF acceleration barrels in each RF acceleration unit does not exceed 10, reducing the floor space.

[0046] Example 2:

[0047] Based on the same inventive concept as that of the first embodiment, please refer to Figures 1-4. This embodiment specifically provides an ion implanter, including an ion source 2, an extraction device 3, a mass analysis magnet 4, the segmented radio frequency acceleration system 1 described in the above embodiment, an energy analysis magnet 5, a focusing device 6, a scanner 7 and a parallelization magnet 8.

[0048] The ion source 2 is used to generate an ion beam. The ion source 2 can generate multivalent ions of boron, phosphorus, arsenic, argon, xenon or nitrogen.

[0049] The extraction device 3 is arranged downstream of the ion source 2 and is used to extract the ion beam.

[0050] The mass analysis magnet 4 is arranged downstream of the extraction device 3, and is used to perform mass analysis on the extracted ion beam and screen out the ion species required for injection to ensure the purity of the ion species. At the same time, it plays a partial focusing role on the transmitted ion beam and increases the beam transmission efficiency.

[0051] The segmented radio frequency acceleration system 1 is arranged downstream of the mass analysis magnet 4 and is used to perform radio frequency acceleration and achromatic deflection on the screened ion beam while reducing the occupied space.

[0052] The energy analysis magnet 5 is arranged downstream of the segmented RF acceleration system 1 and is used to perform energy analysis on the ion beam after RF acceleration and achromatic deflection.

[0053] The focusing device 6 is disposed downstream of the energy analysis magnet 5 and is used to focus the ion beam after energy analysis, thereby controlling the size of the ion beam and shaping the ion beam into a desired cross-sectional shape. In this embodiment, the focusing device is a quadrupole lens.

[0054] The scanner 7 is arranged downstream of the focusing device 6 and is used to scan the focused ion beam along a preset direction at a preset scanning frequency; the scanner 7 is a deflection scanning device that periodically scans the ion beam back and forth along a horizontal direction orthogonal to the direction of travel of the ion beam through a periodically changing electric field.

[0055] A parallelizing magnet 8 is disposed downstream of the scanner 7 and is used to parallelize the scanned ion beam and adjust the deflected ion beam to align its direction with the pre-scanned ion beam. In other words, the deflected ion beam is bent back to be parallel to a preset ion beam reference trajectory. Finally, the ion beam enters the target chamber 9.

[0056] In this embodiment, the angle of the mass analysis magnet 4 is between 30° and 180°. The angle of the energy analysis magnet 5 is between 30° and 180°. The angle of the parallelization magnet 8 is between 30° and 180°. The angles of the mass analysis magnet 4, energy analysis magnet 5, and parallelization magnet 8 can be flexibly adjusted based on production requirements and the size of the work site. While meeting the requirements of the ion implanter, the ion implanter's footprint is reduced, making the layout of the ion implanter more flexible and diverse.

[0057] Compared with the ion implanter shown in Figures 1-4, the overall footprint of the ion implanter can be adjusted by flexibly adjusting the angles of the mass analysis magnet 4, the energy analysis magnet 5, the parallelization magnet 8 and the achromatic deflection magnet system 12. It can be flexibly adjusted according to actual production operation requirements and the area of ​​the work site, and has stronger applicability.

[0058] The ion implanter of this embodiment also includes a controller and software operating system to meet the wafer transport requirements of the ion implantation process. These systems allow the operator to input required conditions, calculate various parameters based on the input conditions, and further control various components. The controller and software operating system utilize control methods and software operating systems commonly used in the art and will not be further described here.

[0059] In this embodiment, the segmented RF acceleration system 1 can reduce the footprint of the ion implanter, and the angle design of the mass analysis magnet 4, energy analysis magnet 5 and parallelization magnet 8 further reduces the footprint of the ion implanter, making the layout of the ion implanter more flexible and diversified.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and simple improvements made to the essential contents of the embodiments of the present invention should be included in the scope of protection of the present invention.

Claims

1. A segmented radio frequency acceleration system, wherein: The invention comprises a plurality of radio frequency acceleration units (11) and an achromatic deflection magnet system (12), wherein the achromatic deflection magnet system (12) is arranged between two adjacent radio frequency acceleration units (11), and the achromatic deflection magnet system (12) comprises one or more achromatic deflection magnets (13) with non-uniform magnetic field distribution.

2. The segmented radio frequency acceleration system according to claim 1, wherein: The angle of the achromatic deflection magnet system (12) is 45° to 360°.

3. The segmented radio frequency acceleration system according to claim 1, wherein: The angles of the multiple achromatic deflection magnets (13) of the achromatic deflection magnet system (12) are the same or different.

4. The segmented radio frequency acceleration system according to claim 1, wherein: The number of radio frequency acceleration barrels of the multiple radio frequency acceleration units (11) is the same or different.

5. An ion implanter, wherein: It comprises an ion source (2), an extraction device (3), a mass analysis magnet (4), a segmented radio frequency acceleration system (1) as claimed in any one of claims 1 to 4, an energy analysis magnet (5), a focusing device (6), a scanner (7) and a parallelization magnet (8), The ion source (2) is used to generate an ion beam; The extraction device (3) is arranged downstream of the ion source (2) and is used to extract the ion beam; The mass analysis magnet (4) is arranged downstream of the extraction device (3) and is used to perform mass analysis on the extracted ion beam and screen out the ion species required for injection; The segmented radio frequency acceleration system (1) is arranged downstream of the mass analysis magnet (4) and is used to perform radio frequency acceleration and achromatic deflection on the screened ion beam; The energy analysis magnet (5) is arranged downstream of the segmented radio frequency acceleration system (1) and is used to perform energy analysis on the ion beam after radio frequency acceleration and achromatic deflection; The focusing device (6) is arranged downstream of the energy analysis magnet (5) and is used to focus the ion beam after energy analysis; The scanner (7) is arranged downstream of the focusing device (6) and is used to scan the focused ion beam along a preset direction at a preset scanning frequency; The parallelizing magnet (8) is arranged downstream of the scanner (7) to parallelize the scanned Ion beam parallelization.

6. The ion implanter according to claim 5, wherein: The angle of the mass analysis magnet (4) is 30° to 180°.

7. The ion implanter according to claim 5, wherein: The angle of the energy analysis magnet (5) is 30° to 180°.

8. The ion implanter according to claim 5, wherein: The angle of the parallelization magnet (8) is 30° to 180°.

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