A structure for improving the acceleration efficiency of a radio frequency acceleration bucket in an ion implantation system

Abstract

The application relates to a structure for improving the acceleration efficiency of a radio frequency accelerating bucket in an ion implantation system. The radio frequency accelerating bucket structure comprises an inductor coil for feeding radio frequency power into an accelerating electrode through a matching circuit, a radio frequency accelerating bucket cavity for providing an insulation environment for the inductor coil and an additional capacitor, a capacitor adjusting ring for matching adjustment of the whole circuit, an accelerating electrode for generating a voltage for accelerating ions in an accelerating unit, ground electrodes 1 and 2 for forming an accelerating gap with the accelerating electrode, SF6 filled in the radio frequency bucket cavity for increasing the high-voltage resistance of the inductor coil, an isolation component for isolating the radio frequency accelerating bucket cavity and the accelerating cavity, an inductor coil adjusting cap for adjusting the size of the inductor, and a radio frequency power feeding head for feeding power into the inductor coil in the radio frequency accelerating bucket cavity. The ion accelerating implantation system can make ions obtain higher accelerating energy under the condition of equal radio frequency power feeding.

Description

Technical Field

[0001] The present invention relates to the technical field of ion implantation, in particular to a structure for improving the acceleration efficiency of an eccentric inductance coil of a radio frequency acceleration barrel in an ion implantation acceleration system. Background Art

[0002] High-energy ion implanters can accelerate ions, potentially raising ion energies to megavolt levels. However, the structures used to accelerate ions vary significantly between different ion implanters: DC high-voltage series acceleration, alternating field acceleration, and cyclotron acceleration. Compared to the other two acceleration methods, alternating field acceleration offers advantages such as improved stability, reduced technical complexity, ease of operation, and a higher accelerated beam current.

[0003] General alternating field ion acceleration is achieved by connecting an external RF acceleration barrel to an accelerating electrode, and converting the RF power into an accelerating voltage through the central inductor coil inside the RF acceleration barrel and applying it to the accelerating electrode, thereby forming an alternating electric field with the ground electrode to accelerate specific ions within a certain period of time. One disadvantage of this RF acceleration barrel structure is that the RF power conversion efficiency is low, and a certain acceleration voltage can only be formed on the accelerating electrode when a higher RF power is applied. This leads to an increase in the power consumption of the RF power supply, and puts forward more stringent requirements on additional protective equipment such as radiation and water cooling, which increases the difficulty of the entire ion implantation system. For example, a certain RF barrel acceleration barrel structure such as Figure 1 As shown, 101 is ground electrode 1, 102 is ground electrode 2, 103 is the accelerating electrode, 104 is the RF barrel accelerating cavity, 105 is an inductor coil of a specific shape and number of turns, 106 is a capacitance adjustment ring, 107 is an isolation component, 108 is the SF6 filling the RF accelerating cavity, 109 is the power feed head, and 110 is the inductor adjustment cap. With power sources of 500, 1500, and 3000W, respectively, the maximum voltage generated on the accelerating electrode after matching the inductor coils is only 80kV. The high RF power required to accelerate ions to the desired energy requires increased lead shielding and water cooling temperature control.

[0004] When accelerating ions to the desired energy, the ion implantation system needs to reduce power consumption as much as possible and improve acceleration efficiency. Therefore, the efficiency issues of the existing radio frequency acceleration barrel structure will reduce the efficiency of the ion implantation machine. Summary of the Invention

[0005] To address the aforementioned RF accelerator efficiency issues, embodiments of the present invention provide an eccentric RF accelerator structure. Compared to conventional RF accelerator structures, this structure achieves a higher electric field between the accelerating electrode and ground electrodes 1 and 2, even when fed with the same RF power, resulting in better ion acceleration. It also reduces overall machine power consumption and associated features such as shielding and water cooling.

[0006] A radio frequency acceleration barrel structure is characterized in that a high electric field can be generated in the acceleration electrode of the acceleration unit, so that ions are accelerated by the electric field when passing through this area to obtain the expected ion energy.

[0007] The radio frequency accelerator barrel of the embodiment of the present invention changes the feed end of the inductor coil from the original central structure to an eccentric structure, so that the field strength obtained on the accelerating electrode is higher, the acceleration efficiency of the radio frequency accelerator barrel is improved, the power consumption is reduced and the ions reach a higher ion energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The accompanying drawings illustrate exemplary embodiments of the examples of the present invention and together with the description serve to explain the principles of the embodiments of the present invention. These drawings are included to provide a further understanding of the examples of the present invention and are incorporated in and constitute a part of this specification.

[0009] Figure 1 It is an existing radio frequency acceleration barrel structure.

[0010] Figure 2 The radio frequency acceleration barrel structure according to one embodiment of the present invention.

[0011] Figure 3 The invention provides an ion implantation acceleration system. DETAILED DESCRIPTION

[0012] The following is a further detailed description of the embodiments of the present invention in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for the purpose of explaining the relevant content and are not intended to limit the embodiments of the present invention. It should also be noted that, for ease of description, only the portions relevant to the embodiments of the present invention are shown in the accompanying drawings.

[0013] It should be noted that, in the absence of conflict, the implementation methods and features of the implementation methods in the embodiments of the present invention can be combined with each other. The following will describe the embodiments of the present invention in detail with reference to the accompanying drawings and in combination with the implementation methods.

[0014] The structure of the radio frequency acceleration barrel of the present invention is shown in FIG. Figure 2As shown: 201 is ground electrode 1, 202 is ground electrode 2, 203 is the accelerating electrode, 204 is the RF accelerator cavity, 205 is the inductor coil, 206 is the capacitor adjustment ring, 207 is the isolation component, 208 is the SF6 filling inside, 209 is the RF power feed port, 210 is the inductor coil adjustment cap, and 211 is the accelerating cavity. 210 primarily acts as the iron core inside the inductor coil 205, dynamically adjusting the inductor coil's inductance to match the RF power input, ensuring the reflected power from the RF power feed port 209 is minimized. The capacitor adjustment ring 206 also adjusts the frequency to match the resonant frequency of the RF accelerator. The RF accelerator cavity 204 and the accelerating cavity 211 are physically isolated by the isolation component 207, ensuring a high-pressure SF6 environment inside the RF accelerator cavity 204 and a high-vacuum environment inside the accelerating cavity 211. When the same RF power and the same number of turns of the inductor are fed into the RF power feed port, Figure 2 The voltage amplitude ratio of the eccentric barrel structure on the 203 accelerating electrode is Figure 1 The center barrel of the ion accelerator is 12.5% ​​higher, which means that higher ion energy can be achieved with the same power consumption during ion acceleration.

[0015] On the other hand, the present invention also provides an ion implantation acceleration system: 301 is an ion source, 302 is an extraction electrode, 303 is a mass analysis magnet, 304 is a mass analysis light barrier, 305 is an ion acceleration chamber, 306 is an eccentric radio frequency acceleration barrel, 307 is an energy analysis magnet, 308 is an analysis light barrier, 309 is a focusing lens, 310 is a scanning device, 311 is a parallel lens, and 312 is an implantation target chamber. The direction indicated by the arrow in the figure is the direction of beam movement. The ion acceleration chamber 305 includes multiple radio frequency acceleration barrel devices 306 for accelerating ions. Compared with a central radio frequency acceleration barrel structure, this device can accelerate ions to higher energy under the same power input.

[0016] In the description of this specification, the description with reference to the terms "an example / method", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the example / method or example are included in at least one example / method or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same example / method or example. Moreover, the specific features, structures, materials or characteristics described may be combined in an appropriate manner in any one or more examples / methods or examples. In addition, those skilled in the art may combine and combine the different embodiments / methods or examples described in this specification and the features of the different embodiments / methods or examples, unless they are mutually contradictory.

[0017] In the description of the examples of the present invention, the term "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined. Furthermore, in the description of the examples of the present invention, unless otherwise specifically defined, the terms "connected" and "connected" should be understood broadly. For example, they can mean fixed connection, detachable connection, or integral connection; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the examples of the present invention based on the specific circumstances.

[0018] Those skilled in the art will appreciate that the above embodiments are merely intended to clearly illustrate examples of the present invention and are not intended to limit the scope of the examples of the present invention. Those skilled in the art may make other changes or modifications based on the above disclosure, and such changes or modifications are still within the scope of the examples of the present invention.

Claims

1. A radio frequency acceleration barrel structure, characterized in that: A high electric field can be generated in the accelerating electrode of the acceleration unit, so that ions are accelerated by the electric field when passing through this area and obtain corresponding electric field energy. The RF acceleration barrel structure includes: an inductor coil, used to feed radio frequency power to the accelerating electrode through a matching circuit; The RF acceleration barrel cavity provides an insulating environment and additional capacitance for the inductor coil; Capacitor adjustment loop, which performs matching adjustment for the entire circuit; an accelerating electrode, which generates a voltage for accelerating ions in the accelerating cell; A first ground electrode is located on one side of the accelerating electrode and forms an accelerating gap with the accelerating motor; The second ground electrode is located on the other side of the accelerating electrode and forms an accelerating gap with the accelerating electrode; SF6 is filled in the RF barrel cavity to increase the insulation resistance of the inductor coil; Isolation components are used to isolate the SF6 environment with a certain pressure inside the cavity and the accelerating electrode located in the high vacuum area; Inductance coil adjustment cap, used to adjust the inductance; RF power feed head, which feeds power to the inductive coil in the RF acceleration barrel cavity; The feeding end of the inductor coil can be reasonably set at any position at one end of the cavity, and the output end of the inductor coil is connected to the accelerating electrode at the side of the inductor coil that deviates from the central axis.

2. The radio frequency acceleration barrel structure according to claim 1, characterized in that: The first ground electrode, the second ground electrode and the radio frequency acceleration barrel cavity are at the same potential.

3. The radio frequency acceleration barrel structure according to claim 1, characterized in that: The inductor coil is located in a radio frequency acceleration barrel cavity filled with a certain SF6 pressure, extends through the isolation component, and is connected to an acceleration electrode located in a high vacuum area.

4. The radio frequency acceleration barrel structure according to claim 1, characterized in that: Inserting an inductor coil adjustment cap into the inductor coil can dynamically and in real time adjust the inductance.

5. The radio frequency acceleration barrel structure according to claim 1, characterized in that: The isolation component is a non-conductive material that can physically isolate the environment in which the inductive coil and the accelerating electrode are located.

6. The radio frequency acceleration barrel structure according to claim 1 or claim 2, characterized in that: The distance between the output end of the inductor coil located inside the radio frequency acceleration barrel and the central axis of the inductor coil is equal to the radius of the inductor coil.

7. An ion implantation acceleration system, characterized in that: include: An ion source, used for providing ion beams of various valence states; The extraction electrode is used to extract the ion beam from the ion source and give the ion beam a certain energy; a mass analyzer, which separates the different types of ion beams; Mass analysis light bar, used to select the type of ions to be injected; An acceleration component, for accelerating ions to a desired energy, the acceleration component comprising a plurality of radio frequency acceleration barrel structures as claimed in claim 1; Energy analyzer, used to analyze ions of different energies; Energy analysis light bar, used to select ions of specific energy; A focusing lens for focusing the ion beam; A scanning device that deflects the ion beam to different angles; A parallel lens converts the ion beam passing through the scanning device into a parallel beam; The target chamber is used to inject ions into the implanted workpiece through a certain movement.

8. The ion implantation system according to claim 7, wherein: Its mass analyzer, energy analyzer, scanning device and parallel lens can be electric field or magnetic field components or a combination of the two.

9. The ion implantation system according to claim 7, wherein: The focusing lens may be one or more electric lenses, magnetic lenses or permanent magnet lenses or a combination thereof.

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