Radio frequency resonator of high-energy ion implanter

Abstract

The invention discloses a radio frequency resonator of a high-energy ion implanter. The radio frequency resonator comprises a shell, an inductance coil, a coupling ring and a coaxial feed-through, the inductance coil is spirally arranged in the shell, the bottom of the inductance coil penetrates through the bottom of the shell and then extends into the vacuum acceleration cavity in a sealed mode, and the top of the inductance coil penetrates through the top of the shell. The coaxial feed-through comprises an inner conductor and an outer conductor, one end of the coupling ring is connected with the end of the inner conductor, and the other end is connected with the end of the outer conductor; after the coaxial feed-through is installed on the top of the shell in a penetrating mode, the inner conductor, the outer conductor and the coupling ring are all located in the shell, and a gap exists between the coupling ring and the inductance coil. The coaxial feed-through is rotated to drive the coupling ring to rotate, so that the coupling degree between the radio frequency resonator and the external circuit is adjusted, and the coupling ring and the inductance coil do not interfere with each other in the adjusting process. The coupling degree adjusting device has the characteristics of compact structure, high stability, high adjusting flexibility and the like, and overcomes the defects of complex coupling degree adjusting operation and long time consumption in the prior art.

Description

Technical Field

[0001] The invention relates to the technical field of radio frequency resonators, and in particular to a radio frequency resonator for a high energy ion implanter. Background Art

[0002] Ions commonly used in ion implantation are called heavy ions (such as phosphorus, boron, etc.). They have a large mass, so even if they have a high energy, their speed will not be very high. Therefore, when using a radio frequency accelerator as an ion implantation machine acceleration module, the microwave frequency used is not high (less than 30MHz, 13.56MHz is commonly used). At this frequency, its radio frequency resonator is closer to a lumped parameter circuit, that is, the resonator has components that clearly show capacitance or inductance characteristics, rather than a cavity resonator that is often used at higher frequencies.

[0003] From the perspective of circuit theory, the RF resonator can be understood as a parallel RLC resonant circuit. When the circuit resonates, an electric field similar to a sinusoidal oscillation will be generated between the RF electrode and the ground electrode. The oscillating electric field can be used to achieve periodic acceleration of charged ions.

[0004] In the RF resonator used in the existing high-energy ion implanter, the common excitation method is to directly connect the inner conductor of the coaxial feedthrough to the inductor coil in the RF resonator through a bendable wire, but there will be a problem of impedance matching and coupling adjustment. If the contact position of the wire with the inductor coil or the bending of the wire in the RF resonator barrel is not accurate, the RF barrel will have a large reflection, and the energy generated by the power source cannot be fed into the RF resonator with the maximum efficiency.

[0005] Adjusting the connection position between the wire and the inductor coil and the bending of the wire itself is an important step in assembling the RF resonator. In the existing operation process, all parts are assembled and then the RF resonator is tested. If the coupling degree does not reach the design value, it is necessary to remove the hole specially left on the top cover, reach in to change the bending of the wire or the connection position between the wire and the inductor coil (if screws are used, the connection position can be changed). Then seal the top cover and test again, repeating the above operation until the coupling degree reaches the design value.

[0006] The above operation is not only cumbersome, but also requires a special adjustment hole to be opened on the top of the barrel, which increases the risk of leakage of the RF resonator. In actual use of the existing technology, sulfur hexafluoride gas is filled into the barrel to prevent microwave ignition in the barrel. Summary of the invention

[0007] The technical problem to be solved by the present invention is: in view of the prior art, the feed antenna is directly coupled, the excitation electrode and the inductor coil in the radio frequency resonator are directly connected together by screws or welding, and the coupling degree needs to be adjusted by disassembling the barrel cover, manually changing the electrode shape, and then installing the barrel cover to test the coupling degree. If it cannot be adjusted in one go, the adjustment operation needs to be repeated. The whole process is complicated and time-consuming. A high-energy ion implantation machine radio frequency resonator is provided with a compact structure, high stability and high adjustment flexibility.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0009] A radio frequency resonator for a high energy ion implanter comprises: a shell, an inductor coil, a coupling ring and a coaxial feedthrough; the inductor coil is spirally arranged in the shell, the bottom of the inductor coil penetrates the bottom of the shell and then extends into a vacuum acceleration chamber in a sealed manner and is connected to a radio frequency electrode in the vacuum acceleration chamber, and the top of the inductor coil penetrates the top of the shell; the coaxial feedthrough comprises an inner conductor and an outer conductor, one end of the coupling ring is connected to the end of the inner conductor, and the other end of the coupling ring is connected to the end of the outer conductor to form a loop; when the coaxial feedthrough is installed through the top of the shell, the inner conductor, the outer conductor and the coupling ring are all located inside the shell, and there is a gap between the coupling ring and the inductor coil; the coaxial feedthrough is rotated to drive the coupling ring to rotate, thereby realizing the adjustment of the coupling degree between the radio frequency resonator and the external circuit, and the coupling ring and the inductor coil do not interfere with each other during the adjustment process.

[0010] As a further improvement of the present invention, a slip-on flange is provided on the outer periphery of the coaxial feedthrough, and the slip-on flange is used to achieve a sealed connection between the coaxial feedthrough and the top of the shell, and to achieve axial rotation of the coaxial feedthrough on the top of the shell.

[0011] As a further improvement of the present invention, the central axis of the coaxial feedthrough is parallel to the central axis of the housing.

[0012] As a further improvement of the present invention, the coupling ring is connected to the inner conductor and the outer conductor by plug-in type.

[0013] As a further improvement of the present invention, the coupling ring is made of high-purity oxygen-free copper.

[0014] As a further improvement of the present invention, the horizontal plane where the coupling ring is located is parallel to the top plane of the shell.

[0015] As a further improvement of the present invention, the coupling ring is a single circular ring structure or a spiral circular ring structure.

[0016] As a further improvement of the present invention, a frequency adjustment block is further provided inside the shell, the frequency adjustment block is connected to the top of the shell, and the frequency adjustment block is located at the center of the spiral ring of the inductor coil and is coaxial with the inductor coil.

[0017] As a further improvement of the present invention, the bottom of the shell is connected and fixed to the top of the vacuum acceleration chamber through an end flange, and a ceramic insulating cone is provided at the bottom inner side of the shell to achieve vacuum sealing between the shell and the vacuum acceleration chamber; the bottom of the inductor coil passes through the ceramic insulating cone and extends into the vacuum acceleration chamber.

[0018] As a further improvement of the present invention, the inductor coil is a double-layer coil nested inside and outside, and a cooling loop is formed between the double-layer coils.

[0019] Compared with the prior art, the advantages of the present invention are:

[0020] The high-energy ion implanter radio frequency resonator of the present invention realizes the connection between the coupling ring and the coaxial feedthrough by connecting one end of the coupling ring to the inner conductor end of the coaxial feedthrough and the other end of the coupling ring to the outer conductor end of the coaxial feedthrough; when the coaxial feedthrough is installed on the top of the shell, the inner conductor, the outer conductor and the coupling ring are all located inside the shell, and there is a gap between the coupling ring and the inductor coil, and they do not interfere with each other; by rotating the coaxial feedthrough, the coupling ring can be driven to rotate, thereby realizing the adjustment of the coupling degree between the radio frequency resonator and the external circuit, realizing real-time feedback of adjustment and testing, and being able to complete the coupling degree adjustment of the radio frequency resonator more quickly, making up for the defects of the prior art that the operation of adjusting the coupling degree is complicated and time-consuming. At the same time, there is no need to open an adjustment hole on the top of the shell, reducing the risk of air leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structural principle of a radio frequency resonator in a specific embodiment of the present invention;

[0022] Figure 2 It is a schematic diagram of the overall structural principle when no handle is provided in the radio frequency resonator in a specific embodiment of the present invention;

[0023] Figure 3 It is a schematic diagram of the partial structural principle of a radio frequency resonator in a specific embodiment of the present invention;

[0024] Figure 4 It is a schematic diagram of the structural principle of a coaxial feedthrough in a specific embodiment of the present invention;

[0025] Figure 5 A schematic diagram of the circuit principle of a radio frequency resonator in a specific embodiment of the present invention;

[0026] Legend: 1. Shell; 2. Inductor coil; 3. Coupling ring; 4. Coaxial feedthrough; 5. Frequency adjustment block; 6. Handle; 7. Vacuum acceleration chamber; 8. Ion beam channel; 9. Ground electrode; 10. RF electrode; 11. End flange; 12. Inner conductor; 13. Outer conductor; 14. Loose flange; 15. Ceramic insulating cone. DETAILED DESCRIPTION

[0027] 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.

[0028] 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.

[0029] 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.

[0030] Example

[0031] like Figure 1 , Figure 2 and Figure 3 As shown, the radio frequency resonator of the high energy ion implanter of the present invention comprises: a shell 1, an inductor 2, a coupling ring 3 and a coaxial feedthrough 4. A handle 6 is provided on the outside of the shell 1 to facilitate the transportation and installation of the radio frequency resonator. The inductor 2 is spirally arranged in the shell 1. The bottom of the inductor 2 passes through the bottom of the shell 1 and then extends into the vacuum acceleration chamber 7 in a sealed manner, and is connected to the radio frequency electrode 10 in the vacuum acceleration chamber 7. The top of the inductor 2 passes through the top of the shell 1. A ground electrode 9 is also provided in the vacuum acceleration chamber 7. Both ends of the radio frequency electrode 10 are respectively matched with the ground electrode 9 in a gap, and an ion beam channel 8 is formed in the vacuum acceleration chamber 7. The ions to be accelerated enter from one end of the vacuum acceleration chamber 7, complete acceleration in the ion beam channel 8, and are output from the other end of the vacuum acceleration chamber 7. As shown Figure 4As shown, the coaxial feedthrough 4 includes an inner conductor 12 and an outer conductor 13, and the coupling ring 3 adopts a single circular ring structure, one end of the coupling ring 3 is connected to the end of the inner conductor 12, and the other end of the coupling ring 3 is connected to the end of the outer conductor 13 to form a loop. When the coaxial feedthrough 4 is installed through the top of the shell 1, the inner conductor 12, the outer conductor 13 and the coupling ring 3 are all located inside the shell 1, and there is a gap between the coupling ring 3 and the inductor 2. Considering the beam load, it is necessary to adjust the coupling between the RF resonator and the external circuit to an over-coupling or critical coupling state, that is, to adjust the coupling degree to a specific value. In this embodiment, by rotating the coaxial feedthrough 4 to drive the coupling ring 3 to rotate, the coupling degree between the RF resonator and the external circuit can be adjusted, and the coupling ring 3 and the inductor 2 do not interfere with each other during the adjustment process.

[0032] After the inductor 2 protrudes from the bottom of the housing 1, it enters the vacuum acceleration chamber 7. Figure 5 As shown, the RF electrode 10, the ground electrode 9, the shell 1 and the inductor 2 constitute an RLC resonant circuit as a whole, wherein the loss on the conductor surface and the internal medium during microwave resonance can be equivalent to a resistance R, the inductor 2 mainly exhibits inductance, and the capacitive properties between the RF electrode and the ground electrode, between each turn of the coil itself, and between the coil and the barrel shell 1 can be unified into a total capacitance C. During operation, an external power source generates a microwave signal of a specific frequency, which is transmitted to the power feed port of the RF resonator, that is, the coaxial feedthrough 4, through a coaxial transmission line. Energy is transmitted to the inside of the shell 1 through the coaxial feedthrough 4, and resonance is stimulated inside the RF resonator, thereby generating a standing wave acceleration field between the RF electrode 10 and the ground electrode 9 to accelerate the charged ions. Since there are two gaps between the RF electrode 10 and the ground electrode 9, both of which can be accelerated, the acceleration structure formed between the RF electrode 10 and the ground electrode 9 can also be called a double-gap acceleration structure.

[0033] In this embodiment, the coupling ring 3 is connected to the coaxial feedthrough 4 by connecting one end of the coupling ring 3 to the end of the inner conductor 12 of the coaxial feedthrough 4, and the other end of the coupling ring 3 to the end of the outer conductor 13 of the coaxial feedthrough 4. When the coaxial feedthrough 4 is installed through the top of the shell 1, the inner conductor 12, the outer conductor 13 and the coupling ring 3 are all located inside the shell 1, and there is a gap between the coupling ring 3 and the inductor 2, and they do not interfere with each other; by rotating the coaxial feedthrough 4, the coupling ring 3 can be driven to rotate, thereby realizing the adjustment of the coupling degree between the RF resonator and the external circuit, realizing real-time feedback of adjustment and testing, and being able to complete the coupling degree adjustment of the RF resonator more quickly, which makes up for the defects of the prior art that the coupling degree adjustment operation is complicated and time-consuming. At the same time, there is no need to open an adjustment hole on the top of the shell 1, reducing the risk of air leakage.

[0034] like Figure 1 and Figure 4As shown, a slip-on flange 14 is provided on the outer periphery of the coaxial feedthrough 4. The slip-on flange 14 is used to realize the sealed connection between the coaxial feedthrough 4 and the top of the housing 1, and realize the axial rotation of the coaxial feedthrough 4 on the top of the housing 1. The signal is fed in using the coaxial feedthrough 4, and the coupling degree of the RF resonator is adjusted by adjusting the feedthrough angle outside the housing 1.

[0035] Furthermore, the central axis of the coaxial feedthrough 4 is parallel to the central axis of the housing 1, and a certain distance is spaced between the two central axes. When the coaxial feedthrough 4 rotates through the slip-on flange 14, the coupling ring 3 in the housing 1 is driven to move in the housing 1. The coupling ring 3 can produce different couplings at different positions in the housing 1, thereby adjusting the coupling degree between the RF resonator and the external circuit. When the coupling degree reaches the design value, the slip-on flange 14 is fixed with screws, thereby realizing the connection and fixation of the coaxial feedthrough 4 and the housing 1.

[0036] In this embodiment, the coupling ring 3 is connected to the inner conductor 12 and the outer conductor 13 by plug-in connection. When the adjustment capability of the coupling ring 3 used is insufficient, the coupling ring 3 can be replaced quickly and conveniently. It can be understood that the adjustment capability of the same coupling ring 3 is limited, or in other words, its coupling degree can only be adjusted within a certain range. The adjustment range can be changed by changing the ring diameter of the coupling ring 3 to obtain a stronger coupling degree adjustment capability. Alternatively, setting the coupling ring 3 to a spiral structure can also achieve the effect of improving the coupling degree adjustment capability.

[0037] Furthermore, the coupling ring 3 can be made of high-purity oxygen-free copper, and the horizontal plane where the coupling ring 3 is located is parallel to the top plane of the shell 1 to obtain better coupling adjustment capability.

[0038] like Figure 1 As shown, a frequency adjustment block 5 is also provided inside the housing 1. The frequency adjustment block 5 is connected to the top of the housing 1 through a bellows, and the frequency adjustment block 5 is located above the central axis of the spiral ring of the inductor 2. The frequency adjustment block 5 is coaxial with the inductor 2, but the frequency adjustment block 5 does not contact the inductor 2. The frequency block 5 is moved up and down in the housing 1 by controlling the retractable bellows to change the position of the frequency adjustment block 5 in the housing 1, thereby achieving frequency adjustment. The coupling ring 3 does not interfere with the inductor 2 and the frequency adjustment block 5 during movement, so as not to interfere with the coupling degree adjustment.

[0039] In other embodiments, the bottom of the inductor coil 2 connected to the RF electrode 10 can also be changed to protrude from the side wall opening of the shell 1, and then the frequency adjustment block 5 is set on the other side of the shell 1, that is, the coaxial feedthrough 4 and the frequency adjustment block 5 are respectively set on both sides of the shell 1 to avoid interference between the coupling loop 3 and the frequency adjustment block 5 when adjusting.

[0040] like Figure 1 and Figure 3 As shown, the inner bottom of the housing 1 is connected and fixed to the top of the vacuum acceleration chamber 7 through an end flange 11, and a ceramic insulating cone 15 is provided at the bottom of the housing 1 to achieve vacuum sealing between the housing 1 and the vacuum acceleration chamber 7. The bottom of the inductor 2 passes through the ceramic insulating cone 15 and extends into the vacuum acceleration chamber 7, and the ceramic insulating cone 15 can electrically insulate the bottom of the inductor 2 from the housing 1.

[0041] In this embodiment, the inductor coil 2 is a double-layer coil nested inside and outside, and a cooling circuit is formed between the double-layer coils. The top of the inductor coil 2 passes through the top of the shell 1 and is connected to the cooling system to achieve real-time cooling of the inductor coil 2 and improve the stability of the operation of the RF resonator.

[0042] The RF resonator of this embodiment has a new type of feeding antenna, and its excitation mode is indirect coupling. It can adjust the coupling degree of the RF resonator by adjusting the rotation angle of the feeding antenna outside the shell 1 after assembly is completed, so that adjustment and testing can be carried out simultaneously, and the coupling degree adjustment status can be measured in real time, which greatly saves the assembly time of the RF resonator and also improves the adjustment accuracy of the coupling degree.

[0043] 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. A radio frequency resonator for a high energy ion implanter, characterized in that: include: A shell (1), an inductor coil (2), a coupling ring (3) and a coaxial feedthrough (4); the inductor coil (2) is spirally arranged in the shell (1); the bottom of the inductor coil (2) penetrates the bottom of the shell (1) and then extends into the vacuum acceleration chamber (7) in a sealed manner, and is connected to the radio frequency electrode (10) in the vacuum acceleration chamber (7); the top of the inductor coil (2) penetrates the top of the shell (1); the coaxial feedthrough (4) comprises an inner conductor (12) and an outer conductor (13); one end of the coupling ring (3) is connected to the end of the inner conductor (12), and the other end of the coupling ring (3) is connected to the end of the outer conductor (13) to form a loop; when the coaxial feedthrough (4) is installed through the top of the shell (1), the inner conductor (12), the outer conductor (13) and the coupling ring (3) are all located inside the shell (1), and there is a gap between the coupling ring (3) and the inductor coil (2); The coaxial feedthrough (4) is rotated to drive the coupling ring (3) to rotate, thereby adjusting the coupling degree between the radio frequency resonator and the external circuit, and during the adjustment process, the coupling ring (3) and the inductor coil (2) do not interfere with each other.

2. The high energy ion implanter radio frequency resonator according to claim 1, characterized in that: The outer periphery of the coaxial feedthrough (4) is provided with a slip-on flange (14), and the slip-on flange (14) is used to achieve a sealed connection between the coaxial feedthrough (4) and the top of the shell (1), and to achieve axial rotation of the coaxial feedthrough (4) on the top of the shell (1).

3. The high energy ion implantation machine radio frequency resonator according to claim 2, characterized in that: The central axis of the coaxial feedthrough (4) and the central axis of the housing (1) are parallel to each other.

4. The high energy ion implantation machine radio frequency resonator according to claim 3, characterized in that: The coupling ring (3) is connected to the inner conductor (12) and the outer conductor (13) in a plug-in manner.

5. The high energy ion implantation machine radio frequency resonator according to claim 4, characterized in that: The coupling ring (3) is made of high-purity oxygen-free copper.

6. The high energy ion implantation machine radio frequency resonator according to claim 4, characterized in that: The horizontal plane where the coupling ring (3) is located is parallel to the top plane of the shell (1).

7. The high energy ion implantation machine radio frequency resonator according to claim 4, characterized in that: The coupling ring (3) is a single circular ring structure or a spiral circular ring structure.

8. The high energy ion implanter radio frequency resonator according to any one of claims 1 to 7, characterized in that: A frequency adjustment block (5) is also provided inside the shell (1). The frequency adjustment block (5) is connected to the top of the shell (1). The frequency adjustment block (5) is located above the center of the spiral ring of the inductor (2) and is coaxial with the inductor (2).

9. The high energy ion implantation machine radio frequency resonator according to any one of claims 1 to 7, characterized in that: The inner bottom of the shell (1) is connected and fixed to the top of the vacuum acceleration chamber (7) via an end flange (11), and a ceramic insulating cone (15) is provided at the bottom of the shell (1) to achieve vacuum sealing between the shell (1) and the vacuum acceleration chamber (7); the bottom of the inductor coil (2) passes through the ceramic insulating cone (15) and then extends into the vacuum acceleration chamber (7).

10. The high energy ion implantation machine radio frequency resonator according to any one of claims 1 to 7, characterized in that: The inductor coil (2) is a double-layer coil nested inside and outside, and a cooling circuit is formed between the double-layer coils; the top of the inductor coil (2) passes through the top of the shell (1) and is connected to the cooling system.

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