Insulating structure, manufacturing method of insulating structure, ion generation device, and ion implantation device

Abstract

The present invention provides an insulating structure capable of suppressing a decrease in insulating performance due to the adhesion of contaminants. The insulating structure (74) includes: a first end portion (82); a second end portion (84); a shaft portion (86) connecting between the first end portion (82) and the second end portion (84); and an enclosing portion (88) having an inner surface (96) facing the outer surface (94) of the shaft portion (86) and extending from the first end portion (82) toward the second end portion (84). A gap (90) between the outer surface (94) of the shaft portion (86) and the inner surface (96) of the enclosing portion (88) is configured to communicate with the outside. The first end portion (82), the second end portion (84), the shaft portion (86), and the enclosing portion (88) are made of an electrically insulating material.

Description

Technical Field

[0001] This application claims priority based on Japanese Patent Application No. 2020-192598 filed on November 19, 2020. The entire contents of the Japanese application are incorporated herein by reference.

[0002] The present invention relates to an insulating structure, a method for manufacturing the insulating structure, an ion generation device, and an ion implantation device. Background Art

[0003] In a semiconductor manufacturing process, for the purpose of changing the conductivity of a semiconductor, changing the crystal structure of the semiconductor, etc., a process of implanting ions into a semiconductor wafer (also referred to as an ion implantation process) is conventionally performed. A device used in the ion implantation process is generally referred to as an ion implantation device. The ion implantation device includes an ion generation device for generating ions by plasmaizing a source gas. The ions generated by the ion generation device are extracted by an electric field applied by an extraction electrode. The extraction electrode is supported by an insulating structure (for example, refer to Patent Document 1).

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2014-235814

[0005] Due to the use of the ion implantation device, conductive contaminants adhere to the surface of the insulating structure. If contaminants adhere, the insulating performance of the insulating structure deteriorates, so regular maintenance is required. If the maintenance frequency of the insulating structure is high, the productivity of the ion implantation device will decrease. Summary of the Invention

[0006] One exemplary object of one aspect of the present invention is to provide an insulating structure capable of suppressing a decrease in insulating performance due to the adhesion of contaminants.

[0007] An insulating structure according to one aspect of the present invention includes: a first end portion; a second end portion; a shaft portion connecting between the first end portion and the second end portion; and an enclosing portion having an inner surface facing the outer surface of the shaft portion and extending from the first end portion toward the second end portion. A gap between the outer surface of the shaft portion and the inner surface of the enclosing portion is configured to communicate with the outside. The first end portion, the second end portion, the shaft portion, and the enclosing portion are made of an electrically insulating material.

[0008] Another aspect of the present invention is a method for manufacturing an insulating structure. The insulating structure includes: a first end portion; a second end portion; a shaft portion connecting between the first end portion and the second end portion; and an enclosing portion having an inner surface facing the outer surface of the shaft portion and extending from the first end portion toward the second end portion, and a gap between the outer surface of the shaft portion and the inner surface of the enclosing portion is configured to communicate with the outside. The method includes forming the first end portion, the second end portion, the shaft portion, and the enclosing portion from an electrically insulating material.

[0009] Another aspect of the present invention is an ion generation device. The ion generation device includes: an arc chamber having a plasma generation chamber for generating plasma and a front slit; and an extraction electrode series for extracting ions generated in the plasma generation chamber to the outside of the arc chamber via the front slit. The ion generation device is characterized in that the extraction electrode series includes: a first extraction electrode located downstream of the front slit, which is a suppression electrode and is applied with a suppression voltage so as to be at a negative potential with respect to the ground potential; a second extraction electrode located downstream of the first extraction electrode, which is a ground electrode and is connected to the ground potential; and an insulating structure for supporting the first extraction electrode and the second extraction electrode between the first extraction electrode and the second extraction electrode to electrically insulate the first extraction electrode and the second extraction electrode from each other. The insulating structure includes: a first end portion; a second end portion; a shaft portion connecting between the first end portion and the second end portion; and an enclosing portion having an inner surface facing the outer surface of the shaft portion and extending from the first end portion toward the second end portion. A gap between the outer surface of the shaft portion and the inner surface of the enclosing portion is configured to communicate with the outside, and the first end portion, the second end portion, the shaft portion, and the enclosing portion are made of an electrically insulating material.

[0010] Another aspect of the present invention is an ion implantation device. The ion implantation device includes: an ion generation device; a beam line device for transporting an ion beam extracted from the ion generation device; and an implantation processing chamber for implanting the ion beam output from the beam line device into a workpiece. The ion implantation device is characterized in that the ion generation device includes: an arc chamber having a plasma generation chamber for generating plasma and a front slit; and an extraction electrode series for extracting ions generated in the plasma generation chamber to the outside of the arc chamber via the front slit. The extraction electrode series includes: a first extraction electrode located downstream of the front slit, which is a suppression electrode and is applied with a suppression voltage so as to be at a negative potential with respect to the ground potential; a second extraction electrode located downstream of the first extraction electrode, which is a ground electrode and is connected to the ground potential; and an insulating structure for supporting the first extraction electrode and the second extraction electrode between the first extraction electrode and the second extraction electrode to electrically insulate the first extraction electrode and the second extraction electrode from each other. The insulating structure includes: a first end portion; a second end portion; a shaft portion connecting between the first end portion and the second end portion; and an enclosing portion having an inner surface facing the outer surface of the shaft portion and extending from the first end portion toward the second end portion. A gap between the outer surface of the shaft portion and the inner surface of the enclosing portion is configured to communicate with the outside, and the first end portion, the second end portion, the shaft portion, and the enclosing portion are made of an electrically insulating material.

[0011] In addition, any combination of the above constituent elements mutually replaced among a method, an apparatus, a system, etc., or a constituent element or a way of expression of the present invention is equally effective as an embodiment of the present invention.

[0012] Advantageous Effects of the Invention

[0013] According to one aspect of the present invention, an insulating structure capable of suppressing a decrease in insulating performance due to adhesion of contaminants can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a top view schematically showing a schematic structure of an ion implantation apparatus according to an embodiment.

[0015] Figure 2 is showing Figure 1 a side view of a schematic structure of an ion implantation apparatus.

[0016] Figure 3 is a view schematically showing a structure of an ion generation apparatus according to an embodiment.

[0017] Figure 4 is a cross-sectional view showing in detail a structure of an insulating structure according to an embodiment.

[0018] Figure 5 is showing Figure 4 a perspective view of an appearance of an insulator shown.

[0019] Figure 6 is a view schematically showing a process of forming an intermediate by a laminated molding method.

[0020] Figure 7 is schematically showing Figure 4 a cross-sectional view of another structural example of an insulator shown.

[0021] Figure 8 is a perspective view schematically showing a process of joining Figure 7 a plurality of components.

[0022] Figure 9 is a cross-sectional view showing in detail a structure of an insulator according to a modification.

[0023] Figure 10 is a cross-sectional view showing in detail a structure of an insulator according to another modification.

[0024] Figure 11 is showing Figure 10 a side view of an appearance of a first component.

[0025] Figure 12 is a cross-sectional view showing in detail a structure of an insulator according to still another modification.

[0026] In the figure: 74 - insulation structure, 80 - insulator, 82 - first end portion, 84 - second end portion, 86 - shaft portion, 88 - surrounding portion, 90 - gap, 92 - opening, 94 - outer surface, 94a - inner concave portion, 94b - inner convex portion, 96 - inner surface, 96a - outer convex portion, 96b - outer concave portion, 120 - intermediate body, 122 - main body member, 124 - support member. Detailed Embodiment

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same reference numerals are assigned to the same components in the description of the drawings, and repeated descriptions are appropriately omitted. Moreover, the structures described below are examples and do not limit the scope of the present invention in any way.

[0028] Figure 1 is a top view schematically showing an ion implantation apparatus 10 according to an embodiment, Figure 2 and is a side view showing a schematic structure of the ion implantation apparatus 10. The ion implantation apparatus 10 is configured to perform an ion implantation process on the surface of a workpiece W. The workpiece W is, for example, a substrate, such as a semiconductor wafer. For the sake of convenience of explanation, in this specification, the workpiece W may sometimes be referred to as the wafer W, but this is not intended to limit the object of the implantation process to a specific object.

[0029] The ion implantation apparatus 10 is configured to reciprocally scan the beam in one direction and reciprocally move the wafer W in a direction orthogonal to the scanning direction, thereby irradiating an ion beam onto the entire processing surface of the wafer W. In this specification, for the sake of convenience of explanation, the traveling direction of the ion beam traveling along the designed beam line A is defined as the z - direction, and the plane perpendicular to the z - direction is defined as the xy - plane. When scanning the ion beam on the workpiece W, the scanning direction of the beam is set as the x - direction, and the direction perpendicular to the z - direction and the x - direction is set as the y - direction. Therefore, the reciprocal scanning of the beam is performed in the x - direction, and the reciprocal movement of the wafer W is performed in the y - direction.

[0030] The ion implantation apparatus 10 includes an ion generation device 12, a beam line device 14, an implantation processing chamber 16, and a wafer transfer device 18. The ion generation device 12 is configured to supply an ion beam to the beam line device 14. The beam line device 14 is configured to transfer the ion beam from the ion generation device 12 to the implantation processing chamber 16. A wafer W to be implanted is accommodated in the implantation processing chamber 16, and an implantation process of irradiating the ion beam supplied from the beam line device 14 onto the wafer W is performed. The wafer transfer device 18 is configured to carry an unprocessed wafer before the implantation process into the implantation processing chamber 16 and carry out a processed wafer after the implantation process from the implantation processing chamber 16. The ion implantation apparatus 10 includes a vacuum exhaust system (not shown) for providing a desired vacuum environment to the ion generation device 12, the beam line device 14, the implantation processing chamber 16, and the wafer transfer device 18.

[0031] The beam line device 14 sequentially includes a mass spectrometry unit 20, a beam stopper device 24, a beam shaping unit 30, a beam scanning unit 32, a beam parallelization unit 34, and an angular energy filter (AEF; Angular Energy Filter) 36 from the upstream side of the beam line A. In addition, the upstream of the beam line A refers to the side close to the ion generation device 12, and the downstream of the beam line A refers to the side close to the implantation processing chamber 16 (or the beam blocker 46).

[0032] The mass spectrometry unit 20 is provided downstream of the ion generation device 12 and is configured to select a required ion species from the ion beam extracted from the ion generation device 12 by mass spectrometry. The mass spectrometry unit 20 includes a mass spectrometry magnet 21, a mass spectrometry lens 22, and a mass spectrometry slit 23.

[0033] The mass spectrometry magnet 21 applies a magnetic field to the ion beam extracted from the ion generation device 12 and deflects the ion beam in different paths according to the value of the mass-to-charge ratio M = m / q (m is the mass and q is the charge). The mass spectrometry magnet 21 applies a magnetic field in the y direction (in Figure 1 and Figure 2 it is the -y direction) to the ion beam and deflects the ion beam in the x direction. The magnetic field strength of the mass spectrometry magnet 21 is adjusted so that ion species having a desired mass-to-charge ratio M pass through the mass spectrometry slit 23.

[0034] The mass spectrometry lens 22 is provided downstream of the mass spectrometry magnet 21 and is configured to adjust the focusing / diverging force on the ion beam. The mass spectrometry lens 22 adjusts the focusing position of the ion beam traveling direction (z direction) passing through the mass spectrometry slit 23 and adjusts the mass resolution M / dM of the mass spectrometry unit 20. In addition, the mass spectrometry lens 22 is not an essential component, and the mass spectrometry lens 22 may not be provided in the mass spectrometry unit 20.

[0035] The mass spectrometry slit 23 is provided downstream of the mass spectrometry lens 22 and at a position far from the mass spectrometry lens 22. The mass spectrometry slit 23 is configured such that the beam deflection direction (x-direction) caused by the mass spectrometry magnet 21 coincides with the slit width direction, and has an opening 23a with a relatively short x-direction and a relatively long y-direction.

[0036] The mass spectrometry slit 23 may also be configured such that the slit width is variable for adjusting the mass resolution. The mass spectrometry slit 23 may also be composed of two shielding members capable of moving in the slit width direction, and is configured such that the slit width can be adjusted by changing the interval between the two shielding members. The mass spectrometry slit 23 may also be configured such that the slit width is variable by switching to any one of a plurality of slits with different slit widths.

[0037] The beam stopping device 24 is configured to temporarily retract the ion beam from the beam line A and shield the ion beam directed toward the downstream implantation processing chamber 16 (or the wafer W). The beam stopping device 24 can be disposed at any position in the middle of the beam line A, for example, between the mass spectrometry lens 22 and the mass spectrometry slit 23. Since a certain distance is required between the mass spectrometry lens 22 and the mass spectrometry slit 23, by disposing the beam stopping device 24 therebetween, compared with the case of disposing it at other positions, the length of the beam line A can be shortened, and the entire ion implantation device 10 can be miniaturized.

[0038] The beam stopping device 24 includes a pair of stopping electrodes 25 (25a, 25b) and a beam collector 26. The pair of stopping electrodes 25a, 25b are opposed across the beam line A and opposed in the direction (y-direction) orthogonal to the beam deflection direction (x-direction) of the mass spectrometry magnet 21. The beam collector 26 is disposed at a position downstream of the beam line A relative to the stopping electrodes 25a, 25b and is disposed away from the beam line A in the opposing direction of the stopping electrodes 25a, 25b.

[0039] The first stopping electrode 25a is disposed at a position above the beam line A in the direction of gravity, and the second stopping electrode 25b is disposed at a position below the beam line A in the direction of gravity. The beam collector 26 is disposed at a position further away from the beam line A in the direction of gravity and is disposed below the opening 23a of the mass spectrometry slit 23 in the direction of gravity. The beam collector 26 is, for example, composed of a portion of the mass spectrometry slit 23 where the opening 23a is not formed. The beam collector 26 may also be separately formed from the mass spectrometry slit 23.

[0040] The beam stopping device 24 deflects the ion beam by using the electric field applied between a pair of stopping electrodes 25a and 25b, and causes the ion beam to avoid the beam line A. For example, by applying a negative voltage to the second stopping electrode 25b with respect to the potential of the first stopping electrode 25a, the ion beam deflects downward in the direction of gravity and enters the beam collector 26. In Figure 2 the trajectory of the ion beam toward the beam collector 26 is indicated by a dashed line. Further, the beam stopping device 24 causes the ion beam to pass downstream along the beam line A by setting the pair of stopping electrodes 25a and 25b to the same potential. The beam stopping device 24 is configured to be able to switch between a first mode in which the ion beam passes downstream and a second mode in which the ion beam enters the beam collector 26 and operate.

[0041] An injector Faraday cup 28 is provided downstream of the mass spectrometry slit 23. The injector Faraday cup 28 is configured to be able to enter the beam line A by the operation of the injector drive unit 29. The injector drive unit 29 moves the injector Faraday cup 28 in a direction (for example, the y direction) orthogonal to the extending direction of the beam line A. As shown by Figure 2 the dashed line, when the injector Faraday cup 28 is disposed on the beam line A, the ion beam toward the downstream side is blocked. On the other hand, as shown by Figure 2 the solid line, when the injector Faraday cup 28 is removed from the beam line A, the blocking of the ion beam toward the downstream side is released.

[0042] The injector Faraday cup 28 is configured to measure the beam current of the ion beam that is mass-spectrometrized by the mass spectrometry unit 20. The injector Faraday cup 28 can measure the mass spectrometry spectrum of the ion beam by measuring the beam current while changing the magnetic field strength of the mass spectrometry magnet 21. Using the measured mass spectrometry spectrum, the mass resolution of the mass spectrometry unit 20 can be calculated.

[0043] The beam shaping unit 30 includes focusing / diverging devices such as a focusing / diverging quadrupole lens (Q lens), and is configured to shape the ion beam that has passed through the mass spectrometry unit 20 into a desired cross-sectional shape. The beam shaping unit 30 is constituted by, for example, an electric field type three-stage quadrupole lens (also referred to as a tripole Q lens), and includes three quadrupole lenses 30a, 30b, and 30c. The beam shaping unit 30 can independently adjust the focusing or divergence of the ion beam in the x direction and the y direction by using the three lens devices 30a to 30c. The beam shaping unit 30 may include a magnetic field type lens device, or may include a lens device that shapes the beam by using both an electric field and a magnetic field.

[0044] The beam scanning unit 32 is configured to provide reciprocating scanning of the beam and is a beam deflection device that scans the shaped ion beam in the x direction. The beam scanning unit 32 has a pair of scanning electrodes opposed to each other in the beam scanning direction (x direction). The pair of scanning electrodes is connected to a variable voltage power supply (not shown), and by periodically changing the voltage applied between the pair of scanning electrodes, the electric field generated between the electrodes is changed, causing the ion beam to be deflected at various angles. As a result, the ion beam is scanned over the entire scanning range in the x direction. In Figure 1 , the scanning direction and scanning range of the beam are illustrated by the arrow X, and a plurality of trajectories of the ion beam in the scanning range are represented by a single-dot chain line.

[0045] The beam parallelization unit 34 is configured to make the traveling direction of the scanned ion beam parallel to the trajectory of the designed beam line A. The beam parallelization unit 34 has a plurality of parallelization lens electrodes in an arc shape with a passage slit for the ion beam provided at the central portion in the y direction. The parallelization lens electrodes are connected to a high-voltage power supply (not shown), and the electric field generated by applying a voltage is made to act on the ion beam to align the traveling directions of the ion beam in parallel. In addition, the beam parallelization unit 34 may be replaced by other beam parallelization devices, and the beam parallelization device may be configured as a magnet device using a magnetic field.

[0046] An AD (Accel / Decel) column (not shown) for accelerating or decelerating the ion beam may also be provided downstream of the beam parallelization unit 34.

[0047] The angular energy filter (AEF) 36 is configured to analyze the energy of the ion beam and deflect the ions with the required energy downward and guide them to the implantation processing chamber 16. The angular energy filter 36 has a pair of AEF electrodes for electric field deflection. The pair of AEF electrodes is connected to a high-voltage power supply (not shown). In Figure 2 , by applying a positive voltage to the upper AEF electrode and a negative voltage to the lower AEF electrode, the ion beam is deflected downward. In addition, the angular energy filter 36 may be constituted by a magnet device for magnetic field deflection, or may be constituted by a combination of a pair of AEF electrodes for electric field deflection and a magnet device for magnetic field deflection.

[0048] In this way, the beam line device 14 supplies the ion beam to be irradiated onto the wafer W to the implantation processing chamber 16.

[0049] The implantation processing chamber 16 sequentially includes an energy slit 38, a plasma shower device 40, a side cup 42, a center cup 44, and a beam stopper 46 from the upstream side of the beam line A. As Figure 2 shown, the implantation processing chamber 16 includes a stage driving device 50 for holding one or more wafers W.

[0050] The energy slit 38 is provided on the downstream side of the angular energy filter 36 and performs energy analysis of the ion beam incident on the wafer W together with the angular energy filter 36. The energy slit 38 is an energy defining slit (EDS) formed by a slit that is horizontally long in the beam scanning direction (x direction). The energy slit 38 allows an ion beam having a desired energy value or energy range to pass through toward the wafer W and shields other ion beams.

[0051] The plasma shower device 40 is located on the downstream side of the energy slit 38. The plasma shower device 40 supplies low-energy electrons to the ion beam and the surface of the wafer W (wafer processing surface) according to the beam current of the ion beam and suppresses charging caused by the accumulation of positive charges on the wafer processing surface due to ion implantation. The plasma shower device 40 includes, for example, a shower tube through which the ion beam passes and a plasma generation device that supplies electrons into the shower tube.

[0052] The side cups 42 (42R, 42L) are configured to measure the beam current of the ion beam during the ion implantation process of the wafer W. As Figure 2 shown, the side cups 42R, 42L are arranged to be offset to the left and right (x direction) with respect to the wafer W disposed on the beam line A and are arranged at positions where they do not shield the ion beam toward the wafer W during ion implantation. Since the ion beam is scanned in the x direction beyond the range where the wafer W is located, a part of the scanned beam is incident on the side cups 42R, 42L even during ion implantation. Thus, the beam current during the ion implantation process is measured by the side cups 42R, 42L.

[0053] The center cup 44 is configured to measure the beam current on the wafer processing surface. The center cup 44 is configured to be movable in the x direction by the operation of the drive unit 45, retracts from the implantation position where the wafer W is located during ion implantation, and inserts into the implantation position when the wafer W is not at the implantation position. The center cup 44 can measure the beam current over the entire beam scanning range in the x direction by measuring the beam current while moving in the x direction. The center cup 44 may also be formed in an array in which a plurality of Faraday cups are arranged in the x direction so that the beam current at a plurality of positions in the beam scanning direction (x direction) can be measured simultaneously.

[0054] At least one of the side cup 42 and the center cup 44 may be provided with a single Faraday cup for measuring the beam current amount, or may be provided with an angle measuring device for measuring the angle information of the beam. The angle measuring device includes, for example, a slit and a plurality of current detection units provided away from the slit in the beam traveling direction (z direction). The angle measuring device can measure the angle component of the beam in the slit width direction by measuring the beam passing through the slit using the plurality of current detection units arranged in the slit width direction. At least one of the side cup 42 and the center cup 44 may also be provided with a first angle measuring device capable of measuring the angle information in the x direction and a second angle measuring device capable of measuring the angle information in the y direction.

[0055] The stage driving device 50 includes a wafer holding device 52, a reciprocating mechanism 54, a twist angle adjusting mechanism 56, and an inclination angle adjusting mechanism 58. The wafer holding device 52 includes an electrostatic chuck or the like for holding the wafer W. The reciprocating mechanism 54 reciprocates the wafer holding device 52 in a reciprocating direction (y direction) orthogonal to the beam scanning direction (x direction), so that the wafer held by the wafer holding device 52 reciprocates in the y direction. In Figure 2 it, the reciprocating movement of the wafer W is illustrated by the arrow Y.

[0056] The twist angle adjusting mechanism 56 is a mechanism for adjusting the rotation angle of the wafer W. By rotating the wafer W about the normal line of the wafer processing surface, the twist angle between the alignment mark provided on the outer peripheral portion of the wafer and the reference position is adjusted. Here, the alignment mark of the wafer refers to a notch or an orientation flat provided on the outer peripheral portion of the wafer, and is a mark that serves as a reference for the angular position of the crystal axis direction or the circumferential direction of the wafer. The twist angle adjusting mechanism 56 is provided between the wafer holding device 52 and the reciprocating mechanism 54, and reciprocates together with the wafer holding device 52.

[0057] The inclination angle adjusting mechanism 58 is a mechanism for adjusting the slope of the wafer W, and adjusts the inclination angle between the traveling direction of the ion beam toward the wafer processing surface and the normal line of the wafer processing surface. In the present embodiment, the angle of the inclination angle of the wafer W with the x-axis as the rotation center axis is adjusted as the inclination angle. The inclination angle adjusting mechanism 58 is provided between the reciprocating mechanism 54 and the inner wall of the implantation processing chamber 16, and is configured to adjust the inclination angle of the wafer W by rotating the entire stage driving device 50 including the reciprocating mechanism 54 in the R direction.

[0058] The stage driving device 50 holds the wafer W so that the wafer W can move between the implantation position where the ion beam irradiates the wafer W and the transfer position where the wafer W is transferred in and out between the stage driving device and the wafer transfer device 18. Figure 2Indicates the state where the wafer W is located at the implantation position, and the platform driving device 50 holds the wafer W in such a manner that the beam line A intersects the wafer W. The transfer position of the wafer W corresponds to the position of the wafer holding device 52 when the transfer mechanism or transfer robot provided in the wafer transfer device 18 transfers the wafer W in or out through the transfer port 48.

[0059] The beam blocker 46 is provided at the most downstream of the beam line A, for example, mounted on the inner wall of the implantation processing chamber 16. When the wafer W is not present on the beam line A, the ion beam is incident on the beam blocker 46. The beam blocker 46 is located near the transfer port 48 connecting the implantation processing chamber 16 and the wafer transfer device 18, and is provided at a position vertically below the transfer port 48.

[0060] Figure 3 Is a cross-sectional view schematically showing the structure of the ion generation device 12 according to the embodiment. The ion generation device 12 includes an arc chamber 60, a cathode 62, a reflector 64, a first extraction electrode 70, a second extraction electrode 72, and an insulating structure 74.

[0061] The arc chamber 60 has a substantially rectangular parallelepiped box shape. The arc chamber 60 partitions the plasma generation chamber R where the plasma P is generated. The arc chamber 60 is made of a high melting point material, for example, made of a high melting point metal such as tungsten (W), molybdenum (Mo), tantalum (Ta) or their alloys, graphite (C), etc. Thereby, in an environment where it becomes a high temperature (for example, 700 °C to 2000 °C) in the plasma generation chamber R, heat-induced damage to the arc chamber 60 can be suppressed.

[0062] The cathode 62 releases thermoelectrons into the plasma generation chamber R. The cathode 62 is a so-called indirectly heated cathode (IHC; Indirectly Heated Cathode), and has a filament 62a and a cathode head 62b. The filament 62a is heated by the filament power supply to generate primary thermoelectrons. The primary thermoelectrons generated in the filament 62a are accelerated by the cathode voltage applied between the filament 62a and the cathode head 62b. The cathode head 62b is heated by the primary thermoelectrons from the filament 62a and supplies secondary thermoelectrons to the plasma generation chamber R. The secondary thermoelectrons generated in the cathode head 62b are accelerated by the arc voltage applied between the arc chamber 60 and the cathode 62.

[0063] The reflector 64 is provided at a position opposite to the cathode 62. The reflector 64 rebounds the secondary thermoelectrons supplied into the plasma generation chamber R or the electrons generated by the ionization of the source gas molecules in the plasma generation chamber R, so that the electrons stay in the plasma generation chamber R, improving the plasma generation efficiency.

[0064] A gas inlet 66 is provided on the side wall of the arc chamber 60. The gas inlet 66 supplies source gas to the plasma generation chamber R from a gas cylinder (not shown) or the like. As the source gas, noble gas, hydrogen (H2), hydrides such as phosphine (PH3) and arsine (AsH3), fluorides such as boron trifluoride (BF3) and germanium tetrafluoride (GeF4) are used. Further, substances containing an oxygen atom (O) such as carbon dioxide (CO2), carbon monoxide (CO), and oxygen (O2) are also used as the source gas.

[0065] In the plasma generation chamber R, a magnetic field B is applied in the direction from the cathode 62 toward the reflector 64 (or the opposite direction). The magnetic field B is generated by an electromagnet (not shown) or the like, and the intensity of the magnetic field B is adjusted by adjusting the magnet current flowing through the electromagnet. Electrons moving in the plasma generation chamber R are confined by the magnetic field B applied to the plasma generation chamber R and move in a spiral along the magnetic field B. The electrons moving in a spiral in the plasma generation chamber R collide with the source gas molecules introduced into the plasma generation chamber R, ionize the source gas molecules to generate ions and new electrons, and generate a plasma P in the plasma generation chamber R. By making the electrons move in a spiral in the plasma generation chamber R, the plasma generation efficiency can be improved.

[0066] A front slit 68 for extracting an ion beam IB is provided on the front surface of the arc chamber 60. The front slit 68 has an elongated shape extending in the direction from the cathode 62 toward the reflector 64. Ions generated in the plasma generation chamber R pass through the front slit 68 and are extracted as an ion beam IB through an extraction electrode series composed of a first extraction electrode 70, a second extraction electrode 72, and an insulating structure 74.

[0067] The first extraction electrode 70 located downstream of the front slit 68 is a suppression electrode and is applied with a suppression voltage so as to be at a negative potential with respect to the ground potential. The second extraction electrode 72 located downstream of the first extraction electrode 70 is a ground electrode and is connected to the ground potential. An extraction voltage is applied to the arc chamber 60 so as to be at a positive potential with respect to the ground potential. An insulating structure 74 is provided between the first extraction electrode 70 and the second extraction electrode 72. The insulating structure 74 mechanically supports the first extraction electrode 70 and the second extraction electrode 72 and electrically insulates the first extraction electrode 70 and the second extraction electrode 72 from each other.

[0068] The insulating structure 74 includes a first cover 76, a second cover 78, and an insulator 80. The first cover 76 and the second cover 78 are made of a conductive material and are made of metal or graphite. The insulator 80 is made of an electrically insulating material and is made of ceramic or resin. The first cover 76 is disposed between the first extraction electrode 70 and the insulator 80. The second cover 78 is disposed between the second extraction electrode 72 and the insulator 80.

[0069] The first cover body 76 and the second cover body 78 are disposed outside the insulator 80 to inhibit attachment of contaminants to the surface of the insulator 80. The first cover body 76 and the second cover body 78 form a nested structure. In the illustrated example, they are configured such that the first cover body 76 is on the outside and the second cover body 78 is on the inside. Alternatively, they can be configured such that the first cover body 76 is on the inside and the second cover body 78 is on the outside.

[0070] Figure 4 It is a cross-sectional view showing in detail the structure of the insulation structure 74 according to the embodiment. The insulation structure 74 is disposed between the first lead electrode 70 and the second lead electrode 72. The insulation structure 74 includes a first cover body 76, a second cover body 78, and an insulator 80. The insulation structure 74 is fixed to the first lead electrode 70 by the first screw 104 and fixed to the second lead electrode 72 by the second screw 106.

[0071] In the description of the insulation structure 74, the direction from the first lead electrode 70 toward the second lead electrode 72 is also referred to as the axial direction. The direction orthogonal to the axial direction, for example, the direction orthogonal to the outer surface 98 of the insulator 80, is also referred to as the radial direction. And the direction orthogonal to both the axial direction and the radial direction, that is, the direction around the axial direction, is also referred to as the circumferential direction.

[0072] The first cover body 76 has a first bottom portion 76a and a first side wall portion 76b, and is configured in a cup shape. The first bottom portion 76a is the portion sandwiched between the first lead electrode 70 and the insulator 80. A through hole for inserting the first screw 104 is provided in the first bottom portion 76a. The first side wall portion 76b is the portion extending axially from the outer periphery of the first bottom portion 76a and is configured in a cylindrical shape. The inner diameter of the first side wall portion 76b is larger than the outer diameter of the second cover body 78. The first side wall portion 76b is disposed radially away from the second cover body 78. The axial length of the first side wall portion 76b is about 50% to 80% of the axial length of the insulator 80. The open end of the first side wall portion 76b is axially away from the second lead electrode 72.

[0073] The second cover body 78 has a second bottom portion 78a and a second side wall portion 78b, and is configured in a cup shape. The second bottom portion 78a is the portion sandwiched between the second lead electrode 72 and the insulator 80. A through hole for inserting the second screw 106 is provided in the second bottom portion 78a. The second side wall portion 78b is the portion extending axially from the outer periphery of the second bottom portion 78a and is configured in a cylindrical shape. The inner diameter of the second side wall portion 78b is larger than the outer diameter of the insulator 80. The second side wall portion 78b is disposed radially away from the insulator 80. The axial length of the second side wall portion 78b is about 30% to 60% of the axial length of the insulator 80. The second side wall portion 78b is configured such that its axial range overlaps with that of the first side wall portion 76b. The open end of the second side wall portion 78b is axially away from the first bottom portion 76a.

[0074] The insulator 80 has a first end portion 82, a second end portion 84, a shaft portion 86, and a surrounding portion 88. The first end portion 82 is the portion connected to the first lead electrode 70 and the first cover body 76 by the first screw 104. A first mounting hole 100 for inserting the first screw 104 is provided at the center of the first end portion 82. The second end portion 84 is the portion connected to the second lead electrode 72 and the second cover body 78 by the second screw 106. A second mounting hole 102 for inserting the second screw 106 is provided at the center of the second end portion 84.

[0075] The shaft portion 86 is the portion connecting the first end portion 82 and the second end portion 84, and extends axially from the first end portion 82 toward the second end portion 84. The shaft portion 86 is provided inside the surrounding portion 88. The shaft portion 86 is a columnar member and has a rotationally symmetric shape. The diameter of the shaft portion 86 is smaller than the diameters of the first end portion 82 and the second end portion 84. The diameter of the shaft portion 86 varies according to the position in the axial direction. An inner concave portion 94a and an inner convex portion 94b are provided on the outer surface 94 of the shaft portion 86. The inner concave portion 94a and the inner convex portion 94b extend continuously in the circumferential direction.

[0076] The surrounding portion 88 is provided outside the shaft portion 86. The surrounding portion 88 extends axially from the first end portion 82 toward the second end portion 84. The surrounding portion 88 is a cylindrical member and has a rotationally symmetric shape. The surrounding portion 88 is connected to the first end portion 82 and is away from the second end portion 84. An opening 92 is formed between the surrounding portion 88 and the second end portion 84. The opening 92 extends radially. The opening 92 is provided near the second end portion 84. The opening 92 is configured such that the opening width becomes larger as it is farther from the shaft portion 86 in the radial direction, and is formed in a tapered shape, for example. The opening 92 is covered by the second cover body 78.

[0077] The surrounding portion 88 has an inner surface 96 and an outer surface 98. The inner surface 96 of the surrounding portion 88 faces the outer surface 94 of the shaft portion 86. A gap 90 is formed between the inner surface 96 of the surrounding portion 88 and the outer surface 94 of the shaft portion 86. The gap 90 communicates with the outside of the insulator 80 through the opening 92. The outer surface 98 of the surrounding portion 88 is a cylindrical surface and is configured to be a substantially smooth surface without irregularities. The outer surface 98 of the surrounding portion 88 faces the first side wall portion 76b of the first cover body 76 and the second side wall portion 78b of the second cover body 78 in the radial direction.

[0078] The inner diameter of the surrounding portion 88 varies according to the axial position. On the inner surface 96 of the surrounding portion 88, an outer convex portion 96a and an outer concave portion 96b are provided. The outer convex portion 96a and the outer concave portion 96b extend continuously in the circumferential direction. The outer convex portion 96a is provided at a position corresponding to the inner concave portion 94a, and the outer concave portion 96b is provided at a position corresponding to the inner convex portion 94b. The shaft portion 86 and the surrounding portion 88 are configured such that the distance between the outer surface 94 of the shaft portion 86 and the inner surface 96 of the surrounding portion 88 (i.e., the width of the gap 90) is substantially constant. Alternatively, the distance between the outer surface 94 of the shaft portion 86 and the inner surface 96 of the surrounding portion 88 may not be constant. For example, it may be configured such that the width of the gap 90 becomes smaller as it moves away from the opening 92.

[0079] The gap 90 formed inside the insulator 80 is configured to have a complex labyrinth structure and has a portion that cannot be directly visually recognized from the outside of the insulator 80. The gap 90 does not extend linearly in the axial direction but extends in a manner that bends radially inward and radially outward. Here, the portion that cannot be directly visually recognized from the outside of the insulator 80 means a portion that cannot be observed when looking at the inside of the gap 90 from the opening 92 because the line of sight is blocked by the shaft portion 86 or the surrounding portion 88. The portion that cannot be directly visually recognized from the outside corresponds to a location where, when drawing a straight line connecting a certain point in the gap 90 to the opening 92, the straight line overlaps at least one of the shaft portion 86 and the surrounding portion 88.

[0080] Figure 5 It represents Figure 4 A perspective view showing the appearance of the insulator 80 as shown. As shown, the insulator 80 is cylindrical as a whole. The outer surface 98 of the surrounding portion 88 is formed by a cylindrical surface. An opening 92 is formed between the surrounding portion 88 and the second end portion 84. The opening 92 is formed to be continuous in the circumferential direction. Therefore, the surrounding portion 88 is spaced apart from the second end portion 84 throughout the circumference. The axial opening width of the opening 92 is preferably constant throughout the circumference.

[0081] According to the insulation structure 74 according to the present embodiment, since the opening 92 is provided between the first end portion 82 and the second end portion 84, even if conductive contaminants adhere to the outer surface 98 of the insulator 80, electrical insulation between the first end portion 82 and the second end portion 84 can be ensured through the opening 92. And, since the gap 90 is provided inside the opening 92, as long as the conductive contaminants do not adhere to the entire gap 90, electrical insulation between the first end portion 82 and the second end portion 84 can be ensured. Since the gap 90 has a labyrinth structure, contaminants that invade the gap 90 from the opening 92 are difficult to reach the inside of the gap 90. As a result, a decrease in the insulation performance of the insulator 80 can be suppressed, and the maintenance frequency such as cleaning or replacement of the insulation structure 74 can be reduced.

[0082] Next, a method for manufacturing the insulator 80 will be described. Regarding the insulator 80, the entire insulator 80 is formed of an electrically insulating material. That is, the first end portion 82, the second end portion 84, the shaft portion 86, and the surrounding portion 88 are formed of an electrically insulating material. In one embodiment, the first end portion 82, the second end portion 84, the shaft portion 86, and the surrounding portion 88 are made of the same material. The insulator 80 is made of, for example, ceramic materials such as alumina (Al2O3), silica (SiO2), magnesia (MgO), aluminum nitride (AlN), and boron nitride (BN). The insulator 80 may be made of an oxide-based ceramic material, or may be made of a monomer or a mixture of alumina, silica, and magnesia. The insulator 80 may also be made of an engineering plastic such as epoxy or polyimide.

[0083] Since the insulator 80 has gaps 90 with a complex maze structure, it is difficult to integrally form the insulator 80 using a conventional processing method such as mechanical cutting. In the case of integrally forming the insulator 80, a so-called three-dimensional printing technology such as a laminated manufacturing method can be used. For example, by laminating and manufacturing the shaft portion 86 and the surrounding portion 88 from the first end portion 82 toward the second end portion 84, the gaps 90 having a maze structure can be integrally formed.

[0084] Figure 6 FIG. schematically shows a process of forming an intermediate body 120 using a laminated manufacturing method. The intermediate body 120 includes a main body member 122 and a support member 124. The main body member 122 is a part that becomes the insulator 80 and has a shape corresponding to at least a part of the first end portion 82, the second end portion 84, the shaft portion 86, and the surrounding portion 88. The support member 124 is a part that mechanically supports the main body member 122 and is arranged to fill the gaps 90 of the insulator 80. The support member 124 may also be arranged outside the main body member 122.

[0085] The intermediate body 120 is formed by scanning a modeling head 110 that laminates the main body member 122 and the support member 124 as shown by an arrow S. The modeling head 110 has a first head 112 for laminating the main body member 122 and a second head 114 for laminating the support member 124. A first material for forming the main body member 122 is ejected from the first head 112, and a second material for forming the support member 124 is ejected from the second head 114, thereby forming a modeling layer 126. The intermediate body 120 is formed by stacking a plurality of modeling layers 126.

[0086] In the illustrated example, the modeling head 110 has the first head 112 and the second head 114, and the first head 112 and the second head 114 are configured to be driven integrally. Alternatively, the first head 112 and the second head 114 may be configured to be separately formed and independently driven.

[0087] The first material includes the material that constitutes the insulator 80. When the insulator 80 is made of a ceramic material, the first material contains ceramic particles. The first material is preferably a liquid substance that can be ejected from the first head 112, and may also contain a liquid such as water or resin. When the first material contains water, the first material can be dried and cured by laminating the first material while heating the intermediate body 120. The first material can contain an ultraviolet curable resin, or the first material can be cured by irradiating ultraviolet light on the first material ejected from the first head 112. When the insulator 80 is made of a resin, the first material can be a resin material. The first material can also be an ultraviolet curable resin or a thermosetting resin.

[0088] The support member 124 is made of a second material different from the first material. The second material is made of a material that can selectively remove only the second material in a state where the first material remains after the intermediate body 120 is formed. The second material is made of a resin material that can be melted, evaporated, or thermally decomposed by heating, or a resin material that can be dissolved using a solvent. The second material is, for example, a thermoplastic resin, and the second material can be laminated by ejecting the second material softened by heating from the second head 114.

[0089] When the first material contains ceramic particles, the main body member 122 can also be cured by heating the intermediate body 120. In the process of heating the intermediate body 120, the support member 124 can also be removed by melting, evaporation, or thermal decomposition. In the process of heating the intermediate body 120, the support member 124 can be completely removed or partially removed. When the support member 124 remains partially, the support member 124 can also be removed using a solvent or the like. The support member 124 can also be removed by mechanical cutting or the like. After removing the support member 124, the main body member 122 can be reheated. The main body member 122 can also be dried in the first heating process before removing the support member 124, and calcined or sintered in the second heating process after removing the support member 124. The second heating process can also be at a higher temperature than the first heating process. By sintering the main body member 122, the insulator 80 made of a ceramic material with excellent electrical insulation is formed.

[0090] When the first material contains an ultraviolet curable resin, the intermediate body 120 may not be heated. The support member 124 included in the intermediate body 120 can be removed using a solvent or the like, or can be removed by mechanical cutting or the like. When the first material contains a thermosetting resin, the main body member 122 can also be cured by heating the intermediate body 120. In the process of heating the intermediate body 120, the support member 124 can also be completely or partially removed by melting, evaporation, or thermal decomposition. The support member 124 can be removed using a solvent or the like, or can be removed by mechanical cutting or the like.

[0091] The first mounting hole 100 and the second mounting hole 102 provided in the insulator 80 can be formed at any time during the process of manufacturing the insulator 80. The first mounting hole 100 and the second mounting hole 102 can also be formed during the process of laminating and shaping the intermediate body 120. At this time, the supporting member 124 can also be filled in the first mounting hole 100 and the second mounting hole 102. The first mounting hole 100 and the second mounting hole 102 can also be formed by mechanically cutting the main body member 122 after the lamination and shaping of the main body member 122. When the main body member 122 contains a ceramic material, the first mounting hole 100 and the second mounting hole 102 can be formed before the sintering of the main body member 122 or after the sintering of the main body member 122.

[0092] The intermediate body 120 can also be formed by a method different from the Figure 6 process shown. For example, the intermediate body 120 can also be formed by alternately repeating the process of discharging a small amount of the first material from the shaping head 110 and the process of curing the small amount of discharged first material. At this time, the intermediate body 120 can also be composed only of the main body member 122. That is, the supporting member 124 can also not be filled in the gap 90.

[0093] Moreover, instead of discharging the first material from the shaping head 110, the intermediate body 120 can be formed by selectively curing the first material by irradiating a laser or the like on a layer of the first material. For example, a laser can be irradiated on a material layer composed of ceramic particles to locally cure or sinter the material layer, thereby laminating and shaping the intermediate body 120. At this time, the supporting member 124 can be filled in the gap 90, or the intermediate body 120 can be formed without filling the supporting member 124 in the gap 90. Therefore, the intermediate body 120 can also be composed only of the main body member 122.

[0094] The insulator 80 can also be formed by joining a plurality of components. For example, a plurality of components constituting a part of the insulator 80 can be separately formed and then joined. Each of the plurality of components can be formed using three-dimensional printing techniques such as the lamination and shaping method, or can be formed using conventional shaping techniques such as mechanical cutting or molds.

[0095] Figure 7 is a schematic cross-sectional view showing Figure 4 another structural example of the insulator 80 shown. In Figure 7In the example, the insulator 80 is composed of a plurality of components 80a, 80b, and 80c. The first component 80a includes a second end portion 84 and a shaft portion 86. The second component 80b includes a first part 82b of the first end portion 82 and a first part 88b of the surrounding portion 88. The third component 80c includes a second part 82c of the first end portion 82 and a second part 88c of the surrounding portion 88. Each of the plurality of components 80a to 80c can be formed by any method. For example, it can be formed using three-dimensional printing technology, can be formed using a mold, or can be formed by mechanical cutting.

[0096] Figure 8 is a perspective view schematically showing the process of joining Figure 7 the plurality of components 80a to 80c. The second component 80b and the third component 80c are arranged around the first component 80a, and the plurality of components 80a to 80c are joined to form Figure 7 the insulator 80. Specifically, the first front end portion 86b of the shaft portion 86 of the first component 80a is joined to the first part 82b of the first end portion 82, and the second front end portion 86c of the shaft portion 86 of the first component 80a is joined to the second part 82c of the first end portion 82. And, while joining the second front end portion 86c to the second part 82c, the second component 80b and the third component 80c are joined to integrate the first end portion 82 and the surrounding portion 88.

[0097] The plurality of components 80a to 80c can also be joined to each other using an adhesive. It is also possible to temporarily join the plurality of components 80a to 80c using an adhesive and then cure the temporarily joined portions of the plurality of components 80a to 80c to fix the plurality of components 80a to 80c to each other. For example, when the insulator 80 is made of ceramics, it is also possible to temporarily join the components 80a to 80c before sintering using a first material, and heat the insulator 80 after temporary joining to sinter it, thereby curing the temporarily joined portions. When temporarily joining the components 80a to 80c before sintering, it is also possible to dispose a support member in the gap 90 between the plurality of components 80a to 80c. Remove the support member before, during, or after sintering of the temporarily joined components 80a to 80c.

[0098] In addition, the dividing positions when dividing the insulator 80 into a plurality of components are not limited to Figure 7 and Figure 8The example shown. For example, the shaft portion 86 of the insulator 80 can also be divided into multiple components. In one embodiment, the first component has the first part of the shaft portion 86, the second component has the second part of the shaft portion 86, and the third component has the third part of the shaft portion 86. At this time, it can also be as follows: The first component further has the second end portion 84, the second component further has the first end portion 82 and a part of the surrounding portion 88, and the third component further has the first end portion 82 and another part of the surrounding portion 88. And when the insulator 80 is divided into multiple components, the number of divisions is not particularly limited, and it can also be divided into four or more components.

[0099] Figure 9 It is a cross-sectional view showing in detail the structure of the insulator 180 according to the modified example. In this modified example, the insulator 180 is composed of a first component 180a and a second component 180b. And in this modified example, an inner concave portion 194a and an inner convex portion 194b are provided on the outer surface 194 of the shaft portion 186, and no unevenness is provided on the inner surface 196 of the surrounding portion 188. The gap 190 formed between the shaft portion 186 and the surrounding portion 188 has a first portion 190a that extends linearly in the axial direction and a second portion 190b that branches from the first portion 190a and extends in the radial direction.

[0100] The insulator 180 includes a first end portion 182, a second end portion 184, a shaft portion 186, and a surrounding portion 188. Each of the first end portion 182 and the second end portion 184 is formed in the same manner as Figure 4 the first end portion 82 and the second end portion 84. The shaft portion 186 is a columnar member that extends in the axial direction from the first end portion 182 toward the second end portion 184. A plurality of inner concave portions 194a and a plurality of inner convex portions 194b are provided on the outer surface 194 of the shaft portion 186. The surrounding portion 188 is a cylindrical member that extends in the axial direction from the first end portion 182 toward the second end portion 184. The inner surface 196 and the outer surface 198 of the surrounding portion 188 are formed by a cylindrical surface and are configured to be substantially smooth surfaces without unevenness. A gap 190 is formed between the shaft portion 186 and the surrounding portion 188. An opening 192 is formed between the surrounding portion 188 and the second end portion 184. The insulator 180 as a whole has a cylindrical shape and has a rotationally symmetric shape. The appearance of the insulator 180 is the same as Figure 5 the appearance of the insulator 80 shown.

[0101] The first component 180a includes a second end portion 184 and a first part 186a of the shaft portion 186. The second component 180b includes a first end portion 182, a second part 186b of the shaft portion 186, and an enclosing portion 188. An engaging portion 200 for connecting the two is provided on the first component 180a and the second component 180b. The engaging portion 200 has an engaging concave portion 200a provided on the first component 180a and an engaging convex portion 200b provided on the second component 180b. Alternatively, an engaging convex portion may be provided on the first component 180a and an engaging concave portion may be provided on the second component 180b. The engaging portion 200 may also have a thread-cutting structure.

[0102] The insulator 180 can be manufactured by joining the first component 180a and the second component 180b. First, each of the first component 180a and the second component 180b is formed by any method. Each of the first component 180a and the second component 180b can be formed using a mold, can be formed by mechanical cutting, or can be formed using three-dimensional printing technology. Then, the engaging portions 200 of the first component 180a and the second component 180b are engaged and joined. The engaging portion 200 can be joined using an adhesive, or the engaging portion 200 can be configured to be non-detachable. In the case where the insulator 180 is made of ceramic, the first component 180a and the second component 180b before sintering can also be joined, and the joined insulator 180 can be heated and sintered to cure and integrate the joined portion.

[0103] In this modified example, the gap 190 of the insulator 180 is also configured to have a portion that cannot be directly visually recognized from the outside. Therefore, the same effects as those of the above-described embodiment can also be achieved in this modified example.

[0104] In Figure 9 the example, unevenness is provided only on the outer surface 194 of the shaft portion 186, but unevenness may also be formed on the inner surface 196 of the enclosing portion 188. At this time, in order to enable the first component 180a to be inserted into the second component 180b, the unevenness on the outer surface 194 of the shaft portion 186 and the unevenness on the inner surface 196 of the enclosing portion 188 may be formed so as not to engage. For example, a convex portion on the inner surface 196 of the enclosing portion 188 may be arranged at a position corresponding to the convex portion on the outer surface 194 of the shaft portion 186, and a concave portion on the inner surface 196 of the enclosing portion 188 may be arranged at a position corresponding to the concave portion on the outer surface 194 of the shaft portion 186. In addition, unevenness may not be provided on the outer surface 194 of the shaft portion 186, and unevenness may be formed only on the inner surface 196 of the enclosing portion 188.

[0105] Figure 10FIG. is a cross-sectional view showing in detail the structure of the insulator 280 according to another modified example. In this modified example, similarly to the above-described modified example, the insulator 280 is composed of a first component 280a and a second component 280b. Further, in this modified example, an inner concave portion 294a and an inner convex portion 294b are provided on the outer surface 294 of the shaft portion 286, and an outer convex portion 296a and an outer concave portion 296b are provided on the inner surface 296 of the surrounding portion 288. In order to enable the first component 280a and the second component 280b to be joined, the concavo-convex portions formed on the outer surface 294 of the shaft portion 286 and the inner surface 296 of the surrounding portion 288 extend in a spiral shape.

[0106] The insulator 280 includes a first end portion 282, a second end portion 284, a shaft portion 286, and a surrounding portion 288. Each of the first end portion 282 and the second end portion 284 is configured in the same manner as the first end portion 82 and the second end portion 84 of Figure 4 . The shaft portion 286 is a columnar member extending in the axial direction from the first end portion 282 toward the second end portion 284. An inner concave portion 294a and an inner convex portion 294b are provided in a spiral shape on the outer surface 294 of the shaft portion 286. The surrounding portion 288 is a cylindrical member extending in the axial direction from the first end portion 282 toward the second end portion 284. The outer convex portion 296a and the outer concave portion 296b extend in a spiral shape on the inner surface 296 of the surrounding portion 288. The outer convex portion 296a is provided at a position corresponding to the inner concave portion 294a, and the outer concave portion 296b is provided at a position corresponding to the inner convex portion 294b. The outer surface 298 of the surrounding portion 288 is formed of a cylindrical surface and is configured to be substantially a smooth surface without concavo-convex portions. A gap 290 extending in a spiral shape is formed between the shaft portion 286 and the surrounding portion 288. An opening 292 is formed between the surrounding portion 288 and the second end portion 284. The insulator 280 as a whole has a cylindrical shape. The appearance of the insulator 280 is the same as the appearance of the insulator 80 shown in Figure 5 .

[0107] The first component 280a includes the second end portion 284 and a first part 286a of the shaft portion 286. The second component 280b includes the first end portion 282, a second part 286b of the shaft portion 286, and the surrounding portion 288. Engagement portions 300 for connecting the two are provided on the first component 280a and the second component 280b. The engagement portion 300 has an engagement concave portion 300a provided on the first component 280a and an engagement convex portion 300b provided on the second component 280b. Alternatively, an engagement convex portion may be provided on the first component 280a and an engagement concave portion may be provided on the second component 280b. The engagement portion 300 may also have a thread cutting structure. The first component 280a and the second component 280b of this modified example can be molded in the same manner as the first component 180a and the second component 180b of Figure 9 .

[0108] Figure 11 is a side view showing the appearance of the first component 280a of Figure 10 . As shown in the figure, on the outer surface 294 of the first part 286a of the shaft portion 286, there are provided an inner concave portion 294a and an inner convex portion 294b extending in a spiral shape. Further, on the inner surface 296 of the surrounding portion 288 of the second component 280b, there are provided an outer convex portion 296a and an outer concave portion 296b extending in a spiral shape corresponding to the inner concave portion 294a and the inner convex portion 294b. By forming the concave and convex portions of the gap 290 of the insulator 280 in a spiral shape, the first component 280a can be inserted into the second component 280b while rotating, and the engaging portions 300 can be engaged with each other. Then, using the same method as Figure 9 the insulator 180 of

[0109] In this modified example, the gap 290 of the insulator 280 is also configured to have a portion that cannot be directly visually recognized from the outside. Therefore, the same effects as those of the above-described embodiment can also be achieved in this modified example.

[0110] Figure 12 is a cross-sectional view showing in detail the structure of the insulator 380 according to still another modified example. The insulator 380 according to this modified example includes a first end portion 82, a second end portion 84, a shaft portion 86, a first surrounding portion 388a, and a second surrounding portion 388b. The first end portion 82, the second end portion 84, and the shaft portion 86 are configured in the same manner as in the above-described embodiment. The first surrounding portion 388a is connected to the first end portion 82 and extends axially from the first end portion 82 toward the second end portion 84. The second surrounding portion 388b is connected to the second end portion 84 and extends axially from the second end portion 84 toward the first end portion 82. A first gap 390a is formed between the shaft portion 86 and the first surrounding portion 388a, and a second gap 390b is formed between the shaft portion 86 and the second surrounding portion 388b. An opening 392 is provided between the first surrounding portion 388a and the second surrounding portion 388b. The first gap 390a and the second gap 390b communicate with the outside of the insulator 380 through the opening 392. The insulator 380 can be integrally formed using three-dimensional printing technology or can be formed by joining a plurality of components.

[0111] In this modified example, the gaps 390a, 390b of the insulator 380 are also configured to have a portion that cannot be directly visually recognized from the outside. Therefore, the same effects as those of the above-described embodiment can also be achieved in this modified example.

[0112] In the above-described embodiments and variations, a case where the insulators 80, 180, 280, 380 are entirely made of the same material is shown. In another embodiment, the plurality of components constituting the insulator may also be made of different materials. In another embodiment, a joining component for joining the plurality of components may also be used. The joining component may also be made of a material different from the material constituting the insulator. The joining component may be made of metal, resin, ceramic, or the like.

[0113] In the above-described embodiment, a case where the insulating structure 74 including the insulators 80, 180, 280, 380 is used for the extraction electrode of the ion generation device 12 is shown. In another embodiment, the insulating structure 74 may also be used at any part of the ion implantation device 10. For example, the insulating structure 74 may be used as a structure provided in the beam stopping device 24, the beam scanning unit 32, the beam parallelization unit 34, the angular energy filter 36, etc. for supporting the electrodes to which a high voltage is applied.

[0114] As described above, the present invention has been described with reference to the above-described embodiments, but the present invention is not limited to the above-described embodiments, and a mode of appropriately combining or replacing the structures of the embodiments also belongs to the present invention. Also, based on the knowledge of those skilled in the art, it is possible to appropriately rearrange the combinations or the order of processing in each embodiment or to add various design changes such as deformation to the embodiments, and an embodiment with such deformation also belongs to the scope of the present invention.

Claims

1. An insulating structure, characterized in that, Comprising: A first end portion; A second end portion; A shaft portion connecting between the first end portion and the second end portion; and A surrounding portion having an inner surface facing the outer surface of the shaft portion and extending from the first end portion toward the second end portion, A gap between the outer surface of the shaft portion and the inner surface of the surrounding portion is configured to communicate with the outside, The outer surface of the shaft portion and the inner surface of the surrounding portion respectively have a concave portion and a convex portion, The inner surface of the surrounding portion has a convex portion provided at a position corresponding to the concave portion of the outer surface of the shaft portion and a concave portion provided at a position corresponding to the convex portion of the outer surface of the shaft portion in a radial direction perpendicular to the direction from the first end portion toward the second end portion, The first end portion, the second end portion, the shaft portion and the surrounding portion are made of an electrically insulating material.

2. The insulating structure according to claim 1, wherein The gap is configured to have a portion that cannot be directly visually recognized from the outside.

3. The insulating structure according to claim 1 or 2, wherein The gap forms a labyrinth structure through the concave portions and convex portions respectively formed on the outer surface of the shaft portion and the inner surface of the surrounding portion.

4. The insulating structure according to claim 1, wherein The concave portion or the convex portion extends in a circumferential direction or in a spiral shape.

5. The insulating structure according to claim 1, wherein The outer surface of the surrounding portion is a cylindrical surface.

6. The insulating structure according to claim 1, wherein The insulating structure has an opening extending in the radial direction, and the gap communicates with the outside through the opening.

7. The insulating structure according to claim 1, wherein The surrounding portion is connected to the first end portion, and an opening is provided between the surrounding portion and the second end portion, and the gap communicates with the outside through the opening.

8. The insulating structure according to claim 6 or 7, wherein The opening is configured such that the opening width becomes larger as it moves away from the shaft portion in the radial direction.

9. The insulating structure according to claim 6 or 7, wherein The gap is configured such that the distance between the outer surface of the shaft portion and the inner surface of the surrounding portion becomes smaller as it moves away from the opening.

10. The insulating structure according to claim 1, wherein The first end portion, the second end portion, the shaft portion and the surrounding portion are made of the same material.

11. The insulating structure according to claim 1, wherein The first end portion, the second end portion, the shaft portion and the surrounding portion are made of a ceramic material or a resin material.

12. An ion generation device, Comprising: an arc chamber having a plasma generation chamber for generating plasma and a front slit; and An extraction electrode series for extracting ions generated in the plasma generation chamber to the outside of the arc chamber via the front slit, The ion generation device is characterized in that The extraction electrode series includes: The first extraction electrode, located downstream of the front slit, is a suppression electrode to which a suppression voltage is applied so as to be at a negative potential with respect to the ground potential; The second extraction electrode, located downstream of the first extraction electrode, is a ground electrode connected to the ground potential; And An insulating structure that supports the first extraction electrode and the second extraction electrode between the first extraction electrode and the second extraction electrode, electrically insulating the first extraction electrode and the second extraction electrode from each other, The insulating structure includes: a first end portion; a second end portion; a shaft portion connecting between the first end portion and the second end portion; and an enclosing portion having an inner surface opposed to an outer surface of the shaft portion and extending from the first end portion toward the second end portion. A gap between the outer surface of the shaft portion and the inner surface of the enclosing portion is configured to communicate with the outside. The outer surface of the shaft portion and the inner surface of the enclosing portion each have a concave portion and a convex portion. The inner surface of the enclosing portion has a convex portion provided at a position corresponding to the concave portion of the outer surface of the shaft portion and a concave portion provided at a position corresponding to the convex portion of the outer surface of the shaft portion in a radial direction perpendicular to the direction from the first end portion toward the second end portion. The first end portion, the second end portion, the shaft portion, and the enclosing portion are made of an electrically insulating material.

13. An ion implantation device, Comprising: an ion generation device; a beam line device for transporting an ion beam extracted from the ion generation device; and an implantation processing chamber for implanting the ion beam output from the beam line device into a workpiece, The ion implantation device is characterized in that, The ion generation device includes: an arc chamber having a plasma generation chamber for generating plasma and a front slit; and an extraction electrode series for extracting ions generated in the plasma generation chamber to the outside of the arc chamber via the front slit, The extraction electrode series includes: The first extraction electrode, located downstream of the front slit, is a suppression electrode to which a suppression voltage is applied so as to be at a negative potential with respect to the ground potential; The second extraction electrode, located downstream of the first extraction electrode, is a ground electrode connected to the ground potential; And An insulating structure that supports the first extraction electrode and the second extraction electrode between the first extraction electrode and the second extraction electrode, electrically insulating the first extraction electrode and the second extraction electrode from each other, The insulation structure includes: a first end portion; a second end portion; a shaft portion connecting between the first end portion and the second end portion; and a surrounding portion having an inner surface facing the outer surface of the shaft portion and extending from the first end portion toward the second end portion. A gap between the outer surface of the shaft portion and the inner surface of the surrounding portion is configured to communicate with the outside. The outer surface of the shaft portion and the inner surface of the surrounding portion respectively have a concave portion and a convex portion. The inner surface of the surrounding portion has a convex portion provided at a position corresponding to the concave portion of the outer surface of the shaft portion and a concave portion provided at a position corresponding to the convex portion of the outer surface of the shaft portion in a radial direction perpendicular to the direction from the first end portion toward the second end portion. The first end portion, the second end portion, the shaft portion, and the surrounding portion are made of an electrically insulating material.

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