JP6595734B1 - Ion implanter, ion source - Google Patents

Abstract

An insulating ring that insulates an ion source tank from a bottom plate is prevented from being broken. A cylindrical first flange 20 is projected from an end 33 of an ion source tank 11 toward a bottom plate 21, and a cylindrical second flange 25 is formed outside the first flange 20. Projecting from the surface 30 of the bottom plate 21 toward the end 33 of the ion source tank 11. The distal end portion of the first flange portion 20 and the distal end portion of the second flange portion 25 are disposed so as to be separated from each other, and the heat rays emitted from the region where the ionization tank 31 in the ion source tank 11 is located are The insulating ring 14 positioned between the end 33 of the ion source tank 11 and the surface 30 of the bottom plate 21 is not directly irradiated, and the insulating ring 14 is not heated. [Selection] Figure 2

Description

  The present invention relates to an ion source that prevents thermal breakdown of an insulating ring and an ion implantation apparatus that uses the ion source.

  An ion implantation apparatus is an apparatus that generates an ion beam in an ion source tank of an ion source, irradiates an irradiation target such as a semiconductor substrate, and injects ions of desired atoms into the irradiation target. There are applications such as changing the properties of the surface of a substance, or injecting a p-type or n-type dopant into a semiconductor to form a pn junction.

  3 indicates a conventional ion source, and an ionization tank 131 is disposed inside a cylindrical ion source tank 111.

  Of the two ends of the ion source tank 111, the bottom plate 121 is airtightly provided at one end by interposing an O-ring (not shown) via an insulating ring 114. When the ion source tank 111 is operated, vacuum exhaust is performed. The apparatus 150 is operated to evacuate the inside of the ion source tank 111 to form a vacuum atmosphere, and the filament 136 disposed inside the ionization tank 131 is energized from the ionization power source 138 to generate heat to emit thermoelectrons. The source gas supplied from the gas source 135 through the pipe 132 to the inside of the ionization tank 131 is irradiated with thermionic electrons to generate ions of the source gas, and the exit side opening 144 is formed using the generated ions as an ion beam. Through the discharge port 112.

  When the emitted ion beam is irradiated onto the irradiation object, ions are injected into the irradiation object.

  In such an ion source using thermoelectrons, the ionization tank 131 is heated by the electron beam or heat ray emitted from the filament 136, and the temperature is raised.

  When the insulation ring 114 is irradiated with the heat rays emitted from the ionization tank 131 whose temperature has been raised, the insulation ring 114 is heated.

  The insulating ring 114 is made of resin, and when the ion beam is strengthened and the temperature of the ionization tank 131 reaches about 800 ° C. in order to improve productivity, the surface of the insulating ring 114 rises to 250 ° C. or more. When the insulating ring 114 is made of resin, the temperature rising part becomes a singular point due to carbonization or the like, and the thermal stress caused by the temperature difference between the ion source tank 111 and the bottom plate 121 is concentrated on this temperature rising part. As a result, crack growth may occur and fracture may occur.

JP 2011-137596 A

  The present invention was created in order to solve the disadvantages of the prior art described above, and it is an object of the present invention to provide a technique for preventing the insulating ring from being broken even when the ionization tank is heated to a high temperature.

In order to solve the above-mentioned problems, the present invention provides an ion source that emits ions generated inside a cylindrical ion source tank as a first ion beam from an emission port; A traveling unit that performs ion acceleration and mass analysis to generate a second ion beam composed of ions having a desired mass-to-charge ratio, and an irradiation object are disposed therein, and the second ion beam is incident thereon. A sample chamber that irradiates the irradiation object, and the ion source includes a bottom plate that hermetically closes an opening at one end of the ion source tank through an insulating ring, and an inside of the ion source tank. An ionization tank disposed and a filament disposed inside the ionization tank, a positive high voltage is applied to the ion source tank, and a negative voltage with respect to the bottom plate is applied to the filament. , the bottom plate Positive high voltage is applied to the serial ion source chamber, the filament is a thermionic by irradiating generates ions of the raw material gas to the raw material gas supplied to the inside of the ionization chamber, the ion source chamber An ion implantation apparatus for emitting the first ion beam from a provided emission port, wherein a flange provided on an outer periphery of the ion source tank and the bottom plate are in airtight contact with the insulating ring, Also, a portion close to the bottom plate is formed into a cylindrical first collar portion protruding toward the bottom plate, and a cylindrical second collar portion larger than the first collar portion is provided on the surface of the bottom plate. The first hook part is set to the same potential as the ion source tank, the second hook part is set to the same potential as the bottom plate, and the first tip and the bottom plate are the tip parts of the first hook part. A first gap is formed between the surface and the first Is the second gap is formed between the second tip is the tip portion of the eaves portion and the flange, the second gap is located in the location closer to the outlet than the first gap, the ionization chamber is located The region to be located is closer to the emission port than the first gap, and is linearly emitted from the region where the ionization tank is located , and the electron beam and the heat ray that have passed through the first gap are It is an ion implantation apparatus that is prevented from passing through the second gap.
In the present invention, the tip of the first collar is inserted into a region surrounded by the second collar, and the first collar and the first gap are between the first gap and the second gap. This is an ion implantation apparatus provided with a portion in which the second hook portion is arranged in a double manner.
The present invention is an ion implantation apparatus in which a cooling pipe is provided on one or both of the bottom plate and the ion source tank.
The present invention includes a cylindrical ion source tank, a bottom plate that hermetically closes an opening at one end of the ion source tank via an insulating ring, an ionization tank disposed in the ion source tank, and the ionization A filament disposed inside the tank, and a positive high voltage is applied to the ion source tank, a negative voltage with respect to the bottom plate is applied to the filament, and the ion source tank is applied to the bottom plate. A positive high voltage is applied to the source gas, and the filament irradiates the source gas supplied to the inside of the ionization tank with thermoelectrons to generate ions of the source gas, and the release gas provided in the ion source tank. an ion source that emits the ion as the first ion beam from the outlet, the flange provided on the outer periphery of the ion source chamber and the bottom plate in contact with the hermetically the insulating ring, than the flange A portion close to the serial bottom plate is in the first overhanging portion of the cylindrical shape projected toward the bottom plate, the second overhanging portion of the large cylindrical shape than the first overhanging portion is provided on the surface of the bottom plate The first hook part is set to the same potential as the ion source tank, the second hook part is set to the same potential as the bottom plate, and the first tip and the surface of the bottom plate are tip parts of the first hook part. A first gap is formed between the second tip and the flange, and the second gap is more than the first gap. The region where the ionization tank is located, located near the discharge port, is located closer to the discharge port than the first gap, and is linearly discharged from the region where the ionization tank is located , The electron beam and the heat ray that have passed through the first gap are prevented from passing through the second gap. It is emissions source.
In the present invention, the tip of the first collar is inserted into a region surrounded by the second collar, and the first collar and the first gap are between the first gap and the second gap. The ion source is provided with a portion in which the two hooks are arranged in a double manner.
The present invention is an ion source in which a cooling pipe is provided in one or both of the bottom plate and the ion source tank.

  Since the heat rays emitted from the ionization tank do not reach the insulating ring, the insulating ring is not thermally destroyed.

  The heat conduction to the insulating ring is reduced by the cooling pipe, and the temperature of the insulating ring is hardly increased.

The figure for demonstrating an example of the ion implantation apparatus of this invention The figure for demonstrating the ion source of this invention Diagram for explaining a conventional ion source

<Ion implantation process>
Reference numeral 2 in FIG. 1 indicates an ion implantation apparatus of the present invention.

  The ion implantation apparatus 2 includes a sample chamber 3, a traveling unit 4, and an ion source 5.

  The traveling unit 4 has a traveling tank 51, and the sample chamber 3 has a sample tank 52. FIG. 2 shows an ion source 5, and the ion source 5 has an ion source tank 11.

  The inside of the ion source tank 11, the inside of the traveling tank 51, and the inside of the sample tank 52 are communicated with each other, and the inside thereof is a vacuum exhaust device connected to the ion source 5 described later or a vacuum connected to the sample tank 52. It is evacuated by an evacuation device to create a vacuum atmosphere.

  In the traveling tank 51, a drawing unit 6, an analysis unit 7, an acceleration unit 8, and a scanning unit 9 are arranged.

  The extraction unit 6 is disposed in a portion of the traveling tank 51 adjacent to the ion source 5, and a plurality of extraction electrodes 53 are provided inside a portion of the traveling tank 51 located at the extraction unit 6. .

  As will be described later, a source gas to be ionized is introduced into the ion source 5 from the gas source 35, and ions of the source gas are generated inside the ion source 5.

  A negative extraction voltage for attracting positively charged ions is applied to the extraction electrode 53, and ions generated inside the ion source 5 are attracted from the ion source 5 by an electric field formed by the extraction electrode 53, and are emitted from the emission port. The ion beam from 12 is emitted into the traveling tank 51 and the ion beam starts traveling inside the traveling tank 51.

  The analyzing unit 7 is arranged in the traveling direction of the ion beam that has started traveling, and a pair of analyzing electromagnets 54a and 54b are provided outside the portion of the traveling tank 51 that is located in the analyzing unit 7.

  The electromagnets 54a and 54b for analysis form a magnetic field having a strength corresponding to the magnitude of the flowing current in the traveling tank 51. The ions in the ion beam incident on the analyzing unit 7 are curved in the traveling direction by the magnetic field formed by the analyzing electromagnets 54a and 54b, and ions having a mass-to-charge ratio corresponding to the strength of the magnetic field pass through the analyzing unit 7.

  An acceleration unit 8 is arranged in the traveling direction of the ion beam composed of ions that have passed through the analysis unit 7, and a plurality of acceleration electrodes 55 are provided inside a portion of the traveling tank 51 that is positioned in the acceleration unit 8. It has been.

  Each acceleration electrode 55 is applied with a positive acceleration voltage with respect to the ground potential, and the ion beam incident on the acceleration unit 8 is accelerated by the acceleration voltage applied to the acceleration electrode 55 while being accelerated. Pass through.

  A scanning unit 9 is arranged in the traveling direction of the ion beam that has passed through the accelerating unit 8, and a scanning device 57 composed of a plurality of electrodes and electromagnets in a portion of the traveling tank 51 located in the scanning unit 9. Is provided.

  An electric field and a magnetic field are formed inside the portion of the traveling tank 51 located at the scanning unit 9 by the scanning device 57, and the traveling direction of the ion beam incident on the scanning unit 9 is bent by the electric field and the magnetic field. It passes through the scanning unit 9.

  A sample tank 52 is arranged in the traveling direction of the ion beam that has passed through the scanning unit 9, and the ion beam is incident on the inside of the sample tank 52 from an incident port 39 that connects the traveling tank 51 and the sample tank 52.

  An irradiation target 59 is arranged in the traveling direction of the incident ion beam, and the irradiation target 59 is irradiated with the ion beam incident on the inside of the sample tank 52.

  The cross-sectional area of the ion beam irradiated to the irradiation target 59 is made smaller than one surface of the irradiation target 59. When the electric field and magnetic field magnitude of the scanning unit 9 is changed, the ion beam irradiation target 59 is changed. The irradiation position is moved, and the ion beam is irradiated onto the entire surface of the irradiation target 59 or a set region. By irradiation with the ion beam, ions contained in the ion beam are implanted into the irradiation target 59 from the surface.

  The traveling tank 51 in the portion where the acceleration unit 8 is located has electrical insulation, and the upstream portion and the downstream portion of the traveling tank 51 are the traveling tank 51 in the portion where the acceleration portion 8 is located. Is insulated by.

A portion of the traveling tank 51 located in the scanning unit 9 downstream of the accelerating unit 8 in the traveling direction of the ion beam and the sample tank 52 are connected to the ground potential. A positive high voltage with respect to the ground potential is applied to the portion where the analysis unit 7 upstream of the ion beam traveling direction, the portion where the extraction unit 6 is located, and the ion source tank 11 are applied to the bottom plate 21. A higher voltage than that of the ion source tank 11 and the traveling tank 51 is applied.
As a result, a high voltage is applied between the bottom plate 21 and the ion source tank 11, and this high voltage is, for example, in the range of about 10 kV to 40 kV, and there is an example of 100 kV depending on the apparatus.

<Ion source>
Referring to FIG. 2, the ion source tank 11 has a cylindrical shape, and of the two ends of the cylindrical shape, a discharge port 12 is provided on the wall surface of one end portion, and on the other bottom surface side. A bottom plate 21 is provided via the insulating ring 14.

  The ion source tank 11 and the bottom plate 21 are electrically insulated by the insulating ring 14. Therefore, the insulating ring 14 is sandwiched between the end of the ion source tank 11 and the bottom plate 21, and is insulated. The ring 14 and the ion source tank 11 are hermetically contacted by interposing an O ring (not shown), and the insulating ring 14 and the bottom plate 21 are hermetically contacted by interposing an O ring (not shown). The internal space 26 of the tank 11 is separated from the atmosphere. The insulating ring 14 may be provided with unevenness in a sectional view of the insulating ring 14 in order to secure a creepage distance and shorten the distance between the ion source tank 11 and the bottom plate 21 and simultaneously reduce the size of the apparatus. . In FIG. 2, which is an embodiment, the insulating ring 14 has a configuration in which one convex portion is provided on the atmosphere side, one convex portion is provided in the center on the vacuum atmosphere side, and a concave portion is provided at each end portion. It is configured to ensure. These uneven portions are the result of considering not only miniaturization but also a decrease in insulation performance due to film deposition or the like, but a plurality of these uneven portions may be provided if necessary.

  The ion source tank 11 is connected to a vacuum evacuation device 50 in which a turbo molecular pump, a cryopump, and the like and a roughing pump are combined. The internal space 26 of the ion source tank 11 is evacuated by the vacuum evacuation device 50. The residual gas in the internal space 26 of the ion source tank 11 is evacuated to form a vacuum atmosphere.

  The inside of the traveling tank 51 and the inside of the ion source tank 11 are connected by the discharge port 12, and the traveling tank 51 is also evacuated by the vacuum exhaust device 50 or other vacuum exhaust device connected to the ion source tank 11. A vacuum atmosphere is also formed inside the traveling tank 51.

  An ionization tank 31 is disposed inside the ion source tank 11. The ionization tank 31 is disposed at a location separated from the two ends of the ion source tank 11 and is fixed to the bottom plate 21 by a member (not shown).

  A tip end portion of a supply pipe 32 is connected to the ionization tank 31, and a base side of the supply pipe 32 is led out of the ion source tank 11 and connected to a gas source 35 (FIG. 1). The bottom plate 21, the supply pipe 32, and the ionization tank 31 are at the same potential. A source gas is disposed in the gas source 35, and the source gas is discharged into the ionization tank 31 from the opening 43 at the tip portion in a state where the flow rate is controlled, and travels inside the ionization tank 31.

  A filament 36 is disposed inside the ionization tank 31.

  An ionization power supply 38 is disposed outside the ion source tank 11, and the filament 36 is electrically connected to the ionization power supply 38, and power is supplied from the ionization power supply 38 to the filament 36. This electric power causes a current to flow through the filament 36, and the filament 36 generates heat to a high temperature.

  A power source is connected between the ionization tank 31 and the filament 36, and a negative voltage is applied to the filament 36 with respect to the ionization tank 31.

  When the filament 36 is heated by energization, thermoelectrons are emitted. The thermoelectrons emitted from the filament 36 are irradiated to the raw material gas traveling inside the ionization tank 31, the raw material gas is ionized, and ions of the raw material gas are generated.

  An exit side opening 44 is formed in the ionization tank 31 at a position facing the discharge port 12.

  Due to the electric field formed by the extraction electrode 53 and entering the inside of the ionization tank 31 from the emission port 12 and the outlet side opening 44, ions inside the ionization tank 31 are attracted to the extraction electrode 53 side and accelerated to be ion beams. It passes through the outlet side opening 44 and is discharged from the discharge port 12 into the traveling tank 51. The emitted ion beam travels inside the traveling tank 51 as described above and is irradiated to the irradiation target 59.

<Insulation ring>
By the way, a part of the heat rays and electron beams emitted from the filament 36 are emitted from the outlet side opening 44 into the ion source tank 11, and the other part is irradiated to the ionization tank 31 to heat the ionization tank 31. The

  In this example, the ionization tank 31 is heated to a temperature of 700 ° C. to 800 ° C., and heat rays are released from the ionization tank 31. Since the filament 36 is located inside the region where the ionization tank 31 is located, and a part of the heat rays of the filament 36 are emitted to the outside of the ionization vessel 31, the heat rays emitted from the region where the ionization vessel 31 is located. Includes both the heat rays emitted from the surface of the ionization tank 31 and the heat rays emitted from the filament 36.

  A part of the heat rays emitted from the region where the ionization tank 31 is located is directed in the direction in which the emission port 12 is located, and the other part is directed to the insulating ring 14 located in the opposite direction.

  In this ion source 5, the end 33 on the bottom plate 21 side of both ends of the ion source tank 11 is formed in a flange shape, and the portion of the end 33 on the bottom plate 21 side that faces the bottom plate 21 has a bottom plate 21. A cylindrical first flange portion 20 protruding toward the end is provided.

  In addition, of the surface 30 exposed to the internal space 26 of the bottom plate 21, the portion facing the end 33 of the ion source tank 11 has a cylindrical shape protruding toward the end 33 of the ion source tank 11. Two hooks 25 are provided.

  The 2nd collar part 25 is made larger than the 1st collar part 20, and is the sum total of the length of the part which the 1st collar part 20 protruded, and the length of the part which the 2nd collar part 25 protruded. The length is longer than the distance between the end portion 33 of the ion source tank 11 and the surface 30 of the bottom plate 21. Therefore, the tip end of the first flange portion 20 is a region surrounded by the second flange portion 25. It is inserted inside, and the part on the edge side of the first collar part 20 and the part on the edge side of the second collar part 25 are arranged so as to overlap by the length of the width B which is the difference in length. Reference numeral 29 indicates an overlapping portion.

  A first gap 27 having a width A is formed between the first tip 34 that is the edge of the first flange 20 and the surface 30 of the bottom plate 21, and the second tip that is the edge of the second flange 25. A second gap 28 having a width C is formed between 37 and the end 33 of the ion source tank 11. The first and second gaps 27 and 28 have a ring shape.

  The ion source tank 11 and the bottom plate 21 are separated by a distance that does not generate discharge in a state where the internal space 26 is in a vacuum atmosphere, and the first and second flange portions 20 and 25 are made of metal, The first collar 20 is set to the same high voltage as the ion source tank 11, the second collar 25 is set to the same potential as the bottom plate 21, and the first collar 20 and the second collar 25 are between They are separated by a distance that does not cause discharge in a vacuum atmosphere. Further, the width A of the first gap 27 and the width C of the second gap 28 are also separated to a size that does not cause discharge in a vacuum atmosphere.

  The region where the ionization tank 31 is located is located closer to the discharge port 12 than the first gap 27. Therefore, one of the heat rays emitted in the direction in which the bottom plate 21 is located from the region where the ionization tank 31 is located. The part can pass through the first gap 27.

  The second gap 28 is located closer to the discharge port 12 than the first gap 27, and the electron beam or heat ray that passes straight through the first gap 27 collides with the surface of the second flange 25 or the bottom plate 21. And cannot pass through the second gap 28. Therefore, the heat rays emitted from the region where the ionization tank 31 is located are not directly applied to the insulating ring 14, and the insulating ring 14 is not easily heated.

  Further, cooling pipes 22 and 23 are respectively wound around the outer periphery of the bottom plate 21 and the outer periphery of the ion source tank 11, and the cooling medium cooled by the cooling device 52 circulates through the cooling pipes 22 and 23, respectively. Then, the bottom plate 21 and the ion source tank 11 are cooled, and the O-ring interposed between the bottom plate 21 and the ion source tank 11 and the insulating ring 14 is set in an allowable temperature range, thereby maintaining the airtight function. Although this is a function necessary as an ion implantation apparatus, it means that the heat flux is directed to the contact surface between the bottom plate 21 and the ion source tank 11 when viewed from the insulating ring 14. That is, when heat is input from the surface of the insulating ring 14 on the vacuum atmosphere side, it is a factor that generates thermal stress based on the temperature difference. However, even if it is this structure, by providing the 1st collar part 20 and the 2nd collar part 25, a surface temperature falls and the thermal stress which leads to destruction does not generate | occur | produce.

  In addition, the 1st collar part 20 and the ion source tank 11 may be formed by integral molding, and you may make it form by attaching the 1st collar part 20 created separately to the ion source tank 11. FIG. Similarly, the second flange 25 and the bottom plate 21 may be integrally formed or may be formed by attachment.

  This configuration is also effective when using the insulating ring 14 having a creepage distance increased by providing unevenness. When heat rays are evenly applied to the surface on the vacuum atmosphere side in FIG. 2, the temperature of the top of the convex portion is highest due to thermal resistance, and stress in the cleavage direction is generated. In the situation shown in FIG. 3, cracks propagated from the top of the convex portion and led to fracture. However, in this configuration (FIG. 2), no crack growth and carbonization of the portion occurring in the case of resin is observed. The effect was confirmed.

2 ... Ion implantation device 3 ... Sample chamber 5 ... Ion source 11 ... Ion source tank 12 ... Ejection port 14 ... Insulating ring 21 ... Bottom plate 27 ... First gap 28 ... Second gap 31 ... ... Ionization tank

Claims (6)

An ion source that emits ions generated inside a cylindrical ion source tank as a first ion beam from an emission port;
A traveling unit that performs acceleration and mass analysis of ions in the first ion beam to generate a second ion beam composed of ions having a desired mass-to-charge ratio;
A sample chamber in which an irradiation object is arranged, and the second ion beam is incident on the irradiation object;
Have
The ion source is
A bottom plate that hermetically closes an opening at one end of the ion source tank through an insulating ring;
An ionization tank disposed inside the ion source tank;
A filament disposed inside the ionization vessel;
Have
A positive high voltage is applied to the ion source tank,
A negative voltage with respect to the bottom plate is applied to the filament,
A positive high voltage is applied to the bottom plate with respect to the ion source tank,
The filament irradiates the source gas supplied to the inside of the ionization tank with thermoelectrons to generate ions of the source gas, and emits the first ion beam from an emission port provided in the ion source tank. An ion implanter,
A flange provided on the outer periphery of the ion source tank and the bottom plate are hermetically contacted with the insulating ring, and a cylindrical first bowl in which a portion closer to the bottom plate than the flange protrudes toward the bottom plate. To be part
On the surface of the bottom plate is provided a second cylindrical flange that is larger than the first flange,
The first collar is set to the same potential as the ion source tank, the second collar is set to the same potential as the bottom plate,
A first gap is formed between the first tip, which is the tip portion of the first collar, and the surface of the bottom plate, and a first gap is formed between the second tip, which is the tip portion of the second collar, and the flange . Two gaps are formed,
The second gap is located closer to the outlet than the first gap, and the region where the ionization tank is located is closer to the outlet than the first gap;
An ion implantation apparatus in which an electron beam and a heat ray, which are linearly emitted from a region where the ionization tank is located and pass through the first gap, are prevented from passing through the second gap. The tip of the first collar is inserted into a region surrounded by the second collar,
2. The ion implantation apparatus according to claim 1, wherein a portion where the first brim part and the second brim part are arranged in a double manner is provided between the first gap and the second gap.   The ion implantation apparatus according to claim 1, wherein a cooling pipe is provided on one or both of the bottom plate and the ion source tank. A cylindrical ion source tank;
A bottom plate that hermetically closes an opening at one end of the ion source tank through an insulating ring;
An ionization tank disposed inside the ion source tank;
A filament disposed inside the ionization vessel;
Have
A positive high voltage is applied to the ion source tank,
A negative voltage with respect to the bottom plate is applied to the filament,
A positive high voltage is applied to the bottom plate with respect to the ion source tank,
The filament irradiates the source gas supplied to the inside of the ionization tank with thermoelectrons to generate ions of the source gas, and the ion is used as a first ion beam from an emission port provided in the ion source tank. An ion source that emits,
A flange provided on the outer periphery of the ion source tank and the bottom plate are hermetically contacted with the insulating ring, and a cylindrical first bowl in which a portion closer to the bottom plate than the flange protrudes toward the bottom plate. To be part
On the surface of the bottom plate is provided a second cylindrical flange that is larger than the first flange,
The first collar is set to the same potential as the ion source tank, the second collar is set to the same potential as the bottom plate,
A first gap is formed between the first tip, which is the tip portion of the first collar, and the surface of the bottom plate, and a first gap is formed between the second tip, which is the tip portion of the second collar, and the flange . Two gaps are formed,
The second gap is located closer to the outlet than the first gap, and the region where the ionization tank is located is closer to the outlet than the first gap;
An ion source that is linearly emitted from a region where the ionization tank is located and that has passed through the first gap and is not allowed to pass through the second gap. The tip of the first collar is inserted into a region surrounded by the second collar,
5. The ion source according to claim 4, wherein a portion where the first brim part and the second brim part are arranged in a double manner is provided between the first gap and the second gap. The ion source according to claim 4, wherein a cooling pipe is provided on one or both of the bottom plate and the ion source tank.

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