JP2008234895A - Ion source and its filament exchange method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ion source and its filament exchange method capable of reducing working time for a filament exchange and improving an operation rate of an ion implanting device, by exchanging a plurality of filaments at the same time. <P>SOLUTION: The ion source 1 is provided with a vacuum box 5 fitted adjacent to a plasma generation vessel 4, a plurality of support arms 7 fitted in the vacuum box 5 and supporting each of a plurality of filaments 3, a gate valve 6 arranged between the vacuum box 5 and the plasma generation vessel 4 and capable of opening/closing and airtightly separating the above, and a vacuum mechanism 9 for making the inside of the vacuum box 5 to be in a vacuum state. The vacuum box 5 is provided with a lid member 8 for releasing air. The gate valve 6 includes an opening part 14 for the support arms 7 and the filaments 3 to freely pass through. The support arms 7 are provided at the vacuum box 5 to make the filaments 3 fitted at tips pass through the opening part 14 of the gate valve in the open state, and move between the vacuum box 5 and the plasma generation vessel 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ion source that has a plurality of filaments that generate thermoelectrons, converts a working gas into plasma by arc discharge in a plasma generation vessel, and extracts an ion beam from the generated plasma, and a method for exchanging the filament.

For example, in the manufacture of a liquid crystal display or a semiconductor device, an ion implanter is used to perform ion implantation into a liquid crystal glass substrate or a semiconductor substrate. The ion implantation apparatus is provided with an ion source for generating plasma and extracting an ion beam.
FIG. 7 is a schematic view showing an example of an ion implantation apparatus having a conventional ion source. An ion source 42 is attached to the processing chamber container 41, and the inside of the processing chamber container 41 and the ion source 42 (more specifically, the plasma generation container 43) is a vacuum exhaust device connected to the processing chamber container 41. The whole is evacuated to vacuum by 44. A processing object 40 such as a substrate is accommodated in the processing chamber container 41.

In this example, the ion source 42 is a bucket type ion source that uses a cusp magnetic field for plasma confinement, and one or more filaments 45 for thermionic emission are disposed in the plasma generation container 43. When a working gas (material gas) is introduced into the plasma generation container 43 to heat the filament 45 and a direct-current arc discharge voltage is applied between the filament 45 and the plasma generation container 43, the filament 45 and the plasma generation container 43 During this period, arc discharge occurs, whereby the working gas is ionized and a plasma 46 is generated. The working gas introduced into the plasma generation container 43 is a gas containing a desired ion species. For example, PH ₃ is used to obtain phosphorus ions, and B ₂ H ₆ is used to obtain boron ions.

  A large number of permanent magnets 47 provided around the plasma generation container 43 form a cusp magnetic field (multi-polar magnetic field) and contribute to confinement of the plasma 46. An ion beam 49 is extracted from the plasma 46 by an extraction electrode system 48 having one or more electrodes. In this example, the ion beam 49 is applied to the object 40 to be processed such as ion implantation.

  By the way, in the ion source 42, since the filament 45 for performing arc discharge deteriorates and breaks with accumulation of the operation time of the ion implantation apparatus, it is necessary to replace the filament 45. Conventionally, the filament 45 needs to be exchanged by returning the plasma generation container 43 to atmospheric pressure and releasing the ion source 42. The vent gas (clean air or nitrogen gas) is introduced into the plasma generation container 43 and the processing chamber container 41 connected thereto. Etc.) was returned to the atmospheric pressure, but because the volume was large, a relatively long time was required, and the operation stop time of the apparatus became long, resulting in a decrease in the operation rate. An ion source and a filament exchange method for solving such a problem are disclosed in Patent Document 1 below.

  FIG. 8 is a diagram showing the configuration of the ion source 50 of Patent Document 1. In FIG. The ion source 50 is provided in a vacuum box 51 provided adjacent to the plasma generation chamber 52, a gate valve 53 that opens and closes the vacuum box 51 and the plasma generation chamber 52 in an airtight state, and the vacuum box 51. The filament 54 passes through the gate valve 53 in an open state, supported by the vacuum box 51 at the base end portion and supported by the vacuum box 51 at the base end portion, and passes through the vacuum box 51 and the plasma generation chamber 2. A support arm 55 that operates to move between the inside, a lid member 56 for opening the vacuum box 51, and an atmospheric suction means 57 for making the inside of the vacuum box 51 in a vacuum state after filament replacement. Yes.

  When the filament 54 is replaced in the ion source 50 configured as described above, the support arm 55 is rotated by 90 ° in the vacuum box 51 and the filament 54 supported at the tip of the support arm 55 is replaced with the gate valve 53. And the gate valve 53 is closed, the lid member 56 of the vacuum box 51 is opened and the filament 54 is replaced, and then the lid member 56 is closed and the atmospheric suction means 57 is used. After the vacuum box 51 is evacuated, the gate valve 53 is opened, the support arm 55 is rotated by 90 ° in the direction of the plasma generation chamber 52, and the filament 54 is moved into the plasma generation chamber 52. Therefore, the filament 54 can be replaced in a short time without opening the plasma generation chamber 52 to the atmosphere.

JP 2002-343265 A

However, the prior art of Patent Document 1 has the following problems.
In the ion source, a plurality of filaments are usually provided instead of one. At the time of filament replacement, in order to reduce the number of replacement operations, not only the filament that has been cut is replaced, but all the used filaments are taken out and replaced with new ones. For this reason, the same number of replacement operations as the number of filaments have occurred. For example, when four filaments are provided, it is necessary to repeat the replacement operation described above four times. If the filament replacement work becomes long, the apparatus stop time accompanying it becomes long, which causes a problem that the operation rate is lowered.

  The present invention has been made in view of the above-described problems, and by replacing a plurality of filaments at the same time, the filament replacement work time can be shortened, and the ion source capable of improving the operating rate of the ion implantation apparatus and the filament replacement thereof It is an object to provide a method.

In order to solve the above problems, the ion source and the filament exchange method of the present invention employ the following means.
(1) The present invention has a plasma generation container for generating plasma therein, emits thermoelectrons from a plurality of filaments in the plasma generation container, generates plasma, and extracts an ion beam from the generated plasma. A vacuum box provided adjacent to the plasma generation vessel, a plurality of support arms provided in the vacuum box and supporting the plurality of filaments at their tips, the vacuum box, and the plasma An openable / closable gate valve disposed between the generation container and airtightly separating the two; and a vacuum mechanism for evacuating the vacuum box; A member is provided, and the gate valve has an opening through which the support arm and the filament can pass, and the support arm The filament provided at the tip is provided in the vacuum box so as to pass between the opening of the gate valve in the open state and move between the vacuum box and the plasma generation vessel. And

  According to the above configuration, by operating the plurality of support arms, the plurality of filaments are moved into the vacuum box, the gate valve is closed, and then the vacuum box is opened to remove the plurality of filaments and the plasma generation container from the atmosphere. They can be replaced at the same time without opening. Therefore, since the filament replacement operation can be performed in a short time, the operating rate of the ion implantation apparatus can be improved.

(2) In the ion source, the plurality of support arms are provided on the side wall connected to the plasma generation container of the vacuum box so as to be rotatable with respect to the side wall.

  According to the above configuration, by moving the support arm, the filament can be easily moved between the plasma generation container and the vacuum box, so that the filament exchange operation is simplified.

(3) In the above ion source, at least two of the plurality of support arms are provided on the same side wall of the vacuum box, and each other even if they rotate in a direction approaching each other. The shape and arrangement are set so as to be accommodated in the vacuum box without mechanical interference.

  According to the above configuration, even if the two support arms rotate in a direction approaching each other, they are accommodated in the vacuum box without mechanical interference with each other, so that the area necessary for the operation of the support arms can be reduced. The vacuum box can be made compact.

(4) In the ion source described above, the distance between the position where the two support arms are supported on the side wall of the vacuum box and the plasma generation vessel are different from each other.

  According to the above configuration, when the two support arms are rotated and accommodated in the vacuum box, the positions of the two support arms from the plasma generation container are different from each other. The support arm does not get in the way, and the replacement work can be performed smoothly.

(5) In the above ion source, the vacuum box has side walls facing each other at an interval, and a plurality of the support arms are provided on each of the facing side walls.

  According to the above configuration, at least four filaments can be exchanged simultaneously in one exchanging operation, and the filament exchanging time can be further shortened.

(6) In the above ion source, a rotation transmission mechanism that rotates the plurality of support arms in conjunction with each other is provided in the vacuum box.

  According to the above configuration, since the plurality of support arms rotate in conjunction with each other, the movement of the plurality of filaments between the plasma generation container and the vacuum box can be performed simultaneously.

(7) The present invention also includes a plasma generation container that generates plasma therein, emits thermoelectrons from a plurality of filaments in the plasma generation container, generates plasma, and generates an ion beam from the generated plasma. A method for exchanging a filament of an ion source to be drawn, wherein a plurality of support arms whose base ends are supported in a vacuum box provided adjacent to the plasma generation container are operated to thereby support filaments supported by the support arms. And after passing through an openable / closable gate valve that hermetically partitions the plasma generation vessel and the vacuum box, the gate is closed and the vacuum box is returned from the vacuum state to a predetermined pressure. The lid member provided in the vacuum box is opened to exchange the plurality of filaments, and then the lid member is Umate, After the inside the vacuum box is evacuated by opening the gate valve, the plurality of support arms is actuated to move the plurality of filaments to the plasma production chamber, characterized in that.

  According to the present invention, by exchanging a plurality of filaments simultaneously, the filament replacement work time can be shortened, and an excellent effect that the operating rate of the ion implantation apparatus can be improved is obtained.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

[First Embodiment]
1 is a perspective view showing an ion source 1 according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view showing a state during operation of the ion source according to the present embodiment, and FIG. It is III sectional drawing.

First, the basic configuration of the ion source 1 will be described.
The ion source 1 has a plasma generation container 4 in which a plasma generation chamber 2 is formed. The inside of the plasma generation container 4 is filled with working gas (material gas) injected from a working gas injection unit (not shown). The working gas is a gas containing a desired ionic species, such as PH ₃ or B ₂ H ₆ .

  A filament 3 serving as a cathode electrode for arc discharge is disposed on the upper part of the plasma generation vessel 4. The anode electrode for arc discharge is provided in an annular shape along the side wall of the plasma generation vessel 4. Magnets for forming a magnetic field for confining plasma are provided in multiple stages on the side wall of the plasma generation vessel 4.

  An extraction electrode system for accelerating ions is provided below the plasma generation container 4. This extraction electrode system is a grid electrode having a large number of holes through which an ion beam passes. A processing chamber communicating with the plasma generation chamber 2 is provided outside the extraction electrode, and a processing object such as a substrate, which is an irradiation target of the ion beam, is placed in the processing chamber. A vacuum evacuation unit is connected to the processing chamber, and the processing chamber and the plasma generation chamber 2 communicating with the processing chamber are evacuated by the vacuum evacuation unit.

  The ion source 1 configured as described above operates as follows. When a working gas (material gas) is introduced into the plasma generation chamber 2, the filament 3 is heated and a DC arc discharge voltage is applied between the filament 3 and the plasma generation vessel 4, the filament 3 and the plasma generation vessel 4 Arcing occurs in between, thereby ionizing the working gas and generating a plasma. An ion beam is extracted by the extraction electrode system, and the object to be processed placed in the processing chamber is irradiated to perform processing such as ion implantation. The basic configuration of the ion source 1 described above is the same as that of the prior art.

Next, a specific configuration of the ion source 1 according to the present embodiment will be described.
The ion source 1 includes a vacuum box 5 provided adjacent to the plasma generation container 4, two support arms 7 provided in the vacuum box 5 and supporting the two filaments 3 at the tip, and a vacuum box 5. And an openable / closable gate valve 6 that is disposed between the plasma generation container 4 and the plasma generation container 4, and a vacuum mechanism 9 for evacuating the vacuum box 5.

  The vacuum box 5 is formed in a rectangular parallelepiped shape, and is arranged on the upper part of the plasma generation container 4 so as to cover the gate valve 6 serving as the introduction part of the filament 3. The vacuum box 5 is provided with a lid member 8 for opening to the atmosphere. The lid member 8 is formed in the upper part of the vacuum box 5 and can partition the inside and outside of the vacuum box 5 in an airtight state. The formation position of the lid member 8 is not limited to the upper part of the vacuum box 5 and may be a side portion as long as the filament 3 can be replaced.

  The gate valve 6 includes an opening 14 formed in a portion of the upper wall of the plasma generation vessel 4 covered with the vacuum box 5 and a closing plate 15 that closes the opening 14. The opening 14 is formed in a long hole shape so that the support arm 7 and the filament 3 can pass therethrough. The filament 3 passes through the opening 14 and moves between the plasma generation vessel 4 and the vacuum box 5. The closing plate 15 is formed in the same shape as the opening 14, and hermetically partitions the plasma generation chamber 2 and the vacuum box 5.

  A rotating rod 17 for moving the closing plate 15 to open and close the opening 14 is spanned between both side walls 16 in the vacuum box 5. The closing plate 15 is integrally fixed to the rotating rod 17 via a bracket 19. At least one of the rotating rods 17 penetrates the side wall 16 in an airtight state and protrudes to the outside. The protruding portion is operated to rotate the rotating rod 17 and move the closing plate 15.

  The support arm 7 is provided in the vacuum box 5 so that the filament 3 provided at the tip is moved between the vacuum box 5 and the plasma generation vessel 4 through the opening 14 of the gate valve 6 in the open state. ing. The support arm 7 includes a pair of pipes 7a and 7a formed in an L shape. The pipe 7a is composed of a first portion 71 extending from the proximal end portion into the vacuum box 5 and a second portion 72 that is bent at a right angle from the distal end of the first portion 71 and extends toward the plasma generation vessel 4 (see FIG. 3), and a conductive wire connected to the filament 3 is inserted therein.

  The two support arms 7 are provided on the same side wall 20 with an interval in the arrangement direction of the two filaments 3 in the plasma generation chamber 2 (left-right direction in FIG. 2). The base end portion of the support arm 7 is supported by a rotating plate 22 provided on the side wall 20 of the vacuum box 5. The rotating plate 22 is formed in a disk shape, rotates while maintaining an airtight state with respect to the side wall 20, and penetrates the conductive wire connected to the filament 3 in an airtight state. The filament 3 is stretched around the ends of the pair of support arms 7.

  When the tip of the support arm 7 faces downward, the filament 3 is positioned in the plasma generation chamber 2 and rotates so that the filament 3 does not contact the periphery of the opening 14 when the rotating plate 22 rotates. When the tip is directed to the side (when the support arm 7 is accommodated in the vacuum box 5), the length is such that the filament 3 does not contact the inner wall of the vacuum box 5. The two support arms 7 are accommodated in the vacuum box 5 by rotating in a direction approaching each other. For this reason, even if it rotates as mentioned above, a shape and arrangement | positioning are set so that it may be accommodated in the vacuum box 5, without mutually interfering mechanically.

  Specifically, as shown in FIG. 3, when the two support arms 7 rotate and move into the vacuum box 5, the second portion 72 of the pipe 7 a does not mechanically interfere with each other. The length of the first portion 71 is different between the two support arms 7 and 7. For this reason, the positions of the second portions 72 of the two support arms 7 are offset with a distance a in the direction of the rotation axis.

  The distance between the position where the two support arms are supported on the side wall 20 of the vacuum box 5 and the plasma generation vessel 4 (the height at which the base end of the support arm 7 is supported in FIG. 2) is the same. There may be, but it is preferable that they are different as shown in FIG. In the present embodiment, when the rotation center positions of the two support arms 7 are used as a reference, there is a height difference of the distance h with respect to the distance to the plasma generation container 4. The effect will be described later.

  The vacuum mechanism 9 includes an atmospheric suction pipe 23 opened and connected to the inside of the vacuum box 5, an on-off valve 24 connected in the middle of the atmospheric suction pipe 23, and a suction device 25 such as a blower (see FIG. 2). It consists of and.

  The vacuum box 5 is connected to a return pressure mechanism 26 for returning the inside of the vacuum box 5 to almost atmospheric pressure. The return pressure mechanism 26 is connected to a gas cylinder (not shown) serving as a supply source of a vent gas 29 (clean air, nitrogen gas, etc.) that is a return pressure gas, and the vent gas 29 from the gas cylinder that is connected to the inside of the vacuum box 5 while being opened. 5 and a vent valve 28 connected in the middle of the vent gas introduction pipe 27.

  The two support arms 7 may be configured to rotate independently of each other. However, as shown in FIG. 4, it is preferable to provide a rotation transmission mechanism 30 that rotates the two support arms 7 together. FIG. 4 is a perspective view of the vacuum box 5 as seen from the base end side of the support arm 7. The rotation transmission mechanism 30 shown in FIG. 4 is a rotation gear mechanism, and includes an output gear 31 fixed to each of the two support arms 7, and intermediate gears 32a, 32b, 32c, 32d disposed between the output gears 31. It consists of The intermediate gears 32a, 32b, 32c, 32d are provided so that the two support arms 7 rotate in opposite directions (that is, even numbers). One intermediate gear 32a is provided with a rotation operation shaft 33. By rotating the rotation operation shaft 33, the rotational force is transmitted, and the two support arms 7 can be rotated in opposite directions. The rotation operation shaft 33 may be manually rotated, but the support arm 7 can be easily moved by rotating it using a drive source such as a motor. The rotation transmission mechanism 30 is not limited to the rotation gear mechanism, and may be another transmission mechanism such as a link mechanism.

  Next, the filament replacement method of the ion source 1 having the above configuration will be described.

  First, after stopping the operation, as shown in FIG. 5A, the rotating plate 22 is rotated by 90 degrees to rotate the two support arms 7 in the opposite directions so as to approach each other. As a result, the filament 3 supported at the tip of the support arm 7 moves into the vacuum box 5 through the opening 14 of the gate valve 6 that opens and closes the plasma generation chamber 2 and the vacuum box 5 in an airtight state. Will be housed.

  Thereafter, as shown in FIG. 5B, the rotating rod 17 is rotated to fit the closing plate 15 into the opening 14, and the plasma generation chamber 2 and the vacuum box 5 are partitioned in an airtight state.

  Then, after the return pressure mechanism 26 introduces the vent gas 29 into the vacuum box 5 and returns only the vacuum box 5 to a predetermined pressure (substantially atmospheric pressure), as shown in FIG. Open and replace the filament 3 at the tip of the support arm 7.

  After the replacement, after cleaning the inside of the vacuum box 5, the lid member 8 is closed, the air in the vacuum box 5 is sucked out by the vacuum mechanism 9, the on-off valve 24 is closed, and the inside of the vacuum box 5 is brought into a vacuum state. return. Then, the gate valve 6 is opened to allow the vacuum box 5 and the plasma generation chamber 2 to communicate with each other. Thereafter, the rotating plate 22 is rotated 90 degrees so that the support arm 7 faces the plasma generation chamber 2, and the filament 3 is moved into the plasma generation chamber 2, and the replacement operation of the filament 3 is completed.

  According to the above-described embodiment, by operating the two support arms 7, the two filaments 3 are moved into the vacuum box 5, the gate valve 6 is closed, and then the vacuum box 5 is opened. The two filaments 3 can be exchanged at the same time without opening the plasma generation container 4 to the atmosphere. For this reason, since the filament replacement work can be performed in a short time, the operating rate of the ion implantation apparatus can be improved.

  Moreover, since the filament 3 can be easily moved between the plasma generation vessel 4 and the vacuum box 5 by rotating the support arm 7, the filament exchange operation can be easily performed.

  In addition, since the positions of the second portions 72 of the two support arms 7 are offset with a distance a in the direction of the rotation axis, even if the two support arms 7 rotate in the direction approaching each other, It can be accommodated in the vacuum box 5 without mechanical interference. Therefore, the area required for the operation of the support arm 7 can be reduced, and the size of the vacuum box 5 can be made compact.

  Further, by providing a height difference h at the installation position of the two support arms 7, when the two support arms 7 are rotated and accommodated in the vacuum box 5, the two support arms 7 from the plasma generation vessel 4 are provided. Since the positions of are different from each other, when one filament 3 is exchanged, the other support arm 7 does not get in the way, and the exchange operation can be performed smoothly.

  Further, since the two support arms 7 rotate in conjunction with each other by the rotation transmission mechanism 30, the two filaments 3 can be moved simultaneously between the plasma generation vessel 4 and the vacuum box 5.

  Note that the number of support arms 7 provided in the vacuum box 5 may be three or more, and in this case, the shape and the arrangement are set so as to fit in the vacuum box 5 without mechanically interfering with each other. In addition, when there are three or more support arms 7, it is preferable that the three or more support arms 7 rotate in conjunction with the rotation transmission mechanism 30.

[Second Embodiment]
FIG. 6 is a perspective view showing an ion source 1 according to the second embodiment of the present invention. In the present embodiment, four support arms 7 are provided in the vacuum box 5.
Two support arms 7 are provided on each side wall 20, 21 facing each other in the vacuum box 5, and one gate valve 6 is provided for each of the two support arms 7 on each side. That is, in this embodiment, two sets of two support arms 7 and one gate valve 6 are provided for one vacuum box 5. The configuration of each pair of support arm 7 and gate valve 6 is the same as that of the first embodiment.

A filament replacement method for the ion source 1 according to the present embodiment will be described.
After stopping the operation, the four support arms 7 are rotated, and the filaments 3 supported by the respective support arms 7 are passed through the gate valves 6 provided corresponding to the respective groups and are put into the vacuum box 5. Move. Thereafter, the gate valve 6 is closed, and the return pressure mechanism 26 returns the inside of the vacuum box from a vacuum state to a predetermined pressure (substantially atmospheric pressure), and then the lid member 8 of the vacuum box 5 is opened to replace the four filaments 3. To do. After the filament 3 is replaced, the lid member 8 is closed and the vacuum box 5 is evacuated by the vacuum mechanism 9, then the gate valve 6 is opened, the four support arms 7 are rotated, and the four filaments 3 are turned into plasma. Move into the production container 4. Thereby, the replacement | exchange operation | work of the filament 3 is complete | finished.

  According to the above-described embodiment, the four filaments 3 can be exchanged simultaneously by one exchange operation, and the filament exchange operation can be further shortened. Note that the number of support arms 7 provided in the vacuum box 5 may be five or more, and in this case, the shape and the arrangement are set so as to fit in the vacuum box 5 without mechanically interfering with each other.

  Although the embodiments of the present invention have been described above, the embodiments of the present invention disclosed above are merely examples, and the scope of the present invention is not limited to these embodiments. . The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

It is the perspective view which showed the ion source concerning 1st Embodiment of this invention. It is sectional drawing which showed the state at the time of the driving | operation of the ion source concerning 1st Embodiment of this invention. It is the III-III sectional view taken on the line of FIG. It is the perspective view which showed the rotation transmission mechanism of the ion source concerning 1st Embodiment of this invention. It is a figure explaining the filament exchange method of the ion source concerning 1st Embodiment of this invention. It is the perspective view which showed the ion source concerning 2nd Embodiment of this invention. It is the schematic which shows an example of the ion implantation apparatus provided with the conventional ion source. It is the perspective view which showed the structure of the ion source of patent document 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ion source 2 Plasma generation chamber 3 Filament 4 Plasma generation container 5 Vacuum box 6 Gate valve 7 Support arm 7a Pipe 71 1st site | part 72 2nd site | part 8 Lid member 9 Vacuum mechanism 14 Opening part 15 Closure board 16, 20, 21 Side wall Reference Signs List 17 Rotating rod 19 Bracket 22 Rotating plate 23 Atmospheric suction pipe 24 Opening / closing valve 25 Suction device 26 Return pressure mechanism 27 Vent gas introduction pipe 28 Vent valve 29 Vent gas 30 Rotation transmission mechanism 31 Output gears 32a, 32b, 32c, 32d Intermediate gear 33 Rotating operation axis

Claims (7)

An ion source having a plasma generation container for generating plasma therein, emitting thermoelectrons from a plurality of filaments in the plasma generation container to generate plasma, and extracting an ion beam from the generated plasma,
A vacuum box provided adjacent to the plasma generation container; a plurality of support arms provided in the vacuum box for supporting the plurality of filaments at their tips; and between the vacuum box and the plasma generation container An openable / closable gate valve that is arranged in an airtight manner, and a vacuum mechanism for making the inside of the vacuum box a vacuum state,
The vacuum box is provided with a lid member for opening to the atmosphere, the gate valve has an opening through which the support arm and filament can pass, and the support arm has a filament provided at the tip, An ion source provided in the vacuum box so as to move between the vacuum box and the plasma generation container through an opening of the gate valve in an open state.   The ion source according to claim 1, wherein the plurality of support arms are provided on a side wall connected to the plasma generation container of the vacuum box so as to be rotatable with respect to the side wall.   At least two support arms of the plurality of support arms are provided on the same side wall of the vacuum box, and do not mechanically interfere with each other even if they rotate in a direction approaching each other. The ion source according to claim 2, wherein the shape and arrangement are set so as to be accommodated in the ion source.   The ion source according to claim 3, wherein the distance between the position where the two support arms are respectively supported on the side wall of the vacuum box and the plasma generation container are different from each other.   5. The ion source according to claim 2, wherein the vacuum box has side walls facing each other at an interval, and a plurality of the support arms are provided on each of the facing side walls.   The ion source according to claim 1, wherein a rotation transmission mechanism that rotates the plurality of support arms in conjunction with each other is provided in the vacuum box. An ion source filament exchange method that includes a plasma generation vessel that generates plasma therein, emits thermoelectrons from a plurality of filaments within the plasma generation vessel, and generates an ion beam from the generated plasma. And
A plurality of support arms whose base end portions are supported in a vacuum box provided adjacent to the plasma generation container are operated, and the filaments supported by the support arms are sealed between the plasma generation container and the vacuum box. After passing through an openable / closable gate valve that is partitioned into the vacuum box, the gate valve is closed, the vacuum box is returned from a vacuum state to a predetermined pressure, and then a lid member provided in the vacuum box is Open and replace the plurality of filaments, and then close the lid member and evacuate the vacuum box, then open the gate valve and operate the plurality of support arms to remove the plurality of filaments. A method for exchanging filaments of an ion source, wherein the filaments are moved into the plasma generation vessel.

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