JP6890084B2 - High voltage potential plasma generator and ion source - Google Patents

Description

An embodiment of the present invention relates to a high voltage potential plasma generator and an ion source using a vacuum chamber having a high voltage portion inside.

In the case of a plasma generator and an ion source that use a vacuum chamber having a high voltage section inside, the high voltage section causes an electrical short circuit between the high voltage section where plasma is generated and the inner wall of the vacuum chamber via plasma. The form of the high-voltage plasma generation chamber is such that plasma does not leak out.

JP-A-2009-37764

In the above-mentioned closed high-voltage plasma generation chamber, in order to prevent plasma from leaking from the high-voltage portion, it is not possible to positively provide a large exhaust port inside the chamber for vacuum exhaust. Therefore, it is difficult to continuously and stably generate plasma having certain characteristics. On the other hand, if the exhaust port is provided in the closed container, as described above, an electrical short circuit is caused between the high voltage portion and the inner wall of the vacuum chamber via the plasma.

An object of the present invention is to obtain a high voltage potential plasma generator and an ion source having a long path to suppress a short circuit due to plasma and having a simplified exhaust path.

The high-voltage potential plasma generator according to the present embodiment is installed in a high-voltage potential plasma generation container that is installed inside the vacuum chamber via an insulating material and whose inside is vacuum-exhausted, and in the high-voltage potential plasma generation container. It is composed of a target as a plasma component material, and the inside of the high voltage potential plasma generation container and the inside of the vacuum chamber are communicated by a bent exhaust path, and the bent exhaust path is an opening of the high voltage potential plasma generation container. The high-voltage potential plasma generation container lid is formed by forming a predetermined gap with the portion and arranged in the high-voltage potential plasma generation container, and the high-voltage potential plasma generation container lid is the high-voltage potential plasma generation container lid of the high-voltage potential plasma generation container lid. It is characterized in that a predetermined gap is formed with the opening of the high voltage potential plasma generation container by an inner surface or a position adjusting device attached to the high voltage potential plasma generation container.
Further, the high-voltage potential plasma generator according to the present embodiment is installed in a high-voltage potential plasma generation container which is installed inside the vacuum chamber via an insulating material and whose inside is vacuum-exhausted, and in the high-voltage potential plasma generation container. It is composed of a target that becomes a plasma component material, and the inside of the high voltage potential plasma generation container and the inside of the vacuum chamber are communicated by a bent exhaust path, and the bent exhaust path has an insulating material inside the vacuum chamber. A high-voltage potential plasma generation container having an opening formed through which the inside is vacuum-exhausted, and a high-voltage potential plasma generation container installed with a predetermined gap formed through a stage stand column in the high-voltage potential plasma generation container. It is characterized by being formed by a stage.

The ion source according to the present embodiment is characterized in that an ion extraction electrode is connected to or internally supported by the high voltage potential plasma generator.

The embodiment of the present invention has been made to solve the above-mentioned problems, and it is possible to take a long exhaust path from the inside of the high-voltage potential plasma generation container to the vacuum chamber which is the ground potential, and the volume of the exhaust path is large. The high-density plasma generated inside the high-voltage potential plasma generator becomes sufficiently low in plasma density or ion electron regeneration by the time it reaches the inside of the vacuum chamber from the high-voltage potential plasma generator. Neutralized by binding. Therefore, it is possible to prevent a short circuit between the high voltage potential plasma generation container and the inner wall surface of the vacuum chamber which is the ground potential.

The side view which shows the high voltage potential plasma generation apparatus which concerns on Example 1. FIG. The side view which shows the high voltage potential plasma generation apparatus which concerns on Example 2. FIG. FIG. 5 is a plan sectional view showing a high voltage potential plasma generator according to the third embodiment. The side view which shows the ion source which concerns on Example 4. FIG.

(Example 1)
Example 1 of the present invention will be described with reference to FIG. In FIG. 1, a high-voltage potential plasma generation container 3 connected to a high-voltage portion 9 via an insulating porcelain 2 which is an insulating material is installed inside the vacuum chamber 1 constituting the high-voltage potential plasma generation device 40. There is. A target 4 serving as a plasma component material is installed in the high-voltage potential plasma generation container 3, and a plasma generation point 5 is formed on the surface thereof. The target 4 may be not only a solid but also a gas.

Regarding the plasma generation point 5, plasma generation by condensing a laser guided from the outside of the vacuum chamber 1 onto the solid surface of the target 4, or ionization of microwave gas vapor guided from the outside of the vacuum chamber 1 in the same manner. It is formed by plasma generation by. On the upper part of the high-voltage potential plasma generation container 3, hooks 7, which are position adjusting devices, are attached at several points on the inner surface thereof, and are bent to block a passage linearly connected to the opening of the high-voltage potential plasma generation container 3. A high-voltage potential plasma generation container lid 6 is placed by forming a predetermined gap around the exhaust path (maze structure) 30. The hook 7 may be attached to the outer wall or opening of the high-voltage potential plasma generation container 3 instead of the inside of the high-voltage potential plasma generation container lid 6. The inside of the high-voltage potential plasma generation container 3 in which plasma is generated is evacuated through the exhaust path 8. Any position adjusting device that can change the size and length of the hook 7 may be used, and shapes such as bolts and nuts can be substituted. By adjusting the position of the hook 7, the volume of the exhaust path including the opening of the high-voltage potential plasma generation container 3 and the gap formed by the high-voltage potential plasma generation container lid 6 can be adjusted.

As described above, the high-density plasma generated from the target 4 inside the high-voltage potential plasma generation container 3 has a long exhaust path through the gap between the high-voltage potential plasma generation container 3 and the high-voltage potential plasma generation container lid 6. Therefore, the plasma density becomes sufficiently low or neutralized by ion-electron recombination by the time the high-voltage potential plasma generation container 3 reaches the inside of the vacuum chamber 1. Therefore, it is possible to prevent a short circuit between the high voltage potential plasma generation container 3 and the inner wall surface of the vacuum chamber 1 which is the ground potential. Further, since the gap between the wall (high voltage potential) of the high voltage potential plasma generation container 3 and the lid 6 of the high voltage potential plasma generation container 3 extends over the entire outer periphery of the opening of the high voltage plasma generation container 3, the exhaust efficiency is improved. Can be made to.

Although described in the embodiment in which the opening of the high-voltage potential plasma generation container 3 is at the top, this opening can also be provided on the side surface or the bottom.

(Example 2)
Example 2 of the present invention will be described with reference to FIG. In FIG. 2, the same parts as those in FIG. 1 are designated by the same reference numerals, and the description of the configuration will be omitted.

In FIG. 2, a high-voltage potential plasma generation container 10 having an opening 13 formed at a lower portion via an insulator 2 is installed inside a vacuum chamber 1 constituting the high-voltage potential plasma generation device 41. A high-voltage stage 12 is installed at the inner bottom of the high-voltage potential plasma generation container 10 via a stage stand column 11. The high-voltage potential plasma generation container 10, the high-voltage stage stand 12, and the stage stand support 11 are set to have the same potential. A target 4, which is a plasma component material, is installed on the stage of the high-voltage stage table 12, and a plasma generation point 5 is formed on the surface thereof. The target 4 can be not only a solid but also a gas.

Regarding the plasma generation point 5, plasma generation by condensing a laser guided from the outside of the vacuum chamber 1 onto the solid surface of the target 4, or ionization of microwave gas vapor guided from the outside of the vacuum chamber 1 in the same manner. It is formed by plasma generation by. The inside of the high-voltage potential plasma generation container 10 in which plasma is generated is evacuated through the exhaust path 8. The second embodiment is a form in which the exhaust path 8 serving as the bent exhaust path (maze structure) 31 of the first embodiment is provided at the bottom of the high voltage potential plasma generation container 10.

As described above, the high-voltage plasma inside the high-voltage potential plasma generation container 10 is exhausted from the bottom plate opening 13 by the stage stand column 11 via the high-voltage stage 12 and the bottom plate of the high-voltage potential plasma generation container 10. Will be done.

Through the exhaust path 8 described above, the high-voltage plasma has a sufficient plasma density to reach the inside of the vacuum chamber 1 from the high-voltage portion composed of the high-voltage potential plasma generation container 10, the high-voltage stage stand 12, and the like. It becomes low or neutralized by ionic electron recombination. Therefore, it is possible to prevent a short circuit between the high voltage portion including the high voltage potential plasma generation container 10, the high voltage stage base 12, and the inner wall surface of the vacuum chamber 1 which is the ground potential. Further, since the gap between the wall (high voltage potential) of the high voltage potential plasma generation container 10 and the high voltage stage 16 extends over the entire inner circumference of the high voltage potential plasma generation container 13, the exhaust efficiency can be improved. ..

Although described in the embodiment in which the opening of the high voltage potential plasma generation container 3 is set as the lower part, this opening can also be provided on the side surface or the upper part.

(Example 3)
Example 3 of the present invention will be described with reference to FIG. FIG. 3 shows a plan sectional view of Example 1 or Example 2 as viewed from above. In FIG. 3, the same parts as those in FIGS. 1 and 2 are designated by the same reference numerals, and the description of the configuration will be omitted.

In FIG. 3, a high-voltage potential plasma generation container 3 is installed inside the vacuum chamber 1 constituting the high-voltage potential plasma generation device 42 via an insulator 2. The high-voltage potential plasma generation container 3 is configured to include a high-voltage potential plasma generation container inner wall 14 and a high-voltage potential plasma generation container outer wall 15.

As described above in Example 1 or 2, the target 4 is installed inside the high-voltage potential plasma generation container 3, and the plasma generation point 5 is formed on the surface thereof. The target 4 may be a gas as well as a solid. Regarding the plasma generation point 5, plasma generation by condensing a laser guided from the outside of the vacuum chamber 1 onto the solid surface of the target 4, gas or steam of gas or steam by microwaves guided from the outside of the vacuum chamber 1 to gas or steam. It is formed by plasma generation due to ionization. The plasma at the plasma generation point 5 is a curved exhaust path (maze structure) formed by a gap between the high voltage plasma generation container inner wall 14 and the high voltage plasma generation container outer wall 15 through the opening 16 formed in the high voltage plasma generation container inner wall 14. ) 32, and the plasma is exhausted from the opening 17 formed in the outer wall 15 of the high-voltage plasma generation container. The inner wall 14 of the high-voltage plasma generation container and the outer wall 15 of the high-voltage plasma generation container can be rotated, and the distance of the exhaust path 8 formed from the opening 16 and the opening 17 can be adjusted.

Then, the opening 17 of the outer wall 15 of the high-voltage plasma generation container is positioned so that the opening of the inner wall 14 of the high-voltage plasma generation container 14 is symmetrical at a maximum of 180 °, with the intention of taking a long exhaust path 8 which is the maze structure 32. Is preferable.

As described above, the high-voltage plasma inside the high-voltage plasma generation container 3 has a high-voltage portion due to the exhaust path 8 which is a maze structure 32 passing through the gap between the high-voltage plasma generation container inner wall 14 and the high-voltage plasma generation container outer wall 15. By the time it reaches the vicinity of the opening 17 of the outer wall 15 of the high-voltage plasma generation vessel 15, the plasma density becomes sufficiently low or is neutralized by ion-electron recombination. Therefore, it is possible to prevent a short circuit between the high voltage portion composed of the high voltage plasma generation container inner wall 14 and the high voltage plasma generation container outer wall 15 and the inner wall surface of the vacuum chamber 1 which is the ground potential.

Since the length of the exhaust path 8 can be adjusted and the volume of the exhaust path can be increased, the trade-off between the exhaust capacity and the dielectric strength can be adjusted.

By appropriately combining the third embodiment with the first to third embodiments, the exhaust path 8 having a maze structure 32 can be taken longer. Further, although the vacuum chamber 1 described in Examples 1 to 3 has a cylindrical cross section, it can also be applied to a polygonal cross section such as a spherical shape or a square shape.

(Example 4)
Example 4 of the present invention will be described with reference to FIG. In FIG. 4, the same parts as those in FIG. 1 are designated by the same reference numerals, and the description of the configuration will be omitted.

Example 4 is an example in which the high voltage potential plasma generators 40, 41, and 42 according to the first to third embodiments are applied to the ion source 20.

The ion extraction electrode 21 is connected to or supported from the inside in the high voltage potential plasma generation container 3. The ion extraction electrode 21 has the same potential as the high voltage potential plasma generation container 3. Ions are drawn out by the potential difference between the opening 23 of the ion drawing electrode 21 and the vacuum chamber 1 which is the external ground potential.

The plasma ion beam 22 extracted from the opening 23 as the ions starts from the plasma generation point 5, passes through the opening 23 of the ion extraction electrode 21, and is used as an ion supply source, so that the entire system of Example 4 becomes the ion source 20. Functions as.

Examples 1 to 3 can be applied to the high-voltage plasma generation container used as the ion source as described above. As a result, the vacuum exhaust efficiency in the plasma generation chamber is improved, plasma having a certain characteristic can be continuously and stably generated, and it can be applied as a stable ion source. The ions extracted from this ion source can be utilized in a linear accelerator, a heavy particle beam irradiator, and the like.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention.

These embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations can be made without departing from the gist of the invention.

These embodiments and modifications thereof are included in the scope and gist of the invention, as well as in the scope of the invention described in the claims and the equivalent scope thereof.

1 ... Vacuum tank 2 ... Insulator 3 ... High voltage potential plasma generation container 4 ... Target 5 ... Plasma generation point 6 ... High voltage potential plasma generation container lid 7 ... Hook (position adjustment device)
8 ... Exhaust path 9 ... High voltage part 10 ... High voltage potential plasma generation container 11 ... Stage stand support 12 ... High voltage stage stand 13 ... Opening 14 ... High voltage potential plasma generation container inner wall 15 ... High voltage potential plasma generation container outer wall 16, 17 ... Opening 20 ... Ion source 21 ... Ion extraction electrode 22 ... Plasma ion beam 23 ... Openings 30, 31, 32, 33 ... Labyrinth structure (bent exhaust path)
40, 41, 42, 43 ... High voltage potential plasma generator

Claims (8)

It is composed of a high-voltage potential plasma generation container installed inside the vacuum chamber via an insulating material and vacuum exhausted inside, and a target installed in the high-voltage potential plasma generation container and used as a plasma component material. The inside of the voltage-potential plasma generation container and the inside of the vacuum chamber are communicated by a bent exhaust path.
The bent exhaust path is formed by a high-voltage potential plasma generation container lid that forms a predetermined gap with the opening of the high-voltage potential plasma generation container and is arranged in the high-voltage potential plasma generation container.
The high-voltage potential plasma generation container lid is formed between the opening of the high-voltage potential plasma generation container and a predetermined gap by a position adjusting device attached to the inner surface of the high-voltage potential plasma generation container lid or the high-voltage potential plasma generation container. A high-voltage potential plasma generator characterized by forming the above. By changing the size and length of the position adjusting device, the volume of the bent exhaust path formed by the opening of the high-voltage potential plasma generation container and the gap formed by the lid of the high-voltage potential plasma generation container can be adjusted. The high voltage potential plasma generator according to claim 1, wherein the high voltage potential plasma generator can be adjusted. It is composed of a high-voltage potential plasma generation container installed inside the vacuum chamber via an insulating material and vacuum exhausted inside, and a target installed in the high-voltage potential plasma generation container and used as a plasma component material. The inside of the voltage-potential plasma generation container and the inside of the vacuum chamber are communicated by a bent exhaust path.
The bent exhaust path includes a high-voltage potential plasma generation container in which an opening is formed inside the vacuum chamber via an insulating material and the inside is vacuum-exhausted, and a stage stand support in the high-voltage potential plasma generation container. A high-voltage potential plasma generator, characterized in that it is formed by a high-voltage stage that is installed with a predetermined gap formed therein. The high-voltage potential plasma generation vessel has a double structure of an inner wall and an outer wall having an opening formed on a side surface thereof, and the gap thereof is a bent exhaust path, according to any one of claims 1 to 3. The high voltage potential plasma generator according to any one of the items. The high-voltage potential plasma generator according to claim 4, wherein the inner wall and the outer wall are rotatably configured and an exhaust path can be adjusted. The high-voltage potential plasma generator according to any one of claims 1 to 5, wherein the insulating material is formed of an insulator and supports the high-voltage potential plasma generation container. The high voltage potential plasma generator according to any one of claims 1 to 6, wherein the vacuum chamber has a spherical shape, a cylindrical shape, or a square cylinder shape. An ion source characterized in that an ion extraction electrode is connected to or internally supported by the high voltage potential plasma generator according to any one of claims 1 to 7.

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