JPH0982231A - Microwave ion source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance maintenance ability by constituting a plasma chamber inner wall (a window 4, a liner 5, a shield 6) so as to be capable of detaching it from the ion taking out side of a plasma chamber 1. SOLUTION: A window 4 and a liner 5 are formed so as to be capable of attaching/detaching by notching work or screwing work, and when a plasma chamber inner wall is taken out from a plasma chamber 1 for maintenance, the window 4 and the liner 5 are integrally constructed, but when the plasma chamber inner wall is cleaned after taking out, the window 4 and the liner 5 are separated and handled separately.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave ion source for use in, for example, an ion implantation apparatus to generate plasma and extract ions from the plasma. In particular, the inner wall surface of the plasma chamber is covered with a dielectric material. The present invention relates to a microwave ion source.

[0002]

2. Description of the Related Art In recent years, ion sources for converting elements into plasma and extracting ions in the plasma as ion beams have been used in various fields including an ion implantation apparatus. This ion source is equipped with ECR (Electron Cyclotron R
There are many types such as microwave type such as esonance) ion source and PIG (Penning Ionization Gauge) type such as Freeman ion source. These various ion sources are required to have required ion species and energy, The most suitable model can be used according to the current.

For example, in the case of an ion source having a filament such as a Freeman ion source, the life of the ion source is relatively short due to the consumption of the filament, and frequent maintenance is required. On the other hand, an ECR ion source using microwaves does not use a filament and is advantageous in terms of life. The structure of the ECR ion source will be described below as an example.

As shown in FIG. 12, the ECR ion source uses the microwave output from a magnetron (not shown) through a microwave introducing rod 53 and a window (microwave introducing window) 54 inside the plasma chamber 51 (plasma). Electron cyclotron resonance (E
Microwave discharge is generated in a magnetic field of (CR) condition, and the gaseous ion source material introduced inside through the gas feedthrough 57 is made into plasma.

After the plasma is generated in the plasma chamber 51, a high voltage (extraction voltage) is applied between the plasma chamber 51 and the extraction electrode system 60 provided outside the plasma chamber 51 to generate an electric field. By doing so, ions are extracted from the plasma slit 52 of the plasma chamber 51, and an ion beam is formed. The ion beam formed in this way is used for processing such as ion implantation.

The inner wall of the plasma chamber 51 is covered with a dielectric such as BN. This is because if the inner wall of the conductive plasma chamber 51 is not covered with a dielectric, the conductive material that has jumped out of the inner wall of the chamber due to sputtering by the plasma-forming substance adheres to the window 54 and the microwave is reflected. This is because there is a disadvantage that the efficiency of introducing microwaves into the interior is reduced.

Normally, the plasma chamber inner wall made of a dielectric material is
The window 54, the liner 55 covering the inner surface of the side wall of the plasma chamber 51, and the shield 56 covering the inner surface of the plasma slit 52 are divided into three parts.

[0008]

In the above ECR ion source, the plasma chamber inner wall is made of an ion species substance or a material forming the plasma slit 52, the extraction electrode system 60, or the like as the cumulative operating time increases. Since it is contaminated by conductive materials such as carbon, it requires regular maintenance. In the case of the plasma chamber of the ECR ion source, since the filament is not used, the maintenance work of the ion source is performed mainly for cleaning the inner wall of the plasma chamber. Therefore, the cleaning time of the inner wall portion is a major factor in determining the maintenance time.

The cleaning of the inner wall of the plasma chamber is mainly intended to remove deposits on the window 54 which hinders the introduction of microwaves into the plasma chamber. It is necessary to take out the window 54.

In the above conventional structure, since the window 54 and the liner 55 are separated from each other, if the window 54 is to be taken out of the plasma chamber 51 during maintenance work, the window 54 must be removed to the outer wall of the plasma chamber. Normally, it takes time and effort to remove the outer wall of the plasma chamber, but today, there is also a type in which a heater wire 58 for heating is attached to the outer wall surface of the plasma chamber. In such a type, the removal is particularly complicated. It takes work and takes time.

If the window 54 and the liner 55 are integrated, the window 54 can be taken out without removing the outer wall of the plasma chamber by pulling out the liner 55.
Since this one-piece product has a cup-like shape, it is difficult to clean dirt on the surface of the window 54, which is the bottom of the cup (a work of scraping off adhered substances on the surface with a file or the like).

Further, since the liner 55 forming the side surface of the inner wall of the plasma does not have a special positioning mechanism in the plasma chamber 51, for example, in a horizontal extraction ion source, as shown in FIG. Is positioned downward in the plasma chamber 51 due to its own weight. If the liner 55 is displaced in the plasma chamber 51 in this manner, the following inconvenience occurs.

That is, since the liner 55 that substantially forms the internal space of the plasma chamber and the ion extraction hole 52a formed in the plasma slit 52 are displaced from each other, the state of the plasma sheath surface is adversely affected. At the same time, it becomes difficult to form a good beam extraction system, and at the same time, the position reproducibility affects the beam reproducibility. In particular, when the ion source is designed to be compact, the ratio of the length of the ion extraction hole 52a in the slit longitudinal direction to the diameter of the plasma chamber 51 becomes large, and the distance between the end of the ion extraction hole 52a and the liner 55 becomes short. So the liner 55
And the position of the ion extraction hole 52a are important.

As a method of solving the above-mentioned inconvenience, the inner diameter of the plasma chamber 51, which is the outer wall of the plasma chamber, and the outer diameter of the liner 55, which is the inner wall of the plasma chamber, are made substantially the same, and the plasma chamber 51 is fitted by fitting them. It is conceivable to position the liner 55 inside. However, in this case, the standard pipe cannot be used as it is, and high-precision processing is required, resulting in high cost. Further, since the fitting portion between the plasma chamber 51 and the liner 55 is long, considerable machining accuracy is required. Further, in this case, since the inner diameter of the plasma chamber 51 and the outer diameter of the liner 55 are processed to have substantially the same diameter,
There is also a problem that the liner 55 cannot be easily attached to and detached from the plasma chamber 51, which makes maintenance work difficult.

The present invention has been made in view of the above, and an object thereof is to maintain the plasma chamber inner wall made of a dielectric material from the front side (ion extraction side) of the plasma chamber to improve maintainability. It is to provide an ion source that can be improved. Another object of the present invention is to provide a microwave ion source capable of easily and reliably positioning the liner 55 forming the side surface of the inner wall of the plasma inside the plasma chamber 51.

[0016]

A microwave ion source according to the invention of claim 1 has a microwave introducing portion on one wall surface and an ion extracting portion on a wall surface opposite to the microwave introducing portion.
A plasma chamber, which is a plasma chamber for generating plasma, is provided, and an inner wall surface of the plasma chamber is covered with a dielectric material forming the inner wall of the plasma chamber. To this end, the following measures are taken.

That is, the first plasma chamber inner wall portion covering the inner wall surface of the plasma chamber having the microwave introducing portion and the cylindrical shape covering the side wall surface of the plasma chamber in which the microwave introducing portion and the ion extracting portion are not present. The second plasma chamber inner wall portion is detachably formed.

According to the above construction, since the first plasma chamber inner wall portion and the second plasma chamber inner wall portion are detachably formed, the first plasma chamber inner wall portion is taken out from the plasma chamber during maintenance. While the plasma chamber inner wall portion and the second plasma chamber inner wall portion have an integrated structure, they can be separated and handled as separate bodies at the time of cleaning after taking out.

Therefore, during maintenance work of the ion source, if the wall surface on the ion extraction side of the plasma chamber is removed and only the ion extraction side is opened, and the second plasma chamber inner wall portion is extracted, the first plasma is simultaneously released. The indoor wall portion can also be taken out from the plasma chamber. As described above, the inner wall of the plasma chamber can be easily taken out without completely disassembling the plasma chamber, which is superior to the conventional one in maintainability.

Further, after the plasma chamber inner wall is taken out from the plasma chamber, the first plasma chamber inner wall portion and the second plasma chamber inner wall portion can be separated and separately cleaned. There is no hindrance to the work.

A microwave ion source according to a second aspect of the present invention is the microwave introduction rod according to the first aspect of the invention, wherein the microwave introduction rod is made of a dielectric material for introducing microwaves from the microwave introduction part into the plasma chamber. A positioning projection is formed on one of the microwave introducing rod and the first plasma chamber inner wall portion, and a positioning recess is formed on the other of the positioning projection to be fitted with the positioning projection. I am trying.

According to the above structure, the positioning convex portion and the positioning concave portion formed on the microwave introducing rod and the first plasma chamber inner wall portion are fitted to each other, whereby the first plasma chamber in the plasma chamber is fitted. The wall portion is positioned, so that the second plasma chamber inner wall portion integrally formed with the first plasma chamber inner wall portion is also positioned in the plasma chamber. In this configuration, since the plasma chamber itself is not used for positioning, the ion source can be designed and manufactured without considering the fitting tolerance between the first and second plasma chamber inner wall portions and the plasma chamber,
The processing accuracy for positioning the plasma chamber inner wall is greatly eased.

Furthermore, since the outer diameters of the first and second plasma chamber inner walls can be set to a size that allows them to be withdrawn from the plasma chamber with a margin, the first and second plasma chamber inner walls can be taken in and out from the ion extraction side of the plasma chamber. In this case, it can be easily taken in and out without being caught on the inner wall of the plasma chamber. Therefore, the maintainability can be further improved.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION

[Embodiment 1] The following will describe one embodiment of the present invention in reference to FIGS. 1 to 10.

The microwave ion source of this embodiment is an ECR ion source that generates a plasma by generating a microwave discharge in a magnetic field under the electron cyclotron resonance condition and extracts ions from the plasma as a beam. It is applied to ion beam application equipment such as equipment.

The ion source has, for example, a magnetron that outputs a microwave of 2.45 GHz and a magnetron power supply that operates the magnetron. As shown in FIG. 2, the microwave generated by the magnetron is It is guided to the cylindrical plasma chamber 1 via a waveguide (not shown) and a microwave introduction rod 3 made of a dielectric material such as ceramic connected to the waveguide.

The inside of the plasma chamber 1 is a plasma chamber for converting the ion source material into plasma. In the plasma chamber 1, a gaseous ion source material such as BF ₃ is supplied to the plasma chamber. A gas introducing pipe 13 for introducing and a solid oven 14 for vaporizing a solid ion source material such as metal are connected.

The microwave introducing rod 3 is inserted into the metallic transition tube 20 and connected to the plasma chamber 1. A window 4 (first plasma chamber inner wall portion) made of a dielectric material such as BN is arranged on a wall surface (one wall surface having a microwave introducing portion) connected to the microwave introducing rod 3 of the plasma chamber 1. It is set up. This window 4 allows the microwave that has passed through the microwave introducing rod 3 to pass through the plasma chamber 1.
It is to be introduced inside. Also, this window 4
As will be described later, is also a member forming the rear surface of the plasma inner wall made of a dielectric material.

A wall surface of the plasma chamber 1 facing the window 4 is formed by a plasma slit 2 (ion extraction portion) having a slit-shaped ion extraction hole 2a.

The plasma chamber 1 forming the outer wall of the plasma chamber is made of metal such as stainless steel or molybdenum. The inner wall of the plasma chamber 1 is covered with a dielectric material such as BN. That is, the rear surface (microwave introduction side) of the plasma chamber 1 is formed by the window 4, the side surface is formed by the liner 5 (second plasma chamber inner wall portion) made of a dielectric material such as BN, and the front surface (ion extraction side) is formed. It is covered with a shield 6 made of a dielectric material such as BN.

The window 4 and the liner 5 are detachable.

As a specific example thereof, as shown in FIG. 3, there is one in which the connection portion of the window 4 and the liner 5 is cut. The through hole 4b formed in the window 4 is an inlet for gas supplied from the gas inlet pipe 13, and the through hole 4c is an inlet for steam supplied from the solid oven 14. Details of the window 4 are shown in FIGS. 4 and 5, and details of the liner 5 are shown in FIGS. 6 and 7.

FIG. 4 is a plan view of the window 4 as seen from the side connected to the liner 5, and FIG.
FIG. The peripheral portion of the window 4 is composed of a large-diameter portion 4d that is substantially the same as or slightly larger than the outer diameter of the liner 5 and a small-diameter portion 4e that is approximately the same as or slightly smaller than the inner diameter of the liner 5, and the small-diameter portion 4e Two convex portions 4a and 4a are formed. The distance from the center of the tip of the convex portion 4a is
It is formed to be larger than the radius of the inner diameter of the liner 5 and smaller than the radius of the outer diameter of the liner 5.

FIG. 6 is a plan view of the liner 5 as viewed from the side connected to the window 4, and FIG. 7 is a plan view of the liner 5 of FIG.
FIG. 7 is a sectional view taken along line AA of FIG. On the inner wall surface near the connection end of the liner 5 with the window 4, an engagement groove 5a into which the above-mentioned convex portions 4a, 4a enter is formed. Further, at the connection end of the liner 5 with the window 4, a cutout portion 5b for guiding the convex portions 4a, 4a of the window 4 to the engaging groove 5a.
5b are formed.

As shown in FIG. 3, the convex portion 4 of the window 4 is
The window 4 and the liner 5 can be easily integrated by fitting the a and 4a into the cutouts 5b and 5b of the liner 5 and then turning them in the circumferential direction. Further, if the reverse operation is performed, the window 4 and the liner 5 can be easily separated.

As another specific example in which the window 4 and the liner 5 are attachable / detachable, as shown in FIG. 8, there is one in which the connection portion of the window 4 and the liner 5 is threaded. That is, a convex screw is formed on the small-diameter portion 4e of the window 4, and a concave screw to be screwed with the convex screw is formed on the liner 5 side. Even with this configuration, the window 4 and the liner 5 can be easily integrated and separated from each other as in the case of cutting.

As shown in FIG. 2, an extraction electrode system 10 is arranged outside the plasma chamber 1 at a position facing the plasma slit 2. This extraction electrode system 10
Consists of an extraction electrode 8 and a ground electrode 9 each having a beam passage hole 8a, 9a formed in the center thereof. An extraction power source 11 is connected between the ground electrode 9 and the plasma chamber 1, and a deceleration power source 12 is connected between the extraction electrode 8 and the ground electrode 9. The ground electrode 9 has a ground potential, and the extraction electrode 8 provided closer to the plasma chamber 1 than the ground electrode 9 has a lower potential than the ground electrode 9 by the deceleration power supply 12.

The extraction electrode system 10 is operated by the extraction power source 11.
When a high voltage is applied to the plasma chamber 1 so as to have a negative potential higher than that of the plasma chamber 1, a strong external electric field is formed around the plasma slit 2, and the external electric field pulls out the ions in the plasma chamber 1 to generate an ion beam. Are formed. As described above, by setting the extraction electrode 8 to a negative potential than the ground electrode 9, the extraction electrode 8
It is possible to prevent the backflow of electrons generated downstream.

The plasma chamber 1 is maintained in a high vacuum state by a vacuum exhaust means (not shown). Further, the plasma chamber 1 is built in an ion source chamber (not shown) together with the extraction electrode system 10, and the inside of the ion source chamber is also kept in a high vacuum state by a vacuum exhaust means (not shown).

A source magnet 15 having a solenoid coil is arranged around the plasma chamber 1, and the source magnet 15 is located inside the plasma chamber 1 and is substantially parallel to the beam extraction direction. It is designed to form a magnetic field under resonance conditions.

On the outer wall surface of the plasma chamber 1,
A heater wire 16 for heating the plasma chamber 1 is wound.

The operation of the ion source in the above structure will be described.

First, in a state where the plasma chamber 1 and the ion source chamber are kept in a high vacuum by the vacuum exhaust means, the source magnet 15 forms a magnetic field under the electron cyclotron resonance condition in the plasma chamber 1, and the magnetic field is output from the magnetron. The microwave that has passed through the waveguide is introduced into the plasma chamber 1 through the microwave introduction rod 3 and the window 4, and a gaseous ion source material is introduced into the plasma chamber 1. This allows ECR
Microwave discharge occurs due to the phenomenon, and plasma chamber 1
The ion source material introduced into the inside is turned into plasma to generate ions. After the plasma is turned on, the microwave introduced into the plasma chamber 1 is absorbed by the plasma and the plasma is maintained. After that, ions in the plasma chamber 1 are extracted from the ion extraction hole 2a of the plasma slit 2 by an electric field to form an ion beam. This ion beam is used for ion implantation processing and the like.

When the above-mentioned ion source is used for a long time, the inner wall of the plasma is contaminated with an ion species substance or a conductive substance such as carbon which is a material forming the plasma slit 2 and the extraction electrode system 10. . So, next,
The maintenance work of the ion source will be described.

First, as shown in FIG. 1, in order to open the front side (ion extraction side) of the plasma chamber, the plasma slit 2 and the shield 6 are removed from the main body of the plasma chamber 1. For example, when a screw is used to attach the plasma slit 2, the screw is removed.
Further, as shown in FIG. 9, a cylindrical plasma chamber cover 1 having a diameter larger than that of the plasma chamber 1.
7 and a plurality of spring hooks 18 for urging the plasma chamber cover 17 in the direction opposite to the ion extraction direction, the plasma chamber cover 17 is fixed when the plasma slit 2 is fixed by the urging force of the spring. If removed, the plasma slit 2 and the shield 6 can be easily removed.

Next, as shown in FIG. 1, the liner 5 is pulled out from the front side of the opened plasma chamber. In this case, since the liner 5 and the window 4 have an integrated structure, the window 4 can be taken out of the plasma chamber 1 at the same time by pulling out the liner 5.

After taking out the liner 5 and the window 4 having the integral structure from the plasma chamber 1, the window 4 and the liner 5 are separated as shown in FIG. 3 or 8. Then, the window 4 and the liner 5 are separately cleaned (the work of scraping off the adhered matter on the inner surface with a file or the like). In addition, the inner surface of the shield 6 that was previously removed is also cleaned.

When the above cleaning work is completed, the window 4 and the liner 5 are again joined and integrated, and this is inserted from the front side of the plasma chamber. After that, the maintenance work is completed by attaching the plasma slit 2 and the shield 6.

As described above, the ion source of this embodiment is
The window 4 and the liner 5 are detachably formed, and when the window 4 and the liner 5 are taken out from the plasma chamber 1, the both have an integral structure, but when cleaning after taking out, they can be divided and handled as separate bodies. You can do it. Therefore, the window 4 and the liner 5 can be easily taken out simultaneously from the plasma chamber 1 by opening only the front side of the plasma chamber without completely disassembling the plasma chamber 1, and the window 4 and the liner 5 can be easily removed. The inner surface can be cleaned normally. Therefore, the ion source of the present embodiment can improve the maintainability as compared with the conventional one.

In the above structure, as shown in FIG. 10, the diameter of the large diameter portion 4d of the window 4 which abuts the wall surface of the plasma chamber 1 on the microwave introduction side is set to the liner 5 diameter.
The outer diameter of the plasma chamber 1 is made larger than the outer diameter of the plasma chamber 1, and the diameter of the large diameter portion 4d and the inner diameter of the plasma chamber 1 are set to be substantially the same. It is preferable to position the liner 5 in.

As described above, the window 4 is attached at the time of installation.
If the liner 5 and the liner 5 can be integrally formed, if the liner 5 is aligned according to the positional relationship between the window 4 and the plasma chamber 1 having a small number of fitting portions, the liner 5 and the plasma chamber 1 having a wide fitting portion can be formed. The required processing accuracy is relaxed as compared with the case of using the positional relationship of.
Furthermore, since the outer diameter of the liner 5 is smaller than the inner diameter of the plasma chamber 1, the liner 5 can be attached to and detached from the plasma chamber 1 relatively easily, and the maintainability is also improved.

[Second Embodiment] The following will describe another embodiment of the present invention in reference to FIG. For convenience of description, members having the same configurations and functions as the members shown in the drawings used in the first embodiment will be designated by the same reference numerals, and the description thereof will be omitted.

As described above, by adopting the configuration shown in FIG. 10, it is possible to relax the processing accuracy for positioning the liner 5 to some extent. In this case, however, the inner wall surface of the cylindrical plasma chamber 1 is reduced. It is necessary to cut the fitting portion of the window 4 with the window 4. The cutting of such an inner wall of the cylinder requires a relatively high cost. Further, the window 4 and the plasma chamber 1 are used for positioning the liner 5.
Therefore, when the window 4 and the liner 5 having an integral structure are removed or inserted from the plasma chamber 1, it is inevitable that the window 4 portion is easily caught on the inner wall of the plasma chamber 1. .

Therefore, in this embodiment, the construction of the ion source is shown, which can further reduce the processing accuracy for positioning the liner 5 and further improve the maintainability.

As shown in FIG. 11, the ion source of this embodiment has the same basic structure as that of the first embodiment, but the tip of the microwave introducing rod 3 is further extended into the plasma chamber 1. A recessed portion 4f (positioning recessed portion) that is protruding and fits into the protruding portion 3a (positioning protruding portion) of the microwave introduction rod 3 is formed on the microwave introduction surface side of the window 4 and is used for microwave introduction. The projection 3a of the rod 3 and the recess 4f of the window 4 are fitted to each other so that alignment can be achieved. That is, by fitting the protrusion 3a and the recess 4f, the window 4 in the plasma chamber 1 is positioned, and thus the liner 5 integrated with the window 4 is also positioned in the plasma chamber 1. .

In this case, since the plasma chamber 1 is not used for positioning, the ion source can be designed and manufactured without paying special attention to the fitting tolerances of the window 4 and the plasma chamber 1 and the liner 5 and the plasma chamber 1. That is, the processing accuracy for positioning the liner 5 is significantly eased. Therefore, it is not necessary to cut the inner surface of the plasma chamber 1, and the plasma chamber 1 can be manufactured at low cost by using, for example, a commercially available standard pipe.

Further, as shown in FIG. 11, not only the liner 5 but also the outer diameter of the window 4 is changed to the plasma chamber 1
Since the window 4 and the liner 5 having an integral structure can be pulled out from the front of the plasma chamber 1, the window 4 and the liner 5 can be easily pulled in and out without being caught by the inner wall of the plasma chamber 1. Therefore, further improvement in maintainability can be expected.

Here, an example is shown in which the microwave introducing rod 3 is projected and the concave portion 4f fitted therein is formed on the window 4 side. On the contrary, a convex portion is formed on the window 4, Even if a concave portion is formed on the microwave introducing rod 3 side, alignment can be taken.

In each of the above embodiments, the plasma chamber 1 has a cylindrical shape, but of course, it may have a rectangular shape. Further, the microwave introducing rod 3 may be cylindrical or prismatic in shape. Further, the ECR ion source has been described as an example, but the present invention is also applicable to other microwave ion sources in which the plasma chamber inner wall is provided in the plasma chamber 1.
The above-described embodiments are merely for clarifying the technical contents of the present invention, and should not be construed in a narrow sense by limiting only to such specific examples. Can be changed and implemented.

[0060]

As described above, the microwave ion source according to the first aspect of the present invention includes the first plasma chamber inner wall portion that covers the inner wall surface of the plasma chamber having the microwave introduction portion,
The second plasma chamber inner wall portion, which covers the side wall surface of the plasma chamber without the microwave introduction portion and the ion extraction portion, is detachably formed.

Therefore, when the plasma chamber inner wall is taken out from the plasma chamber at the time of maintenance, the first plasma chamber inner wall portion and the second plasma chamber inner wall portion have an integral structure, while at the time of cleaning after taking out, both are separated. Can be treated as a separate body. Therefore, the plasma chamber inner wall can be easily taken out from the front side (ion extraction side) of the plasma chamber without completely disassembling the plasma chamber, so that the maintainability can be improved more than ever before.

The microwave ion source according to the invention of claim 2 is
The structure of the invention according to claim 1, further comprising: a microwave introduction rod made of a dielectric material for introducing microwaves from the microwave introduction part into the plasma chamber, wherein the microwave introduction rod and the first plasma chamber inner wall are provided. One of the parts is provided with a positioning projection, and the other is provided with a positioning recess that fits with the positioning projection.

Therefore, in addition to the effect of the first aspect of the invention, since the plasma chamber itself is not used for positioning, the fitting tolerance between the first and second plasma chamber inner wall portions and the plasma chamber must be taken into consideration. The ion source can be designed and manufactured without the need for processing, and the processing accuracy for positioning the plasma chamber inner wall can be greatly relaxed. Furthermore, since the outer diameters of the first and second plasma chamber inner walls can be made to have a size that allows them to be withdrawn from the plasma chamber with a margin, when the first and second plasma chamber inner walls are taken in and out from the ion extraction side of the plasma chamber, It can be easily taken in and out without being caught on the inner wall of the plasma chamber, and the maintainability can be further improved.

[Brief description of drawings]

1 shows an embodiment of the present invention, which is an ECR
FIG. 5 is a schematic cross-sectional view for explaining a procedure for taking out the plasma chamber inner wall from the plasma chamber during maintenance of the ion source.

FIG. 2 is a cross-sectional view showing a schematic configuration of the ECR ion source.

FIG. 3 is a perspective view showing a window and a liner that are detachably formed in the ECR ion source.

FIG. 4 is a plan view of the window shown in FIG. 3 as viewed from the side connected to the liner.

5 is a front view of the window shown in FIG. 4. FIG.

FIG. 6 is a plan view of the liner shown in FIG. 3 as viewed from the side connected to the window.

7 is a cross-sectional view of the liner shown in FIG. 6 taken along the line AA.

FIG. 8 is a perspective view showing a modified example of a window and a liner that are detachably formed in the ECR ion source.

FIG. 9 is a schematic cross-sectional view showing an example of a plasma slit mounting structure in the ECR ion source.

FIG. 10 is a schematic longitudinal sectional view showing another embodiment of the ECR ion source.

FIG. 11 is a schematic vertical sectional view showing still another embodiment of the ECR ion source.

FIG. 12 is a cross-sectional view showing a schematic configuration of a conventional ECR ion source.

FIG. 13 is a vertical cross-sectional view showing a configuration of a main part of the conventional ECR ion source.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plasma chamber 2 Plasma slit (ion extraction part) 2a Ion extraction hole 3 Microwave introduction rod 3a Projection part (positioning convex part) 4 Window (1st plasma chamber inner wall part) 4f Recessed part (positioning concave part) 5 Liner ( Second plasma chamber inner wall portion) 6 shield 10 extraction electrode system

Claims (2)

[Claims] 1. A plasma chamber having a microwave introduction portion on one wall surface and an ion extraction portion on a wall surface opposite to the microwave introduction portion, the inside being a plasma chamber for generating plasma, and the inside of the plasma chamber. In a microwave ion source whose wall surface is covered with a dielectric forming a plasma chamber inner wall, a first plasma chamber inner wall portion covering the inner wall surface of the plasma chamber having the microwave introducing portion and a microwave chamber Ion source, and a cylindrical second plasma chamber inner wall portion that covers the side wall surface of the plasma chamber in which the ion extraction portion is not present are detachably formed. 2. A microwave introducing rod made of a dielectric material for introducing microwaves from the microwave introducing portion into the plasma chamber, wherein either the microwave introducing rod or the first plasma chamber inner wall portion is provided. 2. The microwave ion source according to claim 1, wherein a positioning projection is formed on one side, and a positioning recess that fits with the positioning projection is formed on the other side.