JPH09106778A - Corpuscular beam radiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an radiation area more efficient, at low costs, and to enhance mass production, by shaping an ion draw-out electrode and the shape of an ion source in a polygonal shape and using the structure commonly. SOLUTION: Heat electrons are emitted by electrifying/heating a heater filament 17 introduced into a case 16 having a square cross-section and a direct current electric field is applied so that the hat filament 17 may have a negative potential and the case 16 a positive potential. Plasma 19 is thereby generated in a plasma chamber 18, its ions being drawn out by an electric field made by an ion draw-out electrode 23 comprizing an acceleration electrode 20, a deceleration electrode 21, and a ground electrode 22, and an ion beam is formed. A structural body, which is defined by the case 16 and the draw-out electrode 23, forms one ion source and a plurality of the ion sources are juxtaposed. A permanent magnet 24 for confining plasma is shared with a neighboring ion source and the draw-out electrode 23 is attached to each of the ion sources. A magnetic field of a neighboring ion source is utilized effectively, a structure using easily workable, low cost electrodes of small area can be employed, and an radiation area can be made more efficient.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ion source apparatus or a plasma source apparatus used for thin film formation such as ion implantation and ion irradiation, and more particularly to a particle beam irradiation apparatus suitable for processing a large area substrate.

[0002]

2. Description of the Related Art One example of a conventional ion source device will be described with reference to a bucket type ion source device using a hot filament shown in FIG.

In the figure, 1 is a metal housing of the ion source device, 2 is a housing formed by the housing 1, and a plasma chamber for generating plasma and ions is introduced into the plasma chamber 2. Hot filament, 4 filament 3
Of the filament power source for heating, 5 is a gas introduction port to the plasma chamber 2, 6 is an ion beam extraction electrode provided in the housing 1 via an insulator 7, and is an acceleration electrode 8, a deceleration electrode 9, and a ground electrode. It is composed of 10. Reference numeral 11 denotes a plurality of permanent magnets provided on the outside of the housing 1, which is formed of an annular body or a rod-shaped body and forms a cusp magnetic field inside the housing 1.

Reference numeral 12 is an arc power source, and the anode is the casing 1
Then, the cathode is connected to the filament power supply 4, and the anode voltage is applied to the housing 1. An accelerating power source 13 has its anode connected to the accelerating electrode 8 and the cathode of the arc power source 12, and its cathode is grounded. A deceleration power source 14 applies a negative voltage to the deceleration electrode 9.

The filament 3 is a thermoelectron emission source as a cathode, and is maintained at a high temperature by resistance heating of the filament power source 4 to emit thermoelectrons, and the emitted thermoelectrons are formed by the arc power source 12. The gas particles accelerated by the DC electric field and introduced from the gas introduction port 5 are ionized by collision to generate plasma 15.

Further, a cusp magnetic field is formed by the permanent magnet 11, the plasma 15 is confined, and the beam extraction action of the extraction electrode 6 causes the ions in the plasma 15 to be extracted as an ion beam.

In addition, as a method of generating an ion source or a plasma source, other than this, a high frequency ion source using high frequency discharge, a microwave ion source using microwave discharge, and a plasma cathode type ion using primary plasma as an electron source. Sources, various ion sources such as an electron beam excitation type ion source for extracting an electron beam for impact ionization, and a plasma source without a beam extraction electrode group.

By the way, when it is attempted to irradiate a large area substrate with an ion beam or plasma from such an ion source or plasma source, it is necessary to make the irradiation area of the ion source or plasma source large in accordance with the size of the substrate. Therefore, the device is very large.

In the case of a large-scale apparatus, in particular, the ion extraction electrode needs to suppress warpage and distortion to the utmost in order to extract the beam uniformly, and its processing becomes very difficult.

Particularly, when the irradiation of a substrate of 1 m square or more as required in recent years is performed, the difficulty of processing the electrode and the cost are dramatically increased. Further, even if a cusp magnetic field is used for plasma confinement as in the conventional example, it is difficult to generate plasma uniformly with an ion source or a plasma source of 1 m square or more, and due consideration should be given to the position of the filament and the like. There is a need.

Further, the sizes of these ion source and plasma source depend on the size of the substrate and the positional relationship, and in order to meet individual requirements, standard sizes have been set so far to reduce the cost by mass production. It is impossible at all.

Therefore, it is necessary to design each device from the beginning, the design cost cannot be reduced, and the parts cannot be shared, resulting in a high cost and a very long delivery time.

Further, since such a device is expensive and special, it is impossible to prepare spare parts, and there is a risk that the production line will be stopped for a long time in the case of a failure.

On the other hand, Japanese Unexamined Patent Publication No. 4-147972 (C
23C 14/48), it has been invented that a plurality of ion beam generators are arranged in parallel to perform irradiation in order to deal with a large area.

[0015]

By the way, as described in the above publication, when a plurality of devices are installed side by side, the outer shape of the devices is circular, so that a large gap is generated between the adjacent devices, which becomes a dead space. However, there is a problem that the ion beam cannot be effectively irradiated.

An object of the present invention is to provide a particle beam irradiation apparatus which takes into account the above points and is capable of coping with various large-area shapes and making the irradiation area effective.

[0017]

In order to solve the above-mentioned problems, a particle beam irradiation apparatus of the present invention comprises a plasma chamber for generating plasma and an ion beam, and a magnetic field generating means for generating a magnetic field in the plasma chamber. And an ion source device in which a plurality of ion sources each having an extraction electrode for extracting ions generated in the plasma chamber by an electric field to generate an ion beam are arranged adjacent to each other,

Alternatively, in a plasma source device in which a plurality of plasma sources having a plasma emission port for diffusing and emitting the plasma toward the sample stage instead of the extraction electrode are arranged adjacent to each other,

The outer shape of the plasma chamber, the shape of the ion extracting electrode, or the shape of the plasma source is polygonal. Therefore, each ion source or each plasma source can be brought close to each other without a gap, a dead space is not generated, a large area shape can be dealt with, and an irradiation area can be made effective. Furthermore, the structure of each ion source or plasma source can be made common, and the cost can be reduced due to the effect of mass production. Moreover, it is possible to prepare it as a spare by the common use, and it becomes possible to replace it instantly even in the case of a failure.

Further, the magnetic field generating means is shared with an adjacent ion source or plasma source. Therefore,
Since the magnetic field applying means is shared, the cost can be further reduced.

Further, as the magnetic field generating means, one or more coils are provided in the ion source or the plasma source, and the direction of the magnetic field formed in the plasma chamber by the coils is changed by the coils provided in the adjacent ion source or plasma source. The direction is the same as or opposite to the direction of the magnetic field formed in the plasma chamber.

Therefore, by making the directions of the magnetic fields opposite to each other, the magnetic fields generated by the coils of the adjacent ion sources can be effectively utilized, which reduces the capacity of the power supply required to energize the coils. It is possible to reduce the space by reducing the cost and the number of coil turns.

On the contrary, by making the directions of the magnetic fields the same, the magnetic field strength in the vicinity of the extraction electrode can be reduced, and the increase of divergence of the beam due to the leakage magnetic field in the vicinity of the extraction electrode can be suppressed. be able to.

In addition, the shape of the plurality of ion sources or plasma sources outside the plasma chamber, the shape of the ion extracting electrode, or the shape of the plasma source is the same. Therefore, since they have the same shape, they can be mass-produced and the cost can be further reduced.

Further, the particle beam irradiation directions of a plurality of ion sources or plasma sources are expanded outward or toward the central part. Therefore, the irradiation direction can be expanded outward, and an ion beam with a low density and a large area can be formed. Further, by setting the irradiation direction toward the center, an ion beam with a high density and a small area can be formed. Can be formed.

Further, a plurality of ion sources or plasma sources are arranged adjacent to each other outside the central space. Therefore, since the ion source or the plasma source is not arranged in the central portion, it is possible to avoid concentration of the irradiation on the central portion of the irradiation area, and it is possible to perform uniform irradiation.

Further, gas conductance adjusting means is provided between the ionized gas inlet of each ion source or each plasma source and the gas flow rate adjusting means. Therefore, it is not necessary to provide an expensive gas flow rate regulator for each ion source or each plasma source, and each gas flow rate can be adjusted by one gas flow rate adjusting means and a plurality of inexpensive gas conductance adjusting means. Therefore, the cost can be reduced.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described with reference to FIGS. In these figures, the same reference numerals indicate the same or corresponding components.

(Mode 1) Mode 1 will be described with reference to FIGS. 1 is a cross-sectional view when a plurality of bucket ion sources are closely arranged, FIG. 2A is a cross-sectional view taken along the line SS ′ of FIG. 1, FIG. 2B is a view taken in the direction of arrow T of FIG. 1, and FIGS. 3A and 3B. Shows the shape of the beam profile from each ion source and each plasma source.

By heating the hot filament 17 introduced into the casing 16 having a square cross section by energizing and heating it to emit thermoelectrons, by applying a direct current electric field with the thermofilament 17 at a negative potential and the casing 16 at a positive potential. , The plasma 19 is generated in the plasma chamber 18, the ions generated in the plasma 19 are extracted by the electric field formed by the ion beam extraction electrode 23 including the acceleration electrode 20, the deceleration electrode 21, and the ground electrode 22, Is formed, and the structure partitioned by the housing 16 and the extraction electrode 23 forms one ion source, and the plurality of ion sources are arranged like a grid.

The cusp magnetic field for plasma confinement is constituted by the permanent magnets 24 and forms magnetic lines of force 25 as shown in FIG. 2A, each permanent magnet 24 is shared with the adjacent ion source, and the extraction electrode 23 is each. It is attached to each ion source, and is composed of small area electrodes that are easy and inexpensive to process.

Therefore, since the area is small, the irradiation area of the beam extracted from each ion source is small,
It is possible to irradiate a large area ion beam which is equal to or larger than the conventional one.

Further, as shown in FIGS. 3A and 3B, the uniformity of the ion beam depends on whether the individual ion source has a uniform beam profile 26 or a Gaussian shape. By adjusting the spacing, the overall beam profile 2 is uniform throughout.
7 can be obtained.

(Mode 2) Further, the ion source is not limited to the structure as shown in FIG. 1, but various structures can be applied. That is, FIG. 4 is an application of an ion source generally called a Kaufman type ion source, and magnetic force lines 25 are formed in the axial direction as shown in the drawing. In this case as well, the permanent magnet 24 is shared with the adjacent ion source.

(Mode 3) A microwave ion source is a typical example of an ion source that does not use a filament.
FIG. 5 shows an example in which this is applied, and microwaves are supplied by the waveguide 28 through the dielectric window 29 to the plasma chamber 18 in which a magnetic field is formed. Further, an antenna can be used as a microwave transmission method.

(Mode 4) Further, as shown in FIG. 6, a microwave plasma cathode (MP cathode) type ion source in which microwave plasma is generated in the sub plasma chamber (MP cathode) 30 and is used as an electron supply source. There are various ion sources and plasma generation methods such as an electron beam excitation type ion source or a plasma cathode type ion source for generating plasma by extracting an electron beam to impact ionize gas.

The present invention is not affected by the structure and the plasma generation method as described above and can be applied to all of them.

(Mode 5) As a method of forming a magnetic field in the plasma chamber 18, not only a permanent magnet but also a coil 31 as shown in FIGS. 7A and 7B can be used. In this case, the directions of energizing the ion source and the coil 31 are reversed, and in this case, the magnetic field generated by the coil 31 of the adjacent ion source can be effectively used. This makes it possible to reduce the cost by reducing the capacity of the power supply required to energize the coil 31, and to reduce the wasted space by reducing the number of coil turns. FIG.
B is, on the contrary, energized in the same direction as the adjacent coil 31 of the ion source. In this case, it is possible to suppress an increase in beam divergence due to a leakage magnetic field in the vicinity of the ion beam extraction electrode 23, and the extraction electrode 23 The magnetic field strength in the vicinity of can be reduced. That is, the energization direction of the coil 31 is selected according to the purpose.

On the other hand, the plasma source is basically different from the ion source only in the extraction electrode, and most of them have an open end or a single electrode, and the present invention similar to the ion source can be applied.

Although it has been described above that a large-area ion source or plasma source can be easily realized, ion sources or plasma sources of various shapes can be realized by the arraying method.

That is, FIGS. 1 and 2 show the ion source arrangement for forming a square ion beam, but the arrangement shown in FIG. 8A or 8B makes it possible to form a circular or linear ion beam. Is.

Further, by standardizing the size of each ion source or plasma source, it is possible to achieve a large cost reduction by mass production and a drastic reduction in delivery time while meeting the requirements of various shapes. You can This is because it is possible to use common parts and greatly simplify the design.

Further, since an ion source of the same shape can be realized at a low cost, by providing a plurality of spare ion sources, it is possible to restore instantaneously in the event of a failure and improve the reliability of the device.

Further, as shown in FIGS. 9A and 9B, an angle can be provided between adjacent ion sources or plasma sources. FIG. 9A shows the case where the irradiation direction of the particle beam is expanded outward to form a low-density, large-area ion beam, and FIG. 9B is the irradiation direction of the particle beam near the center, and the high-density, small-area ion beam is used. In this case, various ion beams can be formed depending on the irradiation direction. Further, it is possible to form a space in the central portion and to arrange a plurality of ion sources or plasma sources adjacent to each other outside the space. In this case, high density of the central portion can be avoided.

In addition, the cross-sectional shape of the ion source or the plasma source is a square shape as shown in FIG. 2 so that the substantial irradiation area does not become small when arrayed, that is, the useless area is minimized. Or, a polygonal shape such as a rectangular shape, a hexagonal shape, or a triangular shape is desirable.

(Mode 6) Further, if a gas flow rate regulator is provided for each ion source as a gas introducing means to a large number of ion sources, it becomes extremely expensive. Therefore, the number of expensive gas flow rate regulators should be as small as possible. That is, as shown in FIG. 10, a needle valve or the like is provided between a gas flow rate adjuster 34 as a gas flow rate adjusting means provided in a cylinder 32 via a valve 33 and an inlet of each ion source or plasma source. Inexpensive gas conductance adjusting means 35
Is provided. Then, each gas conductance adjusting means 35
Thus, the flow rate of each gas can be adjusted to reduce the cost.

[0047]

Since the present invention is configured as described above, the following effects can be obtained. By making the outer shape of the plasma chamber, or the shape of the ion extraction electrode or the shape of the plasma source polygonal, each ion source or each plasma source can be brought close to each other without a gap, dead space does not occur, and a large area shape can be accommodated. The irradiation area can be made effective. Furthermore, the structure of each ion source or plasma source can be made common, and the cost can be reduced due to the effect of mass production. Moreover, it is possible to prepare it as a spare by the common use, and it becomes possible to replace it instantly even in the case of a failure.

Further, the cost can be further reduced by sharing the magnetic field generating means with the adjacent ion source or plasma source.

Further, the direction of the magnetic field formed in the plasma chamber by the coil provided in the ion source or plasma source as the magnetic field generating means is formed in the plasma chamber by the coil provided in the adjacent ion source or plasma source. The magnetic field generated by the coil of the adjacent ion source can be effectively used by setting the direction opposite to the direction of the magnetic field for the coil, thereby reducing the cost by reducing the capacity of the power supply required for energizing the coil and reducing the coil. The space can be reduced by reducing the number of turns.

On the contrary, by setting the directions of the magnetic fields in the same direction, it is possible to reduce the magnetic field strength in the vicinity of the extraction electrode and suppress an increase in beam divergence due to the leakage magnetic field in the vicinity of the extraction electrode. be able to.

Moreover, by making the outer shape of the plurality of ion sources or plasma sources outside the plasma chamber, or the shape of the ion extraction electrodes or the shape of the plasma source, mass production can be achieved, and the cost can be further reduced.

Further, by spreading the particle beam irradiation directions of a plurality of ion sources or plasma sources outward, it is possible to form an ion beam of low density and a large area, and the irradiation direction is closer to the central portion. By this, high density,
A small area ion beam can be formed.

Further, by arranging a plurality of ion sources or plasma sources adjacent to each other outside the space in the central portion, it is possible to avoid concentration of the irradiation on the central portion of the irradiation area, and to perform uniform irradiation. it can.

Further, by providing gas conductance adjusting means between the ionized gas introduction port of each ion source or each plasma source and the gas flow rate adjusting means, an expensive gas is supplied to each ion source or each plasma source. It is not necessary to provide a flow rate adjuster, and each gas flow rate can be adjusted by one gas flow rate adjusting means and a plurality of inexpensive gas conductance adjusting means, and cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of an essential part of a first embodiment of the present invention.

2 is a sectional view taken along the line SS ′ of FIG. 1, and B is a view taken in the direction of arrow T of FIG.

3A and 3B are shape diagrams of beam profiles, respectively.

FIG. 4 is a sectional view of an essential part of a second embodiment of the present invention.

FIG. 5 is a cross-sectional view of a main part of a third embodiment of the present invention.

FIG. 6 is a sectional view of a main part of a fourth embodiment of the present invention.

FIG. 7A and FIG. 7B are cross-sectional views of the essential parts of the fifth embodiment of the present invention.

FIG. 8A and FIG. 8B are exemplary views of the arrangement of the present invention.

9A and 9B are illustrations of irradiation directions of the present invention, respectively.

FIG. 10 is a schematic diagram of a sixth embodiment of the present invention.

FIG. 11 is a schematic view of a conventional example.

[Explanation of symbols]

 18 Plasma chamber 19 Plasma 23 Extraction electrode

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H05H 1/46 H05H 1/46 A

Claims (7)

[Claims] 1. A plasma chamber for generating plasma to generate ions, a magnetic field generating means for generating a magnetic field in the plasma chamber, and an extraction electrode for extracting ions generated in the plasma chamber by an electric field to generate an ion beam. An ion source device having a plurality of adjacent ion sources arranged adjacently, or a plurality of plasma sources having a plasma emission port instead of the extraction electrode, which diffuses and emits the plasma toward the sample stage, are adjacently arranged. In the plasma source device described above, a particle beam irradiation device in which the plasma outside shape, the ion extraction electrode shape, or the plasma source shape is polygonal. 2. The particle beam irradiation apparatus according to claim 1, wherein the magnetic field generating means is shared with an adjacent ion source or plasma source. 3. A coil is provided in the ion source or the plasma source as a magnetic field generating means, and the direction of the magnetic field formed in the plasma chamber by the coil is controlled in the plasma chamber by the coil provided in the adjacent ion source or plasma source. The particle beam irradiation apparatus according to claim 1, wherein the direction of the magnetic field formed is the same as or opposite to the direction of the magnetic field formed. 4. A plasma chamber outer shape of a plurality of ion sources or plasma sources, an ion extraction electrode shape or a plasma source shape is the same.
The particle beam irradiation apparatus described. 5. The particle beam irradiation apparatus according to claim 1, 2, 3 or 4, wherein the particle beam irradiation directions of a plurality of ion sources or plasma sources are expanded outward or toward the central portion. 6. A plurality of ion sources or plasma sources are arranged adjacent to each other on the outside between the chambers in the central portion.
Alternatively, the particle beam irradiation apparatus according to claim 4. 7. A plasma chamber for generating plasma to generate ions, a magnetic field generating means for generating a magnetic field in the plasma chamber, and an extraction electrode for extracting the ions generated in the plasma chamber by an electric field to generate an ion beam. An ion source device having a plurality of adjacent ion sources arranged adjacently, or a plurality of plasma sources having a plasma emission port instead of the extraction electrode, which diffuses and emits the plasma toward the sample stage, are adjacently arranged. In the above plasma source device, a particle beam irradiation device in which gas conductance adjusting means is provided between the ion source or the ionized gas inlet of each plasma source and the gas flow rate adjusting means.