JP3550831B2 - Particle beam irradiation equipment - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ion source device or a plasma source device used for forming a thin film such as ion implantation or ion irradiation, and particularly to a particle beam irradiation device suitable for processing a substrate having a large area.
[0002]
[Prior art]
As an example of a conventional ion source device, a bucket type ion source device using a hot filament shown in FIG. 11 will be described.
[0003]
In the figure, reference numeral 1 denotes a metal casing of an ion source device, 2 denotes a plasma chamber formed by the casing 1 for generating plasma and generating ions, and 3 denotes a hot filament introduced into the plasma chamber 2. Reference numeral 4 denotes a filament power supply for heating the filament 3, reference numeral 5 denotes a gas inlet to the plasma chamber 2, and reference numeral 6 denotes an ion beam extraction electrode provided in the housing 1 via an insulator 7, and includes an acceleration electrode 8, a deceleration electrode It comprises an electrode 9 and a ground electrode 10. Reference numeral 11 denotes a plurality of permanent magnets provided outside the housing 1 and is formed from an annular body or a rod-like body, and forms a cusp magnetic field inside the housing 1.
[0004]
Reference numeral 12 denotes an arc power supply, the anode of which is connected to the housing 1 and the cathode of which is connected to the filament power supply 4, and applies an anode voltage to the housing 1. Reference numeral 13 denotes an accelerating power source. The anode is connected to the accelerating electrode 8 and the cathode of the arc power source 12, and the cathode is grounded. Reference numeral 14 denotes a deceleration power supply for applying a negative voltage to the deceleration electrode 9.
[0005]
The filament 3 is a thermoelectron emission source serving as a cathode. The filament 3 is maintained at a high temperature by the resistance heating of the filament power supply 4 and emits thermoelectrons. The emitted thermoelectrons are generated by a DC electric field formed by the arc power supply 12. The plasma 15 is generated by accelerating and ionizing the gas particles introduced from the gas inlet 5 by collision.
[0006]
Further, a cusp magnetic field is formed by the permanent magnet 11, confining the plasma 15, and the ions in the plasma 15 are extracted as an ion beam by the extraction operation of the extraction electrode 6.
[0007]
Other methods of generating the ion source and the plasma source include a high-frequency ion source using a high-frequency discharge, a microwave ion source using a microwave discharge, a plasma cathode ion source using a primary plasma as an electron source, and an electron source. There are various ion sources such as an electron beam excitation type ion source for extracting a beam and performing impact ionization, and a plasma source having no beam extraction electrode group.
[0008]
By the way, when it is attempted to irradiate a large-area substrate with an ion beam or plasma using such an ion source or a plasma source, it is necessary to increase the irradiation area of the ion source or the plasma source according to the substrate size. Is very large.
[0009]
In the case of a large-sized apparatus, in particular, the ion extraction electrode needs to suppress warpage and distortion to the maximum in order to extract a beam uniformly, and its processing becomes extremely difficult.
[0010]
Particularly, in the case of irradiation of a substrate of 1 m square or more, which is required in recent years, the processing difficulty and cost of the electrode dramatically increase. Even if a cusp magnetic field is used for confining the plasma as in the conventional example, it is difficult to generate plasma uniformly when the ion source or the plasma source is 1 m square or more, and the position of the filament must be carefully considered. There is a need.
[0011]
Furthermore, the size of these ion sources and plasma sources depends on the size and arrangement of the substrate. To meet individual requirements, there is no way to set a standard size and reduce the price by mass production. Can not.
[0012]
Therefore, it is necessary to design each device from the beginning, and the design cost cannot be reduced. Also, since the components cannot be shared, the cost is high and the delivery time has to be very long.
[0013]
In addition, since such a device is expensive and special, no spare parts can be prepared, and in the case of a failure, there is a risk that the production line will be stopped for a long period of time.
[0014]
On the other hand, as described in Japanese Patent Application Laid-Open No. 4-147772 (C23C 14/48), it has been invented that a plurality of ion beam generators are arranged side by side to cope with a large area. .
[0015]
[Problems to be solved by the invention]
By the way, as described in the above publication, when a plurality of devices are provided side by side, a large gap is generated between adjacent devices because the outer shape of the devices is circular, dead space occurs, and ion beam irradiation cannot be performed effectively. There is a problem.
[0016]
It is an object of the present invention to provide a particle beam irradiation apparatus which takes into account the above points, and which responds to various large-area shapes and makes the irradiation area effective.
[0017]
[Means for Solving the Problems]
In order to solve the above problems, the particle beam irradiation apparatus of the present invention comprises a plasma chamber for generating generates the plasma ions, and magnetic field generating means for generating a magnetic field to the plasma chamber, generated in the plasma chamber An ion source device having a plurality of ion sources provided with extraction electrodes for extracting ions by an electric field and generating an ion beam,
[0018]
Alternatively, in the plasma source device, a plurality of plasma sources having a plasma emission port for diffusing and emitting the plasma in the direction of the sample table in place of the extraction electrode are arranged adjacently.
[0019]
The shape outside the plasma chamber, the shape of the ion extraction electrode or the shape of the plasma source is polygonal , and the magnetic field generating means is shared with an adjacent ion source or plasma source .
Therefore, each ion source or each plasma source can be brought close to each other without any gap, dead space does not occur, it is possible to cope with a large area shape, and effective irradiation area can be achieved. Furthermore, the structure of each ion source or plasma source can be shared, and the cost can be reduced due to the effect of mass production. In addition, it can be prepared as a spare by common use, and instantaneous replacement is possible even in case of failure.
[0020]
In addition , since the means for applying the magnetic field is shared, the cost can be further reduced.
[0021]
Further, one or more coils are provided in the ion source or the plasma source as the magnetic field generating means, and the direction of the magnetic field formed in the plasma chamber by the coils is changed by the coil provided in the adjacent ion source or the plasma source. In the same direction as or opposite to the direction of the magnetic field formed in
[0022]
Therefore, by setting the direction of the magnetic field to the opposite direction, it is possible to effectively use the magnetic field generated by the coil of the adjacent ion source. Space can be reduced by reducing the number of coil turns.
[0023]
Conversely, by setting the direction of the magnetic field in the same direction, the magnetic field intensity in the vicinity of the extraction electrode can be reduced, and the increase in the divergence of the beam due to the leakage magnetic field in the vicinity of the extraction electrode can be suppressed. .
[0024]
In addition, a plurality of ion sources or plasma sources have the same shape outside the plasma chamber, or the shape of the ion extraction electrode or the shape of the plasma source.
Therefore, since the shapes are the same, mass production can be performed, and the cost can be further reduced.
[0025]
In addition, the irradiation direction of the particle beam of the plurality of ion sources or plasma sources is expanded outward or closer to the center.
Therefore, the irradiation direction can be expanded outward, and a low-density, large-area ion beam can be formed. Also, by setting the irradiation direction closer to the center, a high-density, small-area ion beam can be formed. Can be formed.
[0026]
Further, a plurality of ion sources or plasma sources are arranged adjacent to each other outside the space at the center.
Therefore, since the ion source or the plasma source is not arranged at the center, the concentration of the irradiation to the center of the irradiation area can be avoided, and the irradiation can be performed uniformly.
[0027]
Further, a 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 controller for each ion source or each plasma source, and each gas flow can be adjusted by one gas flow adjusting device and a plurality of inexpensive gas conductance adjusting devices. Thus, 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 drawings, the same reference numerals indicate the same or corresponding components.
[0029]
(Form 1)
Embodiment 1 will be described with reference to FIGS. 1 is a cross-sectional view when a plurality of bucket-type ion sources are closely arranged, FIG. 2A is a cross-sectional view taken along the line SS ′ in FIG. 1, FIG. 2B is a view as viewed from the arrow T in FIG. Indicates the shape of the beam profile from each ion source and each plasma source.
[0030]
The hot filament 17 introduced into the casing 16 having a square cross section is heated by heating to emit thermoelectrons, and the hot filament 17 is set to a negative potential and the casing 16 is set to a positive potential to apply a DC electric field. A plasma 19 is generated at 18 . The ions generated in the plasma 19 are extracted by an electric field formed by an ion beam extraction electrode 23 including an acceleration electrode 20, a deceleration electrode 21, and a ground electrode 22, and an ion beam is formed. The components delimited by 23 form one ion source, and a plurality of the ion sources are arranged like a grid.
[0031]
The cusp magnetic field for confining the plasma 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 an adjacent ion source, and the extraction electrode 23 is connected to each ion source. Each is mounted, and is composed of small-area electrodes that are simple and inexpensive to process.
[0032]
Therefore, although the area of the beam is small, the beam irradiation area per one ion source is small, but a large area ion beam irradiation equal to or more than the conventional one can be performed as a whole.
[0033]
Also, as shown in FIGS. 3A and 3B, the uniformity of the ion beam can be adjusted by adjusting the interval between the individual ion sources when the beam profile 26 of the individual ion source is uniform or in a Gaussian shape. By doing so, a uniform overall beam profile 27 can be obtained.
[0034]
(Form 2)
Further, the ion source is not necessarily limited to the structure as shown in FIG. 1, and various structures can be applied. That is, FIG. 4 shows an application of an ion source generally called a Kauffman-type ion source, in which magnetic lines of force 25 are formed in the axial direction as shown. Also in this case, the permanent magnet 24 is shared with an adjacent ion source.
[0035]
(Form 3)
A typical example of an ion source that does not use a filament is a microwave ion source, and FIG. 5 shows an example in which the ion source is applied. A microwave is applied by a waveguide 28 through a dielectric window 29 to form a magnetic field. To the plasma chamber 18.
Further, an antenna can be used as a microwave transmission method.
[0036]
(Form 4)
As shown in FIG. 6, a microwave plasma is generated in a sub-plasma chamber (MP cathode) 30, a microwave plasma cathode (MP cathode) type ion source using the generated plasma as an electron supply source, and an electron beam is extracted to generate a gas. 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 ionized plasma by impact ionization.
[0037]
The present invention is completely unaffected by the structure and the method of generating plasma as described above, and can be applied to all of them.
[0038]
(Form 5)
As a method for forming a magnetic field in the plasma chamber 18, not only a permanent magnet but also a coil 31 can be used as shown in FIGS. 7A and 7B. FIG. The direction in which the power is supplied is reversed, and in this case, the magnetic field generated by the coil 31 of the adjacent ion source can be used effectively. This makes it possible to reduce costs by reducing the capacity of the power supply required for energizing the coil 31 and to reduce unnecessary space by reducing the number of coil turns. FIG. 7B shows the case where the current is applied in the same direction as the coil 31 of the adjacent ion source. In this case, the increase in the divergence of the beam due to the leakage magnetic field near the ion beam extraction electrode 23 can be suppressed. The magnetic field intensity in the vicinity of the extraction electrode 23 can be reduced. That is, the energizing direction of the coil 31 is selected according to the purpose.
[0039]
On the other hand, the plasma source basically differs from the ion source only in the extraction electrode, and most of the plasma sources have an open end or a single electrode, and the present invention similar to the ion source can be applied.
[0040]
Although it has been described above that an ion source or a plasma source having a large area can be easily realized, ion sources or plasma sources having various shapes can be realized depending on the arrangement method.
[0041]
That is, FIGS. 1 and 2 show an ion source arrangement in the case of forming a square ion beam. By using the arrangement shown in FIG. 8A or 8B, a circular or linear ion beam can be formed.
[0042]
In addition, by standardizing the size of each ion source or plasma source, it is possible to greatly reduce costs by mass production and significantly shorten the delivery time while responding to requests for various shapes. This is because the parts can be shared and the design can be greatly simplified.
[0043]
Furthermore, since an ion source of the same shape can be realized at low cost, provision of a plurality of spare ion sources enables instantaneous recovery from a failure, thereby improving the reliability of the apparatus.
[0044]
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. FIG. 9B shows the case where the irradiation direction of the particle beam is shifted toward the center, and the high-density, small-area ion beam is formed. Is formed, and various ion beams can be formed depending on the irradiation direction. Furthermore, it is also possible to form a space in the center and arrange a plurality of ion sources or plasma sources adjacent to the outside of the space. In this case, it is possible to avoid high density in the center.
[0045]
In addition, the cross-sectional shape of the ion source or the plasma source should be square or rectangular as shown in FIG. 2 so that a substantial irradiation area does not become small when arranged, that is, a useless area is reduced as much as possible. Alternatively, a polygonal shape such as a hexagonal shape and a triangular shape is desirable.
[0046]
(Form 6)
Further, if a gas flow controller is provided for each ion source as a means for introducing gas to a large number of ion sources, it becomes extremely expensive. Therefore, the number of expensive gas flow controllers is reduced as much as possible. That is, as shown in FIG. 10, a needle valve or the like is provided between a gas flow controller 34 as a gas flow controller 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. The individual gas flow rates can be adjusted by the respective gas conductance adjusting means 35 to reduce the cost.
[0047]
【The invention's effect】
The present invention is configured as described above, and has the following effects.
By making the external shape of the plasma chamber, or the shape of the ion extraction electrode or the plasma source a polygonal shape, each ion source or each plasma source can be brought close to each other without any gap, and dead space does not occur, and a large area shape can be handled. The irradiation area can be made effective. Furthermore, the structure of each ion source or plasma source can be shared, and the cost can be reduced due to the effect of mass production. In addition, it can be prepared as a spare by common use, and instantaneous replacement is possible even in case of failure.
[0048]
Further , by sharing the magnetic field generating means with an adjacent ion source or plasma source, it is possible to further reduce the cost.
[0049]
Furthermore, 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 changes the direction of the magnetic field formed in the plasma chamber by the coil provided in the adjacent ion source or plasma source. By making the direction opposite to the direction, the magnetic field generated by the coil of the adjacent ion source can be used effectively, thereby reducing the cost of the power supply required for energizing the coil and reducing the number of coil turns. Space can be reduced by the reduction.
[0050]
Conversely, by setting the direction of the magnetic field in the same direction, the magnetic field intensity in the vicinity of the extraction electrode can be reduced, and the increase in the divergence of the beam due to the leakage magnetic field in the vicinity of the extraction electrode can be suppressed. .
[0051]
In addition, when the plurality of ion sources or plasma sources have the same shape outside the plasma chamber, or the shape of the ion extraction electrode or the shape of the plasma source, the mass production can be achieved and the cost can be further reduced.
[0052]
In addition, by widening the irradiation direction of the particle beam from a plurality of ion sources or plasma sources, a low-density, large-area ion beam can be formed. A high-density, small-area ion beam can be formed.
[0053]
Furthermore, 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 the concentration of irradiation to the central portion of the irradiation area, and to perform uniform irradiation.
[0054]
Further, by providing gas conductance adjusting means between the ionized gas inlet of each ion source or each plasma source and the gas flow rate adjusting means, an expensive gas flow rate adjuster is provided for each ion source or each plasma source. Need not be provided, each gas flow rate can be adjusted by one gas flow rate adjusting means and a plurality of inexpensive gas conductance adjusting means, and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a sectional view of a main part according to a first embodiment of the present invention.
2A is a cross-sectional view taken along the line SS ′ of FIG. 1, and FIG.
3A and 3B are shape diagrams of a beam profile, respectively.
FIG. 4 is a sectional view of a main part according to a second embodiment of the present invention.
FIG. 5 is a sectional view of a main part according to a third embodiment of the present invention.
FIG. 6 is a sectional view of a main part according to a fourth embodiment of the present invention.
FIGS. 7A and 7B are cross-sectional views of main parts of a fifth embodiment of the present invention.
FIGS. 8A and 8B are illustrations of the sequences of the present invention.
FIGS. 9A and 9B are illustrations of irradiation directions according to the present invention.
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

Claims (8)

An ion source including a plasma chamber that generates plasma and generates ions, a magnetic field generating unit that generates a magnetic field in the plasma chamber, and an extraction electrode that extracts an ion generated in the plasma chamber by an electric field and generates an ion beam. A plurality of adjacent ion source devices,
Alternatively, in the plasma source device, a plurality of plasma sources having a plasma emission port for diffusing and emitting the plasma in the direction of the sample table in place of the extraction electrode are arranged adjacently.
The plasma chamber outer shape, or the ion extraction electrode shape or the plasma source shape is a polygonal shape ,
A particle beam irradiation apparatus in which the magnetic field generating means is shared with an adjacent ion source or plasma source . A coil is provided in the ion source or plasma source as a magnetic field generating means, and the direction of the magnetic field formed in the plasma chamber by the coil is changed by the coil provided in the adjacent ion source or plasma source. The particle beam irradiation apparatus according to claim 1 , wherein the direction is the same as or opposite to the direction . 3. The particle beam irradiation apparatus according to claim 1, wherein a plurality of ion sources or plasma sources have the same shape outside the plasma chamber, or the shape of an ion extraction electrode or the shape of the plasma source . An ion source including a plasma chamber that generates plasma and generates ions, a magnetic field generating unit that generates a magnetic field in the plasma chamber, and an extraction electrode that extracts an ion generated in the plasma chamber by an electric field and generates an ion beam. A plurality of adjacent ion source devices,
Alternatively, in the plasma source device, a plurality of plasma sources having a plasma emission port for diffusing and emitting the plasma in the direction of the sample table in place of the extraction electrode are arranged adjacently.
The plasma chamber outer shape, or the ion extraction electrode shape or the plasma source shape is a polygonal shape,
And, wherein the plurality of particle beam irradiation direction of the ion source or a plasma source, the particle beam irradiation apparatus which splayed or central portion closer. A plurality of the particle beam irradiation direction of the ion source or a plasma source, the claims and the splayed or central closer 1, 2 or the particle beam irradiation apparatus according to claim 3. An ion source including a plasma chamber that generates plasma and generates ions, a magnetic field generating unit that generates a magnetic field in the plasma chamber, and an extraction electrode that extracts an ion generated in the plasma chamber by an electric field and generates an ion beam. A plurality of adjacent ion source devices,
Alternatively, in the plasma source device, a plurality of plasma sources having a plasma emission port for diffusing and emitting the plasma in the direction of the sample table in place of the extraction electrode are arranged adjacently.
The plasma chamber outer shape, or the ion extraction electrode shape or the plasma source shape is a polygonal shape,
And particle sagittal irradiation apparatus arranged adjacent to the outside more ion source or plasma source between an empty central portion. 6. The particle beam irradiation apparatus according to claim 1, wherein a plurality of ion sources or plasma sources are arranged adjacent to each other outside the central space . The 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, respectively. Particle beam irradiation device.

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