JP6972693B2 - Ion generator and ion generation method - Google Patents

Description

The present invention relates to an ion generator and an ion generation method.

Conventionally, an ion generator that generates ions has been used in the manufacturing process of a semiconductor device.

The ion generator ionizes a gas as a raw material to generate ions (see, for example, Patent Document 1). The ions generated by the ion generator are, for example, accelerated to a predetermined incident energy and injected into the substrate. Further, the ions generated by the ion generator are formed into a focused ion beam and used for microfabrication (see, for example, Patent Document 2).

In the ion generator, an attractive force is applied to the ions generated in the chamber that generates ions by using an electric field generated by an extraction electrode having a predetermined potential, and the ions are extracted from the chamber. The ions extracted from the chamber are subjected to processes such as orbit adjustment and acceleration, and are irradiated to the substrate and the like.

Japanese Unexamined Patent Publication No. 1-2191161 Japanese Unexamined Patent Publication No. 7-320670

A voltage having the opposite polarity to the polarity of the ions is applied to the extraction electrode in order to apply an attractive force to the ions generated in the chamber. For example, a negative voltage is applied to the extraction electrode in order to apply an attractive force to a positively charged ion (positive ion).

Since an attractive force acts between the extraction electrode and the cation, the extraction electrode may be charged with the cation attached. In addition, the raw material gas or decomposition products of ions may adhere to the extraction electrode.

In this way, when positive ions adhere to the extraction electrode and become charged, a discharge occurs between the inside of the chamber and the deposits on the extraction electrode, making it difficult to maintain the voltage of the extraction electrode at a predetermined voltage. There is. Further, when a discharge occurs to the extraction electrode, the electrode may be damaged or deposits may adhere to the extraction electrode.

If the voltage of the extraction electrode becomes unstable, it affects the control of extracting ions from the chamber. Therefore, in some cases, the ion generation device may be stopped to perform maintenance work on the device.

It is an object of the present specification to provide an ion generator and an ion generation method for preventing the adhesion of ions and the like to the extraction electrode.

According to one embodiment of the ion generation apparatus disclosed in the present specification, an electric field is applied to an ion generation unit that generates ions and an ion generated by the ion generation unit, and an attractive force is applied to the ions to apply an attractive force to the ion generation unit. It is placed between the extraction electrode that draws ions from and the movement path and the extraction electrode where the ions extracted from the ion generation part move, and physically separates the movement path and the extraction electrode to provide electrical insulation. It is provided with a shielding portion having a shield.

Further, according to one embodiment of the ion generation method disclosed in the present specification, an electric field is applied to the ions generated by the ion generation unit using an extraction electrode having a predetermined potential, and an attractive force is applied to the ions to generate ions. It is defined by a shielding part that draws ions from the generation part and is placed between the moving path and the extraction electrode where the ions move, physically separates the moving path and the drawing electrode, and has electrical insulation. This includes moving the ions extracted from the ion generator along the moving path.

According to one form of the ion generator disclosed in the present specification described above, it is possible to prevent the adhesion of ions and the like to the extraction electrode.

Further, according to one form of the ion generation method disclosed in the present specification described above, it is possible to prevent the adhesion of ions and the like to the extraction electrode.

The objects and effects of the present invention will be recognized and obtained specifically by using the components and combinations pointed out in the claims.

Both the general description described above and the detailed description below are exemplary and descriptive and do not limit the invention described in the claims.

It is a figure which shows the ion generation apparatus of 1st Embodiment disclosed in this specification. It is a figure which shows the shielding part and the extraction electrode. It is a figure explaining the neutralization process of an ion generator. It is a figure which shows the modification 1 of the ion generation apparatus of 1st Embodiment disclosed in this specification. It is a figure which shows the modification 2 of the ion generation apparatus of 1st Embodiment disclosed in this specification. It is a figure which shows the ion generation apparatus of the 2nd Embodiment disclosed in this specification.

Hereinafter, a preferred first embodiment of the ion generator disclosed in the present specification will be described with reference to the drawings. However, the technical scope of the present invention is not limited to those embodiments, but extends to the inventions described in the claims and their equivalents.

FIG. 1 is a diagram showing an ion generator of the first embodiment disclosed in the present specification. FIG. 2 is a diagram showing a shielding portion and a drawing electrode.

The ion generator (hereinafter, also simply referred to as an apparatus) 10 generates various ions depending on the raw material. The generated ions are, for example, sorted by a mass spectrometer (not shown), their orbits are adjusted, and are accelerated to a predetermined incident energy by an accelerating unit (not shown) to irradiate a substrate or the like.

The device 10 includes an arc chamber 11, a gas supply unit 12, a first filament 13, a first magnetic force line generation unit 14, a reflector 15, a suppression electrode 16, an extraction electrode 17, a shielding unit 18, and a second. The filament 19 and the second magnetic force line generation unit 20 are provided.

The inside of the arc chamber 11 is decompressed to a predetermined pressure, and the raw material gas is ionized by an arc discharge to provide a space where ions are generated. The arc chamber 11 has a first opening 11a and a second opening 11b facing the first opening 11a via an internal space. The arc chamber 11 has electrical conductivity.

The device 10 has a DC power supply P1 for applying a positive voltage to the arc chamber 11 and a switch S1 for controlling the application of the voltage to the arc chamber 11. The switch S1 is controlled by a control unit (not shown).

The gas supply unit 12 generates molecules 30 of the raw material gas that is a raw material for ions and supplies them into the arc chamber 11 from the first opening 11a of the arc chamber 11. The device 10 has a DC power supply P2 that supplies electric power to the gas supply unit 12, and a switch S2 that controls the operation of the gas supply unit 12. The switch S2 is controlled by a control unit (not shown). _{For example, BF 3} can be used as the raw material gas.

The first filament 13 emits electrons 31 into the arc chamber 11 by being supplied with electric power from the DC power source P3 and heated. The device 10 has a switch S3 that controls the operation of the first filament 13. The switch S3 is controlled by a control unit (not shown). Further, the DC power supply P3 is connected in series with the DC power supply P1 and applies a positive voltage to the arc chamber 11.

The first magnetic force line generation unit 14 generates magnetic force lines and radiates the magnetic force lines into the arc chamber 11. The device 10 has a DC power supply P6 that supplies electric power to the first magnetic force line generation unit 14, and a switch S6 that controls the operation of the first magnetic force line generation unit 14. The switch S6 is controlled by a control unit (not shown).

The magnetic force lines radiated from the first magnetic force line generation unit 14 apply Lorentz force to the electrons 31 emitted by the first filament 13 to cause the electrons 31 to rotate in the arc chamber 11. As a result, the flight distance of the electron 31 in the arc chamber 11 is increased, the probability that the electron 31 collides with the molecule 30 of the raw material gas is improved, and the positive ion 32 is efficiently generated in the arc chamber 11. In the arc chamber 11, a plasma containing positive ions 32 generated by the molecules 30 of the raw material gas losing electrons and electrons and the like emitted from the molecules 30 of the raw material gas is generated. _{When BF 3} is used as the raw material gas, the device 10 generates positive ions of B and positive ions of F.

The reflector 15 emits secondary electrons when the electrons 31 emitted by the first filament 13 collide with each other. The electrons emitted by the reflector 15 also collide with the molecules 30 of the raw material gas in the arc chamber 11 to generate positive ions 32.

In the device 10, the above-mentioned arc chamber 11, the gas supply unit 12, the first filament 13, the first magnetic force line generation unit 14, and the reflector 15 cooperate to generate ions.

The suppression electrode 16 has a rectangular plate shape in a plan view and has an opening 16a inside. The opening 16a forms a part of the movement path M in which the cations 32 drawn from the inside of the arc chamber 11 move. The suppression electrode 16 is arranged so that the opening 16a overlaps with the second opening 11b of the arc chamber 11 when viewed from the drawing direction of the cation 32.

A negative voltage lower than the reference potential (potential of the substrate irradiated with ions, about 0 to 1E-2V: red box potential) is applied to the suppression electrode 16 by the DC power supply P5 to generate an electric field. The electric field generated by the suppression electrode 16 exerts a repulsive force on the electrons 31 in the arc chamber 11 to prevent the electrons 31 from being drawn out from the inside of the arc chamber 11 through the second opening 11b. The device 10 has a switch S5 that controls the application of a voltage to the suppression electrode 16. The switch S5 is controlled by a control unit (not shown). Further, the DC power supply P5 is controlled by a control unit (not shown), and the polarity of the applied voltage can be reversed.

As shown in FIG. 2, the extraction electrode 17 has a rectangular plate shape in a plan view, and has a rectangular opening 17a inside. The opening 17a forms a part of the movement path M in which the positive ions 32 drawn from the inside of the arc chamber 11 move. The shape of the opening 16a of the suppression electrode 16 described above in a plan view is the same as that of the opening 17a. The extraction electrode 17 is arranged so that the opening 17a overlaps the opening 16a of the suppression electrode 16 and the second opening 11b of the arc chamber 11.

A reference potential is applied to the extraction electrode 17 to generate an electric field. The extraction electrode 17 is electrically connected to the arc chamber 11 via the switch S4 and the DC power supply P4. The potential of the arc chamber 11 is higher than that of the extraction electrode 17 at the reference potential by the amount of the voltage applied by the DC power supply P4. The electric field generated by the extraction electrode 17 exerts an attractive force on the positive ions 32 in the arc chamber 11 to draw the positive ions 32 from the second opening 11b to the movement path M. Further, the electric field generated by the arc chamber 11 applies a repulsive force to the positive ions 32 in the arc chamber 11 to support the positive ions 32 being drawn out from the second opening 11b to the movement path M. The switch S4 is controlled by a control unit (not shown). Further, the DC power supply P4 is controlled by a control unit (not shown), and the polarity of the applied voltage can be reversed.

As shown in FIG. 2, the shielding portion 18 has the shape of a square cylinder having a quadrangular cross section, and has electrical insulation. The shielding portion 18 penetrates through the opening 16a of the suppression electrode 16 and the opening 17a of the extraction electrode 17 and extends into the second opening 11b of the arc chamber 11. The inside of the shielding portion 18 defines a movement path M in which the ions drawn from the arc chamber 11 in which the ions are generated move. The movement path M is a square columnar space surrounded by the shielding portion 18, and connects the space inside the arc chamber 11 and the space outside the extraction electrode 17.

The shielding portion 18 is arranged between the movement path M to which the ions extracted from the arc chamber 11 move and the extraction electrode 17, and physically separates the movement path M and the extraction electrode 17.

The extraction electrode 17 moves the ions generated in the arc chamber 11 in the movement path M defined by the shielding portion 18 and draws them out from the inside of the arc chamber 11. The ions of the arc chamber 11 are drawn in from the opening on the arc chamber 11 side of the shielding portion 18 and discharged to the outside through the opening on the extraction electrode 17 side.

By extending the shielding portion 18 into the second opening 11b of the arc chamber 11, the ions generated in the arc chamber 11 are prevented from adhering to the suppression electrode 16 or the extraction electrode 17.

The material forming the shielding portion 18 preferably has a low dielectric constant from the viewpoint of not dampening the electric field generated by the suppression electrode 16 and the extraction electrode 17.

As the relative permittivity of the material forming the shielding portion 18, for example, about 4 to 7 can be used. Further, as the resistivity of the material forming the shielding portion 18, for example, one having a resistivity of 1E13 to 1E15 ohm cm can be used.

As the material for forming the shielding portion 18, for example, ceramics such as aluminum oxide or boron nitride, high specific rigidity ceramics such as SiCIC, quartz (silicon dioxide) and the like can be used.

The second filament 19 is supplied with electric power from the DC power source P7 to generate electrons by heating, and emits electrons from the first opening 11a into the arc chamber 11. The device 10 has a switch S7 that controls the operation of the second filament 19. The switch S7 is controlled by a control unit (not shown).

The second magnetic force line generation unit 20 generates magnetic force lines and radiates the magnetic force lines into the arc chamber 11. The device 10 has a DC power supply P8 that supplies electric power to the second magnetic force line generation unit 20, and a switch S8 that controls the operation of the second magnetic force line generation unit 20. The switch S8 is controlled by a control unit (not shown).

The magnetic force lines generated by the second magnetic force line generation unit 20 apply Lorentz force to the electrons emitted by the second filament 19 to cause the electrons to rotate in the arc chamber 11. As a result, the flight distance of the electrons in the arc chamber 11 is increased, and the electrons can be moved to the inside of the shielding portion 18.

Next, the operation of the above-mentioned device 10 will be described below. The apparatus 10 has an ion generation step of generating ions and a neutralization step of neutralizing the positive ions adhering to the inside of the shielding portion 18 with electrons.

First, the ion generation process will be described.

In the ion generation step, as shown in FIG. 1, the switches S1 to 6 are controlled and closed by a control unit (not shown). On the other hand, the switches S7 and S8 are controlled and opened by a control unit (not shown).

The gas supply unit 12 generates molecules 30 of the raw material gas that is a raw material for ions and supplies them to the arc chamber 11 from the first opening 11a of the arc chamber 11. Further, the first filament 13 emits electrons 31 into the arc chamber 11 by being supplied with electric power from the DC power source P3 and heated. The magnetic force lines generated by the first magnetic force line generation unit 14 cause the electrons 31 emitted by the first filament 13 to rotate. The reflector 15 emits secondary electrons when the electrons 31 emitted by the first filament 13 collide with each other. In the arc chamber 11, the electron 31 collides with the molecule 30 of the raw material gas to generate a cation 32. In the arc chamber 11, a plasma containing positive ions 32 generated by the molecules 30 of the raw material gas losing electrons and electrons and the like emitted from the molecules 30 of the raw material gas is generated.

The electric field generated by the extraction electrode 17 exerts an attractive force on the positive ions 32 in the arc chamber 11 to draw the positive ions 32 from the second opening 11b to the movement path M. The ions of the arc chamber 11 are drawn in from the opening on the arc chamber 11 side of the shielding portion 18, move along the movement path M, and are discharged to the outside from the opening on the extraction electrode 17 side. Further, since the electron 31 in the arc chamber 11 receives a repulsive force by the electric field generated by the suppression electrode 16, it is restricted from moving to the movement path M. The suppression electrode 16 and the extraction electrode 17 are prevented from adhering to the positive ions 32 by arranging the shielding portion 18 between the suppression electrode 16 and the extraction electrode 17.

Next, the neutralization step will be described.

FIG. 3 is a diagram illustrating a neutralization step of the ion generator.

In the ion generation step described above, the inner surface of the shielding portion 18 that defines the movement path M may be charged with the positive ions 32 attached to it. There is a possibility that a discharge path for discharging electrons in the arc chamber 11 may be formed on the positively charged deposits on the inner surface of the shielding portion 18. Therefore, in the apparatus 10, in the neutralization step, electrons are supplied to the positively charged deposits to electrically neutralize them.

In the neutralization step, as shown in FIG. 3, the switches S4, S5, S7, and S8 are controlled and closed by a control unit (not shown). On the other hand, the switches S1 to S3 and S6 are controlled and opened by a control unit (not shown). That is, the generation of positive ions is stopped in the arc chamber 11.

Further, the DC power supplies P4 and P5 are controlled by a control unit (not shown), and the polarity of the applied voltage is inverted with respect to the time of the ion generation step. That is, a negative voltage is applied to the arc chamber 11. Further, a positive voltage is applied to the suppression electrode 16.

The second filament 19 is supplied with electric power from the DC power source P7 to generate electrons by heating, and emits electrons from the first opening 11a into the arc chamber 11. The magnetic force lines generated by the second magnetic force line generating unit 20 cause the electrons emitted by the second filament 19 to rotate, increase the flight distance of the electrons in the arc chamber 11, and shield the electrons facing the second filament 19. It reaches the inside of the part 18. The electric field generated by the suppression electrode 16 exerts an attractive force on the electrons in the arc chamber 11 and draws the electrons from the second opening 11b to the movement path M. Further, the electric field generated by the arc chamber 11 applies a repulsive force to the electrons in the arc chamber 11 to support the electrons being drawn from the second opening 11b to the movement path M. The electrons that reach the inside of the shielding portion 18 are adsorbed on the deposits adhering to the inner surface of the shielding portion 18 to neutralize the electric charge. This suppresses the generation of electric discharge between the inside of the arc chamber 11 and the positively charged deposits on the inner surface of the shielding portion 18.

Further, the neutralization step includes a step of supplying an etching gas for dry etching the deposits adhering to the inner surfaces of the arc chamber 11 and the shield portion 18 to the arc chamber 11 and the shield portion 18 to remove the deposits. It may be.

According to the apparatus of the present embodiment described above, by arranging the shielding portion between the suppression electrode and the extraction electrode and the moving path, it is possible to prevent the adhesion of ions and the like to the suppression electrode and the extraction electrode. As a result, it is possible to prevent the discharge from the inside of the arc chamber to the extraction electrode, so that the voltages of the suppression electrode and the extraction electrode can be kept stable. Further, it is possible to prevent the suppression electrode and the extraction electrode from being damaged by the electric discharge.

Therefore, according to the apparatus of the present embodiment, it is possible to shorten the period for stopping the apparatus for maintenance of the apparatus and to increase the operating time of the apparatus.

Next, the modified example 1 and the modified example 2 of the apparatus 10 of the first embodiment described above will be described below with reference to FIGS. 4 and 5.

FIG. 4 is a diagram showing a modification 1 of the ion generator of the first embodiment disclosed in the present specification.

In this modified example, the thickness of the shielding portion 18 defining the movement path M becomes thinner from the arc chamber 11 side toward the extraction electrode 17 side. Specifically, the thickness of the wall surface of the shielding portion 18 forming the quadrangular square tube becomes thinner from the arc chamber 11 side toward the extraction electrode 17 side.

The strength of the electric field generated by the extraction electrode 17 is weaker due to the arrangement of the shielding portion 18 than in the case where the shielding portion 18 is not arranged.

Therefore, in this modified example, by reducing the thickness of the shielding portion 18 on the extraction electrode 17 side, the strength of the electric field applied to the ions moving in the movement path M on the extraction electrode 17 side is increased, and the ions are generated. The attractive force given to is strengthened.

In the example shown in FIG. 4, the thickness of the shielding portion 18 continuously decreases from the arc chamber 11 side toward the extraction electrode 17, but the thickness of the shielding portion 18 decreases stepwise. May be.

FIG. 5 is a diagram showing a modification 2 of the ion generator of the first embodiment disclosed in the present specification.

In this modified example, the size of the movement path M defined by the shielding portion 18 decreases from the arc chamber 11 side toward the extraction electrode 17 side. The shielding portion 18 is a square tube having a tapered shape as a whole. The size of the movement path M may be said to be the cross-sectional area of the movement path M in the direction orthogonal to the traveling direction of the ions moving in the movement path M.

As described above, the strength of the electric field generated by the extraction electrode 17 is weaker due to the arrangement of the shielding portion 18 than in the case where the shielding portion 18 is not arranged, so that the attractive force to the ions is reduced and the degree of focusing of the ions is reduced. Tends to decline and spread.

Therefore, in this modified example, the cross-sectional area of the movement path M defined by the shielding portion 18 is narrowed in a taper shape toward the traveling direction of the ions to increase the attractive force for the ions and to focus the extracted ions. The degree is increasing.

In the example shown in FIG. 5, the size of the movement path M continuously decreases from the arc chamber 11 side toward the extraction electrode 17, but the size of the movement path M decreases stepwise. May be.

Next, a second embodiment of the above-mentioned ion generator will be described below with reference to FIG. The detailed description of the first embodiment described above is appropriately applied to the points not particularly described with respect to the second embodiment. Further, the same components are designated by the same reference numerals.

FIG. 6 is a diagram showing an ion generator of the second embodiment disclosed in the present specification.

The device 10 of the present embodiment arcs to the first extraction electrode 17 (corresponding to the extraction electrode of the first embodiment) arranged on the arc chamber 11 side and the first extraction electrode 17 as extraction electrodes. It has a second extraction electrode 21 located on the opposite side of the chamber 11.

A negative voltage lower than the reference potential (potential of the substrate irradiated with ions, about 0 to 1E-2V) is applied to the second extraction electrode 21 by the DC power supply P9 to generate an electric field. The device 10 has a switch S9 that controls the application of a voltage to the second extraction electrode 21. The switch S9 is controlled by a control unit (not shown).

The electric field generated by the second extraction electrode 21 exerts an attractive force on the cation 32 in the arc chamber 11 and draws the cation 32 from the second opening 11b to the movement path M.

As described above, the strength of the electric field generated by the first extraction electrode 17 is weaker due to the arrangement of the shielding portion 18 than in the case where the shielding portion 18 is not arranged, so that the attractive force to the ions is reduced and the ions are generated. The degree of focusing tends to decrease and spread.

Therefore, in the present embodiment, by arranging the second extraction electrode 21 in addition to the first extraction electrode 17, the attractive force for the ions is increased and the degree of focusing of the extracted ions is increased.

The contour of the second extraction electrode 21 in a plan view has the same shape as the first extraction electrode 17.

As described above, the first extraction electrode 17 has an opening 17a through which the shielding portion 18 defining the movement path M penetrates. The second extraction electrode 21 also has an opening 21a through which the shielding portion 18 defining the movement path M penetrates.

The size of the opening 21a of the second extraction electrode 21 is smaller than that of the opening 17a of the first extraction electrode 17. That is, the diameter of the opening 21a of the second extraction electrode 21 is smaller than the opening 17a of the first extraction electrode 17.

The opening 21a of the second extraction electrode 21 is arranged so that the position of the center thereof coincides with the center of the opening 17a of the first extraction electrode 17.

Therefore, the distance between the surface of the shielding portion 18 and the edge of the opening 21a of the second extraction electrode 21 is larger than the distance between the surface of the shielding portion 18 and the edge of the opening 17a of the first extraction electrode 17. It gets shorter.

Therefore, the attractive force of the electric field generated by the second extraction electrode 21 acting on the positive ions 32 in the arc chamber 11 is larger than that of the first extraction electrode 17. As a result, in the device 10, the attractive force for the ions is further increased, and the degree of focusing of the extracted ions is further increased.

According to the apparatus 10 of the present embodiment described above, the attractive force for drawing ions out of the arc chamber is increased, and the degree of focusing of the drawn ions is increased. In addition, the same effect as that of the first embodiment described above is obtained.

In the present invention, the ion generation apparatus and the ion generation method of the above-described embodiment can be appropriately changed as long as they do not deviate from the gist of the present invention. Further, the constituent requirements of one embodiment can be appropriately applied to other embodiments.

For example, in each of the embodiments described above, the device generated positive ions, but may generate negative ions. When the device produces negative ions, the polarities of the voltages applied to the suppression and ground electrodes are opposite. When generating negative ions, the second filament generates charged particles (positive ions) having a positive polarity opposite to that of negative ions, and is charged so that the charged particles can be released into the movement path. It is preferable to use a particle generation unit.

Further, in each of the above-described embodiments, the shielding portion extends into the second opening of the arc chamber, but the shielding portion does not have to extend into the second opening.

All examples and conditional terms given herein are intended for educational purposes to help the reader gain a deeper understanding of the inventions and concepts contributed by the inventor. All examples and conditional terms mentioned herein should be construed without limitation to such specifically stated examples and conditions. Also, such exemplary mechanisms in the specification are not related to exhibiting superiority and inferiority of the invention. Although embodiments of the invention have been described in detail, it should be understood that various modifications, replacements or modifications thereof can be made without departing from the spirit and scope of the invention.

10 Ion generator 11 Arc chamber 11a 1st opening 11b 2nd opening 12 Gas supply part 13 1st filament 14 1st magnetic field line generator 15 Reflector 16 Suppression electrode 16a Opening 17 Drawer electrode 17a Opening 18 Shielding part 19 2 filaments (charged particle generator)
20 Second magnetic force line generator 21 Second extraction electrode S1 to S9 Switch P1 to P9 DC power supply 30 Gas molecule 31 Electron 32 Ion M Movement path

Claims (7)

An ion generator that generates ions and
An extraction electrode that applies an electric field to the ions generated by the ion generation unit and applies an attractive force to the ions to extract the ions from the ion generation unit.
An electrical insulating shielding portion that is arranged between a moving path through which ions drawn from the ion generating section move and an extraction electrode, physically separates between the moving path and the extraction electrode, and has electrical insulation. ,
Equipped with
The ion generation unit has an opening for discharging the generated ions.
The shielding section, an ion generating device that extends to within the opening. The thickness of the shielding portion defining a path of travel, the ion generating apparatus according to claim 1 which is thinner toward the side opposite to the ion generator from the ion generation portion. The movement path is a space surrounded by the shielding portion, and is a space.
The ion generation device according to claim 1 or 2 , wherein the size of the movement path decreases from the ion generation unit side toward the side opposite to the ion generation unit. The drawer electrode is
With the first electrode
A second electrode arranged on the side opposite to the ion generating unit with respect to the first electrode,
Have,
The first electrode has a first opening through which the movement path penetrates.
The second electrode has a second opening through which the movement path penetrates.
The ion generator according to any one of claims 1 to 3 , wherein the size of the second opening is smaller than that of the first opening. One of claims 1 to 4 , wherein a charged particle generation unit having a charged particle generation unit capable of generating charged particles having a polarity opposite to that of the ion generated by the ion generation unit and discharging the charged particles into the movement path is provided. The ion generator according to. Using an extraction electrode having a predetermined potential, an electric field is applied to the ions generated by the ion generation unit, and an attractive force is applied to the ions to extract the ions emitted from the opening of the ion generation unit.
Arranged so as to extend to the opening between the movement path through which ions move and the extraction electrode, the movement path and the extraction electrode are physically separated, and are defined by a shielding portion having electrical insulation. To move the ions extracted from the ion generation unit along the movement path to be carried out,
Ion generation method including. In addition,
With the ion generation unit stopped producing ions, charged particles having a polarity opposite to that of the ions generated by the ion generation unit are radiated into the movement path to the shielding unit. The ion generation method according to claim 6 , which comprises.

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