WO2025141823A1 - Charged particle beam device - Google Patents

Abstract

Provided is a charged particle beam device comprising: an extraction electrode that forms an electric field for extracting ions from an opening of a plasma ion source; a current-limiting diaphragm that narrows an ion beam extracted by the extraction electrode and adjusts a beam spot diameter formed on a sample and a beam current applied to the sample; and a control device that controls the voltage applied to the extraction electrode. The control device: stores a first voltage set for the applied voltage, a second voltage set lower than the first voltage, and a prescribed current set for the beam current of the ion beam; sets the applied voltage to the first voltage; drives the current-limiting diaphragm to control the beam spot diameter and change the beam current within a range of the prescribed current or more; and in a range where the beam current falls below the prescribed current, sets the applied voltage to the second voltage and reduces the beam spot diameter as compared with a case where the applied voltage is set to the first voltage.

Description

Charged Particle Beam Device

The present invention relates to a charged particle beam device equipped with a plasma ion source.

Some charged particle beam devices use a plasma ion source, as described in JP 2020-71904 A (Patent Document 1). Charged particle beam devices using a plasma ion source can scan a sample with a higher current ion beam than conventional focused ion beam devices that use a gallium ion source, which is a liquid metal light source, and can shorten the scanning time for large samples.

JP 2020-71904 A

Compared to charged particle beam devices using gallium ion sources, charged particle beam devices using plasma ion sources have the advantage of being able to irradiate a sample with a high-current ion beam, but the beam spot is large, which reduces the processing accuracy and resolution of the observed image.

The objective of the present invention is to provide a high-resolution charged particle beam device that uses a plasma ion source.

In order to achieve the above object, the present invention provides a charged particle beam device comprising a plasma ion source, an extraction electrode that forms an electric field that extracts ions from an opening of the plasma ion source, a current limiting aperture that narrows the ion beam extracted by the extraction electrode and adjusts the beam spot diameter formed on a sample and the beam current irradiated to the sample, and a control device that controls the voltage applied to the extraction electrode, the control device storing a first voltage set for the applied voltage, a second voltage set lower than the first voltage, and a predetermined current set for the beam current of the ion beam, the control device sets the applied voltage to the first voltage, drives the current limiting aperture to control the beam spot diameter and change the beam current in a range equal to or greater than the predetermined current, and when the beam current is below the predetermined current, sets the applied voltage to the second voltage, and reduces the beam spot diameter more than when the applied voltage is set to the first voltage.

The present invention makes it possible to improve the resolution of a charged particle beam device using a plasma ion source.

1 is a schematic diagram of a charged particle beam device according to an embodiment of the present invention; 2 is a schematic diagram of a power supply circuit for an extraction electrode provided in a charged particle beam device according to an embodiment of the present invention. FIG. 1 is a diagram showing a schematic shape of an ion emission surface at an opening of a plasma ion source provided in a charged particle beam device according to an embodiment of the present invention in a high voltage mode. 1 is a diagram showing a schematic shape of an ion emission surface at an opening of a plasma ion source provided in a charged particle beam device according to an embodiment of the present invention in a low voltage mode. 1 is a diagram showing the relationship between the beam current and the beam spot diameter of an ion beam in a charged particle beam apparatus according to an embodiment of the present invention.

The following describes an embodiment of the present invention using the drawings.

-Charged particle beam device-
Fig. 1 is a schematic diagram of a charged particle beam apparatus according to an embodiment of the present invention. The charged particle beam apparatus 1 shown in Fig. 1 is a composite charged particle beam apparatus (FIB-SEM) equipped with a plasma ion source 31, and is capable of processing and observing a sample S using an ion beam (FIB) extracted from a plasma, and observing the sample S using an electron beam (EB). The charged particle beam apparatus 1 can irradiate a high-current ion beam IB onto the sample S, and the sample S can be, for example, a relatively large (e.g., 300 mm diameter) semiconductor wafer or other large-volume sample.

The charged particle beam device 1 comprises a sample chamber 10, a stage (sample table) 20, an ion beam lens barrel 30, an electron beam lens barrel 40, a detector 50, and a control device 60. Although not shown in FIG. 1, the charged particle beam device 1 may also comprise a manipulator that supports a sample piece cut out from the sample S, a gas gun that emits a specific gas such as an etching gas or a deposition gas onto the sample S, and the like.

- Sample chamber -
During processing or observation of the sample S, the inside of the sample chamber 10, together with the ion beam column 30 and the electron beam column 40, is depressurized to a predetermined vacuum level.

-stage-
The stage 20 holds and fixes the sample S inside the sample chamber 10. The stage 20 includes a sample stage on which the sample S is placed, and a mechanism for displacing the sample stage with five degrees of freedom. The mechanism for displacing the sample stage has, for example, five degrees of freedom, and includes an XYZ movement mechanism for translating the sample stage along the X-axis, Y-axis, and Z-axis, a rotation mechanism for rotating the sample stage around the vertical Z-axis, and a tilt mechanism for rotating the sample stage around the horizontal X-axis (or Y-axis). The X-axis and Y-axis are two axes that are mutually orthogonal in a horizontal plane, and the Z-axis is orthogonal to these X-axis and Y-axis. The stage 20 displaces the sample stage to move a desired portion of the sample S to the beam spot of the ion beam IB or the electron beam.

- Ion beam tube -
The ion beam column 30 is fixed to the sample chamber 10 and used for processing or observing the sample S, and irradiates the sample S held on the stage 20 with an ion beam IB. Although Fig. 1 illustrates a configuration in which the ion beam column 30 is provided in the sample chamber 10 in a state inclined with respect to the vertical, the ion beam column 30 may be provided in the sample chamber 10 in a vertical position. The ion beam column 30 is controlled by a control device 60.

The ion beam tube 30 includes a plasma ion source 31, an extraction electrode 32, a capacitor electrode (condenser lens) 33, a current limiting aperture 34, and a focus electrode (objective lens) 35.

The plasma ion source 31 is configured to include, for example, a plasma generation chamber (plasma generator) 31a (Figure 2) that maintains plasma inside and allows ions to flow out, and a plasma aperture (plasma electrode) 31b (Figure 2) that draws ions out from the plasma generation chamber 31a. A rare gas is used as the plasma gas that forms the plasma in the plasma ion source 31. The plasma gas is, for example, one or more types of gas selected from neon, argon, xenon, and krypton.

The extraction electrode 32 forms an electric field that extracts ions from the opening of the plasma ion source 31, i.e., the orifice 31c of the plasma aperture 31b (Figure 2). This extraction electrode 32 is disposed between the plasma ion source 31 and the capacitor electrode 33. The ions extracted from the plasma ion source 31 by the extraction electrode 32 are focused by ion optical manipulation performed by the ion optical system, and are irradiated onto the sample S as an ion beam IB.

The ion optical system is provided with the above-mentioned capacitor electrode 33, current limiting aperture 34, and focus electrode 35, in that order from the plasma ion source 31 side toward the sample chamber 10. The capacitor electrode 33 is an element that forms an electric field that collects ions extracted by the extraction electrode 32. The current limiting aperture 34 is an element that narrows the ion beam IB extracted by the extraction electrode 32, and adjusts the diameter of the beam spot formed on the sample S and the beam current irradiated to the sample S. The focus electrode 35 is an element that forms an electric field that focuses ions on the sample S. In addition, although not shown, the ion optical system is provided with an aligner, a polarizer, etc. The aligner is an element that adjusts the optical axis of the ion beam IB that has passed through the current limiting aperture 34, for example. The polarizer is an element that scans the ion beam IB on the surface of the sample S.

-Electron beam tube-
The electron beam column 40 is fixed to the sample chamber 10 and used for observing the sample S, and irradiates the sample S held on the stage 20 with an electron beam extracted from an electron source by an extraction electrode to scan the sample S. FIG. 1 illustrates a configuration in which the electron beam column 40 is installed in the sample chamber 10 in a vertical position, but the electron beam column 40 may be installed in the sample chamber 10 in a state inclined relative to the vertical. The electron beam column 40 is controlled by a control device 60. The charged particle beam device 1 is also provided with a shutter 41 that opens and closes an outlet 42 (electron beam exit port) of the electron beam column 40. For example, by blocking the outlet 42 of the electron beam column 40 with the shutter 41 during processing of the sample S with the ion beam IB, the intrusion of sputters generated during processing into the electron beam column 40 is suppressed, and insulation deterioration of the electron beam column 40 is suppressed.

-Detector-
The detector 50 detects secondary charged particles (secondary electrons, secondary ions, etc.) generated in the sample S due to irradiation with the ion beam IB or the electron beam.

-Control device-
The control device 60 is a computer having an arithmetic device 60a (CPU, etc.) and a storage device 60b (RAM, ROM, HHD, SSD, etc.), and controls operating devices such as the ion beam column 30, the electron beam column 40, and the stage 20, and detects secondary charged particles (secondary electrons, etc.) from the sample S, and captures a signal input from the detector 50 in synchronization with a scanning signal of a charged particle beam (ion beam IB or electron beam) to generate image data of an observation image (SIM image, SEM image, etc.) of the sample S. The generated image data is stored in the storage device 60b and appropriately displayed on a display device 61 (monitor, etc.). In addition to the display device 61, an input device 62 (keyboard, etc.) is connected to the control device 60, and, for example, items and conditions related to processing and observation are input by the input device 12 and instructed to the control device 60. The control device 60 loads a program stored in the memory device 60b into the calculation device 60a and executes it, and in accordance with instructions, irradiates the sample S with a charged particle beam to obtain an observation image of the sample S, or irradiates the sample S with an ion beam IB to process the sample S.

- Power supply circuit for extraction electrodes -
Fig. 2 is a schematic diagram of a power supply circuit for the extraction electrode. As shown in Fig. 2, the extraction electrode 32 is connected to the control device 60 via a power supply device 70. That is, the extraction electrode 32 is connected to the power supply device 70, and the control device 60 is connected to the power supply device 70.

The charged particle beam device 1 of this embodiment is provided with two beam modes for the ion beam IB: a low voltage mode and a high voltage mode. For example, in response to a predetermined operation of the input device 62, the control device 60 can cause the display device 61 to display a beam mode setting screen showing button A for selecting the low voltage mode and button B for selecting the high voltage mode. When the operator presses either button A or B to select and set the beam mode, the control device 60 controls the power supply device 70 in response to the selection to switch the extraction voltage applied to the extraction electrode 32, and switch the beam mode of the ion beam IB.

-Beam mode-
FIG. 3 is a diagram showing a typical shape of the ion emission surface at the opening of the plasma ion source in a high voltage mode, and FIG. 4 is a diagram showing a typical shape of the ion emission surface at the opening of the plasma ion source in a low voltage mode.

The plasma ion source 31 has the characteristic of having a high angular current density. Due to this characteristic, the ion emission surface Ps of the plasma P at the opening of the plasma ion source 31 (orifice 31c of plasma aperture 31b) becomes more concave (convex toward the plasma ion source 31) as shown in Figure 3 as the extraction voltage applied to the extraction electrode 32 increases. Conversely, the ion emission surface Ps becomes more convex (convex toward the sample S) as shown in Figure 4 as the extraction voltage decreases.

When the charged particle beam device 1 is in use, the inside of the sample chamber 10 and the ion beam column 30 are maintained in a high vacuum state, so that the plasma P inside the plasma generation chamber 31a is drawn into the sample chamber 10 and tries to flow out of the plasma generation chamber 31a even if no voltage is applied to the extraction electrode 32. Then, by applying an extraction voltage to the extraction electrode 32 while the plasma P is being generated in the plasma generation chamber 31a, ions are drawn out of the plasma P that tries to flow out of the plasma generation chamber 31a and accelerated to form an ion beam IB. In the FIB device, the extraction voltage is usually set so that ions are drawn out at a high density from the plasma P so that the sample S can be irradiated with a high-current ion beam IB. In this case, the ion beam IB is drawn out at a faster pace than the plasma P is drawn into the sample chamber 10, so that the ion emission surface Ps of the plasma P becomes a concave shape at the opening of the plasma ion source 31 (the orifice 31c of the plasma aperture 31b) as shown in FIG. 3. The extraction voltage set so that the ion emission surface Ps has a concave shape is called the first voltage V1. In contrast, the example shown in FIG. 4 shows a state in which the extraction voltage is set to a second voltage V2, which is lower than the first voltage V1, so that the ion emission surface Ps of the plasma P has a convex shape.

As shown in FIG. 3, ions are emitted from the concave ion emission surface Ps toward the sample S with a velocity component in the direction toward the optical axis C of the ion beam IB (inward in the beam diameter direction). Therefore, the outer circumferential surface of the ion beam IB emitted from the concave ion emission surface Ps (the outline of the cross section of the ion beam IB including the optical axis C) has a concave constricted shape in the middle part in the extension direction of the optical axis C as shown in the figure. On the other hand, as shown in FIG. 4, ions are emitted from the convex ion emission surface Ps toward the sample S with a velocity component in the direction away from the optical axis C of the ion beam IB (outward in the beam diameter direction). Therefore, the outer circumferential surface of the ion beam IB emitted from the convex ion emission surface Ps (the outline of the cross section of the ion beam IB including the optical axis C) has a convex bulging shape in the middle part in the extension direction of the optical axis C as shown in the figure.

The light source of the ion beam IB is projected onto the sample S as a beam spot. In the case of the ion beam IB extracted from the plasma P, the point where the trajectories of the individual ions or their extensions are most densely concentrated is assumed to be the light source. In the case of the ion beam IB that is convexly constricted as shown in FIG. 3, this virtual light source L corresponds to the constricted portion of the ion beam IB. In this case, the size of the cross section of the constricted portion of the ion beam IB cut by a plane perpendicular to the optical axis C is the size of the virtual light source L. On the other hand, in the case of the ion beam IB that is convexly convex as shown in FIG. 4, the focal point of the intersecting extension lines (two-dot chain lines) of the trajectories of the individual ions of the ion beam IB extending from the ion emission surface Ps to the plasma ion source 31 side (the opposite side to the sample S) corresponds to the virtual light source L. In this case, the size of the cross section of the focus of the ion trajectory cut by a plane perpendicular to the optical axis C is the size of the virtual light source L. Therefore, the virtual light source L of ions projected onto the sample S is located closer to the sample S than the extraction electrode 32 when the applied voltage is set to the first voltage V1 and the ion emission surface Ps has a concave shape, and is located closer to the plasma ion source 31 than the extraction electrode 32 when the applied voltage is set to the second voltage V2 and the ion emission surface Ps has a convex shape. Therefore, compared to when the applied voltage is set to the first voltage V1, when the applied voltage is set to the second voltage V2, the virtual light source L is farther from the sample S. Also, compared to when the applied voltage is set to the first voltage V1 in FIG. 3, the virtual light source L is smaller in the case of FIG. 4 where the applied voltage is set to the second voltage V2. For example, the virtual light source L in FIG. 4 is smaller than the opening diameter of the orifice 31c of the plasma aperture 31b. Thus, compared to when the applied voltage is set to the high voltage mode in FIG. 3, in the low voltage mode in FIG. 4, the virtual light source L is smaller and the distance from the sample S is longer, and the optical magnification is effectively smaller.

Here, Figure 5 is a graph (log-log graph) showing the relationship between the beam current [μA] of the ion beam IB and the beam spot diameter [μm].

The beam current of the ion beam IB that reaches the sample S is substantially proportional to the beam diameter of the ion beam IB, and the beam current decreases with the beam diameter. The beam current is adjusted mainly by the amount of ion beam IB blocked by the current-limiting aperture 34 (Figure 1). For example, the current-limiting aperture 34 is equipped with multiple orifices with different opening diameters, and the beam diameter and spot diameter of the ion beam IB passing through the orifice changes depending on the opening diameter of the selected orifice. The beam current of the ion beam IB that reaches the sample S changes depending on the change in the opening diameter of the current-limiting aperture 34, i.e., the change in the beam diameter of the ion beam IB. The beam current value can also be adjusted, for example, by excitation control of the focus electrode 35.

When performing high-resolution observation or processing, it is preferable to narrow the beam diameter of the ion beam IB. In this case, in the high-voltage mode, the orifices of the current-limiting aperture 34 are sequentially switched to reduce the opening diameter, thereby reducing the beam current and beam spot diameter. However, the beam spot diameter is restricted by the length of the ion beam tube 30, etc., and there is a limit to how much it can be reduced. Therefore, in the high-voltage mode, when the beam current falls below a predetermined current Is (e.g., 10 pA), the beam spot diameter does not change even if the beam current is reduced, as shown by the solid line in FIG. 5. The predetermined current Is corresponds to the beam current of the ion beam IB that reaches the sample S when, for example, the first voltage V1 is applied to the extraction electrode 32 (i.e., in the high-voltage mode) and the opening of the current-limiting aperture 34 is set to the minimum (the minimum orifice is selected). However, the predetermined current Is used as a judgment value for switching between high and low voltage modes does not necessarily have to be a value that depends on the orifice diameter of the current limiting aperture 34, and a current value that is preset in consideration of the appropriateness of switching the beam mode can be used.

In this embodiment, in order to further reduce the beam spot diameter in the region where the beam current falls below a predetermined current Is, the beam mode is switched to a low voltage mode, and the light source itself projected onto the sample S is reduced. In the low voltage mode, as shown by the dashed line in Figure 5, the beam spot diameter is further reduced beyond the minimum beam spot diameter in the high voltage mode as the beam current decreases.

In the charged particle beam device 1, data relating to the relationship between the beam current and the beam spot diameter as shown in FIG. 5, which is experimentally or theoretically specified in advance, is stored in the storage device 60b of the control device 60. For example, the storage device 60b stores the first voltage V1 set for the applied voltage, the second voltage V2 set lower than the first voltage V1, and the predetermined current Is set for the beam current of the ion beam IB. The control device 60 reads out these data and programs from the storage device 60b, and in the high voltage mode in which the applied voltage is set to the first voltage V1, the control device 60 drives the current limiting aperture 34 to control the beam spot diameter and changes the beam current in a range equal to or greater than the predetermined current Is, and in the low voltage mode in which the applied voltage is set to the second voltage V2, the beam spot diameter can be reduced more than in the high voltage mode in the range in which the beam current is below the predetermined current Is. For example, the control device 60 controls the beam current based on the relationship in FIG. 5 according to the beam mode and beam spot diameter input by the input device 62. The control device 60 can also be configured to automatically switch the beam mode depending on the input beam spot diameter or beam current.

-effect-
(1) In this embodiment, the voltage applied to the extraction electrode 32 is set to the first voltage V1 to drive the current limiting aperture 34, thereby controlling the beam spot diameter and changing the beam current in a range equal to or greater than a predetermined current Is. In addition, in a range in which the beam current is below the predetermined current Is, the voltage applied to the extraction electrode 32 is set to a second voltage V2 lower than the first voltage V1, and the beam spot diameter can be reduced more than when the applied voltage is set to the first voltage V1. In other words, by lowering the voltage applied to the extraction electrode 32 to the second voltage V2 (switching to the low voltage mode), it becomes possible to perform observation or processing with a higher resolution than under the condition in which the first voltage V1 is applied to the extraction electrode 32 (high voltage mode). Therefore, for example, when processing a large volume of sample S, a large beam current in the high voltage mode is used to efficiently process the sample S, and when the resolution is insufficient in the high voltage mode to observe the sample S in detail, the voltage applied to the extraction electrode 32 is lowered from the first voltage V1 to the second voltage V2 and the mode is switched to the low voltage mode, thereby making it possible to observe the sample S with a higher resolution than during processing. Of course, it also becomes possible to finely process the sample S in the low voltage mode.

(2) The first voltage V1 is set so that the ion emission surface Ps has a concave shape, and the second voltage V2 is set so that the ion emission surface Ps has a convex shape. By storing such first voltage V1 and second voltage V2 in the memory device 60b, the control device 60 can change the shape of the ion emission surface Ps by switching the extraction voltage according to the magnitude of the beam current of the ion beam IB to be irradiated to the sample S, and switch the beam mode.

(3) The virtual light source L of the ion beam IB is farther away from the sample S when the applied voltage is set to the second voltage V2 than when the applied voltage is set to the first voltage V1. In this way, by switching the extraction voltage, the distance between the sample S and the light source can be changed, thereby controlling the effective optical magnification.

(4) Furthermore, the virtual light source L is smaller when the applied voltage is set to the second voltage V2 than when the applied voltage is set to the first voltage V1. This improves the resolution in the low voltage mode of FIG. 4 compared to the high voltage mode of FIG. 3.

(5) The charged particle beam device 1 is a composite charged particle beam device equipped with an electron beam tube 40, and can, for example, process a sample S with an ion beam IB while observing the sample S with an electron beam. However, the maximum resolution when using the ion beam IB in high voltage mode is lower than the maximum resolution when using an electron beam with the electron beam tube 40. In contrast, in this embodiment, the voltage applied to the extraction electrode 32 is reduced from the first voltage V1 to the second voltage V2 to switch to the low voltage mode, making it possible to process the sample S more finely than in the high voltage mode.

(6) In addition, the charged particle beam device 1 equipped with the electron beam tube 40 may process the sample S while observing it with the ion beam IB. In this case, if sputter generated during processing enters the inside of the electron beam tube 40, the insulation of the electron beam tube 40 may deteriorate. In contrast, the charged particle beam device 1 of this embodiment is equipped with a shutter 41 that opens and closes the exit 42 of the electron beam tube 40, so that it is possible to prevent sputter from entering the inside of the electron beam tube 40 and, in turn, to prevent the insulation of the electron beam tube 40 from deteriorating.

--Modifications--
The present invention is not limited to the above-described embodiment, and may include various modified examples. For example, the above-described embodiment has been described in detail to easily explain the present invention, and is not necessarily limited to an embodiment having all of the configurations described. For example, it is possible to replace a part of the configuration with another configuration. It is also possible to delete a part of the configuration of the embodiment, or to add another configuration.

For example, in the above embodiment, an example was described in which the invention was applied to a composite charged particle beam device having an electron beam tube 40, but the invention can also be applied to an FIB device that does not have an electron beam tube 40, and similar essential effects can be obtained. Also, an example was described in which the invention was applied to a charged particle beam device having only one ion beam tube 30, but the invention can also be applied to a charged particle beam device having multiple ion beam tubes, and similar essential effects can be obtained. In this case, the ion beam tube added in addition to the ion beam tube 30 may be one that uses a plasma ion source or one that uses a liquid metal light source such as a gallium ion source.

1...charged particle beam device, 31...plasma ion source, 31c...orifice (opening of plasma ion source), 32...extraction electrode, 33...capacitor electrode, 34...current limiting aperture, 35...focus electrode, 40...electron beam tube, 41...shutter, 42...exit, 60...control device, IB...ion beam, Is...predetermined current, L...virtual light source, Ps...ion emission surface, S...sample, V1...first voltage, V2...second voltage

Claims (9)

a plasma ion source;
an extraction electrode that forms an electric field that extracts ions from an opening of the plasma ion source;
a current limiting aperture that limits the ion beam extracted by the extraction electrode and adjusts a beam spot diameter formed on a sample and a beam current irradiated onto the sample;
a control device for controlling a voltage applied to the extraction electrode;
The control device includes:
a first voltage set for the applied voltage, a second voltage set lower than the first voltage, and a predetermined current set for the beam current of the ion beam;
setting the applied voltage to the first voltage, and driving the current limiting aperture to control the beam spot diameter and vary the beam current within a range equal to or greater than the predetermined current;
a beam spot diameter detecting section for detecting a beam spot diameter of a charged particle beam having a diameter smaller than that of a beam spot having a diameter equal to or ... larger than that of a beam spot having a diameter equal to or larger than that of a beam spot having a diameter equal to or larger than that 2. The charged particle beam device according to claim 1,
a first voltage applied to the extraction electrode and a second voltage applied to the current limiting aperture when the aperture is set to a minimum value, the first voltage being equal to a beam current of an ion beam reaching the sample; 2. The charged particle beam device according to claim 1,
a capacitor electrode that forms an electric field for collecting the ions extracted by the extraction electrode;
a focusing electrode that forms an electric field for focusing the ions onto the sample;
4. The charged particle beam device according to claim 3, wherein the extraction electrode is disposed between the plasma ion source and the capacitor electrode. 2. The charged particle beam device according to claim 1,
the first voltage is set so that an ion emission surface at an opening of the plasma ion source has a concave shape;
4. The charged particle beam device according to claim 3, wherein the second voltage is set so that the ion emission surface has a convex shape. 2. The charged particle beam device according to claim 1,
13. A charged particle beam device comprising: a virtual source of the ion beam configured to be farther from the sample when the applied voltage is set to the second voltage than when the applied voltage is set to the first voltage. 6. The charged particle beam device according to claim 5,
11. A charged particle beam device, comprising: a first voltage source connected to a first electrode and a second voltage source connected to a first electrode; a first voltage source connected to a second electrode and a second voltage source connected to a first electrode; 7. The charged particle beam device according to claim 6,
A charged particle beam device, wherein the virtual source is a point where the orbits of the ions or their extensions are most densely concentrated. 2. The charged particle beam device according to claim 1,
A charged particle beam device comprising an electron beam column. 9. The charged particle beam device according to claim 8,
4. A charged particle beam device comprising: a shutter for opening and closing an exit of the electron beam column.

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