WO2015083973A1

WO2015083973A1 - Charged particle beam probe forming device and method for using same

Info

Publication number: WO2015083973A1
Application number: PCT/KR2014/011388
Authority: WO
Inventors: 조복래; 배문섭; 한철수; 안상정; 김주황; 박인용
Original assignee: 한국표준과학연구원
Priority date: 2013-12-02
Filing date: 2014-11-26
Publication date: 2015-06-11
Also published as: KR101554594B1; KR20150064311A

Abstract

The present invention relates to a charged particle beam probe forming device and a method for observing or processing a sample using the same, the device comprising: a charged particle source for emitting a charged particle beam; a focusing lens group comprising at least one intermediate focusing lens, which is provided adjacent to the charged particle source to focus the charged particle beam by means of an electric field or a magnetic field, and an objective lens provided adjacent to a sample as a final focusing lens to form a charged particle beam probe, which is a beam spot focused on a sample; a vacuum chamber containing the charged particle source and the focusing lens group therein and having an aperture that serves as a passage, through which a charged particle beam emitted from the charged particle source is aimed at a sample via the objective lens; at least one deflector for controlling and changing the aiming direction of the charged particle beam; and a sample stage which supports a sample to be observed or processed, and which can move the sample.

Description

Charged particle beam probe forming device and method of using the same

The present invention relates to an apparatus for forming a charged particle beam probe, such as an electron beam or an ion beam, and a method of using the same, and more particularly, a beam in which charged particle beams emitted from a charged particle beam source are concentrated on a sample under atmospheric pressure or under a reduced atmosphere. The present invention relates to a device capable of adjusting the formation position of a spot charged particle beam probe and a method of observing or processing a sample using the same.

As a method for observing the surface form or structure of a material on a nanoscale or atomic scale or processing the material under atmospheric pressure or under a low vacuum atmosphere, a charged particle beam such as an electron beam or an ion beam can be used.

Using a charged particle beam, such as an electron beam or an ion beam, can be expanded beyond the limit of resolution by an optical microscope to obtain information at a nano or atomic level for a material to be observed at a nano or atomic level. In addition to obtaining the information on the material, by removing a portion of the surface of the material or to provide an additional structure, it can be applied to the next-generation semiconductor materials and the like.

In this case, when the charged particle beam is used under atmospheric pressure or under a low vacuum atmosphere as described above, a non-conductive sample that cannot be observed in a general high vacuum environment, or a sample containing volatile components can be easily obtained without a metal coating. Alternatively, the surface of the sample can be processed.

As described above, in order to observe or process the surface form or structure of the material under atmospheric pressure or under a low vacuum atmosphere, the charged particle beam emitted from a charged particle beam source such as an electron beam or an ion beam in the vacuum chamber is lower than the pressure in the vacuum chamber. Charged particle beam probes, which are beam spots, must be focused on a sample that is in a vacuum or at atmospheric pressure.

As described above, the apparatus for forming a charged particle beam probe for observing or processing the surface form or structure of a sample under atmospheric pressure or under a low vacuum atmosphere may be, for example, an Environmental Scanning Electron Microscope (E-SEM), air. It can be applied to a scanning electron microscope (Air Scanning Electron Microscope: Air-SEM), a focused ion beam device, a sample processing device using a particle beam.

1 shows an apparatus for forming a charged particle beam probe according to the prior art. In more detail, the apparatus for forming a charged particle beam probe may be a charged particle source 10 in a vacuum chamber, an intermediate focusing lens 22 provided on the charged particle source side in the vacuum chamber, and a final focusing lens provided on the sample side. A vacuum chamber 30 having a focusing lens group 20 including an objective lens 24, an aperture 35 which is a passage through which the charged particle beam emitted from the charged particle source is irradiated onto the sample through the objective lens; A sample stage 50 provided between the intermediate focusing lens and the objective lens and capable of supporting and moving the deflector 40 for controlling and changing the irradiation direction of the charged particle beam and the sample 55 located outside the vacuum chamber. It may include.

Here, the apparatus for forming a charged particle beam probe in FIG. 1 focuses a charged particle beam emitted from a charged particle source in a vacuum chamber into a plurality of focusing lens groups to form a beam spot that is focused on a sample, that is, a probe. One or more deflectors are used to adjust the beam trajectory to move the position of the probe so that the beam is scanned on the sample to observe the shape of the sample or to process the shape. In this case, since the charged particle beam may collide with air molecules and be scattered, a space in the vacuum chamber including the charged particle source and the beam scanning region between the focusing lens group and the aperture may be used in a high vacuum environment using a vacuum pump. Exhaust is to be maintained.

In this case, in order to maintain the pressure in the vacuum chamber including the charged particle source and the focusing lens group at a high vacuum, a vacuum pump may be generally provided to have a pressure of 10 ⁻⁴ mbar or less, preferably 10 ⁻⁵ mbar or less. .

At this time, the charged particle beam emitted from the charged particle source is focused by a rotationally symmetric electric or magnetic field induced from the focusing lens group about the optical axis indicated by a dotted line in FIG. 1. In this case, in the case of the charged particle beam, the magnetic field formed by the electric field or the electric coil formed by the electrode, unlike the optical system, serves as the focusing lens group.

Here, the size of the probe, which is a beam spot focused by the focusing lens group and formed on the surface of the sample, determines the resolution when observing the sample shape and the precision when the sample is processed. In general, the smaller the probe, the better the resolution and precision.

On the other hand, the electron beam lens has an aberration, and the size of the probe is determined by the aberration, and as the aberration increases, the probe size becomes large, resulting in a decrease in observation resolution and processing accuracy.

In addition, when the trajectory of the charged particle beam is out of the center of the objective lens, the aberration rapidly increases to increase the spot size. Accordingly, in order to prevent this, a deflector may be generally provided on the objective lens. 2 and 3 show a charged particle beam probe forming system having the deflector. FIG. 2 shows a charged particle beam probe forming apparatus used for a sample in a low vacuum environment, and in FIG. The charged particle beam probe forming apparatus used for the sample is shown. 2 or 3, the beam trajectory is controlled so that the trajectory of the beam passes through the center of the lens by configuring a deflector between the objective lens and the intermediate focusing lens in order to reduce aberration when the beam is scanned on the sample. have.

In general, in the case of forming a charged particle beam probe on the sample in a low vacuum environment, as shown in FIG. 2, the pressure in the sample chamber region including the sample may be maintained at a low vacuum of ¹ × 10 ⁻² mbar or more. In order to maintain the low vacuum in the indoor area, a separate vacuum pump may be provided to maintain a pressure difference from the vacuum chamber of the high vacuum area including the charged particle source and the focusing lens group. In this case, the aperture may be formed to open in the form of an opening in the vacuum chamber, and includes a vacuum including the sample region and the charged particle source according to the diameter or surface area of the aperture, the capacity of each vacuum pump, and the like. The pressure difference between the inner regions of the chamber can be adjusted.

In addition, as shown in FIG. 3, in order to perform observation or processing of a biological sample, the sample is placed under atmospheric pressure in a sample chamber region including the sample without using a vacuum chamber. In this case, the aperture forms a diaphragm having a predetermined thickness, not an opening, as shown in FIG. 3. The diaphragm may be manufactured by, for example, etching a material such as SiN or using a thin film material such as graphene, and may have a thickness in a range of 1 to 2000 nm, preferably 2 to 500 nm.

Meanwhile, the maximum formation area of the probe formed on the sample may be determined by the size of the aperture and the distance between the aperture and the objective lens.

That is, when the aperture size is large or the distance between the aperture and the objective lens is short, the scanning range, which is a region in which the probe can be formed in a fixed state without moving the sample using the deflector, will be widened. Can be.

In general, fixing the sample and observing or processing the sample through the control of the focusing lens group and the deflector, etc., enlarges the viewing area rather than moving the sample while fixing the control conditions of the focusing lens group and the deflector. It is convenient for the user in reducing, and also has the advantage of finding a specific area quickly and easily.

However, when the size of the aperture is increased, it is difficult to maintain a pressure difference between the region including the sample and the inner region of the vacuum chamber including the charged particle source, so that the charged particle beam may scatter and collide with the air molecules. However, there is a limit that can have an unreasonable effect on the system.

As a prior art of such a charged particle beam probe forming apparatus, European Patent Publication No. EP 0786145 B1 uses an environmental scanning electron microscope (E-SEM) that provides excellent spatial resolution even when a sample is accommodated in a gaseous environment of a sample chamber. And J. Vac. Sci. Technol. B 9, 1557 (1991) describes an Air Scanning Electron Microscopy (Air SEM) in which a sample can be observed at atmospheric pressure using a silicon nitride thin film.

The charged particle beam probe forming apparatus in the related art, which can be applied to an environmental scanning electron microscope (E-SEM) as shown in FIG. 2, maintains the pressure in the sample chamber region at a low vacuum of 1x10 ^-2 mbar or more. And an aperture communicating between the inside of the vacuum chamber of the high vacuum region and the sample chamber region of the low vacuum region such that the vacuum chamber including the charged particle source is not influenced to maintain a high vacuum of 1x10 ^-4 mbar or less. It should be provided with a very small diameter (<1 mm).

In addition, the charged particle beam probe forming apparatus in the prior art that can be applied to the air scanning electron microscope (Air-SEM) as shown in FIG. 3 maintains the pressure around the sample at atmospheric pressure, and also the charged particle source It should be provided with a thin film having a very small diameter (<1mm) and a constant thickness (<hundreds of nm) so as not to affect the high vacuum state of 1x10 ^-4 mbar or less in a vacuum chamber including a.

However, in the prior arts including the prior art, the charged particle beam trajectory is such that the charged particle beam trajectory necessarily passes through the center of the objective lens in order to reduce aberration in the objective lens which is the final focusing lens. The trajectory must be controlled via a deflector, and while the charged particle beam passes through the center of the objective lens and passes through the aperture in FIGS. 2 and 3, the scanning range must be narrowed. The field of view that can be observed without moving is narrowed, and in the case of a sample processing device, there is a problem of causing a result that the processable area is narrowed without moving the sample.

Therefore, there is a continuing need for the development of a charged particle beam probe forming apparatus capable of securing a wide field of view that can be observed without moving a sample and having a wide area that can be processed without moving a sample.

Accordingly, an object of the present invention is to provide a charged particle beam charged particle beam probe forming apparatus that can be applied to an observation device that can observe a wide field of view without moving a sample in order to solve the above problems. .

In addition, another object of the present invention is to provide a charged particle beam probe forming apparatus that can secure a wide processing range without moving a sample.

In another aspect, the present invention can provide a scanning electron microscope, a sample processing device or a focused ion beam device including the charged particle beam probe forming apparatus.

In addition, the present invention can provide a method for observing or processing a sample that can secure a wide field of view or a wide processing area without moving the sample using the charged particle beam probe forming apparatus.

The present invention is provided on the charged particle source for emitting a charged particle beam, the charged particle source side, at least one intermediate focusing lens for focusing the charged particle beam by an electric or magnetic field, and a final focusing lens on the sample side, A focusing lens group including an objective lens for forming a charged particle beam probe that is a beam spot focused on a sample, the charged particle source and a focused lens group are provided therein, and the charged particle beam emitted from the charged particle source is an objective lens. A vacuum chamber having an aperture, which is a passage irradiated to the sample through, one or more deflectors for controlling and changing the irradiation direction of the charged particle beam, and a sample capable of supporting the sample to be observed or processed and moving the sample. A charged particle beam probe forming apparatus comprising a stage, wherein the charged particle beam probe forming apparatus comprises a true Charged particle beam probe, characterized in that the first region in the chamber and the second region having a relatively higher pressure than the first region and containing the sample, wherein the deflector is located between the objective lens and the sample Provided is a forming apparatus.

The present invention also provides a scanning electron microscope, a focused ion beam (FIB) device, or a sample processing device including the charged particle beam probe forming device.

The present invention also provides a charged particle source; And a charged particle beam probe provided at the charged particle source side, the at least one intermediate focusing lens for focusing the charged particle beam by an electric field or a magnetic field, and provided at the sample side as a final focusing lens, and a beam spot focused on the sample. A vacuum chamber having an aperture therein, wherein the focused lens group includes an objective lens configured to provide an aperture through which the charged particle beam emitted from the charged particle source is irradiated onto the sample through the objective lens. Setting and maintaining a pressure in each region such that the pressure in the first region has a pressure that is relatively lower than the pressure in the second region comprising the sample, emitting a charged particle beam from the charged particle source, the Focusing the emitted charged particle beam by the focusing lens group to pass the aperture, between the objective lens and the sample Positioned to control one or more deflectors to change the irradiation direction of the charged particle beam to change the irradiation direction of the charged particle beam, and the charged particle beam of which the irradiation direction is changed is irradiated onto the sample on the sample stage, A method of observing or processing a sample using a charged particle beam is provided.

The charged particle beam probe forming apparatus according to the present invention uses a scanning electron microscope, a focused ion beam (FIB) device, or a charged particle beam, which can observe and process a wide field of view without moving a sample. A charged particle beam charged particle beam probe forming apparatus that can be applied to an apparatus for processing a sample can be provided.

In addition, the charged particle beam charged particle beam probe forming apparatus of the present invention can control the direction of the beam trajectory by a single deflector of the charged particle beam irradiated to the sample after passing through the center of the objective lens, as in the prior art Likewise, there is an advantage in that the irradiation area of the sample can be easily controlled without the need for providing a plurality of deflectors between the objective lens and the intermediate focusing lens.

In addition, the charged particle beam charged particle beam probe forming apparatus of the present invention includes a deflector between the objective lens and the sample, and by controlling the distance between the deflector and the aperture, it is possible to widen or narrow the observation or processing area of the sample. There is an advantage.

In addition, the present invention can ensure a wide field of view or a wide processing area without moving the sample in the observation or processing of the sample using the charged particle beam probe forming apparatus, so that the process of the process requiring consumption and professional skills In addition to shortening the running time, it is possible to observe or process the sample more conveniently and quickly, thereby providing convenience to the user, and also charged particle beam probe including a charged particle source or the like in comparison with the prior art. It is possible to prevent shortening the life of the forming apparatus.

1 is a view showing a charged particle beam probe forming apparatus according to the prior art.

2 is a view illustrating a device for forming a charged particle beam probe according to the related art, in which the charged particle beam probe is formed in a low vacuum environment.

3 is an apparatus for forming a charged particle beam probe according to the prior art, in which the sample is a device in which the charged particle beam probe is formed in an environment of atmospheric pressure.

4 is a diagram illustrating a device in which the charged particle beam probe is formed in a low vacuum environment according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating an apparatus in which the charged particle beam probe is formed in an environment of a sample according to another embodiment of the present invention.

6 is a view showing a detailed image of the lens portion and the deflector portion of the charged particle beam probe forming apparatus according to the present invention.

Figure 7a) is a view showing the image range in the environmental scanning microscope according to the prior art, Figure 7b) is a view showing the image range in the environmental scanning microscope obtained according to an embodiment of the present invention.

4 and 5 are diagrams showing the emission image obtaining apparatus of the particle beam according to an embodiment of the present invention.

It is provided with a charged particle source 10 for emitting a charged particle beam, at least one intermediate focusing lens 22 provided at the charged particle source and focusing the charged particle beam by an electric or magnetic field, and a sample as a final focusing lens. And a focusing lens group 20 including the objective lens 24 for forming a charged particle beam probe that is a beam spot focused on a sample, the charged particle source and the focusing lens group provided therein, and the charged particles A vacuum chamber 30 having an aperture 35 which is a passage through which the charged particle beam emitted from the source is irradiated to the sample through the objective lens, and at least one deflector 40 which controls and changes the irradiation direction of the charged particle beam. And a charged particle beam probe forming apparatus including a sample stage 50 capable of supporting the sample to be observed or processed and moving the sample.

Here, the focusing lens group 20 including the charged particle source, the intermediate focusing lens 22 and the objective lens 24, the vacuum chamber 30 including the aperture, and the sample stage 50 are shown in FIGS. As described in FIG. 3, the components used in the prior art may be used as they are.

In more detail, if the charged particle beam used in the present invention is emitted from the charged particle source and the irradiation direction of the particle beam can be controlled by the focusing lens group 20 and the deflector 40, its kind Can be used without limitation. In one embodiment, the charged particle beam may be an electron beam or an ion beam.

When an ion beam is used as the charged particle beam, helium ion beams, neon ion beams, hydrogen ion beams, and the like may be used, but are not limited thereto. In addition, ion beams such as Ga, In, Ar, and Ne can be used as the ion beams used as the use of the focused ion beam (FIB) device.

In addition, the charged particle beam source used in the present invention is a form capable of generating a charged particle beam, such as the electron beam or ion beam, which can emit the charged particle beam, hot electron emission source such as tungsten filament, metal tip And an extraction lens (not shown) for extracting the particle beam emitted from the metal tip to guide the focusing lens group 20.

In addition, the metal tip 11 capable of emitting the particles is preferably short, sharp and symmetrical in length.

Tungsten tip, molybdenum, iridium, platinum-iridium alloy, etc. may be used as the metal tip because the material of the source tip of the particle beam satisfies such a condition and the metal tip having the characteristics of easy processing and long life is preferable. Can be.

In addition, filaments of tungsten, tantalum, iridium, and iridium-tungsten alloys having high melting point and relatively good electron emission, and yttrium, barium, cesium and its Oxide coated filaments may be used.

On the other hand, the focusing lens group 20 serves to focus the charged particle beam by an electric field or a magnetic field, and is provided on the sample side as one or more intermediate focusing lenses 22 and the final focusing lens provided on the charged particle source side. And an objective lens 24 for forming a charged particle beam probe, which is a beam spot focused on a sample.

The focusing lens group 20 including the intermediate focusing lens 22 and the objective lens in the focusing lens group may slow down or accelerate or accelerate the charged particle beam emitted from the charged particle source through an electrode included therein. It can be changed and can exist in the form of multiple coils wound in various forms.

In this case, the charged particle beam may be controlled to pass through the center of the objective lens to reduce aberration. That is, the beam deflected by the deflector at the time of scanning can be controlled to pass through the center of the objective lens which is the final focusing lens.

In order to achieve this, the present invention may include a deflector used in the prior art between the intermediate focusing lens and the objective lens as in the prior art, and may control the irradiation direction of the charged particle beam by the deflector.

In addition, the charged particle beam probe forming apparatus according to the present invention may include a vacuum chamber having an aperture that is a passage through which the charged particle beam emitted from the charged particle source is irradiated onto the sample through the objective lens.

The charged particle beam probe forming apparatus of the present invention may be divided into a first region inside the vacuum chamber surrounded by the vacuum chamber and a second region including the sample, and the second region is relatively larger than the first region. Have high pressure.

The first region may be a high vacuum region having a range of 10 ⁻⁴ mbar or less, and preferably a high vacuum region having a range of 10 ⁻⁵ mbar or less.

To this end, it may be provided with a vacuum system having a high vacuum vacuum pump to maintain the pressure inside the vacuum chamber as described above.

In exemplary embodiments, the vacuum chamber forms a vacuum space in which high vacuum is maintained by a vacuum pump.

The vacuum pump may be a dry pump, a diffusion pump, a turbo molecular pump, an ion pump, a cryopump, a rotary pump, a scroll or a diaphragm pump, or the like. It may be provided including one or more selected from a dry pump (dry pump) of.

In this case, the second region is a region containing a sample, and may generally correspond to a region inside the sample chamber in which the sample is located, and the sample chamber independently corresponds to a region decompressed by a separate low vacuum vacuum pump. It may be a closed area or an open area under the same pressure as outside air, such as in an atmospheric environment.

Meanwhile, in the present invention, the pressure difference between the first region and the second region may represent a pressure difference of 100 times or more, and preferably, a pressure difference of 1000 times or more.

In addition, in the present invention, the aperture may be a boundary that separates the first region and the second region. That is, the aperture communicates between the vacuum chamber internal region, which is the first region, and the second region, which includes the sample, and may be an opening having a circular, polygonal, ellipse, or arbitrary shape, and the sample region. According to the degree of vacuum of the two regions, the opening portion of the opening may be sealed by a thin membrane.

The aperture may have a diameter of 3000 um or less, preferably 2000 um or less, and more preferably 1000 um or less.

Thus, the vacuum chamber is partially sealed by an aperture having an opening or by an aperture including a diaphragm so that charged particles emitted from the charged particle source in the vacuum chamber can be irradiated onto the sample without scattering. .

In the present invention, when the pressure in the sample chamber including the sample is a low vacuum having a pressure range of 10 ⁻³ mbar or more, preferably a pressure range of 10 ⁻² mbar or more, the apertures are opened to each other so as to have only an opening shape, The atmosphere of the second region, which is the sample region, may freely flow into the first region inside the vacuum chamber.

When the aperture is opened in an open shape, the pressure in the first region and the second region may vary depending on the measurement point of the pressure, and is a position that is a reference point for the pressure measurement of each region. The region may be near the charged particle source source and the second region may be near the sample on the sample stage.

On the other hand, when the pressure in the second region including the sample is an atmospheric pressure environment, when the aperture is formed only in the opening form, it may not be easy to control the pressure in the first region in the vacuum chamber including the charged particle source, In addition, the emission of the charged particle beam may be scattered or disturbed by air particles present in atmospheric pressure, such that the aperture may be in the form of an opening sealed by a thin septum.

Thus, when the aperture is sealed by the diaphragm as described above, the first region can be isolated from the second region.

In this case, the thickness of the diaphragm may be 10 nm to 3000 nm, preferably 20 nm to 2000 nm, and more preferably 20 nm to 500 nm.

The diaphragm material may be any one selected from silicon nitride (SiN), graphene, or a composite layer thereof.

In the present invention, the sample is located in the sample chamber under the objective lens. In this case, as described above, the sample chamber pressure may be maintained in an environment under atmospheric pressure or low vacuum pressure, and the surface of the sample may be exposed to the charged particle beam.

In addition, the sample chamber may include a sample stage on which the sample is to be placed, and the sample stage supports the sample below 0.1 to 100 mm, preferably 1 to 30 mm, of the aperture and is parallel to the ground. And it may be provided so that the position movement in the z-direction perpendicular to the y-direction and the ground.

In addition, the deflector in the present invention may include at least one coil device for generating a magnetic field used to deflect the charged particle beam.

In the prior art, the deflector is generally provided between the intermediate focusing lens 22 and the objective lens 24. Therefore, as shown in FIGS. 2 and 3, a plurality of deflectors are provided between the middle focusing lens 22 and the objective lens 24 at the upper end 41 and the lower end 42, so that the trajectory of the charged particle beam is controlled. The beam trajectory is controlled to be set to pass through the center of the.

In this case, the maximum angle of the charged particle beam irradiated to the sample based on the optical axis may be limited according to the size of the aperture. For example, referring to FIG. 2, the charged particle beam irradiated onto the sample is limited within a spatial range having an angle smaller than the maximum angle so as to pass through the inner opening than the portion corresponding to the outermost portion of the aperture to irradiate the sample. If it is irradiated with an angle wider than this, it cannot pass through an aperture.

However, in the present invention, the deflector is provided to be positioned between the objective lens and the sample, so that the area irradiated with the charged particle beam is freely expandable.

That is, the charged particle beam charged particle beam probe forming apparatus of the present invention includes a deflector between the objective lens and the sample, and by controlling the distance between the deflector and the aperture, it is possible to widen or narrow the observation or processing area of the sample. There is an advantage.

The deflector may be provided to enable height adjustment with respect to the Z direction in the optical axis direction.

When the deflector is provided at the position between the objective lens and the specimen as described above, after the charged particle beam passes through the center of the objective lens, the direction of the beam trajectory is controlled by the deflector to be controlled by the prior art in the desired irradiation direction. It is possible to perform beam irradiation of a much wider area than the area to be.

For example, when the deflector is placed between the objective lens and the sample, the closer the deflection point corresponding to the position where the beam irradiation direction is changed by the deflector toward the sample from the objective lens, the wider the range of the sample can be observed or processed. In addition, the beam irradiation range is also widened.

That is, as shown in FIG. 4, when the second region, which is the sample region, is low vacuum, when the deflector is placed between the objective lens and the sample, the charged particle beam passing through the center of the objective lens is formed by changing the traveling direction by the deflector. As the deflection point becomes closer to the sample from the objective lens, the area range and irradiation range of the sample that can be observed or processed at the deflection point become wider. In FIG. 5, when the second area, which is the sample area, is atmospheric pressure, as described above, When the deflector is placed between the objective lens and the sample, the deflection point formed by changing the traveling direction of the charged particle beam passing through the center of the objective lens may be observed or processed at the deflection point as it approaches the object lens from the objective lens. The range of the sample and the range of irradiation are widened.

Referring to this in more detail with reference to FIG. 4, unlike FIG. 2 and FIG. 3, the deflector is not provided between the intermediate focusing lens and the objective lens, but is provided to be positioned near the aperture between the objective lens and the sample. . As a result, the deflection point is formed at the same position as that of the deflector near the aperture, whereby the charged particle beam passing through the center of the objective lens can be irradiated with the irradiation direction being changed to the desired direction by the deflector. have.

In this case, the irradiation angle of the charged particle beam, which can be changed by the deflector when the optical axis is referenced, is irradiated to the sample at an angle much larger than the maximum angle irradiated by the deflector in FIGS. 2 and 3 according to the prior art. It can be.

In more detail, the charged particle beam probe forming apparatus of the present invention has a lens magnetic circuit 26 of soft magnetic material for the role of the intermediate focusing lens 22 in the focusing lens group 20 around the optical axis 60. ) Is provided on the upper end of the objective lens 24, and the lens magnetic circuit 26 of soft magnetic material is provided at the lower position of the intermediate focusing lens 22 to serve as the objective lens.

At this time, the aperture portion of the lower portion of the objective lens is a deflector 40 below the position of the aperture 35 having a predetermined (about 1 mm) width, as shown in the rectangular figure shown as the enlarged portion of FIG. 6. You can see that it is provided.

The deflector 40 is located between the objective lens and the sample in the present invention, but may be additionally provided between the objective lens and the intermediate focusing lens as described above.

On the other hand, the charged particle beam probe forming apparatus according to the present invention can be similarly applied to the case where the second region, which is the sample region, is at atmospheric pressure, as shown in FIG. 5.

In the present invention, the deflector may be positioned between the sample and the aperture in the vertical direction. Preferably, the position of the deflector may be provided at the same height as the aperture.

Meanwhile, the vacuum chamber of the present invention may include at least one connector that is externally accessible. The connector is a connection part for electrical connection between the vacuum chamber and the external environment, and supplies power and control signals to the charged particle source and focusing lens group in the vacuum chamber. (Ii) The control signal thereof when an additional deflector is provided in the vacuum chamber. And (iii) power supply and control of a detector capable of providing information on abnormalities of the charged particle source, focusing lens group, and deflector in (i) and (ii). have.

In addition, the charged particle beam probe forming apparatus in the present invention may be further provided with a gas injector capable of injecting additional gas containing water vapor, He, nitrogen, argon to enhance the detection or control of the sample. Such a gas mixture may be provided in proximity to the sample, but is not limited thereto.

Also, the charged particle beam probe forming apparatus of the present invention may have various additional components according to its application. For example, when the charged particle beam probe forming apparatus is used as an environmental scanning electron microscope, various signals emitted from the surface of the sample, that is, a low energy secondary electron signal, a high energy backscattered electron signal, a small angle reflected electron signal And an electronic detector of suitable geometry that serves to separate large angle reflective electronic signals.

The detector is connected to a display device such as a display device indicating the shape of the surface of the sample, and finally information is displayed in an image.

In addition, the charged particle beam probe forming apparatus of the present invention controls the emission intensity and the release time of the charged particles in the charged particle source, and additionally provided with a control unit for controlling the focusing lens group and the deflector, adjusting the position of the sample stage, etc. can do.

In this case, a controller for adjusting the vacuum degree of the vacuum chamber including the charged particle source and the vacuum degree in the sample chamber may be included in the controller individually or integrally, whereby the pressure of each region may be controlled. have.

As the charged particle beam probe forming apparatus is entirely controlled by the controller, the charged particle beam probe may be formed on the sample.

In addition, the charged particle beam probe forming apparatus of the present invention can be used in a scanning electron microscope, a focused ion beam (FIB) device or a sample processing device.

Looking at the process of forming the charged particle beam probe in the charged particle beam probe forming apparatus of the present invention, first, it is emitted from the charged particle source.

For example, when an electron beam is used as the charged particle beam, the charged particle source may be an electron gun such as a tungsten-hairpin gun, a lanthanum-hexaboride gun, or an field-emission gun, and the electron beam may be subjected to an acceleration voltage supplied to the electron gun. Is accelerated by

On the other hand, in general, since the diameter of the beam directly formed by the electron beam source is too large to form a sharp image at a high magnification, the electron beam may be guided through the focusing lens group so that the beam may be reduced and irradiated onto the sample. .

That is, the accelerated charged particle beam is focused by an electric or magnetic field formed by the intermediate focusing lens in the focusing lens group in the high vacuum state in the vacuum chamber, and passes through the objective lens which is the final focusing lens.

In this case, the charged particle beam may be irradiated toward the sample through the aperture while passing through the center of the objective lens to reduce aberration.

The charged particle beam irradiated on the surface of the sample generates various kinds of secondary particles emitted from the sample through various interactions with the surface of the sample, or the sample can be processed, and the secondary particles are detected or By processing the sample can be used for the desired use.

The present invention also provides a method for observing or processing a sample using a charged particle beam.

Looking at the method in detail, the charged particle source (10); And a charged particle beam which is provided on the charged particle source side and is provided on the sample side as one or more intermediate focusing lenses 22 and final focusing lens that focus the charged particle beam by an electric or magnetic field, and is a beam spot focused on the sample. A focusing lens group 20 including an objective lens 24 for forming a probe; and having a passage therein, in which a charged particle beam emitted from the charged particle source 10 is irradiated onto a sample through the objective lens. The pressure in each region is set such that the pressure in the first region, which is an internal region of the vacuum chamber 30 having the aperture 35, is lower than the pressure in the second region including the sample. Maintaining, releasing a charged particle beam from the charged particle source 10, focusing the emitted charged particle beam by a focusing lens group 20 to pass an aperture; Changing the irradiation direction of the charged particle beam by controlling one or more deflectors 40 positioned between the water lens and the sample and changing the irradiation direction of the charged particle beam, and the charged particle beam having the changed irradiation direction And irradiating the sample 55 on the 50.

This describes the method of forming the charged particle beam probe by using the charged particle beam probe forming apparatus of the present invention described above, wherein the deflector is positioned between the objective lens and the sample, and the specific method is as described above. .

FIG. 7 is a result of applying to an environmental scanning electron microscope using a charged particle beam probe forming apparatus according to the present invention. In FIG. 7a), a low magnification image obtained from an environmental scanning electron microscope according to the prior art is shown. 7b) shows a low magnification image obtained by an environmental scanning electron microscope when the deflector is installed at the same height position as the aperture under the objective lens on the optical axis according to an embodiment of the present invention. It is.

As shown in Fig. 7B), when the deflector in the present invention is provided to be positioned between the objective lens and the sample, the field of view limited by the conventional 1 mm aperture in the prior art is a general scanning electron microscope even in an environmental scanning electron microscope. In the same way as the visible field of view, a low magnification image of a wide range of about 5 mm can be obtained, which is not limited by the aperture.

Therefore, when the charged particle beam probe forming apparatus of the present invention is used in a scanning electron microscope, the image can be obtained up to a portion where the viewing angle is restricted by the spreading in the prior art, so that the sample position desired for observation can be easily found. It can be confirmed that.

While the configuration of the present invention has been described in detail, those skilled in the art can variously modify and change the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand.

According to the present invention, it is possible to provide a charged particle beam charged particle beam probe forming apparatus capable of observing a wide field of view or processing a sample without controlling the sample and controlling the direction of the beam trajectory. The present invention can provide a charged particle beam charged particle beam probe forming apparatus which can easily control the irradiation area of the sample and control the distance between the deflector and the aperture to widen or narrow the observation or processing area of the sample. have.

Claims

A charged particle source emitting a charged particle beam;

At least one intermediate focusing lens provided on the charged particle source side to focus the charged particle beam by an electric or magnetic field, and a charged particle beam probe provided on the sample side as a final focusing lens and focused on the sample. A focusing lens group including an objective lens to be used; .

A vacuum chamber having the charged particle source and the focusing lens group therein and having an aperture that is a passage through which the charged particle beam emitted from the charged particle source is irradiated onto the sample through the objective lens;

At least one deflector for controlling and changing the irradiation direction of the charged particle beam; And

A charged particle beam probe forming apparatus comprising; a sample stage for supporting a sample to be observed or processed and capable of moving the sample;

The charged particle beam probe forming apparatus is divided into a first region inside the vacuum chamber and a second region having the pressure higher than the first region and including the sample,

The deflector is charged particle beam probe forming apparatus, characterized in that located between the objective lens and the sample.
The method of claim 1,

The size of the aperture is charged particle beam probe forming apparatus, characterized in that the diameter of less than 3000um.
The method of claim 1,

The charged particle beam is a charged particle beam probe forming apparatus, characterized in that the ion beam or electron beam.
The method of claim 1,

The charged particle beam probe forming apparatus, characterized in that for reducing the aberration by passing through the center of the objective lens.
The method of claim 1,

Charged particle beam probe forming apparatus, characterized in that the high vacuum region having a range of 10 −3 mbar or less.
The method of claim 1,

And the pressure in the second region is a low vacuum region having a range of 10 −2 mbar or more.
The method of claim 1,

And the aperture is an opening in the form of a hole, wherein the first region and the second region are open to each other through the aperture.
The method of claim 1,

The aperture is formed of a diaphragm having a thickness of 2000 nm or less to isolate the first region from the second region.
The method of claim 1,

And the deflector is positioned between the sample and the aperture.
The method of claim 1,

Charge deflector beam probe forming apparatus characterized in that the deflector is provided at the same height as the aperture.
The method of claim 1,

Charged particle beam probe forming apparatus, characterized in that the pressure difference between the first region and the second region represents a pressure difference of more than 100 times.
The scanning electron microscope containing the charged particle beam probe formation apparatus of any one of Claims 1-11.
The sample processing apparatus containing the charged particle beam probe formation apparatus of any one of Claims 1-11.
A focused ion beam (FIB) device comprising the charged particle beam probe forming device according to any one of claims 1 to 11.
A method of observing or processing a sample using a charged particle beam,

Charged particle source; And a charged particle beam probe provided at the charged particle source side, the at least one intermediate focusing lens for focusing the charged particle beam by an electric field or a magnetic field, and provided at the sample side as a final focusing lens, and a beam spot focused on the sample. A vacuum chamber having an aperture therein, wherein the focused lens group includes an objective lens configured to provide an aperture through which the charged particle beam emitted from the charged particle source is irradiated onto the sample through the objective lens. Setting and maintaining the pressure in each region so that the pressure in the first region has a pressure lower than that in the second region comprising the sample,

Emitting a charged particle beam from the charged particle source,

Focusing the emitted charged particle beam by a focusing lens group to pass an aperture;

Changing the irradiation direction of the charged particle beam by controlling one or more deflectors positioned between the objective lens and the sample and changing the irradiation direction of the charged particle beam; and

And irradiating the sample on the sample stage with the charged particle beam of which the irradiation direction is changed.