stage

Abstract

To provide a stage that can be transported under vacuum or the like.SOLUTION: A stage according to the present invention includes a sample base on which a sample is mounted, a shutter function capable of isolating the atmosphere inside the stage from the atmosphere outside the stage, and a sealing portion. In a preferred embodiment of the stage according to the present invention, the stage further includes a first valve capable of automatic evacuation. In a preferred embodiment of the stage according to the present invention, the stage further includes a second valve whose degree of opening and closing can be adjusted.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a stage, and particularly to a stage capable of being transferred under vacuum or the like.

Background Art

[0002] In recent years, high-resolution analysis in electron microscopes such as transmission electron microscopes (TEM: Transmission Electron Microscope) and scanning transmission electron microscopes (STEM: Scanning Transmission Electron Microscope) has advanced. For example, high-resolution analysis from the nano-order to the pico-order has been demanded. These days, "in-situ observation" that performs cooling (or heating, electric field application, magnetic field application, rotation, etc.) while observing a sample in an electron microscope has attracted attention. In particular, sample cooling is considered effective for reducing damage to the sample by an electron beam, and sample cooling from this perspective has also been tried.

[0003] Also, although the magnification of SEM is lower than that of TEM, since there are fewer restrictions on the size of the observation sample, a large sample can be observed, and it is easier to use than TEM, so the difficulty level of observation analysis is lower than that of TEM. Therefore, electron microscope manufacturers are developing products that can observe various objects.

[0004] For example, as an apparatus having a cooling means, in the sample chamber of a scanning electron microscope, a cooling stage for installing a sample from which moisture has been sublimated, and a manipulator that extends on this cooling stage and cuts out the necessary components of the sample under the observation of the scanning electron microscope are provided. A sample processing apparatus using a scanning electron microscope is known (Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] Given this need for cooling, conventional technologies, including the aforementioned Patent Document 1, only use the method of attaching the sample to the upper surface of the sample base of the existing cooling stage, and cooling is limited to the lower surface of the sample.

[0007] Furthermore, conventional technology enables sample observation by transferring the sample to an externally cooled SEM stage under vacuum. That is, a method is employed in which a cartridge containing the sample is inserted into the SEM using a rod or similar device. However, because this transfer is done from outside the electron microscope, it is physically impossible to bring electrical wiring and other components into the vacuum. For this reason, many researchers are eagerly awaiting an SEM stage that can observe the sample while simultaneously cooling it and supplying power.

[0008] Therefore, the present invention aims to provide a stage that can be used for transfer under vacuum or other conditions. [Means for solving the problem]

[0009] In order to achieve the above objective, the inventors diligently studied the mechanism of the stage and, as a result, came to discover the present invention.

[0010] In other words, the stage of the present invention is a stage having a sample base on which a sample is mounted, a shutter function capable of blocking the atmosphere inside and outside the stage, and a sealing part. and further having a first valve capable of automatic exhaust It is characterized by the following:

[0012] Furthermore, a preferred embodiment of the stage of the present invention is characterized by having a second valve whose degree of opening and closing can be adjusted.

[0013] Furthermore, a preferred embodiment of the stage of the present invention is characterized by having a motor capable of opening and closing the shutter of the shutter function.

[0014] Furthermore, a preferred embodiment of the stage of the present invention is characterized by having a feedthrough section.

[0015] Furthermore, a preferred embodiment of the stage of the present invention is characterized by further having an electrode portion.

[0016] Furthermore, in a preferred embodiment of the stage of the present invention, the sample base is characterized by being equipped with an attachment mounting device.

[0017] Furthermore, a preferred embodiment of the stage of the present invention is characterized by having a cooling section.

[0018] Furthermore, a preferred embodiment of the stage of the present invention is characterized by having a thermoelectric element installed in close proximity to the cooling section.

[0019] Furthermore, in a preferred embodiment of the stage of the present invention, the attachment mounting device is characterized by being a screw hole or a clamp.

[0020] Furthermore, in a preferred embodiment of the stage of the present invention, the thermoelectric element is characterized by being a thermoelectric element that utilizes an effect selected from at least one of the Peltier effect or the Thomson effect.

[0021] Furthermore, in a preferred embodiment of the stage of the present invention, the heat dissipation side of the thermoelectric element is in contact with the cooling section.

[0022] Furthermore, in a preferred embodiment of the stage of the present invention, the cooling unit is characterized by comprising at least one of a solid refrigerant, a liquid refrigerant, or a gaseous refrigerant.

[0023] Furthermore, in a preferred embodiment of the stage of the present invention, the sample base and the thermoelectric element are in contact. [Effects of the Invention]

[0024] According to the stage of the present invention, there is an advantageous effect that it can be transferred under vacuum, Ar, etc. Further, according to another aspect of the stage of the present invention, electrodes and the like can also be arranged, and for example, there is an advantageous effect that it is possible to observe an object while flowing electricity through a battery.

Brief Description of the Drawings

[0025] [Figure 1] FIG. 1 shows a conceptual diagram of the sample pedestal portion of the stage in one embodiment of the present invention. FIG. 1(a) shows a top view of the sample pedestal portion of the stage in one embodiment of the present invention, FIG. 1(b) shows a side view of the sample pedestal portion of the stage, and FIG. 1(c) shows a perspective view of the sample pedestal portion of the stage, respectively. [Figure 2] FIG. 2 shows one embodiment of a thermoelectric element applicable to the present invention. FIG. 2(a) shows a cross-sectional view of a Peltier element, and FIG. 2(b) shows a schematic diagram of the principle of the Peltier element. [Figure 3] FIG. 3 is a view showing a perspective view of a stage with a shutter function in one embodiment of the present invention. [Figure 4] FIG. 4 is a view showing a top view of a stage with a shutter function in one embodiment of the present invention. [Figure 5] FIG. 5 is a view showing a side cross-sectional view of a stage with a shutter function in one embodiment of the present invention. [Figure 6] FIG. 6 is a view showing a side view of a stage with a shutter function in one embodiment of the present invention. [Figure 7] FIG. 7 is a view showing a side cross-sectional view of a stage with a shutter function in one embodiment of the present invention. [Figure 8]Figure 8 is a five-view drawing of a stage with a shutter function according to one embodiment of the present invention. Figures 8(a) and (e) are side views of the stage with a shutter function according to one embodiment of the present invention. Figure 8(c) is a top view of the stage with a shutter function according to one embodiment of the present invention. Figure 8(b) is a front view of the stage with a shutter function according to one embodiment of the present invention. Figure 8(d) is a rear view of the stage with a shutter function according to one embodiment of the present invention. [Figure 9] Figure 9 is a perspective view of a stage with a shutter function according to one embodiment of the present invention. [Figure 10] Figure 10 shows an example of a cooling SEM stage system in one embodiment of the present invention. [Modes for carrying out the invention]

[0026] The stage of the present invention is characterized by having a sample base for mounting a sample, a shutter function capable of blocking the atmosphere between the inside and outside of the stage, and a sealing part. In the present invention, the sample base for mounting a sample is not particularly limited in shape, structure, etc., as long as it is capable of mounting a sample to be observed in an electron microscope. Furthermore, the present invention has a shutter function capable of blocking the atmosphere between the inside and outside of the stage. By providing this shutter function, it is possible to create a structure in which electrodes can also be placed, provided that the structure is capable of vacuum transfer independently, and it becomes possible to observe while electricity is flowing through the battery. For example, in the present invention, after creating a vacuum in the glove box to remove moisture, etc., Ar can be filled in. The sample is mounted in the glove box, and after being sealed with a vacuum transfer shutter with a cooling function under Ar gas filling or under vacuum using the shutter function, the stage can be transferred to the SEM under vacuum or Ar.

[0027] Furthermore, in the present invention, the sealing portion is not particularly limited as long as it can block the atmosphere between the inside and outside of the stage during transport under vacuum or the like. As long as it can block the atmosphere between the inside of the stage (sample placement side) and the outside, the sealing portion may be provided on the stage side, on the shutter side, on one side or both sides.

[0028] Furthermore, a preferred embodiment of the stage of the present invention is characterized by having a first valve capable of automatic exhaust. For example, in a glove box, Ar gas can be filled and brought to the SEM, and the SEM can be vacuumed and the lid opened to achieve non-exposure to the atmosphere. However, if the shutter is opened suddenly, a large amount of argon may flow into the SEM, potentially causing the SEM to shut down. Therefore, by having a first valve capable of automatic exhaust, it is possible to mitigate the inflow. For example, by providing a check valve as the first valve capable of automatic exhaust, the valve can release the differential pressure generated between the SEM and the stage chamber, making it possible to more safely vacuum the chamber or the SEM, etc.

[0029] Furthermore, in a preferred embodiment of the stage of the present invention, it is further characterized by having a second valve whose degree of opening and closing can be adjusted. By having a second valve whose degree of opening and closing can be adjusted, it becomes possible to slowly replace the vacuum with an Ar atmosphere or the like. For example, when transferring from the SEM to the glove box, the chamber of the stage is under vacuum, so the second valve whose degree of opening and closing can be adjusted can be used as an opening and closing valve to slowly replace the vacuum with argon in the glove box.

[0030] Furthermore, in a preferred embodiment of the stage of the present invention, the shutter function is further characterized by having a motor capable of opening and closing the shutter. The motor allows for smooth opening and closing of the shutter. The motor may directly operate the shutter, or, as will be described later, it may be opened and closed via, for example, gears. It is also possible to remotely operate the shutter with a motor drive.

[0031] Furthermore, a preferred embodiment of the stage of the present invention is further characterized by having a feedthrough section. As described above, conventional air-free electron microscopes are designed so that voltage cannot be applied because the sample is placed on a cartridge and transported under vacuum from outside the electron microscope. To conduct electricity, a feedthrough is required to isolate the wiring from the vacuum. A feedthrough can be defined as a vacuum component attached to a vacuum wall that separates the vacuum from the atmosphere in order to transport and control electrical signals, physical motion, fluids, etc., inside a device that maintains a vacuum state. In the present invention, the feedthrough section makes it possible, for example, to observe the sample while applying voltage.

[0032] Furthermore, in a preferred embodiment of the stage of the present invention, it is further characterized by having an electrode section. One or more electrode sections can be set. In the present invention, it is possible to attach an electrode shape desired by the user. This makes it possible to customize the way electricity is applied as desired by the researcher.

[0033] Furthermore, in a preferred embodiment of the stage of the present invention, the sample base is characterized by being equipped with an attachment mounting device. That is, in the embodiment equipped with the attachment mounting device of the present invention, attachments can be easily attached and removed, and various attachments can be exchanged. The position in which the attachment mounting device is provided may be the same as the position of the electrodes described above, or it may be provided separately from the electrodes.

[0034] Furthermore, in a preferred embodiment of the stage of the present invention, it is further characterized by having a cooling unit. In the present invention, the cooling unit is not particularly limited in shape, structure, etc., as long as it is capable of cooling the sample observed in the electron microscope. The sample base portion can be cooled by the cooling unit or a Peltier element, but the parts other than the cooling unit are at a higher temperature. Therefore, if an attachment is connected and fixed to a part other than the area around the cooling unit (outside the cooling system), the attachment will be heated by heat from outside the cooling system. In this case, when the attachment is heated, heat is transferred to the sample, so the sample that has been cooled will be heated, and the cooling effect will be reduced. In an embodiment in which the sample base of the present invention is equipped with an attachment mounting device, the attachment is located within the cooling system via the attachment mounting device, and consequently, it is possible to cool the sample with minimal heat loss.

[0035] Furthermore, in a preferred embodiment of the stage of the present invention, the attachment mounting device is characterized by being a screw hole or a clamp, from the viewpoint of being able to firmly and reproducibly fix the attachment. In the present invention, since an attachment mounting device, such as a screw part, is provided, it becomes easy to change the attachment according to the purpose. Double-sided tape and adhesives are difficult to remove once the attachment is fixed and are not intended for reuse. In addition, the degree of thermal contact between the attachment and the sample base changes each time it is changed, and it is difficult to control the posture of the attachment. In contrast, in the present invention, since the attachment can be changed reproducibly by attaching the attachment mounting device, it has the advantage of being able to flexibly respond to various applications.

[0036] Furthermore, while the attachment is not particularly limited as long as it can be attached, in a preferred embodiment of the stage of the present invention, the attachment is characterized by being at least one selected from a FIB grid holding attachment, a sample fixing attachment, and an electrical supply attachment. In addition to the FIB grid holding attachment and the top surface fixing attachment, if the sample is observed with the clamping direction oriented sideways, a temperature gradient can be created from the clamped portion toward the free end portion by cooling from the clamped portion. In the present invention, an attachment capable of providing such a temperature gradient can also be installed. Attachments that have a cold trap function to prevent contamination by placing a cooling member near the top surface of the sample can also be considered.

[0037] Here, when the term "cold trap" is used, it can be understood as a device that cools and captures trace amounts of suspended matter (gases: hydrocarbons, etc.) in a vacuum. In other words, if there is gas in the vacuum, it is expected that it will be struck against the sample when irradiated with an electron beam and accumulate on top of the sample. As in the present invention, when a cooling member is placed near the top surface, it is possible to create a mechanism that surrounds the area near the sample with a cooled metal member (cooling member) in a range that does not obstruct electron beam irradiation, etc., thereby creating a region with a locally high vacuum. This makes it possible to construct a mechanism that cools and condenses the released gas in order to collect it, and consequently makes it possible to prevent gas present in the vacuum within the electron microscope from adhering to the sample.

[0038] Furthermore, when considering applications that involve not only cooling but also simultaneously applying current to the sample, the influence of external temperature can be reduced by fixing electrodes and sample holders using attachment devices such as screw parts, or by fixing and applying current to the sample on an extended platform fixed with an attachment device. Such attachments can also be attached in this invention.

[0039] Furthermore, in a preferred embodiment of the stage of the present invention, the attachment mounting device is characterized by being made of a thermally conductive material. Examples of materials with high thermal conductivity include copper and copper alloys, aluminum and aluminum alloys, silver, and gold. In the present invention, for example, an attachment mounting device, such as screw holes, is integrally arranged on the sample base portion of the stage for cooling a sample in a scanning electron microscope (SEM), making it possible to attach attachments of shapes and forms according to the purpose. As a result, the attachment is also incorporated into the cooling system, reducing the influence of external heat and enabling various cooling methods.

[0040] Furthermore, in a preferred embodiment of the stage of the present invention, the cooling unit is characterized by comprising at least one of a solid refrigerant, a liquid refrigerant, or a gaseous refrigerant. In the cooling unit, the refrigerant can be appropriately set depending on the application and is not particularly limited. From the viewpoint of versatility, a liquid can be mentioned as a preferred medium. If a liquid (such as water) is used, the temperature can be adjusted using a general-purpose device (cooling chiller), but because it is a fluid, it can become a source of vibration. Liquid nitrogen or liquid helium can also be used as the liquid.

[0041] Furthermore, in this invention, the cooling unit may be a solid refrigerant, as it is possible to reduce the effects of vibrations caused by water flow and pulsation to virtually zero compared to water cooling. That is, in this invention, the heat dissipation surface of a Peltier element or the like can be cooled with a solid refrigerant such as dry ice. This makes it possible to reduce the effects of vibrations caused by water flow and pulsation to virtually zero compared to water cooling. In the case of a solid, the difficulty in adjusting the temperature of the cooling unit can be addressed by using a thermoelectric element as described later.

[0042] On the other hand, when the cooling gas is flowed at a minute flow rate, the effect of vibration is minimal, so these methods can also be used in the present invention. Examples of cooling gases include those extracted by gasifying liquid nitrogen. This makes it possible to cool the sample effectively. In the present invention, the cooling gas is not limited to liquid nitrogen. If the gas is simply passed weakly through the heat dissipation surface, the effect of vibration is almost negligible, and it is considered to be practical. Therefore, in the present invention, as described above, even when a solid refrigerant is actually used as the cooling unit, it is sufficient to apply the cold air with a gap rather than pressing it against the heat dissipation surface. Similarly, when using liquid nitrogen gas, observation is possible without being affected by vibration by passing the cooling gas through the heat dissipation surface. The difficulty in adjusting the temperature of the cooling unit can be controlled using a thermoelectric element as described later.

[0043] Furthermore, in a preferred embodiment of the stage of the present invention, it is further characterized by having a thermoelectric element installed in close proximity to the cooling section. In the present invention, the placement position of the thermoelectric element is not particularly limited, as long as it is installed in close proximity to the cooling section. The thermoelectric element makes it possible to efficiently set the temperature required for the sample, i.e., to control the temperature. In the embodiment using a thermoelectric element, the cooling and heating response is good, and the effects of thermal drift can be minimized. Also, because the cooling and heating response is good, precise temperature control is possible. In the embodiment using a thermoelectric element, cooling and heating can be achieved with a single element simply by reversing the direction of current flow, and at the same time, because the cooling and heating response is fast, it is easy to change to a predetermined temperature. Furthermore, precise temperature control is possible by adjusting the output of the input power, so precise temperature control is possible, and the effects of thermal drift can be minimized.

[0044] Furthermore, in a preferred embodiment of the stage of the present invention, the heat dissipation side of the thermoelectric element is in contact with the cooling section. That is, in the present invention, the thermoelectric element only needs to be positioned close to the cooling section. For example, it may be a structure in which the cooling section, such as a solid refrigerant, is pressed against the heat dissipation side (heat dissipation surface side), or a structure in which cold air is applied with a gap. When applying cold air, natural convection or forced convection using a fan may be used, but if forced convection generates vibration, natural convection is preferable, depending on the degree of forced convection. Even in the case of natural convection, since the solid refrigerant has a sufficiently low temperature, there is a large temperature gradient between the heat dissipation surface side and the cold air from the cooling section such as the solid refrigerant, so it is thought that sufficient heat transfer occurs and the heat dissipation surface can be appropriately cooled. It should be noted that heat dissipation by forced convection is more effective than natural convection, and by water cooling is more effective than air cooling.

[0045] Furthermore, in a preferred embodiment of the stage of the present invention, the thermoelectric element is characterized by being a thermoelectric element that utilizes an effect selected from at least one of the Peltier effect or the Thomson effect. The Peltier effect (also called the Peltier effect) is an effect that converts electrical energy into thermal energy, and is a phenomenon in which a temperature difference is generated at both ends when an electric current is passed through two dissimilar metals (or semiconductors) connected at both ends. It is particularly called a Peltier element and is used for cooling precision equipment and wine cellars. The Thomson effect, on the other hand, is an effect that occurs when an electric current is passed through a uniform metal (or dissimilar metals) with a temperature gradient, resulting in the generation of heat other than Joule heat (heat absorption when the current is reversed). Both can generate or absorb heat.

[0046] Furthermore, a heat dissipation member may be installed between the thermoelectric element and the cooling unit, etc., from the viewpoint of efficiently dissipating heat from the thermoelectric element.

[0047] Furthermore, in a preferred embodiment of the stage of the present invention, the thermoelectric element is characterized by being a Peltier element, from the viewpoint of having good cooling and heating response and minimizing the effects of thermal drift. A Peltier element is also called a Peltier element (thermo-module), and this is a general term for elements that utilize the Peltier effect. The structure that is currently mainstream and is considered to have the best performance is called the "π type," which has the structure shown in Figure 2. By passing an electric current through a PN junction using a P-type semiconductor and an N-type semiconductor, heat can be dissipated between the PN and heat absorbed between the NP.

[0048] The principle is as follows. Figure 2 shows one embodiment of a thermoelectric element applicable to the present invention. Figure 2(a) shows a cross-sectional view of a Peltier element, and Figure 2(b) shows a schematic diagram of the principle of the Peltier element. In Figure 2(a), 21 is the hot side metal (mainly Cu), 22 is the ceramic substrate (mainly alumina), 23 is the heat dissipation surface, 24 is the N-type semiconductor, 25 is the P-type semiconductor, 26 is the electric wire, 27 is the power supply, 28 is the heat absorption, 29 is the conduction band of the N-type semiconductor, 30 is the heat dissipation, 31 is the positive side, 32 is the heat absorption side, 33 is the valence band, 34 is the heat dissipation side, 35 is the negative side, 36 is the cold side metal (mainly Cu), 37 is the cold side metal (mainly Cu), 38 is the electron, 39 is the hole, and 40 is the conduction band of the P-type semiconductor.

[0049] In Figure 2(a), the negative electrode is connected to the metal 36 on the N-type semiconductor 24 side. Therefore, the voltage pushes electrons from the conduction band of metal 36 to the conduction band 29 of the N-type semiconductor 24. At this time, because there is an energy gap between the conduction band of metal 36 and the conduction band 29 of the N-type semiconductor 24, the electrons absorb thermal energy from metal 36, thereby cooling it. Subsequently, the electrons flow and fall from the conduction band 29 of the N-type semiconductor 24 to the conduction band of metal 21. Due to the energy gap between the two bands, the electrons release thermal energy. In this way, the hot-side metal 21 is heated. Furthermore, the incoming electrons fall from the conduction band of metal 21 into holes 39 that have flowed through the P-type semiconductor 25, releasing thermal energy and heating the hot-side metal 21. In the P-type semiconductor 25, holes 39 are produced by the voltage and flow from the cold side 37 to the hot side 21. The electrons generated at that time are pushed up to the conduction band of the cold-side metal by the voltage, and absorb thermal energy corresponding to the energy gap, cooling the cold-side metal 37. In this way, heat is transferred from the cold side to the hot side of the Peltier module by the flow of current. In addition to the thermal energy transferred by current, there is also thermal energy transferred by heat conduction, but since the direction of heat conduction is reversed, the less thermal energy transferred by heat conduction there is, the better the performance of the Peltier module will be. In other words, removing the thermal energy from the hot side as quickly as possible with a heat sink or the like will allow the Peltier module to perform well. Simply put, electrons carry (or remove) heat.

[0050] While there are no particular limitations on semiconductor materials, and any of them can be applied, Bi-Te semiconductors are considered to have the best performance and are therefore the mainstream.

[0051] The performance of a Peltier cooler can generally be considered in terms of how much temperature difference ΔT can be created relative to the temperature Th of the heat-dissipating side, when the temperature of the heat-dissipating side is kept constant. For example, for Th = 75, 50, 25 (°C), ΔT = 93, 85, 75. If the heat-dissipating surface is simply cooled to, for example, the temperature of liquid nitrogen (-196°C), the heat-absorbing surface is thought to exceed minus 200 degrees Celsius. However, in reality, due to the properties of the material, ΔT is assumed to be around 10°C near liquid nitrogen. This is because the lower the temperature, the less heat is available to excite electrons, thus reducing the Peltier cooling capacity. Also, at lower temperatures, the electrical resistance of the semiconductor part increases, resulting in self-heating due to the current, which reduces the overall cooling capacity.

[0052] Furthermore, in a preferred embodiment of the present invention, the heat-dissipating side of the thermoelectric element is cooled, which allows for setting a lower temperature. This is characterized by the contact between the heat-dissipating side of the thermoelectric element and the cooling section. The following embodiments mainly describe the cooling case, but in the present invention, heating is also possible using the thermoelectric element. During heating, the lower surface of the thermoelectric element cools down, so it is necessary to heat the cooling section before use (to process at a higher temperature than the lower surface). In this case, the cooling section can function as a heating section rather than a cooling section.

[0053] In the case of heating, the phenomenon is simply the reverse of that in the case of cooling, but the practicality also changes depending on the shape of the thermoelectric element (whether it is multi-stage or not), such as a Peltier element. Basically, when aiming for the lowest possible temperature, a multi-stage thermoelectric element, such as a Peltier element, can be used. In this case, a pyramidal structure can be made in which the area of ​​the heat-absorbing surface (upper stage) is small and the area increases towards the heat-dissipating surface. The reason for this structure is that, basically, a larger area absorbs more heat, so the heat absorbed by the small area upper stage is dissipated by the larger area lower stage element. When using it for heating by reversing the polarity of the current, it is not simple, and there is a tendency for heat from the larger area lower stage to flow rapidly into the small area upper stage. If the upper stage cannot absorb that heat, the heat accumulates in the middle stage and tends to become hotter than the upper stage. For this reason, even when using Peltier elements for heating, the temperature is thought to be around +100°C (the temperature at which the solder at the junction does not deteriorate). Peltier elements create heat-absorbing and heat-dissipating surfaces through electron movement, and by controlling the amount of current flowing through the Peltier element, it is theoretically possible to precisely control the temperature from near room temperature to below freezing. These effects enable stable, high-resolution observation.

[0054] Furthermore, in a preferred embodiment of the stage of the present invention, the sample base and the thermoelectric element are in contact, from the viewpoint of cooling the sample base portion and beyond. [Examples]

[0055] The following describes a stage in one embodiment of the present invention with reference to the drawings, but the present invention is not limited to these embodiments. Furthermore, it goes without saying that the present invention can be modified as appropriate without departing from its spirit.

[0056] Figure 1 shows a conceptual diagram of the sample base portion of a stage in one embodiment of the present invention. Figure 1(a) shows a top view of the sample base portion of the stage in one embodiment of the present invention, Figure 1(b) shows a side view of the sample base portion of the stage, and Figure 1(c) shows a perspective view of the sample base portion of the stage. In Figure 1, 1 is the sample base, 2 is an attachment mounting device or electrode, 3 is a thermoelectric element (if a thermoelectric element is required), 4 is a heat dissipation member, and 5 is a cooling section.

[0057] Referring to the figures, the roles of each component and the connections between them in the sample base of the stage in one embodiment of the present invention will be explained as follows. First, there is the stage body, which in Figure 1 has a cooling section 5. However, in the case of heating as described above, the lower surface of the thermoelectric element cools down during heating, so it is necessary to heat the cooling section before use (to process at a temperature higher than the lower surface). In this case, it can be used as a heating section instead of a cooling section. In this example, a thermoelectric element 3 is also used, but in embodiments where the thermoelectric element 3 is not used, the thermoelectric element 3 can be omitted. In this example, since the thermoelectric element 3 is used, a heat dissipation member 4 may be provided as needed, as shown in the figure. In this example, the attachment mounting device 2 is specifically a screw hole, but as described above, it may be a clamp or the like, and is not particularly limited as long as the attachment can be attached and detached. The attachment mounting device 2 is preferably made of a thermally conductive material. This makes it possible to avoid heat loss as much as possible. If the attachment mounting device is not used, it can be an electrode 2.

[0058] Furthermore, the Peltier element and the sample base can be positioned directly above or with a lateral offset, as long as they are in thermal contact. Also, although the clamp is shown vertically in the diagram, it can be clamped to position the sample horizontally. One characteristic feature is that the attachment mounting holes or electrodes are integrated with the sample base. The mounting holes or electrodes may be machined as a single piece, or the screw holes may be manufactured separately and then press-fitted or bonded later.

[0059] Although not shown in the diagram, a FIB grid may also be installed as an attachment. In this case, the FIB grid holder attachment can be attached to the FIB grid holder base using copper screws or the like. It is also possible to fix the FIB sample holder base to the sample base as a cooling attachment. The FIB mesh can be clamped so that it stands vertically in the center of the FIB grid's divisions. This reduces damage from electron beams and ion beams through the cooling effect. If the base is made a little larger, it is also possible to clamp and observe regular samples. A structure that allows the sample to be clamped horizontally may also be used.

[0060] Furthermore, although not shown in the diagram, it is also possible to fix the sample from above using an attachment. The top surface of the observation sample can be fixed by a sample fixing attachment installed at the top. If the sample is fixed from above using an attachment, and if the attachment is made of a thermally conductive material, it is possible to cool the sample from above as well. In this invention, since attachments can be changed with good reproducibility by attaching an attachment mounting device, it has the advantage of being able to flexibly respond to various applications.

[0061] Next, Figure 3 is a perspective view of a stage with a shutter function in one embodiment of the present invention. In Figure 3, 50 is the shutter, 51 is the motor, 52 is the sample base (with a cooling section below, if present), 53 is the attachment mounting device or electrode, 54 is the first valve, and 55 is the second valve. In Figure 3, the shutter 50 is shown in the open state, showing an example of the inside of the stage. The shutter can be opened and closed, and although not shown, when the shutter is closed, the inside of the stage can be made into a vacuum or Ar atmosphere, allowing for the transfer of vacuum or other materials. The motor 51 can open and close the shutter 50, as will be described later. 52 can also function as the sample base, and by extension, as a cooling or heating section for the sample. In this example, cooling is performed using a Peltier element. Peltier cooling enables overwhelmingly high throughput. Cooling with liquid nitrogen requires a considerable amount of time before and after observation: 1 hour to cool the temperature, 1 hour for the temperature to stabilize, and 1 hour to return to room temperature after observation. However, because Peltier cooling simply involves passing an electric current, it can cool down to -100 degrees Celsius in 3 minutes and to room temperature in 1 minute, allowing for a significantly faster research pace. The reason why liquid nitrogen was used conventionally is that conventional Peltier cooling stages could only cool down to -50 degrees Celsius. At -50 degrees Celsius, it is not possible to reduce damage from electron beams or focused ion beams, and cooling to -80 to -100 degrees Celsius is necessary. Therefore, even if one wanted to use Peltier cooling, the only option was to use a liquid nitrogen type. Surprisingly, however, this invention makes it possible to achieve -100 degrees Celsius with the Peltier cooling method.

[0062] 53 is an attachment mounting device or electrode. If it is an attachment mounting device, the contents of Figure 1 described above can be cited as an example. The attachment mounting device and electrode can be used together, but the electrode may also be used alone. The electrode can be attached in any shape desired by the user, and its shape, arrangement, etc., are not limited. In Figure 3, four electrodes are shown, but there can be one or more electrodes. The method of applying electricity can be customized according to the researcher's requirements.

[0063] Furthermore, valve 54 is the first valve, which, for example, can be automatically evacuated in a vacuum. Inside the glove box, Ar gas or the like is filled and brought to the SEM, and the SEM is evacuated and the lid is opened to prevent exposure to the atmosphere. However, if the shutter is opened suddenly, a large amount of argon will flow into the SEM, which may cause the SEM to shut down. Therefore, by providing an automatically evacuating valve, such as a check valve, a pressure difference is created between the SEM and the stage chamber, and this pressure difference causes the valve to open, making it possible to create a vacuum inside the chamber.

[0064] 55 is a second valve, which can be, for example, a valve whose degree of opening and closing can be adjusted. Conversely to the above, when the stage is transferred from the SEM to the glove box, the second valve 55 functions as an on / off valve that more slowly replaces the vacuum with argon in the glove box, since the stage chamber is under vacuum.

[0065] Next, Figure 4 is a top view of a stage with a shutter function in one embodiment of the present invention. In Figure 4, 50 is the shutter, 51 is the motor, 52 is the sample base (with a cooling section below, if present), 54 is the first valve, 55 is the second valve, 60 is the shutter opening / closing screw, and 61 is the opening / closing lid connecting gear. The shutter 50, motor 51, sample base (with a cooling section below, if present) 52, first valve 54, and second valve 55 can be described in the above explanation. 60 is the shutter opening / closing screw, and when the motor 51 rotates, the shutter opening / closing screw 60 rotates, causing the shutter to move forward to seal the inside of the stage. In this example, the rotation of the motor is used to open and close the shutter using the opening / closing lid connecting gear 61.

[0066] Next, Figure 5 is a lateral cross-sectional view of a stage with a shutter function in one embodiment of the present invention. In Figure 5, 70 is a rotating shaft, 71 is a sealing auxiliary part, 72 is a shutter, and 73 is a shutter opening / closing screw. In this example, the rotating shaft 70 is threaded, and the shutter opening / closing screw 73 is threaded to mesh with the rotating shaft 70. When the rotating shaft 70 is rotated by the motor, the rotational movement is transmitted to the shutter opening / closing screw 73, and the shutter moves to the right in Figure 5 in accordance with the rotation. A sealing part, such as an O-ring, is placed on the back side of the shutter 72, and when the shutter closes, the atmosphere inside the stage and the outside are blocked. In this example, the sealing auxiliary part 71 is a tapered part installed on the side of the shutter. When the shutter closes, a guide pin bites into the tapered part 71, pressing the lid (stage lid, shutter) against the base (stage body). This makes it possible to further enhance the sealing effect of the O-ring. Note that while the sticker is placed on the shutter side, it can also be placed on the stage side.

[0067] Next, Figure 6 is a side view of a stage with a shutter function according to one embodiment of the present invention. In Figure 6, 80 is a guide rail, 81 is a guide pin, and 82 is a tapered section. The guide pin 81 can move along the guide rail in accordance with the opening and closing movement of the shutter. The tapered section 82 is tapered, and in the final stage when the shutter closes, the guide pin 81 applies a downward force to the lid (the top of the stage, the shutter) to hold the lid in place, so that the O-ring can be effective against the sealing surface. The guide pins 81 on both sides and the tapered section 82 can firmly press the entire lid against the sealing surface. This structure makes it possible to provide a compact atmosphere isolation function.

[0068] Next, Figure 7 shows a lateral cross-sectional view of a stage with a shutter function in one embodiment of the present invention. In Figure 7, 90 indicates the first valve and 91 indicates the feed-through section. The first valve 90 can be described in the above description. In the present invention, the position of the feed-through section is not particularly limited. The feed-through section makes it possible, for example, to observe a sample while applying voltage.

[0069] Next, Figure 8 is a five-view drawing of a stage with a shutter function according to one embodiment of the present invention. Figures 8(a) and (e) are side views of the stage with a shutter function according to one embodiment of the present invention. Figure 8(c) is a top view of the stage with a shutter function according to one embodiment of the present invention. Figure 8(b) is a front view of the stage with a shutter function according to one embodiment of the present invention. Figure 8(d) is a rear view of the stage with a shutter function according to one embodiment of the present invention.

[0070] Next, Figure 9 is a perspective view of a stage with a shutter function in one embodiment of the present invention. In Figure 9, 50 is the shutter, 51 is the motor, 52 is the sample base (with a cooling section below, if present), and 53 is the attachment mounting device or electrode. These can be described in reference to Figure 3.

[0071] Next, Figure 10 shows an example of a cooling SEM stage system in one embodiment of the present invention. In Figure 10, 100 represents a temperature control controller, 101 represents a feedthrough, and 102 represents a refrigerant supply device. The temperature control controller 100 is responsible for controlling the temperature within the stage. The feedthrough 101 is a component for passing electricity, temperature measurement, and cooling water into a vacuum. The refrigerant supply device 102 is a device that can deliver refrigerant without vibration.

[0072] Thus, according to the stage of the present invention, by incorporating a shutter function into the stage, it is possible to create a structure that allows for independent vacuum transfer, and electrodes can also be arranged, thereby achieving the advantageous effect of enabling observation while electricity is flowing through the battery. In particular, it has been found that speedy experiments can be performed in embodiments using Peltier cooling. [Industrial applicability]

[0073] The stage can be transported under vacuum or other conditions, and in-situ observation can be performed even under cooling conditions, making it applicable in a wide range of technical fields. [Explanation of symbols]

[0074] 1. Sample base 2. Attachment mounting device or electrode 3. Thermoelectric elements (if thermoelectric elements are required) 4 Heat dissipation components 5 Cooling section 21 Hot-side metals (mainly Cu) 22. Ceramic substrates (mainly alumina) 23 Heat radiation surface 24 N-type semiconductor 25 P-type semiconductor 26 Electric wire 27 Power supply 28 Endothermic 29 Conduction band of N-type semiconductors 30 Heat dissipation 31 Positive side 32 Heat absorption side 33 Valence band 34 Heat dissipation side 35 Negative side 36. Cold-side metals (mainly Cu) 37. Cold-side metals (mainly Cu) 38 electronic 39 holes 40 Conduction band of P-type semiconductors 50 shutters 51 Motor 52 Sample base (cooling section below, if present) 53 Attachment mounting device or electrode 54 First Valance 55 The Second Defense 60 Screws for opening and closing shutters 61 Gear for connecting opening and closing lids 70 rotation shaft 71 Seal support part 72 shutters 73 Screws for opening and closing the shutter 80 Guide Rails 81 Guide pins 82 Tapered section 90 First Valve 91 Feed-through section 100 Temperature Control Controller 101 Feedthrough 102 Refrigerant supply device

Claims

1. A stage comprising a sample base for mounting a sample, a shutter function capable of separating the atmosphere inside and outside the stage, and a sealing section, further characterized by having a first valve capable of automatic exhaust.

2. Furthermore, the stage according to claim 1 is characterized by having a second valve whose degree of opening and closing can be adjusted.

3. Furthermore, the stage according to claim 1 or 2 is characterized by having a motor capable of opening and closing the shutter of the shutter function.

4. Furthermore, the stage according to claim 1 or 2, characterized in that it has a feedthrough section.

5. Furthermore, the stage according to claim 1 or 2, characterized in that it has an electrode portion.

6. The stage according to claim 1 or 2, characterized in that the sample base is equipped with an attachment mounting device.

7. Furthermore, the stage according to claim 1 or 2, characterized in that it has a cooling section.

8. The stage according to claim 7, characterized in that it has a thermoelectric element installed in close proximity to the cooling section.

9. The stage according to claim 6, characterized in that the attachment mounting device is a screw hole or a clamp.

10. The stage according to claim 8, characterized in that the thermoelectric element is a thermoelectric element that utilizes an effect selected from at least one of the Peltier effect or the Thomson effect.

11. The stage according to claim 8, characterized in that the heat dissipation side of the thermoelectric element and the cooling section are in contact.

12. The stage according to claim 7, characterized in that the cooling unit comprises at least one of a solid refrigerant, a liquid refrigerant, or a gaseous refrigerant.

13. The stage according to claim 8, characterized in that the sample base and the thermoelectric element are in contact.

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