stage

Abstract

To provide a stage to which an attachment can be easily attached in order to solve the problem in the present invention.SOLUTION: A stage of the present invention, is a stage including a sample pedestal for mounting a sample and a cooling part, in which the sample pedestal comprises an attachment attached device. Also, in a preferable embodiment of the stage of the present invention, a heat electric element set so as to be approached to the cooling part is further included. In addition, in the preferable embodiment of the stage of the present invention, the cooling part includes an extensible heat conduction part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a stage, and more particularly to a stage to which an attachment can be attached. [Background technology]

[0002] In recent years, high-resolution analysis using electron microscopes such as transmission electron microscopes (TEM) and scanning transmission electron microscopes (STEM) has progressed, and there is a demand for high-resolution analysis, for example, from the nano-order to the pico-order. Recently, "in-situ observation," in which a sample is cooled (or heated, or subjected to electric or magnetic field application, or rotation) while being observed inside the electron microscope, has attracted attention. In particular, sample cooling is considered effective in reducing damage to the sample caused by the electron beam, and sample cooling from this perspective has also been attempted. For example, a sample processing device using a scanning electron microscope is known, which includes a cooling stage in the sample chamber of the scanning electron microscope on which a sample with sublimated water is placed, and a manipulator extending above the cooling stage that extracts required components of the sample under observation by the scanning electron microscope (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 62-85840 Summary of the Invention [Problem to be solved by the invention]

[0004] Despite this need for cooling, existing techniques, including those described in Patent Document 1, only allow the sample to be attached to the upper surface of the sample pedestal, limiting cooling to the sample from below. This poses challenges for specialized applications, such as FIB (Focused Ion Beam) processing on a cooling stage. For example, when performing FIB processing while cooling, the stubs holding the FIB grid must be fixed with double-sided tape or adhesive. However, these methods often use materials with low thermal conductivity. Furthermore, gaps and other inconsistencies in thermal contact occur each time the grid is fixed, resulting in heat loss and inefficiency in terms of thermal conduction. Furthermore, double-sided tape fixation is unstable and insufficient for precise FIB processing, posing problems such as the risk of peeling. While adhesives provide strong adhesion, they require the adhesive to be removed for normal observation, which often requires significant effort. Furthermore, residual adhesive on the sample pedestal can affect subsequent observations, making this method undesirable. Similar difficulties are expected not only when fixing a pedestal that holds an FIB grid, but also when fixing a pre-tilted sample stage.

[0005] SUMMARY OF THE INVENTION In order to solve the above problems, the present invention aims to provide a stage to which an attachment can be easily attached. [Means for solving the problem]

[0006] In order to achieve the above object, the inventors have conducted extensive research into the stage mechanism and have come up with the present invention.

[0007] That is, the stage of the present invention comprises a sample base on which a sample is mounted; Cooling the sample a cooling unit; and a stage having the sample pedestal, Attachment and attaching the attachment Equipped with attachment mounting device The sample holder further includes a thermoelectric element disposed adjacent to the cooling unit, and the thermoelectric element is in contact with the sample holder. It is characterized by:

[0009] In a preferred embodiment of the stage of the present invention, the cooling section has an extendable heat conducting section.

[0010] In a preferred embodiment of the stage of the present invention, the attachment mounting device is a screw hole or a clamp.

[0011] In a preferred embodiment of the stage of the present invention, the attachment is at least one selected from an FIB grid holding attachment, a sample fixing attachment, and an electrical current attachment.

[0012] In a preferred embodiment of the present invention, the thermoelectric element is a thermoelectric element utilizing at least one effect selected from the Peltier effect and the Thomson effect.

[0013] In a preferred embodiment of the stage of the present invention, the heat radiation side of the thermoelectric element is in contact with the cooling portion or the heat conduction portion.

[0014] In a preferred embodiment of the stage of the present invention, the cooling section is made of at least one of a solid refrigerant, a liquid refrigerant, and a gas refrigerant.

[0015] In a preferred embodiment of the stage of the present invention, the sample pedestal and the thermoelectric element are Through the heat dissipation member, It is characterized by being in contact.

[0016] In a preferred embodiment of the stage of the present invention, the attachment mounting device is made of a thermally conductive material. [Effects of the Invention]

[0017] The stage of the present invention has the advantageous effect that an attachment can be attached to it, and also has the advantageous effect that heat loss can be suppressed even when an attachment is attached to it. [Brief explanation of the drawings]

[0018] [Figure 1] Figure 1 shows a conceptual diagram of an example stage in one embodiment of the present invention, where Figure 1(a) shows a top view of the stage in one embodiment of the present invention, Figure 1(b) shows a side view of the stage, and Figure 1(c) shows a perspective view of the stage. [Figure 2] Figure 2 shows an embodiment of a thermoelectric element applicable to the present invention, where 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. [Figure 3] FIG. 3 is a conceptual diagram of a stage showing an example in which an FIB grid is installed as an attachment in one embodiment of the present invention. [Figure 4] FIG. 4 is a conceptual diagram of a stage showing an example of a case in which a sample is fixed from above as an attachment in one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] The stage of the present invention includes a sample pedestal for mounting a sample and a cooling unit, and the sample pedestal is characterized in that it includes an attachment mounting device. In the present invention, the sample stage for mounting a sample is not particularly limited, including its shape and structure, as long as it is capable of mounting a sample to be observed in an electron microscope. In the present invention, the cooling unit is not particularly limited, including its shape and structure, as long as it is capable of cooling a sample to be observed in an electron microscope. In the present invention, the sample pedestal is equipped with an attachment mounting device. That is, the only method for fixing a sample to a conventional cooling stage is to attach the sample to the upper surface of the sample pedestal with double-sided tape or adhesive, which results in unstable fixation. However, in the present invention, the sample pedestal includes an attachment mounting device, which allows for easy attachment and removal of attachments and enables various attachments to be replaced. Although the sample pedestal can be cooled by a cooling unit or Peltier element, areas other than the cooling unit are hotter. Therefore, if an attachment is connected and fixed to an area other than the cooling unit (outside the cooling system), the attachment will receive heat from outside the cooling system and warm up. In this case, when the attachment warms up, heat is transferred to the sample, warming the sample that has been cooled and reducing the cooling effect. In the present invention, the sample pedestal is equipped with an attachment mounting device, so the attachment is present within the cooling system via the attachment mounting device, making it possible to cool the sample with minimal heat loss.

[0020] In a preferred embodiment of the stage of the present invention, from the viewpoint of being able to fix an attachment firmly and with good reproducibility, The aforementionedThe attachment mounting device is characterized by being a screw hole or a clamp. In the present invention, the attachment mounting device, for example, a screw portion, etc., is provided, making it easy to change attachments depending on the purpose. Double-sided tape and adhesives are difficult to remove once the attachment is fixed, and are not intended for reuse. In addition, each time the attachment is replaced, the thermal contact between the attachment and the sample pedestal changes, and the attachment's posture is difficult to control. In contrast, in the present invention, by attaching an attachment mounting device, attachments can be changed with good reproducibility, which has the advantage of being able to flexibly accommodate a variety of applications.

[0021] Furthermore, the attachment is not particularly limited as long as it can be attached, but in a preferred embodiment of the stage of the present invention, the attachment is at least one selected from an FIB grid holder attachment, a sample fixing attachment, and an electrical current attachment. In addition to the FIB grid holder attachment and top surface fixing attachment shown in the drawings described below, when a sample is observed with the clamping orientation horizontal, a temperature gradient can be created by cooling the clamped portion toward the free end. In the present invention, attachments capable of creating such a temperature gradient can also be installed. Attachments that have a cold trap function to prevent contamination by arranging a cooling member near the top surface of the sample are also conceivable.

[0022] Here, the term "cold trap" can be understood as a device that cools and captures trace amounts of suspended matter (gases, such as hydrocarbons) in a vacuum. In other words, if gas is present in the vacuum, it is expected that it will be bombarded by the sample along with the electron beam and accumulate on the sample. When a cooling element is placed near the top surface, as in the present invention, a mechanism can be realized that surrounds the vicinity of the sample with a cooled metal element (cooling element) within a range that does not block the electron beam irradiation, thereby creating a locally high vacuum region. This allows for the construction of a mechanism that cools and condenses the released gas in order to collect it, thereby preventing the gas present in the vacuum inside the electron microscope from coming into contact with the sample.

[0023] Furthermore, when considering applications where a current is applied to a sample in addition to cooling, the influence of external temperatures can be reduced by fixing the electrodes and sample clamps using (via) an attachment device such as a screw, or by fixing and applying current to the sample on an extended table fixed by the attachment device. Such attachments can also be installed in the present invention.

[0024] In a preferred embodiment of the stage of the present invention, the attachment mounting device is 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, a sample pedestal portion of a stage that cools a sample in a scanning electron microscope (SEM) is integrally provided with an attachment mounting device, such as a screw hole, allowing attachments of various shapes and configurations to be attached. This incorporates the attachment into the cooling system, minimizing the influence of external heat and enabling various cooling modes.

[0025] In a preferred embodiment of the stage of the present invention, the cooling section is characterized by comprising at least one of a solid refrigerant, a liquid refrigerant, and a gaseous refrigerant. The refrigerant in the cooling section can be appropriately selected depending on the application and is not particularly limited. A preferred medium is a liquid from the viewpoint of versatility. While a liquid (such as water) can be used to adjust the temperature using a general-purpose device (a cooling chiller), being a fluid, it can become a source of vibration. Liquid nitrogen or liquid helium can also be used as the liquid.

[0026] Furthermore, in the present invention, the cooling unit may be a solid refrigerant, from the viewpoint that the influence of vibrations due to water flow or pulsating flow can be reduced to almost zero compared to water cooling. That is, in the present 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 to almost zero the influence of vibrations due to water flow or pulsating flow compared to water cooling. Furthermore, in the case of a solid, it is difficult to adjust the temperature of the cooling unit, but this can be controlled using a thermoelectric element as described below.

[0027] On the other hand, even when a cooling gas is flowed at a very low flow rate, the influence of vibration is minimal, and this can also be used in the present invention. Examples of cooling gases include gasified liquid nitrogen. This allows for effective cooling of the sample. In the present invention, the cooling gas is not limited to liquid nitrogen. It is believed that simply passing a weak gas through a heat dissipation surface is practically unaffected by vibration. Therefore, as described above, even when a solid refrigerant is actually used as the cooling unit, it is sufficient to apply cold air through a gap rather than pressing it against the heat dissipation surface. Similarly, when liquid nitrogen gas is used, passing the cooling gas through the heat dissipation surface allows observation without being affected by vibration. The difficulty of adjusting the temperature of the cooling unit can be addressed by using a thermoelectric element, as described below.

[0028] In a preferred embodiment of the stage of the present invention, the cooling unit includes an extendable heat-conducting portion. That is, a sample can be cooled by placing an extendable heat-conducting portion extending laterally from the cooling surface on the heat-conducting portion. In the figures described below, the stage is stacked on top of the stage to save space, but it is also possible to fix a sample separately on the heat-conducting portion at a location separate from the stage and extend the heat-conducting path to that location. In the embodiment using a thermoelectric element described below, the thermoelectric element can be placed on the extendable heat-conducting portion. The extendable heat-conducting portion may have any shape, such as an arm or a clamp. That is, in the present invention, the extendable heat-conducting portion can be made of a thermally conductive material, and the heat-conducting portion is not particularly limited, including its shape and structure, as long as it can contact the cooling unit and the sample stage and transmit the cold source from the cooling unit to the sample stage.

[0029] In a preferred embodiment of the stage of the present invention, the stage further comprises a thermoelectric element installed adjacent to the cooling unit. As described above, in an embodiment in which an extensible heat-conducting unit is provided, the thermoelectric element can be installed on the heat-conducting unit. In the present invention, the placement position of the thermoelectric element is not particularly limited as long as it is installed adjacent to the cooling unit. The thermoelectric element enables efficient temperature control, i.e., temperature control, to be performed at the required temperature for the sample. In an embodiment using a thermoelectric element, the cooling and heating response is excellent, minimizing the effects of thermal drift. Furthermore, the excellent cooling and heating response allows for precise temperature control. In an embodiment using a thermoelectric element, cooling and heating can be achieved with a single element by simply reversing the current flow direction. At the same time, the rapid cooling and heating response makes it easy to adjust the temperature to the desired level. Furthermore, precise temperature control is possible by adjusting the input power output, enabling precise temperature control and minimizing the effects of thermal drift.

[0030] 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 unit or the heat conduction unit. That is, in the present invention, the thermoelectric element may be positioned adjacent to the cooling unit or the heat conduction unit. For example, the cooling unit or the heat conduction unit, such as a solid refrigerant, may be pressed against the heat dissipation side (heat dissipation surface side), or a gap may be provided between them to allow cold air to be applied. When applying cold air, natural convection or forced convection using a fan or the like may be used. However, if forced convection generates vibrations, natural convection is preferable, depending on the level of forced convection. Even in the case of natural convection, the solid refrigerant has a sufficiently low temperature, so there is a large temperature gradient between the heat dissipation surface side and the cold air from the cooling unit, such as a solid refrigerant, resulting in sufficient heat transfer and adequate cooling of the heat dissipation surface. Note that forced convection is more effective than natural convection, and water cooling is more effective than air cooling for heat dissipation.

[0031] In a preferred embodiment of this stage of the present invention, the thermoelectric element is a thermoelectric element utilizing at least one of the Peltier effect and the Thomson effect. The Peltier effect (also called the Peltier effect) is an effect of converting electrical energy into thermal energy, and is a phenomenon in which a temperature difference occurs between the two ends of two dissimilar metals (or semiconductors) when the two ends are connected and a current is passed through them. This is particularly called a Peltier element and is used to cool precision instruments, wine cellars, etc. The Thomson effect is an effect that occurs when a current is passed through a homogeneous metal (or dissimilar metals) with a temperature gradient, generating heat other than Joule heat (heat is absorbed when the current is reversed). Both are capable of generating and absorbing heat.

[0032] A heat dissipation member may be provided between the thermoelectric element and the cooling unit or the like from the viewpoint of efficient heat dissipation from the thermoelectric element.

[0033] In a preferred embodiment of this stage of the present invention, the thermoelectric element is a Peltier element, which provides good cooling and heating response and minimizes the effects of thermal drift. Peltier elements are also called Peltier elements (thermo-modules), a general term for elements that utilize the Peltier effect. The currently mainstream structure that is considered to have the best performance is called the "π-type," which has a structure as shown in Figure 2. By passing a current through a PN junction using a P-type semiconductor and an N-type semiconductor, heat can be dissipated between the PN and absorbed between the NP.

[0034] 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 a Peltier element. In Figure 2(a), 21 indicates the hot-side metal (mainly Cu), 22 indicates the ceramic substrate (mainly alumina), 23 indicates the heat dissipation surface, 24 indicates the N-type semiconductor, 25 indicates the P-type semiconductor, 26 indicates the electric wire, 27 indicates the power source, 28 indicates the heat absorption, 29 indicates the conduction band of the N-type semiconductor, 30 indicates the heat dissipation, 31 indicates the positive side, 32 indicates the heat absorption side, 33 indicates the valence band, 34 indicates the heat dissipation side, 35 indicates the negative side, 36 indicates the cold-side metal (mainly Cu), 37 indicates the cold-side metal (mainly Cu), 38 indicates the electron, 39 indicates the hole, and 40 indicates the conduction band of the P-type semiconductor.

[0035] In Figure 2(a), the negative pole is connected to metal 36 on the N-type semiconductor 24 side. Therefore, the voltage pushes electrons up from the conduction band of metal 36 to the conduction band 29 of 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 N-type semiconductor 24, the electrons absorb thermal energy from metal 36, thereby cooling it. The electrons then flow and fall from the conduction band 29 of N-type semiconductor 24 to the conduction band of metal 21. The energy gap between the two bands causes the electrons to release thermal energy. In this way, the hot-side metal 21 is heated. The flowing electrons then fall from the conduction band of metal 21 to holes 39 flowing through the P-type semiconductor 25, releasing thermal energy and heating the hot-side metal 21. In the P-type semiconductor 25, the voltage generates holes 39, which flow from the cold side 37 to the hot side 21. The electrons generated at that time are pushed up into the conduction band of the cold side metal by the voltage, absorbing thermal energy according to the energy gap and cooling the cold side metal 37. In this way, heat is transported from the cold side to the hot side of the Peltier module as a result of the current flow. In addition to the thermal energy carried by the current, there is also thermal energy carried by thermal conduction, but because the thermal energy carried by thermal conduction flows in the opposite direction, the less of it there is, the better the performance of the Peltier module. In other words, removing the thermal energy from the hot side as quickly as possible using a heat sink or similar will enable the Peltier module to perform well. Simply put, electrons carry (remove) heat.

[0036] There are no particular restrictions on the semiconductor material, and any can be used, but Bi-Te semiconductors are considered to have the best performance and are the mainstream.

[0037] Generally, Peltier device performance can be measured by the temperature difference ΔT that can be achieved relative to the temperature Th when the heat-dissipating side is kept constant. For example, for Th = 75, 50, or 25°C, ΔT = 93, 85, or 75°C. If the heat-dissipating side were simply cooled to, say, liquid nitrogen temperature (-196°C), the heat-absorbing side would likely reach temperatures exceeding minus 200°C. However, due to the characteristics of the material, in reality, ΔT is estimated to be 10°C at temperatures near liquid nitrogen. The lower the temperature, the less heat there is to excite electrons, reducing the Peltier device's cooling capacity. Additionally, the lower the temperature, the greater the electrical resistance of the semiconductor, causing it to self-heat due to electrical current, reducing the overall cooling capacity.

[0038] In addition, in a preferred embodiment of the present invention, the heat radiation side of the thermoelectric element is in contact with the cooling part or the heat conduction part, from the viewpoint that it is possible to set a lower temperature by cooling the heat radiation side of the thermoelectric element. Although the following examples mainly describe the case of cooling, in the present invention, heating is also possible using the thermoelectric element. Since the lower surface of the thermoelectric element cools during heating, it is necessary to heat the cooling part (to process at a temperature higher than the lower surface). In this case, it can function as a heating part rather than a cooling part.

[0039] In the case of heating, the phenomenon is simply reversed compared to cooling, but its practicality also depends on the shape of the thermoelectric element (such as a Peltier element, whether it is multi-stage or not). Basically, if you are aiming for the lowest possible temperature, you can use a multi-stage thermoelectric element, such as a Peltier element. In this case, a pyramid-like structure can be used, with the heat-absorbing surface (top layer) being smaller and the heat-dissipating surface becoming larger. This structure is used because, since the larger the surface area, the greater the heat absorption capacity, the heat absorbed by the smaller upper layer can be dissipated by the larger lower layer. When using a Peltier element for heating by reversing the polarity of the current, it is not simple; heat from the larger lower layer tends to flow into the smaller upper layer all at once. If the upper layer cannot absorb the heat, heat accumulates in the middle layer, which tends to be higher than the upper layer. For this reason, it is thought that most Peltier elements, even when used for heating, will reach around +100°C (a temperature at which the solder at the joint does not deteriorate). Peltier elements create heat absorption and heat dissipation surfaces through the movement of electrons, and by controlling the amount of current passing through the Peltier element, it is possible, in principle, to precisely control the temperature from near room temperature to the negative range. These effects enable stable, high-resolution observations.

[0040] In a preferred embodiment of the stage of the present invention, the sample pedestal and the thermoelectric element are in contact with each other, from the viewpoint of cooling the area after the sample pedestal.

[0041] Hereinafter, the stages of one embodiment of the present invention will be described with reference to the drawings, but the present invention is not intended to be limited to these.

[0042] Figure 1 shows a conceptual diagram of an example stage in one embodiment of the present invention. Figure 1(a) shows a top view of the stage in one embodiment of the present invention, Figure 1(b) shows a side view of the stage, and Figure 1(c) shows a perspective view of the stage. In Figure 1, 1 shows a sample base, 2 shows an attachment mounting device, 3 shows a thermoelectric element (if a thermoelectric element is required), 4 shows a heat dissipation member, and 5 shows a cooling unit.

[0043] The role of each component and the connections between components of a stage according to one embodiment of the present invention will be described below with reference to the drawings. First, there is the stage body. In FIG. 1, the stage body includes a cooling unit 5. However, in the case of the heating described above, the underside of the thermoelectric element cools during heating, so the cooling unit must be heated (processed at a higher temperature than the underside). In this case, the cooling unit can function as a heating unit rather than a cooling unit. While this example also includes a thermoelectric element 3, in an embodiment without the thermoelectric element 3, the thermoelectric element 3 can be omitted. Since this example uses a thermoelectric element 3, a heat dissipation member 4 may be provided as needed, as shown in the drawing. In this example, the attachment mounting device 2 is specifically a screw hole. However, as described above, a clamp or the like may also be used. There is no particular limitation as long as the attachment can be attached and detached. The attachment mounting device 2 is preferably made of a thermally conductive material. This further reduces heat loss.

[0044] As long as the Peltier element and the sample pedestal are in thermal contact, they can be directly above each other or offset to the side and extended. The clamp is shown standing vertically in the figure, but it can also clamp the sample horizontally. One important feature is that the attachment holes are integrated with the sample pedestal. The attachment holes can be machined as a single piece, or the screw holes can be manufactured separately and then press-fit or glued in later.

[0045] FIG. 3 is a conceptual diagram of an example stage in which an FIB grid is installed as an attachment in one embodiment of the present invention. In FIG. 3, 50 denotes an FIB grid holder, 51 denotes a copper screw, and 52 denotes an FIB grid holder attachment. In this example, the FIB grid holder attachment 52 is attached and detached via the copper screw 51, which is a thermally conductive material. However, the material is not particularly limited as long as it is attachable and detachable. This example shows an example in which a FIB sample holder is fixed to a sample holder as a cooling attachment. The FIB mesh can be clamped vertically in the center of the gap. This arrangement reduces damage caused by electron beams or ion beams due to the cooling effect. Although the example shows a FIB sample holder, a normal sample can also be clamped and observed (if the base portion is made a little larger). The sample may be configured to be clamped horizontally.

[0046] Figure 4 is a conceptual diagram of a stage showing an example of a case in which a sample is fixed from above as an attachment in one embodiment of the present invention. In Figure 4, 60 indicates the observation sample, and 61 indicates the sample fixing attachment (for fixing the upper surface). If the sample is fixed from above as an attachment and the attachment is made of a thermally conductive material, it is possible to cool the sample from above as well. [Industrial Applicability]

[0047] The attachments are easy to replace, and in-situ observation is possible even under cooling conditions, making it applicable to a wide range of technical fields. [Explanation of symbols]

[0048] 1. Sample stand 2 Attachment mounting device 3 Thermoelectric element (if required) 4 Heat dissipation material 5 Cooling section 21 Hot side metal (mainly Cu) 22 Ceramic substrate (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 minus 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 FIB grid holder 51 Copper screws 52 FIB Grid Holder Attachment 60 Observation Samples 61 Sample fixing attachment (for upper surface fixing)

Claims

1. A stage having a sample pedestal for mounting a sample and a cooling section for cooling the sample, wherein the sample pedestal is provided with an attachment and an attachment mounting device for mounting the attachment, and further has a thermoelectric element installed adjacent to the cooling section, and the sample pedestal and the thermoelectric element are in contact with each other.

2. 2. The stage of claim 1, wherein the cooling portion comprises an expandable heat conducting portion.

3. 3. The stage according to claim 1, wherein the attachment mounting device is a screw hole or a clamp.

4. 4. The stage according to claim 1, wherein the attachment is at least one selected from the group consisting of an FIB grid holding attachment, a sample fixing attachment, and an electrical current attachment.

5. 2. The stage according to claim 1, wherein the thermoelectric element is a thermoelectric element utilizing at least one of the Peltier effect and the Thomson effect.

6. 3. The stage according to claim 2, wherein the heat radiation side of the thermoelectric element is in contact with the cooling portion or the heat conduction portion.

7. 7. The stage according to claim 1, wherein the cooling portion is made of at least one of a solid refrigerant, a liquid refrigerant, and a gas refrigerant.

8. 2. The stage according to claim 1, wherein the sample pedestal and the thermoelectric element are in contact with each other via a heat dissipation member.

9. 9. The stage according to claim 1, wherein the attachment mounting device is made of a thermally conductive material.

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