JPH04248237A - Specimen switch-over device for electron microscope - Google Patents

Abstract

PURPOSE:To enable each specimen to be microscopically examined efficiently while plural specimens are being discriminated individually by inserting the plural specimens into a vacuum chamber, and thereby switching each specimen over to a definite position in order. CONSTITUTION:A device is furnished with a support frame acting as a connecting means which flexibly connects plural specimen holders 8 to one another, and the support frame is made up of a first connecting frame 18 including plural holding sections which hold the specimen holders 8, and of a second connecting frame 22 which flexibly connects the first connecting frame 18. Each specimen holder 8 is mechanically connected to the first connecting frame 18, each specimen holder 8 is moved as the support frame is moved, and when the support frame is suspended, each specimen holder 8 is held as it is while being unaffected by drift and vibration. This arrangement enables plural specimens to be microscopically examined in order with no vacuum condition affected, and also enables pictures to be taken in the high resolving power range while being unaffected by drift and vibration.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sample switching device for an electron microscope, and more particularly to a sample switching device for an electron microscope suitable for application to a side entry type sample stage.

0002

[Prior Art] In a so-called side entry type sample stage, in which a sample is inserted from the side of the objective lens of an electron microscope between the upper and lower poles of the lens, multiple Attempts have been made to sequentially switch specimens to predetermined positions without breaking the vacuum within the electron microscope. This is because the efficiency of microscopy can be improved.

By the way, one of the factors that affects the resolution and image quality of an electron microscope is the influence of vibration, drift, etc. Since vibrations and drifts occur each time the sample movement mechanism is adjusted to move (fine movements) in order to change the observation field of the sample, waiting for a period of time until the sample becomes stable significantly impairs the efficiency of microscopy. Therefore, it is desirable to be able to efficiently examine multiple samples without being affected by vibrations, drift, etc.

[0004] As disclosed in Japanese Patent Application Laid-Open No. 61-200657, conventional sample switching devices include a sample switching device that supports a plurality of samples in order to sequentially switch the samples to predetermined positions. There is a method that moves the entire support, and as disclosed in Japanese Patent Laid-Open No. 54-53957, etc., there is a method that moves the entire support. There is one that moves a plurality of samples relatively along the line.

[0005]

[Problem to be Solved by the Invention] Among the above-mentioned conventional techniques,
The former requires a separate moving space for the sample support required to switch samples, so the number of samples is limited to about 4 to 5, and one end of the sample support is free. Since it is not mechanically fixed, insufficient consideration is given to vibration and drift, and if external vibration is applied to the sample support, problems such as fluctuations in the observation field will occur.

Furthermore, although the latter has the advantage of being able to load a large number of samples into a small space, the former has the advantage that the samples are movable so that they can be sequentially switched, that is, they are not mechanically fixed. Insufficient consideration is given to the same vibration and drift. Furthermore, there is a fundamental problem that sample switching cannot be performed sufficiently. A plurality of sample holders, each holding a sample, are arranged along a sample movement path formed on the sample support, and all of the sample holders function like a kind of chain. Even if you try to switch the sample holder sequentially along the , it will not work. Even if a pushing force is applied to an adjacent sample holder in the direction of movement, the force is not transmitted to the previous sample holder because the sample holder is ring-shaped as a whole. This is because it has been experimentally confirmed that switching is not possible unless a pulling force is applied on the other hand. Furthermore, since the individual sample holders are not fixed, the sample holders themselves may rotate, causing the problem that the observation field of view cannot be reproduced. To further explain why the sample holder cannot be switched sufficiently, the sample holder must be pulled and pushed at the same time to move.
It was also found that the device did not move even if there was a time difference between the pulling and pushing forces due to play in the mechanism. In addition, when an endless chain is constructed by combining plate-shaped links, a slightly larger space is required, making the entire sample support larger, and loading a sample mesh with a diameter of 2.3 mm is the most that can be done on a daily basis. It turned out that it was impossible to load the sample mesh used, which had a diameter of 3.0 mm. This is because the dimensions of the sample support are designed to be optimal when one or two samples are loaded, and no allowance is made for dimensions.

The present invention has been made in view of the above points, and its purpose is to improve vibration and drift, which have conventionally been problems in electron microscopes, while also improving the ability to handle multiple samples and diameters of 3 To smoothly switch samples with a sample size of .0 mm to predetermined positions one after another without breaking the vacuum inside the electron microscope, and to easily determine which sample is being observed among multiple samples. There is a particular thing.

[0008]

[Means for Solving the Problems] The present invention is characterized in that a plurality of sample holders arranged in a vacuum and a sample moving path for transporting the sample holders are formed. A support body, an engaging means for moving the sample holder along the sample movement path, and a driving force generated by an operation outside the vacuum to switch and arrange the sample holder at a predetermined position in the vacuum. In the electron microscope specimen switching device, the specimen switching device has a drive means for flexibly connecting the plurality of specimen holders, and the specimen holder can be switched to a predetermined position by operation from outside the vacuum. The reason is that we have prepared the following.

[0009] In a preferred embodiment, the connecting means includes a support piece, and the support piece includes a holding part for holding the sample holder, an engaging part for abutting with the engaging means, and the supporting piece. In a further preferred embodiment, the supporting piece includes a first connecting piece having a plurality of holding parts that hold sample holders, and a first connecting piece having a plurality of holding parts that hold sample holders. and a second connection piece that connects the sample holder with flexibility, and has a contact surface made of the same material on the upper and lower surfaces of the support piece, and a coating of molybdenum disulfide or the like is formed on the contact surface, and the sample holder is The supporting piece is mechanically connected to the piece with good thermal conductivity, the outer radius of the supporting piece is smaller than the outer radius of the sample holder, and the supporting piece and the sample holder are labeled with reference numerals.

0010

[Operation] According to the above structure, the driving force from outside the vacuum is transmitted to the connecting means (in a preferred embodiment, the supporting piece) through the engaging means.
Because the connecting means is connected, both pushing and pulling actions occur on the sample holder at the same time, allowing the sample holders to be smoothly switched and positioned one by one to the fixed position. I was able to confirm. Since the upper and lower surfaces of the support piece are in contact with the same member, floating can be prevented and thermal balance can be maintained, allowing for stable movement with good vibration resistance.

A film of molybdenum disulfide or the like serves as a lubricant. Since the sample holder is mechanically coupled to the support piece with good thermal conductivity, the sample holder itself does not rotate, and the multiple samples are not affected by vibration or drift. Furthermore, the outer diameter radius of the support piece is smaller than the outer diameter radius of the sample holder, so it is possible to easily accommodate a sample mesh with a diameter of 3.0 mm, which is commonly used, without increasing the size of the sample support. It is possible to load. In addition, the support piece and sample holder have 1, 2, 3...
Since the sample holder is marked with a code, it is easy to determine which code the sample holder is being observed. According to the present invention, it is possible to efficiently examine a plurality of samples without being influenced by vibrations and drifts.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be explained with reference to the drawings.

In FIG. 1, a base cylinder 3 is attached to a wall 2 for forming a vacuum chamber 1 in a vacuum-proof manner, and a oscillating mechanism 5 moves a oscillating movement mechanism 5 around a spherical body part 4 to the base cylinder. A swinging shaft 6 that swings is inserted in a vacuum-proof manner. A hollow shaft-shaped sample support 7 passes through the vacuum chamber 1 from the outside to the inside through the oscillation shaft 6 in a vacuum-proof manner. As shown in FIG. 2, a sample moving path 10 is formed in the tip 7' of the sample support 7 in the shape of a donut and an ellipse. As shown in FIG. 3, a protrusion 11 is formed in the middle portion of the sample moving path 10 in the cross-sectional direction and protrudes inside the groove, and is configured to prevent the first connecting piece described later from lifting up. . 12 is an insertion notch for inserting the first connecting piece into the groove. 8 is a sample holder, which is a stand on which a sample 9 is placed for observation with an electron microscope;
In this embodiment, eight sample holders 8a to 8h can be placed on the sample moving path 10. Sample holder 8
It is composed of a holder part 13, an inner diameter threaded part 14, and a threaded part 15 formed on the lower surface. Reference numeral 16 denotes a sample holder, which is formed with a threaded portion 17 that engages with the inner diameter threaded portion 14 of the sample holder 8, and is configured to hold the sample 9 by screwing together the screws. 18 is the first connecting piece and the sample holder 8
two holding parts 19 for holding, an engaging part 20 that engages with an engaging means to be described later, and a connecting part 2 that connects the connecting pieces.
1, and the holding part 19 has a sample holder 8.
An inner diameter thread 19' is formed to be screwed into the threaded portion 15 of.

In this embodiment, since the first connecting piece 18 has two holding parts 19, the entire loop consists of four first connecting pieces 1.
It is composed of 8. Reference numeral 22 denotes a second connecting piece, which is composed of a connecting part 23 that fits into the connecting part 21 of the first connecting piece 18 and connects the first connecting piece flexibly, and an engaging part 24 that engages with an engaging means to be described later. has been done. The sliding surfaces of the first connecting piece 18 and the second connecting piece 22 are coated or applied with a lubricant such as molybdenum disulfide (not shown). 25
is a feed wheel serving as an engaging means, and is connected to the engaging portion 2 of the first connecting piece 18.
0 and the engaging part 24 of the second connecting piece 22, a meshing part 26 consisting of four 1/4 circumference shapes, a square part 27 that fits into a driving means to be described later, and a sample holder 8. It is composed of a cylindrical portion 28 that presses the connecting pieces 18 and 22 from floating, and a presser portion 29 that presses the connecting pieces 18 and 22 from floating. Reference numeral 30 denotes a square hole wheel consisting of tooth portions 31 and a square hole 32 that fits into the square portion 27 of the feed wheel 25. Reference numeral 33 denotes a transmission wheel, which has a toothed portion 34 and a fitting portion 36 that engages with the drive shaft 35.
The tooth portion 34 of No. 3 is engaged with the tooth portion 34 of No. 3. The drive shaft 35 passes through the sample support 7 in a vacuum-proof manner and extends from the outside of the vacuum chamber 1 toward the inside thereof. The tip of the sample support 7 is received by a receiver 37 arranged coaxially with the sample support 7, and the receiver 37 is connected to a sample fine movement mechanism (not shown). Note that among the eight sample holders 8, the center of the sample holder 8a is a point 38 through which the electron beam should pass (see FIG. 2).
matches.

The above is a description of the components of this embodiment, but if this is explained in more detail along the assembly procedure,
The sample was placed on the sample holder 8 and fixed with the sample holder 16.
The four sample holders 8a to 8h are screwed to the holding part 19 of the first connecting piece 18, and the four connecting parts 21 of the first connecting piece 18 are
are similarly connected flexibly by the connecting portions 23 of the four second connecting pieces 22. The connecting pieces 18 and 22 are installed through the insertion notch 12 of the sample support 7 provided in the sample moving path 10. Then, the first connecting piece 18 and the second connecting piece 22
The feed wheel 25 is arranged so as to mesh with the engaging portions 20 and 24, and the square hole wheel 30 is fixed to the feed wheel 25 with screws. A transmission wheel 33 is made to mesh with this square hole wheel 30. The operation of the electron microscope sample switching device having the above configuration will be described next. If the swing motion mechanism 5 is operated to swing the swing motion shaft 6 around the spherical body portion 4 in a direction perpendicular to the electron beam passing through the point 38, the sample holder 8a will be at the position of the point 38.
are also swung in the same direction. Further, when a sample fine movement mechanism (not shown) is operated, the receiver 37 moves slightly in the direction of arrow A in response to the operation, and therefore the sample support 7 also moves slightly in the same direction. In this way, the two-dimensional position adjustment of the sample 9 held by the sample holder 8 at the position of point 38 within a plane perpendicular to the electron beam is performed. On the other hand, when the drive shaft 35 is rotated, the feed wheel 25 is driven via the transmission wheel 33 and the ratchet wheel 30. As a result, the feed wheel 25 is moved to the engaging portion 20 of the connecting piece.
or 24 to rotate the connecting pieces 18 and 22 along the sample moving path 10 to send the sample holder 8e to the next position.
The next sample holder 8h is sent to the electron beam irradiation position. At this time, since the first connecting piece 18 is flexibly connected by the second connecting piece 22, a pushing force acts on the sample holder 8f located in front of the sample holder 8e to which feeding force is applied from the outside, so that the Sample holders 8f to 8a above 2 (correctly the first and second connecting pieces 18, 22)
is pushed and tries to move, while the pieces at the back are connected, so a pulling force is applied to the sample holder 8d,
The sample holders 8b to 8d in the lower part of FIG. 2, to which the pushing force was not sufficiently transmitted because the force was conventionally dispersed at the sample holder 8a at the leftmost end, try to move by the pulling action. Therefore, regardless of whether the sample moving path 10 is circular or elliptical, the sample holders 8a to 8h can be slid smoothly. Even when the drive shaft 35 is rotated in the opposite direction, the sample holders 8a to 8h can smoothly slide in the opposite direction on the sample moving path 10 by the same pushing and pulling action. In this way, the eight sample holders 8a to 8h are sequentially switched to the electron beam irradiation position, so that a plurality of samples can be efficiently examined.

Next, the sizes of the outer radius of the support pieces (here, the first connecting piece 18 and the second connecting piece 22) and the outer radius of the sample holder 8 will be explained. As shown in FIG. 3, the support piece has a structure such that it is housed in the sample support 7, and the lower surface of the support piece has a sample movement path 10, and the upper surface has a protrusion extending inside the groove. Since it is in contact with the sample support 11 by the same member, lifting is prevented and thermal equilibrium with the sample support 7 is quickly maintained, and stable movement is possible in terms of vibration resistance.

As described above, since there is no need to incorporate another member into the sample support 7, the sample support 7 does not become large compared to the size of the support piece. Since the sample holder 8 is attached to the support piece and exposed on the upper surface of the sample support 7, it can take up a larger spatial space than the support piece. In other words, since we were able to make the outer diameter of the support piece smaller than the outer diameter of the sample holder 8, we could create a sample mesh with a diameter of 3.0 mm, which is larger than a sample mesh with a diameter of 2.3 mm, without increasing the size of the sample support 7. It became possible to load. In addition, since the sample holder 8 is closely connected to the first connecting piece 18, it has good thermal conductivity, and the eight sample holders 8a
Sample 9 held for ~8h is unaffected by vibration and thermal drift. The first connecting piece 18 and the sample holder 8 are numbered a to h or 1 to 8, and the sample holder located at the electron beam irradiation position is located on the atmospheric pressure side of the drive shaft 35. Since the same reference numeral 40 is displayed, it is possible to easily identify which sample holder is being observed from outside the vacuum.

In this example, the number of sample holders is eight, but this is not a limitation, and as many samples as possible can be examined using the limited small space without breaking the vacuum. This is extremely suitable for meeting the requirements for a side entry type sample stage.

[0019]

[Effect of the invention] As is clear from the above,
In the present invention, the sample holder is not simply moved;
Since the sample holder is once fixed to a flexible connecting means and then moved, pushing and pulling forces act on the sample holder at the same time, so compared to the conventional method in which the sample holder is moved only by pushing force. The sample holder can be smoothly moved along the sample movement path.

Furthermore, since the sample holder itself is fixed and does not rotate during movement, the same field of view can be seen again at the same location even if repeated observations are made. Furthermore, since the sample is not affected by vibration or drift, it is possible to observe and photograph the sample image in a high-magnification, high-resolution region.

[0021] In this way, it is possible to efficiently examine a plurality of samples while individually discriminating them, which has a great practical effect.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a sample switching device for an electron microscope showing an embodiment of the present invention.

FIG. 2 is a plan view of the sample holder section in FIG. 1.

FIG. 3 is a vertical cross-sectional view of FIG. 2;

FIG. 4 is an exploded perspective view of main elements.

[Explanation of symbols]

7... Sample support, 8... Sample holder, 9... Sample, 10...
Sample moving path, 18...first connection piece, 19...holding section, 20...
Engagement part, 21... Connection part, 22... Second connection piece, 23... Connection part, 24... Engagement part, 25... Feeding wheel, 30... Square hole wheel, 33
...A telling car.

Claims (9)

[Claims] 1. A plurality of sample holders disposed in a vacuum, a sample support having a sample movement path for transferring the sample holders, and a sample support for transferring the sample holder along the sample movement path. and a drive means for transmitting a driving force generated by an operation outside the vacuum to the engagement means in the vacuum, and the sample holder is moved to a predetermined position in the vacuum by the operation from outside the vacuum. What is claimed is: 1. A sample switching device for an electron microscope that can be switched and disposed in a fixed position, comprising a connecting means for flexibly connecting the plurality of sample holders. 2. The connecting means includes a support piece, and the support piece includes a holding part for holding the sample holder, an engaging part for making contact with the engaging means, and a supporting piece that connects the supporting pieces to each other. 2. The sample switching device for an electron microscope according to claim 1, further comprising a coupling portion for coupling. 3. The supporting piece includes a first connecting piece having a plurality of holding parts for holding the sample holder, and a second connecting piece that flexibly connects the first connecting piece. The sample switching device for an electron microscope according to claim 2, characterized in that: 4. The sample switching device for an electron microscope according to claim 2, wherein the upper and lower surfaces of the support piece are configured to be in contact with each other by the same member. 5. The sample switching device for an electron microscope according to claim 2, wherein a contact surface between the connecting portion of the support piece and the moving path is formed of a thin film different from a base material. 6. The sample switching device for an electron microscope according to claim 2, wherein the support piece and the sample holder are mechanically fixed. 7. The sample switching device for an electron microscope according to claim 2, wherein the outer radius of the support piece is smaller than the outer radius of the sample holder. 8. The electron microscope according to claim 1, wherein the electron microscope is configured such that the sample holder disposed at a predetermined position in the vacuum can be identified from outside the vacuum by an operation from outside the vacuum. sample switching device. 9. The sample switching device for an electron microscope according to claim 8, wherein the support piece and the plurality of sample holders are provided with symbols.