JP5908357B2 - Goniometer stage and electron microscope having the goniometer stage - Google Patents

Description

  The present invention relates to a gonio stage and an electron microscope having the gonio stage, and more particularly to a gonio stage having a valve opening / closing mechanism and an electron microscope having the gonio stage.

  In recent years, high-resolution analysis in electron microscopes such as transmission electron microscopes (TEMs) and scanning transmission electron microscopes (STEMs) has been progressing. There is a demand for resolution analysis. In the existing gonio stage (Gonio), there is an open / close valve when the sample holder (Holder) is inserted from the preliminary chamber into the high vacuum sample chamber (Patent Document 1).

JP 2005-26530 A

  However, in the prior art including Patent Document 1, the valve is opened and closed manually or while rotating the sample holder. That is, in the existing gonio stage (Gonio), the sample holder is inserted, and the part that was at atmospheric pressure before insertion is preliminarily exhausted. After that, the partition valve that has been cut off from the high vacuum (vacuum of the electron microscope housing) provided on the gonio stage is opened, and the holder is inserted. Normally, in order to open the partition valve, a valve opening / closing mechanism cylinder arranged inside the holding cylinder is driven by rotating the sample holder by 90 ° to 120 °, and a spherical valve (partition valve) connected to the valve opening / closing mechanism cylinder is driven. It is a process to rotate and open.

However, when the sample Data acquisition in a cooled state, the sample holder (commonly referred to as cooling the sample holder) is cooled with liquid nitrogen, for cooling the sample holder must be rotated 90 ° to 120 ° is present, liquid nitrogen There may be a situation where liquid nitrogen spills from the container (dewar).

  Therefore, in order to insert the cooled sample holder, the goniometer stage is once rotated and tilted, rotated (rotation angle when inserting the sample holder), the sample holder is inserted straight, and after the preliminary vacuum is drawn, the goniometer stage is returned to its original position. It is necessary to insert it back (see FIGS. 5 and 6). That is, with the partition valve closed, the cooled sample holder is inserted into the goniometer stage with the upper body turned on the shaft so that the liquid nitrogen container (dewar) faces upward. After that, after preliminary exhaust is completed, it is necessary to make the liquid nitrogen container (dewar) face up to turn the partition valve. However, this operation is dangerous, and until the sample holder is loaded It was necessary to stay in place.

  Even in the case of an ordinary sample holder, the operator needs to stay on the spot to wait for preliminary exhaust (usually about 2 minutes) and turn the sample holder by hand to open the partition valve after completion.

  In recent years, analysis of electron microscopes has become severe, and stability of the atmosphere in the electron microscope is regarded as important, and throughput is required for industrial use. For this purpose, humans should be removed from the electron microscope as much as possible, room temperature and air convection should be stabilized, and placed in an environment as much as possible. The disturbance could not be eliminated. Therefore, development of a gonio stage having a valve opening / closing mechanism has been desired. However, there is no such mechanism so far.

  Accordingly, an object of the present invention is to provide a gonio stage having a valve opening / closing mechanism in order to solve the above-mentioned problems.

  In order to achieve the above object, the present inventor has intensively studied the mounting mechanism between the gonio stage and the sample holder, and as a result, has found the present invention.

The gonio stage of the present invention includes a gate type valve, a guide roller provided in the gate type valve, a first vacuum O-ring provided in the gate type valve, and a drive for driving the gate type valve. A valve opening / closing mechanism comprising a shaft, wherein the gate-type valve and the shaft are connected by at least one fulcrum, and the shaft is movable, with a direction substantially perpendicular to the longitudinal direction of the shaft as an axis, A valve opening and closing mechanism is characterized in that the gate type valve is rotatable around the axis .

  In a preferred embodiment of the gonio stage of the present invention, the valve opening / closing mechanism further has a support roller.

  In a preferred embodiment of the gonio stage of the present invention, the valve opening / closing mechanism has a tapered portion for guiding the guide roller.

  In a preferred embodiment of the gonio stage of the present invention, the shaft has a second vacuum O-ring.

  In a preferred embodiment of the gonio stage of the present invention, the shaft is in a shaft holding cylinder in a sample holder holding cylinder.

  In a preferred embodiment of the gonio stage of the present invention, the sample holder holding cylinder has a sample holder holding member.

  The electron microscope of the present invention is characterized by having the goniostage of the present invention.

  According to the gonio stage of the present invention, it is possible to insert the sample holder without rotating, and thus, the insertion while cooling with liquid nitrogen is simplified, and the advantage that misoperation such as zeroing of liquid nitrogen is prevented can be achieved. Has an effect. In addition, according to the gonio stage of the present invention, the use of a gate type valve eliminates the need for a human operation of rotating the sample holder after pre-pumping (Pre pump), so that it is possible to use Auto. There is an advantageous effect. In addition, according to the present invention, the auto operation reduces the staying time in the electron microscope room and has the effect of preventing contamination of the electron microscope room atmosphere due to disturbances such as air flow in the electron microscope room caused by people coming and going. This has the advantageous effect of stabilizing the atmosphere in the observatory. In addition, according to the present invention, since Auto can be achieved, the time required for inserting the Holder is shortened, and the throughput of the work itself is improved, and the productivity is increased.

FIG. 1 is a conceptual diagram of a basic configuration of an example of a transmission electron microscope applicable in the present invention. FIG. 2 shows an embodiment of the gonio stage in an example of the present invention. The state when the gate type valve is closed is shown. FIG. 3 shows an embodiment of the gonio stage in an example of the present invention. The movement of opening and closing the gate type valve is shown. The trajectory of the opening and closing movement is depicted step by step. FIG. 4 shows an embodiment of a gonio stage in an example of the present invention. The state when the gate type valve is opened is shown. FIG. 5 shows an aspect of a conventional gonio stage. Indicates the state when the valve is closed. FIG. 6 shows an aspect of a conventional gonio stage. Indicates the state when the valve is opened.

  The gonio stage of the present invention includes a gate type valve, a guide roller provided in the gate type valve, a first vacuum O-ring provided in the gate type valve, and the gate type valve driving shaft. A valve opening / closing mechanism comprising the valve opening / closing mechanism, wherein the gate valve and the shaft are rotatable by at least one fulcrum. To do. The gate type valve is a valve that can open and close between a sample observation chamber (usually high vacuum) of an electron microscope and a preliminary exhaust chamber. The gate type valve can be designed to move so that the gate type valve can be opened and closed in accordance with the movement of the gate type valve driving shaft. The guide roller provided in the gate type valve is provided so that the valve can be easily opened and closed. Although the guide roller provided in the gate type valve is not essential, the presence or absence of the guide roller makes it possible to open and close the valve more smoothly than when there is no guide roller. In addition, it does not specifically limit about the number of guide rollers, When installing, you may provide one or more guide rollers.

  The first vacuum O-ring provided in the gate type valve is for accurately blocking the sample observation chamber (high vacuum) of the electron microscope from the preliminary exhaust chamber. When the gate type valve is set at a position where the valve is closed, the O-ring can seal between the sample observation chamber of the electron microscope and the preliminary exhaust chamber by high vacuuming.

  The gate valve driving shaft is rotatably connected to the gate valve. For example, the gate valve and the shaft can be rotated by at least one fulcrum of the gate valve and the shaft. For example, the gate type valve can be rotated around the axis about a direction substantially perpendicular to the longitudinal direction of the shaft. As a result, when the valve is closed, the shaft can be gradually bent from the horizontal state to an angle of 90 degrees by moving the shaft in the direction of the sample observation chamber of the electron microscope (the direction of the center of the electron microscope). Is possible. At this time, the guide roller, the support roller, the taper portion, and the like provided on the gate valve can open and close the valve more smoothly. The axial direction of the fulcrum is parallel to the opening / closing surface of the valve. This is because when the valve is closed in such a manner that the gate type valve covers the high vacuum side cylinder on the opening / closing surface, the opening / closing is performed more accurately.

In a preferred embodiment, the valve opening / closing mechanism has a support roller. In a preferred embodiment, the valve opening / closing mechanism has a tapered portion for guiding the guide roller. In the valve opening / closing mechanism, when there is a taper portion or an inclined portion, the gate type valve can be easily introduced to a predetermined position or pulled out from the predetermined position according to the inclination. It is also possible to open and close the gate type valve more accurately. The support roller and the tapered portion can support smooth operation even when the valve is opened. When opening the valve, after preliminary exhausting the preliminary exhaust chamber, moving the shaft outward from the center of the electron microscope closes the valve so that the angle between the gate type valve and the shaft is approximately 90 degrees. From this state, the angle can be changed so that the gate type valve and the shaft are substantially in a straight line. For example, the valve can be in a fully open state in a substantially straight line. At this time, if there is a guide roller, a support roller, a taper part, etc., it supports so that opening and closing of a valve can be performed more smoothly than those without these.

For example, the shaft, if it is intended to extend to substantially the center direction of the electron microscope column (longitudinal direction of the shaft, when a substantially central direction of the electron microscope column) direction perpendicular to the central axis of the electron microscope column The shaft can be movable. Then, for example, the gate type valve and the shaft are closed by an elastic member, for example, a spring, and the gate type valve is closed, that is, the gate type valve and the shaft are approximately 90 degrees (the valve opening and closing surface is approximately the axis of the microscope tube). In this case, if the shaft is set so that the longitudinal direction is substantially perpendicular to the microscope tube, the shaft can be moved toward the sample observation chamber. When it is desired to close the valve, the gate type valve can change the angle and smoothly close the valve through at least one fulcrum of the valve and the shaft.

  In a preferred embodiment, the shaft has a second vacuum O-ring. This is used to block the preliminary exhaust chamber from the outside when performing preliminary exhaust (preliminary evacuation). Even if it is not the second vacuum O-ring, it is not particularly limited as long as it can be shut off from the outside by means of the same. The shaft itself may have a blockable member, or a vacuum O-ring or the like may be provided on the sample holder holding cylinder side.

  In a preferred embodiment, the shaft is in a shaft holding cylinder in a sample holder holding cylinder. The shaft may be integrally formed and incorporated in the sample holder holding cylinder, or may be separately incorporated into the shaft holding cylinder by forming a shaft holding cylinder. The shaft is not particularly limited as long as it can move to open and close the valve.

  In a preferred embodiment, the sample holder holding cylinder has a sample holder holding member. The sample holder holding member has a role of holding the sample holder in the preliminary exhaust state position of the sample holder. Examples of the sample holder holding member include a hook. If the sample holder holding member is held together, after the preliminary evacuation is completed, the gate type valve is opened remotely, and the sample holder holding member, for example, the hook is remotely operated to reserve the sample holder. The evacuation process and the sample holder insertion process can be performed remotely. Thereby, once the sample holder is mounted on the gonio stage, it can be quickly removed from the electron microscope room, so that the disturbance of the environment of the electron microscope room can be minimized. Furthermore, when a cooled sample holder is used, a dangerous accident of overflowing liquid nitrogen can be avoided.

  Moreover, the electron microscope of this invention has the gonio stage of this invention mentioned above, It is characterized by the above-mentioned. The electron microscope is not particularly limited. Hereinafter, the gonio stage and the electron microscope 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.

  FIG. 1 is a conceptual diagram of a basic configuration of an example of a transmission electron microscope applicable in the present invention. In FIG. 1, 1 is a vacuum region, 2 is an electron acceleration electrode, 3 is an insulating gas region, 4 is an X-ray absorbing member, 5 is a condenser aperture (movable mechanism), 6 is an objective aperture (movable mechanism), 7 Is a field limiting aperture (movable mechanism), 8 is a second intermediate imaging lens, 9 is a projection lens, 10 is an observation glass window, 11 is a fluorescent screen, 12 is an image acquisition camera, 13 is a camera room, and 14 is a vacuum. Partition valve, 15 is a first intermediate imaging lens, 16 is a back focus lens, 17 is an objective (lower pole) lens, 18 is an objective (upper pole) lens, 19 is a second convergent lens, 20 is a first convergent lens, Reference numeral 21 denotes a vacuum partition valve, 22 denotes an insulating glass, 23 denotes an electron beam light source (filament), and 24 denotes a high voltage transmission cable. Reference numeral 25 denotes a coil member for an electron beam deflector or astigmatism corrector, and reference numeral 26 denotes a coil member for each converging electron lens. It is possible to incorporate the goniostage of the present invention into an electron microscope according to such an example.

  FIG. 2 shows an embodiment of the gonio stage in an example of the present invention. The state when the gate type valve is closed is shown. FIG. 4 shows an embodiment of a gonio stage in an example of the present invention. The state when the gate type valve is opened is shown. 2 and 4, 31 is a vacuum side, 32 is a gate type valve block, 33 is a vacuum seal O-ring, 34 is a mounting position of an elastic member for gate type valve block, and 35 is an elastic member for gate type valve block. Detachment prevention pins, 36 and 37 are gate type valve block lifting support rollers, 38 is a vacuum seal O-ring, 39 is a sample holder holding cylinder, 40 is a gate type valve block driving shaft, 41 is a sample holder insertion side, Reference numeral 42 denotes a frame and sample holder holding cylinder of a gate type valve block lifting support roller, 43 denotes a route guide roller, 44 denotes a fulcrum, 45 denotes a tapered portion, and 46 denotes a preliminary exhaust chamber. In FIG. 2, the shaft is illustrated on the upper side, but since the same effect can be obtained regardless of whether the shaft is installed on the lateral side or the lower side, the position of the shaft or the like is not limited.

  FIG. 3 shows an embodiment of the gonio stage in an example of the present invention. The movement of opening and closing the gate type valve is shown. The trajectory of the opening and closing movement is depicted step by step. In FIG. 3, 51 is the fulcrum closed position, 52 is the fulcrum open position, 53 is the piston rod stroke distance for opening and closing, 54 is the O-ring position (the O-ring position of the gate type valve opening and closing shaft is the gate type valve opened) It is indicated by the position).

  The steps of inserting the sample holder, observing the sample, and ending the sample observation will be described below with reference to the drawings. Before the sample holder is inserted, the valve is normally closed as shown in FIG. First, the sample holder is inserted up to the preliminary exhaust chamber 46. At this point, the valve is still closed. When a sample holder holding member, for example, a hook (not shown) is installed so that the tip of the sample holder stops once it is not in contact with a valve or the like (not shown), the sample holder is placed at a position corresponding to the sample holder holding member. If a groove or the like is provided on the side, the sample holder temporarily stops.

  After the sample holder moves to the preliminary exhaust chamber, preliminary exhaust can be performed. If it is designed such that when the sample holder is held by the sample holder holding member, the preliminary exhaust is automatically performed by a sensor or the like, the operation that has been relied on manually can be automatically performed.

  After preliminary evacuation, the gate type valve is opened, and the tip of the sample holder (sample loading unit) is guided to the observation room of the electron microscope. The shaft 40 can be pulled out or inserted by an actuator or the like, and can be automated by computer control. That is, it is possible by computer control to pull out the shaft and open and close the valve simultaneously with the signal that the preliminary exhaust is finished. When the valve is fully opened, a signal to release the sample holder from the holding member causes the sample holder to be released from the state temporarily fixed by the holding member and pulled into the high-vacuum electron microscope. . In this way, sample observation becomes possible.

  When the sample observation is completed and the sample holder is again held by the holding member, the shaft can be automatically moved by an air pist, an actuator or the like so as to close the gate type valve. The fixing of the sample holder by the holding member can also be automatically released. Thus, according to the gonio stage of the present invention, a series of operations can be automated. That is, if the sample holder is inserted, all subsequent operations can be automated, and when the sample observation is completed, it is only necessary to take the sample holder. That is, conventionally, all operations such as opening / closing of the valve, insertion / removal of the sample holder and the like have to be performed manually, but in the present invention, all can be automated. Therefore, in the present invention, since the misoperation and the time until the start of observation can be shortened particularly when the sample holder for the cooled sample is inserted, the throughput is improved and the productivity is improved. Further, it has been found that the present invention also has an advantage that the atmosphere in the electron microscope chamber is stabilized by auto conversion.

  Since the misoperation when inserting the sample holder of the cooled sample and the time until the start of observation can be shortened, the throughput is improved and the productivity is improved. Auto makes the atmosphere inside the electron microscope stable and contributes to the improvement of analysis capabilities, such as shortening the data acquisition time and improving the quality of analysis data, and can be applied in a wide range of technical fields.

DESCRIPTION OF SYMBOLS 1 Vacuum area | region part 2 Electron acceleration electrode 3 Insulating gas area | region 4 X-ray absorption member 5 Condenser aperture (movable mechanism part)
6 Objective diaphragm (movable mechanism)
7 Field-limiting diaphragm (movable mechanism)
8 Second intermediate imaging lens 9 Projection lens 10 Observation glass window 11 Fluorescent screen 12 Image acquisition camera 13 Camera room 14 Vacuum partition valve 15 First intermediate imaging lens 16 Rear focus lens 17 Objective (lower pole) lens 18 Objective ( Upper pole) Lens 19 Second converging lens 20 First converging lens 21 Vacuum partition valve 22 Insulating glass 23 Electron light source (filament)
24 High voltage transmission cable 25 This mark indicates a coil member for an electron beam deflector or astigmatism corrector 26 This mark indicates a coil member for each converging electron lens 31 Vacuum side 32 Gate type valve block 33 Vacuum Sealing O-ring 34 Gate type valve block elastic member mounting position 35 Gate type valve block elastic member attachment / detachment prevention pins 36, 37 Gate type valve block lifting support roller
38 Vacuum seal O-ring 39 Sample holder holding cylinder 40 Gate type valve block driving shaft 41 Sample holder insertion side 42 Gate type valve block lifting support roller frame and sample holder holding cylinder 43 Route guide roller
44 fulcrum 45 taper 46 preliminary exhaust chamber 51 closed position 52 open position 53 opening / closing piston rod stroke distance 54 O-ring position (the O-ring position of the gate valve opening / closing shaft is described as the position where the gate valve is opened) .)
61 Vacuum region side 62 Shaft rotating gear 63 Gear for rotating the shaft rotating gear 64 Main holding cylinder 65 Slot for pin holder to rotate 66 Sample holder insertion side (atmosphere side)
67 Valve open / close shaft and sample holder holding cylinder 68 Vacuum seal O-ring 69 Shaft cover 70 Spherical valve

Claims (7)

A valve opening / closing mechanism comprising a gate type valve, a guide roller provided on the gate type valve, a first vacuum O-ring provided on the gate type valve, and a drive shaft for driving the gate type valve The gate-type valve and the shaft are connected by at least one fulcrum, and the shaft is moved to move the shaft around the axis about the direction substantially perpendicular to the longitudinal direction of the shaft. A gonio stage having a valve opening / closing mechanism characterized in that the valve is rotatable.   2. The gonio stage according to claim 1, wherein the valve opening / closing mechanism has a support roller.   The gonio stage according to claim 1 or 2, wherein the valve opening / closing mechanism has a tapered portion for guiding the guide roller.   The gonio stage according to claim 1, wherein the shaft has a second vacuum O-ring.   The gonio stage according to any one of claims 1 to 4, wherein the shaft is in a shaft holding cylinder in a sample holder holding cylinder. 6. The gonio stage according to claim 5 , further comprising a sample holder holding member in the sample holder holding cylinder. The electron microscope which has the gonio stage of any one of Claims 1-6.

Images