JP4898355B2 - Sample holder - Google Patents

Description

  The present invention relates to a sample holder, and more particularly to a sample holder having a mechanism capable of tilting an axis independently of a fulcrum holding member.

An outline of a sample holder having an inclination around an axis orthogonal to the longitudinal direction of the holder body (hereinafter also referred to as β inclination) and an inclination around the axis of the sample holder axis (hereinafter also referred to as α inclination) is shown in FIG. Shown in Such a sample holder is a transmission electron microscope (Transmission Electron).
Microscope (TEM), Scanning transmission electron microscope (Scanning)
It is mainly used in electron microscopes such as Transmission Electron Microscope (STEM).

  For example, the sample holder is mainly composed of a holder body, a sample holder for holding the sample, and a sample presser, and the inclination around the axis of the sample holder axis is considerably limited. A sample table with an angle is known (Japanese Patent Laid-Open No. 2001-15056).

JP2001-15056

However, in the prior art in which the fulcrum holding member as shown in FIG. 1 is essential, the fulcrum holding member 15 of the β tilted sample stage 16 in the sample holder of the electron microscope is used as the pole piece upper pole of the objective lens of the electron microscope. In the constrained space gap between the lower electrode 13 and the lower electrode 14, the member 15 interferes, so that a large inclination angle cannot be secured. That is, when observing with an electron microscope, in addition to the rotational drive of the α tilt axis of the sample holder axis, in the sample holder equipped with the β axis tilt mechanism, as shown in FIG. A sample 17 fixed to the tip of a sample holder inserted in a focal plane 11 existing between an upper pole 13 and a lower pole 14 of a pole piece (hereinafter referred to as PP) of a line lens is connected to an electron beam optical axis 10 When the α axis is tilted at the position where the focal plane 11 intersects, the fulcrum holding member 15 is in contact with the PP upper pole 13 and PP lower pole 14, so a large tilt angle cannot be secured.

In the characteristic X-ray analysis, the fulcrum holding member 15 serves as a barrier for the characteristic X-ray emission path, and therefore an α inclination is necessary to avoid it. That is, in the characteristic X-ray analysis, a combined inclination of the α inclination axis and the β axis inclination is necessary depending on the shape and crystal orientation of the observation sample, but the position where the characteristic X-ray analysis apparatus can be incorporated in the electron microscope is Since it is between P-P13 and the focal plane 11 and it is generally necessary to direct characteristic X-ray emission in the direction of 12, the fulcrum holding member 15 becomes a barrier to the characteristic X-ray emission path, and α inclination to avoid it Was necessary.

Furthermore, since the β-inclined sample stage 16 is incorporated in the fulcrum holding member 15, it is not easy to remove only the sample stage 16 and replace it with another sample stage. In other words, in the characteristic X-ray analysis of the electron microscope, in addition to the focused electron beam that irradiates the sample, there is a background electron beam, and the electron beam irradiated to the sample is further scattered and applied to the sample stage. Since the characteristic X-rays are also generated from the sample stage as a background when the electron beam is indirectly irradiated, the difference in the background characteristic X-ray information can be grasped by changing the material of the sample stage member, and the characteristics are accurate. Although X-ray analysis can be performed, since the sample stage 16 is incorporated in the member 15 that holds the fulcrum shaft on the β axis tilt axis, it is necessary to prepare a plurality of holders incorporating the sample stage 15 made of various materials. was there.

  About the above problem, also in the said patent document 1, it is the same. That is, in Patent Document 1, although the sample holding surface is angled while being tilted around the axis of the holder shaft, means for tilting it around the axis perpendicular to the longitudinal direction of the holder body should be used. In order to add the fulcrum, a fulcrum holding member is essential to maintain the shaft as in the prior art. This is because without the fulcrum holding member, the sample fixing base usually floats in the air and cannot be supported, and the desired axis inclination cannot be achieved.

  Moreover, such a fulcrum holding member is usually essential to ensure the mechanical strength of the holder itself, but has a problem that it becomes a barrier to ensure a desired tilt angle. Therefore, there is a demand for a technique that achieves an inclination around an axis perpendicular to the longitudinal direction of the holder body without using such a fulcrum holding member, but such a technique has not been known so far.

  Accordingly, an object of the present invention is to provide a sample holder that can significantly improve the inclination around an axis orthogonal to the longitudinal direction of the holder body in order to solve the above-described problems.

  In order to achieve the above object, the present inventors have intensively studied the configuration of the sample holder, and as a result, have found the present invention.

That is, the sample holder of the present invention includes a holder main body, a sample fixing base for holding the sample, and an axis tilting mechanism that can rotate about an axis orthogonal to the longitudinal direction of the holder main body. The mechanism includes a drive frame for rotating around a desired axis orthogonal to the longitudinal direction, and a link member connected to the drive frame, and the link member is connected to the holder via at least two fulcrums. It is fixed to the main body .

  In a preferred embodiment of the sample holder of the present invention, the shaft tilting mechanism can be tilted while maintaining a desired shaft position orthogonal to the longitudinal direction on the focal plane.

  In a preferred embodiment of the sample holder of the present invention, the sample fixing base is detachable from the holder body.

  In a preferred embodiment of the sample holder of the present invention, the drive frame is connected to the sample fixing base.

  In a preferred embodiment of the sample holder of the present invention, the drive frame has at least one fulcrum that can rotate as an axis, and a fulcrum that can move in the drive frame.

  In a preferred embodiment of the sample holder of the present invention, the link member has a fulcrum fixed to the holder body, and is connected through the fulcrum of the drive frame.

  In a preferred embodiment of the sample holder of the present invention, the link member is composed of one or more.

  In a preferred embodiment of the sample holder of the present invention, the link member has a fulcrum on the holder shaft.

  In a preferred embodiment of the sample holder of the present invention, the sample fixing base is inclined around a desired axis orthogonal to the longitudinal direction, with a virtual fulcrum existing on the holder axis as a center. To do.

  In a preferred embodiment of the sample holder of the present invention, the holder main body has an axis tilt mechanism that can rotate around the holder axis.

In a preferred embodiment of the sample holder of the present invention, an axis tilting mechanism (hereinafter referred to as β) orthogonal to the on-axis tilting mechanism (hereinafter referred to as α tilt) of the sample holder for loading the observation sample into the sample driving device of the electron microscope Inclination) is characterized in that it is tilted while maintaining the position of the β tilt axis on the focal plane without requiring a member for holding the fulcrum shaft on the β axis tilt axis.

In a preferred embodiment of the sample holder of the present invention, the characteristic X-rays generated from the sample placed on the electron beam optical axis can be obtained by not requiring a member for holding the fulcrum shaft on the β-axis tilt axis. In the emission path between the X-ray analyzers attached to the electron microscope, the barrier by the member can be reduced.

Further, in a preferred embodiment of the sample holder of the present invention, a member for holding the fulcrum shaft on the β-axis tilt axis is not required, so that only the stage for fixing the sample can be easily replaced. And

For example, in the present invention, as a means for solving the above-described problem, in the sample holder of the electron microscope, the force point 32 of the member 22 is used as a tilt driving mechanism of the β tilt shaft 33 as shown in FIG. By driving in the direction of rotation 34, the member 25 is tilted, and the β tilt shaft 33 is rotated while maintaining the height of the holder shaft 38, so that the fulcrum holding member 15 is not required as shown in FIG. Since the space gap of P13 and P-P14 can be used effectively, the α axis inclination range of the holder shaft can be secured large.

Further, for example, by dividing the sample fixing member 25 into a sample tilt driving arm member 35 and a sample table member 36 as shown in FIG. 4, only the sample table member 36 can be replaced with a member of any material or shape.

Since the sample holder of the present invention does not require a member for holding the fulcrum shaft on the β-axis tilt axis as shown in FIG. 2, for example, there is an advantageous effect that a sample holder that can be rotated to a high tilt can be provided.

Furthermore, since the sample holder of the present invention does not require a member for holding the fulcrum shaft on the β-axis tilt axis as shown in FIG. 2, for example, the sample holder reduces the barrier of the characteristic X-ray emission path in the characteristic X-ray analysis. It is possible to provide an advantageous effect that can be provided.

  Furthermore, since the sample holder of the present invention does not require a member for holding the fulcrum shaft on the β-axis tilt axis as shown in FIG. 2, for example, it is possible to provide a sample holder in which only the sample stage can be replaced. Has an effect. Therefore, it is possible to mount the sample stage by rotating it on a plane orthogonal to the optical axis.

First, the effectiveness of the shaft tilt mechanism of the present invention will be described as follows. That is, the existence of the fulcrum holding member as in the prior art is a barrier even if it has the following small dimensions. That is, there is a holder member with a thickness (usually 1.5 to 2.5 mm) in the pole piece gap of 4 to 5 mm with respect to the solid angle between the sample and the surface area of the X-ray detection part (usually 15 to 33 mm ² ). Just do it and it becomes a wall against the solid angle of X-ray capture. Therefore, in order to avoid this, the inclination of the α-axis toward the direction where the detector is present is effective.

This will be described in detail as follows. That is, when an electron beam is irradiated onto a sample, characteristic X-rays are generated, which are scattered in all directions from the irradiated sample. The distribution is non-uniform, and since the electron beam hits from above, the direct direction, that is, the horizontal direction is the least, and the closer to the radial direction the electron beam irradiation direction, the higher the intensity. If the sample is crystalline, the generated intensity changes with the angle of the incident electron beam with respect to the crystal orientation, and the X-ray scattering angle changes with intensity. In an electron microscope, the gap of the objective lens pole piece is limited, and a sample must be loaded in the meantime to obtain X-rays. In other words, the narrower the resolution, the higher the resolution. In general, the resolution priority type electron microscope is designed to be 2.0 to 3 mm. In the case of an electron microscope of a type that sacrifices the resolution slightly, it is about 3 to 5 mm, which is the most popular type in the field of materials research. In addition, there is a sacrificial resolution, which is about 5 to 8 mm, but is usually used for biological systems, and the resolution is too low for the material system to be practically unusable. Therefore, the electron microscope for material analysis is generally 4 to 5 mm. In other words, since there is a pole piece, the X-ray detection part (diameter 8 to 15 mm) cannot be moved to the optical axis (the limit is usually from 13 to 20 mm from the optical axis). Note that the solid angle decreases with increasing distance from the optical axis (pole piece) with respect to the surface area of the X-ray detection unit (usually 15 to 33 mm ² ). become.

Therefore, due to the physical limitations of the pole piece as described above, the relationship between the center of the X-ray detector and the position of the sample on the optical axis irradiated to the electron beam is such that the X-ray detector is arranged almost horizontally. Alternatively, it is possible to make a small angle by slightly moving away from the optical axis (pole piece) and approaching the pole piece upper pole. From these compromises, the end result is that the sample is generally held from above at an angle of 15-20 degrees.

For the above reasons, the holder member has a thickness (usually 1.5 to 2.5 mm) in the pole piece gap of 4 to 5 mm with respect to the solid angle between the sample and the surface area of the X-ray detector (usually 15 to 33 mm ² ). It can be seen that the presence of becomes a wall against the solid angle of X-ray capture, and therefore the inclination of the α axis toward the detector is effective to avoid this.

If the detection efficiency of X-rays is low, if the time is lengthened for that amount, more information can be obtained, but the sample is damaged by the electron beam, and contamination is further added. Different elements are detected. Therefore, it is necessary to efficiently detect in as short a time as possible. Moreover, when acquiring mapping (element distribution), unless the time per point is as short as possible, it will take a tremendous time. For example, in the case of 100 XY angles (100 × 100 = 10000), it takes 10000 seconds even if one point is taken in 1 second. Therefore, it can be said that the idea of capturing as much X-rays as possible is an important technology.

  The sample holder of the present invention having such an effective axis tilting mechanism includes a holder main body, a sample fixing base for holding the sample, and an axis tilt capable of rotating about an axis orthogonal to the longitudinal direction of the holder main body. The shaft tilting mechanism is a mechanism capable of tilting the shaft independently of a fulcrum holding member for rotating around a desired axis orthogonal to the longitudinal direction. Other sample holders include a mechanism that cools the sample, a mechanism that heats the sample, a mechanism that pulls the sample, and a combination of these mechanisms. The sample holders referred to in the invention are not intended to be particularly limited, including these sample holders.

  The material of the holder body is not particularly limited as long as the mechanical strength of the holder itself can be secured. The sample fixing base is for holding the sample, and the sample may be fixed using a sample presser or the like. In this case, the sample is sandwiched and held between the sample fixing base and the sample presser. Further, the shape and material of the sample fixing base are not particularly limited as long as it can hold the sample. For example, various shapes such as a polygon such as a rectangle and a square, and a circle can be employed. In a preferred embodiment, the sample fixing base is detachable from the holder body. Conventionally, the sample fixing base and the fulcrum holding member are integrated and manufactured as one body, and it has not been possible to easily attach and detach the sample fixing base to another sample base. Therefore, it can be easily exchanged.

  The shaft tilting mechanism that can rotate around the axis orthogonal to the longitudinal direction of the holder main body can be tilted independently of the fulcrum holding member. In other words, in the present invention, the fulcrum holding member that holds the shaft to be rotated is not necessarily required. As a result, in the present invention, the use of the fulcrum holding member could be cut, so that when the fulcrum holding member is rotated around an axis parallel to the longitudinal direction of the holder body (also referred to as a holder shaft), the fulcrum holding member becomes a barrier. Therefore, the shaft tilt range can be greatly improved.

  The shaft tilting mechanism is preferably tiltable while maintaining a desired shaft position orthogonal to the longitudinal direction on the focal plane. By tilting while maintaining the desired axial position on the focal plane in this way, even if the sample fixing base is translated in the holder axial direction, the movement is corrected and driven in the sample holder axial direction on the sample stage, for example. Accurate measurement is still possible.

In a preferred embodiment, the shaft tilting mechanism has a drive frame for rotating around a desired axis orthogonal to the longitudinal direction. Furthermore, in a preferred aspect, the drive frame is connected to the sample fixing base.

  For example, the drive frame has at least one fulcrum that can rotate as an axis, and a fulcrum that can be moved within the drive frame, so that the drive frame can be rotated around a desired axis orthogonal to the longitudinal direction of the holder body. Is possible. In a preferred embodiment, the shaft tilt mechanism may have a link member connected to the drive frame. For example, when the reciprocating motion by the member in the holder main body is finally converted into the tilting motion around the axis, the motion can be transmitted through the link member. For example, the link member has a fulcrum fixed to the holder body, and the reciprocation by the member in the holder body can be converted into a tilting motion by connecting via the fulcrum of the drive frame. It is. The link member may be composed of one or more, and is not particularly limited. The link member may have a fulcrum on the holder shaft.

  In this way, the sample fixing base can be tilted around a desired axis orthogonal to the longitudinal direction, with a virtual fulcrum existing on the holder shaft as a center.

  In a preferred embodiment of the sample holder of the present invention, the holder body has an axis tilt mechanism that can rotate about the holder axis. This is because the sample stage can be arbitrarily positioned with respect to the electron beam optical axis when acquiring characteristic X-ray analysis of a sample placed on the electron beam optical axis of an electron microscope or a continuous tilt image for three-dimensional image analysis. To tilt, the sample holder is rotated about the α tilt axis of the sample holder axis (hereinafter referred to as α tilt). However, in the case of a crystalline sample, it is necessary to compensate for the β axis tilt. This is because it is necessary to provide an inclination mechanism (hereinafter referred to as β inclination).

Furthermore, in a preferred embodiment of the sample holder of the present invention, an axis tilting mechanism (hereinafter referred to as β) perpendicular to the on-axis tilting mechanism (hereinafter referred to as α tilt) of the sample holder for loading the observation sample into the sample driving device of the electron microscope. Inclination) is performed while maintaining the position of the β tilt axis on the focal plane without requiring a member for holding the fulcrum shaft on the β axis tilt axis.

In a preferred embodiment of the sample holder of the present invention, the characteristic X-rays generated from the sample placed on the electron beam optical axis can be obtained by not requiring a member for holding the fulcrum shaft on the β-axis tilt axis. In the emission path between the X-ray analyzers attached to the electron microscope, the barrier by the member can be reduced.

Further, in a preferred embodiment of the sample holder of the present invention, a member for holding the fulcrum shaft on the β-axis tilt axis is not required, so that only the stage for fixing the sample can be easily replaced. And

  In order to describe the present invention in more detail, an example of the present invention will be described below with reference to the drawings. However, the present invention is not intended to be construed as being limited to the following examples.

As shown in FIGS. 3 and 4, the drive force point 32 of the member 22 with the pin 26 fixed to the frame member 21 provided at the tip of the holder main body 21a as a fulcrum is used as the drive mechanism for tilting the β tilt shaft 33. By driving in the rotational direction, the signal is transmitted to the member 23 and the member 24 with the pin 27 fixed to the member 21 as a fulcrum, and the member 25 (including the sample fixing base) is moved by moving the positions of the pin 30 and the pin 31. When driven, the β tilting shaft 33 tilts while maintaining the sample holder shaft 38. In this example, the rotation is used to drive in the rotation direction of 34 and is inclined by β. However, if it can be inclined by other remote operations without substantially having a fulcrum holding member of the rotation shaft. The present invention is not particularly limited.

  The means for rotating in the direction of 34 is not particularly limited. For example, it can be rotated by a reciprocating motion parallel to the holder axial direction by a rod-shaped member. .

When the member 24 around the pin 27 fixed to the frame member 21 is rotationally driven, the β inclination shaft 33 is translated in the holder axial direction along with the inclination of the member 25 by the positional movement of the pin 30 attached to the member 24. The β tilt axis 33 can be tilted even on the optical axis 10 by correcting and driving the movement in the sample holder axial direction on the sample stage.

Thereby, since the space gap between the PP upper pole 13 and the PP lower pole 14 can be used effectively, a large tilt range of the α tilt axis can be secured.

3 is divided into a sample tilt drive frame arm member 35 and a sample table member (sample fixing table) 36 as shown in FIG. 4, so that only the sample table member 36 can be detached. Can be replaced with any material or shape.

The screw 37 is used to connect the sample driving frame arm member 35 and the sample fixing member 36. However, the structure is not particularly required as long as it is a connectable mechanism. For example, the tip of the frame arm member 35 has a tweezers structure, that is, By adopting a structure in which the sample fixing member 36 is sandwiched, it is possible to rotate and sandwich only the sample fixing member 36 with respect to the surface orthogonal to the optical axis.

In inputting the driving force to the driving force point 32, a driving force input rod member 39 whose tip is sloped into a wedge shape in a hole coaxially formed in the inside 21a of the sample holder is used as the main body of the sample holder. When the member 39 is pulled out by inserting the member 39, and the member 39 is pulled out, the sample tilt driving frame arm 35 is driven by pushing back the driving force point 32 with the force of the spring 40. There is no need to limit the means and the structure for transmitting the input to the driving force point 32.

In recent years, a technique for analyzing a three-dimensional structure with sub-nanometer accuracy of a material using an electron microscope has become widespread, but when constructing accurate three-dimensional information, ideally while rotating a sample 360 degrees A plurality of observed images are required. In the sample holder of the present invention, since the member that holds the fulcrum shaft can be omitted, the space gap between the PP upper pole 13 and the PP lower pole 14 can be effectively used, so that the axis α inclination range of the sample holder can be increased, Since it is possible to obtain information up to a high inclination, there is an effect of reducing virtual images generated due to information loss in the construction of a three-dimensional solid. Furthermore, it is possible to construct a three-dimensional solid while enabling compensation of the β-axis tilt for alignment necessary for the crystal material.

When performing characteristic X-ray analysis of a minute region using an electron microscope, the characteristic X-rays generated from a sample are minute, and therefore, better detection efficiency is required. In the present invention, the member for holding the fulcrum shaft on the β-axis tilt axis can be omitted, that is, the barrier that hinders the X-ray scattering path in the characteristic X-ray analysis can be eliminated and thus avoided. No inclination is required. Therefore, there is an effect that the freedom of selection of the electron beam incident angle is improved with respect to an arbitrary sample orientation (crystal orientation).

When performing characteristic X-ray analysis using an electron microscope, according to the present invention, only the sample stage can be easily replaced, so that it is not necessary to prepare several types of sample holders as in the prior art.

It is sectional drawing of the electron microscope and sample stand which were seen from the alpha inclination axis direction near the sample insertion part which shows composition of background art. It is sectional drawing of the electron microscope and sample stand seen from the (alpha) inclination axis direction of the sample insertion part vicinity which shows an example of a structure of this invention. It is a conceptual diagram of the β-axis drive configuration viewed from the β tilt axis direction showing an example of the configuration of the present invention. It is a perspective view of the sample holder front-end | tip part which shows an example of a structure of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electron beam optical axis 11 of electron microscope 11 Focal plane and holder insertion axial surface 12 Mounting angle axis 13 of general X-ray detector Pole piece (PP) upper pole 14 of objective electron beam lens Electron beam lens pole piece (PP) Lower pole 15 β tilt axis fulcrum holding member (background technology)
16 Sample stage capable of tilting β (background technology)
17 Sample 18 Sample fixing member (background technology)
19 Sample stage 20 capable of tilting β β Sample fixing member 21 Frame member (integral member provided at the tip of the sample holder main shaft 21a)
21a Sample holder spindle 22 Link member 1
23 Link member 2
24 Link member 3
25 Link member 4 (β tilted sample base frame arm)
26 Fixing pin 1
27 Fixing pin 2
28 Moving pin 1
29 Moving pin 2
30 Assembly pin 1
31 Moving pin 3
32 Driving force point 33 β rotation axis position 34 Driving force point movement 35 β tilt driving frame arm 36 Sample stage 37 Screw 38 for connecting and fixing the sample stage and β tilt driving frame arm 38 Holder insertion axis and α tilting axis 39 For input of driving force Bar member (member to push up the driving force point)
40 Spring (member to push down the driving force point)

Claims (13)

A holder main body; a sample fixing base for holding the sample; and an axis tilting mechanism rotatable around an axis orthogonal to the longitudinal direction of the holder main body, wherein the axis tilting mechanism is orthogonal to the longitudinal direction. A drive frame for rotating around a desired axis and a link member connected to the drive frame, wherein the link member is fixed to the holder body via at least two fulcrums. Sample holder.   The sample holder according to claim 1, wherein the shaft tilting mechanism is tiltable while maintaining a desired axial position orthogonal to the longitudinal direction on a focal plane.   The sample holder according to claim 1, wherein the sample fixing base is detachable from the holder main body. The sample holder according to claim 1, wherein the drive frame is connected to the sample fixing base. The sample holder according to any one of claims 1 to 4 , wherein the drive frame has at least one fulcrum that can rotate as an axis, and a fulcrum that can move in the drive frame. . The sample holder according to any one of claims 1 to 5 , wherein the link member has a fulcrum fixed to the holder body, and is connected via a fulcrum of the drive frame. . The sample holder according to claim 1 , wherein the link member includes one or a plurality of link members. The sample holder according to any one of claims 1 to 7 , wherein the link member has a fulcrum on a holder shaft. The sample holder according to any one of claims 1 to 8 , wherein the sample fixing base is inclined about a desired axis orthogonal to the longitudinal direction with a virtual fulcrum existing on the holder axis as a center. The sample holder according to any one of claims 1 to 9 , wherein the holder body has an axis tilting mechanism that is rotatable around the holder axis. In the axis tilt mechanism (hereinafter referred to as β tilt) orthogonal to the on-axis tilt mechanism of the sample holder (hereinafter referred to as α tilt) for loading the observation sample into the sample driving device of the electron microscope, a fulcrum on the β axis tilt axis 2. The sample holder according to claim 1, wherein the sample holder is tilted while maintaining the position of the β tilt axis on the focal plane without requiring a member for holding the shaft. By not requiring a member that holds the fulcrum shaft on the β-axis tilt axis, the characteristic X-rays generated from the sample placed on the electron beam optical axis are emitted between the X-ray analyzers attached to the electron microscope. The sample holder according to claim 11 , wherein a barrier by the member can be reduced in the path. 12. The sample holder according to claim 11, wherein a member for holding the fulcrum shaft on the β-axis tilt axis is not required so that only the stage for fixing the sample can be easily replaced.

Images