Slide glass holder and charged particle beam device

Abstract

A slide glass holder HZ, on which is mounted a slide glass S to which a sample SAM is fixed, has a plate P having a substantially rectangular slide glass installation surface PS. The slide glass is positioned and placed at a predetermined position on the slide glass installation surface. A dividing line dividing the slide glass installation surface into a plurality of regions is displayed on at least a portion of the slide glass installation surface in contact with the placed slide glass, and a code uniquely identifying the region is displayed inside each of the plurality of regions. As a result, the observation efficiency of a sample, particularly a biological tissue sample, by the charged particle beam device may be improved.

Description

Slide glass holder and charged particle beam device

[0001] The present invention relates to a slide glass holder and a charged particle beam device.

[0002] A scanning electron microscope (SEM) can obtain electron beam images with extremely high contrast and high resolution even at a relatively low accelerating voltage of several tens of kV, making it possible to observe specimens such as tissue samples taken from living organisms.

[0003] Patent Document 1 discloses a sample holder for a scanning electron microscope, which allows a slide glass used for observation under an optical microscope to be used as an observation sample as is, and a scanning electron microscope equipped with this sample holder.

[0004] JP 2012-109171 A

[0005] An example of a scenario in which biological tissue samples are observed using an SEM is when a pathological diagnosis is made on a tissue sample taken from a patient. To ensure the accuracy of the pathological diagnosis, the expert making the diagnosis may request the opinions of other experts. If the other experts are located remotely, the expert may actually send the tissue sample they have observed to the other experts and request that they examine the tissue sample.

[0006] In such cases, it is often difficult for the first specialist to communicate to another specialist the area where the first specialist felt something was wrong. Figure 11 is a schematic diagram showing a sample SAM (here, a biological tissue sample) collected on a glass slide S. Because tissue samples have an irregular shape and are composed entirely of similar cells, it is difficult for other specialists to recognize where on the sample SAM fixed on the glass slide S the first specialist focused. Even if the approximate location can be identified visually, it is even more difficult to introduce the glass slide S into an SEM and locate the location of interest within the narrow field of view of the high-resolution SEM.

[0007] A slide glass holder that is one embodiment of the present invention is a slide glass holder on which a slide glass with a sample fixed thereto is mounted, and has a plate with a substantially rectangular slide glass mounting surface, the slide glass is positioned and placed at a predetermined position on the slide glass mounting surface, and dividing lines that divide the slide glass mounting surface into multiple regions are displayed on at least a portion of the slide glass mounting surface that contacts the placed slide glass, and a code that uniquely identifies the region is displayed inside each of the multiple regions.

[0008] The present invention provides a slide glass holder that can improve the efficiency of observation of samples, particularly biological tissue samples, using a charged particle beam device. Other objects and novel features will become apparent from the description of this specification and the accompanying drawings.

[0009] FIG. 1 is a perspective view of a slide glass holder. FIG. 2 is a perspective view of a plate. FIG. 3 is a schematic cross-sectional view of a slide glass holder. FIG. 4 is a top view of a slide glass holder with a slide glass placed right-justified. FIG. 5 is a top view of a slide glass holder with a slide glass placed left-justified. FIG. 6 is a top view of a slide glass holder. FIG. 7 is a schematic configuration diagram of a scanning electron microscope. FIG. 8 is an example of a display screen. FIG. 9 is a processing flow for linking a slide glass image on a live image display unit and a sub-screen display unit. FIG. 10 is an example of subdividing a digital grid. FIG. 11 is an example of subdividing a digital grid. FIG. 12 is an example of an operation panel. FIG. 13 is a diagram for explaining the problem of the present invention.

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all drawings for explaining the embodiments, components having the same functions are designated by the same reference numerals, and repeated explanations thereof will be omitted. In the following embodiments, explanations of identical or similar parts will not be repeated unless particularly necessary.

[0011] 1 is a perspective view of a slide glass holder HZ. The slide glass holder HZ includes a plate P, a sample stage SD, a slide glass fixing mechanism, and a holder base HB. Each of these components is made of a metal such as aluminum or an alloy such as stainless steel.

[0012] FIG. 2 is a perspective view of the plate P. A slide with a sample to be observed fixed thereon is placed on the slide mounting surface PS. A grid G ​​is engraved on the slide mounting surface PS, and a numbering N (here, 01 to 35) is engraved inside each of the areas divided by the grid G. Because the slide holder HZ is mounted at a fixed position on the stage of the charged particle beam device, as described below, the area on which the grid G ​​is engraved on the slide mounting surface PS is sufficient to cover the area irradiated with the charged particle beam during observation using the charged particle beam device. The size and number of areas divided by the grid G ​​can also be arbitrary. The numbering N can be any code that uniquely identifies the area divided by the grid G, and can be any number, symbol, letter, or combination thereof. The planar shape of the plate P is approximately rectangular to match the shape of the slide, and plate side walls PWL and PWR are provided on both short sides for contacting the sides of the slide. Furthermore, screw holes NA1 to NA3 are provided for passing screws used to attach the plate P to the sample stage SD. The plate P is fixed to the sample stage SD by passing screws NJ1 to NJ3 through the screw holes NA1 to NA3, respectively. If the plate P can always be attached to the sample stage SD in the same positional relationship, the joining member is not limited to screws.

[0013] The sample stage SD is fixed to the holder base HB with a slide fixing mechanism disposed therebetween. Figure 3 shows a schematic cross-sectional view of the slide holder HZ. The structure of the slide fixing mechanism will be explained using Figure 3. The slide fixing mechanism comprises a slide fixing member SH and a spring SP. The slide fixing member SH is a plate-shaped member with extensions extending in opposite directions at both ends of its length. The slide fixing member SH is positioned so that its length coincides with the short side of the plate P. The extension at one end of the slide fixing member SH is referred to as the operating member SHL, and the extension at the other end is referred to as the fixing member SHU. The sample stage SD faces the fixing member SHU and has a wall surface along the long side of the plate P.

[0014] A spring SP is provided between the operating unit SHL and the holder base HB. By pressing the operating unit SHL, the fixing unit SHU moves away from the plate P. When the slide S is placed on the plate P and the operating unit SHL is released, the elastic force of the spring SP causes the fixing unit SHU to come into contact with the slide S, pressing the slide S against the wall surface of the sample stage SD and fixing the slide S to the slide holder HZ. Note that an elastic member such as rubber may be used instead of the spring SP.

[0015] 4A and 4B show examples (top views) of a slide S placed in the slide holder HZ. Fig. 4A shows an example in which the slide S is placed to the right, in contact with the plate side wall PWR. Fig. 4B shows an example in which the slide S is placed to the left, in contact with the plate side wall PWL. Thus, with the slide holder HZ of this embodiment, the slide S is positioned along its short side by the slide fixing mechanism, and along its long side by the plate side walls PWR and PWL.

[0016] As described above, in the slide holder HZ of this embodiment, dividing lines are displayed on at least a portion of the slide mounting surface PS on which the slide S is placed, dividing the slide mounting surface PS into multiple regions, and a code uniquely identifying that region is displayed inside each of the multiple regions, which can be seen through the transparent slide. By positioning and placing the slide S at a predetermined position on the slide mounting surface PS, the slide S can be placed on the slide mounting surface PS with high positional repeatability. This allows the position of interest of a sample SAM fixed on a general-purpose slide to be indicated by identifying the region using the code displayed on the slide mounting surface PS.

[0017] Furthermore, it is desirable that the width (length in the long side direction) of the plate P be greater than the width (length in the long side direction) of the glass slide S. Since the task of fixing a sample SAM, such as a biological tissue sample, to the glass slide S is performed manually, the sampling position of the sample SAM on the glass slide S varies. For this reason, by making the width of the plate P greater than or equal to the width of the glass slide S and selecting either the method of installing the glass slide S shown in FIG. 4A or FIG. 4B depending on the fixing position of the sample SAM, it is possible to prevent the need to resample the glass slide S.

[0018] 2 has a notch NT on one of its long sides, which allows the slide glass S to be easily picked up and removed from the slide glass mounting surface PS.

[0019] (Modification) In Example 1, an example was shown in which a grid G ​​was engraved on the slide glass mounting surface PS of the plate P to divide the surface into grid-like regions in order to identify the position of the sample SAM on the slide glass S. The shape of the dividing lines dividing the regions is not limited to a grid. Fig. 5 shows an example in which concentric circles C that divide the regions are engraved on the slide glass mounting surface PS, and numbering N is engraved within each region divided by the concentric circles C. Concentric region division is suitable when the sample to be observed is a relatively large, circular biological tissue sample.

[0020] In the first embodiment (including the modified example), a general-purpose slide S is assumed to be mounted on the slide holder HZ, but a special size slide may also be used. Furthermore, while an example has been shown in which the slide S is positioned on the slide mounting surface PS using the slide fixing mechanism and the plate side walls PWR and PWL, the positioning of the slide S is not limited to this. For example, the outline of the slide S may be engraved on the slide mounting surface PS, and the slide S may be fixed to the plate P with carbon tape in accordance with this.

[0021] A description will be given of a charged particle beam device in which a slide glass S with a sample fixed thereto is placed on the slide glass holder HZ described in Example 1, and the sample fixed to the slide glass S is observed. Fig. 6 shows a scanning electron microscope (SEM) 100 as an example of the charged particle beam device.

[0022] A stage driving mechanism 7 and a stage 8 driven by the stage driving mechanism 7 are installed below the chamber 1, and a microscope barrel 2 is attached above the chamber 1, facing the stage driving mechanism 7. The holder base HB of the slide glass holder HZ described in Example 1 is attached to the holder attachment position of the stage 8. When the stage 8 with the slide glass holder HZ attached is located at the home position, the area of ​​the plate P on which the grid G ​​is engraved is located directly below the microscope barrel 2. Here, the plane of the stage 8 is parallel to the XY plane defined by the X and Y axes, and the normal direction to the XY plane is defined as the Z axis. The stage driving mechanism 7 can move the stage 8 independently in the X, Y, and Z directions and can also rotate it around a rotation axis extending in the Z direction.

[0023] The electron column 2 houses an electron optical system for irradiating the sample SAM with an electron beam EB. The electron optical system includes an electron gun for emitting the electron beam, an electron lens for focusing the electron beam, and a deflector for scanning the electron beam. When the electron beam EB irradiates the sample SAM, signal electrons SE are emitted due to interaction between the sample SAM and the electrons. The emitted signal electrons SE are detected by a detector 4 attached to the top of the chamber 1. Examples of the signal electrons SE to be detected include secondary electrons (SE) and backscattered electrons (BSE). It is preferable to provide a detector appropriate for the type of signal electrons SE. The detector may be provided inside the electron column 2. An image processing unit 5 generates scanned image data (charged particle beam image data) based on the signal electron SE detection signal from the detector 4 and irradiation position information of the electron beam EB.

[0024] A camera 3 is attached to the top of the chamber 1. A stage driving mechanism 7 moves a stage 8 so that the slide glass holder HZ is within the field of view of the camera 3, and the camera 3 captures an image of the slide glass S placed on the plate P of the slide glass holder HZ. A camera control unit 6 operates the camera 3 to acquire slide glass image data. It is not realistic to identify the grid G ​​and numbering N engraved on the plate P within the narrow field of view of the SEM 100. For this reason, the grid G ​​and numbering N are confirmed by capturing images of them with the camera 3.

[0025] The control device 9 is connected to the electron optical system, the stage driving mechanism 7, the detector 4, the image processing unit 5, and the camera control unit 6, and controls these based on instructions from the user, and also acquires the scanned image data generated by the image processing unit 5 and the slide glass image data acquired by the camera control unit 6. The image data acquired by the control device 9 is displayed on a display device 10 connected to the control device 9.

[0026] Although an example in which the SEM 100 includes the camera 3 has been described here, the SEM 100 does not necessarily have to include the camera 3. For example, before introducing the slide glass holder HZ into the chamber 1, a user may capture an image of the slide glass S placed on the plate P using a camera, and the acquired slide glass image data may be read into the control device 9.

[0027] 7 shows an example of a display screen that the control device 9 displays on the display device 10. The display screen 20 is a user interface screen that enables a user to acquire scanned image data of the sample SAM. The display screen 20 includes, for example, a control panel 21 that displays UI tabs for controlling the SEM 100, an operation panel 22 that displays UI tabs for controlling the acquisition of scanned image data by the SEM 100, a live image display section 23 that displays a scanned image currently being observed by the SEM 100, and a sub-screen display section 24 that displays a slide glass image 25.

[0028] During sample observation using the SEM 100, by linking the live image display unit 23 with the glass slide image 25 on the sub-screen display unit 24, it is possible to grasp, in conjunction with the grid G ​​and the numbering N, where on the glass slide S the magnified image of the sample currently displayed on the live image display unit 23 is located. In addition, by, for example, double-clicking an arbitrary point on the glass slide image 25 in the sub-screen display unit 24 with the cursor 26, the field of view can be moved to the double-clicked point, and the generated scanned image can be displayed on the live image display unit 23.

[0029] FIG. 8 shows a process flow executed by the control device 9 for linking the scanned image displayed on the live image display unit 23 with the slide image 25 displayed on the sub-screen display unit 24. First, slide image data is acquired by the camera 3 (S01). Alternatively, the slide image data may be acquired by reading data of a separately captured slide image. Next, the slide image is matched with the stage coordinate system (S02). As described above, since the mounting position of the slide holder HZ on the stage 8 is fixed, the coordinates in the stage coordinate system of each region divided by the grid G ​​engraved on the plate P are also uniquely determined. This enables linking the field of view of the SEM 100 with the slide image 25. When the user double-clicks any point on the slide image 25 in the sub-screen display unit 24 with the cursor 26, the control device 9 identifies the position on the slide image designated by the user from the double-click position (S03). The control device 9 converts the identified position on the slide image into coordinates in the stage coordinate system and controls the stage drive mechanism 7 to move the stage 8 so that the SEM field of view is aligned with that position.

[0030] In this way, if the method of placing the sample SAM fixed on the glass slide S on the glass slide placement surface PS (right-justified / left-justified) and the numbering of the area divided by the grid G ​​where the sample to be observed is fixed are shared, anyone can identify and observe the position of interest from the sample fixed on the glass slide S.

[0031] 7 shows an example in which a glass slide image corresponding to the entire acquired glass slide image data is displayed on the sub-screen display unit 24. However, the higher the magnification of the scanned image displayed on the live image display unit 23, the more enlarged the glass slide image is displayed. That is, during high-magnification observation, the glass slide image is displayed on the sub-screen display unit 24 with the field of view of the SEM 100 at the center. This makes it possible to specify the position to be observed with the SEM more accurately on the sub-screen display unit 24. Furthermore, by being able to use a low-magnification image (glass slide image) to track the tissue to be observed on a high-magnification image (live image), the user experience is similar to that of observing a biological tissue sample with an optical microscope.

[0032] In the third embodiment, an example of a user interface that makes it easy to observe a sample in the SEM 100 shown in the second embodiment will be described.

[0033] (Dividing Line / Code Superimposition Display) A UI tab for displaying an image of the grid G ​​and an image of the numbering N (referred to as the digital grid and the digital numbering, respectively) on the sub-screen display unit 24 is provided on the operation panel 22. The digital grid and the digital numbering correspond to the grid G ​​and the numbering N engraved on the plate P of the slide glass holder HZ. In cases where the presence of an opaque sample SAM makes it difficult to visually recognize the markings on the plate P, the digital grid and the digital numbering are superimposed on the slide glass image 25. This allows the grid G ​​and the numbering N to be clearly recognized even when the opaque sample SAM covers the grid G ​​and the numbering N.

[0034] Furthermore, if the magnification of the scanned image displayed on the live image display unit 23 increases and the slide glass image 25 displayed on the sub-screen display unit 24 also increases accordingly, it is desirable to provide a function for subdividing the digital grid, as shown in Figure 9A. In this case, when observing an area narrower than the initial area 30, new dividing lines are added to subdivide the area into areas 30-1 to 30-4, for example, and numbering is displayed to distinguish each of the subdivided areas. This function makes it possible to further subdivide the area divided by the grid during high-magnification observation, and to specify the position of the sample SAM using the subdivided areas.

[0035] The above-described division line / code superimposition display also applies to the case of concentric circular area division shown as a modified example of Example 1. Fig. 9B shows an example in which a concentric circular area is subdivided into fan-shaped areas and the subdivided numbering is displayed.

[0036] (Area Recording) During sample observation using the SEM 100, the live image display unit 23 and the glass slide image 25 on the sub-screen display unit 24 are linked. Therefore, when recording the acquired scanned image, the control device 9 records the numbering N of the area where the field of view of the SEM 100 is located as imaging position information as supplementary information. Furthermore, it is advisable to also record the glass slide image displayed on the sub-screen display unit 24 when the scanned image was acquired. This prevents the user from later forgetting the position where the scanned image was acquired. Including imaging position information as supplementary information of the scanned image is convenient when multiple people share scanned image data.

[0037] The same applies when using a digital grid, and particularly when using a subdivided digital grid, it is advisable to record the subdivided grid and numbering as additional information.

[0038] (Moving the field of view by selecting an area) An example of an operation panel for moving the field of view of the SEM to an area divided by a grid with one click is shown in Fig. 10. The operation panel 22 has an area selection section 41 that displays the numbering engraved on the plate P. As long as an area divided by a grid G ​​on the plate P can be uniquely selected, input using a numeric keypad or the like may be used.

[0039] 10, when any area in the area selection unit 41 is clicked with the cursor, the control device 9 moves the field of view of the SEM to the clicked area. After the field of view movement is complete, the user presses the condition setting button 43 to open the condition setting screen and sets conditions such as magnification, scan speed, and fine adjustment of the field of view.

[0040] This can be expanded to allow continuous field of view movement not only for one region but also for multiple regions. After selecting multiple regions in the region selection section 41, continuous image capture begins by pressing the continuous image capture button 42. The image capture conditions for each region are set in advance by pressing the condition setting button 43.

[0041] In the case of continuous imaging, by recording imaging position information as supplementary information of the scanned image, if there is a scanned image of interest after continuous imaging, it becomes easy to return to any desired point again from the supplementary information. In this way, by performing continuous imaging and then re-observing the area of ​​interest, the user's work efficiency can be improved.

[0042] In the above, in Examples 1 to 3, a slide glass holder, a charged particle beam device equipped with the slide glass holder, and functions for improving the efficiency of observation have been described. By using these, different users can easily share information about the position of interest in a sample, such as a biological tissue sample, collected on a general-purpose slide glass, and then each observe the sample. Of course, this is also effective when the same user re-observes a sample at a later time.

[0043] The above embodiments and modifications have been described in detail to make the present invention easier to understand, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment or modification with the configuration of another embodiment or modification, and it is also possible to add the configuration of another embodiment or modification to the configuration of one embodiment or modification. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment or modification with other configurations.

[0044] 1: chamber, 2: microscope barrel, 3: camera, 4: detector, 5: image processing unit, 6: camera control unit, 7: stage driving mechanism, 8: stage, 9: control device, 10: display device, 20: display screen, 21: control panel, 22: operation panel, 23: live image display unit, 24: sub-screen display unit, 25: slide glass image, 26: cursor, 30: area, 41: area selection unit, 42: continuous imaging button, 43: condition setting button, 100: scanning electron microscope, HZ: slide glass holder, P: plate, SD: sample stage, HB: holder base, NJ: screw, SH: slide glass fixing member, SHU: fixing unit, SHL: operation unit, PS: slide glass mounting surface, G: grid, N: numbering, NA: screw hole, PWL, PWR: plate side wall, NT: notch, S: slide glass, SP: spring, SAM: sample, C: concentric circles.

Claims

1. A slide glass holder on which a slide glass on which a sample is fixed is mounted, the slide glass holder having a plate with a substantially rectangular slide glass mounting surface, the slide glass being positioned and placed at a predetermined position on the slide glass mounting surface, at least a portion of the slide glass mounting surface that comes into contact with the placed slide glass being marked with dividing lines that divide the slide glass mounting surface into a plurality of regions, and a code that uniquely identifies the region being marked inside each of the plurality of regions.

2. A slide glass holder according to claim 1, wherein the dividing lines are a grid that divides the slide glass mounting surface into a lattice pattern or concentric circles that divide the slide glass mounting surface into concentric circles.

3. A slide glass holder according to claim 1, wherein the dividing line and the symbol are engraved on the slide glass mounting surface.

4. A slide glass holder according to claim 1, wherein a notch is provided in at least a part of the long side of the plate.

5. A slide glass holder according to claim 1, comprising a sample stage for mounting the plate, and a slide glass fixing mechanism for fixing the slide glass onto the plate, wherein the plate has side walls on both short sides, and the slide glass is positioned by being sandwiched between the slide glass fixing member of the slide glass fixing mechanism and the sample stage with one of the short sides in contact with one of the plate side walls.

6. A slide glass holder according to claim 5, comprising a holder base that supports the sample stage, the holder base being attachable to a mounting position of a stage provided in a charged particle beam device.

7. A microscope comprising: a chamber; a stage installed within the chamber and driven by a stage drive mechanism; a microscope barrel installed in the chamber opposite the stage drive mechanism and incorporating a charged particle optical system; a detector that detects signal electrons emitted by the microscope barrel due to interaction between the charged particle beam emitted from the microscope barrel and a sample; an image processing unit that generates charged particle beam image data based on a detection signal of the signal electrons by the detector; a control unit that controls the stage, the charged particle optical system, the detector, and the image processing unit; and a display unit connected to the control unit, wherein a slide glass holder can be attached to a holder attachment position of the stage, the slide glass holder having a plate with a substantially rectangular slide glass installation surface, a slide glass having a sample fixed thereto is positioned and placed at a predetermined position on the slide glass installation surface, and dividing lines dividing the slide glass installation surface into a plurality of regions are displayed on at least a portion of the slide glass installation surface that contacts the placed slide glass, and a code that uniquely identifies the region is displayed inside each of the plurality of regions, The control device displays a charged particle beam image generated by the image processing unit on a first image display unit of the display device, and a slide image of the slide on the slide placement surface on a second image display unit of the display device, and the control device moves a field of view to a position indicated by the slide image displayed on the second image display unit, and displays the generated charged particle beam image on the first image display unit.

8. A charged particle beam device according to claim 7, further comprising a camera installed in the chamber for taking an image of the slide glass.

9. A charged particle beam device according to claim 7, wherein the control device enlarges and displays the slide glass image displayed on the second image display unit as the magnification of the charged particle beam image displayed on the first image display unit increases.

10. A charged particle beam device according to claim 7, wherein the control device displays the image of the dividing line and the image of the code superimposed on the image of the glass slide displayed on the second image display unit.

11. A charged particle beam device as claimed in claim 10, wherein the control device subdivides each of the areas divided by the dividing lines when enlarging and displaying the glass slide image displayed on the second image display unit, and superimposes images of the dividing lines and images of codes that uniquely identify the subdivided areas on the glass slide image displayed on the second image display unit.

12. A charged particle beam device according to claim 7, wherein the control device displays an area selection section on the operation panel of the display device for selecting a code displayed on the slide glass installation surface, and when any code is selected in the area selection section, the control device moves the field of view to the area corresponding to the selected code and displays the generated charged particle beam image on the first image display section.

13. A charged particle beam device according to claim 12, wherein the region selection unit is capable of selecting a plurality of codes consecutively.

14. A charged particle beam device according to claim 7, wherein the control device records a code corresponding to an area including the field of view of the charged particle beam image as supplementary information of the charged particle beam image data.

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