Sample holder and analyzer

Abstract

The present invention provides a sample holder that can hold the top surface of a sample parallel to the top surface of the stage of an analytical instrument. [Solution] The sample holder 10 comprises a base member 2, a shape-variable support member 3 installed on the base member 2 and configured to support the sample S1, a pressing member 1 including a connecting portion 14 that connects to the base member 2, and a contact portion 12 that abuts against the edge portion S11a of the upper surface of the sample S1. The lower surface 22 of the sample holder 10 and the contact surface 121 on which the contact portion 12 abuts against the edge portion S11a are formed to be parallel.

Description

Technical Field

[0001] The present invention relates to a sample holder and an analytical device.

Background Art

[0002] A scanning probe microscope (SPM) approaches a sharpened probe to a sample on a stage, and while moving the height of the probe up and down with respect to the stage so that the physical quantity acting on the tip of the probe and the surface of the sample becomes constant, scans the upper surface of the sample in the in-plane direction with respect to the stage using the probe, thereby observing the unevenness of the upper surface of the sample with high resolution.

[0003] Since the SPM has high resolution in the surface height direction, it is difficult to acquire the upper surface of the sample as a single image unless the upper surface of the sample is installed parallel or substantially parallel to the upper surface of the SPM stage.

[0004] If the upper surface of the sample is slightly inclined with respect to the upper surface of the stage and is substantially parallel, by performing height correction on the acquired height image (hereinafter referred to as an SPM image), such a slight inclination can be corrected. Japanese Patent No. 6627903 discloses a technique related to such correction.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, if the sample surface is tilted so much relative to the stage surface that its height exceeds the cantilever's drive limit, there is a problem in that an image cannot be acquired for the area of ​​the sample surface that exceeds the cantilever's drive limit. In such cases, in order to obtain an image of that area, it is necessary to move the sample so that the height of that area falls within the drive limit and acquire a new image, which is time-consuming. Therefore, it is desirable to keep the sample surface parallel to the top surface of the analyzer's stage at least to the extent that the sample surface falls within the cantilever's drive limit.

[0007] The object of the present invention is to provide a sample holder that can hold the upper surface of a sample parallel to the upper surface of the stage of an analytical instrument. [Means for solving the problem]

[0008] A sample holder according to one aspect of this invention comprises a base member, a shape-variable support member mounted on the base member and configured to support a sample, and a pressing member including a coupling portion that connects to the base member and a contact portion that abuts against the edge of the upper surface of the sample. The lower surface of the sample holder and the contact surface on which the contact portion abuts against the edge are formed to be parallel. [Effects of the Invention]

[0009] According to the present invention, a sample holder can be provided that can hold the upper surface of a sample parallel to the upper surface of the stage of an analytical instrument. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram showing the configuration of the SPM according to the embodiment. [Figure 2] This figure shows the case where a first sample, whose upper and lower surfaces are not parallel, is placed in the sample holder according to the embodiment. [Figure 3] This figure shows the case where a second sample, with its top and bottom surfaces parallel, is placed in the sample holder shown in Figure 2. [Figure 4]This figure shows the case where the first sample is placed in the SPM according to the comparative example. [Figure 5] This figure shows the case where the first sample is placed in a sample holder with a different configuration than those shown in Figures 2 and 3. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described in detail below with reference to the drawings. In the following description, the same or corresponding parts in the drawings will be denoted by the same reference numerals, and their descriptions will not be repeated in principle.

[0012] [Device configuration] Figure 1 is a schematic diagram showing the configuration of a scanning probe microscope (SPM) 100 according to an embodiment. SPM100 corresponds to one embodiment of the "analytical device". Figures 2 and 3 show the case where a first sample S1 and a second sample S2 are held in the sample holder 10 according to the embodiment. The first sample S1 is a sample in which the upper surface S11 and the lower surface S12 are not parallel, and the second sample S2 is a sample in which the upper surface S21 and the lower surface S22 are parallel. However, in the case of either sample held in the sample holder 10, the upper surface of the sample is parallel to the upper surface 1121 of the stage 112 of the SPM100. In Figure 1, the sample is referred to as the first sample S1. In this specification, unless otherwise specified, when simply referred to as "parallel", it includes cases where the surfaces are slightly inclined (for example, within the driving range of the cantilever 113) but are substantially parallel. Therefore, one example of the first sample S1 is a sample in which the inclination between the upper surface S11 and the lower surface S12 is relatively large (for example, the height range from the lower surface S12 to the upper surface S11 exceeds the drive limit of the cantilever) (see Figure 4 described later).

[0013] In this specification, the direction of gravity is referred to as the negative Z-axis direction, and the horizontal plane is also referred to as the XY plane. Furthermore, the positive Z-axis direction may be described as "upward," and the negative Z-axis direction as "downward."

[0014] Referring to Figures 1 to 3, the SPM100 includes a control device 9, a piezo scanner 111, a stage 112, a cantilever 113, a displacement detection mechanism 120, a feedback signal generation unit 131, and a scanning signal generation unit 133.

[0015] Stage 112 is a sample stage for placing the sample held in the sample holder 10. Note that the size ratio of Stage 112 and the sample holder 10 in Figure 1 has been adjusted for illustrative purposes and does not reflect the actual size ratio. Stage 112 is positioned so that its upper surface 1121 is parallel to the XY plane. In the example in Figure 1, Stage 112 is positioned on the upper surface of the piezo scanner 111.

[0016] The piezo scanner 111 includes a Z scanner 111z that moves the stage 112 in the Z-axis direction based on a control voltage Vz, described later, and an XY scanner 111xy that moves in the X and Y axes based on control voltages Vx and Vy. By moving the piezo scanner 111 in the X, Y and / or Z axes, the sample on the stage 112 can be moved in the X, Y and / or Z axes.

[0017] The cantilever 113 has a probe 114 at its tip. The cantilever 113 is a cantilever beam and is supported at one end. The cantilever 113 has a limit to how far it can move vertically (drive limit), and if the height range of the sample surface exceeds the drive limit, an image of the sample surface cannot be acquired at once. Furthermore, if the cantilever 113 is forcibly moved beyond the drive limit, the probe 114 may collide with the sample surface, potentially causing damage to the cantilever 113 and / or the sample surface.

[0018] The displacement detection mechanism 120 detects the displacement of the cantilever 113. More specifically, the displacement detection mechanism 120 detects the deflection of the cantilever 113 in the Z-axis direction. The displacement detection mechanism 120 includes a laser diode 115 and a photodetector 119. The laser light emitted from the laser diode 115 is reflected by the back surface of the cantilever 113, and the reflected light is received by the photodetector 119. When the cantilever 113 deflects, the position where the laser light emitted from the laser diode 115 is reflected on the back surface of the cantilever 113 changes, and the position where the reflected light is received on the photodetector 119 also changes. The photodetector 119 is composed of, for example, four-divided light detection electrodes. The positions of the light detection electrodes are adjusted so that when the deflection amount of the cantilever 113 is 0, the spot of the laser light comes to the center of the divided electrodes. Then, when deflection occurs in the cantilever 113, the spot of the laser light moves on the divided electrodes, and a change occurs in the voltage output from the divided electrodes.

[0019] In the feedback signal generation unit 131, a deviation signal is calculated based on the difference between the deflection amount of the cantilever 113 and the deflection amount of the cantilever 113 when the physical quantity acting between the probe 114 and the sample is a predetermined target value. The feedback signal generation unit 131 controls the position of the stage 112 so that the deviation signal becomes 0. In one embodiment, the feedback signal generation unit 131 outputs, as a control voltage Vz of the Z scanner 111z, a signal obtained by synthesizing the deviation signal and its integral value based on the deviation signal to the Z scanner 111z. Thereby, the distance between the probe 114 and the sample is controlled so that the distance is such that the physical quantity acting between the probe 114 and the sample is a predetermined target value. In this specification, the "distance between the probe 114 and the sample when the physical quantity acting between the probe 114 and the sample becomes a predetermined target value" is also referred to as the "target distance". As described above, in the SPM 100, the distance between the probe 114 and the sample is controlled to be a constant target distance.

[0020] The feedback signal generation unit 131 also transmits the deviation signal and the control voltage Vz to the control device 9.

[0021] The scanning signal generation unit 133 calculates the control voltage Vx in the X-axis direction and the control voltage Vy in the Y-axis direction so that the sample moves relative to the probe 114 in the XY plane according to a preset scanning pattern, and outputs the control voltages Vx and Vy to the XY scanner 111xy.

[0022] The control device 9 includes a processor 90, a memory 91, an input device 93, and a display device 92. The control device 9 is, for example, a computer and its peripheral devices.

[0023] The processor 90 expands and executes the program stored in the memory 91 in a RAM or the like.

[0024] The memory 91 includes, for example, a ROM (Read Only Memory), a RAM (Random Access Memory), and a non-volatile memory. The program stored in the ROM is a program describing the processing procedure of the control device 9. The program includes a program for executing the image correction method according to the embodiment by causing a computer to execute it. The non-volatile memory stores the data sent from the feedback signal generation unit 131. Note that the memory 91 may include a hard disk device instead of or in addition to the non-volatile memory.

[0025] The input device 93 is a device for inputting a user's instruction to the control device 9. For example, the input device 93 includes a pointing device such as a keyboard and a mouse.

[0026] The display device 92 includes a liquid crystal display or the like. The control device 9 creates a primary image of the sample based on the position of the stage 112. The control device 9 calculates the height of the sample based on the position of the stage 112 in the Z-axis direction. More specifically, the control device 9 calculates the height of the upper surfaces S11 and S21 of the sample from the upper surface 1121 of the stage 112.

[0027] The position of stage 112 in the Z-axis direction is correlated with the control voltage Vz. The control device 9 calculates the height of the sample top surfaces S11 and S21 from the control voltage Vz, based on correlation information showing the relationship between the control voltage Vz and the height of the sample top surfaces S11 and S21. This correlation information is stored in memory 91 in advance.

[0028] The control device 9 creates a three-dimensional image of the sample's top surfaces S11 and S21 by calculating the height of each (X,Y) coordinate at the top surfaces S11 and S21 of the sample. The data of the three-dimensional image is stored in the memory 91. The data of the three-dimensional image includes the (X,Y) coordinates indicating the position on the XY plane and the Z coordinate of the sample at those (X,Y) coordinates. As described above, in this embodiment, the position of the stage 112 is precisely controlled in three dimensions, and a three-dimensional image is created based on the position of the stage 112. Alternatively, the position of the cantilever 113 may be precisely controlled in three dimensions instead of the stage 112, and a three-dimensional image may be created based on the position of the cantilever 113.

[0029] The sample holder 10 includes a pressing member 1, a base member 2, a support member 3, and a plate 4.

[0030] Base member 2 is the base member for the entire sample holder 10. The support member 3 is a shape-variable member that is placed on the base member 2 and configured to support the sample. In one embodiment, the support member 3 is a viscoelastic material having viscosity and elasticity. Furthermore, the support member 3 is easier to handle if it has a thickness of a predetermined value or more (for example, about 1 mm or more).

[0031] The retaining member 1 includes a connecting portion 14 that connects to the base member 2, and a contact portion 12 that abuts against the edges S11a and S21a of the upper surface S11 and S21 of the sample.

[0032] In one embodiment, through holes 13 are formed in the portion of the pressing member 1 corresponding to the central portions S11b and S21b of the upper surface S11 and S21 of the sample. As a result, even when the edge portions S11a and S21a of the sample are pressed down by the pressing member 1, the SPM100 can measure the central portions S11b and S21b of the sample through the through holes 13.

[0033] The lower surface of the sample holder 10 (the lower surface 22 of the base member 2 in the example of Figures 1 to 3) and the contact surface 121 (the lower surface of the contact portion 12 in the example of Figures 1 to 3) where the contact portion 12 contacts the edges S11a and S21a are formed to be parallel.

[0034] Plate 4 is a sample plate for placing a sample, and is positioned between the base member 2 and the support member 3. In one embodiment, plate 4 is a plate-shaped member whose upper and lower surfaces are formed parallel to each other.

[0035] As described above, the sample holder 10 changes shape according to the shape of the sample so that the upper surfaces S11 and S21 of the sample, which are held down by the pressing member 1, are kept parallel to the upper surface 1121 of the stage 112. As a result, whether the first sample S1, whose upper surface S11 and lower surface S12 are not parallel, as shown in Figure 2, is held, or the second sample S2, whose upper surface S21 and lower surface S22 are parallel, as shown in Figure 3, the upper surfaces S11 and S21 of each sample can be held parallel to the upper surface 1121 of the stage 112. Therefore, a sample holder 10 is provided that can hold the upper surface of the sample parallel to the upper surface 1121 of the stage 112.

[0036] Next, a method for storing a sample in the sample holder 10 will be described. In one embodiment, the user first places the support member 3 on the upper surface of the plate 4 and places the sample on the upper surface 31 of the support member 3. This fixes the sample on the plate 4 via the support member 3. Next, the user places the plate 4 on the upper surface 21 of the base member 2. Then, the user connects the retaining member 1 to the base member 2. At this time, the lower surface of the sample holder 10 (the lower surface 22 of the base member 2 in the example of Figures 1 to 3) and the contact surface 121 of the contact portion 12 (the lower surface of the contact portion 12 in the example of Figures 1 to 3) become parallel, so the upper surfaces S11 and S21 of the sample also become parallel to the lower surface of the sample holder 10. Therefore, if the sample holder 10 is placed on the upper surface 1121 of the stage 112 in this state, the upper surfaces S11 and S21 of the sample can be held parallel to the upper surface 1121 of the stage 112.

[0037] While the storage of samples into the sample holder 10 may be performed on the stage 112 instead of the workbench, it is more efficient to do so on the workbench. Specifically, it is more convenient to work on the workbench because it allows for a larger workspace and the ability to place multiple samples in multiple sample holders.

[0038] The sample holder 10 can also be used in systems other than SPM where it is preferable for the sample surface to be parallel to the top surface of the analyzer's stage. For example, if the sample holder 10 is applied to an analyzer other than SPM where it is preferable for the sample surface to be parallel to the top surface of the stage, the sample surface can be held parallel to the top surface of the stage in the analyzer, thus enabling proper analysis.

[0039] Figure 4 shows the case where the first sample S1 is placed in the SPM according to the comparative example. Referring to Figure 4, the first sample S1 is placed directly on the stage 112. In this case, the upper surface S11 of the first sample S1 is tilted beyond the drive limit of the cantilever relative to the upper surface 1121 of the stage 112. In such a case, the SPM according to the comparative example cannot acquire the upper surface S11 of the sample as a single image.

[0040] On the other hand, in the SPM100 including the sample holder 10, the sample top surface S11 is always held parallel to the top surface 1121 of the stage 112, so the sample top surface S11 can be acquired as a single image. This makes it possible to acquire an image of the entire sample top surface S11 without the trouble of acquiring it as multiple images.

[0041] Next, other embodiments of the sample holder 10 according to the embodiment will be described. In one embodiment, the support member 3 is an adhesive or clay. Using a material that easily adheres to its surroundings as the support member 3 is preferable because it prevents the sample from sliding on the support member 3 and shifting position, and prevents the support member 3 from sliding on the upper surface of the member on which it is placed and shifting position.

[0042] As the adhesive, it is preferable to use a material that can be peeled off relatively easily from the bonding surface; for example, correction fluid for stationery can be used. As the clay, for example, a commercially available product (for example, one sold at stationery stores, toy stores, home improvement stores, etc.) can be used. In other embodiments, the support member 3 may be a gel-like mat (for example, a mat that is attached under furniture for anti-slip or seismic reinforcement purposes).

[0043] As described above, if the support member 3 is made of a material that can be peeled off relatively easily from the adhesive surface, it is relatively easy to peel it off from the sample and / or the component placed beneath the support member 3. This allows the sample that was adhered to the support member 3 and / or the component placed beneath the support member 3 to be reused. Furthermore, if clay or a gel-like mat is used as the support member 3, the support member 3 itself can be reused until it hardens due to drying or aging.

[0044] In the sample holder 10, the support member 3 may be placed directly on the upper surface 21 of the base member 2 without providing the plate 4. In this case, the structure of the sample holder 10 becomes simpler. However, the configuration in which the support member 3 is placed on the upper surface of the plate 4 has advantages such as being easier to carry than carrying the sample alone, and the upper surface 21 of the base member 2 not getting dirty (the risk of some residue remaining when peeling the support member 3 from the upper surface 21 can be suppressed). Also, if the base member 2 is a cylindrical shape that is long vertically (for example, the height is longer than the radial length) and the plate 4 is a plate-shaped member, it is easier to place the support member 3 on the upper surface of the plate 4 than to place the support member 3 directly on the upper surface 21 of the base member 2.

[0045] Alternatively, the plate 4 may be placed between the support member 3 and the sample. In this case, since the support member 3 does not directly contact the sample, the possibility of any part of the support member 3 remaining when it is peeled away from the sample can be suppressed.

[0046] The shape and size ratio of each part of the sample holder 10 are not limited to those shown in the figure above. For example, in Figures 2 and 3, the base member 2 consists of an upper part 23 that fits into the retaining member 1 and a lower part 24 that supports the upper part 23. The size of the lower part 24 in the XY direction is larger than the size of the upper part 23 in the XY direction. However, the lower part 24 may be omitted, and the base member 2 may be used with only the upper part 23. In this way, the sample holder 10 can be made smaller. However, by including the lower part 24 in the base member 2, the center of gravity of the sample holder 10 is lowered and the bottom area of ​​the sample holder 10 is increased, so the sample holder 10 is positioned more stably on the stage 112.

[0047] Alternatively, the stage 112 may be used as the base member 2. Figure 5 shows a case where the first sample S1 is placed in a sample holder 10A with a different configuration from Figures 2 and 3. In the sample holder 10A, the support member 3 is placed directly on the stage 112, the first sample S1 is placed on the support member 3, and the edge portion S11a of the first sample S1 is pressed down by the contact portion 12 of the pressing member 1A. In this case, the coupling portion 14A of the pressing member 1A that connects to the stage 112 is formed in a planar shape so as to be in close contact with the upper surface 1121 of the stage 112. The lower surface of the sample holder 10A (the coupling portion 14 in the example of Figure 5) and the contact surface 121 (the lower surface of the contact portion 12 in the example of Figure 5) where the contact portion 12 contacts the edge portion S11a are formed to be parallel. According to the configuration of Figure 5, the number of parts of the sample holder can be reduced compared to the case where an independent base member 2 is provided. However, in the configuration shown in Figure 5, it is necessary to perform detailed tasks such as pressing the pressing member 1 against the sample on the stage 112. Therefore, the configurations shown in Figures 2 and 3 are superior in that these detailed tasks can be performed in a larger space such as a workbench.

[0048] The connecting portion 14 of the retaining member 1 is preferably configured to be in close contact with the base member 2. In one embodiment, the connecting portion 14 of the retaining member 1 and the portion 25 of the base member 2 that connects to the connecting portion 14 are formed of curved surfaces that are in close contact with each other. In another embodiment, the connecting portion 14 and the portion 25 are formed of flat surfaces that are in close contact with each other.

[0049] Furthermore, in other embodiments, it is preferable that the connecting portion 14 and portion 25 are formed so that their respective protrusions and recesses fit together. For example, the connecting portion 14 and portion 25 are threaded, with the connecting portion 14 being a female thread and portion 25 being a male thread. With this configuration, the position of the retaining member 1 relative to the base member 2 can be held even more stably.

[0050] The contact portion 12 of the pressing member 1 only needs to keep the upper surface S11, S21 of the sample parallel to the upper surface 1121 of the stage 112. Therefore, it does not need to contact the entire circumference of the edge portions S11a, S21a of the sample, and may be formed to contact only a part of the edge portions S11a, S21a (for example, three or more places). In this case as well, the central portion S11b, S21b of the sample that is not covered by the contact portion 12 is open to the top and can be measured.

[0051] Similarly, the joining portion 14 of the retaining member 1 does not need to be joined around the entire circumference of the base member 2, as long as the contact surface 121 and the lower surface of the sample holder 10 are kept parallel. It may be configured to be joined only in a part of the base member 2 (for example, at three or more locations).

[0052] The user may use multiple pressing members 1, each having through-holes of different sizes, depending on the size of the sample. For example, when measuring a relatively large sample, a first pressing member with a relatively large through-hole 13 may be used, and when measuring a relatively small sample, a second pressing member with a relatively small through-hole 13 may be used. With this configuration, even for relatively small samples, the second pressing member can hold the upper surface parallel to the upper surface 1121 of the stage 112, and even for relatively large samples, the second pressing member can maintain the upper surface parallel to the upper surface 1121 of the stage 112 while providing a wider area that can be measured by the cantilever than when using the first pressing member.

[0053] [Aspect] Those skilled in the art will understand that the above-described exemplary embodiments are specific examples of the following embodiments.

[0054] (Section 1) A sample holder according to one embodiment comprises a base member, a shape-variable support member installed on the base member and configured to support a sample, and a pressing member including a coupling portion that connects to the base member and a contact portion that abuts against the edge of the upper surface of the sample. The lower surface of the sample holder and the contact surface on which the contact portion abuts against the edge are formed to be parallel.

[0055] According to the sample holder described in paragraph 1, the support member changes shape according to the shape of the sample so that the upper surface of the sample, which is held down by the pressing member, is kept parallel to the upper surface of the stage of the analyzer, thereby enabling the upper surface of the sample to be held horizontally. Therefore, a sample holder is provided that can hold the upper surface of the sample parallel to the upper surface of the stage of the analyzer.

[0056] (Section 2) In the sample holder described in Section 1, the support member is an adhesive or clay.

[0057] The sample holder described in paragraph 2 is preferable because it prevents the sample from sliding on the support member and shifting position, and also prevents the support member from sliding on the upper surface of the member on which it is placed and shifting position.

[0058] (Clause 3) The sample holder described in paragraph 1 or 2 further comprises a plate disposed between the base member and the support member.

[0059] The sample holder described in Section 3 has advantages such as being easier to carry than carrying the sample alone, and preventing the top surface of the base member from getting dirty (which can reduce the risk of some residue remaining when peeling the support member from the top surface).

[0060] (Item 4) An analytical apparatus equipped with a sample holder as described in any one of items 1 to 3. According to the analytical apparatus described in paragraph 4, the upper surface of the sample can be held parallel to the upper surface of the stage in the analytical apparatus. Therefore, if a sample holder is applied to an analytical apparatus in which it is preferable that the upper surface of the sample other than the SPM be parallel to the upper surface of the stage, the upper surface of the sample can be held parallel to the upper surface of the stage in the analytical apparatus, and thus appropriate analysis is possible.

[0061] (Section 5) The analytical instrument described in Section 4 is a scanning probe microscope. In the analytical apparatus described in Section 5, the top surface of the sample is always held parallel to the top surface of the stage, so the top surface of the sample can be acquired as a single image.

[0062] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0063] 1,1A Pressing member, 2 Base member, 3 Support member, 4 Plate, 9 Control device, 10,10A Sample holder, 12 Contact area, 13 Through hole, 14,14A Joint area, 21,31,1121,S11,S21 Top surface, 22,S12,S22 Bottom surface, 23 Upper part, 24 Lower part, 25 Part that connects to the joint area, 90 Processor, 91 Memory, 92 Display device, 93 Input device, 100 Scanning probe microscope (SPM), 111 Piezo scanner, 111xy,111z scanner, 112 Stage, 113 Cantilever, 114 Probe, 115 Laser diode, 119 Photodetector, 120 Displacement detection mechanism, 121 Contact surface, 131 Feedback signal generation unit, 133 Scanning signal generation unit, S1 Sample 1, S2; Sample 2, S11b, S21b; central part, S11, S21; top surface of sample, S11a, S21a; edge part.

Claims

1. A sample holder for holding a sample, Base member and A shape-variable support member is installed on the base member and configured to support the sample, The pressing member includes a connecting portion that connects to the base member and a contact portion that abuts against the edge of the upper surface of the sample, A sample holder formed such that the lower surface of the sample holder and the contact surface in which the contact portion contacts the edge are parallel.

2. The sample holder according to claim 1, wherein the support member is an adhesive or clay.

3. The sample holder according to claim 1 or 2, further comprising a plate disposed between the base member and the support member.

4. An analytical apparatus comprising a sample holder according to claim 1 or 2.

5. The analytical apparatus according to claim 4, wherein the analytical apparatus is a scanning probe microscope.

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