JP2016065800A - Scanning prove microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fix a probe to be removable from a scanner while suppressing mass increase at a probe side in a scanning prove microscope that displaces the probe side for scanning.SOLUTION: In the scanning prove microscope, at least a Z-scanner 21 of a X-scanner, a Y-scanner, and the Z-scanner is arranged near a probe and an elastically deformable probe-fixing member 70 is fixed to an upper base part 11 directly or indirectly. The probe-fixing member 70 is elastically deformed and returns to its original form to press the base part of the probe 40 against the Z-scanner 21 with its own return force, while tracking displacement of the Z-scanner 21. This allows the probe to become removable while suppressing the mass increase for the Z-scanner.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a scanning probe microscope of a type in which a probe side is displaced for scanning, and more particularly to a novel fixing structure for detachably fixing a probe to a scanner.

  A scanning probe microscope includes a sample stage, a probe, a scanner that displaces the sample stage or the probe for scanning, and a detector that detects a change in a physical quantity that occurs in the probe. Have as. A typical example of a scanning probe microscope is an atomic force microscope. In the atomic force microscope, a cantilever tip (a member provided with a very small protruding needle at the tip of the cantilever) is used as a probe.

FIG. 9 is a diagram illustrating a configuration example of a main part of an atomic force microscope of a type in which the sample stage side is displaced for scanning (hereinafter referred to as a sample stage displacement type). The control unit is not shown. As shown in FIG. 9, in the sample stage displacement type apparatus, a sample stage 300 is disposed on a lower base portion (stage-side support base) 100 via an XYZ scanner 200, and a sample M10 is disposed thereon. Is done. In the illustrated example, an XYZ scanner 200 includes a Z scanner 210 that can be displaced in the Z direction (up and down direction in the figure) according to a control signal, and an XY direction (two orthogonal along a plane perpendicular to the drawing sheet). And an XY scanner 220 that can be displaced in the direction). The cantilever chip 400 includes a cantilever 410 and a protruding needle 420, and a base portion thereof is attached to the support member 500. The support member 500 is fixed to an upper base portion (probe-side support base facing the lower base portion) 110. Support member 500 may include a device for applying AC mode vibration to the cantilever.
When the XYZ scanner 200 is controlled and the sample M10 is displaced, a change occurs in the cantilever, and the change is detected by a detector 600 (an optical displacement detector having a light emitting element 610 and a light receiving element 620 in the illustrated example). Then, from the data of each measurement point, the state of the undulation on the sample surface is imaged. The structure of each part of the atomic force microscope and feedback control are described in detail in, for example, Patent Documents 1 and 2.

The sample stage displacement type apparatus as shown in FIG. 9 has an advantage that the structure of the apparatus does not become complicated because the positions of the cantilever chip and the detector are not moved. Further, even if the mass on the cantilever chip side is increased, there is no relationship with the mass on the stage side, so the responsiveness of the scanner does not deteriorate. Therefore, on the cantilever tip side, there is also an advantage that various mechanisms for easily attaching and detaching the cantilever tip can be designed and provided relatively freely.
However, the sample stage displacement type apparatus has a problem in that it cannot be used for a large sample due to mass restrictions because the entire sample stage must be displaced by a scanner, and there is a limit to miniaturization of the sample stage. Therefore, speeding up the response of the scanner is also limited.

On the other hand, an atomic force microscope of the type that displaces the cantilever tip side (tip displacement type) complicates the overall structure of the apparatus, but the responsiveness of the scanner decreases even if the mass on the sample stage side increases. There is no. Therefore, a larger sample such as a semiconductor wafer or a petri dish for cell culture can be set as an observation target.
FIG. 10 is a diagram illustrating a configuration example of a main part of a tip displacement type atomic force microscope. As shown in FIG. 10, in the chip displacement type apparatus, the sample stage 300 is disposed on the lower base portion 100, and the sample M10 is disposed thereon. The base portion of the cantilever chip 400 is attached to a support member 500, and the support member 500 is fixed to the upper base portion 110 via the XYZ scanner 200. The XY scanner 220 may be on the sample stage side. A device for generating vibration for the AC mode may be provided separately as appropriate, or the Z scanner may generate the vibration.
When the cantilever chip 400 is displaced with respect to the sample M10 by the XYZ scanner 200, a change occurs in the cantilever as in the case of the sample stage displacement type, and the change is detected and collected by a detector (not shown). The image of the undulations on the sample surface is imaged by the data relating to.

However, when the present inventors actually manufactured a tip displacement type atomic force microscope as shown in FIG. 10 and studied to further increase the scanning speed, the cantilever tip was changed to a scanner (especially a Z scanner). It has been found that there are the following problems in the fixing structure for fixing to.
The cantilever tip needs to be frequently replaced due to the fixation of the object to be observed and defects in its vibration characteristics. For this reason, the cantilever chip must be detachable from the Z scanner. Moreover, in order to increase the scanning speed, the fixing structure for enabling the detachment has an adverse effect on the operation of the Z scanner. Must not. That is, more specifically, the fixing structure must satisfy the following conditions.
(I) The cantilever tip can be easily attached and detached without applying an excessive force to the Z scanner.
(Ii) Do not add mass that lowers the resonance frequency (natural frequency) of the Z scanner outside the allowable range.
(Iii) When the Z scanner is displaced at a high speed, undesirable vibrations are not generated in the cantilever chip.

In conventional tip displacement type devices, high-speed scanning has not been required, so the Z scanner itself is relatively large (resonance frequency is low), and a mechanism that can attach and detach the cantilever tip is designed relatively freely. Was possible.
However, in order to observe the dynamic behavior of cells and protein molecules in the sample solution in the petri dish, it is necessary to increase the scanning speed of the chip displacement type device. For this purpose, in order to increase the response speed of the Z scanner, it is necessary to reduce the mass of the Z scanner and increase its resonance frequency. In an actuator such as a piezo element constituting a scanner, the response speed of the actuator to a signal is higher, the resonance frequency of the actuator is higher, and the mass of the movable part of the actuator is smaller. Is synonymous and inseparable.
Therefore, among the above conditions (i) to (iii), (i) and (ii) are contradictory conditions. This is because a convenient attachment / detachment mechanism that satisfies (i) requires a large number of parts, thus adding a large mass to the Z scanner and lowering the resonance frequency, so (ii) cannot be satisfied. is there.
Fixing the cantilever tip with screws requires not only male screws but also a base with internal threads, and there is a limit to the reduction of mass. Also, attaching and detaching with a small screw is not an easy operation. As an alternative to screw fixing, a structure in which a fixing jig using a spring is attached to the Z scanner is conceivable. However, even a simple jig requires several parts and increases the mass of the Z scanner. Also, if the cantilever tip is directly fixed to the Z scanner with an adhesive, the mass is substantially only the cantilever tip, but in that case, the cantilever cannot be easily removed and cannot be said to be removable. .
The above-described problem relating to fixing of the cantilever tip is a problem that exists not only in an atomic force microscope but also in a scanning probe microscope in which the probe is displaced by a scanner.

International Publication No. 2010/087114 International Publication No. 2006/129561

  An object of the present invention is to solve the above-mentioned conflicting problems and to suppress the increase in mass on the probe side while suppressing the increase in mass on the probe side, while the probe side is displaced for scanning. The purpose is to enable detachable fixing.

The present inventors diligently studied to solve the above-mentioned problem, and while pressing the probe against the scanner on the probe side by the elastic body fixed to the upper base portion, the probe can be fixed while being detachable. It has been found that an increase in mass harmful to the scanner can be suppressed, and the present invention has been completed.
The main configuration of the present invention is as follows.
[1] A scanning probe microscope in which at least the Z scanner among the X scanner, Y scanner, and Z scanner is disposed on the probe side,
An elastically deformable probe fixing member is directly or indirectly fixed to the upper base portion which is a support base on the probe side,
The probe fixing member is elastically deformed and arranged to press the base of the probe against the Z scanner by its own restoring force while following the displacement of the Z scanner.
The scanning probe microscope.
[2] The probe fixing member is fixed to the upper base portion via a support block, and the support block is set to a value intended for a height difference between the upper base portion and the Z scanner. In order to adjust, the scanning probe microscope according to the above [1], which is fixed to the upper base portion.
[3] The upper base portion is provided with the support blocks at at least two positions with the Z scanner interposed therebetween, and the end portions of the probe fixing members are fixed to the support blocks, respectively. The central portion of the probe fixing member presses the base of the probe against the Z scanner by its own restoring force.
The scanning probe microscope according to [2] above.
[4] The upper base portion is provided with the support block at a necessary location,
One end of the probe fixing member is fixed to the support block, and the other free end of the probe fixing member presses the base of the probe against the Z scanner by its own restoring force. ,
The scanning probe microscope according to the above [2] or [3].
[5] The scanning probe microscope according to any one of [1] to [4], wherein the probe fixing member is a leaf spring.
[6] The scanning according to any one of [1] to [5], wherein a cushion member made of a material having elasticity and flexibility is further interposed between the probe fixing member and the probe. Type probe microscope.
[7] A positioning member for positioning the probe is fixed to the Z scanner,
The scanning probe according to any one of [1] to [6], wherein the probe fixing member is disposed so as to press a base portion of the probe positioned by the positioning member against a Z scanner. microscope.
[8] The scanning probe microscope according to any one of [1] to [7], wherein the scanning probe microscope is an atomic force microscope, and the probe is a cantilever tip including a cantilever and a protruding needle. Scanning probe microscope.

According to the present invention, the scanning probe microscope operates while the probe is pressed against the Z scanner by the probe fixing member. The probe fixing member is not mounted directly on the Z scanner, but is fixed at one end to the upper base portion that is a support base on the probe side (this fixing depends on the shape of the upper base portion as will be described later). , Which may be fixed directly or via a member), the movable part extends to the Z scanner, pressing the probe against the underside of the Z scanner.
With this configuration, since the probe is just pressed against the Z scanner, the probe can be attached to the Z scanner simply by inserting the probe between the Z scanner and the probe fixing member. In addition, the probe can be detached from the Z scanner simply by removing the probe from between the Z scanner and the probe fixing member.
Next, since the probe fixing member follows the high-speed vibration of the Z scanner while pressing the probe against the Z scanner, the operation of the Z scanner is not hindered.
Furthermore, although depending on the shape of the probe fixing member, at least half of the mass of the probe fixing member is supported by the upper base portion, and only the mass of the remaining elastic movable part and the mass of the cantilever tip are It becomes a vibration load.
As described above, according to the present invention, while securing the probe to the scanner in a detachable manner, a large mass as in the conventional attachment / detachment mechanism is not added to the Z scanner.

FIG. 1 is a diagram for explaining the configuration of a scanning probe microscope of the present invention. FIG. 2 is a view of the scanner and probe portion shown in FIG. 1 as viewed in the direction of arrow A in FIG. Inclined portions such as the cantilever 41, the probe fixing member 70, and the lower end portion of the support block positioning member in FIG. 1 are shown in FIG. 2 according to the BB cross-sectional view in FIG. FIG. 3 is a diagram showing another example of the probe fixing member according to the present invention. FIG. 4 is a diagram showing another example of the probe fixing member according to the present invention. FIG. 5 is a diagram showing an example in which a cushion member made of a material having elasticity and flexibility is interposed between a probe and a probe fixing member in the present invention. FIG. 6 is a diagram showing an example of a positioning member for positioning the probe provided in the Z scanner in the present invention. 6A shows an example of a positioning groove formed on the positioning member, and FIG. 6B is a perspective view of FIG. 6A, in which the positioning member is attached to the Z scanner. The fixed state is shown. FIG. 7 is a graph showing the vibration characteristics of the Z scanner in the example of the present invention (FIG. 7A) and the comparative example (FIG. 7B). FIG. 8 is a graph obtained by superimposing the graph of FIG. 7A and the graph of FIG. FIG. 9 is a diagram schematically showing a configuration example of a conventional atomic force microscope, and is a diagram showing a configuration example in which an XYZ scanner is arranged on the stage side. FIG. 10 is a diagram schematically showing another configuration example of a conventional atomic force microscope, and is a diagram showing a configuration example in which an XYZ scanner is arranged on the probe side. In FIG. 10, the same reference numerals as those in FIG. 9 are used for portions corresponding to the respective portions in FIG. In FIG. 10, the detector is not shown.

The configuration of the scanning probe microscope of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram schematically showing a configuration of a scanning probe microscope of the present invention, and shows a configuration example of an atomic force microscope as a specific example of the scanning probe microscope. The atomic force microscope uses a cantilever tip 40 (a member provided with a very small protruding needle (probe) 42 at the tip of the cantilever 41) as a probe, and a cantilever by an interaction between the protruding needle and a sample surface. Through changes in the cantilever tip due to atomic force in DC mode (contact mode and non-contact mode, changes in cantilever vibration in AC mode (sometimes called tapping mode), etc.) It is a microscope which can image the appearance of undulations on the sample surface.
In FIG. 1, only the main part of the apparatus is shown, and the control unit and the detector are not shown. In addition, the size of each part is exaggerated for the sake of explanation, and the size ratio is appropriately changed so that a certain component does not cover other components.

As shown in FIG. 1, the scanning probe microscope of the present invention has a lower base portion 10 that is a support base on the stage side and an upper base portion 11 that is a support base on the probe side, as in the conventional product. Configured. A sample stage 30 is provided on the lower base portion 10, and a sample M1 is disposed thereon. In the example of FIG. 1, the XYZ scanner 20 (XY scanner 22 and Z scanner 21) are all arranged on the probe side, but it is sufficient that at least the Z scanner 21 is arranged on the probe side. A feature of the present invention resides in a probe fixing member. An elastically deformable probe fixing member 70 is fixed to the upper base portion 11 via a support block 80. Depending on the undulation of the lower surface of the upper base portion 11 and the shape of the probe fixing member 70, the probe fixing member 70 may be directly fixed to the upper base portion 11.
As illustrated in FIGS. 2 to 4, the probe fixing member 70 extends to the Z scanner 21 and is disposed in an elastically deformed state (bent state), and the deformation is restored. The probe base (base of the cantilever 41) is pressed against the Z scanner 21 by force. The probe fixing member 70 follows the vibration without pressing the vibration of the Z scanner 21 due to its own elasticity while pressing the base of the probe against the Z scanner 21.

  The present invention can also be said to be a method for detachably fixing the probe to the Z scanner in the scanning probe microscope of FIG. As described above, the probe fixing member 70 is fixed directly or indirectly to the upper base portion 11. Then, the probe fixing member 70 is arranged so that the probe fixing member 70 presses the base of the probe against the Z scanner by its own restoring force while elastically deforming the probe fixing member 70.

  With the above configuration, the probe fixing member 70 functions to detachably fix the probe to the Z scanner while following the displacement of the Z scanner. As a result, the above conditions (i) to (iii) mentioned in the description of the prior art are satisfied, and the above conditions (i) and (ii), which are particularly conflicting conditions, are satisfied. The object of the present invention is achieved, which enables the probe to be detachably fixed to the scanner while suppressing the increase.

The X scanner, Y scanner, and Z scanner are devices for displacing the sample stage or probe in the X, Y, and Z directions for scanning, respectively, and are used in conventionally known scanning probe microscopes. Can be used. Examples of elements that accurately respond to control signals include piezo elements, magnetostrictive elements, and voice coil motors.
In this specification, the X scanner and the Y scanner may be regarded as one unit and called an XY scanner. The arrangement of the X scanner and the Y scanner may be appropriately determined according to the purpose and scale of the apparatus. However, from the viewpoint of observing a large sample, the X-Y scanner, Z A structure in which the scanner is all disposed on the probe side is preferable.

  The resonance frequency of the Z scanner is not particularly limited, but in the case of high-speed vibration of about 1 kHz or higher, particularly about 10 to 100 kHz or higher, conventionally, the probe must be fixed to the Z scanner with an adhesive. Therefore, the usefulness of the detachable configuration of the present invention is particularly remarkable.

The probe fixing member may be any member that is partly fixed to the upper base portion and the other portion extends from there to the Z scanner so that the probe can be pressed against the Z scanner. Normally, the lower surface of the upper base portion is flat as shown in FIG. 1, and at least the Z scanner protrudes downward therefrom. Therefore, there is a large difference in height between the lower surface of the upper base part and the lower surface of the Z scanner (probe mounting surface).
Therefore, in a preferred embodiment of the present invention, as shown in FIGS. 1 and 2, in order to adjust the height difference ΔT between the upper base portion and the Z scanner to an intended value ΔT1, a support block is used. 80 is fixed to the upper base portion, and the probe fixing member 70 is fixed to the upper base portion 11 through the support block 80.
The intended value ΔT1 may be appropriately determined according to the shape of the probe fixing member 70 and the spring constant.
For example, as shown in FIGS. 1 and 2, when the probe fixing member is a simple flat plate spring, the height t1 of the support block 80 is set to be higher than the height t0 of the cantilever attached to the Z scanner. By lowering, the difference (that is, the intended value ΔT1 = t0−t1) becomes the amount of bending of the probe fixing member. Therefore, by appropriately setting the intended value ΔT1, the amount of bending of the probe fixing member can be changed, and the amount of pressing the probe against the Z scanner can be adjusted.
Further, as shown in FIGS. 3 and 4, when the probe fixing member is a leaf spring and its action portion is curved toward the Z scanner, the height t1 of the support block 80 is set to the Z scanner. An appropriate amount of bending of the probe fixing member may be obtained by setting the height to be the same as the height t0 of the cantilever attached to the head or by making it higher.

The probe fixing member only needs to have elasticity necessary for achieving the above-described effects. For example, a plate spring, a linear spring, a coil spring (compression spring, a tension spring), a block member made of an elastic material, an elasticity Examples thereof include a string-like member made of a material.
Examples of the material for the probe fixing member include spring metals such as stainless steel, hardened copper, and bainite steel, natural rubber, synthetic rubber, and organic polymer materials having the necessary elasticity.
The mechanism for pressing the probe from below to the Z scanner is not particularly limited as long as unnecessary excessive mass is not added to the Z scanner. For example, a string-like member made of a tension spring or an elastic material is connected to both ends of a pressing member having a minute mass as a probe fixing member, and the pressing member is elastically pulled toward the upper base portion. By pushing up, a mechanism for pressing the probe to the Z scanner by the pressing member, and a rigid member is extended from the support block shown in FIGS. 2 and 3 to the lower surface of the Z scanner, and from there, a compression spring or elastic material is used. A mechanism for pressing the probe to the Z scanner may be used. However, the space between the lower surface of the probe and the sample is actually very narrow, and often a heavy mechanism cannot be inserted. From such a point, a presser mechanism using a leaf spring as shown in FIGS. 1 to 3 is preferable. If it is a leaf | plate spring, as shown in FIGS. 2-4, a base will be supported by the side of Z scanner, it will extend to just under Z scanner, and it will be easy to press the base of a cantilever to Z scanner.
The leaf spring may be a spring that narrows the width of the plate and exhibits a linear shape as a whole. Even with such a spring having a linear shape, a necessary pressing force may be obtained by using a necessary number of springs.

When the probe fixing member is a leaf spring, as shown in FIGS. 2 and 3, the leaf spring is supported at both ends and presses the base of the cantilever to the Z scanner at the center. Alternatively, as shown in FIG. 4, one end may be supported, and the base of the cantilever may be pressed against the Z scanner by the other free end. 1 to 4, the probe fixing member 70 is fixed to the support block by screws 70a. The portion indicated by reference numeral 70a represents the head of the pan head screw. The probe fixing member 70 may be fixed to the support block by an appropriate one-touch attachment / detachment mechanism.
In the example of FIGS. 2 and 3, support blocks 80 and 81 are provided on the upper base portion 11 at two locations with a Z scanner in between. The support blocks 80 and 81 include probe fixing members ( The end portion of the leaf spring 70 is fixed, and the central portion 71 presses the base portion of the cantilever 41 against the Z scanner by the restoring force. In the example shown in the figure, the support block is a pair, but a plurality of pairs of support blocks may be provided in accordance with the increase in the probe fixing member.
In the example of FIG. 4, one support block 80 is provided behind the Z scanner, and one end of a probe fixing member 70 is fixed to the support block 80, and the probe fixing member The other free end of 70 presses the base of the cantilever 41 against the Z scanner by its own restoring force. In this case, the position and the number of the support blocks may be arbitrary and may be provided so as to surround the periphery of the Z scanner. 2 and 3, only one of the support blocks 80 and 81 may be provided, and the probe fixing member may be fixed to the support block in a cantilever manner. 2 and 3, the probe fixing member 70 may be cut at the center and divided into two cantilevered probe fixing members.
Furthermore, a probe fixing member supported at both ends as shown in FIGS. 2 and 3 and a probe fixing member supported at one end as shown in FIG. 4 may be used in combination.

  The force by which the probe fixing member presses the probe to the Z scanner is the force to return from the bent state to the original shape, the force to return from the compressed state to the original shape, or from the pulled state to the original shape. Or a force to return to the power supply or a combination of these forces. For example, in the example of FIG. 2, the probe fixing member, unlike the case of the cantilever beam, also generates tension inside due to bending, and this tension contributes to the pressing force of the probe.

When the probe fixing member is a plate spring, the plate thickness of the plate spring is not particularly limited. For example, about 200 to 400 μm is exemplified, and the spring constant of the plate spring acting portion (the portion pressing the probe) is exemplified. Is about 1 × 10 ⁵ to 1 × 10 ⁶ [N / m].
In order to press the base of the probe against the Z scanner, the force that should actually be applied to the probe can be pressed to the extent that it can press the probe against the Z scanner and prevent the probe from moving in the XY direction. Any power that can be used. Note that preventing the probe from moving in the XY directions can be achieved by a positioning member described later.
In the case of an atomic force microscope, the total weight of the cantilever tip is generally about several mg. For example, the total weight of the cantilever tip is 5 to 10 mg, the width of the base of the cantilever is 1.6 mm (an example of standard dimensions for maintaining compatibility), and the thickness is 0.3 to 0.5 mm. It is.
In order to keep such a cantilever chip pressed against the Z scanner even if the Z scanner vibrates at a high speed, and in order not to adversely affect the vibration of the Z scanner, when the probe fixing member is set, A preferable example is that the cantilever chip is pressed against the Z scanner with a force of about 5 to 50 N.
The spring constant of the probe fixing member can be appropriately adjusted in order to obtain the required pressing force by changing the material, cross-sectional shape, length, etc. of the probe fixing member.
The expansion / contraction stroke amount of the Z scanner is generally about 0.5 μm to several μm. Therefore, in view of the scale of the leaf spring such as a plate thickness of 200 to 400 μm, since the stroke of the leaf spring is less than 1% of the plate thickness, the return force of the spring varies greatly as the Z scanner expands and contracts. There is no.
In order for the probe fixing member to follow the resonance frequency of the Z scanner described above, the resonance frequency of the probe fixing member itself may be increased.

  When the probe fixing member is a leaf spring, as illustrated in FIG. 4, the end 72 may be curved to be an introduction portion so that the probe base can be easily inserted.

  A mechanism capable of adjusting the height may be added to the support block so that the pressing force of the probe fixing member can be adjusted. The support block may be provided with a structure that can hold and release the end of the probe fixing member with one touch.

In order to bring the probe fixing member and the probe (base of the cantilever) into contact with each other on a wider surface, there is elasticity and flexibility between them as illustrated in FIGS. 5 (a) and 5 (b). It is preferable to interpose a cushion member made of a material.
Examples of the material for the cushion member include natural rubber and synthetic rubber, and organic polymer materials having elasticity and flexibility such as acrylic modified silicone resin and epoxy resin.
The cushion member may be an independent member, but it is convenient for the probe attaching / detaching operation to be provided integrally with the probe fixing member or the probe. From the viewpoint that the probe is a replacement part, the cushion member is preferably provided integrally with the probe fixing member.
The cushion member may be layered as illustrated in FIG. 5 (a), may be discrete dot-shaped as illustrated in FIG. 5 (b), and other various types such as a lattice shape. It may be provided as a pattern. Further, the cushion member may be a composite member composed of a plurality of material layers in consideration of elasticity and flexibility characteristics.

  As shown in FIGS. 1 to 4 and 6, it is preferable that a positioning member 50 for positioning the probe is fixed to the Z scanner. The structure for positioning the probe is not particularly limited, and may be positioning by a projection and a hole or notch for receiving the projection. A hole or a notch may be provided in the probe, or a protrusion may be provided. In the example of FIGS. 6A and 6B, the positioning member 50 is provided with a groove 51 for positioning by positioning the base of the cantilever. The depth of the groove may be determined as appropriate so that the cantilever can be easily positioned. When the depth of the groove is larger than the plate thickness of the cantilever, the cantilever in the groove can be pressed by projecting the action portion of the probe fixing member.

The material of the positioning member is preferably a lighter material so as not to adversely affect the vibration of the Z scanner, and is preferably a material that is difficult to deform for positioning. Examples of such materials include light metals such as aluminum and aluminum alloys, and light and hard inorganic compounds such as Si and SiC.
The positioning member is preferably fixed to the Z scanner with an adhesive so as not to increase the mass. Further, a positioning groove may be provided directly on the lower surface of the Z scanner.

  The scanning probe microscope according to the present invention is not limited to an atomic force microscope, but may be any probe provided with at least a Z scanner on the probe side. Typical examples are scanning tunneling microscopes (which obtain images based on the tunnel current flowing between the probe and sample), scanning near-field optical microscopes (which obtain images based on the interaction between light and the sample) ), Scanning electrochemical microscope (similar to the configuration of scanning tunneling microscope, which obtains an image based on the electrochemical reaction between the probe and sample), scanning ion conduction microscope (micro glass electrode on the probe) And using a change in ion conduction caused by a change in the distance between the probe and the sample).

In this example, an atomic force microscope having the structure shown in FIG. 1 was manufactured, while a comparative product in which the base of the cantilever was fixed with an adhesive was manufactured, and the vibration characteristics of the Z scanner were compared.
[Example product]
As shown in FIGS. 1 and 2, in order to incline the cantilever 41, an angled positioning member 50 was prepared and fixed to the lower surface of the Z scanner (Z piezo) with an adhesive.
The material of the positioning member 50 is SiC. As shown in FIGS. 6A and 6B, a groove 51 for positioning by positioning the base portion of the cantilever was formed in the positioning member.
The total weight of the cantilever tip is 10 mg, the width of the base of the cantilever is 1.6 mm, and the thickness is 0.5 mm.
The upper base portion 11 is provided with support blocks 80 and 81 at two locations with the Z scanner interposed therebetween. A female screw was machined on the lower end surface of the support block so that a probe fixing member, which is a leaf spring, could be screwed. The lower end surface of the support block is an inclined surface having an angle according to the inclination angle of the positioning member.
The probe fixing member is a rectangular flat plate spring provided with holes for passing screws at both ends. The material of the leaf spring is stainless steel, the thickness is 0.4 mm, the distance between the centers of the holes for passing the screws is 6.6 mm, and the short side is 3.5 mm.
The cantilever chip 40 was mounted in the groove of the positioning member 50, covered with a probe fixing member and pressed, and both ends were fixed to the support block with screws.
The relative position between the lower surface of the support block and the lower surface of the cantilever mounted on the positioning member was adjusted so that the leaf spring did not exert a strong force that would reduce the vibration of the Z scanner through the cantilever.
A cushion member made of acryl-modified silicone resin was applied as a layer having a thickness of 200 to 300 μm to the working surface of the leaf spring (the surface in the region in contact with the cantilever). This is because the contact between the leaf spring and the cantilever is brought into contact with the surface. It is also for reducing excessive pressing by the leaf spring. This is because if the plate spring is pressed too hard, not only will the amount of displacement of the Z scanner be reduced, but also excessive vibration of the plate spring will likely cause harmful vibrations in the low frequency region.

[Evaluation]
FIG. 7A is a graph showing the vibration characteristics when the Z scanner is vibrated in a state where the cantilever chip is pressed against the Z scanner by the probe fixing member (plate spring) in the above-mentioned embodiment product. .
The horizontal axis is the frequency (drive frequency) of the signal for driving the Z scanner in a sine wave, the left vertical axis is the displacement (gain) of the tip of the cantilever tip at each drive frequency, and the right vertical axis is the drive of the displacement The phase with respect to the signal. A curve (Ia) in the graph indicates a gain, and a curve (Ib) indicates a phase.
The resonance frequency of the Z scanner itself with no load is 110 kHz, and the resonance frequency when the cantilever chip is pressed against the Z scanner by the probe fixing member is 104 kHz, which is the same as the original resonance frequency. It was not a drop that hindered the control at high speed.

[Comparative product]
An atomic force microscope was manufactured in the same manner as in the above example product, except that the cantilever was fixed to the positioning member with an adhesive without using the probe fixing member.

[Evaluation]
FIG. 7B is a graph showing vibration characteristics when the Z scanner is vibrated in the comparative example product. The vertical and horizontal axes of the graph are the same as those in the graph of FIG. A curve (IIa) in the graph indicates a gain, and a curve (IIb) indicates a phase.
The resonance frequency in the unloaded state of the Z scanner itself was 110 kHz as described above, and the resonance frequency when the cantilever chip was fixed with an adhesive was 100 kHz, which was the same as the original resonance frequency.

[Comparison between Example Product and Comparative Product]
FIG. 8 shows a graph obtained by superimposing the graph of FIG. 7A and the graph of FIG. 7B in order to compare the example product and the comparative product.
From the graph of FIG. 8, it is clear that there is almost no difference in vibration characteristics between fixing the cantilever tip with the probe fixing member and fixing the cantilever with the adhesive.
In addition, it was found that the cantilever tip can be easily attached to and removed from the Z scanner without applying excessive force to the Z scanner. Further, it was found that even when the Z scanner was scanned at high speed, another unintentional vibration was not generated on the cantilever side.

  According to the present invention, the probe can be detachably fixed to the scanner while suppressing an increase in mass on the probe side. As a result, for example, even a high-speed atomic force microscope that operates the probe side at a higher speed does not hinder the operation of the Z scanner, that is, without causing a decrease in resonance frequency or a decrease in displacement. The cantilever tip can now be easily attached and removed.

DESCRIPTION OF SYMBOLS 10 Lower base part 11 Upper base part 20 XYZ scanner 21 Z scanner 22 XY scanner 30 Stage 40 Cantilever tip 41 Cantilever 42 Minute protrusion needle 50 Positioning member 70 Probe fixing member 80 Support block

Claims (8)

Among the X scanner, Y scanner, and Z scanner, a scanning probe microscope in which at least the Z scanner is arranged on the probe side,
An elastically deformable probe fixing member is directly or indirectly fixed to the upper base portion which is a support base on the probe side,
The probe fixing member is elastically deformed and arranged to press the base of the probe against the Z scanner by its own restoring force while following the displacement of the Z scanner.
The scanning probe microscope.   The probe fixing member is fixed to the upper base part via a support block, and the support block adjusts the height difference between the upper base part and the Z scanner to an intended value. Therefore, the scanning probe microscope according to claim 1, which is fixed to the upper base portion. The upper base portion is provided with the support blocks at at least two positions with a Z scanner interposed therebetween, and the end portions of the probe fixing members are fixed to the support blocks, respectively. The central part of the fixing member presses the base of the probe against the Z scanner by its own restoring force.
The scanning probe microscope according to claim 2. In the upper base portion, the support block is provided at a necessary location,
One end of the probe fixing member is fixed to the support block, and the other free end of the probe fixing member presses the base of the probe against the Z scanner by its own restoring force. ,
The scanning probe microscope according to claim 2 or 3.   The scanning probe microscope according to claim 1, wherein the probe fixing member is a leaf spring.   The scanning probe microscope according to claim 1, wherein a cushion member made of a material having elasticity and flexibility is further interposed between the probe fixing member and the probe. A positioning member for positioning the probe is fixed to the Z scanner,
The scanning probe microscope according to claim 1, wherein the probe fixing member is disposed so as to press a base portion of the probe positioned by the positioning member against a Z scanner.   The scanning probe microscope according to any one of claims 1 to 7, wherein the scanning probe microscope is an atomic force microscope, and the probe is a cantilever tip having a cantilever and a protruding needle. .

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