JPH07181030A - Interatomic force microscope - Google Patents

Abstract

PURPOSE:To provide an interatomic force microscope which can measure the profile of a relatively large sample without sacrifice of measuring accuracy and in which the sample can be observed from above through the use of a built-in optical microscope. CONSTITUTION:A Y-axis moving means comprising a parallel spring 15, a multilayer piezoelectric element, etc., is combined with an actuator provided with a cantilever 3 at the forward end thereof and allowing biaxial movement of a tube scanner 5 or the like thus allowing movement of the cantilever 3 in three directions of X, Y and Z axes. A light source section 1 and a detecting section 6 constituting an optical lever are disposed on the outside of the Y-axis inching means and the actuator. This structure allows movement of the cantilever 3 itself. Furthermore, the tube scanner 5 is disposed while setting the axis thereof in parallel with the sample plane 7 and an optical microscope 20 is built in so that the sample 7 and the cantilever 3 can be observed simultaneously from directly above the cantilever 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improving the performance of an atomic force microscope, which is a type of scanning microscope for observing surface topography.

[0002]

2. Description of the Related Art As means for observing the surface shape of a sample,
Atomic force microscopes (hereinafter referred to as "AFM") are known. In this AFM, like a cantilever having a leaf spring shape, a probe provided at the tip of a flexible member is provided on the surface of a sample to be measured, relative to the sample. The surface shape of the sample is measured by moving, scanning, and measuring the amount of vertical displacement of the probe during scanning.

FIG. 3 shows an example of a configuration diagram of a conventional optical lever type AFM.

This AFM is provided with a flexible cantilever 31, a probe 32 provided at the tip of the cantilever 31, an actuator 33 for moving the sample in the XYZ directions, and a rear surface of the cantilever 31. A light source 36 for irradiating a laser beam on the reflecting surface 31a, and a laser beam is condensed (35) for irradiating a predetermined area with the laser beam.
Is a lens 41 for collecting laser light), a two-divided photodetector 37 including two light receiving portions for receiving the laser light reflected by the reflecting surface 31a, control of the operation of the actuator and the Z-axis direction. Control means 38 for performing processing for obtaining the shape of the sample based on the movement amount of the cantilever 31 of
The display means 39 for displaying the obtained surface shape, and an XYZ axis coarse movement stage 40 for moving the sample in the XYZ axis directions up to an area where the shape of a given sample can be measured are configured.

The cantilever 31, the light sources 36, 2
The split photodetector 37 and the lens 41 are fixed to a fixed portion.

Conventionally, the most commonly used actuator is a moving means called a tube scanner. As shown in FIG. 4, such a tube scanner divides and attaches four electrodes on the outer circumference of a cylindrical tube, which is manufactured using a material such as PZT, and moves in the XYZ3 directions. It is an enabled actuator.

Specifically, when the coordinate system is set as shown in FIG. 4, by applying voltages having the same magnitude but different signs to the electrodes 61a and 61b, scanning in the X-axis direction becomes possible, Similarly, by applying voltages having the same magnitude but different signs to the electrodes 62a and 62b, Y
Axial scanning is possible. Further, a common electrode 63 is provided on the inner circumference of the tube, and between the common electrode and all the electrodes 61a, 61b, 62a, 62b,
The tube can be expanded and contracted in the Z direction by applying a predetermined voltage. Therefore, the tube scanner shown in FIG. 4 functions as an actuator that moves the sample in the X, Y, and Z axis directions.

When observing the surface shape of the sample 34 placed on the actuator 33, the control means 38 is used.
The movement amount of the actuator in each axial direction is controlled by, and in a predetermined area on the XY plane on the sample surface,
The sample is moved relative to the probe to perform scanning for measuring the shape of the sample. By such scanning, a so-called atomic force acts between the probe and the sample, the cantilever 31 bends and the probe 32 is displaced in the Z-axis direction due to the magnitude of this force, and thus the amount of deflection of the cantilever is By scanning the sample while performing feedback control so as to be constant, the surface shape of the sample can be obtained corresponding to the feedback control amount. In order to keep the amount of bending of the cantilever constant, the light is emitted from the light source 36, is condensed by the lens 41, and is reflected by the reflecting surface 3 of the cantilever 31.
The laser light reflected by the laser beam 1a and reflected by the 1a is divided into two photodetectors 3
Light may be received at 7, and the movement amount of the actuator may be controlled so that the differential output from each light receiving unit becomes equal to control the sample to move in the Z direction.

The XYZ axis coarse movement stage 40 is not an essential means, but it is usually used for moving the sample 34 in the XYZ axis directions to an area where the shape of a given sample can be measured. Is provided.

Further, the light is emitted from the light source 36 and the lens 41
The optical system that receives the laser beam that has been condensed by the laser beam and is reflected by the reflection surface 31a of the cantilever 31 by the two-division photodetector 37 constitutes a so-called "optical lever". Atomic force microscopes that employ the system are also commonly referred to as "optical lever type". The light is
Specifically, the reflecting surface 31a of the cantilever 31 has a reflection angle that is twice the bending angle of the cantilever 31.
That is, the laser light is reflected from the laser.

A microscope having a structure in which the AFM is equipped with an optical microscope for observing the state of the sample and the position of the cantilever on the sample has also been proposed.

As a method of constructing the method, an optical microscope is provided directly above the cantilever, and the sample is observed from directly above the cantilever, or an optical microscope is provided obliquely to the bottom surface of the fixed portion, and the oblique direction is provided. , A method of observing a sample has been proposed.

[0013]

By the way, in the conventional optical lever type AFM, a sample is placed on an actuator and the sample itself is directly moved in the XYZ directions.

Therefore, a tube scanner manufactured using a piezoelectric material such as PZT (maximum diameter 30 (mm))
There is a limit to the size in manufacturing, and there is also a limit to the size of the sample that can be placed on the tube scanner. In addition, when a large sample is placed, the resonance frequency of the actuator is lowered and the resolution is lowered. That is, usually, the resonance frequency of the mechanical system is set to a high value so that it is less susceptible to the influence of disturbance and the measurement accuracy is improved. There is also a problem that the system becomes susceptible to the influence of disturbance due to the lower resonance frequency.

Further, in the case of a microscope having a structure in which the AFM is equipped with an optical microscope for observing the state of the sample and the position of the cantilever on the sample, an optical microscope is provided directly above the cantilever and directly above the cantilever. In the method of observing the sample from the direction, there is a constraint that a sufficient space for installing the optical microscope must be secured above the cantilever, and with respect to the bottom surface of the fixed part, the optical microscope is installed in an oblique direction, The method of observing a sample from an oblique direction has a drawback that the optical microscope cannot be focused on the entire surface of the sample at the same time because the sample is observed from an oblique direction.

That is, when the observation with the optical microscope is also used, it is advantageous to observe from directly above the cantilever in order to effectively obtain the information of the sample surface. , It was necessary to secure sufficient space for installing the optical microscope.

[0017]

In order to solve the above problems, the following means are considered.

That is, a cantilever having a probe for measuring the shape of a given sample, a light source, a lens for condensing light emitted from the light source, and a reflected light of the cantilever for the condensed light. A light receiver and a first displacement means that fixes the cantilever and can move the cantilever in two orthogonal directions, and a first displacement means that fixes the first displacement means and is orthogonal to the two-axis direction that is the movement direction of the cantilever. Do 1
Second displacement means capable of moving the first displacement means in the axial direction, and processing for giving a predetermined signal to the first and second displacement means to relatively move the probe and the sample. And a control means which corresponds to the output from the light receiver and at least performs a process of measuring the shape of the sample in response to a signal given to the first displacement means for making the amount of bending of the cantilever a predetermined amount. And an atomic force microscope configured to include a display unit for displaying at least the measured shape.

The first displacing means is composed of a tube scanner, and the second displacing means is composed of a parallel spring and a piezoelectric element for pressing the parallel spring. Alternatively, the first displacement means is preferably a tube scanner, and the second displacement means is preferably an atomic force microscope composed of a piezoelectric element.

Further, a structure in which an optical microscope and an objective lens for focusing the optical microscope on the cantilever are provided directly above the cantilever can be considered.

[0021]

According to the present invention, it is possible to move a Y-direction uniaxial fine movement means having a parallel spring, a laminated piezoelectric element and the like, and a cantilever at the tip end thereof in a biaxial direction such as a tube scanner. It is possible to move the cantilever in three directions of X, Y and Z by combining the actuators. And
A light source section and a detection section that constitute an optical lever are provided outside the Y direction uniaxial fine movement means and the actuator. This allows movement of the cantilever itself. Further, the tube scanner is arranged such that its central axis is parallel to the sample surface, and an atomic force microscope capable of simultaneously observing the sample and the cantilever from directly above the cantilever is provided by an optical microscope provided.

With the above construction, only the cantilever is attached to the tip of the tube scanner, and the weight is light and
The feedback control in the Z direction is possible under a certain amount of load.

The scanning of the probe with respect to the sample is performed by moving the probe itself on the XY plane. Therefore,
The restrictions on the size and weight of the sample to be measured are greatly reduced. Also, since the cantilever is placed at the tip of the tube scanner that extends parallel to the sample surface, a sufficient space for mounting an optical microscope can be secured around the cantilever, and the light source part that constitutes the optical microscope and the optical lever is secured. And the arrangement of the detection unit becomes easy.

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of the first embodiment of the present invention.

Reference numeral 7 is a sample whose shape is to be measured.

Reference numeral 3 denotes a cantilever having a probe at its tip, which is made of, for example, silicon or the like into a leaf spring shape. The back surface of the cantilever 3 is provided with a reflection surface that reflects light.

Reference numeral 5 is a tube scanner, the detailed construction of which is shown in FIG. 4 as described in the prior art. The tube scanner 5 can realize a moving mechanism of the cantilever 3 in the X and Z directions.

Reference numeral 1 is a light source for emitting a laser beam, which is realized by using, for example, a semiconductor laser.

Reference numeral 2 is for irradiating the reflection surface provided on the back surface of the cantilever 3 with the light emitted from the light source 1.
It is a condenser lens for condensing laser light.

Reference numeral 6 is a two-division photodetector for detecting the reflected light on the reflecting surface provided on the back surface of the cantilever 3. For example, it can be configured by a silicon photodiode.

Incidentally, FIG. 1B shows the arrangement of the light source 1, the lens 2 and the two-divided photodetector 6 as viewed from the Y-axis direction in FIG. 1A. Although FIG. 1A does not show the light source 1, the lens 2 and the two-divided photodetector 6, in reality, when viewed from the Y-axis direction, FIG.
The optical system as shown in (b) is fixed to the fixed portion 10. The laser light emitted from the light source 1 is condensed by the lens 2 and is reflected by the reflection surface provided on the back surface of the cantilever 3 provided at the tip of the tube scanner 5, and the reflected light is divided into two parts. An optical system that receives light by the detector 6 is formed and constitutes a so-called optical lever. The optical lever is formed inside the extra space outside the tube scanner 5. For measuring the shape of the sample, the cantilever 3 should always be used so that the reflected light can be obtained.
The laser beam needs to be irradiated on the reflection surface provided on the back surface of the.

Reference numeral 17 is a piezoelectric element, and 15 is a parallel spring. For the piezoelectric element 17, for example, a laminated piezoelectric element made of PZT or the like and having piezoelectric materials arranged in a laminated manner may be used. When a predetermined voltage is applied to the piezoelectric element 17 from the control circuit, the piezoelectric element 17 is pressed in the Y-axis direction, and the parallel spring 15 is moved in the Y-axis direction by the pressing. Therefore, the cantilever 3 provided at the tip of the tube scanner 5 provided on the parallel spring 15 moves in the Y-axis direction. In this way, by applying a predetermined amount of voltage to the piezoelectric element 17, the cantilever 3
Can be moved in the Y-axis direction by a predetermined amount. That is, with the configuration having the parallel spring 15 and the piezoelectric element 17, a moving mechanism in the Y-axis direction can be realized.

FIG. 6A shows how the parallel spring 15 is displaced. In the figure, a is a fine movement side of the parallel spring, b is a fixed side of the parallel spring, and b is fixed to the fixing portion 10.

When a force is applied in the Y-axis direction, the parallel spring is deformed into a shape shown by a dotted line. Therefore, by providing the parallel spring 15 with the tube scanner 5 and providing the cantilever 3 at the tip thereof, a mechanism for moving the cantilever 3 in the Y-axis direction can be realized.

Reference numeral 9 denotes an XYZ stage, which is a means for moving the sample 7 mounted on the fine movement mechanism to an area where the shape can be measured, and is a commercially available optical moving stage. Can be configured using. This means is not essential, but it is preferable to have it.

Reference numeral 11 denotes a control circuit, which is a means for performing at least the following processing, such as a CPU, a ROM (a program for performing a predetermined processing is stored in advance), a RAM,
It is realized by various electronic devices such as CMOS.

First, a process of applying a predetermined drive voltage to the tube scanner 5 to move the cantilever 3 in the X and Z directions.

Next, it is a process of transmitting a predetermined signal for moving the cantilever 3 in the Y-axis direction. Specifically, the predetermined voltage is applied to the piezoelectric element 17 as described above.

Further, the two-divided photodetector 6 receives the reflected light from the cantilever 3 and controls the moving amount of the tube scanner 5 so that the differential output from each light receiving section becomes equal, that is, the cantilever. While performing feedback control so that the deflection amount of No. 3 becomes constant, processing for obtaining the surface shape of the sample 7 corresponding to the feedback control amount is performed.

A display device 12 has a function of displaying at least the shape information of the sample 7 detected by the control circuit 11, and is realized by, for example, a CRT, an EL display, or a liquid crystal display.

Reference numeral 10 denotes a fixing portion, which is a means for fixing the light source 1, the lens 2 and the two-divided photodetector 6, and further fixing the XYZ stage 9 to the lower part thereof. For example, a metal material or the like that has been subjected to rust prevention processing may be used and designed and manufactured to have a desired shape.

Reference numeral 20 is an optical microscope, and reference numeral 18 is an objective lens for focusing on the sample 7. The optical microscope 20 is fixed to the fixing portion 10 as shown in FIG.
The sample 7 can be observed from above.

It is understood that the optical microscope is attached to the fixed portion 10 with a sufficient spatial margin.

Further, the fine movement side of the parallel spring 15 driven by the piezoelectric element 17 (in the figure, a is the fine movement side of the parallel spring, and b is the fine movement side).
Is the fixed side of the parallel spring) and the tube scanner 5
It is preferable that the tube scanner 5 is fixed so that the central axis of is parallel to the sample surface, and the cantilever 3 is provided at the lower end of the tip.

Feedback control in the Z direction and one of scanning in the XY plane (generally, scanning with a higher scanning speed: when two-dimensional raster scanning is performed, the scanning speed in one direction is high and the other is The scanning speed in the direction of is slow)
The other operation of the in-plane scanning (that is, the scanning with the slower speed) may be performed by the operation of the tube scanner with the parallel spring.

Further, if an attempt is made to obtain a large displacement amount in the central axis direction of the tube scanner, the tube scanner becomes very long, but since the displacement in that direction is performed by the parallel spring, such a problem is caused. Does not happen.

As an example, "outer diameter 7 (mm), inner diameter 5"
(Mm), length 30 (mm) ", the displacement of about 25 (μm) can be obtained in the bending direction by the applied voltage of ± 250 (V), while the central axis In the direction, with an applied voltage of 500 (V), only a displacement of about 4 (μm) can be obtained.

On the other hand, in the case of a laminated piezoelectric element having a size of “5 × 5 × 18 (mm)”, for example, 1
A displacement of about 15 (μm) can be obtained with an applied voltage of 00 (V), and a displacement of about 30 (μm) can be obtained by enlarging the displacement with a double leverage ratio (mechanical lever ratio) with a parallel spring. Will be obtained.

This will be described with reference to FIG. 6 (b). It is assumed that a force in the Y-axis direction acts on the parallel spring as shown in the figure. The point of action of the force is assumed to be the midpoint of one side e of the parallel spring. At this time, the parallel spring is deformed as shown by the dotted line. Since the force acts on the midpoint of one side e of the parallel spring, it can be seen that the displacement amount d shown in the figure is twice the displacement amount c. Therefore, as described above, the parallel spring can be used to magnify the displacement with a double lever ratio (mechanical lever ratio).

Further, since the tube scanner is used so as to utilize only the biaxial bending operation, it is large in the central axis direction as in the general usage of the triaxial operation.
When the tube is displaced, the defect that the displacement amount in the bending direction is limited does not occur.

The operation will now be described with reference to FIG.

First, the user mounts the sample 7 on the XYZ stage and uses the XYZ stage 9 to
The sample 7 is moved in a three-dimensional direction to a position where the shape of the sample 7 can be measured. Since the optical microscope 20 for observing the cantilever 3 and the sample 7 is arranged in the space immediately above the cantilever, the user can use this to mount the sample properly, that is, the sample 7 It is possible to perform the setting work of the sample 7 while confirming whether or not the position of the sample with respect to the cantilever 3 is appropriate, and the operability of the device is improved.

When the operation of the equipment is started, the control circuit 11 gives a predetermined signal to the tube scanner 5 and the piezoelectric element 17 as described above.

The probe provided at the tip of the cantilever 3 starts scanning the sample 7 in the X and Y axis directions.
Then, the control circuit 11 moves the tube scanner 5 in the Z-axis direction so that the differential outputs from the respective light receiving portions corresponding to the reflected light from the cantilever 3 received by the two-division photodetector 6 become equal. The amount of the cantilever is controlled, that is, the deflection of the cantilever is controlled to be constant, and the surface shape of the sample 7 corresponding to the feedback control amount is obtained while performing feedback control.

The sample is scanned by, for example, a raster scan. Then, in the raster scan, the tube scanner 5 performs scanning in a direction with a high scanning speed (X direction in this embodiment), and a direction with a low scanning speed (Y direction in this embodiment) orthogonal to the X direction. )
The scanning is performed by a moving mechanism including a piezoelectric element 17 and a parallel spring 15. Therefore, high-speed scanning can be realized without being affected by the size and weight of the sample 7 placed on the XYZ stage 9.

The shape measured by the above scanning is displayed on the display device 12, and the shape measurement of the sample 7 is completed.

The laser light emitted from the light source 1 is
Even if the cantilever 3 is moved by scanning after being focused by the lens 2, the irradiation area of the laser light is always so that the reflected light from the reflecting surface of the cantilever 3 can be obtained.
The light source 1 and the lens 2 must be set so as to have a width equal to or larger than a predetermined value. This state is shown in FIG. As shown in FIG. 4, the light source 1 and the lens 2 must be set so that the scanning range of the cantilever exists within the laser spot on the cantilever.

As described above, according to the first embodiment, it is possible to provide an atomic force microscope capable of measuring the shape of a relatively large sample, and the optical microscope installed above the cantilever enables the sample to be measured. You can check the placement status of
Operability is also improved.

FIG. 2 is a block diagram of the second embodiment of the present invention.

The difference between this embodiment and the first embodiment is that instead of the moving means in the Y-axis direction composed of the combination of the piezoelectric element 17 and the parallel spring 15 shown in the first embodiment, a laminated piezoelectric element is used. The piezoelectric element 21 such as an element realizes a moving means in the Y-axis direction.

The components designated by the same reference numerals as in FIG. 1 may be considered to be completely the same as those in FIG. Also in this embodiment, although not shown, the optical system is arranged as shown in FIG. 1B when viewed from the Y-axis direction. Of course, the constituent elements of the optical system may be realized by the same ones as in the first embodiment.

In this embodiment, the piezoelectric element 21 enables the cantilever 3 to move in the Y-axis direction. As the piezoelectric element 21, for example, it is preferable to use a laminated piezoelectric element configured by arranging materials such as PZT in a laminated shape.

The tube scanner 5 is fixed to the side where the piezoelectric element 21 is displaced (the opposite side is fixed as shown in FIG. 2) so that its central axis is parallel to the sample surface,
Further, the cantilever 3 is attached to the tip of the tube scanner 5.
It is a configuration provided with.

When the control circuit 11 applies a predetermined voltage to the piezoelectric element 21, the piezoelectric element 21 is displaced in the Y direction and the tube scanner 5 is moved in the Y direction. Then, the cantilever 3 provided at the tip of the tube scanner 5 can be scanned in the Y direction.

In the present embodiment, as described above, the scanning of the cantilever 3 in the Y direction is realized by the piezoelectric element 21,
The tube scanner 5 performs scanning in the X direction and feedback control in the Z direction.

The other operations and the like are exactly the same as those in the first embodiment, and therefore a duplicate description will be omitted.

As described above, also according to the second embodiment, it is possible to provide the atomic force microscope capable of measuring the shape of a relatively large sample, and the optical microscope provided above the cantilever can be used to measure the sample. You can check the mounting status and improve operability.

The moving mechanism described in the above embodiment is
Needless to say, the present invention can be applied not only to the atomic force microscope but also to various other observation devices.

[0070]

According to the present invention, a three-axis fine movement mechanism having a cantilever is constructed, and the feedback control and XY scanning can be performed under a light weight and a constant load, and a relatively large sample can be obtained. The shape of can be measured. Also,
Since the cantilever is placed at the tip of the tube scanner that extends parallel to the sample surface, it is possible to secure a sufficient space around the cantilever where an optical microscope can be installed, and the light source that constitutes the optical microscope and the optical lever can be detected. The layout of the parts becomes easier and the degree of freedom in design increases.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a conventional atomic force microscope.

FIG. 4 is a configuration diagram of a tube scanner used in a conventional atomic force microscope.

FIG. 5 is an explanatory diagram of a relationship between a laser light irradiation region and a moving region of a cantilever.

FIG. 6 is an explanatory diagram of displacement of a parallel spring.

[Explanation of symbols]

1 ... Light source, 2 ... Lens, 3 ... Cantilever, 5 ... Tube scanner, 6 ... Two-part photodetector, 7 ... Sample, 9 ... XY
Z stage, 10 ... Fixed part, 11 ... Control circuit, 12 ... Display device, 15 ... Parallel spring, 17 ... Piezoelectric element, 18 ... Objective lens, 20 ... Optical microscope, 31 ... Cantilever, 32
... probe, 33 ... actuator, 36 ... light source, 41 ... lens, 37 ... two-part photodetector, 38 ... control means, 39 ...
Display means, 40 ... XYZ axis coarse movement stage

Claims (10)

[Claims] 1. A cantilever having a probe for measuring the shape of a given sample, a light source, a lens for condensing light emitted from the light source, and a reflected light of the cantilever for the condensed light. A first light receiving device, which fixes the cantilever and can move the cantilever in two orthogonal directions.
Displacing means, and second displacing means that supports the first displacing means and is capable of moving the first displacing means in one axial direction orthogonal to the two axial directions that are the moving directions of the cantilever, Corresponding to the process of giving a predetermined signal to the first and second displacement means to relatively move the probe and the sample, and the output from the light receiver, the bending amount of the cantilever is set to a predetermined amount. Atom configured to have at least a process for measuring the shape of the sample in response to a signal given to the first displacement means and a display means for displaying at least the measured shape. Force microscope. 2. The first displacing means according to claim 1, wherein the first displacing means comprises a tube scanner, and the second displacing means comprises a parallel spring and a piezoelectric element for pressing the parallel spring. Atomic force microscope characterized in that 3. The tube scanner according to claim 2, wherein the central axis of the tube scanner is fixed to a displacement side of the parallel spring so that the central axis is parallel to the sample surface, and the cantilever is a tip of the tube scanner. An atomic force microscope characterized by being provided at the bottom. 4. The lens according to claim 1, wherein the lens includes an area including a displacement area of the cantilever as an irradiation area of light from the light source.
An atomic force microscope characterized by collecting light. 5. An atom according to any one of claims 1, 2, 3 and 4, further comprising coarse moving means for placing a sample and allowing the sample to move in three axial directions. Force microscope. 6. The atomic force microscope according to claim 1, wherein the first displacement means is a tube scanner, and the second displacement means is a piezoelectric element. 7. The tube scanner according to claim 6, wherein the center axis of the tube scanner is fixed to a displacement end of the piezoelectric element so that the center axis is parallel to the sample surface, and the cantilever is a tip of the tube scanner. An atomic force microscope characterized by being provided at the bottom. 8. The atomic force microscope according to claim 2, wherein the piezoelectric element is a laminated piezoelectric element. 9. The optical microscope according to any one of claims 1, 2, 3, 4, 5, 6, 7 and 8, wherein an optical microscope and an objective lens for focusing the optical microscope on the cantilever are provided directly above the cantilever. Atomic force microscope characterized in that 10. A sample table on which a given sample is placed, a probe for measuring the sample, a first displacement means for fixing the probe and capable of moving the probe in two orthogonal axis directions, An observing device configured to support one displacing means and have a second displacing means capable of moving the first displacing means in a uniaxial direction orthogonal to the biaxial direction which is a moving direction of the probe .