JPH0493602A - scanning tunneling microscope - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a scanning tunneling microscope, and more particularly to a scanning tunneling microscope having a structure that increases the resolution of three piezo elements for a fine movement mechanism.

[Conventional technology]

In a scanning tunneling microscope (hereinafter referred to as STM),
With a tunnel current flowing between the probe and the sample, the probe is scanned in the X and X directions along the surface of the sample so that the tunnel current remains constant, and A fine movement mechanism is used as a means for following the unevenness and moving in two directions. Conventional fine movement mechanisms in STM typically use piezo tribods that utilize piezo (piezoelectric) elements as actuators to generate required displacements. A typical structure of a piezo tribod is that x and y are orthogonal to each other.

The device is equipped with three piezo elements that generate minute movements in each of the two directions, and one end of these piezo elements that are close to each other is connected to the probe holder, and the other end of each piezo element is connected to the tri-bod base. Was. The probe is attached to a surface of the probe holder opposite to the surface to which the two-way piezo element is coupled. In addition, the inchworm mechanism is discussed in Review of Scientific Instruments, April 60, 1989, pp. 789 to 791, regarding the coarse movement mechanism that brings the probe close enough to allow tunneling current to flow. It is being

This inchworm mechanism includes, for example, a piezo element as an actuator for making coarse movements in two directions, a front leg close to the sample side and a hind leg fixed to each end of the piezo element, and a front leg and a hind leg fixed to each end of the piezo element. and a clamp mechanism for fixing it at an appropriate timing.

[Problem to be solved by the invention]

In the arrangement structure of piezo elements in the x, y, and z directions in the conventional STM fine movement mechanism, for example, when the piezo elements in two directions, which finely move the probe by following the unevenness of the sample surface, are extended, the sample surface is Because each piezo element in the x and y directions must be bent while scanning, the piezo elements in the Due to the structure, the same can be said of the piezo elements in the X direction and the X direction due to the structure.

In addition, in the conventional inchworm mechanism, which is a coarse movement mechanism, the amount of extension of the two-way piezo element of the fine movement mechanism is set to an appropriate value so that the probe can quickly follow the inclination, temperature, and mechanical drift of the sample. Therefore, when the two-way piezo element goes out of its operating range, the piezo element between the front and rear legs adjusts the distance between the probe and the sample so that it falls within the operating range. clamp and hold the front foot unclamped. Therefore, the front legs are in a floating state, and the mass as a vibrating element is large, so the natural frequency of the system consisting of the fine movement mechanism fixed at the front legs and the inchworm is low, which allows the probe to scan at particularly high speeds. When attempting to do so, it could not be tracked, resulting in a decrease in resolution during measurement.

In view of the above problems, an object of the present invention is to provide an STM equipped with a fine movement mechanism and a coarse movement mechanism with high measurement resolution.

[Means to solve the problem]

In order to achieve the above object, the scanning tunneling microscope according to the present invention has the following features.

A first scanning tunneling microscope according to the present invention includes a probe, brings the probe close to a sample to a distance that allows tunneling current to flow, and moves the probe using a fine movement mechanism to scan the surface of the sample. In a scanning tunneling microscope, a fine movement mechanism includes piezo elements in a first direction and a second direction that two-dimensionally scans the surface of a sample, and a probe, and sets the distance between the sample and the probe to the distance through which tunneling current flows. one end of the piezo element in the first direction and the second direction is fixed to the base, the other end is fixed to the connecting member, and one end of the piezo element in the third direction is fixed to the base; is fixed to the surface of the connecting member facing the sample.

A second scanning tunneling microscope according to the present invention includes a probe, brings the probe close to the sample to a distance that allows tunneling current to flow, and moves the probe using a fine movement mechanism to scan the surface of the sample. In a scanning tunneling microscope, the fine movement mechanism includes pinigi elements in the first and second directions that scan the surface of the sample two-dimensionally, and a probe, and sets the distance between the sample and the probe to the distance through which tunneling current flows. One end of the piezo element in the first direction and the second direction is fixed to the base, the other end is fixed to the connecting member, and the piezo element in the third direction is held. One end was fixed to the surface of the connecting member facing the sample, and another piezo element for adjusting the probe position in the third direction was provided between the surface of the connecting member opposite to the surface facing the sample and the base. It is characterized by

A third scanning tunneling microscope according to the present invention includes a probe;
It is equipped with a coarse movement mechanism that brings the probe close to the sample to a distance that allows tunneling current to flow, and a fine movement mechanism that moves the probe to scan the surface of the sample. It consists of two legs, a piezo element that connects these two legs, and a clamp mechanism for each leg, and during measurement, the leg farthest from the sample is in a clamped state, and the leg closest to the sample is in an unclamped state, In a scanning tunneling microscope whose fine movement mechanism has three piezo elements orthogonal to each other,
Among the three piezo elements of the fine movement mechanism, one end of the first and second direction piezo elements that two-dimensionally scan the surface of the sample is fixed to the base of the coarse movement mechanism on the side closer to the sample. and the other end is fixed to the connecting member, and one end of the piezo element in the third direction, which has a probe and maintains the distance between the sample and the probe at a distance through which tunneling current flows, is connected to the surface of the connecting member facing the sample. It is characterized by being fixed at.

A fourth scanning tunneling microscope according to the present invention includes a probe;
It is equipped with a coarse movement mechanism that brings the probe close to the sample to a distance that allows tunneling current to flow, and a fine movement mechanism that moves the probe to scan the surface of the sample. It consists of two legs, a piezo element that connects these two legs, and a clamp mechanism for each leg, and during measurement, the leg farthest from the sample is in a clamped state, and the leg closest to the sample is in an unclamped state, In a scanning tunneling microscope whose fine movement mechanism has three piezo elements orthogonal to each other,
Of the three piezo elements of the fine movement mechanism, one end of each of the piezo elements in the first and second directions, which two-dimensionally scans the surface of the sample, is fixed to the foot of the coarse movement mechanism on the side closer to the sample. One end of a third-direction piezo element is fixed to the base, the other end is fixed to the connecting member, and is provided with a probe and maintains the distance between the sample and the probe at a distance through which tunneling current flows, and one end of the piezo element is attached to the sample of the connecting member. The present invention is characterized in that a shaft member is fixed to the facing surface and is disposed between the connecting member and the base to restrain the positional change of the probe in the third direction.

A fifth scanning tunneling microscope according to the present invention includes a probe;
It is equipped with a coarse movement mechanism that brings the probe close to the sample to a distance that allows tunneling current to flow, and a fine movement mechanism that moves the probe to scan the surface of the sample. In a scanning tunneling microscope in which the fine movement mechanism has three piezo elements orthogonal to each other, the fine movement mechanism consists of two legs, a piezo element that connects these two legs, and a clamp mechanism for each foot. Among the three piezo elements, one end of the piezo elements in the first direction and the second direction, which two-dimensionally scan the surface of the sample, is fixed to a base fixed to the foot of the coarse movement mechanism on the side closer to the sample. The other end is fixed to the connecting member, and one end of a third direction piezo element having a probe and maintaining the distance between the sample and the probe at a distance through which a tunneling current flows is fixed to the surface of the coupling member facing the sample. , a piezo element for adjusting the distance in the third direction is disposed between the base and the connecting member, and the leg on the side closer to the sample is in a clamped state during measurement.

A sixth scanning tunneling microscope according to the present invention includes the fifth scanning tunneling microscope.
In this configuration, the distance adjustment piezo element performs distance adjustment when the distance between the probe and the sample exceeds the movable range of the fine movement piezo element in the third direction.

A seventh scanning tunneling microscope according to the present invention includes a probe;
A scanning tunneling microscope is equipped with a coarse movement mechanism that brings the probe close to the sample to a distance that allows tunneling current to flow, and a fine movement mechanism that moves the probe to scan the surface of the sample. The probe is characterized in that it is equipped with a movement mechanism that moves the probe by a distance shorter than the coarse movement mechanism that moves the needle.

An eighth scanning tunneling microscope according to the present invention includes the seventh scanning tunneling microscope.
In this configuration, the probe is moved by a coarse movement mechanism until a tunneling current flows, and after the tunneling current occurs, the probe is retreated to a predetermined distance, and then the moving mechanism is moved again to a distance where a tunneling current flows. It is characterized in that the fine movement mechanism is operated in the state.

[Effect]

In the scanning tunneling microscope according to the present invention, it is assumed that the scanning tunneling microscope has piezoelectric elements for fine movement in each of three directions perpendicular to each other, and the probe is moved between the three piezoelectric elements to detect the irregularities on the surface of the sample. The piezo element in the direction of movement following the scanning piezo element is configured to operate in an unloaded state without bending the piezo element for scanning.

Similarly, the scanning piezo element is configured to operate without bending the sample surface tracking piezo element.

The scanning tunneling microscope according to the present invention is provided with a moving mechanism for distance adjustment that can move a distance shorter than that of the coarse moving mechanism, and the front and rear legs of the coarse moving mechanism can be clamped during measurement. I made it. This increases the natural frequency of the system, enables high-speed scanning, and increases the resolution of 87M measurements.

〔Example〕

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

FIG. 1 shows a side view of a first embodiment of the STM according to the invention. In Figure 1, 1 is 87M base and 87M
The base 1 has two surfaces 1a and 1 arranged perpendicularly to each other.
b. A sample stage 2 is installed on the surface 1a, and the sample stage 2 includes an X stage 3, a cross roller bearing 4 that guides it, and an X stage 5.
and a cross roller bearing 6 that guides it. The X stage 3 is movable in the X direction (direction perpendicular to the paper plane in Figure 1), and the X stage 5 is movable in the y direction (plane 1
It is movable in the inclination direction of a; the X direction and the y direction are perpendicular to each other. A description of the configuration of the movable mechanisms of the X stage 3 and the X stage 5 will be omitted. A holder stand 7 is arranged on the upper surface of the X stage 5, and a holder 9 to which a sample 8 is attached by adhesive is fixed on the holder stand 7 by a presser spring 1o.

On the other hand, on the surface 1b of the 81M stage 1, components of the STM including a probe, its fine movement mechanism, coarse movement mechanism, etc. are installed. A probe 11 is arranged perpendicularly to the surface of the sample 8, and the probe 11 is fixed to a probe holder 13 with a screw 12. 14 and 15 are the legs of an inchworm, which is a coarse movement mechanism for bringing the probe 11 close to the sample 8 to a distance where a tunnel current is generated between the sample 8 and the probe 11;
It is located at b. Paw 14 is the front paw near sample 8, Paw 1
5 is the hind leg farthest from sample 8. The inchworm moves as follows by a mechanism of front legs 14 and hind legs 15. A voltage is applied to the piezo actuator 16 so as to overcome the spring 17, the clamper 18 is extended, and the clamper 1 is moved from the foot 14.
Release 8 to unclamp. As for the leg 15, the voltage of the piezo actuator 22 of the clamper 19 is turned off and the leg 15 is pulled back by the spring 21 to be in a clamped state. In this state, when a voltage is applied to the piezo actuator 22 connecting the front leg 14 and the rear leg 15, the piezo actuator 22 extends. Next, the mechanism of the front leg 14 is switched to the clamp state, the mechanism of the rear leg 15 is switched to the unclamped state, and the voltage of the piezo actuator 22 is turned off, so that the front leg 14 and the rear leg 15 each move one step forward. By repeating the above operation control, the inchworm can move forward, and this forward movement allows the probe 11 disposed at the upper front end of the inchworm to approach the sample 8 with a large displacement.

Furthermore, the inchworm can move backward by controlling the respective mechanisms of its front legs 14 and hind legs 15 in opposite ways. Note that the front legs 14 and the hind legs 15 are guided by grooves 23 formed in the surface 1b to move.

Next, the configuration of the fine movement mechanism will be explained based on FIGS. 1 and 2. FIG. 2 is a front view of the fine movement mechanism seen from the line -U in FIG. 1. A tri-bod base 24 is attached to the front leg 14.

One end of each piezo element 26.27 for scanning the probe 11 on the surface of the sample 8 in the X direction and in the X direction is connected to the tribod base 24, and the piezo element 26.27
The other end is connected to a tri-body head 25. In this way, the piezo element 26.2 is mounted on the tri-body base 24.
A tri-bod head 25 supported by 7 is disposed. The piezo elements 26 and 27 are orthogonally arranged.

One end of a piezo element 28 that moves slightly in two directions, that is, by causing the probe 11 to follow the irregularities on the surface of the sample 8, is attached to the surface of the tri-bod head 25 facing the sample 8 by adhesive or the like. The aforementioned probe holder 13 is fixed to the other end of the piezo element 28. The probe 11 attached to the probe holder 13 faces the surface of the sample 8 at right angles.

Through the above steps, a piezo tribod is formed, and this piezo tribod has a fine movement mechanism for moving the probe 11 so as to scan along the surface of the sample 8 while maintaining a predetermined interval, thereby creating an STM image. operates as The piezo element 28 moves the probe 11 toward or away from the sample 8 so as to follow the unevenness of the sample surface. The two piezo elements 26 and 27 are used to scan the probe 11 over the surface of the sample 8. When creating an STM image, the probe 11 may deviate from the operable range of the piezo element 28 for two-direction fine movement due to the inclination, temperature, or mechanical drift on the surface of the sample 8. In consideration of this situation, the inchworm's front legs 14 are held in an unclamped state and its hind legs 15 are held in a clamped state, and by adjusting the drive voltage applied to the piezo element 22 that connects the front legs 14 and hind legs 15, It is configured so that the distance between the probe 11 and the sample 8 can be readjusted to a predetermined value.

The above-mentioned 87 equipped with sample stage 2 and STM components
The M base 1 is installed on a base 32 via three metal plates 29 and 30° 31. Beige 32, metal plate 29
~31.87M A rubber member 3 is installed between each of the bases 1 for the purpose of preventing vibrations from being transmitted to the base 32 from the outside.
3 is interposed.

According to the above configuration, the piezo element 28 for fine movement in two directions and the piezo element 26, 27 for fine movement in the X direction and the X direction have a structure that does not affect each other.
can be operated in an unloaded state without bending the scanning piezo elements 26 and 27, which improves tracking of the uneven shape of the surface of the sample 8 and improves the measurement resolution in two directions. Similarly, scanning in the x and X directions can be performed without bending the piezo elements 28 in the two directions, so that the resolution in the X and X directions is also improved.

At the time of STM measurement, the front legs 14 of the inchworm are in an unclamped state, and the front legs 14 are slightly separated from the surface 1b. Therefore, the piezo element 22 for coarse movement, which has low rigidity, acts as a spring, and a vibration system whose masses are the front leg 14 and the piezo tribod is constructed. However, in the configuration according to this embodiment, since the piezo elements 28 in two directions are not attached to the tri-body base 24, the tri-body base 24 can be made smaller and lighter in diameter, and the natural frequency of the system can be increased. Even if you scan at high speed,
The resolution in each direction of y and z can be improved.

Next, a modified embodiment of the piezo tribod will be described based on FIG. Reference numeral 14 denotes the front legs of the inchworm, and a tri-bod base 24 is attached to the front end thereof, and piezo elements 26 and 27, a tri-bod head 25, a piezo element 28, a probe holder 13, a probe 11, etc. are as follows.
The configuration is similar to that of the previous embodiment. An L-shaped connecting member 41 is fixed to the back side of the tri-body base 24, and the connecting member 41 is integrated with the tri-body base 24. The connecting member 41 can also be formed integrally with the tri-body base 24 using the same material. A Z-direction shaft member 42 is fixed between the tip of the connecting member 41 and the tri-body head 25. In the figure, the left end of the shaft member 42 is attached to the surface opposite to the surface of the tri-bod head 25 to which the piezo element 28 for fine movement in two directions is attached. Further, a constricted portion 42a is formed at the right end of the shaft member 42 in the drawing.

The above configuration is suitable for wide area measurement with a large scanning range in the X and y directions. In order to increase the scanning range, it is usually necessary to increase the lengths of the piezo elements 26 and 27 in the X and Y directions. If the lengths of the piezo elements 26 and 27 in the X and Y directions are increased, the processing of the tri-bod head 25, etc.
Due to assembly accuracy, when the probe 11 scans in the x and y directions, the displacement in two directions becomes large, so the shaft member 42 restrains the displacement in the two directions. Due to the structure in which the constricted portion 42a is provided, the shaft member 42 has a structure that is easy to bend around the right end, and the piezo elements 26 and 27 in the X direction and the y direction have a large load and can easily extend. . According to the configuration of this embodiment, it is possible to perform wide-area measurement, and at the same time
, z can be improved.

In addition, in the structure of this embodiment, since the connecting member 41 is provided, the piezo tribod becomes heavier and the natural frequency becomes lower, but in the case of wide area measurement, scanning is performed at a low speed, so
The decrease in resolution due to the decrease in natural frequency is extremely small.

FIG. 4 shows the configuration of another embodiment of the present invention. The configuration shown in FIG. 4 is mostly the same as the configuration shown in FIG. 1, and the same elements are given the same reference numerals. In this embodiment, the structure of the piezo tribod part is particularly changed.

As in each of the previous examples, the inchworm's front legs 1
Piezo elements 26 and 27 in the X direction and the y direction are arranged on the tri-bod base 24 to which No. 4 is attached, and the tri-bod head 25 is further arranged on the piezo elements 26 and 27. The surface of the tri-bod head 25 facing the sample 8 has two
Directional fine movement piezo element 28, probe holder 13, probe 11
etc. are assembled. Further, an L-shaped connecting member 51 is fixed to the back surface of the tri-bod base 24 facing the sample 8, and a distance adjusting member that expands and contracts in two directions is provided between the connecting member 51 and the tri-bod head 25. Piezo element 52
will be placed.

In the above configuration, the front legs 14 of the inchworm, which is the coarse movement mechanism,
The distance between the probe 11 and the sample 8 is adjusted by controlling the clamping and unclamping of the hind legs 15 and the expansion/contraction operation of the piezo actuator 22, and the probe 11 is brought close to the sample 8 until a tunneling current flows. . After a predetermined amount of tunnel current has flowed, the voltage applied to the piezo actuator 22 is lowered, and the front leg 14 is moved back to a predetermined position and clamped. Next, a voltage is applied so that the amount of elongation of the piezo element 28 for two-direction fine movement is maximized, and in this state, the drive voltage of the piezo element 52 for distance adjustment is further increased, and the probe 11
The probe 11 is brought close to the sample 8 until a tunnel current flows between the sample 8 and the sample 8. Thereafter, the voltage applied to the piezo element 52 is further increased, and the piezo element 52 is expanded. At this time, the contraction of the fine movement piezo element 28 is controlled so that the tunnel current is kept constant in accordance with the expansion of the piezo element 52. In this control state, when the amount of elongation of the piezo element 28 for fine movement in the Z direction reaches approximately half, that is, approximately the middle value of the operating range of the piezo element 28, the piezo element 5
The applied voltage of 2 is set to 0, and in this state, the operation of the scanning piezo elements 26 and 27 in each direction of x and y is started, and the STM
Create a statue.

According to the above configuration, similarly to each of the embodiments described above, the piezo element 28 for fine movement in the Z direction can be operated with no load without bending the piezo elements 26 and 27 for scanning in the x and y directions. Therefore, the ability to follow the surface shape of the sample 8 is improved, and the resolution in the Z direction is improved. Furthermore, since the piezo element 52 for adjusting the distance in the Z direction is provided, it is possible to measure 87M while holding the front legs 14 of the inchworm in a clamped state, and the reduction in the natural frequency of the system caused by the piezo actuator 22 can be avoided. can be eliminated and maintained at a high natural frequency. As a result, high-speed scanning becomes possible, especially the X during high-speed scanning.

The resolution in both the y and z directions can be improved. When measuring surface topography at the atomic level or one order of magnitude larger, particularly high-speed scanning is required to avoid the effects of temperature drift.

In this case, the scanning range in the X direction and the y direction is small, and therefore piezo elements 26 and 27 with short lengths in the expansion and contraction directions are used. On the other hand, Tripod Head 25
Since the piezo element 52 for distance adjustment in two directions disposed between the connecting member 51 and the piezo element 52 is longer than the piezo elements 26 and 27, it is difficult to bend. ,! The operation of the piezo element for scanning becomes easier, and the resolution in the X direction and the y direction can also be improved.

Note that the distance that can be adjusted by the piezo element 52 for distance adjustment is shorter than the distance that can be adjusted by the inchworm.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, STM
In the fine movement mechanism, the two-direction piezo elements that operate by following the unevenness of the sample surface can operate without bending the x- and y-direction piezo elements, which eliminates the load and improves resolution. . Similarly, the piezo elements in the x and y directions can be operated with a small load, and their resolution can be improved.

In addition, since the piezo tri-bod is structurally lighter, it is possible to increase the natural frequency, increase the moving speed, and achieve higher speeds.

In addition, a moving mechanism for distance adjustment is provided in addition to the coarse movement mechanism, and the front leg of the inchworm, which is the coarse movement mechanism, can be clamped during measurement, which further increases the natural frequency and enables high-speed scanning. It is possible to realize this and improve the measurement resolution of STM.

Furthermore, in the case where a detail material of a predetermined length is provided between the base and the tri-bod head, changes in the position of the tri-bod head are restrained when scanning is performed by the operation of the scanning piezo element. This makes it possible to perform appropriate scanning without positional fluctuations.

[Brief explanation of drawings]

FIG. 1 is a side view of essential parts of an STM showing an embodiment of the present invention;
Figure 2 is a front view of the fine movement mechanism seen from the line ■-■ in Figure 1, Figure 3 is a diagram showing a modified example of the piezo tribod,
FIG. 4 is a diagram similar to FIG. 1 showing another embodiment of the present invention. [Explanation of symbols] 1. Fist... 2. -. 14... 15... 18.19ψ 22... 24... 25φ... 26.27・ 41... 42... 51...- 52...・ ・37M pace・Sample stage・X stage・Y stage・Sample・Sample holder・Tip holder・Inchworm front legs・Inchworm hind legs・Clamper・Piezo actuator・Tribod base・Tribod head・Scanning piezo element for use, connection member, shaft member, connection member, piezo element for distance adjustment 1...STM base 2...sample stage 3...X stage 9...holder 11...probe 18.19 ... Clamper 22 ... Piezo actuator 24 ... Tri-bod base 41 ... Connection member 42 ... Shaft member 15 ... Inch worm rear leg

Claims (8)

[Claims] (1) In a scanning tunneling microscope that is equipped with a probe, the probe is brought close to the sample to a distance that allows tunneling current to flow, and the probe is moved by a fine movement mechanism to scan the surface of the sample, wherein the fine movement mechanism piezo elements in a first direction and a second direction that two-dimensionally scan the surface of the sample;
a third direction piezo element including the probe and maintaining the distance between the sample and the probe at the distance through which the tunneling current flows, and one end of the piezo element in the first direction and the second direction; A scanning tunneling microscope characterized in that the piezo element is fixed to a base, the other end is fixed to a connecting member, and one end of the piezo element in the third direction is fixed to a surface of the connecting member facing the sample. (2) In a scanning tunneling microscope that is equipped with a probe, the probe is brought close to the sample to a distance that allows tunneling current to flow, and the probe is moved by a fine movement mechanism to scan the surface of the sample, wherein the fine movement mechanism piezo elements in a first direction and a second direction that two-dimensionally scan the surface of the sample;
a third direction piezo element including the probe and maintaining the distance between the sample and the probe at the distance through which the tunneling current flows, and one end of the piezo element in the first direction and the second direction; The piezo element is fixed to a base, and the other end is fixed to a connecting member, and one end of the piezo element in the third direction is fixed to a surface of the connecting member facing the sample, and the piezo element is fixed to a surface of the connecting member opposite to the surface facing the sample. Between the side surface and the base, the third
A scanning tunneling microscope characterized by being provided with another piezo element for adjusting the position of the probe in the direction. (3) comprising a probe, a coarse movement mechanism that brings the probe close to the sample to a distance that allows tunneling current to flow, and a fine movement mechanism that moves the probe to scan the surface of the sample; The mechanism consists of two legs, one close to the sample and one far from the sample, a piezo element that connects these two legs, and a clamp mechanism for each leg. During measurement, the leg that is farthest from the sample is clamped and attached to the sample. In a scanning tunneling microscope in which the near foot is in an unclamped state and the fine movement mechanism has three piezo elements orthogonal to each other, one of the three piezo elements of the fine movement mechanism scans the surface of the sample two-dimensionally. One end of the piezo elements in the first direction and the second direction is fixed to a base fixed to a foot portion of the coarse movement mechanism on the side closer to the sample, and the other end is fixed to a connecting member, and the probe is A scanning tunnel characterized in that one end of a third direction piezo element that maintains the distance between the sample and the probe at the distance through which the tunnel current flows is fixed to the surface of the connecting member facing the sample. microscope. (4) A probe, a coarse movement mechanism that brings the probe close to the sample to a distance that allows tunneling current to flow, and a fine movement mechanism that moves the probe to scan the surface of the sample; The mechanism consists of two legs, one close to the sample and one far from the sample, a piezo element that connects these two legs, and a clamp mechanism for each leg. During measurement, the leg that is farthest from the sample is clamped and attached to the sample. In a scanning tunneling microscope in which the near foot is in an unclamped state and the fine movement mechanism has three piezo elements orthogonal to each other, one of the three piezo elements of the fine movement mechanism scans the surface of the sample two-dimensionally. One end of each of the piezo elements in the first direction and the second direction is fixed to a base fixed to the foot of the coarse movement mechanism on the side closer to the sample, and the other end is fixed to the connecting member, and One end of a third direction piezo element having a needle and maintaining the distance between the sample and the probe at the distance through which the tunneling current flows is fixed to the surface of the connecting member facing the sample, and A scanning tunneling microscope characterized in that a shaft member is disposed between the probe and the base to restrain a change in the position of the probe in the third direction. (5) A probe, a coarse movement mechanism that brings the probe close to the sample to a distance that allows tunneling current to flow, and a fine movement mechanism that moves the probe to scan the surface of the sample; The mechanism consists of two legs on a side near and far from the sample, a piezo element that connects these two legs, and a clamp mechanism for each leg, and the fine movement mechanism has three piezo elements that are orthogonal to each other. In the scanning tunneling microscope, among the three piezo elements of the fine movement mechanism, one end of the piezo elements in the first direction and the second direction that two-dimensionally scans the surface of the sample is located close to the sample of the coarse movement mechanism. A second probe is fixed to a base fixed to a side leg part, the other end is fixed to a connecting member, and is provided with the probe and maintains the distance between the sample and the probe at the distance through which the tunneling current flows. One ends of the piezo elements in three directions are fixed to the surface of the connecting member facing the sample, and a piezo element for distance adjustment in the third direction is disposed between the base and the connecting member. A scanning tunneling microscope characterized by a clamped foot on the side closer to the sample. (6) In the scanning tunneling microscope according to claim 5,
A scanning tunneling microscope, wherein the piezo element for distance adjustment adjusts the distance when the distance between the probe and the sample exceeds the movable range of the fine movement piezo element in a third direction. (7) A scanning tunneling microscope equipped with a probe, a coarse movement mechanism that brings the probe close to the sample to a distance that allows tunneling current to flow, and a fine movement mechanism that moves the probe to scan the surface of the sample. A scanning tunneling microscope characterized in that, in contrast to the coarse movement mechanism that moves the probe over a relatively long distance, a movement mechanism that moves the probe over a distance shorter than the coarse movement mechanism is provided. (8) In the scanning tunneling microscope according to claim 7,
The probe is moved by the coarse movement mechanism until a tunnel current flows, and after the tunnel current is generated, the probe is retreated to a predetermined distance, and then the probe is moved again by the movement mechanism to a distance where a tunnel current flows. A scanning tunneling microscope characterized in that the fine movement mechanism is operated in a state in which the fine movement mechanism is operated.