JPH07128467A - Micromotion carrier - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent surface deviation in the height direction of the movable part and achieve more precise and high-speed drive. [Structure] The fine movement drive carrier is provided with a fixed container 5 which accommodates a fine movement drive mechanism for finely driving in a plane. Inside the fixed container 5, the movable part 1 of the fine movement drive mechanism can be driven in one axis direction (X direction) by a pair of piezoelectric elements 2 arranged so as to sandwich the movable part 1. The piezoelectric element 2 is provided with a ball 3
Is in point contact with the movable portion 1 via the. Furthermore, the movable part 1
Elastic bodies 6 are inserted as Z-direction restraining members above and below,
The elastic body 6 is pressed against the movable portion 1 by the fixed container 5. The movable part 1 has four protrusions 4 that protrude from the upper surface of the fixed container 5.
One transmission part 1a is formed. On the outside of the fixed container 5, a sample table 4 is adhered to the transmission part 1a so as to be parallel to the driving direction of the movable part 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine-tuning drive carrier for use in a scanning tunneling microscope, an information recording and / or reproducing apparatus using or applying the principle of a scanning tunneling microscope, which requires precise position control.

[0002]

2. Description of the Related Art In recent years, an STM that can observe the surface state of a sample on the atomic order has attracted attention. STM developed by G. Binnig et al. [G. Binnig et al., Helvetica Phys
icaActa, 55,726 (1982)] applies a voltage between a conductive substance consisting of a metal probe (probe electrode) and the sample surface,
This is a method of observing the surface state of the sample by utilizing the fact that a tunnel current flows when the probe electrode is brought close to the sample surface to a distance of about 1 nm. This current is sensitive to changes in the distance between the two.By scanning the probe electrode so as to keep the tunnel current constant, or by measuring the change in tunnel current when scanning while keeping the probe electrode at a constant height. , It is possible to know the condition of the sample surface.

At this time, since the resolution in the in-plane direction is very high at about 0.1 nm, the fine movement drive mechanism for relatively moving the probe and the sample can perform accurate positioning in the in-plane direction. There is a demand for a device that does not cause surface wobbling in the height direction during high-speed scanning.

FIG. 9 is a block diagram showing a conventional fine movement drive mechanism.

In the conventional fine movement drive mechanism, as shown in FIG. 9, the cylindrical movable portion 101 has a rectangular first portion via four θ-direction parallel springs 102 at equal intervals in the circumferential direction. It is supported by the frame 104. At the same position as each θ-direction parallel spring 102, the movable portion 101 is
A θ-direction piezoelectric element 104 for driving the actuator in the circumferential direction is provided. The first frame 103 is a rectangular second frame 10 that surrounds the periphery of the first frame 103.
5, a Y-direction piezoelectric element 106 for displacing the first frame 103 in the Y-direction and a Y-direction parallel spring 107 for guiding the first frame 103 in the Y-direction are supported. The second frame 105 is the second frame 10
An X-direction piezoelectric element 10 for displacing the second frame 105 in the X-direction on a base 108 having a rectangular opening that surrounds 5.
9 and the second frame 105 are supported via an X-direction parallel spring 110 for guiding the X-direction and the second frame 105. Based on such a configuration, the movable portion 101 is controlled in the X direction, the Y direction, and the θ direction on the nanometer order by applying a voltage to a predetermined piezoelectric element.

[0006]

However, in the above-described fine movement drive mechanism, when the movable portion is driven by the piezoelectric element, due to axial misalignment of the piezoelectric element at the opposing position, a height direction perpendicular to the driving direction of the piezoelectric element is caused. However, there is a problem that the movable part vibrates.

In order to solve the above problems, the parallel spring portion, which restrains the displacement of the piezoelectric element in the height direction perpendicular to the driving direction, is thickened in the height direction to prevent vibration of the movable portion. However, it was not easy to control the surface runout of the movable part in the height direction on the order of nanometers.

The present invention has been made in view of the above-mentioned problems of the prior art, and it is possible to prevent surface wobbling of the movable portion in the height direction and achieve a more precise and high speed drive carrier. The purpose is to provide.

[0009]

As a means for achieving the above object, a fine movement drive carrier of the present invention is a fine movement drive mechanism for fine movement driving in a plane and a driving direction in the plane of the fine movement drive mechanism. A fixed container that houses a restraint member that restrains fluctuations in the vertical direction with respect to the vertical direction, and is installed outside the fixed container in parallel to the driving direction of the fine movement drive mechanism, and in the plane of the fine movement drive mechanism. And a sample table that moves with fine movement drive.

Further, the fine movement drive mechanism includes a first movable portion, a second movable portion surrounding the first movable portion, and the second movable portion.
A fixed part surrounding the movable part of the first movable part, and a transmission part for transmitting the movement amount of the first movable part to the sample table is formed in the first movable part. A first piezoelectric element that displaces the first movable portion in a first axial direction between the second movable portion and the second movable portion; A first support portion elastically supporting the first movable portion in the axial direction is disposed, and the second movable portion is provided between the second movable portion and the fixed portion. A second piezoelectric element that displaces in a direction, and a second support portion that elastically supports the second movable portion with respect to the fixed portion so that the second movable portion can be guided in the second axial direction. The first axial direction and the second axial direction are orthogonal to each other in a plane, and the restraint member is the first axial direction.
Is provided so as to be sandwiched from a height direction perpendicular to the driving direction of the movable part, one in which the first axial direction of the fine movement driving mechanism is the main scanning direction, and the first and the second The second supporting portion may use a parallel spring. In this case, one or a plurality of the restraining members are provided, or an elastic body having a damping effect or a parallel spring is used as the restraining member. It may be one.

The parallel spring may be a leaf spring,
It may be an elastic hinge spring.

Further, the fixed container may be filled with a viscous liquid.

[0013]

In the present invention constructed as described above, when the sample stage is driven in the plane by the fine movement drive mechanism, fluctuations in the height direction perpendicular to the driving direction in the plane of the fine movement drive mechanism are restrained by the restraining member. The result is that the vibration of the sample table in the height direction is suppressed. Therefore,
When the fine movement drive mechanism of the present invention is used in a scanning tunneling microscope, surface wobbling in the height direction during high-speed scanning does not occur, and more precise observation is possible.

[0014]

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

(First Embodiment) FIG. 1 is a vertical sectional view showing a first embodiment of a fine movement drive carrier of the present invention, and FIG. 2 is a plan view of the fine movement drive carrier shown in FIG. Is.

The fine movement drive carrier of this embodiment is shown in FIGS.
As shown in FIG. 3, a fixed container 5 that houses a later-described fine movement drive mechanism is provided. Inside the fixed container 5, the movable part 1 of the fine movement drive mechanism can be driven in one axis direction (X direction in FIG. 1) by a pair of piezoelectric elements 2 arranged so as to sandwich the movable part 1. . The piezoelectric element 2 is in point contact with the movable portion 1 via the sphere 3 in order to reliably transmit the displacement amount to the movable portion 1. The piezoelectric element 2 is provided with a preload of 2.5 kg in advance. Further, elastic bodies 6 are inserted as Z-direction restraining members above and below the movable portion 1 (positions shown by diagonal lines in FIGS. 1 and 2), and the elastic body 6 is pressed against the movable portion 1 by the fixed container 5. The movable part 1 is formed with four transmission parts 1 a protruding from the upper surface of the fixed container 5. On the outside of the fixed container 5, a sample table 4 is adhered to the transmission part 1a so as to be parallel to the driving direction of the movable part 1. As a result, the sample table 4 can move in the in-plane direction as the movable unit 1 is driven. In addition,
On the upper surface of the fixed container 5, there is provided a clearance through which the holding portion 1a can project and finely move.

Here, the fine movement drive mechanism housed inside the fixed container 5 will be described.

FIG. 3 is a plan view of the fine movement drive mechanism housed in the fixed container shown in FIGS. 1 and 2 as seen from the Z direction.

In FIG. 3, the first axial direction is the X direction and the second axial direction is the Y direction. The X direction and the Y direction are orthogonal to each other in a plane.

The movable part 1 as the first movable part of the fine movement drive mechanism is mounted on a frame 8 as a second movable part having a rectangular shape which surrounds the movable part 1 with a space therebetween. X-direction piezoelectric element 2 as the first piezoelectric element to be displaced in the direction
It is supported via 1a, 21b and X-direction parallel springs 71a to 71d as a first parallel spring part for guiding the movable part 1 in the X-direction. The frame 8 includes a base 9 as a rectangular fixed part that surrounds the frame 8 with a space.
In addition, Y-direction piezoelectric elements 22a and 22b as second piezoelectric elements for displacing the frame 8 in the Y direction, and the frame 8
Are supported via Y-direction parallel springs 72a to 72d as a second parallel spring portion that guides in the Y-direction.

Next, the operation of the fine movement drive mechanism will be described.

In FIG. 3, in order to move the movable portion 1 to the plus side in the X direction, the voltage contracted to the X direction piezoelectric element 21a is set to X.
This is performed by applying a voltage that extends to the directional piezoelectric element 21b. On the contrary, in order to move it to the minus side, a voltage that extends in the X-direction piezoelectric element 21a and a voltage that contracts in 21b is applied. To move in the Y direction, the Y direction piezoelectric element 22
The same voltage as described above may be applied to a and 22b. The movement of the movable portion 1 is defined by a parallel spring in one axial direction, and the displacement is given by a piezoelectric element. When driving the movable part 1,
The moving speed of the movable portion 1 in the X direction is higher than that in the Y direction, and the X-axis direction is the main scanning direction.

For driving, a 2 × 3 × 9 mm piezoelectric element manufactured by Tokin Co., Ltd. having a displacement sensitivity of 6.5 μm / 100 V was used.

The target is adhered onto the sample stage 4 of the fine movement drive carrier shown in FIG. 1, and a voltage is applied such that the displacement amounts of the pair of X-direction piezoelectric elements are opposite to each other, and the displacement amount in the X-direction is adjusted. When the frequency characteristic was measured by detecting with a capacitance type displacement meter, the natural frequency was about 5 kHz. Similarly, when measured in the Y direction, the natural frequency is about 3 kHz.
Met.

The positioning accuracy in the X and Y directions was very good, ranging from several nanometers to several tens of nanometers.

When the displacement amount (vibration) in the Z direction when driven in the X and Y directions was measured by a displacement meter using laser light, it was on the order of nanometers.

In this embodiment, when the movable portion is driven, the outside of the piezoelectric element is used as a means for applying a voltage so that the displacement amounts of the piezoelectric elements arranged so as to sandwich the movable portion are opposite to each other. Apply a predetermined voltage to the electrode of 100V,
It was performed by setting the inner electrode to an equal voltage and changing the value of the voltage applied to the inner electrode.

In the present embodiment, sheet-like silicone rubber is used as the elastic body 6, but any material having a certain elastic constant, such as fluororubber, can be used.
Alternatively, a resin such as polyurethane or Teflon may be used.

As a means for transmitting the movement of the movable portion to the outside of the fixed container 5, the transmission portion 1a formed on the movable portion 1
However, the number is not limited at all, and one transmitting portion 1b may be provided at the center of the movable portion as shown in FIG.

Further, as shown in FIG. 5, a viscous liquid for preventing vibration of the movable part 1 is provided inside the fixed container by providing a shield 10 in a gap around the transmission part 1a protruding from the fixed container 5. It can be enclosed, and as a result, parasitic vibration and the like of the movable portion 1 can be further mitigated.

(Second Embodiment) FIG. 6 is a vertical sectional view showing a second embodiment of the fine movement drive carrier of the present invention, and FIG. 7 is a plan view of the fine movement drive carrier shown in FIG. 6 viewed from the Z direction. It is a figure.

The fine movement drive carrier of this embodiment is shown in FIGS.
As shown in FIG. 5, a fixed container 35 for accommodating a fine movement drive mechanism similar to that of the first embodiment is provided. A movable portion 31 is provided inside the fixed container 35, and the movable portion 31 can be driven in one axis direction (X direction in FIG. 6) by a pair of piezoelectric elements 32 arranged so as to sandwich the movable portion 31. Has become. The piezoelectric element 32 transmits the displacement amount to the movable portion 31 without fail,
It is in point contact with the movable portion 31 via the sphere 33. The piezoelectric element 32 is provided with a preload of 2.5 kg in advance. A constraining ball 36 as a Z-direction constraining member is arranged above and below the movable part 31 inside the fixed container 35, and the constraining ball 36 is pressed against the movable part 31 within the range of elastic deformation by the fixed container 35. The size is determined by the size of the fixed container 35. Specifically, the diameter is 1m
Four m steel balls are inserted between the movable part 31 and the fixed container 35. The movable portion 31 is formed with four transmission portions 31 a protruding from the upper surface of the fixed container 35. A sample table 34 is adhered to the transmission part 31 a, and the sample table 34 moves in the in-plane direction along with the movable part 31. A gap is provided on the upper surface of the fixed container 35 so that the transmission portion 31a can project and finely move.

The target is adhered onto the sample table 34 of the fine movement drive carrier shown in FIG. 6, and a voltage is applied so that the displacement amounts of the pair of X-direction piezoelectric elements are opposite to each other, and the displacement amount in the X-direction is adjusted. When the frequency characteristic was measured by detecting with a capacitance type displacement meter, the natural frequency was about 5 kHz. Similarly Y
When the direction was also measured, the natural frequency was about 3 kHz.
It was z.

The positioning accuracy in the X and Y directions was very good, ranging from several nanometers to several tens of nanometers.

The displacement amount (vibration) in the Z direction when driven in the X and Y directions was measured by a displacement meter using laser light, and was on the order of nanometers.

In this embodiment, when the movable portion is driven, as means for applying a voltage so that the displacement amounts of the piezoelectric elements arranged facing the movable portion are opposite to each other, the outside of the piezoelectric element is used. A predetermined voltage, such as 100 V, was applied to the electrodes, the inner electrodes were made equal voltage, and the value of the voltage applied to the inner electrodes was changed.

In this embodiment, the restraint ball 36 is used as the restraining member in the Z direction, but any restraint ball mechanism may be used as long as it is a parallel spring mechanism. You may use. Alternatively, a protrusion may be formed on the movable portion side.

Further, the parallel springs described in the first and second embodiments may be elastic hinge springs.

(Third Embodiment) FIG. 8 is a schematic structural view showing a scanning tunneling microscope using the fine movement drive carrier of the present invention.

In this embodiment, the fine movement drive carrier described in the first and second embodiments is replaced with a scanning tunneling microscope (hereinafter referred to as S
(Abbreviated as TM) used as an XY fine movement mechanism.

On the upper surface of the XY direction coarse movement mechanism 57 shown in FIG. 8, the same XY direction fine movement mechanism 56 having the sample stage 55 as in the first and second embodiments is fixed, and the upper surface of the sample stage 55. A sample 54 is held in. Above the sample 54,
A Z-direction fine movement mechanism 52 and a Z-direction coarse movement mechanism 53 for driving the platinum-rhodium probe 51 produced by mechanical cutting in the Z direction are installed.

Further, the scanning tunneling microscope described above converts the current flowing between the probe 51 and the sample 54 into a voltage, and the voltage application circuit 59 for applying a bias voltage between the probe 51 and the sample 54. A current amplification circuit 60 for amplifying this,
Z-direction drive circuit 61 for driving the probe 51 in the Z-direction
An XY direction drive circuit 62 for driving the XY direction fine movement and coarse movement mechanisms, a display device 63, and a microcomputer 58 for controlling each circuit and the like, and a probe for keeping the tunnel current constant. The surface state of the sample 54 can be observed using the display device 63 by scanning 51 or measuring the change in tunnel current when scanning is performed while keeping the probe 51 at a constant height.

When a bias voltage of 1 V was applied between the probe and the sample (for example, graphite) by this apparatus and two-dimensional scanning was performed so that the tunnel current was constant at 10 nA,
The atomic image of graphite could be clearly observed without any disturbance in the STM image due to the vibration of the movable part.

[0044]

As described above, according to the present invention, the fine movement drive mechanism is housed in the fixed container, and the elastic member such as the restraining member such as a parallel spring such as a ball or the damper material is provided above and below the movable portion of the fine movement drive mechanism. By arranging, the variation in the height direction of the movable portion is prevented, and as a result, more precise and higher speed driving can be performed.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a first embodiment of a fine movement drive carrier according to the present invention.

FIG. 2 is a plan view of the fine movement drive carrier shown in FIG. 1, seen from the Z direction.

FIG. 3 is a plan view of the fine movement drive mechanism housed in the fixed container shown in FIGS. 1 and 2 as viewed from the Z direction.

FIG. 4 is a diagram showing another example of the transmission portion in the first embodiment of the fine vibration mechanism of the present invention.

FIG. 5 is a diagram showing an example of further preventing vibration in the first embodiment of the fine movement drive mechanism of the present invention.

FIG. 6 is a longitudinal sectional view showing a second embodiment of the fine movement drive carrier of the present invention.

FIG. 7 is a plan view of the fine movement drive carrier shown in FIG. 6, viewed from the Z direction.

FIG. 8 is a schematic configuration diagram showing a scanning tunneling microscope using a fine movement drive carrier of the present invention.

FIG. 9 is a configuration diagram showing a conventional fine movement drive mechanism.

[Explanation of symbols]

 1,31 Movable part 1a, 1b, 31a Transmission part 2,32 Piezoelectric element 3,33 Sphere 4,34,55 Sample stand 5,35 Fixed container 6 Elastic body 8 Frame 9 Base 10 Shield 21a, 21b X direction piezoelectric element 22a , 22b Y direction piezoelectric element 36 Restraint sphere 71a-71d X direction parallel spring 72a-72d Y direction parallel spring 51 Probe 52 Z direction fine movement mechanism 53 Z direction coarse movement mechanism 54 Sample 56 XY direction fine movement mechanism 57 XY direction coarse movement mechanism 60 current amplification circuit 61 Z-direction drive circuit 62 XY-direction drive circuit 63 display device

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Toshimitsu Kawase 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (11)

[Claims] 1. A fixed container for accommodating a fine movement drive mechanism for fine movement in a plane and a restraint member for restraining fluctuations in a height direction perpendicular to a driving direction of the fine movement drive mechanism, and the fixed container. A fine movement drive carrier having a sample table, which is installed outside of and parallel to the driving direction of the fine movement drive mechanism, and moves along with the fine movement drive in the plane of the fine movement drive mechanism. 2. The fine movement drive mechanism includes a first movable portion, a second movable portion that surrounds the first movable portion, and a fixed portion that surrounds the second movable portion. A transmission part that transmits the movement amount of the first movable part to the sample stage is formed in the movable part of the first movable part, and the first movable part and the second movable part are provided between the first movable part and the first movable part. A first piezoelectric element that displaces the movable portion in a first axial direction; and a first piezoelectric element that elastically supports the first movable portion with respect to the second movable portion so that the movable portion can be guided in the first axial direction. And a second piezoelectric element for displacing the second movable portion in a second axial direction between the second movable portion and the fixed portion. A second supporting portion that elastically supports the movable portion of the movable portion relative to the fixed portion so as to be guided in the second axial direction, the first axial direction and the second axial direction. Axial micromotion drive carrier of claim 1, wherein the mutually orthogonal in a plane. 3. The fine movement drive carrier according to claim 2, wherein the restraint member is provided so as to be sandwiched from a height direction perpendicular to a driving direction of the first movable portion. 4. The fine movement drive carrier according to claim 2, wherein a first axial direction of the fine movement drive mechanism is a main scanning direction. 5. The fine movement drive carrier according to claim 2, wherein the first and second support portions are parallel springs. 6. One of the restraint members according to claim 1, wherein one or a plurality of restraint members are provided.
The fine movement drive carrier according to item. 7. The fine movement drive carrier according to claim 1, wherein an elastic body having a damping effect is used as the restraint member. 8. The fine movement drive carrier according to claim 1, wherein a parallel spring is used as the restraint member. 9. The fine movement drive carrier according to claim 5, wherein the parallel spring is a leaf spring. 10. The fine movement drive carrier according to claim 5, wherein the parallel spring is an elastic hinge spring. 11. The viscous liquid is sealed inside the fixed container.
The fine movement drive carrier described in any one of 1.