JPH09117165A - Tremor unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfy both the large displacement and highly accurate micro displacement through a single body without causing increase in size of unit. SOLUTION: The tremor unit comprises a tubular piezoelectric element 12 extending/contracting in the axial direction (Z-axis direction) and being deformed in the direction included in a plane intersecting the axial direction perpendicularly (X-axis and Y-axis direction) upon application of a voltage, and a rigid part 13 disposed in the inner space of tubular piezoelectric element 12. The tubular piezoelectric element 12 and the rigid part 13 are secured, at each end part to a common end face member 11 while aligning the axial direction. When the tubular piezoelectric element 12 has a standard length, the end face is flush with that of the rigid part 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine movement device, and more particularly, to a fine movement mechanism for moving an observation portion or an observation object in a high-power microscope or a movement mechanism of a semiconductor inspection device for producing a fine displacement. Regarding the device.

[0002]

2. Description of the Related Art In the field of high-magnification microscopes such as scanning probe microscopes, semiconductor inspection equipment, etc., it is necessary to generate a fine movement to obtain a fine displacement of several μm or less. As an actuator for a mechanism that generates such a fine movement, a piezoelectric element is often used. FIG. 9 shows a typical example of a conventional actuator.

FIG. 9 (a) is a diagram of Japanese Patent Application Laid-Open No. 61-209846.
2 shows a piezoelectric element actuator disclosed in Japanese Patent Publication No. In this actuator, two rigid body portions 71, 72 are connected by two flat plate portions 73, 74, and each rigid body portion 71, 7 is connected.
A rod-shaped piezoelectric element 77 is arranged between the protrusions 75 and 76 protruding from 2. In the structure in which one rigid body portion 71 is fixed and the other rigid body portion 72 is free, the piezoelectric element 7
When a voltage is applied to 7, the flat plate portions 73 and 74 elastically deform while maintaining parallelism, and the other rigid body portion 72 is displaced in translation. By using this structure as a basic structure and combining it with other similar structures, it is possible to configure a fine movement device that causes displacement of two or more axes.

FIG. 9 (b) is a diagram of Japanese Patent Laid-Open No. 63-236992.
2 shows a piezoelectric element actuator disclosed in Japanese Patent Publication No. In this actuator, the common electrode 82 is provided on the inner surface of the cylindrical piezoelectric element 81, and the Z-axis driving electrode 83 is provided on the outer surface.
An X-axis driving electrode 84 and a Y-axis driving electrode 85, which are formed by being divided into four in the circumferential direction, are provided in an upper and lower two-stage configuration. One end surface of the cylindrical piezoelectric element 81 is fixed, and by applying a predetermined voltage to the electrodes 82 to 85, the other end surface can be displaced in three axial directions.

[0005]

Each of the fine movement devices described above can generate a fine displacement with high accuracy. However, the magnitude of displacement obtained by these fine movement devices is
It is limited by the displacement capability of the piezoelectric element and is at most several μm to several tens of μm. Therefore, conventionally, when these fine movement devices are used as a sample table of a high-power microscope, for example, a large displacement and a highly accurate displacement have been achieved by combining them with another moving device that generates a large displacement.

However, if the conventional device configuration is adopted, at least two moving devices having different structures must be used, which causes a problem that the device becomes large, complicated and expensive. .

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a fine movement apparatus which can achieve both large displacement and highly accurate minute displacement by itself without causing an increase in size of the apparatus. Especially.

[0008]

In order to achieve the above-mentioned object, the fine movement device according to the first aspect of the present invention (corresponding to claim 1) has an axial direction (Z
A cylindrical piezoelectric element that expands and contracts in the axial direction) and deforms in the directions (for example, each of the X axis and the Y axis) included in a plane orthogonal to the axial direction, and a columnar portion arranged in the inner space of the cylindrical piezoelectric element. And each end of the cylindrical piezoelectric element and the strut are fixed to a common end face member so that the axial directions of the cylindrical piezoelectric element and the strut are the same, and the cylindrical piezoelectric element has a standard length ( Preferably, the non-fixed end surface of the cylindrical piezoelectric element and the non-fixed end surface of the column portion are located on the same plane when they are in a natural length that does not expand or contract in the axial direction.

According to the first aspect of the present invention, the cylindrical piezoelectric element fixedly mounted on the common end face member and the respective end surfaces of the supporting column are arranged so as to be substantially on the same plane, and the cylindrical piezoelectric element as the moving means is By minutely driving the end face in the axial direction and the moving direction, the end face of the column portion can be projected, and conversely, the end face of the cylindrical piezoelectric element can be projected. The fine movement device is installed on the flat base surface with each end face facing downward, and the cylindrical piezoelectric element is driven to expand / contract in the axial direction and is also deformed in the direction in which it is desired to move. By utilizing the relationship between the axial length of the column and the length of the column, by using the cylindrical piezoelectric element and each lower end of the column as the leg, it is possible to repeat a minute movement in a predetermined cycle in the moving direction. Thus, it is possible to move with a relatively large displacement. The fine movement device according to the present invention can achieve both large displacement and highly accurate displacement by itself by repeating the above-described periodic operation as necessary.

A fine movement device according to a second aspect of the present invention (corresponding to claim 2) is the fine movement device according to the first aspect of the present invention, wherein the support column is arranged in either one of the inner space and the outer space of the cylindrical piezoelectric element. It is characterized by

A fine movement device according to a third aspect of the present invention (corresponding to claim 3) is characterized in that, in the first or second aspect of the invention, the support column is a rigid member.

A fine movement device according to a fourth aspect of the present invention (corresponding to claim 4) is characterized in that, in the first or second aspect of the invention, the support column is formed of a laminated piezoelectric element. In this configuration, the supporting column is formed of the laminated piezoelectric element, and the laminated piezoelectric element can change its length by being controlled by the applied voltage. It becomes easy to adjust the position of each end face portion of the laminated piezoelectric element.

A fine movement device according to a fifth aspect of the present invention (corresponding to claim 5) is the fine movement device according to the first or second aspect of the present invention, wherein the support column portion expands and contracts in the axial direction by voltage application and is orthogonal to the axial direction. Another cylindrical piezoelectric element that deforms in a direction included in a plane, and when each of the cylindrical piezoelectric element and the other cylindrical piezoelectric element has a standard length, the non-fixed end surface of the cylindrical piezoelectric element and the other It is characterized in that the non-fixed end face of the cylindrical piezoelectric element is located on the same plane. By using two cylindrical piezoelectric elements, it is possible to increase the moving speed during large displacement movement.

A fine movement device according to a sixth aspect of the present invention (corresponding to claim 6) is that in each of the above aspects, the cylindrical piezoelectric element is
It is configured to have a first drive unit that expands and contracts in the axial direction and a second drive unit that deforms in the direction of at least one of the two orthogonal axes included in the plane.

A fine movement device according to a seventh aspect of the present invention (corresponding to claim 7) is that in each of the above aspects, the cylindrical piezoelectric element is:
It is configured to have a first drive unit that expands and contracts in the axial direction and a second drive unit that deforms in the direction of at least one of two orthogonal axes included in a plane on both sides of the first drive unit. To be done.

A fine movement device according to an eighth aspect of the present invention (corresponding to claim 8) is the fine movement device according to each of the above aspects, wherein another cylindrical piezoelectric element is provided with a first drive portion that expands and contracts in the axial direction. It is configured to have a second drive unit that deforms in the direction of at least one of the two included orthogonal axes.

A fine movement device according to a ninth aspect of the present invention (corresponding to claim 9) is the above invention, wherein the other cylindrical piezoelectric element includes a first drive portion for expanding and contracting in the axial direction, and a first drive portion. On both sides of the section, it is configured to have a second drive section that deforms in the direction of at least one of two orthogonal axes included in the plane.

[0018]

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

FIG. 1 shows a first embodiment of a fine movement device according to the present invention. In the fine movement device according to this embodiment, the cylindrical piezoelectric element 12 and the cylindrical rigid portion 13 are fixedly mounted on the common plate 11 located at the upper end face in the figure. The plate 11 has a required thickness and rigidity. The rigid body portion 13 is preferably arranged in the inner space of the cylindrical piezoelectric element 12 and functions as a pillar during movement as described later. Rigid part 13
The cylindrical piezoelectric element 12 and the cylindrical piezoelectric element 12 are integrally formed with each other via the plate 11.
The axial directions of 2 are the same. Cylindrical piezoelectric element 1
A ring 14 that serves as a leg portion of the present fine movement device is fixedly mounted on the lower end surface of 2. On the other hand, the rigid body portion 13 has a function as a column portion that supports the fine movement device when the cylindrical piezoelectric element 12 contracts. Preferably, when the axial length of the cylindrical piezoelectric element 12 is a standard length (the length when the cylindrical piezoelectric element 12 does not expand or contract in the axial direction), the rigid body portions 13 have substantially the same axial length. Is set to. The standard length of the cylindrical piezoelectric element 12 can be arbitrarily defined.

In the cylindrical piezoelectric element 12, a common electrode 15 is arranged on substantially the entire inner surface thereof, a Z-axis driving electrode 16 is formed on the outer surface thereof, and X is formed by being divided into four in the circumferential direction.
The axis drive electrode 17 and the Y axis drive electrode 18 are arranged in a two-stage configuration. The Z-axis direction coincides with the axial direction of the cylindrical piezoelectric element 12, and the X-axis and the Y-axis are included in a plane orthogonal to the Z-axis and are also orthogonal to each other. Outer electrodes 16, 1
When voltage is applied to 7 and 18 as appropriate, X, Y and Z
It is possible to drive in any direction of the three axes or a combination thereof.

When the axial length of the cylindrical piezoelectric element 12 is a standard length, the lower end surface of the rigid body portion 13 and the ring 14 are
The lower end surfaces of the are configured to be substantially flush with each other. By applying a required voltage to the Z-axis driving electrode 16 of the cylindrical piezoelectric element 12 and minutely driving it in the Z-axis direction, the end surface of the rigid body portion 13 is projected from the end surface of the ring 14 of the cylindrical piezoelectric element 12, On the contrary, the end surface of the ring 14 can be projected from the end surface of the rigid body portion 13.

A reference potential is applied to the common electrode provided on the inner surface of the cylindrical piezoelectric element 12. By applying a required voltage to at least one of the electrodes 16, 17, and 18 on the outer surface of the cylindrical piezoelectric element 12, it is possible to cause the piezoelectric element 12 to undergo a necessary change for movement. In FIG. 1, a structure for applying a necessary voltage to each electrode of the cylindrical piezoelectric element 12 is not shown. This fine movement device
The movement is performed by a combination of the expansion / contraction operation of the cylindrical piezoelectric element 12 in the Z-axis direction and the deformation operation in the direction in which it is to be moved, that is, the deformation operation in the X-axis direction or the Y-axis direction.

Next, the operation of the fine movement apparatus according to the present embodiment will be described with reference to the movement examples of FIGS. FIG. 2 shows an example in which the fine movement device is moved in the X-axis direction. FIGS. 2A to 2E show five basic operations for moving. The contents of each basic operation are as follows.

(A): The cylindrical piezoelectric element 12 is contractively driven in the Z-axis direction, and the lower end surface of the rigid portion 13 is placed on the flat base surface 19 in a state of protruding from the lower end surface of the ring 14. At this time, only the lower end surface of the rigid part 13 is the base surface 19
It comes into contact with and stands still. This state is the reference state.

(B): By deforming and driving the cylindrical piezoelectric element 12 in the X-axis direction, the lower end surface on which the ring 14 is fixed is moved in the X-axis direction.

(C): In the state shown in (b), the cylindrical piezoelectric element 12 is driven to extend in the Z-axis direction until the lower end surface of the ring 14 projects downward from the lower end surface of the rigid portion 13. Then, the lower end surface of the ring 14 is brought into contact with the base surface 19,
Make them stand still. At this time, the axial length of the cylindrical piezoelectric element 12 is longer than the axial length of the rigid portion 13, and the lower end surface of the rigid portion 13 is separated from the base surface 19.

(D): By deforming and driving the cylindrical piezoelectric element 12 in the X-axis direction, the rigid body portion 13 is moved in the X-axis direction via the plate 11. The rigid portion 13 has a base surface 19
Kept away from.

(E): The cylindrical piezoelectric element 12 is driven to contract again in the Z-axis direction. The length of the cylindrical piezoelectric element 12 in the axial direction is shorter than the length of the rigid body portion 13, and the lower end surface of the rigid body portion 13 contacts the base surface 19 and stands still. Thus, the fine movement device returns to the reference state. By returning to the reference state, the movement for one cycle is completed. At this time, the position of the fine movement device is displaced by a small amount in the X-axis direction with respect to the initial position shown in FIG.

By repeating the above basic operations (a) to (e), it is possible to perform a large displacement movement by the fine movement device with respect to the movement in the X-axis direction. Further, it is possible to generate a minute displacement by reducing the number of repetitions or by causing deformation in a stationary state. In this way, with respect to the movement in the X-axis direction, it is possible to achieve both a large displacement movement and a highly precise minute displacement by a single fine movement device. With respect to the movement in the Y-axis direction as well, by combining the expansion drive in the Z-axis direction and the deformation drive in the Y-axis direction, both a large displacement movement and a high-precision small displacement are performed by a single fine movement device in the same manner as described above. be able to.

In the above embodiment, the rigid body portion 13 is fixed inside the cylindrical piezoelectric element 12 via the plate 11, but conversely, the rigid body portion is provided on the outer side and the cylindrical piezoelectric element is provided on the inner side. With the configuration, the same action as described above can be produced.

FIG. 3 shows a second embodiment of the fine movement device according to the present invention. In the fine movement device according to the present embodiment, a laminated piezoelectric element is used instead of the rigid body portion 13. Cylindrical piezoelectric element 12 and laminated piezoelectric element 20 via a common plate 11
Are fixed, and further, a ring 14 and a block 21, which are the legs of the fine movement device, are fixed to the lower end surfaces of the cylindrical piezoelectric element 12 and the laminated piezoelectric element 20, respectively. The configuration of the cylindrical piezoelectric element 20 and the operation as the fine movement device are as follows.
This is based on the fine movement device described in the first embodiment.

The feature of the fine movement device according to the present embodiment is that the laminated piezoelectric element 20 capable of expanding and contracting in the Z-axis direction is provided in the inner space of the cylindrical piezoelectric element 12, so that the individual piezoelectric elements 12, By extending and contracting 20 in the Z-axis direction, the relative distances in the X-, Y-, and Z-axis directions between the lower end surface of the ring 14 and the lower end surface of the block 21 are set to the fine movement of the first embodiment. It can be made larger than in the case of the device. Therefore, it is possible to easily adjust the positional relationship between the end surface of the ring 14 and the end surface of the block 21 when assembling the fine movement device according to the present embodiment. Note that, in FIG. 3, a power supply unit and a control unit for driving the laminated piezoelectric element 20 to expand and contract are omitted.

FIG. 4 shows a third embodiment of the fine movement device according to the present invention. In the fine movement device according to the present embodiment, the second
Contrary to the embodiment, at least two laminated piezoelectric elements 2
2 is arranged outside the cylindrical piezoelectric element 12. Operation and action of fine movement device according to the present embodiment
The effects and the like are substantially the same as those of the fine movement device described in the second embodiment. 4, elements that are substantially the same as the elements shown in FIG. 3 are assigned the same reference numerals.

FIG. 5 shows a fourth embodiment of the fine movement device according to the present invention. In the fine movement device according to the present embodiment, the two cylindrical piezoelectric elements 12 and 23 are fixed by the inner and outer double coaxial structure via the common plate 11 located above.
A ring 14 and a block 24, which are the legs of the present fine movement device, are fixedly attached to the respective lower end surfaces of the cylindrical piezoelectric elements 12 and 23. The respective configurations of the cylindrical piezoelectric elements 12 and 23 are substantially the same as those described in the first embodiment.

FIG. 6 shows the X of the fine movement device according to the fourth embodiment.
The movement operation in the axial direction is shown. 6A to 6F
Each of the operations corresponds to the operations in (a) to (e) of FIG. The basic operation of the movement according to the present embodiment is substantially the same as the basic operation of the movement according to the first embodiment, except that another cylindrical piezoelectric element 23 is used instead of the rigid body portion 13 in the first embodiment. Are the same. Further, although the rigid body portion 14 does not perform the expansion / contraction operation itself, the cylindrical piezoelectric element 23 used in place thereof is configured to expand / contract appropriately as necessary.

The feature of the fine movement device according to the present embodiment is that both of the two cylindrical piezoelectric elements 12 and 23 have a moving function in the three axial directions, and in particular, FIGS. As shown in the figure, the cylindrical piezoelectric elements 12 and 23 can be deformed in the direction in which they are to be moved, so that the amount of movement by one cycle of the movement operation is made larger than that of the fine movement device according to the first embodiment. be able to. by this,
The moving speed of the fine movement device can be increased.

Further, if the driving operation of either one of the cylindrical piezoelectric elements 12 and 23 is held in a stationary state, it is possible to generate a fine movement with high precision in the case of a fine displacement.
In this way, a single fine movement device can perform a large displacement movement and a highly accurate minute displacement.

In each of the above-mentioned embodiments, the cylindrical piezoelectric element having the electrode arrangement shown in FIG. 9B is used.
Of course, the electrode arrangement is not limited to this. An example of a cylindrical piezoelectric element having another electrode arrangement is shown in FIG.
And FIG.

In the cylindrical piezoelectric element shown in FIG. 7, the X-axis drive electrode 1 formed by being divided into four in the circumferential direction.
7 and the Y-axis drive electrode 18 are connected to the XY-axis drive electrode portion 2
It is sandwiched between individual Z-axis driving electrodes 16 to form a three-stage structure. As a result, the distance between the XY-axis drive section and each of the end faces of the cylindrical piezoelectric element is made equal, and even if either the upper end or the lower end of the cylindrical piezoelectric element 12 is fixed, a uniform X
The displacement in the Y-axis direction can be obtained.

The cylindrical piezoelectric element shown in FIG. 8 has a three-stage structure in which the Z-axis drive electrode 16 is sandwiched between two XY-axis drive electrode portions. As a result, the upper and lower XY
It becomes possible to drive each of the axis drive parts independently,
When driving in the XY axis directions, it is possible to move horizontally without causing movement in the rotational direction.

[0041]

As is apparent from the above description, according to the present invention, since the fine movement device itself has a structure of a self-propelled function, a large displacement movement can be performed by a single fine movement device without increasing the size of the device. It is possible to perform both high precision movement of minute displacement.

[Brief description of the drawings]

FIG. 1 is a partially cutaway external perspective view showing a first embodiment of a fine movement device according to the present invention.

FIG. 2 is an explanatory diagram showing a basic operation of the fine movement device according to the first embodiment.

FIG. 3 is a partially cutaway external perspective view showing a second embodiment of a fine movement device according to the present invention.

FIG. 4 is a front view showing a third embodiment of a fine movement device according to the present invention.

FIG. 5 is a partially cutaway external perspective view showing a fourth embodiment of a fine movement device according to the present invention.

FIG. 6 is an explanatory diagram showing the basic operation of the fine movement device of the fourth embodiment.

FIG. 7 is an external perspective view showing another example of the cylindrical piezoelectric element.

FIG. 8 is an external perspective view showing another example of the cylindrical piezoelectric element.

FIG. 9 is a configuration diagram showing an example of a conventional fine movement device.

[Explanation of symbols]

 11 Plate (End Face Member) 12 Cylindrical Piezoelectric Element 13 Rigid Body Section 14 Ring 15 Common Electrode 16 Z-Axis Driving Electrode 17 X-Axis Driving Electrode 18 Y-Axis Driving Electrode 19 Base Surface 20, 22 Multilayer Piezoelectric Element 23 Cylindrical Piezoelectric element

Claims (9)

[Claims] 1. A cylindrical piezoelectric element that expands and contracts in the axial direction when a voltage is applied and is deformed in a direction included in a plane orthogonal to the axial direction, and a column portion. When the cylindrical piezoelectric element and each end portion of the column portion are fixed to the end face member with the same axial direction, and when the cylindrical piezoelectric element has a standard length, the cylindrical piezoelectric element is not fixed. A fine movement device, characterized in that the end face and the non-fixed end face of the pillar portion are arranged on the same plane. 2. The fine movement device according to claim 1, wherein the support column is arranged in either one of an inner space and an outer space of the cylindrical piezoelectric element. 3. The fine movement device according to claim 1, wherein the support column is a rigid member. 4. The fine movement device according to claim 1, wherein the pillar portion is a laminated piezoelectric element. 5. The column portion is another cylindrical piezoelectric element that expands and contracts in the axial direction by a voltage application and deforms in a direction included in a plane orthogonal to the axial direction. When each of the cylindrical piezoelectric elements has a standard length, the non-fixed end surface of the cylindrical piezoelectric element and the non-fixed end surface of the other cylindrical piezoelectric element are arranged on the same plane. The fine movement device according to claim 1 or 2, characterized in that: 6. The cylindrical piezoelectric element includes a first driving unit that expands and contracts in the axial direction, and a second driving unit that is included in the plane and is orthogonal to each other.
The fine movement device according to any one of claims 1 to 5, further comprising a second drive unit that deforms in a direction of at least one of the shafts. 7. The cylindrical piezoelectric element includes a first driving unit that expands and contracts in the axial direction, and at least one of two orthogonal axes included in the plane on both sides of the first driving unit. The fine movement device according to any one of claims 1 to 5, further comprising a second drive unit that deforms in the direction of. 8. The other cylindrical piezoelectric element is configured to deform in a direction of at least one of a first driving unit that expands and contracts in the axial direction and two orthogonal axes included in the plane. The fine movement device according to claim 5, wherein the fine movement device has two driving portions. 9. The other cylindrical piezoelectric element comprises: a first drive unit that expands and contracts in the axial direction; and both sides of the first drive unit.
The fine movement apparatus according to claim 5, further comprising a second drive unit that deforms in a direction of at least one of two orthogonal axes included in the plane.