JPH0358855B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a fine movement mechanism for rotating and rectilinearly moving an object position with high precision.

[Technical background of the invention and its problems]

In recent years, electron beam lithography equipment, reduction projection type transcription equipment, X-ray transcription equipment, etc. have been developed to form fine patterns on samples such as semiconductor wafers and mask substrates. A fine movement mechanism is required to drive minute displacements in order to maintain accuracy. Further, a fine movement mechanism with high precision is required not only in the above-mentioned apparatus but also in fields where precise measurements are performed using measuring instruments.

Fine movement mechanisms include those that move in a uniaxial direction and those that perform rotational movement, but conventional rotary fine movement mechanisms that perform rotational movement have the following problems. That is, if the stroke is long, it is difficult to perform fine movement, and if the stroke is possible, the stroke cannot be made long. Furthermore, there is a demand for a fine movement mechanism that can perform both rotational and linear movements, but no such mechanism has been reported that is capable of fine movement and has a long stroke.

In order to solve the above problem, the present inventors have recently proposed a fine movement mechanism as shown in FIGS. 7a, b, and c (Japanese Patent Application No. 72422/1982). Note that a is a plan view,
b is a sectional view taken along arrow A-A in a, and c is a cross-sectional view taken along arrow B-B in a.
It is a sectional view, and 71, 74 in the figure are moving members,
75 is a base; 76, -, 79 are driving members such as piezoelectric elements; 81a, -, 82d are power sources; 91, -, 9
4 indicates an electrostatic chuck, respectively. In this device, the movable members 71, . . . , 74 can be moved linearly and rotationally in minute steps by expanding and contracting the drive members 76, .

However, this type of device has the following problems. That is, unless the voltage-displacement characteristics of all drive members used are the same, it is extremely difficult to move the drive members in the desired direction. Furthermore, it is desirable that the voltage-attractive force characteristics of the electrostatic chucks used as the fixing member be the same for all the electrostatic chucks used. For this reason, a driving power source must be provided for each driving member and fixing member to supply the necessary voltage, resulting in an increase in the size of the overall structure and incurring a large amount of cost. On the other hand, if we consider the above points and use one power supply to reduce the size and cost of the control circuit system, the voltage-displacement characteristics of the drive members must be the same, and the voltage-attractive force of the fixed members must be the same. It is desirable to make the characteristics the same, and to achieve this it is necessary to minimize the machining error of the parts, which requires a great deal of effort and expense.

[Purpose of the invention]

It is an object of the present invention to make it possible to precisely move a movable member in a desired direction without increasing the machining accuracy of parts such as driving members and fixed members to the utmost limit, and to miniaturize and simplify the overall configuration. The purpose of this invention is to provide a fine movement mechanism that can be used for measurement.

[Summary of the invention]

The gist of the present invention is to perform fine movement by expanding and contracting a drive member made of a piezoelectric element.
A further object is to compensate for differences in the voltage-displacement characteristics of the drive members.

That is, the present invention comprises a plurality of moving members movably placed on a base and a piezoelectric element that expands and contracts according to applied voltage, and each of the moving members is attached to both ends of the moving member in the direction of expansion and contraction. It includes a driving member that connects adjacent members, and a fixing member that fixes each of the movable members on the base, and the movable members can be rotated and moved in a straight line by the expansion and contraction action of the drive member and the fixing action of the fixed member. In the fine movement mechanism for causing movement, a voltage adjustment circuit for adjusting the power supply voltage to a predetermined voltage is provided between a drive circuit that separately drives the drive members and a power supply.

〔Effect of the invention〕

According to the present invention, since a voltage adjustment circuit is provided for each drive member to compensate for the voltage-displacement characteristics of the drive members, it is not necessary to increase the machining accuracy of the parts to the utmost limit, and manufacturing thereof is easy. Furthermore, since there is no need to provide a power source for each member, the overall configuration can be made smaller and simpler.

In addition, by appropriately combining the expansion and contraction actions of two or more drive members (same number as the number of moving members) and the fixing actions of a plurality of fixed members, rotational movement and linear movement of the moving member by the same driving source can be achieved. Exercise becomes possible. In addition, there is no drawback that the stroke becomes extremely small when fine movement is performed as in the conventional mechanism, and a sufficiently long stroke can be obtained with fine movement, and in principle, infinite rotation and straight movement are possible. Therefore, mechanisms for coarse movement and fine movement become unnecessary. Further, since the movable member is directly driven by a drive member made of a piezoelectric element as a drive source, it is possible to reliably perform ultra-fine movement of 0.005 [μm] with an applied voltage of 1 [V], for example. Furthermore, the number of members with piezoelectric effect differs depending on the magnitude of the applied voltage.
It is possible to generate a force of 100 [Kg] to several [t], and it is possible to provide a fine movement mechanism that generates a large torque.

Further, since the present invention has an extremely simple configuration and does not use any parts that may break down, it is sufficiently reliable even when used by being incorporated into measuring instruments or various semiconductor devices. Furthermore, in devices that use charged particles such as electron beams and ion beams, the charged particles are affected by fluctuations in the magnetic field, but in the present invention, all constituent materials can be made of non-magnetic materials, and this point can be overcome. Therefore, it is extremely useful for devices that use charged particles.

[Embodiments of the invention]

FIG. 1 is a plan view showing a schematic configuration of a fine movement mechanism according to an embodiment of the present invention, FIG. 2a is a sectional view taken along arrow A-A in FIG. 1, and FIG. -B sectional view. In the figure, reference numerals 11, 12, 13, and 14 are rectangular plate-shaped movable members, and these movable members 11, 12, 13, and 14 are placed spaced apart on a conductive base 15 so as to form a square as a whole. has been done.
Adjacent moving members 11, -, 14 are connected by drive members 16, 17, 18, 19, respectively. That is, a driving member 16 is provided between the moving members 11 and 12, a driving member 17 is provided between the moving members 12 and 13, a driving member 18 is provided between the moving members 13 and 14, and a driving member 18 is provided between the moving members 14 and 11. A drive member 19 is provided. Drive member 16,~,1
9 is a piezoelectric element, for example, made of lead zirconate titanate, which expands and contracts according to the applied voltage, and the movable members 11, -, 14 are fixedly attached to both ends of the piezoelectric element in the direction of expansion and contraction (in the direction of the arrow shown in the figure). has been done. Note that this fixing may be done by adhesion, screwing, press-fitting, or the like.

A drive circuit 21a is connected to the drive member 16,
Similarly, a drive circuit 21b is connected to the drive member 17, a drive circuit 21c is connected to the drive member 18, and a drive circuit 21b is connected to the drive member 19. Drive circuit 2
A voltage adjustment circuit 22a is connected to 1a, and this voltage adjustment circuit 22a connects the power supply 25 to the branch circuit 2.
The power supply voltage supplied through the drive circuit 6 is adjusted to a predetermined voltage and applied to the drive circuit 21a. Similarly, voltages adjusted by voltage adjustment circuits 22b to 22d are applied to the other drive circuits 21b to 21d. Here, the voltage adjustment circuit 22
a, ~, 22d are driving members 1 by voltage application;
The voltage is adjusted so that the amount of expansion of the voltages 6 to 19 is the same. As a result, the output V _R of the voltage adjustment circuits 22a, 22d, Va, and
~, Vd, the amount of expansion of the driving member 16 due to the application of Va, the amount of expansion of the driving member 17 due to the application of Vb,
The amount of expansion of the driving member 18 due to the application of Vc and the amount of expansion of the driving member 19 due to the application of Vd are the same. The drive circuits 21a, -, 21d are
Controlled by the CPU 27, the voltage adjustment circuit 22a,
~, 22d output voltage V _R , its intermediate voltage (1/2)
Selecting V _R and zero voltage, driving member 11, ~,
14.

On the other hand, an electrode 31a is provided at the bottom of the moving member 11.
and an electrostatic chuck (fixed member) 31 consisting of insulating layers 31b and 31c.
2, 33, and 34 are provided, respectively. These electrostatic chucks 31, -, 34 attract and fix the movable members 11, -, 14 onto the base 15 by applying voltage. In addition, the electrostatic chuck 31,
. . . , 34 are provided with a drive circuit 35 similar to the moving member.
a, ~, 35d and voltage adjustment circuit 36a, ~, 3
6d is connected, and the voltage from the power source 25 is adjusted to a predetermined voltage and applied. The voltage adjustment circuits 36a, . . . , 36d adjust the voltage so that the attraction forces of the electrostatic chips 31, . As a result, the voltage adjustment circuits 26a, . . . , 26
If the output voltage V _S of d is Va, ~, Vd, the attraction force of the electrostatic chuck 31 due to the application of Va,
The attraction force of the electrostatic chuck 32 due to the application of Vb, the attraction force of the electrostatic chuck 33 due to the application of Vc, and the attraction force of the electrostatic chuck 34 due to the application of Vd are made equal.

Next, the operation of the mechanism of this embodiment configured as described above will be explained.

First, the voltage V _R applied to the drive circuits 21a, -, 21d by the voltage adjustment circuits 22a, -, 22d
are adjusted as described above, and the drive circuits 35a, 35a, 36d are adjusted as described above.
. . , 35d are adjusted as described above. And the drive circuit 21a,
~, 21d are voltage adjustment circuits 22a, ~, during steady state.
A voltage (1/2) V _R that is half of the output voltage V _R of 22d is applied, and the driving members 16, -, 19 are
It is assumed that a voltage of V _R is applied when expanding, and a voltage of zero is applied when contracting. Further, the drive circuits 35a, 35d are connected to the electrostatic chucks 31,
. . . , 34, the voltage adjustment circuit 36a,
It is assumed that an output voltage V _S of .about., 46d is applied.

Now, in order to make rotational movement, we need to use electrostatic chuck 3.
After fixing the movable members 13 and 14 on the base 15 by means 3 and 34, the driving member 1 is fixed as shown in FIG. 3a.
7 is extended, and the driving member 19 is contracted. This causes the moving members 11 and 12 to rotate slightly in the direction of arrow P. Next, electrostatic chucks 31, 3
After the movable members 11 and 12 are fixed on the base 15 by 2, the fixation of the movable members 13 and 14 by the electrostatic chucks 33 and 34 is released. In this state, as shown in FIG. 3b, when the driving member 17 is contracted and the driving member 19 is extended, the moving member 1
3 and 14 rotate slightly in the direction of arrow P. By repeating the above operations, the moving members 11, -, 1
4 will be rotated in the direction of arrow P.

For straight movement, electrostatic chuck 32,3
After fixing the movable members 12 and 13 on the base 15 using the steps 3 and 3, the driving members 16 and 1 are fixed as shown in FIG. 4a.
8 together. As a result, the moving member 1
1 and 14 make slight movements (straight movement) in the direction of arrow Q. Next, after the movable members 11 and 14 are fixed on the base 15 by the electrostatic chucks 31 and 34, the movable members 12 and 1 are fixed by the electrostatic chucks 31 and 33.
Unfix 3. In this state, when the drive members 16 and 18 are both retracted as shown in FIG. 4B, the movable members 12 and 13 are slightly moved in the direction of the arrow Q.
By repeating the above operations, the moving member 11,
. . . , 14 are forced to go straight in the direction of arrow Q.

Thus, according to this embodiment, the moving member 11,
. . . , 14 can be rotated or linearly moved, and it is also possible to rotate and linearly move simultaneously. Moreover, the moving members 11, -, 14
The direction of movement can be freely set by appropriately selecting the expansion and contraction actions of the driving members 16, .

In addition to this, the voltage adjustment circuits 22a, -, 22
By providing d, 36a, to 36d, the following effects can be obtained. That is, since only one power supply is required, the overall configuration can be made smaller. Moreover, the drive members 16, -, 19 and the electrostatic chuck 3
Since the differences in voltage-displacement characteristics and voltage-attractive force characteristics of Nos. 1 to 34 are compensated for, accurate fine movement can be achieved regardless of the machining accuracy of the parts.

FIG. 5 is a plan view showing the main structure of another embodiment. Note that the same parts as in FIG. 1 are given the same reference numerals, and detailed explanation thereof will be omitted. This embodiment differs from the previously described embodiments in that the movable members 11, -, 14 are connected by an elastic hinge 51 that utilizes elastic deformation of the material, and other points are different from the previous embodiments. The same is true. With such a configuration, it goes without saying that the same effects as the previous embodiment can be achieved.
The drive members 16, -, 19 and the electrostatic chuck 31,
. . , 34 during driving and fixing.

Note that the present invention is not limited to the embodiments described above. In the embodiment described above, a case has been described in which four moving members and four driving members are used, but this can be modified as appropriate as long as the number of driving members is at least two or more. For example, if there are three, moving members 61, 62, 63 and driving members 64, 65, 66 are used as shown in FIG. In this case, the driving members 64 and 65 may be expanded and contracted simultaneously. Furthermore, in this case, the elastic hinges 67 provided between the moving members 61, . . . , 63 and the driving members 64, .

Further, the shape, dimensions, etc. of the moving member may be determined as appropriate according to specifications. Furthermore, the fixing member is not necessarily limited to an electrostatic chuck, but may be an electromagnetic chuck or other material. Also,
The driving method of the movable member that combines the expansion and contraction action of the driving member and the fixing action of the fixed member may be changed as appropriate depending on conditions such as the desired movement and its direction. Furthermore, the voltage applied to the drive member may be determined as appropriate depending on conditions such as desired speed of movement and amount of movement. In addition, various modifications can be made without departing from the gist of the present invention.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a schematic configuration of a fine movement mechanism according to an embodiment of the present invention, FIG. 2a is a sectional view taken along arrow A-A in FIG. 1, and FIG. The BB sectional view, FIGS.
6 is a plan view showing a modified example, and FIGS. 7 a to 7 c are diagrams showing a schematic structure of a conventional example. 11, ~, 14... Moving member, 15... Base, 1
6, ~, 19... Drive member, 21a, ~, 21d,
35a, ~, 35d...drive circuit, 22a, ~, 2
2d, 36a, ~, 36d... Voltage adjustment circuit, 25
...power supply, 26...branch circuit, 27...CPU, 31,
~, 34... Electrostatic chuck (fixing member).

Claims (1)

[Scope of Claims] 1. Consisting of a plurality of moving members movably placed on a base and a piezoelectric element that expands and contracts according to applied voltage, each of the moving members is attached to both ends of the piezoelectric element in the direction of expansion and contraction. Two or more drive members that connect adjacent moving members, a drive circuit that is separately connected to each of these drive members and divides an input voltage and applies it to each of the drive members, and these drive circuits. 1
The power supply voltage is adjusted to a predetermined voltage so that the amount of expansion and contraction of each drive member is equal when a voltage is applied to each drive member via the drive circuit. A fine movement mechanism comprising: a voltage adjustment circuit for applying to a drive circuit; and a fixing member for selectively fixing each of the movable members on the base. 2. The drive circuit that drives the drive member selects the voltage V _R adjusted by the voltage adjustment circuit, the half voltage (1/2) V _R , and zero voltage and applies them to the drive member. The fine movement mechanism according to claim 1, characterized in that: 3. The fine movement mechanism according to claim 1, wherein the movable member is rotated and moved by the expansion and contraction action of the driving member and the fixing action of the fixed member. 4. The fine movement mechanism according to claim 1, wherein the fixed member is formed by forming an electrostatic chuck consisting of an electrode and a dielectric layer on the surface layer of each moving member. 5 Drive circuits for selectively applying an input voltage to the fixed members are connected to each of the fixed members, and a connection between the drive circuits for these fixed members and the power source or another power source is connected to the fixed members. are respectively connected to voltage adjustment circuits, and these voltage adjustment circuits are connected to the power supply so that the attraction force of each of the fixed members is equal when the input voltage of the drive circuit for the fixed member is applied to the fixed member. Claim 4, characterized in that the voltage is adjusted to a predetermined voltage and applied to the drive circuit for the fixing member.
Fine movement mechanism described in section.