JPH071447B2 - Fine positioning device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a fine positioning device used in a semiconductor manufacturing apparatus, an electron microscope, or any other apparatus requiring adjustment on the order of μm.

[Conventional technology]

In recent years, in various technical fields, a device capable of fine displacement adjustment on the order of μm has been demanded. A typical example thereof is a semiconductor manufacturing apparatus such as an LSI (Large Scale Integrated Circuit), a mask aligner used in a manufacturing process of a VLSI, an electron beam drawing apparatus and the like. In these devices, μm
Fine positioning on the order is required, and as the positioning accuracy improves, the degree of integration increases, and high-performance products can be manufactured. Such fine positioning is necessary not only in the above-mentioned semiconductor device but also in various high-magnification optical devices such as electron microscopes, and by improving its precision, even in advanced technologies such as biotechnology and space development. Will greatly contribute to the development of.

By the way, in the higher-order positioning, translational displacement that moves in one direction along one plane and rotational displacement that rotates about one axis are considered. Among these, as a fine positioning device for performing rotational displacement, Japanese Patent Publication No.
The device shown in Japanese Patent Publication has been proposed. This will be described with reference to the drawings.

FIG. 3 is a partially cutaway perspective view of a conventional fine positioning device that performs fine rotational displacement. In the figure, 11 is a cylindrical central fixing portion, and 11a, 11b, 11c are vertical grooves formed on the circumferential surface of the central fixing portion 11 at equal intervals in the longitudinal direction. Reference numeral 12 denotes a ring-shaped stage that is rotatably provided around the central fixed portion 11.
a _{1 to} 12a ₃ , 12b _{1 to} 12b ₃ , 12c _{1 to} 12c ₃ are vertical grooves 11a, 11 respectively.
The U-shaped metal fitting is fixed to the stage 12 so as to face b and 11c. 13 is each vertical groove 11a, 11b, 11c and each U-shaped metal fitting 12a _{1 to} 12c
A bimorph type piezoelectric element 13A mounted between the two and ₃ is a projection fixed to a portion of the bimorph type piezoelectric element 13 that engages with the U-shaped metal fitting. The central fixed portion 11, the stage 12, the U-shaped bracket 12a ₁ ~12c ₃ is rigid both. Here, the bimorph type piezoelectric element 13 will be briefly described with reference to FIG.

FIG. 4 is a perspective view of a bimorph type piezoelectric element. In the figure,
Reference numerals 13a and 13b are piezoelectric elements, and 13c is a common electrode provided between the piezoelectric elements 13a and 13b. The piezoelectric elements 13a and 13b are the common electrode 1
They are closely attached to each other with 3c clinging together. Reference numerals 13d and 13e denote surface electrodes fixed to the piezoelectric elements 13a and 13b, respectively. In this state, a voltage with a polarity that contracts the piezoelectric element 13a is applied between the surface electrode 13d and the common electrode 13c, and at the same time, a voltage with a polarity that extends the piezoelectric element 13b between the surface electrode 13e and the common electrode 13c is applied. When applied, each piezoelectric element 13a, 13b expands and contracts in the direction of the arrow, so that the entire bimorph piezoelectric element 13 is deformed as shown in the figure. With such a bimorph piezoelectric element 13, it is possible to obtain a large displacement amount as compared with a single piezoelectric element.

Such a bimorph-type piezoelectric element 13 has the one end fixed to the longitudinal grooves 11a, 11b, 11c and the other end free end in the apparatus shown in FIG. 3, and the projection 13A is formed on each corresponding U-shaped metal fitting. Are in contact through. Now, when an appropriate voltage is applied to each bimorph type piezoelectric element 13 to cause the deformation shown in FIG. 4,
The stage 12 is rotationally displaced about the central fixed portion 11 according to the deformation. Therefore, if the fine movement table is placed and fixed on the stage 12, a fine rotational displacement of the fine movement table can be obtained.

The above-mentioned conventional device includes a U-shaped metal fitting and a bimorph piezoelectric element.
13 and both are held in an engaged state, which allows the bimorph type piezoelectric element 13 to be mounted while being naturally deformed,
In addition, displacement constraint (interference) that occurs when the bimorph piezoelectric element 13 is fixed to the stage 12 is prevented.

[Problems to be Solved by the Invention]

By the way, the conventional fine positioning apparatus shown in FIG. 3 has the following problems. That is, the configuration of the device is
Not only is the configuration itself complicated, but the mounting position of each U-shaped metal fitting must be determined in accordance with the tip position of each bimorph-type piezoelectric element 13, which requires a great deal of labor and time to manufacture. In addition, the engagement between the bimorph-type piezoelectric element 13 and the U-shaped metal fitting is not allowed to be loose, and therefore the sliding resistance with the U-shaped metal fitting when the bimorph-shaped piezoelectric element 13 is deformed. There is a large and still large interference.

Further, with the device shown in FIG. 3, although rotational displacement about the axis along the central fixed portion 11 can be obtained, rotational displacement about other axes cannot be obtained. And like this 2
It is possible to combine two devices shown in FIG. 3 in order to obtain rotational displacement about one axis, but it is difficult to construct this combination.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a fine positioning device capable of obtaining rotational displacement about two axes with an extremely simple structure.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a rigid support plate, and at least one radial flexure provided on the support plate and generating a rotational displacement about a first axis. A beam displacement mechanism, at least one radial flexural beam displacement mechanism provided on the support plate for generating a rotational displacement about a second axis orthogonal to the first axis, and a rotational displacement about the first axis A fine movement table connected to the side of the radial flexure beam displacement mechanism opposite to the support plate, and one side of the radial flexure beam displacement mechanism opposite to the support plate of the radial flexure beam displacement mechanism that generates rotational displacement about the second axis. It is characterized in that the fine positioning device is constituted by a fixed part connected to the other end and connected to the fixed end on the other side.

[Action]

When the radial flexible beam displacement mechanism that generates rotational displacement about the first axis is driven, the rotational displacement due to this drive appears on the fine movement table on the opposite side of the support plate in the radial flexible beam displacement mechanism, and also the second axis. When the radial flexure beam displacement mechanism that causes rotational displacement is driven, the rotational displacement caused by this drive appears on the fine movement table via the support plate and the radial flexure beam displacement mechanism that causes rotational displacement about the first axis.

〔Example〕

 Hereinafter, the present invention will be described based on the illustrated embodiments.

FIG. 1 is a perspective view of a fine positioning device according to an embodiment of the present invention. In the figure, x, y, and z indicate coordinate axes. Reference numeral 15 is a support plate made of a rigid member. 16Mya and 16Myb are radial bending beam displacement mechanisms symmetrically arranged on the support plate 15. The radial flexure beam displacement mechanisms 16Mya and 16Myb generate rotational displacements around a common axis (y 'axis) extending in the y-axis direction. 16Mxa and 16Mxb are radial bending beam displacement mechanisms symmetrically arranged on the support plate 15, and each generate a rotational displacement about a common axis (x 'axis) extending in the x-axis direction. Radial flexible beam displacement mechanism 16Mya, 16Myb, 16Mxa,
The structure of 16Mxb will be described later.

Reference numerals 17a and 17b are one rigid body portion (the other rigid body portion is a support plate 15) constituting the radial flexure beam displacement mechanism 16Mya, 16Myb, 18
a and 18b are the rigid body parts of the radiating flexible beam displacement mechanism 16Mxa and 16Mxb, respectively (the other rigid body part is also the support plate 15)
Is. Reference numerals 19a and 19b are L-shaped fixed legs fixed to the rigid body portions 18a and 18b, respectively, and 20 is a fine movement table fixed to the rigid body portions 17a and 17b. An object to be finely positioned is placed and fixed on the fine movement table 20.

Here, the radial flexible beam displacement mechanism will be described with reference to the drawings. 2 (a) and 2 (b) are side views of the radial flexible beam displacement mechanism. In the figure, 25a and 25b are rigid body portions existing on the left and right sides, respectively. Reference numerals 26 and 26 'denote flat-plate radiating flexible beams which are integrally formed between the rigid body portions 25a and 25b, respectively, and are arranged radially around the fixed point O. Reference numeral 27 is a through hole formed to integrally form the radial bending beams 26, 26 'and the rigid body portion. 28a is a protrusion protruding from the rigid body portion 25a into the through hole 27, 28b is a protrusion protruding from the rigid body portion 25b into the through hole 27, these protrusions 28a, 28b are spaced from each other in the vertical direction of the drawing. It overlaps. 29 is a protrusion 28a and a protrusion 2
It is a piezoelectric actuator fixed between 8b and. When a circle passing through the piezoelectric actuator 29 with the point O as the center is drawn, the piezoelectric actuator 29 draws a force f in the tangential direction of the circle.
(Corresponding to the torque related to the point O) is generated to cause bending deformation in each radial flexible beam. The magnitude of these forces is controlled by the voltage applied to the piezoelectric actuator 29. Reference numeral 30 denotes a rigid body structure that supports the rigid body portion 25a.

In the above structure, the rigid body portions 25a, 25b, the radial flexible beam 26,
26 ', the protrusions 28a, 28b, and the piezoelectric actuator 29 constitute a radial bending beam displacement mechanism 32. A line perpendicular to the paper surface passing through the point O is used as a reference axis indicating the position and installation direction of the radial flexible beam displacement mechanism 32.

Next, the operation of the radial bending beam displacement mechanism described above is shown in FIG. 2 (b).
Will be described with reference to. FIG. 2 (b) is FIG. 2 (a).
FIG. 9 is a side view after the deformation of the radial flexible beam displacement mechanism 32 shown in FIG. Now, a voltage is applied to the piezoelectric actuator 29 to generate the force f in the contact line direction. Then, the protrusion 28b
Is pushed upward along the tangent line by the force generated in the piezoelectric actuator 29. Since the rigid body portion 25b is connected to the rigid body portion 25a by the radiating flexible beams 26, 26 ', the rigid body portion 25a of the radiating flexible beam 26, 26' is subjected to the above force.
Is a straight line extending radially from the point O.
A portion of L ₁ and L ₂ which is connected to the rigid body portion 25b is a straight line slightly deviated from the straight lines L ₁ and L ₂ (this straight line is also a straight line extending radially from the point O.) L ₁ There is a small displacement that shifts on ′, L ₂ ′. Therefore, the rigid portion 25b rotates clockwise by a minute angle δ in the figure. Since the magnitude of this rotational displacement δ is determined by the bending rigidity of the radial bending beams 26, 26 ′, if the force F is accurately controlled, the rotational displacement δ can be controlled with the same accuracy.

When the voltage applied to the piezoelectric actuator 29 is removed, each radiating flexible beam 26, 26 'returns to the state before deformation,
The radial flexible beam displacement mechanism 32 returns to the state shown in FIG. 2 (a), and the rotational displacement δ becomes zero.

From the above description of the radial flexible beam displacement mechanism, the reference axis of the radial flexible beam displacement mechanism 16Mya, 16Myb shown in FIG. 1 is the y ′ axis, and the reference axis of the radial flexible beam displacement mechanism 16Mxa, 16Mxb is the x ′ axis. I know there is. Further, the support plate 15 shown in FIG. 1 corresponds to the rigid body portion 25a, and the rigid body portions 17a, 17b, 18a, 18b are rigid body portions 25a.
We also know that it corresponds to b. However, in the radial flexible beam displacement mechanisms 16Mxa and 16Mxb, the rigid body structure supporting them is on the rigid body portions 18a and 18b side.

Furthermore, each radial flexural beam displacement mechanism 16Mya, 16 shown in FIG.
The reference axes y ', x'of Myb, 16Mxa, 16Mxb are made to pass on the surface of the fine movement table 20 by selecting the radiation angle .theta. Of their radial bending beams 26, 26'.

Here, the operation of this embodiment will be described. Radiant flexible beam 16My
When the same voltage is applied to the piezoelectric actuators a and 16 Myb, the radiating flexible beam is deformed as shown in FIG. 2 (b) according to this voltage. In this case, the support plate 15 is fixed to the fixed legs 19a, 19
b, Since the radial flexible beam displacement mechanism 16Mxa, 16Mxb is in a fixed state, the radial flexible beam displacement mechanism 16Mya, 16Myb is y ′
Rotational displacement is generated around the axis, which causes the fine movement table.
20 is rotationally displaced about the y'axis.

Further, when the same voltage is applied to the piezoelectric actuators of the radial flexure beam displacement mechanisms 16Mxa and 16Mxb, the radial flexure beam is deformed according to this voltage, and rotational displacement about the x'axis is generated. This rotational displacement is caused by the support plate 15 and the radial flexible beam displacement mechanism 16
A voltage is applied to the fine movement table 20 via Mya and 16Myb, and the fine movement table 20 is rotationally displaced about the x ′ axis.

Further, when the radial flexible beam displacement mechanisms 16Mya, 16Myb and the radial flexible beam displacement mechanisms 16Mxa, 16Mxb are driven simultaneously, the rotational displacement of the fine movement table 20 becomes a rotational displacement that is a combination of the rotational displacements of the two.

Thus, in this embodiment, two radial bending beam displacement mechanisms that cause rotational displacement about the y'axis are symmetrically provided on one support plate, and x that is orthogonal to the y'axis is provided on the support plate. 'Because two radial bending beam displacement mechanisms that generate rotational displacement around the axis are provided symmetrically, the fine movement table is fixed to the front rigid body part, and the fixing legs are fixed to the latter rigid body part, so it is simple, small, and It is possible to obtain rotational displacement about two axes with a configuration that is easy to mount on a device to be used and is easy to use. In addition, y ′, which is the reference axis of each radial flexible beam displacement mechanism,
Since the axis and the x'axis are on the fine movement table, the rotational center of the rotational displacement is also on the fine movement table, and accurate rotational displacement can be performed.

In the description of the above embodiment, an example in which two radial bending beam displacement mechanisms of each axis are symmetrically provided is described.
The invention is not limited to this, and one of them may be provided in the center. In this case, when one radial flexible beam displacement mechanism provided at the center does not fix the fixed portion, the rigid body portion serves as a fine movement table. Also, the y'axis,
The x'axis does not necessarily have to be present on the surface of the fine movement table and can be arbitrarily selected.

〔The invention's effect〕

As described above, according to the present invention, a radial flexible beam displacement mechanism for generating a rotational displacement about one axis on a rigid support plate, and a radial flexible beam displacement for generating a rotational displacement about an axis orthogonal to the axis. Since it has a mechanism, it is simple, compact,
In addition, it is possible to obtain the rotational displacement about the two axes with a configuration that is easy to mount on the target device and is easy to use.

[Brief description of drawings]

FIG. 1 is a perspective view of a fine positioning device according to an embodiment of the present invention, FIGS. 2 (a) and 2 (b) are side views of the radial bending beam displacement mechanism shown in FIG. 1, and FIG. FIG. 4 is a partially cutaway perspective view of the positioning device, and FIG. 4 is a perspective view of the bimorph piezoelectric element shown in FIG. 15 …… Support plate, 16Mya, 16Myb, 16Mxa, 16Mxb …… Radial flexural beam transformation mechanism, 17a, 17b, 18a, 18b …… Rigid body, 19a, 19b ……
Fixed legs, 20 ... Fine movement table.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ken Murayama 650 Jinrachi-cho, Tsuchiura City, Ibaraki Prefecture Tsuchiura Plant, Hitachi Construction Machinery Co., Ltd. (56) References JP-A 61-209846 (JP, A) JP-A Sho 61-243511 (JP, A) JP-A-62-187912 (JP, A) JP-A-60-25284 (JP, A) US Patent 3786332 (US, A)

Claims (5)

[Claims] 1. A rigid support plate, at least one radial bending beam displacement mechanism provided on the support plate for generating rotational displacement about a first axis, and the first support beam provided on the support plate. At least one radial flexible beam displacement mechanism for generating rotational displacement about a second axis orthogonal to the axis, and on the opposite side of the support plate of the radial flexible beam displacement mechanism for generating rotational displacement about the first axis; A fine movement table connected thereto; and a fixed portion connected to the opposite side of the radial bending beam displacement mechanism for generating rotational displacement about the second axis from the support plate and the other connected to a fixed end. A fine positioning device characterized in that 2. The radiating flexible beam displacement mechanism according to claim 1, wherein the radial bending beam displacement mechanism is the first shaft or the second shaft.
A plurality of flexible beams extending radially with respect to the axis of
A fine positioning device comprising: an actuator that causes the bending beam to generate bending deformation due to a moment about the axis. 3. The fine positioning device according to claim (2), wherein the actuator is a piezoelectric actuator. 4. The radial flexure beam displacement mechanism according to claim (1), which is provided on the support plate so as to face each other, so that the radial deflection beam displacement mechanism generates a rotational displacement about the first axis. A fine positioning device. 5. The radial flexure beam displacement mechanism according to claim (1), wherein two radial deflection beam displacement mechanisms that generate rotational displacement about the second axis are provided facing each other on the support plate. A fine positioning device.