JP2758185B2 - Micro-motion stage - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine moving stage used for a surface shape measuring device, a laser microscope, and the like, and in particular, a movable range of a fine moving stage using a parallel leaf spring. Regarding improvement.

[Conventional technology]

In recent years, there has been an increasing need for observing the surface structure of a highly integrated semiconductor element and the defect structure of a material surface of a high-density sintered body, glass, or a metal at a high resolution for each minute region.

The fine movement stage used for such observation is required to be one that performs high-precision displacement movement with little change in posture and hysteresis due to movement of the stage.
As shown in JP-A-219584 and the like, a structure in which a stage is elastically supported by a parallel leaf spring is used.

A fine moving table using this parallel leaf spring generally has a structure as shown in FIGS. That is, two thin rectangular leaf springs 4, 5 are bridged and fixed at both ends of two fixed blocks 2, 3 fixed on the base 1 so as to bridge the parallel leaf springs 4, 5, respectively. The stage 6 is erected and fixed so as to bridge the respective central portions of the parallel leaf springs 4 and 5, and the stage 6 is fixed to two fixed blocks 2 and 3 by two sets of parallel leaf springs a1. , a2 so as to be elastically supported and fixed. The stage 6 is moved in a direction perpendicular to the parallel leaf springs a1 and a2 by an actuator 7 such as a laminated piezoelectric element fixed to the base 1, ie, Y
And displaced. The object placed on the stage 6 is deformed with high reproducibility with good reproducibility together with the stage 6 by the two sets of parallel leaf springs a1 and a2 being elastically deformed with the change of the urging force of the actuator 7. Can be performed.

When moving in the X direction and the Y direction with such a fine moving stage, another fine moving stage is installed on the stage so that the moving directions are orthogonal to each other.

[Problems to be solved by the invention]

However, the conventional finely movable stage using the parallel leaf springs a1 and a2 moves the stage by the elastic deformation (bending and slight elongation) of the parallel leaf spring itself in response to the vertical biasing force acting on the parallel leaf spring. Therefore, it is necessary to move the stage within a region where the permanent leaf spring and the hysteresis do not occur in the parallel leaf spring, and there is a problem that the possible range of the stage cannot be made large.

For example, the length of the elastically deformed portions of the parallel leaf springs a1 and a2 is 10 m.
m, the leaf spring is 0.12μ to move the stage by 50μm just by paying attention to the extension of the deformation of the leaf spring.
In order to move the stage by 100 μm, the leaf spring needs to expand by 0.50 μm. However, in order to secure this elongation, excessive tension acts on the parallel leaf springs a1 and a2, and the fixed blocks 2 and 3 are drawn inward by the base 1 flexing and the movement of the stage 6 is linear. However, there is a problem that it becomes an arc shape instead of a shape and sinks as it moves. FIG. 9 shows an actual measurement example,
The horizontal axis indicates the amount of movement (μm) of the stage, and the vertical axis indicates the amount of displacement (μm) of the stage in the height direction due to movement. In this example, it is shown that when the stage is moved by 100 μm, the stage moves in an arc shape with a height D = 0.1 μm and sinks by H = 0.39 μm. Under these circumstances, the movable region of the stage can be used only in a very narrow range when a highly accurate displacement movement is required.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the above-mentioned problems and to provide a fine moving stage having a wider movable range in which a highly accurate displacement movement is maintained.

[Means for solving the problem]

The present invention has achieved the object by solving the above problems by the following means.

That is, a base, a stage provided movably with respect to the base, an actuator fixed to the base, and provided so as to apply a moving force to the stage,
A fine moving stage including at least a first elastic member elastically deformed in a direction including a moving direction of the stage and at least a second elastic member elastically deformed in a direction including a direction perpendicular to the moving direction of the stage; The stage is supported and fixed to the second elastic member via the first elastic member, and the second elastic member moves right and left of a virtual center line drawn in parallel with the moving direction of the stage. And four elastically deformable portions provided in the second elastically deformable member, and the elastically deformable portions are formed by making cuts in the second elastically deformable member.

Further, a base, a stage movably provided with respect to the base, an actuator fixed to the base and provided so as to apply a moving force to the stage, and a direction including at least a moving direction of the stage. And a second elastic member elastically deformed in a direction including at least a direction perpendicular to the moving direction of the stage, wherein the stage comprises the first elastic member. Are supported and fixed to the second elastic member via the elastic member, and the second elastic member has four elastic members provided on the left and right of a virtual center line drawn in parallel with the moving direction of the stage. The elastic deformation portion includes a support member for supporting the first elastic deformation member, a fixing member fixed to the base, and connecting the support means and the fixing member together with the elastic deformation portion. It is formed from the coupling elastic deformation portion that.

[Action]

By taking such a measure, the following operation occurs.

The first elastic member is deformed in the direction including the moving direction of the stage by the action of the moving force applied to the actuator. The stage moves accordingly. At this time, tension is generated in the first elastic member, but the second elastic member is elastically deformed to reduce the tension generated in the first elastic member. Therefore, the stage can be moved without applying excessive tension to the first elastic member when the stage is moved. In addition, due to the deformation of the first elastic member and the second elastic member, the linearity is excellent even in a wide range of movement,
In addition, the stage moves with little sinking.

〔Example〕

 Hereinafter, the present invention will be described in detail with reference to examples.

FIGS. 1 and 2 are a plan view and a front view, respectively, showing a first embodiment of a fine movement stage according to the present invention. The same members as those in the examples of FIGS. 7 and 8 described in the prior art are denoted by the same reference numerals.

As shown in the figure, two stainless steel rectangular parallelepiped fixing blocks 2 and 3 are fixed on the upper surface of the base 1 in parallel with screws at an interval, and the two fixing blocks 2 and 3 are fixed. The T-shaped slits 8, 89, 9 'are formed by wire saws at both ends of the elastic deformation parts 10, 10', respectively.
11, 11 'and the leaf spring mounting part provided at the tip thereof,
12 ', 13, 13' are provided integrally with the respective fixed blocks 2, 3. It should be noted that the fixing block 2,
The mounting surface 3 has a shape shown by a dotted line in the figure, so that the elastically deforming portion and the leaf spring mounting portion do not contact the base 1.

The leaf springs 4 are bridged and fixed between the leaf spring mounting portions 12 and 12 'so as to bridge them, and the leaf spring mounting portions 13 and 13' are fixed.
The parallel leaf springs 4 and 5 are formed by erecting and fixing the leaf spring 5 between them. In this example, phosphor bronze plates are used as the leaf springs 4 and 5. Both ends of the stage 6 are erected and fixed so as to bridge the respective central portions of the parallel leaf springs 4 and 5, and the stage 6 is provided with four leaf spring mounting portions 12, 12 ', 13, 1
3 'is elastically supported and fixed by two sets of parallel leaf springs a1 and a2.

To attach and fix the leaf springs 4 and 5 to the leaf spring mounting section and the stage, hold down the leaf springs 4 and 5 with the holding plates 14, 14 ', 15, 15', 16, 17 and screw 18 to fix them. It is done by tightening. The stage 6 is formed with a concave portion 19 which is opened on the lower side, in which the laminated piezoelectric actuator 7 is disposed, and one end is fixed to a base.
And the other end thereof is in contact with an adjustment contact 21 screwed to the side wall of the stage 6.

The leaf springs 4 and 5 are arranged in a direction orthogonal to the moving direction (Y direction) of the stage 6 by the actuator 7, and the stage 6 and the leaf spring mounting portions 12 and 12 ′ The stage 6 and the leaf spring mounting portions 13 and 13 'are connected to the two equal length elastic deformation portions 5- of the leaf spring 5 via the same length elastic deformation portions 4-1 and 4-2. 1,5-2
Are connected to each other via a support. The elastic deformation portions 10, 10 ', 11, 11' fixed to the fixed blocks 2, 3 are arranged in a direction substantially parallel to the moving direction of the stage 6.

In other words, the stage 6 is supported by a symmetrical support structure with respect to an imaginary center plane provided in a direction parallel to the moving direction of the stage and perpendicular to the base 1. be able to.

 Next, the operation of the first embodiment will be described.

When the stage 6 moves in the Y direction by the operation of the actuator 7, the parallel springs a1 and a2 arranged in the X direction generate a tension as well as bending deformation as the stage 6 moves. In accordance with this tension, the elastic deformation portions 10, 10 ', 11, 11' provided on the fixed blocks 2, 3 are each bent inward and elastically deformed, so that the leaf spring mounting portion is formed.
Since the 12,12 ', 13,13' are displaced inward, that is, in the X direction, the tension applied to the parallel springs a1, a2 is maintained at an appropriate value without becoming excessive.

Further, since the support structure of the stage 6 is symmetrical with respect to the center line drawn in the movement direction (Y direction), the plate spring 4
The tensions applied to the elastically deformable portions 4-1 and 4-2 of the leaf spring 5 are equal in opposite directions.
The same applies to the tension applied to the elastic deformation portion 5-2 and the elastic deformation portions 5-2. Therefore, the left and right displacement amounts of the elastic deformation portions 10 and 11 and the elastic deformation portions 10 'and 11' become equal in opposite directions. Does not move in the X direction due to the movement in the Y direction.

FIG. 3 shows an actual measurement example of the fine moving table of this embodiment. The horizontal axis is the amount of movement of the stage in the Y direction (μm)
The vertical axis indicates the amount of displacement (μm) of the stage in the height direction due to the movement of the stage. In this example, 100μ
In the movement of the stage m, the stage moves linearly, and the sinking amount H of the stage is also extremely low at 0.05 μm, which is significantly improved as compared with the measurement result of the conventional example shown in FIG. You can see that it is done.

As described above, the effect of relieving the tension applied to the parallel leaf springs by providing an elastically deformable portion integrally by forming a slit in the leaf spring mounting portion of the fixed block to which the parallel leaf springs a1 and a2 are attached is remarkable. This is because the elastically deformable portions 10, 10 ', 11, 11' formed integrally with the fixed block form the elastically deformable portions 4-1, 4-1 of the leaf springs 4, 5 supporting the stage 6.
The elastic constant is larger than 2,5-1,5-2 and it is rigid, and it only plays a role of relaxing the tension applied to the elastic deformation part of the leaf spring without generating other noise. Conceivable.

Therefore, the shape of the slit and the shape of the elastically deformable portion formed in the fixed block are not limited to those of this embodiment, and may be any shape that elastically deforms so as to reduce the tension applied to the parallel leaf spring supporting the stage. I just need. Also,
Without providing an elastic deformation portion on the side of the fixed block, the stage 6
May be provided to elastically support the mounting portions of the parallel leaf springs a1 and a2.

FIG. 4 is a plan view showing a second embodiment of the present invention. The same members as those in the example of FIG. 1 are denoted by the same reference numerals, and description thereof is omitted.

In this second embodiment, elastic deformation members 26, 26 ', 27, 27' for connecting between the fixed blocks 22, 23 and the leaf spring mounting members 24, 24 '25, 25' are screwed together with a holding plate. The difference from the first embodiment lies only in the external connection.
The elastically deformable members 26, 26 ', 27, 27' are parallel plate springs a1, a2.
A rigid leaf spring having a larger elastic constant than that is used to form parallel leaf springs b1 and b2 arranged in a direction parallel to the moving direction of the actuator.

FIG. 5 is a plan view showing a third embodiment of the present invention. The same members as those in the previous examples are denoted by the same reference numerals, and description thereof will be omitted.

This example is a modification of the second embodiment, but has basically the same structure.

The center portions of the leaf springs 30 and 31 are attached to the side surfaces of the fixed blocks 28 and 29 provided on the base 1, respectively, and both ends of the leaf springs are extended outward. Leaf spring mounting members 32, 32 ', 33, 33' are mounted respectively. The ends of the leaf springs 4 and 5 whose center portions are attached to the end surfaces of the stage 6 are attached to the corresponding leaf spring attachment members 32, 32 ', 33 and 33' at a ratio of 1: 1. ing.

The leaf springs 30 and 31 have a higher elastic coefficient than the leaf springs 4 and 5, and therefore have rigidity.

Thereby, the stage 6 is provided symmetrically with respect to the virtual center line drawn in parallel with the moving direction of the stage.
Elastic supports, one of which is a leaf spring 4
The elastically deformable portion 4-1 and the elastically deformable portion 30-1 of the leaf spring 30 are supported by a leaf spring attachment member 32.

In other words, two sets of parallel leaf springs a1 and a2 arranged in a direction orthogonal to the direction of movement of the stage 6 and two sets of parallel leaf springs arranged in a direction parallel to the direction of movement of the stage 6 The stage 6 is elastically supported by the base 1 by the parallel plate springs b1 and b2.

Now, when the stage 6 moves in the Y direction by operating an actuator (not shown), the elastic deformation portions 4-1 and 4 of the leaf springs 4 and 5 disposed in a direction perpendicular to the Y direction.
Bending elastic deformation occurs at -2,5-1,5-2, and tension is generated. This tension causes the elastically deforming portions 30-1, 31 of the leaf springs 30, 31, which are arranged in a direction parallel to the moving direction of the stage.
Bend elastic deformation occurs in -1,30-2,31-2, and the leaf spring mounting members 32,32 ', 33,33' are respectively moved inward.

Therefore, the tension generated in the elastically deformed portions of the leaf springs 4 and 5 does not become excessive, the highly accurate movement of the stage 6 is stably maintained, and the movable range is expanded.

FIG. 6 is a plan view showing a fourth embodiment of the present invention.

This example, contrary to the previous examples,
Leaf springs b1, b2 arranged in a direction parallel to the direction of movement of
Stage 34 and leaf spring mounting members 35, 35 ', 36, 3
6 'and fixed blocks 37, 38 provided on the base 1 by means of parallel leaf springs a1, a2 arranged in a direction perpendicular to the moving direction of the stage, and leaf spring mounting members 35, 3
5 ', 36, 36'.

Also in this example, the parallel leaf springs b1 and b2 are
A rigid material having a larger elastic coefficient than a2 is used.

 The operation of this embodiment is as follows.

When the stage 34 moves in the Y direction, the parallel leaf springs b1, b2
Then, the leaf spring mounting members 35, 35 ', 36, 36' are moved in the Y direction, so that the parallel leaf springs a1, a2 undergo bending elastic deformation and generate tension. Due to this tension,
Bending elastic deformation occurs in the parallel leaf springs b1 and b2, displacing the leaf spring mounting members outward, respectively.
The tension of the stage 34 does not become excessive, and the movement of the stage 34 is maintained with high accuracy.

Therefore, this example can be said to have substantially the same configuration and operation as the configuration and operation when the stage is moved in the X direction on the fine moving stage shown in FIG.

The present invention is not limited to the embodiments described above, but includes many modifications and changes.

For example, if the supporting structure of the stage has a structure which is symmetrical with respect to an imaginary moving direction parallel to the moving direction of the stage and perpendicular to the base, if it is an apparatus (a component perpendicular to the moving direction, that is, a component force in the X direction) Are offset each other), the parallel leaf springs a1, a2, b1, and b2 do not have to be strictly orthogonal or parallel to the moving direction, and the parallelism and the length of the elastically deformed portion in each differ. You may.

Further, in the third and fourth embodiments, the ends of the parallel leaf springs a1 and a2 and the ends of the parallel leaf springs b1 and b2 may be constituted by an integral leaf spring directly connected without interposing a leaf spring mounting member. it can.

Furthermore, if an actuator for urging in the X direction is provided in addition to the main actuator for urging the stage in the Y direction,
Although a wide movable range cannot be obtained in the X direction, an X, Y movable stage can be used.

〔The invention's effect〕

According to the present invention, it is possible to move the stage with high accuracy, and it is possible to provide a finely movable stage having a wider movable range.

[Brief description of the drawings]

1 and 2 are a plan view and a front view, respectively, showing a first embodiment of a finely-moving stage according to the present invention, FIG. 3 is a graph showing the movement accuracy of the stage in the first embodiment, and FIG. FIG. 5 is a plan view showing a second embodiment of the fine moving table of the present invention, FIG. 5 is a plan view showing a third embodiment of the fine moving table of the present invention, and FIG. 6 is a fourth embodiment of the present invention. FIGS. 7 and 8 are a plan view and a front view showing a conventional fine moving stage, and FIG. 9 is a graph showing the movement accuracy of the stage in this conventional example. 1 Base 6 34 Stage 7 Actuator a1, a2, b1, b2 Parallel leaf springs 4-1 4-2-5-1 5-2 -10 10,10 ', 11 11 ', 30-1,30-2,3
1-1,31-2 ... Elastic deformation part 26,26 ', 27,27' ... Elastic deformation member 8,8 ', 9,9' ... Slit 12,12 ', 13,13' ... Plate Spring mounting parts 24,24 ', 25,25', 32,32 ', 33,33', 35,35 ', 36,36' ...
… Leaf spring mounting member

Claims (4)

(57) [Claims] 1. A base, a stage movably provided with respect to the base, an actuator fixed to the base and provided to apply a moving force to the stage, and at least a moving direction of the stage. A first elastic member elastically deformed in a direction including: and a second elastic member elastically deformed in a direction including at least a direction perpendicular to the direction of movement of the stage. The second elastic member via the first elastic member;
The second elastic member includes four elastic deformation portions provided on the left and right of a virtual center line drawn in parallel with the movement direction of the stage. Is formed by making a cut in said second elastically deformable member. 2. A base, a stage movably provided with respect to the base, an actuator fixed to the base and provided so as to apply a moving force to the stage, and at least a moving direction of the stage. A first elastic member elastically deformed in a direction including: and a second elastic member elastically deformed in a direction including at least a direction perpendicular to the direction of movement of the stage. The second elastic member via the first elastic member;
The second elastic member includes four elastic deformation portions provided on the left and right of a virtual center line drawn in parallel with the movement direction of the stage. Is formed of a supporting means for supporting the first elastic member, a fixing member fixed to the base, and a coupling elastic deformation portion for elastically deforming the supporting means and the fixing member. A micro-moving stage. 3. The finely movable stage according to claim 1, wherein the first elastic member is two sets of leaf springs. 4. The finely movable stage according to claim 2, wherein said coupling elastically deforming portions are leaf springs provided at four elastically deforming portions, respectively.