JPH06795Y2 - Fine rotation stage - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a fine movement rotary stage, and more particularly to a small, high resolution, high rigidity fine movement rotary stage applicable to a mask stage of an X-ray exposure apparatus.

[Technical environment]

The exposure apparatus for semiconductor manufacturing in recent years tends to be highly accurate. In particular, the X-ray exposure system uses a mask and wafer of 10 to 50 μm
This is a technique for transferring fine patterns of 0.5 μm or less by holding it through a minute gap of (1) and performing fine alignment of 0.1 μm or less using an alignment mark, and has recently received special attention. The mask stage that holds the mask is equipped with a fine movement rotary stage that has a hole in the central exposure area, and the mask pre-aligned to about 0.5 mrad must be finely moved with a precision rotation stay of about 5 μrad. I won't. Therefore, the fine movement rotary stage must have a large stroke: 1 mrad, a high resolution of 1 μrad, a high rigidity, and a small size.

[Conventional technology]

As shown in Japanese Patent Application No. 60-039155 (see Japanese Utility Model Application Laid-Open No. 61-154322), a conventional fine movement rotary stage has four thin-walled flexible parts for connecting a fixed part and a movable part to each other. 3 and a piezo element that is in contact with the protruding portion of the movable portion.

FIG. 2 is a plan view showing an embodiment of a conventional fine movement rotary stage.

The fine movement rotary stage shown in FIG. 2 has a fixed part 1 and a movable part 2.
Are integrally formed with four thin-walled flexible portions 3. The four thin-walled flexible portions are arranged rotationally symmetrically with respect to the center of the circular movable portion, and the piezo element 4 is connected between the protruding portion 5 of the movable portion 2 and the fixed portion 1 by point contact. When a voltage is applied to the piezo element 4, a displacement of Δ occurs, and when the distance between the point of action and the center of rotation is r, the movable portion 2 uses the thin flexible portion 3 as a guide and Δ.
A rotational displacement of / r rad can be obtained. Piezo element 4
Has a structure in which the fixed portion 1 and the protruding portion 5 of the movable portion 2 are in point contact with each other. Can be converted into a smooth minute rotational displacement without stick-slip. The stroke of the piezo element 4 is about 15 μm, and if r = 50 mm, the rotation stroke is 0.3 mrad. Therefore, when increasing the rotation stroke, it is necessary to increase the stroke of the piezo element 4 or move the point of linear displacement closer to the center of rotation to reduce r.

[Problems to be solved by the invention]

In the conventional fine movement rotary stage described above, since the piezo element 4 is directly in point contact with the protruding portion 5 of the movable portion 2, the rotation stroke is determined by the generated displacement of the piezo element 4 and the distance from the rotation center of the point of action. However, there is a drawback that a large stroke cannot be obtained.

When applied to a mask stage of an X-ray exposure apparatus, a hole for exposure is required in the central part of the movable part, and the distance between the working point of the piezo element 4 and the center of rotation cannot be reduced, so 0.3 mrad
Only a slight amount of stalk was obtained, which was not enough for the rotary stage of the mask stage.

Further, if the number of laminated piezoelectric elements 4 is increased to increase the generated displacement, a relatively large stroke can be obtained, but the stage becomes large and the rigidity of the entire stage cannot be increased.

[Means for solving problems]

The fine movement rotary stage of the present invention includes a fixed part, at least three or more thin-walled flexible parts radially protruding from the fixed part, a movable part supported by the other end of the thin-walled flexible part, the fixed part, and the fixed part. First between the movable parts and aligned in the centripetal direction of the movable parts
And an input arm connected via a second elastic hinge,
A linear actuator that is held between the fixed portion and the input arm via a third elastic hinge to generate displacement in a direction perpendicular to the centripetal direction of the movable portion, or a piezo element that is press-fitted and held. It

Further, the fixed portion, the movable portion, the three or more thin-walled flexible portions, the input arm connected through the two elastic hinges, and the third elastic hinge are integrally formed. Configured.

〔Example〕

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a plan view showing an embodiment of the present invention.

The fine movement rotary stage shown in FIG. 1 has a hollow fixed portion 1 and a hollow disk-shaped movable portion 2 inside the fixed portion 1, and these two members are connected to each other to form four thin-walled flexible layers. The first elastic hinge 6 is provided in the gap between the portion 3 and the fixed portion 1 and the movable portion 2.
And an input arm 8 connected via a second elastic hinge 7
And a piezo element 4 which is press-fitted into the gap between the fixed element 1 and the fixing element 1 via a third elastic hinge 9.

The thin flexible portion 3 is arranged to rotate about the central axis Z of the movable portion 2, and the input arm 8 is arranged in a straight line passing through the central axis Z. In addition, all the components other than the piezo element 4 are integrally formed. The piezo element 4 is press-fitted and held without a gap in a posture in which displacement is generated in the tangential direction of the movable portion 2.

When a voltage is applied to the piezo element 4, a minute linear displacement of Δ is generated and transmitted to the input arm 8 via the third elastic hinge 9 provided at the tip of the piezo element 4. Since the input arm 8 and the fixed portion 1 are connected by the first elastic hinge 6,
When the distance between the first elastic hinge 6 and the third elastic hinge 9 is a, the input arm 8 causes a tilt of Δ / arad with the first elastic hinge 6 as a fulcrum. When the distance between the first elastic hinge 6 and the second elastic hinge 7 is b, the input arm 8
At the tip of the lever, a magnifying displacement of Δxb / a occurs due to the magnifying action of the lever. Since the movable part is supported by the fixed part 1 by the four thin flexible parts 3, it is constrained in a direction other than the rotational direction, and the expanded displacement of the input arm 8 is converted to obtain a rotational displacement of Δb / arrad. . The input arm 8 receives a tensile force while tilting as it rotates, but a rotational displacement of 1 m
The force is extremely small in the range of rad, and the two elastic hinges 6 and 7 at both ends of the input arm 8 allow inclination and extension, and highly accurate rotational displacement can be obtained by the rotational guide of the thin flexible portion 3.

Further, since the piezo element 4 is press-fitted and held in the fixed portion 1 via the elastic hinge 9, even if the input arm 8 is tilted due to the rotational movement, a unilateral contact or a gap may occur at both ends of the piezo element 4. Since there is no backlash or stick-slip, a smooth and reproducible rotational displacement can be obtained.

Furthermore, since the movable portion 2, the thin flexible portion 3 and the input arm portion are integrally formed without a fastening portion, a displacement of the joint portion due to a screw or the like does not occur and a highly rigid dynamic characteristic can be obtained.

[Effect of device]

The fine movement rotary stage of the present invention is driven by the displacement of the input arm instead of directly driving the movable portion by the displacement in the circumferential direction, so that the fine movement linear displacement of the linear actuator such as the piezo element is relatively large. Since the input arm portion is also integrally formed, it is possible to obtain a smooth rotational displacement without backlash and stick-slip, and it is also highly rigid. Further, instead of bringing the action point of the linear actuator close to the center of rotation, by providing an input arm, the displacement can be expanded and a relatively large fine rotational displacement of about 1 mrad can be obtained, so that the mask stage of the X-ray exposure apparatus can be obtained. It is possible to reduce the size of the mask and the like, and it is possible to roughen the mask pre-alignment accuracy.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, and FIG. 2 is a plan view showing an example of a conventional fine movement rotary stage. 1 ... Fixed part, 2 ... Movable part, 3 ... Thin flexible part, 4
...... Piezo element (linear actuator), 5 ... projection, 6,7,9 ... elastic hinge, 8 ... input arm.

Claims (3)

[Scope of utility model registration request] 1. A fixed part, at least three or more thin-walled flexible parts radially protruding from the fixed part, a movable part supported by the other end of the thin-walled flexible part, the fixed part and the movable part. And an input arm connected via first and second elastic hinges arranged in the centripetal direction of the movable part, and held between the fixed part and the input arm via a third elastic hinge. And a fine movement rotary stage including a linear actuator that generates a displacement in a direction perpendicular to the centripetal direction of the movable portion. 2. The fixed portion, the thin flexible portion, the movable portion,
The fine movement rotary stage according to claim 1, characterized in that the input actuator is integrally formed and a linear actuator is press-fitted therein. 3. The fine movement rotary stage according to claim 1, wherein the linear actuator is a piezo element.