JPH0527034Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fine-movement rotary stage, and particularly to a small-sized, highly rigid fine-movement rotary stage that can be applied to a mask stage of an X-ray exposure apparatus.

[Technological environment]

In recent years, there has been a trend toward higher precision in exposure apparatuses for semiconductor manufacturing. In particular, X-ray exposure equipment holds the mask and wafer through a minute gap of 10 to 50 μm.
This method uses alignment marks to perform fine positioning of 0.1 μm or less and transfer fine patterns of 0.5 μm or less, and has recently attracted particular attention. The mask stage that holds the mask is equipped with a fine rotation stage with a hole in the exposure area in the center, and the mask, which is pre-aligned to about 0.5mrad, must be rotated finely with an accuracy of about 5μrad. . Therefore, the fine rotation stage must have a large stroke of 1mrad, high resolution of 1μrad, high rigidity, and small size.

[Conventional technology]

The conventional fine-movement rotary stage is
(Refer to Japanese Utility Model Application Publication No. 154322/1983), the fixed part 1, the movable part 2, and the
The piezo element 4 is configured to include two thin flexible parts 3 and a piezo element 4 in contact with a protruding part of the movable part.

FIG. 2 is a plan view showing an example of a conventional fine rotation stage. The fine rotation stage shown in FIG.
It is integrally formed. The four thin flexible parts are
The piezo element 4 is arranged rotationally symmetrically with respect to the center of the circular movable part, and is connected between the protruding part 10 of the movable part 2 and the fixed part 1 by point contact. Piezo element 4
When a voltage is applied to , a displacement of Δ is generated, and if the distance between the point of application and the center of rotation is r, the movable part 2 can obtain a rotational displacement of 〓 _r rad using the thin flexible part 3 as a guide. Since the piezo element 4 has a structure in which it makes point contact with the fixed part 1 and the protrusion part 10 of the movable part 2, even if displacement occurs again between the protrusion part 10 of the movable part 2 and the end face of the piezo element 4, the piezo element 4 will not be damaged. It is possible to convert minute linear displacement into smooth minute rotational displacement without stick slip. The stroke of piezo element 4 is 15μ
If r = 50 mm, the rotation stroke will be 0.3 mrad. Therefore, when increasing the rotation stroke, it is necessary to increase the stroke of the piezo element 4 or to move the point of action of linear displacement closer to the center of rotation to decrease r.

[Problem that the invention attempts to solve]

The above-mentioned conventional fine rotation stage has a movable part 2
Since the piezoelectric element 4 is in direct point contact with the protrusion 10, the rotation stroke is determined by the generated displacement of the piezoelectric element 4 and the distance from the center of rotation of the point of action, and therefore, there is a drawback in that a large stroke cannot be obtained.

When applied to the mask stage of an X-ray exposure device, an exposure hole is required at the center of the movable part, and this is not possible due to the small distance between the point of action of the piezo element 4 and the center of rotation, so a stroke of only about 0.3 mrad can be obtained. This was not sufficient as a rotation stage for the mask stage. Furthermore, if the number of laminated piezo 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 rotation stage of the present invention includes a fixed part, at least three thin flexible parts projecting radially from the fixed part, a movable part supported at the other end of the thin flexible part, and a plurality of thin flexible parts. two linear actuators having points of action equidistant from the focal point, arranged parallel to each other and symmetrical with respect to the focal point, and held by the fixed part and the movable part via elastic hinges at both ends, respectively; , or two piezo elements press-fitted and held.

Further, the fixed part, the movable part, the thin flexible part, and the elastic hinge are integrally formed.

〔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 rotation stage shown in Fig. 1 has a hollow fixed part 1 and a hollow disc-shaped movable part 2 inside the fixed part 1, and these two parts are connected and four thin-walled movable parts are arranged radially. It is configured to include a flexible section 3 and piezo elements 4 and 5 arranged to generate a couple on the outer wall of the movable section 2. Further, the piezo elements 4 and 5 are held by the fixed part 1 and the movable part 2 via elastic hinges 6 to 9 at both ends. The thin flexible part 3 is arranged rotationally symmetrically with respect to the central axis Z of the movable part 2, and the displacement directions of the piezo elements 4 and 5 have points of action at an equal distance S from the central axis Z, and operate parallel to each other. It is arranged so that Further, all parts other than the piezo elements 4 and 5 are integrally formed, and the piezo elements 4 and 5 are press-fitted and held between the fixed part 1 and the elastic hinge protruding from the movable part 2 without any gaps.

When equal voltages are applied to the piezo elements 4 and 5, each generates a minute linear displacement of Δ, which is transmitted to the movable part 2 via the elastic hinges 7 and 9 protruding from the outer periphery of the movable part 2. Since the movable part 2 is supported by the four thin flexible parts 3, it is restrained in directions other than the direction of rotation and is guided in rotation about the central axis Z. When a minute linear displacement Δ, which is a distance S from the central axis Z in the acting direction, is applied to the movable part 2, a couple is applied to the movable part 2,
The rotational displacement 〓 _s rad can be obtained by overcoming the elastic force of the rotational guide.

Here, as the movable part 2 rotates, the elastic hinge 7
and 9 move, but the elastic hinge 6 on the fixed part side
and 8 as well as allow for inclination. Further, the rotational torque generated in this time angle hinge is an extremely small force when the rotational displacement of the stage is about 1 mrad, and highly accurate rotational displacement can be obtained by rotational guidance.

Moreover, the piezo elements 4 and 5 are connected to elastic hinges 6 to 6.
Since the piezo elements 4 and 5 are press-fitted and held in the fixed part 1 and the movable part 2 through the pins 9, there is no uneven contact or gaps at both ends of the piezo elements 4 and 5, so that the piezo elements 4 and 5 can be smoothly mounted without buckling or sliding. Rotational displacement with good reproducibility can be obtained.

Furthermore, since all the piezo elements except for the piezo elements 4 and 5 are integrally formed without fastening parts, there is no displacement of the joint parts due to screws, etc., and the piezo elements are highly rigid, so that good dynamic characteristics can be obtained.

[Effect of idea]

In the fine-movement rotation stage of the present invention, the protrusion protruding from the movable part is directly driven by a single piezo element.
By installing two linear actuators such as piezo elements and applying a couple to the movable part, it is possible to obtain high resolution and a relatively large fine rotational displacement of about 1 mrad, making it suitable for use as a mask in X-ray exposure equipment. It can be mounted on a stage, etc., and has the effect of making the pre-alignment accuracy of the mask rough.

Furthermore, since the displacement is expanded by the force couple, even if the movable part is hollow, such as when securing the exposure area, it is necessary to set the distance between the point of application of the couple and the center of rotation. Since the resolution and maximum displacement can be selected by this method, it is possible to realize a highly accurate fine-movement rotary stage without losing its features of being small and having high rigidity.

[Brief explanation of the drawing]

Figure 1 is a plan view showing one embodiment of the present invention;
The figure is a plan view showing an example of a conventional fine rotation stage. DESCRIPTION OF SYMBOLS 1...Fixed part, 2...Movable part, 3...Thin flexible part, 4, 5...Piezo element (linear actuator), 6-9...Elastic hinge, 10...Protrusion part.

Claims (1)

[Claims for Utility Model Registration] 1. A fixed part, at least three thin flexible parts protruding radially from the fixed part, a movable part supported by the other end of the thin flexible part, and the thin flexible part. two linear actuators having points of action equidistant from a convergence point of the parts, arranged parallel to each other and symmetrical with respect to the convergence point, and held by the fixed part and the movable part through elastic hinges at both ends, respectively; A fine rotation rotation stage characterized by including a Yueta. 2. A fixed part, a thin flexible part, a movable part, and elastic hinges at both ends of the two linear actuators are integrally formed, and the two linear actuators are press-fitted and held. A fine movement rotary stage according to claim 1 of the utility model registration claim. 3. The fine movement rotation stage according to claim 1, wherein the two linear actuators are piezo elements.