JP2690510B2 - Aori Stage - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a tilt stage, and more particularly to a thin, high resolution, high rigidity tilt stage applicable to a mask stage or a wafer 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 a wafer of 10 μm to 50 μm.
It is held in parallel through a minute gap of μm, fine alignment of 0.1 μm or less is performed using an alignment mark, and a fine pattern of 0.5 μm or less is transferred.
Recently, it has received special attention.

For a mask stage that holds an X-ray mask and a wafer stage that holds a wafer, a tilting stage that is thin, has high resolution, and has high rigidity is required for parallelizing the mask and the wafer.

[Conventional technology]

As a conventional technique, for example, there is a tilt stage shown in the conventional example of Japanese Patent Laid-Open No. 61-904320.

This conventional tilt stage will be described with reference to the drawings.

FIG. 5 is a plan view showing a mask stage of an X-ray exposure apparatus having a conventional tilt stage, and FIG. 6 is a front sectional view of FIG.

The conventional tilt stage includes a hollow cylindrical stage base 114, a hollow disc spring 115 whose outer periphery is fixed inside the stage base 114, and a mask chuck mounting frame 113 fixed to the inner periphery of the hollow disc spring 115. And mask chuck mounting frame 1
The mask chuck 102 held by the armature 13 and the armatures 109 to 112 arranged equiangularly on the upper surface of the mask chuck mounting frame 113.
And electromagnets 105 to 108 attached to the stage base 114 so as to face the armatures 109 to 112.

When a positive current is applied to the electromagnet 105 and a negative current is applied to the electromagnet 107, an attractive force is generated between the electromagnet 105 and the armature 109, and a repulsive force is generated between the electromagnet 107 and the armature 111, which balances with the restraining force of the hollow disc spring. Posture, that is, the mask chuck attachment frame 113 to which the armature 111 is attached is displaced in the arrow F direction. Further, the same magnitude of current is applied to the electromagnets 105 to 108 so that the electromagnets 105 to 108 can be displaced in the Z direction.

Therefore, the mask 11 held by the mask chuck mounting frame 113 via the mask chuck 102 can be positioned parallel to the wafer 12 with a predetermined gap amount.

[Problems to be solved by the invention]

In the conventional tilt stage described above, when the mask 11 is subjected to tilt displacement and Z direction displacement, the hollow disk spring 115 is used.
Since the outer circumference and the inner circumference are fixed to the stage base 114 and the mask chuck mounting frame 113, respectively, complicated deformation must be performed to control the currents flowing through the electromagnets 105 to 108 in a complicated manner. It takes a lot of time to align them in parallel.

Further, in the case of the X-ray exposure apparatus, as described in JP-A-60-201344 and the like, it is necessary to dispose the positional deviation detection device between the mask 11 and the wafer 12 on the upper surface of the mask 3 and in the vicinity of the exposure area. Although it must have a thin structure, the provision of an electromagnet has a drawback that it is difficult to form a thin structure.

Further, since the force that can be generated by the electromagnet is small, a slit is provided in the hollow disk spring to obtain a stable tilting displacement, or there is a means using a columnar elastic member as described in JP-A-61-190432. However, since the force generated by the electromagnet is small, the spring constant must be made small, and the rigidity of the entire stage cannot be increased, which is disadvantageous in that it is weak against vibration.

[Means for solving the problem]

The tilt stage of the present invention is divided into a tip portion, an intermediate portion, and a support portion by two hinges, and three cantilever beams radially arranged, and three cantilever beams fixed to the three tip portions of the cantilever beam. Cylindrical hinges, a tilt plate fixed to the cylindrical hinges, three piezo elements fixed to the supporting portion of the cantilever, and one end separated by one hinge to the movable surface of the piezo element. It is configured to include three connecting portions which are fixed and whose other end is fixed to an intermediate portion of the cantilever.

〔Example〕

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

FIG. 1 is a sectional view showing the principle of one embodiment of the present invention.

The tilt stage shown in FIG. 1 is a cantilever 6 having a supporting portion 3, an intermediate portion 4 and a tip 5 formed by hinges 1 and 2, and a cylindrical hinds fixed to the tip 5 of the cantilever 6. 7, a tilt plate 8 fixed to the cylindrical hinge 7, a piezo element 9 fixed to the support portion 3 of the cantilever 6, and a movable portion of the piezo element 9 attached to the cantilever 6 via a hinge 10.
And a connecting portion 10 fixed to the intermediate portion 4.

 Next, the operation principle will be described with reference to the drawings.

When a voltage is applied to the piezo element 9, a straight displacement S is generated,
A link mechanism composed of the supporting portion 3 of the cantilever 6, the hinge 1, the intermediate portion 4, and the pinge 10 of the connecting portion 11 converts the angular displacement t about the hinge 1 as a rotation center.

The intermediate portion 4 can be transmitted to the tip portion 5 via the hinge 2, and the tilting plate 8 can be tilted and displaced via the cylindrical hinge 7.

When the distance between the hinge 1 and the hinge 2 is m, and the distance between the hinge 1 and the hinge 10 is m, the displacement S of the piezo element 9 is multiplied by / m and converted into an angular displacement t.

FIG. 2 is an exploded perspective view showing a mask stage of an X-ray exposure apparatus having a tilt stage according to the present invention.

In the tilt stage shown in FIG. 2, the cantilever 6 whose principle is shown in FIG. 1 is arranged on the circumference, and three cantilever beams 6a, 6b,
The supporting portion 3'of 6c is integrally formed, and the cylindrical hinges 7a, 7b, 7c are fixed to the tip portions 5a, 5b, 5c of the cantilever beams 6a, 6b, 6c, and the upper portions of the cylindrical hinges 7a, 7b, 7c are fixed. A mask chuck (orientation plate) 8'is fixed. In the case of the mask stage for the X-ray exposure apparatus, holes are provided in the support portion 3'and the mask chuck (orientation plate) 8'to escape the X-ray area.

Each of the three cantilever beams 6a, 6b, 6c is formed integrally with the hollow disc-shaped support portion 3'and is arranged symmetrically with respect to the central axis Z of the support portion 3 '. Hinge 1a, 2a, 1b, 2b, 1c, 2
It is provided with c and is separated into intermediate portions 4a, 4b, 4c and tip portions 5a, 5b, 5c. Then, the cylindrical hinges 7a, 7a are attached to the tips 5a, 5b, 5c.
b and 7c are fixed.

Also, the three connecting portions 11a, 11b, 11c are provided with hinges 9a, 9b, 9c and fixed to the intermediate portions 4a, 4b, 4c of the cantilevers 6a, 6b, 6c,
Piezo elements 9a, 9b, 9c, both ends of which are supported by the support portion 3'and the connecting portions 11a, 11b, 11c, are arranged. The mask chuck (orientation plate) 8'is provided with a vacuum groove for sucking and holding the mask 12, and the tip portions 5a, 5b, 5c of the cantilevers 6a, 6b, 6c.
Is fixed via cylindrical hinges 7a, 7b, 7c.

 Next, the operation will be described in order with reference to the drawings.

FIG. 3 is a front sectional view of the tilt stage shown in FIG. 2, and FIG. 4 is an operation explanatory view when FIG. 3 is operated.

When a voltage is applied to the piezo element 9a, a straight displacement S is generated,
Since the piezo element 9a is fixed to the supporting portion 3'and the connecting portion 11a, the displacement S is surely transmitted to the intermediate portion 4a of the cantilever 6a via the hinge 10a. Here, since the intermediate portion 4a is supported by the supporting portion 3'via the hinge 1a, the link mechanism causes the angular displacement t shown in the figure about the hinge 1a as shown in the principle of FIG.

Mask chuck (orientation plate) 8'is cantilevered 6
Since the tips 5a, 5b, 5c of a, 6b, 6c are supported via the cylindrical hinges 7a, 7b, 7c, the hinges 2a, 2b, 2c are slightly rotated by the angular displacement t of the intermediate portion 4a, respectively, and the mask Since the chuck (flapping plate) 8'is angularly connected by the tip portions 5a, 5b, 5c and the cylindrical hinges 7a, 7b, 7c, it is possible to obtain a tilting displacement θ independent of each axis without interference displacement. As a result, the mask 12 attracted to the mask chuck (orientation plate) 8'can be easily positioned parallel to the wafer 13.

Further, by applying the same voltage to the piezo elements 9a, 9b, 9c, similarly, only the displacement in the Z direction can be obtained, so that the gap between the mask 12 and the wafer 13 can be positioned to a predetermined size.

The stroke of the piezo elements 9a, 9b, 9c is about 15 μm,
Since the stroke required for the tilt stage is about 50 μm, the distance between the hinges is 50/10 = l / m.

Since the piezo element is a laminated type that can be driven at a low voltage of about 100 V, it is small in size and can generate large stress, and heat generation can be almost ignored. All can be made of a highly rigid elastic body.

Further, since the support portion 3'and the three cantilever beams 6a, 6b, 6c can be integrally formed, the dimensional accuracy of the hinge portion can be easily controlled, and the spring constants for the three tilts can be uniformly formed.

〔The invention's effect〕

The tilt stage of the present invention can be formed with high dimensional accuracy without a fastening portion by providing a cantilever elastic body integrally formed with a base plate instead of a hollow disc or a columnar elastic spring for supporting the tilt plate. Therefore, it can be supported with high rigidity without any looseness. Further, by providing a rotatable cylindrical hinge between the cantilever elastic body and the tilt plate, interference displacement due to displacement of the triaxial cantilever elastic body is eliminated, so that the tilt stage can be easily controlled. Further, by providing a piezo element instead of the electromagnet, heat generation is small, large stress and minute displacement can be generated, so that high-resolution and highly-accurate tilt displacement can be obtained. Further, by arranging the piezo elements radially, a thin structure can be obtained, so that there is an effect that the mask stage and the wafer stage of the X-ray exposure apparatus can be downsized.

[Brief description of the drawings]

1 is a sectional view showing the principle of an embodiment of the present invention, FIG. 2 is an exploded perspective view showing an embodiment of a tilt stage of the present invention, FIG. 3 is a front sectional view of FIG. 2, and FIG. FIG. 5 is an operation explanatory view when FIG. 3 is operated, FIG. 5 is a plan view showing an example of the conventional art, and FIG. 6 is a front sectional view of FIG. 1,2,10 …… Hinges, 1a, 2a, 10a …… Hinges, 1b, 2b, 10b…
… Hinges, 1c, 2c, 10c …… Hinges, 3,3 ′ …… Supporting parts, 4,
4a, 4b, 4c …… Middle part, 5,5a, 5b, 5c …… Tip part, 6,6a, 6b,
6c ... cantilever, 7,7a, 7b, 7c ... cylindrical hinge, 8 ... tilt plate, 8 '... mask chuck, 9,9a, 9b, 9c ...
… Piezo element, 11 …… Connecting part.

Claims (1)

(57) [Claims] 1. A cantilever, which is divided into a tip portion, an intermediate portion, and a support portion by two hinges and is radially arranged, and three cantilever beams fixed to the three tip portions of the cantilever. A cylindrical hinge, a tilt plate fixed to the cylindrical hinge, three piezo elements fixed to the supporting portion of the cantilever, and one end separated by one hinge to the movable surface of the piezo element. A tilt stage comprising: three connecting portions having the other end fixed to the middle portion of the cantilever.