JP2007299925A - Stage device, and exposure apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stage device capable of super-precise positioning and also reduction in size and weight. <P>SOLUTION: The stage device comprises: a base mount 2, fixed frames 4a and 4b of a C-shaped section provided on the base mount 2, and a stage 3 arranged in a mutual inner side gap in the vertically opposing sides of the C-shaped section of the fixed frames 4a and 4b. Spherical seats 7 are made to interpose directly between the base mount 2 and the frames 4a and 4b. Further, air pads 5 for surfacing are formed in a mutual inner side in the vertically opposing sides of the C-shaped section of the fixed frames 4a and 4b. Pads 6 are formed in a part of the stage 3 opposing the air pads 5 for surfacing via the gap so that the stage 3 may be surfaced with the air pads 5 for surfacing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a stage apparatus in which a magnetic levitation stage for mounting and moving / positioning a pattern original (mask, reticle) or the like is supported in a non-contact manner, driven by a linear motor, and positioned at an arbitrary position. In particular, the present invention relates to a support mechanism and relates to an exposure apparatus provided with this stage apparatus.

  A stage apparatus is used in the field of so-called lithography technology for forming a fine pattern of a semiconductor device or the like. In an optical exposure apparatus which is currently mainstream in lithography technology, an electromagnetic actuator such as a linear motor having a high thrust and capable of high resolution positioning linear control is widely used as a stage drive source. A high-resolution laser interferometer is widely used for stage position measurement. Furthermore, as an XY guide system for the stage on the surface plate, a highly rigid hydrostatic bearing with preload exhaust is used so that the stage can be easily positioned. As a result, positioning of the stage on the order of several nm is becoming possible.

  In an optical exposure apparatus, a pattern is projected and transferred onto a sensitive substrate while synchronously scanning an original stage on which the pattern original plate is placed and a sensitive substrate stage on which a sensitive substrate on which the original pattern is transferred (so-called scan exposure). ) In an optical exposure apparatus that performs this type of scan exposure, the sensitive substrate stage is moved to position the exposure area to be transferred on the optical axis of the projection optical system, while the original stage and the sensitive substrate stage are moved synchronously. The scanning operation for scanning exposure is repeated.

Then, in order to transfer a circuit board of a semiconductor integrated circuit or a liquid crystal substrate onto a photosensitive substrate, a magnetic levitation stage apparatus having an advantage that high speed and high acceleration can be realized and throughput can be improved, and exposure provided with such a stage apparatus For example, a device disclosed in Patent Document 1 is disclosed.
Japanese Patent Laying-Open No. 2005-79368 (page 15, FIGS. 1 and 2)

5A and 5B are diagrams showing an internal configuration of the stage apparatus according to the invention described in Patent Document 1, wherein FIG. 5A is a top view and FIG. 5B is a side sectional view.
In the figure, a stage apparatus 100 includes a plate-like stage base 101.
The stage base 101 has three protruding portions 101a, 101b, and 101c on the outer periphery.
Each of the protruding portions 101a, 101b, and 101c of the stage base 101 is disposed on the body BD (FIG. 5B) of the exposure apparatus via the spherical seats 102a, 102b, and 103c.
Fixed frames 103 and 104 extending in parallel with each other along the Y direction are fixed to the lower surface of the stage base 101.
A square frame-shaped counter mass frame 105 is attached to the inside of these fixed frames 103 and 104, and the upper and lower surfaces (total of eight) of the four corners of the counter mass frame 105 and the inner sides of the fixed frames 103 and 104. Air pads 106 are interposed between the upper and lower surfaces. Each air pad 106 is a rectangular member made of a porous orifice material. When air is supplied from an air source (not shown), the air is ejected from the porous orifice, and the counter mass frame 105 is not in contact with the fixed frames 103 and 104. It is a mechanism that is supported by contact.

The gap length of the air pad portion 106 that supports the counter mass frame 105 in a non-contact manner is as small as several μm. However, if it is not accurately held, the required flying characteristics cannot be obtained, and in the worst case, the air pads 106 that face each other. May come into contact and bite. Therefore, extremely high accuracy is required for the flatness of the air pad surfaces 106 of the counter mass frame 105 and the fixed frames 103 and 104 and the parallelism of each other. The reason why the stage base 101 is supported by the three spherical seats 102a, 102b, 102c is to prevent the stage base 101 from being deformed by distortion of the base (body BD).
However, the stage base 101 supported by the spherical seats 102a, 102b, and 102c is deformed due to its own weight, the weight of the structure to be attached, and the like. However, since it is difficult to accurately predict the amount in advance, the air pad 106 attached to the amount needs to be processed in-situ. As the material of the air pad 106, ceramics are often used because of its high rigidity, surface hardness, small thermal expansion, etc., and since it is difficult to cut, it requires high processing technology and a great deal of processing. Processing time was required and cost increase was inevitable.
Further, in order to suppress the deformation of the stage base 101, it is effective to increase the rigidity of the stage base itself, but on the other hand, the weight tends to increase, which is also a cause of increasing the weight of the entire stage apparatus.
Accordingly, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a stage apparatus that can be configured without using a stage base and an exposure apparatus that uses the stage apparatus.

In order to solve the above problem, the present invention is as follows.
The invention according to claim 1 relates to a stage apparatus, a base, a fixed frame having a U-shaped cross section provided on the base, and an inner gap between the U-shaped opposite sides of the fixed frame. A stage device provided with a spherical seat directly interposed between the base and the fixed frame, and inside the opposite sides of the U-shape of the fixed frame. A levitation air pad is provided, and a pad is provided at a portion of the stage facing the levitation air pad via a gap, and the stage is levitated by the levitation air pad.
According to a second aspect of the present invention, in the stage device according to the first aspect of the present invention, there is provided a mechanism for supplying air to the spherical seat and causing the upper seat to float by blowing air to the mating surface of the upper and lower seats of the spherical seat. It is characterized by having.
According to a third aspect of the present invention, in the stage device according to the first aspect, the fixed frame is supported in a rotationally difficult manner by an elastic hinge member attached to the base. .
According to a fourth aspect of the present invention, in the stage apparatus according to the first or third aspect, the fixed frame is supported by a hinge base that is erected on the base.
According to a fifth aspect of the present invention, in the stage device according to the first aspect, the levitation air pads are provided at both ends in the length direction of the fixed frame.
According to a sixth aspect of the present invention, in the stage device according to any one of the third to fifth aspects, the floating air pads are separately provided on the fixed frame, and each floating air pad has one spherical seat. It is characterized by being supported by.
A seventh aspect of the present invention relates to an exposure apparatus, wherein a light source, an optical system for reflecting / condensing light from the light source, a stage device capable of attaching a mask to a lower surface, and a wafer are mounted in a vacuum chamber. In an exposure apparatus comprising a wafer stage to be placed, the stage apparatus includes the stage apparatus according to any one of claims 1 to 6, and relatively moving the stage apparatus and the wafer stage, A reduced image of the circuit pattern drawn on the mask is formed on the wafer.

According to the present invention, since the stage base is not used and each air pad is directly supported by the spherical seat, it is not affected by the deformation of the stage base.
According to the present invention, when air pads are installed on a plurality of spherical seats, even if the air pads are inclined and installed due to friction between the upper and lower seats of the spherical seats, the air pads are lifted from the spherical seats by floating the upper seats. Is released, and the air pads facing each other become parallel due to the flying force of the air pads themselves. After that, by stopping the supply of air and lowering the upper seat, it is possible to install the air pads facing each other in a completely parallel state.
When the air pad is supported by only one spherical seat, even when air is supplied to the spherical seat and the upper seat is lifted, or even when the upper seat is lowered without air supply, According to the present invention, when the external force is applied to the air pad, the air pad rotates and the fixed frame that fixes the air pad may come into contact with the counter mass frame. Therefore, by providing elastic support, disturbance elements for the air pad such as deformation and vibration of the base can be blocked.
According to the present invention, when one air pad is supported by a plurality of spherical seats, when air is supplied to the spherical seat and the upper seat is lifted, or when the upper seat is lowered without supplying air. Even so, it is possible to prevent the air pad from rotating when some external force is applied to the air pad.
According to the present invention, the structure of the stage becomes simple and the processing of the air pad becomes easy, so that it is possible to significantly reduce the cost, and a stage base that occupies a large proportion of the weight of the entire stage apparatus is not required. Therefore, the exposure apparatus using such a stage apparatus can also be reduced in weight.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

1A and 1B are views showing a stage apparatus according to Embodiment 1 of the present invention, in which FIG. 1A is a top view and FIG. 1B is a side view.
In the figure, 1 is a stage device, 2 is a base, and 3 is a stage. An air pad 5 having a porous orifice is provided on the inner upper and lower surfaces of the fixed frames 4a and 4b having a U-shape in a longitudinal section. Pads 6 are fixed to the upper and lower surfaces of the four corners of the stage 3 at positions facing the air pads 5. Air is supplied to the air pad 5 from the outside, and the stage 3 is floated in a non-contact manner by the air ejected from the porous orifice.
In order to obtain sufficient rigidity with respect to the load capacity for floating the stage 3 and the load acting on the stage 3 from the outside, the gap length between the air pad 5 and the pad 6 at the time of floating may be usually set to several μm. Many.
The fixed frames 4 a and 4 b are installed on the base 2 through three spherical seats 7. The upper surface of the lower seat of the spherical seat 7 has a porous orifice. By supplying air from the outside, air can be ejected between the upper seat and the lower seat to float the upper seat in a non-contact manner. Yes.
When the fixed frames 4a and 4b are installed on the spherical seat 7, if the friction between the upper and lower seats of the spherical seat is zero, the fixed frames 4a and 4b are positioned so that the air pad 5 and the pad 6 are parallel to each other. Actually, the friction between the upper and lower seats of the spherical seat is not zero, so when the air pad 5 and the pad 6 are not completely parallel to each other, or while generating internal stress on the fixed frames 4a and 4b and the stage 3 It may be parallel.
Further, if the stage 3 or the base 2 is deformed while the assembly of the stage apparatus 1 is progressing, the parallel state of the air pad 5 and the pad 6 also changes.

In the present invention, when the assembly of the stage device 1 is completed, air is supplied to the spherical seat 7 and the upper seat is lifted so that the friction between the upper seat and the lower seat is zero, and the air pad 5 and the pad 6 are mutually connected. The fixed frames 4a and 4b can be moved to positions that are parallel to each other.
Since the fixed frame 4b is supported by one spherical seat 7, the fixed frame 4b is used when the upper seat of the spherical seat 7 is lifted or when an external force is applied to the fixed frame 4b when the upper seat is lowered. There is a risk of rotating and coming into contact with the stage 3.
In order to prevent this, the hinge base 8 raised from the base 2 and the fixed frame 4b are connected by a hinge member 9 having elasticity. Since the hinge member 9 has strong rigidity in the horizontal direction and low rigidity in the other directions, it is difficult to rotate in the rotation direction with respect to the fixed frame 4b. Is weakening its binding power.

2A and 2B are views showing a stage apparatus according to Embodiment 2 of the present invention, in which FIG. 2A is a top view and FIG. 2B is a side view.
In the figure, each of the three fixed frames 10a, 10b, and 10c is supported by one spherical seat 7, and the three fixed frames 10a, 10b, and 10c are independently moved by floating the upper seat of the spherical seat. The air pad 5 and the pad 6 can be in the most parallel state. The three fixed frames 10a, 10b, and 10c need to be prevented from rotating by the hinge base 8 and the hinge 9, respectively.

FIGS. 3A and 3B are diagrams for explaining the structure and operation of the spherical seat 7 shown in FIGS. 1 and 2. FIG. 3A shows a non-floating state, FIG. 3B shows a floating state, and FIG.
In the figure, the spherical seat 7 is composed of an upper seat 71 and a lower seat 72. The lower seat 72 has porous orifices 72a to 72e extending vertically upward from below with respect to the upper seat 71, and air to these porous orifices 72a to 72e. And a common hole 72p.
(A) is a state in which the air L is not supplied to the common hole 72p. In this case, the upper seat 71 rides on the lower seat 72 and is in a non-floating state.
In (b), air L is supplied to the common hole 72p from the outside, and the upper seat 71 floats from the lower seat 72.
Since the upper seat 71 is in a non-contact state with the lower seat 72 as described above, the upper seat 71 can freely move on the lower seat 72 as shown in (c) only by applying a slight force F to the upper seat 71. It becomes possible.

FIG. 4 is a diagram of an exposure apparatus according to the third embodiment of the present invention, which is an exposure apparatus including the stage device according to the first or second embodiment. In the figure, 11 is an exposure apparatus, and 12 is a vacuum chamber in which the exposure apparatus 11 is housed. A light source 13 emits EUV light having a wavelength of 13.5 to 400 nm. Reference numeral 1 denotes a stage device according to the present invention, which is one of the two-axis positioning devices described in the first or second embodiment.
A mask 15 is attached to the lower surface of the stage apparatus 1. On the mask 15, a pattern of a circuit formed on the wafer 16 is drawn. The wafer 16 is placed on the wafer stage 17.
The EUV light emitted from the light source 13 is collected by the condenser mirror 18, reflected by the mask 15, and repeatedly reflected in the order of the concave mirror 19, convex mirrors 20 and 21, and concave mirror 22 to reach the wafer 16.
Further, the stage apparatus 1 and the wafer stage 17 move relatively in phase so that a reduced image of the circuit pattern drawn on the mask 15 is formed on the wafer 16 on the surface of the wafer 16.

  INDUSTRIAL APPLICABILITY The present invention is useful as a stage apparatus that freely positions an object in a plane in the field of semiconductor manufacturing or the like.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the stage apparatus based on Example 1 of this invention, (a) is a top view, (b) is a sectional side view. It is a figure which shows the stage apparatus based on Example 2 of this invention, (a) is a top view, (b) is a sectional side view. FIGS. 3A and 3B are diagrams for explaining the structure and operation of the spherical seat shown in FIGS. 1 and 2, in which FIG. 1A shows a non-floating state, FIG. 2B shows a floating state, and FIG. It is a schematic block diagram of the exposure apparatus provided with the stage apparatus which concerns on this invention. It is a figure which shows the internal structure of the stage apparatus based on invention of patent document 1, (a) is a top view, (b) is a sectional side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stage apparatus 2 Base 3 Stage 4 Fixed frame 5 Air pad 6 Pad 7 Spherical seat 71 Upper seat 72 Lower seat 72a-72e Porous orifice 72p Common hole 8 Hinge base 9 Hinge member 10 Fixed frame 11 Exposure apparatus 12 Vacuum chamber 13 Light source 15 Mask 16 Wafer 17 Wafer Stage 18 Condenser Mirror 19 Concave Mirror 20 Convex Mirror 21 Convex Mirror 22 Concave Mirror 100 Stage Device 101 Stage Base 102 Spherical Seat 103 Fixed Frame 104 Fixed Frame 105 Counter Mass Frame 106 Air Pad L Air F Force

Claims (7)

A stage apparatus comprising: a base; a fixed frame having a U-shaped cross-section provided on the base; and a stage provided in a gap between the vertically opposite sides of the fixed frame. There,
A spherical seat is directly interposed between the base and the fixed frame, and a floating air pad is provided inside each other of the U-shaped opposite sides of the fixed frame, and the floating air pad is interposed through a gap. A stage apparatus, wherein a pad is provided at a portion of the stage facing the stage, and the stage is levitated by the levitating air pad.   2. The stage apparatus according to claim 1, further comprising a mechanism for supplying air to the spherical seat and ejecting the air to a mating surface between the upper seat and the lower seat to float the upper seat.   2. The stage apparatus according to claim 1, wherein the fixed frame is supported by a hinge member having elasticity attached to the base so as not to rotate in the rotation direction.   The stage apparatus according to claim 1, wherein the fixed frame is supported by a hinge base that is erected on the base.   2. The stage apparatus according to claim 1, wherein the floating air pads are provided at both ends of the fixed frame in the length direction.   6. The stage apparatus according to claim 3, wherein the floating air pads are separately provided on the fixed frame, and each floating air pad is supported by one spherical seat. . In an exposure apparatus provided with a light source, an optical system for reflecting / condensing light from the light source, a stage device capable of mounting a mask on the lower surface, and a wafer stage for placing a wafer in a vacuum chamber ,
As the stage device, comprising the stage device according to any one of claims 1 to 6,
An exposure apparatus, wherein the stage apparatus and the wafer stage are relatively moved to form a reduced image of a circuit pattern drawn on the mask on the wafer.

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