JPH05102011A - Vertical XY stage - Google Patents

Abstract

(57) [Abstract] [Purpose] The objective is to shorten the width in the horizontal plane orthogonal to the SOR optical axis to achieve high speed, high accuracy, and improved safety. [Structure] The X-axis slider 32 is formed in an L shape, and its horizontal portion 32A serves as a slider body, and the vertical portion 32B serves as a guide for the Y-axis slider 22. Horizontal part 32A and vertical part 32B
The stage 20 is arranged in the space surrounded by and, and the stage 20 is rotatably connected to the Y-axis slider 22 by the inverted shaft 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical XY stage suitable for application to a fine pattern exposure apparatus for semiconductor integrated circuits, and more particularly to an exposure apparatus using synchrotron orbit radiation as a light source.

[0002]

2. Description of the Related Art In a semiconductor element manufacturing process, an exposure apparatus for printing a circuit pattern on a semiconductor element substrate called a wafer coated with a photosensitive material is used. For this purpose, a vertical XY stage that moves the wafer in two axial directions is used in order to print the same circuit pattern on many points on the wafer surface.

On the other hand, the wavelength of the transfer light source has been shortened in response to the high integration of semiconductor elements, and as a future technology, the synchrotron orbital radiation whose wavelength is two digits or more shorter than the ultraviolet ray which is the current transfer light source. Development of a pattern transfer technique using light (hereinafter referred to as SOR light) is in progress. This is because light having a shorter wavelength has less diffraction and interference, and a fine pattern can be transferred.

The SOR light is an electromagnetic wave radiated in a tangential direction in which a high-energy electron beam close to the speed of light is bent by an electromagnet, and the beam propagates in a tangential direction, and has high directivity including visible light to X-rays. Light having a strong brightness is taken out, and soft X-rays having a wavelength in the vicinity of 1 nm are extracted from this light and used as a light source for pattern transfer.

FIG. 8 shows a conventional example of a vertical XY stage used in an exposure apparatus using such SOR light as a light source. A brief description will be given of the conventional XY stage.
The OR light 1 is emitted from a donut-shaped ring 2 in which a high-energy electron beam is stored in a closed orbit in all directions in a horizontal plane of a tangent line where the electron beam travels, and an X-ray mask 3 is provided in that direction. It is provided. A circuit pattern is formed on the X-ray mask 3, and the SOR light 1 that has passed through this circuit pattern is shaded. Four
Is a mask stage for holding the X-ray mask 3 and controlling its position and orientation, 5 is a wafer stage for sucking and holding the wafer 6, and 7 is a position for observing the X-ray mask 3 and the alignment mark previously provided on the wafer 6. This is a detection system that optically detects the amount of deviation. 8 is an XY for moving the wafer 6 in the XY directions
On the stage, the XY stage 8 and the mask stage 4 are moved and adjusted based on the displacement detection signal from the alignment mark to perform alignment, and then the SOR light 1 is radiated to form the pattern of the X-ray mask 3. Are transferred to the photosensitive material on the wafer 6.

The SOR light 1 is emitted in a horizontal plane. Therefore, the X-ray mask 3 and the wafer 6 are vertically placed in the vertical plane, and the XY stage 8 is also vertical. Further, since the SOR light 1 has a high directional property but has a slight divergence property, the shape of the projected pattern is distorted or blurred when the distance between the X-ray mask 3 and the wafer 6 is increased. Normal exposure becomes difficult. Therefore, it is necessary to make the distance between the surface of the X-ray mask 3 and the surface of the wafer 6 extremely small, for example, 50 μm.
m or less.

In FIG. 8, the wafer 6 is not on the axis of the SOR light 1 on which the mask 3 is now placed, but at a position far away from the mask 3. Therefore, the X-ray mask 3 and the wafer 6 can be easily exchanged with each other. If only the exposure of the wafer 6 is required, the movement amount corresponding to the exposure area of the wafer 6 may be given to the XY stage 8. However, the wafer 6 needs to be sequentially replaced, and the XY stage 8 has only the exposure area. This is because it is almost impossible to replace the X-ray mask 3 and the wafer 6 without damaging each other when the X-ray mask 3 and the wafer 6 face each other with a small gap if they have only a moving amount. Therefore, after the X-ray mask 3 and the wafer 6 are exchanged in the directions shown by the arrows 9 and 10, the wafer 6 is moved to a position facing the X-ray mask 3 by the XY stage 8 and exposure is started. That is why.

The XY stage 8 has an X-axis guide 11 which is a guide for moving the wafer 6 in the X-direction, that is, a horizontal direction, an X-axis slider 12, and an X-axis feed screw 1.
3, a Y-axis guide 14 that is a guide for moving the wafer 6 in the Y-direction, that is, a vertical direction, a Y-axis slider 15, a Y-axis feed screw 16, and the like. It has a structure with
The X and Y axis guides 11 and 14 are fixed, and the feed screw 13 and
16, the X and Y axis sliders 12 and 15 are respectively
It is moved in the X-axis and Y-axis directions. 17 is an X-axis slider 12
A horizontal surface plate on which the Y-axis slider 15 is orthogonally coupled, 18 is an X-axis drive motor, and 19 is a Y-axis drive motor. In this case, the X-axis drive motor 18 holds the X-axis slider 12, the lateral surface plate 17, the Y-axis guide 14 and the Y-axis slider 15 and drives the X-axis drive motor 18, so that the load is larger than that of the Y-axis drive motor 19. For this reason, it is inevitable that the capacity of the X-axis drive motor 18 becomes large. In particular, the X-axis slider 12 requires not only a stroke corresponding to the exposure area but also a movement amount including a stroke required for exchanging the X-ray mask 3 and the wafer 6, which is about 3 to 5 times the exposure area. Double movement is required. Therefore, the X-axis slider 12 is the Y-axis slider 1.
The length is longer than that of No. 5, and the horizontal width of the vertical XY stage 8 is widened.

[0009]

As described above, the SOR
In the conventional vertical XY stage 8 used in the exposure apparatus, the movement amount of the X-axis slider 12 is required to be about 3 to 5 times as much as the exposure area. Therefore, the width of the stage 8 in the horizontal direction is inevitable. However, as a result, there were problems as described below. As described above, the SOR light 1 is emitted in all directions in the horizontal plane of the tangent line where the electron beam travels. Therefore, as the width of the vertical XY stage 8 becomes narrower, a larger number of exposure apparatuses can be installed in the radial direction around the ring 2 and the ring 2 can be effectively used. However, in the conventional vertical XY stage 8, the X-ray mask is used. In order to facilitate replacement of the wafer 3 and the wafer 6, the width in the horizontal plane orthogonal to the axis of the SOR light 1, that is, the width in the X-axis direction is widened, which causes a problem that the ring 2 is not effectively used. The feed accuracy of the XY stage 8 decreases. The feed precision of the XY stage 8 is determined by the guide precision and the feed precision for maintaining the posture of the stage, and the precision may be considered to be the machining precision of the constituent members. However, there are XY stage 8 inside
There is also a method to correct the error by adding a mechanism that slightly moves by the amount of the feed error and an error measurement system separately to improve the accuracy, but the mechanism system, measurement system, control system that has an accuracy and performance that exceeds the main body by an order of magnitude. It is necessary to additionally mount the above components, resulting in an increase in weight, an extremely expensive stage, a complicated stage, and a stage prone to failure. In order to avoid this, it is desirable to be able to secure the final accuracy only with the main body, so with a simple structure as much as possible,
It is important that the constituent members also have a shape that can improve the processing accuracy. Further, if the X-axis slider 12 becomes longer,
The X-axis guide 11 and the X-axis feed screw 13 also need to be elongated by this amount. The processing accuracy is inversely proportional to the length even if the member strength is infinite, and further, the member strength is inversely proportional to the cube of the length and the cube of the diameter. That is, various forces and stresses such as cutting force and grinding force, residual stress and thermal stress due to plastic deformation, or chucking force applied when the member is fixed to the processing device act on the member during processing. However, if a force is applied, the member will be deformed, so the more deformed it becomes, the more difficult it is to carry out precise processing. As described above, the member strength is the largest factor that affects the processing accuracy.
In short, increasing the length of the members significantly reduces the processing accuracy,
The processing accuracy deteriorates the feed accuracy of the XY stage 8. A gravity imbalance of the Y-axis slider 15 is generated. X
Since the weight applied to the shaft slider 12 acts in the direction orthogonal to the X-axis guide 11, the guide surface supports it. In this case, the static rotational load applied to the X-axis feed screw 13 is only the frictional force on the screw surface, and the weight of the X-axis slider 12 itself does not become a load. On the other hand, the weight applied to the Y-axis slider 15 acts in the guide direction of the Y-axis slider 15, so that the Y-axis feed screw 16 supports it. Therefore, the weight of the Y-axis slider 15 directly becomes the rotational load of the Y-axis feed screw 16. The rotation load due to this gravity acts in the opposite direction to the rotation direction of the Y-axis drive motor 19. This is the Y-axis slider 1
This means that it is necessary to change the energy applied to the Y-axis drive motor 16 by raising and lowering 5. This adversely affects the drive control of the Y-axis slider 15 and, as a result, reduces the positioning accuracy of the Y-axis slider 15 and hinders high-speed feed. The lighter the weight of the X-axis slider 12 and the Y-axis slider 15, the better. As is well known, this is to reduce the load on the drive motor and to make high-speed and highly accurate positioning advantageous in terms of control. Lack of safety against disabilities. The X-axis slider 12 reciprocates between the replacement position of the wafer 6 and the exposure position. There is no problem on the outward path, but since the mask stage 4 and the wafer stage 5 pass each other on the return path, it is difficult for the hand and fingers to be caught here during the start-up and maintenance of the apparatus. Because X
Since the shaft slider 12 holds the Y-axis guide 14, the Y-axis slider 15 and the horizontal surface plate 17 in addition to its own weight, it has a considerable weight and does not stop when it starts to move, and it is more difficult to stop it during motor drive. However, it puts an excessive burden on safety measures.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to reduce the width in the horizontal plane orthogonal to the SOR optical axis and to achieve high speed. The purpose of the present invention is to provide a vertical XY stage that is designed to have higher accuracy and improved safety.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and a first invention thereof comprises an X-axis slider and a Y-axis slider, and a horizontal portion of the X-axis slider. Is a slider body, the vertical portion is a guide of the Y-axis slider, and a stage is arranged in a space surrounded by a horizontal portion and a vertical portion. The stage is inverted on the Y-axis slider by an inverted shaft or an open / close shaft. It is connected so that it can be opened and closed. In a second aspect based on the first aspect, a drive motor that inverts or opens and closes the stage is disposed on a device fixing portion side where a vertical XY stage is provided,
The rotation of the drive motor is transmitted to the stage at a fixed position in the XY stroke through clutch means. In a third aspect based on the first or second aspect, a pulley is provided above the vertical portion of the X-axis slider, and a take-up drum using a spiral spring is provided below the X-axis slider, and the Y-axis slider and the take-up drum are provided. Is connected by a wire via the pulley, and the weight applied to the Y-axis slider and the torque of the winding drum are balanced by the spiral spring.

[0012]

In the present invention, the stage is connected to the Y-axis slider by an inverted shaft or an open-close shaft so as to be inverted or openable and closable, and is opened or closed on the opposite side of the X-ray mask and opened. The X-ray mask wafer can be replaced from the front side of the. When the stage is inverted, the vertical XY stage movement stroke is only the exposure area.
Since the stage stands upside down with respect to the mask stage, there is no chance of passing each other. The force of the spiral spring hardly changes even if it is extended. Therefore, the holding force of the Y-axis slider is substantially constant, and the weight applied to the Y-axis slider and the torque of the winding drum are balanced.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the drawings. FIG. 1 is a partially broken exploded perspective view of a vertical type XY stage according to an embodiment of the present invention in a state where the stage is tilted, and FIG. 2 is an exploded perspective view of main constituent members. In these figures, reference numeral 20 denotes a stage on which the wafer stage 5 is installed, and the stage 20 is connected to the Y-axis slider 22 by a horizontal inverted shaft 23 so that the stage 20 shown in FIG.
Is rotatable between a horizontal position (exchange position) indicated by a solid line and an upright position (exposure position) indicated by a broken line 21, and is rotated by a pulse motor 29.

The same thing can be done by opening and closing the stage 20 in the horizontal direction. Such an example is shown in FIG. In FIG. 2, the inverted shaft 23 is the Y-axis slider 22.
Although it is installed parallel to the horizontal axis of the L-shaped part, the inverted shaft 23 can also be installed parallel to the vertical axis of the L-shaped part. In this case, the inverted shaft will be referred to as the opening / closing shaft. The object of the present invention can be achieved regardless of whether it is upside down or open / closed. However, the difference between the inverted type and the open-closed type is that the inverted type is adversely affected by gravity. This will be described with reference to FIG. 20a is the center of gravity of the stage 20, 2
Reference numeral 3a is a torsion coil spring mounted on the inverted shaft 23. In FIG. 4, the position of the center of gravity changes depending on whether the stage 20 is upright or inverted, and the inverted axis 2 is moved by this amount.
A difference occurs in the moment applied to 3. Since the magnitude of the moment is the product of the distance in the direction perpendicular to the gravity connecting the center of gravity 20a and the inverted axis and the weight of the stage 20, the stage 20
When it is upright, it is almost zero and is minimum, but when it is inverted, it is maximum. On the other hand, the power required to rotate the inverted shaft, that is, the horsepower of the pulse motor 29 needs to be equal to or larger than the maximum value of the moment applied thereto. However, if the torsion coil spring 23a is added as shown in the figure, the torsion coil spring 23a is also bent and deformed when the stage 20 is inverted, so that the maximum value of the moment based on the action of gravity can be greatly reduced. As a result, the inverted power system including the pulse motor 29 can be downsized. In the open / close type, since the rotation of the stage 20 is in the direction perpendicular to gravity, the above-mentioned adverse effect does not exist.

Referring again to FIGS. 1 and 2, the pulse motor 29 is fixedly arranged via the air cylinder 28 to the scale 35 fixedly arranged with respect to the base 100 which constitutes the apparatus fixing portion of the vertical XY stage. However, in FIG. 1, since it is shaded by the stage 20 and is not actually shown in the figure, it is shown together with the air cylinder 28 from the scale 35 for the sake of convenience.
In the embodiment, the ikele 35 is L-shaped and vertically arranged like the Y-axis slider. The rotation of the pulse motor 29 is transmitted to the worm 24 via the drive clutch 26 and the driven clutch 27, and the rotation of the worm 24 is transmitted to the worm wheel 25, thereby rotating the inverted shaft 23, and thereby the stage. 20 is reciprocally rotated between a horizontal exchange position and a vertical exposure position. 61
Is a positioning pin having a spherical tip, which is used to fix the upright position of the stage 20. Although not shown in FIG. 1 (see FIG. 5), the positioning pin 61 is fitted on the back surface of the upright stopper 30. There is a hole 62. Also,
Reference numeral 30b denotes a suction ring made of a ring-shaped thin film, which is installed on the back surface of the upright stopper 30 for vacuum-sucking the stage 20. Hereinafter, the operation of fixing the upright position of the stage 20 by suction will be described in detail with reference to FIG.

FIG. 5A is a view showing a state of the stage 20 immediately before suction fixing, which is a cross section of only the vicinity of the positioning pin 61. 30a is provided in a closed track shape surrounding the tapered hole 62 with a convex step, and an extremely thin film is adhered on the convex step 30a outwardly in a cantilever shape to form a suction pad 30b. An exhaust passage 30c is connected to the hose 30d. A proximity sensor 30e detects that the stage 20 is in the upright position. With such a suction structure, if the hose 30d is evacuated by the operation of the proximity switch 30e,
First, the gap between the suction pad 30b and the stage 20 is exhausted and air flows. For this reason, the pressure in the direction perpendicular to the flow decreases (principle of atomization), so the adsorption pad 30b formed of a thin film is pushed from behind by atmospheric pressure, and as shown in FIG.
As shown in (b), it automatically adheres to the stage 20 to make the closed space inside the suction pad 30 (b) airtight, and as a result, the positioning pin 61 is strongly pressed against the taper hole 62 by the atmospheric pressure and the stage 20 stands upright. The position is fixed.

In FIG. 1, the drive clutch 26 and the driven clutch 27 are engaged and disengaged by driving the air cylinder 28 to move the pulse motor 29 forward and backward. Therefore, the inverted position of the stage 20 is X,
It is limited to the fixed position of the Y-axis direction stroke. The Y-axis slider 22 is provided with an upright stopper 30 which holds the stage 20 in an upright position by vacuum suction.
An electromagnetic fall stopper 31 for adsorbing and holding the stage 20 in a horizontal position is integrally provided on the scale 35. Note that the stopper 31 is not shown in FIG.

As shown in FIG. 2, the Y-axis slider 22 is formed in an L shape, and a bracket 22A for pivotally supporting the shaft end of the inverted shaft 23 is integrally provided on the upper surface of a horizontal portion 22a thereof, and a vertical portion thereof is provided. 22b is provided with the upright stopper 30, an air pad 53 and a Y-axis magnet 54, which will be described later.

Reference numeral 32 denotes an L-shaped X-axis slider. A horizontal portion 32A of the X-axis slider 32 constitutes a slider body, and a vertical portion 32B constitutes a guide of the Y-axis slider 22. The stage 20 is arranged together with the Y-axis slider 22 in a space surrounded by the vertical portion 32B. The Y-axis slider 22
Is held by an air bearing configured by sandwiching the vertical portion 32B with a plurality of Y-axis air pads 33, and has a Y-axis nut 34 screwed to the Y-axis feed screw 16. When the Y-axis feed screw 16 is rotated by the Y-axis motor 19, the rotation is converted into a linear movement of the Y-axis nut 34, whereby the Y-axis slider 22 is moved up and down along the vertical portion 32B.

The X-axis feed screw 13 for reciprocating the X-axis slider 32 in the horizontal direction is arranged on the scale 35, which supports the entire vertical XY stage.
An aerostatic X-axis nut 36 fixedly connected to the slider body 32A of the shaft slider 32 is screwed. Therefore, when the X-axis feed screw 13 is rotated by the X-axis motor 18, the rotation of this screw is converted into a linear motion by the X-axis nut 36, and the X-axis slider 32 is reciprocated. The X-axis feed screw 13 and the Y-axis feed screw 16 of the Y-axis slider 22 are the slider body 32 of the X-axis slider 32.
A and the vertical portion 32B are positioned parallel to this and near the middle of the stage 20, and the thrust center of the feed screw, that is, the slider body 32A and the vertical portion 32B are both nuts 34,
The position of 36 is near the center of gravity of the slider on the X and Y planes. Similarly to the Y-axis slider 22, the X-axis slider 32 is also air-bearing-guided by sandwiching an X-axis guide 37 integrated with the squid 35 and the base 100 with a plurality of X-axis air pads 38.

Reference numeral 39 denotes an X-axis sub-slider, which is air-bearing-guided to an X-axis sub-guide 40 fixed to the upper portion of the scale 35, and is composed of the upper surface of the X-axis slider 32 and a flexible material. Are connected by a connecting plate 41. A Z-shaped groove 42 is formed in the upper part of the connecting plate 41 so that the force in the traveling horizontal plane of the X-axis sub-slider 39 is more transmitted and the other force is deformed and escapes. ..

Here, the structure of the connecting plate 41 will be described in detail with reference to FIG. FIG. 6A is an enlarged view of the connecting plate 41. The connecting plate 41 has two parallel notches 41a corresponding to the top and bottom sides of the Z-shape and a notch 4 that obliquely connects the top and bottom of the Z-shape.
1b is engraved. Therefore, the connecting plate 41 is extremely strong in the plate surface direction required to support the vertical portion 32B of the X-axis slider 32, but the notch portion is bent, so that the connecting plate 41 is unnecessary in the plate surface orthogonal direction to support the vertical portion 32B. It has a very weak shape. Since it has such a shape, as shown in FIG. 6B, the vertical portion 32B of the X-axis slider 32 is formed.
It is not necessary to increase the assembly accuracy of the X-axis slider 32 and the X-axis sub-slider 39 so much. Particularly, in this vertical stage, the connecting plate 41 absorbs mechanical deformation caused by the Y-axis weight being suspended by the X-axis sub-slider 39, and the deformation is not transmitted to the X-axis slider 32, which requires precision. is there.

At the end of the horizontal portion 22a of the Y-axis slider 22, a U-shaped Y-axis sub-slider 43 is provided.
Y fixed to the slider body 32A of the X-axis slider 32
Air bearing is guided around the shaft sub-guide 44. The structure of this air bearing guide is configured by a combination of magnets and air blowouts like other air bearing guide structures. Reference numeral 43a is a magnet provided in the Y-axis sub-slider 43. The X-axis sub-slider 40 and the Y-axis sub-slider 43 are the slider body 32A of the X-axis slider 32.
The tip and the tip of the horizontal portion 22a of the Y-axis slider 22 are devised so as to support only the axial direction (hereinafter referred to as the Z direction) orthogonal to the X and Y planes, and the Z-shaped groove 42 described above is also a part thereof. This is because if guides are provided parallel to both ends of the slider in the longitudinal direction, there is a problem in parallelizing the two axes, and if the distance between the two axes is misaligned due to thermal expansion, the guide and the slider will be caught and will not move. This is because it is usually necessary to leave one end at both ends to escape.

Reference numeral 45 is a suspension hook fixed to the rear surface of the Y-axis slider 22 by screws, and reference numeral 46 is a suspension fitting fixed to the X-axis sub-slider 39, and two pulleys 47 (47a, 4).
7b). Reference numeral 48 is a constant force mechanism having a built-in spiral leaf spring 48a having the same function as the mechanism for rewinding the cord of the vacuum cleaner.
9 can be wound with a constant torque, and it is determined to balance with the weight of the Y-axis slider 22. 50 is a suspension wire, one end of which is fixed to the suspension hook 45 and the other end of which is fixed to the winding drum 49 via two pulleys 47a and 47b. The take-up drum 49 is arranged so that the center of gravity of the X-axis slider 32 is located below the X-axis nut 36 for weight distribution, and the suspension hook 45 is located above the center of gravity of the Y-axis slider 22, that is, the Y-axis nut 34. The position and inclination of 47 are defined.

Reference numeral 51 is an X-axis magnet, and the same number is provided on the opposite side of the X-axis guide 37. Reference numeral 52 denotes a Z-axis guide plate made of a magnetic material that supports the Z-direction of the X-axis slider 32, and the attraction force of the magnet acts between the X-axis magnet 51 and the Z-axis guide plate. Since this suction force is balanced with the air bearing of the X-axis air pad 38, the X-axis slider 32 floats in a non-contact manner. 53 is an air pad that supports the Z direction of the Y-axis slider 22, and the Y-axis Z guide surfaces 32c are both sides of the back surface of the vertical portion 32B of the X-axis slider 32. Reference numeral 54 denotes a Y-axis magnet, which is not shown but is opposed to a Y-axis magnetic material plate 32d corresponding to the Z-axis guide plate 52 of the X-axis slider 32.
The back surface of the vertical portion 32B of 2 is engraved and fixed by adhesion. Although the X-axis slider 32 is made of the same member as the Z-axis guide plate 52 and the magnetic material, the Y-axis slider 22 is made of a different member, but the air bearing pressure and the attractive force of the magnet are different. The fact that it has emerged in the balance with does not change.
Here, the balance levitation will be described in detail by taking the Y axis as an example.

FIG. 7 shows the vertical portion 32B of the X-axis slider 32.
FIG. 3 is a cross-sectional view as seen from above, which is horizontally cut including the Y-axis slider 22. The Y-axis magnet 54 is contained in a yoke 54a for efficiently guiding the magnetic flux to the Y-axis magnetic material plate 32d,
It is fixed to the Y-axis slider 22. Reference numeral 22a is an air supply passage for supplying high pressure air to the bearing gaps of the Y-axis Z guide surface 32c and the Y-axis X guide surface 33a. With this structure, when the high-pressure air is supplied, the pressure in the bearing gap rises, but the Y-axis air pad 3 does not move with respect to the vertical portion 32B.
Since 3 exists facing each other, the left and right bearing pressures are balanced and there is no problem. However, since the bearing gap is in the same plane between the Y-axis slider and the Y-axis Z guide surface 32c, if the bearing pressure increases, only that much. The air bearing cannot be used because the bearing gap increases and as a result, no pressure is generated in the bearing gap. However, in the structure shown in the drawing, the attraction force by the magnetic force acts between the Y-axis magnet 54 and the Y-axis magnetic material plate 32d to balance with the bearing pressure. ..

In FIG. 1, the Z-axis of the X-axis sub-slider 40 and the Y-axis sub-slider 43 are also levitated by the balance between the air bearing pressure and the attractive force of the magnet, but the description is omitted because they are duplicated. ..

In summary, the XY plane directions are sandwiching type air bearing guides (33, 38), and the Z direction is a balance levitation type air bearing guide of magnetic force and air bearing force. Since the balance levitation type requires only one guide surface for each axis, the air pad can be reduced accordingly, and thus the guiding accuracy is slightly lower than the sandwiching type levitation guide, but it is advantageous in reducing the size and weight of the slider. As far as the vertical XY stage is concerned, importance is placed on the feed accuracy in the XY directions and speedup. Therefore, the balance levitation type is adopted only in the Z direction to reduce the weight of the stage and to cope with the speeding up of positioning and low powering. The guides are air bearings for both the X-axis and Y-axis sliders 32, 22.
In addition, as described above, an aerostatic screw is also used for feeding, and the vertical XY stage of the present invention is an all-air floating stage. It is a well-known fact that air bearings can obtain guiding accuracy that exceeds the machining accuracy of members by an order of magnitude due to the effect of uniforming the floating clearance, and similar results have been obtained for the feeding accuracy of the aerostatic screw. 1 and 2, the half stroke position of the X-axis and Y-axis sliders 32 and 22 is the wafer stage 5.
It is drawn so as to be the inverted position of the stage 20.

Next, the operation of the vertical XY stage will be described. In FIG. 2, when the stage 20 is horizontally tilted as shown by the solid line, the X-ray mask and the wafer 6 can be exchanged using the space above the stage 20. After the replacement, the air cylinder 28 is driven forward to set the drive clutch 26 to Y
When the pulse motor 29 is rotated by being coupled to the driven clutch 27 of the shaft slider 22, the rotation is transmitted to the inverted shaft 23 via the worm 24 and the worm wheel 25, so that the stage 20 is shown by a chain double-dashed line in FIG. Turn forward and stand upright. Upright stopper 30 in the upright state
A positioning pin 61 having a spherical tip provided on the stage 20 is inserted into a conical tapered hole 62 (FIG. 6A) provided on the stage 20 to position the stage 30, and then provided on the upright stage 30. If the stage 20 is vacuum-sucked by the vacuum suction pad 30b, the exposure position is accurately determined. Thereafter, when the air cylinder 28 is moved backward, the drive clutch 26 and the driven clutch 27 are disengaged, and when the X-axis motor 18 is driven, the X-axis slider 32 moves in the X-axis direction along the X-axis guide 37 in the Y-axis direction. When the axis motor 19 is driven, the Y-axis slider 22 is guided by the vertical portion 32B of the X-axis slider 32 and moves in the Y-axis direction, resulting in the stage 2
0 is moved in the XY directions. Needless to say, the movement amount of the vertical XY stage is sufficient if the X and Y axis sliders 32 and 22 have a stroke corresponding to the exposure area in order to invert the stage 20 and replace the X-ray mask and the wafer 6.

After the SOR exposure is completed by moving the X and Y axis sliders 32 and 22 in the XY directions, the stage 20 is returned to the above-mentioned inverted position and the operation opposite to the upright operation of the stage 20 is performed. Falls down as shown. When the coil of the tilt stopper 31 is excited after tilting, a magnetic body (not shown) provided on the stage 20 is attracted, so that the horizontal position as well as the upright position is accurately determined, and the operation completes one cycle.

In the present invention, the L-shaped X-axis slider has been described as a main constituent element, but the shape including the X-axis sub-slider and the Y-axis sub-slider is close to a square shape. Therefore, the main structure is not limited to the L-shape. Further, although the stage 20 is shown as an inverted type, the inverted shaft 23 is not limited to one and parallel, and if it is driven by vertical and two interlocking movements, it will be a double opening and closing door type. Can do the same. Air bearings are used for the guides and feed screws because it is not possible to ensure the final accuracy required for the SOR exposure system only with the vertical XY stage. If accuracy is not so required, rolling ball guides or ball screws should be used. Even if it is used, it can be configured, and in an extreme case, a linear motor can be adopted instead of the aerostatic screw, and the present invention is not limited to this. Further, although it has been shown that the sequential replacement of the X-ray mask and the wafer can be realized without increasing the stroke of the vertical XY stage, it goes without saying that the same sequential replacement can be performed even if the mask is not the X-ray mask or the wafer. In addition, the feed screws 13, 16 of the X, Y axis sliders 32, 22
Can be driven in the vicinity of the center of gravity in the XY plane by arranging the stage 20 and the X-axis guide, and the Y-axis guide, that is, the vertical portion 32B of the X-axis slider 32, in the XY plane. It's not limited
It goes without saying that any point other than the midpoint may be used as long as it is parallel to the guide. Although the spherical positioning pin 61 and the tapered hole 62 are used to fix the inverted position of the stage 20, there are various combinations such as a ball and a plane, a taper, a cylindrical shaft and a hole, and the like.
Although the positioning pin 61 is also provided at one location, a plurality of positioning pins 61 may be used. It has been shown that it is attached and detached and fixed by vacuum or magnetic force, but it goes without saying that electrostatic force may be used. Also, stage 2
In the inverted position of 0, the difference in gravitational moment was reduced by the torsion coil spring 20a. However, if the spring is bent and deformed as the stage 20 rotates, even if the spring is not a torsion coil spring, for example, a simple leaf spring, or tension or compression. It goes without saying that it can be easily realized by a coil spring of the formula. In addition, the notch 41b of the connecting plate 41 is also shown in a U-shape, but V-shape, U-shape, etc. can be easily imagined, and the notch is not limited to this.

In any case, in the vertical XY stage in which the horizontal portion 32A of the L-shaped X-axis slider 32 serves as the slider body and the vertical portion 32B serves as the guide for the Y-axis slider 22, it is surrounded by the horizontal portion and the vertical portion. The stage 20 connected to the Y-axis slider 22 via an inverted shaft or an opening / closing shaft is provided in the open space portion, and the rotation of the stage 20 is used to supply and collect the object to and from the vertical XY stage. Various changes can be made without departing from the scope.

[0033]

As described above, the vertical X according to the present invention
According to the Y stage, the movement stroke in the X direction is required only for the exposure area of the wafer, and the guide of the X-axis slider and the length of the feed screw can be shortened by this amount as compared with the conventional apparatus shown in FIG. it can. This improves the processing accuracy of the constituent members and, as a result, improves the feeding accuracy of the vertical XY stage, and also has the advantage that the device width can be shortened and a large number of devices can be installed in the radial direction around the horizontal plane orthogonal to the SOR optical axis. In addition, since the mask stage and the wafer stage do not pass each other, various advantages such as a high safety advantage against accidents during assembly and adjustment of the apparatus and maintenance are produced. In addition, the drive mechanism that inverts the stage is not mounted on the vertical XY stage.
The method of separately placing the power in the fixed position of the Y-direction stroke and transmitting the power through the clutch means has the advantage of reducing the weight load on the stage as compared with the method of mounting the drive mechanism on the stage, and limits the inverted position. Therefore, there is an advantage that the back surface of the vertical XY stage, that is, the space in the direction in which the stage falls down can be used separately. Further, the addition of the torsion coil spring in the inversion mechanism reduces the moment force and reduces the size and weight of the mechanism, but as a result, it has the effect of speeding up the operation. In addition, when the upright position is fixed with a thin cantilever type suction pad, the thin film automatically sticks to the opposing suction surface to make it airtight, so even if the suction surface accuracy is a little poor, it will be between the suction surfaces. Even if there is a gap, the thin film becomes airtight following the mating surface, so an extremely strong adsorption force is obtained, and as a result, not only the power of the vacuum exhaust system is lowered,
It has the effect of firmly maintaining the upright position. In addition, the connecting plate with the Z-shaped notch has adverse effects such as assembly error of the mechanism, thermal expansion of members and dimensional change due to suspension of Y-axis stage weight.
This has the effect of not transmitting to the XY axes, which is the main function of the Y stage. Further, the horizontal portion of the L-shaped X-axis slider serves as a slider body, the vertical portion serves as a guide for the Y-axis slider, and the Y-axis slider and the stage are mounted in a space surrounded by the horizontal portion and the vertical portion. Therefore, the feed screw can be arranged at the center of gravity between the mounting mechanism and the horizontal portion or the vertical portion, as well as providing the advantage of facilitating the transfer of the X-ray mask or the wafer. It is possible to realize driving near the center of gravity without swinging the shaft slider. Furthermore, the constant force mechanism using the spiral spring has the advantage of equalizing the forward and reverse load of the motor due to the vertical movement of the Y-axis slider, and of course the wire path can be freely designed by the position and inclination of the pulley. There are advantages, and there is also an advantage that weight distribution and suspension of the center of gravity are facilitated. As a result, the center of gravity drive can be realized, which is effective for fine positioning control. If a total static pressure levitation system with air bearings for guides and feed screws is used, the air bearings can achieve feed accuracy that exceeds the machining accuracy of the members by an order of magnitude, so the final accuracy required for SOR exposure can only be achieved with the vertical XY stage. There are advantages that can be realized, and X
A sandwiching type air bearing is used in the Y direction, and an air bearing that balances the air bearing pressure and the attractive force of the magnet is used in the Z direction, which is orthogonal to the XY plane. The effects of achieving both compatibility and the features such as averaging of bearing gaps unique to air bearings, no friction, long life, and cleanness have various effects on positioning accuracy and device operation.

[Brief description of drawings]

FIG. 1 is a partially cutaway exploded perspective view showing an embodiment of a vertical XY stage according to the present invention.

FIG. 2 is an exploded perspective view of main constituent members.

FIG. 3 is a diagram showing an example in which a stage is opened and closed horizontally.

FIG. 4 is a diagram for explaining the effect of gravity on an inverted stage.

5A and 5B are diagrams showing a vacuum suction mechanism of a stage.

6A and 6B are perspective views of a connecting plate that connects the X-axis slider and the X-axis sub-slider.

FIG. 7 is a diagram showing a flying mechanism of an X-axis slider.

FIG. 8 is a perspective view showing a conventional example of a vertical XY stage.

[Explanation of Codes] 1 SOR light 3 X-ray mask 4 Mask stage 5 Wafer stage 6 Wafer 18 X-axis drive motor 19 Y-axis drive motor 22 Y-axis slider 23 Inverted shaft 29 Pulse motor 32 X-axis slider 48 Constant force mechanism 48a Swirl Spring 49 winding drum

Claims (3)

[Claims] 1. A space provided with an X-axis slider and a Y-axis slider, wherein a horizontal portion of the X-axis slider serves as a slider body and a vertical portion serves as a guide for the Y-axis slider, and is surrounded by the horizontal portion and the vertical portion. A vertical type X characterized in that a stage is disposed in a portion and the stage is connected to the Y-axis slider so as to be upside down or openable / closable by an inverted shaft or an open / close shaft.
Y stage. 2. The vertical XY stage according to claim 1, wherein a drive motor that inverts or opens and closes the stage is disposed on a device fixing portion side where the vertical XY stage is provided,
A vertical XY stage characterized in that the rotation of the drive motor is transmitted to the stage at a fixed position in the XY direction through clutch means. 3. The vertical XY according to claim 1 or 2.
In the stage, a pulley is provided above the vertical portion of the X-axis slider and a take-up drum using a spiral spring is provided below the stage. The Y-axis slider and the take-up drum are connected by a wire via the pulley, A vertical XY stage characterized in that the weight of the axial slider and the torque of the winding drum are balanced by the spiral spring.