JP3084418B2 - Vertical XY stage for SOR exposure - Google Patents

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 (hereinafter referred to as a vertical XY stage) for SOR exposure which is suitable for use in an exposure apparatus for fine patterns of a semiconductor integrated circuit, particularly an exposure apparatus using synchrotron radiation emitted from a light source. Stage) .

[0002]

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

On the other hand, the wavelength of a transfer light source has been shortened in response to the high integration of semiconductor elements. As a future technology, synchrotron orbit radiation whose wavelength is shorter than that of ultraviolet light, which is the current transfer light source, by more than two orders of magnitude will be described. Development of a pattern transfer technique using light (hereinafter, referred to as SOR light) is underway. This is because light with a shorter wavelength has less diffraction and interference and can transfer a fine pattern.

[0004] 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 has high directivity including visible light to X-ray. Soft X-rays having a wavelength of about 1 nm are taken out of the light having high luminance and used as a light source for pattern transfer.

FIG. 8 shows a conventional example of a vertical XY stage used in such an exposure apparatus using SOR light as a light source.
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 any direction in a horizontal plane of a tangent line where the electron beam travels. Is provided. A circuit pattern is formed on the X-ray mask 3, and the SOR light 1 passing through the circuit pattern causes a pattern shadow. 4
Denotes a mask stage that holds the X-ray mask 3 and controls its position and attitude, 5 denotes a wafer stage that holds the wafer 6 by suction, and 7 denotes a position for observing a positioning mark provided on the X-ray mask 3 and the wafer 6 in advance. This is a detection system that optically detects a shift amount. An XY 8 moves the wafer 6 in the XY directions.
After the XY stage 8 and the mask stage 4 are moved and adjusted on the basis of a position shift detection signal from the alignment mark, the XY stage 8 and the mask stage 4 are aligned, and then the SOR light 1 is irradiated. Is transferred to the photosensitive agent on the wafer 6.

[0006] The SOR light 1 is emitted in a horizontal plane. For this reason, the X-ray mask 3 and the wafer 6 are placed vertically in a vertical plane, and the XY stage 8 is also vertical. In addition, since the SOR light 1 has a small divergence even though it has high directivity, when the distance between the X-ray mask 3 and the wafer 6 is increased, the shape of the projected pattern may be distorted or blurred. Normal exposure becomes difficult. Therefore, the distance between the surface of the X-ray mask 3 and the surface of the wafer 6 needs to be extremely small.
m or less.

In FIG. 8, the wafer 6 is not located on the axis of the SOR light 1 on which the mask 3 is to be installed, but at a position far from the mask 3. Thus, the X-ray mask 3 and the wafer 6 can be easily exchanged with each other. This means that if only the exposure of the wafer 6 is performed, a 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 them in a situation where the X-ray mask 3 and the wafer 6 face each other while maintaining a small gap. Therefore, after exchanging the X-ray mask 3 and the wafer 6 from the directions of the arrows 9 and 10 at the illustrated position, the XY stage 8 moves the wafer 6 to a position facing the X-ray mask 3 to start exposure. That is.

The XY stage 8 includes an X-axis guide 11 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 for guiding 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 is a structure carrying
The X and Y axis guides 11 and 14 are fixed,
16, the X and Y axis sliders 12 and 15 respectively
It is moved in the X-axis and Y-axis directions. 17 is the X-axis slider 12
A horizontal platen 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, since the X-axis drive motor 18 is driven by holding the X-axis slider 12, the horizontal platen 17, the Y-axis guide 14, and the Y-axis slider 15, the load is larger than that of the Y-axis drive motor 19. Accordingly, it is inevitable that the capacity of the X-axis drive motor 18 becomes large. In particular, the X-axis slider 12 is required to have a movement amount obtained by adding a stroke required for exchanging the X-ray mask 3 and the wafer 6 as well as a stroke corresponding to the exposure area. Double travel is required. Therefore, the X-axis slider 12 is
5, the width of the vertical XY stage 8 in the horizontal direction is increased.

[0009]

SUMMARY OF THE INVENTION As described above, SOR
In the conventional vertical XY stage 8 used for the exposure apparatus, since the X-axis slider 12 needs to move about 3 to 5 times the exposure area, the horizontal width of the stage 8 is inevitably increased. However, as a result, there are the following problems. 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 is smaller, a larger number of exposure apparatuses can be installed in the radial direction around the ring 2 and the ring 2 can be used more effectively. In order to facilitate the exchange of the wafer 3 or the wafer 6, the width in the horizontal plane direction perpendicular to the axis of the SOR light 1, that is, the width in the X-axis direction is widened, so that there is a problem that the ring 2 is not effectively used. The feed accuracy of the XY stage 8 decreases. The feed accuracy of the XY stage 8 is determined by the guide accuracy and feed accuracy for maintaining the posture of the stage, and the accuracy may be considered to be the processing accuracy of the constituent members. However, XY stage 8
There is a method to improve the accuracy by adding a mechanism that moves minutely by the feed error and an error measurement system separately to correct the error, but the mechanism, measurement system, and control system that have accuracy and performance one digit higher than the main unit And the like must be additionally mounted, resulting in an increase in weight, an extremely expensive, complicated, and easily broken stage. In order to avoid this, it is desirable that the final accuracy can be secured only with the main body, and therefore, with a simple structure,
It is important that the constituent members have a shape that can enhance the processing accuracy. When the X-axis slider 12 becomes longer,
The X-axis guide 11 and the X-axis feed screw 13 also need to be elongated accordingly. The processing accuracy is inversely proportional to the length even if the strength of the member is infinite, and the strength of the member decreases in inverse proportion to the cube of the length and the cube of the diameter. That is, various forces and stresses such as a cutting force and a grinding force, a residual stress and a thermal stress due to plastic deformation, and a chucking force applied when the member is fixed to the processing device are applied to the member during processing. However, if a force is applied, the member is deformed, so that the more deformed, the more precise processing cannot be expected. As described above, the member strength is the largest factor affecting the processing accuracy.
In short, the lengthening of the members significantly reduces the processing accuracy,
The processing accuracy deteriorates the feeding accuracy of the XY stage 8. The gravity imbalance of the Y-axis slider 15 occurs. X
Since the weight applied to the shaft slider 12 acts in a direction orthogonal to the X-axis guide 11, the guide surface supports the weight. In this case, the static rotational load applied to the X-axis feed screw 13 is only the frictional force of the screw surface, and the weight itself of the X-axis slider 12 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 the weight. Therefore, the weight of the Y-axis slider 15 directly affects the rotational load of the Y-axis feed screw 16. This rotational load due to gravity acts in a direction opposite to the rotational direction of the Y-axis drive motor 19. This is Y-axis slider 1
This means that it is necessary to change the energy applied to the Y-axis drive motor 16 between the rise and fall of 5. This has an adverse effect on the drive control of the Y-axis slider 15 and, as a result, is a drawback that the positioning accuracy of the Y-axis slider 15 is reduced or the speed of the feed is prevented. The lighter the weight of the X-axis slider 12 and the more the Y-axis slider 15, the better. This is because, as is well known, the load on the drive motor is reduced, and high-speed, high-precision positioning is advantageous in terms of control. Lack of safety against disability. The X-axis slider 12 reciprocates between the exchange position of the wafer 6 and the exposure position. There is no problem on the outward path, but on the return path, the mask stage 4 and the wafer stage 5 pass each other. Therefore, when the apparatus is started up and maintained, if a hand or a finger is caught here, it will be serious. Because X
The axis slider 12 has a considerable weight because it has the Y-axis guide 14, the Y-axis slider 15 and the horizontal platen 17 in addition to its own weight, so it does not stop when it starts moving, and it is difficult to stop further during motor driving. , Which places an excessive burden on safety measures.

Accordingly, 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 operation. It is another object of the present invention to provide a vertical XY stage capable of achieving high precision and improved safety.

[0011]

Means for Solving the Problems The present invention has been made to achieve the above object, and the first invention is directed to a horizontal direction.
X-axis slider that can translate in
A Y-axis slider attached and vertically translatable;
A predetermined wafer attached to this Y-axis slider and loaded
And a stage capable of being mounted, wherein the stage
Inverted or openable and closable
In this state, the slider is connected to the Y-axis slider. According to a second aspect of the present invention, in the first aspect, a drive motor for inverting or opening and closing the stage is disposed on a device fixing portion side provided with a vertical XY stage, and the rotation of the drive motor is fixed at a fixed position in an XY direction stroke. The data is transmitted to the stage via a clutch means. According to a third invention, in the first or second invention, a pulley is provided above a vertical portion of the X-axis slider, and a winding drum using a spiral spring is provided below the X-axis slider, and the Y-axis slider and the winding drum are provided. Are 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 so as to be capable of being inverted or opened and closed by an inverted shaft or an opening / closing shaft. Of the X-ray mask wafer can be exchanged from the front side. When the stage is inverted, the movement stroke of the vertical XY stage can be reduced by the exposure area.
The stage is inverted with respect to the mask stage in the opposite direction, so that the stages do not pass 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]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. FIG. 1 is an exploded perspective view showing an embodiment of a vertical XY stage according to the present invention, in which the stage is turned down and partially broken away, and FIG. 2 is an exploded perspective view of main components. In these figures, reference numeral 20 denotes a stage on which the wafer stage 5 is set, and this stage 20 is connected to a Y-axis slider 22 by a horizontal inverted shaft 23, whereby
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 configured to be rotated by a pulse motor 29.

Here, the same can be achieved 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 a Y-axis slider 22.
Are installed in parallel with the horizontal axis of the L-shaped portion, but the inverted shaft 23 can be installed in parallel with the vertical axis of the L-shaped portion. In this case, the inverted shaft is referred to as an opening / closing shaft. There is no change in that the object of the present invention can be achieved by using either the inverted method or the open / close method. However, the difference between the inverted type and the opening and closing type is that the inverted type is affected by the adverse effect of gravity. This will be described with reference to FIG. 20a is the center of gravity of the stage 20, 2
3a is a torsion coil spring mounted on the inverted shaft 23. In FIG. 4, the position of the center of gravity changes between when the stage 20 is upright and when it is inverted, and the inverted shaft 2
There is a difference in the moment applied to 3. The magnitude of the moment is the product of the distance in the direction perpendicular to gravity connecting the center of gravity point 20a and the inverted axis and the weight of the stage 20.
When it is upright, it is almost zero and becomes minimum, but when it is inverted, it becomes maximum. On the other hand, the power required for rotating the inverted shaft, that is, the horsepower of the pulse motor 29, needs to be equal to or greater than the maximum value of the moment applied thereto. However, if the torsion coil spring 23a is added as shown in the drawing, the torsion coil spring 23a also bends and deforms with the inversion of the stage 20, so that the maximum value of the moment based on the action of gravity can be significantly reduced by that much, Consequently, the size of the inverted power system including the pulse motor 29 can be reduced. In the open / close type, since the rotation of the stage 20 is in the direction perpendicular to the gravity, the above-mentioned adverse effect does not exist.

Referring again to FIGS. 1 and 2, the pulse motor 29 is fixedly disposed via an air cylinder 28 on an scale 35 fixedly disposed on a base 100 constituting a device fixing portion of the vertical XY stage. However, in FIG. 1, since it is a position that cannot be actually shown due to the shadow of the stage 20, it is removed together with the air cylinder 28 from the scale 35 for convenience.
In the embodiment, the scale 35 is L-shaped and is vertically provided 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 further, the rotation of the worm 24 is transmitted to the worm wheel 25 to rotate the inverted shaft 23, and thereby the stage 20 is reciprocated between a horizontal exchange position and a vertical exposure position. 61
Is a positioning pin having a spherical tip for fixing the upright position of the stage 20. Although not shown in FIG. 1 (see FIG. 5), a taper on the back surface of the upright stopper 30 to which the positioning pin 61 is fitted. A hole 62 is present. Also,
Numeral 30b denotes a suction ring made of a ring-shaped thin film provided on the back surface of the upright stopper 30 for vacuum suction of the stage 20. Hereinafter, the operation of suction-fixing the upright position of the stage 20 will be described in detail with reference to FIG.

FIG. 5A is a view showing a state of the stage 20 immediately before the suction fixing, in which only the vicinity of the positioning pin 61 is sectioned. A convex step 30a is installed in a closed orbit around the tapered hole 62, and a very thin film is adhered outward on the convex step 30a in a cantilever manner 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, a gap between the suction pad 30b and the stage 20 is exhausted and air flows. As a result, the pressure in the direction perpendicular to the flow decreases (the principle of spraying), so that the suction pad 30b formed of a thin film is pushed from behind by the atmospheric pressure, and the pressure in FIG.
As shown in (b), the space is automatically adhered to the stage 20 to make the closed space in the suction pad 30 (b) airtight. As a result, the positioning pin 61 is strongly pressed against the tapered hole 62 by the atmospheric pressure, and the stage 20 stands upright. The position is fixed.

In FIG. 1, the coupling and disengagement of the driving clutch 26 and the driven clutch 27 are performed 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 a fixed position in the Y-axis direction stroke. The Y-axis slider 22 is provided with an upright stopper 30 for holding the stage 20 in an upright position by vacuum suction.
An electromagnetic tilt stopper 31 for holding the stage 20 in a horizontal position by suction is provided integrally with the scale 35. In FIG. 2, illustration of the stopper 31 is omitted.

The Y-axis slider 22 is formed in an L-shape as shown in FIG. 2, and a bracket 22A for supporting the shaft end of the inverted shaft 23 is integrally provided on the upper surface of a horizontal portion 22a. The upright stopper 30, an air pad 53 described later, and a Y-axis magnet 54 are provided at 22b.

Reference numeral 32 denotes an X-axis slider formed in an L-shape. The horizontal portion 32A of the X-axis slider 32 constitutes a slider main body, and the vertical portion 32B constitutes a guide of the Y-axis slider 22, respectively. 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 formed by sandwiching the vertical portion 32B between 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 linear motion 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 disposed on the scale 35 supporting the entire vertical XY stage.
An air static pressure type X-axis nut 36 fixedly connected to the slider main 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 linear motion by the X-axis nut 36, and the X-axis slider 32 reciprocates. The X-axis feed screw 13 and the Y-axis feed screw 16 of the Y-axis slider 22 are connected to a slider body 32 of the X-axis slider 32.
A and the vertical portion 32B are positioned in parallel with this and near the middle of the stage 20, and the thrust center of the feed screw, that is, both the slider body 32A and the vertical portion 32B are nuts 34
The position of 36 is located 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 guided by an air bearing by sandwiching the X-axis guide 37 integrated with the scale 35 and the base 100 by a plurality of X-axis air pads 38.

Reference numeral 39 denotes an X-axis sub-slider. The sub-slider 39 is guided by an air bearing on an X-axis sub-guide 40 fixed to the upper part of the scale 35, and is made of a flexible material with the upper surface of the X-axis slider 32. 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 transmitted more and the other force is deformed to escape the connecting plate 41. .

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-character, and a notch 4 for connecting the upper and lower sides of the Z-character obliquely.
1b is engraved. For this reason, the connecting plate 41 is extremely strong in the plate surface direction necessary for supporting the vertical portion 32B of the X-axis slider 32, but is not required for supporting the vertical portion 32B because the notch portion is bent. Very weak shape. As shown in FIG. 6B, the vertical portion 32B of the X-axis slider 32 has such a shape.
Therefore, it is not necessary to increase the assembly accuracy of the X-axis slider 32 and the X-axis sub-slider 39 so much. In particular, in this vertical stage, the deformation of the mechanism caused by the weight of the Y-axis suspended on the X-axis sub-slider 39 is absorbed by the connecting plate 41, and the deformation is not transmitted to the X-axis slider 32 requiring accuracy. is there.

At the tip 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
The air bearing is guided around the shaft sub-guide 44. This structure of the air bearing guide is constituted by a combination of a magnet and an air blowout like other air bearing guide structures. 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 designed so as to support only the axial direction (hereinafter, referred to as the Z direction) orthogonal to the X and Y planes. This is because if guides are provided in parallel to both ends in the longitudinal direction of the slider, there is a problem in paralleling the two axes, and if the distance between the two axes is misaligned due to thermal expansion, the guide and the slider will bite and will not move. Usually, it is necessary to leave one end of the both ends free.

Reference numeral 45 denotes a hanging hook fixed to the back surface of the Y-axis slider 22 by screwing, and 46 denotes a hanging bracket fixed to the X-axis sub-slider 39.
7b). A constant force mechanism 48 has a built-in spiral type 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 is determined so as to balance with the weight of the Y-axis slider 22. A suspension wire 50 is fixed at one end to the suspension hook 45 and at the other end to the winding drum 49 via two pulleys 47a and 47b. The take-up drum 49 is lowered for weight distribution so that the center of gravity of the X-axis slider 32 is on the X-axis nut 36, and the pulling hook 49 is positioned on the center of gravity of the Y-axis slider 22, that is, on the Y-axis nut 34. The position and inclination of 47 are defined.

Reference numeral 51 denotes 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 for supporting the X-axis slider 32 in the Z direction, and a magnet attracting force acts between the X-axis slider 51 and the X-axis magnet 51. 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. Reference numeral 53 denotes an air pad for supporting the Y-axis slider 22 in the Z direction. The Y-axis Z guide surfaces 32c are both sides on 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, and 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 second vertical portion 32B is engraved and fixed. The X-axis slider 32 is formed of the same member as the Z-axis guide plate 52 and the magnetic material, whereas the Y-axis slider 22 is formed of a separate member. However, the air bearing pressure and the attractive force of the magnet are different. The fact that we have emerged in balance with that remains unchanged.
Here, the balance levitation will be described in detail using the Y axis as an example.

FIG. 7 shows a vertical portion 32B of the X-axis slider 32.
FIG. 2 is a cross-sectional view cut along a horizontal plane including a Y-axis slider 22 and viewed from above. The Y-axis magnet 54 is included 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 denotes an air supply passage for supplying high-pressure air to the bearing gap between the Y-axis Z guide surface 32c and the Y-axis X guide surface 33a. With such a structure, the pressure in the bearing gap increases when high-pressure air is supplied, but the Y-axis air pad 3
Since the bearing pressures 3 are opposed to each other, there is no problem in balancing the left and right bearing pressures. However, since the bearing gap between the Y-axis slider and the Y-axis Z guide surface 32c is in the same plane, if the bearing pressure increases, the bearing pressure increases. Since the bearing gap increases and no pressure is generated in the bearing gap as a result, it cannot be an air bearing. However, in the illustrated structure, a magnetic attraction 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 X-axis sub-slider 40 and the Y-axis sub-slider 43 are similarly floated in the Z direction by the balance between the air bearing pressure and the attracting force of the magnet. .

In summary, the XY plane direction is a pinching type air bearing guide (33, 38), and the Z direction is a floating type air bearing guide that balances magnetic force and air bearing force. Since the balance levitation type requires only one guide surface per axis, the number of air pads can be reduced, so that the guide accuracy is slightly lower than that of the sandwich type levitation guide, but it is advantageous for reducing the size and weight of the slider. As far as the vertical XY stage is concerned, the feeding accuracy and speeding up in the XY directions are emphasized. Therefore, the balance levitation type is used only in the Z direction to reduce the weight of the stage and to cope with the high-speed positioning and low power. The guides are air bearings for both the X-axis and Y-axis sliders 32 and 22.
In addition, as described above, an air static pressure 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 an air bearing can achieve a guiding accuracy one order of magnitude higher than the machining accuracy of a member due to the effect of equalizing the floating clearance, and similar results have been obtained for the feeding accuracy of an aerostatic screw. 1 and 2, the half-stroke position of the X-axis and Y-axis sliders 32 and 22 is
It is drawn so as to be the inverted position of the stage 20 and the stage 20.

Next, the operation of the vertical XY stage will be described. In FIG. 2, when the stage 20 is horizontally inclined as shown by a 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 so that the drive clutch 26
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, and the stage 20 is shown by a two-dot chain line in FIG. And turn upright to stand upright. With the upright stopper 30 in the upright state
After the positioning pin 61 having a spherical tip provided on the stage 20 is inserted into the conical tapered hole 62 (FIG. 6A) provided thereon to position the stage 30, it is 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 retracted, the connection between the drive clutch 26 and the driven clutch 27 is released. When the X-axis motor 18 is driven, the X-axis slider 32 moves along the X-axis guide 37 in the X-axis direction. When the shaft 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.
0 is moved in the XY directions. It is needless to say that the X and Y-axis sliders 32 and 22 need only have a stroke corresponding to the exposure area in order to exchange the X-ray mask and the wafer 6 by inverting the stage 20 for the vertical XY stage.

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

In the present invention, the X-axis slider formed in an L-shape has been described as a main component. However, the shape including the X-axis sub-slider and the Y-axis sub-slider is similar to the B-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 vertically and in conjunction with two, it will be a double opening door type. The same is possible. In addition, the use of air bearings for the guides and feed screws is because only the vertical XY stage is used to secure the final accuracy required for an SOR exposure apparatus. In an extreme case, a linear motor can be used instead of the aerostatic screw, and the present invention is not limited to this. Furthermore, 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 is possible without using the X-ray mask or the wafer. In addition, the feed screws 13, 16 of the X, Y axis sliders 32, 22
When the center is located between 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, driving near the center of gravity in the XY plane can be realized. It is not limited,
It goes without saying that other than the intermediate point 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 or a cylindrical shaft and a hole, and the like.
Although one positioning pin 61 is provided, a plurality of positioning pins 61 may be used. Although shown as attachment and detachment by vacuum or magnetic force, it goes without saying that electrostatic force may be used. Stage 2
When the stage 20 is inverted, the torsion coil spring 20a reduces the difference in gravitational moment. However, if the spring is flexed and deformed as the stage 20 rotates, it is not a torsion coil spring but a simple leaf spring or a tension or compression spring. It is needless to say that a coil spring of the type can be easily realized. In addition, the notch 41b of the connecting plate 41 is also shown in a U-shape, but a V-shape, a U-shape or the like is easily imagined, and the present invention 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 is the slider body and the vertical portion 32B is the guide of the Y-axis slider 22, it is surrounded by the horizontal portion and the vertical portion. The main object of the present invention is to provide a stage 20 coupled to a Y-axis slider 22 via an inverted axis or an opening / closing axis in the space provided, and to supply and collect an object to a vertical XY stage by using the rotation of the stage 20. Various changes can be made without departing from the scope.

[0033]

As described above, the vertical X according to the present invention is used.
According to the Y stage, the movement stroke in the X direction only needs to correspond to the exposure area of the wafer, and it is possible to reduce the length of the guide of the X-axis slider and the length of the feed screw by that much as compared with the conventional apparatus shown in FIG. it can. This has the advantage of increasing the processing accuracy of the component members and consequently increasing the feed accuracy of the vertical XY stage, as well as the advantage of being able to reduce the device width and installing a number of devices in the radial direction around the horizontal plane perpendicular to the SOR optical axis. Further, since the mask stage and the wafer stage do not pass each other, various effects such as an advantage of high safety against an accident at the time of assembling adjustment and maintenance of the apparatus can be obtained. Also, the drive mechanism for inverting the stage is not mounted on the vertical XY stage,
The method of transmitting power via the clutch means separately placed at the fixed position in the Y-direction stroke has the advantage of reducing the weight load on the stage as compared with the method in which the drive mechanism is mounted on the stage, and also limits the inverted position. This has the advantage that the back of the vertical XY stage, that is, the space in the direction in which the stage falls, can be used separately. Further, the addition of the torsion coil spring in the inverted mechanism reduces the moment force and reduces the size and weight of the mechanism, but as a result, there is an effect that the operation can be speeded up. Also, fixing the upright position with a thin cantilever type suction pad automatically attaches the thin film to the opposite suction surface to make it airtight, so even if the suction surface accuracy is slightly poor, even between the suction surfaces Even if there is a gap, a very strong suction force can be obtained because the thin film follows the mating surface to make it airtight. As a result, not only can the vacuum exhaust system be powered down,
This has the effect of firmly maintaining the upright position. In addition, the connecting plate with the Z-shaped notch has the adverse effects such as assembly errors of the mechanism, thermal expansion of the members and dimensional changes due to suspension of the weight of the Y-axis stage, etc.
There is an effect of not transmitting to the XY axes, which is the main function of the Y stage. The horizontal portion of the L-shaped X-axis slider serves as a slider body and the vertical portion serves as a 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, for example, an advantage such as easy transfer of an X-ray mask or a wafer can be obtained. In addition, a feed screw can be arranged at a center of gravity located between a mounting mechanism and a horizontal portion or a vertical portion. Driving near the center of gravity without swinging the shaft slider can be realized. Furthermore, the constant force mechanism using the spiral spring has the advantage of equalizing the forward / 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 is an advantage, and there is also an advantage that the weight distribution and the hanging of the center of gravity are facilitated, and as a result, the center of gravity driving can be realized, which is effective for fine positioning control. If a full hydrostatic levitation system using guides and feed screws as air bearings is used, the air bearings can achieve a feed accuracy that is one order of magnitude higher than the processing accuracy of the members, so the final accuracy required for SOR exposure can be reduced only with the vertical XY stage. There are advantages that can be realized, and X
In the Y direction, a pinch-type air bearing is used, and in the Z direction orthogonal to the XY plane, an air bearing that balances the air bearing pressure and the attractive force of the magnet is adopted. The characteristics of air bearings such as averaging of bearing gaps, frictionlessness, long life, and cleanness have various effects on positioning accuracy and device operation.

[Brief description of the drawings]

FIG. 1 is an 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 components.

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

FIG. 4 is a diagram illustrating the influence of gravity on an inverted stage.

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

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

FIG. 7 is a view showing a floating mechanism of the X-axis slider.

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

[Explanation of symbols]

 Reference Signs List 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 Spiral spring 49 Winding drum

Continuation of front page (56) References JP-A-1-181522 (JP, A) JP-A-2-42426 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03F 1 / 00-1/16

Claims (3)

(57) [Claims] An X-axis slider translatable in a horizontal direction,
Attached to this X-axis slider and vertically translatable
Versatile Y-axis slider and attached to this Y-axis slider
And a stage on which a predetermined wafer can be placed,
The stage is tilted by a predetermined inverted axis or open / close axis.
Connected to the Y-axis slider in a free or openable state
A vertical XY stage for SOR exposure, characterized in that: 2. A vertical XY stage for SOR exposure according to claim 1, wherein a drive motor for inverting or opening and closing said stage is disposed on a device fixing unit side provided with a vertical XY stage, and the rotation of said drive motor is XY. A vertical XY for SOR exposure characterized in that the stage is transmitted to the stage via a clutch means at a fixed position of a directional stroke.
stage. 3. The SOR dew according to claim 1 or claim 2.
In the vertical XY stage for light , a pulley is provided above the vertical portion of the X-axis slider, and a winding drum using a spiral spring is provided below the X-axis slider, and the Y-axis slider and the winding drum are connected by a wire via the pulley. A vertical XY stage for SOR exposure , wherein the weight applied to the Y-axis slider and the torque of the winding drum are balanced by the spiral spring.