JPH11142555A - Positioning device, exposure device and manufacture of the device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a peak in the natural vibration of a stage to enable fast and highly precise positioning by providing a hollow structure in the constituent member of a positioning device and enclosing a damping material in the hollow structure. SOLUTION: A top board 1 is molded of ceramic, and constitutes a molding body of a hollow structure 2. The hollow structure 2 comprises a plurality of divided ceramic elements. The ceramic element can be manufactured by a press molding method or the like and joined by re-sintering. Foaming material is sealed in the hollow inside as a damping material, and injected from an injection port 3 provided in the lower part of the top board 1. After the damping material is injected in the hollow structure 2, a plug is provided on the port 3, and tightly sealed so that the damping material does not come into contact with atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning apparatus for moving and positioning a substrate such as a wafer at a high speed and with high precision in an exposure apparatus, various precision processing machines, various precision measuring instruments, and the like used in a lithography process of semiconductor manufacturing. Furthermore, a method for manufacturing a device such as an exposure apparatus and a semiconductor device using such a positioning apparatus also belongs to the present invention.

[0002]

2. Description of the Related Art FIG. 13 is a perspective view showing the configuration of an XY stage which is a conventional positioning device.

In FIG. 1, reference numeral 42 denotes a surface plate having a reference surface 43 for supporting a stage device, and reference numeral 38 denotes a fixed Y guide fixed to the surface plate 42, the side surface of which is a reference surface. 3
Reference numeral 7 denotes a Y stage as a moving body, which is guided by a fixed Y guide 38 by a Y linear motor 41 and moves in the Y direction. An X stage 32 includes an X linear motor mover (not shown), is guided in an X direction by an X guide 33 provided on a Y stage 37, and is driven by an X linear motor stator 34 also provided on the Y stage 37. X
Thrust is given in the direction.

The top plate 31 constituting the X stage 32 has a plate shape as shown in FIG. An X-direction mirror 45 and a Y-direction mirror 45 are provided on the top plate 31 for position measurement in the X-direction and the Y-direction.
A direction mirror 46 is provided, a laser beam is irradiated to each mirror, and the positions in the X and Y directions are measured from the reflected light.

Further, by mounting a not-shown θZT drive mechanism on the stage, the Z direction parallel to the exposure optical axis and directions around the X, Y, Z axes (θ _x , θ _y , θ _z ) Can also be moved.

FIG. 14 is a control block diagram showing various degrees of freedom of the conventional positioning device. 57 is a mechanical characteristic Go of the positioning device, and when a force f is input, a displacement x is generated.
Reference numeral 58 denotes a controller controller characteristic Gc, which includes a general controller PID characteristic, an amplifier characteristic, and various stabilizing filters, and generates a predetermined force f when a value obtained by subtracting the displacement x from the target position xr is input. For example, the displacement x during the positioning control in the X and Y directions is an output value of the laser interferometer. Following the target position with each degree of freedom with high speed and high accuracy determines the quality of the performance of the positioning device.

FIG. 15 shows a gain phase characteristic of a control system of a conventional positioning device. FIG. 15 shows a combination of the mechanical characteristics Go and the controller characteristics Gc of FIG.
It is called loop transfer characteristic. In order to obtain the high-speed and high-precision tracking performance described above, it is desirable that the gain characteristic of the positioning device be higher (higher gain). However, the mechanical characteristic Go has various natural frequencies, and in the conventional plate-shaped stage structural member 31, the natural frequency having a high peak (poor attenuation) is in a low frequency band (300 Hz or higher). May occur.

[0008] The vibration of the stage structural member leads to the vibration of the position measuring mirror mounted on the stage, which causes deterioration of the positioning accuracy.

Further, since an excessively high gain causes oscillation at the natural frequency, the gain characteristics of the control system (in FIG. 15, the zero-cross frequency which is a measure of the high gain is about 40 Hz) is limited.

For this reason, conventionally, a stabilizing filter such as a low-pass filter or a notch filter has been frequently used, and it has been necessary to perform compensation for relaxing high peaks. Alternatively, it was necessary to design a mechanism to bring the natural frequency to a higher frequency region.

[0011]

However, when the stabilizing filter is used frequently as in the conventional example, the delay of the phase characteristic of the control system shifts to a lower frequency band in the frequency domain, and when the gain is increased, the phase is turned by 180 degrees. Then, the system oscillates and does not contribute to high gain.

In the future, semiconductor wafers to be processed by an exposure apparatus having a positioning device having such a configuration will be manufactured in a large-diameter, large-size semiconductor wafer in order to increase the area of semiconductor elements and reduce costs. Tend to use. Therefore, it is difficult to design a large-size positioning device and increase the natural frequency of the device in a high frequency range.

The cause of the problem to be solved is that the structure has a natural vibration having a high peak, and the characteristics of the structure of the top stage, which is a plate-like member and supports the mass of a mirror or the like, are particularly dominant. It has become a target.

In view of the problems of the prior art, an object of the present invention is to provide a positioning apparatus used in an exposure apparatus, various types of precision processing machines or various types of precision measuring instruments, by suppressing peaks in the natural vibration of the stage to achieve high-speed, high-precision Is to perform accurate positioning.

[0015]

In order to achieve the above object, the positioning device of the present invention is characterized in that a hollow member is provided in a structural member constituting the positioning device, and an attenuating material is sealed in the hollow. I do. Preferably, the structural member is made of ceramic.

Further, it is preferable that the structural member has an inlet for enclosing the damping material in the hollow structure. Further, after the damping material is injected, a plug may be provided at the injection port to make the hollow structure a closed space.

Further, it is desirable that the hollow structure includes a rib. Further, the shape of the rib is preferably columnar or plate-like, and in the case of a plate-like rib, it is more preferable to provide a hole.

Preferably, the damping material is a foam material, and more preferably, the foam material is a resin.

Preferably, the hollow structure is provided at least near the measurement mirror.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS <Embodiment 1> FIG. 1 is a schematic view of an embodiment of a top plate which is a component constituting a positioning device of the present invention.

In FIG. 1, reference numeral 1 denotes a top plate constituting an X stage. The top plate 1 is formed of ceramic, and has a hollow structure as shown in the figure. As shown in FIG. 2, the hollow structure 2 is formed of two or more ceramic elements. Each element made of the ceramic can be produced by various known molding methods such as a pressure molding method and a CIP method. Each element is joined by re-sintering to form the hollow structure 2. However, if the hermeticity of the hollow structure after molding and the rigidity of the top plate 1 function sufficiently, the joining method of each element is not limited to resintering, and the elements are joined using an adhesive or the like. You may.

Further, as shown in FIG. 3, the hollow structure 2 may be provided with ribs. The rib 5 in the figure is joined by interposing a plurality of prismatic elements in the hollow structure of the top plate. Rib 5
Has a function of reinforcing the strength and rigidity of the top plate 1. Therefore, the shape of the rib 5 is not limited to a prismatic shape, and a rod-shaped member such as a cylindrical member, a plate-shaped member, or a lattice-shaped member may be used. Also, as shown in FIG. 4, if a plate-like member or a lattice-like member is used, the rib 5 partitions the hollow structure as a partition, so that the top plate 1
A plurality of hollow structures 2 can be provided therein. In addition, as another method of providing the ribs 5 in the hollow structure 2, as shown in FIG. 5, each element made of ceramic may be formed to have a concavo-convex shape in advance, and then each element may be joined.

A highly damping foam material 4 is sealed in the hollow interior as a damping material. The foam material 4 is injected from an injection port 3 provided below the top plate 1. However, the injection port 3 is not limited to the lower part of the stage unless it affects the rigidity of the top plate 1 and the installation of the measurement mirror and the like mounted on the top plate 1.

If a plurality of hollow structures 2 are provided in the top plate 1, a plurality of injection ports 3 may be provided. Further, a hole may be formed in a part of the rib 5 serving as a partition so that the damping material 4 penetrates into the hollow structure.

Further, a hollow structure may be provided on the top plate where strength, rigidity, vibration resistance, etc. are required. For example, when a position measurement mirror is mounted on a top plate, strength, rigidity, and vibration resistance are required near the mirror mounting portion of the top plate in order to support the mirror mass and improve measurement accuracy. Therefore, as shown in FIG. 6, an attenuating material may be sealed in a part of the hollow structure near the position measuring mirror. However, as long as vibration resistance or the like is required, the location of the hollow structure into which the damping material is injected is not limited to the vicinity of the mirror.

After injecting the damping material 4 into the hollow structure 2, it is desirable to provide a plug at the injection port 3 and to seal the hollow structure 2 so that the damping material 4 does not come into contact with the atmosphere.

FIG. 7 is a perspective view showing the structure of an XY stage which is a positioning device using the above-mentioned top plate.

The configuration of the stage is the same as in the conventional example. In the figure, reference numeral 22 denotes a reference surface 23 supporting a stage device.
Reference numeral 18 denotes a fixed Y guide fixed to the surface plate 22, and its side surface is used as a reference surface. Reference numeral 17 denotes a Y stage as a moving body, which is driven by a Y linear motor 21.
It is guided by the fixed Y guide 18 and moves in the Y direction. 12
Denotes an X stage, which includes an X linear motor mover (not shown), is guided in an X direction by an X guide 13 provided on a Y stage 17, and is driven by an X linear motor stator 14 also provided on the Y stage 17. Thrust is given in the direction.

The top plate 11 which is a component of the X stage 12
Is provided with an X-direction mirror 25 and a Y-direction mirror 26 for position measurement in the X-direction and the Y-direction. Each mirror is irradiated with a laser beam, and the positions in the X-direction and the Y-direction are measured from the reflected light.

By mounting a θZT drive mechanism (not shown) on the stage, the Z direction parallel to the exposure optical axis and directions around the X, Y, Z axes (θ _x , θ _y , θ _z ) Can also be moved.

FIG. 8 is a control block diagram in each degree of freedom of the positioning device of the present embodiment. Reference numeral 7 denotes a mechanical characteristic Go of the positioning device, and when a force f is input, a displacement x is generated. Reference numeral 8 denotes a controller controller characteristic Gc, which includes a general controller PID characteristic, an amplifier characteristic, and various stabilizing filters, and generates a predetermined force f when a value obtained by subtracting the displacement x from the target position xr is input. For example, the displacement x during the positioning control in the X and Y directions is an output value of the laser interferometer. Following the target position with each degree of freedom with high speed and high accuracy determines the quality of the performance of the positioning device.

FIG. 9 shows a gain phase characteristic diagram of the control system of the positioning apparatus of this embodiment. FIG. 9 shows the mechanical characteristic Go7 of FIG.
And a loop transfer characteristic obtained by combining the control controller characteristic Gc8. In order to obtain the high-speed, high-precision tracking performance described above, it is desirable that the gain characteristics of the positioning device be higher (higher gain). By injecting the foam material into the hollow structure 2, vibrations transmitted from the stage, the surface plate, or the stage driving unit, for example, surface waves and compressional wave vibrations are rapidly attenuated, and the vibration isolation of the stage is improved. Can be.
For this reason, the peak of the natural vibration of the mechanical characteristics represented by the stage characteristics, which has conventionally limited the gain characteristics, is reduced, and the gain characteristics of the control system are greatly improved.
, The zero-cross frequency is achieved up to about 100 Hz.

In addition, by reducing the vibration generated on the stage, especially the vibration near the measurement mirror is reduced, thereby improving the positioning accuracy. Further, in the exposure apparatus using such a stage, it is possible to prevent the alignment accuracy and the resolution of the projection lens and the like of the not-shown alignment optical system from being impaired by vibration.

The top plate of the stage is made of highly rigid Al ₂
A ceramic material such as O ₃ or Si ₃ N ₄ is desirable, but not limited thereto. Further, in the present embodiment, a foaming material is mentioned as the damping material, but a resin is preferable, and a two-component mixed urethane resin is particularly preferable. However, the damping material is not limited to the foam material, and it is sufficient that the damping material has a damping property. For example, rubber, sand, metal particles, oils and fats, or a combination thereof may be used.

In this embodiment, the top plate is made of ceramic,
By providing a hollow structure inside the top plate, weight reduction, high strength, high rigidity, and wear resistance of the top plate were achieved. In addition, the strength and rigidity of the top plate were reinforced by providing ribs inside the top plate.

In this embodiment, an injection port for the damping material is provided in the hollow structure in the top plate, the damping material is injected into the hollow structure, and the damping material is sealed by plugging. Thereby, the vibration generated on the top plate can be reduced, and the vibration proof property is improved.

In addition, since the top plate is formed by resintering at a high temperature as a ceramic joining method, if the damping material is injected into the hollow at this time, the damping material may be deteriorated or burnt. is there. Therefore, by providing an injection port in the top plate, the attenuation material can be injected into the hollow after the top plate is formed. This facilitates the enclosing of the damping material into the hollow structure, and also increases the degree of freedom in selecting the material of the top plate and the damping material.

Further, by making the shape of the rib into a columnar shape or by providing a hole when the shape is a plate-like shape, it becomes easy for the attenuation material to penetrate into the hollow structure from the injection port.

Further, by providing the top plate with a plug, the hollow structure of the top plate can be sealed, and the damping material does not come into contact with the atmosphere. Therefore, deterioration of the damping material over time can be reduced, and contamination of the atmosphere by the damping material can be prevented.

Further, by using such a top plate as a structural member of the XY stage, it is possible to realize a stage device excellent in lightweight, high strength, high rigidity, and excellent wear resistance. Further, since the vibration generated in the stage, the disturbance, and the vibration transmitted from the stage driving source can be rapidly attenuated, a stage having excellent vibration proofing properties can be provided. Therefore, it is possible to prevent the alignment accuracy of the alignment optical system, the resolution of the projection lens, and the like from being impaired by the vibration, and to perform high-speed, high-precision positioning.

<Embodiment 2> Next, an embodiment of a scanning type exposure apparatus in which the stage of the positioning apparatus described above is mounted as a reticle stage or a wafer stage will be described with reference to FIG.

The reticle stage base 71A supporting the reticle stage 73 is connected to the wafer stage 9 of the exposure apparatus.
The linear motor base 71 </ b> B is supported by a support frame 90 directly fixed to the floor F separately from the base 92, while being integral with a frame 94 erected on a base 92 supporting the base 3. Exposure light for exposing the wafer W on the wafer stage 93 via the reticle on the reticle stage 73 is generated from a light source device 95 shown by a broken line.

The frame 94 supports the reticle stage base 71A and also supports the projection optical system 96 between the reticle stage 73 and the wafer stage 93. Since the stator 75 of the linear motor that accelerates and decelerates the reticle stage 73 is supported by the support frame 90 that is separate from the frame 94, the reaction force of the driving force of the linear motor of the reticle stage 73 is transmitted to the wafer stage 93. Or a disturbance of the drive unit, or the projection optical system 9
There is no danger of causing 6 to vibrate.

The wafer stage 93 is scanned by the driving unit in synchronization with the reticle stage 73. During the scanning of the reticle stage 73 and the wafer stage 93, their positions are continuously detected by the interferometers 97 and 98, respectively, and are fed back to the driving units of the reticle stage 73 and the wafer stage 93, respectively. As a result, both the scanning start positions can be accurately synchronized, and the scanning speed of the constant-speed scanning region can be controlled with high accuracy.

<Embodiment 3> Next, an embodiment of a method of manufacturing a semiconductor device using the above-described exposure apparatus will be described. FIG. 11 shows a flow of manufacturing semiconductor devices (semiconductor chips such as ICs and LSIs, liquid crystal panels, CCDs, thin-film magnetic heads, micromachines, etc.). Step S11
In (circuit design), a circuit of a semiconductor device is designed.
In step S12 (mask production), a mask on which the designed circuit pattern is formed is produced. On the other hand, step S13
In (wafer manufacturing), a wafer as a substrate is manufactured using a material such as silicon. Step S14 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the prepared mask and wafer. The next step S15 (assembly) is called a post-process, and is a process of forming a semiconductor chip using the wafer manufactured in step S14, and includes processes such as an assembly process (dicing and bonding) and a packaging process (chip encapsulation). including. In step S16 (inspection), inspections such as an operation check test and a durability test of the semiconductor device manufactured in step S15 are performed. Through these steps, a semiconductor device is completed and shipped (step S17).

FIG. 12 shows a detailed flow of the wafer process. In step S21 (oxidation), the surface of the wafer is oxidized. In step S22 (CVD), an insulating film is formed on the wafer surface. In step S23 (electrode formation), electrodes are formed on the wafer by vapor deposition. Step S2
In step 4 (ion implantation), ions are implanted into the wafer. In step S25 (resist processing), a photosensitive agent is applied to the wafer. In step S26 (exposure), the circuit pattern of the mask is printed and exposed on the wafer by the exposure apparatus described above. In step S27 (developing), the exposed wafer is developed. In step S28 (etching), portions other than the developed resist image are removed. In step S29 (resist stripping), unnecessary resist after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer. By using the manufacturing method of the present embodiment, a highly integrated semiconductor device can be manufactured.

[0047]

According to the first aspect of the present invention, the weight of the positioning device is reduced by providing a hollow structure in the structural member, and the damping material is sealed in the hollow to improve the vibration isolation of the positioning device.

According to the second aspect of the present invention, since the structural member is made of ceramic, a positioning device excellent in light weight, high strength, high rigidity, and excellent wear resistance can be realized.

According to the third aspect of the present invention, since the injection port is provided in the structural member, the damping material can be injected into the hollow after forming the structural member, and the sealing of the damping material becomes easy.

According to the fourth and fifth aspects of the present invention, the hollow structure can be sealed by plugging the injection port after the injection of the damping material. As a result, deterioration of the performance of the positioning device due to deterioration of the damping material over time is reduced, and contamination of the atmosphere caused by the damping material coming into contact with the atmosphere is prevented.

According to the sixth aspect of the present invention, since the ribs in the hollow structure function as reinforcement of the structural members, the positioning device can have high strength and high rigidity.

According to the thirteenth aspect of the present invention, a high-speed and high-precision exposure apparatus can be realized by the exposure apparatus having the above-described positioning device.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a top plate according to a first embodiment of the present invention.

FIG. 2 is an exploded configuration diagram of a top plate according to the first embodiment of the present invention.

FIG. 3 is a partial view of a top plate having a rib according to the first embodiment of the present invention.

FIG. 4 is a partial view of a top plate having a grid-like element according to the first embodiment of the present invention.

FIG. 5 is a cross-sectional view of the top plate by the concave-convex shape element according to the first embodiment of the present invention.

FIG. 6 is a sectional view of a top plate partially provided with a hollow structure according to the first embodiment of the present invention.

FIG. 7 is a perspective view of a configuration of a positioning device according to the first embodiment of the present invention.

FIG. 8 is a control block diagram of a positioning device according to the first embodiment of the present invention.

FIG. 9 is a diagram showing a gain phase characteristic of a positioning device control system according to the first embodiment of the present invention.

FIG. 10 is a schematic view of an exposure apparatus using the positioning apparatus of the present invention.

FIG. 11 is a flow chart of semiconductor production.

FIG. 12 is a semiconductor process flow diagram.

FIG. 13 is a perspective view of a configuration of a conventional positioning device.

FIG. 14 is a control block diagram of a conventional positioning device.

FIG. 15 is a diagram showing a gain phase characteristic of a conventional positioning device control system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Top plate 2 Hollow structure 3 Inlet 4 Foam material 5 Rib 6 Hole 7 Mechanical characteristics 8 Controller characteristics 11 Top plate 12 X stage 13 X guide 14 X linear motor stator 17 Y stage 18 Fixed Y guide 19 Y linear motor fixed Element 20 Y linear motor movable element 21 Y linear motor 22 Surface plate 23 Reference surface 25 X direction mirror 26 Y direction mirror 31 Top plate 32 X stage 33 X guide 34 X linear motor stator 37 Y stage 38 Fixed Y guide 39 Y linear Motor stator 40 Y linear motor mover 41 Y linear motor 42 Surface plate 43 Reference surface 45 X-direction mirror 46 Y-direction mirror 57 Mechanical characteristics 58 Control controller characteristics

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 21/68 H01L 21/30 515F 520A

Claims (14)

[Claims] 1. A positioning device, wherein a hollow structure is provided in a structural member constituting the positioning device, and an attenuating material is sealed in the hollow. 2. The positioning device according to claim 1, wherein said structural member is made of ceramic. 3. The positioning device according to claim 1, wherein an injection port for injecting the damping material is provided in the hollow of the structural member. 4. The positioning device according to claim 3, wherein a plug is provided at an injection port after the damping material is injected. 5. The positioning device according to claim 1, wherein the hollow is a closed space. 6. The positioning device according to claim 1, wherein the hollow structure includes a rib. 7. The positioning device according to claim 6, wherein the rib has a columnar shape. 8. The positioning device according to claim 6, wherein the rib has a plate shape. 9. The positioning device according to claim 8, wherein a hole is provided in said plate-shaped rib. 10. The positioning device according to claim 1, wherein said damping material is a foam material. 11. The positioning device according to claim 10, wherein the foam material is a resin. 12. The apparatus according to claim 1, wherein said hollow structure is provided at least near a measurement mirror.
The positioning device according to any one of the above. 13. An exposure apparatus comprising the positioning device according to claim 1. Description: 14. A device manufacturing method, comprising manufacturing a device using the exposure apparatus according to claim 13.