JPH07183192A - Moving stage mechanism and exposure apparatus using the same - Google Patents

Abstract

(57) [Abstract] [Purpose] To realize a highly reliable moving mechanism that can improve the moving speed and positioning accuracy of the stage, reduce heat generation. A first and a second actuator unit for generating thrust for moving a stage, and a clutch for controlling a transmission state of the thrust by the first actuator unit to the stage are provided. The actuator unit and the clutch are provided in parallel between the first actuator unit and the stage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving mechanism used in a semiconductor manufacturing exposure apparatus, and more particularly to a moving mechanism for a stage on which a mask, a wafer and the like are mounted and which requires precise positioning.

[0002]

2. Description of the Related Art In an exposure apparatus for manufacturing a 256 M DRAM, a stage moving mechanism for mounting a mask, a wafer and the like is required to have the following performance.

1. Positioning accuracy ~ 0.01 μm 2. Step movement time including positioning settling time ~ 0.
3 seconds 3. Step movement distance ~ 30 mm 4. A small amount of heat generation, which hinders alignment, and a general structure that is simple and highly reliable. Conventionally, as a moving mechanism of this type, Japanese Patent Laid-Open No. 2-1003 has been proposed.
As shown in the description relating to FIG. 17 in Japanese Patent Publication No. 11, the coarse movement mechanism having a large movement amount and the fine movement mechanism for performing delicate positioning are combined.

FIG. 8 is a view showing the concept of the conventional moving mechanism as described above.

The stage 806 is mounted on a fine movement guide 805, and the fine movement guide 805 is mounted on a base 801 via a coarse movement guide 802.

A coarse movement telescopic actuator unit 803 and a laser interferometer 809 are attached to the base 801. Telescopic actuator unit for coarse movement 80
3 is connected to a fine movement guide 805 via a cylinder 810, and a rotation-straight translation conversion unit (not shown) using a motor, a ball screw and a nut is provided inside thereof, and it corresponds to the rotation of the motor. The cylinder 810 expands and contracts, and the fine movement guide 805 moves. Further, the rotation amount of the motor is measured by the encoder 804, and thus the coarse movement amount of the fine movement guide 805 is measured.

A length-measuring mirror 808 is provided at one end of the stage 806 facing the laser interferometer 809, and a projection for attaching a piezo actuator 807 is provided on the fine movement frame. The stage 806 is connected to the fine movement guide 805 by a piezo actuator 807, and the stage 8 is connected by the piezo actuator 807.
Fine movement of 06 is performed.

The laser light emitted from the laser interferometer 809 is reflected by the length measuring mirror 808, and the positions of the laser interferometer 809 and the stage 806 are measured using this reflected light. The piezo actuator 807 is driven based on this measurement result, and the stage 806 is positioned.

When performing the step movement of the stage as described above, the coarse movement actuator is used to drive the stage, and thereafter the positioning is performed using the piezo actuator which can be driven at high speed and high resolution. The included fine movement control was performed.

[0010]

In the above-mentioned conventional moving mechanism, the following points are points to be improved.

1. Since a piezo actuator is used for the fine movement mechanism, it is not possible to take a sufficient stroke,
It takes time to assemble and adjust.

2. A piezo actuator that can be driven at high speed and high resolution is used as a connecting member with the stage. However, since the piezo actuator itself transmits external vibration, it is difficult to suppress vibration after positioning. Therefore, the positioning time becomes long due to residual vibration of the coarse actuator and the positioning accuracy deteriorates.

3. Two guides are required, one for coarse movement and one for fine movement, and the structure is complicated.

The present invention has been made in view of the problems of the above-mentioned conventional techniques, and can improve the moving speed and positioning accuracy of the stage, reduce heat generation, and have high reliability. The purpose is to realize a moving mechanism.

[0015]

The moving stage mechanism of the present invention includes first and second moving stage mechanisms for generating thrust for moving the stage.
Actuator unit and a clutch for controlling the transmission state of thrust by the first actuator unit to the stage, and the second actuator unit and the clutch are provided between the first actuator unit and the stage. Are provided in parallel with each other.

In this case, the second actuator unit may be a voice coil motor.

The exposure apparatus of the present invention comprises a moving stage mechanism on which the mask or wafer constructed as described above is mounted,
It has an exposure means for exposing the wafer.

[0018]

In the present invention, the second actuator unit and the clutch are provided in parallel between the first actuator unit and the stage. When the first actuator unit is for coarse movement and the second actuator unit is for fine movement, the vibration after the completion of the coarse movement is converged by the second actuator unit and the clutch. Therefore, even if the second actuator unit having low rigidity is used, it is possible to speed up the convergence of vibration and speed up the step movement by performing the coarse movement operation with the clutch engaged. It will be possible.

After the coarse movement operation is completed, the clutch is disengaged so that the driving can be performed only by the second actuator unit, and the positioning can be performed with high accuracy.

When a voice coil motor which transmits only the driving force in a non-contact manner is used as the second actuator unit, the clutch is disengaged so that
The stage and each actuator are mechanically separated from each other, and the disturbance by the first actuator unit is not transmitted to the stage.

[0021]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1 is a perspective view showing the structure of an embodiment of the present invention.

The present embodiment is an X-ray exposure apparatus using synchrotron radiation as an exposure light source, and shows the structure of a stage used for moving a wafer, a mask and the like.
Here, the wafer, the mask, and the exposure optical system are omitted from the drawing for the sake of simplicity.

On the upper portion of the base 101, two parallel Y-shaped guides 102 for Y, a coarse movement telescopic actuator unit 103 for Y, a laser interferometer 110 for Y, and an X for X are provided.
Laser interferometer 111 is provided.

On the Y guide 102, the Y guide 10
A Y stage 114 that moves in the longitudinal direction of No. 2 is mounted. On the Y stage 114, two rail-shaped X guides 106 for X and a coarse movement telescopic actuator unit 107 for X that are parallel and orthogonal to the Y guide 102 are provided.

An X stage 115 that moves in the longitudinal direction of the X guide 106 is mounted on the X guide 106.
A wafer chuck 112, the Y laser interferometer 110 and the X laser interferometer 111 described above are provided on the stage 115.
A laser interference length measuring mirror 113 for reflecting the laser beam for length measurement from is provided.

Coarse-motion telescopic actuator unit 10 for Y
3 is connected to the Y fine movement actuator unit 105 provided at the end of the Y stage 114 via the Y rod 102, and the X coarse movement telescopic actuator unit 107 is X.
It is connected via a rod 108 to an X fine movement actuator unit 109 provided at the end of the X stage 115.

Coarse-motion telescopic actuator unit 10 for Y
Each of the coarse movement telescopic actuator units 107 for X and X, like the coarse movement telescopic actuator unit of the conventional example shown in FIG. 8, has an electric motor, an encoder, a key, a ball nut, a screw, and a bearing (both not shown). In the rotation-straight conversion unit, the Y rod 104 and the X rod 108 expand and contract in accordance with the rotation of the electric motor, and the Y stage 114 and the X stage 1
Coarse movement is performed by moving each of 15.

Further, the Y coarse movement telescopic actuator unit 103 and the X coarse movement telescopic actuator unit 1 are provided.
Each of 07 is a Y fine movement actuator unit 1
05 and X fine movement actuator unit 109, and the fine movement control by these is performed after the above coarse movement control is completed.

The support of the Y stage 114 by the Y guide 102 and the support of the X stage 115 by the X guide 106 in the present embodiment are made by air bearings, but it is also conceivable to use a cross roller guide. To be

Wafer channel 11 for base 101
The position 2 is always performed by the Y laser interferometer 110 and the X laser interferometer 111. Based on the measurement result, the coarse movement control and the fine movement control are performed by a control device (not shown).

It should be noted that each of the coarse motion telescopic actuator units described above is selected to have sufficient power so that the load mass can be moved stepwise by 30 mm within 0.3 seconds.

FIG. 2 is a diagram showing the concept of the configuration of the X-axis or Y-axis stage shown in FIG. The fine movement actuator unit is provided between the rod 205 from the coarse movement expansion / contraction actuator unit 201 and the stage 207, and is composed of a voice coil motor 204 and a clutch 206 provided in parallel.

As described above, the position of the stage 207 is constantly measured by the laser interferometer 210, and the length measurement mirror 208 for performing the measurement is provided on the stage 207. The stage 207 is guided by one guide 209 in one direction.

In the present embodiment, the clutch 206 is brought into the connected state when the coarse movement expansion / contraction actuator unit 201 performs the step movement, the step movement control ends, and the precision positioning by the voice coil motor 204 is performed. It is set apart.

When the clutch 206 is released, fine movement control is performed by the voice coil motor 204 based on the length measurement signal from the laser interferometer 210.

3 and 4 are partially cut side views showing the structures of the voice coil motor 204 and the clutch 206 of the fine movement mechanism described above.

First, the structure of the voice coil motor 204 will be described with reference to FIG.

The voice coil motor is provided between the rod 205 from the coarse motion telescopic actuator and the stage 207 on which the wafer, mask, etc. are mounted.
5, bobbin 306 for winding coil 305, permanent magnet 307, and yoke 3 that houses permanent magnet 307
It is composed of 08. The bobbin 306 and the coil 305 are provided on the rod 303 side, and the permanent magnet 307 and the yoke 308 are provided on the stage 301 side. As a result, the thrust when a current is applied to the coil 305 is configured to act between the rod 303 and the stage 207.

Next, the structure of the clutch 206 will be described with reference to FIG.

The clutch mechanism is a U-shaped frame member 4
09, the inner peripheral surface of the frame member 409, the visor plate 40 protruding from the inside of the frame member 409 toward the open end
2, an air pad 403 that holds 2 from both sides, and a leaf spring 40 that extends from the outer peripheral surface of the frame member 409 toward the open end.
6 and an end portion of the leaf spring 406, and is constituted by an electromagnet unit 410 in which a coil 405 is housed.

The clutch constructed as described above is connected to the rod 205 of the coarse movement expansion / contraction actuator unit by the leaf spring 401, and the frame member 409 is attached to the movable body side 408 which is the stage, so that the coarse movement expansion / contraction actuator is mounted. It is configured to control the transmission of the driving force of the unit.

The operation of the clutch constructed as above will be described.

As described above, the mating plate 402 is the leaf spring 4.
It is attached to the rod 205 of the coarse motion telescopic actuator unit via 01. The electromagnet unit 410 attached to the frame member 409 fixed to the moving body side 408 via the leaf spring 406 is the coil 4
By applying an electric current to 05, the leaf spring 406 is attracted to the mast plate 402 in a deformed state. When the rod 205 is moved in this state, the driving force is transmitted to the stage 207 by the mating force of the electromagnet unit 410 and the mating plate 402. When no current is flowing through the coil 405, the electromagnet unit 410 and the slab 402 are not in contact with each other, so that the driving force is not transmitted even if the rod 205 moves.

In the clutch mechanism constructed as described above, the air pad 403 is provided in order to keep the clearance between the mast plate 402 and the electromagnet unit 410 proper, and by constantly letting out air, An air bearing is formed between the plate 402 and a part thereof.
When the postures of the driving member 407 and the moving body side 408 change, the leaf spring 401 is deformed by the thrust force of the air bearing mechanism described above.

Each of the leaf springs 401 and 406 is made of a material and has a size capable of transmitting the driving force without buckling due to the force applied when moving the movable body side 408.

FIG. 5 is a block diagram showing the control operation of this embodiment configured as described above.

In the figure, for the fine movement actuator unit, the voice coil motor is a linear motor, and its command operation is shown in the upper part. Regarding the coarse motion telescopic actuator unit, the motor and cylinder (OR ball screw) that are its constituent elements are used, and its command operation is shown in the lower part.

The clutch mechanism shown in FIG. 4 is brought into the engaged state during the coarse movement during the step movement by the coarse movement expansion / contraction actuator unit.

The coarse motion telescopic actuator unit is controlled based on the amount of rotation of the motor measured by the encoder provided in the unit shown in FIG. 2, and the command is, for example, a continuous position having a speed pattern. It is done in the form of giving orders. The clutch is released after the predetermined step movement is performed by the above command,
Fine control is performed.

The current signal component included in the command is amplified by the current amplifier (S507) and then supplied to the motor (S508). As a result, the cylinder expands and contracts, and thrust is applied to the stage to move the stage (S
509). After that, it is confirmed that the step movement is completed (S511), and when the movement is confirmed, the clutch is released (S510), and the control moves to the fine movement control operation.

The command value for performing the movement is given to both the coarse movement telescopic actuator unit and the fine movement actuator unit (S501).

At the time of fine movement after the end of the step movement by the fine movement actuator unit, the clutch mechanism shown in FIG. 4 is disengaged.

In the fine movement actuator unit, the current signal component included in the command is extracted by the filter (S5
02), after amplification by the current amplifier (S50
3) Send to switch 1. The changeover switch 1 limits the current to the linear motor (S50
4) Then, it is confirmed whether the supplied current value is within the allowable value (S506), and if it is within the allowable value, the current is supplied to the linear motor (S505). As a result, thrust is applied to the stage by the fine movement actuator, and movement control to a desired position is performed (S512).

In the embodiment described above, the position command is given to both the coarse-movement telescopic actuator unit and the fine-movement actuator unit in the same manner, but after the driving by the coarse-movement telescopic actuator unit is completed, The position command may be divided and given to each actuator unit so that the fine movement actuator unit drives.

As described above, in this embodiment,
Since the coarse movement control is performed with the clutch engaged, high-speed step movement can be performed by ensuring sufficient performance of the coarse movement telescopic actuator unit. At this time, the heat generated by the actuator is far away from the stage, and therefore has little influence.

Further, in the fine movement control performed thereafter, the driving force by the voice coil motor having extremely high positioning accuracy is directly applied to the stage, so that accurate positioning can be performed. Since the voice coil motor does not directly transmit the driving force but only the driving force, during the fine movement control when the clutch is released,
The coarse motion telescopic actuator unit will be mechanically completely separated from the stage in the driving direction, and the disturbance will not be transmitted from the coarse motion telescopic actuator unit.
Highly accurate and high-speed positioning is performed. Further, in the fine movement control, since the driving amount is extremely small, a current flowing through the mother chair coil motor is small and heat generation can be reduced.

In the above embodiments, the stage for performing the step movement has been described as an example, but the present invention can also be applied to a scanning exposure stage for performing exposure while scanning the stage. The scanning movement requires a weeding area for acceleration before the scanning movement in order to move the wafer or mask on the stage within the exposure area at a substantially constant scanning speed.

Precise positioning is not required in this weeding area, but the actuator needs power to reach a predetermined speed in a short time. On the other hand, precise positioning accuracy is required during scanning exposure, but high power is not required. When applied to a scanning exposure stage, the coarse movement telescopic actuator unit accelerates while the clutch is in the connected state during acceleration movement. After reaching the scanning exposure state, the clutch is disengaged and the stage is driven by the voice coil motor. During the scanning movement, the movement command is also given to the coarse movement actuator so that the movement is within the allowable range in which the clutch operates. This command is given according to a predetermined data table using an encoder. Alternatively, the current value of the voice coil motor is monitored and the positional deviation of the voice coil motor, that is, the relative distance between the rod of the coarse actuator and the stage is calculated from the current value, and the distance is controlled within a predetermined range. You may.

When the scanning movement of the exposure area is completed,
The clutch is connected to drive the coarse actuator to decelerate the stage. The above scanning is S51 in FIG.
This can be realized by replacing 1 with the determination as to whether scanning exposure is in progress.

While the clutch is engaged, the target position and the stage position are largely apart from each other because the step movement is in progress, and a command value is given to the linear motor so that a large driving force is exerted. At this time, the current limitation works, and the changeover switch 1 operates to prevent useless current from flowing through the linear motor.

Next, an embodiment of a device manufacturing method using the exposure apparatus having the above-described moving mechanism will be described.

FIG. 6 is a flow chart showing a manufacturing process of a minute device (semiconductor chip such as IC or LSI, liquid crystal panel, CCD, thin film magnetic head, micromachine, etc.). In step 61 (circuit design), the circuit of the semiconductor device is designed. In step 62 (mask manufacturing), a mask having the designed circuit pattern is manufactured. This mask is a reflective mask and has the features described above. On the other hand, in step 63 (wafer manufacturing), a wafer is manufactured using a material such as silicon. Step 64 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer by lithography using the mask and wafer prepared above. The next step 65 (assembly) is called a post-process, and is a process of forming a semiconductor chip by using the wafer manufactured in step 64, such as an assembly process (dicing, bonding), a packaging process (chip encapsulation) and the like. including. Step 6
In 6 (inspection), the semiconductor device manufactured in step 5 undergoes inspections such as an operation confirmation test and a durability test. Through these steps, the semiconductor device is completed and shipped (step 67).

FIG. 7 is a flow chart showing the detailed steps of the wafer process. In step 71 (oxidation), the surface of the wafer is oxidized. In step 72 (CVD), an insulating film is formed on the wafer surface. In step 73 (electrode formation), electrodes are formed on the wafer by vapor deposition. In step 74 (ion implantation), ions are implanted in the wafer. In step 75 (resist process), a photosensitive agent is applied to the wafer. In step 76 (exposure), the circuit pattern of the mask is printed and exposed on the wafer by the above-described mask and exposure apparatus. In step 77 (developing), the exposed wafer is developed. In step 78 (etching), parts other than the developed resist image are removed. Step 79
In (resist stripping), the unnecessary resist after etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer. By using the manufacturing method of this embodiment, it is possible to manufacture a highly integrated semiconductor device, which has been difficult to manufacture in the past.

[0065]

Since the present invention is constructed as described above, it has the following effects.

The acceleration operation before the step movement or the scanning movement is performed by the efficient rotary motor, and the motor can be arranged at a position distant from the stage, so that the effect of heat generation can be reduced.

Since the positioning is performed by the linear motor,
The positioning accuracy is improved, and the linear motor drive amount is small, so that heat generation is small.

By using the voice coil motor and the clutch, the coarse motion expansion / contraction actuator unit is separated, so that vibration is not transmitted from the coarse motion expansion / contraction actuator unit to the stage in the drive direction. Therefore, the positioning time is shortened and the positioning accuracy is improved. There is an effect that can be.

Since the guide mechanism for performing the coarse movement control and the fine movement control is common, there is an effect that the apparatus constitution can be simplified and the reliability and the apparatus life can be improved.

Based on each of the above effects, a stage for an exposure apparatus having a high performance is realized, and an LSI having a high degree of integration is realized.
There is an effect that can be manufactured.

[Brief description of drawings]

FIG. 1 is a perspective view showing the configuration of an embodiment of the present invention.

FIG. 2 is a side view showing in detail the configuration of each fine movement actuator unit shown in FIG.

FIG. 3 is a partially cut side view showing the structure of a voice coil motor 204 of the fine movement mechanism.

FIG. 4 is a partially cutaway side view showing the structure of a clutch 206 of the fine movement mechanism.

FIG. 5 is a block diagram showing a control operation of the embodiment of the present invention.

FIG. 6 is a flowchart showing manufacturing steps of a semiconductor device.

FIG. 7 is a flowchart showing detailed steps of a wafer process.

FIG. 8 is a side view showing a schematic configuration of a conventional moving mechanism.

[Explanation of symbols]

 101 base 102 Y guide 103 Y coarse movement telescopic actuator unit 104 Y rod 105 Y fine movement actuator unit 106 X guide 107 X coarse movement telescopic actuator unit 108 X rod 109 X fine movement actuator unit 110 Y laser interferometer 111 X laser interferometer 112 Wafer chuck 113 Laser interference measuring mirror 114 Y stage 115 X stage 201 Coarse expansion / contraction actuator unit 203 Base 204 Voice coil motor 205 Rod 206 Clutch 207 Stage 208 Measuring mirror 209 Guide 210 Laser interferometer 302 Clamper support portion 303 Rod 305 Coil 306 Bobbin 307 Permanent magnet 308 Yoke 401 Leaf spring 402 Mass plate 403 Apaddo 406 leaf spring 407 drive member

Claims (3)

[Claims] 1. A first unit for generating thrust for moving a stage
And a second actuator unit, and a clutch for controlling the transmission state of the thrust by the first actuator unit to the stage, the second actuator unit and the clutch,
A moving stage mechanism provided in parallel between the first actuator unit and the stage. 2. The moving stage mechanism according to claim 1, wherein the second actuator unit is a voice coil motor. 3. An exposure apparatus comprising: the movable stage mechanism according to claim 1 or 2 on which a mask or a wafer is mounted, and an exposure means for exposing the wafer.