JP2000216084A - Projection aligner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress vibrations with synchronous moves of a reticle or a wafer and avoid deteriorating the image forming characteristics. SOLUTION: A reticle stage RS holding a reticle R is disposed at the downside, a wafer stage WS holding a wafer W is disposed at the upside, illumination optical systems 21-23 introduce illumination lights IL from the downside, a rigid member 25 is rotatably provided on a base 11 adjacent to the apparatus body 10, and the reactions due to driving of the stages RS, WS are transmitted to this member 25 through transmitting means 27, 28 and mutually cancelled through the member 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection exposure apparatus used in a photolithography process for manufacturing various micro devices such as a semiconductor device, an image pickup device, a liquid crystal display device and a thin film magnetic head, and more particularly to a mask and a photosensitive substrate. The present invention relates to a structure suitable for a scanning type exposure apparatus for transferring a mask pattern onto a photosensitive substrate by synchronously moving the mask and the photosensitive substrate, and for preventing vibration accompanying movement of the stage of the mask and the photosensitive substrate.

[0002]

2. Description of the Related Art In a photolithography process of a semiconductor device, a mask or a reticle pattern is transferred onto a wafer or a glass plate (hereinafter, also referred to as a photosensitive substrate) coated with a photoresist. As a projection exposure apparatus, a step-and-repeat type exposure apparatus (hereinafter, also referred to as a stepper) has been widely used. This step and repeat type exposure apparatus
Exposure is performed by collectively reducing and projecting the reticle pattern onto each shot area of the wafer.When exposure of one shot area is completed, the wafer is moved to perform exposure of the next shot area, and this is sequentially performed. It is a method that repeats.

Further, in order to expand the exposure range of the reticle pattern, the exposure light from the illumination system is limited to a slit shape (rectangular shape), and a part of the reticle pattern is reduced and projected onto a wafer using the slit light. In such a state, a step-and-scan type exposure apparatus for synchronously scanning a reticle and a wafer with respect to a projection optical system has been developed. This step-and-scan type exposure apparatus (hereinafter, also referred to as a scanning stepper) has the advantages of an aligner transfer method for transferring the entire pattern of the reticle onto the entire surface of the wafer at a single magnification by one scanning exposure, and the above-described stepper. It has the advantages of the transfer method.

In an exposure apparatus of a batch exposure system such as the former stepper, when transferring a reticle pattern to each shot area of a wafer, the reticle and the wafer need to be kept almost completely stationary. The base of the apparatus main body is installed on the floor via a vibration isolator so that vibrations from the main body are not directly transmitted to the exposure apparatus main body.

In the latter step-and-scan exposure apparatus, it is necessary to move the reticle and the wafer stably at a constant speed ratio during exposure. It is installed on the floor.

[0006]

However, in a projection exposure apparatus using a projection optical system in which the optical axis from the reticle to the wafer is formed linearly, a reticle stage for holding the reticle is conventionally provided with a projection optical system. The reticle stage and the wafer stage are arranged at the lower part of the projection optical system. The reticle stage and the wafer stage are vertically separated from each other by, for example, about 80 to 150 cm. Then
There has been a problem that the entire apparatus is tilted due to the synchronous movement of the reticle stage and the wafer stage, and the columns and bases constituting the apparatus main body are vibrated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and provides a projection exposure apparatus capable of improving the imaging characteristics by suppressing the generation of vibration due to the driving of a stage. With the goal.

[0008]

In the following description, in order to facilitate understanding, constituent elements of the present invention will be described with reference numerals shown in the drawings of the embodiments. Are not limited by these reference numerals.

1. To achieve the above object, according to a first aspect of the present invention, in a projection exposure apparatus for transferring a pattern of a mask (R) onto a photosensitive substrate (W), a pattern image from the mask is transferred to the photosensitive substrate. A projection optical system (14) for projecting the mask, a first stage (RS) for holding the mask, a second stage (WS) for holding the photosensitive substrate disposed above the mask, In order to transfer a pattern onto the photosensitive substrate, the first stage and the second stage are moved so that the mask and the photosensitive substrate are synchronously moved in a direction orthogonal to an optical axis of the projection optical system.
And a drive device (20) for driving each of the stages.

In such a so-called step-and-scan type exposure apparatus, a first stage for holding a mask and a second stage for holding a photosensitive substrate are synchronously moved by a driving device at a speed ratio corresponding to the magnification of the projection optical system. While transferring the mask pattern. If vibration occurs due to the driving of the first and second stages during this synchronous movement, image quality may be degraded due to optical axis deviation or the like. However, in the projection exposure apparatus of the present invention, the upper side of the mask (first stage) is exposed to light. Since the second stage for holding the substrate is arranged, the occurrence of vibration can be reduced.

That is, in this type of projection exposure apparatus, an image of a mask pattern is reduced and projected onto a photosensitive substrate (1/4, 1/4).
1/5), the speed ratio and acceleration ratio of the first stage holding the mask and the second stage holding the wafer are inversely proportional to the projection magnification, and the speed and acceleration of the mask are higher than those of the photosensitive substrate. large. Therefore, depending on the mass of the mask and the first stage, etc., and the mass of the photosensitive substrate and the second stage, etc., it is assumed that they are almost the same (the former tends to be heavier or heavier due to the enlargement of the mask, etc.). .), The reaction force acting on the apparatus body due to the movement of the first stage is about 4 to 5 times larger than the reaction force acting on the apparatus body due to the movement of the second stage. Since the moment generated in the apparatus main body by these reaction forces is proportional to the distance from the installation surface of the apparatus main body, the first stage having a relatively large reaction force is moved downward (toward the side close to the installation surface). By arranging the second stage having a small size on the upper side (far side with respect to the installation surface), it is possible to reduce the twist generated in the apparatus main body, and to reduce the vibration generated due to the movement of the stage. Therefore, deterioration of the imaging characteristics can be prevented, and by manufacturing a micro device using the projection exposure apparatus of the present invention, a micro device having excellent characteristics and quality can be manufactured.

In addition, by suppressing the vibration, alignment (superposition) between the mask and the photosensitive substrate during scanning exposure is performed.
Since the accuracy can be improved and the acceleration of the first and second stages before the scanning exposure can be increased, the approaching (pre-scanning) distance and the time can be reduced, and the throughput can be improved. Note that the distance and time required for deceleration of each stage after scanning exposure can be similarly reduced. Further, since the apparatus is stable, it is possible to cope with an increase in the weight of the mask and its stage accompanying the enlargement of the mask.

2. To achieve the above object, according to a second aspect of the present invention, in a projection exposure apparatus for transferring a pattern of a mask (R) onto a photosensitive substrate (W), a pattern image from the mask is transferred to the photosensitive substrate (W). A projection optical system (14) for projecting thereon, a first stage (RS) for holding the mask, and a second stage (W) for holding the photosensitive substrate
(S) a driving device (20) for driving the first stage and the second stage, respectively, so as to synchronously move the mask and the photosensitive substrate in a direction orthogonal to an optical axis of the projection optical system; And a vibration isolator (25, 27, 28, 39, etc.) for canceling a part or all of the respective reaction forces generated by driving the first stage and the second stage. An apparatus is provided.

In such a so-called step-and-scan type exposure apparatus, a first stage holding a mask and a second stage holding a photosensitive substrate are synchronously moved by a driving device at a speed ratio corresponding to the magnification of the projection optical system. While transferring the mask pattern. If vibration occurs due to the driving of the first and second stages during this synchronous movement, it leads to deterioration of the imaging characteristics due to optical axis deviation and the like. However, in the projection exposure apparatus of the present invention, this is caused by driving of the first and second stages. Since the anti-vibration device is provided for canceling a part or all of the respective reaction forces, the occurrence of such vibration is suppressed, and the deterioration of the imaging characteristics can be prevented.

Further, by suppressing the vibration, alignment (superposition) between the mask and the photosensitive substrate during scanning exposure is performed.
Since the accuracy can be improved and the acceleration of the first and second stages before the scanning exposure can be increased, the approaching (pre-scanning) distance and the time can be reduced, and the throughput can be improved. Note that the distance and time required for deceleration of each stage after scanning exposure can be similarly reduced.

3. According to a third aspect of the present invention, there is provided a projection exposure apparatus for transferring a pattern of a mask (R) onto a photosensitive substrate (W). A projection optical system (14) for projecting thereon, a first stage (RS) for holding the mask, and a second stage (W) for holding the photosensitive substrate
(S) a driving device (20) for driving the first stage and the second stage, respectively, so as to synchronously move the mask and the photosensitive substrate in a direction orthogonal to an optical axis of the projection optical system; A rigid member (2) rotatably supported on an installation surface (11) on which an apparatus main body including a projection optical system, the first stage, and the second stage is installed.
5) and at least one of a reaction force generated in a direction orthogonal to the optical axis as the first stage is driven and a reaction force generated in a direction orthogonal to the optical axis as the second stage is driven. Transmission means (27, 2) for transmitting to the rigid member
8), a projection exposure apparatus is provided.

In such a so-called step-and-scan exposure apparatus, a first stage for holding a mask and a second stage for holding a photosensitive substrate are synchronously moved by a driving device at a speed ratio corresponding to the magnification of a projection optical system. While transferring the mask pattern. If vibration occurs due to the driving of the first and second stages during this synchronous movement, it leads to deterioration of the imaging characteristics due to optical axis deviation and the like, but in the projection exposure apparatus of the present invention, the reaction force accompanying the driving of the first stage is increased. ,
And one or both of the reaction forces accompanying the driving of the second stage are transmitted to a rigid member rotatably supported with respect to an installation surface on which the apparatus main body is installed. Is reduced. Thereby, the twist generated in the apparatus main body due to the reaction force can be reduced, and the vibration generated due to the movement of the stage is also reduced. Therefore, the imaging characteristics can be improved, and a microdevice having excellent characteristics and quality can be manufactured by manufacturing a microdevice using the projection exposure apparatus of the present invention.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. First Embodiment FIG. 1 is a front view showing a schematic configuration of a first embodiment of a projection exposure apparatus of the present invention, FIG. 2 is a sectional view showing an embodiment of an actuator according to the present invention, and FIG. 3 is an actuator according to the present invention. It is sectional drawing which shows other embodiment of.

The projection exposure apparatus according to the present embodiment is a so-called step-and-scan type projection exposure apparatus, in which four vibration-proof pads (vibration removing mechanisms) 12 ( The base member 13 is installed via two (only two are shown in FIG. 1). Anti-vibration pad 12
Are disposed near the four corners of the base member 13, and are not limited thereto, and for example, a pneumatic damper or a mechanical damper having a compression coil spring in a damping liquid is used. When a pneumatic damper is used, the height of the vibration isolating pad 12 can be adjusted by air pressure, so that it can be used also as a vertical movement mechanism in addition to the vibration isolating function.

On the base member 13, a first column 15 holding a projection optical system 14 is provided integrally therewith, and a support 16 is integrally provided at an intermediate portion of the first column 15. It is installed horizontally. A reticle stage (first stage) R for holding the reticle R by suction is provided on the support base 16.
S is installed. Above the first column 15, a second column 17 is further provided integrally. Above the second column 17, a wafer stage (second stage) WS for sucking and holding a wafer W as a photosensitive substrate is provided. is set up.

The reticle R sucked and held on the reticle stage RS and the wafer W sucked and held on the wafer stage WS have positions in the direction (Z direction in FIG. 1) along the optical axis AX of the projection optical system 14. Different faces,
Two-dimensional directions (X direction and Y direction) in a plane orthogonal to the optical axis AX.
Direction).

Although not shown in detail, the reticle stage RS has a fixed body 18a and a movable body 18b.
The movable body 18b that holds the reticle is the Y of the fixed body 18a.
Is mounted on a guide extending in the direction via an air bearing, and can be moved (scanned) at a constant speed in the Y direction with respect to the support base 16 by a linear motor, and further moved in the X, Y, and rotation directions (θ direction). The position of the reticle R can be adjusted.

The position of the reticle stage RS in the X and Y directions is always set to a resolution of about 0.001 μm by a movable mirror integrally formed with the reticle stage RS (movable body 18b) and a laser interferometer (not shown). In addition, the rotation angle of the reticle stage RS is also measured, and these measured values are sent to the control unit of the stage driving device 20 to control the linear motor according to the measured values. Constant speed movement, positioning, etc. are performed. The reticle stage RS has a function of holding a reticle R on which a pattern to be transferred is formed, with its pattern forming surface facing upward, in the vicinity of the periphery thereof by suction. Support 16
Is configured to be able to illuminate the reticle R by transmitting the illumination light IL introduced from below.

In this embodiment, the fixed body 18a of the reticle stage RS is held slidably (slidably) in the Y direction on the support base 16 via slide means 18c having an air bearing or the like. The fixed body 18
a may be fixed on the support 16.

On the other hand, the wafer W to which the reticle pattern is to be transferred is mounted on a wafer stage WS, though not shown in detail. The wafer stage WS has a fixed body 19a and a movable body 19b, and the movable body 19b is mounted on a guide of the fixed body 19a via an air bearing. Then, the movable body 19b of the wafer stage WS
Is configured to be capable of scanning and stepping movement at a constant speed in the Y direction with respect to the second column 17 by a linear motor on the fixed body 19a, and stepping movement in the X direction. Also, the wafer stage W
In S, the wafer W is moved in a predetermined range in the Z direction.
A stage mechanism and a tilt mechanism (leveling mechanism) for adjusting the tilt angle are incorporated.

The wafer stage WS (including the wafer holder and the like) has a function of holding the wafer W with its surface (device forming surface) facing downward and holding the vicinity of the periphery thereof by suction. 2nd column 17
Is configured to be able to illuminate the surface (lower surface) of the wafer W by transmitting illumination light IL introduced from below.

A moving mirror integrally formed on the wafer stage WS (movable body 19b) and a laser interferometer (not shown) can always position the wafer stage WS in the X and Y directions with a resolution of about 0.001 μm. And the rotation angle of the wafer stage WS is also measured, and these measured values are sent to the control unit of the stage driving device 20 to control the driving linear motor of the wafer stage WS according to the measured values. Thus, constant-speed movement, stepping, positioning, and the like of wafer stage WS are performed. Note that the wafer stage WS may be configured to be fixed with the suction surface of the wafer holder that vacuum-suctions the back surface (the surface opposite to the device formation surface) of the wafer W facing downward.

Further, in this embodiment, the fixed body 19a of the wafer stage WS is slidably held in the Y direction on the second column 17 via slide means 19c having an air bearing or the like. In addition, the fixed body 1
9a may be fixed on the second column 17.

By the way, at the time of scanning exposure, a command to start exposure is sent from the main controller 33 to the stage driving device 20. In response, the stage driving device 20 moves the reticle R through the reticle stage RS in the + Y direction. The wafer W is moved at the speed Vw in synchronization with the scanning movement of the wafer W in the −Y direction at the speed Vw. At this time, when the projection magnification from the reticle R to the wafer W is β, that is, the projection magnification of the projection optical system 14 is β, the scanning speed Vw of the wafer W
Is set to β · Vm. The reticle R may be moved in the −Y direction and the wafer W may be moved in the + Y direction.

An excimer laser or X
A light source 21 such as a line is provided.
An illumination optical system 23 having a reflection mirror 22 and the like is provided on the base member 13 of the light source 0. Illumination light IL laterally emitted from the light source 21 toward the apparatus main body 10 is reflected by the illumination optical system 23. The light is reflected upward by the mirror 22 at right angles, and illuminates the reticle R held on the reticle stage RS from below.

When the light source 21 is small, the light source 2
1 can be arranged on the base member 13, so that the configuration can be simplified such that the reflection mirror 22 becomes unnecessary. Further, the light source 21 can be arranged below the base member 11 so as to emit illumination light through the base member 11, the base member 13, and the like. In addition to that, the light source 21 does not need to be disposed in the clean room, and there is no need to secure an unnecessary device space in the clean room, so that the equipment cost for constructing the clean room increases accordingly. Can be prevented. Further, in the present invention, the illumination optical system 2
The arrangement structure of 3 is not limited at all, and the illumination optical system 23 may be provided on the base member 11 below the base member 13.

The illumination optical system 23 is illumination light that extends in a slit shape (rectangular shape) in a cross section in a direction (X direction) orthogonal to the scanning direction (Y direction) at the time of scanning exposure, by a rectangular pattern area of the reticle R. Irradiate from below. The irradiation area on the reticle R of the slit-shaped illumination light linear in the X direction is located at the center of the circular visual field on the object plane side perpendicular to the optical axis AX of the projection optical system 14, and has a predetermined reduction magnification β ( For example, through a 1/4) projection optical system 14, the reticle R
Is projected onto the wafer W at a resolution of, for example, 0.35 μm or less. As the projection optical system 14, one that projects a reduced inverted image of a pattern formed on the pattern surface of the reticle R onto the wafer W is used.

As described above, the projection exposure apparatus of the present embodiment
With the reticle stage RS holding the reticle R down,
The wafer stage WS holding the wafer W is moved to the reticle R
And the illumination optical system 23 illuminates the reticle R from below, so that vibrations generated in the apparatus main body 10 can be reduced.

That is, the image of the pattern of the reticle R is reduced and projected onto the wafer W by the projection optical system 14 (1/4, 1
/ 5), the reticle stage RS holding the reticle R has a higher speed and acceleration than the wafer stage WS holding the wafer W, and the reticle stage RS has a higher speed than the wafer stage WS. Since the mass is generally large, the absolute value of the reaction force generated by these movements is significantly larger (for example, about 4 to 5 times) by the reticle stage RS. Since the moment generated in the apparatus main body 10 by these reaction forces is proportional to the distance from the installation surface (base member 11) of the apparatus main body 10, the reticle stage R having a relatively large reaction force is used.
By arranging S on the lower side (closer to the installation surface) and the wafer stage WS with a small reaction force on the upper side (farther from the installation surface), it is possible to reduce the twist generated in the apparatus main body 10. The vibration generated by the movement of the stage is also reduced.

Further, since the illumination light IL is introduced from the lower side of the apparatus main body 10 and guided vertically upward, the illumination optical system 23 and the like can be arranged below the apparatus main body 10 and the center of gravity of the apparatus main body 10 is located. Can be set lower by that amount, so that the stability of the apparatus main body 10 can be increased, and the illumination optical system 23 is less likely to be affected by the vibration of the apparatus main body 10, thereby increasing the exposure accuracy. Can be.

As described above, in the projection exposure apparatus of the present embodiment, the reticle stage RS is placed on the lower side of the wafer stage WS.
Are arranged on the upper side and the illumination light IL is introduced from the lower side, compared with a configuration in which the reticle stage RS is arranged on the upper side and the wafer stage WS is arranged on the lower side and the illumination light is introduced from the upper side. Although the vibration generated in the apparatus main body 10 is remarkably small, in this embodiment, the following anti-vibration measures are taken in order to further ensure the safety. That is, as shown in FIG.
A rigid member 25 having a plate-like or rod-like rigidity is provided upright in the vertical direction. The lower end of the rigid member 25 is rotatably supported on the base member 11 via a support member 26.

The apparatus body 10 and the rigid member 25 may be provided directly on the installation surface (floor) without the base member 11. Further, the apparatus main body 10 is disposed on the base member 11,
The support member 26 may be arranged directly on the installation surface (floor). Further, in this embodiment, the rigid member 25 is
Although supported on the base member 11, another base member can be provided on the installation surface independently of the base member 11, and can be installed on the other base member. If you do this,
The apparatus main body 1 from the rigid member 25 side via the base member 11
This is because vibration is less likely to be transmitted to the zero side.

The rigid member 25 and the fixed body 18a of the reticle stage RS are connected by a first transmission means (device) 27 having a transmission member 27A made of, for example, a rod-shaped member, and are used for driving the reticle stage RS. The resulting reaction force is transmitted to the rigid member 25 via the first transmission means 27. Further, between the rigid member 25 and the fixed body 19a of the wafer stage WS, a second transmission unit 2 having a transmission member 28A made of, for example, a rod-shaped member is provided.
The reaction force generated when the wafer stage WS is driven is transmitted to the rigid member 25 via the second transmission means 28.

These first and second transmission means 27, 28
Has actuators 27B and 28B, respectively. The details of the actuators 27B and 28B are shown in FIG. 2 (the actuator 27B provided between the fixed body 18a of the reticle stage RS and the transmission member 27A is shown in FIG. 2 as a representative). RS
The stator 31 fixed to the fixed body 18a of the transmission member 2
7A is a so-called voice coil actuator composed of a mover 32 fixed to 7A.
In response to the command signal from 3, the vibration generated in the ± Y direction of the fixed body 18a of the reticle stage RS is absorbed.

As shown in FIG. 2, the actuator 27B
The stator 31 is made of a magnetized body having an S-pole cylindrical shaft 31B formed around an N-pole shaft 31A. In addition, the mover 32
Consists of an inner cylinder 32A loosely fitted on the shaft 31A of the stator 31 with a gap, a coil 32B wound around the outer periphery of the inner cylinder 32A, and an outer cylinder 32C covering the coil 32B, and flows through the coil 32B. The current is adjusted by the control device 33 so that the stator 31 and the mover 32
A force in a direction parallel to B (± Y direction in a projection exposure apparatus) is generated. Note that the stator 31 is provided on the transmission member 27A, and the mover 32 is mounted on the fixed body 18a of the reticle stage RS.
May be provided. The configuration of the actuator 28B is the same as that of the actuator 27B, and a description thereof will be omitted.

The actuators 27B and 28 according to the present invention
B is not limited to the voice coil actuator shown in FIG. 2, but may be, for example, the actuator 34 shown in FIG. Another example of the actuator shown in the figure includes a stator 35 fixed to the fixed body 18a of the reticle stage RS, and a movable element 36 fixed to the transmission member 27A. The arm member 35A fixed to the fixed body 18a is provided with a magnetic body 35B. On the other hand, the mover 36 is configured by providing an inner cylinder 36B on the arm 36A fixed to the transmission member 27A so as to sandwich the magnetic body 35B, and winding a coil 36C around the outer periphery of the inner cylinder 36B. I have. Also in this case, by adjusting the current flowing through each coil 36C of the mover 36 by the control device 33, the balance of the attraction force between the stator 35 and the mover 36 is changed, and the direction shown in FIG. A force is generated in the ± Y direction in the device.

Further, in the projection exposure apparatus of this embodiment, as shown in FIG. 1, when the reaction force (vibration) of the stage is absorbed by using the actuators 27B and 28B, it is applied to the reticle stage RS and the wafer stage WS. From driving force, reticle stage RS and wafer stage WS
Since the reaction force (vibration) generated in the fixed members 18a and 19a can be known, the drive signal of the stage drive device 20 is sent to the control device 33, and the actuators 27B and 28B are controlled based on the drive signal. Therefore, the reaction force generated on the stationary members 18a and 19a of the stage can be canceled substantially in synchronization with the movement of the stage.

In the projection exposure apparatus according to the present embodiment, acceleration sensors (vibration detectors) 37 and 38 for detecting a reaction force (vibration) accompanying the movement of the reticle stage RS and the wafer stage WS are provided in the respective stages. RS and WS are provided on fixed bodies 18a and 19a. Outputs from the acceleration sensors 37 and 38 are sent to the control device 33. Therefore, the control device 33 can also perform feedback control of the actuators 27B and 28B based on the outputs from the acceleration sensors 37 and 38. Reticle stage RS
The detector for detecting information on the reaction force (vibration) accompanying the movement of the wafer stage WS is not limited to such an acceleration sensor.

Further, the projection exposure apparatus of the present embodiment comprises a fixed body 18a of reticle stage RS and a wafer stage W
A movable mirror (reflection surface) is provided integrally with each of the S fixed bodies 19a, and the first column 15 (or the support base 16) is provided.
The interferometer 51 is fixed to the second column 17 and the position information of each stage accompanying the reaction force (vibration) is detected from these outputs. Therefore, in the projection exposure apparatus of the present embodiment, the position signals from the interferometers 51 and 52 are sent to the control device 33, and the actuators 27B and 28B are feedback-controlled based on the position signals from the interferometers 51 and 52. The reaction force generated in the fixed bodies 18a and 19a of each stage can be canceled substantially in synchronization with the movement of the stage.

In controlling the actuators 27B and 28B, a driving signal from the stage driving device 20
Output from acceleration sensors 37 and 38 and interferometer 5
It is not necessary to use all the outputs from 1, 52, and at least one of them may be used as appropriate.

Further, the projection exposure apparatus of the present embodiment is provided with an actuator 39 for absorbing a reaction force (vibration) of the rigid member 25. A frame member (not shown) is provided on the base member 11 or on the installation surface. The movable member of the actuator 39 is provided on the frame member, and the stator of the actuator 39 is provided on the rigid member 25. Since the configuration of the actuator 39 itself is the same as that of the actuator shown in FIGS. 2 and 3, the detailed description is omitted. When absorbing the reaction force (vibration) of the rigid member 25 using the actuator 39, the stage driving device 20
Is sent to the control device 33, and the actuator 39 is controlled based on the drive signal. Therefore, the reaction force (vibration) generated in the rigid member 25 can be canceled substantially in synchronization with the movement of the stage, and the rigid member transmitted to the exposure apparatus main body via the rigid member 25, the support member 26, and the base member 11. 25 can be made extremely small.

In the projection exposure apparatus of the present embodiment, an acceleration sensor (vibration detector) 41 for detecting a reaction force (vibration) of the rigid member 25 is provided on the rigid member 25.
The output from the acceleration sensor 41 can be sent to the control device 33, and the actuator 39 can be feedback-controlled based on the output from the acceleration sensor 41.

In controlling the actuator 39, it is not necessary to use both the drive signal from the stage drive device 20 and the output from the acceleration sensor 41, and it is sufficient to use at least one of them as appropriate.

Here, the reaction force (first reaction force) Fr due to the movement of the reticle stage RS is the mass of the movable portion of the reticle stage RS (the mass of the entire movable portion including the masses of the movable body 18b and the reticle R). Mr, and the acceleration is αr,

## EQU1 ## Fr = Mr · αr. The reaction force (second reaction force) Fw accompanying the movement of wafer stage WS is represented by Mw, the mass of the movable portion of wafer stage WS (the mass of the entire movable portion including mass of movable body 19b and wafer W), and its acceleration. Is αw,

## EQU2 ## Fw = Mw.αw

The dimension (first dimension) from the position at which the rigid member 25 is supported by the support member 26 to the position at which the first transmitting means 27 is attached to the rigid member 25 (the point where the first reaction force is applied). From the position of the rigid member 25 supported by the support member 26 to the transmission member 2 of the second transmission means 28.
The dimension (second dimension) up to the mounting position (the point where the second reaction force acts) on the 8A rigid member 25 is defined as Lw, so that the sum of the moments due to the respective reaction forces becomes zero, ie,

(3) Fr · Lr + Fw · Lw = 0 (1) The mass Mr and acceleration αr of the reticle stage RS, the mass Mw and acceleration αw of the wafer stage WS, or the first dimension Lr and the second dimension Lw so as to satisfy (1). Is set. This allows the rigid member 25 to maintain a balanced state when the reticle stage RS and the wafer stage WS move.

For the sake of design, the mass Mr of the reticle stage RS, its acceleration αr, and the mass M of the wafer stage WS are set so as to satisfy the above equation (1).
w, the acceleration αw, or the first dimension Lr, the second dimension Lw
Cannot be set, the force Fe on the rigid member 25 by the actuator 39 and the dimension Le from the support position of the rigid member 25 to the point of application of the force by the actuator 39
By setting appropriately

[Formula 4] Fr · Lr + Fw · Lw + Fe · Le = 0 (2)

Next, the operation will be described. First, the wafer stage WS is driven to position the first shot area on the wafer W at a predetermined approach (acceleration) start position, and the reticle stage RS is returned to a predetermined reset position (acceleration start position).

Next, a command is given to the stage driving device 20 to drive the reticle stage RS and the wafer stage WS to start exposure of the shot area. In the case of the present embodiment, the reticle stage RS moves in the + Y direction,
Wafer stage WS moves in the −Y direction. Regarding the moving speed ratio at this time, the projection magnification of the projection optical system 14 is 1
If it is / 4, the moving speed of wafer stage WS is set to 1/4 times the moving speed of reticle stage RS. Note that reticle stage RS and wafer stage W
The acceleration ratio of S is set similarly.

A reduced image of the pattern in the slit-shaped illumination area of the reticle R is projected onto an exposure area on the wafer W by the projection optical system 14, and the reticle R and the wafer W are synchronously scanned, so that the pattern on the reticle R is scanned. Is formed in one shot area on the wafer W.

When the exposure of one shot area on the wafer W is completed in this way, a command is given to the stage driving device 20 to drive the wafer stage WS, and the wafer W next to the exposed shot area of the wafer W is driven. The second shot area is positioned at the acceleration start position. Then, reticle stage RS is moved in the opposite direction (−Y direction) to the previous exposure to start exposure of the shot area. In this case, wafer stage WS is moved in the + Y direction at a speed of １ ／ of the speed of reticle stage RS. Thereafter, similarly, the exposure of the shot area of the wafer W is performed by the step-and-scan method.

At this time, the accelerations αr and αw of the reticle stage RS and the wafer stage WS, respectively,
In other words, an electric signal corresponding to the forces Fr and Fw serving as vibration sources is sent to the control device 33, and the control device 33 generates forces -Fr and -Fw that cancel out the detected forces Fr and Fw. A current flows through the coil 32B of each of the actuators 27B and 28B. Thereby, fixed bodies 18a and 19a of reticle stage RS and wafer stage WS are formed.
Is applied in the ± Y direction to cancel the reaction force caused by the movement of the stages RS and WS, such vibration can be attenuated, and the deterioration of the imaging characteristics of the wafer W can be prevented. Can be.

At least one of the output signal to the actuators 27B and 28B or the drive signal to both stages of the stage driving device 20 is simultaneously or slightly delayed with the driving of the stage so as to satisfy the relationship of the above equation (2). Based on the value, the control device 33 can send a drive signal to the actuator 39 to operate the actuator 39. If necessary, the actuator 39 is feedback-controlled based on a value detected by the acceleration sensor 41 for detecting the vibration of the rigid member 25 or at least one of the feedback signals of the actuators 27B and 28B. The actuator 39 may be directly controlled based on the value detected by the acceleration sensor 41. Further, the actuators 27B and 28B are
It is operated based on the detection value of the acceleration sensor 41 for detecting the vibration of the rigid member 25, or the acceleration sensor 37, 38
And 41 may be operated based on the detected values.

As described above, the projection exposure apparatus of this embodiment has the reticle stage RS
Since the illuminating light IL is introduced from the lower side by arranging the S on the upper side, that is, the reticle stage RS having a large moving speed (acceleration) and a large mass is arranged relatively below the apparatus main body 10, so that the reticle Compared to a configuration in which the stage RS is arranged on the upper side and the wafer stage WS is arranged on the lower side and the illumination light is introduced from the upper side, the reaction force moment acting on the main unit 10 is small, so that the twist generated in the main unit 10 is reduced. The vibration of the apparatus main body 10 is reduced.

In addition to the above, the first reaction force accompanying the movement of the reticle R is transmitted to the rigid member 25 by the first transmission means 27, and the second reaction force accompanying the movement of the wafer W is transmitted to the second transmission means 2.
8, the reaction force is transmitted to the rigid member 25, so that the mutual reaction forces are offset via the rigid member 25, and the vibration is further suppressed.

Further, in the projection exposure apparatus of this embodiment,
The reticle stage RS is provided below the projection optical system 14, and the illumination optical system 23 is provided below so as to illuminate from below the projection reticle stage RS. The position of the center of gravity of the reticle stage RS is lower than that of a projection exposure apparatus in which a reticle stage is arranged above a projection optical system and illuminated from above, thereby increasing the stability of the apparatus body 10. In addition, the vibration itself caused by driving the wafer stage WS can be suppressed.

In addition, in this embodiment, since the fixed body 18a of the reticle stage RS and the fixed body 19a of the wafer stage WS are slidably held by slide means 18c, 19c, respectively, the stages RS, WS
Almost all of the reaction force accompanying the driving of the transmission means 27, 2
8 and less transmitted to the support base 16 and the second column 17, thereby also reducing the vibration of the apparatus main body 10.

The rigid member 25 is rotatably supported by a support member 26, in order to prevent vibration from remaining due to elastic deformation of the rigid member 25 itself.
Depending on the force acting on the rigid member 25 and the rigidity of the rigid member 25, it is not always necessary to rotatably support the rigid member. Also,
In this embodiment, since the light source 21 is provided on the side of the apparatus main body 10, the rigid member 25 has a through hole 25 for light transmission.
A is provided, but depending on the position of the light source 21, the through hole 25A is unnecessary.

Further, in this embodiment, the vibration detector 3
The actuators 27B, 28B, and 39 are operated by dynamically detecting the occurrence of vibration by providing 7, 38, and 41. However, in advance, the movement of the reticle stage RS and the wafer stage WS causes the The vibration may be measured and stored, and the operation of the actuators 27B, 28B, 39 may be controlled based on the measurement result. The actuators 27B, 28B, and 39 do not need to be composed of a single actuator, but may be a combination of a plurality of actuators connected in series or in parallel.

In addition to the embodiments shown in FIGS. 2 and 3, a combination of a linear motor actuator, a pneumatic damper, a mechanical damper, a dynamic vibration absorber, a mass damper, and the like may be used as the actuators 39. it can. Further, the position of the actuator 39 is not limited to the position shown in FIG. 1, and may be provided at another position. in addition,
Although not shown, similar actuators may be provided between the support member 26 and the installation surface. Further, as disclosed in Japanese Patent Application Laid-Open No. 8-63231, a vibration isolating mechanism may be employed in which the reaction force generated when moving each stage is reduced by a counterweight.

Second Embodiment FIG. 4 is a front view showing a schematic configuration of a projection exposure apparatus according to a second embodiment of the present invention. Members common to those in the first embodiment described above are denoted by the same reference numerals. The description is omitted. The projection exposure apparatus of the present embodiment is different from the projection exposure apparatus of the first embodiment in the following points.

That is, in the above-described first embodiment, the support base 16 is provided horizontally on the first column 15, but in the second embodiment, the support base 16 is integrally provided with a column portion, and the support base is provided. The column is fixed to the base member 13 so as to be provided on the base member 13. The first column 15 is provided not on the base member 13 but on the base member 11 via a newly provided anti-vibration pad 42. The configuration of the anti-vibration pad 42 is substantially the same as that of the anti-vibration pad 12. With such a configuration, the mutual influence of the reaction force (vibration) caused by the movement of the reticle stage RS and the wafer stage WS can be reduced, and the vibration of each stage can be easily suppressed. Other configurations and effects are the same as those in the first embodiment.

Third Embodiment FIG. 5 is a front view showing a schematic configuration of a third embodiment of a projection exposure apparatus according to the present invention. The same members as those in the first embodiment are denoted by the same reference numerals. The description is omitted. The projection exposure apparatus of the present embodiment is different from the projection exposure apparatus of the first embodiment in the following points.

In the first embodiment, the reticle stage RS is arranged on the lower side and the wafer stage WS is arranged on the upper side.
Although the illumination light IL is introduced from below, in the third embodiment, the reticle stage RS is arranged on the upper side, the wafer stage WS is arranged on the lower side, and the illumination light IL is introduced from above. The points are different. That is, the reticle stage RS is provided on the second column 17,
6 is removed and the wafer stage W
S is provided. The third column 43 is provided on the second column 17, and the illumination optical system 23 and the like are provided on the third column 43.

The base member 11 is divided into a first base member 11A and a second base member 11B, and is installed independently on an installation surface (floor), and the apparatus body 10 is installed on the first base member 11A. The rigid member 25 is supported on the second base member 11B. The reason why the base member is divided into two is to reduce the effect of vibration between each other, and particularly to prevent the vibration of the rigid member 25 from being transmitted to the apparatus main body 10. Other configurations and effects including a configuration for image stabilization and image stabilization are the same as those in the above-described first embodiment, except for the position of the stages RS and WS.

The first base member 11A and the second base member 11B need not be installed on the same installation surface (floor). Further, the height (thickness) of the first base member 11A and the second base member 11B may be different. further,
The height of the support member 26 (the dimension from the second base member 11B to the pivotal support position of the rigid member 25) is also arbitrary. The support member 26 may be provided directly on the installation surface (floor) without the second base member 11B.

Fourth Embodiment FIG. 6 is a front view showing a schematic configuration of a fourth embodiment of a projection exposure apparatus according to the present invention, and members common to the first to third embodiments described above are denoted by the same reference numerals. And description thereof will be omitted. The projection exposure apparatus of the present embodiment differs from the projection exposure apparatus of the third embodiment in the following points.

That is, in the fourth embodiment, the first column 15 is provided not on the base member 13 but on the first base member 11A via a newly provided anti-vibration pad 42. The configuration of the anti-vibration pad 42 is as follows.
Is almost the same as With this configuration, it is possible to reduce the mutual influence of the reaction force (vibration) accompanying the movement of reticle stage RS and wafer stage WS. Other configurations and effects are the same as those of the above-described first to third embodiments.

In each of the above embodiments, the projection optical system 14 need not be a reduction optical system, but may be a unit magnification system or an enlargement system. In each of the above-described embodiments, the fixed body 18a of the reticle stage RS and the wafer stage W
S fixed body 19a and transmission member 27A of first transmission means 27
The actuators 27B and 28B are provided one each between the transmission member 28A of the second transmission means 28 and the transmission member 28A, but the number may be arbitrary. The same applies to the actuator 39. Also, the actuators 27B, 2
8B and 39 are not necessarily required, and can be omitted.

Further, although not shown in the above-described embodiment, between the base member 13 and the base member 11 (11A), for example, an X
At least one actuator that generates a force in the direction can be provided. The X-axis actuator is disposed between the base member 13 and a frame provided separately from the base member 13 on the base member 11.

Here, for example, when exposing the wafer W by the step-and-scan method, the wafer W is scanned in the scanning direction (Y direction) after the scanning exposure of one shot area is completed.
Stepping in the direction (X direction) orthogonal to
The vibration of the apparatus main body 10 can be reduced by generating forces for canceling the reaction forces generated during acceleration and deceleration of the wafer stage WS before and after the stepping operation by the shaft actuator.

In each of the above embodiments, the rigid member 2
5. The vibration isolator including the first transmission means 27 and the second transmission means 28 prevents vibration accompanying the movement of the reticle stage RS and the wafer stage WS in the Y direction. Alternatively or independently, a vibration isolator having a similar configuration (however, the second transmission means 28 may be omitted) may be provided to prevent at least vibration accompanying the step movement of the wafer stage WS in the X direction. it can.

Exposure illumination light used in a projection exposure apparatus (such as a scanning stepper) to which the present invention is applied includes bright lines (for example, g-line and i-line) emitted from a mercury lamp and K
rF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), _{F 2} laser (wavelength 15
7 nm) or a higher harmonic such as a YAG laser. In the projection exposure apparatus using F ₂ laser, the majority and reticle of the plurality of refractive optical elements constituting the illumination optical system or the projection optical system (lens or the like) is composed of fluorite, the illumination optical system and the projection optical All air in the optical path of the system is replaced by helium. Further, the present invention can be applied to a catadioptric projection exposure apparatus.

As the illumination light for exposure, for example, 5 to 1
EUV having an oscillation spectrum at 5 nm (soft X-ray region)
(Extreme Ultra Violet) light may be used. A projection exposure apparatus using EUV light defines an illumination area on a reflective mask in an arc slit shape and has a reduced projection optical system including only a plurality of reflective optical elements (mirrors). The reflection mask and the wafer are synchronously moved at a speed ratio according to the magnification of the system to transfer the pattern of the reflection mask onto the wafer.

The embodiments described above are described for facilitating the understanding of the present invention, but are not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

[0080]

As described above, according to the present invention, the vibration accompanying the movement of the mask and the photosensitive substrate can be suppressed or attenuated, and the deterioration of the imaging characteristics can be prevented. A micro device having characteristics can be manufactured. Further, the moving speed of the mask and the photosensitive substrate can be increased, the productivity can be improved, and a large-sized mask can be used.

[Brief description of the drawings]

FIG. 1 is a front view showing a schematic configuration of a first embodiment of a projection exposure apparatus of the present invention.

FIG. 2 is a cross-sectional view showing an embodiment of the actuator according to the present invention.

FIG. 3 is a cross-sectional view showing another embodiment of the actuator according to the present invention.

FIG. 4 is a front view showing a schematic configuration of a second embodiment of the projection exposure apparatus of the present invention.

FIG. 5 is a front view showing a schematic configuration of a third embodiment of the projection exposure apparatus of the present invention.

FIG. 6 is a front view showing a schematic configuration of a fourth embodiment of the projection exposure apparatus of the present invention.

[Explanation of symbols]

 R: reticle (mask) W: wafer (photosensitive substrate) RS: reticle stage (first stage) WS: wafer stage (second stage) AX: optical axis 10: apparatus main body 11, 13: base member 14: projection optical system 15 first column 17 second column 18a, 19a fixed body 18b, 19b movable body 18c, 19c sliding means 20 stage drive 21 light source 23 illumination optical system 25 rigid members 27, 28 transmission Means 27A, 28A Transmission member 27B, 28B, 39 Actuator 33 Controller 37, 38, 41 Acceleration sensor (vibration detector) 40 Anti-vibration pad

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/30 503B 518

Claims (15)

[Claims] 1. A projection exposure apparatus that transfers a pattern of a mask onto a photosensitive substrate, a projection optical system that projects a pattern image from the mask onto the photosensitive substrate, a first stage that holds the mask, A second stage for holding the photosensitive substrate disposed above the mask, and for transferring the pattern of the mask onto the photosensitive substrate, the mask and the photosensitive substrate are orthogonal to the optical axis of the projection optical system. And a driving device for driving the first stage and the second stage, respectively, so as to move synchronously in the direction of the projection exposure. 2. The projection exposure apparatus according to claim 1, further comprising an anti-vibration device for reducing vibration generated when the first stage and the second stage are driven. 3. The projection exposure apparatus according to claim 2, wherein the anti-vibration device cancels a part or all of respective reaction forces generated by driving the first stage and the second stage. apparatus. 4. A projection exposure apparatus that transfers a pattern of a mask onto a photosensitive substrate, a projection optical system that projects a pattern image from the mask onto the photosensitive substrate, a first stage that holds the mask, A second stage for holding a photosensitive substrate; and a driving device for driving the first stage and the second stage, respectively, so as to synchronously move the mask and the photosensitive substrate in a direction orthogonal to an optical axis of the projection optical system. A projection exposure apparatus, comprising: a vibration isolator for canceling a part or all of respective reaction forces generated by driving the first stage and the second stage. 5. An anti-vibration device comprising: a rigid member having rigidity supported on a predetermined installation surface; and a first reaction force generated in a direction orthogonal to the optical axis with driving of the first stage. A first transmission unit that transmits the rigid member; and a second transmission unit that transmits a second reaction force generated in a direction orthogonal to the optical axis with the driving of the second stage to the rigid member. The projection exposure apparatus according to claim 4, characterized in that: 6. An apparatus body including the projection optical system, the first stage, and the second stage is fixed to a base member installed on the installation surface, and the rigid member is connected to the base member. The projection exposure apparatus according to claim 5, wherein the projection exposure apparatus is independently supported by another base member installed on the installation surface. 7. The projection exposure apparatus according to claim 5, wherein the rigid member is movably supported. 8. A product obtained by multiplying a product of a first dimension from the supporting position of the rigid member to a point where the first reaction force is applied by the first transmitting means and the first reaction force, and a supporting position of the rigid member. The mass of the first stage and the first stage so that the sum of the product of the second dimension up to the point where the second reaction force acts on the second transmission means and the second reaction force becomes substantially zero. The projection exposure according to claim 5, wherein at least one of a stage acceleration, a mass of the second stage, an acceleration of the second stage, the first dimension, and the second dimension is adjusted. apparatus. 9. A projection exposure apparatus that transfers a pattern of a mask onto a photosensitive substrate, a projection optical system that projects a pattern image from the mask onto the photosensitive substrate, a first stage that holds the mask, A second stage for holding a photosensitive substrate, a driving device for driving the first stage and the second stage respectively to move the mask and the photosensitive substrate in a direction orthogonal to the optical axis of the projection optical system; A rigid member rotatably supported with respect to a predetermined installation surface; a reaction force generated in a direction orthogonal to the optical axis when the first stage is driven; and a reaction force generated when the second stage is driven. A transmission unit for transmitting at least one of the reaction forces generated in a direction perpendicular to the optical axis to the rigid member. 10. The apparatus according to claim 1, further comprising a vibration detector configured to detect information relating to vibration of at least one of the first stage and the second stage, wherein the transmission unit is configured to detect the optical axis based on a value detected by the vibration detector. The projection exposure apparatus according to claim 9, further comprising an actuator that generates a force in a direction orthogonal to the projection exposure apparatus. 11. The projection exposure apparatus according to claim 10, wherein the vibration detector includes an interferometer. 12. The transmission unit includes an actuator that generates a force in a direction orthogonal to the optical axis based on at least one of information on a driving force on the first stage and information on a driving force on the second stage. The projection exposure apparatus according to claim 9, wherein: 13. The projection exposure apparatus according to claim 9, further comprising a vibration damping device for suppressing vibration of the rigid member. 14. The apparatus according to claim 13, further comprising a vibration detector for detecting information on vibration of the rigid member, wherein the vibration control device is controlled based on a detection result of the vibration detector. The projection exposure apparatus according to claim 1. 15. The projection exposure apparatus according to claim 13, wherein the vibration control device is controlled based on at least one of drive information of the first stage and drive information of the second stage.