JP2001345256A - Stage device and aligner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the correlation between the deformation of a body column and the position of a stage body. SOLUTION: This stage device where a surface plate is supported by a support part via actuators 13A to 13D and anti-vibration pads 12A to 12D is equipped with a stage body that moves on the surface plate, the actuators 13A to 13D that are supported by the support part for adding thrust that opposes counterforce with the movement of the stage body, and the anti- vibration pads 12A to 12D, a first control system 73 that controls the driving of the anti-vibration pads by sets being equal to or smaller than the number of the anti-vibration pads, a second control system 74 that controls the driving of actuators by the sets of the actuators corresponding to each of the sets of anti-vibration pads, and a third control system 75 that controls the first and second control systems 73 and 74 and drives a pair of the corresponding sets of the anti-vibration pad and actuator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stage device in which a stage body for holding a mask, a substrate and the like moves on a surface plate, and an exposure for performing an exposure process using the mask and the substrate held by the stage device. The present invention relates to an apparatus, and particularly to a stage apparatus and an exposure apparatus suitable for use in a lithography process when manufacturing a device such as a semiconductor integrated circuit or a liquid crystal display.

[0002]

2. Description of the Related Art Conventionally, in a lithography process which is one of the manufacturing processes of a semiconductor device, a circuit pattern formed on a mask or a reticle (hereinafter referred to as a reticle) is coated with a resist (photosensitive agent) on a wafer. Alternatively, various exposure apparatuses for transferring the image onto a substrate such as a glass plate have been used. For example, as an exposure apparatus for a semiconductor device, a reticle pattern is projected onto a wafer using a projection optical system in accordance with the miniaturization of the minimum line width (device rule) of a pattern accompanying the high integration of an integrated circuit in recent years. A reduction projection exposure apparatus that performs reduction transfer is mainly used.

As this reduction projection exposure apparatus, a step-and-repeat type static exposure reduction projection exposure apparatus (so-called stepper) for sequentially transferring a reticle pattern to a plurality of shot areas (exposure areas) on a wafer.
And an improved version of this stepper.
No. 043, etc., a reticle and a wafer are synchronously moved in a one-dimensional direction to transfer a reticle pattern to each shot area on the wafer. Scanning steppers) are known.

In these reduction projection exposure apparatuses, as a stage apparatus, first, a base plate serving as a reference of the apparatus is installed on the floor surface, and a reticle stage, a wafer, and a reticle are placed on the base plate via a vibration isolating table for isolating floor vibration. A stage on which a main body column supporting a stage, a projection optical system (projection lens), and the like is mounted is often used. In recent stage devices, for example, four actuators such as an air mount (vibration isolating pad) and a voice coil motor which are arranged near each vertex of a quadrilateral and whose internal pressure can be controlled are provided as the vibration isolating table. An active anti-vibration table mounted on a main frame) that controls the vibration of the main body column by controlling the voice coil motor and the like based on measurement values of, for example, six accelerometers is employed.

Since the above-mentioned stepper or the like repeats exposure of a certain shot area on a wafer and then successive exposure of another shot area, the wafer stage (in the case of a stepper) or a reticle stage and a reticle stage are used. The reaction force generated by acceleration and deceleration of the wafer stage (in the case of a scanning stepper) causes vibration of the main body column, causing a relative position error between the projection optical system and the wafer, etc., which differs from the design value on the wafer. When a pattern is transferred to a position or when the position error includes a vibration component, there is a disadvantage that image blurring (increase in pattern line width) is caused.

Therefore, conventionally, in the above-described active vibration isolating table, a reaction force applied to the surface plate when the stage main body moves on the surface plate is measured by an accelerometer, and a thrust (hereinafter referred to as "thrust force") for canceling the reaction force. , A counterforce) is generated by the actuator, thereby suppressing the above-described inconvenience. However, as the amount of movement of the stage body increases, the amount of change in the center of gravity of the exposure apparatus body also increases,
The thrust required by the actuator to make up for it also increases. Since the driving of the actuator generally generates heat, an increase in the driving frequency and the driving amount of the actuator causes a large temperature change in the space where the exposure apparatus is installed, which may hinder high-precision exposure processing. There is.

[0007] Therefore, in the related art, after correcting an unbalanced load due to the stage movement by an actuator, the actuator is switched to an air servo using an air mount to cancel steady heat generation (low-frequency component of thrust generated by the actuator). A part of the thrust required for the actuator is replaced by the thrust of the air mount, thereby suppressing the heat generation of the actuator itself. Here, the drive of the air mount is performed, for example, in a case where the two located on the rear side have a smaller span than the two located on the front side, the two on the rear side have the same pneumatic pressure in order to reduce the twist with respect to the base plate. In the system, the remaining two are controlled by so-called pseudo three-point control in which each is controlled by a separate pneumatic system, and the actuators are driven by four-point control in which four are controlled by separate electric systems.

[0008]

However, the conventional platen control device and exposure apparatus as described above have the following problems. In recent years, demands for miniaturization of semiconductor devices and speeding up of exposure processing have been increasing more and more, and an exposure apparatus capable of responding to this demand has been demanded. However, in the actual machine, even if the target position of the stage body is managed by a laser interferometer or the like and the accuracy is adjusted to a sufficient level, there is a relative positional deviation between the chips of about 10 nm when the exposed chip is measured. It has been found that the relative position shift between the chips tends to increase as the acceleration and speed of the chip increase.

As a cause of this, there is a part depending on distortion of the whole main body column (or the base plate) or minute deformation. That is, if the main body column is deformed,
The positional relationship between the laser interferometer and the projection optical system and the stage body also fluctuates, and an error occurs in the position control of the stage body. As one of the causes of the deformation of the main body column, when switching from the actuator to the air servo to correct the eccentric load due to the stage movement, a pseudo 3
It is conceivable that the air mount may be twisted by an air mount configured by point control. In this case, the positional relationship between the laser interferometer installed on the main body column side and the stage main body changes, and the apparent position of the stage main body measured by the laser interferometer also changes. As a result, for example, the position of the stage main body with respect to the projection optical system cannot be managed accurately.

Therefore, when this minute deformation can be predicted, it is conceivable to correct the position of the stage body in accordance with the deformation. However, since the control modes of the actuator and the air mount are actually different, the thrust of both the actuator and the air mount are different. It was difficult to take a correlation with the deformation, and the position of the stage body could not be completely corrected.

The present invention has been made in consideration of the above points, and has as its object to provide a stage apparatus and an exposure apparatus which can easily manage the correlation between the deformation of the main body column and the position of the stage main body. And Another object of the present invention is to provide a stage apparatus and an exposure apparatus which can cancel the influence of the deformation of the main body column on the control of the stage position.

[0012]

In order to achieve the above object, the present invention employs the following structure corresponding to FIGS. 1 to 5 showing an embodiment. The platen control device of the present invention includes a stage body (2, 5) moving on a platen (3, 6) and a stage body (2, 5) supported by a support portion (8, 10). A plurality of actuators (13A) for applying thrusts against the accompanying reaction force to the surface plate (3, 6)
To 13D, 31A to 31D) and vibration-isolating pad (12A
To 12D, 30A to 30D), and a surface plate (3, 6).
Are actuators (13A to 13D, 31A to 31D)
And anti-vibration pads (12A-12D, 30A-30D)
A stage device (4, 7) supported by a support portion (8, 10) through a plurality of anti-vibration pads (12A to 12A).
D, 30A to 30D) is driven by the vibration-isolating pad (12A to 1D).
2D, 30A to 30D) and a plurality of actuators (13A to 13D);
D, 31A to 31D) are driven by actuators (13A to 13D, 31A to 31D) corresponding to the vibration-isolating pads (12A to 12D, 30A to 30D) forming the set.
D), a second control system (74) controlled by a set, and a first control system (73) and a second control system (74) are controlled to form anti-vibration pads (12A to 12D, 30A to 30D). A third control system (75) for driving a corresponding pair of actuators (13A to 13D, 31A to 31D) in pairs is provided.

Therefore, in the platen control device of the present invention, for example, the first control system (73) includes four anti-vibration pads (12A to 1A).
When the 2D, 30A to 30D) are controlled by a set of pseudo three points, the second control system (74) forms a set of vibration isolating pads (12A, 30A to 30D).
To 12D, 30A to 30D) and the corresponding actuators (13A to 13D, 31A to 31D) with the vibration isolating pad (1
As in the case of 2A to 12D and 30A to 30D), control is performed by a set of three pseudo points, and these are synchronously driven, so that these vibration isolating pads (12A to 12D, 30A to 30D) and actuators (13A to 13D, 31A to Deformation with high reproducibility can be generated in the supporting portions (8, 10) that support the 3D). Therefore, anti-vibration pads (12A to 12A
D, 30A-30D), actuators (13A-13)
D, 31A to 31D) corresponding to the thrusts (8, 1
0), the supporting portions (8, 1
The correlation between the amount of deformation 0) and the position of the stage main body (2, 5) can be managed.

The exposure apparatus according to the present invention is an exposure apparatus (1) for exposing a pattern of a mask (R) held on a mask stage (2) to a substrate (W) held on a substrate stage (5). The stage device (4, 7) according to any one of claims 1 to 4 is used for at least one of the mask stage (2) and the substrate stage (5). is there.

Therefore, in the exposure apparatus of the present invention, when exposing the pattern of the mask (R) to the substrate (W), the amount of deformation of the supporting portions (8, 10) and the position of the stage main bodies (2, 5) are determined. By managing the correlation of
The position of at least one of the mask (R) and the substrate (W) can be managed according to the deformation amount of 0).

Further, in the exposure apparatus of the present invention, the mask stage (2) for holding a mask (R) having a pattern and the substrate stage (5) for holding a substrate (W) are synchronously moved, and (1) that exposes a substrate (W) through a projection optical system (PL), holds at least one of a mask stage (2) and a substrate stage (5) and a projection optical system (PL). An exposure body (8);
A stage controller (62) for changing at least one of the mask stage (2) and the substrate stage (5) based on the amount of deformation of the exposure main body (8) caused by the synchronous movement. It is characterized by the following.

Therefore, in the exposure apparatus of the present invention, the position control of at least one of the mask stage (2) and the substrate stage (5), which occurs according to the amount of deformation of the exposure main body (8), is performed by the stage controller (62). ) Is the stage (2, 5)
Can be corrected by changing the movement amount of the mask (R) even if the exposure main body (8) is deformed during the synchronous movement of the two stages (2, 5) without affecting the position control of the stage. The position of at least one of the substrate and the substrate (W) can be controlled with high accuracy.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a stage apparatus and an exposure apparatus according to the present invention will be described below with reference to FIGS. Here, an example in which a scanning stepper that transfers a circuit pattern of a semiconductor device formed on a reticle onto a wafer while synchronously moving a reticle and a wafer is used as an exposure apparatus will be described. In this exposure apparatus, the stage apparatus of the present invention is applied to both a reticle stage and a wafer stage.

An exposure apparatus 1 shown in FIG. 1 includes a light source (not shown).
An illumination optical system IU for illuminating a rectangular (or circular) illumination area on a reticle (mask) R with uniform illumination by exposure illumination light from the reticle (mask) R, and a reticle stage (stage body) as a mask stage for holding the reticle R 2) and a stage apparatus 4 including a reticle surface plate (surface plate) 3 for supporting the reticle stage 2, a projection optical system P for projecting illumination light emitted from the reticle R onto a wafer (substrate) W
L, a stage device 7 including a wafer stage (stage main body) 5 as a substrate stage for holding the wafer W and a wafer surface plate (surface plate) 6 for holding the wafer stage 5;
Reaction frame (exposure main body, support) for supporting (holding) stage device 4 and projection optical system PL
8. Here, the optical axis direction of the projection optical system PL is defined as the Z direction, the direction of the synchronous movement of the reticle R and the wafer W is defined as the Y direction, and the direction of the asynchronous movement is defined as the X direction in a direction perpendicular to the Z direction. The rotation directions around the respective axes are denoted by θZ, θY, and θX.

The illumination optical system IU is supported by a support column 9 fixed on the upper surface of the reaction frame 8. Examples of the illumination light for exposure include far ultraviolet light (DUV light) such as an ultraviolet bright line (g-line, i-line) and KrF excimer laser light (wavelength: 248 nm) emitted from an ultra-high pressure mercury lamp, and ArF. Excimer laser light (wavelength 19
Vacuum ultraviolet light (VUV) such as 3 nm) and F ₂ laser light (wavelength 157 nm).

The reaction frame 8 is installed on a base plate (supporting portion) 10 placed horizontally on the floor surface, and its upper and lower sides have step portions 8a and 8b protruding inward. Are formed respectively.

In the stage device 4, the reticle platen 3 is
Step 8a of reaction frame 8 at each corner
(FIG. 1 does not show the anti-vibration unit on the back side of the drawing), and a pattern image formed on the reticle R passes through the center of the reticle R. Opening 3a is formed. The anti-vibration unit 11 includes air mounts (anti-vibration pads) 12A to 12D (in FIG. 1, the front side 12A, 12B
(Shown only) and voice coil motors (actuators) 13A to 13D (only the front side 13A and 13B are shown in FIG. 1) composed of a stator and a mover are arranged in series on the step 8a in pairs. It has a configuration.

As shown in FIG. 2, the air mounts 12A and 12B on the front side are controlled by individual pneumatic systems in which air supplied from an air supply source 71 is adjusted by solenoid valves 72A and 72B, respectively. . Also, air mount 12A,
The rear air mounts 12C and 12D arranged with a span smaller than 12B are controlled by the same pneumatic system in which the air supplied from the air supply source 71 is adjusted by one electromagnetic valve 72C.

That is, the four air mounts 12A to 12A
In 2D, pseudo three-point (three sets) control is constructed in which two are controlled by the same pneumatic system and the remaining two are controlled by individual pneumatic systems. These air mounts 12A to 12D
The flow rate of the air supplied to the solenoid valves 72A to 72C is determined by the effective sectional area of the throttles and the pressure ratio in the solenoid valves 72A to 72C. The operation of each of the solenoid valves 72A to 72C is controlled by a pneumatic control system (first control system) 73.

The voice coil motors 13A to 13D
Also, in the same manner as in the air mounts 12A to 12D, the front voice coil motors 13A and 13B are individually controlled by the voltage control system (second control system) 74 for the current flowing through the coils in the mover. The rear voice coil motors 13C and 13D arranged at a smaller span than the voice coil motors 13A and 13B are controlled by the same control system by the voltage control system 74.

In other words, the four voice coil motors 1
3A to 13D are air mounts 12 controlled by pseudo three points.
A pseudo three points (3
Pair). The air pressure control system 73 and the voltage control system 74 are totally controlled by a vibration control unit (third control system) 75. Although not shown, the stage device 4 also has a voice coil motor which is controlled by a voltage control system 74 and urges the reticle platen 3 in the ± X direction and the ± Y direction. The reticle stage 2 is fixed (moved) by the voice coil motor and the air mount.
A counterforce is provided to counter the reaction force associated with.

A reticle stage 2 is supported on the reticle base 3 so as to be two-dimensionally movable along the reticle base 3. On the bottom surface of the reticle stage 2, a plurality of air bearings (air pads) which are non-contact bearings
The reticle stage 2 is levitated and supported by the air bearings 14 on the reticle surface plate 3 with a clearance of about several microns.
At the center of the reticle stage 2, there is formed an opening 2a which communicates with the opening 3a of the reticle platen 3 and through which the pattern image of the reticle R passes.

The reticle stage 2 will be described in detail.
As shown in FIG. 3, the reticle stage 2 includes a reticle coarse movement stage 16 driven on the reticle surface plate 3 by a pair of Y linear motors 15 and 15 in a predetermined stroke in the Y-axis direction. A pair of X above
A reticle fine movement stage 18 that is finely driven in the X, Y, and θZ directions by a voice coil motor 17X and a pair of Y voice coil motors 17Y is provided. As illustrated).

As shown in the control block diagram of FIG. 4, the reticle stage 2 has these Y linear motors 15 and
15. The drive of the stage is controlled by a stage control unit (stage control device) 62 via an RS drive unit 61 including an X voice coil motor 17X and a Y voice coil motor 17Y. Then, the stage control unit 62
The main control unit 47 together with the illumination optical system IU, the projection optical system PL, and the like.
Is generally controlled by

Each Y linear motor 15 has a reticle surface plate 3
A stator 20 floating above and supported in the Y-axis direction by a plurality of air bearings (air pads) 19 as non-contact bearings, and a reticle coarse movement stage provided corresponding to the stator 20 via a connecting member 22 The movable element 21 is fixed to the movable element 16.

The reticle coarse movement stage 16 is guided in the Y-axis direction by a pair of Y guides 51, 51 fixed to the upper surface of an upper protruding portion 3b formed in the center of the reticle surface plate 3 and extending in the Y-axis direction. It has become. The reticle coarse movement stage 16 is supported by the Y guides 51 and 51 by an air bearing (not shown) in a non-contact manner.

A reticle R is held on the reticle fine movement stage 18 via a vacuum chuck (not shown). -Y of reticle fine movement stage 18
A pair of Y moving mirrors 52a and 52b formed of corner cubes are fixed to the ends in the direction, and an X moving mirror formed of a plane mirror extending in the Y axis direction is provided to the + X direction end of the reticle fine movement stage 18. 53 is fixed. Then, three laser interferometers (all not shown) for irradiating the movable mirrors 52a, 52b, and 53 with a measurement beam.
By measuring the distance from each movable mirror, the position of the reticle stage 2 in the X, Y, θZ (rotation around the Z axis) direction can be measured with high accuracy.

Returning to FIG. 1, as the projection optical system PL, here, both the object plane (reticle R) side and the image plane (wafer W) side are telecentric and have a circular projection visual field. A refraction optical system having a 1/4 (or 1/5) reduction magnification composed of a refraction optical element (lens element) made of a glass material is used. For this reason, when the reticle R is irradiated with the illumination light, of the circuit pattern on the reticle R, an image forming light beam from a portion illuminated by the illumination light enters the projection optical system PL, and the circuit pattern is partially inverted. The image is limited to a slit shape and formed at the center of the circular field on the image plane side of the projection optical system PL. Thus, the projected partial inverted image of the circuit pattern is transferred to the wafer W placed on the image forming plane of the projection optical system PL.
Of the plurality of upper shot areas, the reduced transfer is performed to the resist layer on the surface of one shot area.

A flange 23 integrated with the lens barrel is provided on the outer periphery of the lens barrel of the projection optical system PL. Then, the projection optical system PL is mounted on a lens barrel base 25 made of a casting or the like substantially horizontally supported on the step portion 8b of the reaction frame 8 via a vibration isolating unit 24 with the optical axis direction being the Z direction. And the flange 23 is engaged.

The material of the flange 23 is a material having a low thermal expansion, for example, Invar (nickel 36%,
(A low-expansion alloy composed of 0.25% of manganese and iron containing trace amounts of carbon and other elements). The flange 23 constitutes a so-called kinematic support mount that supports the projection optical system PL at three points with respect to the barrel base 25 via points, surfaces, and V-grooves. When such a kinematic support structure is employed, it is easy to assemble the projection optical system PL to the lens barrel base 25, and it is caused by vibrations, temperature changes, and the like of the assembled lens barrel base 25 and the projection optical system PL. There is an advantage that stress can be reduced most effectively.

The anti-vibration unit 24 is disposed at each corner of the lens barrel base 25 (the anti-vibration unit on the back side of the drawing is not shown), and an air mount (anti-vibration pad) 26A whose internal pressure can be adjusted. To 26D (26A on the front side in FIG. 1,
26B) and voice coil motors (actuators) 27A to 27D (only the front 27A and 27B are shown in FIG. 1) composed of a stator and a mover are arranged in series on the step 8b. I have. These vibration isolation units 24 insulate, at the micro G level, minute vibrations transmitted to the lens barrel base 25 (and the projection optical system PL) via the base plate 10 and the reaction frame 8. The air mounts 26A to 26A
D and the voice coil motors 27A to 27D are also driven.
It is controlled by the vibration control unit 75 via the air pressure control system 73 and the voltage control system 74, respectively.

The stage device 7 mainly includes a wafer stage 5 for holding a wafer W, and a wafer surface plate 6 for supporting the wafer stage 5 movably in a two-dimensional direction along the XY plane. A plurality of air bearings (air pads) 28 which are non-contact bearings are fixed to the bottom surface of the wafer stage 5.
The wafer stage 5 is floated and supported on the wafer surface plate 6 by a clearance of, for example, about several microns.

The wafer surface plate 6 is supported substantially horizontally above the base plate 10 via an anti-vibration unit 29. The anti-vibration units 29 are arranged at the corners of the wafer surface plate 6 (the anti-vibration units on the back side of the drawing are not shown in FIG. 1), and air mounts (anti-vibration pads) 30A to which the internal pressure can be adjusted. 30D (in FIG. 1, the front side 30D).
A and 30B only) and voice coil motors (actuators) 31A to 31D (in FIG.
(Only 1B is shown) are arranged in parallel on the base plate 10.

As shown in FIG.
The air mounts 30A and 30B on the front side in 30D are
Similarly to the reticle stage 2, the air supplied from the air supply source 81 is controlled by individual pneumatic systems adjusted by solenoid valves 82A and 82B, respectively. The rear air mounts 30C and 30D arranged at a smaller span than the air mounts 30A and 30B are controlled by the same pneumatic system in which the air supplied from the air supply source 81 is adjusted by one electromagnetic valve 82C. Have been.

That is, the four air mounts 30A to 30A
In 0D, pseudo three-point (three sets) control is constructed in which two are controlled by the same pneumatic system and the remaining two are controlled by individual pneumatic systems. These air mounts 30A to 30D
Since the flow rate of air supplied to the electromagnetic valves 82A to 82C is determined by the effective cross-sectional area of the throttles and the pressure ratio in the solenoid valves 82A to 82C, the air supply amount per unit time can be arbitrarily set by a combination of the two. The operation of each of the solenoid valves 82A to 82C is also controlled by the pneumatic control system 73.

The voice coil motors 31A to 31D
In the same manner as in the air mounts 30A to 30D, the voice coil motors 31A and 31B on the front side are individually controlled by the voltage control system 74 for the current flowing through the coils in the mover. And the voice coil motor 31A,
The voice coil motors 31C and 31D on the rear side arranged with a span smaller than 31B are controlled by the same control system by the voltage control system 74.

In other words, the four voice coil motors 3
1A to 31D are air mounts 30 controlled by pseudo three points.
A pseudo three points (3
Pair). Although not shown, the stage device 7 also has a voice coil motor, which is controlled by the current control system 74 and urges the wafer base 6 in the ± X direction and the ± Y direction, is fixed on the floor (not shown). It is provided fixed to a support. The voice coil motor and the air mount provide a counter force for counteracting a reaction force accompanying movement (drive) of the wafer stage 5.

As shown in FIG. 4, the counter force of the reticle stage 2 and the wafer stage 5 is converted into a stage thrust signal of the reticle stage 2 and the wafer stage 5 by a counter force calculator 49 connected to the main controller 47. It is calculated based on. Here, the calculated counterforce is output to the vibration control unit 75 via the main control unit 47.

The wafer stage 5 is
A pair of linear motors 32 for driving the wafer in the X direction (a linear motor on the front side of the paper surface with respect to the wafer stage 5 is not shown)
And a pair of linear motors 33 for driving the wafer stage 5 in the Y direction, so that the wafer stage 5 can be moved on the wafer surface plate 6 in the XY two-dimensional directions. The stator of the linear motor 32 is extended along the X direction on both outer sides of the wafer stage 5 in the Y direction, and both ends are connected to each other by a pair of connecting members 34 to form a rectangular frame 35. Have been.
The mover of the linear motor 32 is provided on both sides of the wafer stage 5 in the Y direction so as to face the stator.

Movers 36, 36 each composed of an armature unit are provided on the lower end surfaces of the pair of connecting members 34 or the linear motor 32 constituting the frame 35, respectively. Are extended in the Y direction and protrude from the base plate 10. The moving coil 36 and the stator 37 constitute a moving coil type linear motor 33. The moving element 36 is driven in the Y direction by electromagnetic interaction with the stator 37. I have. That is, this linear motor 33
Thereby, the wafer stage 5 is driven integrally with the frame 35 in the Y direction.

Further, as shown in FIG. 4, the wafer stage 5 includes a W
The drive is controlled by the stage control section 62 via the S drive section 63.

On the upper surface of the wafer stage 5, a wafer W is fixed via a wafer holder 41 by vacuum suction or the like. Further, the position of wafer stage 5 in the X direction measures a change in position of movable mirror 43 fixed to a part of wafer stage 5 with reference to reference mirror 42 fixed to the lower end of the barrel of projection optical system PL. The measurement is performed in real time by the laser interferometer 44 at a predetermined resolution, for example, about 0.5 to 1 nm. The reference mirror 42, the moving mirror 43,
The position of the wafer stage 5 in the Y direction is measured by a reference mirror, a moving mirror, and a laser interferometer (not shown) that are arranged substantially orthogonal to the laser interferometer 44. At least one of these laser interferometers is a multi-axis interferometer having two or more measurement axes. Based on the measurement values of these laser interferometers, the XY
In addition to the position, the θ rotation amount or the leveling amount in addition to the θ rotation amount can be obtained.

The exposure apparatus 1 has three vibration sensors (for example, an accelerometer; not shown) for measuring vibrations of the reticle surface plate 3, the wafer surface plate 6, and the lens barrel surface plate 25 in the Z direction.
And three vibration sensors (for example, accelerometers; not shown) for measuring vibrations in the XY plane direction. Two of the latter vibration sensors measure the vibration of each surface plate in the Y direction, and the remaining vibration sensors measure the vibration in the X direction (hereinafter, for convenience, these vibration sensors are referred to as a vibration sensor group). Name). The six degrees of freedom (X, Y, Z, θX, θY, θ) of the reticle surface plate 3, the wafer surface plate 6, and the barrel surface plate 25 based on the measurement values of these vibration sensor groups.
The vibration of Z) can be obtained respectively.

Further, three laser interferometers 45 are fixed to three different locations on the flange 23 of the projection optical system PL (however, one of these laser interferometers is typically shown in FIG. 1). Has been). Openings 25a are formed in portions of the barrel base 25 facing each of the laser interferometers 45, and a measurement beam in the Z direction is sent from each laser interferometer 45 through these openings 25a to the wafer base. Irradiation toward 6. A reflection surface is formed on the upper surface of the wafer surface plate 6 at a position facing each measurement beam. Therefore, the three laser interferometers 45 measure three different Z positions of the wafer surface plate 6 with reference to the flange 23 (however, in FIG. 1,
The state where the central shot area of the wafer W on the wafer stage 5 is directly below the optical axis of the projection optical system PL is shown, so that the length measurement beam is blocked by the wafer stage 5). Note that an interferometer that forms a reflection surface on the upper surface of the wafer stage 5 and measures three different Z-direction positions on the reflection surface with reference to the projection optical system PL or the flange 23 may be provided.

Then, as shown in FIG. 4, the measurement results of the vibration sensor and the laser interferometer are output to the main controller 47. The main controller 47 is provided with a storage device 83. The storage device 83 stores the position correction amounts of the reticle stage 2 and the wafer stage 5 when the counter force is applied to the reticle stage 2 and the wafer stage 5, respectively.

Next, the exposure apparatus 1 configured as described above
The operation at the time of scanning exposure will be described. First, before starting the scanning exposure, an index provided on each of the stages 2 and 5 is measured by an index sensor or the like installed so as not to be affected by the reaction frame 8 or the twist of the base plate 10. At this time, in reticle stage 2,
Air mounts 12A to 12D, voice coil motor 13
A to 13D are operated with a constant thrust. The difference between the measurement results of the laser interferometer that measures the position of the reticle stage 2 and the index sensor is defined as the amount of displacement (movement correction amount) in the X and Y directions of the reticle stage 2 corresponding to the thrust at this time. Ask for each. Further, air mounts 12A to 12D, voice coil motors 13A to 1
By changing the 3D thrust and repeating the same procedure,
As shown in FIG. 7, the thrust of the air mounts 12A to 12D and the voice coil motors 13A to 13D and the reticle stage 2
Is obtained in advance in the X direction and the Y direction, and is stored in the storage device 83 in advance. At this time, the amount of positional deviation of the reticle stage 2 in the Z direction is also obtained, and
3 is stored.

In the same procedure as for reticle stage 2, air mount 30 A is also mounted on wafer stage 5.
30D, the correlation between the thrust of the voice coil motors 31A-31D and the amount of displacement of the wafer stage 5 in the X and Y directions is obtained in advance and stored in the storage device 83 in advance. At the same time, the positional shift amount of the wafer stage 5 in the Z direction is also obtained and stored in the storage device 83.

In the exposure apparatus 1, a predetermined rectangular illumination area on the reticle R is illuminated with uniform illumination by exposure illumination light from the illumination optical system IU during exposure.
In synchronization with the reticle R being scanned in the Y direction with respect to this illumination area, the wafer W is scanned with respect to an exposure area conjugate with respect to this illumination area and the projection optical system PL. As a result, the illumination light transmitted through the pattern area of the reticle R is reduced to 1/4 by the projection optical system PL, and is irradiated onto the wafer W coated with the resist. Then, the pattern of the reticle R is sequentially transferred to the exposure area on the wafer W,
The entire surface of the pattern area on the reticle R is transferred to the shot area on the wafer W by one scan.

In the exposure apparatus 1, the main controller 47 scans the reticle stage 2 in the Y direction at a speed βV at the time of the scanning exposure (1 / β; reduction magnification of the projection optical system PL).
Then, a command signal for synchronously scanning the wafer stage 5 in the −Y direction at the speed V is output to the stage control unit 62. The stage control unit 62 controls the reticle stage 2 and the wafer stage 5 to scan at predetermined positions at a predetermined speed while monitoring the measurement values of the laser interferometer.

In this case, the reticle stage 2 and the wafer stage 5 are composed of the linear motor 15, the voice coil motors 17X and 17Y and the linear motors 32, 3
3, the reticle stage 2 and the wafer stage 5 generate a reaction force due to acceleration and deceleration when moving. Here, according to a command from the main control unit 47,
Stage controller 62 transmits a thrust signal of reticle stage 2 and wafer stage 5.

The counter force calculation section 49 calculates a thrust signal for canceling the thrust signal transmitted through the main control section 47 for each stage, and outputs the calculated thrust signal to the vibration control section 75 and the stage control section 62. Vibration control unit 75
Is based on the calculated thrust signal,
29, that is, the voice coil motor and the air mount are driven in pairs for each of the stages 2 and 5. At this time, the relationship between the voltage to be applied to each of the voice coil motors 13A to 13D and 31A to 31D and the lapse of time accompanying the movement of each of the stages 2, 5 is stored in the storage device 83 for each of the movement patterns of each of the stages 2, 5. And at least a part of the thrust required for each of the voice coil motors 13A to 13D and 31A to 31D based on this voltage.
These air mounts 12A to 12D and 30A to 30D are replaced with thrusts of 12D and 30A to 30D, respectively.
The supply amount of air supplied to D is adjusted.

On the other hand, voice coil motors 13A to 13D
When the air mounts 12 </ b> A to 12 </ b> D operate in pairs while being controlled by three pseudo points, a large deformation occurs in the reaction frame 8. Similarly, voice coil motors 31A to 31D and air mount 30A
30D operate in pairs with each other controlled by three pseudo points, so that the base plate 10 is greatly deformed. However, voice coil motors 13A to 13D,
31A-31D and air mounts 12A-12D, 30A
-30D are controlled by three pseudo points so that each paired one has a correspondence, so that the reproducibility is high even if the deformation amount is large.

Therefore, based on the thrust signal transmitted from the counterforce calculator 49, the stage controller 62 controls the reticle stage 2 to be controlled with respect to the scanning exposure via the RS driver 61 and the WS driver 63, respectively.
And the position and the amount of movement of the wafer stage 5 on the XY plane are controlled while correcting (changing) the position of the measurement result of the laser interferometer with the position deviation corresponding to the thrust of the voice coil motor and the air mount stored in advance. I do. Thus, even if the reaction frame 8 and the base plate 10 are twisted by the operation of the voice coil motor and the air mount, and the position of the laser interferometer for monitoring the position of each of the stages 2 and 5 fluctuates, the reticle stage 2 and the wafer stage 5 Can be driven at a predetermined position and a predetermined movement amount. Note that the position shift of each of the stages 2 and 5 in the Z direction is corrected by performing autofocus adjustment at the time of exposure.

As described above, in the stage apparatus and the exposure apparatus according to the present embodiment, the voice coil motors 13A to 13D corresponding to the air mounts 12A to 12D and 30A to 30D controlled by the pseudo three points, respectively. ,
Similarly, since pseudo three-point control is performed in 31A to 31D and these are driven in pairs, deformation with high reproducibility can be positively generated in the reaction frame 8 and the base plate 10. Therefore, air mount,
The correlation between the thrust of the voice coil motor and the amount of displacement of each of the stages 2 and 5 can be easily obtained and managed.

In the present embodiment, the stage controller 62 corrects the measurement result of the laser interferometer based on the above correlation, so that the reticle stage 2 and the wafer stage 5
And the amount of movement can be controlled with high accuracy. Therefore, even if the reaction frame 8 and the base plate 10 are twisted, their influence on the position control of each of the stages 2 and 5 is canceled, and the positional relationship between the reticle R and the wafer W and the projection with these. The positional relationship with the optical system PL can also be controlled with high precision, and for example, a pattern of a miniaturized semiconductor device can be printed on the wafer W with high precision.

In the present embodiment, the relationship between the thrust of the air mount and the voice coil motor and the amount of displacement of each of the stages 2 and 5 is stored in the storage device 83 in advance, so that each of the stages can be quickly moved even during scanning exposure. The position of the stages 2 and 5 can be corrected, and the above-mentioned correlation is stored for each pattern related to the generation of thrust and for each pattern related to the synchronous movement of each stage 2 and 5, thereby supporting various exposure modes. A highly versatile stage apparatus and exposure apparatus can be provided.

In the above embodiment, the stage device for performing pseudo three-point control is applied to both the reticle stage and the wafer stage. However, the present invention is not limited to this. Alternatively, the configuration may be applied to only one of them.
Further, the air mounts 26A to 26D for supporting the lens barrel base 25 holding the projection optical system PL and the voice coil motors 27A to 27D may be controlled at three pseudo points.

In the above embodiment, the air mount which is a pneumatic damper is used as the vibration isolating pad. However, the present invention is not limited to this. For example, a mechanical damper in which a compression coil spring is put in a damping liquid is used. May be used. Further, in the above embodiment, the stage apparatus of the present invention is applied to the exposure apparatus 1. However, the present invention is not limited to this. In addition to the exposure apparatus 1, a transfer mask drawing apparatus and a mask pattern position The present invention is also applicable to precision measuring devices such as coordinate measuring devices.

Further, in the above embodiment, the storage device 8
3, the correlation between the thrust of the air mount and the voice coil motor and the amount of displacement of each stage is stored. However, the present invention is not limited to this configuration. The amount of deformation of the reaction frame 8 and the base plate 10 to be performed may be stored, and the position and the amount of movement of each stage may be corrected during scanning exposure according to the amount of deformation.

The substrate of the present embodiment is not limited to a semiconductor wafer W for a semiconductor device, but may be a glass substrate for a liquid crystal display device, a ceramic wafer for a thin-film magnetic head, or a mask or a mask used in an exposure apparatus. Reticle master (synthetic quartz, silicon wafer)
Etc. are applied.

The exposure apparatus 1 includes a step-and-scan type scanning exposure apparatus (scanning stepper; US Pat. No. 5,473,410) for scanning and exposing the pattern of the reticle R by synchronously moving the reticle R and the wafer W. To
The present invention can also be applied to a step-and-repeat type projection exposure apparatus (stepper) that exposes the pattern of the reticle R while the reticle R and the wafer W are stationary and sequentially moves the wafer W stepwise.

The type of the exposure apparatus 1 is not limited to an exposure apparatus for manufacturing a semiconductor device for exposing a semiconductor device pattern onto a wafer W, but may be an exposure apparatus for manufacturing a liquid crystal display element, a thin film magnetic head, an image pickup device (CCD). Alternatively, the present invention can be widely applied to an exposure apparatus for manufacturing a reticle and the like.

As a light source of the illumination light for exposure, a bright line (g-line (436 nm), h
Line (404.7 nm), i-line (365 nm)), KrF
Not only an excimer laser (248 nm), an ArF excimer laser (193 nm), and an F ₂ laser (157 nm) but also a charged particle beam such as an X-ray or an electron beam can be used. For example, when an electron beam is used, a thermionic emission type lanthanum hexaborite (LaB ₆ ) or tantalum (Ta) can be used as an electron gun. When an electron beam is used, a configuration using a reticle R may be used, or a configuration may be used in which a pattern is directly formed on a wafer without using the reticle R. Alternatively, a high frequency such as a YAG laser or a semiconductor laser may be used.

The magnification of the projection optical system PL may be not only a reduction system but also an equal magnification system or an enlargement system. Further, As the projection optical system PL, using a material which transmits far ultraviolet rays such as quartz and fluorite as the glass material when using a far ultraviolet ray such as an excimer laser, catadioptric system, or in the case of using the F ₂ laser or X-ray An optical system of a refraction system (a reticle R of a reflection type is also used). When an electron beam is used, an electron optical system including an electron lens and a deflector may be used as the optical system. It is needless to say that the optical path through which the electron beam passes is in a vacuum state. Further, the present invention can also be applied to a proximity exposure apparatus that exposes the pattern of the reticle R by bringing the reticle R and the wafer W into close contact without using the projection optical system PL.

A linear motor (see US Pat. No. 5,623,853 or US Pat. No. 5,528,118) is mounted on the wafer stage 5 or the reticle stage 2.
Is used, any of an air levitation type using an air bearing and a magnetic levitation type using Lorentz force or reactance force may be used. In addition, each stage 2, 5
May be a type that moves along a guide or a guideless type that does not have a guide.

As a driving mechanism of each of the stages 2 and 5, a magnet unit (permanent magnet) having a two-dimensionally arranged magnet and an armature unit having a two-dimensionally arranged coil are opposed to each other, and each stage 2 and 5 is driven by electromagnetic force. 5 may be used. In this case, one of the magnet unit and the armature unit may be connected to the stages 2 and 5, and the other of the magnet unit and the armature unit may be provided on the moving surface side (base) of the stages 2 and 5.

As described above, the exposure apparatus 1 of the present embodiment
Is a system that includes various components including the components listed in the claims of the present application, with predetermined mechanical accuracy, electrical accuracy,
It is manufactured by assembling to maintain optical accuracy. Before and after this assembly, in order to ensure these various precisions, adjustments to achieve optical precision for various optical systems, adjustments to achieve mechanical precision for various mechanical systems, and various electrical systems Are adjusted to achieve electrical accuracy. The process of assembling the exposure apparatus from various subsystems includes mechanical connections, wiring connections of electric circuits, and piping connections of pneumatic circuits among the various subsystems. It goes without saying that there is an assembling process for each subsystem before the assembling process from these various subsystems to the exposure apparatus. When the process of assembling the various subsystems into the exposure apparatus is completed, comprehensive adjustment is performed, and various precisions of the entire exposure apparatus are secured. It is desirable that the exposure apparatus be manufactured in a clean room in which the temperature, cleanliness, and the like are controlled.

As shown in FIG. 6, for a semiconductor device, a step 201 for designing the function and performance of the device, a step 202 for manufacturing a mask (reticle) based on the design step, a step 203 for manufacturing a wafer from a silicon material A wafer processing step 204 of exposing a reticle pattern to a wafer by the exposure apparatus 1 of the above-described embodiment, a device assembling step (dicing step,
(Including a bonding step and a package step) 205, an inspection step 206, and the like.

[0074]

As described above, in the stage device according to the first aspect, the first control system controls the driving of the vibration isolating pad by a plurality of sets, and the second control system controls the driving of the actuator by the vibration isolating pad. And a third control system controls the first control system and the second control system to drive a corresponding set of the vibration isolation pad and the actuator in pairs. Has become. As a result, in this stage device, since a highly reproducible deformation can be positively generated in the supporting portion, the correlation between the vibration isolating pad and the thrust of the actuator and the position of the stage body can be easily obtained. The effect of being able to manage is obtained.

According to a second aspect of the present invention, the stage controller changes the moving amount of the stage main body based on the amount of deformation of the supporting portion caused by driving the actuator and the vibration isolating pad. Thus, in this stage device, the effect of canceling the influence of the deformation of the support portion and controlling the position and the movement amount of the stage main body with high accuracy can be obtained.

According to a third aspect of the present invention, the storage device stores the amount of movement correction of the stage body corresponding to the amount of deformation of the supporting portion. As a result, in this stage device, the position of the stage main body can be quickly corrected, and a movement correction amount corresponding to various types of movement of the stage main body can be set.

The stage device according to the fourth aspect is configured to control the number of sets equal to or less than the number of the actuators and the number of the anti-vibration pads. Thus, in this stage device, even when performing pseudo control in which the number of control systems is reduced in order to reduce the arrangement interval and reduce the twist of the support portion, the thrust of the vibration isolating pad and the actuator and the position of the stage main body are reduced. And the correlation can be easily obtained and managed.

An exposure apparatus according to a fifth aspect is configured such that the stage apparatus according to any one of the first to fourth aspects is used for at least one of a mask stage and a substrate stage. Thereby, in this exposure apparatus,
At least one of a mask stage and a substrate stage,
The effect is obtained that the correlation between the vibration isolating pad and the thrust of the actuator can be easily obtained and managed. In addition, by changing the amount of movement of the mask stage or the substrate stage, it is possible to control the positional relationship between the mask and the substrate with high precision. For example, a pattern of a miniaturized semiconductor device can be accurately placed on the substrate. Can be burned.

The exposure apparatus according to claim 6 is configured such that exposure is performed during synchronous movement of the mask stage and the substrate stage. This allows the exposure apparatus to easily obtain and manage the correlation between at least one of the mask stage and the substrate stage, the vibration isolating pad, and the thrust of the actuator when transferring the pattern of the mask onto the substrate by scanning exposure. The effect that it can be obtained is obtained.

According to a seventh aspect of the present invention, the stage controller changes at least one of the mask stage and the substrate stage based on the amount of deformation of the exposure main body caused by the synchronous movement. I have. This allows the exposure apparatus to cancel the influence of the deformation of the exposure main body and control the positional relationship between the mask and the substrate, and also the positional relationship between them and the projection optical system, with high accuracy. Thus, for example, there is obtained an effect that a pattern of a miniaturized semiconductor device can be accurately printed on a substrate.

The exposure apparatus according to claim 8 is configured such that the storage device stores the amount of deformation of the exposure main body. Thus, in this exposure apparatus, the position of the mask stage and the substrate stage can be quickly corrected even during scanning exposure, and the above correlation is obtained for each pattern related to thrust generation and each pattern related to synchronous movement of each stage. Can be used in various exposure modes, and the effect of increasing versatility can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an exposure apparatus in which a reticle stage, a wafer stage, and a projection optical system are independently arranged with respect to vibration.

FIG. 2 is a view showing an embodiment of the present invention, and is a schematic configuration diagram in which an air mount and a voice coil motor are controlled at three pseudo points.

FIG. 3 is an external perspective view of a reticle stage included in the exposure apparatus of the present invention.

FIG. 4 is a block diagram showing a control system of the exposure apparatus of the present invention.

FIG. 5 is a relationship diagram showing a correlation between a thrust of an air mount and a voice coil motor and an amount of displacement of a stage.

FIG. 6 is a flowchart illustrating an example of a manufacturing process of a semiconductor device.

[Explanation of symbols]

PL Projection optical system R Reticle (mask) W Wafer (substrate) 1 Exposure device 2 Reticle stage (stage body, mask stage) 3 Reticle surface plate (surface plate) 4, 7 Stage device 5 Wafer stage (stage body, substrate stage) 6 Wafer surface plate (surface plate) 8 Reaction frame (exposure main body, support) 10 Base plate (support) 12A to 12D, 30A to 30D Air mount (anti-vibration pad) 13A to 13D, 31A to 31D Voice coil motor ( Actuator) 62 Stage control unit (stage control device) 73 Pneumatic control system (first control system) 74 Voltage control system (second control system) 75 Vibration control unit (third control system) 83 Storage device

Claims (8)

[Claims] 1. A stage body that moves on a surface plate, and a plurality of actuators and vibration isolation pads that are supported by a support portion and apply a thrust to the surface plate against a reaction force accompanying the movement of the stage body. A stage device in which the surface plate is supported by the support unit via the actuator and the vibration isolating pad, wherein the first device controls the driving of the plurality of vibration isolating pads by a plurality of sets.
A control system; a second control system that controls the driving of the plurality of actuators by the set of actuators corresponding to each of the vibration-isolating pads in the set; and controls the first control system and the second control system. And a third control system for driving a corresponding pair of the vibration isolating pad and the actuator in pairs. 2. The stage device according to claim 1, further comprising: a stage control device configured to change a moving amount of the stage main body based on a deformation amount of the support portion caused by driving the actuator and the vibration isolating pad. A stage device characterized by the above-mentioned. 3. The stage device according to claim 2, further comprising a storage device that stores a movement correction amount of the stage main body corresponding to a deformation amount of the support portion. 4. The stage device according to claim 1, wherein the number of sets of the actuator and the number of the vibration-isolating pads are controlled to be equal to or less than the respective numbers. 5. An exposure apparatus for exposing a pattern of a mask held on a mask stage to a substrate held on a substrate stage, wherein at least one of the mask stage and the substrate stage has at least one of them. An exposure apparatus, wherein the stage apparatus according to claim 1 is used. 6. The exposure apparatus according to claim 5, wherein the exposure is performed during synchronous movement of the mask stage and the substrate stage. 7. An exposure apparatus for synchronously moving a mask stage holding a mask having a pattern and a substrate stage holding a substrate to expose the pattern to the substrate via a projection optical system, wherein the mask stage An exposure main body that holds at least one of the substrate stage and the projection optical system; and at least one of the mask stage and the substrate stage based on a deformation amount of the exposure main body caused by the synchronous movement. An exposure apparatus, comprising: a stage control device that changes an amount of movement of the exposure device. 8. The exposure apparatus according to claim 7, further comprising a storage device for storing an amount of deformation of the exposure main body.