JP3271759B2 - Scanning exposure method, scanning exposure apparatus, and device manufacturing method using the method - Google Patents

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 for manufacturing, for example, a semiconductor integrated circuit or a liquid crystal display device in a lithography process, and more particularly to a projection exposure apparatus for performing exposure by a so-called slit scan exposure method. .

[0002]

2. Description of the Related Art When a semiconductor device or a liquid crystal display device is manufactured by a lithography process, a pattern image of a photomask or a reticle (hereinafter, collectively referred to as a "reticle") is exposed through a projection optical system under exposure light. 2. Description of the Related Art A projection exposure apparatus that projects an image on a photosensitive substrate is used. As such an apparatus, a projection exposure apparatus of a slit scan exposure type is known.

FIG. 6 shows a conventional projection exposure apparatus of the slit scan exposure type. In FIG. 6, exposure light IL emitted from a light source system 1 is mirror 2, field stop 3, relay lens 4, mirror 5 and mirror 5. The reticle 7 is illuminated with uniform illuminance through the condenser lens 6. The light source system 1 includes a light source such as a mercury lamp or a laser light source, an optical integrator, and the like. The arrangement surface of the field stop 3 and the pattern forming surface on the lower surface of the reticle 7 are conjugate, and a slit-shaped illumination area is set on the pattern formation surface of the reticle 7 by the field stop 3. In this case, the direction parallel to FIG. 6 in the plane parallel to the reticle 7 is the X direction, and FIG.
It is assumed that the longitudinal direction of the slit-shaped illumination area is set to the Y direction, and the direction of relative scanning between the reticle 7 and the slit-shaped illumination area is the X direction.

[0004] The reticle 7 is moved in the X direction and Y direction.
The reticle XYθ stage 8 is held on a reticle XYθ stage 8 that moves and rotates in the direction, and the reticle XYθ stage 8 is slidably supported on a reticle side base 9. A movable mirror 10 is fixed to one end of the reticle XYθ stage 8 in the X direction, which is a relative scanning direction, and a laser interferometer 11 for the X axis.
Is reflected by the moving mirror 10. The X-axis laser interferometer 11 detects the coordinates of the reticle XYθ stage 8 in the X direction by photoelectrically converting an interference beam between the laser beam from the movable mirror 10 and the laser beam from the reference mirror. The coordinate and the rotation angle in the Y direction perpendicular to the direction of relative scanning of the reticle XYθ stage 8 are measured by a capacitance sensor (not shown). The measurement coordinates of the X-axis laser interferometer 11 and the measurement results obtained by the capacitance sensors are supplied to the main control system 12, and the main control system 12 sets the moving speed, position, and rotation angle of the reticle XYθ stage 8 in an exposure sequence. Set accordingly.

Under the exposure light IL, a pattern image on the reticle 7 is projected and exposed on a wafer 14 via a projection optical system 13. At this time, since the conjugate image of the slit-shaped illumination area on the reticle 7, that is, the exposure field of the projection optical system 13 is smaller than the one shot area on the wafer 14, the reticle 7 is scanned in the −X direction, for example. The wafer 14 is scanned at a constant speed in the X direction in synchronization with the exposure, thereby exposing an area for one shot on the wafer 14. Therefore, the wafer 14 is held on a wafer XY stage 15 that moves the wafer 14 in the X and Y directions, and the wafer XY stage 15 is
It is slidably supported above.

A movable mirror 17 is fixed to an end of the wafer XY stage 15 in the X direction, and a laser beam from a laser interferometer 18 for the X axis is reflected by the movable mirror 17. Although not shown, a moving mirror is fixed to an end of the wafer XY stage 15 in the Y direction, and a laser beam from a Y-axis laser interferometer not shown is reflected by the moving mirror. The X-axis laser interferometer 18 and the Y-axis laser interferometer photoelectrically convert interference light between the laser beam from the moving mirror and the laser beam from the reference mirror on the wafer XY stage 15, respectively.
The X coordinate and the Y coordinate of the Y stage 15 are detected. The X coordinate and the Y coordinate are also supplied to the main control system 12, and the main control system 12 sets the moving speed and the position of the wafer XY stage 15 according to the exposure sequence.

Next, a description will be given of a relative scanning method of the wafer 14 and the reticle 7 when performing exposure by the conventional slit scan exposure method. First, at the time of exposure, the wafer 14
Since it is necessary to scan in the X direction at a constant speed so that the exposure amount becomes constant at each point on the exposure surface, speed control is performed based on the measurement result of the laser interferometer 18. Specifically, the differential value of the coordinate in the X direction, which is the measurement result of the laser interferometer 18, is appropriately filtered and controlled so that the value becomes constant.

On the other hand, if the reduction magnification of the projection optical system 13 from the reticle 7 to the wafer 14 is β (β <1), the scanning of the reticle 7 in the −X direction is performed by the laser interferometer 1.
1 / β which is the reciprocal of the reduction ratio with respect to the measurement result by 8
Is calculated by calculating the difference between the value obtained by multiplying by the laser interferometer 11 and controlling the position so that the difference becomes zero.

[0009]

In the prior art as described above, the speed stability of the wafer 14 and the reticle 7 during relative scanning is required. Therefore, the wafer XY stage 15 and the reticle XYθ stage 8 each have a relatively large weight and are less affected by disturbance using inertia, so that the wafer 14 and the reticle 7 can be stably moved at a constant speed. Relative scanning.

[0010] These relatively large weight wafers XY
The stage 15 and the reticle XYθ stage 8 are stable during constant velocity movement. However, when the relative position between the reticle 7 and the wafer 14 (difference in the measurement result of the laser interferometer) is deviated, the controllability deteriorates due to the weight thereof,
There is an inconvenience that distortion of the image exposed on the wafer 14 is caused.

Further, the reticle 7 and the wafer 14 need to be substantially stationary in the Y direction perpendicular to the relative scanning direction and in the rotation direction. For this purpose, the relative positions of the reticle 7 and the wafer 14 must be adjusted. A mechanism capable of minute position control for adjusting in the Y direction and the rotation direction is required. Conventionally, the wafer XY stage 15 and the reticle XYθ stage 8 also have a mechanism capable of controlling the minute position. However,
Since both stages have a relatively large weight, there are disadvantages that the response is poor and the control is complicated.
That is, in the projection exposure apparatus of the conventional slit scan exposure type, the constant speed drive control in the relative scanning direction and the X direction, Y direction
There has been an inconvenience that it is difficult to simultaneously control the method and the alignment in the rotation direction with high accuracy.

In the case of exposure by the slit scan exposure method, the reticle and the wafer move in the synchronous movement direction during the exposure, respectively. It is necessary to measure the position of the reticle and the wafer in the synchronous movement direction with high accuracy. In view of the above, the present invention raises the position of at least one of the reticle and the wafer in the synchronous movement direction when transferring the pattern of the reticle as the first object onto the wafer as the second object by the slit scan exposure method. It is an object of the present invention to provide a scanning exposure method and a scanning exposure apparatus that can measure with high accuracy.

It is a further object of the present invention to simultaneously drive the reticle and the wafer at a constant speed in the relative scanning direction and to align the reticle and the wafer with high accuracy. Another object of the present invention is to provide a device manufacturing method capable of manufacturing a device with high accuracy using the scanning exposure method.

[0014]

A scanning exposure apparatus according to the present invention moves a second object (14) in synchronism with movement of a first object (7) with respect to an exposure beam. In a scanning type exposure apparatus for scanning and exposing an object, a holding member capable of holding and moving the first object, a first interferometer system for measuring position information of the holding member in a direction of the synchronous movement, and the exposure Almost through the center of the beam irradiation area
Measurement axis, and in the direction intersecting the direction of the synchronous movement
Interferometer system for measuring the position information of the holding member
The air conditioner includes a stem and an air-conditioning mechanism that air-conditions an optical path of a measurement beam of the first interferometer system. In this case, it is desirable to further include a first drive system for moving the first object, and a second drive system for moving the second object independently of the first drive system.

[0015] The first drive system includes a first drive system.
First drive means for moving the first object so that the object is scanned by the exposure beam; and independently of the first drive means when the first object is being moved by the first drive means. It is desirable to have second driving means for relatively moving the exposure beam and the first object. A first device manufacturing method according to the present invention includes a step of performing exposure using the scanning exposure apparatus of the present invention. Next, scanning exposure method according to the invention, the first object (7) to move the second object (14) and synchronization, exposure bi through the first object
In the scanning exposure method of scanning and exposing the second object with a camera, position information on the direction of the synchronous movement of one of the first object and the second object is stored in the first interferometer system.
System and measure the exposure area of the exposure beam.
A second interferometer system with a measurement axis passing through the center of the
One of the directions intersecting the direction of the synchronous movement of
It measures the position information of the body and air-conditions the optical path of the measurement beam of the first interferometer system. Further, a second device manufacturing method according to the present invention uses the scanning exposure method of the present invention.

[0016]

According to the present invention, the position of at least one of the first object (mask) and the second object (photosensitive substrate) in the synchronous movement direction at the time of scanning exposure is measured by the interferometer system. Furthermore, since the optical path of the measurement beam of the interferometer system is air-conditioned, even if the optical path becomes longer during the scanning exposure, the measurement value hardly fluctuates due to air fluctuation or the like. And the position of at least one of the second object in the synchronous movement direction can be measured with high accuracy.

The means for driving a first object (7), for example, composed of a mask, comprises a first drive means having a relative scanning drive section and a guide section, and a second drive means for causing the first object to translate and rotate. When separated into driving means, these two driving means are independently controlled. Therefore, as the first driving means, for example, a heavy stage capable of performing stable constant-velocity movement during relative scanning and a guide capable of driving a long distance with high accuracy in only one axial direction are used. 2 As the driving means, for example, a slit scan exposure with good uniformity and position controllability can be achieved by using a lightweight stage and guide with good controllability that can move in a small amount in the translation direction and the rotation direction. Done.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a projection exposure apparatus of the slit scan exposure type of this embodiment. In FIG. 1, an X-axis extends in a direction perpendicular to the plane of FIG.
The Y axis is taken in a direction parallel to the plane of FIG. 1 and the Z axis is taken perpendicular to the XY plane. Further, the relative scanning direction at the time of slit scan exposure is defined as an X direction.

First, in the stage system for the reticle 7, an air guide long in the X direction is formed on the reticle side base 19, and the reticle side scanning stage is slidable on the reticle side base 19 in the XY plane in the X direction. 20 is placed. Then, the reticle-side fine movement stage 21 is placed on the reticle-side scanning stage 20 in a state where translation and rotation in the XY plane can be performed, and the reticle 7 is held on the reticle-side fine movement stage 21. At the time of exposure, the pattern area of the reticle 7 is illuminated with a slit-shaped illumination area by exposure light IL from the illumination optical system 22, and the reticle 7 is scanned in the X direction with respect to the slit-shaped illumination area. Illumination optical system 2
Reference numeral 2 includes a light source, a shutter, an optical integrator, a field stop for setting a slit-shaped illumination area, a condenser lens, and the like.

On the reticle-side fine movement stage 21, three movable mirrors (only the movable mirror 33 is shown in FIG. 1) are fixed.
Using the laser beams reflected from these three movable mirrors, the position of the reticle-side fine movement stage 21 is detected by three laser interferometers (only the laser interferometer 35 is shown in FIG. 1). The measurement results from these laser interferometers are supplied to the main control system 23. From the three position measurement results, the position and rotation angle of the reticle-side fine movement stage 21 in the XY plane are obtained. The main control system 23 is connected to the reticle-side scanning stage 2 via a relative scanning driving device 24.
By controlling the operation of the reticle 7, the relative scanning speed and the position of the reticle 7 are controlled by controlling the operation of the reticle-side fine movement stage 21 via the fine movement control drive device 25.

At the time of exposure, a pattern image of a slit-like illumination area in the pattern area of the reticle 7 is projected.
Is projected and exposed on the wafer 14 via the. In the stage system for the wafer 14, an air guide long in the X direction is formed on the wafer side base 26, and the X
The wafer-side X stage 27 is slidable in the X direction within the Y plane.
Is placed. Then, XY is placed on the wafer-side X stage 27.
The wafer-side Y stage 28 is placed so as to be movable in the Y direction within the plane, and the wafer 14 is held on the wafer-side Y stage 28. Although not shown, a Z stage, a leveling stage, and the like are provided between the wafer side Y stage 28 and the wafer 14. Wafer side X
A stepping motor 29 is fixed to one end on the stage 27, and the ball screw 3 is
Then, the wafer-side Y stage 28 is driven in the Y direction via 0.

On the wafer-side Y stage 28, three movable mirrors (only the movable mirror 45 is shown in FIG. 1) are fixed, and three movable mirrors are used by using laser beams reflected from these three movable mirrors. Laser interferometer (laser interferometer 4 in FIG. 1)
7B only), the wafer side Y stage 2
8 is detected. The measurement results of these laser interferometers are also supplied to the main control system 23. From the three position measurement results, the position and rotation angle of the wafer-side Y stage 28 in the XY plane are obtained. The main control system 23 controls the relative scanning speed and position of the wafer 14 by controlling the operations of the wafer-side X stage 27 and the wafer-side Y stage 28 via the driving device 31.

FIG. 2 is a plan view of the reticle stage system shown in FIG. 1. In FIG. 2, two rows of air guides 19a and 19b are formed on the reticle side base 19 in the X direction. X on each side
The electromagnets 32A and 32B are embedded in a line in the direction. The reticle-side scanning stage 20 is mounted on the air guides 19a and 19b.
The reticle-side fine movement stage 21 is mounted thereon. A permanent magnet is embedded in the back surface of the reticle-side scanning stage 20,
The reticle-side scanning stage 20 is driven by a linear motor in the X direction. The reticle-side scanning stage 20 has a cooling function (for example, a method of circulating a temperature-controlled gas or fluid) so that the heat of the linear motor is not transmitted to the reticle-side fine movement stage 21 side. A movable mirror 33 having a reflecting surface perpendicular to the Y axis and having a long surface in the X direction is attached to an end of the reticle-side fine movement stage 21 in the Y direction. Moving mirrors 34A and 34 having reflecting surfaces perpendicular to the axis
Attach 4B.

A Y-axis laser interferometer 35 is arranged so as to be fixed to the reticle side base 19 so as to face the movable mirror 33, and the X-axis laser interferometer 35 is opposed to the movable mirror 34A. 36A in total on reticle side base 1
9, and a laser interferometer 36B for rotation measurement is arranged to be fixed to the reticle-side base 19 so as to face the movable mirror 34B. Y coordinate data RSy of reticle side fine movement stage 21 measured by Y axis laser interferometer 35, X coordinate data RSx of reticle side fine movement stage 21 measured by X axis laser interferometer 36A, and rotation measurement The rotation angle data RSθ of the reticle-side fine movement stage 21 measured by the laser interferometer 36B is supplied to the main control system 23 in FIG. Since the beam of the laser interferometer 36A for the X axis has a long optical path, an independent air conditioning mechanism (not shown) is mounted. Specifically, a fixed cover (cylinder) covering the beam optical path is provided with a beam splitter and a movable mirror for emitting a beam directed to each of the movable mirror 34A and the fixed mirror (for example, fixed to the barrel of the projection optical system 13). And / or substantially the whole or a part of the optical path between the beam splitter and the fixed mirror. A gas whose temperature is controlled may flow into the inside of the fixed cover.

The reticle-side scanning stage 20 shown in FIG.
Actuators 38 and 40 for finely moving the reticle-side fine movement stage 21 in the X direction and actuators 42 for finely moving the reticle-side fine movement stage 21 in the Y direction are provided above.
Is fixed. The contact positions between the actuators 38 and 40 and the reticle-side fine movement stage 21 are substantially symmetrical to the movable mirrors 34A and 34B. The reticle-side fine movement stage 21 has three pairs of springs 37A, 37B, 39A, 39.
B and are urged in the direction of actuators 38, 40 and 42 via 41A and 41B, respectively. By adjusting the displacement amounts of the three actuators 38, 40 and 42, the reticle-side fine movement stage 21 and the reticle 7
Can be moved and rotated in the XY plane.

On the reticle 7, a slit-shaped illumination area 43 long in the Y direction is formed by the exposure light IL, and passes through the center 43a of the illumination area 43 in a straight line parallel to the Y axis. The optical axis of the laser interferometer 35 is set. When rotating the reticle 7, it is necessary to rotate the reticle 7 about the center 43 a of the illumination area 43. However, when the reticle 7 is scanned in the X direction, the position of the center 43 a on the reticle 7 also changes. Therefore, by adjusting the displacement amounts of the three actuators 38, 40 and 42, the rotation center of the reticle 7 is shifted to follow the position of the center 43a.

FIG. 3 is a plan view showing the wafer stage system. In FIG. 3, two rows of air guides 26a and 26b are formed on the wafer side base 26 in the X direction, and are provided on both sides of the air guides 26a and 26b. Electromagnets 44A and 44B are embedded in a line in the X direction. Further, the wafer-side X stage 27 is placed on the air guides 26a and 26b.
And the wafer-side Y stage 28 is placed on the wafer-side X stage 27. A permanent magnet is embedded in the back surface of the wafer-side X stage 27,
Directly driven by a linear motor system in the direction. The wafer-side X stage 27 has a cooling function so that the heat of the linear motor is not conducted to the wafer-side Y stage 28 side. In addition, the wafer side X stage 27
A row of air guides 27a and 27b are formed, and a wafer side Y stage 28 is driven in the Y direction by a stepping motor 29 along these air guides 27a and 27b.

A movable mirror 45 having a reflecting surface perpendicular to the Y-axis and long in the X-direction is attached to an end of the wafer-side Y-stage 28 in the Y-direction. Y
A movable mirror 46 having a reflective surface that is long in the direction is attached. A laser interferometer 47A for Y-axis and a laser interferometer 47B for rotation measurement are arranged so as to be fixed to the wafer-side base 26 at a predetermined interval in the X direction so as to face the movable mirror 45. , X to face the moving mirror 46
The axis laser interferometer 48 is arranged to be fixed to the wafer side base 26. Laser interferometer for Y axis 4
7A, the Y coordinate data WSy of the wafer side Y stage 28 measured by 7A, the X coordinate data WSx of the wafer side Y stage 28 measured by the X axis laser interferometer 48,
FIG. 1 shows rotation angle data WSθ of wafer-side Y stage 28 measured by laser interferometer 47B for rotation measurement.
Of the main control system 23.

In this case, the optical axis of the projection optical system 13 is located at the intersection of the optical axis of the laser interferometer 47A and the optical axis of the laser interferometer 48. Further, an off-axis type alignment system 49 is arranged on the side of the projection optical system 13 in the Y direction, but the detection center of the alignment system 49 is located on the optical axis of the laser interferometer 47B, and the alignment is performed. The optical axis of the laser interferometer 48 is on a straight line passing through the detection center of the system 49 and parallel to the X axis. The area of the conjugate image on the wafer 14 by the projection optical system 13 in the slit-shaped illumination area 43 in FIG. 2 is a slit-shaped exposure area 43P that is long in the Y direction. However, since the end in the Y direction of the illumination area 43 in FIG. 2 is slightly cut off by the light shielding portion of the reticle 7, the length of the exposure area 43P in the Y direction is shorter than the length of the conjugate image of the illumination area 43 itself. ing.

Next, a control method at the time of slit scan exposure in the embodiment of FIG. 1 will be described. Generally, the pattern of the reticle 7 is reduced and projected on the wafer 14. The reason is,
This is because reduction projection is advantageous in terms of the pattern size of the reticle 7 and dust management. However, assuming that the projection magnification from the reticle 7 to the wafer 14 is β, at the time of slit scan exposure, the stage on the reticle side needs to be driven at a high speed with respect to the stage on the wafer side by the inverse of the projection magnification β. There is. Therefore, the processing capability for relative scanning and stage control during exposure often depends on the driving capability of the stage on the reticle side.

The main control system 23 shown in FIG.
When the wafer is moved in the X direction and the Y direction, the drive device 31 is provided with an X direction drive command ODWx and a Y direction drive command OD for the wafer.
Emits Wy. The X-direction drive command ODWx and the Y-direction drive command ODWy control the movements of the linear motor of the wafer-side X stage 27 and the stepping motor 29 for the wafer-side Y stage 28, respectively. Furthermore,
When moving the reticle 7 in the X direction, which is a relative scanning direction, the main control system 23 issues a first driving command ODR1 for the reticle to the scanning driving device 24, and moves the reticle 7 in the XY plane. When the rotation is performed, the second drive command ODR2 for the reticle is issued to the fine movement drive device 25. The first drive command ODR1 controls the operation of the linear motor of the reticle-side scanning stage 20, and the second drive command ODR2 operates the three actuators 38, 40, 42 (see FIG. 2) of the reticle-side fine movement stage 21. Control.

Here, an example of the control method will be described with reference to the flowchart of FIG . 4 and FIG. FIG. 5A shows a relative positional relationship between the reticle 7 and the slit-shaped illumination region 43, and FIG. 5B shows a relative positional relationship between the wafer 14 and the slit-shaped exposure region 43P. In this example, the reduced images of the pattern of the reticle 7 are
It is assumed that two adjacent shot areas 50A and 50B on 4 are sequentially exposed. For convenience of explanation, in the initial state, the center of the illumination area 43 in FIG. 5A is located at the position A of the center of the reticle 17, and the center of the exposure area 43P in FIG. It is assumed that it is located at the center position AP of 50A. Furthermore, in the initial state, the reticle 7
Is scanned at a speed V / β in the X direction, and the wafer 14 is scanned at a speed V in the −X direction.
It is assumed that the error of the relative position and the rotation angle with respect to is zero. The process shifts from this initial state to step 101 in FIG.

In step 101 of FIG. 4, the main control system 23 of FIG.
The reticle-side scanning stage 20 is driven at a constant speed in the X direction at a speed V / β. In order to drive the wafer-side X stage 27 at a constant speed, the main control system 23 samples a differential value of the X coordinate data WSx supplied from the laser interferometer 48, and the differential value is a constant value corresponding to the speed V. An X-direction drive command ODWx is issued so that
Similarly, to drive the reticle-side scanning stage 20 at a constant speed, the main control system 23 samples the differential value of the X coordinate data RSx supplied from the laser interferometer 36A,
The first drive command ODR1 is issued so that this differential value becomes a constant value corresponding to the speed V / β.

However, only the constant speed control may cause relative displacement and rotation between the reticle 7 and the wafer 14. Therefore, the main control system 23 controls the position of the wafer-side Y stage 28 and the position of the reticle-side fine movement stage 21. That is, the main control system 23 calculates the difference WSx−RSx / β between the X coordinate data WSx on the wafer 14 side and the X coordinate data RSx / β on the reticle 7, the Y coordinate data WSy on the wafer 14 side, and the Y value on the reticle 7 side. Difference WSy−RSy / β from coordinate data RSy / β, wafer 1
The difference WSθ−RSθ between the rotation angle data WSθ on the fourth side and the rotation angle data RSθ on the reticle 7 side is sampled.

Then, the main control system 23 issues a Y-direction drive command ODWy to the drive device 31 and issues a second drive command ODR2 to the drive device 25 so that the difference between the three becomes a predetermined value. Perform position control. As a result, FIG.
5A, the center of the illumination area 43 reaches the position B outside the pattern area of the reticle 7 from the position A, and in FIG.
4 and reaches the position BP outside the first shot area 50A, and the first slit scan exposure is completed.

Next, in step 102, the main control system 23 decelerates the wafer-side X stage 27 once,
The wafer side Y stage 28 is driven to accelerate in the
Is once accelerated in the Y direction and then decelerated. Concurrently, the main control system 23 decelerates the reticle-side scanning stage 20 and resets the position of the reticle-side fine movement stage 21 to the reference position. As a result, in FIG. 5A, the center of the illumination area 43 reaches the position C further outside from the position B and stops. In FIG. 5B, the center of the exposure area 43P moves from the position BP to the fourth position of the wafer 14. 2 shot area 50B
To the position CP outside of. At this position CP, the wafer-side X stage 27 has already started scanning at a constant speed in the X direction.

Next, in step 103, the main control system 23 drives the wafer-side X stage 27 at a constant speed V in the X direction and stabilizes the position of the wafer-side Y stage 28 by position control. As a result, the vibration caused by acceleration and deceleration of the wafer-side Y stage 28 is attenuated. At the same time, the reticle-side scanning stage 20 is accelerated in the −X direction. As a result, in FIG. 5A, the center of the illumination area 43 reaches the position D near the reticle 7 from the position C, and in FIG. 5B, the center of the exposure area 43P moves from the position CP to the second position of the wafer 14. The position DP is reached near the shot area 50B. At the position D, the reticle-side scanning stage 20 starts moving at a constant speed in the X direction at a speed V / β. Therefore, the relative scanning speed between the reticle 7 and the wafer 14 has reached the design value, but the relative position and the relative rotation angle between the reticle 7 and the wafer 14 may be shifted.

Then, proceeding to step 104, the main control system 23 drives the wafer side X stage 27 at a constant speed in the X direction at a speed V, and drives the reticle side scanning stage 20 at a speed V / V.
Drive at a constant speed in the -X direction at β. Further, the main control system 23
Performs position control of the wafer-side Y stage 28 and position control of the reticle-side fine movement stage 21. That is, the main control system 2
3 is the X coordinate data WSx on the wafer 14 side and the reticle 7
WSx−RSx / with the X coordinate data RSx / β on the side
β, the difference WSy−RSy / between the Y coordinate data WSy on the wafer 14 side and the Y coordinate data RSy / β on the reticle 7 side.
β, the difference WSθ−RSθ between the rotation angle data WSθ on the wafer 14 side and the rotation angle data RSθ on the reticle 7 side is sampled. Then, the main control system 23 issues a Y-direction drive command ODWy to the drive device 31, issues a second drive command ODR2 to the drive device 25, and performs position control so that the difference between the three becomes a predetermined value. Do.

Thus, the displacement between the reticle 7 and the wafer 14 is corrected. At this time, as shown in FIG. 5A, the center of the illumination area 43 is located at a position E outside the pattern area of the reticle 7, and as shown in FIG. At the position EP outside the second shot area 50B. Then, step 10
5, at the time when the reticle 7 and the wafer 14 have been driven at the same speed and the displacement has been corrected, the center of the illumination area 43 is located at the position F immediately before the pattern area of the reticle 7 as shown in FIG. As shown in FIG. 5B, the center of the exposure region 43P is
It is at the position FP just before 0B.

Then, by performing the same control as in step 101, as shown in FIG.
Scans the reticle 7 relatively to the center position G, and FIG.
As shown in (b), the exposure area 43P relatively scans the second shot area 50B of the wafer 14 to the center position GP. Thereafter, by repeating the operation from step 101 onward, the second previous shot area 50 of the wafer 14 is
Exposure of a reduced image of the pattern of the reticle 7 to B and the next shot area is performed.

As described above, according to this embodiment, the stage on the reticle 7 side is the reticle side scanning stage 20 for relative scanning.
And a reticle-side fine movement stage 21 for positioning, and the reticle-side scanning stage 20 and the reticle-side fine movement stage 21 can be driven independently. For this reason, even when the reticle 7 and the wafer 14 are each driven at a constant speed, the displacement between the reticle 7 and the wafer 14 can be easily and quickly corrected. Therefore, an image of the pattern of the reticle 7 can be exposed to each shot area of the wafer 14 without distortion.

Further, in this embodiment, a reticle-side fine movement stage 21 is mounted on the reticle-side scanning stage 20. Then, the weights of the reticle-side scanning stage 20 and the reticle-side fine movement stage 21 are respectively set to M1 and M2.
Then, the linear motor for relative scanning is (M1 + M
2), the actuators 38, 40 and 42 shown in FIG.
Of the reticle-side fine movement stage 21 is performed. Therefore, the responsiveness of the position correction is good. Further, when acceleration a is applied to the reticle-side fine movement stage 21 on the reticle-side scanning stage 20 and the acceleration of the reticle-side scanning stage 20 due to a reaction acting on the reticle-side scanning stage 20 is b, the following equation is established. . M2 · a = (M1 + M2) b

Accordingly, the acceleration b becomes smaller than the acceleration a, and even if the position of the reticle-side fine movement stage 21 is controlled, the constant-speed scanning of the reticle-side scanning stage 20 is hardly affected. Therefore, stable speed control is performed. In the above-described embodiment, since the refractive optical system is used as the projection optical system 13, the illumination area 43 on the reticle 7 has a rectangular slit shape. On the other hand, when a catadioptric system is used as the projection optical system 13,
The illumination area 43 on the reticle 7 may be formed in an arc shape.

It should be noted that the present invention is not limited to the above-described embodiment, but can adopt various configurations without departing from the gist of the present invention.

[0045]

According to the present invention, since the optical path of the measurement beam of the interferometer system is air-conditioned, even if the optical path becomes long during the scanning exposure, the fluctuation of the measured value due to air fluctuations or the like is almost impossible. Does not occur. Therefore, the position of at least one of the first object (mask) and the second object (photosensitive substrate) in the synchronous movement direction can be measured with high accuracy.

The driving means for the first object (mask) is
When the first driving unit for relatively scanning the first object and the second driving unit for adjusting the position of the first object are separated from each other, both the first object and the second object maintain uniform velocity. And the optimal control for relative positioning can be separated, and the driving of the first object and the second object in the relative scanning direction and the positioning of the first object and the second object can be simultaneously performed with high accuracy. There are advantages that can be done. In addition, since the second driving unit does not include a mechanism for relative scanning and can be reduced in weight, positioning of the first object and the second object can be performed with high responsiveness.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an entire projection exposure apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view showing a reticle-side stage system shown in FIG. 1;

FIG. 3 is a plan view showing a system on the wafer side stage of FIG. 1;

FIG. 4 is a flowchart illustrating an example of a control method during a slit scan exposure operation according to the embodiment.

5A is a plan view showing a relative positional relationship between a reticle and an illumination area, and FIG. 5B is a plan view showing a relative positional relationship between a wafer and an exposure area corresponding to FIG. 5A.

FIG. 6 is a block diagram showing a conventional slit scan exposure type projection exposure apparatus.

[Explanation of symbols]

7 Reticle 14 Wafer 19 Reticle-side base 20 Reticle-side scanning stage 21 Reticle-side fine movement stage 23 Main control system 26 Wafer-side base 27 Wafer-side X-stage 28 Wafer-side Y-stage 35, 36A, 36B, 47A, 47B, 48 Laser interferometer 43 Slit illumination area 43P Slit exposure area

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ identification code FI H01L 21/30 518 (58) Investigated field (Int.Cl. ⁷ , DB name) H01L 21/027 G03F 7/20 521 G03F 9 / 00 G12B 5/00 H01L 21/68

Claims (19)

(57) [Claims] 1. A scanning type exposure apparatus for moving a second object in synchronization with a movement of a first object with respect to an exposure beam, and scanning and exposing the second object. A movable holding member, a first interferometer system for measuring position information of the holding member in the direction of the synchronous movement, and a measurement axis passing substantially at the center of the exposure area of the exposure beam.
And the security in a direction intersecting with the direction of the synchronous movement.
A scanning exposure apparatus comprising: a second interferometer system for measuring position information of a holding member; and an air conditioning mechanism for air-conditioning an optical path of a measurement beam of the first interferometer system. 2. The scanning exposure apparatus according to claim 1, wherein the air-conditioning mechanism allows a temperature-controlled gas to flow. 3. The air conditioning mechanism according to claim 1, further comprising a cover for covering an optical path of the measurement beam.
4. The scanning exposure apparatus according to claim 1. 4. The air conditioner according to claim 1, wherein the first interferometer system includes a beam splitter that emits the measurement beam to each of a reference surface serving as a measurement reference and a reflection surface formed on the holding member. 4. Air-conditioning at least a part of at least one of an optical path between the beam splitter and the reflection surface and an optical path between the beam splitter and the reference surface. A scanning exposure apparatus according to claim 1. 5. The system according to claim 1, wherein the first interferometer system has a plurality of measurement axes.
And a plurality of measurement units for measuring the second object.
A third interferometer system having a plurality of measurement axes
Scanning according to any one of claims 1 to 4, characterized in that:
Type exposure equipment. 6. An image of a pattern of the first object is formed on the second object.
The apparatus according to claim 1, further comprising: a projection system for projecting onto the object; and a third interferometer system having a measurement axis passing through an optical axis of the projection system and measuring the second object. The scanning exposure apparatus according to any one of claims 1 to 4 . 7. An alignment system for detecting alignment information of the second object, and a fourth interferometer system having a measurement axis passing through a detection center of the alignment system and measuring the second object. The scanning exposure apparatus according to claim 1, wherein: 8. The image of the pattern of the first object is formed on the second object.
It passes through the optical axis of the projection system for projecting onto an object, and having a measurement axis that passes through the detection center of the alignment system for detecting alignment information of the second object, the fifth performing measurement of the second object The scanning exposure apparatus according to any one of claims 1 to 7, further comprising an interferometer system. 9. The system further comprises: a first drive system for moving the first object; and a second drive system for moving the second object independently of the first drive system. The scanning exposure apparatus according to any one of claims 1 to 8, wherein: 10. The first driving system comprises: first driving means for moving the first object so that the first object is scanned by the exposure beam; and the first object is moved by the first driving means. The scanning exposure apparatus according to claim 9, further comprising a second driving unit that moves the exposure beam and the first object relatively to each other independently of the first driving unit during the operation. apparatus. 11. The second driving unit moves the first object based on a relative positional relationship between the first object and the second object obtained from a measurement result of the interferometer system. The scanning exposure apparatus according to claim 10, wherein: 12. The second drive system further comprises : third drive means for moving the second object so that the second object is scanned by the exposure beam; and the second object is moved by the third drive means. The scanning type device according to claim 9, further comprising: a fourth driving unit that moves the second object independently of the third driving unit when performing the scanning. Exposure equipment. 13. A device manufacturing method comprising the step of performing exposure using a scanning type exposure apparatus according to any one of claims 1 to 12. 14. Synchronously moving a first object and a second object ,
Scanning the second object with an exposure beam through the first object
In a scanning exposure method for exposing, a position information on a direction of the synchronous movement of one of the first object and the second object is stored in a first interferometer system
In the irradiation area of the exposure beam.
A second interferometer system having a measurement axis passing through the heart;
Of the one object with respect to the direction intersecting the direction of
A scanning exposure method , comprising measuring position information and air-conditioning an optical path of a measurement beam of the first interferometer system. 15. The scanning exposure method according to claim 14 , wherein the air conditioning is performed by flowing a temperature-controlled gas. 16. The air conditioning, the scanning exposure method according to claim 14 or 15, characterized in that is carried out by covering the optical path of the measuring beam with a cover. 17. The first interferometer system includes a beam splitter that emits the measurement beam to each of a reference surface serving as a reference for measurement and a reflection surface formed on a holding member that holds the one object. The air conditioning mechanism air-conditions at least a part of at least one of an optical path between the beam splitter and the reflection surface and an optical path between the beam splitter and the reference surface. 17. The scanning exposure method according to any one of 14 to 16 . 18. The optical path length of the measurement beam from claim 14, characterized in that the change in length during a scanning exposure 17
The scanning exposure method according to any one of the above. 19. The device manufacturing method using the scanning exposure method according to any one of claims 14 to 18.