JP2000100721A - Scanning exposure method and scanning-type aligner and manufacture of apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve throughput while synchronization precision between a mask and a substrate is maintained as in the conventional apparatus. SOLUTION: In this scanning exposure method, a wafer (substrate) W and a reticle (mask) R are moved synchronously, and a pattern of the reticle R is sequentially transferred on the respective shot regions 31, 32 of the wafer W. At this time, at least one of the response characteristics of a main control system 13 which controls the movement of the wafer W, a wafer stage 17 and a wafer stage control system (board moving control system), and response characteristics of a main control system 13 controlling movement of the reticle R, a reticle stage 11 and reticle stage control system 27 (mask movement control system) is charged in an exposure section 38, in a movement section 34 except for the exposure section 38 and in an acceleration section 36 (unexposed section).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for synchronizing a mask and a substrate in a photolithography process for manufacturing a semiconductor device such as a semiconductor device, a liquid crystal display device, an imaging device (such as a CCD), or a thin film magnetic head. The present invention relates to a scanning exposure method and a scanning exposure apparatus for sequentially transferring a mask pattern to each shot area of a substrate by relatively moving the mask pattern.

[0002]

2. Description of the Related Art Japanese Patent Application Laid-Open No. 9-134864 discloses a conventional technique relating to an exposure method. In the conventional technique described in this publication, a part of a circuit pattern formed on a reticle as a mask is projected on a wafer as a photosensitive substrate coated with a photoresist or the like via a projection optical system. Then, the reticle and the wafer are synchronously moved in directions opposite to each other, and the projection light is scanned on the wafer, so that a predetermined area (shot area) on the wafer is obtained.
The circuit pattern is transferred to the printer. Such an exposure method is called a scanning exposure method.

[0003] On the surface (XY plane) of the wafer, a number of shot areas are set in the X and Y directions. When a circuit pattern is transferred to each of such shot areas, the circuit area is transferred to all shot areas on one wafer by sequentially irradiating the shot area with projection light of the circuit pattern in a predetermined order. It is carried out. In this case, the wafer is held on a wafer stage controlled by a control unit described later. With this wafer stage, the wafer moves in a two-dimensional plane (X direction and Y direction). The reticle is also held on a reticle stage controlled by the control means. Then, the reticle moves in a two-dimensional plane by the reticle stage. For example, when transferring a circuit pattern to the (n + 1) th shot area adjacent in the Y direction following the nth shot area, the control means moves the wafer stage at a predetermined speed in the X direction, and The circuit pattern is exposed and transferred to the n-th shot area. Subsequently, after moving the wafer stage in the Y direction by a predetermined pitch, the circuit pattern is transferred to the (n + 1) th shot area by accelerating to the predetermined speed and moving the wafer stage in the -X direction. At this time, the control means moves the wafer stage in a direction opposite to the moving direction of the wafer and at a predetermined speed ratio to the moving speed of the wafer while synchronizing the movement of the reticle stage.

Thus, in a scanning exposure apparatus,
Exposure is performed by relatively moving the mask stage and the wafer stage at a predetermined speed ratio while synchronizing the movement of the mask stage and the movement of the wafer stage. In the conventional scanning type exposure apparatus, the control for the movement of the wafer stage and the mask stage is performed in a state where predetermined control characteristics (set values such as a proportional coefficient in a control system) are always kept constant. That is, movement of the stage (including movement of the mask stage and the wafer stage.
Stages are collectively referred to as appropriate. ) Is divided into an exposure section where the shot area is exposed and a non-exposure section where the shot area is not exposed. In the conventional stage control, the control of the exposure section and the control of the non-exposure section are the same. This was performed based on the control characteristics.

[0005] As shown in FIG. 5A, the non-exposure section includes an acceleration section (t0 in FIG. 5A) in which the stage speed is increased to a stage speed Vmax necessary for exposing the stage. To t1), and a settling section in which the vibration of the stage caused by the acceleration is converged to a predetermined state before exposure (between t1 and t2 in FIG. 5A).
And are included.

[0006]

Generally, in a scanning exposure apparatus, MEA is used as a parameter for evaluating the synchronization accuracy between the movement of the wafer stage and the movement of the reticle stage.
There are N values (moving average value of error) and MSD (moving standard deviation of error). In the conventional scanning type exposure apparatus, in order to suppress high frequency components among the vibration components of the stage, the setting value of the stage control system is preferentially considered regardless of the exposure section and the non-exposure section, regardless of the MSD value. Was set. However, if the setting value of the stage control system is determined by giving priority to the MSD value, the vibration of the high frequency component can be suppressed, but the vibration of the low frequency component increases.
For this reason, the time (settling time) for setting the vibration of the low-frequency component within an allowable range that does not adversely affect the exposure accuracy has been long. As a result, the throughput of the exposure apparatus itself has been reduced. An object of the present invention is to solve such a problem.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, a scanning exposure method for transferring a pattern of a mask onto the substrate by synchronously moving the substrate and the mask. A method, comprising: an exposure step of moving the substrate and the mask while transferring the pattern; a non-exposure step of moving the substrate and the mask outside of the exposure step; and a substrate movement controlling movement of the substrate. At least one of a response characteristic of a control system and a response characteristic of a mask movement control system controlling movement of the mask is switched between a first characteristic used in the exposure step and a second characteristic used in the non-exposure step. And step. According to the first aspect of the present invention, the response characteristics of the exposure step and the non-exposure step are changed by changing the response characteristic of the mask movement control system or the response characteristic of the substrate movement control system between the exposure step and the non-exposure step. Can be optimized. As a result, the time of the non-exposure step (settling section) is shortened, and the throughput can be improved. According to a second aspect of the present invention, in the scanning exposure method according to the first aspect, the second characteristic is set so as to improve the response characteristic more than the first characteristic. According to a third aspect of the present invention, in the scanning exposure method according to the second aspect, the substrate movement control system or the mask movement control system is configured to perform the movement of the substrate or the mask by proportional integration control. A first proportional coefficient used for the proportional integral control during the non-exposure step is set to a value higher than a second proportional coefficient used for the proportional integral control during the exposure step. According to a fourth aspect of the present invention, in the scanning exposure method according to the third aspect, the first proportional coefficient and the second
When the proportional coefficient is switched, the differential coefficient at each time from the start to the end of the change of the proportional coefficient is configured to be continuously changed. According to a fifth aspect of the present invention, in the scanning exposure method according to the first aspect, the pattern is transferred to a plurality of regions on the substrate, and the next region is transferred after the transfer of the pattern to the predetermined region is completed. When the substrate was moved up to that point, the movement trajectory of the substrate was set to be a smooth curve in which the differential coefficient continuously changed. According to a sixth aspect of the present invention, there is provided a device manufacturing method in which a predetermined pattern is formed at least partially, wherein the pattern is formed by using the exposure method according to the first aspect. In the invention according to claim 7, there is provided a scanning exposure apparatus for transferring a pattern of a mask onto the substrate by synchronously moving a substrate and a mask, wherein the substrate driving unit moves the substrate; Mask driving means for moving a mask, and control means for controlling at least one of the substrate driving means and the mask driving means, provided, the control means,
The response characteristic at the time of the control is used in an exposure section in which the substrate and the mask are moved while transferring the pattern, and in a non-exposure section in which the substrate and the mask are moved outside the exposure section. The second characteristic is configured to be switched. According to an eighth aspect of the present invention, in the scanning exposure apparatus according to the seventh aspect, the control unit sets the second characteristic such that the response characteristic is more improved than the first characteristic. According to the ninth aspect of the present invention, in the scanning exposure apparatus of the eighth aspect,
The control means is configured to perform the movement of the substrate or the mask by proportional integral control, and a first proportional coefficient used for the proportional integral control in the non-exposure section is used for the proportional integral control in the exposure section. The value was set to a value higher than the second proportional coefficient used. According to a tenth aspect of the present invention, in the scanning exposure apparatus according to the ninth aspect, the control means includes:
When switching between the first proportional coefficient and the second proportional coefficient, the differential coefficient at each time from the start to the end of the change of the proportional coefficient is continuously changed. According to an eleventh aspect of the present invention, in the scanning exposure apparatus according to the seventh aspect, the pattern is transferred to a plurality of regions on the substrate, and the control means controls the transfer of the pattern to a predetermined region. When the substrate was moved to the next area after the end, the movement locus of the substrate was set to be a smooth curve in which the differential coefficient continuously changed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a scanning exposure method according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a functional configuration of a scanning exposure apparatus to which the scanning exposure method of the present invention is applied. In FIG.
The light source system 1 includes a light source and a dimming unit for adjusting the illuminance on the wafer (substrate) W. The light source system 1 includes a main control system 13
The light source, the dimming unit, and the like are controlled by the control unit. Then, the illuminance of the illumination light IL on the wafer W is adjusted by controlling the light source and the dimming unit. The illumination light IL emitted from such a light source system 1 is incident on a fly-eye lens 4. As the illumination light IL, for example, a KrF excimer laser light, an ArF excimer laser light, a harmonic of a copper vapor laser or a YAG laser, or an ultraviolet bright line (g line, i line, or the like) of an ultra-high pressure mercury lamp is used. .

The fly-eye lens 4 is used to illuminate the reticle (mask) R with a uniform illuminance distribution so that the illumination light IL
On the basis of which a number of secondary light sources are formed. An aperture stop 5 of an illumination system is arranged on the exit side of the fly-eye lens 4. Illumination light IL emitted from the aperture stop 5
The (secondary light source) is incident on the beam splitter 6 having a small reflectance and a large transmittance. The beam splitter 6 receives the illumination light IL incident from the aperture stop 5.
Is transmitted through the first relay lens 7 </ b> A, and a part of the light is reflected toward the condenser lens 19.

The illumination light I transmitted through the beam splitter 6
L passes through the opening of the movable blind 8 via the first relay lens 7A. The movable blind 8 is arranged on a conjugate plane with respect to the pattern plane of the reticle R. The opening of the movable blind 8 is configured such that its width and position in the scanning direction are continuously changed by the blind drive system 8a. The blind drive system 8a is controlled by the blind drive system 8a based on a command issued from the main control system 13.
The movable blind 8 is opened and closed via. Thus, the illumination area of the illumination light IL is continuously adjusted, and exposure to portions other than the shot area is prevented.

Illumination light IL that has passed through movable blind 8
Is a second relay lens 7B and a mirror 9 for bending the optical path.
Then, the light passes through the main condenser lens 10 and irradiates the slit-shaped illumination area 24 on the reticle R with a uniform illuminance distribution. The pattern formed in the illumination area 24 on the reticle R by the illumination light IL applied to the illumination area 24 is inverted and reduced at the projection magnification β (β is, for example, １ ／) via the projection optical system 15. In this state, the light is projected and exposed on the slit-shaped exposure area 24W on the wafer W. In the following description, the direction parallel to the optical axis of the projection optical system 15 is defined as the Z axis, and the scanning direction of the reticle R with respect to the slit-shaped illumination area 24 in a plane perpendicular to the optical axis (the direction parallel to the plane of the paper). ) Is the X direction, and the direction perpendicular to the X axis and the Z axis (the direction perpendicular to the paper surface) is the Y direction.

The reticle R is a reticle holder (not shown).
Is mounted on the reticle stage 11 via the. The reticle stage 11 finely moves two-dimensionally in an XY plane perpendicular to the optical axis of the projection optical system 15 to position the reticle R and move at a predetermined scanning speed in the scanning direction, that is, the X direction. It is configured. The reticle stage 11 is driven by, for example, a servomotor. The moving stroke of the reticle stage 11 is set to a width that allows the entire surface of the reticle R to cross at least the illumination area 24 in the scanning direction.

A movable mirror 22b for reflecting a laser beam emitted from an external laser interferometer 22a is fixed to an end of the reticle stage 11 in the -X direction.
The reticle stage 1 is controlled by the laser interferometer 22a.
The position of 1 is constantly monitored. Reticle stage 1
The position information of 1 is output from the laser interferometer 22a to the reticle stage control system 27, and further transmitted from the reticle stage control system 27 to the main control system 13. The main control system 13 controls the position and the moving speed of the reticle stage 11 via the reticle stage control system 27 based on the position information of the reticle stage 11. The reticle stage control system 27 directly controls and drives the movement of the reticle stage 11 based on an instruction input from the main control system 13. The reticle stage control system 27 can be constituted by, for example, a PID controller or the like. Main control system 13, reticle stage 1
The reticle stage control system 1 and the reticle stage control system 27 constitute a mask movement control system.

The wafer W is mounted on a Z tilt stage 16 via a wafer holder (not shown). Z tilt stage 16 is mounted on wafer stage 17. The wafer stage 17 includes a wafer stage control system 2
8 drive in the X and Y directions. The wafer stage 17 realizes a step-and-scan operation in which scanning (scanning) of the illumination light IL onto each shot area on the wafer W and stepping to the next exposure start position are repeated. The Z tilt stage 16 and the wafer stage 17 are driven by, for example, a servomotor. In addition, the movement of the wafer W in the Z direction and the inclination with respect to the XY plane are adjusted by the Z tilt stage 16. A movable mirror 23b that reflects the laser beam emitted from the external laser interferometer 23a is fixed to an end of the Z tilt stage 16. This laser interferometer 2
The position of the Z tilt stage 16 (wafer W) is constantly monitored by 3a. The position information of the Z tilt stage 16 is output from the laser interferometer 23a to the wafer stage control system 28, and further supplied from the wafer stage control system 28 to the main control system 13.

The main control system 13 controls the position and the moving speed of the wafer W via the wafer stage control system 28 based on the position information of the Z tilt stage 16. The wafer stage control system 28 directly controls and drives the Z tilt stage 16 and the wafer stage 17 based on an instruction output from the main control system 13. This wafer stage control system 28 can be constituted by, for example, a PID controller or the like. The main control system 13, the wafer stage 17, and the wafer stage control system 28 constitute a substrate movement control system. In addition, the main control system 13,
The reticle stage control system 27 and the substrate stage control system 28 constitute a part of a control circuit (control means) in the scanning exposure apparatus of the present embodiment.

FIG. 2 is a control block diagram of the wafer stage control system 28. This wafer stage control system 28
Subtractor 28a, proportional unit (linear amplifier) 28b, integrator 2
8c, an adder 28d, and a phase compensation filter 28e. Wafer W output from laser interferometer 23a
Is input to the subtractor 28a as a control signal. This position information is subtracted from the target value of the position of the wafer W output from the main control system 13 in the subtracter 28a. The output of the subtractor 28a is output as an error signal to the proportional unit 2
8b and the integrator 28c.

The proportional unit 28b performs a proportional conversion (amplification) of the error signal based on a predetermined proportional coefficient KP (amplification rate) and outputs the error signal to an adder 28d. The integrator 28c integrates the error signal with a fixed integration coefficient KI and outputs the result to the adder 28d. The adder 28d includes the proportional unit 28b and the integrator 2
8c are added together and output to the phase compensation filter 28e. The phase compensation filter 28e is a filter whose zero is defined by "a" and whose pole is defined by "b". The phase compensation filter 28e performs a process of advancing the phase of the signal output from the adder 28d, and outputs the processed signal to the wafer stage 17 as an operation signal.

Here, the proportional unit 28b of the present embodiment is configured to be able to switch the proportional coefficient KP based on a switching signal output from the main control system 13. That is, in the present embodiment, by switching the proportional coefficient KP among the control parameters (proportional coefficient KP, integral coefficient KI, zero point a, pole b, etc.) that define the control characteristics,
It is configured to switch control characteristics in position control of the wafer W. Note that the values of these control parameters are determined in consideration of the inertia of the wafer stage 17 and the operating characteristics of the servomotor that moves and drives the wafer stage 17. The reticle stage control system 27
Is configured similarly to the wafer stage control system 28. However, regarding the control parameters, the inertia of the reticle stage 11 and the reticle stage 11
Is determined in consideration of the operating characteristics and the like of the servo motor that moves and drives the motor.

Returning to FIG. 1, in the present scanning type exposure apparatus, for example, the wafer W moves in the -X direction (or + X direction) in synchronization with the movement of the reticle R in the + X direction (or -X direction). Assuming that the moving speed of the reticle R at this time is VR and the moving speed of the wafer W is VW, the ratio (VW / VR)
Is exactly the same as the reduction magnification β of the projection optical system 15. As a result, the pattern on the reticle R is accurately transferred to each shot area of the wafer W. The illumination light reflected by the beam splitter 6 is received by an integrator sensor 20 including a photoelectric conversion element via a condenser lens 19. The photoelectric conversion signal of the integrator sensor 20 is transmitted to the main control system 1
3.

The correlation between the photoelectric conversion signal of the integrator sensor 20 and the illuminance of the illumination light IL on the exposure surface of the wafer W is determined in advance and stored in the main control system 13. The main control system 13 controls the exposure amount on the wafer W based on the correlation and the photoelectric conversion signal input from the integrator sensor 20. Although not shown, the scanning type exposure apparatus includes an oblique incidence type focus position detection system for detecting the position of the exposure surface of the wafer W and the inclination angle of the exposure surface, and the reticle R and the wafer W. And a plurality of alignment sensors for performing alignment with each shot area.

Next, the operation of the present scanning type exposure apparatus will be described.
This will be described in detail with reference to FIGS. FIG. 3 is a diagram illustrating a movement path of the wafer W. In the step-and-scan type scanning exposure apparatus that sequentially exposes each of the shot areas 31 and 32 as in the present scanning type exposure apparatus, the wafer W moves at a predetermined speed along a locus 33. (Specified speed S). Then, when the exposure of the shot area 31 is completed, the wafer W moves from the position P to the scanning start position 35 of the next shot area 32. Next, after the wafer W is accelerated from the scanning start position 35 to the specified speed S, the shot area 32
Is exposed. In FIG. 3, a section from the position P to the scanning start position 35 is a moving section 34 of the wafer stage 17. A section in which the wafer stage 17 is raised to the specified speed S is an acceleration section 36 of the wafer stage 17. A section provided to settle (converge) the vibration of the wafer stage 17 after acceleration is a settling section of the wafer stage 17. Also, the wafer stage 1
The exposure section 38 of the wafer stage 17 is a section in which the speed of 7 is constant at the specified speed S and exposure is being performed.

Next, a reticle stage control system 27 as a mask movement control system controls the reticle stage 11 to follow the wafer stage 17 in synchronization with the wafer stage 17. For this control, reticle stage control system 27 receives control information output from wafer stage control system 28 via main control system 13 and controls reticle stage 11 based on this control information.
Hereinafter, the reason why main control system 13 causes reticle stage 11 to follow wafer stage 17 will be described. Normal,
The wafer stage 17 is heavy since a wafer holder for holding the wafer W, various sensors, and the like are mounted.
For this reason, the inertial force acting on the wafer stage 17 is inevitably increased, and it is difficult to perform rapid acceleration and sudden stop. Therefore, compared to reticle stage 11, wafer stage 17
It is difficult to control the movement of the robot quickly and with high precision.
Therefore, in the scanning type exposure apparatus, it is desirable that the reticle stage 11 follow the wafer stage 17 in which a certain degree of movement error is allowed in synchronization. Therefore, in the present embodiment, the present invention is applied to the reticle stage 11 which is relatively light and can be controlled quickly and with high accuracy.

However, the present invention is not limited to control on reticle stage 11. For example,
(1) When reticle stage 11 is heavier than wafer stage 17, (2) Relatively heavier wafer stage 1
If the requirement for the movement accuracy is not strict for the reticle 7, the wafer stage 17 can be configured to follow the reticle stage 11, and the present invention can be applied to the movement control of the wafer stage 17. When it is not necessary to control the synchronization accuracy of the reticle stage 11 and the wafer stage 17 with very high accuracy, the reticle stage 11 and the wafer stage 17 can be controlled independently. In this case, the present invention can be applied to movement control for each stage.

Here, since the reticle stage 11 performs only one-dimensional operation in the scanning direction (X direction), the drawing of its configuration is omitted. FIG. 5A is a diagram illustrating a speed characteristic of the reticle stage 11, and FIG. 5B is a diagram illustrating a position characteristic of the reticle stage 11. FIG.
In (a), the vertical axis represents the speed V of the reticle stage 11 in the scanning direction (X direction), and the horizontal axis is the time t.
Represents In FIG. 5B, the vertical axis represents the scanning direction (X
Direction) of the reticle stage 11 with respect to the
The horizontal axis represents time t. Also, at time t on the horizontal axis, t
0 indicates when the wafer stage 17 has reached the scanning start position 35, t1 indicates when the wafer stage 17 moves from the acceleration section 36 to the settling section 40, and t2 indicates when the wafer stage 17 moves from the settling section 40 to the exposure section 38. Indicates when to move.

The reticle stage 11, which is synchronized (follows) with the movement of the wafer stage 17, exhibits speed characteristics and position characteristics as shown in FIG. The conventional stage control for the reticle stage 11 has the same set value for the control system for both the non-exposure section (t0 to t2) including the acceleration section and the settling section shown in FIG. (The proportional coefficient KP
Etc.). That is, in order to suppress the vibration of the high-frequency component within the allowable range in the exposure section, when a control system setting value that reduces the MSD value is determined in advance, the determined setting value is independent of the stage movement section. Used uniformly. Therefore, as described above, the settling time in the non-exposure section has been long. Hereinafter, the reason why the settling time becomes long will be described in detail. In this description, the low frequency is assumed to be a frequency of about 20 Hz or less, and the high frequency is assumed to be a frequency of about 60 to 100 Hz or more.

First, among the parameters for evaluating the synchronization accuracy, when the set value of the control system is determined for the purpose of reducing the MEAN value, the low frequency component of the vibration component of the stage is suppressed. On the other hand, when the set value of the control system is determined for the purpose of reducing the MSD value, the high frequency component of the vibration component of the stage is suppressed. MEA
The relationship between the N value and the MSD value is a relative relationship, and the MEA
Decreasing the N value increases the MSD value, and conversely, decreasing the MSD value increases the MEAN value. Therefore, conventionally, on the premise that the set value is kept constant regardless of the moving section of the stage, the set value of the control system is determined so as to reduce the MSD value in order to suppress the vibration of the high frequency component. I was Therefore, the vibration of the low frequency component remains, but the vibration of the low frequency component is
The vibration can be eliminated by taking time to settle (converge). Therefore, conventionally, the influence of the vibration of the low-frequency component is reduced by setting a longer time for the vibration to settle, that is, a longer settling time.

On the other hand, in the present embodiment, for the non-exposure section, the control system set value is set such that the MEAN value becomes smaller and the MSD value becomes larger. That is, M
In order to reduce the EAN value, a set value of a control system described later (for example, a proportional coefficient KP) is set to a value larger than the value of the exposure section. Thus, in the non-exposure section, the vibration of the high frequency component increases, but the vibration of the low frequency component is suppressed. Therefore, the time required to settle the vibration of the low frequency component is reduced.

Hereinafter, the proportional coefficient KP is set as the control system set value.
Using FIG. 2 as an example, the process of shortening the settling time during exposure will be described with reference to FIG. Under the control of the main control system 13, the reticle stage control system 27 switches the value of the proportional coefficient of the proportional device 28b among the set values of the control system shown in FIG. Specifically, as shown in FIG. 4, the proportionality coefficient is set to KP1 in the acceleration section (t0 to t1), and is set to KP2 (<KP1) in the exposure section (t2 and thereafter). That is, the proportional coefficient in the non-exposure section is set to a higher value (KP1) than in the exposure section. As a result, in the non-exposure section, the vibration of the high frequency component increases as compared with the case where the proportional coefficient is KP2.
However, since the vibration of the low frequency component can be suppressed, the settling time for stabilizing the vibration of the low frequency component can be shortened. In other words, when the proportionality coefficient is set to a high value (K
By setting P1), the sensitivity in the low frequency band is increased, and the responsiveness (rapid response) is improved. As shown in FIG. 7, by setting the proportional coefficient to KP1, the amplitude A ′ of the low frequency component is obtained.
Is smaller than the amplitude A when the proportional coefficient is set to KP2. The time (the initial value of the exposure section) t2 at which the sensitivity in the low frequency band increases and the vibration converges within the allowable range is t2.
2 ', indicating that the responsiveness (quick response) is significantly improved.

The reticle stage control system 27 sets the proportional coefficient KP2 in the exposure section as in the prior art, for the purpose of reducing the MSD value. this is,
As described above, in the exposure section, the vibration of the high frequency component which adversely affects the exposure accuracy is removed. Note that the proportional coefficient KP1 in the settling section from t1 to t2.
It is desirable to use a continuous curve as shown in FIG. 4 for switching from to KP2. By continuously changing the value of the proportional coefficient, the proportional coefficient is changed smoothly, and sudden vibration of the reticle stage can be suppressed. Therefore, the possibility of adversely affecting the exposure accuracy is reduced. For a continuous curve, for example, a curve whose derivative coefficient changes continuously, such as a sin curve, can be used.

As described above, in the scanning exposure method according to the present embodiment, the response characteristics of the mask movement control system are changed between the exposure section and the non-exposure section, so that the response characteristics in the exposure section and the non-exposure section are changed. Characteristics can be optimized. This makes it possible to shorten the settling time while ensuring synchronization between the reticle and the wafer during exposure, and to improve throughput.

The present invention is not limited to the above embodiment, but can be modified as follows. (1) In the embodiment, the movement trajectory of the wafer stage 17 synchronized with the reticle stage 11 is set as shown in FIG. 3, but may be, for example, an arc-shaped movement trajectory as shown in FIG. In this case, the reticle stage 11 is synchronized with the movement of the wafer stage 17 with this arc-shaped movement locus. The movement trajectory of the wafer stage (wafer W) shown in FIG. 6 includes a point Q2 which enters a settling section from an exposure end point Q1.
In the meantime, the wafer stage control system 28 is formed by continuously driving the wafer stage 17 in the scanning direction (X direction) and the non-scanning direction (Y direction). Using the movement trajectory shown in FIG. 6 reduces the time required for movement of the wafer stage 17 between shots as compared with the movement trajectory shown in FIG. Therefore, the throughput at the time of exposure is improved.

(2) In the embodiment, in the non-exposure period 34, the sensitivity in the low frequency band is increased by setting the proportional coefficient KP of the proportional unit 28b to be large to improve the response characteristic (quick response). However, as a technique for improving the response characteristics in the movement control of the reticle stage 11, various other techniques can be considered. The control system is designed in consideration of the balance of various control characteristics.
Control parameters other than the proportional coefficient KP of 8b (integral coefficient K
In some cases, it is better to improve response characteristics by manipulating I, zero a, pole b, etc.). In that case, it is conceivable to improve response characteristics in the non-exposure section 34 by operating other control parameters.

(3) In the embodiment, the wafer stage 17
It is assumed that the reticle stage 11 is synchronized (follows) with the movement of the reticle stage, and the present invention is applied to the reticle stage control system 27. However, the present invention is not limited to the wafer stage 17.
Can also be applied to the wafer stage control system 28 for controlling the movement of the wafer. In this case, unlike the reticle stage 11, the wafer stage 17 moves in two-dimensional directions of X and Y, so that the present invention may be applied to movement control in each direction.

The exposure apparatus of this embodiment can be applied to a proximity exposure apparatus that exposes a mask pattern by bringing a mask and a substrate into close contact without using a projection optical system. Further, the application of the exposure apparatus is not limited to an exposure apparatus for manufacturing a semiconductor. For example, an exposure apparatus for a liquid crystal that exposes a liquid crystal display element pattern to a square glass plate, or a thin film magnetic head is manufactured. Widely applicable to the exposure apparatus. The light source of the exposure apparatus of the present embodiment includes g-line (436 nm) and i-line (365n).
m), KrF excimer laser (248 nm), ArF excimer laser (193 nm), F2 laser (157 n)
Not only m) but also charged particle beams such as X-rays and electron beams can be used. For example, when an electron beam is used, a thermionic emission type lanthanum hexaborite (La
B6), tantalum (Ta) can be used. further,
When an electron beam is used, a structure using a mask may be used, or a pattern may be formed directly on a substrate without using a mask.

The magnification of the projection optical system is not limited to a reduction system, and may be any of an equal magnification system and an enlargement system. As a projection optical system, when far ultraviolet rays such as an excimer laser are used, a material which transmits far ultraviolet rays such as quartz or fluorite is used as a glass material. When an F2 laser or X-ray is used, a catadioptric or refractive optical system is used. A system is used (a reticle is also of a reflection type). When an electron beam is used, an electron optical system including an electron lens and a deflector may be used as an optical system. It goes without saying that the optical path through which the electron beam passes is in a vacuum state.

When a linear motor is used for the wafer stage or reticle stage, either an air levitation type using an air bearing or a magnetic levitation type using Lorentz force or reactance force may be used. Further, the stage may be of a type that moves along a guide, or may be a guideless type in which a guide is not provided. When a planar motor is used as the stage driving device, one of the magnet unit (permanent magnet) and the armature unit is connected to the stage, and the other of the magnet unit and the armature unit is connected to the stage moving surface side (base). May be provided.

The reaction force generated by the movement of the wafer stage may be mechanically released to the floor (ground) by using a frame member as described in Japanese Patent Application Laid-Open No. 8-166475. The present invention is also applicable to an exposure apparatus having such a structure. The reaction force generated by the movement of the reticle stage may be mechanically released to the floor (ground) using a frame member as described in JP-A-8-330224. The present invention is also applicable to an exposure apparatus having such a structure.

As described above, the exposure apparatus of the present embodiment
It is manufactured by assembling various subsystems including each component recited in the claims of the present application so as to maintain predetermined mechanical accuracy, electrical accuracy, and optical accuracy. Before and after this assembly, adjustments to achieve optical accuracy for various optical systems, adjustments to achieve mechanical accuracy for various mechanical systems, and various electric systems to ensure these various accuracy 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 manufacture of the exposure apparatus be performed in a clean room in which the temperature, cleanliness, and the like are controlled.

As shown in FIG. 8, in the semiconductor device, step 201 for designing the function and performance of the device,
Step 202 of manufacturing a mask (reticle) based on this design step, step 203 of manufacturing a wafer from a silicon material, wafer processing step 204 of exposing a reticle pattern to the wafer by the exposure apparatus of the above-described embodiment, device assembly step (Including dicing, bonding, and packaging processes) 20
5. It is manufactured through an inspection step 206 and the like.

[0040]

As described above, in the invention described in each claim, the response characteristic of the mask movement control system is
By changing between the exposure section and the non-exposure section, the response characteristics in each of the exposure section and the non-exposure section can be optimized. This makes it possible to shorten the settling time while ensuring synchronization between the reticle and the wafer during exposure, and to improve throughput.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a functional configuration of an embodiment of the present invention.

FIG. 2 is a control block diagram of a wafer stage control system according to an embodiment of the present invention.

FIG. 3 is a plan view showing a movement path of a wafer.

FIG. 4 is a graph showing switching characteristics of a proportional coefficient KP.

FIG. 5 is a characteristic diagram showing a speed characteristic and a position characteristic of a mask stage.

FIG. 6 is a plan view showing another movement path of the wafer.

FIG. 7 is a diagram for explaining that response characteristics are improved.

FIG. 8 is a flowchart illustrating an example of a manufacturing process of a semiconductor device.

[Explanation of symbols]

R Reticle (mask) W Wafer (substrate) 11 Reticle stage (mask movement control system, mask driving means) 13 Main control system (mask movement control system, substrate movement control system) 17 Wafer stage (substrate movement control system, substrate driving means) 27) reticle stage control system (mask movement control system) 28 wafer stage control system (substrate movement control system) 31, 32 shot area 34 movement section (non-exposure section) 36 acceleration section (non-exposure section) 38 exposure section

Claims (11)

[Claims] 1. A scanning exposure method for transferring a pattern of a mask onto said substrate by synchronously moving a substrate and a mask, wherein said exposure is performed by moving said substrate and said mask while transferring said pattern. A non-exposure step of moving the substrate and the mask other than the exposure step; a response characteristic of a substrate movement control system for controlling the movement of the substrate;
And switching at least one of response characteristics of a mask movement control system for controlling movement of the mask between a first characteristic used in the exposure step and a second characteristic used in the non-exposure step. A scanning exposure method. 2. The scanning exposure method according to claim 1, wherein said second characteristic is set so as to improve said response characteristic more than said first characteristic. 3. The substrate movement control system or the mask movement control system controls the movement of the substrate or the mask in a proportional-integral manner, and is used for the proportional-integral control in the non-exposure step. 3. The scanning exposure method according to claim 2, wherein the proportional coefficient is set to a value higher than a second proportional coefficient used for the proportional integral control in the exposure step. 4. When the first proportional coefficient and the second proportional coefficient are switched, the differential coefficient at each time from the start to the end of the change of the proportional coefficient is continuously changed. 4. The scanning exposure method according to claim 3, wherein: 5. The method according to claim 1, wherein the pattern is transferred to a plurality of regions on the substrate, and when the substrate is moved to a next region after the transfer of the pattern to the predetermined region is completed, the movement locus of the substrate is changed. 2. The scanning exposure method according to claim 1, wherein the differential coefficient is set to a smooth curve that changes continuously. 6. A method of manufacturing a device having a predetermined pattern formed on at least a part thereof, wherein the pattern is formed by using the exposure method according to claim 1. . 7. A scanning exposure apparatus for transferring a pattern of a mask onto the substrate by synchronously moving the substrate and the mask, the substrate driving means for moving the substrate, and the moving of the mask. And a control unit for controlling at least one of the substrate driving unit and the mask driving unit.The control unit controls the response characteristics during the control, while transferring the pattern and the substrate. A scanning type exposure apparatus characterized by switching between a first characteristic used in an exposure section for moving the mask and a second characteristic used in a non-exposure section for moving the substrate and the mask outside the exposure section. 8. The scanning type exposure apparatus according to claim 7, wherein said control means sets said second characteristic so that said response characteristic is higher than said first characteristic. 9. The control means controls the movement of the substrate or the mask by proportional-integral control, and calculates a first proportional coefficient used for the proportional-integral control in the non-exposure section and the proportional-integral control in the exposure section. 9. The scanning exposure apparatus according to claim 8, wherein the value is set to a value higher than a second proportional coefficient used for the control. 10. The control means, when switching between the first proportional coefficient and the second proportional coefficient, continuously calculates a differential coefficient at each time from the start to the end of the change of the proportional coefficient. 10. The method according to claim 9, wherein:
The scanning type exposure apparatus according to the above. 11. The method according to claim 11, wherein the pattern is transferred to a plurality of regions on the substrate, and the control means moves the substrate to a next region after the transfer of the pattern to a predetermined region is completed. 8. The scanning exposure apparatus according to claim 7, wherein the moving trajectory is set as a smooth curve in which the differential coefficient changes continuously.