JP3500737B2 - Scanning exposure equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning type exposure apparatus,
For example, it is suitable for application to an exposure apparatus used for manufacturing a liquid crystal display substrate.

[0002]

2. Description of the Related Art Conventionally, as this type of exposure apparatus, a structure shown in FIG. 4 has been generally used. The exposure apparatus 1 holds the mask 2 and the photosensitive substrate 3 in a state of being opposed to each other by a stage holder 4, and the stage holder 4 is moved by a driving mechanism 5 relative to the projection optical system PL. Thus, the image of the mask 2 is projected and exposed on the photosensitive substrate 3.

Incidentally, the stage holder 4 and the drive unit 5 are mounted on the upper surface of the base 7 supported by the anti-vibration mechanism 6, respectively, so that external vibration does not propagate to the stage holder 4. There is. Further, the exposure apparatus 1 constantly measures the relative positional relationship in the in-plane direction between the mask 2 held by the mask stage 2A and the photosensitive substrate 3 held by the substrate stage 3A by means of the laser interferometer 8 and The controller 10 controls the feedback control of the drive unit 9 that drives the mask stage 2A so that the mask 2 and the photosensitive substrate 3 maintain a predetermined positional relationship during movement (scanning exposure). .

[0004]

However, in the case of the exposure apparatus 1 of this mechanism, in order to raise the stage holding table 4 to a speed suitable for scanning exposure (0.2 [m / s] in the case of FIG. 5B). The relative displacement (FIG. 5C) between the mask 2 and the photosensitive substrate 3 due to the acceleration applied from the drive unit 5 (FIG. 5A) deteriorates the exposure performance. I got it.

This is because the connecting mechanism 9A for connecting the mask stage 2A and the driving unit 9 is not a completely rigid body (a speed reducing mechanism using gears or the like is required to obtain the thrust required to drive the mask stage 2A). This is because these elements cannot be made completely rigid), and the coupling mechanism 9A is compressed by the inertial force acting on the mask stage 2A during acceleration of the stage holder 4.

Therefore, it is conceivable to start the exposure after correcting the positional deviation caused by such acceleration.
In order to realize this, an extra run-up section for accelerating the stage holder 4 and statically determining the mask stage 2A is required, which causes a problem that the exposure apparatus itself becomes large and the throughput decreases. .

The present invention has been made in consideration of the above points, and there is no risk of exposure performance deterioration, and it is possible to maintain a high throughput by positioning the mask and the photosensitive substrate with high precision while being small in size. It is intended to propose a scanning type exposure apparatus.

[0008]

In order to solve such a problem, a scanning exposure apparatus according to claim 1 is a projection optical system (PL) for projecting a light beam transmitted through a mask (2) onto a photosensitive substrate (3). And a mask stage (2A ) for mounting the mask (2) and a substrate stage (3 for mounting the photosensitive substrate (3).
The stage holding table (4) that integrally holds the stage holding table (4) and the projection optical system (P).
And L) to the drive means for relatively moving (5), provided on the scan tape <br/> di holder (4), the relative position between the mask (2) and the photosensitive substrate (3) during relative movement A mask (2) provided with a first stage driving means (9) for correcting the displacement.
And a scanning exposure apparatus that exposes onto the photosensitive substrate (3) the entire surface of the mask (2) and the photosensitive substrate (3) while maintaining a predetermined positional relationship, the stage holder by a driving means (5) (4 acceleration and the acceleration measuring means for measuring (21) occurring), the acceleration measuring means (21) mask stage during the movement acceleration of approximately the same size as the measured acceleration by (2A) and or the substrate stage (3A) Give,
Generated between the stage and the stage holding table (4), a second stage drive means for correcting the positional deviation due to the acceleration and (22), and a. Running according to claim 2
In the inspection type exposure apparatus, the stage holder (4) is a vibration isolation mechanism.
Supported by (6). The scanning type dew according to claim 3.
The optical device scans the mask (2) and the photosensitive substrate (3).
To expose the pattern of the mask (2) on the photosensitive substrate (3).
Scanning exposure apparatus that holds the mask (2)
The moving mask stage (2A) and the mask stage (2
A stage holder (4) that moves with A), and a stage
Acceleration sensor (21) for detecting the acceleration of the holding table (4)
According to the detection result of the acceleration sensor (21)
An auxiliary drive unit (22) for applying thrust to the tage (2A),
Is equipped with. The scanning exposure apparatus according to claim 4 is an auxiliary
The drive unit (22) has a linear motor. Claim 5
The scanning type exposure apparatus described above is at the position of the mask stage (2A).
A laser interferometer (8) for detecting the position is provided.

[0009]

In the scanning exposure apparatus according to the first aspect of the present invention, the acceleration of the stage holder (4) during relative movement is measured by the acceleration measuring means (21), and the acceleration of substantially the same magnitude as the measured acceleration is applied. The mask stage (2A) and / or the substrate stage (3A) that are moving relative to each other are acted on to correct the positional deviation caused by acceleration. This accelerates the mask stage (2A) or substrate stage (3A).
It is possible to prevent the relative position between the mask (2) and the photosensitive substrate (3) from changing due to the positional deviation that occurs in 1), and to start scanning exposure promptly without degrading the exposure performance. The scanning exposure apparatus according to claim 2, wherein a vibration isolation mechanism is provided.
(6) does not transmit external vibration to the stage holder (4)
I am trying to stay. The scanning exposure apparatus according to claim 3 is
The acceleration sensor (21) accelerates the stage holder (4).
Is detected, the auxiliary drive unit (22) detects the acceleration sensor (21).
The thrust is applied to the mask stage (2A) according to the detection result of
I am. The scanning type exposure apparatus according to claim 4 is a linear model.
Thruster is applied to the mask stage (2A)
It The scanning type exposure apparatus according to claim 5 is a laser interferometer.
(8) is detecting the position of the mask stage (2A)
It

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1 in which parts corresponding to those in FIG. 4 are designated by the same reference numerals, 20 denotes an exposure apparatus as a whole, and the exposure apparatus 20 is an acceleration sensor 21 for measuring the acceleration of the stage holder 4 in the scanning direction. And an auxiliary drive unit 22 for correcting the positional deviation between the mask and the photosensitive substrate at the start of scanning (at the time of acceleration) by causing the mask stage 2A to act on the mask stage 2A with an acceleration substantially equal to the measured acceleration. And has the same configuration as the exposure apparatus 1.

In the case of this embodiment, the auxiliary driving section 22 is a linear motor mechanism, and is provided on the stage holding table 4.
From the back surface of the mask stage 2A, an acceleration having a magnitude corresponding to an instruction from the control unit 23 is applied to correct the positional deviation of the mask stage 2A caused by the acceleration at the start of scanning. Incidentally, the control unit 23 controls the auxiliary driving unit 22 based on the measurement result of the acceleration sensor 21, and also controls the relative alignment between the mask 2 and the photosensitive substrate 3 and scans the stage holding table 4. It is designed to be used for control of.

A series of exposure operations by the exposure apparatus 20 having the above configuration will be described. However, it is assumed that the relative alignment (alignment processing, etc.) of the mask 2 and the photosensitive substrate 3 has already been completed with the stage holder 4 stationary. First, the control unit 23 takes in the position CX of the stage holder 4 measured by the laser interferometer 8 at regular sampling intervals, and from the amount of change, the moving speed CVk (k is a sampling number) of the stage holder 4,
The following formula

[Equation 1] Based on.

The control unit 23 accelerates the stage holding table 4 based on the moving speed CV _k determined connexion by the equation (1), the moving speed CV _k of the stage holding table 4 after reaching the final target speed is a constant speed The drive unit 5 is controlled so that Figure 2
As shown in (A), the control unit 23 operates about 1
During [seconds], the acceleration of the stage holder 4 is linearly increased so that the speed of the stage holder 4 is about half of the final target speed (0.2 [m / s]) as shown in FIG. 2B. increase. Then, the control unit 23 continues for about 1 second,
The acceleration of the stage holder 4 is reduced, the speed of the stage holder 4 is gradually brought close to the final target speed, and after reaching the final target speed, the speed is maintained.

Simultaneously with the speed control of the stage holder 4, the control unit 23 gives a command for the relative position (only in the scanning direction) between the mask 2 and the photosensitive substrate 3, which has been previously obtained based on the result of the alignment process. The position CX of the stage holder 4 and the position MX of the mask stage are taken in from the laser interferometer 8 so as to follow, and the relative position ΔX between the mask and the photosensitive substrate is calculated by

[Equation 2] To ask.

Then, the control unit 23 gives a control command to the drive unit 9 and controls so that the obtained relative position ΔX matches the relative position command. However, the control by the drive unit 9 is feed back control, and the response band is only about 10 Hz because of mechanical resonance included in the loop system. Due to this response delay, the relative displacement between the mask and the photosensitive substrate due to the acceleration of the stage holder 4 cannot be corrected only by the drive unit 9.

[0017] Therefore the thrust F _k required for the control unit 23 cancels the inertia force acting on the mask stage 2A takes in the acceleration a _k of each instant had it occurred in measured acceleration sensor 21, the following equation

[Equation 3] And is given to the mask stage 2A via the auxiliary drive unit 22. However, m is the mass of the mask stage 2A.

A DC linear motor has a characteristic that a thrust F having a magnitude corresponding to a product of a thrust constant p peculiar to the motor and a current i (that is, F = p × i) is generated, and the current i should be controlled. Therefore, an arbitrary generated thrust F can be generated. Therefore, it is possible to easily apply the acceleration having substantially the same magnitude as the measurement result of the acceleration sensor 21 to the mask stage 2A.

Incidentally, in this embodiment, since the auxiliary drive unit 22 having a small maximum thrust is used, the control unit 23 is used.
As shown in FIG. 2 (C), the thrust F having the same magnitude as the thrust commanded by is started at about 2 seconds immediately before the end of acceleration. That is, during the period from the start of acceleration to immediately before the end of acceleration, the thrust F commanded by the control unit 23 becomes larger than the maximum thrust (10 [N]) of the auxiliary drive unit 22, so that the maximum thrust F continues to act on the mask stage 2A.

According to the above configuration, a thrust of a predetermined magnitude is applied to the mask stage 2A from the start of acceleration of the stage holder 4 until immediately before the end of acceleration, and after the end of acceleration, the acceleration of the stage holder 4 is accelerated. The mask stage 2A is made to follow the speed of the stage holder 4 quickly by applying substantially the same acceleration to the mask stage 2A, so that the misalignment between the mask stage 2A and the stage holder 4 can be quickly reduced. You can

The effect of this misregistration correction is shown by superimposing the misregistration of the embodiment on the misregistration produced by the conventional device.
You can see from That is, in the case of the conventional apparatus, a periodical positional deviation was observed in a sine wave even after shifting to the constant velocity movement, but in the case of the exposure apparatus 20 adopting the mechanism of the embodiment, such positional deviation is almost present. It has not occurred. By using the exposure apparatus 20 in this way, the settling time after the end of acceleration can be shortened, and the positional deviation after the end of acceleration can be suppressed as small as possible. That is, it is possible to obtain a scanning type exposure apparatus capable of performing exposure with high throughput without deteriorating the exposure performance.

In the above embodiment, the case where the linear motor mechanism is used as the auxiliary drive unit 22 has been described, but the present invention is not limited to this, and another drive mechanism such as a voice coil motor mechanism may be used. . Also in this case, the same effect as that of the embodiment can be obtained.

In the above embodiment, the case where the auxiliary drive unit 22 having a small maximum thrust is used has been described. However, the present invention is not limited to this, and the one having a large maximum thrust is used for the acceleration period. The thrust force due to the acceleration having the same magnitude as the acceleration at the time of acceleration may be applied. By doing so, the positional deviation that occurs during acceleration can be further reduced.

Further, in the above-described embodiment, the case where the thrust F generated by the auxiliary drive unit 22 is acted from the start of acceleration has been described, but the present invention is not limited to this, and it may be acted immediately before the end of acceleration. The starting time point at which the thrust is applied can be set arbitrarily.

Further, in the above-described embodiment, the case where the auxiliary drive unit 22 drives the mask stage 2A to correct the positional deviation caused by acceleration has been described, but the present invention is not limited to this, and the substrate is not limited to this. The positional deviation may be corrected by driving the stage 3A. Alternatively, both the mask stage 2A and the substrate stage 3A may be driven.

[0026]

As described above, the scanning exposure according to claim 1 is carried out.
According to the apparatus , the acceleration of the stage holding table during relative movement is measured by the acceleration measuring means, and an acceleration of approximately the same magnitude as the measured acceleration is applied to the mask stage and / or substrate stage during relative movement to accelerate the acceleration. By correcting the positional deviation caused by the above, it is possible to easily realize a scanning type exposure apparatus capable of transferring a mask image with high throughput without deteriorating the exposure performance. The scanning exposure apparatus according to claim 2 is an external device.
Vibrations are not transmitted to the stage holder, so external vibrations
Exposing the image of the mask onto the photosensitive substrate without receiving
You can The scanning exposure apparatus according to claim 3 is an acceleration sensor.
Sensor detects the acceleration of the stage holder and the auxiliary drive unit
Thrust on the mask stage according to the detection result of the acceleration sensor
Is high, without deteriorating the exposure performance.
Exposing the mask pattern on the photosensitive substrate at a throughput
be able to. The scanning type exposure apparatus according to claim 4 is a linear type.
The motor gives thrust to the mask stage
It is possible to apply thrust to the mask stage with simple control.
it can. The scanning type exposure apparatus according to claim 5 is laser interference.
Since the meter detects the position of the mask stage,
The position of the stage can be detected with high accuracy.

[Brief description of drawings]

FIG. 1 is a schematic side view showing an embodiment of a scanning exposure apparatus according to the present invention.

FIG. 2 is a characteristic curve diagram showing a change in relative positional relationship between a thrust applied to a stage and a mask photosensitive substrate. In the figure, (A) shows the stage holder acceleration, (B) shows the stage holder speed, (C) shows the thrust of the auxiliary drive unit, and (D) shows the relative displacement between the mask and the photosensitive substrate.

FIG. 3 is a characteristic curve diagram showing the relationship between the positional deviation that occurs when the exposure apparatus of the embodiment is used and the positional deviation that occurs when the conventional apparatus is used.

FIG. 4 is a schematic side view showing a conventional device.

FIG. 5 is a characteristic curve diagram showing a change in relative positional relationship between mask photosensitive substrates which occurs when a stage holding table is accelerated by a conventional apparatus. In the figure, (A) shows the stage holder acceleration, (B) shows the stage holder speed, (C) shows the thrust of the auxiliary drive unit, and (D) shows the relative displacement between the mask and the photosensitive substrate.

[Explanation of symbols]

1, 20 ... Exposure device, 2 ... Mask, 2A ... Mask stage, 3 ... Photosensitive substrate, 3A ... Substrate stage, 4
...... Stage holder 5,9 ...... Drive unit, 6 …… Vibration isolation mechanism, 7 …… Base, 8 …… Laser interferometer 10,23 ……
Control unit, 21 ... Acceleration sensor, 22 ... Auxiliary drive unit.

Continuation of the front page (56) Reference JP-A-61-251027 (JP, A) JP-A-61-278142 (JP, A) JP-A-6-140305 (JP, A) JP-A-6-232021 (JP , A) JP-A-6-163353 (JP, A) JP-A-8-83744 (JP, A) JP-A-7-335542 (JP, A) JP-A-2-272719 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/027 G03F 7/20

Claims (5)

(57) [Claims] 1. A projection optical system that projects a light beam that has passed through a mask onto a photosensitive substrate, a mask stage on which the mask is mounted, and a substrate stage on which the photosensitive substrate is mounted are integrally faced to each other. A stage holding table for holding, a driving means for moving the stage holding table relative to the projection optical system, and a relative position of the mask and the photosensitive substrate provided on the stage holding table during the relative movement. and a first stage drive means for correcting the deviation, in the scanning type exposure apparatus for exposing the entire surface of the mask while maintaining said photosensitive substrate and the mask in a predetermined positional relationship to said photosensitive substrate, wherein Acceleration measuring means for measuring the acceleration generated on the stage holder by the driving means, and an acceleration having substantially the same magnitude as the acceleration measured by the acceleration measuring means. Applied to the mask stage and or the substrate stage during the movement, generated between the stage holding table with the stage, a second stage drive means for correcting the positional deviation due to the acceleration, in that it comprises a Characteristic scanning exposure device. 2. The stage holder is supported by a vibration isolation mechanism.
The scanning dew according to claim 1, wherein the scanning dew is held.
Light equipment. 3. A mask and a photosensitive substrate are scanned to move the mask.
A scanning type exposure device for exposing a pattern of a mask onto the photosensitive substrate.
In the A mask stage that holds and moves the mask; A stage holder that moves together with the mask stage; Acceleration sensor for detecting the acceleration of the stage holder
When, According to the measurement result of the acceleration sensor, the mask stay
And an auxiliary drive unit that gives thrust to the gear.
Scanning exposure device. 4. The auxiliary drive unit has a linear motor.
4. The scanning type exposure apparatus according to claim 3, wherein 5. A register for detecting the position of the mask stage.
5. A laser interferometer according to claim 3, further comprising a laser interferometer.
The scanning exposure apparatus described.