JP2000250226A - Exposure device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily execute the positioning of a blind device in a short time. SOLUTION: This exposure device is provided with the blind device 10 regulating the illuminating area of a mask R having a pattern, and a pattern image transmitted through the illuminating area is exposed on a base plate P. The blind device 10 possesses a mark showing the position of the blind device 10, and is provided with a detector 6 detecting the mark provided at the blind device 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus for transferring a reticle pattern onto a photosensitive substrate by a beam from a light source, and more particularly, to an exposure apparatus for irradiating a beam from a light source onto a reticle through a blind opening. Things.

[0002]

2. Description of the Related Art As an exposure apparatus for manufacturing a liquid crystal display element or the like, after exposing a pattern formed on a reticle to a predetermined area of a photosensitive substrate, the photosensitive substrate is stepped by a predetermined distance, and the pattern of the reticle is changed again. There is a so-called step-and-repeat type (stepper) that repeats exposure.

Conventionally, for example, when an LCD pattern for a liquid crystal display element is formed by a stepper, a normal screen synthesizing method is used. This screen composition method uses a divided LCD
Using multiple reticles corresponding to each of the patterns,
After exposing the reticle pattern to the exposure area of the glass substrate corresponding to one reticle, the glass substrate is stepped and the reticle is replaced with another one, and the reticle pattern is exposed to the exposure area corresponding to the reticle. Exposure is to form an LCD pattern in which a plurality of patterns are synthesized on a glass substrate.

[0004] By the way, when performing the above-mentioned screen composition method,
A step occurs at the joint of the pattern due to a pattern writing error of the reticle, an aberration of the lens of the projection optical system, a positioning error of the stage for moving the glass substrate step by step, etc., thereby deteriorating the characteristics of the device and further reducing the screen. When the synthesized divided patterns are superimposed on multiple layers, in order to avoid that the overlay error of the exposure area of each layer and the line width difference of the pattern change discontinuously at the seam of the pattern, the device quality is reduced. That is, a so-called splicing is performed.

[0005] In the overlap splicing, the seam portion is overlap-exposed in an adjacent exposure region, and the exposure amount of the seam portion is proportionally shifted toward the boundary by changing the exposure time in each exposure region. By reducing the amount, the exposure amount of this portion is made substantially equal to the exposure amount of the other portion when the overlay exposure is performed.

In order to reduce the exposure amount, for example,
A method has been adopted in which the exposure time at the end of the displaced opening is changed by moving the opening of a blind device defining an illumination area of the reticle at a constant speed in a direction orthogonal to the exposure light during the exposure. Therefore, when performing the splicing, it is necessary to position the reticle and the opening of the blind device with high accuracy.

[0007]

However, the conventional exposure apparatus as described above has the following problems. The reticle is easily positioned by detecting a reticle mark formed on the reticle with a mark detection system. However, the positioning of the blind device is performed by once performing test exposure on the substrate, developing the substrate, and separately reading and measuring the transferred pattern. Met.

[0008] The positioning operation is performed by a trial and
Since the error is repeated, more work time is required, and there is also a problem that the adjustment time varies more.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to provide an exposure apparatus capable of easily positioning a blind apparatus in a short time.

[0010]

In order to achieve the above object, the present invention employs the following structure corresponding to FIGS. 1 to 5 showing an embodiment. The exposure apparatus according to the present invention includes a blind device (10) for defining an illumination region of a mask R having a pattern, and the exposure device (1) for exposing a pattern image transmitted through the illumination region to a substrate (P) is blind. The device (10) is connected to the blind device (1)
0) and marks (15a to 15d) indicating the position of the mark (15) provided on the blind device (10).
a to 15d) are provided.

Therefore, in the exposure apparatus of the present invention, the position of the blind device (10) is detected by the detecting device (6) detecting the marks (15a to 15d) provided on the blind device (10). Can be. Therefore, the blind device (10) can be positioned with respect to the mask (R).

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an exposure apparatus according to the present invention will be described below with reference to FIGS. Here, an example in which the exposure apparatus is a stepper method will be described. FIG. 1 is a schematic configuration diagram of the exposure apparatus 1. The exposure apparatus 1 of the present embodiment is a liquid crystal exposure apparatus that exposes an LCD pattern on a glass plate by the screen synthesis method described in the related art. The exposure apparatus 1 projects and transfers a pattern (for example, a liquid crystal display element pattern) formed on a reticle (mask) R onto a substrate P which is a square glass plate, and includes a mercury lamp 2 and an illumination optical system 3. ,
A control device 1 that controls the projection optical system 4, the substrate stage 5, a reticle stage RS that can hold and move the reticle R, a mark detection device (detection device) 6, and the entire exposure device 1.
It is schematically configured from 00.

The mercury lamp 2 has a beam B as exposure light.
It emits. This mercury lamp 2 has an elliptical mirror 2
a is attached. The elliptical mirror 2a focuses the exposure light emitted from the mercury lamp 2.

The illumination optical system 3 includes reflection mirrors 7a and 7b.
A wavelength selection filter 8, a fly-eye integrator 9, a reticle blind (blind device) 10,
It is roughly composed of a relay lens 11 and a half mirror 12. The reflection mirror 7a reflects the beam B condensed by the elliptical mirror 2a toward the wavelength selection filter 8. The reflection mirror 7b reflects the beam B passing through the relay lens 11 toward the reticle R.

The wavelength selection filter 8 allows only the wavelength (g-line or i-line) of the beam B necessary for exposure to pass. The fly-eye integrator 9 makes the illuminance distribution of the beam B passing through the wavelength selection filter 8 uniform.

The reticle blind 10 is for setting an illumination area where the beam B passing through the fly-eye integrator 9 illuminates the reticle R.
a, 10b and a drive mechanism (not shown), and sets an illumination area based on the control of the control device 100. The opening members 10a and 10b are opposed to each other with a small gap (for example, 300
(about μm), and are movable in directions perpendicular to each other in a plane perpendicular to the beam B.

As shown in FIG. 2, the opening member 10a is
A light shielding portion 13a having a rectangular shape in a plan view, which is shielded from light by vapor deposition or the like.
And a rectangular opening 14a in a plan view formed substantially at the center of the light shielding portion 13a. Similarly, the opening member 10b includes a light shielding portion 13b having a rectangular shape in plan view.
And an opening 14b. Then, by moving the opening members 10a and 10b and combining the openings 14a and 14b, the position and size of the illumination area of the reticle R are set. The opening member 10
As disclosed in Japanese Patent Application Laid-Open No. 7-235466, the light-attenuating portions a and 10b are provided on any side of the opening 14a (14b) so that the transmittance changes from the opening 14a (14b) toward the periphery. May be used.

In the light shielding portion 13a of the opening member 10a, alignment marks (marks) 15a and 15b indicating the position of the opening member 10a are provided at predetermined intervals from the opening 14a with the opening 14a interposed therebetween. . Similarly, the light shielding portion 13b of the opening member 10b has the opening member 1
Alignment mark (mark) 15 indicating the position of 0b
c and 15d are provided. As shown in FIG. 3, each of the alignment marks 15a to 15d has a slit-shaped opening pattern extending in each direction in order to perform measurement in the X direction and the Y direction.

The driving mechanism drives the movement of the opening members 10a and 10b in directions orthogonal to each other in a plane orthogonal to the beam B and the rotational movement around the beam B, respectively.

The relay lens 11 forms an image of the illumination area set by the openings 14a and 14b of the reticle blind 10 with the reticle R. Half mirror 12
Transmits the beam B having passed through the fly-eye integrator 9 toward the reticle blind 10,
The detection light emitted from a light emitting unit (irradiation unit) 16 described later is reflected toward a photomultiplier tube (light receiving unit) 17.

The projection optical system 4 forms an image of a pattern existing in the illumination area of the reticle R on the substrate P. The substrate stage 5 holds the substrate P, and is movable in directions orthogonal to each other under the control of the control device 100. A movable mirror 18 is provided on the substrate stage 5. A laser beam is emitted from a laser interferometer 19, which is a position detecting device, to the movable mirror 18,
Based on the interference between the reflected light and the incident light, the distance between the movable mirror 18 and the laser interferometer 19, that is, the substrate stage 5
Is detected. The output of the laser interferometer 19 is input to the control device 100.

The mark detecting device 6 includes alignment marks 15a to 15d provided on the reticle blind 10 and a reticle mark (not shown) formed on the reticle R.
, And mainly includes the light emitting section 16 and the photomultiplier tube 17. The light emitting unit 16
The detection light for detecting the mark is emitted toward the projection optical system 4, and is arranged on the substrate stage 5. In addition, the light emitting unit 16 includes the light emitting unit 16 shown in FIG.
A slit-shaped opening pattern is formed similarly to the alignment marks 15a to 15d of the reticle blind 10 shown in FIG. The detection light is emitted in the form of the slit. Photomultiplier tube 17
Is for receiving the detection light emitted from the light emitting unit 16 through the projection optical system 4, converting the detection light into an electric signal, and outputting the electric signal to the control device 100.

The reticle R has a pattern area (not shown) in which the pattern is formed on the surface on the side of the projection optical system 4, and the reticle mark is formed around the pattern area. These reticle marks are the alignment marks 15a to 15c of the reticle blind 10 shown in FIG.
Similarly to 15d, a slit-shaped opening pattern is formed.

In the exposure apparatus having the above configuration, the control device 1
A procedure for positioning the reticle R and the reticle blind 10 according to 00 will be described. Here, the position of the light emitting section 16 with respect to the substrate stage 5, the position of the reticle mark with respect to the reticle R, the opening 14 in the opening member 10a.
It is assumed that the relationship between a and the alignment marks 15a and 15b and the relationship between the opening 14b and the alignment marks 15c and 15d in the opening member 10b are known.

Opening member 1 of reticle blind 10
In order to position Oa, first, the opening member 10b is retracted to a position where it does not interfere with the detection light from the light emitting unit 16. Next, prior to moving the substrate stage 5, the opening member 10a is moved so that the alignment mark 15a of the opening member 10a is substantially located in the optical path of the detection light. Then, the substrate stage 5 is scanned and moved in, for example, the X direction while irradiating the detection light from the light emitting unit 16.

This detection light is transmitted to the projection optical system 4 and the reticle R
And the image is formed on the reticle conjugate plane by the relay lens 11, and passes through the slit of the alignment mark 15a when the alignment mark 15a is located on the optical path of the detection light.

Here, the reticle R is moved in advance so that the detection light passes through the transparent portion, or a transparent reticle on which no pattern is formed is used. Further, the reticle R may be removed. When the substrate stage 5 is moved in the X direction, the alignment mark 15a
Of these, a slit extending in the Y direction is used.

The detection light transmitted through the slit is reflected by the half mirror 12, enters the photomultiplier tube 17, and is converted into an electric signal. FIG. 4 shows the relationship between the position of the light emitting unit 16 in the scanning direction and the signal level of the detection light incident on the photomultiplier tube 17. As shown in the figure, the maximum value of the signal level occurs when the position of the light emitting section 16 matches the position of the alignment mark 15a. When the substrate stage 5 is moved, the laser interferometer 19 emits the laser beam 18 toward the movable mirror 17 on the substrate stage 5 to accurately detect the position of the substrate stage 5, so that the controller 100 can detect the X coordinate of the alignment mark 15a from the position coordinates of the substrate stage 5 and the position of the light emitting section 16 when the signal level of the detection light reaches the maximum value.

Subsequently, the substrate stage 5 is moved to Y in the same procedure.
The scanning movement in the direction, the alignment mark 1
The Y coordinate of 5a is determined. At this time, a slit extending in the X direction among the alignment marks 15a is used. Further, the opening member 15a is aligned with the alignment mark 1
5b is moved so as to be located substantially in the optical path of the detection light. Then, the X coordinate and the Y coordinate of the alignment mark 15b are determined by the same procedure as described above. Here, since the positional relationship between the alignment marks 15a and 15b and the opening 14a is known, the coordinates of the opening 14a on the substrate stage 5 can be accurately detected.

Next, after the opening member 10a is moved to a position where it does not interfere with the detection light from the light emitting section 16, the opening member 1a is moved.
0a, the alignment mark 1 of the opening member 10b.
The X and Y coordinates of 5c and 15d are detected, respectively. Since the positional relationship between the alignment marks 15c and 15d and the opening 14b is also known, the coordinates of the opening 14b on the substrate stage 5 can be accurately detected.

Then, the amount of deviation between the obtained positions of the openings 14a, 14b and the ideal position to be designed is obtained, and the rotation correction amount and the XY shift correction amount of the opening members 10a, 10b are obtained. Based on these correction amounts, the opening members 10a,
10b is positioned using a drive mechanism.

Subsequently, the reticle R
The procedure for positioning is described. First, the opening 14
The opening members 10a and 10b are moved so that the optical path of the detection light is located in the positions a and b. Next, the reticle R is moved so that the reticle mark of the reticle R is located substantially on the optical path of the detection light. Then, the opening members 10a, 10
Similarly to the case of detecting the alignment marks 15a and 15b of b, the X- and Y-coordinates of the reticle mark are detected by scanning and moving the substrate stage 5 while emitting the detection light from the light emitting unit 16.

Then, a deviation amount between the obtained position of the reticle mark and an ideal position to be designed is obtained, and a rotation correction amount, an XY shift correction amount, and an XY magnification offset amount of the reticle R are obtained. The reticle R is positioned based on these correction amounts. Thus, reticle blind 10
And reticle R is positioned in the coordinate system of substrate stage 5.

When the substrate P is set on the substrate stage 5 and aligned, the exposure process starts. When reticle R is set in alignment with reticle stage RS, opening member 10 of reticle blind 10
a and 10b are moved. Thus, an illumination area corresponding to the openings 14a and 14b is set on the reticle R. At the same time as moving the opening members 10a and 10b, the substrate stage 5 is moved to a position corresponding to the illumination area set by the openings 14a and 14b.

When the reticle blind 10 and the substrate stage 5 are set at predetermined positions, the beam B, which is exposure light from the mercury lamp 2, is condensed by the elliptical mirror 2a and enters the wavelength selection filter 8 from the reflection mirror 7a. . Beam B that has passed only the wavelength required for exposure by wavelength selection filter 8
Is adjusted to a uniform illuminance distribution by the fly-eye integrator 9 and then reaches the reticle blind 10 through the half mirror 12.

The beam B having passed through the opening of the reticle blind 10 enters the relay lens 11. After the image of the opening of the reticle blind 10 is reflected by the reflection mirror 7b by the relay lens 11, the image is formed by the reticle R, and the illumination area of the reticle R corresponding to the opening is illuminated.
The image of the pattern existing in the illumination area of the reticle R is formed on the substrate P by the projection optical system 4. Thereby, the pattern of the reticle R is transferred onto the substrate P. Although the aperture members 10a and 10b are separated from the conjugate plane of the reticle R by a small distance, the depth of focus of the optical system that forms the detection light of the light emitting unit 16 is different from the conjugate plane and the aperture members 10a and 1b.
There is no inconvenience as long as the distance is longer than 0b.

In the exposure apparatus of the present embodiment, the opening members 10a and 10b can be positioned by detecting the alignment marks 15a to 15d provided on the opening members 10a and 10b of the reticle blind 10 with the mark detection device 6, The test exposure on the substrate P is not required when positioning the reticle blind 10, so that the operation can be simplified and the time required for developing the substrate P and reading the pattern due to the test exposure can be eliminated, thereby shortening and stabilizing the operation time. Can be realized. In addition, since it is not necessary to separately provide materials and equipment necessary for the test exposure, it is possible to reduce the size and cost of the apparatus. In the present embodiment, reticle blind 1 is controlled by control device 100.
Although the positioning of 0 is performed, it goes without saying that the positioning may be performed manually without using the control device 100.

Further, in the exposure apparatus of the present embodiment, since a device for detecting a reticle mark is used as the mark detection device 6, the alignment marks 15a to 15
It is not necessary to separately provide a device for detecting d, and it is possible to further reduce the size and cost of the device.

Further, in the exposure apparatus of the present embodiment, the light emitting section 16 is provided on the substrate stage 5, and the alignment marks 15a to 15d are detected while moving the substrate stage 5, so that the distortion of the projection optical system 4 is reduced. The amount of correction can be obtained in a state similar to the state actually projected on the substrate P, including the reticle R and the opening member 10a.
The positioning of 10b can be performed with high accuracy.

Further, in the exposure apparatus of the present embodiment, the movement of the opening members 10a and 10b moved by the drive mechanism is provided, so that the opening 14 is provided.
It is possible to automatically correct the positions of a and 14b,
Even if the positions of the openings 14a and 14b change due to aging or thermal deformation, the position can be appropriately corrected, and the effect of maintaining the accuracy of the apparatus can be obtained.

In the above embodiment, the light emitting section 1
Although the configuration is such that the detection light is irradiated from the mercury lamp 6, the present invention is not limited to this. For example, the beam B irradiated from the mercury lamp 2 is guided to the substrate stage 5 by a light propagation means such as a light guide, and the detection light is transmitted The configuration may be a beam B. In this case, it is not necessary to separately provide a light emitting unit, which can contribute to miniaturization and cost reduction of the device.

Further, in the above embodiment, the light emitting section 16 is provided on the substrate stage 5, and the photomultiplier 17 is provided between the fly-eye integrator 9 and the reticle blind 10. However, the present invention is not limited to this. Instead, as shown in FIG. 5, the light emitting portion is a mercury lamp 2, a photomultiplier tube 17 is provided on the substrate stage 5, and a beam B as detection light is applied to the photomultiplier tube 1 via a reflection mirror 12a.
7 may be used.

In the above-described embodiment, the alignment marks 15a to 15d and the reticle mark are formed as slit-shaped opening patterns. However, not the openings but the shielding slit marks and other various shapes can be adopted.

As the substrate P, not only a glass substrate for a liquid crystal display device, but also a semiconductor wafer for a semiconductor device, a ceramic wafer for a thin-film magnetic head, or an original mask or reticle (synthetic quartz) used in an exposure apparatus. , Silicon wafer) and the like.

The exposure apparatus 1 includes a reticle R and a substrate P
In a step-and-repeat type exposure apparatus (stepper) that exposes the pattern of the reticle R while the substrate P is stationary and sequentially moves the substrate P stepwise, the pattern of the reticle R is moved synchronously with the reticle R and the substrate P. And a step-and-scan type scanning projection exposure apparatus (scanning stepper).

The types of the exposure apparatus 1 include not only the above-described liquid crystal display device manufacturing but also an exposure apparatus for manufacturing a semiconductor, an exposure apparatus for manufacturing a thin film magnetic head, an imaging device (CCD), a reticle R, and the like. Can be widely applied.

As the light source of the illumination optical system 3, bright lines (g-line (436 nm), i-line (365 nm)) generated from the mercury lamp 2 and a KrF excimer laser (248n)
m), an ArF excimer laser (193 nm), an F ₂ laser (157 nm), X-rays, or the like can be used. Alternatively, a high frequency such as a YAG laser or a semiconductor laser may be used.

The magnification of the projection optical system 4 may be not only a reduction system but also an equal magnification or an enlargement system. Further, as the projection optical system 4, when far ultraviolet rays such as an excimer laser are used, a material that transmits far ultraviolet rays such as quartz or fluorite is used as a glass material, and when a F ₂ laser is used, a catadioptric or refraction type is used. Use an optical system.

When a linear motor is used for the substrate stage 5 or the reticle stage RS, either an air levitation type using an air bearing or a magnetic levitation type using Lorentz force or reactance force may be used. In addition, each stage may be of a type that moves along a guide, or may be a guideless type in which no guide is provided.

The reaction force generated by the movement of the substrate stage 5 may be mechanically released to the floor (ground) using a frame member. The reaction force generated by the movement of the reticle stage RS may be mechanically released to the floor (ground) using a frame member.

The illumination optical system 3 and the projection optical system 4 each composed of a plurality of optical elements are respectively incorporated in the exposure apparatus main body to adjust the optical properties, and the reticle stage RS and the substrate stage 5 composed of many mechanical parts are exposed. The exposure apparatus 1 of the present embodiment can be manufactured by attaching wires and pipes to the apparatus main body and performing comprehensive adjustments (electrical adjustment, operation confirmation, and the like). It is desirable that the manufacture of the exposure apparatus 1 be performed in a clean room in which temperature, cleanliness, and the like are controlled.

For a device such as a liquid crystal display device or a semiconductor device, a step of designing the function and performance of each device, a step of manufacturing a reticle R based on the design step, a step of manufacturing a glass substrate P, a wafer, etc. Exposing the pattern of the reticle R to the substrate P and the wafer by the exposure apparatus 1 of the embodiment described above;
It is manufactured through a step of assembling each device, an inspection step, and the like.

[0053]

As described above, in the exposure apparatus according to the first aspect, the blind device has the mark indicating the position of the blind device, and the detecting device detects the mark. . Thus, in this exposure apparatus, it is possible to simplify the work and eliminate the work time generated due to the test exposure, to shorten and stabilize the work time, and to separately provide materials and equipment necessary for the test exposure. Since the necessity is eliminated, the effect that the size and cost of the device can be reduced can be obtained.

According to a second aspect of the present invention, in the exposure apparatus, the detecting device comprises:
It is configured to include an irradiation unit that irradiates the detection light and a light receiving unit that receives the detection light from the mark. Accordingly, in this exposure apparatus, the position of the blind device can be detected by receiving the detection light emitted by the irradiation unit by the light receiving unit.
This simplifies the work involved in the test exposure and eliminates the work time involved in the test exposure, shortening and stabilizing the work time, and eliminating the need for additional materials and equipment required for the test exposure. In addition, it is possible to obtain an effect that the size and cost of the device can be reduced.

The exposure apparatus according to claim 3 has a configuration in which the irradiation unit is provided on the substrate stage. Thus, in this exposure apparatus, it is possible to obtain the correction amount in a state similar to the state of being actually projected on the substrate, including the distortion of the projection optical system, and to perform the positioning of the mask and the blind apparatus with high accuracy. The effect that it can be obtained is obtained.

The exposure apparatus according to claim 4 has a configuration in which the detection device detects a mark while the substrate stage moves. As a result, in this exposure apparatus, it is possible to obtain the correction amount in a state closer to the state actually projected on the substrate, and it is possible to obtain the effect that the positioning of the mask and the blind apparatus can be performed with high accuracy.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an embodiment of the present invention, and is a schematic configuration diagram of an exposure apparatus including a mark detection device.

FIG. 2 is a plan view showing an opening member of a reticle blind constituting the exposure apparatus.

FIG. 3 is a plan view of an alignment mark formed on the opening member.

FIG. 4 is a diagram illustrating an embodiment of the present invention, and is a diagram illustrating a relationship between a position of a light emitting unit in a scanning direction and a signal level detected by a photomultiplier tube.

FIG. 5 is a view showing another embodiment of the present invention,
FIG. 2 is a schematic configuration diagram of an exposure apparatus in which a photomultiplier is provided on a substrate stage.

[Explanation of symbols]

P Substrate R Reticle (mask) 1 Exposure device 5 Substrate stage 6 Mark detection device (detection device) 10 Reticle blind (blind device) 15a, 15b, 15c, 15d Alignment mark (mark) 16 Light emitting unit (irradiating unit) 17 Photoelectron increase Doubler (light receiving part)

Claims (4)

[Claims] 1. An exposure apparatus, comprising: a blind device for defining an illumination area of a mask having a pattern; and exposing a pattern image transmitted through the illumination area to a substrate, wherein the blind apparatus indicates a position of the blind apparatus. An exposure apparatus having a mark, and comprising a detection device for detecting the mark provided on the blind device. 2. The apparatus according to claim 1, wherein the detection device includes an irradiation unit that irradiates detection light for detecting the mark, and a light receiving unit that receives the detection light from the mark. Exposure equipment. 3. The exposure apparatus according to claim 2, further comprising a substrate stage that holds and moves the substrate, and wherein the irradiation unit is provided on the substrate stage. 4. The exposure apparatus according to claim 3, wherein the detection device detects the mark while moving the substrate stage.