JPH07295229A - Alignment method of projected image for magnifiedprojection type aligner - Google Patents

Abstract

PURPOSE:To make it possible to exposure circuit patters of a color liquid crystal display panel while maintaining high superposition accuracy with color filters with a magnified projection type aligner having a non-telecentric optical system. CONSTITUTION:A color filter substrate is first supplied onto a stage 107 and the positions of the alignment marks formed thereon are previously measured and are stored in a memory. A glass substrate 103 is supplied onto the stage 107. The preferable exposure positions and inclination are calculated within the three-dimensional space of the glass substrate 103 in accordance with the measurement results stored in this memory. Next, the stage 107 is finely adjusted in accordance with the results of the calculation and the exposure positions and inclination of the glass substrate 103 are adjusted. Consequently, the circuit patterns are deformed according to the deformation and are exposed on the glass substrate 103 even if the color filter patterns on the color filter substrate are deformed from the correct absolute sizes and, therefore, the good superposing accuracy is obtd. between the circuit patterns and the color filters.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of aligning a projected image in a magnifying projection type exposure apparatus, and more specifically, in a magnifying projection type exposure apparatus used for producing a color liquid crystal display panel, The present invention relates to a method of aligning an exposure position of an image projected on a screen.

[0002]

2. Description of the Related Art Generally, a circuit pattern is formed in a liquid crystal display panel by repeating steps such as film formation, resist coating, exposure, development and etching on a glass substrate. In particular, in the case of a color liquid crystal display panel, the circuit pattern can be made finer in order to increase the number of pixels, improve the aperture ratio, and realize high bonding accuracy with the color filter. High overlay accuracy and high absolute dimensional accuracy are required. Hereinafter, the accuracy required in the case of the color liquid crystal display panel will be described in more detail.

FIG. 10 shows a thin film transistor (TFT; T).
FIG. 3 is an exploded perspective view showing a general laminated structure of a color liquid crystal display panel using a thin film transistor). In FIG. 10, the TFT panel 1 is configured by forming a circuit pattern having a multilayer structure on a glass substrate. The color filter 2 is composed of R, G, B pixel filters arranged in a matrix on a glass substrate. The TFT panel 1 and the color filter 2 are attached to each other with a predetermined gap so that the transistor forming position and the pixel filter forming position coincide with each other. At this time, liquid crystal is filled in the gap between them. Furthermore, the upper surface of the color filter 2 and T
The polarizing plate 3 is arranged on the lower surface of the FT panel 1, and the color liquid crystal display panel 10 is completed.

In the color liquid crystal display panel 10 as described above, when the circuit pattern is exposed on the TFT panel 1, high overlay accuracy is required between the circuit patterns of the multilayer structure. Moreover, high absolute dimensional accuracy is required between each circuit pattern and the color filter 2. If misalignment occurs between circuit patterns, a thin film transistor that does not perform the desired switching operation is formed,
The display becomes impossible in that part. If the absolute dimensional accuracy between the color filter and the color filter is low, when the TFT panel 1 and the color filter 2 are bonded together, the thin film transistor forming position and the R, G, B pixel filter forming position are formed therebetween. The back light (back illuminating light) whose transmission / blocking is controlled by the thin film transistor element does not pass through the pixel filter of the corresponding color, resulting in color misregistration. In particular,
Since the color filter 2 is manufactured in a completely different process from the TFT panel 1, positional deviation easily occurs, and maintaining a high absolute dimensional accuracy between them is an important issue for improving the yield. However, recently, in order to improve mass productivity, a glass substrate on which a circuit pattern for a plurality of panels is formed and a glass substrate on which a color filter pattern for a plurality of panels are formed are stuck together and then cut into a plurality of sheets. Color liquid crystal display panels are being manufactured at the same time, and in such a case, simply increasing the absolute dimensional accuracy would not work well for bonding between the two, and a large number of defective products might occur. .

In view of the above technical circumstances, an exposure apparatus (hereinafter, simply referred to as an exposure apparatus) for exposing a circuit pattern of a color liquid crystal display panel on a glass substrate,
High positioning accuracy is required. Many conventional exposure apparatuses apply the exposure technique used in the manufacturing process of semiconductor devices to meet such requirements.

FIG. 11 is a diagram showing the structure of an optical system in a conventional exposure apparatus. In FIG. 11, light from a light source that has passed through a reticle (original plate on which a mask pattern of a circuit pattern is drawn) 101 is converged by a projection lens 102 and imaged on a glass substrate 103. As shown in FIG. 11, in the conventional exposure apparatus, a principal ray (a ray passing through the center of the aperture stop of the luminous flux that contributes to image formation) on the exit side, that is, between the projection lens 102 and the glass substrate 103. A so-called telecentric optical system that is parallel to the optical axis of 102 is adopted. The conventional exposure apparatus adopts such a telecentric optical system because it is formed on the glass substrate 103 even if the upper surface position of the glass substrate 103 fluctuates vertically within the depth of focus due to individual differences in thickness and the like. This is because the magnification, that is, the size of the formed image does not change.

[0007]

By the way, in the exposure apparatus using the above-mentioned telecentric optical system, the aperture of the projection lens 102 has an exposure size of one shot, that is, an image projected on the glass substrate 103. Must be larger than size. However, if a circuit pattern of a 10-inch class liquid crystal display panel is exposed in one shot, the diameter of the projection lens will be about 400 mm, which is difficult to realize in terms of manufacturing cost and weight.

Therefore, the conventional exposure apparatus had no choice but to reduce the exposure size of one shot, and it was not possible to expose a 10-inch class circuit pattern once. Therefore, in the conventional exposure apparatus, as shown in FIG. 12, one circuit pattern 104 is divided into a plurality of areas indicated by dotted lines, and partial exposure is performed in each of the divided areas, so that the whole area is exposed. I was trying to get the circuit pattern as. However, in such a method, it is necessary to repeat the exposure work in order to draw one circuit pattern, which requires a great deal of labor and time. Further, since high connection accuracy is required between each area, accurate positioning work must be performed in each area, which requires much labor and time.

Therefore, as shown in FIG. 13, it is conceivable to obtain a large exposure size by using a projection lens having a small aperture by employing a non-telecentric optical system at least on the exit side. That is, in the optical system of FIG. 13, since the chief ray between the projection lens 102 and the glass substrate 103 is inclined with respect to the optical axis of the projection lens, the light pattern transmitted through the reticle 101 is equal to or larger than the aperture of the projection lens 102. It is possible to enlarge and project. Therefore, a large exposure size can be obtained even with a projection lens having a small aperture. However, in the magnifying projection type exposure apparatus which employs such a non-telecentric optical system, the following other problems occur.

(1) Since the chief ray around the exposure area is inclined, if the distance between the projection lens 102 and the glass substrate 103 changes due to individual differences in the thickness of the glass substrate 103, it is projected on the glass substrate 103. The size of the image of the reticle 101 is changed. Therefore, the dimensional accuracy of the exposed circuit pattern deteriorates. When exposing the circuit pattern of the first layer, there is no alignment mark to be superimposed on the glass substrate 103, and the absolute size of the projected image of the circuit pattern is large due to the position in the direction perpendicular to the surface of the glass substrate 103. It fluctuates.

(2) As described above, the circuit pattern of the color liquid crystal display panel must be manufactured with correct absolute dimensions in order to bond it to the color filter 2 (see FIG. 10). If the dimensions change, the bonding accuracy with the color filter is significantly reduced.

Therefore, an object of the present invention is to make it possible to expose a circuit pattern in a magnifying projection type exposure apparatus having a non-telecentric optical system so that the overlay accuracy with a color filter becomes high. .

[0013]

The invention according to claim 1 is
A method for aligning an exposure position of an image projected on a substrate in a magnifying projection type exposure apparatus used for manufacturing a color liquid crystal display panel, wherein the magnifying projection type exposure apparatus has a substrate on its upper surface. The stage to be placed,
A light pattern transmitted through the reticle is magnified and projected on the substrate on the stage, and at least the non-telecentric projection lens in which the chief ray between the substrate and the optical axis is inclined, and the stage is used as the optical axis of the projection lens. First driving means for driving in the orthogonal XY plane, second driving means for independently driving the stage in at least three places in the Z-axis direction parallel to the optical axis of the projection lens, and on the substrate. A plurality of alignment scopes for observing the formed or projected alignment marks or images thereof, and a stage X
An XY position detecting means for detecting a position in the Y plane and an upper surface position detecting means for detecting the upper surface position of the substrate along the Z-axis direction at a plurality of positions are provided, and the color filter pattern and the upper surface position detecting means are provided on the upper surface. A first substrate on which a plurality of alignment marks are formed is supplied onto a stage.
On the first substrate, and the second step of fixing the first substrate at a predetermined position in the three-dimensional space by moving the stage by the first and second driving means. A third step of observing each alignment mark with each alignment scope and measuring their positions in the XY plane using XY position detecting means;
A fourth step of storing and holding the measurement result of the third step in the memory
And the fifth step of replacing the first substrate on the stage with the second substrate on which the circuit pattern is to be exposed, and based on the measurement results stored and held in the memory,
A sixth step of calculating a preferable exposure position and inclination of the second substrate in the three-dimensional space, and controlling the first and second driving means based on the calculation result of the sixth step, A seventh step of adjusting the exposure position and inclination of the second substrate.

[0014]

In the invention according to claim 1, the position of the alignment mark on the first substrate (on which the color filter pattern is formed) is measured and stored in advance, and the second substrate (the circuit pattern is (Exposure) is supplied onto the stage, a preferable exposure position and inclination in the three-dimensional space of the second substrate is calculated based on the measurement result stored in advance, and based on the calculation result. The exposure position and the inclination of the second substrate are adjusted. As a result, even if the color filter pattern on the first substrate is deformed from the correct absolute size, the circuit pattern is deformed according to such deformation and is exposed on the second substrate. The overlay accuracy between the first substrate and the second substrate is good.

[0015]

1 is an external perspective view showing the structure of a magnified projection type exposure apparatus for carrying out an alignment method according to an embodiment of the present invention. In FIG. 1, a reticle 101 is housed and arranged above a projection lens 102 in a holder (not shown). At the center of this reticle 101,
A mask figure 105 for a circuit pattern is drawn. Further, alignment marks P1 to P4 for positioning are drawn at four corners around the mask figure 105. Although not shown, a main light source for irradiating the mask figure 105 and a plurality of alignment light sources for individually irradiating each of the alignment marks P1 to P4 are arranged above the reticle 101.

Below the projection lens 102, a stage 107 is arranged on a base (not shown).
The glass substrate 103 is placed on 07. The stage 107 has six drive axes X1, X2, Y, Z1, Z2, Z3 in a three-dimensional Cartesian coordinate system X, Y, Z, and is configured to be movable along each of these drive axes. ing.
The drive axes X1 and X2 parallel to the X axis are orthogonal to the optical axis of the projection lens 102 and the first side (short side in the figure) of the stage 107. By thus having two drive axes X1 and X2 in the X-axis direction, the stage 107
Can be rotated around the optical axis of the projection lens 102, that is, in the θ-axis direction. The drive axis Y is the optical axis of the projection lens 102 and the second side of the stage 107 (the side orthogonal to the first side, which is the long side in the figure).
Is orthogonal to. Drive axes Z1, Z2 parallel to the Z-axis direction
Z3 is parallel to the optical axis of the projection lens 102.
The drive axes Z1, Z2, Z3 are preferably arranged on the vertices of an equilateral triangle or an isosceles triangle. Also, four or more drive shafts may be provided in the Z-axis direction.

Mirrors 108 and 109 are attached to the first and second sides of the stage 107, respectively. In the vicinity of the mirror 108, two laser interferometers 110 and 111 are fixedly provided on a base (not shown). These laser interferometers 110 and 111 are
In cooperation with the mirror 108, the position of the stage 107 along the drive axis X1 and the position of the stage 107 along the drive axis X2 are measured with high accuracy by utilizing the interference effect of laser light. In addition, in the vicinity of the mirror 109, the laser interferometer 11
2 is fixedly provided on a base (not shown). The laser interferometer 112 cooperates with the mirror 109 and utilizes the interference effect of the laser light to make the stage 107 along the drive axis Y.
The position of is measured with high accuracy. These laser interferometers 110
Through 112, the position of the stage 107 in the XY plane and the rotation angle in the θ-axis direction can be measured with high accuracy. A reference mark 113 is formed on the upper surface of the stage 107 near the first side.

Above the stage 107, the glass substrate 1
Four alignment scopes 114 to 117 are provided in order to observe the images P′1 to P′4 of the alignment mark formed on the display panel 03 or the alignment mark enlarged and projected on the glass substrate 103. Each of the alignment scopes 114 to 117 includes an objective lens 114a to
117a and a television camera 114b including a CCD element and the like
To 117b. Further, above the stage 107, laser displacement meters 119 to 122 for fixedly detecting the upper surface position of the glass substrate 103 along the Z-axis direction are provided fixedly. The alignment scopes 114 to 117 can be independently moved according to the size of the reticle 101 to be exposed.
Further, as a device for detecting the upper surface position of the glass substrate 103 in a non-contact manner, the above laser displacement meters 119 to 12
Instead of 2, an air micrometer or an electrostatic displacement meter may be used. The projection lens 102, the reticle 101 holder, the alignment scopes 114 to 117, and the laser displacement meters 119 to 122 are supported by a support member (not shown).

FIG. 2 is a block diagram showing the electrical construction of the magnified projection type exposure apparatus of FIG. In Figure 2, CP
The U 131 is an operation device 13 such as a memory 132 and a keyboard.
3 together with the display device 134 to form the workstation 130. In addition, the CPU 131
The lighting control unit 14 via the system bus 135.
1, each axis control unit 142, alignment scope 114 ~
117, laser displacement meters 119 to 122, laser interferometer 1
10 to 112 are connected. The lighting control unit 141
The turning on / off of the above-mentioned main light source and alignment light source is controlled. Each axis control unit 142 has each drive axis X1, X2,
Each drive motor (not shown) provided corresponding to Y, Z1, Z2, Z3 is controlled.

The operation of the magnifying projection type exposure apparatus shown in FIGS. 1 and 2 will be described below. In this embodiment, as an example, a circuit pattern for four panels is formed on one glass substrate 103. Shall be done. Therefore, on the glass substrate 103, exposure is performed at the first to fourth exposure positions as shown in FIG.

First, referring to the flow chart of FIG.
The calibration operation of each of the alignment scopes 114 to 117 will be described. The CPU 131 initializes the count value of the counter n (for example, provided in the memory 132) to 1 (step S101). Next, the CPU 131 activates each axis control unit 142, and at the center of the visual field of the alignment scope (first, the first alignment scope 114) corresponding to the count value of the counter n, the reference mark 11 is displayed.
The stage 107 is moved so that 3 is positioned (step S102). Next, the CPU 131 measures the XY coordinate position of the stage 107 using the laser interferometers 110 to 112, and stores the measurement result in the memory 132 (step S103). Next, the CPU 131 adds 1 to the count value of the counter n (step S104),
It is determined whether the count value is 5 or more (step S105). If the count value of the counter n is 4 or less (in the case of n ≦ 4), there is an alignment scope whose measurement has not been completed, and therefore the CPU 131 executes the operations of the above steps S102 to S104 again, and remains. Repeat the measurement operation for the alignment scope of. When the measurement operation for all the alignment scopes is completed, the CPU 131 determines each alignment scope 114 based on the measurement data stored in the memory 132.
The absolute distances K1, K2, K3, K4 (see FIG. 5) between 1 to 117 are calculated (step S106). For example, the absolute distance K1 is 1 from the measurement value of the second laser interferometer 110.
It is obtained by subtracting the measurement value of the laser interferometer 110 for the second time. Further, the absolute distance K2 is calculated from the measurement value of the laser interferometer 112 for the third time and the laser interferometer 112 for the second time.
It is obtained by subtracting the measured value of. The calculation result of step S106 is stored in the memory 132 (step S107).

Next, referring to the flowchart of FIG.
The position measuring operation for the color filter substrate will be described.
First, the color filter substrate is supplied onto the stage 107 (step S201). The color filter substrate supplied at this time has four panels of color filter patterns drawn on the glass substrate at the first to fourth drawing positions (corresponding to the first to fourth exposure positions shown in FIG. 3). Four alignment marks are drawn at predetermined positions around each color filter pattern. Next, CP
The U 131 activates each axis control unit 142 and adjusts the upper surface position of the color filter substrate to the optimum focus surface of the projection lens 102 and the alignment scopes 114 to 117 (step S202). The position of the optimum focus plane is
It is measured in advance at the time of assembling the exposure apparatus, and the measured value is stored in the memory 132 as the substrate upper surface reference position data. Therefore, the CPU 131 uses the laser displacement meter 11
The upper surface position of the color filter substrate is adjusted so that the measured values 9 to 122 match the substrate upper surface reference position data stored in the memory 132.

Next, the CPU 131 controls each axis control section 142.
Is started, and the stage 107 is moved in the drive axes X1, X2, and Y directions so that the four alignment marks attached to the color filter pattern at the first drawing position are within the visual fields of the alignment scopes 114 to 117, respectively. (Step S203). Each alignment scope 114
The alignment marks that have entered the visual field of to 117 are displayed on the display device 134.

Next, the CPU 131 uses the laser interferometer 11
The XY coordinate position of each alignment mark is measured using 0 to 112 (step S204). Here, the absolute distances K1 to K between the alignment scopes 114 to 117
4 is measured in advance and stored in the memory 132 (see FIG. 4), each alignment scope 114-1
If the amount of deviation of each alignment mark from the center of the visual field 17 is measured on the screen of the display device 134, the XY coordinate position of each alignment mark can be easily obtained from the measurement values of the laser interferometers 110 to 112. Next, the measurement result of step S204 is stored in the memory 132 (step S205). Next, the CPU 131 determines whether or not there is a drawing position whose measurement has not been completed on the color filter substrate (step S206). if,
If there is a drawing position that has not been measured, the CPU
The 131 moves the stage 107 to the next drawing position (for example, the second drawing position) (step S207), and repeats the operations of steps S204 to S206 described above. on the other hand,
When the measurement work for all the drawing positions, that is, the first to fourth drawing positions is completed, the color filter substrate is ejected from the stage 107 (step S208).

By the way, when manufacturing the color filter substrate as described above, each color filter pattern and each associated alignment mark are accurately positioned and drawn at a predetermined absolute position. Are stored in the memory 132 in advance. Therefore,
The circuit pattern may be exposed at the absolute position corresponding to the color filter pattern and the alignment mark. However, the drawing positions of the color filter pattern and the alignment mark on the color filter substrate may be displaced or distorted for some reason (for example, the difference between the lots of the thickness of the color filter substrate).
Therefore, in the present embodiment, the deviation or distortion of the drawing position generated on the color filter substrate is allowed as it is, and the circuit pattern of the first layer is intentionally displaced by the same amount as the deviation or distortion generated on the color filter substrate. The glass substrate is exposed to light or distorted to improve the overlay accuracy between the circuit pattern and the color filter pattern. Since it is possible to assume that the amount of displacement or distortion generated on the color filter substrate is the same in the same lot, the alignment mark on the color filter substrate may be measured every time the lot changes.

Next, referring to the flowchart of FIG.
The operation of exposing the first layer circuit pattern on the glass substrate 103 will be described. First, the reticle 101 on which the mask pattern 105 of the first layer circuit pattern and the alignment mark are drawn is attached to the magnifying projection type exposure apparatus (step S301). Next, stage 10
A new glass substrate 103 with no light exposure on 7
(However, the photoresist film is applied) is supplied (step S302). Next, the CPU 131
Each axis control unit 142 is activated, and the stage 107 is moved so that the projection lens 102 and the alignment scopes 114 to 117 are located above the first exposure position (see FIG. 3) (step S303).

Next, the CPU 131 reads the coordinate data of the alignment mark measured at the corresponding drawing position on the color filter substrate from the memory 132 (step S304). Next, the CPU 131, based on the coordinate data read from the memory 132, performs the first exposure to be performed.
A preferable position / size / inclination of the circuit pattern of the layer is calculated (step S305). That is, the CPU 131
Calculates the position, size, and inclination of the circuit pattern to be exposed, so as to match the position, size, and inclination of the color filter pattern on the color filter substrate. Next, the CPU 131 activates each axis control unit 142 and moves the stage 107 to the X position according to the calculation result of step S305.
Finely move in the YZθ direction (step S306). As a result, the position / shape of the image of the circuit pattern projected on the glass substrate 103 matches the position / shape of the color filter pattern on the color filter substrate.

Next, the CPU 131 has the illumination control section 141.
To turn on the main light source and the alignment light source,
The circuit pattern and the alignment mark of the first layer are exposed on the glass substrate 103 (step S307). At this time, on the glass substrate 103, as shown in FIG. 8, together with the circuit pattern of the first layer, for example, five sets of alignment marks Ma1 to Ma4, Mb1 to Mb4, Mc1 to M are formed.
c4, Md1 to Md4 and Me1 to Me4 are exposed.
The alignment marks Ma1 to Ma4 are used for alignment of the second layer circuit pattern, the alignment marks Mb1 to Mb4 are used for alignment of the third layer circuit pattern, and the alignment mark Mc1.
To Mc4 are used for the alignment of the circuit pattern of the fourth layer, the alignment marks Md1 to Md4 are used for the alignment of the circuit pattern of the fifth layer, and the alignment marks Me1 to Me4 are the uppermost layers. It is used for alignment of the circuit pattern of the sixth layer. The alignment marks Mb1 to Mb used for alignment of the circuit patterns on the third and subsequent layers.
4, Mc1 to Mc4, Md1 to Md4, Me1 to Me4
May be formed at the time of forming the circuit patterns of the second and subsequent layers.

Next, the CPU 131 uses the glass substrate 103.
It is determined whether or not there is an exposure position where the exposure has not ended (step S308). If there is an exposure position where the exposure has not ended, the CPU 131 moves the stage 107 to the next exposure position (for example, the second exposure position) (step S309), and the above-described step S30.
The operations of 4 to S308 are repeated. On the other hand, when the exposure work for all the exposure positions, that is, the first to fourth exposure positions is completed, the CPU 131 ends the exposure operation of the circuit pattern of the first layer. Then, the glass substrate 103 is discharged from the stage 107, and undergoes steps such as development and etching to form a first-layer circuit pattern and alignment marks as shown in FIG. 8 on its upper surface.

Next, referring to the flowchart of FIG.
The operation of exposing the second and subsequent circuit patterns on the glass substrate 103 will be described. First, the reticle 101 is mounted on the magnifying projection type exposure apparatus (step S401).
The reticle 101 mounted at this time has the i-th layer (i
Is an integer greater than or equal to 2) circuit pattern mask figure 105
Is drawn. Next, the glass substrate 103 is supplied to the stage 107 (step S402). The glass substrate 103 supplied at this time is provided with, for example, five sets of alignment marks M together with the circuit patterns up to the i-1th layer.
a1 to Ma4, Mb1 to Mb4, Mc1 to Mc4, Md
1 to Md4 and Me1 to Me4 are formed. However, each set of alignment marks may be formed at the time of exposure of at least one layer before the circuit pattern layer in which it is used.

Next, the CPU 131 controls each axis control section 142.
Is started, and the stage 107 is moved in the drive axes X1, X2, and Y directions so that the alignment scopes 114 to 117 are located at the first exposure position (see FIG. 3) of the glass substrate 103 (step S403). Next, the CPU 131
Activates the illumination controller 141 to turn on the alignment light source (not shown) (step S404). As a result, on the glass substrate 103, the images P′1 to P4 of the alignment marks P1 to P4 formed on the reticle 101 are formed.
P′4 is projected (see FIG. 1).

Next, the CPU 131 observes the alignment mark images P'1 to P'4 on the glass substrate 103 using the alignment scopes 114 to 117, and measures the respective XY coordinate positions (step S405). Since the absolute distances K1 to K4 between the alignment scopes 114 to 117 have already been measured (see FIG. 4), the alignment mark images P′1 to P′4 from the visual field centers of the alignment scopes 114 to 117 are obtained. The XY coordinate position of each can be measured by detecting the deviation. Next, the CPU 131 uses the alignment scopes 114 to 117 to align the alignment marks Ma1 to Ma4, M4 formed on the glass substrate 103.
b1-Mb4, Mc1-Mc4, Md1-Md4, Me
Observe the corresponding one among 1 to Me4, and check their X
The Y coordinate position is measured (step S406). Then C
The PU 131 calculates an error between the position of each alignment mark image measured in step S405 and the position of the real image of each alignment mark measured in step S406 (step S407).

Next, the CPU 131 executes the above step S4.
It is determined whether or not the error calculated in 07 is within a predetermined allowable range (close enough to 0) (step S408). If the error is out of the allowable range, the CPU 131 causes the drive axes (X1, X1) of the stage 107 so that the error falls within the allowable range.
A correction amount in the 2, Y, Z1 to Z3, θ axis direction is calculated (step S409). Next, the CPU 131 causes each axis control unit 1 to operate according to the correction amount calculated in step S409.
42 is controlled to finely move the stage 107 in each drive axis direction (step S410). After that, the CPU 131
Until the error falls within the allowable range, the above step S40
The operations of 5 to S410 are repeated.

When the above error is within the allowable range, the CPU 1
31 exposes the circuit pattern of the i-th layer on the glass substrate 103 (step S411). Next, the CPU 131
Determines whether or not there is an unexposed exposure position on the glass substrate 103 (step S412).
If there is an exposure position that has not been exposed,
The CPU 131 moves the stage 107 to the next exposure position (for example, the second exposure position) (step S413),
The operations of steps S404 to S412 described above are repeated.
On the other hand, when the exposure operation at all the exposure positions on the glass substrate 103 (that is, the first to fourth exposure positions) is completed, the CPU 131 ends the operation and the glass substrate 103 is ejected from the stage 107.

As described above, on the glass substrate 103, the circuit pattern of the i-th layer (if necessary, the alignment mark is formed) on the circuit pattern of the (i-1) th layer with extremely high overlay accuracy. ) Is exposed. Next, the glass substrate 103 is subjected to steps such as development and etching to form an i-th layer circuit pattern on the upper surface thereof.

In the above embodiment, the alignment is performed by using different alignment marks for each layer for the following reason. That is, in the above-described embodiment, during alignment, the alignment light is accompanied by the fine movement of the stage 107 (see step S410) and the glass substrate 103.
This is because the area around the alignment mark to be observed is exposed in that layer, and it is difficult to perform alignment of other circuit patterns using the same alignment mark again.

Further, in the above embodiment, the alignment mark observed on the glass substrate 103 during the alignment of the circuit pattern of the i-th layer is the first mark as described above.
It may be formed with the circuit pattern of the layer, or may be formed with the circuit pattern of any of the second layer to the (i-1) th layer. In an actual color liquid crystal display panel, there are some layers that have strict overlay accuracy and some layers that do not have that strict overlay accuracy.Therefore, for layers with strict overlay accuracy, the alignment mark formation points are dispersed so that alignment marks can be directly compared. You may allow it.

In the above embodiment, the glass substrate 10 is used when the circuit patterns of the second and subsequent layers are aligned.
Although the alignment mark image is projected on 3 to match the already formed alignment mark, the alignment mark is temporarily projected on the test glass substrate and its position is stored as data. Alignment may be performed by moving the stage 107 so that the position as the data and the actual position of the alignment mark observed on the glass substrate 103 match. That is, in the present invention, the method of aligning the circuit patterns on the second and subsequent layers is not limited to the method of the above embodiment, and various methods can be adopted.

In the present invention, at least the principal ray between the projection lens 102 and the stage 107 (emission-side principal ray) is not telecentric, and the reticle 10 is used.
The chief ray between the 1 and the projection lens (the chief ray on the incident side) is
It may be telecentric or non-telecentric.

[0040]

According to the present invention, the position of the alignment mark on the first substrate (on which the color filter pattern is formed) is measured and stored in advance, and the second substrate (circuit Pattern is exposed) is supplied onto the stage, the preferable exposure position and inclination in the three-dimensional space of the second substrate are calculated based on the measurement result stored in advance, and the calculated result is obtained. Since the exposure position and the inclination of the second substrate are adjusted based on
Even if the color filter pattern on the first substrate is deformed from the correct absolute size, the circuit pattern is deformed accordingly and exposed on the second substrate.
Therefore, the overlay accuracy is good between the first substrate and the second substrate.

[Brief description of drawings]

FIG. 1 is an external perspective view showing the configuration of a magnified projection type exposure apparatus that executes an alignment method according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an electrical configuration of the enlarged projection type exposure apparatus of FIG.

FIG. 3 is a diagram showing each exposure position on the glass substrate when the circuit patterns for a plurality of panels are exposed on the glass substrate.

FIG. 4 is a flowchart showing an operation when calibrating the absolute distance between each alignment scope in the magnified projection type exposure apparatus of FIG.

5 is a diagram showing a positional relationship between a projection lens and each alignment scope in the magnified projection type exposure apparatus of FIG.

6 is a flowchart showing an operation of measuring an alignment mark formation position on a color filter substrate in the magnified projection type exposure apparatus of FIG.

7 is a flowchart showing an operation when exposing a circuit pattern of a first layer in the magnified projection type exposure apparatus of FIG.

FIG. 8 is a diagram showing an example of a circuit pattern and an alignment mark formed on a glass substrate.

9 is a flowchart showing an operation when exposing a circuit pattern of a second layer and subsequent layers in the magnified projection type exposure apparatus of FIG. 1. FIG.

FIG. 10 is an exploded perspective view showing an example of a laminated structure of a color liquid crystal display panel.

FIG. 11 is a diagram showing a configuration of a telecentric optical system used in a conventional exposure apparatus.

FIG. 12 is a diagram for explaining divisional exposure of a circuit pattern which is executed by a conventional exposure apparatus.

FIG. 13 is a diagram showing a configuration of a non-telecentric optical system.

[Explanation of symbols]

 101 ... Reticle 102 ... Projection lens 103 ... Glass substrate 110-112 ... Laser interferometer 113 ... Reference mark 114-117 ... Alignment scope 119-122 ... Laser displacement meter 130 ... Workstation 131 ... CPU 132 ... Memory 133 ... Manipulator 134 Display unit 141 Lighting control unit 142 Each axis control unit

Claims (1)

[Claims] 1. A magnifying projection type exposure apparatus used for manufacturing a color liquid crystal display panel, which is a method for aligning an exposure position of an image projected on a substrate, wherein the magnifying projection type exposure apparatus comprises: , A stage on which the substrate is placed and a light pattern transmitted through the reticle are magnified and projected onto the substrate on the stage, and at least the principal ray between the substrate and the stage is inclined with respect to the optical axis. A telecentric projection lens; a first driving means for driving the stage in an XY plane orthogonal to the optical axis of the projection lens; and a Z stage parallel to the optical axis of the projection lens at least at three locations. Second driven independently in the axial direction
Driving means, a plurality of alignment scopes for observing the alignment marks formed or projected on the substrate or images thereof, and XY for detecting the position of the stage in the XY plane.
The position detecting means and the upper surface position detecting means for detecting the upper surface position of the substrate along the Z-axis direction at a plurality of positions are provided, and a color filter pattern and a plurality of alignment marks are formed on the upper surface. A first step of supplying a first substrate onto the stage; and a step of moving the stage by the first and second driving means so that the first substrate is predetermined in a three-dimensional space. A second step of fixing the alignment marks on the first substrate, observing the alignment marks on the first substrate with the alignment scopes, and measuring their positions in the XY plane using the XY position detecting means. 3, a fourth step of storing and holding the measurement result of the third step in a memory, a first substrate on the stage, a circuit pattern Is replaced with a second substrate to be exposed, and a preferable exposure position and inclination of the second substrate in the three-dimensional space are calculated based on the measurement result stored and held in the memory. A sixth step, and a seventh step of adjusting the exposure position and the inclination of the second substrate by controlling the first and second driving means based on the calculation result of the sixth step. A method for aligning a projected image, comprising: