JP2001358050A - Exposure substrate manufacturing method and electro-optical device manufacturing method, and exposure substrate and electro-optical device - Google Patents

Abstract

(57) [Problem] To manufacture an exposure substrate and an electro-optical device through a projection exposure process using a projection optical system, an exposure substrate for facilitating observation of the occurrence of distortion during the exposure process. Provided are a manufacturing method, a method of manufacturing an electro-optical device, an exposure substrate, and an electro-optical device. SOLUTION: At four corners of a TFT array substrate 10 constituting an electro-optical device, hole patterns 400 as exposure evaluation patterns formed through a projection exposure step using a projection optical system are arranged. By observing the shape of each hole pattern 400 arranged at the four corners, it is observed whether or not distortion has occurred during the exposure step.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical fields of a method for manufacturing an exposure substrate and a method for manufacturing an electro-optical device, and an exposure substrate and an electro-optical device. In particular, a method of manufacturing an exposure substrate manufactured through a process of imaging transmitted light transmitted through a photomask on a substrate to be exposed using a projection optical system, such as a projection exposure process using a projection optical system and a mirror The present invention relates to a method of manufacturing an electro-optical device, an exposure substrate, and an electro-optical device.

[0002]

2. Description of the Related Art For example, a liquid crystal device as an electro-optical device has a structure in which a liquid crystal layer is held in a gap between a TFT (Thin Film Transistor) array substrate and a counter substrate which are arranged to face each other. In a TFT array substrate, a semiconductor layer is disposed on a substrate such as a quartz substrate, a gate insulating film is disposed so as to cover the semiconductor layer, and a plurality of scanning lines are disposed on the gate insulating film. Part of the scanning line is arranged corresponding to the channel region of the semiconductor layer, and functions as a gate electrode of a TFT as a switching element. Further, a first interlayer insulating film is arranged on the gate insulating film so as to cover the scanning lines, and a plurality of data lines are arranged on the first interlayer insulating film so as to intersect with the scanning lines.
The data line is electrically connected to a source region of the semiconductor layer via a contact hole formed in the gate insulating film and the first interlayer insulating film. In addition, the first
A second interlayer insulating film is disposed on the interlayer insulating film, and a pixel electrode is disposed on the second interlayer insulating film at each intersection of a scanning line and a data line. The pixel electrode is electrically connected to the drain region of the semiconductor layer via contact holes formed in the gate insulating film, the first interlayer insulating film, and the second interlayer insulating film.

In the process of manufacturing a TFT array substrate as an exposure substrate, a photolithography process is performed a plurality of times, and wiring, electrodes, switching elements, contact holes, and the like are formed by the photolithography process. This photolithography process is generally performed as follows, and a case where a contact hole is formed in an insulating film will be described below as an example.

First, an insulating film is formed on a substrate, and a resist film is formed on the insulating film. Next, the resist film is exposed through a photomask on which a contact hole pattern is drawn. By this exposure step, the resist film is exposed to light corresponding to the image of the pattern of the photomask, and a resist pattern is formed through a development step. Thereafter, the insulating film is etched using the resist pattern as a mask, thereby forming a contact hole in the insulating film.

An exposure apparatus 31 used in the above-described exposure process
6A, the illumination optical system having the light source 301 and the photomask 302 are illuminated by the illumination optical system as shown in FIG. 6A, and the transmitted light is projected onto the substrate 304 by the image projection optical system 305. And a projection optical system 303 for forming an image. As shown in FIG. 6B, the photomask 302
Is transmitted through the image projection optical system 305 to form an image on the substrate to be exposed to form an image 306. In a normal case, the image is drawn on the photomask 302 as shown in FIG. An image 306 similar in shape to the pattern being formed is formed on the substrate to be exposed. However, when a projection exposure apparatus using a lens is used, the shape of the image 306 may be distorted due to subtle distortion of the imaging projection optical system 305 or habit of the exposure apparatus itself. When such image plane distortion (distortion) such as image plane inclination and image plane curvature occurs, the resist pattern formed on the substrate to be exposed cannot be uniformly formed in a desired shape in the substrate surface. As a result, when a contact hole is formed through an etching process using such a resist pattern as a mask,
The size of the contact hole varies in the plane of the substrate, and in some cases, the contact hole may not be opened. Therefore, there arises a problem that a defective pixel is generated and a variation in switching element characteristics in a substrate surface is generated. Furthermore, such an exposed substrate is
When used in an electro-optical device as a T-array substrate, there is a problem in that display variations occur in the display surface and display characteristics deteriorate.

In the manufacturing process of the TFT array substrate, as shown in FIG. 7, when a plurality of TFT array substrates 304a are collectively manufactured from a single substrate to be exposed 304, as described above, the above-described method is employed. Due to the occurrence of such a distortion, the display characteristics vary among the TFT array substrates 304a, which causes a problem that it is difficult to always obtain a TFT array substrate having stable product characteristics.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and makes it easy to find distortion in an exposure process. It is an object of the present invention to provide a method for manufacturing an exposure substrate having stable product characteristics, an exposure substrate, and a method for manufacturing an electro-optical device having stable display characteristics without any display variation within a display surface.

[0008]

In order to solve such a problem, the present invention employs the following configuration.

The method of manufacturing an exposure substrate according to the present invention comprises the steps of (a) forming a photosensitive film on a substrate and (b) using a photomask having a pattern at a position corresponding to the outer peripheral portion of the substrate. An exposure step of projecting and exposing the film using a projection optical system; and (c) forming an exposure evaluation pattern on an outer peripheral portion of the substrate by developing the exposed film. It is characterized by.

According to such a configuration of the present invention, since the exposure evaluation pattern is formed on the outer peripheral portion of the substrate, it is possible to confirm with high accuracy whether or not distortion has occurred during the exposure step. Have. That is, when a projection exposure apparatus using a projection optical system is used, the projection optical system of the exposure apparatus is adjusted so that the focus is located near the center of the exposure substrate. For this reason, when the distortion occurs, the pattern formed on the outer peripheral portion of the substrate shows more abnormal pattern shape due to the distortion than the pattern formed on the central portion of the exposed substrate. Therefore, by forming the exposure evaluation pattern on the outer peripheral portion of the substrate, it is possible to detect the occurrence of distortion during the exposure step with high accuracy. Here, as an evaluation method, the shape of the exposure evaluation pattern in the normal case is compared with the shape of the formed exposure evaluation pattern by previously grasping the shape of the exposure evaluation pattern when there is no distortion. By doing so, it is sufficient to determine whether or not distortion has occurred.

Another method of manufacturing an exposure substrate according to the present invention comprises:
(A) a step of forming a film on the substrate, (b) a step of forming a resist film on the film, and (c) a photomask having a pattern at a position corresponding to an outer peripheral portion of the substrate. An exposure step of projecting and exposing the resist film using a projection optical system, and (d) forming a resist pattern by developing the exposed resist film;
(E) etching the film using the resist pattern as a mask to form an exposure evaluation pattern on the outer periphery of the substrate.

According to such a configuration of the present invention, since the exposure evaluation pattern is formed on the outer peripheral portion of the substrate, it is possible to confirm with high accuracy whether or not distortion has occurred during the exposure step. Have. That is, when a projection exposure apparatus using a projection optical system is used, the projection optical system of the exposure apparatus is adjusted so that the focus is located near the center of the exposure substrate. For this reason, when the distortion occurs, the pattern formed on the outer peripheral portion of the substrate has a remarkable abnormality in the pattern shape due to the distortion as compared with the pattern formed on the central portion of the exposed substrate.
Therefore, by forming the exposure evaluation pattern on the outer peripheral portion of the substrate, it is possible to detect the occurrence of distortion during the exposure step with high accuracy. Here, as an evaluation method, the shape of the exposure evaluation pattern in the normal case is compared with the shape of the formed exposure evaluation pattern by previously grasping the shape of the exposure evaluation pattern when there is no distortion. By doing so, it is sufficient to determine whether or not distortion has occurred.

Further, the present invention is characterized in that there are a plurality of the exposure evaluation patterns. According to such a configuration, it is possible to confirm the presence or absence of distortion over a wide area within the substrate surface, and it is possible to perform more accurate exposure evaluation.

Further, the substrate has a rectangular shape, the photomask has the same pattern at positions corresponding to the four corners of the substrate, and the exposure evaluation pattern is located at each of the four corners of the substrate. It is characterized by being formed.
According to such a configuration, when the substrate has a rectangular shape, the four corners of the substrate are most likely to exhibit an abnormal pattern shape due to distortion at the time of the exposure step, so that the exposure evaluation pattern is formed at the four corners of the substrate. This enables highly accurate exposure evaluation. Further, by comparing the difference in the shape of the exposure evaluation pattern formed at each of the four corners, it is possible to grasp the tendency of distortion over the entire surface of the substrate.

Further, the exposure evaluation pattern formed without any distortion in the exposure step has a circular cross section parallel to the substrate. According to such a configuration, since the exposure evaluation pattern formed without occurrence of distortion is set so that its cross-sectional shape becomes a circular pattern, the shape of the formed exposure evaluation pattern can be observed. Thus, whether or not distortion has occurred can be determined.
That is, if the shape of the exposure evaluation pattern formed on the substrate is an ellipse, it can be determined that distortion has occurred.

The pattern of the photomask has an ellipse having a major axis of a first length and a minor axis of a second length, a minor axis substantially parallel to the major axis and having a minor axis of the second length. An ellipse substantially parallel to the minor axis and having a major axis of the first length, a circle having a diameter of the first length, and a circle having a diameter of the second length. It is characterized by having.

According to such a configuration, when no distortion occurs during the exposure step, the shape of the exposure evaluation pattern is formed to be similar to the shape of the photomask. Otherwise, it can be determined that distortion has occurred. Furthermore, by forming a circle or an ellipse each having a different axis or diameter, when distortion occurs, observing the shape of the exposure evaluation pattern,
It is possible to determine in which direction and how much displacement has occurred.

The pattern of the photomask includes a rectangle having a long side having a first length and a short side having a second length, and a short side substantially parallel to the long side and having the second length. A rectangle substantially parallel to the short side and having the long side of the first length, a square having the side of the first length, and a square having the side of the second length It is characterized by having.
As described above, the shape of the photomask pattern may be square or rectangular so that the deformation of the photomask pattern at the time of exposure substrate transfer is anticipated and corrected. In such a configuration, when no distortion occurs during the exposure step, the shape of the exposure evaluation pattern is such that a circular pattern is formed with respect to the square pattern of the photomask, and the rectangular shape of the photomask is formed. An elliptical pattern is formed with respect to the shape pattern.
Even in such a case, by comparing the shape of the exposure evaluation pattern when no distortion occurs and the shape of the formed exposure evaluation pattern, it is possible to determine whether or not distortion has occurred. Furthermore,
By forming an exposure evaluation pattern using a photomask having a square or rectangular pattern with different side lengths, when distortion occurs, observe the shape of the exposure evaluation pattern and determine in which direction It is possible to determine how much displacement has occurred.

Further, a difference between the first length and the second length is set according to a resolution of an exposing machine used in the exposing step. According to such a configuration, when distortion occurs,
It is possible to accurately determine which position shift has occurred in which direction. For example, the size of the pattern formed on the photomask and the size of the exposure confirmation pattern are 1:
In the case of the same-size exposure that becomes 1, the first length and the second
Is the same as the value of the resolution line width. In the case of reduction exposure or enlargement exposure in which the size of the pattern formed on the photomask and the size of the exposure confirmation pattern are different, the length corresponding to the first length of the exposure confirmation pattern and the length of the exposure confirmation pattern The value of the difference between the first length and the second length is set such that the value of the difference from the length corresponding to the second length becomes the value of the resolution line width.
Here, the resolution line width is a practically available minimum line width when a linear resist pattern having the same width and interval is formed on a substrate.

Further, the photomask further includes an element pattern corresponding to a central portion of the substrate, and the element pattern is formed in the central portion of the substrate simultaneously with the formation of the exposure evaluation pattern. Features. According to such a configuration, the element pattern and the exposure evaluation pattern are formed at the same time. Therefore, when it is determined that distortion has occurred by observing the exposure evaluation pattern, the element pattern has a desired shape. It can be determined that the exposure substrate is not defective, and it can be easily determined whether or not the exposure substrate is non-defective.

According to a method of manufacturing an electro-optical device of the present invention, there is provided a method of manufacturing an electro-optical device including an exposure substrate on which a plurality of switching elements are arranged, wherein the exposure substrate is formed by the above-described method of manufacturing an exposure substrate. It is characterized by being manufactured. According to such a configuration, by observing the exposure evaluation pattern formed on the exposure substrate, only a non-defective exposure substrate can be selected and incorporated into the electro-optical device. Therefore, a good electro-optical device can be efficiently obtained.

An exposure substrate according to the present invention is manufactured by the above-described method for manufacturing an exposure substrate. According to such a configuration, it is possible to easily determine whether or not the exposure substrate is non-defective by observing the exposure evaluation pattern, so that a non-defective exposure substrate is always stably obtained.

According to another aspect of the present invention, there is provided an exposure substrate including a substrate and an exposure evaluation pattern formed on a peripheral portion of the substrate through a projection exposure process using a lens.

According to this structure of the present invention, since the exposure evaluation pattern is arranged on the outer peripheral portion of the substrate, it is possible to confirm with high accuracy whether or not distortion has occurred during the exposure step. Have. That is,
When a projection exposure apparatus using a projection optical system is used, the projection optical system of the exposure apparatus is adjusted so that the focus is near the center of the exposure substrate. For this reason, when distortion occurs, the pattern formed on the outer peripheral portion of the substrate is compared with the pattern formed on the central portion of the exposed substrate.
Abnormality of the pattern shape due to the focus shift appears remarkably. Therefore, by forming the exposure evaluation pattern on the outer peripheral portion of the substrate, it is possible to detect the occurrence of distortion during the exposure step with high accuracy.

Further, a plurality of the exposure evaluation patterns are arranged on the outer peripheral portion of the substrate. According to such a configuration, it is possible to confirm the presence or absence of distortion over a wide area within the substrate surface, and it is possible to perform more accurate exposure evaluation.

Further, the substrate has a rectangular shape, and the exposure evaluation pattern having the same pattern is arranged at each of four corners of the substrate. According to such a configuration, when the substrate has a rectangular shape, the four corners of the substrate are most likely to exhibit an abnormal pattern shape due to distortion at the time of the exposure step, so that the exposure evaluation pattern is formed at the four corners of the substrate. This enables highly accurate exposure evaluation. Further, by comparing the difference in the shape of the exposure evaluation pattern formed at each of the four corners, it is possible to grasp the tendency of distortion over the entire surface of the substrate.

Further, the exposure evaluation pattern is formed by forming a plurality of holes in the film, and the cross section of the holes parallel to the substrate has a major axis of a first length and a major axis of a second length. An ellipse having a minor axis, a minor axis substantially parallel to the major axis and the second length, and an ellipse substantially parallel to the minor axis and a major axis of the first length; A circle having a diameter of one length and a circle having a diameter of the second length.

An electro-optical device according to the present invention is manufactured by the above-described method for manufacturing an electro-optical device. According to such a configuration, there is no display unevenness in the substrate plane,
An electro-optical device with stable product characteristics can be obtained.

Further, an electro-optical device according to the present invention is an electro-optical device having an exposure substrate on which a plurality of switching elements are arranged, wherein the exposure substrate comprises the above-described exposure substrate. According to such a configuration, it is possible to obtain an electro-optical device having stable product characteristics without display unevenness in the substrate surface.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings, taking a liquid crystal device as an electro-optical device as an example. In each of the drawings, the scale is appropriately set for each configuration so that each configuration has a size recognizable in the drawings.

First, the structure of the liquid crystal device is shown in FIGS.
This will be described with reference to FIG. FIG. 1 is a plan view of a TFT array substrate as an exposure substrate together with components formed thereon as viewed from the counter substrate side. FIG. 2 is a vertical cross-sectional view of the entire liquid crystal device, taken along line HH ′ of FIG. 1 including a counter substrate.
It is sectional drawing. FIG. 3 is an equivalent circuit of various elements, wirings, and the like arranged in an image display area of a TFT array substrate constituting the liquid crystal device. FIG. 4 is a plan view illustrating the image display area of the TFT array substrate. FIG. 5 is a sectional view taken along the line BB 'of FIG. FIG. 8 is an enlarged view of a hole pattern as an exposure evaluation pattern formed at four corners of the TFT array substrate.

As shown in FIG. 1, in the liquid crystal device, a sealing material 52 is provided on a TFT array substrate 10 along the edge thereof, and in parallel with the inside thereof, a light shielding film 5 is formed in a frame shape.
3 are provided. In a region outside the sealing material 52,
A data line drive circuit 101 and an external circuit connection terminal 102 are provided along one side of the TFT array substrate 10,
The scanning line driving circuit 104 is provided along two sides adjacent to the one side. Further, on the remaining one side of the TFT array substrate 10, a plurality of wirings 105 for connecting between the scanning line driving circuits 104 provided on both sides of the screen display area are provided. Hole patterns 400 are arranged at four corners on the outer periphery of the TFT array substrate. The hole pattern 400 functions as an exposure evaluation pattern, and by observing the pattern shape of the hole pattern, the TFT
Whether or not distortion has occurred during the exposure step during the manufacture of the array substrate can be confirmed. A method of observing the shape of the hole pattern 400 and the occurrence of distortion will be described later. In at least one of the corners of the opposing substrate 20, a conductive material 106 for establishing electric conduction between the TFT array substrate 10 and the opposing substrate 20 is provided. Then, as shown in FIG. 2, the counter substrate 20 having substantially the same contour as the sealing material 52 shown in FIG. 1 is fixed to the TFT array substrate 10 by the sealing material 52. A liquid crystal layer 50 is sandwiched between the opposing substrate 20 and the TFT array substrate 10.

As shown in FIGS. 3 and 4, a plurality of unit pixel areas formed in a matrix and constituting an image display area surrounded by the above-mentioned seal are provided with a plurality of scanning lines 3a crossing each other. , A pixel electrode 9a arranged in a matrix at each intersection, and a thin film transistor (hereinafter, TFT) 30 as a switching element for controlling the pixel electrode 9a. The scanning line 3a includes a linear portion and a protrusion protruding from the linear portion, and the protrusion functions as a gate electrode of the TFT 30. Further, a capacitor line 3b is arranged substantially in parallel with the scanning line 3a, and the capacitor line 3b and the pixel electrode 9a overlap each other via a first interlayer insulating film and a second interlayer insulating film, which will be described later, to form a storage capacitor 70. are doing. TFT30
Are a semiconductor layer 1, a gate insulating film described later, and a gate electrode 3.
a, and a source region described later of the semiconductor layer 1 is electrically connected to a data line 6 to which an image signal is supplied,
A drain region described later of the semiconductor layer 1 is electrically connected to the pixel electrode 9a. The data line 6 has an image signal S
, Sn are supplied to the scanning line 3a in a pulsed manner at predetermined timing with the scanning signals G1, G2,.
Is applied. When a scanning signal is applied to the scanning line 3a, the switch of the TFT 30 is turned on, and the pixel electrode 9a is turned on.
Are the image signals S1, S2, supplied from the data line 6,
.., Sn are written at a predetermined timing. The image signals S1, S2,..., Sn of a predetermined level written to the liquid crystal via the pixel electrodes 9a are held for a certain period between the counter electrodes (described later) formed on the counter substrate. The liquid crystal is
By changing the orientation and order of the molecular assembly according to the applied voltage level, the light is modulated to enable a gray scale display. Here, in order to prevent the held image signal from leaking, the above-described storage capacitor 70 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 9a and the counter electrode.

As shown in FIG. 5, the liquid crystal device 200
A liquid crystal layer 50 is provided between the FT array substrate 10 and the counter substrate 20.
Is sandwiched.

In the TFT array substrate 10, the semiconductor layer 1 is disposed on a substrate 60 such as a quartz substrate, and the gate insulating film 2 is disposed so as to cover the semiconductor layer 1. Gate insulating film 2
A plurality of scanning lines 3 and capacitance lines 3b are arranged above. The gate electrode 3a which is a part of the scanning line 3 is a semiconductor layer 1
On the channel region 1a. Further, a first interlayer insulating film 4 is arranged so as to cover the scanning lines 3 and the capacitor lines 3b, and a plurality of data lines 6 are arranged on the first interlayer insulating film 4. The data line 6 is electrically connected to the source region 1b of the semiconductor layer 1 via a contact hole 5 formed in the gate insulating film 2 and the first interlayer insulating film 4. On the second interlayer insulating film 7 including the data lines 6, a pixel electrode 9a is formed, and further, an alignment film 16 is formed. The pixel electrode 9a is electrically connected to the drain region 1c of the semiconductor layer 1 via a contact hole 8 formed in the gate insulating film 2, the first interlayer insulating film 4, and the second interlayer insulating film 7. The storage line 70 is formed in a region where the capacitor line 3b and the pixel electrode 9a overlap with the first interlayer insulating film 4 and the second interlayer insulating film 7 interposed therebetween. An alignment film 1 made of polyimide is formed on the second interlayer insulating film 7 including the pixel electrode 9a.
6 are arranged.

On the other hand, the opposing substrate 20 is formed on a substrate 80 such as a glass substrate on a matrix array of light-shielding layers 2 arranged along the scanning lines 3 and the data lines 6 on the TFT array substrate 10.
3 and a frame-shaped light-shielding layer 53 are arranged. Further, ITO (Indium Tin Oxid) is formed on the substrate 80 including the light shielding layer.
e) and an alignment film 22 made of polyimide are sequentially arranged.

Next, a detailed shape of the above-described hole pattern 400 and a method of observing the occurrence of distortion will be described with reference to FIG. FIG. 8 is an enlarged view of hole patterns formed at four corners of the TFT array substrate through an exposure process using a projection exposure apparatus using a projection optical system. FIG. 8A shows a hole pattern formed when no distortion occurs in the exposure step.
FIG. 8B shows a hole pattern formed when distortion occurs in the exposure step. For example, x
This is a hole pattern when a displacement of 0.40 μm occurs in the direction.

Here, when a projection exposure apparatus using a projection optical system is used, the projection optical system of the exposure apparatus is adjusted so that the focus is located near the center of the substrate to be exposed. For this reason, when distortion occurs, it becomes easier to find an abnormality in the hole pattern shape due to a focus shift in the outer peripheral portion of the substrate than in the central portion of the substrate to be exposed. In the present invention, since hole patterns for confirming the presence or absence of distortion are arranged at the four corners of the substrate to be exposed, it is possible to detect a hole pattern abnormality caused by distortion with high accuracy. Therefore,
By observing the shape of the hole pattern, it is possible to easily determine whether or not the pattern formed in the central portion of the substrate, that is, in the image display area and the drive circuit area here, has a predetermined shape.

The hole pattern 400 has a shape in which a plurality of holes are formed in the gate insulating film 2, the first interlayer insulating film 4, and the second interlayer insulating film 7 as films. These holes are formed such that the cross-sectional shape cut substantially parallel to the substrate becomes a circular shape or an elliptical shape. Each drawing in FIG. 8 is a diagram showing a cross-sectional shape of these holes, and corresponds to a diagram when viewed in a direction perpendicular to the substrate plane. In addition, the plurality of holes of the hole pattern 400 are formed such that the major axis and the minor axis of the ellipse of the cross-sectional shape are substantially parallel to the long side and the short side of the rectangular TFT array substrate, respectively. In FIG. 8, the hole pattern 400 is formed such that the long side of the TFT array substrate is parallel to the illustrated x direction and the short side of the TFT array substrate is parallel to the y direction.
It is arranged on an array substrate.

In the exposure step, when no distortion occurs, the hole pattern 400 is formed as shown in FIG. That is, in the drawing, from left to right along the x direction, the diameter of the circle or the length of the axis of the ellipse parallel to the x direction is 0.80 μm, 1.00 μm, and 1.20 μm.
m, 1.40 μm, 1.60 μm, and from top to bottom along the y direction, the diameter of a circle or the length of an axis parallel to the y direction of an ellipse is 0.80 μm, 1.
00 μm, 1.20 μm, 1.40 μm, 1.60 μm
And a plurality of holes 401a to 401
e, 402a-402e, 403a-403e, 404
a to 404e and 405a to 405e are formed in a matrix. For example, the hole 401a is a circle having a diameter of 0.8 μm, the hole 402b is a circle having a diameter of 1.00 μm,
The hole 401b has a major axis length of 1.00 μ along the x direction.
The length of the minor axis along the m and y directions is an ellipse of 0.80 μm, and the hole 402a has a major axis along the x direction with a length of 0.80 μm.
The ellipse is 0 μm, and the length of the minor axis along the y direction is 1.00 μm. If there is no distortion,
Hole pattern 4 at each of the four corners of the TFT array substrate
The shapes of 00 are all as shown in FIG. In this embodiment, an exposure apparatus having a resolution of 0.20 μm is used.

On the other hand, when distortion occurs, T
The shape of at least one of the hole patterns 400 at the four corners of the FT array substrate is, for example, as shown in FIG.
The result is as shown in FIG. FIG. 8B shows that 0.times.
It is a cross-sectional shape of a hole when a displacement of 40 μm occurs. If such a displacement occurs, it should be 0.
The shape of the hole 501a which is a circle having a diameter of 80 μm is an ellipse having a major axis length in the x direction of 1.00 μm and a minor axis length in the y direction of 0.80 μm. And FIG.
By observing the hole pattern 400 shown in (b), it is easily found that distortion has occurred. As a result, it is possible to easily find out that the patterns in the image display area and the drive circuit area are defective, and it is possible to obtain a TFT array substrate with stable product characteristics. In FIG. 8B,
Since the cross-sectional shapes of the holes 503a, 504b, and 505c are circular, it can be determined that there is a displacement of 0.40 μm in the x direction.

In this embodiment, the value of the diameter of the circle or the value of the major axis and the value of the minor axis of the ellipse are changed stepwise in the x direction and the y direction, respectively, so that the cross section has a circular or elliptical shape. Since the holes are formed, even if distortion occurs, it is possible to determine the degree of misalignment in the x or y direction by observing the shape of the hole pattern. it can.

In this embodiment, since the hole patterns are arranged at the four corners of the substrate, the tendency of distortion over the entire surface of the substrate can be grasped.

Next, a method of manufacturing a liquid crystal device will be described.

First, a method for manufacturing the TFT array substrate 10 will be described with reference to FIG. 6A and FIGS.
FIG. 6A is a perspective view of an exposure device 310 used in an exposure process in a TFT array substrate manufacturing process. 9 and 10 are process diagrams showing the manufacturing process. 9 and 10 are a cross-sectional view of an image display area and a cross-sectional view of a hole pattern 400 forming area of the TFT array substrate, respectively. 'Corresponds to the sectional view. FIG. 11 is a partially enlarged view of a photomask used in an exposure step when forming a hole pattern, and shows a photomask portion on which a pattern corresponding to the hole pattern is drawn.

First, as shown in FIG. 9A, a semiconductor layer 1 is formed on a quartz substrate 60. Specifically, the quartz substrate 6
Pressure CVD using monosilane gas, disilane gas or the like at a flow rate of about 400 to 600 cc / min in a relatively low temperature environment of about 450 to 550 ° C., preferably about 500 ° C.
An amorphous silicon film is formed by (for example, CVD at a pressure of about 20 to 40 Pa). Thereafter, the polysilicon film is annealed in a nitrogen atmosphere at about 600 to 700 ° C. for about 1 to 10 hours, preferably for 4 to 6 hours, so that the polysilicon film has a thickness of about 50 to 200 nm, preferably about Solid phase growth is performed to a thickness of 100 nm. As a method for solid phase growth, laser annealing or the like may be used. After the formation of the polysilicon film, the semiconductor layer 1 is formed by patterning the polysilicon film by a photolithography process, an etching process, or the like. At this time, the semiconductor layer 1 is planarly formed as shown in FIG.

Next, as shown in FIG.
, A gate insulating film 2 having a thickness of 50 to 120 nm is formed on the substrate 60 by using a mixed gas of TEOS (tetraethyl orthosilicate) and oxygen gas as a source gas by PECVD. Here, the source gas is Si
H ₄ and oxygen gas may be used.

Next, as shown in FIG. 9C, on the gate insulating film 2, a scanning line 3a and a capacitor line (not shown), a part of which is a gate electrode, are formed of polysilicon. Specifically, first, a polysilicon film is deposited to a thickness of about 100 to 500 nm on the gate insulating film 2 by a low-pressure CVD method or the like, and phosphorus (P) is thermally diffused to make the polysilicon film conductive. Become Then, a resist pattern having a shape corresponding to the scanning lines 3a and the capacitance lines 3b as shown in FIG. 4 is formed on the polysilicon film by a photolithography process.
Thereafter, the polysilicon film is etched using the resist pattern as a mask, and the resist pattern is removed, thereby forming the scanning lines 3a and the capacitance lines as shown in FIG. 9C. The gate electrode, which is a part of the scanning line 3a,
It is formed so as to overlap with a part of the semiconductor layer 1.

Thereafter, using the gate electrode as a mask, a dopant of a group V element such as P is doped at a high concentration, for example, P ions at a dose of ¹ to 3 × 10 ¹⁵ / cm ² . Thus, the semiconductor layer 1 has the source region 1b and the drain region 1c formed on both sides of the channel region 1a.

Next, as shown in FIG. 9D, TEOS and ozone gas are used as source gases by PECVD on the gate insulating film 2 so as to cover the scanning lines 3 and the capacitance lines (not shown). Thus, a first interlayer insulating film 4 made of SiO _{2 having} a thickness of 1500 nm is formed.

Next, a first photolithography process is performed.
Forming a resist pattern having a shape in which only a region corresponding to the contact hole 5 is opened on the first interlayer insulating film 4;
The first interlayer insulating film 4 is formed by using this resist pattern as a mask.
Then, the gate insulating film 2 is etched. Thereafter, by removing the resist pattern, a first contact hole 5 for a data line 6 to be formed later is formed in the gate insulating film 2 and the first interlayer insulating film 4 as shown in FIG.

Next, as shown in FIG. 9 (6), the gate insulating film 2 including the first contact holes 5 and the cutting holes 91 is formed.
On top, a film thickness of 200 to 600 nm by sputtering,
Here, an aluminum film 6 having a thickness of 400 nm is formed. Further, a resist pattern having a shape corresponding to the data line is formed on the aluminum film 6 by a photolithography process. By etching the aluminum film using this resist pattern as a mask, data lines 6a are formed as shown in FIG. 9 (7). After that, the resist pattern is removed.

Next, as shown in FIG. 9 (8), a second interlayer insulating film 7 made of BPSG (silicate glass film containing boron and phosphorus) is formed on the first interlayer insulating film 4.

Next, as shown in FIG. 10 (9), a portion corresponding to the contact hole 8 and the holes 401a to 401e of the hole pattern 400 as shown in FIG. 8 are formed on the second interlayer insulating film 7 by a photolithography process. 401e, 402a-
402e, holes 403a to 403e, holes 404a to 404
e, a resist pattern 410 having openings at portions corresponding to the holes 405a to 405e is formed. The formation of the resist pattern 410 is performed in detail as follows.

First, a negative resist film is formed on the entire surface of the second interlayer insulating film 7. Thereafter, the negative type resist film is exposed by an exposure device 310 shown in FIG. 6A through a photomask 500 in which patterns as shown in FIG. 11 are drawn at four corners. Note that a pattern corresponding to the contact hole 8 is drawn in the center of the photomask 500.

As shown in FIG. 6A, the exposure device 310
Is an illumination optical system having a light source 301 and a photomask 3
02 is illuminated by an illumination optical system, and a projection optical system 303 that forms an image of the transmitted light on a substrate 304 to be exposed by an image projection optical system 305. In the present embodiment, a photomask 500 partially having the pattern shape shown in FIG. 11 is used as the photomask denoted by reference numeral 302 in FIG. Further, as the substrate to be exposed which is denoted by reference numeral 304 in FIG. 6A, the second interlayer insulating film 7 having the structure shown in FIG.
A substrate having a negative resist film formed thereon is used.

As shown in FIG. 11, the portion of the photomask 500 corresponding to the hole pattern has a plurality of circular and elliptical pattern shapes. Is formed so as to transmit light. On the other hand, a contact hole 8 is provided at the center of the photomask 500 corresponding to the image display area.
Are formed, and only this pattern portion is formed to transmit light from the light source 301. The circular or elliptical pattern formed on the photomask 500 has the diameter of the circular pattern or the length of the axis parallel to the x direction of the elliptical pattern in the drawing from left to right along the x direction. Is 0.80μ
m, 1.00 μm, 1.20 μm, 1.40 μm, 1.
It is set to be 60 μm, and the length of the axis parallel to the y direction of the diameter of the circular pattern or the ellipse pattern is 0.80 μm from top to bottom along the y direction,
1.00 μm, 1.20 μm, 1.40 μm, 1.60
μm, and a plurality of circular or elliptical patterns 510 a to 510 e, 511 a to 5
11e, 512a to 512e, 513a to 513e, 5
14a to 514e are formed in a matrix. For example, the pattern 510a has a diameter of 0.8 μm
The circle 511b has a diameter of 1.00 μm, and the pattern 510b has a major axis length of 1.00 μm along the x direction and a minor axis length of 0.80 μm along the y direction.
The pattern 511a is an ellipse having a major axis length of 0.80 μm along the x direction and a minor axis length of 1.00 μm along the y direction.

Here, the size of the pattern shape drawn on the photomask and the size of the image formed on the substrate to be exposed are set to be the same, but similar shapes having different sizes are used. You may set so that it may become. Although a negative resist film is used as the resist film, a positive resist film can be used. In this case, only the circular and elliptical pattern portions as the photomask block light from the light source 301. Should be used.

After the formation of the resist pattern 410, the gate insulating film 2, the first interlayer insulating film 4, and the second
The interlayer insulating film 7 is etched, and thereafter, the resist pattern is removed. As a result, as shown in FIG. 10 (10), a contact hole 8 connecting the drain region 1c of the semiconductor layer and a pixel electrode to be formed later is formed. If no distortion occurs during the exposure step, a plurality of holes 401a to 401a as shown in FIG.
401e, 402a to 402e, 403a to 403e,
A hole pattern 400 having 404a to 404e and 405a to 405e is formed.

Next, as shown in FIG.
On the interlayer insulating film 7, 50 to 200 nm by sputtering.
An ITO film 9 having a thickness of about the same is formed.

Thereafter, as shown in FIG.
The TO film 9 is patterned through a photolithography process, an etching process, and the like to obtain a pixel electrode 9a. Thereafter, as shown in FIG. 5, a polyimide film is formed on the second interlayer insulating film 7 including the pixel electrode 9, and is subjected to an alignment treatment to form an alignment film 16, whereby a TFT array substrate is manufactured.

In the TFT array substrate manufactured as described above, the presence or absence of distortion is determined by observing the hole patterns formed at the four corners. The TFT array substrate determined to have no distortion by this observation is regarded as having no abnormality in the pattern formed in the effective area such as the image display area and the drive circuit area, and is used as a TFT array substrate for an electro-optical device. Can be used. On the other hand, a TFT array substrate that has been determined to have distortion by the above observation is excluded as a defective product.

On the other hand, the counter substrate 20 is formed as follows. First, on a substrate 80 such as a glass substrate, a light-shielding layer 23 made of a light-shielding metal such as Cr, a black resin, or the like in a matrix, A frame-shaped light shielding layer 53 is formed along the portion. Next, the counter electrode 21 made of ITO is formed on the entire surface of the substrate 80 including the light shielding layers 23 and 53. After that, a polyimide film is formed on the counter electrode 21 and is subjected to an alignment treatment to form an alignment film 22.

The T formed as such is determined to be non-defective.
The FT array substrate 10 and the counter substrate 20 are shown in FIGS.
As shown in (1), a sealing material 52 is applied by a dispenser to one of the substrates along the outer edge of the substrate in a rectangular shape leaving one opening to be a liquid crystal injection port 52a later. Thereafter, the two substrates are attached to each other, a liquid crystal is injected into the gap between the substrates from the injection port 52a, and the opening is sealed with the sealing material 54, whereby the liquid crystal device is completed.

Here, as shown in FIG. 7, when a plurality of TFT array substrates 304a are manufactured collectively from one exposure substrate 304, hole patterns are formed at the four corners of each TFT array substrate 304a. Will be arranged. When adopting such multi-panning,
The opposing substrate is adhered only to the TFT array substrate determined to be non-defective, and after liquid crystal injection, it is cut and divided into individual TFT array substrates to complete the liquid crystal device. In the case where the multi-panning is adopted as described above, T
Since the counter substrate is bonded only to the FT array substrate, the counter substrate is not bonded to the defective TFT array substrate. Therefore, the counter substrate can be used without waste, and the working efficiency can be improved.

As described above, in the present embodiment, since the hole patterns for confirming the occurrence of distortion are formed at the four corners of the substrate, it is easy to determine whether the TFT array substrate is non-defective. Therefore, it is possible to stably manufacture a TFT array substrate having uniform switching element characteristics in the substrate plane. Further, by using such a TFT array substrate as an electro-optical device, it is possible to stably manufacture a high-quality electro-optical device having uniform display characteristics within the substrate surface.

Further, in the above-described embodiment, the formation of the hole pattern is performed in the same step as the formation of the contact hole 8, but may be performed simultaneously with the formation of the contact hole 5, for example. In this case, it is possible to confirm whether or not distortion has occurred during the exposure step performed when the contact hole 5 is formed. As described above, the hole pattern can be formed during the exposure step using the projection optical system during the manufacture of the element pattern in the image display area and the drive circuit area, and the presence or absence of distortion at the time of exposure can be performed. Can be observed.

In the above-described embodiment, the pattern shape of the photomask corresponding to the hole pattern is a circle and an ellipse. However, as in the photomask 600 shown in FIG. Is also good. In this case, the shape of the image formed on the substrate to be exposed via the photomask 600 may be circular or elliptical. That is, the photomask 600 only has to function as an auxiliary pattern that anticipates deformation of the pattern of the photomask onto the substrate to be exposed when the pattern is transferred, and corrects it. The method of observing a hole pattern formed using such a photomask 600 is the same as the method of observing a hole pattern in the above-described embodiment.

As shown in FIG. 12, a photomask 600
Is formed so that each side thereof is parallel to the x direction or the y direction in the drawing. The pattern formed on the photomask 600 is from left to right along the x direction in the drawing,
The length of the side parallel to the x direction is 0.80 μm, 1.00 μm
m, 1.20 μm, 1.40 μm, 1.60 μm, and y from top to bottom along the y direction.
The length of the side parallel to the direction is 0.80 μm, 1.00 μm,
It is set to be 1.20 μm, 1.40 μm, and 1.60 μm, and a plurality of square or rectangular patterns are arranged in a matrix.

In the above embodiment, the hole patterns are formed at the four corners of the substrate. However, one hole pattern may be formed at the outer periphery of the substrate. In this case, although it is not possible to determine whether or not distortion has occurred on the entire surface of the substrate, it is possible to observe whether or not distortion has occurred near the hole pattern, and it is possible to inspect whether or not the substrate is non-defective. Further, the number of holes formed in the hole pattern can be reduced to one. In such a case, if the cross-sectional shape of the hole in a normal state is, for example, circular, and if the shape of the hole in the hole pattern is observed to be elliptical instead of circular, it is determined that distortion has occurred. can do.

In the above embodiment, a plurality of holes are formed in each of the hole patterns formed at the four corners of the substrate. However, one hole may be used. in this case,
The hole patterns formed in the four corners may have the same pattern shape in a normal state, and the shape is not specified. In this case, by comparing the shapes of the hole patterns formed at the four corners of the substrate, it is possible to determine that distortion has occurred if there is a different shape.

In the above embodiment, the hole patterns are formed at the four corners of the rectangular substrate. However, the hole patterns are not limited to the four corners and may be formed at the outer peripheral portion of the substrate. However, when projection exposure is performed using a projection optical system with a rectangular substrate as the substrate to be exposed, since the four corners of the substrate are most likely to cause image distortion due to distortion, hole patterns are formed at the four corners of the substrate. It is desirable to form. This makes it possible to more accurately observe the presence or absence of distortion.

Further, in the above-described embodiment, the TFT array substrate of the liquid crystal device has been described as an example of the exposure substrate. However, the present invention can be applied to a semiconductor wafer or the like. That is, the present invention can be applied to those manufactured through an exposure process using a projection optical system, and it is possible to easily determine whether or not distortion has occurred by forming a hole pattern on the outer peripheral portion of an exposure substrate. In addition to a semiconductor wafer, the present invention can be applied to, for example, a color filter substrate used in a liquid crystal device. In the color filter substrate, a color filter pattern made of R (red), G (green), and B (blue) colored resins is formed on the substrate in a stripe shape through a photolithography process and an etching process. The present invention can be applied during the exposure step in the photolithography step, and an exposure evaluation pattern can be formed in a region other than a region contributing to image display. The exposure evaluation pattern is formed, for example, for each color, and a plurality of holes may be respectively formed in the colored resin as a film as in the hole pattern of the present embodiment. This makes it possible to evaluate whether or not the pattern shape such as the width of the color filter pattern for each color and the distance between the patterns is appropriately formed.
Further, when the colored resin as the film is a photosensitive resin, the step of forming a resist pattern as in the above-described embodiment may be omitted. That is, the photosensitive resin can be directly exposed through a photomask and developed to form a color filter pattern and an exposure evaluation pattern.

[Brief description of the drawings]

FIG. 1 is a plan view of a liquid crystal device according to an embodiment when a TFT array substrate is viewed from a counter substrate side together with constituent elements formed thereon.

FIG. 2 is a sectional view taken along line H-H 'of FIG.

FIG. 3 is a plan view illustrating an equivalent circuit such as various elements and wirings in an image display area of the liquid crystal device.

FIG. 4 is a plan view illustrating an arrangement of various elements, wirings, and the like in an image display area of the liquid crystal device.

FIG. 5 is a sectional view taken along line B-B 'of FIG.

FIG. 6A is a perspective view of an exposure apparatus used in an exposure step in manufacturing a TFT array substrate.
FIG. 2B is a perspective view illustrating a projection optical system of the exposure apparatus.

FIG. 7 is a plan view illustrating an exposure substrate of multiple exposure.

FIG. 8 is an enlarged plan view of hole patterns formed at four corners of a TFT array substrate, and FIG. 8A shows a hole pattern formed when no distortion occurs in an exposure process; () Shows a hole pattern formed when distortion occurs in the exposure step.

FIG. 9 is a plan view illustrating a manufacturing process (part 1) of the TFT array substrate of the liquid crystal device in the embodiment.

FIG. 10 is a plan view illustrating a manufacturing process (part 2) of the TFT array substrate of the liquid crystal device in the embodiment.

FIG. 11 is a partial plan view of a photomask on which a pattern corresponding to a hole pattern is drawn.

FIG. 12 is a partial plan view of another photomask on which a pattern corresponding to a hole pattern is drawn.

[Explanation of symbols]

2 gate insulating film 4 first interlayer insulating film 7 second interlayer insulating film 10 TFT array substrate 60 substrate 200 liquid crystal device 310 exposure device 302, 500, 600 photomask 304 substrate to be exposed 305 Projection optical system (projection lens) 400 Hole pattern 410 Resist pattern 510a-510e, 511a-511e, 512a-
512e, 513a to 514e: circular or elliptical patterns 610a to 610e, 611a to 611e, 612a to
612e, 613a to 614e: square or rectangular pattern

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H088 EA02 FA11 FA18 FA25 FA30 MA20 2H092 JA24 JB77 MA14 MA15 MA16 MA35 MA55 NA27 2H095 BA03 BB02 5F046 AA25 BA03 CB17 DB05 DB14 DD06 LA18

Claims (17)

[Claims] 1. A step of: (a) forming a photosensitive film on a substrate; and (b) projecting the film through a photomask having a pattern at a position corresponding to the outer peripheral portion of the substrate. And (c) forming an exposure evaluation pattern on an outer peripheral portion of the substrate by developing the exposed film. Method. (A) forming a film on the substrate; (b) forming a resist film on the film; and (c) photo having a pattern at a position corresponding to an outer peripheral portion of the substrate. An exposure step of projecting and exposing the resist film through a mask using a projection optical system; (d) forming a resist pattern by developing the exposed resist film; and (e) forming a resist pattern. Etching the film using the pattern as a mask to form an exposure evaluation pattern on the outer periphery of the substrate. 3. The method according to claim 1, wherein a plurality of the exposure evaluation patterns are provided. 4. The substrate has a rectangular shape, the photomask has the same shape of the pattern at positions corresponding to the four corners of the substrate, and the exposure evaluation pattern is at each of the four corners of the substrate. 4. The method according to claim 3, wherein the substrate is formed. 5. The exposure evaluation pattern formed without generating distortion in the exposure step has a circular cross-sectional pattern parallel to the substrate. A method for producing an exposure substrate according to claim 1. 6. The pattern of the photomask, comprising: an ellipse having a major axis of a first length and a minor axis of a second length; and an ellipse substantially parallel to the major axis and having a second length. An ellipse having a minor axis, a major axis substantially parallel to the minor axis, and a major axis of the first length, a circle having a diameter of the first length, and a circle having a diameter of the second length 6. The method for manufacturing an exposure substrate according to claim 5, comprising: 7. A pattern of the photomask, comprising: a rectangle having a long side having a first length and a short side having a second length; and a pattern substantially parallel to the long side and having a second length. A rectangle having a short side, a long side substantially parallel to the short side and the long side of the first length, a square having a side of the first length, and a square having a side of the second length 6. The method for manufacturing an exposure substrate according to claim 5, comprising: 8. The apparatus according to claim 6, wherein a difference between the first length and the second length is set according to a resolution of an exposing machine used in the exposing step. The method for producing an exposure substrate according to any one of the above. 9. The photomask further includes a device pattern corresponding to a central portion of the substrate, wherein the device pattern is formed in the central portion of the substrate simultaneously with the formation of the exposure evaluation pattern. The method for manufacturing an exposure substrate according to claim 1, wherein the method includes the steps of: 10. A method of manufacturing an electro-optical device including an exposure substrate on which a plurality of switching elements are arranged, wherein the exposure substrate is manufactured according to any one of claims 1 to 9. A method for manufacturing an electro-optical device, characterized by being manufactured by a method. 11. An exposure substrate manufactured by the method for manufacturing an exposure substrate according to any one of claims 1 to 9. 12. An exposure substrate comprising: a substrate; and an exposure evaluation pattern formed on an outer peripheral portion of the substrate through a projection exposure step using a projection optical system. 13. The exposure evaluation pattern according to claim 1, wherein a plurality of the exposure evaluation patterns are arranged on an outer peripheral portion of the substrate.
3. The exposure substrate according to 2. 14. The exposure substrate according to claim 13, wherein the substrate has a rectangular shape, and the exposure evaluation patterns each having the same pattern are arranged at four corners of the substrate. 15. The exposure evaluation pattern is formed by opening a plurality of holes in a film, and the cross-sectional shape of the holes parallel to the substrate has a major axis of a first length and a major axis of a second length. An ellipse having a minor axis; an ellipse having a minor axis substantially parallel to the major axis and the second length; and an ellipse having a major axis substantially parallel to the minor axis and the first length. The exposure substrate according to any one of claims 12 to 14, comprising: a circle having a diameter of one length; and a circle having a diameter of the second length. 16. An electro-optical device manufactured by the method for manufacturing an electro-optical device according to claim 10. 17. An electro-optical device comprising an exposure substrate on which a plurality of switching elements are arranged, wherein the exposure substrate comprises the exposure substrate according to any one of claims 12 to 14. Electro-optical device.