JP2003344872A - Production method of liquid crystal panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the deterioration of display quality such as blocklike irregularity of brightness by disposing an uniform layer on a substrate by using the successive exposure method. <P>SOLUTION: When active elements on a liquid crystal panel are formed by a photolithography method, exposure is performed in such a manner that the joint of a pattern mask of each layer is shifted every each layer. Thereby, the difference of pattern dimensions between masks due to the fluctuation in photomask production is suppressed and the pattern dimensions of the active elements are allowed to be constant. Therefore, the capacitance of the active elements is allowed to be constant, the effective voltage written into the elements is made uniform and the contrast irregularity in a screen of the liquid crystal panel is dissolved. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal panel manufacturing method.

[0002]

2. Description of the Related Art Conventionally, as a method for manufacturing an MIM element, "
David R.D. Baraff et al. , SI
D'80 Digest, p200-201, 19
As shown in 80 ", photolithography was used to form a pattern. The exposure method was a contact method in synchronization with the development process of the exposure apparatus.
The proximity method was mainly used. In recent years, mirror projection type and stepper type devices have come to be supplied from exposure machine manufacturers as liquid crystal panel manufacturing applications, and active matrix liquid crystal panels using TFTs, MIMs and the like can be manufactured by these devices. However, in order to meet the market demand for high definition and large screen, exposure methods such as contact, proximity, and mirror projection limit the high definition and large screen of MIM liquid crystal panels in terms of device performance. was there. Specifically, although the contact method and the proximity method can cope with an increase in size, a fine pattern cannot be formed because the resolution is insufficient from the viewpoint of high definition. In addition, the photomask and the work substrate are in contact with or close to each other. Therefore, there is a defect that the yield is poor such as pattern failure due to dust. On the other hand, the mirror projection method has a limitation in increasing the size due to a problem of accuracy of optical system components constituting a device such as a mirror. The sequential exposure method using a stepper has a high resolution of the lens and can achieve high definition, and since it can respond to a large screen by increasing the number of exposure steps, it is said that the optical components such as the lens limit the high definition and large screen. No problem.

However, when a large screen is exposed by connecting the dies by the sequential exposure method, there is a drawback that the contrast varies for each die after the liquid crystal panel is completed. So-called "block division" occurs and the display quality of the liquid crystal panel deteriorates. This is the biggest problem when using the sequential exposure method.

[0004]

SUMMARY OF THE INVENTION The present invention is to prevent deterioration of display quality such as "block division" by providing a uniform layer on a substrate by using a sequential exposure method.

[0005]

A method of manufacturing a liquid crystal panel according to the present invention is a method of manufacturing a liquid crystal panel having active elements, the first resist being provided on a first layer on a substrate of the liquid crystal panel. Is sequentially exposed to a plurality of regions by exposure, and the second resist provided on the second layer on the substrate of the liquid crystal panel is divided into a plurality of regions by the sequential exposure to expose the liquid crystal. On the surface of the substrate of the panel, the position where the respective regions of the first resist are connected and the position where the respective regions of the second resist are connected are arranged at mutually different positions in plan view. And

The photomask used for exposing the first resist or the second resist has a pattern and a light-shielding band surrounding the periphery of the pattern.

Further, the pattern of the photomask is formed by a positive process method.

Further, the pattern of the photomask is formed by a multiple exposure method.

Further, the manufacturing method of the MIM element has the following features in order to solve the above problems. (1) A method of manufacturing an MIM using photolithography is characterized in that at least an MIM element pattern of a screen portion is formed by a sequential exposure method. (2) In the manufacturing method of forming the MIM element pattern by the sequential exposure method described in the item 1, at least the MIM element pattern of the screen portion is formed by the same photomask for each layer. (3) In the successive exposure method described in item 1, the connecting position of each die is shifted for each layer forming the MIM element pattern. (4) The method of manufacturing an MIM element according to the first aspect, characterized in that the connection between the dies in the sequential exposure method according to the first aspect has a position displaced from the pattern forming the MIM element.

[0010]

In the MIM liquid crystal panel, the liquid crystal layer and the MIM element are arranged in series as shown in FIG. 5, and the driving voltage applied to this system is divided by the capacitance ratio of the liquid crystal layer and the MIM element as shown in the following equation. .

[0011]

[Equation 1]

When the pattern size of the MIM element changes, M
Since the IM element capacitance changes, the voltage applied to the MIM element changes.

Therefore, since the ON resistance of the MIM element is varied and the effective voltage written in the liquid crystal layer is varied, the operating state of the liquid crystal is changed and uneven contrast occurs in the screen of the liquid crystal panel. Therefore, in the sequential exposure method, how to suppress the change in the MIM element size for each die is important. By exposing the screen part with the same photomask, the pattern size difference between the masks due to the manufacturing variation of the photomask is eliminated, and the joint position of each die is shifted for each layer, so that the size of each electrode forming the MIM element Since the position where the change occurs shifts, "block division" can be suppressed.

[0014]

EXAMPLES Examples according to the present invention will be described below in order.

On the insulating substrate made of glass or the like, tantalum or the like, which will be the base electrode pattern of the MIM element and the signal line, is formed by sputtering. Next, a photoresist is applied on the tantalum film, and the screen portion is sequentially exposed by repeating the same photomask having the pattern of the first layer as shown in FIG. Except for the screen part, there is no problem if it is exposed by allocating to multiple masks.

Here, as the photomask, a mask whose pattern dimension variation is as small as possible within the screen by a positive process method or a multiple exposure method is used. The photomask corresponding to the normal sequential exposure method is surrounded by a Cr pattern having a width of 1.5 to 5 mm called a shading band around each pattern group as shown in FIG. 4, and in a repeated pattern in the screen and in the vicinity of the shading band. The pattern dimensions are changing. To solve this problem, the positive process method and the multiple exposure method are effective.

Next, development, etching and resist stripping are performed to obtain a base electrode pattern and a signal line. Next, a tantalum oxide film is formed as an insulating layer of the MIM element on the base electrode pattern and the signal line by the anodic oxidation method. Then, for example, chromium, titanium, and tantalum are deposited by a sputtering method, and the coupling electrode of the MIM element and the screen portion of the signal line are sequentially exposed by the same photomask of the second layer. At this time, as shown in FIG. 2, when the dies are connected so that the positions where the respective dies are connected are deviated from the base electrode pattern of the first layer and the coupling electrode pattern of the second layer, the variation of the MIM element area is coupled with the base electrode. This is less than when the electrodes are connected at the same position.

On the other hand, although it is the position where the dies are connected, the influence of the connection accuracy can be reduced by separating the position from the pattern for forming the MIM element as shown in FIG. Then, development, etching and resist peeling are performed to complete the MIM element. Finally, for example, ITO is formed into a film by a sputtering method to form a pixel electrode.

The method of forming the MIM element has been described above.
Even in FT, variations in pattern dimensions cause variations in gate stray capacitance.
Similar to IM, "block division" occurs. Therefore, the present invention has a high effect of suppressing variations in pattern dimensions, and is also effective for TFTs in that sense.

[0020]

As described above, the present invention makes use of the advantages of the sequential exposure method, such as high accuracy and easy size increase, while reducing the change in pattern size of each die in the display portion. This has the effect of obtaining a uniform display. According to the present invention, high definition for liquid crystal panel,
It has become possible to meet the market demand for larger size.

[0021]

[Brief description of drawings]

FIG. 1 is an MIM of a screen portion according to one embodiment of the present invention.
It is a figure which shows the state which carried out sequential exposure of the element by repeating the same mask.

FIG. 2 is a diagram showing a state in which a die connecting position of a screen portion, which is one of embodiments of the present invention, is deviated between the MIM first layer and the second layer.

FIG. 3 is a diagram showing a state in which a die connecting position, which is one of the embodiments of the present invention, is positionally displaced from a pattern for forming an MIM element.

FIG. 4 is a diagram showing a light-shielding band surrounding a pattern group used for a photomask used in a sequential exposure method.

FIG. 5 is a diagram showing an electrically connected state between a MIM element and a liquid crystal layer in an MIM liquid crystal panel.

Claims (4)

[Claims] 1. A method of manufacturing a liquid crystal panel having an active element, comprising: a first layer provided on a first layer on a substrate of the liquid crystal panel.
Of the second resist is sequentially exposed to be divided into a plurality of regions and exposed, and a second layer is formed on the second layer on the substrate of the liquid crystal panel.
Of the resist is sequentially exposed to a plurality of regions by exposure, and a position on the surface of the substrate of the liquid crystal panel where the respective regions of the first resist are connected and the respective regions of the second resist are A method for manufacturing a liquid crystal panel, characterized in that the connecting positions are arranged at positions different from each other in plan view. 2. The photomask used for exposing the first resist or the second resist has a pattern and a light-shielding band surrounding the periphery of the pattern. A method for manufacturing the liquid crystal panel described. 3. The method of manufacturing a liquid crystal panel according to claim 2, wherein the pattern of the photomask is formed by a positive process method. 4. The method of manufacturing a liquid crystal panel according to claim 2, wherein the pattern of the photomask is formed by a multiple exposure method.