JP2003202675A - Method for manufacturing liquid crystal panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent deterioration of display quality such as 'block pattern separation' by forming uniform MIM (metal-insulator-metal) elements on a substrate by using a sequential exposing method. <P>SOLUTION: In forming the MIM elements on an MIM liquid crystal panel with photolithography, patterns on a specified layer are sequentially exposed by repeatedly using an identical photomask. As difference in pattern dimension between masks caused by variation in photomask manufacturing is eliminated, the pattern dimensions of the MIM elements are made constant. Consequently as capacitance of the MIM elements is made constant, effective voltage written in the elements becomes uniform and as result uneven contrast in a screen of the liquid crystal panel is dissolved. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

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

[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]

An object of the present invention is to prevent the deterioration of display quality such as "block division" by forming uniform MIM elements on a substrate by using a sequential exposure method.

[0005]

The method for manufacturing an MIM element of the present invention has the following features in order to solve the above problems.

(1) MI using photolithography
In the manufacturing method of M, at least the MIM element pattern of the screen portion is formed by a sequential exposure method.

(2) M is obtained by the sequential exposure method described in item 1.
In the manufacturing method of forming the IM element pattern, 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 the first item, the connecting position of each die is shifted for each layer forming the MIM element pattern.

(4) The MIM according to the first aspect is characterized in that the connection between the dies in the sequential exposure method according to the first aspect is at a position displaced from the pattern forming the MIM element.
Device manufacturing method.

(5) The liquid crystal panel manufacturing method of the present invention is
In a method of manufacturing a liquid crystal panel having a substrate on which a first layer and a second layer are provided, a first resist provided on the first layer is divided into a plurality of regions and exposed by a sequential exposure method. And a second layer provided on the second layer.
Exposing the resist into a plurality of areas by a sequential exposure method, and, on the surface of the substrate,
A position where the respective regions of the first resist are connected and a position where the respective regions of the second resist are connected are arranged at mutually different positions in plan view.

[0011]

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. .

[0012]

[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.

[0015]

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

On an insulating substrate such as glass, a film of tantalum or the like, which will be the base electrode pattern of the MIM element and a 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, for example, 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 on the base electrode pattern and the signal line as an insulating layer of the MIM element 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.

[0021]

As described above, the present invention makes use of the advantages of the sequential exposure method, such as high accuracy and easy size increase, in forming MIM elements, while reducing the change in pattern size for each die in the display area. This has the effect of obtaining a uniform display. The present invention makes it possible to meet the market demand for higher definition and larger size of MIM liquid crystal panels.

[0022]

[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.

[Procedure amendment]

[Submission date] October 31, 2002 (2002.10.
31)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Title of invention

[Correction method] Change

[Correction content]

Title of the invention: Method for manufacturing liquid crystal panel

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

Claims (5)

[Claims] 1. A method of manufacturing an MIM element, which comprises forming at least a MIM element pattern on a screen portion by a sequential exposure method. 2. A manufacturing method for forming an MIM element pattern by a sequential exposure method, wherein M of at least a screen portion is formed.
The method of manufacturing an MIM element according to claim 1, wherein the IM element pattern is formed for each layer by the same photomask. 3. The method for manufacturing an MIM element according to claim 1, wherein the connecting position of each die in the sequential exposure method is shifted for each layer constituting the MIM element pattern. 4. The method of manufacturing an MIM element according to claim 1, wherein the connection between the dies in the sequential exposure method is at a position displaced from the pattern forming the MIM element. 5. A method of manufacturing a liquid crystal panel having a substrate provided with a first layer and a second layer, wherein a first resist provided on the first layer is formed into a plurality of regions by a sequential exposure method. And exposing the second resist provided on the second layer into a plurality of regions by a sequential exposure method, and exposing the substrate on the surface of the substrate. A method of manufacturing a liquid crystal panel, wherein a position where the respective regions of the first resist are connected to each other and a position where the respective regions of the second resist are connected to each other are two-dimensionally different from each other.