JP4888244B2 - Alkali development method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an alkaline development method for reducing line width dispersion, which is produced when developing is stopped with hardly a time difference between the front end part and the rear end part of a glass substrate 11 during water rinsing, after consecutive developing which is carried out through conveyance via a plurality of developing tanks 20, in the longitudinal direction of the glass substrate. <P>SOLUTION: A pH value of an alkaline developer jetted to the glass substrate 11 is maximized in a developing tank, in the center of a plurality of serial developing tanks, and the pH value is reduced gradually step by step so that it is brought close to a neutral value, toward a developing tank in the front end part adjacent to a convey-in device and directed toward a developing tank in the rear-end part which is adjacent to a carry-out device. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a method for developing colored pixels of a color filter, and in particular, development is performed in a developing tank composed of a plurality of developing tanks, and the glass substrate has a leading edge and a trailing edge in a subsequent washing tank. The present invention relates to an alkali development method capable of reducing the variation in line width that occurs when development is stopped with almost no time difference between them.

In a display device, it is a useful means to use a color filter for purposes such as color display, reflectance reduction, contrast improvement, and spectral characteristic control.
In many cases, the color filter used in the display device is formed as a pixel. A photolithography method is widely used as a method of forming pixels of a color filter used in this display device.

FIG. 1 is a plan view schematically showing an example of a color filter used in a liquid crystal display device. 2 is a cross-sectional view of the color filter shown in FIG. 1 taken along line XX ′.
As shown in FIGS. 1 and 2, in the color filter used in the liquid crystal display device, a black matrix (51), a colored pixel (52), and a transparent conductive film (54) are sequentially formed on a glass substrate (50). It has been done.
FIG. 1 and FIG. 2 schematically show a color filter, and 12 colored pixels (52) are represented. In an actual color filter, for example, several hundreds are displayed on a 17-inch diagonal screen. A large number of colored pixels of about μm are arranged.

The black matrix (51) is a matrix having light shielding properties, and the colored pixels (52) have, for example, red, green, and blue filter functions.
The black matrix determines the position of the colored pixels of the color filter, makes the size uniform, and shields unwanted light when used in a display device, making the image of the display device uniform and uniform. In addition, it has a function of making an image with improved contrast.
This black matrix (51) is an example of being formed on a glass substrate (50) by a photolithography method using a black photoresist for forming a black matrix, and the black matrix formed using a resin is a resin black matrix. (51).

  The colored pixel (52) is a photolithography method using a negative colored photoresist in which a pigment such as a pigment is dispersed on the glass substrate (50) on which the resin black matrix (51) is formed. That is, it is formed as a colored pixel by exposure through a photomask to the coating film of the colored photoresist and development processing. Red, green, and blue colored pixels are sequentially formed.

In addition, the transparent conductive film (54) is formed by forming a transparent conductive film on a glass substrate on which a resin black matrix and colored pixels are formed by using, for example, ITO (Indium Tin Oxide) by a sputtering method. It has been.
The transparent conductive film is formed by annealing at a room temperature and then crystallizing by annealing, a method for forming a film at a temperature higher than the crystallization temperature, or a crystallization at about 100 ° C. There is a method of obtaining desired characteristics by annealing after performing low-temperature heating before performing. Recently, in order to reduce the influence on the color filter, a method of forming at room temperature or low temperature heating is common.

The color filter shown in FIGS. 1 and 2 has a basic function as a color filter used in a liquid crystal display device. The liquid crystal display device incorporates such a color filter to realize full color display, and its application range is dramatically expanded, and many products using liquid crystal display devices such as liquid crystal color TVs and notebook PCs are created. It was done.
With the development and practical use of various liquid crystal display devices, various functions have been added to the color filters used in the liquid crystal display devices in addition to the above basic functions.

  Examples of functions added to the color filter shown in FIG. 1 include a spacer function, an alignment division function, a high reliability function, a combined transmission / reflection function, a spectral characteristic adjustment function, an optical path adjustment function, and a light scattering function. . Among these functions, one function or a plurality of functions are added to the color filter shown in FIG. 1 based on the use and specification of the color filter.

  When forming the accompanying layer on the color filter having the basic function described above, any of the protective layer (overcoat layer) not formed as a pattern and the transparent conductive film formed by the sputtering method is used. Similar to the black matrix (51) and the colored pixels (52), the layer is also formed into a pattern by photolithography using a photoresist.

  When forming the black matrix, the colored pixels, and the associated layers as a pattern by photolithography, for example, the glass substrate is first subjected to a cleaning treatment as necessary, and then each photoresist by a coating apparatus is used. Coating, pre-drying with a vacuum dryer, pre-baking with a pre-baking device, pattern exposure with an exposure device, development with a developing device, and post-baking with a post-baking device are sequentially applied to form a predetermined pattern on the glass substrate. To do.

  As a developing method at the time of forming colored pixels, for example, an alkali developer is showered from a nozzle and sprayed onto a glass substrate to dissolve and remove the unexposed colored photoresist, and then pure water is discharged from the nozzle. A method is generally used in which a shower is formed and sprayed onto a glass substrate to remove a residue of a colored photoresist in an unexposed portion, and the alkali developer is replaced with pure water.

FIGS. 3A and 3B are cross-sectional views schematically illustrating an example of a developing device when forming colored pixels. As shown in FIGS. 3A and 3B, the developing device shown as an example includes a carry-in device (10), a developing tank (20), a carry-out device (40), a carry-in device (60), and a washing tank (30). ), A carry-out device (70), and a conveyor device (80) for carrying out development and washing while conveying the glass substrate.
The developing tank (20) includes a developing tank 1 (20-1) to a developing tank n (20-n), and a nozzle (21) is provided in each of the developing tanks 1 to n. The washing tank (30) is one tank, and a nozzle (31) is provided in the washing tank.

As the developer, for example, an alkali developer composed of sodium carbonate, sodium bicarbonate, a surfactant, and an organic compound is used. From the nozzles (21) of each developer tank 1 to developer tank n, a developer having the same alkali concentration is used. It comes to be injected.
In FIG. 3A, the glass substrate denoted by reference numeral (11) is charged into the developing tank 1 (20-1) from the left in FIG. Is done. Development starts from the front end (a) of the glass substrate (11), and gradually begins to develop toward the rear end (b).

  The glass substrate (11) is developed while being conveyed between the developing tank 1 (20-1) to the developing tank n (20-n), and is carried out to the carry-out device (40). The leading end portion (a) of the unloaded development glass substrate (11B) is in a state where the developing time is longer than that of the trailing end portion (b).

  In the subsequent rinsing tank (30), a larger amount of pure water is ejected than the developer in each developing tank. There is almost no difference in time for supplying pure water at the front end portion (a) and the rear end portion (b) of the glass substrate (11C) as compared with the developer in the developing tank, and the pure water is almost simultaneously applied to the entire surface of the glass substrate (11C). Are ejected in large quantities, and the developed alkaline developer is replaced with pure water.

Thus, in the washing tank (30), the development is stopped with almost no time difference between the front end (a) and the rear end (b) of the glass substrate. The fact that the development time is longer at the front end (a) of the glass substrate than at the rear end (b) at the end of development affects the line width of the colored pixels.
That is, the line width variation (in-plane line width non-uniformity) such that the line width of the colored pixels is narrower at the front end (a) in the length direction (transport direction) of the glass substrate than at the rear end (b). Is a problem.
JP-A-10-123720

  The present invention has been made to solve the above-described problem. In the development method of the colored pixels of the color filter, the development is continuously performed while being conveyed in a developing tank composed of a plurality of developing tanks, and the subsequent pure The tip of the glass substrate in the length direction (conveyance direction), which occurs when the development is stopped with almost no time difference between the front end and the rear end of the glass substrate by washing with water, compared to the rear end. It is an object of the present invention to provide an alkali developing method capable of reducing variation in line width (in-plane line width non-uniformity) such that the line width of a colored pixel is reduced.

  The present invention performs development by spraying a glass substrate onto a glass substrate with an alkaline developer made into a shower from a nozzle provided in the developing tank while horizontally conveying the glass substrate in a plurality of continuous developing tanks. Then, while transporting the inside of the washing tank horizontally, the pure water showered from the nozzle provided in the washing tank is sprayed onto the glass substrate with almost no time difference between the front end portion and the rear end portion of the glass substrate. In the alkali developing method for washing with water, the pH value of the alkaline developer sprayed onto the glass substrate is maximized in the central developing tank of a plurality of continuous developing tanks, and the developing tank at the tip adjacent to the carry-in device And an alkali developing method characterized by gradually reducing the density toward the neutral value toward the developing tank at the rear end adjacent to the carry-out device.

The present invention performs development by spraying a glass substrate onto a glass substrate with an alkaline developer made into a shower from a nozzle provided in the developing tank while horizontally conveying the glass substrate in a plurality of continuous developing tanks. Then, while transporting the inside of the washing tank horizontally, the pure water showered from the nozzle provided in the washing tank is sprayed onto the glass substrate with almost no time difference between the front end portion and the rear end portion of the glass substrate. In the alkali developing method for washing with water, the pH value of the alkaline developer sprayed onto the glass substrate is maximized in the central developing tank of a plurality of continuous developing tanks, and the developing tank at the tip adjacent to the carry-in device And an alkali development method that gradually reduces the neutral value gradually toward the developing tank at the rear end adjacent to the carry-out device, so that the rear end of the glass substrate in the length direction (conveyance direction) Colored image compared to the edge The alkali developing method capable of reducing the variation of the line width, such as line width becomes narrower (non-uniformity of the surface extension width).
As a result, the line width variation is improved within an allowable range of 0.5 to 1.0 μm compared to the conventional line width variation of 1.0 to 1.5 μm, and the conventional color pixel film thickness variation is improved. The film thickness variation is improved within an allowable range of 0.5 to 1.0% with respect to 1.0 to 2.0%.

Embodiments of the present invention will be described below.
In the alkali developing method according to the present invention, the pH value of the alkaline developer is maximized in the developing tank at the center of a plurality of continuous developing tanks, and is adjacent to the developing tank and the unloading apparatus at the tip adjacent to the carrying-in apparatus. It is characterized by being gradually reduced toward the developing tank at the end so as to approach the neutral value.

For example, the pH value of the alkaline developer sprayed from the nozzle of the developing tank 1 (20-1) at the tip adjacent to the carry-in device (10) shown in FIG. The pH value of the alkaline developer in the tank 2 (20-2) and thereafter is maximum toward the developing tank (developing tank i (20-i), not shown) at the center of a plurality of continuous developing tanks. It is assumed that the value is gradually increased to a value.
Thereby, the influence which the time difference of the front-end | tip part (a) on a glass substrate in the early stage of development and a rear-end part (b) has on the line width of a coloring pixel shall be made small. The value closest to the neutral value is about pH 9.0 to pH 9.5.

The pH value is gradually increased stepwise toward the developing tank i (20-i) in the center of the developing tank, and the developing action is gradually increased to promote development. The developing action is maximized in the central developing tank i (20-i).
Further, the pH value of the alkaline developer after the developing tank (i + 1) (20- (i + 1)) is set to the developing tank n (20-n) at the rear end adjacent to the carry-out device (40) shown in FIG. ) And gradually decrease so as to approach the neutral value most.
Thereby, the influence which the time difference of the front-end | tip part (a) on a glass substrate in the last stage of development and a rear-end part (b) has on the line width of a coloring pixel shall be made small. The value closest to the neutral value is about pH 9.0 to pH 9.5.

  Therefore, although the front-end | tip part (a) of the glass substrate after the development carried out to the carrying-out apparatus (40) is in the state where development time is long compared with the rear end part (b), the length direction ( At the front end portion (a) in the transport direction), the line width variation (in-plane line width non-uniformity) such that the line width of the colored pixels becomes narrower than the rear end portion (b) is reduced.

Since the development amount with the alkaline developer is the cumulative amount of development in a plurality of continuous development tanks, the pH values of the plurality of continuous development tanks are appropriately set so as to obtain a desired development amount. .
The pH value of each developing tank is expressed as follows: [pH value of developing tank 1] = [pH value of developing tank n], [Developing tank 2] with the pH value of the developing tank i (20-i) in the center as a symmetric reference. PH value] = [pH value of developing tank (n-1)],...

Table 1 shows the constitution of the developing tank and the pH value of the alkaline developer in each developing tank in an example of the alkali developing apparatus used in the alkali developing method according to the present invention.
As shown in Table 1, this alkali developing device is composed of eight tanks, a developing tank 1 to a developing tank 8. The pH value of the alkaline developer sprayed from the nozzle of the developing tank 1 at the tip adjacent to the carry-in device is the closest to the neutral value, and thereafter gradually increases step by step to the central developing tank 4. At 5 and 5, pH 12 is the maximum value.

また、現像槽４及び５以降は、段階的に漸減し、現像槽８にては最も中性値に近いｐＨ９となっている。
また、〔現像槽１のｐＨ９〕＝〔現像槽８のｐＨ９〕、〔現像槽２のｐＨ１０〕＝〔現像槽７のｐＨ１０〕、・・・・と対称の関係を保っている。

Further, the developing tanks 4 and 5 and thereafter are gradually decreased, and the developing tank 8 has a pH 9 that is closest to the neutral value.
Also, [pH 9 of developing tank 1] = [pH 9 of developing tank 8], [pH 10 of developing tank 2] = [pH 10 of developing tank 7],...

The average pH value of the alkali developer in this alkali developing device is 10.5. That is, “pH 10.5 × 8 tank” is a schematic representation of the development amount in this alkali development method.
As described above, the line width variation is improved within an allowable range of 0.5 to 1.0 μm compared to the conventional line width variation of 1.0 to 1.5 μm, and the conventional color pixel film thickness variation is also improved. The film thickness variation was improved within an allowable range of 0.5 to 1.0% with respect to 1.0 to 2.0%.

It is the top view which showed typically an example of the color filter used for a liquid crystal display device. It is sectional drawing in the X-X 'line | wire of the color filter shown in FIG. (A), (b) is sectional drawing which shows the outline of an example of the image development apparatus at the time of forming a colored pixel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 60 ... Carry-in apparatus 11 ... Glass substrate 11B ... Glass substrate 11C after image development ... Glass substrate 20 in washing tank ... Developing tank (20-1)-(20-n) ... Developing tank 1 to developing tank n
21, 31 ... Nozzle 30 ... Washing tub 40, 70 ... Unloading device 50 ... Glass substrate 51 ... Black matrix 52 ... Colored pixel 54 ... Transparent conductive film 80 ... Conveyor device a ... tip end b of glass substrate ... rear end of glass substrate

Claims (1)

  While the glass substrate is transported horizontally in a plurality of continuous developing tanks, the alkali developer in the form of a shower is sprayed onto the glass substrate from the nozzles provided in the developing tank, and then development is performed. Alkaline for water washing by spraying pure water in the form of a shower from a nozzle provided in the water rinsing tank onto the glass substrate with little time difference between the front and rear ends of the glass substrate while transporting the inside horizontally. In the developing method, the pH value of the alkaline developer sprayed onto the glass substrate is maximized in the developing tank at the center of a plurality of continuous developing tanks, and the developing tank and the unloading apparatus at the front end adjacent to the carrying-in apparatus are used. An alkali developing method characterized by gradually reducing the thickness toward a neutral value toward an adjacent rear end developing tank.

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