JPH0915417A - Color filter forming method - Google Patents

Abstract

(57) [Abstract] [Purpose] By making both sides of the cross-sectional shape of the color filter trapezoidal with optimal inclined surfaces, defects are not caused in the thin film and the like formed on the top of this color filter, and Provided is a method for forming a color filter that can obtain good color characteristics. A method of forming a color filter having a predetermined pattern by exposing a photosensitive color resist film 2 through an exposure mask 4 and then developing the exposed color resist film. By moving 1 up and down to change the distance between the color resist film 2 and the exposure mask 4, the color resist film 2 is exposed with light having an intensity distribution according to the change in the distance. Then, the color resist film 2
However, this light intensity distribution is optimally controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a color filter using a photosensitive color resist.

[0002]

2. Description of the Related Art In a color liquid crystal display device for displaying a color image, a method of forming a color filter provided on one substrate is to coat a substrate with a photosensitive color resist, and to pass the resist film through an exposure mask. A method is known in which a color filter having a predetermined pattern is formed by performing development processing after exposure by exposure.

By the way, in a color liquid crystal display element, a transparent electrode on the side of a substrate on which a color filter is provided is formed on the color filter, and a color filter is formed on the transparent electrode (ITO). There are things.

When forming an electrode on a color filter, if the side surface of the color filter is a surface close to vertical, the side surface of the color filter is formed when an ITO film or the like is formed thereon by a sputtering device or the like. In this case, the ITO film does not deposit well, so that the formed electrode becomes thin on the side surface portion of the color filter, and the resistance value at that portion becomes large, or disconnection occurs in an extreme case.

Therefore, when the electrodes are formed on the color filters, the color filters are appropriately formed on both side surfaces of the color filters so that the ITO film can be formed on the side surfaces of the color filters with a sufficient thickness. It is desirable to form the cross-sectional shape with an inclination.

On the other hand, in forming a color filter using the above-mentioned photosensitive color resist, the light for exposing the color resist film has an intensity distribution corresponding to the distance between the film surface of the color resist film and the exposure mask. A color filter having a cross-sectional shape corresponding to the intensity distribution is formed on the color resist film exposed by light.

Therefore, conventionally, in order to form a color filter having a cross-sectional shape having no extreme steps on both sides, the gap between the color resist film and the exposure mask is appropriately set,
The color resist film is exposed. The distance between the color resist film and the exposure mask is called the proximity amount.

[0008]

However, conventionally, even if the proximity amount is appropriately set, it is not possible to strictly control the intensity distribution of light actually radiated to the color resist film. , The side surface of the formed color filter has a stepped shape, which causes an increase in the resistance value or disconnection of the electrode formed on the side surface, or the thickness of the color filter is thin as a whole, and a good color is obtained. The characteristics could not be obtained.

The present invention has been made to solve the above-mentioned problems, and is formed on the upper part of the color filter by forming both sides of the cross-sectional shape of the color filter into trapezoidal shapes having optimum inclined surfaces. It is an object of the present invention to provide a method for forming a color filter that does not cause defects in the formed thin film and can obtain good color characteristics.

[0010]

In order to achieve the above object, a method of forming a color filter according to the present invention comprises exposing a photosensitive color resist film through an exposure mask and then developing it to form a predetermined pattern. The method for forming a color filter is characterized in that a gap between the color resist film and the exposure mask is changed during exposure of the color resist film.

Further, in the method for forming a color filter of the present invention, the distance between the color resist film and the exposure mask is set to
It is characterized in that it is continuously changed between 50 μm and 400 μm.

Further, in the method for forming a color filter of the present invention, the distance between the color resist film and the exposure mask is set to
It is characterized in that the distance is continuously changed in the direction of increasing the distance between 50 μm and 400 μm.

Further, in the method for forming a color filter of the present invention, the distance between the color resist film and the exposure mask is
It is characterized in that the distance is continuously changed in the direction of decreasing the distance between 400 μm and 50 μm.

[0014]

In the method for forming a color filter of the present invention, after exposing the photosensitive color resist film through the exposure mask,
A method of developing to form a color filter having a predetermined pattern, the intensity distribution of light to be exposed by changing a distance between the color resist film and the exposure mask during exposure of the color resist film. Is optimized to optimize the distribution of the exposure dose on both sides of the color resist film, whereby a color filter having a trapezoidal cross section is formed.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining a color filter forming method according to an embodiment of the present invention.

An exposure table 1 having an elevating function and movable up and down
A transparent substrate (for example, a glass substrate) 3 having a negative type photosensitive color resist film 2 applied on the entire upper surface is placed thereon, and an exposure mask 4 is arranged above the color resist film 2 so as to face it. Then, the color resist film 2 is irradiated with light from the light source 5 arranged on the upper part thereof to perform an exposure process.

Then, while the color resist film 2 is being irradiated with light from the light source 5, that is, during exposure, the exposure table 1 is moved up and down to increase the proximity amount from 50 μm to 400 μm (preferably). Is continuous).

As described above, by changing the proximity amount from 50 μm to 400 μm during the exposure, the light intensity distribution of the irradiation light on the side surface of the color resist film 2 can be continuously changed.

2 (a), (b), (c), and FIG.
In (a) and (b), the proximity amount (Proximit
y) between 50 μm and 400 μm, 50,1
The figure which selected five kinds of 00,150,200,400, and calculated | required each exposure intensity distribution is shown. The slit width (D) of the exposure mask 4 at this time is 10 μm, and the incident light wavelength λ of the exposure light is 365 nm.

Further, FIG. 4A shows a substrate (eg, glass substrate) 11 on which the proximity amount is fixed at 50 μm, and after exposure, development processing is performed to form a color filter having a predetermined pattern. 4B is a view showing a cross-sectional shape of the color filter 12 of FIG. 4B, and FIG. 4B shows the substrate 1 when the proximity amount is fixed to 400 μm, and after exposure, development processing is performed to form a color filter having a predetermined pattern.
It is a figure which shows the cross-sectional shape of the color filter 12 above 1.

As shown in FIG. 2A, when the proximity amount is 50 μm, the peak of the light intensity distribution of the incident light from the mask opening exists in the portion corresponding to the pattern cross section, so that FIG. ), The cross-sectional shape of the color filter 12 is stepwise. Further, as shown in FIG. 3B, when the proximity amount is 400 μm, the light intensity distribution of the incident light from the mask opening becomes weak in a wide range, so that as shown in FIG. Color filter 12
The film thickness is reduced in the cross-sectional shape, and the pattern is blurred.

Therefore, in this forming method, as described above, the proximity amount is changed from 50 μm to 400 μm during the exposure.
The intensity distribution of the light to be exposed is optimally controlled by changing the exposure amount to μm, and the distribution of the exposure amount on both side surfaces of the color resist film is optimized. By superimposing the intensity distributions of the above, it is possible to form a continuous light intensity distribution of the irradiation light on both side surfaces of the color filter. Therefore, by exposing the color resist with light having this light intensity distribution, both side surfaces of the cross-sectional shape of the color filter can be made into a trapezoidal shape having an optimal inclined surface.

FIG. 5 is a diagram showing a cross-sectional shape of a color filter manufactured by the method for forming a color filter of the above-described embodiment. A color filter 12 manufactured according to the present embodiment is formed on the substrate 11, and the cross-sectional shape of the color filter 12 is substantially trapezoidal with both side surfaces being inclined surfaces.

FIG. 6 is a sectional view of an active matrix type liquid crystal display device to which the color filter formed according to this embodiment is applied. Of a pair of transparent substrates (for example, glass substrates) 11 and 21 facing each other across the liquid crystal layer, a plurality of transparent pixel electrodes 22 made of ITO or the like are provided on the inner surface of one substrate 21 and these pixel electrodes. Thin film transistors (hereinafter, referred to as TFTs) 23 corresponding to 22
Are formed. Further, these pixel electrode 22 and TF
An alignment film 24 is formed on the entire surface of T23.

On the inner surface of the other substrate 11, color filters 12 manufactured according to this embodiment are formed so as to face the respective pixel electrodes 22, and ITO is formed on the entire surface of the color filters 12. A transparent counter electrode 25 made of, for example, is formed, and an alignment film 26 is formed on the entire surface of the counter electrode 25.

The color filter 12 is composed of, for example, a red filter R, a green filter G, and a blue filter B.
Color filters, and filters R, G, and
B are arranged alternately on the inner surface of the substrate 11 by repeating the forming method of this embodiment three times.

A liquid crystal 27 is filled between the pair of substrates 11 and 21, and both substrates 11 and 21 are filled.
A polarizing plate or the like (not shown) is attached to the outside of the. In the active matrix type liquid crystal display device having such a structure, the cross-sectional shape of the color filter 12 formed according to the present embodiment is substantially trapezoidal with both side surfaces being inclined surfaces. Color filter 12
Even if the counter electrode 25 is provided on the counter electrode 25, defects such as an increase in resistance value and disconnection are unlikely to occur in the counter electrode 25.

In the above embodiment, the proximity amount is set to 50 during exposure by moving the exposure table 1 up and down.
It was changed from μm to 400 μm. This is because the proximity amount is changed from 50 μm to 400 μm by moving the exposure mask 4 and the light source 5 or the exposure mask 4 up and down.
You may change to m.

In the above embodiment, the proximity amount is increased, that is, from 50 μm to 400 μm.
Although it is changed to m, it may be changed to a direction in which the proximity amount decreases, that is, from 400 μm to 50 μm. Further, the form of the change in the proximity amount may be continuous or discontinuous.

Further, FIG. 6 shows an example in which the present embodiment is applied to an active matrix type liquid crystal display element, but the present embodiment is a simple matrix type liquid crystal display element or M
Even when applied to an active matrix type liquid crystal display element using a two-terminal non-linear resistance element such as IM, the same effect can be obtained.

[0031]

As described above, according to the present invention, the distance between the color resist film and the exposure mask is changed during the exposure of the color resist film, and the color resist film responds to the change in the distance. By exposing the color filter to light having an intensity distribution so that both sides of the cross-sectional shape of the color filter have a trapezoidal shape with optimal inclined surfaces, defects may occur in the thin film formed on the top of this color filter. It is possible to provide a method for forming a color filter that does not cause the color filter and can obtain good color characteristics.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a method of forming a color filter according to an embodiment of the present invention.

FIG. 2A is a diagram showing an exposure intensity distribution when the proximity amount (Proximity) during color filter exposure is 50 μm, and FIG. 2B shows the proximity amount (Proximity) during color filter exposure. It is a figure which shows the exposure intensity distribution when it is 100 micrometers, (c) shows the proximity amount (Proximity) at the time of color filter exposure of 150 micrometers.
It is a figure which shows the exposure intensity distribution when it is set to m.

3A is a diagram showing an exposure intensity distribution when the proximity amount (Proximity) at the time of color filter exposure is 200 μm, and FIG. 3B is a diagram showing the proximity amount (Proximity) at the time of color filter exposure. It is a figure which shows exposure intensity distribution when it is 400 micrometers.

4A is a diagram showing a cross-sectional shape of the color filter 12 when a color filter having a predetermined pattern is formed by fixing the proximity amount to 50 μm, and FIG. 4B is a diagram showing the proximity amount to 400 μm. Color filter 1 when fixed and forming a color filter of a predetermined pattern
It is a figure which shows the cross-sectional shape of 2.

FIG. 5 is a diagram showing a cross-sectional shape of a color filter manufactured by the method for forming a color filter of the example.

FIG. 6 is a cross-sectional view of an active matrix type liquid crystal display device to which a color filter formed according to an example is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Exposure stage 2 ... Color resist film 3 ... Glass substrate 4 ... Exposure mask 5 ... Light source 11 ... Substrate 12 ... Color filter 21 ... Substrate 22 ... Pixel electrode 23 ... Thin film transistor (TFT) 24 ... Alignment film 25 ... Counter electrode 26 ... Alignment film 27 ... Liquid crystal

Claims (4)

[Claims] 1. A method of forming a color filter having a predetermined pattern by exposing a photosensitive color resist film through an exposure mask and then developing it, wherein the color resist film and the color resist film are exposed during the exposure of the color resist film. A method of forming a color filter, characterized in that a distance from the exposure mask is changed. 2. The method of forming a color filter according to claim 1, wherein the distance between the color resist film and the exposure mask is continuously changed between 50 μm and 400 μm. 3. The formation of the color filter according to claim 1, wherein the distance between the color resist film and the exposure mask is continuously changed in the direction of increasing the distance between 50 μm and 400 μm. Method. 4. The formation of a color filter according to claim 1, wherein the distance between the color resist film and the exposure mask is continuously changed in the direction of decreasing the distance between 400 μm and 50 μm. Method.