KR101917620B1 - Photo mask - Google Patents

Abstract

The present invention relates to a photomask, and a photomask of the present invention includes a body portion; A first wing portion disposed on one side of the body portion; And a second wing portion disposed on the other side of the body portion and arranged to be offset from the first wing portion, thereby forming a fine pattern.

Description

Photomask {Photo mask}

The present invention relates to a photomask, and more particularly, to a photomask capable of realizing a fine pattern.

In general, a liquid crystal display device is widely used in the display industry field because it can be driven not only at a low power consumption but also at a thin thickness.

Such a liquid crystal display device includes a color filter substrate and a thin film transistor substrate which are mutually interposed with a liquid crystal interposed therebetween. Here, when a voltage is applied to the electrodes disposed on the color filter substrate and the thin film transistor substrate, the vertical electric field formed by the applied voltage difference controls the direction of the liquid crystal molecules. At this time, the transmittance of light passing through the liquid crystal is controlled according to the direction of the liquid crystal molecules, and the liquid crystal display device displays an image.

Here, when the liquid crystal display device adopts the method of driving the liquid crystal by vertical vertical electric fields, there is a problem that the viewing angle characteristics are deteriorated. To solve this problem, a liquid crystal driving method using an in-plane switching (IPS) method using a horizontal electric field has been proposed.

In such a transverse electric-field liquid crystal display device, pixel electrodes having a bar shape and common electrodes are arranged alternately at certain intervals in each pixel. Here, when a data voltage is applied to the pixel electrode and a common voltage is applied to the common electrode, the transverse electric field type liquid crystal display device forms a transverse electric field in a horizontal direction with respect to the substrate. At this time, the liquid crystal is driven by the transverse electric field to provide an image having excellent symmetrical viewing angle characteristics.

However, the transverse electric field type liquid crystal display device can improve the viewing angle characteristics compared with other schemes, but the liquid crystal corresponding to the upper portion of the pixel electrode and the upper portion of the common electrode is not driven, and the light transmittance transmitted through the liquid crystal display device may be lowered . At this time, as the line width of the pixel electrode and the common electrode is reduced, the light transmittance of the transverse electric field type liquid crystal display device can be improved.

On the other hand, the common electrode and the pixel electrode can be formed through a photolithography process. Specifically, in the photolithography process for forming the common electrode or the pixel electrode, a conductive film and a photoresist are formed on a substrate, and then a photoresist pattern having a predetermined pattern is formed through a photolithography process using a mask. Thereafter, the pixel electrode or the common electrode can be formed by patterning the conductive film using the photoresist pattern as an etching mask. At this time, the line width of the common electrode or the pixel electrode can be reduced by improving the resolution of the photo equipment, but it is difficult to form the common electrode or the pixel electrode having a fine line width of 4 μm or less due to the resolution limit of the photo equipment.

Therefore, the lateral electric field type liquid crystal display device is required to develop a photo apparatus capable of improving the resolution in order to form a common electrode or a pixel electrode having a fine line width.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a photomask for forming a pattern having a fine line width of 4 μm or less by improving the resolution of a photographic equipment.

A photomask of one solution according to the present invention is provided. The photomask according to the present invention may include a body portion, a first wing portion disposed on one side of the body portion, and a second wing portion disposed on the other side of the body portion and staggered from the first wing portion.

A photomask of another solution according to the present invention is provided. The photomask according to the present invention may include a body portion, a constructive interference portion connected to the body portion to cause a constructive interference of light, and a destructive interference portion facing the constructive interference portion with the body portion interposed therebetween, have.

The photomask according to the embodiment of the present invention can form a photoresist pattern having a fine line width of 4 탆 or less by forming the body portion and the wings on both sides of the body portion.

In addition, the photomask according to the embodiment of the present invention can further reduce the width of the body portion without considering the loss of the photoresist pattern due to the destructive interference of light by arranging the wing portions staggered from both sides of the body portion, Can be formed.

1 is a plan view showing a part of a photomask according to a first embodiment of the present invention.
Fig. 2 is an enlarged view of the area A shown in Fig. 1. Fig.
3 is a schematic view showing the photolithography process on line I-I 'of FIG.
4 is a plan view of a transverse electric field type liquid crystal display device manufactured through the mask of FIG.
5 is a plan view of a photomask according to a second embodiment of the present invention.

Embodiments of the present invention will be described in detail with reference to the drawings of a photomask. The following embodiments are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention.

Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the size and thickness of an apparatus may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

1 is a plan view showing a part of a photomask according to a first embodiment of the present invention.

Fig. 2 is an enlarged view of the area A shown in Fig. 1. Fig.

1 and 2, the photomask according to the first embodiment of the present invention includes a body part 111 and first and second wing parts 112a and 112b disposed on both sides of the body part 111, . ≪ / RTI >

Here, the photomask may include a mask pattern 110 having a shape corresponding to a pattern to be formed and a peripheral portion 120 disposed along the periphery of the mask pattern 110. The mask pattern 110 may be a light transmitting region or a light blocking region, depending on the characteristics of the photosensitive resin used in the photo process. For example, when a positive photosensitive resin is used in the photolithography process, the mask pattern 110 may be formed of a blocking material that blocks light. The positive photosensitive resin is decomposed or softened when exposed to light and can be removed by the developer. Accordingly, in the photolithography process using the photomask, a photoresist pattern having a shape corresponding to the light shielding region can be formed.

In the embodiments of the present invention, the description has been given of the description of the photolithography process using the positive photosensitive resin, but the present invention is not limited thereto. For example, when a positive photosensitive resin is used in the photolithography process, the mask pattern 110 may be made of a light-transmitting material or an opening. The negative photosensitive resin is crosslinked or cured when exposed to light and is not removed by the developer. Accordingly, in the photolithography process using the photomask, a photoresist pattern having a shape corresponding to the light transmission region can be formed.

The mask pattern 110 may include a sub-mask pattern 110a for forming a fine pattern. Here, the sub mask pattern 110a may include a body part 111, first and second wing parts 112a and 112b. For example, the sub mask pattern 110a may correspond to a formation region of the first pixel electrode (321 in Fig. 4) of the pixel electrodes of the later-described lateral electric field type liquid crystal display device. However, in the embodiment of the present invention, the application of the sub mask pattern 110a is not limited, and can be applied to request a fine pattern. For example, the sub mask pattern 110a may be used to form a first common electrode (331 in FIG. 4) or wiring that forms a transverse electric field in the pixel electrode bar.

The body part 111 may have a shape corresponding to a fine pattern to be formed. For example, the body part 111 may be in the shape of a bar in the form of a line. However, the shape of the body part 111 is not limited in the embodiment of the present invention, and may be variously changed according to the shape of the fine pattern to be formed.

The first and second wing portions 112a and 112b may be disposed on both sides of the body portion 111, respectively.

The first wing portion 112a may have a triangular shape. At this time, the base of the triangle may be disposed on the side surface of the body portion 111. Here, the first wing portions 112a may be connected to one another along one side of the body portion 111, and may be arranged in a plurality of ways. The protruding first wing portions 112a may be disposed on one side of the body portion 111 and the first concave portion 113a may be formed between adjacent first wing portions 112a. Here, the first concave portion 113a may have a shape corresponding to the first wing portion 112a. Accordingly, the first wing portion 112a and the first concave portion 113a may be alternately disposed on one side of the body portion 111. [

The second wing portion 112b may have a triangular shape. Here, the second wing portion 112b may have the same shape as the first wing portion 112a. Here, the second wing portions 112b may be connected to each other along the other side of the body portion 111 and may be disposed in a plurality of positions. Accordingly, the protruded second wing portions 112b may be disposed on one side of the body portion 111, and a second recessed portion 113b may be formed between the adjacent second wing portions 112b. Here, the second wing portion 112b may have a shape corresponding to the second wing portion 112b. Accordingly, the second recess 112b of the second wing portion 112b may be alternately arranged on the other side of the body portion 111. [

Here, since the first and second wing portions 112a and 112b have a triangular shape, constructive interference of light may occur around the vertex of the triangle. In addition, destructive interference of light may occur around the vertexes of the first and second concave portions 113a and 113b. Accordingly, the sub mask pattern 110a may include a constructive interference portion formed by a wing portion formed of a protruding portion of a triangle and a destructive interference portion formed by a triangular concave portion recessed inward of the body portion. That is, the first and second constructive interference parts 114a and 114b may be formed on both sides of the body part 111, respectively. In addition, first and second destructive interference units 115a and 115b may be disposed on both sides of the body part 111, respectively. Accordingly, the first constructive interference unit 114a and the first destructive interference unit 115a may be alternately disposed on one side of the body part 111, and the second constructive interference unit 114a may be disposed on the other side of the body part 111, The first destructive interference unit 114b and the second destructive interference unit 115b may be alternately arranged.

When the sub mask pattern 110a does not include the wing portion, light penetrates into the region corresponding to the body portion by diffraction of light, and the photoresist pattern corresponding to the body portion is lost without being formed There was a problem. Accordingly, there is a limit in reducing the width of the conventional mask pattern, and it is difficult to form a fine pattern. However, by disposing the first and second wing portions 112a and 112b on both sides of the body portion 111 as in the present invention, light can be incident on the region corresponding to the body portion 111 through the reinforcement and cancellation of light, It is possible to minimize penetration. As a result, the width of the mask pattern can be reduced compared with the conventional method, and the fine photoresist pattern can be formed as compared with the case where the first and second wing portions are not provided.

When the first and second wing portions 112a and 112b are disposed to face each other with the body portion 111 interposed therebetween, the first and second concave portions 113a and 113b also contact the body portion 111 Can face each other in between. Accordingly, simultaneous destructive interference occurs simultaneously on both sides of the body part 111 facing each other with the body part 111 interposed therebetween. As a result, the first and second concave portions 113a and 113b face each other at the same time, light penetrates into the region corresponding to the body portion 111, and consequently, the first and second concave portions 113a and 113b, And the photoresist pattern corresponding to the body part 111 connected to the body part 111 may be lost. Accordingly, there is a limit in reducing the width of the body portion 111 in consideration of the problem of disappearance of the photoresist pattern.

Since the width of the body part 111 is an important factor for determining the width of the photoresist pattern to be formed, there is a limitation in reducing the width of the photoresist pattern due to the limitation of reducing the width of the body part 111 have.

In order to solve this problem, the first and second wing parts 112a and 112b may be staggered from each other on both sides of the body part 111. [ Here, the vertex of the first wing portion 112a may be aligned with the vertex of the second wing portion 112b, that is, the vertex of the second recess 113b. The first staple interfering portion 114a faces the second staple interfering portion 115b with the body portion 111 interposed therebetween and the first staple interfering portion 115a intervenes between the body portion 111 and the first staple interfering portion 115a. And can face the second reinforcing interfering portion 114b. In other words, destructive interference of light can occur alternately at one side or the other side of the body part 111. Accordingly, when the first and second wing parts 112a and 112b are arranged to be shifted from each other, as compared with the case where the first and second wing parts 112a and 112b are disposed to face each other, It is possible to prevent the light from penetrating into the inner side at the same time. That is, when the first and second wing portions 112a and 112b are arranged to be offset from each other than when the first and second wing portions 112a and 112b are disposed to face each other, The width of the body part 111 can be further reduced.

The angle of the vertex of each of the first and second wings 112a and 112b may have an angle of 50 to 130 degrees. This is because the first and second wings 112a and 112b are transferred in the photolithography process to form the first and second wings 112a and 112b when the angle of the vertex is less than 50 ° or the angle of the vertex is more than 130 °. A photoresist pattern corresponding to the photoresist pattern can be formed.

The height of each of the first and second wing portions 112a and 112b may be 0.1 to 1.6 占 퐉. If the height is out of the range, the first and second wings 112a and 112b may be transferred in the photolithography process to form a photoresist pattern corresponding to the first and second wings.

The width of the body portion 111 may be 0.4 to 4 占 퐉. Here, when the width of the body portion is less than 0.4 탆, the photoresist pattern may be lost due to destructive interference of light, so that it can not be used as an etching mask. On the other hand, when the width of the body part 111 is 4 탆 or more, there is no reason to use the photomask of the present invention because a photoresist pattern which can be sufficiently formed through a conventional photolithography process can be formed. Preferably, the width of the body portion may be 0.4 to 3 占 퐉 to form a fine pattern

The line width MW of the sub mask pattern 110a can be expressed by the following equation (1).

Here, BW is the width of the body, h1 is the height of the first wing, and h2 is the height of the second wing.

Accordingly, when the first and second wing portions 112a and 112b are arranged to be shifted from each other rather than when the first and second wing portions 112a and 112b are disposed to face each other, It is possible to further reduce the line width of the sub mask pattern 110a.

Hereinafter, the photolithography process using the photomask according to the first embodiment of the present invention will be described in detail with reference to FIG.

3 is a schematic view showing the photolithography process on line I-I 'of FIG.

Referring to FIG. 3, a positive photoresist 210 is formed on a substrate 200, and then a photolithography process is performed using a photomask (PM). Here, the photomask PM may include first and second wing portions 112a and 112b disposed on both sides of the body portion 111 and the body portion 111 in a staggered manner.

In the photo process, light may be diffracted into the first and second wings 112a, 112b along the edges of the first and second wings 112a, 112b. Here, as the first and second wing portions 112a and 112b have a triangular shape, constructive interference of light may occur at the vertexes of the first and second wing portions 112a and 112b. In addition, destructive interference may occur between the first wing portions 112a, that is, between the first concave portion 113a and the second wing portions 112b, that is, the second concave portion 113b.

Accordingly, in the photolithography process using the photomask PM, light can be penetrated into the inside of the body portion 111 from the vertexes of the first and second recesses 113a and 113b by optical diffraction.

Here, when the first and second wing portions 112a and 112b are disposed to face each other, the line width MW of the sub mask pattern 110a is smaller than the width BW of the body portion 111, And the heights h1 and h2 of the wing portions 112a and 112b. When the first and second wing portions 112a and 112b are arranged to be shifted from each other, the line width MW of the sub mask pattern 110a is determined by the width BW of the body portion 111, (BW) of the body portion 111 by subtracting the height h2 of the second wing portion 112b from the sum of the height h1 of the first wing portion 112a and the height h1 of the first wing portion 112a. Accordingly, when the first and second wing portions 112a and 112b are arranged to be offset from each other than when the first and second wing portions 112a and 112b face each other, the line width of the sub mask pattern 110a can be reduced have.

When the first and second wing parts 112a and 112b are arranged to be offset from each other as compared with the case where the first and second wing parts 112a and 112b face each other, It is not necessary to consider the loss of the photoresist pattern, so that the width of the body portion 111 can be further reduced.

Accordingly, when the first and second wing portions 112a and 112b are arranged to be shifted from each other, the line width of the photoresist pattern to be formed is further reduced, as compared with the case where the first and second wing portions 112a and 112b face each other .

4 is a plan view of a transverse electric field type liquid crystal display device manufactured through the mask of FIG.

As shown in Fig. 4, the transverse electric field type liquid crystal display device includes pixels arranged in the region defined by the gate wiring 311 and the data wiring 312 intersecting with each other, and arranged in parallel with the gate wiring 311 across the region And may include a common wiring 313 formed thereon. The pixel includes a thin film transistor TFT connected to the gate wiring 311 and the data wiring 312, a pixel electrode 320 connected to the thin film transistor TFT, a common electrode 330 connected to the common wiring 313, . ≪ / RTI >

Here, the pixel electrode 320 includes a plurality of bar-type first pixel electrodes 321 having spaced spaces from each other and a second pixel electrode 322 electrically connecting the plurality of first pixel electrodes 321 to each other. ).

The common electrode 330 includes a first common electrode 331 and a second common electrode 332 electrically connecting the first common electrode 331 and the bar common electrode 331, ).

Here, the first pixel electrode 321 and the first common electrode 331 are alternately arranged with a spacing space therebetween, so that a transverse electric field that horizontally aligns the liquid crystal by the electric field can be formed.

As shown in FIGS. 1 and 4, the photomask according to the first embodiment of the present invention is used in a photolithography process for forming a pixel electrode of a transverse electric field type liquid crystal display device. The photomask and the pixel electrode have shapes corresponding to each other Lt; / RTI > Here, in the transverse electric field liquid crystal display device, in order to improve light transmittance, it is necessary to form the first pixel electrode 321 of the pixel electrode in a fine pattern. Accordingly, the photomask connects the first and second wing portions 112a and 112b, which are alternately arranged on both sides of the body portion 111 of the mask pattern corresponding to the first pixel electrode 321, The electrode 320 can be formed.

In the first embodiment of the present invention, the photomask has been described by way of example only in the case of forming the pixel electrode, and the photomask is not limited to the common electrode, the gate wiring, the data wiring and the common wiring of the liquid crystal display device, And a thin film transistor, and the shape of the photomask can be variously changed according to the shape of the pattern to be formed.

5 is a plan view of a photomask according to a second embodiment of the present invention.

Here, the second embodiment of the present invention includes the same technical constitution as the first embodiment described above except that it further includes an interference prevention bar. Therefore, the description of the first embodiment and the repeated description will be omitted, and the same technical constitution will be given the same reference numerals.

5, the photomask according to the second embodiment of the present invention includes a body part 111 and a plurality of first wing parts 112a disposed on one side of the body part 111, a body part 111, And a plurality of second wing portions 112b disposed on the other side of the first wing portion 112a and staggered with the first wing portion 112a.

Here, the mask pattern 110 may include a plurality of sub-mask patterns arranged at a predetermined interval. The sub-mask patterns may include a body part 111 and first and second wing parts staggered from each other on both sides of the body part to form a fine pattern. For example, the mask pattern 110 may include neighboring first and second sub-mask patterns 110a1 and 110a2.

An interference phenomenon may occur between the first and second sub-mask patterns 110a1 and 110a2 in the photo process. That is, the constructive interference portion of the first sub-mask pattern 110a1 can affect the second sub-mask pattern 110a2. Or the destructive interference portion of the first sub-mask pattern 110a1 may affect the second sub-mask pattern 110a2.

As a result, the stiffening interfering portion or the destructive interference portion of the sub mask pattern 110a affects the light applied to the adjacent sub mask pattern 110a, and an unwanted photoresist pattern can be formed.

In order to solve this problem, the interference prevention bar 130 may be further formed on at least one side of the sub mask pattern 110a so as to face at least one of the destructive interference unit or the constructive interference unit. Here, the interference prevention bar 130 may be disposed between adjacent sub-mask patterns 110a. In addition, the interference prevention bar 130 may be disposed in parallel with the sub mask pattern 110a. Here, the interference prevention bar 130 may be formed apart from other mask patterns. That is, the interference prevention bar 130 may be formed in an island shape. This is because the anti-interference bar 130 in the photolithography process may affect the photoresist pattern to be formed.

In addition, the width of the interference prevention bar 130 can be set to 1 m or less. This is because, if the width of the interference prevention bar 130 exceeds 1 탆, the shape of the interference prevention bar 130 can be transferred in the photo process.

Therefore, the photomask according to the second exemplary embodiment of the present invention further includes an interference prevention bar to prevent interference of light that may occur between adjacent sub-mask patterns, thereby preventing a pattern defect from occurring.

110: mask pattern 110a: sub mask pattern
110a1: first sub mask pattern 110a2: second sub mask pattern
120: peripheral portion 111:
112a: first wing portion 112b: second wing portion
113a: first concave portion 113b: second concave portion
114a: first reinforcing interference part 114b: second reinforcing interference part
115a: first destructive interference unit 115b: second destructive interference unit
130: interference prevention bar

Claims (15)

A plurality of body portions mutually spaced apart;
A first wing portion disposed at one side of the plurality of body portions;
A second wing portion disposed on the other side of the plurality of body portions and staggered from the first wing portion; And
And an interference preventive bar disposed to be spaced apart from a vertical direction parallel to the plurality of body parts and facing the wings of at least one of the first wings or the second wings,
Wherein the interference prevention bar has a width of 1 mu m or less.
The method according to claim 1,
Wherein each of the first and second wings has a triangular shape.
3. The method of claim 2,
Wherein a vertex of the first wing portion is disposed on a straight line with a point where the second wing portions neighbor each other.
3. The method of claim 2,
Wherein an angle of a vertex of each of the first and second wings is 50 to 130 DEG.
3. The method of claim 2,
And each of the first and second wings has a height of 0.1 to 1.6 mu m.
3. The method of claim 2,
Wherein the width of the body portion is 0.4 to 3 mu m.
delete A plurality of body portions mutually spaced apart;
A constructive interference unit connected to the plurality of body parts and causing a constructive interference of light;
A destructive interference unit facing the constructive interference unit with the plurality of body parts interposed therebetween and causing destructive interference of light; And
And an interference preventing bar disposed to be spaced apart in a vertical direction parallel to the plurality of body portions and facing at least one of the destructive interference unit and the constructive interference unit,
Wherein the interference prevention bar has a width of 1 mu m or less.
9. The method of claim 8,
Wherein the constructive interfering portion includes first and second constructive interfering portions formed on both sides of the body portion, and the destructive interference portion includes first and second destructive interference portions formed on both sides of the body portion, respectively.
10. The method of claim 9,
Wherein the first constructive interference unit and the first destructive interference unit are alternately disposed on one side of the body and the second constructive interference unit and the second destructive interference unit are alternately disposed on the other side of the body.
9. The method of claim 8,
Wherein the constructive interference portion comprises a wing portion formed of a protruding portion of a triangle.
9. The method of claim 8,
Wherein the destructive interference unit is formed as a triangular concave portion recessed inward of the body portion.
9. The method of claim 8,
Wherein the interfering interfering portion comprises a wing portion formed by a protruding portion of a triangle and the destructive interference portion has the same shape as the wing portion and is formed as a concave portion recessed inward of the body portion.
delete 9. The method of claim 8,
Wherein the interference prevention bar is formed in an island shape.

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