KR100311531B1 - In-plane switching mode liquid crystal display device and method of manufacturing thereof - Google Patents

Abstract

A transverse electric field liquid crystal display device of the present invention comprises: a first substrate and a second substrate; A data electrode, a common electrode, and a common wiring formed on the first substrate; A gate insulating film formed over the data electrode and the common electrode over the first substrate and having data holes in the data electrode area; A storage electrode formed on the gate insulating layer so as to overlap the common wiring or the common electrode; A passivation layer formed over the storage substrate over the first substrate and having a hole at the same position as the data hole and having a storage hole in the storage electrode region; A connection electrode formed on the passivation layer so as to cover the data hole and the storage hole area and electrically connecting the data electrode and the storage electrode; The liquid crystal layer is formed between the first substrate and the second substrate. In the above structure, since the common electrode and the data electrode are formed of the same material on the same layer, the two electrodes are uniformly spaced and the CD uniformity is obtained so that a uniform electric field is applied to the liquid crystal layer, thereby obtaining excellent image quality with no staining. Can be.

Description

Transverse electric field type liquid crystal display device and manufacturing method therefor {IN-PLANE SWITCHING MODE LIQUID CRYSTAL DISPLAY DEVICE AND METHOD OF MANUFACTURING THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a transverse electric field type liquid crystal display device and a method of manufacturing the same, which control an arrangement of liquid crystals with an electric field parallel to the substrate.

In recent years, a large area has been strongly demanded in a thin film transistor liquid crystal display (TFT LCD), which is widely used in portable televisions and notebook computers. However, the above-described TFT LCD has a problem in that contrast ratio is changed depending on the viewing angle. In order to solve this problem, various liquid crystal display devices such as a twisted nematic liquid crystal display device equipped with an optical compensation plate and a multi-domain liquid crystal display device have been proposed. The device is difficult to solve the problem that the contrast ratio is lowered and the color changes depending on the viewing angle.

In order to realize a wide viewing angle, a liquid crystal display device for adjusting the arrangement of liquid crystals by an electric field parallel to the substrate has been proposed.

1 and 2 are plan and cross-sectional views illustrating a thin film transistor substrate of a conventional transverse electric field type liquid crystal display device, and FIG. 2 is a cross-sectional view taken along line AA ′ of FIG. 1. As shown in the figure, the gate wiring 1 and the data wiring 2 are formed on the first substrate 10 to divide the first substrate 10 into a plurality of pixels. In the drawings, only one pixel is shown for convenience. The common wiring 3 is arranged in parallel to the gate wiring 1 in the pixel, and at the intersection of the gate wiring 1 and the data wiring 2, the gate electrode 5, the gate insulating film 12, and the semiconductor layer ( 15, and a thin film transistor composed of a source electrode 6 and a drain electrode 7 is formed. In the pixel, the data electrode 8 and the common electrode 9 are formed in parallel with the data wiring 2. The data electrode 8 has a region overlapping with the common wiring 3 and the common electrode 9 to form a storage capacitor. The common electrode 9 is connected to the common wiring 3 and the data electrode 8 Is formed on the gate insulating film 12 and is connected to the drain electrode 7. The passivation layer 13 is formed on the thin film transistor, the data electrode 8, and the gate insulating layer 12.

The color filter layer 12 is formed on the second substrate 20, and the liquid crystal layer 22 is formed between the two substrates 10 and 20.

Although not shown in the drawings, polarizers for linearly polarizing the transmitted light are provided on the outer surfaces of the two substrates 10 and 20, and an alignment layer is formed on the inner surfaces of the two substrates 10 and 20 so as to contact the liquid crystal layer. The orientation direction of the layer is determined.

In the conventional transverse electric field type liquid crystal display device configured as described above, when a voltage is applied from an external driving circuit, a transverse electric field parallel to the substrates 10 and 20 is formed between the data electrode 8 and the common electrode 9. Occurs. Accordingly, the liquid crystal molecules oriented in the liquid crystal layer 22 rotate in a state parallel to the substrate along the transverse electric field, thereby controlling the amount of light passing through the liquid crystal layer 22. At this time, since the gray scale is driven while the liquid crystal molecules are parallel to the substrate, the difference in the light transmittance according to the viewing angle is reduced.

However, in the conventional transverse electric field type liquid crystal display device, since the data electrode 8 and the common electrode 9 for applying an electric field to the liquid crystal layer are formed on different layers, the gate electrode and the source and drain electrodes are formed. When the layers overlap, the arrangement of the electrodes is incorrect, resulting in uneven spacing between the data electrodes and the common electrode. Accordingly, the distance between the electrodes is different, and different electric fields are applied to the liquid crystals between the electrodes, so that the desired arrangement of the liquid crystals cannot be obtained.

In addition, in the above structure, the larger the size of the entire screen, the greater the CD uniformity. As a result, the gap between the data electrode and the common electrode becomes nonuniform, resulting in unevenness in driving the screen.

The present invention is to overcome the problems of the prior art described above, by forming the data electrode and the common electrode on the same layer in the same layer to improve the CD uniformity, preventing the unevenness of the screen transverse electric field type liquid crystal display It is to provide an apparatus and a method of manufacturing the same.

A first embodiment of a transverse electric field type liquid crystal display device according to the present invention comprises: a first substrate and a second substrate; A data electrode, a common electrode, and a common wiring formed on the first substrate; A first insulating layer formed over the data electrode and the common electrode over the entire first substrate and having data holes in the data electrode region; At least one storage electrode formed on the first insulating layer to overlap the common wiring or the common electrode; A second insulating layer formed over the storage electrode over the entire first substrate, having a hole at the same position as the data hole, and having a storage hole in the storage electrode area; A connection electrode formed on the second insulating layer to cover the data hole and the storage hole area and electrically connecting the data electrode and the storage electrode; It comprises a liquid crystal layer formed between the first substrate and the second substrate.

The common electrode and the data electrode are made of Al, Cr, Ta, Al alloy or ITO.

The connection electrode is connected to the data electrode through the data hole, and is connected to the storage electrode through the storage hole, preferably formed of a transparent conductive material such as ITO.

A method of manufacturing a transverse electric field type liquid crystal display device having the above structure includes the steps of providing a first substrate and a second substrate; Stacking and patterning a metal film on the first substrate to form a common wiring, a common electrode, and a data electrode; Stacking a first insulating film thereon; Stacking and patterning a metal film on the first insulating film to form a storage electrode; Stacking a second insulating layer on the storage electrode; Etching a portion of the storage electrode region of the second insulating layer to form a storage hole, and etching a portion of the data electrode regions of the first and second insulating layer to form a data hole; Forming a connection electrode covering the data hole and the storage hole by coating and patterning an electrically conductive material on the second insulating layer; And forming a liquid crystal layer by injecting a liquid crystal between the first substrate and the second substrate. The connection electrode is preferably formed of a transparent conductive material such as ITO.

A second embodiment of a transverse electric field type liquid crystal display device according to the present invention comprises: a first substrate and a second substrate; A data electrode, a common electrode, and a common wiring formed on the first substrate; A first insulating film formed over the first substrate over the data electrode and the common electrode and having a data hole in the data electrode region; A second insulating film formed over the first insulating film and having a hole at the same position as the data hole; A connection electrode formed to overlap the portion of the common electrode or the common wiring and formed on the second insulating layer to cover the data hole; And a liquid crystal layer formed between the first substrate and the second substrate.

A transverse electric field liquid crystal display device of a third embodiment according to the present invention comprises: a first substrate and a second substrate; A data electrode, a common electrode, and a common wiring formed on the first substrate; A first insulating film formed over the first substrate over the data electrode and the common electrode and having a data hole in the data electrode region; A storage electrode formed on the first insulating layer to overlap the common wiring or the common electrode and covering the data hole to be connected to the data electrode; And a liquid crystal layer formed between the first substrate and the second substrate.

In the transverse electric field type liquid crystal display device according to the present invention having the above-described structure, since the data electrode and the common electrode are formed of the same material on the same layer, the distance between the two electrodes can be made uniform and thus applied to the liquid crystal layer. The intensity of the electric field becomes uniform, the CD uniformity is improved, and excellent image quality can be obtained.

1 is a plan view showing a first substrate of a conventional transverse electric field type liquid crystal display device.

FIG. 2 is a cross-sectional view taken along the line AA ′ of FIG. 1.

3 is a plan view illustrating a first substrate of a transverse electric field type liquid crystal display device according to a first exemplary embodiment of the present invention.

4 is a cross-sectional view taken along the line BB ′ of FIG. 3.

5 is a cross-sectional view taken along the line CC ′ of FIG. 3.

FIG. 6 is a cross-sectional view taken along the line D-D 'of FIG. 3.

7 is a plan view showing a second embodiment of the present invention.

8 is a plan view showing a third embodiment of the present invention.

Hereinafter, a transverse electric field type liquid crystal display device according to the present invention will be described in detail with reference to the drawings.

3 is a plan view illustrating a first substrate of a transverse electric field type liquid crystal display device according to a first exemplary embodiment of the present invention, FIG. 4 is a cross-sectional view taken along line BB ′ of FIG. 3, and FIG. 5 is C-C of FIG. 3. 6 is a cross-sectional view taken along line D-D of FIG. 3.

As shown in the figure, the gate wiring 101 and the data wiring 102 of this embodiment are formed on the first substrate 110 to define a plurality of pixels. For convenience, only one pixel is shown. The common wiring 103 is arranged in parallel with the gate wiring 101 in the pixel, and a thin film transistor is formed at the intersection of the gate wiring 101 and the data wiring 102. The thin film transistor includes a gate electrode 105 formed on the first substrate 110, a gate insulating film 112 formed thereon, a semiconductor layer 115 formed thereon, a source electrode 106 and a drain electrode formed thereon. 107). The common electrode 109 integrally connected to the common wiring 103 is formed in the pixel to be parallel to the gate wiring 101, and has a storage capacitor 109 ′ for obtaining the storage capacitance on the opposite side of the portion connected to the common wiring 103. Has Unlike the related art, the data electrode 108 is formed in the same layer as the common electrode 109 in parallel with the common electrode 109, and is formed so that both ends thereof are separated from the common electrode 109 or the common wiring 103 by a predetermined distance. do. The gate insulating film 112 is formed to cover all of the gate wiring 101, the common wiring 103, the gate electrode 105, the data electrode 108, and the common electrode 109.

As shown in FIGS. 3 and 6, the first storage electrode 131 formed on the gate insulating film 112 is integrally formed with the drain electrode 107, with the gate insulating film 112 interposed therebetween to obtain a storage capacitance. It is formed to overlap with the storage capacitor portion 109 ′ of the common electrode 109.

In addition, the second storage electrode 132 formed on the same layer as the first storage electrode 131 is formed to overlap the common wiring to obtain the storage capacitance.

The passivation layer 113 is formed on the drain electrode 107, the source electrode 106, and the first and second storage electrodes 131 and 132 over the entire first substrate 110. 3 and 6, a first storage hole 141 is formed in a region of the first storage electrode 131 of the passivation layer 113, and a second storage hole 142 is formed in a region of the second storage electrode 132. 3 and 5, the first data hole 143, the second data hole 144, and the third data hole 145 are formed in the data electrode 108 region of the passivation layer 113. And a fourth data hole 146. A first connection electrode 151 and a second connection electrode of conductive material are formed on the passivation layer 113 to cover both the data hole and the storage hole. Accordingly, the first connection electrode 151 is connected to the first storage electrode 131 through the first storage hole 141, and the second connection electrode is connected to the second storage electrode 132 through the second storage hole 142. ). In addition, the first connection electrode 151 is connected to the data electrode 108 through the first and second data holes 143 and 144, and the second connection electrode 152 connects the third and fourth data holes 145 and 146. It is connected to the data electrode 108 through. Therefore, the first connection electrode 151 serves to connect the first storage electrode 131 and the data electrode 108, and the second connection electrode 152 is the second storage electrode 132 and the data electrode ( 108) to connect. The connecting electrodes 151 and 152 may be formed of a metallic conductive material, and may be formed of indium tin oxide (ITO), which is a transparent conductive material, to form an ITO (ITO On Passivation) structure, and the connecting electrodes 151 and 152. Since a) may block an electric field formed between the data electrode 108 and the common electrode 109, it is preferable not to form a connection electrode in the region between the data electrode 108 and the common electrode 109.

The color filter layer 121 is formed on the second substrate 120, and the liquid crystal layer 122 is formed between the first substrate 110 and the second substrate 120.

Although not shown, an alignment layer is formed on inner surfaces of the two substrates 110 and 120 to contact the liquid crystal layer 122 to determine the alignment direction of the liquid crystal.

In order to manufacture a transverse electric field liquid crystal display device having such a structure, first, a conductive material such as Al, Mo, Ta, Al alloy or ITO is laminated on the first substrate 110 by a sputtering method and then photolithography. The gate electrode 105, the gate wiring 102, the common electrode 109, the common wiring 103, and the data electrode 108 are formed by patterning by the method.

Subsequently, the gate insulating film 112 is formed by stacking SiNx or SiOx or the like on the substrate by plasma CVD (plasma chemical vapor deposition).

Subsequently, amorphous silicon is stacked and etched thereon by a plasma CVD method to form a semiconductor layer 115, and n + a-Si in the source and drain regions of the semiconductor layer 115 is not shown in the figure. Stacked to form an ohmic contact layer. In this case, the gate insulating film 112, the semiconductor layer 115, and the n + a-Si layer may be sequentially stacked and then patterned at the same time.

Subsequently, metals such as Al, Cr, and Al alloys are stacked and patterned thereon to form source and drain electrodes 106 and 107 and storage electrodes 131 and 132.

Subsequently, an inorganic material such as SiOx, SiNx, or the like, or an organic material such as benzocyclobutene (BCB) or acrylic (Acryl) is laminated on the entire first substrate 110 to form a protective film 113, and then the first, second, third, And the passivation layer 113 and the gate insulating layer 112 in the fourth data holes 143, 144, 145, and 146, and the passivation layer 113 in the first and second storage holes 141 and 142. In this case, although not shown in the drawing, a gate pad hole is formed by etching the gate insulating layer 112 and the passivation layer 113 of the gate pad region connected to the gate wiring 101 and the gate driving circuit, and forming a data wiring 102 and data. The passivation layer 113 of the data pad region connected to the driving circuit is etched to form a gate pad hole, and the data pad hole 102 is etched from the data pad region and the protection layer 113 of the data pad region connected to the data driving circuit. Form.

Subsequently, a transparent conductive material such as indium tin oxide (ITO) is stacked thereon and patterned to form connection electrodes 151 and 152. Although not shown in the drawing, the electrical connection characteristics between the two wirings 101 and 102 and the respective driving circuits are shown. In order to improve the quality, ITO is also laminated on the pad area. In this case, the connecting electrodes 151 and 152 may be formed of a metal such as Al, Mo, Ta, or Al alloy.

Next, although not shown in the drawing, a polyimide or the like is applied thereon and then rubbed to form a first alignment film. The first alignment layer may be formed of a photoalignment material such as polysiloxane or cellulose cinnamate. In this case, the alignment direction is determined by irradiating ultraviolet light instead of rubbing.

The color filter layer 121 is formed on the second substrate 120, and a second alignment layer (not shown) is formed on the second substrate 120 in the same manner as the first alignment layer.

In this embodiment, since the data electrode 108 and the common electrode 109 are formed of the same material on the same layer, the distance between the two electrodes 108 and 109 can be made uniform, so that the electric field applied to the liquid crystal layer 122 The strength of the uniformity is uniform, there is an advantage that the CD uniformity is improved.

FIG. 7 is a plan view showing a first substrate 110 of a transverse electric field type liquid crystal display device according to a second embodiment of the present invention. Hereinafter, the same parts as those of the first embodiment are denoted by the same reference numerals. Omit the description. In the present exemplary embodiment, the third connection electrode 133 is formed to overlap with the storage capacitor 109 ′ of the common electrode 109 without forming the storage electrode of the first embodiment, and the fourth connection electrode 134. ) Is formed to overlap the common wiring 103. The connection electrodes 133 and 134 of the present embodiment not only connect the drain electrode 107 and the data electrode 108, but also the storage in the first embodiment. Simultaneously serves as an electrode. In this case, without forming the first and second storage holes 141 and 142 of the first embodiment, the protective layer 113 in the drain electrode 107 region is etched to form the contact hole 147 and the third connection electrode 133. ) Is connected to the drain electrode 107 through the contact hole 147.

8 is a plan view illustrating a first substrate 110 of a transverse electric field type liquid crystal display device according to a third exemplary embodiment of the present invention. Unlike the first embodiment, the connection electrode is not formed, and portions of the fifth and sixth storage electrodes 135 and 136 overlap the data electrode 108, and the storage electrodes 135 and 136 and the data electrodes ( The data electrodes 108 and the storage electrodes 135 and 136 are directly connected to each other through the fifth, sixth, seventh, and eighth data holes 148, 149, 160, and 161 formed in the gate insulating layer 112 in the region overlapping 108. The storage electrodes 135 and 136 may be formed of any conductive material, but a metallic material such as Al, Mo, Ta, or Al alloy is preferable, and since the connection electrode is not formed, no holes are formed in the passivation layer 113. In addition, when the storage electrodes 135 and 136 are formed of a metallic material, a transparent conductive material such as ITO may be formed in the data holes 148, 149, 160 and 161 to ensure electrical connection between the storage electrodes 135 and 136 and the data electrode 108, although not shown in the drawing. It is also possible to further form a redundancy electrode made of a material. The redundancy electrode may be formed between the storage electrodes 135 and 136 in the data holes 148, 149, 160 and 161 and the gate insulating layer 112, and may be formed on the storage electrodes 135 and 136 in the data holes 148, 149, 160 and 161. This embodiment has the same structure as the first embodiment except for the above-described structure.

In the transverse electric field liquid crystal display according to the present invention, since the data electrode and the common electrode are formed of the same material on the same layer, the distance between the two electrodes can be made uniform, so that the intensity of the electric field applied to the liquid crystal layer is increased. It becomes uniform, CD uniformity improves, and the outstanding image quality can be obtained.

Claims (20)

A first substrate and a second substrate, A data electrode, a common electrode, and a common wiring formed on the first substrate; A first insulating layer formed over the data electrode, the common electrode, and the common wiring over the entire first substrate, and having a data hole in the data electrode region; At least one storage electrode formed on the first insulating layer so as to overlap the common wiring or the common electrode; A second insulating layer formed on the entirety of the first substrate over the storage electrode, having a hole at the same position as the data hole, and having a storage hole in the storage electrode area; A connection electrode formed on the second insulating layer so as to cover the data hole and the storage hole area and electrically connecting the data electrode and the storage electrode; A transverse electric field liquid crystal display device comprising a liquid crystal layer formed between the first substrate and the second substrate. The transverse electric field liquid crystal display device according to claim 1, wherein the data electrode and the common electrode are made of the same material. The transverse electric field liquid crystal display device according to claim 1, wherein the distance between the data electrode and the common electrode is the same. The transverse electric field liquid crystal display device according to claim 1, wherein the connection electrode is made of indium tin oxide (ITO). The method of claim 1, One of the at least one storage electrode overlaps with the common wiring, And the other of the at least one storage electrode is integrally formed with the drain electrode and overlaps with a part of the common electrode. A first substrate and a second substrate, A data electrode, a common electrode, and a common wiring formed on the first substrate; A first insulating film formed over the first substrate over the data electrode, the common electrode, and the common wiring and having a data hole in the data electrode region; A second insulating film formed over the first insulating film and having a hole at the same position as the data hole; A connection electrode formed to overlap with the common electrode or a part of the common wiring and formed on the second insulating layer to cover the data hole; A transverse electric field liquid crystal display device comprising a liquid crystal layer formed between the first substrate and the second substrate. The transverse electric field liquid crystal display device according to claim 6, wherein the data electrode and the common electrode are made of the same material. The thin film transistor of claim 6, further comprising a thin film transistor including a drain electrode formed between the first insulating film and the second insulating film. A contact hole is formed in the second insulating layer of the drain electrode region; And the connection electrode is formed to cover the contact hole and is connected to the drain electrode. The transverse electric field liquid crystal display device according to claim 6, wherein the connection electrode is made of indium tin oxide (ITO). A first substrate and a second substrate, A data electrode, a common electrode, and a common wiring formed on the first substrate; A first insulating film formed over the first substrate over the data electrode, common electrode, and common wiring and having data holes in the data electrode region; A storage electrode formed on the first insulating layer so as to overlap the common wiring or the common electrode and covering the data hole; A transverse electric field liquid crystal display device comprising a liquid crystal layer formed between the first substrate and the second substrate. The transverse electric field liquid crystal display device according to claim 10, wherein the data electrode and the common electrode are made of the same material. The thin film transistor of claim 10, further comprising a thin film transistor including a drain electrode formed on the first insulating layer. Two storage electrodes are formed, One of the storage electrodes overlaps with the common wiring, And the other storage electrode is integrally formed with the drain electrode and overlaps a part of the common electrode. The transverse electric field liquid crystal display device according to claim 10, wherein a redundancy electrode is formed in the data hole region. The transverse electric field liquid crystal display device according to claim 13, wherein the material constituting the redundancy electrode is indium tin oxide (ITO). The transverse electric field liquid crystal display device according to claim 13, wherein the redundancy electrode is formed between the first insulating layer and the storage electrode. The transverse electric field liquid crystal display device according to claim 13, wherein the redundancy electrode is formed on the storage electrode. In a transverse electric field type liquid crystal display device inducing an electric field parallel to the substrate by a data electrode and a common electrode formed on the substrate, And the data electrode and the common electrode are formed of the same material on the same layer. The transverse electric field liquid crystal display device according to claim 17, wherein a distance between the data electrode and the common electrode is the same. Preparing a first substrate and a second substrate; Stacking and patterning a metal film on the first substrate to form a common wiring, a common electrode, and a data electrode; Stacking a first insulating film thereon; Stacking and patterning a metal film on the first insulating layer to form a storage electrode; Stacking a second insulating layer on the storage electrode; Etching a portion of the storage electrode region of the second insulating layer to form a storage hole, and etching a portion of the data electrode regions of the first and second insulating layer to form a data hole; Forming a connection electrode covering the data hole and the storage hole by coating and patterning an electrically conductive material on the second insulating layer; A method of manufacturing a transverse electric field type liquid crystal display device comprising the step of forming a liquid crystal layer between the first substrate and the second substrate. 20. The method of manufacturing a transverse electric field type liquid crystal display device according to claim 19, wherein the electrically conductive material is ITO.