KR100499570B1 - method for forming input metal line of liquid crystal display device - Google Patents

Abstract

The present invention relates to a method for forming an input wiring of a liquid crystal display device to reduce an area by electrically connecting two wiring layers simultaneously through one contact hole, the first wiring layer being formed in a predetermined region on an insulating substrate, and A first interlayer insulating film formed of a silicon nitride film on an entire surface of an insulating substrate including a first wiring layer, a second wiring layer formed of molybdenum so as to overlap the first wiring layer on the first interlayer insulating film, and the second wiring layer A second interlayer insulating film formed of a silicon nitride film on an entire surface of the insulating substrate, a contact hole formed through the second interlayer insulating film, the second wiring layer, and the first interlayer insulating film to expose a predetermined portion of the surface of the first wiring layer; I on the second interlayer insulating film to electrically connect the first wiring layer and the second wiring layer through the contact hole. And a third wiring layer formed of a TO film.

Description

Method for forming input metal line of liquid crystal display device

The present invention relates to a liquid crystal display device, and more particularly, to a method for forming input wiring of a liquid crystal display device suitable for reducing an area.

As the information society develops, the demand for display devices is increasing in various forms.In recent years, liquid crystal display (LCD), plasma display panel (PDP), electro luminescent display (ELD), and vacuum fluorescent display (VFD) have been developed. Various flat panel display devices have been studied, and some are already used as display devices in various devices.

Among them, LCD is the most widely used as a substitute for CRT (Cathode Ray Tube) for the use of mobile image display device because of the excellent image quality, light weight, thinness, and low power consumption, and mobile type such as monitor of notebook computer. In addition, it is being developed in various ways, such as a television for receiving and displaying broadcast signals, and a monitor of a computer.

As described above, although various technical advances have been made in order for the liquid crystal display device to serve as a screen display device in various fields, the task of improving the image quality as the screen display device has many advantages and disadvantages.

Therefore, in order to use a liquid crystal display device in various parts as a general screen display device, the key to development is how much high definition images such as high definition, high brightness, and large area can be realized while maintaining the characteristics of light weight, thinness, and low power consumption. It can be said.

Such a liquid crystal display device may be broadly divided into a liquid crystal panel displaying an image and a driving unit for applying a driving signal to the liquid crystal panel, wherein the liquid crystal panel includes first and second glass substrates having a space and are bonded to each other; It consists of a liquid crystal layer injected between the said 1st, 2nd glass substrate.

The first glass substrate (TFT array substrate) may include a plurality of gate lines arranged in one direction at a predetermined interval, a plurality of data lines arranged at regular intervals in a direction perpendicular to the gate lines, and A plurality of pixel electrodes formed in a matrix form in each pixel region defined by crossing each gate line and data line, and a plurality of thin films that transmit signals of the data line to each pixel electrode by being switched by signals of the gate line The transistor is formed.

The second glass substrate (color filter substrate) includes a black matrix layer for blocking light in portions other than the pixel region, an R, G, B color filter layer for expressing color colors, and a common electrode for implementing an image. Is formed. Of course, the common electrode is formed on the first glass substrate in the transverse electric field type liquid crystal display device.

The first and second glass substrates are bonded by an actual material having a predetermined space and a liquid crystal injection hole by a spacer, and a liquid crystal is injected between the two substrates.

In this case, in the liquid crystal injection method, the liquid crystal is injected between the two substrates by osmotic pressure when the liquid crystal injection hole is immersed in the liquid crystal container by maintaining the vacuum state between the two substrates bonded by the reality. When the liquid crystal is injected as described above, the liquid crystal injection hole is sealed with a sealing material.

1 is a schematic diagram illustrating a general liquid crystal display device.

As shown in FIG. 1, a pixel region 12 for displaying an image and driver ICs 10 and 11 for generating an image signal are provided, and a plurality of gate lines 14 and The plurality of data lines 16 cross each other to form a matrix, and the thin film transistor 13 is formed at the crossing point.

Although not shown in the drawing, a common electrode and a color filter are formed on an opposing substrate facing the substrate on which the thin film transistor 13 is formed, and the liquid crystal display is configured in such a manner that liquid crystal is injected and sealed between the two substrates. do.

FIG. 2 is a cross-sectional view illustrating the thin film transistor of FIG. 1.

As shown in FIG. 2, a gate electrode 22 formed of a metal such as aluminum (Al), chromium (Cr), or molybdenum (Mo) in a predetermined region on the glass substrate 21, and the gate electrode 22. A semiconductor layer 24, an ohmic contact layer 25, and chromium and molybdenum on the gate insulating layer 23 formed on the entire surface of the glass substrate 21 including the semiconductor substrate 23 and the gate insulating layer 23 on the gate electrode 22. A source electrode 26 and a drain electrode 27 made of metal such as this are constituted.

The passivation layer 28 is formed on the entire surface of the glass substrate 21 including the source electrode 26 and the drain electrode 27, and is electrically connected to the drain electrode 27 through the passivation layer 28. It consists of the pixel electrode 29 formed.

Here, the gate electrode 22 is connected to the gate line 14 of FIG. 1, the source electrode 26 is connected to the data line 16, and the drain electrode 27 is connected to the data line 16. The pixel electrode 29 is in contact with the pixel electrode 29 formed in the region surrounded by the gate line 14.

In the thin film transistor having the above structure, when a data voltage is applied to the gate electrode 22 through the gate line 14, the signal voltage flowing through the data line 16 is transferred from the source electrode 26 to the drain electrode 27. It operates to be applied through the ohmic contact layer 25 and the semiconductor layer 24.

When a signal voltage is applied to the source electrode 26, a voltage is applied to the pixel electrode 29 connected to the source electrode 26, thereby generating a voltage difference between the pixel electrode 29 and the common electrode.

Due to the voltage difference between the pixel electrode 29 and the common electrode, the molecular arrangement of the liquid crystal interposed therebetween changes, and since the molecular arrangement of the liquid crystal is changed, the light transmittance of the pixel changes, so that the data voltage is applied to the pixel. And color difference between pixels not applied. The color difference is used to control the screen of the display device.

However, when high voltage static electricity is generated from the outside in the process of manufacturing the substrate of the liquid crystal display device in which the thin film transistor or the like is formed, the TFT array may be damaged by the static electricity.

Therefore, generally, an antistatic element (not shown) is provided in each of the gate line and the data line.

Meanwhile, the liquid crystal display module is classified into a chip on glass (COG) mounting method and a tape automated bonding (TAB) mounting method according to a mounting method of a driving drive IC.

The TAB mounting method refers to a task of connecting a tape carrier package (TCP) with a drive driver IC to an LCD panel and a PCB. The connection process between TCP and LCD panels uses anisotropic conductive film instead of lead, depending on the specificity of the glass and metal material and the fixation of the pitch of about 0.2 mm or less. The process is connected using lead.

In contrast, the COG mounting method directly mounts the drive driver IC in the gate area and the data area of the LCD panel to transmit an electrical signal to the LCD panel. Usually, the anisotropic conductive film is used to adhere the drive drive IC to the LCD panel. .

On the other hand, in the COG type liquid crystal display device, a LOG (Line On Glass) method of forming a conductor on a lower glass substrate is used to apply a signal to each driving drive IC.

3 is a structural cross-sectional view of a general COG type liquid crystal display device.

As shown in FIG. 3, the upper substrate 101, the lower substrate 102, a printed circuit board (PCB) substrate 103, a flexible printed circuit (FPC) 104, and a data transmission cable 105 are formed. .

Although the upper substrate 101 is not shown in the figure, a polarizing plate is attached to one surface, and a color filter and a common electrode are formed on the opposite surface.

If the lower substrate 102 has a larger area than the upper substrate 101, although not shown in the drawing, a polarizer is attached to one surface.

In addition, an opposite surface on which the polarizer is not attached to the lower substrate 102 is configured to face the common electrode of the upper substrate 101, and the gate driving IC 106, the data driving IC 107, and the gate perpendicular to each other are formed. Line 108 and data line 109.

The data driver IC 107 receives various input signals generated from the driver circuit of the PCB substrate 103. In this case, the data line driving input wiring 110 through which the input signal flows is connected to the FPC 104 and the data driving IC 107, and the output wiring 111 of the data driving IC 107 is the data line 109. Make a one-to-one connection with each line of).

The gate driving IC 106 receives the gate input signal of the driving circuit of the PCB substrate 103 from the FPC 104 through the gate driving input wiring 110 to generate and output a gate voltage for driving the liquid crystal display device. Output to the terminal. At this time, the output terminal of the gate driving IC 106 makes one-to-one connection with each line of the gate line 108 through the gate output wiring 112.

The data transmission cable 105 is installed to connect the PCB substrate 103 and the FPC 104 in order to apply a signal generated in the driving circuit of the PCB substrate 103 to the input wiring 110 of the data driving IC. do. That is, the signal generated by the driving circuit of the PCB substrate 103 is applied to the data driving input wiring 110 of the FPC 104 via the data transmission cable 105.

However, the LCD according to the related art requires a large amount of the FPC 104. This is because the width of the FPC 104 should be wide so that the input wirings 110 respectively connected to the input terminals of the driving ICs 106 and 107 are not shorted to each other.

Thus, a so-called LOG (Line On Glass) structure in which the data driver IC 107 and the input wiring 110 of the gate driver IC 106 are formed directly on the lower substrate 102 in order to reduce the usage of the FPC 104. A liquid crystal display device having a has also been developed.

4 is a diagram illustrating a COG type liquid crystal display device in which a general input wiring is directly mounted on a substrate.

As shown in FIG. 4, the circuit board includes a PCB substrate 103, an FPC 104 having a transmission line, an upper substrate 101, and a lower substrate 102.

The lower substrate 102 may include an input wiring 114 of a gate driving IC mounted directly on the lower substrate 102, an input wiring 113 of a data driving IC mounted directly on the lower substrate 102, and a common voltage wiring (not shown). And the gate driver IC 106, the data driver IC 107, the gate line 108, and the data line 109.

A common electrode is formed on the upper substrate 101. Although not shown, the common electrode is connected to the common voltage line of the lower substrate 102.

The general liquid crystal display shown in FIG. 4 has a structure in which various input signals necessary for driving the liquid crystal display are generated in the driving circuit of the PCB substrate 103, and the input signals are input to the transmission line of the FPC 104.

Each transmission line of the FPC 104 makes one-to-one connection with the input wiring 114 of the gate driving IC mounted directly on the lower substrate 102 and the input wiring 113 of the data driving IC.

The input signals applied to the input wirings 113 and 114 are input signals of the gate driving IC 106 and the data driving IC 107, and the output signals of the driving ICs 106 and 107 are the gate lines 108 and the data lines. 109 is applied. The liquid crystal display is driven according to the signals of the gate line 108 and the data line 109 to which the output signal is applied.

Hereinafter, an input wiring and a method of forming the same will be described with reference to the accompanying drawings.

5 is a plan view illustrating input wiring of a liquid crystal display according to the related art.

As shown in FIG. 5, the first and second wiring layers 52 and 54 formed at regular intervals, and the first and second wiring layers 52 and 54 are first and second contacts. The third wiring layer 58 is electrically connected through the holes 56 and 57.

FIG. 6 is a structural cross-sectional view of a LOG input line of a conventional liquid crystal display device according to line II-II of FIG. 5.

As shown in FIG. 6, the first wiring layer 52 is formed in a predetermined region on the insulating substrate 51, and the first interlayer insulating film (1) is formed on the entire surface of the insulating substrate 51 including the first wiring layer 52. 53 is formed, and a second wiring layer 54 is formed on the first interlayer insulating film 53.

Next, a second interlayer insulating layer 55 is formed on an entire surface of the insulating substrate 51 including the second wiring layer 54 by an organic insulating material such as benzocyclobutene (BCB).

The first and second contact holes 56 and 57 are selectively removed so that the surfaces of the first and second wiring layers 52 and 54 are partially exposed. And a third wiring layer on the second interlayer insulating layer 55 to electrically connect with the first and second wiring layers 52 and 54 through the first and second contact holes 56 and 57. 58 is formed.

7A to 7D are cross-sectional views illustrating a method of forming input wirings of a conventional liquid crystal display device.

As shown in FIG. 7A, a first metal film of aluminum (Al), chromium (Cr), molybdenum (Mo), or the like is deposited on the insulating substrate 51, and the first metal film is selectively formed through a photo and etching process. Removal to form the first wiring layer 52.

As shown in FIG. 7B, a first interlayer insulating film 53 is formed on the entire surface of the insulating substrate 51 including the first wiring layer 52, and aluminum (Al) is formed on the first interlayer insulating film 53. , A second metal film such as chromium (Cr) and molybdenum (Mo) is deposited.

Subsequently, the second metal layer is selectively removed through a photo and etching process to form a second wiring layer 54.

As shown in FIG. 7C, a second interlayer insulating layer 55 is formed on the entire surface of the insulating substrate 51 including the second wiring layer 54, and the first wiring layer 52 and The first and second contact holes 56 and 57 are formed by selectively removing the second interlayer insulating film 55 and the first interlayer insulating film 53 so that the surface of the second wiring layer 54 is partially exposed.

As shown in FIG. 7D, a third metal film, such as indium tin oxide (ITO), is formed on the entire surface of the insulating substrate 51 including the first and second contact holes 56 and 57, and a photo and etching process is performed. Selectively removing the third metal layer through the third wiring layer 58 electrically connected to the first and second wiring layers 52 and 54 through the first and second contact holes 56 and 57. Form.

However, the input wiring and the method of forming the conventional liquid crystal display device as described above have the following problems.

That is, after forming two wiring layers at regular intervals, contact holes are formed in each of the two wiring layers to electrically connect the wiring layers, and the two wiring layers are electrically connected through the contact holes, thereby occupying space according to contact hole formation. This increases the overall area.

Disclosure of Invention The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a method for forming an input wiring of a liquid crystal display device, which reduces the area by electrically connecting two wiring layers simultaneously through one contact hole. have.

According to the present invention, there is provided a method for forming an input wiring of a liquid crystal display according to the present invention, the method comprising: forming a first wiring layer in a predetermined region on an insulating substrate, and forming a first silicon layer on the entire surface including the first wiring layer. Forming an interlayer insulating film, forming molybdenum on the first interlayer insulating film and selectively removing the molybdenum to form a second wiring layer so as to overlap the first wiring layer, and to a front surface including the second wiring layer Forming a second interlayer insulating film with a silicon nitride film, and selectively removing the second interlayer insulating film, the second wiring layer, and the first interlayer insulating film with an etching gas including SF ₆ to expose a predetermined portion of the surface of the first wiring layer. Forming a contact hole, forming an ITO film on the entire surface including the contact hole, and selectively removing the ITO film. Through the contact hole characterized in that the first and formed by a step of forming a third wiring layer to be electrically connected to the second wiring layer.

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Hereinafter, an input wiring and a method of forming the liquid crystal display according to the present invention will be described in detail with reference to the accompanying drawings.

8 is a plan view illustrating input wiring of a liquid crystal display according to the present invention.

As shown in FIG. 8, a first wiring layer 62 having a predetermined width, a second wiring layer 64 formed by overlapping a predetermined portion with the first wiring layer 62, and the first wiring layer ( A contact hole 66 formed through the second wiring layer 64 and the first and second wiring layers 62 and 64 through the contact hole 66 at the same time so that a predetermined portion of the surface of the surface 62 is exposed; It consists of the 3rd wiring layer 67 electrically connected.

FIG. 9 is a structural cross-sectional view illustrating an input wiring of the liquid crystal display according to the present invention along the line IV-IV of FIG. 8.

As shown in FIG. 9, the first interlayer insulating film formed on the entire surface of the insulating substrate 61 including the first wiring layer 62 formed in a predetermined region on the insulating substrate 61 and the first wiring layer 62. An insulating substrate including a second wiring layer 64 and a second wiring layer 64 formed on the first interlayer insulating layer 63 while the first wiring layer 62 overlaps a predetermined portion; The second interlayer insulating film 65, the second wiring layer 64, and the first interlayer insulating film 65 formed on the entire surface of the layer 61 and the surface of the first wiring layer 62 are partially exposed. A second interlayer insulating layer 65 for electrically connecting the first and second wiring layers 62 and 64 through the contact hole 66 formed through the 63 and the contact hole 66. It is comprised including the 3rd wiring layer 67 formed on ().

Here, the first wiring layer 62 is one of a metal such as aluminum (Al), chromium (Cr), molybdenum (Mo), titanium or tantalum, or a molybdenum alloy (Mo alloy) such as MoW, MoTa or MoNo, The second wiring layer 64 is any one of a metal such as chromium (Cr), molybdenum (Mo), titanium, or tantalum, or a molybdenum alloy (Mo alloy) such as MoW, MoTa, or MoNo, and the third wiring layer 67 ) Is selected from at least one of ITO (Indium-Tin-Oxide), IZO (Indium-Zinc-Oxide), ITZO (Indium-Tin-Zinc-Oxide), Al, AlNd, Cr, Mo.

In addition, the first and second interlayer insulating layers 63 and 65 may be formed of an inorganic insulating material such as silicon nitride (Si ₃ N ₄ ) or silicon oxide (SiO ₂ ), an acryl-based organic compound, Teflon, The dielectric constant of BCB (benzocyclobuten), cytotop (Cytop), PFCB (Perfluorocyclobutane) is formed at least one of small organic materials.

10A through 10D are cross-sectional views illustrating a method for connecting metal wirings of a liquid crystal display according to the present invention.

As shown in FIG. 10A, a metal such as aluminum (Al), chromium (Cr), molybdenum (Mo), titanium, or tantalum, or a molybdenum alloy such as MoW, MoTa, or MoNo (Mo alloy) is formed on the insulating substrate 61. The first metal layer is deposited using at least one of the layers), and the first metal layer is selectively removed through a photo and etching process to form the first wiring layer 62.

Here, the first metal film is deposited to a thickness of about 1500 to 4000 kPa by a CVD method or a sputtering method.

As shown in FIG. 10B, a first interlayer insulating film 63 is formed on the entire surface of the insulating substrate 61 including the first wiring layer 62, and a second metal film is formed on the first interlayer insulating film 63. Deposit.

Here, the first interlayer insulating layer 63 may be an inorganic insulating material such as silicon nitride (Si ₃ N ₄ ) or silicon oxide (SiO ₂ ), or an acrylic organic compound, Teflon, BCB (benzocyclobuten) It is formed by selecting at least one of organic materials having a low dielectric constant such as Cytop, Cytop, or PFCB (Perfluorocyclobutane).

On the other hand, the second metal film is a metal such as chromium (Cr), molybdenum (Mo), titanium or tantalum, or at least one of molybdenum alloys (Mo alloy) such as MoW, MoTa or MoNo by the CVD method or sputtering method 1000 ~ Deposit at a thickness of about 2000.

Subsequently, the second metal layer may be selectively removed through a photo and etching process to form a second wiring layer 64 overlapping the first wiring layer 62 with the first interlayer insulating layer 63 therebetween.

As shown in FIG. 10C, a second interlayer insulating film 65 is formed on the entire surface of the insulating substrate 61 including the second wiring layer 64, and the photolithography and etching processes are performed on the first wiring layer 62. The contact hole 66 is formed by selectively removing the second interlayer insulating layer 65, the second wiring layer 64, and the first interlayer insulating layer 63 so that the surface is partially exposed.

Here, the second interlayer insulating film 65 is formed of the same material as the first interlayer insulating film 63.

Meanwhile, the etching process for forming the contact hole 66 may use an etching gas such as SF ₆ , SF ₆ + O ₂ / He, C ₂ F ₆ + O ₂ , or a mixed etchant of ammonium fluoride + hydrofluoric acid. Proceed by dry or wet method.

As shown in FIG. 10D, a third metal film is formed on the entire surface of the insulating substrate 61 including the contact hole 66, and the third metal film is selectively removed through photo and etching processes. A third wiring layer 67 is formed to be electrically connected to the first and second wiring layers 62 and 64 through 66.

Here, the third metal layer is a CVD method using a conductive material such as Indium-Tin-Oxide (ITO), Indium-Zinc-Oxide (IZO), or Indium-Tin-Zinc-Oxide (ITZO), Al, AlNd, Cr, Mo, etc. Or by sputtering.

On the other hand, the present invention described above is not limited to the above-described embodiment and the accompanying drawings, it is possible that various substitutions, modifications and changes within the scope without departing from the technical spirit of the present invention. It will be apparent to those of ordinary skill in Esau.

As described above, the input wiring forming method of the liquid crystal display according to the present invention has the following effects.

That is, by connecting two wiring layers simultaneously through one contact hole, the overall area can be reduced.

1 is a schematic configuration diagram showing a general liquid crystal display device

2 is a cross-sectional view illustrating the thin film transistor of FIG. 1.

3 is a structural cross-sectional view of a general COG type liquid crystal display device

4 illustrates a COG type liquid crystal display device in which a general input wiring is directly mounted on a substrate.

5 is a plan view illustrating input wiring of a liquid crystal display according to the related art.

FIG. 6 is a structural cross-sectional view of a LOG input line of a conventional LCD according to line II-II of FIG. 5.

7A to 7D are cross-sectional views illustrating a method of forming input wirings of a conventional liquid crystal display device.

8 is a plan view showing the input wiring of the liquid crystal display according to the present invention.

FIG. 9 is a structural cross-sectional view illustrating input wirings of a liquid crystal display according to the present invention according to line IV-IV of FIG. 8.

10A through 10D are cross-sectional views illustrating a method of forming input wirings of a liquid crystal display according to the present invention.

Explanation of symbols for the main parts of the drawings

61: insulating substrate 62: first wiring layer

63: first interlayer insulating film 64: second wiring layer

65 second interlayer insulating film 66 contact hole

67: third wiring layer

Claims (11)

delete delete delete delete delete Forming a first wiring layer in a predetermined region on the insulating substrate; Forming a first interlayer insulating film with a silicon nitride film over the entire surface including the first wiring layer; Forming molybdenum on the first interlayer insulating film and selectively removing the molybdenum to form a second wiring layer to overlap the first wiring layer; Forming a second interlayer insulating film with a silicon nitride film over the entire surface including the second wiring layer; Forming a contact hole by selectively removing the second interlayer insulating layer, the second wiring layer, and the first interlayer insulating layer with an etching gas including SF ₆ to expose a predetermined portion of the surface of the first wiring layer; And forming a third wiring layer electrically connected to the first and second wiring layers through the contact hole by forming an ITO film on the entire surface including the contact hole and selectively removing the ITO film. The input wiring forming method of the liquid crystal display device. The method of claim 6, wherein the first wiring layer is a metal such as aluminum (Al), chromium (Cr), molybdenum (Mo), titanium or tantalum, or at least one of molybdenum alloys such as MoW, MoTa, or MoNo CVD or And forming a sputtering method by selectively removing the sputtering method. delete delete delete delete