KR100338009B1 - Thin Film Transistor Substrate for Liquid Crystal Display Panels And a Manufacturing Method of thereof - Google Patents

Abstract

A gate layer and an auxiliary data line are formed on a transparent substrate using a single layer of aluminum or an aluminum alloy, and a gate insulating film and an upper portion of the gate electrode having contact holes for exposing the gate pad and the auxiliary data line are formed by a photolithography process using a mask. A semiconductor layer is formed over the gate insulating film. Subsequently, a first auxiliary gate pad is formed to cross the gate line and to cover the gate pad through the contact hole and the data line including the data line and the source and drain electrodes connected to the auxiliary data line through the contact hole. Next, a second conductive gate pad and an auxiliary data pad covering the first auxiliary gate pad and the data pad are formed while the pixel electrode connected to the drain electrode is formed of ITO, which is a transparent conductive film. A passivation layer having a contact hole exposing the second auxiliary gate pad and the auxiliary data pad is formed. In this way, a structure having a protective film on the top layer can be obtained while using five masks, whereby the data line can be made low in resistance and the data line can be prevented from being disconnected. In addition, the manufacturing process can be simplified by forming the single gate wiring, the contact hole and the semiconductor layer into one mask.

Description

Thin Film Transistor Substrate for Liquid Crystal Display Panels And a Manufacturing Method of

The present invention relates to a method for manufacturing a thin film transistor substrate of a liquid crystal display device.

In general, a liquid crystal display device has a structure in which a liquid crystal is injected between two substrates on which an electrode is formed, and a light transmission amount is controlled by adjusting the intensity of a voltage applied to the electrode.

In the case where the liquid crystal display is in a twisted nematic mode, a pixel electrode through which an image signal is transmitted and a common electrode through which a reference voltage is transmitted are respectively provided on different substrates, and ITO, which is a transparent conductive material, is provided. (indium tin oxide).

There are various methods of manufacturing a thin film transistor substrate, which is one of two substrates of a liquid crystal display, and one method of forming a pixel electrode as the uppermost layer is also a method. First, a gate wiring including a gate electrode and a gate line is formed, and a gate insulating film is formed on a substrate on which the gate wiring is formed. Next, an amorphous silicon layer and an n + amorphous silicon layer are sequentially formed on the gate insulating film formed on the gate electrode, and a data line including a source electrode and a drain electrode on the n + amorphous silicon layer and a data line crossing the gate line to define a pixel. Form. Next, a protective film is formed on the entire surface of the substrate, and a pixel electrode connected to the drain electrode is formed in the pixel through the contact hole of the protective film on the protective film. When forming the pixel electrode, an auxiliary data line of ITO connected to the data line through the contact hole may be further formed to prevent the data line from being disconnected. The thin film transistor substrate thus formed has a structure in which the pixel electrode is formed on the top layer (top ITO). On the other hand, a color filter and a black matrix are formed on the color filter substrate, and a common electrode of ITO is formed thereon. It is.

However, in assembling the completed thin film transistor substrate and the color filter substrate in the method of manufacturing such a liquid crystal display device, when there are conductive particles between the two substrates, the pixel electrode of the thin film transistor substrate or the common electrode of the data line and the color filter substrate This short-circuit problem occurs.

In addition, as the liquid crystal display becomes larger, a delay of a signal occurs in repairing a data line, thereby causing a problem in that a transmitted signal is distorted.

In addition, a signal line, particularly a gate wiring that transmits a scan signal, uses aluminum or an aluminum alloy having low resistance. When the external portion is exposed to the outside, the physical or chemical properties are not good, and thus, the pad portion reinforces aluminum using ITO. Since the contact characteristics of aluminum or an aluminum alloy and ITO are not good, there is a problem that the manufacturing process is complicated and the production cost is increased by forming the gate wiring as a multilayer.

An object of the present invention is to reduce the defect of the display device by preventing the two substrates for the liquid crystal display device from being short-circuited by the conductive material.

Another object of the present invention is to prevent disconnection of data lines and to reduce signal delay.

Another object of the present invention is to simplify the manufacturing process of the liquid crystal display device.

1 is a plan view of a thin film transistor substrate of a liquid crystal display according to an exemplary embodiment of the present invention;

FIG. 2 is a cross-sectional view taken along the line II-II 'of the thin film transistor substrate shown in FIG. 1;

3 is a cross-sectional view taken along line III-III ′ of the thin film transistor substrate shown in FIG. 1;

4 is a cross-sectional view taken along the line IV-IV 'of the thin film transistor substrate shown in FIG. 1;

5A through 8D are cross-sectional views illustrating a manufacturing process of a thin film transistor substrate of a liquid crystal display according to an exemplary embodiment of the present invention.

In the thin film transistor substrate according to the present invention and a method of manufacturing the same, an auxiliary data line is formed while the gate wiring is formed of a single layer with a low resistance, a data line and a pixel electrode connected to the auxiliary data line are formed, and then a protective film is formed. Form on the top floor.

More specifically, in the method for manufacturing a thin film transistor substrate for a liquid crystal display according to the present invention, first, a gate line and an auxiliary data line formed of a gate electrode and a gate electrode which is a branch or part of a gate line are formed on a transparent substrate. Subsequently, a semiconductor layer is formed on the gate insulating film having the contact hole on the auxiliary data line and on the gate insulating film of the gate electrode. Next, a data line including a data line connected to the auxiliary data line is formed through the contact hole of the source electrode, the drain electrode, and the gate insulating layer facing each other with respect to the gate electrode. Subsequently, a pixel electrode made of a transparent conductive material is formed in the pixel surrounded by the gate line and the data line, and a protective layer is formed to form an opening that exposes the pixel electrode.

Here, the gate wirings and the auxiliary data lines are preferably formed of a single film of aluminum or aluminum alloy.

In the liquid crystal display and the manufacturing method thereof according to the present invention, the gate wiring and the data wiring further include a gate pad connected to the gate line and a data pad connected to the data line. When the data line is formed, a first auxiliary gate pad connected to the gate pad may be further formed through a contact hole of the gate insulating layer, and the second auxiliary gate connected to the gate pad and the data pad may be formed in the forming of the pixel electrode. The pad and the auxiliary data pad may be further formed. In the forming of the pixel electrode, a data line reinforcement may be further formed on the data line passing through the gate line.

Now, a method of manufacturing a thin film transistor substrate according to an embodiment of the present invention will be described in detail.

First, the structure of a thin film transistor substrate for a liquid crystal display according to an exemplary embodiment of the present invention will be described with reference to FIGS. 1 to 4. 1 is a plan view of a thin film transistor substrate of a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line II-II 'of the thin film transistor substrate of FIG. FIG. 3 is a cross-sectional view taken along line III-III 'of the thin film transistor substrate of FIG. 1 and illustrates the gate pad portion, and FIG. 4 is line IV-IV' of the thin film transistor substrate of FIG. A cross-sectional view of the data pad portion is taken along the line.

A gate which is connected to the gate line 20 in the horizontal direction, the gate electrode 210 which is a branch of the gate line, and the gate line 20 on the substrate 10 to the gate line 20 to receive scan signals from the outside. The gate wiring is formed by the pad 220. In addition, the auxiliary data line 23 is formed on the substrate 10 in the vertical direction adjacent to the gate electrode 21. Here, the gate wirings 20, 21, 22 and the auxiliary data lines 23 are formed of a single film of aluminum or aluminum alloy.

A gate insulating film 30 is formed on the substrate 10 to cover the gate wirings 20, 21, 22, and the auxiliary data line 23. In this case, the gate insulating layer 30 has contact holes 31 and 32 exposing the auxiliary data line 23 and the gate pad 22.

A semiconductor layer 40 made of a semiconductor such as amorphous silicon is formed on the gate insulating film 20 of the gate electrode 140, and n-type impurities are heavily doped on both sides of the gate electrode 21. Resistive contact layers 51 and 52 made of amorphous silicon are formed.

On each of the ohmic contacts 51 and 52, a source electrode 61 and a drain electrode 62 separated from both sides with a gate electrode 21 therebetween are formed. In this case, the source electrode 61 is formed to intersect the gate line 20, and overlaps with the auxiliary data line 23 and is connected to the auxiliary data line 23 through the contact hole 31. 60 is connected to the data line 60, and on one side of the data line 60, a data pad 63 receiving an image signal from the outside and transmitting the image signal to the data line 60 is formed. In addition, the first auxiliary gate pad 64 connected to the gate pad 22 through the contact hole 32 is formed on the gate insulating layer 30 of the gate pad 22 through the data lines 60, 61, 62, and 63. It is formed of the same layer as). The first auxiliary gate pad 64 prevents the gate pad 22 made of aluminum or aluminum alloy from directly contacting the ITO. The data lines 60, 61, 62, and 63 and the first auxiliary gate pad 64 may be formed of a single layer of aluminum, an aluminum alloy, molybdenum, molybdenum alloy, or chromium, or multiple layers thereof.

On the gate insulating layer 30 of the pixel surrounded by the gate line 20 and the data line 60, a pixel electrode 70 made of ITO, which is a transparent conductive material, is connected to the drain electrode 62. In addition, a data line reinforcing part 71 is formed on the same layer as the pixel electrode 70 and above the data line 60 that intersects the gate line 20, and the first auxiliary gate pad 64 and the data. The second auxiliary gate pad 72 and the auxiliary data pad 73 are formed on the pad 63. Here, the data line reinforcement unit 71 is to reinforce the data line 60 which may be disconnected due to the step that occurs when the data line 60 intersects the gate line 20.

A passivation layer 80 made of silicon nitride or silicon oxide is formed on the entire surface of the substrate 10, and the opening 81 and the second auxiliary gate pad 72 exposing most of the pixel electrode 70 are formed in the passivation layer 80. And contact holes 82 and 83 exposing the auxiliary data pad 73, respectively.

Next, a method of manufacturing a thin film transistor substrate for a liquid crystal display device having the structure shown in FIGS. 1 to 4 will be described with reference to FIGS. 5A to 8D and FIGS. 1 to 4.

First, as shown in FIGS. 5A to 5D, an aluminum or aluminum alloy is laminated and patterned on the transparent insulating substrate 10 to form a gate wiring including a gate line 20, a gate electrode 21, and a gate pad 22. The auxiliary data line 23 is formed. As such, when the gate wirings 20, 21, 22 and the auxiliary data lines 23 are formed as a single layer, the deposition process and the etching process can be omitted, compared to the case of forming a double layer or a triple layer, thereby reducing manufacturing costs. have.

Next, as shown in FIGS. 6A to 6D, the gate insulating film 30 of silicon nitride or silicon oxide, the semiconductor layer 40 made of amorphous silicon, and the doped amorphous silicon layer 50 are sequentially stacked, and one mask is used. The semiconductor layer 40 and the doped amorphous silicon layer 50 on the gate electrode 21 are etched by etching the doped amorphous silicon layer 50, the semiconductor layer 40, and the gate insulating layer 30 by a photolithography process using a photolithography process. And a gate insulating film 30 having contact holes 31 and 32 exposing the auxiliary data line 23 and the gate pad 22. In this case, the third mask to be used may leave a photosensitive film having a partially different thickness by using a mask that may partially vary the intensity of transmitted light, and then etch the remaining photosensitive film as a mask. That is, at this time, the mask prevents light from passing through the first portion corresponding to the semiconductor layer 40 and the doped amorphous silicon layer 50, and the second portion corresponding to the contact holes 31 and 32. Most of the light is transmitted and the remaining third portion can arbitrarily adjust the intensity of light through the transparent and opaque mosaic pattern or the passage or the slit. When the photoresist is exposed using such a mask, the semiconductor layer 40 and the doped amorphous silicon layer 50 have a first thickness, and portions corresponding to the contact holes 31 and 32 have no thickness or are fine. The thickness, the remaining portion may form a photosensitive film pattern having a thickness between the first thickness and the third thickness. Subsequently, when the etching process is performed using the photoresist pattern, a portion of the gate insulating layer 30 is etched to form contact holes 32 and 31 exposing the gate pad 22 and the auxiliary data line 23. The gate insulating layer 30 may be exposed leaving only the semiconductor layer 40 and the doped amorphous silicon layer 50 on the gate electrode 21, thereby completing the structure of FIGS. 6B to 6D.

Here, in the step of forming the contact holes 32 and 31, it is preferable to form the photoresist pattern of the third part in a sufficient thickness in the exposure process so that the photoresist remains at a constant thickness in the third part. Because the thickness of the photoresist film of the third part may not be uniform during the etching process, the photoresist film is left at a constant thickness, and the photoresist film remaining in the third part is completely removed through an ashing process using oxygen (O ₂ ). After the etching of the amorphous silicon layer of the third portion, the gate insulating film 30 can be formed to have a uniform thickness. At this time, the etching conditions are applied SF ₆ / HCl / O ₂ / Ar gas.

Next, as shown in FIGS. 7A to 7D, the data line conductive material is stacked and patterned to be connected to and overlapped with the auxiliary data line 23 through the contact hole 31 and completely cover the contact hole 31. A data line consisting of a data pad 63 and a drain electrode 62 facing the source electrode 61 are formed around the source electrode 61 and the gate electrode 21, which are branches of the 60 and the data line 60. do. In this case, the first auxiliary gate pad 64 connected to the gate pad 22 through the contact hole 32 is formed to completely cover the contact hole 32. This structure allows the image signal to be transmitted through the auxiliary data line 23 made of low-resistance aluminum or aluminum alloy even when a disconnection occurs in the data line 60, so that no delay occurs for the signal. It can be applied easily. In addition, direct contact between the aluminum or aluminum alloy and ITO may be prevented by connecting the gate pad 22 and the second auxiliary gate pad 72 formed thereafter via the first auxiliary gate pad 64. Subsequently, the n ⁺ amorphous silicon layer 50 not covered by the data lines 60, 61, and 62 is etched to complete the ohmic contacts 51 and 52, and the semiconductor layer 40 between the ohmic contacts 51 and 52. )

Subsequently, a transparent conductive material made of ITO or the like is stacked and patterned on the substrate 10 to form the pixel electrode 70 connected to the drain electrode 62. The first auxiliary gate pad 64 and the data pad ( A second auxiliary gate pad 72 and an auxiliary data pad 73 covering the 63 are formed.

Finally, as shown in FIGS. 1 to 4, the opening 81 and the second auxiliary gate pad 72 exposing the pixel electrode 70 by stacking and patterning silicon nitride or silicon oxide on the substrate 10. And a protective film 80 having contact holes 82 and 83 exposing the auxiliary data pad 73.

Therefore, according to the embodiment of the present invention, since the protective film is formed on the top layer, even if there are conductive particles when assembling the two substrates, it is possible to prevent the data line from being short-circuited with the common electrode of the upper plate. In addition, the gate line may be formed of a single layer of aluminum or an aluminum alloy to simplify the process, thereby reducing manufacturing costs. In addition, the data line reinforcement part may be placed on the data line crossing the gate line to prevent the data line from being disconnected. The auxiliary data line may be prevented from the low resistance aluminum or aluminum alloy to prevent the disconnection of the data line. A liquid crystal display device can be manufactured. In addition, the production cost may be reduced by forming the contact hole and the semiconductor layer exposing the gate pad using the same mask using a photolithography process using one mask.

Claims (21)

delete delete delete delete delete delete delete delete delete Forming a gate line and an auxiliary data line including the gate line and the gate electrode on the (correction) transparent substrate, Stacking a gate insulating film and a semiconductor layer, Patterning the gate insulating film and the semiconductor layer to form a first contact hole exposing the auxiliary data line, and leaving a semiconductor layer only over the gate insulating film over the gate electrode; Forming a data line including a data line, a source electrode, and a drain electrode connected to the auxiliary data line through the first contact hole; Stacking and patterning a transparent conductive material to form a pixel electrode electrically connected to the drain electrode in the pixel surrounded by the gate line and the data line; and Forming a protective film Method of manufacturing a thin film transistor substrate for a liquid crystal display device comprising a. In claim 10, Stacking the semiconductor layer and then stacking a doped amorphous silicon layer and patterning the doped amorphous silicon layer, And etching the doped amorphous silicon layer in the step of forming the data line. delete delete Forming a gate wiring including a gate line, a gate electrode, and a gate pad on the (correction) transparent substrate, Stacking a gate insulating film and a semiconductor layer, Patterning the gate insulating film and the semiconductor layer to form a first contact hole exposing the gate pad, leaving a semiconductor layer only over the gate insulating film over the gate electrode; Forming a data line including a first gate auxiliary pad, a data line, a source electrode, and a drain electrode on the gate pad through the first contact hole; Forming a pixel electrode electrically connected to the drain electrode; Forming a second gate auxiliary pad electrically connected to the first gate auxiliary pad; and Forming a protective film Method of manufacturing a thin film transistor substrate for a liquid crystal display device comprising a. delete (Correction) In any one of 10, 11, 14, And forming a data line reinforcement on an upper portion of the data line crossing the gate line in the forming of the pixel electrode. delete delete (Correction) In clause 11, The first contact The manufacturing method of the thin film transistor substrate for liquid crystal display devices which performs a hole formation and the said semiconductor layer leaving process in one photography process. (Correction) In clause 19, The mask used in the photographing process may differently adjust the intensity of light of the first portion corresponding to the semiconductor layer, the second portion corresponding to the first contact hole, and the third portion except the first and second portions. The manufacturing method of the thin film transistor substrate for liquid crystal display devices. (Correction) In clause 19, The photoresist pattern formed in the photographing process may have a first thickness in a portion corresponding to the first portion, a second thickness thinner than a first thickness in a portion corresponding to the third portion, and a thickness in a portion corresponding to the second portion. The thin film transistor substrate for a liquid crystal display device having a third thickness that is absent or thinner than the second thickness.