KR20060118202A - Metal line and method of the same and display substrate having the same - Google Patents

Abstract

A metal wiring, a method for manufacturing the same, and a display substrate having the same are provided to improve the electrical characteristic of a display device, by forming the metal wiring of triple metal layers where a middle layer is shield by a lower layer and an upper layer. A first conductive material layer(130) is formed above a substrate(110). A second conductive material layer(120) is formed on a lower surface of the first conductive material layer, and shields the lower surface of the first conductive material layer. A third conductive material layer(140) is formed on an upper surface of the first conductive material layer, and shields the upper surface of the first conductive material layer.

Description

TECHNICAL LINE AND METHOD OF THE SAME AND DISPLAY SUBSTRATE HAVING THE SAME}

1 is a cross-sectional view showing the structure of a metal wiring according to a comparative example.

2 is a cross-sectional view showing the structure of a metal wiring according to an embodiment of the present invention.

3A to 3E are schematic flowcharts illustrating a method of manufacturing a metal wiring according to an embodiment of the present invention.

4 is a cross-sectional view illustrating a thin film transistor including a metal wire formed according to an embodiment of the present invention.

5 is a plan view illustrating a portion of a display device including a metal wire formed according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

20, 110, 300: substrate 30, 120: second conductive material film

40, 130: first conductive material film 50, 140: third conductive material film

142: first shielding film 144: second shielding film

150: first PR pattern 160: second PR pattern

210: gate electrode 220: gate insulating film

230: semiconductor layer 240: ohmic contact layer

250: source / drain electrodes 260: protective film

270 pixel electrode 310 gate line

320: data line 330: storage wiring

The present invention relates to a metal wiring, a method for manufacturing the same, and a display substrate having the same, and more particularly, to a metal wiring, a method for manufacturing the same, and a display substrate having the same, to improve electrical characteristics of a display device.

 In general, the display device may be defined as a device that displays a predetermined image so that a user can recognize data processed by the information processing device. Such a display device is widely used for a small size, light weight, high resolution, and the like.

Currently, the flat panel display device which is most widely used is a liquid crystal display device, and the liquid crystal display device may be defined as a device for performing a display using a liquid crystal whose light transmittance is changed according to the intensity of an electric field.

The liquid crystal display device includes a display unit. The display unit includes a display substrate on which a thin film transistor (TFT), which is a switching element, is formed, an opposite substrate facing the display substrate, and a liquid crystal layer interposed between the display substrate and the opposite substrate.

The display substrate includes the thin film transistor, gate lines and data lines electrically connected to the thin film transistor. As the screen size of the liquid crystal display device needs to be enlarged and a high resolution is required, the RC delay of the wiring lines is increased so that the liquid crystal display device cannot be driven smoothly. This is required.

In general, aluminum (Al) or an aluminum alloy is widely used as the wiring of the liquid crystal display device, but when aluminum (AL) or an aluminum alloy is applied to the wiring in a single layer, most of the hillocks are generated on the surface thereof. This may cause poor coverage of the insulating film covering the wiring. In addition, a conductive oxide film which is a pixel electrode material, for example, indium tin oxide (ITO), indium zinc oxide (IZO), aluminum (Al), or an aluminum alloy has a high contact resistance, which is a problem.

In addition, since the thin film specific resistance of the wiring made of aluminum (Al) or an aluminum alloy is 3 to 5uΩ ?? cm, it is difficult to apply to a large display device, for example, a large display device of 40 inches or more. Due to this problem, in order to use silver (Ag) or copper (Cu) having a low film resistivity to replace aluminum (Al) or an aluminum alloy, other layers constituting the liquid crystal display when the process is applied There are problems such as contactability, surface coagulation due to high temperature processes, and diffusion into other layers, making it difficult to commercialize.

An object of the present invention to solve the above problems is to provide a metal wiring that has a low RC delay, good contact with other layers of the display device, and can improve the electrical properties of the display substrate without surface aggregation phenomenon. To provide.

Another object of the present invention is to provide a method for producing the metal wiring.

Another object of the present invention is to provide a display substrate having the metal wiring.

In order to achieve the above object, the metal wire according to an embodiment of the present invention includes a first conductive material film, a second conductive material film, and a third conductive material film. The first conductive material film is formed on a substrate. The second conductive material film is formed under the first conductive material film to shield the bottom surface of the first conductive material. The third conductive material film is formed on the first conductive material film to shield the upper surface and the side surface of the first conductive material film.

The first conductive material film is made of at least one metal selected from the group consisting of aluminum, aluminum alloy, copper, copper alloy, silver, and silver alloy.

The second and third conductive material films may be formed of one or more metals selected from the group consisting of molybdenum, molybdenum alloys, nickel, nickel alloys, chromium, chromium alloys, titanium, titanium alloys, tantalum and tantalum alloys.

In addition, the second and third conductive material film may be formed of one or more metals selected from the group consisting of molybdenum, molybdenum nitride, nickel (Ni), nickel nitride, chromium, chromium nitride, titanium, titanium nitride, tantalum, tantalum nitride. .

In addition, the second and third conductive material films may be formed of indium oxide or nitrogen oxide.

In addition, the second and third conductive material films may be made of the same material, and the second and third conductive material films may be made of different materials.

In order to achieve the another object of the present invention, a method of manufacturing a metal wiring according to an embodiment of the present invention comprises the steps of forming a lower conductive material film on the substrate, the step of forming an internal conductive material film on the lower conductive material film First patterning the lower and inner conductive material layers through a photo process, forming an upper conductive material layer to surround the patterned lower and inner conductive material layers, and second patterning the upper conductive material layer through the photo process It includes a step.

In order to achieve the another object of the present invention, a display substrate according to an embodiment of the present invention is a substrate, a gate wiring formed on the substrate, the data wiring formed so as to cross and electrically insulate from the gate wiring, the gate electrode A pixel electrode connected to the drain electrode of the switching device and a source electrode connected to the data wire, the source electrode extending to a gate wire, wherein at least one of the gate wire and the data wire comprises: a first conductive material film; A second conductive material film shielding the lower surface of the first conductive material and a third conductive material film shielding the upper surface and the side surfaces of the first conductive material film.

According to such a metal wiring, a method of manufacturing the same, and a display substrate having the same, a material such as silver (Ag) or copper (Cu) having a small specific resistance can be used as the main wiring material, thereby reducing the RC delay of the display substrate. By doing so, the electrical characteristics of the display device can be improved.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view showing the structure of a metal wiring according to a comparative example, Figure 2 is a cross-sectional view showing the structure of a metal wiring according to an embodiment of the present invention.

Referring to FIG. 1, a pure aluminum (Al) or an aluminum alloy generally used as a wiring material of a display device, for example, an aluminum alloy such as AlNd, has a specific resistance of 3.1 uΩ ?? cm and 4.5 uΩ, respectively. Due to the large RC delay of ?? cm, it is difficult to apply to large display devices larger than 40 inches. In order to solve this problem, when silver (Ag) or copper (Cu) having a thin film resistivity of about half of aluminum (Al) is used, it can be applied as a wiring material for larger display devices.

However, the silver (Ag) is in contact with the lower or upper layer at the position where the wiring of the display device is formed due to damage generated in the etching process, for example, chemical reaction with ion particles in the dry etching process. There is a problem that a lifting phenomenon occurs.

In addition, the silver Ag is not uniformly applied by high temperature heat during the manufacturing process of the display device, and agglomeration of the surface of the display device may occur, thereby preventing the surface from being uniformly formed. . Accordingly, there is a problem that poor coverage of the insulating film covering the wiring occurs.

In addition, even when copper (Cu) is used as a wiring material, there is a problem that copper (Cu) is diffused into the lower or upper layer at the position where the wiring is formed.

The problem can be solved by forming the structure of the metal wiring 10 as a structure consisting of a three-layer film as shown in FIG. That is, the second conductive material film 30 is formed on the substrate 20, and the first conductive material film 40 is formed using a material used as a main wiring, for example, silver (Ag) or copper (Cu). Is formed adjacent to the upper surface of the second conductive material film (30). In addition, the third conductive material film 50 is formed on the upper surface of the first conductive material film 40, thereby forming a wiring structure in which a protective film is formed on the upper and lower surfaces of the first conductive material film 40. do.

However, as shown in FIG. 1, in the case of a three-layer film structure, a protective film is not formed, and thus, a manufacturing process is performed in an open region 42 on the side of the first conductive material film 40 exposed to the outside under a high temperature environment. In addition, the first conductive material film 40 is not uniformly applied, and a surface aggregation phenomenon in which the components constituting the film, for example, silver (Ag) and the like, are agglomerated occurs. In addition, there is a problem that surface aggregation occurs in the open area 42 due to thermal stress and high heat during use of the display device.

Referring to FIG. 2, the wiring structure 100 of the display device according to the exemplary embodiment may include the second conductive material film 120, the first conductive material film 130, and the third conductive material film 140. It is formed into a three-layer film structure.

The second conductive material layer 120 is formed on the substrate 110 in a flat structure. To this end, the second conductive material layer 120 may be formed by a sputtering method. The second conductive material layer 120 may be formed of at least one metal selected from the group consisting of molybdenum, molybdenum alloy, nickel, nickel alloy, chromium, chromium alloy, titanium, titanium alloy, tantalum and tantalum alloy. In addition to the above-described metals, it is obvious that various metals may be used as the second conductive material layer 120. For example, the second conductive material layer 120 may be formed of indium oxide or nitrogen oxide.

The first conductive material layer 130 is formed to have a flat structure adjacent to an upper surface of the second conductive material layer 120. To this end, the first conductive material layer 130 may be formed by a sputtering method. The first conductive material layer 130 is formed of silver (Ag), copper (Cu), and alloys of the metals, which are main wiring materials of the wiring structure 100 of the display device. In addition, the first conductive material layer 130 may be formed of aluminum (Al) and alloys thereof.

The lower surface of the first conductive material layer 130 is shielded and protected from the outside such as contact with the substrate 110 by the second conductive material layer 120. Therefore, when silver (Ag) is used as the main wiring material, the contact between the first conductive material film 130 and the lower layer is enhanced through the second conductive material film 120, thereby lifting a phenomenon of lifting with the lower layer. It can prevent, and can prevent the surface agglomeration phenomenon occurring under the high temperature environment on the lower surface.

In addition, when the first conductive material layer 130 uses copper (Cu) as the main wiring material, diffusion of copper (Cu) into the lower layer may be prevented.

The third conductive material layer 140 is formed adjacent to the upper surface of the first conductive material layer 130 and is formed in a form surrounding the side surface of the first conductive material layer 130. To this end, the third conductive material layer 140 includes a first shielding layer 142 and a second shielding layer 144.

The first shielding layer 142 is formed adjacent to an upper surface of the first conductive material layer 130, and shields the upper surface of the first conductive material layer 130 from the outside.

The second shielding film 144 extends from both ends of the first shielding film 142 to shield the side surface 132 of the first conductive material film 130 from the outside.

That is, in contrast to the comparative example shown in FIG. 1, the second shielding film 144 extending downward from the first shielding film 142 is further shielded so that the open area 42 of the first conductive material film 40 is shielded. Equipped.

The third conductive material layer 140 may be formed by a sputtering method, whereby the second shielding layer 144 may have a side surface 132 and the second surface of the first conductive material layer 130. The sidewalls 122 of the conductive material layer 120 may be wrapped to be in contact with the substrate 110.

Therefore, when silver (Ag) is used as the main wiring material, the contact between the first conductive material film 130 and the upper layer is enhanced through the third conductive material film 140, thereby lifting the upper layer. Phenomena can be prevented, and surface cohesion can be prevented from occurring in a high temperature environment on the upper surface of the first conductive material layer 130.

In addition, when copper (Cu) is used as the first conductive material layer 130, a phenomenon in which copper (Cu) is diffused to an upper layer may be prevented.

In addition, the side surface 132 of the first conductive material film 130 is shielded from the outside by the second shielding film 144, compared with the comparative example shown in FIG. Surface agglomeration which may occur under the high temperature manufacturing process and use environment at the side surface 42 can be prevented.

The third conductive material layer 140 may be formed of at least one metal selected from the group consisting of molybdenum, molybdenum alloy, nickel, nickel alloy, chromium, chromium alloy, titanium, titanium alloy, tantalum and tantalum alloy. In addition to the above-described metals, it is obvious that various metals may be used as the third conductive material layer 140. For example, the third conductive material layer 140 may be formed of indium oxide or nitrogen oxide.

In addition, the second and third conductive material layers 120 and 140 may be formed of the same material or may be formed of different materials from each other. In the wiring structure 100 of the display device, the cross section is illustrated to have a rectangular shape, but may be formed to have a cross section having a predetermined slope during the etching process.

The first, second, and third conductive material films 120, 130, and 140 have been described as being formed by a sputtering method, but the present invention is not limited thereto. For example, the first, second, and third conductive material films 120, 130, and 140 may be formed by a chemical vapor deposition (CVD) method or an imprint method without departing from the spirit and scope of the present invention. It can also be formed using Electoless Plating and a variety of other methods.

Here, look at the manufacturing method of the metal wiring according to an embodiment of the present invention.

3A to 3E are schematic flowcharts illustrating a method of manufacturing a metal wiring according to an embodiment of the present invention. Here, the lower conductive material film, the inner conductive material film, and the upper conductive material film used in the claims are to be understood in advance to mean the second conductive material film, the first conductive material film and the third conductive material film, respectively. Hereinafter, description will be made using terms of the first, second and third conductive material films.

Referring to FIGS. 3A to 3E, in the method for forming a wire of the display device according to the exemplary embodiment of the present invention, first, as shown in FIG. 3A, the second conductive material film 120 is formed on the substrate 110. . The second conductive material film 120 serves as a protective film for protecting the lower surface of the first conductive material film 130 and is formed to prevent lifting of the first conductive material film 130. For example, the second conductive material layer 120 is formed to have a uniform thickness on the substrate 110 by a sputtering method.

In addition, the first conductive material layer 130, which is a main wiring, is formed adjacent to an upper surface of the second conductive material layer 120. The first conductive material layer 130 may also be formed to have a uniform thickness by the sputtering method similarly to the second conductive material layer 120.

Thereafter, the second and first conductive material layers 120 and 130 are first patterned through a photo process. A first photo resist pattern (PR) pattern 150 having a width equal to the wiring width L1 set on the second and first conductive material layers 120 and 130 is formed.

As shown in FIG. 3B, after the first PR pattern 150 is formed and a first etching process is performed, the second and first conductive material layers 120 and 130 may be formed during the first etching process. The wiring width L3 is reduced by a predetermined width (2 × L2) than the set wiring width L1 due to the inclination angle generated by the chemical or the reactive gas performing the first etching process.

Subsequently, a post-processing step of removing the first PR pattern 150 is performed to complete the photo process.

As shown in FIG. 3C, after the post-treatment process, a third conductive material layer 140 is formed on the upper surface of the first conductive material layer 130 formed to have the wiring width L3 on the substrate 110. do. The third conductive material layer 140 may be formed by the sputtering method in the same manner as the second and first conductive material layers 120 and 130. In this case, the third conductive material layer 140 may cover the first shielding layer 142 and the side surface 132 of the first conductive material layer 130 applied to the upper surface of the first conductive material layer 130. A second shielding film 144 extending downward while being wrapped is formed. When the second shielding film 144 is formed by a sputtering method, the second shielding film 144 is formed to extend with the substrate 110 while surrounding the side surface 122 of the second conductive material film 120.

Next, as shown in FIGS. 3D and 3E, the second PR pattern 160 having the same width as the wiring width L1 initially set on the wiring structure on which the third conductive material layer 140 is formed. Is formed to perform the same photo process as that described in FIG. 3B.

After the second PR pattern 160 is formed, when a second etching process is performed, the third conductive material layer 140 may perform the second etching process during the second etching process. Due to the inclination angle generated by the to be formed to have a width including the thickness of the wiring width (L3) and the second shielding film (144).

Subsequently, a post process is performed to remove the second PR pattern 160 to complete the photo process, thereby forming a metal wiring structure.

4 is a cross-sectional view illustrating a thin film transistor including a metal wire formed according to an embodiment of the present invention.

Referring to FIG. 4, a thin film transistor 200 including a metal wire formed according to an embodiment of the present invention may include a gate electrode 210, a gate insulating film 220, a semiconductor layer 230, and an ohmic contact layer 240. , A source / drain electrode 250 and a passivation layer 260. In the case of the thin film transistor used in the display device, one of the source / drain electrodes is electrically connected to the pixel electrode 270.

The gate electrode 210 is formed in a three-layer film structure as shown in FIG. 2. That is, the second conductive material film 211 is formed on the substrate 300, and the first conductive material film 212 using main wiring material, for example, silver (Ag) or copper (Cu) is formed. 2 is formed adjacent to the upper surface of the conductive material film 211, and both ends of the first shielding film 213a and adjacent to the upper surface of the first conductive material film 212 and the first shielding film 213a The third conductive material layer 213 having the second shielding layer 213b formed to extend from the first conductive material layer 212 to surround the side of the first conductive material layer 212 is formed.

By forming the gate electrode 210 in a three-layer film structure, the first conductive material film 212 formed of silver (Ag) or copper (Cu) as the main wiring material, the substrate 300, and the gate insulating film 220 are formed. It is possible to improve contact with the substrate, to prevent surface aggregation of the first conductive material layer 212, and to improve an electrical property by reducing a resistance component of the gate electrode 210.

The gate insulating film 220 is a silicon nitride film, a silicon oxide film, or a similar insulating film.

The semiconductor layer 230 and the ohmic contact layer 240 may be formed of a silicon layer, and in particular, the ohmic contact layer 240 may be formed of a silicon layer doped with N +.

The source / drain electrodes 250 are formed in the three-layer film structure shown in FIG. 2. In other words, a second conductive material film 251 is formed on the gate insulating film 220 or the semiconductor layer 230, and a main wiring material, for example, silver (Ag) or copper (Cu) is used. The first conductive material film 252 is formed adjacent to the upper surface of the second conductive material film 251, and then the first shielding film 253a is formed adjacent to the upper surface of the first conductive material film 252. The third conductive material layer 253 may be formed to extend from both ends of the first shielding layer 253a and include a second shielding layer 253b formed to surround the side surface of the first conductive material layer 252.

By forming the source / drain electrodes 250 in a three-layer film structure, the first conductive material film 252 and the gate insulating film 220 or the ohmic contact layer formed of silver (Ag) or copper (Cu), which are the main wiring materials, are formed. It is possible to improve contact with the 240, prevent surface agglomeration of the first conductive material layer 252, and reduce electrical resistance of the source / drain electrode 250 to improve electrical characteristics. .

In the passivation layer 260, a contact hole CNT is formed to expose a portion of the drain electrode in order to electrically connect the electrode used as the drain electrode among the source / drain electrodes 250 with the pixel electrode 270. . The passivation layer 260 serves to protect the semiconductor layer 230.

5 is a plan view illustrating a portion of a display device including a metal wire formed according to an embodiment of the present invention. In particular, a display substrate on which the thin film transistor shown in FIG. 4 is formed is shown.

Referring to FIG. 5, the display substrate 400 according to an exemplary embodiment of the present invention includes a thin film transistor 200 formed on the substrate 300 and a pixel electrode 270 electrically connected to the thin film transistor 200. The pixel region expressing one color is formed by the common electrode and the color filter corresponding to the thin film transistor 200 and the pixel electrode 270. The common electrode and the color filter may be formed on an opposing substrate (not shown) disposed to face the display substrate 400, or may be formed directly on the display substrate 400. A liquid crystal layer (not shown) is interposed between the display substrate 400 and the opposing substrate to form a display device.

In the display substrate 400, a plurality of gate lines 310 and a plurality of data lines 320 are arranged to be orthogonal to each other in a matrix form. The thin film transistor 200 and the pixel electrode 270 are disposed in an area surrounded by the gate line 310 and the data line 320. Meanwhile, a separate storage line 330 is formed under the pixel electrode 270 to form a storage capacitor.

The gate electrode 210 and the source / drain electrode constituting the thin film transistor 200 are connected to the gate line 310 and the data line / pixel electrode, respectively.

In this case, the gate electrode 210, the source / drain electrode 250, the gate line 310, the data line 320, and the storage line 330 may be formed in the three-layer film structure shown in FIG. 2. That is, all the electrical wirings formed on the display substrate 400 may be formed in the three-layer film structure. Alternatively, only some of the wirings may be formed in the three-layer film structure.

Although the liquid crystal display device has been described as an example of the display device of the present invention, the technical idea of the present invention is not limited thereto. That is, the wiring structure according to the present invention can be applied not only to the display device but also to other electronic devices other than the display device requiring the low resistance wiring structure.

According to the present invention as described above, the structure of the metal wiring is formed of a three-layer film, the main wiring is formed in the middle of the three-layer film, and the main wiring is cut off from the outside, whereby silver (Ag) or copper (with a low specific resistance) Materials such as Cu) can be used as the main wiring material.

In addition, by using a material having a small specific resistance as the main wiring material, the electrical characteristics of the display device can be improved.

In addition, when the silver (Ag) or copper (Cu) having a low specific resistance is used as the main wiring material, contact between the main wiring and other layers of the display device may be improved.

In addition, when a material that generates surface coagulation under high temperature process conditions and driving environment such as silver (Ag) is used as the main wiring, the main wiring may be blocked from the outside to prevent surface coagulation and commercialization. Suitable for

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (11)

A first conductive material film formed on the substrate; A second conductive material film formed under the first conductive material film and shielding a lower surface of the first conductive material film; And And a third conductive material film formed on the first conductive material film and shielding an upper surface and a side surface of the first conductive material film. The metal wiring of claim 1, wherein the first conductive material film is at least one metal selected from the group consisting of aluminum, aluminum alloy, copper, copper alloy, silver, and silver alloy.  The method of claim 1, wherein the second and third conductive material film is at least one metal selected from the group consisting of molybdenum, molybdenum alloy, nickel, nickel alloy, chromium, chromium alloy, titanium, titanium alloy, tantalum, tantalum alloy. Metal wiring.  The method of claim 1, wherein the second and third conductive material film is at least one metal selected from the group consisting of molybdenum, molybdenum nitride, nickel, nickel nitride, chromium, chromium nitride, titanium, titanium nitride, tantalum, tantalum nitride. Metal ship line. The metal line of claim 1, wherein the second and third conductive material films are formed of indium oxide or nitrogen oxide. The metal line of claim 1, wherein the second and third conductive material films are formed of the same material. The metal line of claim 1, wherein the second and third conductive material films are formed of different materials from each other. Forming a lower conductive material film on the substrate; Forming an inner conductive material film on the lower conductive material film; First patterning the lower and inner conductive material layers through a photo process; Forming an upper conductive material layer to surround the patterned lower and inner conductive material layers; And And second patterning the upper conductive material layer through the photo process. The method of claim 8, wherein the lower and upper conductive material layers are formed of the same material. The method of claim 8, wherein the lower and upper conductive material layers are formed of different materials from each other. Board; A gate wiring formed on the substrate; A data line formed to cross and electrically insulate the gate line; A switching element having a gate electrode extending to the gate wiring and a source electrode connected to the data wiring; And A pixel electrode connected to the drain electrode of the switching element, At least one of the gate wiring and the data wiring may include a first conductive material film, a second conductive material film for shielding the bottom surface of the first conductive material, and a third conductive material for shielding the top and side surfaces of the first conductive material film. A display substrate comprising a material film.

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