KR101391088B1 - Manufacturing method of array substrate for liquid crystal display - Google Patents

Abstract

The present invention relates to a method of manufacturing an array substrate for a liquid crystal display, comprising the steps of: forming a molybdenum-based metal / aluminum-based metal double layer on a substrate in a gate electrode forming step, Forming an indium oxide film in the step of forming the electrode, and etching the substrate with an etchant composition to form a pixel electrode,

Wherein the etchant composition comprises nitrate iron (Fe (NO ₃ ) ₃ ), fluorine compound, sulfate compound, and water, and does not contain an acidic compound. An etchant composition of a molybdenum-based metal / aluminum-based metal double film and an indium oxide film; And a method for etching a molybdenum-based metal / aluminum-based metal double layer or indium oxide layer using the etchant composition.

Nitric oxide, molybdenum, aluminum, indium oxide, etchant composition

Description

TECHNICAL FIELD [0001] The present invention relates to a method of manufacturing an array substrate for a liquid crystal display (LCD)

The present invention relates to a method of manufacturing an array substrate for a liquid crystal display, an etching solution composition of a molybdenum-based metal / aluminum-based metal double film and an indium oxide film, and etching of a molybdenum-based metal / aluminum- ≪ / RTI >

In the manufacture of a semiconductor device for driving a liquid crystal display device, a process of forming a metal wiring on a substrate is usually a process of forming a metal film by sputtering or the like, applying a photoresist, forming a photoresist in a selective region by exposure and development , And an etching process, and includes a cleaning process before and after the individual unit process. This etching process refers to a process of leaving a metal film in a selective region using a photoresist as a mask. Typically, dry etching using plasma or wet etching using an etching solution is used.

In the above-described semiconductor device, a metal commonly used as a wiring material of a TFT-LCD (Thin Film Transistor-Liquid Crystal Display) is aluminum (Al) or an aluminum alloy. Pure aluminum has a weak resistance to a chemical substance, (Mo), chromium (Cr), tungsten (W), tin (Sn) or the like on the aluminum or aluminum alloy layer A multilayer laminated structure can be applied.

However, in the case of a Mo / Al bilayer, for example, in the case of wet etching with a conventional aluminum etching solution using phosphoric acid as a main component, since the etching rate of the upper Mo layer is slower than the aluminum etching rate, Which has a cross-section projecting to the outside of the frame. This poor profile results in poor step coverage in the subsequent process and increases the probability that the upper layer will be broken at the slope or the upper and lower metals will be short-circuited.

In recent years, consisting of a In Korea Patent No. 579 511 No. of nitric acid (HNO _3), be iron oxide _{(Fe (NO 3) 3)} , perchloric acid (HClO ₄₎ and ammonium fluoride (NH ₄ F) in order to solve the above A method of batch etch the molybdenum / aluminum double layer using an etchant was presented. However, when the molybdenum / aluminum double-layer substrate is etched with the etching solution, fine etching residues are left on the substrate, causing a leakage current during TFT On / Off driving, Screen distortion may occur. Further, if the indium oxide film is etched with the etchant, an indium oxide film residue remains.

An object of the present invention is to provide a method of manufacturing a semiconductor device, which does not cause generation of fine etching residues during etching of a molybdenum-based metal / aluminum-based metal double layer and does not generate residues when the indium oxide film is etched, The etching solution can be etched in a batch manner.

The present invention also provides a method for etching a molybdenum-based metal / aluminum-based metal double layer and an indium oxide layer using the etchant composition.

Further, the present invention provides a method for manufacturing an array substrate for a liquid crystal display device, which comprises a step of etching the molybdenum-based metal / aluminum-based metal double film and / or the indium oxide film by using the above etching solution composition.

The present invention relates to a molybdenum-based metal / aluminum-based metal double film and an indium oxide film, which comprises nitrate iron (Fe (NO ₃ ) ₃ ), fluorine compound, sulfate compound and water and does not contain an acidic compound Thereby providing an etchant composition.

In addition,

I) forming a molybdenum-based metal / aluminum-based metal double-layer on a substrate;

II) selectively leaving a photoreactive material on the molybdenum-based metal / aluminum-based metal double layer; And

III) A method of etching a molybdenum-based metal / aluminum-based metal double-layer film comprising the step of etching the molybdenum-based metal / aluminum-based metal double-layer film using the etching liquid composition of the present invention.

In addition,

I) forming an indium oxide film on a substrate;

II) selectively leaving a photoreactive material on the indium oxide film; And

III) etching the indium oxide film using the etching solution composition of the present invention.

Also,

a) forming a gate wiring on the substrate;

b) forming a gate insulating layer on the substrate including the gate wiring;

c) forming a semiconductor layer on the gate insulating layer;

d) forming source and drain electrodes on the semiconductor layer; And

e) forming a pixel electrode connected to the drain electrode, the method comprising the steps of:

In the step (a), a molybdenum-based metal / aluminum-based metal double layer is formed on the substrate, and the gate wiring is formed by etching with the etchant composition of the present invention. In the step (e) And forming a pixel electrode by etching with the etching liquid composition of the present invention.

When the molybdenum-based metal / aluminum-based metal double film or indium oxide film is etched using the etching liquid composition of the present invention, the aluminum-based metal / molybdenum-based metal double film does not generate fine etching residues, It retains the initial etch characteristics due to the minimized galvanic effect and exhibits excellent etch characteristics that do not leave etch residues even if the indium oxide film is etched with the same etchant. Therefore, when the visual liquid composition of the present invention is used for manufacturing an array substrate for a liquid crystal display device including a gate electrode formed of a molybdenum-based metal / aluminum-based metal double film and / or a pixel electrode formed of an indium oxide film, Not only the driving characteristics of the device can be improved, but also the molybdenum-based metal / aluminum-based metal double film and the indium oxide film can be collectively etched, thereby maximizing the process efficiency.

The present invention relates to a molybdenum-based metal / aluminum-based metal double film and an indium oxide film, which comprises nitrate iron (Fe (NO ₃ ) ₃ ), fluorine compound, sulfate compound and water and does not contain an acidic compound To an etchant composition.

In the present invention, the molybdenum-based metal and the aluminum-based metal are concepts including an alloy thereof, and the indium oxide film is a concept including an indium zinc oxide (IZO) film or an indium tin oxide film (ITO).

In the etching liquid composition of the present invention, nitric oxide (Fe (NO ₃ ) ₃ ) is used as an oxidizing agent for etching a molybdenum-based metal / aluminum-based metal double film constituting a gate wiring and an indium oxide film constituting a pixel electrode. The nitrate iron oxide is preferably contained in an amount of 2 to 5% by weight based on the total weight of the etching solution composition of the present invention. When the nitric oxide is contained in an amount of less than 2% by weight, the etching force may be insufficient and sufficient etching may not be performed. If the nitric oxide exceeds 5% by weight, the etching rate with respect to the molybdenum- The etching rate for the molybdenum-based metal / aluminum-based metal film is excessively slowed, so that the upper molybdenum-based metal is over-etched when the molybdenum-based metal / aluminum-based metal double film is etched.

Among the etching liquid compositions of the present invention, the fluorine compound accelerates the aluminum etching speed when the molybdenum metal / aluminum metal double film is etched, and the etching speed of the indium oxide film when the indium oxide film is etched.

The fluorinated compound is preferably contained in an amount of 0.1 to 1% by weight based on the total weight of the composition. If the amount of the fluorine compound is less than 0.1% by weight, the etching rate of the molybdenum-based metal / aluminum-based metal double film and the indium oxide film becomes slow. When the amount of the fluorine compound is more than 1% by weight, The etching rate of the aluminum-based metal is too fast to cause an overhang molybdenum-based metal overhang. When the indium oxide film is etched, the lower insulating film of the indium oxide film can be attacked.

The fluorinated compound is preferably at least one selected from the group consisting of NH ₄ FHF, KFHF, NaFHF, KF and NaF, and more preferably NH ₄ FHF, but is not limited thereto.

Among the etching composition of the present invention, the sulfate compound accelerates the etching rate of the molybdenum-based metal / aluminum-based metal double-layered film when it is etched.

The sulfate compound is preferably contained in an amount of 1 to 5% by weight based on the total weight of the composition. If the amount of the sulfate compound is less than 1% by weight, the etching rate for the molybdenum-based metal / aluminum-based metal double film is slowed and etching residue of the molybdenum-based metal may be generated. Aluminum-based metal double-layer etching rate is too fast to control the process time.

Examples of the sulfate compound include sodium sulfate, potassium sulfate, and ammonium sulfate. These compounds may be used alone or in combination of two or more. Examples of the sulfate compound include sodium sulfate, potassium sulfate, and ammonium sulfate. Can be used.

In the etchant composition according to the present invention, the water is not particularly limited, but deionized water is preferable. More preferably, deionized water having a resistivity value of 18 M OMEGA / cm or more can be used to show the degree of removal of ions in the water. The water content is in the range of 89 to 96.9% by weight based on the total weight of the composition and is adjusted according to the contents of the other constituents.

Since the etchant composition of the present invention does not contain an acidic compound, it has an advantage that etching (particularly, glass substrate) of a problematic substrate is minimized when an acidic compound is included.

The nitrate iron oxide, fluorine compound, and sulfate compound used in the etchant composition of the present invention can be produced by a commonly known method and preferably have purity for semiconductor processing.

In the present invention, the etchant composition comprises 2 to 5% by weight of iron oxide (Fe (NO ₃ ) ₃ ), 0.1 to 1% by weight of a fluorine compound, 5% by weight of a sulfate compound 1, By weight to 96.9% by weight.

In addition, the etchant composition according to the present invention may further include any additives conventionally used in the art to improve the etching performance, for example, a surfactant, a sequestering agent or a corrosion inhibitor. Surfactants decrease the surface tension and increase the uniformity of etching. As such a surfactant, a surfactant which is resistant to an etching solution and has compatibility with the surfactant is preferable. Examples thereof include any of anionic, cationic, amphoteric or nonionic surfactants and the like. Further, a fluorine-based surfactant can be used as a surfactant. The additive is not limited thereto, and various other additives known in the art can be selected and added for better effect of the present invention.

The etchant composition according to the present invention can collectively etch a molybdenum-based metal / aluminum-based metal double film and indium oxide films such as indium zinc oxide (IZO) and indium tin oxide (ITO).

The etchant composition according to the present invention does not generate fine etching residues for the molybdenum-based metal / aluminum-based metal double film, and therefore has excellent etching properties and does not generate indium oxide film residue. Therefore, the defect caused by the residue of indium oxide film is minimized .

Further, according to the present invention,

I) forming a molybdenum-based metal / aluminum-based metal double-layer on a substrate;

II) selectively leaving a photoreactive material on the molybdenum-based metal / aluminum-based metal double layer; And

III) etching the molybdenum-based metal / aluminum-based metal double-layer film by etching the molybdenum-based metal / aluminum-based metal double-layer film using the etching liquid composition of the present invention.

Further, according to the present invention,

I) forming an indium oxide film on a substrate;

II) selectively leaving a photoreactive material on the indium oxide film; And

III) etching the indium oxide film using the etching solution composition of the present invention.

In the etching method of the present invention, the photoreactive material is preferably a conventional photoresist material, and may be selectively left by conventional exposure and development processes.

Further, according to the present invention,

a) forming a gate wiring on the substrate;

b) forming a gate insulating layer on the substrate including the gate wiring;

c) forming a semiconductor layer on the gate insulating layer;

d) forming source and drain electrodes on the semiconductor layer; And

e) forming a pixel electrode connected to the drain electrode, the method comprising the steps of:

In the step (a), a molybdenum-based metal / aluminum-based metal double layer is formed on the substrate, and the gate wiring is formed by etching with the etchant composition of the present invention. In the step (e) And forming a pixel electrode by etching with the etching liquid composition of the present invention.

In the method of manufacturing an array substrate for a liquid crystal display according to the present invention, the step a) may include: a1) depositing a molybdenum-based metal / aluminum-based metal double layer on a substrate using a vapor deposition method or a sputtering method; And a2) forming the gate wiring by patterning the molybdenum-based metal / aluminum-based metal double layer with the etching solution of the present invention. Here, the method of forming the molybdenum-based metal / aluminum-based metal double-layer on the substrate is not limited to the above-described examples.

In the method for manufacturing an array substrate for a liquid crystal display according to the present invention, in step (b), silicon nitride (SiN _x ) is deposited on a gate wiring formed on a substrate to form a gate insulating layer. Here, the material used in forming the gate insulating layer is not limited to silicon nitride (SiN _x ) but may be a material selected from various inorganic insulating materials including silicon oxide (SiO ₂ ) to form a gate insulating layer It is possible.

In the method for manufacturing an array substrate for a liquid crystal display according to the present invention, in the step c), a semiconductor layer is formed on the gate insulating layer by a chemical vapor deposition method (CVD). That is, an active layer and an ohmic contact layer are sequentially formed, and patterned through dry etching. Here, the active layer is generally formed of pure amorphous silicon (a-Si: H), and the ohmic surface layer is formed of amorphous silicon (n ⁺ a-Si: H) containing impurities. Chemical vapor deposition (CVD) may be used to form the active layer and the ohmic contact layer, but the present invention is not limited thereto.

In the method for manufacturing an array substrate for a liquid crystal display according to the present invention, the step d) includes the steps of: d1) forming source and drain electrodes on the semiconductor layer; And d2) forming an insulating layer on the source and drain electrodes. In the step d1), a metal film is deposited on the ohmic surface layer by sputtering, and the source electrode and the drain electrode are formed by etching with the etching solution of the present invention. Here, the method of forming the metal film on the substrate is not limited to the above-described example. Wherein d2) step, including the inorganic insulating group, or benzocyclobutene (BCB) and acrylic (acryl) resins (resin) containing silicon nitride (SiN _x) and silicon oxide (SiO ₂₎ on the source and drain electrodes The organic insulating material is selected from the group of organic insulating materials to form an insulating layer as a single layer or a double layer. The material of the insulating layer is not limited to those illustrated above. Particularly, when the source and drain electrodes are formed of the same material as the gate wiring, the etchant composition can be applied to a process for forming source and drain electrodes.

In the method of manufacturing an array substrate for a liquid crystal display according to the present invention, the pixel electrode connected to the drain electrode is formed in step e). For example, a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO) is deposited by sputtering and etched using the etchant composition according to the present invention to form a pixel electrode. The method of depositing the indium oxide film is not limited to the sputtering method.

Further, in the method for manufacturing an array substrate for a liquid crystal display device, in the step (e) etching step using the etching solution composition according to the present invention, the attack to the data line including the drain electrode located under the pixel electrode can be minimized , It is possible to manufacture an array substrate for a liquid crystal display device which can improve the driving characteristics of the TFT-LCD and improve the productivity of the array substrate for a liquid crystal display device.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the following examples are intended to illustrate the present invention, and the present invention is not limited by the following examples, but may be variously modified and changed.

Example  1 to 10: Etchant  Preparation of composition

The grades for the semiconductor process, Fe (NO ₃ ) ₃ , NH ₄ FHF, Na ₂ SO ₄ , and deionized water were mixed as described in Table 1 to prepare an etchant.

Etchant composition (% by weight) Fe (NO _{3) 3} NH ₄ FHF Na ₂ SO ₄ Deionized water Example 1 2.0 0.3 One Balance Example 2 2.5 0.3 One Balance Example 3 3.0 0.4 3 Balance Example 4 3.5 0.4 2 Balance Example 5 3.5 0.3 3.5 Balance Example 6 3.5 0.5 4 Balance Example 7 4.0 0.8 5 Balance Example 8 4.0 1.0 2 Balance Example 9 4.5 0.8 2 Balance Example 10 5.0 0.9 3 Balance

Comparative Example  One: Etchant  Preparation of composition

3% by weight of Fe (NO ₃ ) ₃ , 0.4% by weight of NH ₄ FHF, 10% by weight of HNO ₃ , ₃ % by weight of HClO ₄ and a total of 100% by weight.

Comparative Example  2: Etchant  Preparation of composition

5% by weight oxalic acid and 95% by weight deionized water.

Test Example  1: molybdenum / aluminum Double membrane  And indium Oxide film Etching  Character rating

A molybdenum / aluminum double film was sequentially deposited on the glass substrate by the sputtering method, and the indium oxide film was also deposited by the same method as above. Then, a photoresist of about 1 mu m or so was coated thereon, . The test piece was etched using the spraying method with the etching solutions of Examples 1 to 10 and Comparative Examples 1 and 2. Each of the test pieces etched in Examples 1 to 10 and Comparative Examples 1 and 2 was examined using a scanning electron microscope (SEM; Hitach, S-4700). The results are shown in Table 2 and FIGS. 1 to 4 Respectively.

The criteria for evaluation of etching properties of molybdenum / aluminum double film and indium oxide film are as follows.

- Etching characteristics of molybdenum / aluminum double film

?: No fine residue occurred,

X: Fine residue was generated.

- Etching Characteristics of Indium Oxide Film

O: no residue,

X: Residual occurred.

Etch characteristics Molybdenum / aluminum double layer Indium oxide film Example 1 ○ ○ Example 2 ○ ○ Example 3 ○ ○ Example 4 ○ ○ Example 5 ○ ○ Example 6 ○ ○ Example 7 ○ ○ Example 8 ○ ○ Example 9 ○ ○ Example 10 ○ ○ Comparative Example 1 × × Comparative Example 2 × ×

In the etchant composition of Comparative Example 1, a residue of a fine molybdenum oxide film was formed when the molybdenum / aluminum double layer was etched (see FIG. 3), and the etchant composition of Comparative Example 2 containing oxalic acid produced a residue of the indium oxide film ).

However, as shown in Table 2, residue (minute residue) was not generated when the molybdenum / aluminum double film and the indium oxide film were etched with the etching liquid compositions according to the present invention (Examples 1 to 10). This fact can be confirmed also in Fig. 1 (surface SEM image of the molybdenum / aluminum double film etched with the etching liquid composition of Example 1) and Fig. 2 (surface SEM image of the indium oxide film etched with the etching liquid composition of Example 1).

Therefore, it can be seen that the etching solution of the present invention exhibits excellent etching properties for molybdenum / aluminum and indium oxide films.

1 is a scanning electron microscope (SEM) image of an entire surface of a molybdenum / aluminum double-layer film etched using the etchant composition according to Example 1 of the present invention,

2 is an electron micrograph of the surface of the indium oxide film etched using the etchant composition according to Example 1 of the present invention,

3 is a scanning electron microscope (SEM) image of an entire surface of a molybdenum / aluminum double-layer film etched using the etchant composition according to Comparative Example 1 of the present invention,

4 is an electron micrograph of the surface of the indium oxide film etched using the etchant composition according to Comparative Example 2 of the present invention.

Claims (16)

a) forming a gate wiring on the substrate; b) forming a gate insulating layer on the substrate including the gate wiring; c) forming a semiconductor layer on the gate insulating layer; d) forming source and drain electrodes on the semiconductor layer; And e) forming a pixel electrode connected to the drain electrode, the method comprising the steps of: In the step (a), a molybdenum-based metal / aluminum-based metal double layer is formed on the substrate, and the gate wiring is formed by etching with the etching composition. In step (e), an indium oxide layer is formed, Thereby forming a pixel electrode, The etchant composition does not contain an acidic compound, 2 to 5% by weight of iron oxide (Fe (NO ₃ ) ₃ ), 0.1 to 1% by weight of a fluorine compound, 1 to 5% by weight of a sulfate compound and 89 to 96.9% by weight of water, based on the total weight of the composition Of the substrate (1). The method according to claim 1, wherein the fluorinated compound is at least one selected from the group consisting of NH ₄ FHF, KFHF, NaFHF, KF, and NaF. The method according to claim 1, wherein the sulfate compound is at least one selected from the group consisting of sodium sulfate, potassium sulfate, and ammonium sulfate. Way. delete The method of manufacturing an array substrate for a liquid crystal display device according to any one of claims 1 to 3, wherein the indium oxide film is an indium zinc oxide film (IZO) or an indium tin oxide film (ITO). The method of manufacturing an array substrate for a liquid crystal display according to any one of claims 1 to 3, wherein the array substrate for a liquid crystal display is a thin film transistor (TFT) array substrate. An etchant composition that does not contain an acidic compound, 2 to 5% by weight of iron oxide (Fe (NO ₃ ) ₃ ), 0.1 to 1% by weight of a fluorine compound, 1 to 5% by weight of a sulfate compound and 89 to 96.9% by weight of water, based on the total weight of the composition Based metal / aluminum-based metal double film and indium oxide film. The etching solution composition of claim 7, wherein the fluorinated compound is at least one selected from the group consisting of NH ₄ FHF, KFHF, NaFHF, KF, and NaF. . [7] The method of claim 7, wherein the sulfate compound is at least one selected from the group consisting of sodium sulfate, potassium sulfate, and ammonium sulfate. Film and an indium oxide film. The etchant composition according to claim 7, further comprising at least one additive selected from the group consisting of a surfactant, a sequestering agent, and a corrosion inhibitor. The etchant composition of claim 7, wherein the indium oxide film is indium zinc oxide (IZO) or indium tin oxide (ITO). delete I) forming a molybdenum-based metal / aluminum-based metal double-layer on a substrate; II) selectively leaving a photoreactive material on the molybdenum-based metal / aluminum-based metal double layer; And III) A method for etching a molybdenum-based metal / aluminum-based metal double-layer film comprising the step of etching the molybdenum-based metal / aluminum-based metal double-layer film using the etching composition according to any one of claims 7 to 11. I) forming an indium oxide film on a substrate; II) selectively leaving a photoreactive material on the indium oxide film; And III) etching the indium oxide film using the etching liquid composition according to any one of claims 7 to 11. 14. The method of claim 13, wherein the photoreactive material is a photoresist material and is selectively left by an exposure and development process. [16] The method of claim 14, wherein the photoreactive material is a photoresist material and is selectively left by an exposure and development process.

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