KR101507159B1 - Manufacturing method of array substrate for liquid crystal display - Google Patents

Abstract

A) forming a gate electrode on a substrate; b) forming a gate insulating layer on the substrate including the gate electrode; 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, wherein in the steps a) and d), a molybdenum-based metal / aluminum-based metal double layer film A source electrode and a drain electrode are formed in step a), a gate electrode is formed in step a), a source electrode and a drain electrode are formed in step d), and an indium oxide film is formed in step e) Wherein the etchant composition comprises A) from 2 to 5% by weight of iron oxide (Fe (NO ₃ ) ₃ ), based on the total weight of the composition; B) 0.1 to 1% by weight of a fluorine compound; C) nitric acid (HNO ₃₎ 8 to 15% by weight; D) 0.1 to 5% by weight of copper chloride (CuCl ₂ ); And E) the remaining amount of water. The present invention also relates to a method of manufacturing an array substrate for a liquid crystal display device.

Molybdenum, aluminum, indium oxide, bilayer, 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 device, a molybdenum-based metal / aluminum-based metal double film and an etchant composition for an indium oxide film used in the method, Or an etching method of an indium oxide film.

The process of forming a metal wiring on a substrate during manufacture in the manufacture of a semiconductor device for driving a liquid crystal display device typically includes a metal film forming process by sputtering and the like, a photoresist coating process, a photoresist Forming process, 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 semiconductor device described above, a metal generally used as a wiring material of a TFT-LCD (Thin Film Transistor-Liquid Crystal Display) is aluminum (Al) or an aluminum alloy, pure aluminum is weak in resistance to a chemical substance, It is possible to use a metal layer such as molybdenum (Mo), chromium (Cr), tungsten (W) or tin (Sn) on the aluminum or aluminum alloy layer Layer laminated structure is used.

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.

In order to realize a high image quality, an etchant that does not generate fine etching residues is required. In order to simplify the process, a molybdenum / aluminum double film used as a gate wiring and an indium oxide film used as a pixel electrode are collectively etched The development of an etchant composition capable of forming an etchant is desired.

Accordingly, the present invention provides a method of manufacturing a semiconductor device, which does not generate fine etching residues when the molybdenum-based metal / aluminum-based metal double layer is etched, maintains the initial etching property due to a galvanic effect minimized even when a large amount of substrate is etched, It is another object of the present invention to provide an etchant composition capable of performing batch etching of the molybdenum-based metal / aluminum-based metal double film and the indium oxide film even when the oxide film is etched.

It is another object of the present invention to provide a method for etching a molybdenum-based metal / aluminum-based metal double layer and an indium oxide layer using the etchant composition.

It is still another object of the present invention to provide a method for manufacturing an array substrate for a liquid crystal display device, which comprises the step of etching the molybdenum-based metal / aluminum-based metal double film and / or the indium oxide film by using the etchant composition.

According to the present invention,

A) 2 to 5% by weight of iron oxide (Fe (NO ₃ ) ₃ );

B) 0.1 to 1% by weight of a fluorine compound;

C) nitric acid (HNO ₃₎ 8 to 15% by weight;

D) 0.1 to 5% by weight of copper chloride (CuCl ₂ ); And

E) residual water, and an etchant composition of an indium oxide film.

Further, according to the present invention,

Forming a molybdenum-based metal / aluminum-based metal double layer on the substrate;

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

There is provided a method of etching a molybdenum-based metal / aluminum-based metal double-layer film including the step of 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,

Forming an indium oxide film on the substrate;

Selectively leaving a photoreactive material on the indium oxide film; And

There is provided a method of etching an indium oxide film including a step of etching the indium oxide film using the etching solution composition of the present invention.

Further, according to the present invention,

a) forming a gate electrode on a substrate;

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

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) and the step d), a molybdenum-based metal / aluminum-based metal double layer is formed on the substrate and then etched by the etchant composition of the present invention to form a gate electrode in step a) and a source electrode and a drain electrode And forming an indium oxide film in the step e), and then etching the substrate with the etching solution composition of the present invention to form a pixel electrode.

In addition, the present invention provides an array substrate for a liquid crystal display comprising at least one of a gate wiring, a source and a drain electrode, and a pixel electrode etched using the above etching solution composition.

When the molybdenum-based metal / aluminum-based metal double film or the 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. In addition, even if a large amount of substrate is etched, it maintains the initial etching property due to the minimized galvanic effect, and exhibits an excellent etching characteristic that does not leave an etching residue even if the indium oxide film is etched with the same etching solution. Therefore, in the production of an array substrate for a liquid crystal display device comprising a gate electrode formed of a molybdenum-based metal / aluminum-based metal double film, a source electrode and a drain electrode, and / or a pixel electrode formed of an indium oxide film, The driving characteristics of the liquid crystal display device can be improved. In addition, it is possible to simultaneously etch the molybdenum-based metal / aluminum-based metal double layer and the indium oxide layer, thereby maximizing the process efficiency.

I . Etchant  Composition

The present invention relates to a molybdenum-based metal material comprising A) iron oxide (Fe (NO ₃ ) ₃ ), B) fluorine compound, C) nitric acid (HNO ₃ ), D) copper chloride (CuCl ₂ ) / Aluminum-based metal double film and indium oxide film.

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, A) iron oxide (Fe (NO ₃ ) ₃ ) is used as an oxidizing agent for etching molybdenum metal / aluminum metal double film and indium oxide film. It is preferable that the A) iron oxide is contained in an amount of 2 to 5% by weight based on the total weight of the etching solution composition of the present invention. If it is contained in an amount less than 2% by weight, etching may not be performed due to insufficient etching force. If the amount exceeds 5% by weight, the etching rate for the molybdenum-based metal is accelerated and the etching rate for the aluminum- The upper molybdenum-based metal is over-deflected to cause etching non-uniformity.

Among the etching liquid compositions of the present invention, the fluorine-containing compound (B) accelerates the aluminum etching rate when the molybdenum-based metal / aluminum-based metal double film is etched and the etching rate of the indium oxide film is accelerated when the indium oxide film is etched. The B) fluorine compound is preferably contained in an amount of 0.1 to 1% by weight based on the total weight of the composition. If it is contained in an amount of 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 slower. When the molybdenum-based metal / aluminum- The upper molybdenum-based metal overhang may occur, and when the indium oxide film is etched, the lower insulating film of the indium oxide film may be attacked.

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

Among the etching liquid compositions of the present invention, C) nitric acid (HNO ₃ ) accelerates the etching rate when the molybdenum-based metal / aluminum-based metal double film is etched. It is preferable that the C) silver nitrate is contained in an amount of 8 to 15% by weight based on the total weight of the composition. If it is contained in an amount of less than 8% by weight, the etching rate for the molybdenum-based metal / aluminum-based metal double film may be slower as well as etch residues may be generated. The etching rate is too fast to control the process time.

The etching rate can be increased when the molybdenum-based metal / aluminum-based metal double-layered film is etched without containing an acid other than nitric acid (HNO ₃ ).

In the etching liquid composition of the present invention, D) copper (CuCl ₂ ) prevents the molybdenum-based metal oxide film from being reabsorbed on the substrate. This is possible because D) copper chloride has a mechanism for removing the molybdenum-based metal oxide film. It is preferable that D) copper chloride is contained in an amount of 0.1 to 5% by weight based on the total weight of the composition. If it is contained in an amount of less than 0.1% by weight, it is difficult to prevent re-adsorption of the molybdenum-based metal oxide film. If it exceeds 5% by weight, residues may remain in the case of etching the indium oxide film.

In the etchant composition according to the present invention, water is not particularly limited, but deionized water is preferred. 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.

B) fluorine compounds, C) nitric acid, and D) copper chloride, which are used in the present invention, can be prepared by a conventionally known method and preferably have a purity for semiconductor processing.

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.

The surfactant serves to lower the surface tension and increase the uniformity of the 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. As the surfactant, a fluorine-based surfactant may be used.

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

The etchant composition according to the present invention does not generate fine etching residues for the molybdenum metal / aluminum-based metal double film and has excellent etching properties. Even when the indium oxide film is etched, the residue is not generated. And has excellent properties to minimize the amount of the particles.

Ⅱ . Etching method

The present invention provides a method of manufacturing a semiconductor device, comprising: forming a molybdenum-based metal / aluminum-based metal double layer on a substrate; Selectively leaving a photoreactive material on the molybdenum-based metal / aluminum-based metal double layer; And etching the molybdenum-based metal / aluminum-based metal double-layer film using the etching liquid composition of the present invention.

The present invention also provides a method of manufacturing a semiconductor device, comprising: forming an indium oxide film on a substrate; Selectively leaving a photoreactive material on the indium oxide film; And etching the indium oxide film using the etching solution composition of the present invention.

The photoreactive material is preferably a conventional photoresist material and may be selectively left by conventional exposure and development processes.

Ⅲ . Method for manufacturing array substrate for liquid crystal display

The present invention provides a method of manufacturing a semiconductor device, comprising: a) forming a gate electrode on a substrate; b) forming a gate insulating layer on the substrate including the gate electrode; 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) and the step d), a molybdenum-based metal / aluminum-based metal double layer is formed on the substrate and then etched by the etchant composition of the present invention to form a gate electrode in step a) and a source electrode and a drain electrode And forming an indium oxide film in the step e) and then etching the substrate with the etchant composition of the present invention to form a pixel electrode.

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 of 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 electrode formed on a substrate to form a gate insulating layer. Here, the material used in the formation of the gate insulating layer is not limited to silicon nitride (SiN _x ), but a material selected from various inorganic insulating materials including silicon oxide (SiO ₂ ) may be used to form the gate insulating layer have.

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 contact 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 step d1), a metal film is deposited on the ohmic contact layer by a sputtering method, 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. In particular, when the source and drain electrodes are formed of the same material as the gate electrode, the etchant composition may be applied to the 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 and Comparative Example  1, 2: Etchant  Preparation of composition

Semiconductor process grades Fe (NO ₃ ) ₃ , NH ₄ FHF, HNO ₃ , CuCl ₂ And oxalic acid were mixed as described in Table 1 below, and deionized water was added to make the total weight of the composition 100 wt% to prepare an etchant.

Fe (NO _{3) 3} NH ₄ FHF HNO ₃ CuCl ₂ Oxalic acid Deionized water Example 1 2.0 0.3 8 0.1 - Balance Example 2 2.5 0.3 9 0.2 - Balance Example 3 3.0 0.4 10 0.5 - Balance Example 4 3.5 0.4 11 1.0 - Balance Example 5 3.5 0.3 8 0.2 - Balance Example 6 3.5 0.5 12 0.3 - Balance Example 7 4.0 0.8 12 1.0 - Balance Example 8 4.0 1.0 14 0.7 - Balance Example 9 4.5 0.8 12 2.0 - Balance Example 10 5.0 0.9 15 4.0 - Balance Comparative Example 1 3.0 0.4 10 - - Balance Comparative Example 2 - - - - 5.0 Balance

Test Example  1: molybdenum-based metal / aluminum-based metal 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 deposited by the same method as described above. A photoresist having a thickness of about 1 占 퐉 was coated thereon, and then a pattern was selectively formed to prepare a test piece. The test pieces were 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 Example 1 and Comparative Example 2 was inspected using a scanning electron microscope (SEM; Hitach, S-4700). The results are shown in Tables 2 and 3 1 to 4.

The criteria for evaluating the etch characteristics of the molybdenum-based metal / aluminum-based metal double film and indium oxide film are as follows.

- Etching Characteristics of Molybdenum Metal / Aluminum Metal Double Layer

○: No fine residue occurred, ×: Fine residue was observed.

- Etching Characteristics of Indium Oxide Film

O: No residue, X: Residual occurrence.

Etch characteristics Molybdenum-based metal / aluminum-based metal 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 × ×

As shown in Table 2 above, copper chloride-free In the case of etching with the etching composition of Comparative Example 1, a fine molybdenum oxide film residue was generated upon etching of the molybdenum / aluminum double film (see FIG. 3). Residues also occurred when the indium oxide film was etched. On the other hand, in the case of etching with the etchant composition of Comparative Example 2 containing oxalic acid and deionized water, molybdenum oxide remained on the occasion of etching the molybdenum / aluminum double layer, and indium oxide remained on etching the indium oxide layer Reference).

However, when the molybdenum / aluminum double film and the indium oxide film were etched with the etching liquid compositions (Examples 1 to 10) according to the present invention, residues (minute residues) were not generated. 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 characteristics with respect to the molybdenum-based metal / aluminum-based metal and the indium oxide film.

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

FIG. 2 is a scanning electron micrograph of the entire surface after etching the indium oxide film using the etching solution composition according to Example 1 of the present invention. FIG.

FIG. 3 is a scanning electron micrograph of a molybdenum / aluminum metal double film etched using the etchant composition according to Comparative Example 1 of the present invention and observing the entire surface thereof.

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 (12)

a) forming a gate electrode on a substrate; b) forming a gate insulating layer on the substrate including the gate electrode; 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 steps a) and d), a molybdenum-based metal / aluminum-based metal double layer is formed on the substrate and etched by the etchant composition to form a gate electrode in step a) and a source electrode and a drain electrode in step d) , Forming an indium oxide film in the step (e), etching the substrate with an etchant composition to form a pixel electrode, Wherein the etchant composition does not contain any acid other than nitric acid (HNO ₃ ) and comprises 2 to 5% by weight of iron oxide (Fe (NO ₃ ) ₃ ) relative to the total weight of the composition; B) 0.1 to 1% by weight of a fluorine compound; C) nitric acid (HNO ₃₎ 8 to 15% by weight; D) 0.1 to 5% by weight of copper chloride (CuCl ₂ ); And E) the remaining amount of water. 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 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 claim 1, wherein the array substrate for a liquid crystal display is a thin film transistor (TFT) array substrate. It does not contain any acid other than nitric acid (HNO ₃ ) About the total weight of the composition A) 2 to 5% by weight of iron oxide (Fe (NO ₃ ) ₃ ); B) 0.1 to 1% by weight of a fluorine compound; C) nitric acid (HNO ₃₎ 8 to 15% by weight; D) 0.1 to 5% by weight of copper chloride (CuCl ₂ ); And E) molybdenum metal / aluminum-based metal double film and indium oxide film. The etchant composition of claim 5, wherein the fluorinated compound is at least one selected from the group consisting of NH ₄ FHF, KFHF, NaFHF, KF, and NaF. delete [6] The method of claim 5, wherein the etchant composition further comprises one or more additives selected from the group consisting of a surfactant, a sequestering agent for metal ions, and a corrosion inhibitor, and a molybdenum- Etchant composition of indium oxide film. The etchant composition of claim 5, wherein the indium oxide film is indium zinc oxide (IZO) or indium tin oxide (ITO). Forming a molybdenum-based metal / aluminum-based metal double layer on the substrate; Selectively leaving a photoreactive material on the molybdenum-based metal / aluminum-based metal double layer; And 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 composition of claim 5. Forming an indium oxide film on the substrate; Selectively leaving a photoreactive material on the indium oxide film; And A method of etching an indium oxide film, comprising: etching the indium oxide film using the etching solution composition of claim 5. An array substrate for a liquid crystal display comprising at least one of gate wirings, source and drain electrodes, and pixel electrodes etched using the etchant composition of claim 5.

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