KR20090050141A - Manufacturing method of array substrate for liquid crystal display - Google Patents

Abstract

The present invention relates to an indium oxide film containing 5 to 15% by weight of sulfuric acid, 3 to 20% by weight of acetic acid, 1 to 5% by weight of hydrochloric acid, 0.1 to 3% by weight of an azole compound, and 57 to 90.9% by weight of water. An etchant composition and a method of manufacturing an array substrate for a liquid crystal display device using the same.

Indium oxide film, etching solution composition

Description

Method for manufacturing array substrate for liquid crystal display device {MANUFACTURING METHOD OF ARRAY SUBSTRATE FOR LIQUID CRYSTAL DISPLAY}

The present invention provides excellent etching characteristics and minimizes attack on the lower metal layer during the etching process of the indium oxide film used as the pixel electrode of the manufacturing process of a flat panel display (FPD). The present invention relates to an etching liquid composition capable of improving driving characteristics of a device, and a method of manufacturing an array substrate for a liquid crystal display device using the same.

In general, a transparent pixel electrode used in a flat panel display device is formed by stacking an indium oxide film on a glass substrate or the like through sputtering or the like, coating a photoresist thereon, and forming a pattern through an exposure and development process. It is formed by etching the oxide film.

Indium oxide film is a material that is not easy to etch by chemical reaction because of excellent chemical resistance. Examples of the etchant that has been conventionally used to etch the indium oxide film include aqua regia (HCl + HNO ₃ ) etchant described in Korean Patent Publication No. 1996-2903; An etchant consisting of hydrochloric acid described in Korean Laid-Open Patent Publication No. 1997-65685 and one substance selected from weak acids and alcohols; Iron chloride-based (FeCl ₃ + HCl) etchant described in US Pat. An etchant containing oxalic acid and its salt or aluminum chloride as described in Korean Patent Laid-Open No. 2000-0017470; And etching solutions containing hydrogen iodide (HI) and iron chloride (FeCl ₃ ) described in US Pat.

However, in the case of aqua regia solution, the etching solution is inexpensive but the etching side of the pattern is large, and since the hydrochloric acid or nitric acid is volatilized after forming the etching solution, the etching solution composition is highly fluctuated and formed of a metal under the pixel electrode formed of the indium oxide film. The disadvantage is that an attack is applied to the data line.

Even in the case of the iron chloride-based etching solution, there is a problem in that the variation of the component appears in the same way as the aqua regia system, since hydrochloric acid is the main component etching solution.

The etching solution made of oxalic acid has a disadvantage in that even though etching is easy, a low solubility is generated at low temperatures, and thus a process takes a long time because the etching rate is slow.

In addition, the etching solution composed of hydrogen iodide has a high etching rate and low side etching, but it is expensive, toxic and corrosive, and attacks on data wiring under the transparent pixel electrode have limitations for use in actual processes. .

As described above, in the case of the conventional etchant, most of the etchants have strong chemical activity, and thus the multilayer film is formed by influencing adjacent metals such as molybdenum (Mo), copper (Cu), aluminum (Al) and the like that have little chemical resistance during etching. In the case of an electronic component (for example, a TFT-LCD) to be used, there are problems in that a lot of constraints are involved in selecting a material for forming a metal film.

Accordingly, an object of the present invention is to improve driving characteristics of a flat panel display device by minimizing an attack on a lower metal during etching of an indium oxide film to form a pixel electrode in a method of manufacturing an array substrate for a liquid crystal display device. At the same time, to provide an etching liquid composition that can improve the productivity by shortening the etching process time.

In addition, the present invention is to provide an etching method of the indium oxide film using the etchant composition.

In addition, the present invention is to provide a method for manufacturing an array substrate for a liquid crystal display device comprising the use of the etchant composition.

In order to achieve the above object, the present invention, with respect to the total weight of the composition,

A) 5-15 wt% sulfuric acid,

B) 3-20 wt% acetic acid,

C) 1-5% by weight of hydrochloric acid,

D) 0.1 to 3% by weight of an azole compound, and

E) 57 ~ 90.9 wt% water

It provides an etching solution composition of the indium oxide film comprising a.

In addition, the present invention,

I) forming an indium oxide film on the substrate;

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

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

It provides an etching method of the indium oxide film comprising a.

In addition, 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

In the method of manufacturing an array substrate for a liquid crystal display device comprising a, in the step (e) after forming the indium oxide film, the liquid crystal display device array characterized in that by etching with the etchant composition of the present invention to form a pixel electrode. Provided is a method of manufacturing a substrate.

Indium oxide film in the present invention includes an indium zinc oxide film (IZO) or indium tin oxide film (ITO).

Hereinafter, the present invention will be described in detail.

The present invention is an indium containing 5 to 15% by weight of sulfuric acid, 3 to 20% by weight of acetic acid, 1 to 5% by weight of hydrochloric acid, 0.1 to 3% by weight of an azole compound, and 57 to 90.9% by weight of water. It provides an etching solution composition of the oxide film.

In the etchant composition of the present invention, sulfuric acid is used as the main oxidizing agent for etching the indium oxide film, and has little attack on other metals under the indium oxide film.

The sulfuric acid is preferably included in 5 to 15% by weight based on the total weight of the composition of the present invention. When sulfuric acid is included in less than 5% by weight may not be enough etching due to the lack of etching power, if more than 15% by weight of the lower metal located below the photoresist and indium oxide film on the indium oxide film It will attack the act.

In the etchant composition of the present invention, acetic acid is to provide an etching uniformity and to speed up the etching rate, it is preferably included 3 to 20% by weight relative to the total weight of the composition. If the acetic acid is less than 3% by weight, the etching uniformity is lowered, the etching rate is slowed, and if it is more than 20% by weight may attack the lower metal film of the indium oxide film.

In the etching liquid composition of the present invention, hydrochloric acid serves to accelerate the etching rate and to remove the residue of the indium oxide film by etching.

Hydrochloric acid is preferably contained 1 to 5% by weight based on the total weight of the composition, if less than 1% by weight is the etch rate is slow, the residue removal ability of the indium oxide film by etching is lowered, in excess of 5% by weight indium The oxide removal ability of the oxide film is excellent, but it can accelerate the attack on the underlying metal film.

In the etchant composition of the present invention, the azole compound serves to prevent attack on the lower metal film.

It is preferable that the azole compound is included in an amount of 0.1 to 3% by weight based on the total weight of the composition. When the amount of the azole compound is less than 0.1% by weight, attack occurs on the lower metal film. Is excellent, but an etching residue of the indium oxide film may occur.

The azole compound may be aminotetrazole, imidazole, indole, pyrazole, pyridine, pyrrole, benzotriazole and other water-soluble cyclic amine compounds. Preference is given to one or more compounds selected from the group comprising cyclic amine compounds, preferably benzotriazole.

In the etching liquid composition which concerns on this invention, although the said water is not specifically limited, Deionized water is preferable. More preferably, deionized water having a specific resistivity of 18 ㏁ / cm or more, which shows the degree of ions removed from the water, may be used.

The sulfuric acid, acetic acid, hydrochloric acid, and azole compounds described above can be usually produced by a 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 commonly used in the art for improving etching performance, for example, a surfactant, a metal ion sequestrant or a corrosion inhibitor. The surfactant serves to lower the surface tension to increase the uniformity of the etching. Such surfactants are preferably surfactants that can withstand etching solutions and are compatible. Examples thereof include any anionic, cationic, zwitterionic or nonionic surfactant. Moreover, a fluorine-type surfactant can be used as surfactant. The additive is not limited to this, but in order to further improve the effects of the present invention, various other additives known in the art may be selected and added. The additive is preferably included from 0.0001 to 0.01% by weight relative to the total weight of the composition.

An indium oxide film such as an indium zinc oxide film (IZO) and an indium tin oxide film (ITO) may be etched using the etching liquid composition according to the present invention.

The etchant composition according to the present invention has excellent etching performance with respect to the indium oxide film used for manufacturing the array substrate for the liquid crystal display device, reduces the attack on the lower metal film during the etching process, and compares it with the conventional oxalic acid based etching solution. Since the etching rate is fast and no residue of the indium oxide film is generated, it has excellent characteristics of minimizing defects caused by the residue of the indium oxide film.

In addition, the etchant composition according to the present invention has no crystallization phenomenon of oxalic acid at 0 ° C. or lower, which is known as a problem of conventional oxalic acid etchant, and does not affect the lower metal film appearing in the hydrochloric acid etchant. Therefore, there is an advantage that the productivity can be increased in the process of manufacturing the liquid crystal display device.

In addition, the present invention,

I) forming an indium oxide film on the substrate;

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

III) provides an etching method of the indium oxide film comprising etching the indium oxide film using the etchant composition of the present invention.

In the etching method according to the invention, the step (a) comprises the steps of (a1) preparing a substrate; And (a2) forming an indium oxide film on the substrate. Of course, a conventional cleaning process may be performed on the substrate, and an indium oxide film may be deposited.

In the step (a1), the substrate may be a glass substrate or a quartz substrate, and a glass substrate is preferable.

In the step (a2), various methods known to those skilled in the art may be used as a method of forming an indium oxide film on a substrate. For example, the indium oxide film may be deposited on a substrate by a sputtering method. The indium oxide film can be deposited to have a thickness of approximately 500 to 200 GPa.

The step (a) may further include forming a structure for a liquid crystal display device between the substrate and the indium oxide film.

The structure for a liquid crystal display device includes at least one of an organic insulating film by a method such as chemical vapor deposition, a conductive material by a method such as sputtering, and a semiconductor film such as an amorphous or polycrystalline silicon film. It may be a structure manufactured by.

In the etching method according to the invention, the step (b) comprises the steps of (b1) forming a photoreactive material coating layer by applying a photoreactive material on the indium oxide film; (b2) selectively exposing the photoreactive material coating layer through a photomask; And (b3) developing the photoreactive material coating layer by using a developer such that a predetermined region of the entire area of the photoreactive material coating layer remains on the indium oxide film.

In the step (b1), the photoreactive material may be coated on the indium oxide film using a spin coater, and the thickness thereof is preferably about 1 μm. Here, in addition to the spin coater, a slit coater may be used, and the spin coater and the slit coater may be used in combination. The present coating process may further include a conventional process such as ashing, heat treatment.

In step (b1), a photoresist may be used as the photoreactive material. A photoresist is a kind of photosensitive polymer that reacts when it receives light at a specific wavelength range (photo exposure), where the reaction is the polymer chain of the exposed part when a part of the photoresist is exposed. This means breaking or bonding stronger. The exposed photopolymer may be selected from a positive photoresist in which the polymer bond chain of the exposed portion is broken and a negative photoresist on the contrary.

In the step (b2), the photoreactive layer is selectively irradiated with light in the ultraviolet region using a photo mask.

In the step (b3), through the exposure step (b2), the photoreactive material coating layer of the relatively weak bonding portion is melted using a developer. Accordingly, it is possible to selectively leave a photoreactive material on the indium oxide film.

In the etching method of the present invention, in the step (c), the indium oxide film may be etched using the etching solution composition of the indium oxide film according to the present invention.

Such an etching process may be performed according to methods known in the art, and examples thereof include a method of dipping, spraying, and the like. The temperature of the etching solution during the etching process may be 20 ~ 50 ℃, the appropriate temperature can be changed as necessary in consideration of other processes and other factors.

In addition, 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

In the method of manufacturing an array substrate for a liquid crystal display device comprising a, in the step (e), after forming the indium oxide film, the liquid crystal display device for forming a pixel electrode by etching with the etchant composition of the present invention Provided is a method of manufacturing an array substrate.

In the method of manufacturing an array substrate for a liquid crystal display device according to the present invention, the step a) comprises the steps of: a1) depositing a metal film on the substrate by vapor deposition or sputtering; And a2) patterning the metal to form a gate wiring. Here, the method of forming a metal film on a board | substrate, and the material of a metal film are not limited.

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

In the method of manufacturing an array substrate for a liquid crystal display device according to the present invention, in the step c), a semiconductor layer is formed on the gate insulating layer by chemical vapor deposition (CVD). In other words, the active layer and the ohmic contact layer are sequentially formed and then patterned by 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 is not limited thereto.

In the method of manufacturing an array substrate for a liquid crystal display device according to the present invention, the step d) comprises: 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 and etched on the ohmic contact layer by sputtering to form a source electrode and a drain electrode. Here, the method of forming the metal film on the substrate is not limited to the above examples. In step d2), an inorganic insulating group including silicon nitride (SiN _x ) and silicon oxide (SiO ₂ ) or a benzocyclobutene (BCB) and an acrylic resin are included on the source electrode and the drain electrode. The insulating layer may be formed of a single layer or a double layer by selecting from a group of organic insulating materials. The material of the insulating layer is not limited to only those exemplified above.

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

In the method of manufacturing an array substrate for a liquid crystal display device, during the step (e) etching process using the etchant composition according to the present invention, the attack speed to the data line including a drain electrode located at the lower side of the pixel electrode while the etching speed is high As a result, an excellent array substrate for a liquid crystal display device capable of improving driving characteristics of the TFT-LCD can be manufactured, and productivity of the array substrate for a liquid crystal display device can be improved.

In the method of manufacturing an array substrate for a liquid crystal display device, when the etching liquid composition according to the present invention is used in the etching process of the indium oxide film, it is possible to minimize the attack on the lower metal, driving characteristics of the liquid crystal display device An excellent array substrate for a liquid crystal display device can be manufactured. In addition, when manufacturing the array substrate for the liquid crystal display device, the etching process time may be shortened to improve productivity of the array substrate for the liquid crystal display device, and the etching uniformity may be maintained even when the size of the substrate is large.

Hereinafter, the present invention will be described in more detail using examples and comparative examples. However, the following Examples and Comparative Examples are intended to illustrate the present invention, the present invention is not limited to the following Examples and Comparative Examples can be variously modified and changed.

Example  1-26: Etchant  Preparation of the composition and Etch Characteristic Evaluation

Sulfuric acid, acetic acid, hydrochloric acid and benzotriazole, which are grades for semiconductor processing, were mixed as shown in Table 1 below, and the etching liquids of Examples 1 to 26 were prepared by adding deionized water such that the total weight of the composition was 100% by weight. .

The test piece was prepared by depositing an indium tin oxide film on the glass substrate by sputtering to a thickness of about 500 kPa, coating a photoresist of about 1 μm or more thereon, and then selectively forming a pattern. The test piece was etched with the etching solution of Examples 1 to 26 using a spray method at 40 ° C. for 80 seconds. Each of the test pieces etched in Examples 1 to 26 was examined using an electron scanning microscope (SEM; Hitach, S-4700), and the results are shown in Table 1 and FIGS. 1 to 3.

[Etch Characteristic Evaluation Criteria]

X: Residue, no lower metal film attack.

O: Residual occurrence, lower metal film attack.

Example Composition (wt%) (sulfuric acid / acetic acid / hydrochloric acid / benzotriazole / deionized water) Residue Bottom metal attack One 5/15/2 / 0.1 / residual quantity X X 2 15/10/1 / 0.1 / residual quantity X X 3 12/11/2 / 0.1 / residual quantity X X 4 15/20/5 / 0.1 / residual quantity X X 5 15/17/4 / 0.1 / residual quantity X X 6 14/16/3 / 0.1 / residual quantity X X 7 13/15/2 / 0.5 / residual quantity X X 8 12/17/1 / 0.5 / residual quantity X X 9 11/15/4 / 0.5 / remaining amount X X 10 10/18/3 / 0.5 / residual quantity X X 11 10/19/2 / 0.5 / residual quantity X X 12 9/14/5 / 0.5 / residual quantity X X 13 8/10/4/1 / residual quantity X X 14 7/9/3/1 / residual quantity X X 15 7/14/5/1 / residual quantity X X 16 7/12/1/1 / residual quantity X X 17 6/15/3/2 / residual quantity X X 18 6/12/2/2 / residual quantity X X 19 5/5/5/2 / residual quantity X X 20 5/20/5/2 / residual quantity X X 21 5/18/4/3 / residual quantity X X 22 5/18/5/3 / residual quantity X X 23 5/20/5/3 / residual quantity X X 24 5/10/5/3 / residual quantity X X 25 15/3/5/3 / Remaining X X 26 15/5/3/3 / residual quantity X X

As shown in Table 1, it was found that Examples 1 to 26, which are the etchant composition of the present invention, exhibited good etching characteristics without the occurrence of residue and the attack of the lower metal film. In addition, as shown in FIG. 1, no residue remained on the surface of the indium oxide film etched by the etchant of Example 1, indicating that the etching characteristics were excellent. In addition, in order to show that the etching liquid composition of the indium oxide film according to the present invention does not affect the lower metal film of the indium oxide film, as an example, as Example 1 of the present invention on a substrate on which a copper metal film and a photoresist are formed Compared to before etching (see FIG. 2) and after etching (FIG. 3), even after using the etching solution of Example 1 of the present invention, there was no attack on the lower metal film and no effect on the photoresist. Could confirm.

Comparative example  One: Etchant  Preparation of the composition and Etch Characteristic Evaluation

An etching solution containing 18% by weight of hydrochloric acid, 4% by weight of nitric acid, and 78% by weight of deionized water was used relative to the total weight of the composition. Etching under to evaluate the indium oxide film etching characteristics are shown in Table 2 and FIG.

As shown in Table 2, when the etchant of Comparative Example 1 was used, the etching residue did not occur, but attack of the lower metal film occurred. In addition, as shown in FIG. 4, it was found that the attack on the lower metal layer was more severe than before etching (see FIG. 2).

Comparative example  2: Etchant  Preparation of the composition and Etch Characteristic Evaluation

An etching solution containing 5% by weight of oxalic acid and 95% by weight of deionized water was used with respect to the total weight of the composition, using the same specimen as in Comparative Example 1, and etching under the same etching conditions to evaluate the indium oxide film etching characteristics. And FIG. 5.

As shown in Table 2 and Figure 5, it can be seen that the etching residue occurs when using the etching solution of Comparative Example 2.

Comparative example Composition (% by weight) Residue Bottom metal attack One Hydrochloric Acid / Nitric Acid / Deionized Water (18/4/78) X O 2 Oxalic Acid / Deionized Water (5/95) O X

Accordingly, it was found that the etchant of the present invention prevents attack on the lower metal layer and at the same time, exhibits excellent etching characteristics with respect to the indium oxide layer.

1 is a scanning electron microscope photograph of the entire surface after etching the indium oxide film using an etchant composition according to Example 1 of the present invention,

2 is an electron scanning microscope photograph taken before etching of a substrate on which a lower metal film (copper film) and a photoresist are formed;

3 is an electron scanning micrograph after etching an indium oxide film on a substrate on which a lower metal film (copper film) and a photoresist are formed by using the etchant composition according to Example 1 of the present invention;

4 is an electron scanning microscope photograph after etching an indium oxide film on a substrate on which a lower metal film (molybdenum film) and a photoresist are formed by using the etchant composition according to Comparative Example 1 of the present invention;

FIG. 5 is an electron scanning micrograph after etching an indium oxide film on a substrate on which a lower metal film (molybdenum film) and a photoresist are formed by using an etching solution composition according to Comparative Example 2 of the present invention.

Claims (12)

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 In the manufacturing method of the array substrate for a liquid crystal display device comprising: A method of manufacturing an array substrate for a liquid crystal display device, wherein after forming an indium oxide film in the step (e), the pixel electrode is formed by etching with an etchant composition. The etchant composition, with respect to the total weight of the composition, A) 5-15 wt% sulfuric acid, B) 3-20 wt% acetic acid, C) 1-5% by weight of hydrochloric acid, D) 0.1 to 3% by weight of an azole compound, and E) 57 ~ 90.9 wt% water Method for producing an array substrate for a liquid crystal display device comprising an etchant composition comprising a. The method of claim 1, wherein the azole compound is aminotetrazole, imidazole, indole, pyrazole, pyridine, pyrrole, benzotriazole, and the like. A method for manufacturing an array substrate for a liquid crystal display device, characterized in that at least one selected from the group comprising a water-soluble cyclic amine compound. The method according to claim 1 or 2, 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 device according to claim 1, wherein the liquid crystal display device is a thin film transistor (TFT). Regarding the total weight of the composition, A) 5-15 wt% sulfuric acid, B) 3-20 wt% acetic acid, C) 1-5% by weight of hydrochloric acid, D) 0.1 to 3% by weight of an azole compound, and E) 57 ~ 90.9 wt% water Etch liquid composition of the indium oxide film comprising a. The method of claim 5, wherein the azole compound is aminotetrazole, imidazole, indole, pyrazole, pyridine, pyrrole, benzotriazole, and the like. Etch liquid composition of the indium oxide film, characterized in that at least one selected from the group comprising a water-soluble cyclic amine compound (cyclic amine compound). The etchant composition of claim 5, wherein the water is deionized water. The etchant composition of claim 5, further comprising 0.001 to 0.01 wt% of the additive based on the total weight of the composition. The etchant composition of claim 8, wherein the additive is selected from at least one of a surfactant, a metal ion sequestrant or a corrosion inhibitor. The etching solution composition according to any one of claims 5 to 9, wherein the indium oxide film is an indium zinc oxide film (IZO) or an indium tin oxide film (ITO). I) forming an indium oxide film on the 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 5 to 9. The method of claim 11, wherein the photoreactive material is a photoresist material and is selectively left by an exposure and development process.

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