KR102384564B1 - Composition for Etching Indium Oxide Layer and Molybdenum Layer - Google Patents

Abstract

The present invention provides an etching composition for an indium oxide film, a molybdenum film, or a multilayer film of an indium oxide film and a molybdenum film, comprising nitric acid, a cyclic amine compound, a fluorine-containing compound, and an organic acid, wherein the organic acid is 0.1 to 5.0 weight by weight based on the total weight of the composition It provides an etching composition included in an amount of %. The etching composition according to the present invention has excellent etching performance for an indium oxide film and a molybdenum film used as a pixel electrode of an array substrate for a liquid crystal display, can minimize damage to the lower metal, and prevents the generation of an upper tip during multilayer etching can be suppressed, and the driving characteristics of the liquid crystal display device can be improved.

Description

Etching composition for indium oxide film and molybdenum film {Composition for Etching Indium Oxide Layer and Molybdenum Layer}

The present invention relates to an etching composition for an indium oxide film and a molybdenum film, and more particularly, has excellent etching performance for an indium oxide film and a molybdenum-based metal film, can minimize damage to the lower metal, and generates an upper tip during multilayer etching It relates to an etching composition capable of suppressing the

In general, a display panel includes a display substrate on which a thin film transistor is formed as a switching element for driving a pixel. The display substrate includes a plurality of metal patterns, and the metal patterns are mainly formed through a photolithography method. In the photolithography method, a photoresist film is formed on a metal film to be etched on a substrate, the photoresist film is exposed and developed to form a photoresist pattern, and then the photoresist pattern is used as an anti-etching film and an etchant is used. It is a process capable of patterning the metal layer by etching the metal layer.

A transparent conductive film made of a material having transparent optical properties and high electrical conductivity is used for the pixel electrode of the array substrate for a liquid crystal display, and the transparent conductive film is mainly made of indium zinc oxide (IZO) or indium tin oxide (ITO). of indium oxide is used.

As the etching solution for the indium oxide layer, a mixed aqueous solution of hydrochloric acid and nitric acid (aqua regia, HCl+CH ₃ COOH+HNO ₃ ), an aqueous solution of ferric hydrochloride (FeCl ₃ /HCl), an aqueous oxalic acid solution, etc. has been used (refer to Korean Patent Publication No. 10-2010-0053175).

Among them, the hydrochloric acid-based etchant is inexpensive, but the side surface of the pattern is etched faster, so that the profile is poor, and a chemical attack may occur to the underlying metal. In addition, the oxalic acid aqueous solution tends to generate residues around the pattern of the indium oxide layer, and the solubility of oxalic acid is low at low temperature, so that precipitates are generated, which may cause failure of the etching equipment.

In addition to the indium oxide film, a molybdenum-based metal film may be used as a multilayer film with the indium oxide film for the pixel electrode. However, when such a multilayer film is used, there is a problem in that an upper tip occurs during etching.

Therefore, in the etching process for forming the pixel electrode, the indium oxide film and the molybdenum-based metal film can be efficiently etched, and the development of an etching composition capable of suppressing the generation of the upper tip during multilayer etching while minimizing the chemical attack of the lower metal continues. is requested as

Republic of Korea Patent Publication No. 10-2010-0053175

The present invention is to solve the above problems, and one object of the present invention is to have excellent etching performance for an indium oxide film and a molybdenum-based metal film, to minimize damage to the lower metal, and to etch the upper tip of the multilayer film. To provide an etching composition capable of suppressing generation.

Another object of the present invention is to provide a pixel electrode formed using the etching composition.

Another object of the present invention is to provide an array substrate for a liquid crystal display including the pixel electrode.

On the other hand, the present invention provides an etching composition for an indium oxide film, a molybdenum film, or a multilayer film of an indium oxide film and a molybdenum film, comprising nitric acid, a cyclic amine compound, a fluorine-containing compound, and an organic acid, wherein the organic acid is 0.1 based on the total weight of the composition To provide an etching composition included in an amount of 5.0% by weight.

In one embodiment of the present invention, the organic acid may be tartaric acid.

In one embodiment of the present invention, the indium oxide film is formed of indium zinc oxide (IZO), indium tin oxide (ITO) or a mixture thereof, and the molybdenum film is molybdenum, or molybdenum and titanium (Ti), tantalum (Ta) , may be formed of an alloy of one or more metals selected from the group consisting of chromium (Cr), nickel (Ni) and neodymium (Nd).

In one embodiment of the present invention, the etching composition comprises 3 to 30% by weight of nitric acid, 0.1 to 10% by weight of a cyclic amine compound, 0.01 to 5.0% by weight of a fluorine-containing compound, and 0.1 to 5.0% by weight of an organic acid based on the total weight of the composition and may include the remaining amount of water so that the total weight of the composition is 100% by weight.

On the other hand, the present invention provides a pixel electrode formed by using the etching composition.

On the other hand, the present invention provides an array substrate for a liquid crystal display including the pixel electrode.

The etching composition according to the present invention has excellent etching performance for an indium oxide film and a molybdenum film used as a pixel electrode of an array substrate for a liquid crystal display, can minimize damage to the lower metal, and prevents the generation of an upper tip during multilayer etching can be suppressed, and the driving characteristics of the liquid crystal display device can be improved.

Hereinafter, the present invention will be described in more detail.

One embodiment of the present invention is an etching composition for an indium oxide film, a molybdenum film, or a multilayer film of an indium oxide film and a molybdenum film, comprising nitric acid (A), a cyclic amine compound (B), a fluorine-containing compound (C) and an organic acid (D) Including, wherein the organic acid relates to an etching composition included in an amount of 0.1 to 5.0% by weight based on the total weight of the composition.

In one embodiment of the present invention, the indium oxide layer includes indium oxide as a component of the layer, and the indium oxide may be indium zinc oxide (IZO), indium tin oxide (ITO), or a mixture thereof.

The molybdenum film includes not only a molybdenum metal film, but also an alloy film of molybdenum and one or more metals selected from the group consisting of titanium (Ti), tantalum (Ta), chromium (Cr), nickel (Ni), and neodymium (Nd). .

In particular, the etchant composition of the present invention may be applied to a multilayer film in which a molybdenum film is laminated on an indium oxide film.

The thickness of the indium oxide layer may be in the range of 50 to 500 Å, and the thickness of the molybdenum layer may be in the range of 50 to 500 Å.

Hereinafter, components of the etching composition according to an embodiment of the present invention will be described in more detail.

Nitric acid (A)

In one embodiment of the present invention, the nitric acid (A) is a main oxidizing agent that exhibits excellent etching performance for an indium oxide film and a molybdenum film, and the etching rate for these films is fast, so a large side etch required for manufacturing a pixel electrode; For example, a side etch of 0.3 μm or more can be secured.

The silver nitrate may be included in an amount of 3 to 30% by weight, preferably 5 to 20% by weight, based on the total weight of the composition. If the content of nitric acid is less than 3 wt%, the etching rate of the film may be slowed, and if it exceeds 30 wt%, chemical attack may occur on the underlying and adjacent metals, and process control may be difficult due to the excessive etching rate It can be difficult.

Cyclic amine compound (B)

In one embodiment of the present invention, the cyclic amine compound (B) serves to minimize chemical attack on the copper wiring coming into contact with the pixel electrode.

Examples of the cyclic amine compound include triazole, benzotriazole, tetrazole, imidazole, indole, purine, pyrazole, pyridine ( At least one selected from the group consisting of pyridine), pyrimidine, pyrrole, pyrrolidine and pyrroline may be used, and specifically benzotriazole may be used.

The cyclic amine compound may be included in an amount of 0.1 to 10% by weight, preferably 0.5 to 2.0% by weight, based on the total weight of the composition. If the content of the cyclic amine compound is less than 0.1% by weight, attack on the copper wiring may occur, and if it exceeds 10% by weight, the attack prevention effect on the copper wiring is excellent, but the etching rate of the indium oxide film and the molybdenum film may be reduced there is.

Fluorine-containing compound (C)

In one embodiment of the present invention, the fluorine-containing compound (C) is a compound that dissociates in water to generate fluorine ions, and serves to remove residues during etching of the indium oxide layer and the molybdenum layer.

The fluorine-containing compound is not particularly limited as long as it can generate fluorine ions or polyatomic fluorine ions in solution. Specifically, the fluorine-containing compound is ammonium fluoride (NH ₄ F), sodium fluoride (NaF), potassium fluoride (KF), ammonium bifluoride (NH ₄ F HF) , sodium bifluoride (NaF HF) and potassium bifluoride (potassium bifluoride: KF HF) may be at least one selected from the group consisting of, among them, ammonium bifluoride (ammonium bifluoride: NH ₄ F HF) This is preferable.

The fluorine-containing compound may be included in an amount of 0.01 to 5.0 wt%, preferably 0.05 to 2.0 wt%, based on the total weight of the composition. If the content of the fluorine-containing compound is less than 0.01% by weight, residues may be generated during the etching of the indium oxide film and the molybdenum film, and if it exceeds 5.0% by weight, etching damage to the underlying glass substrate and silicon layer may occur. can

organic acid (D)

In one embodiment of the present invention, the organic acid may suppress the generation of an upper tip during multilayer etching of the indium oxide film and the molybdenum film.

The organic acid (D) may be tartaric acid.

The organic acid may be included in an amount of 0.1 to 5.0 wt%, preferably 0.3 to 3.0 wt%, based on the total weight of the composition. If the content of the tartaric acid is less than 0.1% by weight, an upper tip may be generated and an etch profile may be deteriorated, and if it exceeds 5.0% by weight, erosion may occur due to excessive etching of the upper layer.

In addition, the etching composition according to an embodiment of the present invention may include a remaining amount of water such that the total weight of the composition is 100% by weight. In the present invention, the water is not particularly limited, but deionized water is preferable, and deionized water having a specific resistance value of 18 MΩ cm or more showing the degree of removal of ions in the water is more preferable.

The etching composition according to an embodiment of the present invention may further include, in addition to the above components, additives commonly used in the art, for example, a sequestering agent, a corrosion inhibitor, and the like.

One embodiment of the present invention relates to a pixel electrode formed using the above-described etching composition.

A pixel electrode according to an embodiment of the present invention includes the steps of forming an indium oxide layer on a substrate by an etching process commonly known in the art, for example, sputtering on a substrate using the above-described etching composition; patterning after forming a photoresist film on the indium oxide film; and etching the indium oxide layer using the above-described etching composition.

One embodiment of the present invention relates to an array substrate for a liquid crystal display including the pixel electrode described above. For example, the array substrate for a liquid crystal display of the present invention may be a thin film transistor array substrate.

An array substrate for a liquid crystal display according to an embodiment of the present invention includes a typical process in the art, for example, a) forming a gate electrode on the substrate; b) forming a gate insulating layer on the substrate including the gate electrode; c) forming a semiconductor layer (n+a-Si:H and a-Si:G) on the gate insulating layer; d) forming source/drain electrodes on the semiconductor layer; and e) forming a pixel electrode connected to the drain electrode, in step e), forming an indium oxide film, a molybdenum film, or a multilayer film of an indium oxide film and a molybdenum film, and etching the film with the above-described etching composition to form a pixel electrode.

Hereinafter, the present invention will be described in more detail by way of Examples, Comparative Examples and Experimental Examples. These Examples, Comparative Examples, and Experimental Examples are only for illustrating the present invention, and it is apparent to those skilled in the art that the scope of the present invention is not limited thereto.

Example 1 to 3 and comparative example 1 to 4:

As shown in Table 1 below, each component was mixed to prepare 180 kg of an etching composition (unit: wt %).

nitric acid Cyclic Amine Compounds
(benzotriazole) Fluorine-containing compounds
(ammonium bifluoride) tartaric acid water Example One 8 1.0 0.1 1.0 remaining amount 2 15 1.5 0.1 2.0 remaining amount 3 10 0.7 1.0 2.5 remaining amount comparative example One 15 1.5 0.1 - remaining amount 2 10 0.7 1.0 - remaining amount 3 10 0.7 1.0 0.05 remaining amount 4 10 0.7 1.0 7 remaining amount

Experimental example One:

In order to evaluate the etching performance of the prepared etching composition, an indium tin oxide film (ITO) 400 Å as a lower film and a molybdenum-titanium (Mo-Ti) alloy film 100 Å as an upper film were sequentially formed on a glass substrate (100 mm × 100 mm). Then, a photolithography process was performed to form a pattern.

At this time, the etching process was carried out using experimental equipment (ETCHER (TFT), SEMES, Inc.) of a spray-type etching method, and the temperature of the etching composition during the etching process was about 35°C. The etching time was carried out for about 50 to 100 seconds.

After etching, the etched cross section of the Mo-Ti/ITO metal film was observed using SEM (S-4700, Hitachi Corporation). As a side etch, the distance (㎛) between the end of the photoresist and the end of the metal in the pattern formed after etching was measured. In addition, the presence or absence of the ITO residue, the occurrence of the upper Mo-Ti tip, and the chemical attack on the lower metal copper wiring were observed, and the results are shown in Table 2 below.

side etch (μm) residue Upper Mo-Ti tip Bottom metal (Cu) attack Example One 0.35 X doesn't exist doesn't exist 2 0.45 X doesn't exist doesn't exist 3 0.42 X doesn't exist doesn't exist comparative example One 0.37 X upper tip occurrence doesn't exist 2 0.40 X upper tip occurrence doesn't exist 3 0.35 X upper tip occurrence doesn't exist 4 0.42 X upper over-etched doesn't exist

As can be seen in Table 2, the etching compositions of Examples 1 to 3 according to the present invention did not generate a residue after etching as they contained tartaric acid as an organic acid in a predetermined amount, and the tip was formed in the upper layer of Mo-Ti. Not only did it not occur, there was also no chemical attack on the underlying metal. On the other hand, in Comparative Examples 1 to 4 in which tartaric acid was not used, or a small amount or an excessive amount was used, an upper tip was generated or the upper layer was etched excessively.

As the specific part of the present invention has been described in detail above, for those of ordinary skill in the art to which the present invention pertains, it is clear that these specific techniques are only preferred embodiments, and the scope of the present invention is not limited thereto. Do. Those of ordinary skill in the art to which the present invention pertains will be able to make various applications and modifications within the scope of the present invention based on the above contents.

Accordingly, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Claims (6)

As an etching composition for a multilayer film of an indium oxide film and a molybdenum film,
3 to 30% by weight of nitric acid, 0.1 to 10% by weight of a cyclic amine compound, 0.01 to 5.0% by weight of a fluorine-containing compound, and 0.1 to 5.0% by weight of tartaric acid, based on the total weight of the composition, wherein the total weight of the composition is 100% by weight An etching composition comprising a remaining amount of water as possible. delete According to claim 1, wherein the indium oxide film is formed of indium zinc oxide (IZO), indium tin oxide (ITO) or a mixture thereof, the molybdenum film is molybdenum, or molybdenum and titanium (Ti), tantalum (Ta), chromium (Cr), an etching composition formed of an alloy of one or more metals selected from the group consisting of nickel (Ni) and neodymium (Nd). delete A pixel electrode formed using the etching composition according to claim 1 or 3. An array substrate for a liquid crystal display comprising the pixel electrode according to claim 5 .