KR101264421B1 - Etchant for metal layer - Google Patents

Abstract

The present invention relates to a metal film etching solution, 1 to 15% by weight of nitric acid relative to the total weight of the composition; 0.1-10% by weight of halogen-based additives relative to the total weight of the composition; 75 to 98.9% by weight of water relative to the total weight of the composition.

When etching the metal film etching solution according to the present invention, when etching a single film or a multilayer film provided with at least one selected from the group consisting of indium oxide film, aluminum, aluminum alloy, molybdenum and molybdenum alloy, very good etching characteristics can be provided. . Furthermore, in the case of using the metal film etching solution according to the present invention when manufacturing the array substrate for a liquid crystal display device, even if the size of the substrate is large, it is possible to maintain the etching uniformity and to prevent staining.

Array substrate for liquid crystal display, metal film, etching, nitric acid, halogen based additive

Description

Metal Film Etching Solution {ETCHANT FOR METAL LAYER}

1A to 1F are views illustrating a manufacturing process of an array substrate for a liquid crystal display using a metal film etching solution according to the present invention;

2a and 2b is a scanning electron micrograph of the surface after etching the molybdenum single layer with a metal film etching solution according to the present invention,

3a and 3b is a scanning electron micrograph of the surface after etching the molybdenum / aluminum alloy double layer with a metal film etching solution according to the present invention,

4a and 4b is a scanning electron micrograph of the surface after etching the indium oxide film with a metal film etching solution according to the present invention,

5 and 6 are scanning electron micrographs of molybdenum monolayer and molybdenum / aluminum alloy double layer after treatment with an etching solution according to Comparative Example 2,

7 and 8 are scanning electron micrographs of molybdenum monolayer and molybdenum / aluminum alloy double membrane after treatment with an etching solution according to Comparative Example 3. FIG.

Description of the Related Art [0002]

10: substrate 20: metal layer

20a: gate electrode 30: gate insulating layer

40: active layer 41: omic contact layer

50 source electrode 51 drain electrode

60: insulating film 70: pixel electrode

The present invention relates to a metal film etching solution, and more particularly, to a metal film capable of etching a single film or a multilayer film formed of at least one selected from the group consisting of indium oxide film, aluminum, aluminum alloy, molybdenum and molybdenum alloy. It relates to an etching solution.

In general, the liquid crystal display includes a liquid crystal panel including a thin film transistor substrate, a color filter substrate, and a liquid crystal layer injected between the two substrates.

The liquid crystal layer is printed around the edges of the two substrates and bonded with a sealant to trap the liquid crystal layer. Since the liquid crystal panel is a non-light emitting device, a backlight unit is positioned on the rear surface of the thin film transistor substrate. The amount of light emitted from the backlight is controlled according to the arrangement of liquid crystal molecules.

Wiring is formed on the thin film transistor substrate to transmit a signal to the liquid crystal layer. The wiring of the thin film transistor substrate includes a gate wiring and a data wiring.

The gate line includes a gate line to which a gate signal is applied and a gate electrode of the thin film transistor. The data line is insulated from the gate line and the drain electrode and the source electrode forming the data electrode of the thin film transistor and the data line to which the data signal is applied. Include. Here, the signal coming through the drain electrode is directly transmitted to the liquid crystal side by the pixel electrode made of a transparent metal.

Such wiring may be made of a metal single layer or an alloy single layer, or may be formed in multiple layers to compensate for the disadvantages of each metal or alloy and to obtain desired physical properties.

Aluminum is commonly used to form wires. Pure aluminum has low corrosion resistance to chemicals and may cause wiring defects in subsequent processes. Metal layers For example, multiple layers in which metal layers such as molybdenum, chromium, tungsten, and tin are laminated may be used.

This multilayer deposited on the substrate material is patterned into the wiring via etching. Etching includes dry etching and wet etching, and uniform etching and high productivity wet etching are frequently used.

As an example of the etching solution used for such wet etching, a technique for etching a Mo / Al-Nd bilayer using an etching solution containing phosphoric acid, nitric acid, acetic acid and water is disclosed in Korean Patent No. 0330582 by the present applicant. It has been suggested.

Here, by specifically changing the composition ratio of phosphoric acid, nitric acid and acetic acid of the etching solution, it is possible to prevent the occurrence of a poor profile in which the upper molybdenum layer has a cross section protruding to the outside of the lower aluminum alloy layer, and further dry etching. It is possible to obtain a profile so good that this is not necessary.

However, as the size of the substrate on which the metal layer is deposited gradually increases in size, when the metal layer deposited on the large substrate is etched with the conventional etching solution, staining may occur due to a decrease in overall uniformity, and thus the present applicant is not suitable. To solve this problem, the company has developed a metal film etching solution with new properties.

Accordingly, an object of the present invention can provide very good etching characteristics when etching a metal film, and can maintain etch uniformity even when the size of a substrate is large in manufacturing an array substrate for a liquid crystal display device, and prevent staining. To provide an etching solution for the metal film.

The object is, according to the invention, 1 to 15% by weight of nitric acid, relative to the total weight of the composition; 0.1-10% by weight of halogen-based additives relative to the total weight of the composition; It is achieved by a metal film etching solution, characterized in that it comprises 75 to 98.9% by weight of water relative to the total weight of the composition.

Here, the halogen-based additive is HF, (NH ₄ ) F, (NH ₄ ) HF ₂ , KF, NaF, MgF ₂ , AlF ₃ , HCl, (NH ₄ ) Cl, KCl, NaCl, MgCl ₂ , FeCl ₃ , It is preferably selected from the group consisting of AlCl ₃ , HBr, (NH ₄ ) Br, KBr, NaBr, MgBr ₂ , AlBr ₃ , HI, (NH ₄ ) I, KI, NaI, MgI ₂ and AlI ₃ .

In addition, it may further include one or more of an etching control agent, a surfactant, a metal ion sequestrant, a corrosion inhibitor and a pH adjusting agent.

In addition, it is preferable to use for etching the gate electrode, the source electrode, the drain electrode and the pixel electrode of the TFT-LCD.

On the other hand, according to the present invention, (a) forming a metal layer on a substrate; (b) etching the metal layer to form a gate electrode; (c) forming a gate insulating layer on the gate electrode; (d) forming a semiconductor layer on the gate insulating layer; (e) forming source and drain electrodes on the semiconductor layer; (f) forming a pixel electrode on the source and drain electrodes, and in at least one of the steps (b), (e), and (f), etching with the metal film etching solution is performed. It is also achieved by a method for producing an array substrate for liquid crystal display devices.

In the step (b), the metal layer is preferably a single film or a multilayer film provided with at least one selected from the group consisting of aluminum, aluminum alloy, molybdenum and molybdenum alloy.

In the step (e), the source and the drain electrode may be formed by etching a single layer or a multilayer layer formed of at least one selected from aluminum, an aluminum alloy, molybdenum, and molybdenum alloy with the metal film etching solution.

In the step (f), the pixel electrode may be formed by etching an indium oxide film with the metal film etching solution.

Hereinafter, the present invention will be described in detail.

The metal film etching solution according to the present invention is a group consisting of an indium oxide film used for a pixel electrode of a TFT-LCD, a gate electrode, a source electrode and a drain electrode of a TFT-LCD, an aluminum alloy, molybdenum and molybdenum alloy. It is a solution for etching a single film or a multilayer film is provided with one or more selected from.

Here, a single film or a multilayer film formed of at least one selected from the group consisting of aluminum, aluminum alloy, molybdenum and molybdenum alloy may be varied in form, and may include a single film such as Al, Mo, Al-Nd, and Mo-W; Double membranes such as Mo / Al-Nd and Mo-W / Al; Triple films, such as Mo / Al / Mo, Mo / Al-Nd / Mo, and Mo-W / Al / Mo-W, etc. are mentioned.

And aluminum alloy or molybdenum alloy is an alloy form containing other metals such as Nd, W, Ti, Cr, Ta, Hf, Zr, Nb and V with aluminum or molybdenum as a main component; Nitride, silicide and carbide forms of molybdenum or aluminum; The aluminum alloy or molybdenum alloy may be in the form of nitrides, silicides, carbides and the like.

In addition, examples of the indium oxide film used to form the pixel electrode include an indium zinc oxide (hereinafter referred to as "IZO") film, an indium tin oxide (hereinafter referred to as "ITO") film, and the like. Can be.

Here, IZO is an oxide in which In ₂ O ₃ and ZnO are mixed in an appropriate ratio, and ITO is an oxide in which In ₂ O ₃ and SnO ₂ are mixed in an appropriate ratio, and in the case of ITO, crystalline and It is classified as amorphous.

Metal film etching solution according to the present invention for etching such a metal film is 1 to 15% by weight of nitric acid based on the total weight of the composition, 0.1 to 10% by weight of the halogen-based additives and the total weight of the composition 75 to 98.9 weight percent water. If necessary, a small amount of an etching regulator, a surfactant, a metal ion sequestrant, a corrosion inhibitor, a pH regulator, and the like may be added.

Nitric acid is a main oxidizing agent, if less than 1% by weight may not be enough etching due to the lack of etching power, if more than 15% by weight excess etching force may prevent the etched metal film to act as an electrode. .

Halogen-based additives are etching initiators and etching aids, which activate the surface of the metal film to be etched by the main oxidizing agent, and compensate for insufficient etching power during the etching process to prevent residues and poor profiles. It also plays a role.

Here, the halogen-based additive is of an inorganic halide, halogen elements F ^-, Cl ^-, Br ^- is preferably a compound containing a ^-, I.

For example, HF, (NH ₄ ) F, (NH ₄ ) HF ₂ , KF, NaF, MgF ₂ , AlF ₃ , HCl, (NH ₄ ) Cl, KCl, NaCl, MgCl ₂ , FeCl ₃ , AlCl ₃ , HBr , (NH ₄ ) Br, KBr, NaBr, MgBr ₂ , AlBr ₃ , HI, (NH ₄ ) I, KI, NaI, MgI ₂ , AlI ₃ , and the like. However, it is not limited thereto.

Although water is not specifically limited, Deionized water is preferable. More preferably, deionized water having a specific resistance value of the water (that is, the degree of removal of ions in the water) of 18 kW / ��� or more is used.

Hereinafter, Examples 1 to 8 according to the present invention will be described in detail. However, the present invention is not limited to the following examples.

Example  1 to 9

A molybdenum (Mo) single film, a Mo / Al-Nd double film, and an amorphous ITO single film substrate were prepared. An etchant containing nitric acid, KF and residual water in the composition ratio to the total weight of the total composition of Table 1 was prepared to be 180 kg. Etching solution prepared in a spray etching experiment equipment (manufactured by KDNS, model name: ETCHER (TFT)) was added to warm the temperature set to 40 ℃, the etching process was performed when the temperature reached 40 ± 0.5 ℃. O / E (Over Etch) was performed at 30% based on EPD (End Point Detection) of the pad part. After the substrate was inserted and spraying was started and the etching was completed, the substrate was taken out, washed with deionized water, dried using a hot air dryer, and removed using a photoresist stripper. After washing and drying, the etching profile was evaluated using a scanning electron microscope (SEM; manufactured by HITACHI, model name: S-4700) with an inclination angle, loss of side etching CD (critical dimension), etching residue, and the like. The results are shown in Table 1.

<Table 1>

Example Composition (% by weight)
(Nitric acid / KF / water) Mo Mo / Al-Nd Amorphous ITO One 5 / 0.1 / 94.9 △ △ ○ 2 5 / 0.5 / 94.5 △ △ ◎ 3 5/1 / 94.0 ○ ○ ○ 4 10 / 0.1 / 89.9 ○ ○ ○ 5 10 / 0.5 / 89.5 ◎ ○ ◎ 6 10/1 / 89.0 ○ ○ ○ 7 15 / 0.1 / 84.9 ○ ◎ ○ 8 15 / 0.5 / 84.5 ◎ ◎ ◎ 9 15/1 / 84.0 ○ ○ ○ * ◎: Excellent / ○: Good / △: Normal / X: Poor

As can be seen from Table 1, when the etching using the metal film etching solution according to Examples 1 to 9 of the present invention, it can be confirmed that it provides a good etching characteristics.

After etching the molybdenum monolayer with the metal film etching solution according to the present invention, scanning electron micrographs (see FIGS. 2A and 2B) of the surface and the molybdenum / aluminum alloy double layer were etched with the metal film etching solution according to the present invention. After scanning electron micrographs (see FIGS. 3a and 3b) of the surface, and the indium oxide film was etched with the metal film etching solution according to the present invention, it can also be confirmed by scanning electron micrographs (see FIGS. 4a and 4b). have. That is, as a result of observing the center and the end of the molybdenum monolayer, the center and the end of the molybdenum / aluminum alloy double layer, and the center and the end of the indium oxide film, the etching profile was uniform, as shown in FIGS. 2A to 4B. Can be.

In addition, the conventional etching solution composed of a compound of phosphoric acid, nitric acid, acetic acid has a high viscosity due to the high phosphoric acid content, which causes a significant drop in fluidity of the etching solution. Unlike a phenomenon in which a part gathers in a part, the metal film etching solution according to the present invention does not contain phosphoric acid and has a low viscosity so that the liquidity of the etching solution is good, and thus, there is an advantage that it can be spread evenly throughout the substrate. Etch uniformity can be maintained and stain generation due to etching nonuniformity can be prevented.

Meanwhile, Table 2 shows the etching results of Comparative Examples 1 to 3 compared to Examples 1 to 9 according to the present invention. Herein, Comparative Examples 1 to 3 were subjected to the etching process in the same manner as in Examples 1 to 9.

 <Table 2>

Comparative example Composition (% by weight)
(Nitric acid / KF / water) Mo Mo / Al-Nd Amorphous
ITO One 5 / 0.05 / 94.95 Not etched Not etched △ 2 20 / 0.1 / 79.9 X X ○ 3 25 / 0.1 / 74.9 X X ○

As such, it can be seen from Table 2 that the etching solutions according to Comparative Examples 1 to 3 cannot be sufficiently etched. Molybdenum after etching with a molybdenum monolayer after etching with an etching solution according to Comparative Example 2, a scanning electron micrograph (see FIGS. 5 and 6) of the molybdenum / aluminum alloy double layer and the etching solution according to Comparative Example 3 Scanning electron micrographs (see FIGS. 7 and 8) of the monolayer and the molybdenum / aluminum alloy bilayer can also be confirmed. As shown in FIGS. 5 and 7, the molybdenum single layer has a dirty etching surface and does not maintain a straight line. As shown in FIGS. 6 and 8, the molybdenum / aluminum alloy double layer has an upper molybdenum etch and the molybdenum layer and the aluminum alloy layer. It can be seen that the step is severely shown.

Meanwhile, the manufacturing process of an array substrate for a liquid crystal display device using the metal film etching solution according to the present invention will be described.

According to an aspect of the present invention, there is provided a method of manufacturing an array substrate for a liquid crystal display device using a metal film etching solution, the method including: (a) forming a metal layer on a substrate; (b) etching the metal layer to form a gate electrode; (c) forming a gate insulating layer on the gate electrode; (d) forming a semiconductor layer on the gate insulating layer; (e) forming source and drain electrodes on the semiconductor layer; (f) forming a pixel electrode on the source and drain electrodes.

Referring to Figures 1a to 1f, it will be described in detail as follows.

As shown in FIG. 1A, the metal layer 20 is deposited on the substrate 10 by sputtering, and then etched with a metal film etching solution according to the present invention. As shown in FIG. 1B, the gate electrode 20a is removed. Form. Here, the metal layer 20 to be deposited on the substrate 10 is preferably provided with a single film or a multilayer film provided with at least one selected from the group consisting of aluminum, aluminum alloy, molybdenum and molybdenum alloy, in the present embodiment Although sputtering was used as a method of forming the 20 on the substrate 10, the present invention is not limited thereto.

As shown in FIG. 1C, a gate insulating layer 30 is formed by depositing silicon nitride (SiN _X ) on the gate electrode 20a formed on the substrate 10. Here, the gate insulating layer 30 is formed of silicon nitride (SiN _x ), but is not limited thereto. The gate insulating layer 30 may be formed using a material selected from various inorganic insulating materials including silicon oxide (SiO ₂ ). Can be formed.

The semiconductor layers 40 and 41 are formed on the gate insulating layer 30 by using chemical vapor deposition (CVD). That is, after the active layer 40 and the ohmic contact layer 41 are formed sequentially, a pattern is formed as shown in FIG. 1D through dry etching.

Here, the active layer 40 is generally formed of pure amorphous silicon (a-Si: H), and the ohmic contact layer 41 is formed of amorphous silicon (n ⁺ a-Si: H) containing impurities. When the active layer 40 and the ohmic contact layer 41 are formed, the chemical vapor deposition (CVD) method is described, but the present invention is not limited thereto.

Then, a metal layer is deposited on the ohmic contact layer 41 by sputtering and etched with a metal film etching solution according to the present invention to form a source electrode 50 and a drain electrode 51 as shown in FIG. 1E. . Here, the metal layer is preferably provided with a single film or a multilayer film provided with at least one selected from the group consisting of aluminum, aluminum alloy, molybdenum and molybdenum alloy.

Inorganic insulating group or benzocyclobutene (BCB) and acrylic containing silicon nitride (SiN _x ) and silicon oxide (SiO ₂ ) on the entire surface of the substrate 10 on which the source electrode 50 and the drain electrode 51 are formed. After the insulating film 60 is formed from a group of organic insulating materials including a resin, a single layer or a double layer, an indium oxide film [ITO (indium) is formed through a sputtering method on the entire surface of the substrate 10 on which the insulating film 60 is formed. tin oxide), an indium zinc oxide (IZO)], and the like, are deposited and etched with a metal film etching solution according to the present invention to form a pixel electrode 70, as shown in FIG. 1F.

As described above, in the method of manufacturing an array substrate for a liquid crystal display device, when the metal film etching solution according to the present invention is used, the etching uniformity can be maintained even when the size of the substrate 10 is large, so that staining can be prevented. do.

As described above, in the case of etching a single film or a multilayer film formed of at least one selected from the group consisting of indium oxide film, aluminum, aluminum alloy, molybdenum and molybdenum alloy, the metal film etching solution according to the present invention has very good etching characteristics. Can be provided. Furthermore, in the case of using the metal film etching solution according to the present invention when manufacturing the array substrate for a liquid crystal display device, even if the size of the substrate is large, it is possible to maintain the etching uniformity and to prevent staining.

Claims (11)

delete delete delete delete (a) forming a metal layer on the substrate; (b) etching the metal layer to form a gate electrode; (c) forming a gate insulating layer on the gate electrode; (d) forming a semiconductor layer on the gate insulating layer; (e) forming source and drain electrodes on the semiconductor layer; (f) forming a pixel electrode on the source and drain electrodes, The forming of the gate electrode of step (b) may include 1 to 15% by weight of the metal layer of the single layer or the multilayer layer formed of at least one selected from the group consisting of aluminum, aluminum alloy, molybdenum and molybdenum alloy. Nitric acid; 0.1-10% by weight of halogen-based additives relative to the total weight of the composition; It is formed by etching with a metal film etching solution, characterized in that it comprises 75 to 98.9% by weight of water relative to the total weight of the composition, Forming the source and drain electrodes of the step (e) comprises a single film or a multilayer film made of at least one selected from aluminum, aluminum alloy, molybdenum and molybdenum alloy with 1 to 15% by weight of nitric acid, based on the total weight of the composition; ; 0.1-10% by weight of halogen-based additives relative to the total weight of the composition; It is formed by etching with a metal film etching solution, characterized in that it comprises 75 to 98.9% by weight of water relative to the total weight of the composition, Forming the pixel electrode of the step (f) comprises the indium oxide film of 1 to 15% by weight of nitric acid based on the total weight of the composition; 0.1-10% by weight of halogen-based additives relative to the total weight of the composition; A method of manufacturing an array substrate for a liquid crystal display device, characterized in that formed by etching with a metal film etching solution, characterized in that it comprises 75 to 98.9% by weight of water relative to the total weight of the composition. delete delete delete The method of claim 5, The halogen-based additive is HF, (NH ₄ ) F, (NH ₄ ) HF ₂ , KF, NaF, MgF ₂ , AlF ₃ , HCl, (NH ₄ ) Cl, KCl, NaCl, MgCl ₂ , FeCl ₃ , AlCl ₃ , HBr, (NH ₄ ) Br, KBr, NaBr, MgBr ₂ , AlBr ₃ , HI, (NH ₄ ) I, KI, NaI, MgI ₂ and AlI ₃ for a liquid crystal display device Method of manufacturing an array substrate. The method of claim 5, The metal film etching solution further comprises at least one of an etch control agent, a surfactant, a metal ion blocking agent, a corrosion inhibitor and a pH control agent. 11. The method according to claim 9 or 10, The metal film etching solution is used to etch a multi-layered or single metal film for forming a gate electrode, a source electrode, a drain electrode, and a pixel electrode of a TFT-LCD.

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