KR102707568B1 - Etching solution composition, etching method using thereof and preparing method of an array substrate for display using the same - Google Patents

Abstract

The present invention, to achieve the above object, provides a multilayer etchant composition comprising A) about 0.5 wt% to about 20.0 wt% of a persulfate; B) about 0.01 wt% to about 2.0 wt% of a fluorine compound; C) about 5.0 wt% to about 15.0 wt% of an inorganic acid; D) about 10.0 wt% to about 30.0 wt% of an organic acid; E) about 0.1 wt% to about 10.0 wt% of an organic acid; F) about 0.1 wt% to about 5.0 wt% of a cyclic amine compound; G) about 0.1 wt% to about 6.0 wt% of sulfamic acid; H) about 0.1 wt% to about 5.0 wt% of glycine; and I) a residual amount of water, an etching method using the same, and a method for manufacturing an array substrate for a display device using the same.

Description

{Etching solution composition, etching method using the same and preparing method of an array substrate for display using the same}

The present invention relates to a multilayer etchant composition, an etching method using the same, and a method for manufacturing an array substrate for a display device using the same.

Liquid crystal display devices (LCD devices) are receiving the most attention among flat panel display devices because they provide clear images with excellent resolution, consume less electricity, and allow for thinner display screens. Today, the representative electronic circuit that drives display elements used in these liquid crystal displays is the thin film transistor (TFT) circuit, and a typical thin film transistor liquid crystal display (TFT-LCD) element forms a pixel of the display screen. The TFT, which functions as a switching element in the TFT-LCD element, is manufactured by filling a liquid crystal material between the TFT substrate arranged in a matrix form and the color filter substrate facing the substrate. The entire TFT-LCD manufacturing process is largely divided into the TFT substrate manufacturing process, color filter process, cell process, and module process, and the importance of the TFT substrate and color filter manufacturing processes is very great in displaying accurate and clear images.

In order to implement the desired electric circuit lines on the pixel display electrodes, an etching process is required to cut away the thin film layer according to the circuit pattern.

However, although existing etchant compositions can mainly etch simultaneously double films formed by depositing main wiring on a barrier film, it is not easy to etch simultaneously various types of metals and wirings deposited in more layers through a wet etching process. Specifically, in the case of a quadruple film, the same etching amount must be maintained for all four films, but since the etching rates of each film corresponding to the quadruple film are all different, a problem occurs in which etching is not uniformly performed due to the different etching rates for each film.

Meanwhile, Korean Patent Publication No. 10-2015-0089887 discloses an etchant composition that uses persulfate instead of hydrogen peroxide as a primary oxidizing agent to etch a double layer of titanium and copper. However, when a wet etching process is performed on a multilayered wiring having three or more layers using the composition of the above-mentioned patent, there is a problem that the batch etching effect is reduced. To solve this problem, there is a need for an improved etchant composition that can etch multiple layers.

Republic of Korea Publication Patent No. 10-2015-0089887

The present invention provides an etchant capable of etching wires made of various metal types and multi-films at once with a single chemical solution for future multifunctionality, such as a multi-film including an indium oxide film used as a pixel electrode of an array substrate for a display device, thereby reducing the overall process time and cost, thereby improving the operating characteristics of a thin film transistor-display element, an etching method using the same, and a method for manufacturing an array substrate for a display device using the same.

The present invention, to achieve the above object, comprises: A) about 0.5 wt% to about 20.0 wt% of a persulfate; B) about 0.01 wt% to about 2.0 wt% of a fluorine compound; C) about 5.0 wt% to about 15.0 wt% of an inorganic acid; D) about 10.0 wt% to about 30.0 wt% of an organic acid; E) about 0.1 wt% to 10.0 wt% of an organic acid; F) about 0.1 wt% to about 5.0 wt% of a cyclic amine compound;

A multilayer etchant composition is provided, comprising: G) about 0.1 wt % to about 6.0 wt % of sulfamic acid; H) about 0.1 wt % to about 5.0 wt % of glycine; and I) a balance of water.

The present invention provides a multilayer etching method comprising the steps of: (1) forming a multilayer on a substrate; (2) selectively leaving a photoreactive material on the multilayer; and (3) etching the multilayer using an etchant composition according to any one of claims 1 to 9.

The present invention provides a method for manufacturing an array substrate for a display device, comprising: (1) a step of forming a gate wiring on a substrate; (2) a step of forming a gate insulating layer on a substrate including the gate wiring; (3) a step of forming an oxide semiconductor layer on the gate insulating layer; (4) a step of forming source and drain electrodes on the oxide semiconductor layer; and (5) a step of forming a pixel electrode connected to the drain electrode, wherein step (5) includes a step of forming a multilayer and etching the multilayer with an etchant composition to form a pixel electrode, and the method for manufacturing an array substrate for a display device is characterized in that the multilayer etchant composition of the present invention described above is provided.

The present invention aims to provide an etchant composition for multi-layers that can collectively etch wires made of various metal types and multi-layers for future multifunctionality, without the aid of other processes or other etchants, by using only the etchant composition of the present invention, thereby reducing the overall process time and cost.

The present invention enables the etching of not only double films or triple films composed of titanium/copper or titanium/copper/titanium, but also quadruple films composed of titanium/indium oxide/aluminum/indium oxide, using only the etching composition of the present invention without the aid of other processes or other etchants.

Figure 1 is a drawing related to the results of a multi-layer etching experiment.

The present invention relates to an etchant composition for a multilayer film and an etching method using the same, and when the composition contains A) persulfate, B) fluorine compound, C) inorganic acid, D) organic acid, E) organic acid, F) cyclic amine compound, G) sulfamic acid, and H) glycine, the multilayer film can be etched at once in a wet manner, thereby shortening the time for the entire process and maximizing efficiency, and also reducing the cost, thereby improving the operating characteristics of a thin film transistor-display element, an etching method using the same, and a method for manufacturing an array substrate for a display device using the same.

The multilayer of the present invention means a multilayer of three or more layers, and may be a triple layer, a quadruple layer, a quintuple layer, or a sextuplet layer. Preferably, the multilayer may be a quadruple layer, and more specifically, may include at least one layer including at least one of titanium, indium oxide, and silver. An example of the multilayer of the present invention may include a quadruple layer composed of titanium/indium oxide/silver/indium oxide, but is not limited thereto.

The indium oxide film of the present invention may include, but is not limited to, indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), or indium gallium zinc oxide (IGZO).

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

A) Persulfate

The persulfate of the present invention acts as an oxidizing agent for the metal film.

The persulfate of the present invention may be contained in an amount of about 0.5 wt% to about 20.0 wt% based on the total weight of the composition, and preferably 5.0 wt% to 12.0 wt%. If the persulfate is contained in an amount less than the above range, the etching rate may decrease and sufficient etching may not be achieved. If the persulfate is contained in an amount greater than the above range, the etching rate may be too fast, making it difficult to control the degree of etching, and thus the metal film may be overetched.

The above persulfate may include, but is not limited to, one or more selected from the group consisting of potassium persulfate (K ₂ S ₂ O ₈ ), sodium persulfate (Na ₂ S ₂ O ₈ ), and/or ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ).

B) Fluorine compounds

The above fluorine compound etches the titanium film, etc. included in the multilayer film and removes residues that may be generated by the etching.

The above fluorine compound may be contained in an amount of about 0.01 wt% to about 2.0 wt% based on the total weight of the etchant composition, and preferably 0.1 wt% to 1.0 wt%. If the content of the fluorine compound is lower than the above range, etching of titanium is difficult and the frequency of residue generation increases, and if it is higher than the above range, damage may occur to the laminated glass substrate.

The above fluorine compound may include, but is not limited to, at least one selected from the group consisting of ammonium fluoride, sodium fluoride, potassium fluoride, ammonium bifluoride, sodium bifluoride, and/or potassium bifluoride.

C) Weapon Mountain

The above inorganic acid is an auxiliary oxidizing agent. The etching rate can be controlled depending on the content of the above inorganic acid in the above etching composition. The above inorganic acid can react with Ag ions in the above etching composition, thereby preventing an increase in the Ag ions and a decrease in the etching rate.

The above-mentioned inorganic acid is contained in an amount of about 5.0 wt% to about 15.0 wt%, and preferably about 10.0 to 15.0 wt%, based on the total weight of the above-mentioned etching composition. If the content of the above-mentioned inorganic acid is lower than the above range, the etching rate decreases and a sufficient etching speed cannot be reached, and if it is higher than the above range, cracks may occur in the photosensitive film used when etching a metal film or the photosensitive film may be peeled off. If the cracks occur in the photosensitive film or the photosensitive film is peeled off, the indium oxide film or Ag film located below the photosensitive film is excessively etched.

The above inorganic acid may include at least one selected from the group consisting of nitric acid, sulfuric acid, and/or perchloric acid, but is not limited thereto.

D) Organic acid

The organic acid increases the etching speed of all metal films as its content in the etchant increases. In the case of the organic acid, it may be contained in an amount of about 10.0 to about 30.0 wt% based on the total weight of the etchant composition, and is preferably contained in an amount of about 15.0 to about 30.0 wt%. If the content of the organic acid is lower than the above range, the etching speed decreases, and if the content of the organic acid is higher than the above range, the etching speed increases and the Taper Angle becomes higher than intended, which causes a problem.

The organic acid may include at least one selected from the group consisting of tartaric acid, acetic acid, butanoic acid, citric acid, formic acid, gluconic acid, glycolic acid, malonic acid, pentanoic acid, and/or oxalic acid, but is not limited thereto.

E) Organic acid salt

The organic acid salt lowers the etching rate as the content in the etchant increases. In particular, it acts as a chelate to form a complex with the metal ion in the etchant composition, thereby controlling the etching rate of the metal. The organic acid salt is contained in an amount of about 0.1 wt% to 10.0 wt%, and preferably 0.5 wt% to 5.0 wt%, based on the total weight of the etchant composition. If the content of the organic acid salt is lower than the above range, it is difficult to control the etching rate of copper, which may cause overetching, and if it is higher than the above range, the etching rate of copper decreases, which increases the etching time in the process. Accordingly, the number of substrates to be processed decreases.

The above organic acid salt is preferably selected from the group consisting of potassium salts, sodium salts and ammonium salts of an organic acid selected from the group consisting of tartaric acid, acetic acid, butanoic acid, citric acid, formic acid, gluconic acid, glycolic acid, malonic acid, pentanoic acid and/or oxalic acid, and is more preferably, but not limited to, one or more of potassium acetate, sodium acetate and ammonium acetate.

F) Ring type Amin Compound

A cyclic amine compound can be used as a corrosion inhibitor. The cyclic amine compound is contained in an amount of about 0.1 wt% to about 5.0 wt% based on the total weight of the etchant composition, and preferably 0.3 wt% to 3.0 wt%. If the content of the cyclic amine compound is lower than the above range, the etching rate of the metal film increases, which may result in a risk of overetching, and if it is higher than the above range, the etching rate of the metal film decreases, which may result in failure to achieve a desired degree of etching.

The cyclic amine compound may include, for example, aminotetrazole, imidazole, indole, purine, pyrazole, pyridine, pyrimidine, pyrrole, pyrrolidine and/or pyrroline. Alternatively, the cyclic amine compound may include a mixture of two or more of these.

G) Sulphamic acid ( Sulfamic acid)

Sulfamic acid functions as an additive for preventing change over time, and in particular, it functions to maintain the initially intended Taper Angle. The sulfamic acid is contained in an amount of about 0.1 wt% to about 6.0 wt% based on the total weight of the etchant composition, and preferably 1.0 wt% to 5.0 wt%. If the content of the sulfamic acid is lower than about the above range, it fails to function to maintain the etching shape, so the replacement cycle of the etchant becomes short, and if it is higher than the above range, the etching speed becomes too fast, which results in many restrictions in the process.

H) Glycine ( Glycine )

Glycine acts as a corrosion inhibitor for the metal film and maintains the initially intended side etch amount. The component itself does not change over time, and it also plays a role in stabilizing the chemical solution by chelating metal ions dissolved in the chemical solution well. The glycine is contained in an amount of about 0.1 wt% to about 5.0 wt% based on the total weight of the etchant composition. If the content of the glycine is lower than about 0.1 wt%, the chelating effect for metal ions dissolved in the metal film is reduced, reducing the stability of the chemical solution. If it is higher than 5.0 wt%, the etching speed for the metal film is reduced, resulting in a longer process time. It is preferably 0.1 wt% to 3.0 wt%.

A) persulfate, B) fluorine compound, C) inorganic acid, D) organic acid, E) organic acid, F) cyclic amine compound, G) sulfamic acid, H) glycine, etc. used in the present invention can be manufactured by a conventionally known method, and it is preferable that the etchant composition of the present invention has a purity suitable for semiconductor processing.

In addition, the present invention provides a multilayer etching method including: (1) a step of forming a multilayer on a substrate; (2) a step of selectively leaving a photoreactive material on the multilayer; and (3) a step of etching using an etchant composition of the present invention.

In addition, the present invention provides a method for manufacturing an array substrate for a display device, comprising: (1) a step of forming a gate wiring on a substrate; (2) a step of forming a gate insulating layer on a substrate including the gate wiring; (3) a step of forming an oxide semiconductor layer on the gate insulating layer; (4) a step of forming source and drain electrodes on the oxide semiconductor layer; and (5) a step of forming a pixel electrode connected to the drain electrode. The method for manufacturing an array substrate for a display device is characterized in that the step (5) includes a step of forming a multilayer and etching the multilayer with an etchant composition to form a pixel electrode, wherein the etchant composition is the etchant composition of the present invention described above.

The multilayer etchant composition of the present invention can etch not only a double layer but also a multilayer having three or more layers and six or fewer layers, and the quadruple layer among the multilayers is preferably a quadruple layer composed of titanium/indium oxide/aluminum/indium oxide, but is not limited thereto.

In the present invention, the indium oxide film may be at least one selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), and indium gallium zinc oxide (IGZO), but is not limited thereto.

The above-described matters regarding the etchant composition of the present invention are equally applicable to the multilayer etching method and the method for manufacturing an array substrate for a display device.

< Etching agent Composition Preparation>

According to the compositions shown in Table 1 below, 10 kg of each of the etchant compositions of Examples 1 to 3 and Comparative Examples 1 to 8 was prepared, and the remaining amount of water was included so that the total weight of the etchant composition became 100 wt%.

[Table 1]

Experimental example 1: Multi-membrane Etching evaluation

This is an experimental condition to find out whether batch etching is possible for each composition of a quadruple film after maintaining each solution at 30℃. The etcher uses equipment (Mini Etching Station, AST) that can process 0.5 generation Glass Size, the solution injection is Spray Type, and the spray pressure is 0.1 MPa. The exhaust pressure in the etcher zone is maintained at 20 Pa. The etching temperature is 30℃, and the etching time is 60% of the time until the lower film Ti is etched, so that overetching (OverEtch=60%) was performed. The quadruple film substrate structure prepared for the experiment is a quadruple film deposited in the order of titanium (Ti)/indium oxide (IZO)/aluminum (Al)/indium oxide (IZO) from the bottom.

[Table 2]

The difference (step) for each etching amount was measured based on aluminum. If the etching amounts of Ti, lower IZO, and upper IZO are the same with aluminum as the center, the step difference is all '0', which is an ideal batch etching. Based on this, in the above experiment, it was determined that batch etching was possible especially when the lower IZO and upper IZO showed a step difference of less than 0.1 μm. The contents listed in Table 2 are the results obtained by SEM measurement after quadruple-layer etching by composition. In the cases of Examples 1 to 3, the etching difference between the main layer, aluminum film, and the indium oxide film (IZO) deposited above and below that layer was very small, less than 0.1 μm, indicating that batch etching was possible. On the other hand, in the case of Comparative Examples 1 to 5, the etching speeds of aluminum and indium oxide films were different, so that the remaining residue of the indium oxide films located above and below the aluminum film was large. Since a size larger than 0.1㎛ usually causes a break in the wiring or a short circuit in the post-process, the compositions of Comparative Examples 1 to 8 cannot be applied in the process.

Claims (11)

A) 0.5 to 20.0 wt% of persulfate;
B) 0.01 to 2.0 wt% of fluorine compound;
C) 5.0 to 15.0 wt% of inorganic acid;
D) 10.0 to 30.0 wt% of organic acid;
E) 0.1 to 10.0 wt% of organic acid salt;
F) 0.1 to 5.0 wt% of cyclic amine compound;
G) 0.1 to 6.0 wt% of sulfamic acid;
H) 0.1 wt% to 5.0 wt% of glycine; and
I) Contains residual water,
The above cyclic amine compound is a multilayer etchant composition containing 5-aminotetrazole,
A multilayer etchant composition characterized in that the multilayer is a quadruple layer composed of titanium/indium oxide/aluminum/indium oxide.
A multilayer etchant composition according to claim 1, wherein the persulfate comprises at least one selected from the group consisting of potassium persulfate (K ₂ S ₂ O ₈ ), sodium persulfate (Na ₂ S ₂ O ₈ ), and ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ).
A multilayer etchant composition according to claim 1, wherein the fluorine compound comprises at least one selected from the group consisting of ammonium fluoride, sodium fluoride, potassium fluoride, ammonium bifluoride, sodium bifluoride, and potassium bifluoride.
A multilayer etchant composition according to claim 1, wherein the inorganic acid comprises at least one selected from the group consisting of nitric acid, sulfuric acid, and perchloric acid.
A multilayer etchant composition according to claim 1, wherein the organic acid comprises at least one selected from the group consisting of tartaric acid, acetic acid, butanoic acid, citric acid, formic acid, gluconic acid, glycolic acid, malonic acid, pentanoic acid, and oxalic acid.
A multilayer etchant composition according to claim 1, wherein the organic acid salt comprises at least one selected from the group consisting of potassium salts, sodium salts and ammonium salts of an organic acid selected from the group consisting of tartaric acid, acetic acid, butanoic acid, citric acid, formic acid, gluconic acid, glycolic acid, malonic acid, pentanoic acid and oxalic acid.
delete delete A multi-film etchant composition according to claim 1, wherein the indium oxide film is at least one selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), and indium gallium zinc oxide (IGZO).
(1) A step of forming a multilayer on a substrate;
(2) a step of selectively leaving a photoreactive material on the multilayer; and
(3) A step of etching the multilayer using an etchant composition according to any one of claims 1 to 6 and claim 9.
The above multilayer film is a quadruple film composed of titanium/indium oxide/aluminum/indium oxide.
Multilayer etching method.
(1) A step of forming a gate wiring on a substrate;
(2) A step of forming a gate insulating layer on a substrate including the gate wiring;
(3) A step of forming an oxide semiconductor layer on the gate insulating layer;
(4) a step of forming source and drain electrodes on the oxide semiconductor layer; and
(5) A method for manufacturing an array substrate for a display device, comprising the step of forming a pixel electrode connected to the drain electrode,
The above step (5) includes a step of forming a multilayer film, which is a quadruple film composed of titanium/indium oxide film/aluminum/indium oxide film, and etching the multilayer film with an etchant composition to form a pixel electrode.
A method for manufacturing an array substrate for a display device, characterized in that the etchant composition is a multilayer etchant composition according to any one of claims 1 to 6 and claim 9.