Etchant composition, and method for manufacturing metal pattern and thin film transistor substrate using the same

Abstract

The etching solution composition of one embodiment comprises 5% by weight or more and 20% by weight or less of persulfate, 0.1% by weight or more and 5% by weight or less of phosphoric acid or phosphate, 0.01% by weight or more and 2% by weight or less of carbonyl ring compound, 0.01% by weight or more and 1% by weight or less of trinitrogen ring compound, 0.1% by weight or more and 2% by weight or less of tetranitrogen ring compound, 0.1% by weight or more and 0.9% by weight or less of fluorine compound, 0.1% by weight or more and 0.5% by weight or less of hydrogen sulfate, 1% by weight or more and 3% by weight or less of amphoteric ionic compound, and water such that the total weight of the composition is 100% by weight, and the weight ratio between the amphoteric ionic compound and the persulfate satisfies 1:1.6 to 1:20, thereby enabling etching of titanium / copper multilayer films and can be used to manufacture metal pattern and thin film transistor substrates having good etching pattern characteristics.

Description

Technology Field

[0001] The present invention relates to an etching solution composition and a method for manufacturing a metal pattern and a thin-film transistor substrate using the same, and more specifically, to an etching solution composition provided for etching a multilayer metal film and a method for manufacturing a metal pattern and a thin-film transistor substrate using the same. Background Technology

[0002] As the flat panel display industry demands the realization of high resolution, large area, and 3D displays, the need for faster response speeds is emerging. In particular, to achieve high resolution, it is necessary to reduce the width of the metal pattern of the wiring used on the circuit board of the display device. In this case, the height of the pattern increases to control the resistance value, and consequently, a problem arises where the step coverage of the stacked metal films becomes poor.

[0003] Therefore, when etching metal wiring, there is a need for an etching solution composition that can control the taper etching profile and maintain its properties even when dissolved copper ions accumulate over a long period of time. The problem to be solved

[0004] The objective of the present invention is to provide an etching solution composition in which patterned metal wiring has an excellent taper angle and can maintain etching performance for a long period of time.

[0005] Another objective of the present invention is to provide a method for forming metal wiring in which wiring defects, such as open circuits, are reduced.

[0006] Another objective of the present invention is to provide a method for manufacturing a thin-film transistor substrate that reduces manufacturing time and cost and reduces wiring defects such as open circuits. means of solving the problem

[0007] The etching solution composition of the present invention comprises 5% by weight or more and 20% by weight or less of persulfate; 0.1% by weight or more and 5% by weight or less of phosphoric acid or phosphate; 0.01% by weight or more and 2% by weight or less of carbonyl ring compound; 0.01% by weight or more and 1% by weight or less of trinitrogen ring compound; 0.1% by weight or more and 2% by weight or less of tetranitrogen ring compound; 0.1% by weight or more and 0.9% by weight or less of fluorine compound; 0.1% by weight or more and 0.5% by weight or less of hydrogen sulfate; 1% by weight or more and 3% by weight or less of amphoteric ionic compound; and water such that the total weight of the entire composition is 100% by weight, wherein the weight ratio of the amphoteric ionic compound to the persulfate is 1:1.6 to 1:20.

[0008] In one embodiment, the weight ratio of the hydrogen sulfate salt to the amphoteric ionic compound may be 1:2 or more and 1:25 or less.

[0009] In one embodiment, the carbonyl ring compound may include at least two carbonyl groups forming a ring.

[0010] In one embodiment, the carbonyl ring compound may include at least one of thiazolidinedione, hydantoin, and succinimide.

[0011] In one embodiment, the trinitrogen ring compound may be a triazole comprising at least one thiol group as a substituent.

[0012] In one embodiment, the trinitrogen ring compound may include at least one of 3-mercapto-4-methyl-4H-1,2,4-triazole, 3-amino-1,2,4-triazole-5-thiol, and 1H-1,2,4-triazole-3-thiol.

[0013] In one embodiment, the persulfate may include at least one of potassium persulfate (K2S2O8), sodium persulfate (Na2S2O8), and ammonium persulfate ((NH4)2S2O8).

[0014] In one embodiment, the tetranitrogen ring compound may include at least one of aminotetrazole, methyltetrazole, and mercaptomethyltetrazole.

[0015] In one embodiment, the fluorine compound may include at least one of hydrofluoric acid (HF), ammonium fluoride (NH4F), potassium fluoride (KF), sodium fluoride (NaF), ammonium bifluoride (F2H5N), potassium bifluoride (KHF2), and sodium bifluoride (NaHF2).

[0016] In one embodiment, the hydrogen sulfate may include at least one of ammonium hydrogen sulfate (NH4HSO4), lithium hydrogen sulfate (LiHSO4), potassium hydrogen sulfate (KHSO4), and sodium hydrogen sulfate (NaHSO4).

[0017] In one embodiment, the amphoteric ionic compound may include at least one of sulfamic acid, aminomethanesulfonic acid, taurine, and homotaurine.

[0018] In one embodiment, the etching solution composition can etch a multilayer film composed of a titanium film and a copper film.

[0019] A method for manufacturing a metal pattern according to the present invention comprises: a step of forming a metal film; a step of forming a photoresist pattern on the metal film; a step of providing an etching solution composition on the metal film on which the photoresist pattern is formed; and a step of removing the photoresist pattern; wherein the etching solution composition comprises: 5% by weight or more and 20% by weight or less of persulfate; and 0.1% by weight or more and 5% by weight or less of phosphoric acid or phosphate.

[0020] Carbonyl ring compound 0.01 wt% or more and 2 wt% or less; trinitrogen ring compound 0.01 wt% or more and 1 wt% or less; tetranitrogen ring compound 0.1 wt% or more and 2 wt% or less; fluorine compound 0.1 wt% or more and 0.9 wt% or less; hydrogen sulfate 0.1 wt% or more and 0.5 wt% or less;

[0021] It comprises 1 weight % or more and 3 weight % or less of an amphoteric ionic compound; and water such that the total weight of the entire composition is 100 weight %, wherein the weight ratio of the amphoteric ionic compound to the persulfate is 1:1.6 to 1:20.

[0022] In one embodiment, the step of forming the metal film may include the step of forming a first metal film comprising titanium and the step of forming a second metal film comprising copper on the first metal film.

[0023] In one embodiment, the weight ratio of the hydrogen sulfate salt to the amphoteric ionic compound may be 1:2 or more and 1:25 or less.

[0024] In one embodiment, the carbonyl ring compound may include at least two carbonyl groups forming a ring.

[0025] In one embodiment, the carbonyl ring compound may include at least one of thiazolidinedione, hydantoin, and succinimide.

[0026] In one embodiment, the trinitrogen ring compound may be a tria comprising at least one thiol group as a substituent.

[0027] A method for manufacturing a thin-film transistor substrate according to the present invention comprises: a step of forming a gate line and a gate electrode connected to the gate line on a substrate; a step of forming a data line intersecting the gate line insulatedly, a source electrode connected to the data line, and a drain electrode spaced apart from the source electrode; and a step of forming a pixel electrode connected to the drain electrode; wherein the step of forming the gate line and the gate electrode comprises: a step of forming a metal film comprising titanium and copper; a step of forming a photoresist pattern on the metal film; a step of providing an etching solution composition on the metal film having the photoresist pattern formed thereon; and a step of removing the photoresist pattern; wherein the etching solution composition comprises 5 wt% or more and 20 wt% or less of persulfate; 0.1 wt% or more and 5 wt% or less of phosphoric acid or phosphate; 0.01 wt% or more and 2 wt% or less of a carbonyl ring compound; 0.01 wt% or more and 1 wt% or less of a trinitrogen ring compound; and 0.1 wt% or more and 2 wt% or less of a tetranitrogen ring compound. It comprises 0.1 wt% or more and 0.9 wt% or less of a fluorine compound; 0.1 wt% or more and 0.5 wt% or less of a hydrogen sulfate; 1 wt% or more and 3 wt% or less of an amphoteric ionic compound; and water such that the total weight of the entire composition is 100 wt%, wherein the weight ratio of the amphoteric ionic compound to the persulfate is 1:1.6 to 1:20.

[0028] In one embodiment, the step of forming the metal film may include the step of forming a first metal film comprising titanium and the step of forming a second metal film comprising copper on the first metal film. Effects of the invention

[0029] According to an etching solution composition according to one embodiment of the present invention, the generation of environmentally regulated substances can be suppressed, and etching characteristics such as taper angle and critical dimension (CD) skew can be improved.

[0030] According to a method for manufacturing a metal pattern according to one embodiment of the present invention, the occurrence of electrical short circuits or wiring defects can be reduced.

[0031] According to a method for manufacturing a thin-film transistor substrate according to one embodiment of the present invention, manufacturing time or process costs can be reduced. Brief explanation of the drawing

[0032] FIGS. 1a to 1e are cross-sectional views sequentially illustrating the steps of a method for manufacturing a metal pattern of one embodiment using an etching solution composition of one embodiment. FIG. 2 is a plan view illustrating a pixel structure of a display device including a thin film transistor substrate according to an embodiment of the present invention. Figure 3 is a cross-sectional view along I-I' of Figure 2. Figure 4 is a scanning electron microscope image of a metal pattern of one embodiment. FIGS. 4a to 4c are plan views sequentially illustrating the manufacturing process of a thin-film transistor substrate in one embodiment of the present invention. FIGS. 5a to 5c are cross-sectional views along the line I-I' of FIGS. 4a to 4c. FIG. 6 is a scanning electron microscope image showing the side view of a metal film etched with the etching solution of Comparative Examples 1 to 20 of the present invention. Figures 7a and 7b are scanning electron microscope images showing the sides of a metal film etched with the etching solution of Example 1 and Comparative Example 2, respectively. Figure 8 is a graph showing the measured copper etching rates of Example 1 and Example 45. Specific details for implementing the invention

[0033] The present invention is capable of various modifications and may take various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the invention to the specific disclosed forms, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0034] In describing each drawing, similar reference numerals have been used for similar components. In the attached drawings, the dimensions of the structures are depicted enlarged from their actual size for clarity of the invention. Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the invention, the first component may be named the second component, and similarly, the second component may be named the first component. A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0035] In this application, terms such as "comprising" or "having" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0036] In this application, when a part such as a layer, film, region, or plate is described as being "on" or "upper" to another part, this includes not only cases where it is "immediately above" the other part, but also cases where there is another part in between. Conversely, when a part such as a layer, film, region, or plate is described as being "under" or "lower" to another part, this includes not only cases where it is "immediately below" the other part, but also cases where there is another part in between. Furthermore, in this application, being "placed on" may include cases where it is placed not only on the upper part but also on the lower part.

[0037] Hereinafter, an etching solution composition according to one embodiment of the present invention will be described.

[0038] An etching solution composition according to one embodiment of the present invention may be used to form a metal pattern by etching a metal film. An etching solution composition according to one embodiment of the present invention may be used for etching a metal film comprising copper (Cu) and titanium (Ti). For example, an etching solution composition of one embodiment may be used to form a metal pattern by etching a metal film having a multi-film structure in which a titanium metal film comprising titanium and a copper metal film comprising copper are stacked. Specifically, the metal film may be a double film in which a titanium metal film and a copper metal film are sequentially stacked.

[0039] The etching solution composition of one embodiment comprises a persulfate, phosphoric acid or phosphate, a carbonyl ring compound, a trinitrogen ring compound, a tetranitrogen ring compound, a fluorine compound, a hydrogen sulfate, an amphoteric ionic compound, and water.

[0040] In the etching solution composition of one embodiment, the persulfate may be a major oxidizing agent and may be an etchant for etching a metal film containing copper. However, the embodiment is not limited thereto, and the persulfate may also etch a metal film containing titanium.

[0041] Persulfate may be included in an amount of about 5% by weight to about 20% by weight based on the total weight of the etching solution composition. For example, persulfate may be included in an amount of about 10% by weight to about 20% by weight based on the total weight of the etching solution composition. Specifically, persulfate may be included in an amount of about 10% by weight to about 18% by weight based on the total weight of the etching solution composition.

[0042] If the persulfate content exceeds about 20 weight%, the etching rate of the metal film using the etching solution composition of one embodiment becomes excessively fast, making it difficult to control the degree of etching, and consequently, the metal film containing copper may be overetched. In addition, if the persulfate content is less than about 5 weight%, the etching rate decreases, and sufficient etching may not be achieved.

[0043] The persulfate may be potassium persulfate (K2S2O8), sodium persulfate (Na2S2O8), or ammonium persulfate ((NH4)2S2O8), etc. The etching solution composition of one embodiment may include at least one of potassium persulfate, sodium persulfate, and ammonium persulfate as the persulfate. That is, the etching solution composition of one embodiment may include any one of potassium persulfate, sodium persulfate, and ammonium persulfate, or two or more of these as the persulfate.

[0044] The etching solution composition of one embodiment includes phosphoric acid (H3PO4) or phosphate. Phosphoric acid or phosphate is included in the etching solution composition to control galvanic corrosion of a copper film or a titanium film. That is, phosphoric acid or phosphate acts as a galvanic regulator between copper and titanium, slowing down the rate at which electrons from the titanium-containing metal film are transferred to the copper-containing metal film, thereby reducing skew caused by over-etching and lowering the taper angle. In addition, phosphoric acid or phosphate can play a role in maintaining the taper angle even when copper ions increase.

[0045] The etching solution composition of one embodiment may contain phosphoric acid or a phosphate in an amount of about 0.1% by weight to about 5% by weight based on the total weight of the etching solution composition. For example, the etching solution composition of one embodiment may contain phosphoric acid or a phosphate in an amount of about 0.1% by weight or more and about 2% by weight or less based on the total weight of the etching solution composition.

[0046] If the content of phosphoric acid or phosphate exceeds about 5% by weight based on the total weight of the etching solution composition, the initial taper angle of the copper film and titanium film becomes too low, which may cause problems such as reduced wiring volume and decreased charge mobility. In addition, if the content of phosphoric acid or phosphate is less than about 0.1% by weight, the etching rate of the underlying titanium film cannot be slowed down, so the taper angle becomes high, which may result in defects caused by differences in step cover coverage.

[0047] For example, the phosphate may include at least one of monoammonium phosphate (NH4H2PO4), monosodium phosphate (NaH2PO4), and monopotassium phosphate (KH2PO4).

[0048] An etching solution composition of one embodiment comprises a carbonyl ring compound. In this specification, a carbonyl ring compound refers to a compound in which a carbon atom of a carbonyl group is included as a ring-forming carbon of a ring compound. In one embodiment, the carbonyl ring compound may include at least two carbonyl groups forming a ring. For example, it may be a carbonyl ring compound in which the carbon atoms of two carbonyl groups become ring-forming carbons.

[0049] The carbonyl ring compound included in the etching solution of one embodiment may act as a sulfate radical scavenger to remove sulfate radicals generated during the etching process of a copper metal film. The persulfate included in the etching solution composition of one embodiment generates sulfate radicals during the etching of a copper metal film, and the generated sulfate radicals can attack and decompose the tetranitrogen ring compound. In addition, some of the decomposed tetranitrogen ring compound may be adsorbed onto the copper metal film, thereby degrading the etching performance of the etching solution composition. Therefore, when the etching solution composition of one embodiment includes a carbonyl ring compound, the carbonyl ring compound can inhibit the decomposition of the tetranitrogen ring compound, thereby improving the etching performance of the etching solution composition.

[0050] A carbonyl ring compound having two or more carbonyl groups may be included in an amount of about 0.01 weight% to about 2.0 weight% or less based on the total weight of the etching solution composition. Specifically, the etching solution composition of one embodiment may include a carbonyl ring compound in an amount of about 0.01 weight% or more and about 1.0 weight% or less based on the total weight of the etching solution composition.

[0051] If the content of the carbonyl ring compound exceeds about 2 weight%, the carbonyl ring compound is adsorbed onto the metal film, which may cause a problem in which the etching performance of the etching solution composition is reduced. In addition, if the content of the carbonyl ring compound is less than about 0.01 weight%, the carbonyl ring compound cannot sufficiently perform the radical scavenger function, so it cannot suppress the decomposition of the tetranitrogen ring compound in the etching solution composition, and consequently, a problem in which the etching performance is reduced may occur.

[0052] The carbonyl ring compound may be a thiazolidinedione, hydantoin, or succinimide, etc. The etching solution composition of one embodiment may include at least one of a thiazolidinedione, hydantoin, and succinimide as the carbonyl ring compound. For example, the etching solution composition of one embodiment may include any one of a thiazolidinedione, hydantoin, and succinimide, or a mixture of two or more of these as the carbonyl ring compound.

[0053] An etching solution composition of one embodiment comprises a trinitrogen ring compound. In this specification, a trinitrogen ring compound refers to a compound in which three of the atoms forming the ring are nitrogen atoms.

[0054] In one embodiment, the trinitrogen ring compound may include a thiol group (-SH). The trinitrogen ring compound may be a substituted triazole compound. For example, the trinitrogen ring compound may be a substituted triazole compound containing a thiol group as a substituent.

[0055] The trinitrogen ring compound included in the etching solution composition of one embodiment may act as an oxygen radical scavenger to remove oxygen radicals generated during the etching process of a copper metal film. The persulfate included in the etching solution composition of one embodiment generates oxygen radicals in addition to sulfate radicals during the etching process of a copper metal film, and the generated oxygen radicals can attack and decompose carbonyl ring compounds. Furthermore, if the carbonyl ring compound decomposes, the carbonyl ring compound cannot act as a sulfate radical scavenger to inhibit the decomposition of the tetranitrogen ring compound, thereby reducing the etching performance of the etching solution composition. That is, the etching solution composition of one embodiment includes a trinitrogen ring compound having a thiol group, thereby preventing the decomposition of carbonyl ring compounds and tetranitrogen ring compounds, which can improve etching performance.

[0056] The trinitrogen ring compound may be included in an amount of about 0.01 weight% to about 1 weight% based on the total weight of the etching solution composition. For example, the etching solution composition of one embodiment may include the trinitrogen ring compound in an amount of about 0.01 weight% or more and about 0.5 weight% or less based on the total weight of the etching solution composition. Specifically, the etching solution composition of one embodiment may include the trinitrogen ring compound in an amount of about 0.02 weight% or more and about 0.4 weight% or less based on the total weight of the etching solution composition.

[0057] If the content of trinitrogen ring compounds exceeds about 1 weight%, an excess amount of trinitrogen ring compounds may be adsorbed onto the metal film being etched, thereby reducing the etching performance of the etching solution composition. Additionally, if the content of trinitrogen ring compounds is less than about 0.01 weight%, oxygen radicals generated during the etching process are not removed, causing carbonyl ring compounds and tetranitrogen ring compounds to decompose, which may consequently lower the etching quality of the etching solution composition.

[0058] Meanwhile, in the etching solution composition of one embodiment, the carbonyl ring compound and the trinitrogen ring compound may be included in a weight ratio of 1:0.2 or higher and 1:2 or lower. In the etching solution composition of one embodiment, the carbonyl ring compound and the trinitrogen ring compound are included in a weight ratio of 1:0.2 or higher and 1:2 or lower, thereby effectively removing oxygen radicals generated during the etching process and preventing a decrease in etching performance.

[0059] An etching solution composition of one embodiment comprises a tetranitrogen ring compound. The tetranitrogen ring compound prevents the corrosion of copper, thereby stably maintaining the copper surface profile being etched. In this specification, a tetranitrogen ring compound refers to a compound in which four of the atoms forming the ring are nitrogen atoms.

[0060] The tetranitrogen ring compound may be included in an amount of about 0.1% by weight to about 2% by weight based on the total weight of the etching solution composition. For example, the etching solution composition of one embodiment may include the tetranitrogen ring compound in an amount of about 0.1% by weight or more and about 1% by weight or less based on the total weight of the etching solution composition. Specifically, the etching solution composition of one embodiment may include the tetranitrogen ring compound in an amount of about 0.2% by weight or more and about 0.7% by weight or less based on the total weight of the etching solution composition.

[0061] If the content of the tetranitrogen ring compound exceeds about 2 weight%, the etching rate slows down due to the influence of the excess tetranitrogen ring compound, which may reduce the process capability of the etching process using the etching solution composition of one embodiment. In addition, if the content of the tetranitrogen ring compound is less than about 0.1 weight%, the etching rate of the metal film containing copper increases excessively, making it difficult to control the degree of etching of the metal film.

[0062] The tetranitrogen ring compound may be a substituted or unsubstituted tetrazole compound. For example, the tetranitrogen ring compound may be aminotetrazole, methyltetrazole, or mercaptomethyltetrazole. The etching solution composition of one embodiment may include at least one of aminotetrazole, methyltetrazole, and mercaptomethyltetrazole as the tetranitrogen ring compound. That is, the etching solution composition of one embodiment may include any one of aminotetrazole, methyltetrazole, and mercaptomethyltetrazole, or two or more of these, as the tetranitrogen ring compound.

[0063] In the etching solution composition of one embodiment, the weight ratio of the tetranitrogen ring compound to the carbonyl ring compound may be 1:0.1 or higher and 1:2 or lower. If the weight ratio of the tetranitrogen ring compound to the carbonyl ring compound is less than 1:0.1, the carbonyl ring compound cannot act as a radical scavenger, resulting in reduced etching performance; if the weight ratio of the tetranitrogen ring compound to the carbonyl ring compound exceeds 1:2, the carbonyl ring compound becomes more adsorbed onto the metal film, which may cause a problem of reduced etching quality.

[0064] The etching solution composition of one embodiment includes a fluorine compound. The fluorine compound refers to a fluoride containing fluorine (F) atoms. The fluorine compound may be an etchant for etching metal films containing titanium. However, the embodiment is not limited thereto, and the fluorine compound may also etch metal films containing copper.

[0065] The fluorine compound may be included in an amount of about 0.1% to about 0.9% by weight based on the total weight of the etching solution composition. For example, the etching solution composition of one embodiment may include the fluorine compound in an amount of about 0.2% by weight or more and about 0.7% by weight or less based on the total weight of the etching solution composition.

[0066] If the content of the fluorine compound exceeds about 0.9 weight%, the metal film containing titanium may be over-etched, which results in an undercut beneath the metal film containing titanium and may cause problems such as additional etching of the insulating film or substrate beneath the metal film. In addition, if the content of the fluorine compound is less than about 0.1 weight%, the etching of the metal film containing titanium may not be effectively performed.

[0067] The fluorine compound may be hydrofluoric acid (HF), ammonium fluoride (NH4F), potassium fluoride (KF), sodium fluoride (NaF), ammonium bifluoride (F2H5N), potassium bifluoride (KHF2), or sodium bifluoride (NaHF2). The etching solution composition of one embodiment may include at least one of hydrofluoric acid (HF), ammonium fluoride (NH4F), potassium fluoride (KF), sodium fluoride (NaF), ammonium bifluoride (F2H5N), potassium bifluoride (KHF2), and sodium bifluoride (NaHF2) as the fluorine compound. For example, the etching solution composition of one embodiment may include any one of hydrofluoric acid (HF), ammonium fluoride (NH4F), potassium fluoride (KF), sodium fluoride (NaF), ammonium bifluoride (F2H5N), potassium bifluoride (KHF2), and sodium bifluoride (NaHF2) as a fluoride compound, or a mixture of two or more of these.

[0068] The etching solution composition of one embodiment includes a hydrogen sulfate. The hydrogen sulfate may be used as a stabilizer for the etching solution composition of one embodiment. In one embodiment, the hydrogen sulfate may be used as a stabilizer for persulfates. For example, the hydrogen sulfate may serve to prevent the decomposition of persulfates by amphoteric ionic compounds, thereby preventing a decrease in etching performance. That is, the hydrogen sulfate may reduce the decomposition rate of persulfates, thereby maintaining a constant etching rate of a metal film containing copper in an etching process using the etching solution composition of one embodiment.

[0069] In the etching solution composition of one embodiment, the hydrogen sulfate salt may be included in an amount of about 0.1% by weight to about 0.5% by weight based on the total weight of the etching solution composition. For example, the etching solution composition of one embodiment may include the hydrogen sulfate salt in an amount of about 0.2% by weight or more and about 0.5% by weight or less based on the total weight of the etching solution composition.

[0070] If the content of hydrogen sulfate exceeds about 0.5 weight%, the etching rate cannot be controlled, and the etching rate of the metal film containing copper increases excessively, which may result in erosion defects. In addition, if the content of hydrogen sulfate is less than about 0.1 weight%, the effect of inhibiting the decomposition of persulfate is not exhibited, and the stability of the etching solution composition of one embodiment may be reduced.

[0071] The hydrogen sulfate salt may be ammonium hydrogen sulfate (NH4HSO4), lithium hydrogen sulfate (LiHSO4), potassium hydrogen sulfate (KHSO4), or sodium hydrogen sulfate (NaHSO4). An etching solution composition of one embodiment may include at least one of ammonium hydrogen sulfate (NH4HSO4), lithium hydrogen sulfate (LiHSO4), potassium hydrogen sulfate (KHSO4), and sodium hydrogen sulfate (NaHSO4) as the hydrogen sulfate salt. For example, an etching solution composition of one embodiment may include any one of ammonium hydrogen sulfate (NH4HSO4), lithium hydrogen sulfate (LiHSO4), potassium hydrogen sulfate (KHSO4), and sodium hydrogen sulfate (NaHSO4), or a mixture of two or more of these, as the hydrogen sulfate salt.

[0072] The etching solution composition of one embodiment includes an amphoteric compound. The amphoteric compound can be used as a strong oxidizing agent. The amphoteric compound increases the etching rate of metal films containing copper and / or titanium and can convert copper into a stable state of divalent cations during etching.

[0073] In the etching solution composition of one embodiment, the amphoteric ion compound may be included in an amount of about 1% to about 3% by weight based on the total weight of the etching solution composition. If the content of the amphoteric ion compound exceeds about 3% by weight, the decomposition of persulfate may be promoted, thereby reducing the stability of the etching solution composition. Additionally, if the content of the amphoteric ion compound is less than about 1% by weight, the etching rate may gradually slow down as the etching process progresses, thereby reducing etching performance.

[0074] In one embodiment, the etching solution composition may include an amphoteric compound with a sulfonate group or a carboxyl group as a functional group. Specifically, the amphoteric compound may include any one of sulfamic acid, aminomethanesulfonic acid, taurine, and homotaurine, or a mixture of two or more of these. Meanwhile, if the amphoteric compound includes a carboxyl group as a functional group, a copper chelating effect may occur due to the amino group and the carboxyl group of the amphoteric compound. As a result, the amphoteric compound may adsorb onto the copper surface, drastically reducing the copper etching rate and potentially lowering product productivity due to an increase in process takt time.

[0075] In order for the amphoteric ionic compound of one embodiment to exhibit optimal performance, it must satisfy the content ratios of hydrogen sulfate and persulfate, respectively.

[0076] In the etching solution composition of one embodiment, the weight ratio of hydrogen sulfate to the amphoteric ion compound may be 1:2 or higher and 1:25 or lower. If the weight ratio of hydrogen sulfate to the amphoteric ion compound is less than 1:2, there is a concern that the taper angle may increase due to an increase in hydrogen sulfate, and if the weight ratio of hydrogen sulfate to the amphoteric ion compound is greater than 1:25, the effect of slowing down the persulfate decomposition rate of hydrogen sulfate is insufficient, which may result in a poor storage stability property.

[0077] In the etching solution composition of one embodiment, the weight ratio of the amphoteric ionic compound to the persulfate may be 1:1.6 or higher and 1:20 or lower, specifically 1:1.67 or higher and 1:20 or lower, and more specifically 1:3.3 or higher and 1:18 or lower.

[0078] If the weight ratio of the amphoteric compound to the persulfate is less than 1:1.6, the decomposition of the persulfate over time during storage is severe, which degrades the etching performance, and if the weight ratio of the amphoteric compound to the persulfate exceeds 1:20, a problem of increasing the initial taper angle occurs.

[0079] When the weight ratio of the amphoteric compound to the persulfate is 1:3.3 or higher, the persulfate decomposes less over time during storage, resulting in excellent etching performance, and when the weight ratio of the amphoteric compound to the persulfate is 1:18 or lower, the initial taper angle is more closely satisfied with the standard value.

[0080] Meanwhile, the etching solution composition of one embodiment includes water. Water may be included in the etching solution composition such that the sum of the compounds constituting the above-described etching solution composition and water is 100 weight percent. That is, water accounts for the remainder of the total etching solution composition, excluding the sum of the weight percent of other components other than water. Semiconductor-grade water or ultrapure water may be used as the water in the etching solution composition of one embodiment.

[0081] The etching solution composition of one embodiment is used in a process for manufacturing electronic devices, for example, in a process for etching a stacked metal film to form a metal pattern during the manufacturing process of an electronic device. In particular, the etching solution composition according to one embodiment can be used in a manufacturing process of a thin-film transistor substrate during the manufacturing process of a display device, and specifically, it can be used to etch a double film composed of titanium and copper to form a gate electrode, etc.

[0082] The etching solution composition of one embodiment is a non-aqueous etching solution composition containing persulfate as a main component, and the metal pattern produced by the etching process using the etching solution composition of one embodiment exhibits good etching characteristics, such as having a small CD skew (critical dimension skew) and a low taper angle. In addition, the etching solution composition of one embodiment can be used for batch etching of a metal film of a multilayer structure in which a titanium film and a copper film are stacked, and the generation of precipitates during the etching process can be minimized, thereby increasing the number of times the etching solution composition can be reused.

[0083] Hereinafter, a method for manufacturing a metal pattern and a method for manufacturing a thin film transistor substrate according to one embodiment of the present invention will be described.

[0084] FIGS. 1a to 1e are cross-sectional views sequentially illustrating a method of forming a metal pattern using an etching solution composition of the above-described embodiment. FIGS. 1a to 1e schematically show a cross-section in a plane parallel to the plane defined by the third direction axis (DR3), which is the thickness direction, and the first direction axis (DR1), which is orthogonal to it.

[0085] A method for manufacturing a metal pattern according to one embodiment may include the steps of forming a metal film, forming a photoresist pattern on the metal film, providing an etching solution composition on the metal film on which the photoresist pattern is formed, and removing the photoresist pattern.

[0086] FIGS. 1a to 1c may illustrate a step of forming a photoresist pattern on a metal film in a method for manufacturing a metal pattern according to one embodiment. The step of forming a photoresist pattern on a metal film may include forming a metal film comprising titanium and copper on a substrate and forming a photoresist pattern on the metal film.

[0087] FIG. 1a may illustrate a step of forming a metal film (CL) containing titanium and copper on a substrate (PSB). The step of forming the metal film (CL) may include a step of forming a first metal film (CL1) on the substrate (PSB) and a step of forming a second metal film (CL2) on the first metal film (CL1). The first metal film (CL1) may be a metal film containing titanium, and the second metal film (CL2) may be a metal film containing copper. Meanwhile, FIG. 1a illustrates a double film in which the first metal film (CL1) and the second metal film (CL2) are sequentially stacked, but the embodiment is not limited thereto. The metal film (CL) may be a single film made of an alloy containing titanium and copper, or a triple film or more in which a titanium metal film and a copper metal film are alternately stacked.

[0088] Meanwhile, the substrate (PSB) may be an insulating substrate. Alternatively, in one embodiment, the substrate (PSB) may be a thin-film transistor substrate during the manufacturing process. For example, the substrate (PSB) may be an unfinished thin-film transistor substrate, or an intermediate thin-film transistor substrate in which a circuit layer is formed on a base substrate. Specifically, the substrate (PSB) may represent a part of the thin-film transistor substrate (SUB1, FIG. 3) in the display device of one embodiment described later, for example, the substrate (PSB) may represent the first base substrate (BS1, FIG. 3).

[0089] As shown in FIG. 1a, a metal film (CL) is formed on a substrate (PSB), and then, as shown in FIG. 1b, a photoresist (PR) is provided on the front surface of the metal film (CL) formed on the substrate (PSB), and then the photoresist (PR) is exposed through a mask (MSK).

[0090] The mask (MSK) may consist of a first part (M1) that blocks all irradiated light and a second part (M2) that transmits only a portion of the light and blocks a portion. The substrate (PSB) and the metal film (CL) may be divided into a first region (R1) and a second region (R2) corresponding to the first part (M1) and the second part (M2).

[0091] Subsequently, after developing the photoresist (PR) exposed through the mask (MSK), as shown in FIG. 1c, a photoresist pattern (PRP) of a predetermined thickness remains in the first region (R1) where light is blocked by the mask (MSK) and no light is provided, and the photoresist is completely removed in the second region (R2) where light transmitted through the second part (M2) of the mask (MSK) is provided, thereby exposing the surface of the substrate (PSB). Meanwhile, in the description of FIG. 1b to 1c, a case in which a positive photoresist is used to remove the photoresist in the exposed portion was described as an example, but the embodiment is not limited thereto, and in one embodiment, a negative photoresist may be used to remove the photoresist in the unexposed portion.

[0092] Next, a first metal film (CL1) and a second metal film (CL2) can be patterned using a photoresist pattern (PRP). The photoresist pattern (PRP) can be used as a mask layer for patterning the metal film (CL). That is, as shown in FIG. 1c, an etching solution composition (not shown) can be provided on the metal film (CL) on which the photoresist pattern (PRP) is formed, and the metal film (CL) on which the photoresist pattern (PRP) is not formed can be etched by the provided etching solution composition to form a metal pattern (ML) as shown in FIG. 1d. The metal pattern (ML) may include a first metal pattern (ML1) and a second metal pattern (ML2). In one embodiment, the first metal pattern (ML1) may be a titanium metal layer, and the second metal pattern (ML2) may be a copper metal layer.

[0093] The etching solution composition of one embodiment may be configured to form a metal pattern (ML) by etching a first metal film (CL1) and a second metal film (CL2) in batches. The etching solution composition provided in the method for manufacturing a metal pattern of one embodiment is the etching solution composition according to one embodiment of the present invention described above.

[0094] Referring to FIG. 1d and FIG. 1e, the photosensitive film pattern (PRP) and the metal pattern (ML) may have a trapezoidal shape in a cross-section defined by the first directional axis (DR1) and the third directional axis (DR3). However, the embodiments are not limited thereto.

[0095] Meanwhile, the maximum width (W2) of the metal pattern (ML) in cross-section may be smaller than the maximum width (W1) of the photoresist pattern (PRP). Meanwhile, in an etching process using the photoresist pattern (PRP), the difference (W1-W2) between the maximum width (W1) of the photoresist pattern (PRP) and the maximum width (W2) of the metal pattern (ML) is defined as CD skew (Critical Dimension Skew), and in FIG. 1d, "CD1" or "CD2" corresponds to one-sided CD skew, respectively.

[0096] A metal pattern (ML) can be formed using a photoresist pattern (PRP), and then the photoresist pattern (PRP) can be removed. FIG. 1e shows the final metal pattern (ML) after the photoresist pattern (PRP) has been removed. The metal pattern (ML) may be a multilayer metal pattern in which a titanium metal pattern and a copper metal pattern are stacked.

[0097] In a method for manufacturing a metal pattern according to one embodiment of the present invention, a metal pattern composed of a first metal and a second metal, i.e., a titanium / copper double-layer metal pattern, can be manufactured. Although the description of FIGS. 1a to 1e discloses a method for forming a metal pattern formed in multiple layers, the embodiments are not limited thereto, and a metal pattern formed in a single layer including copper can also be manufactured in substantially the same way.

[0098] FIG. 2 is a plan view illustrating a pixel structure of a display device including a thin-film transistor substrate manufactured by a method for manufacturing a thin-film transistor substrate according to one embodiment. FIG. 3 is a cross-sectional view along I-I' of FIG. 2. Hereinafter, a thin-film transistor substrate manufactured by a method for manufacturing a thin-film transistor substrate according to one embodiment and a display device equipped with the same will be described with reference to FIG. 2 and FIG. 3.

[0099] A thin-film transistor substrate manufactured by the method of manufacturing a thin-film transistor substrate of one embodiment can be applied as a substrate including an electronic circuit for driving a display device. The type of display device is not particularly limited and may be various display devices such as, for example, a liquid crystal display device, an organic light emitting display device, an electrophoretic display device, an electrowetting display device, a microelectromechanical system display device.

[0100] Meanwhile, in FIGS. 2 and 3, a liquid crystal display device is illustrated as an example of a display device, but the embodiment is not limited thereto, and for example, the display device may be an organic electroluminescent display device. Meanwhile, in one embodiment of a display device having multiple pixels, each pixel is formed with the same structure, so for convenience of explanation, FIGS. 2 and 3 illustrate only one pixel. Meanwhile, in FIG. 2, for convenience of explanation, one pixel (PX) connected to one gate line among the gate lines (GL) and one data line among the data lines (DL) is illustrated, but the embodiment is not limited thereto. For example, one gate line and one data line may be connected to multiple pixels, and multiple gate lines and multiple data lines may be connected to one pixel.

[0101] Referring to FIGS. 2 and 3, the display device (DD) may include a thin film transistor substrate (SUB1) equipped with a pixel (PX), a counter substrate (SUB2) facing the thin film transistor substrate (SUB1), and a liquid crystal layer (LC) disposed between the thin film transistor substrate (SUB1) and the counter substrate (SUB2).

[0102] Referring to FIGS. 2 and 3, a gate line (GL) is formed by extending in the direction of a second directional axis (DR2). The gate line (GL) may be formed on a first base substrate (BS1). A data line (DL) may be provided by extending in the direction of a first directional axis (DR1) that intersects the gate line (GL).

[0103] Each pixel (PX) includes a thin-film transistor (TFT) and a pixel electrode (PE) connected to the thin-film transistor (TFT). The thin-film transistor (TFT) includes a gate electrode (GE), a gate insulating film (GI), a semiconductor pattern (SM), a source electrode (SE), and a drain electrode (DE).

[0104] The gate electrode (GE) may protrude from the gate line (GL) or be provided on a portion of the gate line (GL). The gate electrode (GE) may be made of metal. The gate electrode (GE) may be formed as a single film or multiple films using metal.

[0105] A semiconductor pattern (SM) is provided on a gate insulating film (GI). The semiconductor pattern (SM) is provided on a gate electrode (GE) with the gate insulating film (GI) in between. A portion of the semiconductor pattern (SM) overlaps with the gate electrode (GE). The semiconductor pattern (SM) includes an active pattern (ACT) provided on the gate insulating film (GI) and an ohmic contact layer (OHM) formed on the active pattern (ACT). The active pattern (ACT) may be made of an amorphous silicon thin film, and the ohmic contact layer (OHM) may be made of an n+ amorphous silicon thin film. The ohmic contact layer (OHM) makes ohmic contacts between the active pattern and the source electrode (SE) and drain electrode (DE), respectively.

[0106] The source electrode (SE) is provided branched from the data lines (DL). The source electrode (SE) is formed on the ohmic contact layer (OHM) and a portion of it overlaps with the gate electrode (GE). The data lines (DL) can be placed in the area of ​​the gate insulating film (GI) where the semiconductor pattern (SM) is not placed.

[0107] The drain electrode (DE) is provided spaced apart from the source electrode (SE) with the semiconductor pattern (SM) in between. The drain electrode (DE) is formed on the ohmic contact layer (OHM) and is provided such that a portion of its area overlaps with the gate electrode (GE).

[0108] In one embodiment, the gate line (GL) and the gate electrode (GE) may be formed as a multilayer metal film comprising a metal film containing copper and a metal film containing titanium. That is, the gate line (GL) and the gate electrode (GE) may be a double-layer metal pattern of a titanium metal pattern and a copper metal pattern formed by etching sequentially stacked titanium metal films and copper metal films. However, the embodiment is not limited thereto, and for example, the gate line (GL) and the gate electrode (GE) may be a single-layer metal pattern made of an alloy of titanium and copper, or a multilayer metal pattern in which a titanium metal pattern and a copper metal pattern are stacked in three or more layers.

[0109] In one embodiment, the gate line (GL) and the gate electrode (GE) can be formed by patterning through an etching process using the etching solution composition of the above-described embodiment. In the case of the method for manufacturing a thin film transistor substrate of one embodiment using the etching solution composition of one embodiment, when patterning a double film of a titanium metal film and a copper metal film, the metal pattern can have a small CD skew value and a low taper angle, thereby allowing the gate line (GL) and the gate electrode (GE) to have a good taper profile.

[0110] In addition, in the method for manufacturing a thin film transistor substrate of one embodiment, the etching solution composition of one embodiment can ensure that the gate electrode (GE) has a low taper angle so that the gate insulating layer (GI), semiconductor pattern (SM), source electrode (SE), and drain electrode (DE) formed by subsequent stacking have good step coverage.

[0111] The taper angle of the gate electrode (GE) formed by etching with the etching solution composition of one embodiment may be 30 degrees or more and 60 degrees or less. For example, the taper angle of the gate electrode (GE) may be 40 degrees or more and 45 degrees or less.

[0112] In one embodiment, the insulating layer (PSV) of the thin-film transistor substrate (SUB1) covers the source electrode (SE), the drain electrode (DE), the channel portion, and the gate insulating film (GI), and has a contact hole (CH) that exposes a portion of the drain electrode (DE). The insulating layer (PSV) may comprise, for example, silicon nitride or silicon oxide.

[0113] The pixel electrode (PE) is connected to the drain electrode (DE) through a contact hole (CH) formed in the insulating layer (PSV). The pixel electrode (PE) is formed of a transparent conductive material. In particular, the pixel electrode (PE) is formed of a transparent conductive oxide. The transparent conductive oxide may be indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), etc.

[0114] That is, the thin film transistor substrate (SUB1) may include a thin film transistor (TFT), an insulating layer (PSV), and a pixel electrode (PE) formed on a first base substrate (BS1). Meanwhile, although not shown in the drawing, the thin film transistor substrate (SUB1) may further include an orientation layer (not shown) formed on the pixel electrode (PE).

[0115] The opposing substrate (SUB2) is positioned opposite to the thin-film transistor substrate (SUB1) and may include a second base substrate (BS2), a color filter (CF) positioned below the second base substrate (BS2), a light-blocking portion (BM) positioned between color filters (CF) that implement different colors to block light, and a common electrode (CE) that forms an electric field with the pixel electrode (PE). Meanwhile, although not shown in the drawing, an alignment layer (not shown) may be further positioned below the common electrode (CE).

[0116] FIGS. 4a to 4c are plan views sequentially illustrating the manufacturing process of a thin-film transistor substrate in one embodiment of the present invention. FIGS. 5a to 5c are cross-sectional views along the line I-I' of FIGS. 4a to 4c.

[0117] Hereinafter, a method for manufacturing a thin-film transistor substrate according to an embodiment of the present invention will be described with reference to FIGS. 4a to 4c and FIGS. 5a to 5c.

[0118] Referring to FIGS. 4a and FIGS. 5a, a first wiring portion is formed on a first base substrate (BS1) using a first photolithography process. The first wiring portion includes a gate line (GL) extended along a second directional axis and a gate electrode (GE) connected to the gate line (GL). The gate electrode (GE) can be formed by applying the method described above in FIGS. 1a to 1e.

[0119] Referring to FIGS. 4b and FIGS. 5b, a gate insulating film (GI) is formed on a first base substrate (BS1) on which a first wiring portion is formed, and a semiconductor pattern (SM) and a second wiring portion are formed on the gate insulating film (GI) using a second photolithography process. The second wiring portion includes a data line (DL) extended in a second direction intersecting the first direction, a source electrode (SE) extended from the data line (DL), and a drain electrode (DE) spaced apart from the source electrode (SE).

[0120] A semiconductor pattern (SM) and a second wiring portion are formed by sequentially forming a first semiconductor material, a second semiconductor material, and first and second metals on a first base substrate (BS1), and then selectively etching the first semiconductor material, the second semiconductor material, and the first and second metals, respectively, using a second mask (not shown). The first metal may be made of titanium, and the second metal may be made of copper. The first metal and the second metal may be etched with an etching solution composition according to the embodiment of the present invention described above. Accordingly, the data line (DL), source electrode (SE), and drain electrode (DE) may be formed as a double-film structure in which the first metal and the second metal are sequentially stacked. The second mask may be a slit mask or a diffraction mask.

[0121] Referring to FIG. 4c and FIG. 5c, a pixel electrode (PE) is formed on a first base substrate (BS1) on which a second wiring portion is formed using third and fourth photolithography processes.

[0122] Referring to FIG. 5c, an insulating layer (PSV) having a contact hole (CH) that exposes a portion of a drain electrode (DE) is formed on a first base substrate (BS1) on which a second wiring portion is formed. The insulating layer (PSV) can be formed by laminating a second insulating material layer (not shown) and a photosensitive film (not shown) with a second insulating material on the first base substrate (BS1) on which the second wiring portion is formed, exposing and developing the photosensitive film to form a photosensitive film pattern (not shown), and then removing a portion of the second insulating material layer using the photosensitive film pattern as a mask.

[0123] Referring again to FIG. 5c, a pixel electrode (PE) is formed by using a fourth photolithography process, which is provided on an insulating layer (PSV) and connected to a drain electrode (DE) through a contact hole (CH). The pixel electrode (PE) is formed by sequentially stacking a transparent conductive material layer (not shown) and a photosensitive film (not shown) on a first base substrate (BS1) on which an insulating layer (PSV) is formed, exposing and developing the photosensitive film to form a photosensitive film pattern (not shown), and then patterning the transparent conductive material layer using the photosensitive film pattern as a mask.

[0124] As such, the present embodiment allows for the fabrication of a thin-film transistor substrate through a photolithography process. Here, metal wiring can be formed using an etching solution composition according to an embodiment of the present invention in a photolithography process using first and second masks. However, forming metal wiring using the etching solution composition is not limited thereto; the etching solution composition may be used only when forming a second wiring portion using the second mask, or only when forming a first wiring portion using the first mask. Alternatively, the etching solution composition may be used when forming wiring other than the first and second wiring portions.

[0125] Hereinafter, the etching solution composition according to the present invention will be described in detail along with examples and comparative examples. However, the etching solution composition described in the examples and the metal pattern formed using it are merely examples and do not limit the scope of the embodiments.

[0126] (Preparation of etching solution composition)

[0127] Etching solution compositions according to Examples 1 to 40 and Examples 46 and 46 of the present invention, and etching solution compositions according to Comparative Examples 1 to 24, were prepared with the compositions presented in Table 1 below. In Table 1, the unit indicating the content of each component represents weight% with the total weight of the etching solution composition set to 100%. In Table 1, when the total weight of the etching solution composition is set to 100%, the remaining amount corresponds to water.

[0128] division persulfate Phosphoric acid 2-carbonyl ring compounds trinitrogen cyclic compounds having a thiol group Amphoteric compound 1 (Homotaurine) Amphoteric compound 2 (sulfamic acid) tetranitrogen cyclic compounds Fluorine compounds hydrogen sulfate Example 1 15 1.5 0.3 0.2 1.5 0 0.5 0.5 0.2 Example 2 5 1.5 0.3 0.2 1.5 0 0.5 0.5 0.2 Example 3 10 1.5 0.3 0.2 1.5 0 0.5 0.5 0.2 Example 4 18 1.5 0.3 0.2 1.5 0 0.5 0.5 0.2 Example 5 20 1.5 0.3 0.2 1.5 0 0.5 0.5 0.2 Example 6 15 0.1 0.3 0.2 1.5 0 0.5 0.5 0.2 Example 7 15 2 0.3 0.2 1.5 0 0.5 0.5 0.2 Example 8 15 3 0.3 0.2 1.5 0 0.5 0.5 0.2 Example 9 15 5 0.3 0.2 1.5 0 0.5 0.5 0.2 Example 10 15 1.5 0.01 0.2 1.5 0 0.5 0.5 0.2 Example 11 15 1.5 1 0.2 1.5 0 0.5 0.5 0.2 Example 12 15 1.5 2 0.2 1.5 0 0.5 0.5 0.2 Example 13 15 1.5 0.3 0.01 1.5 0 0.5 0.5 0.2 Example 14 15 1.5 0.3 0.1 1.5 0 0.5 0.5 0.2 Example 15 15 1.5 0.3 0.4 1.5 0 0.5 0.5 0.2 Example 16 15 1.5 0.3 1 1.5 0 0.5 0.5 0.2 Example 17 15 1.5 0.3 0.2 1 0 0.5 0.5 0.2 Example 18 15 1.5 0.3 0.2 3 0 0.5 0.5 0.2 Example 19 15 1.5 0.3 0.2 1.5 0 0.1 0.5 0.2 Example 20 15 1.5 0.3 0.2 1.5 0 0.2 0.5 0.2 Example 21 15 1.5 0.3 0.2 1.5 0 0.7 0.5 0.2 Example 22 15 1.5 0.3 0.2 1.5 0 2 0.5 0.2 Example 23 15 1.5 0.3 0.2 1.5 0 0.5 0.1 0.2 Example 24 15 1.5 0.3 0.2 1.5 0 0.5 0.2 0.2 Example 25 15 1.5 0.3 0.2 1.5 0 0.5 0.7 0.2 Example 26 15 1.5 0.3 0.2 1.5 0 0.5 0.9 0.2 Example 27 15 1.5 0.3 0.2 1.5 0 0.5 0.5 0.1 Example 28 15 1.5 0.3 0.2 1.5 0 0.5 0.5 0.5 Example 29 15 1.5 0.3 0.2 1 0 0.5 0.5 0.5 Example 30 15 1.5 0.3 0.2 2 0 0.5 0.5 0.25 Example 31 15 1.5 0.3 0.2 3 0 0.5 0.5 0.1 Example 32 20 1.5 0.3 0.2 1 0 0.5 0.5 0.2 Example 33 10 1.5 0.3 0.2 2 0 0.5 0.5 0.2 Example 34 5 1.5 0.3 0.2 3 0 0.5 0.5 0.2 Example 35 15 1.5 0.3 0.2 0 1 0.5 0.5 0.5 Example 36 15 1.5 0.3 0.2 0 2 0.5 0.5 0.25 Example 37 15 1.5 0.3 0.2 0 3 0.5 0.5 0.1 Example 38 20 1.5 0.3 0.2 0 1 0.5 0.5 0.2 Example 39 10 1.5 0.3 0.2 0 2 0.5 0.5 0.2 Example 40 5 1.5 0.3 0.2 0 3 0.5 0.5 0.2 Example 46 18 1.5 0.3 0.2 1 0 0.5 0.5 0.2 Example 47 18 1.5 0.3 0.2 0 1 0.5 0.5 0.2 Comparative Example 1 3 1.5 0.3 0.2 1.5 0 0.5 0.5 0.2 Comparative Example 2 22 1.5 0.3 0.2 1.5 0 0.5 0.5 0.2 Comparative Example 3 15 0.05 0.3 0.2 1.5 0 0.5 0.5 0.2 Comparative Example 4 15 6 0.3 0.2 1.5 0 0.5 0.5 0.2 Comparative Example 5 15 1.5 0.005 0.2 1.5 0 0.5 0.5 0.2 Comparative Example 6 15 1.5 2.3 0.2 1.5 0 0.5 0.5 0.2 Comparative Example 7 15 1.5 0.3 0.005 1.5 0 0.5 0.5 0.2 Comparative Example 8 15 1.5 0.3 1.2 1.5 0 0.5 0.5 0.2 Comparative Example 9 15 1.5 0.3 0.2 0.3 0 0.5 0.5 0.2 Comparative Example 10 15 1.5 0.3 0.2 5 0 0.5 0.5 0.2 Comparative Example 11 15 1.5 0.3 0.2 1.5 0 0.05 0.5 0.2 Comparative Example 12 15 1.5 0.3 0.2 1.5 0 2.5 0.5 0.2 Comparative Example 13 15 1.5 0.3 0.2 1.5 0 0.5 0.05 0.2 Comparative Example 14 15 1.5 0.3 0.2 1.5 0 0.5 1.1 0.2 Comparative Example 15 15 1.5 0.3 0.2 1.5 0 0.5 0.5 0.03 Comparative Example 16 15 1.5 0.3 0.2 1.5 0 0.5 0.5 1 Comparative Example 17 21 1.5 0.3 0.2 1 0 0.5 0.5 0.2 Comparative Example 18 25 1.5 0.3 0.2 1 0 0.5 0.5 0.2 Comparative Example 19 21 1.5 0.3 0.2 0 1 0.5 0.5 0.2 Comparative Example 20 25 1.5 0.3 0.2 0 1 0.5 0.5 0.2

[0129] In the examples and comparative examples presented in Table 1, ammonium persulfate was selected as the persulfate, aminotetrazole as the tetranitrogen ring compound, hydantoin as the carbonyl ring compound, ammonium bifluoride as the fluorine compound, 3-amino-1,2,4-triazole-5-thiol as the trinitrogen ring compound, sodium hydrogen sulfate as the hydrogen sulfate, and homotaurine and sulfamic acid as the amphoteric compounds.

[0130] (Metal pattern manufacturing evaluation)

[0131] Etching tests were conducted on double films of titanium and copper metal films using the etching solution compositions presented in Table 1. For the etching tests, the etching solution compositions of the examples and comparative examples were applied to a double film of a 200 Å titanium metal film and a 6000 Å copper metal film at a temperature of 26°C. The level of accumulated etching amount, the initial taper angle, and the degree of maintenance of the taper angle were evaluated based on the point of 100% over-etching, which is twice the time (EPD time, End point detection time) when the upper copper layer and titanium layer are completely etched. The level of accumulated etching amount determined whether the etching quality was maintained due to the increase in copper content in the etching solution composition resulting from the reuse of the etching solution.

[0132] Table 2 below shows the etching quality evaluation results for the examples and comparative examples. Table 2 shows the cumulative etching level, initial taper angle, and taper angle retention when metal patterns were manufactured using the etching solution compositions of the examples and comparative examples in Table 1. The evaluation criteria for the cumulative etching level, initial taper angle, and taper angle retention were based on the following. In addition, the scores for excellent, average, and poor for each of the items regarding the cumulative etching level, initial taper angle, and taper angle retention were combined to show the comprehensive evaluation results in Table 2.

[0133] <Evaluation Criteria for Cumulative Etching Levels>

[0134] ○ (Excellent): When etching quality is good even when Cu ions are contained at 6,000 ppm or more

[0135] △ (Normal): When etching quality is good for Cu ions from 4,000 ppm to less than 6,000 ppm

[0136] × (Defective): When etching quality is good up to less than 4000 ppm of Cu ions

[0137] <Initial Taper Angle Evaluation Criteria>

[0138] ○ (Excellent): 40 degrees or higher ~ less than 50 degrees

[0139] △ (Normal): 30 degrees or more ~ ​​less than 40 degrees, 50 degrees or more ~ ​​less than 60 degrees

[0140] × (Defective): Less than 30 degrees, greater than 60 degrees

[0141] <Evaluation Criteria for Maintaining Taper Angle>

[0142] ○ (Excellent): When the change in taper angle is less than 5° while the Cu ion concentration reaches 6,000 ppm

[0143] × (Defective): If the change in taper angle is 5° or more while the Cu ion concentration reaches 6000 ppm

[0144] In addition, FIG. 6 shows a scanning electron microscope image of a cross-section after the etching process for Comparative Examples 1 to 20, and in FIG. 6, "Cu 0 ppm" and "Cu 6000 ppm" correspond to the case where the etching solution composition was used for the first time and the case where the etching solution composition was reused until the concentration of Cu ions reached 6000 ppm, respectively.

[0145] division Cumulative etching amount level Initial taper angle Maintain taper angle Example 1 O O O Example 2 O O O Example 3 O O O Example 4 O O O Example 5 O O O Example 6 O O O Example 7 O O O Example 8 O O O Example 9 O O O Example 10 O O O Example 11 O O O Example 12 O O O Example 13 O O O Example 14 O O O Example 15 O O O Example 16 O O O Example 17 O O O Example 18 O O O Example 19 O O O Example 20 O O O Example 21 O O O Example 22 O O O Example 23 O O O Example 24 O O O Example 25 O O O Example 26 O O O Example 27 O O O Example 28 O O O Example 29 O O O Example 30 O O O Example 31 O O O Example 32 O O O Example 33 O O O Example 34 O O O Example 35 O O O Example 36 O O O Example 37 O O O Example 38 O O O Example 39 O O O Example 40 O O O Example 46 O O O Example 47 O O O Comparative Example 1 X △ X Comparative Example 2 O X X Comparative Example 3 O X X Comparative Example 4 O X O Comparative Example 5 X O X Comparative Example 6 X O △ Comparative Example 7 X O X Comparative Example 8 △ O △ Comparative Example 9 X △ X Comparative Example 10 △ X △ Comparative Example 11 △ X X Comparative Example 12 △ △ X Comparative Example 13 X X X Comparative Example 14 X X X Comparative Example 15 △ △ △ Comparative Example 16 O X △ Comparative Example 17 O X △ Comparative Example 18 O X △ Comparative Example 19 O X △ Comparative Example 20 O X △

[0146] Referring to the results in Table 2, it can be seen that in Comparative Examples 1 to 14 and 16 to 20, a defect occurred in at least one evaluation, and Comparative Example 15 received an average rating in all three evaluation criteria, whereas Examples 1 to 40, 46, and 47 received an excellent rating in all three evaluation criteria. That is, it can be seen that the etching solution composition according to one embodiment exhibits a good level of etching amount accumulation, an initial taper angle, and taper angle retention characteristics.

[0147] Compared to the examples, it can be seen that the etching quality is degraded in Comparative Examples 1 to 20, in which at least one of the evaluation items of the etching solution composition is not satisfied.

[0148] Specifically, Comparative Example 1 contains a small amount of persulfate, so the copper etching rate is slow and the etching quality is poor as the amount of copper ions increases.

[0149] Comparative Example 2 contains an excessive amount of persulfate, resulting in a high initial taper angle and an etching rate that is too fast, making it difficult to control the process tact time.

[0150] Comparative Example 3 contains a small amount of phosphoric acid, so the etching rate of the lower titanium increases, the initial taper angle is high, and the taper angle is not maintained.

[0151] Comparative Example 4 contains an excess amount of phosphoric acid, so the initial taper angle is very low and the titanium tail is formed long.

[0152] Comparative Example 5 contains a trace amount of carbonyl ring compound, so there is no sulfate radical stabilization effect, and the etching quality is not good as the amount of copper ions increases.

[0153] Comparative Example 6 contains an excess amount of carbonyl ring compounds, and as the carbonyl ring compounds are adsorbed onto copper and the amount of copper ions increases, the etching quality is not good.

[0154] Comparative Example 7 contains a small amount of trinitrogen cyclic compound, so there is no oxygen radical stabilization effect, and the etching quality is not good as the amount of copper ions increases.

[0155] Comparative Example 8 contains an excess amount of trinitrogen cyclic compounds, and as the trinitrogen cyclic compounds are adsorbed onto copper and the amount of copper ions increases, the etching quality is not good.

[0156] Comparative Example 9 contains a small amount of homotaurine, and the etching quality is poor as the amount of copper ions increases due to the lack of a strong oxidizing agent.

[0157] Comparative Example 10 contains an excess amount of homotaurine, resulting in a high taper angle and promoting persulfate decomposition, which leads to poor etching quality as the amount of copper ions increases.

[0158] Comparative Example 11 contains a small amount of a tetranitrogen cyclic compound, so the taper angle increases due to the increased copper etching rate. Comparative Example 12 contains an excessive amount of a tetranitrogen cyclic compound, so the copper etching rate is low, and the etching quality is poor as the amount of copper ions adsorbed on the copper increases.

[0159] Comparative Example 13 contains a small amount of fluorine compound, so the etching of the underlying titanium film is very slow, and productivity is reduced due to increased takt time.

[0160] Comparative Example 14 contained an excessive amount of fluorine compound, which increased undercut and glass substrate damage due to over-etching of the titanium film.

[0161] In Comparative Example 15, the hydrogen sulfate is included in a small amount, so the effect of slowing down the decomposition rate of hydrogen sulfate persulfate is insufficient, making it vulnerable to copper processing capacity.

[0162] In Comparative Example 16, the taper angle is increased because an excess amount of hydrogen sulfate is included.

[0163] In Comparative Examples 17 to 20, when the ratio of persulfate to homotaurine or sulfamic acid is greater than 20, the taper angle increases with the increase in the ratio of persulfate.

[0164] division persulfate Phosphoric acid 2-carbonyl ring compounds trinitrogen cyclic compounds having a thiol group Amphoteric compound 1 (Homotaurine) Amphoteric compound 2 (sulfamic acid) tetranitrogen cyclic compounds Fluorine compounds hydrogen sulfate Example 1 15 1.5 0.3 0.2 1.5 0 0.5 0.5 0.2 Example 41 15 1.5 0.3 0.2 2.7 0 0.5 0.5 0.1 Example 42 15 1.5 0.3 0.2 2.9 0 0.5 0.5 0.1 Example 43 15 1.5 0.3 0.2 0 2.7 0.5 0.5 0.1 Example 44 15 1.5 0.3 0.2 0 2.9 0.5 0.5 0.1 Example 48 10 1.5 0.3 0.2 3 0 0.5 0.5 0.2 Example 49 10 1.5 0.3 0.2 0 3 0.5 0.5 0.2 Comparative Example 21 5 1.5 0.3 0.2 3.3 0 0.5 0.5 0.2 Comparative Example 22 5 1.5 0.3 0.2 5 0 0.5 0.5 0.2 Comparative Example 23 5 1.5 0.3 0.2 0 3.3 0.5 0.5 0.2 Comparative Example 24 5 1.5 0.3 0.2 0 5 0.5 0.5 0.2

[0165] If the ratio between the components is not appropriate, it accelerates the decomposition of persulfates, leading to a decrease in performance during storage. Cases where the ratio is not appropriate include when the ratio of the amphoteric compound to the hydrogen sulfate exceeds 25, or when the ratio of persulfates to the amphoteric compound is less than 1:1.6. The degree of persulfate decomposition during storage was evaluated for Examples 1, 41 to 44, 48, 49 and Comparative Examples 21 to 24, which have the component content conditions according to Table 3. Persulfates decompose in water through a chemical reaction as shown in Formula 1 below, and the addition of strong acids accelerates this decomposition, causing a decrease in the performance of the etching solution composition.

[0166] [Equation 1] (NH4)2S2O8 + H2O → 2NH4 + + HSO4 - + HSO5 -

[0167] division Persulfate concentration (mass percentage) after 3 days of storage Example 1 99.56 Example 41 98.86 Example 42 98.47 Example 43 98.75 Example 44 98.25 Example 48 99.06 Example 49 99.07 Comparative Example 21 98.10 Comparative Example 22 95.94 Comparative Example 23 98.02 Comparative Example 24 95.91

[0168] Table 4 shows the results of the reduced persulfate content after storage for 3 days under conditions of 10±1℃. Meanwhile, a decrease of more than 1% on a percentage basis may cause performance degradation. Example 1 showed the smallest reduction in persulfate compared to other examples or comparative examples.

[0169] In the case of Examples 41 to 44, it was found that when the ratio of homotaurine or sulfamic acid to hydrogen sulfate exceeded 25, the decomposition of persulfate became severe, and as the homotaurine and sulfamic acid content increased, the decomposition became even more severe.

[0170] Examples 48 and 49 showed that when the weight ratio of the amphoteric compound to the persulfate was 1:3.3 or higher, the decomposition of the persulfate was 1% or less.

[0171] Comparative Examples 21 and 24 showed that when the persulfate was less than 1.6 times the homotaurine or sulfamic acid content, the decomposition of the persulfate was severe, and as the homotaurine and sulfamic acid content increased, the decomposition became even more severe.

[0172] Figures 7a and 7b show scanning electron microscope images after the etching process in Example 1 and Comparative Example 2, respectively. Figures 7a and 7b show cross-sectional images of metal patterns (ML, ML') formed under photoresist patterns (PRP, PRP'). Comparing Figures 7a and 7b, it can be seen that the unilateral CD skew (CD1) of the metal pattern (ML) in Example 1 is smaller than the unilateral CD skew (CD1') of the metal pattern (ML') in Comparative Example 2, and that the taper angle (θ1) of the metal pattern (ML) in Example 1 is smaller than the taper angle (θ1') of the metal pattern (ML') in Comparative Example 2. From this, it can be seen that the example forms a good metal pattern having a smaller CD skew value and a smaller taper angle compared to the comparative example.

[0173] Figure 8 is a graph showing the measured copper etching rates of Example 1 and Example 45. Meanwhile, as shown in Table 5, Example 1 contains an amphoteric compound having a sulfo group (homotaurine), and Example 45 contains an amphoteric compound having a carboxyl group (glutamic acid).

[0174] Room classification persulfate Phosphoric acid carbonyl ring compounds trinitrogen cyclic compounds amphoteric compound (sulfo group) Amphoteric compound (carboxyl group) tetranitrogen cyclic compounds fluorine compounds hydrogen sulfate Example 1 15 1.5 0.3 0.2 1.5 0 0.5 0.5 0.2 Example 45 15 1.5 0.3 0.2 0 1.5 0.5 0.5 0.2

[0175] The homotaurine in the text is H +The component that increases the copper etching rate is a strong oxidizing agent with high ion dissociation. When glutamic acid is used, the copper etching rate decreases rapidly due to the copper chelating effect caused by amino and carboxyl groups, which adsorbs to the copper surface, leading to an increase in process takt time and a decrease in product productivity. (Including copper EPD according to etching rate) The etching solution composition of one embodiment can be used for batch etching of multilayer metal films of titanium metal films and copper metal films, and can maintain stable etching characteristics even with repeated use. In addition, the etching solution composition of one embodiment can exhibit excellent etching performance by ensuring that the taper angle, which is an etching characteristic of the metal pattern, is maintained below a certain level, showing a high level of etching amount accumulation, and maintaining a good taper angle. Furthermore, it can be confirmed that the metal pattern and thin-film transistor substrate manufactured using the etching solution composition of one embodiment have a good taper profile.

[0176] Although the present invention has been described above with reference to preferred embodiments, those skilled in the art or those with ordinary knowledge in the art will understand that various modifications and changes can be made to the present invention without departing from the spirit and technical scope of the invention as described in the claims set forth below.

[0177] Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be determined by the claims. Explanation of the symbols

[0178] ML : Metal pattern ML1: First metal pattern ML2: Second metal pattern PRP: Photoresist pattern

Claims

Claim 1 An etching solution composition comprising: 5 wt% or more and 20 wt% or less of persulfate; 0.1 wt% or more and 5 wt% or less of phosphoric acid or phosphate; 0.01 wt% or more and 2 wt% or less of carbonyl ring compound; 0.01 wt% or more and 1 wt% or less of trinitrogen ring compound; 0.1 wt% or more and 2 wt% or less of tetranitrogen ring compound; 0.1 wt% or more and 0.9 wt% or less of fluorine compound; 0.1 wt% or more and 0.5 wt% or less of hydrogen sulfate; 1 wt% or more and 3 wt% or less of amphoteric ionic compound; and water such that the total weight of the entire composition is 100 wt%, wherein the weight ratio of the amphoteric ionic compound to the persulfate is 1:10 to 1:20, and the amphoteric ionic compound comprises at least one of aminomethanesulfonic acid, taurine, and homotaurine. Claim 2 An etching solution composition according to claim 1, wherein the weight ratio of the hydrogen sulfate salt to the amphoteric ion compound is 1:2 or more and 1:25 or less. Claim 3 In claim 2, the carbonyl ring compound is an etching solution composition comprising at least two carbonyl groups forming a ring. Claim 4 In claim 3, the carbonyl ring compound comprises at least one of thiazolidinedione, hydantoin, and succinimide, in an etching solution composition. Claim 5 An etching solution composition according to claim 1, wherein the trinitrogen ring compound is a triazole comprising at least one thiol group as a substituent. Claim 6 In claim 5, the etching solution composition comprises at least one of the trinitrogen ring compound, 3-mercapto-4-methyl-4H-1,2,4-triazole, 3-amino-1,2,4-triazole-5-thiol, and 1H-1,2,4-triazole-3-thiol. Claim 7 The etching solution composition according to claim 1, wherein the persulfate comprises at least one of potassium persulfate (K2S2O8), sodium persulfate (Na2S2O8), and ammonium persulfate ((NH4)2S2O8). Claim 8 The etching solution composition according to claim 1, wherein the tetranitrogen ring compound comprises at least one of aminotetrazole, methyltetrazole, and mercaptomethyltetrazole. Claim 9 The etching solution composition according to claim 1, wherein the fluorine compound comprises at least one of hydrofluoric acid (HF), ammonium fluoride (NH4F), potassium fluoride (KF), sodium fluoride (NaF), ammonium bifluoride (F2H5N), potassium bifluoride (KHF2), and sodium bifluoride (NaHF2). Claim 10 In claim 1, the hydrogen sulfate salt comprises at least one of ammonium hydrogen sulfate (NH4HSO4), lithium hydrogen sulfate (LiHSO4), potassium hydrogen sulfate (KHSO4), and sodium hydrogen sulfate (NaHSO4), forming an etching solution composition. Claim 11 delete Claim 12 In claim 1, the etching solution composition is an etching solution composition for etching a multilayer film composed of a titanium film and a copper film. Claim 13 The method comprises the steps of: forming a metal film; forming a photoresist pattern on the metal film; providing an etching solution composition on the metal film having the photoresist pattern formed thereon; and removing the photoresist pattern; wherein the etching solution composition comprises: persulfate 5 wt% or more and 20 wt% or less; phosphoric acid or phosphate 0.1 wt% or more and 5 wt% or less; carbonyl ring compound 0.01 wt% or more and 2 wt% or less; trinitrogen ring compound 0.01 wt% or more and 1 wt% or less; tetranitrogen ring compound 0.1 wt% or more and 2 wt% or less; fluorine compound 0.1 wt% or more and 0.9 wt% or less; hydrogen sulfate 0.1 wt% or more and 0.5 wt% or less; and amphoteric ionic compound 1 wt% or more and 3 wt% or less. A method for manufacturing a metal pattern comprising water such that the total weight of the entire composition is 100% by weight, wherein the weight ratio of the amphoteric ionic compound to the persulfate is 1:10 to 1:20, and the amphoteric ionic compound comprises at least one of aminomethanesulfonic acid, taurine, and homotaurine. Claim 14 A method for manufacturing a metal pattern according to claim 13, wherein the step of forming the metal film comprises the step of forming a first metal film comprising titanium and the step of forming a second metal film comprising copper on the first metal film. Claim 15 A method for manufacturing a metal pattern according to claim 13, wherein the weight ratio of the hydrogen sulfate salt to the amphoteric ionic compound is 1:2 or more and 1:25 or less. Claim 16 In claim 13, the carbonyl ring compound comprises a method for manufacturing a metal pattern comprising at least two carbonyl groups forming a ring. Claim 17 A method for manufacturing a metal pattern according to claim 16, wherein the carbonyl ring compound comprises at least one of thiazolidinedione, hydantoin, and succinimide. Claim 18 A method for preparing a metal pattern according to claim 13, wherein the trinitrogen ring compound is a triazole comprising at least one thiol group as a substituent. Claim 19 The method comprises the steps of: forming a gate line and a gate electrode connected to the gate line on a substrate; forming a data line intersecting the gate line insulatedly, a source electrode connected to the data line, and a drain electrode spaced apart from the source electrode; and forming a pixel electrode connected to the drain electrode; wherein the step of forming the gate line and the gate electrode comprises the steps of: forming a metal film comprising titanium and copper; forming a photoresist pattern on the metal film; providing an etching solution composition on the metal film having the photoresist pattern formed thereon; and removing the photoresist pattern; wherein the etching solution composition comprises 5 wt% or more and 20 wt% or less of persulfate; 0.1 wt% or more and 5 wt% or less of phosphoric acid or phosphate; 0.01 wt% or more and 2 wt% or less of a carbonyl ring compound; and 0.01 wt% or more and 1 wt% or less of a trinitrogen ring compound. A method for manufacturing a thin film transistor substrate comprising: 0.1 wt% or more and 2 wt% or less of a tetranitrogen ring compound; 0.1 wt% or more and 0.9 wt% or less of a fluorine compound; 0.1 wt% or more and 0.5 wt% or less of a hydrogen sulfate; 1 wt% or more and 3 wt% or less of an amphoteric ionic compound; and water such that the total weight of the entire composition is 100 wt%, wherein the weight ratio of the amphoteric ionic compound to the persulfate is 1:10 to 1:20, and the amphoteric ionic compound comprises at least one of aminomethanesulfonic acid, taurine, and homotaurine. Claim 20 A method for manufacturing a thin-film transistor substrate according to claim 19, wherein the step of forming the metal film comprises the step of forming a first metal film comprising titanium and the step of forming a second metal film comprising copper on the first metal film.

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