KR102577915B1 - Metal layer etchant composition - Google Patents

Abstract

The present invention relates to an etchant composition for selectively etching a copper-based metal film used as an electrode of a TFT-LCD display. According to the present invention, selective etching of a copper-based metal film is possible and the formation of poorly soluble precipitates in the chemical solution. By preventing this, filter clogging and attack on the photoresist can be minimized. In addition, by easily controlling the etching speed, it is possible to stably provide metal wiring with the desired pattern linearity and taper angle.

Description

Metal layer etchant composition}

The present invention relates to a metal film etchant composition, and particularly to an etchant composition that can solve the problem of disconnection of a metal film used as metal wiring of a TFT-LCD display and a method of using the same.

In TFT-LCD display devices, the resistance of metal wiring is a major factor causing RC signal delay. Accordingly, obtaining low-resistance metal wiring is becoming a key to increasing panel size and realizing high resolution. In the prior art, chromium, molybdenum, aluminum niodium or their alloys used as metal wiring materials had high resistance, so there were limitations in their use as gates and data wiring used in large TFT-LCDs.

In this regard, copper (Cu), which has a significantly lower resistance than aluminum or chrome and poses no significant environmental problems, is attracting attention as a material for low-resistance metal wiring. However, in the case of the copper film, many problems were discovered when selectively etching the photoresist pattern as a mask. For example, a problem was discovered in which adhesion to a glass substrate or silicon insulating film deteriorates during etching. To solve this problem, rather than using a single copper film, a technology was proposed that uses an intermediate metal film together to increase the adhesion between the copper film and the glass substrate or silicon insulating film and to suppress diffusion of copper into the silicon insulating film. . Materials for this intermediate metal film include titanium, titanium alloy, molybdenum, or molybdenum alloy.

Under this background, interest in etchant compositions that selectively etch copper-based metal films such as copper and molybdenum or molybdenum alloy films as a material for new low-resistance metal wiring is increasing. However, in the case of such etchant compositions for copper-based metal films, various types are currently used, but they do not meet the performance required by users.

Generally, the use of a strong oxidizing agent is required to etch copper-based metal films. Examples of those widely used as strong oxidizing agents include hydrogen peroxide (H ₂ O ₂ ), ferric iron hydrate (Fe(III)), and the like. Accordingly, Patent Document 1 discloses a mixture of hydrogen peroxide and an inorganic acid or neutral salt, and Patent Document 2 discloses an etchant containing hydrogen peroxide, a copper reaction inhibitor, a peroxide stabilizer, and fluoride ions. Additionally, Patent Document 3 discloses a mixture of iron (III) chloride hexahydrate and hydrofluoric acid (HF). However, although the copper-based metal film etchant containing such a strong oxidizing agent is efficient in etching the copper-based metal film, it easily damages patterns formed before the copper-based metal film in the process of etching the copper-based metal film, which causes the copper-based metal film to be etched. This causes a disconnection problem in the metal film. In addition, because the copper-based metal film etchant uses a strong oxidizing agent, it is difficult to control the etching speed, causing the problem of patterning into a shape different from that theoretically designed by the user.

Accordingly, when selectively etching a copper-based metal film used for metal wiring of a TFT-LCD display, the present inventors can effectively suppress damage to patterns formed before the copper-based metal film and easily control the etching speed. An etchant composition and a method using it have been developed.

KR 10-2002-0050020 A KR 10-2005-0000682 A KR 10-2000-0032999 A

The purpose of the present invention is to provide an etchant composition that can solve the problem of disconnection of a metal film and a method using the same.

In detail, an etchant composition that can improve PR (photo resist) damage as well as short-circuit problems in metal films by effectively suppressing the generation of poorly soluble by-products generated during the process of etching metal films, an etching method using the same, and a display using the same. A method for manufacturing a substrate is provided.

In detail, it provides a metal film etchant composition that can implement good etching characteristics for the desired metal film and can selectively etch without damaging patterns formed before the metal film, an etching method using the same, and a method of manufacturing a display substrate using the same. will be.

In detail, an economical etching method for forming metal wiring with improved electrical properties as well as mechanical reliability using the above-described etchant composition and a method for manufacturing a display substrate including the same are provided.

In order to solve the above-mentioned problems, the present invention provides a perhydric etchant composition containing hydrogen peroxide, an etch inhibitor, an inorganic acid satisfying a pKa3 value of 10 to 15, an ammonium-based compound, and a fluorine-based compound. Specifically, based on the total weight, the etchant composition contains 15 to 25% by weight of the hydrogen peroxide, 0.6 to 1.5% by weight of the etch inhibitor, less than 1.0% by weight of an inorganic acid satisfying the pKa3 value of 10 to 15, and the ammonium-based compound. It may contain 0.1 to 3% by weight, 0.01 to 0.3% by weight of the fluorine-based compound, and the remaining amount of water.

Additionally, the present invention includes the steps of etching a copper-based metal film using the above-described etchant composition; A method for etching a metal film including a is provided.

Additionally, the present invention includes the steps of forming a metal layer including a copper-based metal film on a substrate; and forming a photoresist pattern on the metal layer, then etching the metal layer and the substrate having the photoresist pattern to partially remove the metal layer to form a metal wire. A method of manufacturing a display substrate is provided, including wherein the etching is performed by treating the etchant composition described above.

According to the present invention, the generation of poorly soluble by-products that cause disconnection problems in metal films used for metal wiring of TFT-LCD displays can be improved, and good etching characteristics can be achieved with high selectivity for etching objects. Accordingly, it is possible to provide metal wiring for a TFT-LCD display that satisfies excellent reliability.

According to the present invention, it is possible to dramatically prevent the formation of a silicon bond having a poorly soluble fluorine-silicon bond, which is one of the by-products generated during the process of etching a metal film. Accordingly, it can provide process advantages by preventing problems that may be caused by poorly soluble by-products.

According to the present invention, it is possible to dramatically reduce the production of copper-organic compounds having a bond between organic substances and copper in the etchant composition, which is another by-product generated during the process of etching a metal film. By preventing problems that may be caused by these poorly soluble by-products, it can provide process advantages.

According to the present invention, a high selectivity for copper-based metal films can be realized, and disconnection defects due to photoresist attack can be effectively suppressed. In addition, it is possible to provide metal wiring with good pattern linearity and taper angle by easily controlling the etching speed. Accordingly, low-resistance metal wiring can be provided in a very economical manner, which has the advantage of providing a method for manufacturing a display device that is very commercially advantageous.

Hereinafter, the etchant composition according to the present invention will be described in detail with reference to the attached drawings. The drawings introduced below are provided as examples so that the idea of the present invention can be sufficiently conveyed to those skilled in the art. Accordingly, the present invention is not limited to the drawings presented below and may be embodied in other forms, and the drawings presented below may be exaggerated to clarify the spirit of the present invention. Additionally, like reference numerals refer to like elements throughout the specification.

At this time, if there is no other definition in the technical and scientific terms used, they have the meaning commonly understood by those skilled in the art to which this invention pertains, and the gist of the present invention is summarized in the following description and attached drawings. Descriptions of known functions and configurations that may be unnecessarily obscure are omitted.

As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly dictates otherwise.

In addition, units used without special mention in this specification are based on weight, and as an example, the unit of % or ratio means weight % or weight ratio, and weight % refers to the amount of any one component of the entire composition unless otherwise defined. It refers to the weight percent occupied in the composition.

In addition, the numerical range used in this specification includes the lower limit and upper limit and all values within the range, increments logically derived from the shape and width of the defined range, all double-defined values, and the upper limit of the numerical range defined in different forms. and all possible combinations of the lower bounds. Unless otherwise specified in the specification of the present invention, values outside the numerical range that may occur due to experimental error or rounding of values are also included in the defined numerical range.

As used herein, the term “poorly soluble by-product” refers to a precipitate formed when the etchant composition reacts with the silicon source or copper (Cu) during the etching process, and has no solubility (insoluble) or very low solubility in the etchant composition. It means a substance (poorly soluble). In the present specification, it may refer to a silicon bond having a fluorine-silicon bond or a copper-organic material bond having a bond between an organic material and copper in an etchant composition.

In addition, the term "comprise" in this specification is an open description that has the same meaning as expressions such as "comprises," "contains," "has," or "characterized by" and is not additionally listed. No element, material or process is excluded.

In addition, the term "substantially" in this specification means that other elements, materials, or processes not listed together with the specified element, material, or process impermissibly interfere with at least one basic and novel technical idea of the invention. It means that it can be present in an amount or degree that does not have a significant effect.

In the case of conventional etchant compositions for etching copper-based metal films, PR patterns formed before the copper-based metal film are easily damaged, causing a disconnection problem in the copper-based metal film. Although the exact cause of this problem has not been revealed, the present inventors predict that the cause is poorly soluble by-products formed in the chemical solution due to continuous glass etching as the etching process proceeds, that is, silicon bonds and copper-organic compounds. Invention was deepened.

Specifically, in order to solve this problem, the present inventors analyzed poorly soluble by-products formed during the etching process and conducted research to suppress their formation. Meanwhile, it was confirmed that there was a difference in solubility in the chemical solution depending on the crystal structure of the by-product, and further, it was confirmed that the production of these poorly soluble by-products could be suppressed and the resulting photoresist defects could be dramatically reduced through a specific composition, and the present invention I would like to propose.

Hereinafter, the present invention will be described in detail.

As described above, the present invention provides a perhydric etchant composition that can dramatically reduce the production of poorly soluble by-products generated due to continuous glass etching during the etching process. Specifically, the etchant composition may include hydrogen peroxide, an etch inhibitor, a fluorine-based compound, an ammonium-based compound, and an inorganic acid satisfying a pKa3 value of 10 to 15.

Specifically, the etchant composition according to an embodiment of the present invention satisfies 15 to 25% by weight of hydrogen peroxide, 0.6 to 1.5% by weight of the etch inhibitor, and the pKa3 value of 10 to 15, based on the total weight of the etchant composition. It may contain less than 1.0% by weight of the inorganic acid, 0.1 to 3% by weight of the ammonium-based compound, 0.01 to 0.3% by weight of the fluorine-based compound, and a residual amount of water.

The etchant composition of this type can control the crystal structure of a by-product having a special fluorine-silicon bond by the degree of activation of the chemical solution. That is, according to the present invention, it is expected that the desired effect can be achieved by controlling the crystal structure of poorly soluble by-products that may be generated in the chemical solution during the etching process through continuous glass etching. On the other hand, in the case of an etchant composition that does not satisfy this composition, it shows a minimal effect in suppressing the formation of poorly soluble by-products.

In order to provide more synergy to this effect, it is preferable that the etchant composition does not contain components that provide alkali metals or alkaline earth metals as cations. That is, the etchant composition according to the present invention does not substantially contain components containing alkali metals or alkaline earth metals.

In the etchant composition according to an embodiment of the present invention, the ammonium-based compound may be one or two or more selected from ammonium phosphate-based compounds and ammonium sulfate-based compounds, and a non-limiting example thereof is ammonium sulfate ((NH ₄ ) ₂ SO ₄ ), ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ), ammonium bisulfate ((NH ₄ )HSO ₄ ), ammonium monobasic phosphate (NH ₄ H ₂ PO ₄ ) and ammonium dibasic phosphate. It may be one or a mixture of two or more selected from ((NH ₄ ) ₂ HPO ₄ ).

As an example, the ammonium-based compound may include one or a mixture of two or more selected from the ammonium sulfate-based compounds described above.

As an example, the mixture may include ammonium sulfate as the first ammonium-based compound, and ammonium persulfate, ammonium bisulfate, or a combination thereof as the second ammonium-based compound. In this case, ammonium sulfate acts as an auxiliary chelating agent through the resonance structure of sulfate ions, and ammonium persulfate and ammonium bisulfate have high oxidation potential values, which can improve the etching rate of the metal film. At the same time, when these combinations are used, it is expected to serve as a crystal shape regulator that can effectively control the crystal growth of silicon bonds accumulated during the continuous etching process of the metal film. Accordingly, photoresist attack caused by the silicon binder can be solved. Additionally, in this case, it is also desirable in terms of stability of the chemical solution.

As an example, the mixture may be a mixture of 1 to 10 parts by weight of an ammonium sulfate-based compound selected from ammonium persulfate, ammonium hydrogen sulfate, or a combination thereof, based on 1 part by weight of ammonium sulfate, preferably 1 to 5 parts by weight. It may be mixed in 1 to 3 parts by weight, more preferably 1 to 3 parts by weight.

As an example, when the mixture includes a combination of ammonium persulfate and ammonium bisulfate, their weight ratio is 1:9 to 9:1, or 1:9 to 1:1, or 1:5 to 1:1. It can be included in the scope of .

In the etchant composition according to an embodiment of the present invention, the fluorine-based compound may be one or a mixture of two or more selected from hydrogen fluoride (HF), ammonium fluoride (NH ₄ F), and ammonium bifluoride (NH ₄ HF ₂ ). there is.

In the etchant composition according to an embodiment of the present invention, the inorganic acid may not be limited as long as the pKa3 value satisfies 10 to 15. However, even if this is satisfied, in the case of organic acids, the effect on the activation degree of the chemical solution is minimal, so control of the desired crystal structure cannot be induced. In addition, when an inorganic acid having a pKa value of 2 or less is used, it has a minimal effect on suppressing the formation of poorly soluble by-products and is therefore excluded from the present invention.

For example, the pKa3 value of the inorganic acid may be 11 to 15, or 12 to 14. Here, the fact that the inorganic acid has a pKa3 value means that it has at least three pKa values.

For example, when the pKa1 value of the inorganic acid satisfies the range of 1 to 3, not only can a more stable chemical solution be provided, but the formation of poorly soluble by-products can be more effectively suppressed. Moreover, in this case, it is possible to implement a stable etch profile and prevent wiring short circuits due to PR damage.

For example, when the pKa1 value of the inorganic acid satisfies the range of 7 to 9.5, it is better in terms of being able to easily control the etching rate while achieving the above-described effects.

In an etchant composition satisfying the above-described composition, the inorganic acid and the fluorine-based compound may be mixed at a weight ratio of 1.5 to 15:1 in order to increase the stability of the chemical solution. Additionally, based on 1 part by weight of the fluorine-based compound, the inorganic acid may be included in an amount of 2 to 12 parts by weight, or 4 to 10 parts by weight. If this weight ratio is satisfied, it is possible to minimize the change in pH of the chemical solution and prevent agglomeration due to the formation of amorphous by-products.

The etch inhibitor may be a ring-based compound containing heteroatoms selected from oxygen, sulfur, and nitrogen in the molecule, non-limiting examples of which include pyrrole, piperazine, pyrrolidine, alloxan, imidazole, and pyrazole. , 1,2,3-triazole, 1,2,4-triazole, 5-aminotetrazole, 5-methyltetrazole, tetrazole, pentazole, oxazole, isoxazole, 1,2,3- Oxadiazole, oxadiazole, furazane, 1,3,4-oxadiazole, thiazole, isothiazole, thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadia It may be any one selected from sol, 1,3,4-thiadiazole, and derivatives thereof, or a mixture of two or more. This may play a role in increasing the process margin by controlling the etching speed of the metal film and reducing the variation in the etching profile depending on the number of sheets processed.

More specifically, the etchant composition according to an embodiment of the present invention contains 15 to 20% by weight of hydrogen peroxide, 0.8 to 1.5% by weight of the etch inhibitor, and 0.01% by weight of an inorganic acid satisfying the pKa3 value of 10 to 15, based on the total weight. to 1.9% by weight, 0.2 to 2.8% by weight of the ammonium-based compound, 0.03 to 0.3% by weight of the fluorine-based compound, and a remaining amount of water.

Most specifically, the etchant composition according to an embodiment of the present invention contains, based on the total weight, 15 to 18% by weight of hydrogen peroxide, 0.8 to 1.3% by weight of the etch inhibitor, and 0.1% by weight of an inorganic acid satisfying the pKa3 value of 10 to 15. to 1.5% by weight, 0.5 to 2.5% by weight of the ammonium-based compound, 0.04 to 0.2% by weight of the fluorine-based compound, and the remaining amount of water.

When the above-mentioned composition and weight conditions are satisfied, the degree of activation in the chemical solution can be extremely increased, preventing the growth of poorly soluble by-products, and at the same time changing the poorly soluble by-products into an amorphous form to prevent PR attack. As a result, it is possible to solve the problem of disconnection of the copper-based metal film, which was pointed out as a problem in the prior art. In addition, these poorly soluble by-products may cause clogging of equipment pipes and waste liquid pipes, resulting in problems such as cost for removal of precipitation in equipment and pipes, wastewater treatment, and lower process yield. However, the present invention According to this, it does not cause such problems and can provide advantages in the process.

Additionally, the etchant composition according to an embodiment of the present invention may further include an amine-based compound.

In the etchant composition according to an embodiment of the present invention, the amine-based compound is not limited as long as it is a conventional amine compound, and may be selected from alkylamines and alkanolamines having 10 carbon atoms or less. Here, the alkylamine and alkanolamine may be straight-chain, branched, or cyclic. Non-limiting examples thereof include methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, dimethylamine, diethylamine, trimethylamine, triethylamine, ethanolamine, and dimethylethanolamine. , it may be one or a combination of two or more selected from methylethanolamine, methyldiethanolamine, diethanolamine, and cyclohexylamine.

In the etchant composition according to an embodiment of the present invention, the amine-based compound may be included in an amount of 0.01 to 3% by weight, or 0.05 to 2% by weight, or 0.1 to 1% by weight, based on the total weight of the composition, and is limited thereto. That is not the case.

Additionally, the etchant composition according to an embodiment of the present invention may further include one or two or more selected from a chelating agent having two or more carboxyl groups and an organic acid.

When the etchant composition according to an embodiment of the present invention further includes one or two or more selected from the chelating agent and organic acid, not only can a more stable chemical solution be provided, but the formation of poorly soluble by-products can be more effectively suppressed. It's good to have it. Specifically, it is good because a stable etch profile can be implemented and wiring short circuits due to PR damage can be prevented more effectively.

In the etchant composition according to an embodiment of the present invention, the chelating agent is not particularly limited as long as it contains two or more carboxyl groups, and non-limiting examples include citric acid, oxalic acid, malonic acid, tartaric acid, sulfosuccinic acid, Sulfophthalic acid, succinic acid, malic acid and isocitric acid, tetraacetic acid, propylenediamine tetraacetic acid, butylenediamine tetraacetic acid, diethylenetriamine pentaacetic acid, iminodiacetic acid, N-(2-hydroxyethyl)ethylenediamine triacetic acid, Ethylene glycol-bis(β-aminoethyl ether)-N,N,N',N'-tetraacetic acid, 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetra Acetic acid, nitrile triacetic acid, cyclohexane-1,2-diamine tetraacetic acid, 1,3-diamino-2-hydroxypropane-N,N,N',N'-tetraacetic acid and hexamethylenediamine-N,N It may be one or a combination of two or more selected from ,N',N'-tetraacetic acid, etc.

In the etchant composition according to an embodiment of the present invention, the organic acid is not limited as long as it is a conventional organic acid, and may specifically be selected from organic acids containing one carboxyl group. A non-limiting example thereof may be one or a combination of two or more selected from acetic acid, lactic acid, formic acid, butanoic acid, pentanoic acid, propionic acid, gluconic acid, glycolic acid, benzoic acid, salicylic acid, propenoic acid, etc. More specifically, the organic acid may be one or a combination of two or more selected from acetic acid, lactic acid, and formic acid. More specifically, the organic acid may be an alpha hydroxy acid such as lactic acid. In this case, the exact cause is not known, but it further reduces steric hindrance during coordination of copper or silicon, resulting in poorly soluble by-products. can prevent the formation of.

In one embodiment, the etchant composition may include a combination of the chelating agent and an organic acid. If the etchant composition contains only a chelating agent having two or more carboxyl groups, it may be difficult to coordinate to all coordination sites of copper or silicon due to steric hindrance. However, when an organic acid containing one carboxyl group is included in addition to the chelating agent, the organic acid becomes structurally accessible to copper or silicon, thereby increasing coordination bonds. Accordingly, not only can a more stable chemical solution be provided, but the formation of poorly soluble by-products can be suppressed more effectively.

In the etchant composition according to an embodiment of the present invention, the chelating agent and the organic acid may each independently be included in an amount of 0.01 to 5% by weight, or 0.05 to 4% by weight, or 0.1 to 3% by weight, based on the total weight of the composition. There is, and it is not limited to this.

In the etchant composition according to an embodiment of the present invention, when a chelating agent and an organic acid having two or more carboxyl groups are included, the chelating agent and the organic acid are 1:0.05 to 20, specifically 1:0.05 to 10, more specifically. It may be included in a weight ratio of 1:0.1 to 10. When the chelating agent and the organic acid satisfy the above range, it is good because coordination can be achieved more effectively.

The etching target of the etchant composition according to an embodiment of the present invention may be a copper-based metal film, and specifically, a single film made of copper or a copper alloy; and a multilayer film including the single film and a film made of molybdenum or molybdenum alloy. It may be selected from . At this time, the copper alloy or molybdenum alloy can be used without limitation as long as it is a metal that can be used in the electrode of a TFT-LCD display. Non-limiting examples include tungsten, titanium, tantalum, chromium, neodymium, and niobium. , it may be one or two or more selected from nickel, indium, and tin.

The pH of the etchant composition according to an embodiment of the present invention may be adjusted to a range of 1.0 to 5.0, specifically 1.5 to 4.5, and more specifically 1.5 to 4.0. Here, the water included in the etchant composition is not particularly limited, but may specifically be deionized water, and more specifically, may be deionized water for semiconductor processing, and may have a resistivity value of 18 MΩ·cm or more.

As described above, according to the present invention, the generation of poorly soluble by-products that cause disconnection problems of metal films used as metal wiring of TFT-LCD displays can be dramatically improved. Accordingly, it has a high selectivity for copper-based metal films and can maintain a stable etch profile by implementing excellent etching characteristics, thereby providing highly reliable metal wiring. In addition, according to the present invention, it is very commercially advantageous because it does not cause clogging of pipes and waste liquid pipes of process equipment, and does not require equipment or additional processes for removal.

Accordingly, according to the present invention, when a copper-based metal film is used as a metal wiring material for a gate, source, or drain electrode constituting a TFT (Thin Film Transistor) applied to a liquid crystal display device, an etchant composition for forming a metal wiring or pattern is provided. It can be usefully used.

Additionally, the present invention provides a method of etching a metal film using the above-described etchant composition and a method of manufacturing a display substrate including the same.

In one aspect, a method of etching a metal film according to an embodiment of the present invention includes etching a copper-based metal film using the above-described etchant composition; It may include.

In one aspect, a method of manufacturing a display substrate according to an embodiment of the present invention includes forming a metal layer including a copper-based metal film on a substrate; and forming a photoresist pattern on the metal layer, then etching the metal layer and the substrate having the photoresist pattern to partially remove the metal layer to form a metal wire. It may include, and the etching is performed by treating the etchant composition described above.

The etching method of a metal film and the manufacturing method of a display substrate including the same according to an embodiment of the present invention may include etching a single film made of a copper-based metal film, or simultaneously etching a multilayer film including a copper-based metal film. You can. At this time, when using the etchant composition according to the present invention, it not only implements good etching characteristics for the copper-based metal film, but also effectively suppresses damage to the PR pattern formed before the copper-based metal film, thereby preventing disconnection problems in the copper-based metal film. No.

As an example, good etching characteristics for a copper film may be achieved by satisfying the etching rate (E _Cu ) of 30 to 250 Å/sec, 50 to 200 Å/sec, or 80 to 190 Å/sec. In addition, this means that the above-mentioned etching speed can be stably achieved not only when processing high processing sheets but also when processing large areas.

According to one embodiment of the present invention, it is possible to provide a more reliable metal wire or pattern for electrodes of a TFT-LCD display by satisfying the above-described etch rate as well as a low taper angle at the same time.

According to the method of manufacturing a display substrate according to an embodiment of the present invention, the copper-based metal film is selectively etched but does not cause corrosion or damage to the PR pattern. At this time, the substrate may be used without limitation as long as it is a base substrate that can be commonly used in the manufacture of a display substrate, but preferably may be a glass substrate. Additionally, non-limiting examples of the substrate include a rigid substrate selected from quartz substrates, glass ceramic substrates, and crystalline glass substrates; and a flexible substrate selected from flexible glass substrates, plastic substrates, etc.; can be mentioned. At this time, the plastic substrate may include one or more materials selected from polyimide, polycarbonate, polyphenylene sulfide, polyaryline ether sulfone, etc., but is not limited thereto.

In addition, the metal film, which is one of the etching objects targeted in the present invention, is a single film made of copper or a copper alloy; and a multilayer film including the single film and a film made of molybdenum or molybdenum alloy. It may be selected from . Additionally, the alloy may be one or two or more alloys selected from tungsten, titanium, tantalum, chromium, neodymium, niobium, nickel, indium, and tin.

According to the present invention, the copper film and the molybdenum-containing film, which are metal wiring satisfying low resistance, are stably etched, making it possible to enlarge the TFT-LCD in a very economical manner.

In the method of manufacturing a display substrate according to an embodiment of the present invention, a portion of the surface of the metal layer may further include a single film or two or more multilayer films selected from a silicon insulating film and a transparent conductive film. However, according to the present invention, etching does not occur on the substrate as well as the silicon insulating film and transparent conductive film, so it can be very advantageously used in forming low-resistance metal wiring.

The silicon insulating film may be one or a combination of two or more selected from a silicon nitride film and a silicon oxide film.

For example, the silicon nitride may be a SiNx layer, a SiON layer, or a doped SiNx layer.

For example, the silicon oxide is a Spin On Dielectric (SOD) film, a High Density Plasma (HDP) film, a thermal oxide film, a Borophosphate Silicate Glass (BPSG) film, a Phospho Silicate Glass (PSG) film, and a Boro Silicate (BSG) film. Glass) film, PSZ (Polysilazane) film, FSG (Fluorinated Silicate Glass) film, LP-TEOS (Low Pressure Tetra Ethyl Ortho Silicate) film, PETEOS (Plasma Enhanced Tetra Ethyl Ortho Silicate) film, HTO (High Temperature Oxide) film, MTO (Medium Temperature Oxide) film, USG (Undopped Silicate Glass) film, SOG (Spin On Glass) film, APL (Advanced Planarization Layer) film, ALD (Atomic Layer Deposition) film, PE-oxide film (Plasma Enhanced oxide) or O It may be ₃ -TEOS (O ₃ -Tetra Ethyl Ortho Silicate), etc.

The transparent conductive film can be used without limitation as long as it is a common material used in display substrates, and examples thereof include indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), and gallium oxide. One or a combination of two or more selected from zinc indium (IGZO) and the like can be mentioned.

As described above, the method of manufacturing a display substrate according to the present invention can be usefully utilized in the step of forming a semiconductor structure for display devices such as various types of liquid crystal display devices and plasma display panels.

The etchant composition for a copper-based metal film according to the present invention will be described in more detail through examples below. However, the following examples are only a reference for explaining the present invention in detail, and the present invention is not limited thereto, and may be implemented in various forms. Additionally, unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention pertains. Additionally, the terms used in the description in the present invention are only intended to effectively describe specific embodiments and are not intended to limit the present invention.

(Assessment Methods)

1. Assess the presence of filter crystals

In order to evaluate the presence of filter crystals in the etchant composition according to the present invention, a glass substrate (SiO ₂ ) was added to each etchant composition and an etching evaluation was performed. Afterwards, each etchant composition was passed through a syringe filter (manufactured by Whatman, pore size: 0.45㎛), and then the clogging of the filter was observed using a scanning electron microscope (S-4800, manufactured by Hitachi).

The related evaluation was evaluated by the number of precipitates (poorly soluble by-products) in the filter if they occurred, and if not, it was evaluated as ×.

The results are shown in Table 2 below.

2. Etching performance evaluation

In order to evaluate the etching performance of the etchant composition according to the present invention, a glass substrate (SiO ₂ ), a silicon insulating film (SiNx) deposited to a thickness of 600 Å, a copper film and a molybdenum alloy film deposited to a thickness of 3000 Å (thickness ratio = 10: 1) was manufactured through a photolithography process.

Etching was performed (32°C) using equipment capable of spraying (Mini-etcher ME-001) using each of the etchant compositions of the examples and comparative examples below. After etching. The etching characteristics of the copper film and molybdenum alloy film were observed using a scanning electron microscope (S-4800, manufactured by Hitachi). Here, in order to check the etching characteristics of the copper film and the molybdenum alloy film, an over etch of 30% was performed.

The results are shown in Table 2 below.

3. Evaluation of broken PR

In order to evaluate photoresist cracking of the etchant composition according to the present invention, a glass substrate (SiO ₂ ) was dissolved in each etchant composition of the following Examples and Comparative Examples for 24 hours. Afterwards, etching was performed with each etchant composition. Here, the etching was performed using equipment (Mini-etcher ME-001) capable of spraying a copper film and a molybdenum alloy film (thickness ratio = 10:1, thickness 3000 Å) coated with photoresist formed on a glass substrate. Afterwards, cracking of the photoresist was observed using an optical microscope (KEYENCE, VHX-5000).

The relevant evaluation was evaluated by the number of eroded lines that occurred on the photoresist surface (3 cm

(Examples 1 to 22 and Comparative Examples 1 to 10)

An etchant composition (100 g) was prepared with the ingredients and contents listed in Table 1 below.

division Filter decision present
(SEM analysis results) Cu etch rate PR broken evaluation
(Number in 3 cm x 3 cm) PR broken evaluation
(Number in 5 cm x 5 cm) Example 1 X 140 X 3 Example 2 X 100 X 3 Example 3 X 160 X 3 Example 4 X 120 X 3 Example 5 X 130 X 2 Example 6 X 170 X 3 Example 7 X 80 X 2 Example 8 X 110 X 2 Example 9 X 150 X 2 Example 10 X 130 X 2 Example 11 X 130 X 2 Example 12 X 140 X 2 Example 13 X 130 X X Example 14 X 120 X X Example 15 X 140 X X Example 16 X 130 X X Example 17 X 130 X X Example 18 X 130 X X Example 19 X 130 X X Example 20 X 130 X X Example 21 X 130 X 2 Example 22 X 130 X 2 Comparative Example 1 8 80 10 27 Comparative example 2 11 80 15 42 Comparative Example 3 6 170 9 25 Comparative Example 4 2 160 One 31 Comparative Example 5 5 70 6 16 Comparative Example 6 4 140 7 19 Comparative example 7 15 150 23 62 Comparative example 8 9 150 17 46 Comparative Example 9 5 60 8 21 Comparative Example 10 7 90 13 35

As shown in Table 2, it was confirmed that the etchant composition according to the present invention can effectively prevent the generation of poorly soluble by-products by controlling the crystal structure of by-products generated during the etching process. Accordingly, it was confirmed that problems such as clogging of pipes and filters that occur during the process can be prevented, and photoresist cracking due to photoresist attack by poorly soluble by-products can be dramatically reduced.

On the other hand, in all cases of comparative examples, poorly soluble by-products were formed in the chemical solution during the etching process, and many crystals were confirmed to cause clogging in the pipes and filters, and many photoresist cracks were also confirmed, showing that they were defective. Moreover, in the case of Comparative Examples 7 to 10, which provided cations such as alkali metal or alkaline earth metal in the chemical solution, the production of poorly soluble by-products was more noticeable.

No cracks were found in the etchant compositions according to all examples in the PR crack evaluation within 3 cm It has been done. Through this, it was confirmed that when at least one of a chelating agent with two or more carboxyl groups and an organic acid is further included, the phenomenon of photoresist cracking due to photoresist attack by poorly soluble by-products can be significantly reduced.

In particular, Examples 13 to 18 did not show any photoresist cracking compared to Examples 21 and 22. This shows that the etching composition containing a combination of two or more carboxyl groups or a chelating agent or an organic acid alone was more effective than that of Examples 21 and 22. It was confirmed that this was effective in suppressing photoresist cracking.

In addition, the etchant composition according to the present invention can achieve a good etching speed and excellent etching characteristics for copper-based metal films, so there is little change in CD loss of the desired etching profile. That is, the etchant composition according to the present invention has very excellent selectivity for copper-based metals. In addition, according to the present invention, by adjusting the composition and content of the etchant composition, the etching speed can be easily adjusted, and a highly reliable metal wiring can be stably provided without damaging the patterns formed before the copper-based metal film. good night.

As described above, the present invention has been described with specific details and limited examples and comparative examples, but these are provided only to facilitate a more general understanding of the present invention, and the present invention is not limited to the above examples. Those skilled in the art can make various modifications and variations from this description.

Accordingly, the spirit of the present invention should not be limited to the described embodiments, and the scope of the patent claims described below as well as all modifications that are equivalent or equivalent to the scope of this patent claim shall fall within the scope of the spirit of the present invention. .

Claims (15)

Based on the total weight, 15 to 25% by weight of hydrogen peroxide, 0.6 to 1.5% by weight of an etch inhibitor, more than 0 to less than 1.0% by weight of an inorganic acid with a pKa3 value of 10 to 15, 0.1 to 3% by weight of an ammonium-based compound, and 0.01% by weight of a fluorine-based compound. An etchant composition comprising from 0.3% by weight, 0.01 to 5% by weight of a chelating agent having two or more carboxyl groups, 0.01 to 5% by weight of an organic acid, and the remaining amount of water. According to clause 1,
The ammonium-based compound is,
An etchant composition selected from ammonium phosphate-based compounds and ammonium sulfate-based compounds. According to clause 1,
The ammonium-based compound is,
An etchant composition comprising an ammonium sulfate-based compound. According to clause 1,
The weight ratio of the inorganic acid and the fluorine-based compound is,
An etchant composition that satisfies 1.5 to 15:1. According to clause 1,
The fluorine-based compound is,
An etchant composition selected from hydrogen fluoride (HF), ammonium fluoride (NH ₄ F), and ammonium bifluoride (NH ₄ HF ₂ ). According to clause 1,
The etch inhibitor is,
An etchant composition, which is a ring-based compound containing heteroatoms selected from oxygen, sulfur, and nitrogen in the molecule. According to clause 1,
An etchant composition further comprising an amine-based compound. delete According to clause 1,
The etchant composition wherein the organic acid has one carboxyl group. According to clause 1,
The etchant composition, wherein the organic acid is at least one selected from formic acid, acetic acid, and lactic acid. According to clause 1,
The etchant composition wherein the etching target of the etchant composition is a copper-based metal film. According to claim 11,
The copper-based metal film is,
A single film made of copper or copper alloy; and
A multilayer film including the single film and a film made of molybdenum or molybdenum alloy; A metal film etchant composition selected from . According to clause 1,
A metal film etchant composition that satisfies the pH range of 1.0 to 5.0. Etching a copper-based metal film using a metal film etchant composition according to any one of claims 1 to 7 and 9 to 13; A method of etching a metal film comprising. forming a metal layer including a copper-based metal film on a substrate; and
After forming a photoresist pattern on the metal layer, etching the substrate having the metal layer and the photoresist pattern to partially remove the metal layer to form a metal wiring; Including,
A method of manufacturing a display substrate, wherein the etching is performed by treating the etchant composition according to any one selected from claims 1 to 7 and 9 to 13.