KR20220071662A - 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, it is possible to provide the etchant composition for etching the copper-based metal film, which can selectively etch the copper-based metal film, can provide a metal wire having a linearity and a taper angle of a desired pattern by easy control of an etching rate, and is effective for high-throughput number of sheets as well as large-area processing by implementing a stable etching profile. In the present invention, the etchant composition comprises hydrogen peroxide, a tertiary amine compound, and an N-heterocyclic fused ring compound.

Description

Metal layer etchant composition

The present invention relates to an etchant composition for a metal film, and more particularly, to an etchant composition for selectively etching a copper-based metal film used as an electrode of a TFT-LCD display, and a method using the same.

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

In this regard, copper (Cu), which has a significantly lower resistance than aluminum or chromium and has no environmental problems, is attracting attention as a material for low-resistance metal wiring. However, in the case of the copper film, many problems have been found during selective etching using the photoresist pattern as a mask. For example, it has been found that the adhesive strength with the glass substrate or the silicon insulating film decreases during etching. In order to solve this problem, rather than using a single copper film, a technique of using an intermediate metal film together to increase the adhesion between the copper film and the glass substrate or silicon insulating film and suppress the diffusion of copper into the silicon insulating film has been proposed. . Titanium, a titanium alloy, molybdenum, or a molybdenum alloy may be used as a material of the intermediate metal film.

Under this background, interest in an etchant composition for selectively etching a copper-based metal film such as copper and molybdenum or a molybdenum alloy film as a material for a new low-resistance metal wiring is increasing. However, in the case of such an etchant composition for the copper-based metal film, various types are currently used, but the performance required by the user is not satisfied.

For example, KR 10-2004-0011041 A discloses a copper molybdenum film etchant containing hydrogen peroxide, an organic acid, a sulfate, a cyclic amine compound, and deionized water. However, in this case, the molybdenum residue is highly likely to remain, and the step coverage of the subsequent film is incomplete, causing data open defects, and pixel defects due to the formation of residues due to partial passivation of molybdenum (Mo). There are serious problems that occur.

As another example, KR 10-2006-0099089 A discloses a metal wiring etchant comprising hydrogen peroxide, sulfate, phosphate, fluoride, a water-soluble cyclic amine compound, a chelating agent, and deionized water. However, in this case, there is a problem in that the critical dimension loss of the etch profile increases when the metal ions in the etchant increase to a certain concentration or more, such as an increase in the number of treatments or a large-area treatment.

Therefore, in the art, the development of an etchant composition capable of wet etching a taper having a desired angle without problems such as an increase in the number of treatments or a large area while having excellent etching uniformity and excellent pattern linearity without problems such as undercutting. is still needed

KR 10-2004-0011041 A KR 10-2006-0099089 A

It is an object of the present invention to provide a metal film etchant composition having a high selectivity for a copper-based metal film compared to a lower film such as a silicon insulating film or a transparent conductive film, an etching method using the same, and a method of manufacturing a display substrate using the same.

In detail, good etching characteristics for the copper-based metal film can be realized, and when the metal layer including the copper-based metal film is batch wet-etched, the linearity of the pattern and the low taper angle can be uniformly obtained without damage to the underlying film. It is to provide a metal film etchant composition that can.

In detail, it is to provide a metal film etchant composition capable of continuously maintaining excellent initial etching properties even if the etching is repeatedly performed and reused a number of times, and can maintain a low taper angle even when the number of treatments is increased in this way.

Specifically, it is to provide a metal film etchant composition excellent in inhibiting properties against the change rate of CD loss and the generation of residues during etching.

In detail, to provide a metal film etchant composition that does not generate precipitates and heat generation even when a high concentration of metal ions is present in a chemical solution.

Specifically, to provide a metal film etchant composition having improved storage stability that can continuously maintain excellent initial etching properties before or after use.

In detail, an etching method capable of forming a metal wiring with improved mechanical reliability as well as electrical properties in a desired etch profile using the above-described metal film etchant composition and a method of manufacturing a display substrate including the same are provided.

In order to solve the above problems, in the present invention, as an etchant composition comprising hydrogen peroxide, a tertiary amine compound, and an N-heterocyclic fused-ring compound, the tertiary amine compound and the N-heterocyclic fused-ring compound are represented by Formula 1 below An etchant composition of a metal film that satisfies is provided.

[Formula 1]

[In Equation 1 above,

Z is the number of rings in the N-heterocyclic fused-ring compound;

은 상기 N-복소환 융합고리 화합물의 탄소와 질소 비율(C개수 / N개수)이고;

is the ratio of carbon to nitrogen (number of C / number of N) of the N-heterocyclic fused-ring compound;

pKa1(a) is the pKa1 value of the tertiary amine compound;

pKa1(b) is the pKa1 value of the N-heterocyclic fused-ring compound;

N is the number of substituents directly bonded to the amine group of the tertiary amine compound (N-tertiary amine), and is an integer of 3.]

In the etchant composition according to an embodiment of the present invention, the N-heterocyclic fused-ring compound may have a number of 2 to 5 rings and satisfy Equation 2 below.

[Formula 2]

[In Equation 2 above,

c is the number of carbon atoms (C number) of the N-heterocyclic fused-ring compound;

n is the number of nitrogens (N number) of the N-heterocyclic fused-ring compound.]

In the etchant composition according to an embodiment of the present invention, the N-heterocyclic fused-ring compound may be selected from adenine, guanine, isoguanine, hypoxanthine, xanthine, theobromine and caffeine.

In the etchant composition according to an embodiment of the present invention, the tertiary amine compound may have a substituent selected from C _1-3 alkyl and C _1-3 hydroxyalkyl.

The etchant composition according to an embodiment of the present invention may include 50 to 200 parts by weight of the N-heterocyclic fused-ring compound based on 100 parts by weight of the tertiary amine compound.

The etchant composition according to an embodiment of the present invention, based on the total weight, 5 to 35% by weight of the hydrogen peroxide, 0.01 to 1.0% by weight of the tertiary amine compound, 0.01 to 1.0% by weight of the N-heterocyclic fused-ring compound and It may contain the remaining amount of water.

The etchant composition according to an embodiment of the present invention may further include an additive selected from an etch inhibitor, a chelating agent, an etchant, a pH adjuster, and a fluorine compound.

In the etchant composition according to an embodiment of the present invention, the etch inhibitor is a ring-based compound containing a heteroatom selected from oxygen, sulfur and nitrogen in a molecule; and a phosphonic acid-based compound comprising two or more phosphonic acid groups.

In the etchant composition according to an embodiment of the present invention, the metal layer may include a single layer made of copper or a copper alloy; and a multilayer film including the single film and a film made of molybdenum or a molybdenum alloy.

In the present invention, there is provided a method of etching a metal film including; etching the copper-based metal film using the above-described etching solution composition.

In addition, in the present invention, 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, wherein the etching is performed with the above-described etching solution There is provided a method for manufacturing a display substrate, which is performed by treating the composition.

In the method of manufacturing a display substrate according to an embodiment of the present invention, the taper angle of the metal wiring may satisfy a range of 35 to 45°.

In the method of manufacturing a display substrate according to an embodiment of the present invention, the metal layer may further include one single layer or two or more multilayer layers selected from a silicon insulating layer and a transparent conductive layer on a part of the metal layer. .

According to the present invention, it is possible to implement a high selectivity ratio for the copper-based metal film compared to the lower film such as a silicon insulating film or a transparent conductive film. In addition, it is possible to provide a metal wiring and a pattern having good pattern linearity and a taper angle through easy control of the etching rate. In addition, it is effective for high-throughput as well as large-area processing by implementing a stable etch profile.

According to the present invention, it is possible to realize a low taper angle even when the number of sheets to be treated increases, to realize an etch profile with excellent linearity during etching, and to effectively suppress the generation of metal residues. In addition, there is an excellent effect of inhibiting the occurrence of precipitates and heat generation even in the case of high-processing sheets or large-area treatment.

Accordingly, according to the present invention, when the metal layer including the copper-based metal layer is wet-etched, over-etching of the copper-based metal layer can be effectively suppressed and the CD loss of the copper-based metal layer can be reduced. Accordingly, it is possible to secure the width of the pattern as well as the implementation of the desired linearity of the pattern. In addition, since metal residues are not generated on the surface of the metal wiring, a low resistance metal wiring can be provided in a very economical way. Accordingly, there is an advantage in that it is possible to provide a method for manufacturing a display device that is commercially very advantageous.

1 is a scanning electron microscope (SEM, Hitachi, SU8010) image of a specimen after etching using an etchant composition according to Example 1 of the present invention;
2 is a scanning electron microscope (SEM, Hitachi, SU8010) image of a specimen after etching using the etchant composition according to Comparative Example 1 of the present invention.

Hereinafter, the etchant composition according to the present invention will be described in detail with reference to the accompanying drawings. The drawings introduced below are provided as examples so that the spirit 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. Also, like reference numerals refer to like elements throughout.

At this time, if there is no other definition in the technical terms and scientific terms used, it has the meaning commonly understood by those of ordinary skill in the art to which this invention belongs, and the gist of the present invention in the following description and accompanying drawings Descriptions of known functions and configurations that may be unnecessarily obscure will be omitted.

As used herein, the singular form may also be intended to include the plural form unless the context specifically dictates otherwise.

In addition, in the present specification, the unit used without special mention is based on the weight, for example, the unit of % or ratio means weight % or weight ratio, and the weight % means any one component of the entire composition unless otherwise defined. It means the weight % occupied in the composition.

In addition, the numerical range used herein includes the lower limit and upper limit and all values within the range, increments logically derived from the form and width of the defined range, all values defined therein, and the upper limit of the numerical range defined in different forms. and all possible combinations of lower limits. Unless otherwise defined in the specification of the present invention, values outside the numerical range that may occur due to experimental errors or rounding of values are also included in the defined numerical range.

As used herein, the term "heterocyclic compound" has an equivalent meaning to an N-heterocyclic fused-ring compound.

As used herein, the term “alkyl” or a substituent containing alkyl includes both straight-chain and branched-chain forms. Also, "hydroxyalkyl" refers to the structure of *-alkylene-OH.

As used herein, the term “comprises” is an open-ended description having an equivalent meaning to expressions such as “comprises”, “contains”, “has” or “characterizes”, and is an element not listed further; Materials or processes are not excluded.

In addition, as used herein, the term “substantially” means that other elements, materials, or processes not listed together with the specified element, material, or process are unacceptable for 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 significantly affect it.

Accordingly, when the metal concentration in the etchant composition increases or the number of treatment sheets increases, the CD loss of the etch profile such as a decrease in the etch rate and the etch uniformity increases. There was a problem that the phenomenon occurred. In particular, there was a problem in that the etched metal atoms in the chemical were not dissolved and the passivation was promoted to cause multiple residues, causing side effects such as pixel defects.

Under this background, the present inventors have intensified the study of the etchant composition. In the meantime, a formula that can dramatically improve this problem in a specific composition was devised. Specifically, in order to suppress over-etching of the copper-based metal film and at the same time suppress damage to the underlying film, the number of rings constituting the resonance structure of a heterocyclic compound containing nitrogen and the ratio of carbon to nitrogen act as important factors. found to do At the same time, it was noted that the smaller the bond order of the amine compound causing the competitive reaction, the less the effect of the heterocyclic compound described above is hindered.

In this way, the present inventors propose a formula through pKa1, which is one of the basic physical properties of a heterocyclic compound and an amine compound, along with the above-mentioned factors, and confirm the range showing synergy in the effect, to propose the present invention.

Hereinafter, the present invention will be specifically described.

As described above, the present invention provides an etchant composition capable of selectively etching a copper-based metal film. Specifically, the etchant composition according to the present invention includes hydrogen peroxide, a tertiary amine compound, and an N-heterocyclic fused-ring compound, and the tertiary amine compound and the N-heterocyclic fused-ring compound may satisfy Formula 1 below. have.

[Formula 1]

[In Equation 1 above,

Z is the number of rings in the N-heterocyclic fused-ring compound;

은 상기 N-복소환 융합고리 화합물의 탄소와 질소 비율(C개수 / N개수)이고;

is the ratio of carbon to nitrogen (number of C / number of N) of the N-heterocyclic fused-ring compound;

pKa1(a) is the pKa1 value of the tertiary amine compound;

pKa1(b) is the pKa1 value of the N-heterocyclic fused-ring compound;

N is the number of substituents directly bonded to the amine group of the tertiary amine compound (N-tertiary amine), and is an integer of 3.]

The etchant composition according to an embodiment of the present invention can suppress the occurrence of over-etching of the metal wiring within the range satisfying Equation 1, and the metal ion in the etchant increases by a certain concentration or more, such as in large-area treatment. Even if it does, it does not generate precipitates and heat at all. In addition, contamination by metal residues does not occur during etching. Furthermore, the etchant composition suppresses over-etching of the copper-based metal layer and at the same time does not cause damage to the underlying layer. In particular, according to the present invention, it can be evaluated that the etch rate for the lower layer such as the silicon insulating layer and the transparent conductive layer is 1 Å/sec or less, respectively, so that damage to the lower layer is not substantially caused.

In addition, the etchant composition of the present invention has a low rate of change in sidiros of the etch profile even with an increase in the number of treatment sheets, and stably maintains the rate of change to realize a desired taper angle. Accordingly, the reliability of the metal wiring or pattern including the copper-based metal film is increased, which is economically advantageous.

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

In the etchant composition according to an embodiment of the present invention, Equation 1 may satisfy a range of more than 5 and less than 10, or a range of 5.3 to 9.7, or a range of 5.47 to 9.53. When this range is satisfied, the etchant composition according to the present invention can stably maintain the etching characteristics by increasing the stability of the chemical as well as the desired etch profile even under severe conditions in which the metal concentration in the chemical is increased or the number of treatment sheets is increased. On the other hand, if the range is not satisfied, overetching of the copper-based metal layer as well as the lower layer may occur or metal residues such as molybdenum residues may be generated, which may cause defects in metal wiring or patterns, which is not preferable. It can also cause decomposition of hydrogen peroxide.

In the etchant composition according to an embodiment of the present invention satisfying Equation 1 above, the N-heterocyclic fused-ring compound has 2 to 5 rings, and may satisfy Equation 2 below.

[Formula 2]

[In Equation 2 above,

c is the number of carbon atoms (C number) of the N-heterocyclic fused-ring compound;

n is the number of nitrogens (N number) of the N-heterocyclic fused-ring compound.]

For example, the N-heterocyclic fused-ring compound may have 2 to 4 rings, and may also have 2 or 3 ring numbers.

For example, the N-heterocyclic fused-ring compound has 2 to 3 rings, and Formula 2 may satisfy 0.9 to 1.3.

For example, the N-heterocyclic fused-ring compound has two rings, and Formula 2 may satisfy 1.0 to 1.3.

In the etchant composition according to an embodiment of the present invention, non-limiting examples of the N-heterocyclic fused-ring compound include adenine, guanine, isoguanine, hypoxanthine, xanthine, theobromine and caffeine. have.

In addition, it was confirmed that the etchant composition according to an embodiment of the present invention selectively etches the copper-based metal film without damage to the underlying film, and the bond order of the amine compound acts as an important factor. Specifically, according to the present invention, a tertiary amine compound is employed. Accordingly, by offsetting the competitive reaction of the tertiary amine compound and the N-heterocyclic fused-ring compound, the metal layer may be etched more stably. In particular, it has a selective meaning in that it can overcome over-etching of metal wiring, which could not be realized in an etchant composition including a primary or secondary amine compound having a low bonding order. In addition, in this case, it is more preferable because the stability of hydrogen peroxide is improved and the etch profile is not deformed when the copper-based metal film is etched.

In the etchant composition according to an embodiment of the present invention, the tertiary amine compound may include a lower alkyl group. Specifically, the tertiary amine compound may have a substituent selected from C _1-3 alkyl and C _1-3 hydroxyalkyl, and the alkyl or hydroxyalkyl is preferably a straight chain. In addition, non-limiting examples thereof include triethanolamine, trimethylamine, triethylamine, tripropylamine, dimethylethylamine, methyldiethylamine, methyldipropylamine, methyldiethanolamine, dimethylethanolamine, and diethylaminoethanol. and the like, and may be used as one or a mixture of two or more selected from these.

The etchant composition according to an embodiment of the present invention may include 50 to 200 parts by weight of the N-heterocyclic fused-ring compound based on 100 parts by weight of the tertiary amine compound, specifically 80 to 150 parts by weight, more Specifically, it may be included in an amount of 90 to 120 parts by weight.

In addition, the etchant composition according to an embodiment of the present invention, based on the total weight, 5 to 35% by weight of the hydrogen peroxide, 0.01 to 1.0% by weight of the tertiary amine compound, 0.01 to 1.0% by weight of the N-heterocyclic fused ring compound % and the remaining amount of water may be included, and as long as it satisfies Equation 1 described above, it is of course that the composition may be mixed in various aspects.

Specifically, the etchant composition may include 10 to 30% by weight of the hydrogen peroxide, 0.05 to 1.0% by weight of the tertiary amine compound, 0.05 to 1.0% by weight of the N-heterocyclic fused-ring compound, and the balance of water.

More specifically, it may include 15 to 25 wt% of the hydrogen peroxide, 0.1 to 0.8 wt% of the tertiary amine compound, 0.1 to 0.5 wt% of the N-heterocyclic fused-ring compound, and the balance of water.

When the above-mentioned weight ratio is satisfied, the stability of the chemical can be improved by effectively suppressing the Fenton reaction of hydrogen peroxide. Accordingly, heat generation of the chemical is not generated. In addition, it is good that the desired etching characteristics can be stably provided without causing deformation of the etching profile.

The etchant composition according to an embodiment of the present invention may further include an additive selected from an etch inhibitor, a chelating agent, an etchant, a pH adjuster, and a fluorine compound. Each of the additives may be included in the range of 0.01 to 5 wt%, or 0.03 to 4.5 wt%, or 0.05 to 4 wt%, based on the total weight of the etchant composition.

The etch inhibitor is a ring-based compound containing a heteroatom selected from oxygen, sulfur and nitrogen in the molecule; and a phosphonic acid-based compound comprising two or more phosphonic acid groups; may be one or a mixture of two or more.

In the etch inhibitor, non-limiting examples of the cyclic compound include piperazine, pyrrolidine, alloxane, pyrrole, imidazole, pyrazole, 1,2,3-triazole, 1,2,4- Triazole, 5-aminotetrazole, 5-methyltetrazole, tetrazole, pentaazole, oxazole, isoxazole, 1,2,3-oxadiazole, oxadiazole, furazane, 1,3,4 -oxadiazole, thiazole, isothiazole, thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole and derivatives thereof, etc. Any one or two or more may be selected. Non-limiting examples of the phosphonic acid-based compound include any one or two or more selected from tiludronic acid, alendronic acid, ibandronic acid, risedronic acid, etidronic acid, clodronic acid and pamidronic acid. . In addition, one or a mixture of two or more selected from these may be used.

For example, when the etchant composition includes a mixture of the first etch inhibitor selected from the above-described cyclic compounds and the second etch inhibitor selected from the above-described phosphonic acid compounds, it is more advantageous whether the lower layer is etched.

For example, the mixture of the first etch inhibitor and the second etch inhibitor may include 1 to 20 parts by weight of the second etch inhibitor based on 100 parts by weight of the first etch inhibitor, specifically 3 to 15 parts by weight parts, more specifically 5 to 10 parts by weight.

The chelating agent may be selected from polyvalent carboxylic acids and polyvalent phosphonic acids. Non-limiting examples thereof include 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'-tetraacetic 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,N' , It may be one or a combination of two or more selected from N'-tetraacetic acid and the like. In addition, the polyvalent phosphonic acid is hydroxyethylidenediphosphonic acid, nitrilotri(methylenephosphonic acid), ethylenediaminetetra(methylenephosphonic acid), amino(trismethylenephosphonic acid) and diethylenetriaminepenta(methylenephosphonic acid). ) may be one or a combination of two or more selected from the like. In addition, the chelating agent may be selected from organic acids containing at least two or more carboxylic acid groups. One non-limiting example thereof may be one or a combination of two or more selected from citric acid, oxalic acid, malonic acid, tartaric acid, sulfosuccinic acid, sulfophthalic acid, succinic acid, malic acid and isocitric acid.

The etching additive may be a salt of an inorganic acid selected from hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid, and non-limiting examples thereof include sulfate salts such as ammonium sulfate, potassium sulfate, sodium sulfate, ammonium hydrogen sulfate, sodium hydrogen sulfate and potassium hydrogen sulfate; and nitrates such as ammonium nitrate, sodium nitrate and potassium nitrate. In addition, it is of course that one or a mixture of two or more selected from these may be used.

The pH adjusting agent may be used without limitation as long as it is a commonly used material.

The fluorine compound helps to remove metal residues such as molybdenum residues. Non-limiting examples thereof include ammonium fluoride, sodium fluoride, potassium fluoride, ammonium bifluoride, sodium bifluoride and potassium bifluoride, and may be used as one or a mixture of two or more selected from these.

The water included in the etchant composition according to an embodiment of the present invention is not particularly limited, but specifically may be deionized water, and more specifically, deionized water for a semiconductor process, and a specific resistance value of 18㏁·cm or more. can

As described above, the etchant composition according to an embodiment of the present invention satisfies the above-mentioned Equation 1, has a high selectivity to the copper-based metal film, and can stably maintain an etch profile by implementing excellent etch characteristics. and effectively removes residues generated during etching. In addition, the etchant composition can stably provide a metal wiring that satisfies a good taper angle and an etch bias, and has a commercially very advantageous advantage.

In addition, the etchant composition according to an embodiment of the present invention can implement improved etching characteristics such as taper angle, sidiros and etch straightness. In addition, it is possible to prevent an increase in threshold voltage due to residues generated during the etching process, thereby minimizing electrical defects. Accordingly, the etchant composition is an etchant composition for forming a metal wiring or pattern 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. can be usefully used as

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

In one aspect, the method of etching a metal film according to an embodiment of the present invention may include a step of etching the copper-based metal film by contacting the etching solution composition described above.

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 the substrate; and forming a photoresist pattern on the metal layer, then etching the substrate having the metal layer and the photoresist pattern to partially remove the metal layer to form a metal wiring; It is carried out by treating the etchant composition described above.

The method for etching a metal film and a method for manufacturing 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 multi-layer film including a copper-based metal film. can

For example, the etchant composition may have an etching rate (E _Cu ) for the copper film of 30 to 100 Å/sec, and an etching rate (E _Mo-X ) for the molybdenum film to satisfy 5 to 30 Å/sec. .

For example, E _Cu of the etchant composition may be 40 to 80 Å/sec, and E _Mo-X may satisfy 10 to 25 Å/sec.

For example, E _Cu of the etchant composition may be 50 to 70 Å/sec, and E _Mo-X may satisfy 10 to 20 Å/sec. In addition, the etchant composition may satisfy a large-area treatment as well as a high number of sheets. It is also good that the above-described etching rate can be stably implemented.

Further, according to the present invention, it is possible to satisfy the desired taper angle of the copper film. Specifically, the taper angle of the copper layer in the metal layer may be 35 to 45°. Most specifically, it may be 38 to 43°.

Accordingly, according to the present invention, it is possible to provide a more reliable metal wiring or pattern for an electrode of a TFT-LCD display by simultaneously satisfying the low taper angle as well as the implementation of the above-described etching rate.

According to the method of manufacturing a display substrate according to an embodiment of the present invention, although the copper-based metal layer is selectively etched, corrosion or damage to the substrate and the underlying layer is not caused. In this case, the substrate may be used without limitation as long as it is a base substrate that can be generally used for manufacturing a display substrate. Non-limiting examples thereof include a rigid substrate selected from a glass substrate, a quartz substrate, a glass ceramic substrate and a crystalline glass substrate; and a flexible substrate selected from a flexible glass substrate, a plastic substrate, and the like; can be heard In this case, the plastic substrate may include one or more materials selected from polyimide, polycarbonate, polyphenylene sulfide, polyarylene ether sulfone, and the like, but is not limited thereto.

In addition, the metal film, which is one of the objects to be etched in the present invention, 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 a molybdenum alloy. In addition, 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, it is possible to increase the size of the TFT-LCD in a very economical way by stably etching the copper film and the molybdenum-containing film, which are metal wirings satisfying low resistance.

In the method of manufacturing a display substrate according to an embodiment of the present invention, a portion of the metal layer may further include one single layer or two or more multilayer layers selected from a silicon insulating layer and a transparent conductive layer. However, according to the present invention, since etching does not occur on the substrate as well as the silicon insulating film and the transparent conductive film, it can be very advantageously used for 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 film, an SiON film, or a doped SiNx film (doped SiN 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 phosphoric acid 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 (Undoped 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 ₃ -TEOS (O ₃ -Tetra Ethyl Ortho Silicate) and the like.

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

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

The etchant composition of the copper film and the molybdenum-containing film according to the present invention will be described in more detail through the following examples. However, the following examples are only a reference for describing the present invention in detail, and the present invention is not limited thereto, and may be implemented in various forms. Also, 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 this invention belongs. In addition, the terminology used in the description in the present invention is only for effectively describing specific embodiments, and is not intended to limit the present invention.

(Assessment Methods)

1. Precipitation 　 occurrence, heat generation, 　 etch characteristics and storage change evaluation

In order to evaluate 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 transparent conductive film (ITO) deposited to a thickness of 600 Å, or a copper film deposited to a thickness of 5000 Å A photolithography process was performed on each of the molybdenum alloy film and the molybdenum alloy film (thickness ratio = 10:1) to form a pattern to prepare a specimen.

After dissolving 3000, 4000, or 5000 ppm of copper powder in each etching solution composition of the following Examples or Comparative Examples, while maintaining at 32 ° C. for 24 hours, whether precipitates occur, whether or not heat is generated, 　 Etching characteristics and characteristics of changes over storage were evaluated.

The occurrence of precipitates was evaluated as ○ when precipitates were generated, and × when no precipitates were generated.

In addition, the occurrence of heat generation was evaluated as a temperature rise (○) when the temperature increased by more than 5°C while the 　 etching was performed, and no temperature change (X) at the following temperature change.

In addition, the etching characteristics (CD skew, taper) were evaluated using a mini-etcher equipment by 50% OE of each specimen based on EPD. Specifically, when CD skew is 0.60 µm or more on one side and less than 1.00 µm, the taper is 35 degrees or more When it was less than 45 degrees, it was judged as good, when it was 45 degrees or more, bad, and when it was 50 degrees or more, it was judged as very bad.

In addition, the change over time of storage is confirmed by the date of age through mini-etcher evaluation to confirm the storage stability of the etchant composition (confirmation of change over time: 0 to 5 days). , less than 1 day was evaluated as very poor.

The results are shown in Tables 2 and 3 below.

2.Check whether molybdenum residue and lower layer are etched

It was confirmed whether the lower layer was etched for each etchant composition of the following Examples or Comparative Examples. Specifically, the thickness of the specimen before etching was measured using an ellipsometer (Ellipsometer, J.A WOOLLAM, M-2000U), which is a thin film thickness measuring device. In a quartz bath, each etching process was performed on the specimen using each of the etchant compositions maintained at an etchant temperature of 32°C. At this time, the etching time was controlled in the same way. After the etching was completed, the specimen was washed with ultrapure water, the remaining etchant composition was completely dried using a drying device, and the thickness was measured to evaluate the etch rate.

In addition, the presence or absence of molybdenum residue was analyzed through surface observation during SEM analysis.

The results are shown in Tables 2 and 3 below.

3. Taper angle measurement

After the etching solution composition of the following Examples or Comparative Examples was maintained at 32° C., respectively, 1000 ppm of copper powder was added per hour, and then the specimen was etched. For total etching time, 50% over-etching was performed based on the total EPD, and Etcher used equipment capable of processing 0.5 generation, glass size. At this time, a spray type was used for chemical spraying, the spray pressure was 0.1 MPa, and the exhaust pressure in the Etcher zone was maintained at 20 Pa, and the taper angle (T/A) according to the number of treated sheets was measured, and the amount of change was confirmed. At this time, an appropriate taper angle of the copper film and the molybdenum alloy film was evaluated as 35 to 45°.

1 and 2 below.

(Examples 1 to 9 and Comparative Examples 1 to 10)

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

As shown in Table 2, the etchant composition according to the present invention can implement a fast etch rate and excellent etch characteristics for the copper-based metal film, so that the change in CD loss of the desired etch profile is small. That is, the etchant composition according to the present invention has very good selectivity for copper-based metals. In particular, according to the present invention, even when a high concentration of metal ions is present in the chemical, it does not generate precipitates and effectively suppresses the decomposition of hydrogen peroxide used as the main oxidizing agent, thereby preventing the etchant composition from being overheated.

When the metal ion (Cu) in the etchant composition increases over a certain concentration as in the case of large-area treatment, in general, the CD loss of the etch profile tends to increase. However, when the etchant composition according to the present invention is used, it has a low taper angle of less than 45° without damage to the photoresist at an overetch rate of 50% (refer to FIG. 1), and it can be seen that the change in CD loss according to the number of treatments is small. could

In the case of Comparative Example 1, as the concentration of metal ions increased, the rate of change of sidiros changed abruptly, and as the etching proceeded as soon as the specimen was put in, the etching loss due to over-erosion was rapid, making it impossible to create a pattern (Fig. 2). Reference). In addition, as shown in Table 3, the lower layer was etched at the same time and was evaluated to be very poor, and an excessive amount of precipitates was generated.

In the case of Comparative Examples 2 to 5, the primary or secondary amine compound is employed, and Equation 1 of the present invention is not satisfied. In this case, as shown in Table 3, over-etching of the copper-based metal layer and the underlying layer was caused, and thus the copper-based metal layer was evaluated as bad or very bad, and an excessive amount of precipitates was generated.

In Comparative Examples 6 and 7, the N-heterocyclic fused-ring compound having two or more rings was not included, and a ring-based compound was used as an etch inhibitor. In this case, as the etching proceeded as soon as the specimen is put in, over-etching of the copper-based metal layer and the lower layer was particularly severely observed, which was evaluated as very poor in all cases.

In the case of Comparative Example 8 and Comparative Example 9, Equation 1 of the present invention is not satisfied. In this case, the copper-based metal film exhibited poor over-etching as well as change over storage time.

In addition, in the case of Comparative Example 10, over-etching of the copper-based metal film as well as the lower film could not be suppressed, and the etchant composition was overheated due to the decomposition of hydrogen peroxide. In addition, an excessive amount of precipitates was generated.

As described above, in the present invention, specific matters and limited examples and comparative examples have been described, but these are only provided to help a more general understanding of the present invention, and the present invention is not limited to the above examples, and the present invention is not limited to the above examples. Various modifications and variations are possible from these descriptions by those of ordinary skill in the art.

Therefore, the spirit of the present invention should not be limited to the described embodiments, and not only the claims to be described later, but also all those with equivalent or equivalent modifications to the claims will be said to belong to the scope of the spirit of the present invention. .

Claims (13)

An etchant composition comprising hydrogen peroxide, a tertiary amine compound, and an N-heterocyclic fused-ring compound,
The tertiary amine compound and the N-heterocyclic fused-ring compound are an etchant composition for a metal film that satisfies the following Equation 1:
[Formula 1]

In Equation 1 above,
Z is the number of rings of the N-heterocyclic fused-ring compound;

is the ratio of carbon to nitrogen (number of C / number of N) of the N-heterocyclic fused-ring compound;
pKa1(a) is the pKa1 value of the tertiary amine compound;
pKa1(b) is the pKa1 value of the N-heterocyclic fused-ring compound;
N is the number of substituents directly bonded to the amine group of the tertiary amine compound (N tertiary amine), and is an integer of 3. The method of claim 1,
The N-heterocyclic fused-ring compound is,
Having 2 to 5 rings, the etchant composition that satisfies the following Equation 2:
[Formula 2]
0.8 ≤

≤ 1.5
In Equation 2 above,
c is the number of carbon atoms (C number) of the N-heterocyclic fused-ring compound;
n is the number of nitrogens (N number) of the N-heterocyclic fused-ring compound. The method of claim 1,
The N-heterocyclic fused-ring compound is,
Adenine, guanine, isoguanine, hypoxanthine, xanthine, theobromine and caffeine will be selected from, the etchant composition. The method of claim 1,
The tertiary amine compound is
C _1-3 alkyl and C _1-3 will have a substituent selected from hydroxyalkyl, the etchant composition. The method of claim 1,
The etchant composition,
Based on 100 parts by weight of the tertiary amine compound, the etchant composition comprising 50 to 200 parts by weight of the N-heterocyclic fused-ring compound. The method of claim 1,
The etchant composition,
Based on the total weight, 5 to 35% by weight of the hydrogen peroxide, 0.01 to 1.0% by weight of the tertiary amine compound, 0.01 to 1.0% by weight of the N-heterocyclic fused-ring compound, and the remaining amount of water, the etchant composition . The method of claim 1,
An etchant composition further comprising an additive selected from an etch inhibitor, a chelating agent, an etch additive, a pH adjuster, and a fluorine compound. 8. The method of claim 7,
The etch inhibitor is
a ring-based compound containing a heteroatom selected from oxygen, sulfur and nitrogen in the molecule; And a phosphonic acid-based compound comprising two or more phosphonic acid groups; which will be selected from, the etchant composition. The method of claim 1,
The metal film,
a single film made of copper or copper alloy; and
A copper-based metal film selected from; a multilayer film including the single film and a film made of molybdenum or a molybdenum alloy; the etchant composition. 10. A method of etching a metal film comprising: etching the copper-based metal film using the etchant composition according to any one of claims 1 to 9. 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;
The method for manufacturing a display substrate, wherein the etching is performed by treating the etchant composition according to any one of claims 1 to 9. 12. The method of claim 11,
The taper angle of the metal wiring is,
35 to 45°, a method of manufacturing a display substrate. 12. The method of claim 11,
The method of claim 1, further comprising one single film or two or more multilayer films selected from a silicon insulating film and a transparent conductive film on a portion of the metal layer.

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