KR102829246B1 - Etching composition for copper-based metal film - Google Patents

Abstract

The present invention relates to an etchant composition for a copper-based metal film, and the etchant composition for a copper-based metal film according to the present invention comprises hydrogen peroxide, a peroxide stabilizer, a tetrazole substituted with an amino group, a tetrazole substituted with a (C1-C4) alkyl group, an ammonium compound, and an organic acid containing one carboxyl group.

Description

{ETCHING COMPOSITION FOR COPPER-BASED METAL FILM}

The present invention relates to an etching composition for a copper-based metal film.

Recently, as society has entered the full-fledged information age, the display field, which processes and displays large amounts of information, has developed rapidly, and in response, various semiconductor devices have been developed and are receiving the spotlight. Examples of such semiconductor devices include liquid crystal display devices (LCDs), plasma display panel devices (PDPs), field emission display devices (FEDs), electroluminescence display devices (ELDs), and organic light emitting diodes (OLEDs). With their excellent performances such as thinness, weight reduction, and low power consumption, they are quickly replacing basic cathode ray tubes, and the demand for high-resolution and low-energy display panels is continuously increasing.

In display devices such as the LCD, PDP, FED, ELD, and OLED described above, copper-based metal films are widely adopted as electrode and wiring materials. In particular, in active-drive displays such as LCD and OLED, copper-based metal films are used as wiring materials for thin film transistors (TFTs), and as large substrates of the 8th generation or higher or high performance of 4K and 8K resolutions are required, precise patterning technology for copper-based metal films for TFT wiring is required.

In general, patterning of copper-based metal films is performed through a wet etching process using an etchant. However, since the etchant for copper-based metal films conventionally uses hydrogen peroxide ( _H2O2 ) or strong acids, which are widely used as strong oxidizing agents, _there is a problem that photoresist (PR) patterns already formed on the copper-based metal film are damaged or undercuts occur during the etching process. Damage to the PR pattern and undercuts can cause short circuiting, which can lead to serious quality degradation. In addition, since it is difficult to control the etching speed of the conventional copper-based metal film due to strong oxidizing agents, it can also cause a problem that the film is patterned into a shape different from what the user theoretically designed.

Therefore, there is a demand for a new etchant for copper-based metal films that has high selectivity, excellent etching uniformity, and undercut prevention for the manufacture of high-quality and high-performance displays.

: Republic of Korea Publication of Patent No. 10-2002-0050020

According to one aspect of the present invention, an etchant composition having high etching performance for a target metal film is provided.

According to another aspect of the present invention, an etchant composition is provided which has a high selectivity for a target metal film without causing damage to a heterogeneous film and prevents undercutting.

According to another aspect of the present invention, an etchant composition having excellent etching profile control performance is provided.

The tasks of the present invention are not limited to the above-described contents. Those with ordinary knowledge in the technical field to which the present invention belongs will have no difficulty in understanding additional tasks of the present invention from the overall contents of this specification.

An etchant composition according to one embodiment of the present invention comprises hydrogen peroxide, a peroxide stabilizer, a tetrazole substituted with an amino group, a tetrazole substituted with a (C1-C4) alkyl group, an ammonium compound, and an organic acid containing one carboxyl group.

In an etchant composition according to one embodiment, the weight ratio of the tetrazole substituted with the amino group: the tetrazole substituted with the (C1-C4) alkyl group may be 1:1 to 3.

In an etchant composition according to one embodiment, the fruit stabilizer may be an aliphatic cyclic primary amine.

In an etchant composition according to one embodiment, the etchant composition may include, based on the total weight of the etchant composition, 0.1 to 3 wt% of the ammonium compound, 0.05 to 1.5 wt% of an organic acid containing one carboxyl group, 0.005 to 0.3 wt% of a tetrazole substituted with an amino group, 0.01 to 0.5 wt% of a tetrazole substituted with an alkyl group, 5 to 30 wt% of hydrogen peroxide, 0.05 to 1.5 wt% of a peroxide stabilizer, and a balance of water.

In an etchant composition according to one embodiment, a weight ratio of the ammonium compound: the organic acid containing one carboxyl group may be 1:0.05 to 1.

In an etchant composition according to one embodiment, the ammonium compound may be one or a combination of two selected from an ammonium phosphate compound and an ammonium sulfate compound.

In an etchant composition according to one embodiment, the etchant composition may further include at least one additive selected from a chelating agent, a pH regulator, and a fluorine-based compound.

In an etchant composition according to one embodiment, the chelating agent may include iminodiacetic acid and iminodisuccinic acid.

In an etchant composition according to one embodiment, a weight ratio of the iminodiacetic acid to the iminodisuccinic acid may be 1:0.01 to 0.5.

In an etchant composition according to one embodiment, the etching target of the etchant composition may be a copper-based metal film.

In an etchant composition according to one embodiment, the copper-based metal film may be selected from 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.

A metal film etching method according to one embodiment of the present invention includes a step of etching a copper-based metal film using the above-described etchant composition.

A method for manufacturing a display substrate according to one embodiment of the present invention comprises the steps of S1) forming a metal layer including a copper-based metal film on a substrate; S2) forming a photoresist pattern on the metal layer; and S3) patterning the metal layer using the photoresist pattern as a mask to form a metal wiring, wherein the patterning is performed by treating the above-described etching composition.

An etchant composition according to one aspect of the present invention can have high etching performance for a target metal film.

In addition, an etchant composition according to one aspect of the present invention has a high selectivity without causing damage to a heterogeneous film other than a target metal film, and can prevent undercutting.

In addition, the etchant composition according to one aspect of the present invention can have excellent etching profile control performance.

Unless otherwise defined, technical and scientific terms used in this specification have the meaning commonly understood by a person of ordinary skill in the art to which this invention belongs, and descriptions of well-known functions and configurations that may unnecessarily obscure the gist of the present invention in the following description or accompanying drawings are omitted.

The embodiments of the present invention are provided to more completely explain the present invention to those with average knowledge in the art. Therefore, the scope of the present invention is not limited to the embodiments described below.

The terminology used in the description of the present invention is for the purpose of describing embodiments of the present invention only and should not be taken to be limiting. Unless clearly used otherwise, the singular form includes the plural form.

The term "comprises," as used herein, is an open-ended description equivalent to the expressions "comprises," "contains," "has," or "characterized by," and does not exclude additional elements, materials, or processes not listed herein.

Units used herein, unless otherwise specified, are based on weight, and as an example, units of % or ratio mean weight% or weight ratio, and weight% means the weight % that any one component occupies in the composition among the entire composition, unless otherwise defined.

In addition, the numerical range used in this specification includes the lower and upper limits and all values within that range, the increments logically derived from the shape and width of the defined range, all doubly defined values, and all possible combinations of the upper and lower limits of the numerical range defined in different shapes. Unless otherwise specifically defined herein, values outside the numerical range that may arise due to experimental error or rounding of values are also included in the defined numerical range.

In this specification, terms such as ‘top’, ‘upper part’, ‘top surface’, ‘bottom’, ‘lower part’, ‘bottom’, and ‘side’ are based on the drawings, and may actually vary depending on the direction in which elements or components are arranged.

Additionally, throughout the specification, when we say that a part is 'connected' to another part, this includes not only cases where it is 'directly connected', but also cases where it is 'indirectly connected' with other elements in between.

In this specification, the present invention is described in detail through each embodiment according to the present invention, but each embodiment described in the specification should be considered not only to mean one embodiment but also to mean a combination with other embodiments. Therefore, the citation of a claim in the scope of the patent claims is only an example, and the technical idea of the present invention should not be interpreted only as a combination with the cited claim, and a combination with various claims is also included in the scope of the technical idea of the present invention.

In this specification, “substituent”, “radical”, “group”, “moiety”, and “fragment” are used interchangeably.

In this specification, “CA-CB” means “having carbon atoms greater than or equal to A and less than or equal to B.”

In this specification, 'alkyl' is a monovalent substituent, including both straight-chain and branched-chain forms, and the carbon number of the alkyl in this specification may range from 1 to 4 or from 1 to 3.

Conventionally, in the case of an etchant composition for etching a copper-based metal film, in addition to the copper and the copper-containing metal film that is the etching target, during etching, a pattern that has already been formed, specifically, a photoresist (PR) pattern, and non-target objects such as lower structures such as an insulating substrate such as glass or a semiconductor layer are damaged, or undercut occurs in which a portion under a mask is excessively etched in the horizontal direction, resulting in serious quality degradation problems. In addition, conventional copper-based metal films have a disadvantage in that it is difficult to control the etching speed, making it difficult to design a precise pattern.

Accordingly, the inventors of the present invention, while conducting repeated studies to solve the above-described problems, confirmed that an etchant composition containing heterogeneous tetrazoles substituted with different substituents simultaneously has excellent etching performance, undercut prevention ability, and excellent etching profile control performance for a copper-based metal film.

Hereinafter, the present invention will be described in detail.

The etchant composition according to the present invention comprises hydrogen peroxide, a peroxide stabilizer, a tetrazole substituted with an amino group, a tetrazole substituted with a (C1-C4) alkyl group, an ammonium compound, and an organic acid containing one carboxyl group.

The above etchant composition is characterized by using the hydrogen peroxide, the peroxide stabilizer, the tetrazole substituted with an amino group, the tetrazole substituted with a (C1-C4) alkyl group, the ammonium compound, and the organic acid containing one carboxyl group at the same time. The etchant composition having such a combination can have excellent etching performance for a metal film, particularly, a copper-based metal film. In addition, at the same time, it has high selectivity for the copper-based metal film and does not cause damage to the PR pattern. In addition, as described above, the occurrence of undercut can be prevented by the excellent etching performance and high selectivity, and excellent etching profile controllability can be achieved.

The etching target of the etching composition according to one aspect of the present invention is not particularly limited as long as it is a metal film conventionally used in a semiconductor process. As a non-limiting example, the etching target of the etching composition may be a metal film of a thin film transistor (TFT), and in particular, may be a metal film of a TFT for an active display such as an LCD and an OLED.

According to one aspect of the present invention, the metal film to be etched in the etching composition may be a copper-based metal film, and may be selected from a single film made of copper or a copper alloy; and a multilayer film including a film made of the single film and molybdenum or a molybdenum alloy. Specifically, the multilayer film may mean a structure in which a single film made of copper or a copper alloy (hereinafter, “copper film”) - a film made of molybdenum or a molybdenum alloy (hereinafter, “alloy film”) are sequentially laminated, or conversely, a structure in which an alloy film - a copper film are sequentially laminated. In addition, it may also be a triple metal film or a multilayer film having three or more layers, such as an alloy film - copper film - alloy film, in which copper films and alloy films are alternately laminated. In this case, the copper alloy or molybdenum alloy is not limited as long as it is a metal that can be used for metal wiring of a thin film transistor. As a non-limiting example, the copper alloy or molybdenum alloy may be one or more selected from tungsten, titanium, tantalum, chromium, niobium, and nickel.

In an embodiment, the etchant composition according to one aspect of the present invention may be used in a thin film transistor manufacturing process in which metal wiring is formed of a copper-based metal film. At this time, the etching rate (E _Cu ) for the copper-based metal film using the etchant composition may be 30 to 250 Å/sec or 50 to 100 Å/sec.

As described above, the etchant composition according to the present invention includes a tetrazole substituted with an amino group and a tetrazole substituted with a (C1-C4) alkyl group, that is, a heterogeneous tetrazole substituted with different substituents. Specifically, the tetrazole substituted with an amino group may be at least one selected from the group consisting of 5-aminotetrazole, 5-amino-1H-tetrazole, 5-amino-2H-tetrazole, and 1,5-diaminotetrazole. In addition, the tetrazole substituted with the (C1-C4) alkyl group may specifically be a tetrazole substituted with a (C1-C3) alkyl group or a tetrazole substituted with a (C1-C2) alkyl group, and as a non-limiting example, may be 1-methyl-1H-tetrazole.

As a non-limiting example, the tetrazole substituted with the amino group may be 5-aminotetrazole, and the tetrazole substituted with the (C1-C4)alkyl group may be 1-methyl-1H-tetrazole.

The etchant composition containing the above heterogeneous tetrazoles can reduce the etching rate and etching profile fluctuations of a metal film, thereby implementing a more stable etching profile. Specifically, the etchant composition can have excellent etching profile controllability, with an etching bias of 1 ㎛ or less, a taper angle of 40 to 50 °, and a tail length of 0.1 ㎛ or less in an etching treatment process of 140 seconds. Such an etchant composition enables the manufacturing of more precise, high-quality products.

According to one embodiment, the weight ratio of the amino group-substituted tetrazole: (C1-C4) alkyl group-substituted tetrazole may be 1:0.5 to 5, 1:1 to 3, 1:1.2 to 2.5, or 1:1.5 to 2.3. The etchant composition satisfying the above range can maintain excellent etching performance and undercut prevention performance even when the number of processing sheets is accumulated. That is, the etchant composition satisfying the above range can reduce the etchant exchange cycle of the etching process by improving the cumulative number of processing sheets, and further enhance the etching process efficiency.

The hydrogen peroxide can act as an oxidizing agent that oxidizes copper. In one embodiment, the hydrogen peroxide can be included in an amount of 5 to 30 w%, 10 to 25 w%, 15 to 25 w%, or 17 to 23 w% based on the total weight of the etchant composition. An etchant composition including hydrogen peroxide in the above range can have excellent etching performance.

The above-mentioned peroxide stabilizer may be an aliphatic cyclic primary amine. Specifically, the peroxide stabilizer may be a 3- to 8-membered aliphatic primary amine, more specifically, a 4- to 7-membered aliphatic primary amine. The above-mentioned aliphatic cyclic primary amine may be an aliphatic amine in which a heteroatom is not substituted within the ring, and hydrogen of the aliphatic ring may be further substituted with a C1-C4 alkyl. Without limitation, the cyclic amine may be cyclohexylamine (CHA) or cyclopentylamine (CPA). Such a peroxide stabilizer serves to protect the surface of an oxidized metal film, and the etching rate and selectivity can be appropriately controlled through the peroxide stabilizer.

According to one embodiment, the peroxide stabilizer can be included in an amount of 0.05 to 1.5 w%, 0.1 to 1.2 w%, 0.1 to 1.0 w%, 0.1 to 0.8 w% or 0.2 to 0.7 w% based on the total weight of the etchant composition. The etchant composition including the peroxide stabilizer in the above range can have a high selectivity for a metal film, particularly, a copper-based metal film.

The above ammonium compound and the organic acid containing one carboxyl group can provide synergy to the effect of the heteroaryl tetrazole as an etching additive.

Specifically, the ammonium compound may be one or more selected from ammonium compounds, and non-limiting examples thereof include ammonium sulfate ((NH ₄ ) ₂ SO ₄ ), ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ), ammonium hydrogen sulfate ((NH ₄ )HSO ₄ ), monoammonium phosphate (NH ₄ H ₂ PO ₄ ), and diammonium phosphate ((NH ₄ ) ₂ HPO ₄ ), and the like. As a non-limiting example, the ammonium compound may include one or more mixtures selected from the above-described ammonium sulfate compounds.

The organic acid containing the above one carboxyl group 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, and the like. 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.

According to one embodiment, the weight ratio of the ammonium compound: the organic acid containing one carboxyl group may be 1:0.05 to 1, 1:0.1 to 0.8 or 1:0.1 to 0.5. An etchant composition satisfying the above range can satisfy better etching uniformity, thereby preventing metal residues from being generated even when the number of processing sheets increases, thereby enhancing the reliability of the etching process.

According to one embodiment, the etchant composition may include, based on the total weight of the composition, 0.1 to 3 wt% of the ammonium compound, 0.05 to 1.5 wt% of an organic acid containing one carboxyl group, 0.005 to 0.3 wt% of a tetrazole substituted with an amino group, 0.01 to 0.5 wt% of a tetrazole substituted with an alkyl group, 5 to 30 wt% of hydrogen peroxide, 0.05 to 1.5 wt% of a peroxide stabilizer, and a balance of water. Specifically, the etchant composition may include 0.5 to 2 wt% of the ammonium compound, 0.1 to 1.0 wt% of an organic acid containing one carboxyl group, 0.01 to 0.1 wt% of a tetrazole substituted with an amino group, 0.02 to 0.15 wt% of a tetrazole substituted with an alkyl group, 10 to 25 wt% of hydrogen peroxide, 0.1 to 1.2 wt% of a peroxide stabilizer, and the remainder of water, based on the total weight of the etchant composition. Within the above range, the etchant composition can satisfy excellent etching performance, high selectivity, and excellent etching profile controllability even when the number of treatment sheets increases.

In one embodiment, the etchant composition may further include at least one additive selected from a chelating agent, a pH regulator, and a fluorinated compound. In a specific example, the etchant composition may include all of a chelating agent, a pH regulator, and a fluorinated compound. The etchant composition is a more reliable and stable chemical solution in terms of process, enabling more precise patterning of a metal film, and improving manufacturing efficiency.

The above chelating agent is used to prevent side reactions caused by metal ions by forming a chelate with the metal ions generated during etching and thereby deactivating them. It is not particularly limited as long as it is used in a conventional copper film etchant. Specifically, the chelating agent may contain two or more carboxyl groups. 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'-tetraacetic acid, nitrile triacetic acid, cyclohexane-1,2-diamine tetraacetic acid, 1,3-diamino-2-hydroxypropane-N,N,N',N'-tetraacetic acid and It can be one or a combination of two or more selected from hexamethylenediamine-N,N,N',N'-tetraacetic acid, etc.

In one embodiment, the chelating agent may include iminodiacetic acid and iminodisuccinic acid. At this time, the weight ratio of the iminodiacetic acid: the iminodisuccinic acid may be 1:0.01 to 0.5, 1:0.05 to 0.3, or 1:0.07 to 0.3. The etchant composition including the chelating agent as described above can further prevent the generation of by-products due to metal ions even when the number of processing sheets increases, thereby further increasing process reliability. In particular, when etching a copper film, if a large amount of copper ions remain in the etchant composition as a result of the etching of the copper film, a passivation film is formed and the etching uniformity deteriorates as the copper ions are oxidized. The etchant composition including the chelating agent can maintain excellent etching uniformity even when the number of processing sheets increases by preventing the formation of a passivation film due to copper ions.

In one embodiment, the chelating agent is not particularly limited as long as it has an amount that can achieve the above effect. As a non-limiting example, the etching composition may include, but is not limited to, 0.1 to 5 w%, 1 to 5 w%, or 2 to 5 w% of the chelating agent based on the total weight of the etching composition.

The pH regulator is for controlling the pH (hydrogen ion concentration index) of the etchant composition, and may be at least one selected from sodium hydroxide, potassium hydroxide, sodium carbonate, and ammonium hydroxide. As a non-limiting example, the pH regulator may be sodium hydroxide. The pH regulator is not particularly limited as long as it has an amount that can control the pH of the etchant composition to 3 to 5 based on the total weight of the etchant composition. As a non-limiting example, the etchant composition may include 0.01 to 3 w% or 0.05 to 2.5 w% of the pH regulator based on the total weight of the etchant composition, but is not limited thereto.

The above fluorine-based compound can further reduce the generation of metal residue. The fluorine-based compound is not limited as long as it is a compound that can dissociate to generate F ^- or HF ^2- . As a specific example, the fluorine-based compound can be one or a mixture of two or more selected from hydrogen fluoride (HF), ammonium fluoride (NH ₄ F), and ammonium difluoride (NH ₄ HF ₂ ). The fluorine-based compound can be included in an amount of 0.01 to 1 w% or 0.03 to 0.5 w% based on the total weight of the etching composition. In the above range, effective removal of metal residue, for example, molybdenum residue in a copper/molybdenum film, is possible, and etching of an insulating substrate such as a glass substrate can be suppressed.

In one embodiment of the present invention, the method for etching a metal film includes a step of etching a copper-based metal film using the above-described etchant composition. In detail, the etching method for the metal film is not particularly limited as long as the above-described etchant composition is used in the step of etching a copper-based metal film during the manufacture of a semiconductor device. As a non-limiting example, the etching method for the metal film may use the above-described etchant composition in the process of etching a copper-based metal film during the manufacture of a thin film transistor (TFT) used in the manufacture of a display panel (device). The etching method for the metal film according to one embodiment of the present invention can form a more precise metal line (wiring) with almost no error in the design value by etching the metal film using the above-described etchant.

According to one embodiment of the present invention, a method for manufacturing a display substrate includes the steps of S1) forming a metal layer including a copper-based metal film on a substrate; S2) forming a photoresist pattern on the metal layer; and S3) patterning the metal layer using the photoresist pattern as a mask to form a metal wiring, wherein the patterning is performed by treating the above-described etchant composition. In this case, the patterning may mean etching. The display substrate may be a display device (panel), and specifically, may mean a thin film transistor in the display device, but is not limited thereto.

The method for manufacturing the display substrate as described above may be to etch a single film made of a copper-based metal film, or to etch a multilayer film including a copper-based metal film at the same time. At this time, when the etchant composition described above is used, not only can excellent etching characteristics for the copper-based metal film be implemented, but damage to the PR pattern formed on the copper-based metal film can be effectively suppressed. In addition, since the occurrence of undercut is prevented and the etching profile is easily controlled, it is possible to manufacture a more precise and high-quality display substrate with excellent process efficiency.

Specifically, step S1) is a step of forming a metal layer on a substrate, which can be formed through a conventional metal film (layer) forming method. The substrate can be used without limitation as long as it is a base substrate that can be typically used in the manufacture of a display substrate. As a specific example, it can be a rigid substrate such as a glass substrate, a quartz substrate, a glass ceramic substrate, a crystalline glass substrate, or a flexible substrate such as a flexible glass substrate, a plastic substrate, or the like. At this time, the plastic substrate can include one or more materials selected from polyimide, polycarbonate, polyphenylene sulfide, polyaryline ether sulfone, or the like, but is not limited thereto. As a non-limiting specific example, the substrate can be a glass substrate.

The above metal layer includes a copper-based metal film, and the copper-based metal film is as described above, and a detailed description thereof is omitted below.

In one embodiment, the metal layer may further include one single film or two or more multilayer films selected from a silicon insulating film and a transparent conductive film.

The above silicon insulating film may be at least one selected from a silicon nitride film, a silicon oxide film, etc., and the silicon nitride may be a SiNx film, a SiON film, a doped SiNx film, etc. The above silicon oxide is a SOD (Spin On Dielectric) film, an HDP (High Density Plasma) film, a thermal oxide film, a BPSG (Borophosphate Silicate Glass) film, a PSG (Phospho Silicate Glass) film, a BSG (Boro Silicate Glass) film, a PSZ (Polysilazane) film, a FSG (Fluorinated Silicate Glass) film, a LP-TEOS (Low Pressure Tetra Ethyl OrthoSilicate) film, a PETEOS (Plasma Enhanced Tetra Ethyl Ortho Silicate) film, a HTO (High Temperature Oxide) film, a MTO (Medium Temperature Oxide) film, a USG (Undopped Silicate Glass) film, a SOG (Spin On Glass) film, an APL (Advanced Planarization Layer) film, an ALD (Atomic Layer Deposition) film, a PE-oxide film (Plasma Enhanced oxide) or It may be O3-TEOS (O3-Tetra Ethyl Ortho Silicate), etc.

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

Step S2) is a step of forming a photoresist pattern on a metal layer, which can be performed through a conventional photolithography process, and a detailed description thereof is omitted below. At this time, the photoresist pattern can correspond to the shape (pattern) of the desired metal wiring.

S3) A step of forming a metal wiring by patterning the metal layer, using a photoresist pattern as a mask. The patterning can be performed through wet etching using the etchant composition described above. A portion of the metal layer exposed by the photoresist pattern is etched, thereby forming a metal wiring (pattern) corresponding to the photoresist pattern. Since the etching is performed using the etchant composition, a copper-based metal film can be stably etched, thereby manufacturing a high-quality display substrate.

As described above, the method for 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 liquid crystal display devices and plasma display panels (devices) of various aspects.

Hereinafter, the present invention will be specifically described through examples. However, it should be noted that the examples described below are only intended to illustrate and concretize the present invention, and are not intended to limit the scope of the rights of the present invention. This is because the scope of the rights of the present invention is determined by the matters described in the patent claims and matters reasonably inferred therefrom.

(Examples 1 to 7, Comparative Examples 1 to 2)

An etchant composition was prepared with the components and contents described in Table 1 below.

<Etching performance evaluation method>

In order to evaluate the etching performance of the etchants manufactured in the examples and comparative examples, the etching profile controllability and the occurrence of undercuts and residues were evaluated at 100 sheets (copper ion concentration 1000 ppm) and 600 sheets (copper ion concentration 6000 ppm) of processing, and the results are shown in Table 2 below.

Specifically, a 5,500Å thick copper and 150Å thick molybdenum alloy film were sequentially deposited on a glass substrate, and then a photolithography process was performed to form a photoresist pattern to manufacture a specimen.

The above specimens were etched to form metal wiring using the etchant compositions of Examples 1 to 3 and the etchant compositions of Comparative Examples 1 and 2. The etching process was performed at 32° C. for 140 seconds using equipment capable of spraying (Mini-etcher ME-001).

The above etching profile controllability, occurrence of undercut, and occurrence of residue were observed using a scanning electron microscope (S-4800, manufactured by Hitachi, Ltd.).

The above etching profile controllability was evaluated through etch bias, taper angle, and tail length measurements.

The occurrence of undercut was evaluated by observing the surface (5 cm × 5 cm) of the specimen and determining whether or not an undercut existed. At this time, an undercut was determined to exist when an image of a reverse taper forming in the metal wiring on the surface of the specimen was observed.

The presence or absence of metal residue was evaluated by observing the surface (5 cm × 5 cm) of the specimen. At this time, metal residue was judged to be present if the etched metal residue was observed to be distributed uniformly/unevenly on the etched portion of the specimen surface compared to the surface of the reference specimen (specimen before etching).

When the above undercut and residue (molybdenum alloy) occurred, it was marked as 'O', and when it did not occur, it was marked as '×'.

Referring to Table 2 above, it can be confirmed that the etchant compositions of examples according to the present invention have relatively small values of etching bias, taper angle, and tail length compared to the comparative examples, and that undercut and lower residue do not occur. In particular, in the case of Examples 1 to 3, it can be confirmed that the etching profile controllability is very excellent with the etching bias being less than 1 ㎛, the taper angle being 40 to 50 °, and the tail length being 0.07 ㎛ or less, and it can be confirmed that undercut and lower residue do not occur even as the number of processing sheets increases.

Claims (13)

An etchant composition comprising, based on the total weight of the etchant composition, 5 to 30 wt% of hydrogen peroxide, 0.05 to 1.5 wt% of a peroxide stabilizer, 0.005 to 0.3 wt% of a tetrazole substituted with an amino group, 0.01 to 0.5 wt% of a tetrazole substituted with a (C1-C4) alkyl group, 0.1 to 3 wt% of an ammonium compound, 0.05 to 1.5 wt% of an organic acid containing one carboxyl group, 0.01 to 3 wt% of a pH adjuster, 0.01 to 1 wt% of a fluorine compound, 0.1 to 5 wt% of a chelating agent, and the remainder of water, wherein the organic acid comprises lactic acid. In the first paragraph,
An etchant composition, wherein the weight ratio of the tetrazole substituted with the amino group: the tetrazole substituted with the (C1-C4) alkyl group is 1:1 to 3. In the first paragraph,
An etchant composition, wherein the above-mentioned stabilizer is an aliphatic cyclic primary amine. delete In the first paragraph,
An etching composition wherein the weight ratio of the ammonium compound: the organic acid containing one carboxyl group is 1:0.05 to 1. In the first paragraph,
An etchant composition wherein the ammonium compound is one or a combination of two selected from an ammonium phosphate compound and an ammonium sulfate compound. delete In the first paragraph,
An etchant composition, wherein the chelating agent comprises iminodiacetic acid and iminodisuccinic acid. In Article 8,
An etchant composition wherein the weight ratio of the above iminodiacetic acid: the above iminodisuccinic acid is 1:0.01 to 0.5. In the first paragraph,
An etchant composition, wherein the etching target of the above etchant composition is a copper-based metal film. In Article 10,
The above copper metal film is,
An etching composition selected from 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. A method for etching a metal film, comprising: a step of etching a copper-based metal film using an etchant composition according to any one of claims 1 to 3, 5 to 6, and 8 to 11. S1) A step of forming a metal layer including a copper-based metal film on a substrate;
S2) a step of forming a photoresist pattern on the metal layer; and
S3) a step of forming a metal wiring by patterning the metal layer using the photoresist pattern as a mask;
A method for manufacturing a display substrate, wherein the patterning is performed by treating an etching composition according to any one of claims 1 to 3, 5 to 6, and 8 to 11.