TWI636157B - Etching solution composition for silver layer and display substrate using the same - Google Patents

Abstract

The present invention relates to a silver etchant composition, which contains 30 to 60% by weight of phosphoric acid, 0.5 to 10% by weight of nitric acid, 33 to 50% by weight of acetic acid, 0.01 to 10% by weight of an azole compound, and The balance of the deionized water was such that the total weight of the composition became 100% by weight.

Description

Silver etching solution composition and display substrate using the same Field of invention

The present invention relates to a silver etchant composition and a display substrate using the same. More specifically, it relates to 30 to 60% by weight of phosphoric acid, 0.5 to 10% by weight of nitric acid, and 33 to 50% by weight of the total weight of the composition. %, Azole-based compound 0.01 to 10% by weight, and a balance of deionized water so that the total weight of the composition becomes 100% by weight of the silver etching solution composition and a display substrate using the same.

Background of the invention

With the entry into the real information age, the field of displays that process and display a large amount of information has developed rapidly, and a variety of flat panel displays have been developed and attracted attention.

Examples of such a flat panel display device include a liquid crystal display device (LCD), a plasma display panel device (PDP), a field emission display device (FED), Electroluminescence display device (ELD), Organic Light Emitting Diodes (OLED) Wait. In addition, such a flat panel display device is used not only in the field of home appliances such as televisions and videos, but also in various applications such as computers such as notebook computers and mobile phones. These flat-panel display devices have rapidly replaced conventional cathode ray tubes (CITode Ray Tubes: NIT) due to their excellent performance such as thinness, weight reduction, and low power consumption.

In particular, OLEDs can be driven even at low voltages because the elements emit light by themselves, so they have recently been rapidly applied in the small display market such as portable devices. In addition, the state of OLED is beyond the small display, and has been commercialized for large TVs.

On the other hand, conductive metals such as Indium Tin Oxide (ITO) and Indium Zinc Oxide (IZO) have excellent light transmittance and conductivity, and are therefore used in flat panel display devices. Color filters have been widely used in electrodes. However, these metals also have high resistance, which has become an obstacle to the enlargement of the flat panel display device and the realization of high resolution due to the improvement in response speed.

In the case of a reflection plate, an aluminum (Al) reflection plate has been mainly used for products in the past. However, in order to achieve low power consumption due to improvement in brightness, the state is to change the material to a metal with a higher reflectance. Therefore, a silver (Ag: specific resistance of about 1.59 μΩ cm) film, a silver alloy, or a multilayer film including the same, which has a lower specific resistance and a higher brightness than a metal used in a flat panel display device, is used for color filtering. In order to realize the enlargement of the flat panel display device, the high-resolution, low power consumption, and the like of the electrode, LCD or OLED wiring and reflector of the device, it is required to develop an etching solution suitable for the material.

However, silver (Ag) has extremely poor adhesion to an insulating substrate such as glass or a lower substrate such as a semiconductor substrate composed of truly amorphous silicon, doped amorphous silicon, or the like, and vapor deposition is not easy. It is easy to induce lifting or peeling of the wiring. Moreover, even when a silver (Ag) conductive layer is vapor-deposited on a substrate, an etching solution is used in order to pattern it. As such an etching solution, when a conventional etching solution is used, silver (Ag) is excessively etched, and is etched unevenly, so that floating or peeling of the wiring occurs, and the side profile of the wiring becomes poor. In particular, silver (Ag) is a metal that can be easily reduced. It has a fast etching speed and can be etched without inducing residues. However, at this time, the etching speed is fast without causing a difference in etching speed between the upper and lower portions. It is difficult to form a taper angle, and there are many restrictions on flexible application to wiring. When the metal film is standing upright without a taper angle, a gap may be generated between the silver (Ag) and the insulating film or wiring during the formation of the insulating film or subsequent wiring in the subsequent process, and the generation of such a gap becomes an electrical short. The cause of the bad.

On the other hand, the silver etching solution proposed in Korean Registered Patent No. 10-0579421 uses an auxiliary oxide dissolving agent and a fluorine-containing carbon-based surfactant as additives in phosphoric acid, nitric acid, and acetic acid. However, SO ₄ ^2- compound oxide is used as an auxiliary dissolving agent disadvantage is reacted with silver (Ag) in the form of silver sulfide (Ag ₂ S) as a residue in the substrate remaining, ClO ₄ ^- is now specified compound As an environmentally controlled substance, there are difficulties in use. In addition, when the metal film containing silver is etched using the composition, there is still a problem that it is difficult to form a taper angle after the etching.

Prior art literature

Patent literature

Patent Document 1: Korean Registered Patent No. 10-0579421

An object of the present invention is to provide a silver etchant composition capable of forming a taper angle after etching a metal film containing silver.

Another object of the present invention is to provide a display substrate and wiring using the silver etching solution composition.

In order to achieve the above object, the present invention provides a silver etchant composition, which contains 30 to 60% by weight of phosphoric acid, 0.5 to 10% by weight of nitric acid, 33 to 50% by weight of acetic acid, and 0.01 to azole based on the total weight of the composition. 10% by weight and the balance of deionized water so that the total weight of the composition became 100% by weight.

The present invention also provides a display substrate including a metal film etched with the silver etchant composition.

Furthermore, this invention provides the wiring etched with the said silver etchant composition.

The silver etching solution composition of the present invention may form a taper angle after etching of a metal film containing silver. Therefore, as the subsequent process proceeds, when a subsequent insulating film or wiring is formed, there is an effect of gently forming a taper angle along all four sides.

FIG. 1 is a result of measuring and evaluating the residue using the method of the example of the present application for Example 1. FIG.

FIG. 2 shows the results of measurement and evaluation of residues in Comparative Example 1 by the method of the example of the present application.

FIG. 3 shows the results of measuring and evaluating the presence or absence of re-adsorption using the method of the example of the present application for Example 1. FIG.

FIG. 4 shows the results of Comparative Example 1 in which the presence or absence of re-adsorption was measured and evaluated using the method of the example of the present application.

FIG. 5 is a result of measuring and evaluating a cone angle using the method of the embodiment of the present application for Example 1. FIG.

FIG. 6 shows the results of measuring and evaluating the taper angle for the comparative example 2 using the method of the embodiment of the present application.

FIG. 7 is a diagram showing the understanding of vertical etching during the measurement of the etching rate.

The present invention is explained in more detail below.

The present invention relates to a silver etchant composition, which contains 30 to 60% by weight of phosphoric acid, 0.5 to 10% by weight of nitric acid, 33 to 50% by weight of acetic acid, and 0.01 to 10% by weight of an azole compound relative to the total weight of the silver etchant composition. % And the balance of deionized water so that the total weight of the composition becomes 100% by weight. The present inventors have experimentally confirmed that when the metal film containing silver is etched using the above-mentioned etchant composition, a taper angle after the etching can be formed.

The silver etching solution composition of the present invention is capable of etching a single film made of silver (Ag) or a silver alloy, or a multilayer film made of the single film and a transparent conductive film, and the multilayer films can be etched simultaneously.

The silver alloy may be in the form of an alloy containing silver as a main component, and containing other metals such as In, P, Nd, Cu, Pd, Nb, Ni, Mo, Ni, Cr, Mg, W, and Ti, and silver. There are various forms of nitrides, silicides, carbides, and oxides, but they are not limited to these.

In addition, the transparent conductive film generally has characteristics such as IZO and a-ITO that have a transmittance of about 90% or more and a resistivity of 1 × 10 ^-4 Ω cm or less in the visible light region. Since the transparent conductive film is transparent, generally there must be few conductive electrons. In order to increase the conductivity, there must be more conductive electrons. In the case of a transparent conductive film, two opposite conditions must be satisfied. In the method of vapor-depositing IZO and a-ITO, sputtering is generally used, which has the following advantages compared with the CVD (Chemical Vapor Deposition) method: it is easy to adjust the vapor deposition conditions, and in the case of using a large substrate , It is easy to achieve the uniformity of the thickness of the film and the characteristics of the film. In the case of manufacturing by a sputtering method, there are two methods using an oxide target or an alloy target. When an alloy target is used, it has the following advantages: the vapor deposition rate is fast, and the target life is relatively long. The target can be easily manufactured and reused, but has the disadvantage of being sensitive to changes in the display of program variables. If an oxide target is used, the stoichiometry of the thin film can be controlled reproducibly. However, compared with an alloy target, the vapor deposition rate is slower, and sometimes physical cracks may occur in the target during the vapor deposition, which may occur in the target. Disadvantages of the arc. In the case of sputtering vapor deposition of indium-main component oxide, it reacts with O ₂ and has the form of In ₂ O _3. However, in order to improve the conductivity, Ga, Ge, Si, Ti, Sb, Zr, Sn, and Zn. In the present invention, ITO means a transparent conductive film obtained by mixing In ₂ O ₃ and SnO ₂ at an appropriate ratio, but is not limited thereto. For example, the film quality of GZO made using only Ga and Zn used as a dopant is also applicable. Furthermore, the multilayer film may be a multilayer film formed of a transparent conductive film / silver, a transparent conductive film / silver alloy, a transparent conductive film / silver / transparent conductive film, or a transparent conductive film / silver alloy / transparent conductive film. In the case of the silver etching solution composition of the present invention, it is possible to show etching uniformity without damaging the lower film, and it can be usefully used in wet etching.

The phosphoric acid (H ₃ PO ₄ ) contained in the silver etchant composition of the present invention is a main etchant, and when a single film or a multilayer film is etched, it causes an oxidation-reduction reaction with silver (Ag) or a silver alloy to exert transparency and conductivity. The film dissociates and performs wet etching.

The phosphoric acid contains 30 to 60% by weight, and preferably 40 to 50% by weight, based on the total weight of the silver etching solution composition.

If the phosphoric acid is contained in an amount of less than 30% by weight, the etching ability may be insufficient, and sufficient etching may not be performed. In addition, if more than a certain amount of silver (Ag) is dissolved in the silver etching solution composition during the process, silver (Ag) re-adsorption or silver (Ag) precipitates occur, and an electrical short circuit may occur in the subsequent process. Can be a cause of failure.

When the phosphoric acid exceeds 60% by weight, the etching rate of the transparent conductive film may decrease, and the etching rate of silver or a silver alloy may be excessively accelerated to cause over-etching, which may cause etching to fail to perform the wiring function. the amount. In addition, in the case of a multilayer film in which a transparent conductive film is laminated on silver or a silver alloy, a tip (Tip) caused by a difference in the etching rate between the silver or silver alloy and the transparent conductive film may be generated in a subsequent procedure. problem.

The nitric acid (HNO ₃ ) contained in the silver etchant composition of the present invention is a component that functions as an auxiliary etchant, and when a single film or a multilayer film is etched, it oxidizes silver (Ag) or a silver alloy and a transparent conductive film, The effect of wet etching is performed.

The nitric acid is contained in an amount of 0.5 to 10% by weight, and preferably 2 to 10% by weight, based on the total weight of the silver etching solution composition.

When the content of the nitric acid is less than 0.5% by weight, the etching rate of silver or a silver alloy and the transparent conductive film may decrease. Due to the silver residue, an area where an electrical short circuit and residue remain due to the subsequent procedures may occur. The phenomenon that looks dark, that is, the dark spot is bad. In addition, when the content of nitric acid exceeds 10% by weight, due to the excessive etching speed, it is difficult to adjust the etching on the program, and over-etching occurs, and it cannot function as a wiring.

The acetic acid (CH ₃ COOH) contained in the silver etching solution composition of the present invention functions as a buffer to adjust the reaction rate and the like, and not only that, but also plays a very important role in forming a cone angle of Ag or an alloy.

The acetic acid contains 33 to 50% by weight based on the total weight of the silver etching solution composition.

If the content of the acetic acid is less than 33% by weight, the display substrate may be displayed. More specifically, the etching uniformity of the wiring of the TFT array substrate is reduced, the straightness of the wiring is reduced, the wiring resistance is increased, or Defects are induced in the sequence, and the etching rate in the substrate becomes uneven, causing problems such as spots on the substrate. In addition, there was a problem that a taper angle was not formed due to a decrease in the penetrating force of the lower end of the photoresist due to a decrease in the wettability of the silver surface.

In addition, if the content of the acetic acid exceeds 50% by weight, it becomes a highly volatile composition. When the procedure is applied, the content of the composition changes within 3 hours due to the volatilization of the composition, and the etching rate will change with time. Questions that change over time.

The azole-based compound contained in the silver etching solution composition of the present invention is a component that functions as an anti-corrosive agent that slows down the etching rate of silver (Ag) or a silver alloy. When the speed of the transparent conductive film is not slow, the generation of the tip of the transparent conductive film is controlled, and the etching time is adjusted in a program. In addition, it is possible to prevent over-etching of silver (Ag) and form narrow pixel electrode (Pixel) wirings, and it can be used as an additive in an etchant composition or the like for forming fine-patterned wirings.

In addition, conventionally, when a single film of silver or a silver alloy without a barrier film such as a transparent conductive film is etched with an etchant composition, over-etching occurs. In order to prevent this, a barrier film is applied to the upper and lower portions of the single film, which becomes the reason for the increase in the cost of the procedure.

However, the silver etching solution composition of the present invention can prevent over-etching by using an azole-based compound, and can eliminate the need for a barrier film. This has the advantages of reducing process time, saving raw materials, and reducing production costs.

The azole-based compound of the present invention is preferably a tetrazole compound, and specifically, may be selected from tetrazolium (Tetrazole, TZ), methyltetrazole (Methyltetrazole, MTZ), and aminotetrazole (Aminotetrazole, ATZ) More than that. Most preferably, it may be Methyltetrazole (MTZ).

The azole-based compound is contained in an amount of 0.01 to 10% by weight based on the total weight of the silver etching solution composition. If the content of the azole-based compound is less than 0.01% by weight, the effect of slowing down the etching rate cannot be taken seriously, and when it is used to form a wiring having a fine pattern, there is a possibility that the wiring disappears due to over-etching. In addition, if it exceeds 10% by weight, the etching rate of silver or a silver alloy is significantly reduced, and unnecessary portions are not completely etched, and an electrical short circuit may occur, which may cause a failure. Further, due to the decrease in the etching rate, residues remain, and after the subsequent process, a defective phenomenon such that a part of the area appears dark during the production of the product may be induced.

As the deionized water contained in the silver etching solution composition of the present invention, deionized water for semiconductor processes is used, and water of 18 MΩ / cm or more is preferably used.

The silver etchant composition of the present invention may further include one or more of an etching regulator and a pH regulator generally used in this field in addition to the components mentioned above.

The additional added etching regulator is a compound containing one acetate of potassium acetate or sodium acetate, and the additional added pH regulator is glycolic acid, glutamic acid, or glycine. A compound of one organic acid among acids.

The silver etchant composition of the present invention can be used as a transparent conductive film widely used in the formation of TFT array substrates for displays (OLEDs, LCDs, etc.), TSP Trace wiring, and flexible nanowire wiring, and using silver and silver alloys. A single film or an etching solution using two or more multilayer structures is used. In addition to this, in addition to the above-mentioned explicit display and TSP, it can also be used in electronic component raw materials using the metal film quality such as semiconductors.

In addition, the present invention can provide a display substrate including a metal film etched with the silver etchant composition of the present invention.

In more detail, the display device may be a thin film transistor (TFT) substrate of a liquid crystal display device (LCD) or an organic light emitting element (OLED).

In addition, in the OLED, a metal film can be laminated on the upper and lower portions, and the metal film can be etched with the etchant composition of the present invention. By adjusting the thickness of the metal film and stacking it on the upper and lower portions, in the OLED, the metal film can function as a reflective film and a semi-permeable film.

The reflective film must have a thickness that is almost opaque, and the semi-transmissive film must have a thickness that almost completely transmits light. Therefore, the thickness of the metal film is preferably 50 to 5000 Å.

The metal film is a single film made of silver (Ag) or a silver alloy, or a multilayer film made of the single film and a transparent conductive film.

The silver alloy may be in the form of an alloy containing silver as a main component, and including other metals such as In, P, Nd, Cu, Pd, Nb, Ni, Mo, Ni, Cr, Mg, W, and Ti, and silver. Various forms such as a compound, a silicide, a carbide, and an oxide are not limited to these.

In addition, the transparent conductive film generally has characteristics such as IZO and a-ITO that have a transmittance of about 90% or more and a resistivity of 1 × 10 ^-4 Ω cm or less in the visible light region. Since the transparent conductive film is transparent, generally there must be few conductive electrons. In order to increase the conductivity, there must be more conductive electrons. In the case of a transparent conductive film, two opposite conditions must be satisfied. In the method of vapor-depositing IZO and a-ITO, sputtering is generally used, which has the following advantages compared with the CVD (Chemical Vapor Deposition) method: it is easy to adjust the vapor deposition conditions, and in the case of using a large substrate , It is easy to achieve the uniformity of the thickness of the film and the characteristics of the film. In the case of manufacturing by a sputtering method, there are two methods using an oxide target or an alloy target. When an alloy target is used, it has the following advantages: the vapor deposition rate is fast, and the target life is relatively long. The target can be easily manufactured and reused, but has the disadvantage of being sensitive to changes in the display of program variables. If an oxide target is used, the stoichiometry of the thin film can be controlled reproducibly. However, compared with an alloy target, the vapor deposition rate is slower, and sometimes physical cracks may occur in the target during the vapor deposition, which may occur in the target. Disadvantages of the arc. In the case of sputtering vapor deposition of indium-main component oxide, it reacts with O ₂ and has the form of In ₂ O _3. However, in order to improve the conductivity, Ga, Ge, Si, Ti, Sb, Zr, Sn, and Zn. In the present invention, ITO means a transparent conductive film obtained by mixing In ₂ O ₃ and SnO ₂ at an appropriate ratio, but is not limited thereto. For example, the film quality of GZO made using only Ga and Zn used as a dopant is also applicable.

Further, the multilayer film may be made of transparent conductive film / silver, transparent conductive Multilayer film formed by electrical film / silver alloy, transparent conductive film / silver / transparent conductive film, or transparent conductive film / silver alloy / transparent conductive film.

In addition, the present invention can provide a wiring etched with the silver etchant composition of the present invention.

In more detail, the wiring may be a trace wiring or a flexible silver nanowire wiring that mainly reads signals sensed at the X and Y coordinates in a touch screen panel (TSP).

The wiring is a single film made of silver (Ag) or a silver alloy, or a multilayer film made of the single film and a transparent conductive film.

The silver alloy may be in the form of an alloy containing silver as a main component and containing other metals such as In, P, Nd, Cu, Pd, Nb, Ni, Mo, Ni, Cr, Mg, W, and Ti, and silver nitride , Silicide, carbide, and oxide, but are not limited to these.

In addition, the transparent conductive film generally has characteristics such as IZO and a-ITO that have a transmittance of about 90% or more and a resistivity of 1 × 10 ^-4 Ω cm or less in the visible light region. Since the transparent conductive film is transparent, generally there must be few conductive electrons. In order to increase the conductivity, there must be more conductive electrons. In the case of a transparent conductive film, two opposite conditions must be satisfied. In the method of vapor-depositing IZO and a-ITO, sputtering is generally used, which has the following advantages compared with the CVD (Chemical Vapor Deposition) method: it is easy to adjust the vapor deposition conditions, and it is easy to realize when using a large substrate Uniformity of film thickness and film characteristics. In the case of manufacturing by a sputtering method, there are two methods using an oxide target or an alloy target. When an alloy target is used, it has the following advantages: the vapor deposition rate is fast, and the target life is relatively long. The target can be easily manufactured and reused, but has the disadvantage of being sensitive to changes in the display of program variables. If an oxide target is used, the stoichiometry of the thin film can be controlled reproducibly. However, compared with an alloy target, the vapor deposition rate is slower, and sometimes physical cracks may occur in the target during the vapor deposition, which may occur in the target. Disadvantages of the arc. In the case of sputtering vapor deposition of indium-main component oxide, it reacts with O ₂ and has the form of In ₂ O _3. However, in order to improve the conductivity, Ga, Ge, Si, Ti, Sb, Zr, Sn, and Zn. In the present invention, ITO means a transparent conductive film obtained by mixing In ₂ O ₃ and SnO ₂ at an appropriate ratio, but it is not limited to this. For example, the film quality of GZO made using only Ga and Zn used as a dopant is also applicable.

Furthermore, the multilayer film may be a multilayer film formed of a transparent conductive film / silver, a transparent conductive film / silver alloy, a transparent conductive film / silver / transparent conductive film, or a transparent conductive film / silver alloy / transparent conductive film.

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are used to explain the present invention more specifically, and the scope of the present invention is not limited by the following examples. The following embodiments can be appropriately modified and changed by those skilled in the art within the scope of the present invention.

<Production of Silver Etching Solution Composition>

Examples 1 to 11 and Comparative Examples 1 to 8

The components described in Table 1 below were mixed at this content to produce a silver etchant composition. (unit weight%)

Experimental example 1. Performance test of silver etchant composition

An organic insulating film was vapor-deposited on the substrate, and a single Ag film was vapor-deposited thereon, and cut to 300 x 300 mm with a diamond cutter to prepare a test piece.

The following performance tests were performed using the silver etchant compositions of Examples 1 to 11 and Comparative Examples 1 to 8 described above.

1. Measurement of single-sided etching distance (S / E, Side Etch) of wiring (or reflective film)

The experimental equipment (model name: ETCHER (TFT), KCTech) of the spray etching method was charged with the silver etching solution compositions of Examples 1 to 11 and Comparative Examples 1 to 8, respectively, and the temperature was set to 40 ° C. After the temperature was raised, when the temperature reached 40 ± 0.1 ° C, the etching procedure of the test piece was performed. The total etching time was set to 60 seconds.

Put it into the substrate to start spraying, and take it out when it becomes an etching time of 60 seconds. After washing with deionized water, it was dried using a hot air dryer. After cleaning and drying, the substrate was cut, and the cross-section was measured using an electron scanning microscope (SEM; model name: SU-8010, manufactured by Hitachi). As a measurement standard for the one-sided etching distance, the width of the photoetched metal from the end portion of the photoresist to the inner side was measured, and the following criteria were evaluated. The results are shown in Table 2 below.

<Evaluation Criteria for Measuring Unilateral Etching Distance>

Excellent: below 0.5μm

Good: more than 0.5μm ~ 1.0μm

Defect: more than 1.0 μm

2. Determination of residue

The experimental equipment (model name: ETCHER (TFT), KCTech) of the spray etching method was charged with the silver etching solution compositions of Examples 1 to 11 and Comparative Examples 1 to 8, respectively, and the temperature was set to 40 ° C. After heating, when the temperature reached 40 ± 0.1 ° C, the above-mentioned test piece etching procedure was performed. The total etching time was set to 60 seconds.

The substrate was sprayed, and it was taken out at an etching time of 60 seconds. After washing with deionized water, it was dried with a hot air dryer and the photoresist was removed using a PR stripper. After washing and drying, a residue that does not etch silver (Ag) in a portion not covered with photoresist, that is, a residue, is measured using an electron scanning microscope (SEM; model name: SU-8010, manufactured by Hitachi). The results of the standard evaluation described above are shown in Table 2 below.

<Evaluation criteria for residue measurement>

Excellent: no residue (Figure 1)

Defect: Residue is generated (residue is a phenomenon in which etching becomes incomplete, and it exists in an amorphous form throughout the substrate. Figure 2)

3. Measurement of etching rate

The experimental equipment (model name: ETCHER (TFT), KCTech) of the spray etching method was charged with the silver etching solution compositions of Examples 1 to 11 and Comparative Examples 1 to 8, respectively, and the temperature was set to 40 ° C. After heating, when the temperature reached 40 ± 0.1 ° C, the above-mentioned test piece etching procedure was performed. The total etching time was set to 60 seconds.

End point detection (EPD) was performed with the naked eye, and the vertical etching rate (E / R, Etch Rate) corresponding to time was obtained. By dividing the thickness of the etched metal film by EPD, the etch rate of Å (thickness) (Å / sec) per second (time) can be obtained, and evaluated according to the following criteria. The results are shown in Table 2 below. in.

<Evaluation Criteria for Etching Speed>

Excellent: below 100Å / sec

Good: more than 100Å / sec ~ 200Å / sec

Bad: more than 200Å / sec

4. Determination of stability over time

Using the silver etchant compositions of Examples 1 to 11 and Comparative Examples 1 to 8 described above, a reference etch test was performed, and the remaining silver etchant composition was stored at 25 ° C for a planned date (one Monthly standard). Then, using the stored silver etching solution composition, etching was performed again under the same conditions as in the above-mentioned etching rate test, and the results in the reference etching test Compare. The evaluation criteria are as follows, and the results are shown in Table 2 below.

<Evaluation Criteria for Stability Over Time>

Excellent: Excellent etching profile after 1 month

Good: Etching profile is good after 1 month

Bad: The level of the etching profile after one month has not reached a good level

5. Determination of re-adsorption

The experimental equipment (model name: ETCHER (TFT), KCTech) of the spray etching method was charged with the silver etching solution compositions of Examples 1 to 11 and Comparative Examples 1 to 8, respectively, and the temperature was set to 40 ° C. After heating, when the temperature reached 40 ± 0.1 ° C, the above-mentioned test piece etching procedure was performed. The total etching time was set to 60 seconds.

The substrate was sprayed, and it was taken out at an etching time of 60 seconds. After washing with deionized water, it was dried with a hot air dryer and the photoresist was removed using a PR stripper. After cleaning and drying, using an electron scanning microscope (SEM; model name: SU-8010, manufactured by HITACHI), after etching, specific parts that are exposed to dissimilar metals such as data wiring and the like can be rubbed due to bending. The phenomenon of (Ag) adsorption on the etched portion was analyzed based on comprehensive observation, and evaluated according to the following criteria. The results are shown in Table 2 below.

<Evaluation criteria for resorption measurement>

Excellent: No re-adsorption (Figure 3)

Defect: Re-adsorption occurs (Silver re-adsorption is the adsorption caused by reduction, and a spherical shape is observed in the specific part described above. Figure 4)

6. Measurement of Taper angle

The experimental equipment (model name: ETCHER (TFT), KCTech) of the spray etching method was charged with the silver etchant composition of Examples 1 to 5 and Comparative Examples 1 to 5, respectively, and the temperature was set to 40 ° C. After heating, when the temperature reached 40 ± 0.1 ° C, the above-mentioned test piece etching procedure was performed. The total etching time was set to 60 seconds.

The substrate was sprayed, and it was taken out at an etching time of 60 seconds. After washing with deionized water, it was dried with a hot air dryer and the photoresist was removed using a PR stripper. After cleaning and drying, an electron scanning microscope (SEM; model name: SU-8010, manufactured by Hitachi) was used to vertically cut the wiring to be analyzed of the etched substrate, and then the inside of the wiring and the lower insulating film was measured The angle was analyzed and evaluated according to the following criteria. The results are shown in Table 2 below.

<Evaluation criteria for taper angle measurement>

Excellent: Cone angle above 20 ° ~ 60 ° (Figure 5)

Good: Taper angle exceeds 60 ° ~ 80 °

Bad: Taper angle is less than 20 ° or more than 80 °

From the above experimental results, it was confirmed that the etching solution composition of the present invention is not only excellent in all aspects of one-sided etching distance, residue, etching speed, stability over time, and presence or absence of re-adsorption, but also has properties in etching a metal film containing silver. Effect of forming taper angle after etching.

Claims (18)

A silver etchant composition includes 30 to 60% by weight of phosphoric acid, 0.5 to 10% by weight of nitric acid, 33 to 50% by weight of acetic acid, 0.01 to 10% by weight of an azole compound, and the balance with respect to the total weight of the composition. Deionized water so that the total weight of the composition becomes 100% by weight, wherein the azole-based compound is one or more kinds selected from tetrazole and methyltetrazole. The silver etching solution composition according to claim 1, wherein the azole-based compound is methyltetrazole. The silver etchant composition according to claim 1, wherein the silver etchant composition is capable of simultaneously etching a single film composed of silver or a silver alloy, or a multilayer film composed of the single film and a transparent conductive film. The silver etching solution composition according to claim 3, wherein the transparent conductive film is one or more selected from the group consisting of tin indium oxide, zinc indium oxide, tin zinc indium oxide, gallium zinc oxide, and gallium zinc indium oxide. The silver etching solution composition according to claim 3, wherein the multilayer film composed of the single film and the transparent conductive film is transparent conductive film / silver, transparent conductive film / silver alloy, transparent conductive film / silver / transparent conductive film, or Transparent conductive film / silver alloy / transparent conductive film. The silver etchant composition according to claim 1, wherein the silver etchant composition additionally contains an etching adjuster or a pH adjuster. A display substrate comprising a metal film etched with the silver etchant composition according to any one of claims 1 to 6. The display substrate according to claim 7, wherein the display substrate is a thin film transistor substrate of a liquid crystal display device or an organic light emitting element. The display substrate according to claim 8, wherein the metal film is laminated on an upper portion and a lower portion of the organic light emitting element for the organic light emitting element. The display substrate according to claim 7, wherein the metal film is a single film composed of silver or a silver alloy, or a multilayer film composed of the single film and a transparent conductive film. The display substrate according to claim 10, wherein the transparent conductive film is one or more selected from the group consisting of indium tin oxide, zinc indium oxide, gallium zinc oxide, and gallium zinc indium oxide. The display substrate of claim 10, wherein the multilayer film composed of the single film and the transparent conductive film is transparent conductive film / silver, transparent conductive film / silver alloy, transparent conductive film / silver / transparent conductive film, or transparent conductive film / Silver alloy / Transparent conductive film. A wiring which is etched using the silver etchant composition according to any one of claims 1 to 6. The wiring according to claim 13, wherein the wiring is a trace wiring for a touch screen panel. The wiring of claim 13, wherein the wiring is a flexible silver nanowire. The wiring of claim 13, wherein the wiring is a single film made of silver or a silver alloy, or a multilayer film made of the single film and a transparent conductive film. The wiring according to claim 16, wherein the transparent conductive film is one or more selected from the group consisting of indium tin oxide, zinc indium oxide, gallium zinc oxide, and gallium zinc indium oxide. The wiring of claim 16, wherein the multilayer film composed of the single film and the transparent conductive film is transparent conductive film / silver, transparent conductive film / silver alloy, transparent conductive film / silver / transparent conductive film, or transparent conductive film / Silver alloy / transparent conductive film.