KR102281335B1 - Etchant composition for silver thin layer and ehting method and mehtod for fabrication metal pattern using the same - Google Patents

Abstract

The present invention relates to a silver thin film etchant composition comprising an organic acid, an inorganic acid, an etch initiator, and a residual amount of water, an etch stop index of 0.05 to 0.35, an etchant composition for a silver thin film, an etching method using the same, and a method of forming a metal pattern.

Description

A silver thin film etchant composition, an etching method using the same, and a method of forming a metal pattern {ETCHANT COMPOSITION FOR SILVER THIN LAYER AND EHTING METHOD AND MEHTOD FOR FABRICATION METAL PATTERN USING THE SAME}

The present invention relates to a silver thin film etchant composition comprising an organic acid, an inorganic acid, an etch initiator, and a residual amount of water, an etch stop index of 0.05 to 0.35, an etchant composition for a silver thin film, an etching method using the same, and a method of forming a metal pattern.

As we enter the information age in earnest, the display field that processes and displays a large amount of information has developed rapidly, and in response to this, various flat panel displays have been developed and are in the spotlight.

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), and an electroluminescence display device (Electroluminescence). Display device: ELD), organic light emitting display (Organic Light Emitting Diodes: OLED), etc. are mentioned, and these flat panel display devices are used for various purposes in home appliances such as televisions and videos, as well as computers and mobile phones such as laptops. These flat panel display devices are rapidly replacing conventional cathode ray tubes (NITs) due to their excellent performance such as thinness, weight reduction, and low power consumption.

In particular, OLEDs emit light by themselves and can be driven at low voltages, so they are being rapidly applied to small display markets such as portable devices. In addition, OLED is on the verge of commercialization of large TVs beyond small displays.

On the other hand, conductive metals such as indium tin oxide (ITO) and indium zinc oxide (IZO) have relatively excellent light transmittance and conductivity, so the electrode of a color filter used in a flat panel display device. is widely used as However, these metals also have high resistance, which is an obstacle to enlargement of the flat panel display and realization of high resolution through improvement of response speed.

In the case of reflectors, aluminum (Al) reflectors have been mainly used in products in the past, but in order to realize low power consumption through improved luminance, a material change to a metal having higher reflectance is being sought. For this purpose, a silver (Ag: resistivity about 1.59 μΩcm) film, a silver alloy, or a multi-layer film containing the same, which has a lower resistivity and higher luminance than metals applied to flat panel display devices, is used for color filter electrodes, LCD or OLED wiring and The development of an etchant for the application of this material was required to realize the application to the reflector, the enlargement of the flat panel display, high resolution, and low power consumption.

However, silver (Ag) has extremely poor adhesion to an insulating substrate such as glass or a lower substrate such as a semiconductor substrate made of intrinsic amorphous silicon or doped amorphous silicon. Lifting or peeling is easily induced. In addition, even when the silver (Ag) conductive layer is deposited on the substrate, an etchant is used to pattern the silver (Ag) conductive layer. When a conventional etchant is used as such an etchant, silver (Ag) is excessively etched or etched non-uniformly, causing lifting or peeling of the wiring, and the side profile of the wiring is poor.

In addition, there is a difficulty in the process of implementing low skew for realization of high resolution.

In particular, silver (Ag) is a metal that is easily reduced, and it is etched without inducing residue when the etch rate is fast. At this time, the etch rate is fast and there is no difference in the etch rate between the upper and lower parts, so it is difficult to form a taper angle after etching. Since it is difficult to secure the straightness of the etching pattern, there are many limitations when forming wiring and patterns.

If the metal film stands vertically without a taper angle, a void may occur between the silver (Ag) and the insulating film or wiring when the insulating film or subsequent wiring is formed in the subsequent process. cause of

Accordingly, research to improve etching properties is being actively conducted, and as a representative example thereof, Korean Patent Registration No. 10-579421 discloses a silver etching solution containing nitric acid, phosphoric acid, acetic acid, auxiliary oxide solubilizer, fluorinated carbon-based surfactant and water. A composition is proposed, however, the problem of Ag over-etching and re-adsorption has not been completely solved in the art. Accordingly, there is a demand for an etchant composition having improved etching properties for silver, and active research is being conducted in response to the demand, but an etchant composition having significantly improved etching properties compared to the prior art has not yet been presented. am.

Republic of Korea Patent Registration Republic of Korea Patent No. 10-0579421

The present invention is a single film made of silver or a silver alloy, or the single film made of silver or a silver alloy because the side etch is reduced by having an appropriate etching rate without the occurrence of residues (eg, silver residues and/or indium oxide film residues) and silver re-adsorption problems. An object of the present invention is to provide a silver thin film etchant composition for etching a multilayer film composed of a film and an indium oxide film.

In addition, the present invention provides an etching method using the silver thin film etchant composition.

In addition, there is provided a method of forming a metal pattern using the silver thin film etchant composition.

In order to achieve the above object,

The present invention relates to a silver thin film etchant composition and an etching method using the same, and more particularly, 40 to 65% by weight of an organic acid, based on the total weight of the composition; 5 to 10% by weight of an inorganic acid; 1 to 15 wt% of an etch initiator; And it provides a silver thin film etchant composition comprising a remaining amount of water such that the total weight of the composition is 100% by weight.

In addition, the present invention comprises the steps of forming a single layer made of silver or a silver alloy, or a multilayer layer composed of the single layer and the indium oxide layer on a substrate; selectively leaving a photoreactive material on the single layer made of silver or a silver alloy or a multilayer layer comprising the single layer and the indium oxide layer; and etching the single layer made of silver or silver alloy or the multilayer layer comprising the single layer and the indium oxide layer using the silver thin film etchant composition.

In addition, forming a single film made of silver or a silver alloy, or a multilayer film composed of the single film and the indium oxide film; selectively leaving a photoreactive material on the single layer made of silver or a silver alloy or a multilayer layer comprising the single layer and the indium oxide layer; and etching the single layer made of silver or silver alloy, or the multilayer layer comprised of the single layer and the indium oxide layer using the silver thin film etchant composition.

The silver thin film etchant composition of the present invention has an appropriate etching rate without the occurrence of residues (eg, silver residues and/or indium oxide film residues) and silver re-adsorption problems. It has an excellent effect as a silver thin film etchant composition for etching a single film or a multilayer film composed of the single film and the indium oxide film.

Hereinafter, the present invention will be described in more detail.

The present invention, based on the total weight of the composition, 40 to 65% by weight of an organic acid; 5 to 10% by weight of an inorganic acid; 1 to 15 wt% of an etch initiator; And it relates to a silver thin film etchant composition comprising the remaining amount of water such that the total weight of the composition is 100% by weight.

The present invention is a single film made of silver or a silver alloy, or the single film made of silver or a silver alloy because the side etch is reduced by having an appropriate etching rate without the occurrence of residues (eg, silver residues and/or indium oxide film residues) and silver re-adsorption problems. As a silver thin film etchant composition for etching a multilayer film composed of a film and an indium oxide film, the present invention was completed by showing excellent effects.

The silver thin film etchant composition of the present invention is characterized in that it can etch a single film made of silver (Ag) or a silver alloy, or a multilayer film composed of the single film and the indium oxide film, and the multilayer film can be etched simultaneously.

The silver alloy contains silver as a main component, and includes an alloy type containing other metals such as Nd, Cu, Pd, Nb, Ni, Mo, Ni, Cr, Mg, W and Ti, and nitrides, silicides, carbides and oxides of silver. It may be various in the form, etc., but is not limited thereto.

In addition, the indium oxide is at least one selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), and indium zinc oxide gallium (IGZO).

In addition, the multilayer film may be a multilayer film formed of an indium oxide film/silver, an indium oxide film/silver alloy, an indium oxide film/silver/indium oxide film, or an indium oxide film/silver alloy/indium oxide film, and the silver thin film of the present invention In the case of using an etchant composition, side etching may not occur because it has an appropriate etching rate without problems of residues (eg, silver residues and indium oxide film residues) and silver re-adsorption problems, so it can be usefully used for wet etching. can

The organic acid contained in the silver thin film etchant composition of the present invention is a component used as a main oxidizing agent, and performs a wet etching function by oxidizing silver (Ag) and the transparent conductive film in the transparent conductive film/Ag/transparent conductive film.

The organic acid is included in an amount of 40 to 65 wt%, preferably 43 to 63 wt%, based on the total weight of the silver thin film etchant composition.

With respect to the total weight of the composition, when the content of the organic acid is less than 40% by weight, it may cause a decrease in the etching rate of silver and defects due to the generation of silver residue, and when it exceeds 65% by weight, the etching rate of the transparent conductive film and the amount of silver The etching rate becomes too fast, and an over-etching phenomenon may occur, which may cause a disadvantage in a subsequent process.

The organic acids included in the silver thin film etchant of the present invention are acetic acid, butanoic acid, citric acid, formic acid, gluconic acid, glycolic acid, malonic acid, oxalic acid, pentanoic acid, methanesulfonic acid, sulfobenzoic acid, sulfosuccinic acid, sulfophthalic acid , salicylic acid, sulfosalicylic acid, benzoic acid, lactic acid, glyceric acid, succinic acid, malic acid, tartaric acid, isocitric acid, propenoic acid, iminodiacetic acid and ethylenediaminetetraacetic acid may be at least one selected from the group consisting of acetic acid and citric acid It may be more preferable to include

The inorganic acid contained in the silver thin film etchant composition of the present invention is a component used as an etch improver, and performs a wet etching role by oxidizing silver (Ag) and the transparent conductive film in the transparent conductive film/Ag/transparent conductive film.

The inorganic acid is included in an amount of 5 to 10 wt%, preferably 6 to 9 wt%, based on the total weight of the silver thin film etchant composition.

Based on the total weight of the composition, when the content of the inorganic acid is less than 5% by weight, the etching rate of silver (Ag) and the transparent conductive film is lowered, and thus the etching uniformity in the substrate is deteriorated, so that staining occurs, and it exceeds 10% by weight In this case, there is a disadvantage in that the etching rate of the upper and lower transparent conductive films and the Ag film is accelerated, so that over-etching pattern loss occurs.

The inorganic acid included in the silver thin film etchant of the present invention may be at least one selected from the group consisting of nitric acid, sulfuric acid and hydrochloric acid.

The etch initiator included in the silver thin film etchant composition of the present invention is a component used as an etch rate control agent, and serves to accelerate the etch rate for oxide and Ag metal.

The etch initiator is included in an amount of 1 to 15 wt%, preferably 3 to 12 wt%, based on the total weight of the silver thin film etchant composition.

With respect to the total weight of the composition, when the content of the etch initiator is less than 1% by weight, the etching rate is slowed, and when it exceeds 15% by weight, the etching rate is increased to cause the tip of the upper transparent conductive film to cause problems in the subsequent process. can

The etching initiator included in the silver thin film etchant of the present invention may be one or more selected from the group consisting of a peroxide initiator, an alkyl metal initiator, and a dislocation metal initiator.

The peroxide initiator may be at least one selected from the group consisting of sodium persulfate, ammonium persulfate, potassium persulfate, oxone, and oxalic acid.

The alkyl metal initiator may be at least one selected from the group consisting of sodium nitrate, potassium nitrate, ammonium nitrate, calcium nitrate, sodium sulfate, potassium sulfate, calcium sulfate, sodium chloride, calcium chloride and potassium chloride.

The dislocation metal initiator may be at least one selected from the group consisting of iron nitrate, ferric nitrate, iron sulfate and ferric sulfate.

The water contained in the silver thin film etchant composition of the present invention uses deionized water for a semiconductor process, and preferably 18 MΩ/cm or more of water can be used, and the total weight of the composition is included in the remaining amount such that 100% by weight.

The silver thin film etchant composition of the present invention uses a single film or two or more using an indium oxide film, silver, or silver alloy, which is often used for forming a display (OLED, LCD, etc.) TFT array substrate, TSP trace wiring, and flexible nanowire wiring. It can be usefully used as a multi-layered wet etchant. In addition to the above-mentioned display and TSP, it can be used for electronic component materials using the metal film, such as semiconductors.

In addition, forming a single film made of silver or a silver alloy, or a multilayer film composed of the single film and the indium oxide film on the substrate;

selectively leaving a photoreactive material on the single layer made of silver or a silver alloy or a multilayer layer comprising the single layer and the indium oxide layer; and

It relates to an etching method comprising the step of etching the single layer made of silver or silver alloy, or the multilayer layer composed of the single layer and the indium oxide layer using the silver thin film etchant composition.

In addition, the present invention comprises the steps of forming a single film made of silver or a silver alloy, or a multilayer film composed of the single film and the indium oxide film; and

To a method of forming a metal pattern, the step of etching the single layer made of silver or silver alloy, or the multilayer layer comprising the single layer and the indium oxide layer, using the silver thin film etchant composition.

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

<Preparation of silver thin film etchant composition>

Examples 1 to 7 and Comparative Examples 1 to 3

A silver thin film etchant composition was prepared by mixing the components shown in Table 1 below in the corresponding content. Etch stop refers to the occurrence of an etch stop phenomenon in which etching is no longer performed when the conditions of the etchant composition are changed, and is a parameter that predicts that the value of side etch does not increase before SEM measurement.

Etch stop index of the present invention is (inorganic acid + initiator) / (organic acid + water) in a preferred range of 0.05 to 0.35, and the etching stop index is the ratio of the content of inorganic acid and initiator and the ratio of organic acid chelating metal to speed up the etching rate As an index for , it was possible to predict in advance whether S/E would increase or not increase due to the result according to the ratio.

[Table 1]

(Unit: % by weight)

Experimental Example 1. Performance test of silver etchant composition

A triple layer of ITO/Ag/ITO was formed on the substrate, and the unloading etching process was performed using an experimental equipment (model name: ETCHER (TFT), SEMES, Inc.) of a spray-type etching method. Each of the silver etchant compositions of Examples 1 to 7 and Comparative Examples 1 to 3 was added, the temperature was set to 40°C and the temperature was raised, and then, when the temperature reached 40±0.1°C, the ITO/Ag/ITO triple film was etched The process was carried out. The total etching time was performed for 60 seconds. The initial time of use (0 hours) was evaluated with the etchant composition, and 12 and 24 hours later, the same silver etchant composition was evaluated again.

1. Determination of Silver Residue

Each of the silver etchant compositions of Examples 1 to 12 and Comparative Examples 1 to 17 were put in the spray-type etching test equipment (model name: ETCHER (TFT), SEMES), the temperature was set to 40° C. When the temperature reached 40±0.1° C., the etching process of the specimen was performed. The total etching time was performed for 60 seconds.

After inserting the substrate and starting spraying, when the etching time of 60 seconds is over, it is taken out, washed with deionized water, dried using a hot air dryer, and the photoresist is removed using a photoresist stripper (PR stripper). After washing and drying, the residue, a phenomenon in which silver (Ag) is not etched, is measured in the area not covered with photoresist using a scanning electron microscope (SEM; model name: SU-8010, manufactured by HITACHI). Evaluated as a reference, the results are shown in Table 2 below.

<Residue measurement evaluation criteria>

O: good [residue not generated]

X: bad [residue generation]

2. Silver Resorption

Each of the silver etchant compositions of Examples 1 to 12 and Comparative Examples 1 to 17 were put in the spray-type etching test equipment (model name: ETCHER (TFT), SEMES), the temperature was set to 40° C. When the temperature reached 40±0.1° C., the etching process of the specimen was performed. The total etching time was performed for 60 seconds.

After inserting the substrate and starting spraying, when the etching time of 60 seconds is over, it is taken out, washed with deionized water, and dried using a hot air dryer. After washing and drying, the substrate was cut and the cross section was measured using a scanning electron microscope (SEM; model name: SU-8010, manufactured by HITACHI). The number of Ag adsorbed on the upper Ti of Ti/Al/Ti of the S/D part was measured and evaluated based on the following criteria, and the results are shown in Table 2 below.

<Silver resorption evaluation criteria>

O: Good [less than 50]

X : Bad [50 or more]

3. Etching rate EPD measurement

Etching rate EPD was measured using a timer from the time the substrate was exposed to the chemical solution to the time the metal part of the substrate was etched away, and the results are shown in Table 2 below.

4. Side Etch Measurement

After washing and drying, the substrate was cut and the cross section was measured using a scanning electron microscope (SEM; model name: SU-8010, manufactured by HITACHI). At this time, the distance from the patterned PR tip to the etched metal tip was measured, and the results are shown in Table 2 below.

[Table 2]

When looking at the Examples and Comparative Examples of the present invention, in the composition outside the content range, when the Etch Time increased, the S/E also increased, and the Etch Stop index, Etch Stop index = (inorganic acid + initiator) / (organic acid + water) ), deviates from 0.05 to 0.35. In addition, it was confirmed that the etchant composition of the present invention had an excellent effect as the silver (Ag) residue, silver (Ag) re-adsorption, and side etch due to an appropriate etching rate were decreased.

Claims (15)

Silver thin film etchant composition comprising an organic acid, an inorganic acid, an etch initiator, and water,
The organic acid includes acetic acid and citric acid,
Etch stop index of 0.05 to 0.35, silver thin film etchant composition.
delete delete The method according to claim 1,
Based on the total weight of the silver thin film etchant composition, comprising 40 to 65% by weight of the organic acid, the silver thin film etchant composition.
delete The method according to claim 1,
The inorganic acid is a silver thin film etchant composition comprising at least one selected from the group consisting of nitric acid, sulfuric acid, and hydrochloric acid.
The method according to claim 1,
The etching initiator is a silver thin film etchant composition comprising at least one selected from the group consisting of a peroxide initiator, an alkali metal initiator, and a dislocation metal initiator.
8. The method of claim 7,
The peroxide initiator is a silver thin film etchant composition comprising at least one selected from the group consisting of sodium persulfate, ammonium persulfate, potassium persulfate, oxone, and oxalic acid.
8. The method of claim 7,
The alkali metal initiator is a silver thin film etchant composition comprising at least one selected from the group consisting of sodium nitrate, potassium nitrate, calcium nitrate, sodium sulfate, potassium sulfate, calcium sulfate, sodium chloride, calcium chloride and potassium chloride.
8. The method of claim 7,
The dislocation metal initiator is a silver thin film etchant composition comprising at least one selected from the group consisting of iron nitrate, ferric nitrate, iron sulfate and ferric sulfate.
The method according to claim 1, The silver thin film etchant composition is a silver thin film etchant composition characterized in that it can simultaneously etch a single layer made of silver or a silver alloy, or a multilayer layer composed of the single layer and the indium oxide layer.
The method according to claim 11, wherein the indium oxide film is characterized in that at least one selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin oxide (ITZO) and indium gallium zinc oxide (IGZO). A silver thin film etchant composition.
The method according to claim 11, wherein the multilayer film composed of the single film and the indium oxide film is indium oxide film/silver, indium oxide film/silver alloy, indium oxide film/silver/indium oxide film, or indium oxide film/silver alloy/indium oxide film A silver thin film etchant composition, characterized in that
forming a single film made of silver or a silver alloy or a multilayer film made of the single film and an indium oxide film on a substrate;
selectively leaving a photoreactive material on the single layer made of silver or a silver alloy or a multilayer layer comprising the single layer and the indium oxide layer; and
An etching method comprising: etching a single layer made of silver or a silver alloy, or a multilayer layer comprising the single layer and an indium oxide layer using the composition of claim 1 .
forming a single film made of silver or a silver alloy, or a multilayer film composed of the single film and the indium oxide film; and
A method of forming a metal pattern, comprising: etching a single layer made of silver or a silver alloy, or a multilayer layer comprising the single layer and an indium oxide layer using the composition of claim 1 .