KR102293559B1 - Etchant composition for etching metal layer and method of forming conductive pattern using the same - Google Patents

Abstract

Examples of the present invention provide a metal film etchant composition comprising 33 to 70% by weight of an organic oxidizing agent, 1 to 10% by weight of an etch enhancer including an inorganic acid, 0.5 to 5% by weight of an adsorption inhibitor, and excess water based on the total weight of the composition do. A conductive pattern having reduced etch defects may be formed by using the metal film etchant composition.

Description

Metal film etchant composition and method of forming a conductive pattern using the same

The present invention relates to a metal film etchant composition and a method for forming a conductive pattern using the same. More particularly, it relates to a metal film etchant composition including an acid component and a method for forming a conductive pattern using the same.

For example, a thin film transistor (TFT) is used as a part of a driving circuit of a semiconductor device and a display device. The TFTs are arranged for each pixel on a substrate of, for example, an organic light emitting display (OLED) device or a liquid crystal display device (LCD), and wiring of a pixel electrode, a counter electrode, a source electrode, a drain electrode, a data line, a power supply line, etc. may be electrically connected to the TFT.

In order to form the electrode or wiring, a metal layer is formed on a display substrate, a photoresist is formed on the metal layer, and then the metal layer may be partially removed using an etchant composition.

In order to reduce wiring resistance to prevent signal transmission delay, and to secure chemical resistance and stability of wiring, the metal layer may be formed of a multilayer film including different types of metals having different chemical properties or different types of conductive materials.

For example, a silver (Ag)-containing film may be formed to realize low resistance characteristics, and a transparent conductive oxide film such as indium tin oxide (ITO) may be additionally formed to improve chemical resistance, stability, and transmittance. .

In the etchant composition, as disclosed in Korean Patent No. 10-0579421, an inorganic strong acid such as phosphoric acid, nitric acid, acetic acid, and sulfuric acid is used as a base component. However, when an inorganic strong acid is used, defects such as a non-uniform etch profile, over-etch, and over-hang may occur due to differences in etch rates of different types of conductive layers.

Korean Patent No. 10-0579421

One object of the present invention is to provide an etchant composition for a metal film having improved etch uniformity and reliability.

An object of the present invention is to provide a metal film etchant composition capable of effectively preventing the etched metal from being re-adsorbed on a substrate again.

One object of the present invention is to provide a method for forming a conductive pattern using the metal film etchant composition.

1. Based on the total weight of the composition, 30 to 70% by weight of an organic oxidizing agent; 1 to 10 wt% of an etch enhancer comprising an inorganic acid; 0.5 to 15% by weight of an anti-adsorption agent; and an excess of water, a metal film etchant composition.

2. The above 1, wherein the organic oxidizing agent is 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, sulfo A metal film etchant composition comprising at least one selected from the group consisting of salicylic acid, benzoic acid, lactic acid, glyceric acid, succinic acid, malic acid, tartaric acid, isocitric acid, propenoic acid, iminodiacetic acid and aminetetraacetic acid.

3. The metal film etchant composition of 1 above, wherein the etch enhancer includes at least one selected from the group consisting of nitric acid, sulfuric acid, and hydrochloric acid.

4. In the above 1, the adsorption inhibitor is ammonium sulfate, sodium sulfate, potassium sulfate, calcium sulfate, ammonium hydrogen sulfate, sodium hydrogen sulfate, potassium hydrogen sulfate, calcium hydrogen sulfate, ammonium nitrate, sodium nitrate, potassium nitrate and calcium nitrate. A metal film etchant composition comprising at least one selected from the group consisting of.

5. The metal film etchant composition of 1 above, wherein the metal film includes a silver-containing film.

6. The metal film etchant composition of 5 above, wherein the metal film further comprises a transparent conductive oxide film.

7. The metal film etchant composition of 6 above, wherein the transparent conductive oxide film includes a first transparent conductive oxide film and a second transparent conductive oxide film formed with the silver-containing film interposed therebetween.

8. The method of 6 above, wherein the transparent conductive oxide film is composed of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), gallium zinc oxide (GZO), and indium gallium zinc oxide (IGZO). A metal film etchant composition comprising at least one selected from the group.

9. The metal film etchant composition according to the above 1, which does not contain a fluorine-based compound and a phosphoric acid-based compound.

10. The method of 1 above, based on the total weight of the composition, 40 to 70% by weight of the organic oxidizing agent; 2 to 7% by weight of the etch enhancer; 1 to 3% by weight of the adsorption inhibitor; and a metal film etchant composition comprising excess water.

11. forming a metal film on the substrate; and etching the metal layer using the metal layer etchant composition of any one of 1 to 10 above.

12. The method of forming a conductive pattern according to the above 11, wherein the forming of the metal film includes forming a silver-containing film.

13. The method of 12 above, wherein the forming of the metal film further comprises forming a transparent conductive oxide film.

14. The method of 11 above, further comprising tilting the substrate on which the metal layer is formed.

15. The method of 11 above, further comprising: forming a thin film transistor on the substrate; forming a pixel electrode electrically connected to the thin film transistor; and forming a display layer on the pixel electrode, wherein the metal layer is formed on the display layer.

16. The method according to 15 above, wherein the conductive pattern is provided as a common electrode, a reflective electrode, or a wiring of an image display device.

17. The method of 15 above, wherein the conductive pattern is provided as a trace or a sensing electrode of a touch sensor.

The metal film etchant composition according to the above-described embodiments of the present invention may include an organic oxidizing agent as a base material. Accordingly, over-etching of the metal film (eg, a silver-containing film) caused by the use of a strong acid such as phosphoric acid and a tip phenomenon may be prevented.

In addition, as the content of a strong acid such as phosphoric acid is excluded or reduced, it is possible to prevent damage to the underlying structures other than the etch target layer.

In addition, the metal layer etchant composition may further include an etch enhancer assisting the organic oxidizing agent to improve an etch rate and etch uniformity.

In addition, the metal film etchant composition may further include an adsorption inhibitor assisting the organic oxidizing agent to effectively prevent re-adsorption of the etched metal, for example, silver.

In addition, when the metal film further includes a transparent conductive oxide film, as the organic oxidizing agent is used as the main etchant, for example, the difference in etching rate between the silver-containing film and the transparent conductive oxide film is reduced, so that the profile of the wiring or pattern is reduced. Continuity and uniformity can be improved.

Using the etchant composition, an electrode or wiring such as a reflective electrode of an image display device, a sensing electrode of a touch sensor, a trace or a pad, etc. may be formed to have a desired aspect ratio and profile.

1 and 2 are schematic cross-sectional views for explaining a method of forming a conductive pattern according to example embodiments.
3 is a schematic cross-sectional view illustrating a shape of a conductive pattern formed according to a comparative example.
4 is a schematic cross-sectional view for explaining a method of forming a conductive pattern according to example embodiments.
5 is a schematic cross-sectional view illustrating an image display device manufactured according to some exemplary embodiments.
6 is a schematic plan view illustrating a touch sensor formed in accordance with some exemplary embodiments.

According to embodiments of the present invention, a metal film etchant composition (hereinafter, abbreviated as "etchant composition") including an organic oxidizing agent, an inorganic acid, an inorganic salt, and water is provided. In addition, a method for forming a conductive pattern using the metal film etchant composition is provided.

The term “metal film” used in the present application is used as a term encompassing the metal single layer and the stacked structure of the metal single layer and the transparent conductive oxide layer. Also, the metal layer may include a plurality of metal single layers formed of different metals.

In example embodiments, the metal layer may include a silver-containing layer. The silver-containing film may refer to a film including silver or a silver alloy. In addition, the silver-containing film may include a multilayer structure of two or more layers.

For example, the silver alloy is neodymium (Nd), copper (Cu), palladium (Pd), niobium (Nb), nickel (Ni), molybdenum (Mo), chromium (Cr), magnesium (Mg), tungsten (W), protactinium (Pa), titanium (Ti) or a combination of two or more thereof, and an alloy of silver (Ag); silver compounds containing dopant elements such as nitrogen (N), silicon (Si), and carbon (C); or a combination of two or more thereof.

The transparent conductive oxide may include a transparent metal oxide. For example, the transparent metal oxide may include indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), gallium zinc oxide (GZO), indium gallium zinc oxide (IGZO), or a combination thereof. may include

Hereinafter, embodiments of the present invention will be described in detail, and a case in which the metal film includes a silver-containing film and a transparent conductive oxide film will be described as an example. However, these are preferred examples, and the spirit and scope of the present invention are not necessarily limited thereto.

<etchant composition>

The organic oxidizing agent included in the etchant composition according to embodiments of the present invention may be included as a main etchant or a main oxidizing agent for oxidizing or dissociating a metal layer. In example embodiments, the organic oxidizing agent may be a component included in the largest amount except for water in the etchant composition.

The organic oxidizing agent may be provided as a component implementing a wet etching process by oxidizing or dissociating the silver-containing layer. According to exemplary embodiments, the organic oxidizing agent is 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, aminetetraacetic acid, and the like. In one embodiment, it may be advantageous to include glycolic acid or acetic acid in view of the etch rate. In one embodiment, glycolic acid and acetic acid may be used together as the organic oxidizing agent.

In some embodiments, the organic oxidizing agent may be included in an amount of about 30 to 70% by weight based on the total weight of the composition. When the content of the organic oxidizing agent is less than about 30% by weight, sufficient etching ability may not be secured, and accordingly, silver residues and the number of treatments in the etching process may be reduced. When the content of the organic oxidizing agent exceeds about 70% by weight, over-etching of the silver-containing layer may be caused, and a tip phenomenon may occur in the etched region of the transparent conductive oxide layer.

In an embodiment, the content of the organic oxidizing agent may be adjusted to about 40 to 70 wt% in consideration of a uniform etching rate of the silver-containing layer and the transparent conductive oxide layer.

The etchant composition according to example embodiments may include an etch enhancer including an inorganic acid. The etch enhancer may be provided as a component supplementing an etch rate and etch uniformity in a wet etch process performed through the organic oxidizing agent. In addition, it may be included as a component that promotes etching by inducing a substitution reaction with respect to a transparent conductive oxide film having relatively low oxidation/reduction characteristics compared to silver.

The etch enhancer may include, for example, nitric acid, sulfuric acid and/or hydrochloric acid, preferably nitric acid.

In some embodiments, the etch enhancer may be included in an amount of about 1 to 10% by weight based on the total weight of the composition. When the content of the etch enhancer is less than about 1 wt %, the etch rate may be excessively lowered, the etch uniformity may be poor, and a wiring short due to silver residue may be caused. When the content of the etch enhancer exceeds about 10% by weight, the main oxidizing agent action of the organic oxidizing agent may be inhibited, and poor etching control of the metal layer such as overetching may occur.

In an embodiment, the content of the inorganic acid may be adjusted to about 2 to 7 wt% based on the total weight of the composition in consideration of a uniform etching rate of the silver-containing layer and the transparent conductive oxide layer.

The etchant composition may further include an adsorption inhibitor in addition to the organic oxidizing agent and/or the inorganic acid. The adsorption inhibitor is a component capable of preventing the silver etched from being reduced and re-adsorbed at unwanted positions on the substrate, such as wiring and pad parts during the wet etching process by the organic oxidizing agent. In addition, the adsorption inhibitor may assist the organic oxidizing agent to support an etch rate and an etch uniformity.

The adsorption inhibitor can form, for example, etched silver and micelles, thereby effectively preventing the etched silver from sticking to or adsorbing to other adjacent wirings, thereby preventing short circuits between wirings, clogging of wirings, etc. can be minimized

The adsorption inhibitor may include, for example, an inorganic salt, specifically ammonium sulfate ((NH ₄ ) ₂ SO ₄ ), sodium sulfate (Na ₂ SO ₄ ), potassium sulfate (K ₂ SO ₄ ), calcium sulfate ( CaSO ₄ ), ammonium hydrogen sulfate ((NH ₄ )HSO ₄ ), sodium hydrogen sulfate (NaHSO ₄ ), potassium hydrogen sulfate (KHSO ₄ ), calcium hydrogen sulfate (Ca(HSO ₄ ) ₂ ), ammonium nitrate (NH ₄ NO) ₃ ), sodium nitrate (NaNO ₃ ), potassium nitrate (KNO ₃ ), calcium nitrate (Ca(NO ₃ ) ₂ ) or a combination of two or more thereof, preferably potassium sulfate (K ₂ SO ₄ ) and/or potassium nitrate (KNO ₃ ), more preferably potassium nitrate (KNO ₃ ).

In some embodiments, the anti-adsorption agent may not include a phosphate. Since the etchant composition does not include a phosphate, it is possible to prevent a phenomenon in which the silver re-adsorption phenomenon is accelerated due to an excessively increased etching rate. In addition, the etchant composition can effectively prevent the silver re-adsorption phenomenon while improving the etch rate and etch uniformity by including the above-mentioned adsorption inhibitor.

In some embodiments, the adsorption inhibitor may be included in an amount of about 0.5 to 15% by weight based on the total weight. When the content of the adsorption inhibitor is less than about 0.5% by weight, the effect of preventing re-adsorption of silver is insignificant, and when the content of the adsorption inhibitor is more than about 15% by weight, over-etching of the silver-containing film is caused and a tip phenomenon occurs in the etched region of the transparent conductive oxide film. can

In one embodiment, the adsorption inhibitor may be adjusted to 1 to 3 wt % based on the total weight of the composition in terms of further enhancing the effect of preventing silver re-adsorption and securing an etch rate and etch uniformity.

The etchant composition may include an excess or residual amount of water other than the organic oxidizing agent, the etch enhancer, and the adsorption inhibitor, and may include, for example, deionized water. In the case of the deionized water, for example, it may have a resistivity value of 18 MΩ/cm or more.

As used herein, the term "extra or residual amount", when other additives are included, means a variable amount including the organic oxidizing agent, the etch enhancer, the adsorption inhibitor, and an amount excluding the additive.

In some embodiments, the additive may be included to improve etch efficiency or etch uniformity within a range that does not inhibit the action of the above-described organic oxidizing agent, etch enhancer, and/or adsorption inhibitor. For example, the additive may include a corrosion inhibitor widely used in the art, a pH adjuster, an etching by-product adsorption inhibitor, an agent for controlling a taper angle of an etching pattern, and the like.

In some embodiments, the etchant composition may not include phosphoric acid or a phosphoric acid-based compound (eg, phosphate). The phosphoric acid or the phosphoric acid-based compound may cause loss due to over-etching of the metal layer, damage to the underlying structure, and re-adsorption of silver. In addition, in the case of the phosphoric acid or the phosphoric acid-based compound, the viscosity of the etchant composition may be excessively increased to cause an etching deviation for each region of the etchant layer.

However, since phosphoric acid or the phosphoric acid-based compound is excluded from the etchant composition, and the organic oxidizing agent is used as a stock etch component, over-etching of the silver-containing layer may be prevented and etching uniformity may be improved.

In some embodiments, the etchant composition may not include hydrofluoric acid or a fluorine-based compound. As will be described later, when the etchant composition is used in an electrode forming process such as a reflective electrode of a display device, the etchant composition may be applied on an insulating film such as silicon oxide.

In this case, in order to prevent damage to the insulating film and selectively pattern the conductive film for electrodes, hydrofluoric acid or a fluorine-based compound may be excluded.

In some embodiments, the viscosity of the etchant composition may be about 1.2 to 3.0 cp (eg, at a temperature of ^{25 o C).} Since the etchant composition has a relatively reduced viscosity, fluidity of the composition may be improved, and an increase in etch deviation due to dipping of an object to be etched may be suppressed.

As described above, the etching solution composition according to the exemplary embodiments includes an organic oxidizing agent as a main etching agent, and for example, it can be effectively utilized in the etching process of a silver-containing film or a stacked structure of a silver-containing film/transparent conductive oxide film. can It is possible to prevent over-etching, damage, and re-adsorption of the silver-containing layer, which has a high ionization tendency by the organic oxidizing agent, and to form a pattern having an excellent etch profile and etch uniformity without damaging the lower wiring or the lower conductive pattern. In addition, a relatively low-viscosity etching composition may be implemented to reduce etching deviation due to dipping.

<Method of forming conductive pattern>

1 and 2 are schematic cross-sectional views for explaining a method of forming a conductive pattern according to example embodiments.

Referring to FIG. 1 , a lower conductive pattern 115 and a lower insulating layer 110 may be formed on a substrate 100 .

The substrate 100 may include a glass substrate, a polymer resin or plastic substrate, an inorganic insulating substrate, or the like.

The lower conductive pattern 115 includes, for example, a transparent conductive oxide such as aluminum (Al), copper (Cu), molybdenum (Mo), tungsten (W), titanium (Ti), tantalum (Ta), or ITO. can be formed to The lower insulating layer 110 may be formed to include an organic insulating material such as an acrylic resin or polysiloxane, and/or an inorganic insulating material such as silicon oxide, silicon nitride, or silicon oxynitride.

The lower conductive pattern 115 may be provided as, for example, a conductive via or a conductive contact.

According to exemplary embodiments, the first transparent conductive oxide layer 121 , the silver-containing layer 123 , and the second transparent conductive oxide layer 125 are sequentially stacked on the lower insulating layer 110 and the lower conductive pattern 115 . A metal film 120 including a may be formed.

The first and second transparent conductive oxide layers 121 and 125 may be formed to include a transparent conductive oxide such as ITO, IZO, GZO, IGZO, or the like. The silver-containing layer 123 may be formed to include silver and/or a silver alloy as described above. The first transparent conductive oxide layer 121 , the silver-containing layer 123 , and the second transparent conductive oxide layer 125 may be formed through, for example, a deposition process such as a sputtering process.

A mask pattern 130 may be formed on the metal layer 120 . For example, after forming a photoresist layer on the second transparent conductive oxide layer 125 , the photoresist layer may be partially removed through exposure and development processes to form the mask pattern 130 .

Referring to FIG. 2 , the conductive pattern 120a may be formed by etching the metal layer 120 using the metal layer etchant composition according to the above-described exemplary embodiments. The conductive pattern 120a may include, for example, a first transparent conductive oxide layer pattern 122 , a silver-containing pattern 124 , and a first transparent conductive oxide layer pattern 126 sequentially stacked on the lower insulating layer 110 . can

The conductive pattern 120a may be used as, for example, a pad, an electrode, or a wiring of an image display device. As a relatively silver-containing pattern 124 having low resistance and excellent signal transmission characteristics is formed between the first and second transparent conductive oxide film patterns 122 and 126 having excellent corrosion resistance, low resistance and mechanical and chemical reliability are improved. An improved conductive pattern can be implemented.

In addition, by utilizing an etchant composition containing an organic oxidizing agent, an etch enhancer, and an adsorption inhibitor, and in which the amount of a strong acid such as phosphoric acid is excluded or reduced, over-etching of the silver-containing pattern 124 is prevented, and is substantially uniform and continuous A conductive pattern 120a having a negative sidewall profile may be formed.

In some embodiments, the thickness of the silver-containing layer 123 or the silver-containing pattern 124 may be about 800 Å or more, and in an embodiment, about 1000 Å or more. The thickness of the first and second transparent conductive oxide layer patterns 122 and 126 may be about 50 to 100 Å.

As the thickness of the silver-containing pattern 124 increases and the aspect ratio of the conductive pattern 120a increases in order to realize a low resistance, etching failure due to silver residue and over-etching may occur. However, a wet etching process in which the etching failure is suppressed may be implemented using the etchant composition according to the exemplary embodiments.

3 is a schematic cross-sectional view illustrating a shape of a conductive pattern formed according to a comparative example. For example, the comparative example shows the shape of the conductive pattern 140 formed using the phosphoric acid-based etchant composition.

Referring to FIG. 3 , when the phosphoric acid-based etchant composition is used, one-sided etching of the silver-containing pattern 144 is deepened, so that a tip 150 is formed on the side of the first and second transparent conductive oxide film patterns 142 and 146 . ) may result. In this case, the insulating layer covering the conductive pattern 140 may be torn or peeled off.

In addition, when the lower conductive pattern 115 is exposed while the conductive pattern 140 is formed, the lower conductive pattern 115 may be partially etched and damaged by the phosphoric acid-based etchant composition, resulting in a recess 155 . have. In addition, the lower insulating layer 110 may also be damaged by the phosphoric acid-based etchant composition.

In addition, when an etchant composition containing phosphate or the like is used, the silver etched to form the silver-containing pattern 144 is re-adsorbed to other adjacent wirings due to excessive increase in the etching rate, which may cause problems such as short circuits between wirings and clogging of wirings. have.

However, according to exemplary embodiments, an etchant composition excluding phosphoric acid or phosphate is used, so that the silver re-adsorption problem can be effectively prevented, and the conductive pattern 120a and the lower conductive pattern 115 are used. ), a highly reliable wet etching process with reduced damage can be performed.

4 is a schematic cross-sectional view for explaining a method of forming a conductive pattern according to example embodiments.

Referring to FIG. 4 , as the area of the substrate 100 on which the metal film 120 is formed increases and becomes larger, the substrate 100 is tilted at a predetermined angle to prevent damage to the substrate 100 and etching efficiency. ) can be done. Thereafter, the etchant composition may be sprayed on the metal film 120 formed on the inclined substrate 100 through the etchant spraying device 50 .

In the comparative example, when a phosphoric acid-based etchant composition of high viscosity is used, the lower portion of the substrate 100 (the right part in FIG. 3 ) is immersed or dipped by the etchant composition for a relatively long time, so that the conductive pattern may be damaged or lost.

However, the etchant composition according to the exemplary embodiments may have a low viscosity by excluding phosphoric acid or phosphate, and may reduce an etching deviation according to a height or position difference.

5 is a schematic cross-sectional view illustrating an image display device manufactured according to some exemplary embodiments.

Referring to FIG. 5 , a thin film transistor TFT may be formed on a substrate 200 . For example, the TFT may include an active layer 210 , a gate insulating layer 220 , and a gate electrode 225 .

According to example embodiments, after the active layer 210 is formed on the substrate 200 , the gate insulating layer 220 covering the active layer 210 may be formed.

The active layer 210 may be formed to include polysilicon or an oxide semiconductor such as, for example, indium gallium zinc oxide (IGZO). The gate insulating layer 220 may be formed to include silicon oxide, silicon nitride, and/or silicon oxynitride.

A gate electrode 225 may be formed on the gate insulating layer 220 to overlap the active layer 210 . The gate electrode 225 may be formed to include a metal such as Al, Ti, Cu, W, Ta, Ag, or the like.

After forming the interlayer insulating layer 230 covering the gate electrode 225 on the gate insulating layer 220 , the source electrode 233 passes through the interlayer insulating layer 230 and the gate insulating layer 220 to contact the active layer 210 . ) and a drain electrode 237 may be formed. The source electrode 233 and the drain electrode 237 may be formed to include a metal such as Al, Ti, Cu, W, Ta, Ag, or the like.

A via insulating layer 240 may be formed on the interlayer insulating layer 230 to cover the source electrode 233 and the drain electrode 237 . The via insulating layer 240 may be formed using an organic insulating material such as an acrylic resin or a siloxane resin.

A pixel electrode 245 electrically connected to the drain electrode 237 may be formed on the via insulating layer 240 . The pixel electrode 245 may include a via portion that passes through the via insulating layer 240 and contacts the drain electrode 237 . The pixel electrode 245 may be formed to include a metal such as Al, Ti, Cu, W, Ta, Ag, and/or a transparent conductive oxide.

A pixel defining layer 250 may be formed on the via insulating layer 240 , and a display layer 255 may be formed on the upper surface of the pixel defining layer 250 exposed by the pixel defining layer 250 . The display layer 255 may be formed of, for example, an organic light emitting layer (EML) included in an OLED device or a liquid crystal layer included in an LCD device.

A counter electrode 260 may be formed on the pixel defining layer 250 and the display layer 255 . The counter electrode 260 may serve as a common electrode, a reflective electrode, or a cathode of the image display device.

According to exemplary embodiments, the counter electrode 260 is formed by sequentially stacking a first transparent conductive oxide layer, a silver-containing layer, and a second transparent conductive oxide layer, and then patterning it through a wet etching process using the above-described etchant composition. can be

Accordingly, the counter electrode 260 has a first transparent conductive oxide layer pattern 262 , a silver-containing pattern 124 , and a second transparent conductive oxide layer pattern sequentially stacked on the pixel defining layer 250 and the display layer 255 . (266).

In some embodiments, the image display device may include a display area I and a non-display area II. The aforementioned TFT, the pixel electrode 245 , the display layer 255 , and the counter electrode 260 may be formed on the display region I . A wiring 270 may be formed on the non-display area II. The wiring 270 may be electrically connected to the TFT or the counter electrode 260 .

The wiring 270 also includes, for example, a first transparent conductive oxide layer pattern 272, a silver-containing pattern 274 and a second transparent conductive oxide layer pattern 276 sequentially stacked on the via insulating layer 240, It may be patterned using an etchant composition according to example embodiments.

In an embodiment, the wiring 270 may be formed together through a wet etching process substantially the same as that of the counter electrode 260 on the display area I.

As described above, by forming the counter electrode 260 and/or the wiring 270 of the image display device in a stacked structure including the first transparent conductive oxide film pattern - the silver-containing pattern - the second transparent conductive oxide film pattern, low It is possible to simultaneously improve mechanical/chemical stability and optical properties while realizing resistance properties. In addition, as the etchant composition including the organic oxidizing agent is used, defects such as silver residue, side damage, and tip development can be suppressed.

6 is a schematic plan view illustrating a touch sensor formed in accordance with some exemplary embodiments.

Referring to FIG. 6 , the touch sensor 300 may include a sensing electrode 310 , a trace 320 , and a pad 330 formed on a substrate 300 .

The touch sensor 300 may include a sensing area (A) and a peripheral area (B). The sensing electrode 310 may be formed on the substrate 300 of the sensing region A, and the trace 320 and the pad 330 may be formed on the substrate 300 of the peripheral region B.

The sensing electrode 310 is, for example, parallel to the upper surface of the substrate 300 and arranged in first and second directions perpendicular to each other and the first sensing electrode 310a and the second sensing electrode 310b. may include.

The first sensing electrode 310a may extend in the first direction, and a plurality of first sensing electrodes 310a may be formed along the second direction. The second sensing electrode 310b may extend in the second direction, and a plurality of second sensing electrodes 310b may be formed along the first direction.

Each of the first and second sensing electrodes 310a and 310b may include, for example, polygon-shaped unit patterns, and may include a connection unit connecting neighboring unit patterns to each other. The inside of the unit pattern may include a conductive pattern patterned in a mesh type.

The trace 320 is branched from each of the sensing electrodes 310a and 310b , and a distal end of the trace 320 may be connected to the pad 330 . The touch sensor 300 may be connected to an external circuit such as a flexible printed circuit board (FPCB) through the pad 330 .

In example embodiments, the trace 320 may be formed through a wet etching process using the etchant composition including the above-described organic oxidizing agent. In some embodiments, the trace 320 may be formed in a stacked structure of a first transparent conductive oxide layer pattern-silver-containing pattern-second transparent conductive oxide layer pattern.

In an embodiment, the sensing electrode 310 and/or the pad 330 may also be formed through a wet etching process using the etchant composition. For example, the sensing electrode 310 and/or the pad 330 may be formed together through substantially the same wet etching process as the trace 320 . In this case, the sensing electrode 310 and/or the pad 330 may also be formed in a stacked structure of the first transparent conductive oxide layer pattern—the silver-containing pattern—and the second transparent conductive oxide layer pattern.

As the conductive patterns of the touch sensor 300 include the stacked structure of the silver-containing pattern and the transparent conductive oxide layer pattern described above, electrical properties such as sensing sensitivity and mechanical stability such as crack resistance may be improved together.

As described above, various conductive patterns included in an image display device, a touch sensor, etc. and having improved electrical, mechanical, and chemical properties may be formed using the metal film etchant composition according to the exemplary embodiments.

Hereinafter, experimental examples including specific examples and comparative examples are presented to help the understanding of the present invention, but these are merely illustrative of the present invention and do not limit the appended claims, the scope and description of the present invention It is obvious to those skilled in the art that various changes and modifications to the embodiments are possible within the scope of the spirit, and it is natural that such variations and modifications fall within the scope of the appended claims.

Examples and Comparative Examples

Metal film etchant compositions according to Examples and Comparative Examples were prepared with the components and contents (% by weight) shown in Table 1 below.

division Composition (wt%) organic oxidizer etch enhancer adsorption inhibitor Foshan phosphoric acid phosphate
(potassium phosphate) water glycolic acid acetic acid nitric acid potassium nitrate deionized water Example 1 30 - 2 0.5 - - - remaining amount Example 2 40 - 2 0.5 remaining amount Example 3 30 30 5 3 - - - remaining amount Example 4 30 30 7 3 - - - remaining amount Example 5 30 30 8 3 - - - remaining amount Example 6 - 70 5 15 - - - remaining amount Example 7 50 - 10 5 - - - remaining amount Example 8 60 - 5 10 - - - remaining amount Example 9 70 - One 0.5 - - - remaining amount Comparative Example 1 20 - One One - - - remaining amount Comparative Example 2 - 20 One One - - - remaining amount Comparative Example 3 50 - - 0.5 - remaining amount Comparative Example 4 50 - 0.5 0.5 - remaining amount Comparative Example 5 70 - 5 0.1 - remaining amount Comparative Example 6 30 30 5 - - remaining amount Comparative Example 7 - 15 7.5 2 - 50 - remaining amount Comparative Example 8 50 - 5 - - - 2 remaining amount Comparative Example 9 - 40 5 3 3 - - remaining amount

Experimental example

A triple layer of ITO (100 Å)/Ag (1000 Å)/ITO (100 Å) was formed on a glass substrate (SiO _{2 substrate), and a sample cut to a size of 10 cm×10 cm using a diamond knife was prepared.} A photoresist pattern covering a portion of the surface of the triple layer was formed.

The metal film etchant compositions of Examples and Comparative Examples were injected into a spray-type etching equipment (ETCHER, manufactured by K.C.Tech). After setting the temperature of the metal film etchant composition to 40 °C, when the temperature reached 40 ± 0.1 °C, the metal film etchant composition was sprayed on the sample, and the etching process was performed for 100 seconds.

After the etching process was completed, the specimen was washed with deionized water, dried using a hot air dryer, and the photoresist was removed using a photoresist stripper (PR stripper).

1. Silver (Ag) residue evaluation

After the completion of the etching, silver residues or dark spots on the substrate were observed through an electron scanning microscope (SU-8010, manufactured by HITACHI), and evaluated as follows.

○: Silver residue, no dark spots observed

X: silver residue, dark spots observed

2. Silver (Ag) resorption evaluation

After the etching was completed, the number of sites on which silver (Ag) was adsorbed was measured through full observation using a scanning electron microscope (SEM; model name: SU-8010, manufactured by HITACHI).

3. Etching rate evaluation

The thickness of the etched sample was measured using a scanning electron microscope (SU-8010, manufactured by HITACHI), and the longitudinal etch rate was measured by dividing the thickness of the etched sample by the etching time.

4. Upper and lower gap evaluation

An etching process was performed on the glass substrate on which the triple film was formed while a tilting angle of 10 ^{o was applied.} After the etching process was completed, the upper and lower gaps were measured by comparing the difference in the amount of etching at the top and bottom of the glass substrate in μm using an electron scanning microscope (SU-8010, manufactured by HITACHI).

5. Substrate Damage Assessment

After completion of the etching, the damage to the glass substrate was observed through an electron scanning microscope (SU-8010, manufactured by HITACHI) and evaluated as follows.

○: No change on the surface of the glass substrate

X: Damages such as dimples and recesses of the glass substrate are observed

silver residue silver resorption Etch rate (Å/sec) Upper and lower gap
(μm) board damage Example 1 ○ 0 42 0.10 ○ Example 2 ○ 0 45 0.10 ○ Example 3 ○ 0 39 0.10 ○ Example 4 ○ 0 37 0.13 ○ Example 5 ○ 0 36 0.18 ○ Example 6 ○ 0 40 0.11 ○ Example 7 ○ 0 37 0.18 ○ Example 8 ○ 0 41 0.12 ○ Example 9 ○ 0 38 0.18 ○ Comparative Example 1 Mi-etching Mi-etching Mi-etching Mi-etching ○ Comparative Example 2 Mi-etching Mi-etching Mi-etching Mi-etching ○ Comparative Example 3 X 200 40 0.30 ○ Comparative Example 4 X 150 60 0.29 ○ Comparative Example 5 ○ 40 28 0.32 ○ Comparative Example 6 X 180 28 0.37 ○ Comparative Example 7 ○ 200 25 0.29 ○ Comparative Example 8 ○ 195 50 0.29 ○ Comparative Example 9 ○ 200 25 0.27 X

Referring to Table 2, in the case of Examples in which an etchant composition containing 30 to 70% by weight of an organic oxidizing agent, 1 to 10% by weight of an inorganic acid, and 0.5 to 15% by weight of an inorganic salt is used, the etching rate is lower than that of Comparative Examples There was no silver residue, silver re-adsorption problem, and excellent etching performance and etching uniformity were exhibited without damage to the lower substrate.

In Comparative Examples 1 and 2 in which the content of the organic oxidizing agent is less than 30% by weight, substantially effective etching properties were not implemented. In Comparative Examples 3 to 6 in which the etch enhancer and/or the adsorption inhibitor were not included or included too little, silver re-adsorption was caused, and the upper and lower gaps also significantly increased.

In Comparative Examples 7 and 8 containing phosphoric acid or phosphate, the occurrence of silver re-adsorption intensified and upper and lower gaps increased, and Comparative Example 9 containing hydrofluoric acid caused damage to the glass substrate.

100, 200: substrate 110: lower insulating film
115: lower conductive pattern 120: metal film
120a, 140: conductive pattern
121: first transparent conductive oxide film
122, 142, 262, 272: first transparent conductive oxide film pattern
123: silver-containing film
124, 144, 264, 274: silver containing pattern
125: second transparent conductive oxide film
126, 146, 266, 276: second transparent conductive oxide film pattern
210: active layer 210: gate electrode
233: source electrode 237: drain electrode
245: pixel electrode 260: counter electrode
270: wiring 300: touch sensor
310: sensing electrode 320: trace
330: pad

Claims (17)

of the total weight of the composition,
30 to 70% by weight of an organic oxidizing agent;
1 to 10 wt% of an etch enhancer comprising an inorganic acid;
0.5 to 15% by weight of an anti-adsorption agent; and
containing extra water,
A metal film etchant composition that does not contain a fluorine-based compound and a phosphoric acid-based compound.
The method according to claim 1, wherein the organic oxidizing agent is 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, A metal film etchant composition comprising at least one selected from the group consisting of benzoic acid, lactic acid, glyceric acid, succinic acid, malic acid, tartaric acid, isocitric acid, propenoic acid, iminodiacetic acid and aminetetraacetic acid.
The metal film etchant composition of claim 1 , wherein the etch enhancer comprises at least one selected from the group consisting of nitric acid, sulfuric acid, and hydrochloric acid.
delete The metal film etchant composition of claim 1 , wherein the metal film comprises a silver-containing film.
The method according to claim 5, The metal film further comprises a transparent conductive oxide film, the metal film etchant composition.
The metal film etchant composition of claim 6 , wherein the transparent conductive oxide film includes a first transparent conductive oxide film and a second transparent conductive oxide film formed with the silver-containing film interposed therebetween.
The method according to claim 6, The transparent conductive oxide film is from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), gallium zinc oxide (GZO) and indium gallium zinc oxide (IGZO) A metal film etchant composition comprising at least one selected.
delete The method according to claim 1, in the total weight of the composition,
40 to 70% by weight of the organic oxidizing agent; 2 to 7% by weight of the etch enhancer; 1 to 3% by weight of the adsorption inhibitor; and a metal film etchant composition comprising excess water.
forming a metal film on the substrate; and
A method for forming a conductive pattern, comprising etching the metal layer using the metal layer etchant composition of any one of claims 1 to 3, 5 to 8, and 10.
The method of claim 11 , wherein the forming of the metal film comprises forming a silver-containing film.
The method of claim 12 , wherein the forming of the metal film further comprises forming a transparent conductive oxide film.
The method of claim 11 , further comprising tilting the substrate on which the metal film is formed and maintaining the tilting at a predetermined angle.
12. The method of claim 11,
forming a thin film transistor on the substrate;
forming a pixel electrode electrically connected to the thin film transistor; and
Further comprising the step of forming a display layer on the pixel electrode,
The metal layer is formed on the display layer, the conductive pattern forming method.
The method of claim 15 , wherein the conductive pattern is provided as a common electrode, a reflective electrode, or a wiring of an image display device.
The method of claim 15 , wherein the conductive pattern is provided as a trace or a sensing electrode of a touch sensor.

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