KR20190017473A - Etchant composition for etching metal layer and method of forming conductive pattern using the same - Google Patents

Abstract

According to embodiments of the present invention, provided is an etchant composition for etching a metal layer, which comprises an etch initiator, an inorganic acid, an organic acid, a polyhydric alcohol-based profile improver, and extra water, and has pH of 2 or less. The etchant composition for etching a metal layer is used to form a conductive pattern having a fine size with reduced etching defects.

Description

TECHNICAL FIELD [0001] The present invention relates to a metal film etchant composition and a conductive pattern forming method using the metal film etchant composition.

The present invention relates to a metal film etchant composition and a method for forming a conductive pattern using the same. More particularly, the present invention relates to a metal film etchant composition containing an acid component and a method of 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 TFT is 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 is connected to a pixel electrode, a counter electrode, a source electrode, a drain electrode, May be electrically connected to the TFT.

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

The metal film may be formed of a multi-layered film containing dissimilar metals having different chemical properties, or a different kind of conductive material, in order to prevent the signal transmission delay by reducing the wiring resistance and ensure the chemical resistance and stability of the wiring.

For example, a transparent conductive oxide film such as indium tin oxide (ITO) may be additionally formed for forming a silver (Ag) -containing film and improving chemical resistance, stability, and transparency for realizing a low resistance property .

As described in Korean Patent Registration No. 10-0579421, inorganic acid strong acid such as phosphoric acid, sulfuric acid and the like is used as a base component of the etchant composition. However, when inorganic strong acid is used, it may lead to defects such as uneven etching profile, over-etch, over-hang, etc. depending on the difference in the etching rates of the different kinds of conductive films, It is difficult to control the etching rate.

Korean Patent Registration No. 10-0579421 (2006.05.08.)

An object of the present invention is to provide a metal film etchant composition having improved etching uniformity and high resolution.

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

One aspect of the present invention is to provide a method of manufacturing a display substrate using the metal film etchant composition.

1. etch initiator; Inorganic acids; Organic acids; Polyhydric alcohol series profile improvers; And an excess of water, and having a pH of 2 or less.

2. The metal film etchant composition of 1 above, wherein the etch initiator comprises at least one selected from the group consisting of peroxide peroxide, hydrogen peroxide, persulfate and per nitrate.

3. The metal film etchant composition of 2 above, wherein the etch initiator comprises oxone.

4. The metal film etchant composition of 1 above, wherein the inorganic acid comprises nitric acid.

5. The metal film etchant composition of 1 above, wherein the organic acid comprises a first organic acid and a second organic acid that is weaker than the first organic acid.

6. The method of claim 5, wherein the first organic acid comprises acetic acid,

The second organic acid may be selected from the group consisting of iminodiacetic acid (IDA), ethylenediaminetetraacetic acid (EDTA), glycine, salicylic acid, citric acid, formic acid, But are not limited to, oxalic acid, malonic acid, succinic acid, butyric acid, gluconic acid, glycolic acid and pentanic acid. And at least one selected.

7. The composition of claim 1, wherein the polyol-based profile modifier is selected from the group consisting of glycerol, ethylene glycol, ethylene glycol, triethylene glycol, and polyethylene glycol ≪ / RTI >

8. The metal film etchant composition of 1 above, further comprising a metal salt.

9. The metal film etchant composition of claim 8, wherein the metal salt comprises at least one selected from the group consisting of ferric nitrate, sodium nitrate, and potassium nitrate.

10. The composition of claim 1, wherein,

1 to 20% by weight of the etch initiator; 1 to 15% by weight of the inorganic acid; 0.1 to 20% by weight of the organic acid; 1 to 20% by weight of the polyhydric alcohol-based profile modifier; And an excess of water.

11. The metal film etchant composition of claim 10, further comprising 0.1 to 5% by weight of a metal salt.

12. The metal film etchant composition of claim 1, which does not comprise phosphoric acid or phosphoric acid based compounds.

13. A method comprising: forming a metal film on a substrate; And

And etching the metal film using the metal film etchant composition of any one of [1] to [12] above.

14. The method of claim 13, wherein said forming a metal film comprises forming a silver containing film.

15. The conductive pattern forming method of claim 14, wherein the forming of the metal film further comprises forming a transparent conductive oxide film.

16. The conductive pattern forming method according to 15 above, wherein the transparent conductive oxide film comprises a first transparent conductive oxide film and a second transparent conductive oxide film formed by sandwiching the silver-containing film therebetween.

17. The transparent conductive oxide film of claim 15, wherein the transparent conductive oxide film is made of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), gallium zinc oxide (GZO) and indium gallium zinc oxide (IGZO) Wherein at least one selected from the group comprises at least one selected from the group.

18. The method of claim 13, 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 film is formed on the display layer.

19. The conductive pattern forming method according to 18 above, wherein the conductive pattern is provided as a common electrode, a reflective electrode or a wiring of an image display apparatus.

The metal film etchant composition according to the above-described embodiments of the present invention includes a etch initiator, an inorganic acid, an organic acid, and a polyhydric alcohol series profile modifier, and may have a pH of 2 or less. As the etching rate and the etching efficiency are increased in the pH range, the etching uniformity at the sidewalls of the conductive pattern can be improved by the action of the organic acid and the polyhydric alcohol profile improving agent.

According to exemplary embodiments, the inorganic acid comprises nitric acid, and the etching property control for fine pattern formation can be realized as the content of strong acid such as phosphoric acid, sulfuric acid, etc. is excluded or reduced.

When the metal film includes a silver-containing film and a transparent conductive oxide film, the etchant initiates the metal oxide substitution reaction, and the silver-containing film and the transparent conductive oxide film can be uniformly etched together. The etchant composition further includes a metal salt. In this case, etching uniformity of the silver-containing film and the transparent conductive oxide film can be further improved.

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

1 and 2 are sectional views for explaining a conductive pattern forming method according to exemplary embodiments.
3 is a cross-sectional view illustrating a method of manufacturing a display substrate according to exemplary embodiments.

According to embodiments of the present invention, a metal film etchant composition (hereinafter, abbreviated as "etchant composition") having a pH of 2 or less, which contains a etch initiator, an inorganic acid, an organic acid, and a polyhydric alcohol- A conductive pattern forming method and a display substrate manufacturing method using the metal film etchant composition are also provided.

The term "metal film" used in the present application is used as a term encompassing a metal single film and a laminated structure of the metal single film and the transparent conductive oxide film. In addition, the metal film may include a plurality of single metal films formed of different metals.

In exemplary embodiments, the metal film may comprise a silver containing film. The silver containing film may refer to a film comprising silver or a silver alloy. Further, the silver-containing film may include a multilayer structure of two or more layers.

For example, the silver alloy may be at least one selected from the group consisting of neodymium (Nd), copper (Cu), palladium (Pd), niobium (Ni), nickel (Ni), molybdenum (Mo), chromium (Cr), magnesium (W), protactinium (Pa), titanium (Ti) or a combination of two or more thereof and an alloy of silver (Ag); A silver compound containing dopant elements such as nitrogen (N), silicon (Si), and carbon (C); Or a combination of two or more thereof.

The transparent conductive oxide film may include a transparent metal oxide. For example, the transparent metal oxide may be selected from the group consisting of indium tin oxide (ITO), indium zinc oxide (IZO), indium tin zinc oxide (ITZO), gallium zinc oxide (GZO), indium gallium zinc oxide (IGZO) .

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

≪ Etchant composition &

The etch initiator included in the etchant composition according to embodiments of the present invention may be provided as a component capable of promoting the etching rate of silver (Ag) or the like and improving the etching uniformity. In addition, it may be included as a component for promoting etching by initiating or inducing a metal substitution reaction on a transparent conductive oxide film having a relatively low oxidation / reduction characteristic compared to silver.

In addition, since the etch initiator is included, the activity of the inorganic acid to be described later is promoted, so that the content of the inorganic acid can be relatively reduced. Therefore, it is possible to suppress the overeating angle, the etching unevenness, and the like which are caused when the inorganic acid is contained in excess.

According to exemplary embodiments, the etch initiator may comprise a sulfated peroxide, hydrogen peroxide, persulfate and / or nitrate, and may preferably comprise a sulfated peroxide such as oxone.

As the persulfate, at least one material selected from potassium persulfate (K ₂ S ₂ O ₈ ), sodium persulfate (Na ₂ S ₂ O ₈ ) or ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ) , At least one material selected from the group consisting of potassium nitrate (KNO ₄ ), sodium nitrate (NaNO ₄ ) and ammonium nitrate (NH ₄ NO ₄ ) may be used as the nitrate.

In some embodiments, the etch initiator may be included in an amount of about 1 to 20 weight percent of the total composition weight. If the content of the etch initiator is less than about 1% by weight, the etch rate may be excessively lowered and non-uniform etching may be caused. In addition, wiring shorts may occur due to silver residue, and the effect of promoting etching of the transparent conductive oxide film may be insignificant. If the content of the etch initiator is more than about 20% by weight, the oxidizing action of the inorganic acid may be inhibited.

In one embodiment, the content of the etch initiator may be adjusted to about 3 to 10% by weight in view of minimizing the etching rate difference between the silver-containing film and the transparent conductive oxide film and improving the etching uniformity.

The inorganic acid may act as an oxidant by interacting with the etch initiator described above. For example, the inorganic acid may serve as a main oxidant for a transparent conductive oxide film such as ITO. The inorganic acid and the etch initiator work together, so that the silver-containing film and the transparent conductive oxide film can be uniformly etched together.

According to exemplary embodiments, the inorganic acid may comprise nitric acid. In some embodiments, the inorganic acid may comprise nitrate. Examples of the nitrate include sodium nitrate, potassium nitrate, ammonium nitrate, and the like. These may be used alone or in combination of two or more.

In some embodiments, the inorganic acid may be included in an amount of about 1 to 15 weight percent of the total weight of the composition. If the content of the inorganic acid is less than about 1% by weight, the etching rate may be too low to cause a wiring short due to, for example, ITO residues and silver residues. In addition, dark spots or blind spots may occur due to the ITO residues or silver residues. If the content of the inorganic acid exceeds about 15 wt%, etching control failure of the metal film such as an overexcitation angle may occur.

In one embodiment, the content of the inorganic acid may be adjusted to about 3 to 10% by weight considering the uniform etching rate and the control characteristics of the silver-containing film and the transparent conductive oxide film.

The organic acid may be included, for example, to reduce the critical dimension loss (CD loss) of the conductive pattern obtained by appropriately promoting or controlling the etching rate of the silver-containing film and to promote fine pattern formation.

In some embodiments, the organic acid may comprise a first organic acid and a second organic acid that is less acidic than the first organic acid.

For example, the first organic acid comprises acetic acid and can function as a co-oxidant or as a peroxide for the silver. The second organic acid may be selected from the group consisting of iminodiacetic acid (IDA), ethylenediaminetetraacetic acid (EDTA), glycine, salicylic acid, citric acid, formic acid, But are not limited to, oxalic acid, malonic acid, succinic acid, butyric acid, gluconic acid, glycolic acid, pentanic acid, and the like. . These may be used alone or in combination of two or more.

The second organic acid may function as an etch profile promoter. The oxidative action by the first organic acid is partially suppressed or controlled by the second organic acid, so that the CD loss or the CD bias of the conductive pattern can be remarkably reduced.

In some embodiments, the organic acid may be included in an amount of about 0.1 to 20 weight percent of the total weight of the composition. If the content of the organic acid is less than about 0.1 wt%, the CD loss of the conductive pattern may increase. If the content of the organic acid exceeds about 20% by weight, stability with time of the composition may be lowered.

Considering the improvement of the profile characteristics of the conductive pattern, in one preferred embodiment, the content of the organic acid may be about 10 to 20% by weight.

In the exemplary embodiments, the polyhydric alcohol-based profile modifier is further included so that the etching profile of the conductive pattern can be finely controlled.

For example, as the polyhydric alcohol-based profile modifier includes a plurality of hydroxyl groups, the pH of the etchant composition can be raised to a fine degree to suppress overeating and tip phenomenon. In addition, the polyhydric alcohol-based profile modifier may function as a surfactant for the etchant composition or as a surface protective agent for a conductive pattern, thereby suppressing pattern loss.

The polyhydric alcohol-based profile improving agent may include, for example, glycerol, ethylene glycol, ethylene glycol, triethylene glycol, polyethylene glycol, and the like. have. These may be used alone or in combination of two or more.

Preferably, a divalent alcohol compound may be used as the above-mentioned polyhydric alcohol-based profile modifier in order to prevent excessive inhibition of the etching performance of the composition.

In some embodiments, the polyhydric alcohol-based profile modifier may be included in an amount of about 1 to 20 weight percent of the total weight of the composition. If the content of the polyhydric alcohol-based profile improver is less than about 1 wt%, sufficient surface protection and pH control functions may not be realized. If the content is more than about 20 wt%, the etching performance is excessively inhibited, .

In one embodiment, the content of the polyhydric alcohol-based profile modifier may be adjusted to about 1 to 10% by weight in terms of micro-adjustment of the etching properties.

In some exemplary embodiments, the etchant composition may further comprise a metal salt. The metal salt may further be included to further improve the etching uniformity of the silver-containing film and the transparent conductive oxide film. For example, the metal salt can prevent the etching rate of the transparent conductive oxide film from being lowered by removing or dissociating the silver native oxide film formed on the surface of the transparent conductive oxide film after being desorbed from the silver-containing film. In addition, the overall etching rate can be raised by the metal salt while maintaining the etching uniformity.

In some embodiments, the metal salt may include a metal nitrate, for example, ferric nitrate, sodium nitrate, potassium nitrate, and the like. Preferably, iron nitrate may be used.

In some embodiments, the metal salt may be included in an amount of about 0.1 to 5 weight percent of the total weight of the composition. If the content of the metal salt is less than about 0.1 wt%, silver may be re-adsorbed to the transparent conductive oxide film. If the content of the metal salt is more than about 5 wt%, the etching rate of the containing film may excessively increase, have.

In consideration of uniform etching of the silver-containing film and the transparent conductive oxide film, the metal salt may preferably be contained in an amount of about 0.1 to 3% by weight.

The etchant composition may include excess or residual water except for the above-mentioned components, for example, deionized water. In the case of the deionized water, for example, it may have a resistivity value of 18 M? / Cm or more.

The term "extra or remaining amount " as used in the present application means a variable amount including the amounts of the above-mentioned components and the above additives, when other additives are included.

In some embodiments, the additive may be included to improve etch efficiency or etch uniformity to the extent that it does not interfere with the action of the components described above. For example, the additive may include anti-corrosion, anti-adhesion of etching by-products, formulation for adjusting the taper angle of the etching pattern, and the like widely used in the art.

In some embodiments, the etchant composition may be substantially composed of the etch initiators, inorganic acids, organic acids, polyalcohol-based profile improvers, metal salts and water described above.

In some embodiments, the etchant composition may not comprise phosphoric acid or phosphoric acid based compounds (e.g., phosphates). In the case of the phosphoric acid or phosphoric acid-based compound, loss due to overgrowth of the metal film, damage to the lower structure, and re-adsorption may occur. In addition, in the case of the phosphoric acid or phosphoric acid compound, the viscosity of the etching solution composition may be excessively increased to cause an etching deviation in each region of the etching target film.

However, as the phosphoric acid or the phosphoric acid-based compound is excluded from the etchant composition, it is possible to form a conductive pattern having a fine pattern size while preventing over-etching of the silver-containing film.

The inorganic acid included in the etchant composition according to some exemplary embodiments is substantially composed of nitric acid, and may not include hydrochloric acid and sulfuric acid. Thus, an environmental pollution problem and an etching process with reduced silver precipitation problems can be realized.

The etchant composition according to exemplary embodiments can be adjusted to pH 2 or lower. The above-mentioned composition components can be adjusted in contents within a pH of 2 or less. For example, the pH can be finely controlled through the above-described polyhydric alcohol-based profile modifier within a range of pH 2 or less. Since the pH is adjusted to 2 or less, the defects such as the gouge angle, precipitation of silver, and silver adsorption are reduced, and the etching speed and the etching uniformity can be improved by the interaction of the above-mentioned components.

<Conductive Pattern Forming Method>

1 and 2 are schematic cross-sectional views for explaining a wiring forming method according to exemplary 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 a plastic substrate, an inorganic insulating substrate, or the like.

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

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

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

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

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

Referring to FIG. 2, the metal film 120 may be etched using the metal film etchant composition according to the above-described exemplary embodiments to form the conductive pattern 120a. The conductive pattern 120a includes a first transparent conductive oxide film pattern 122, a silver-containing pattern 124 and a first transparent conductive oxide film pattern 126 which are sequentially stacked on the lower insulating film 110 .

The conductive pattern 120a can be utilized, for example, as a pad, an electrode, or a wiring of an image display apparatus. By forming the relatively silver-containing pattern 124 having a low resistance and a good signal transmission property between the first and second transparent conductive oxide film patterns 122 and 126 having excellent corrosion resistance, a low resistance and mechanical and chemical reliability An improved conductive pattern can be realized.

Also, by utilizing the above-described etchant composition containing an etchant initiator, an inorganic acid, an organic acid, a polyhydric alcohol-based profile improver, a metal salt and the like or excluding or reducing phosphoric acid, overeating of the silver-containing pattern 124 is prevented, A conductive pattern 120a having a uniform and continuous sidewall profile can be formed.

In some embodiments, the thickness of the silver containing film 123 or the silver containing pattern 124 may be at least about 800 A, and in one embodiment at least about 1000 A. The thickness of the first and second transparent conductive oxide film patterns 122 and 126 may be about 50 to 100 ANGSTROM.

As the thickness of the silver-containing pattern 124 increases to realize low resistance and the aspect ratio of the conductive pattern 120a increases, etching defects may be caused by the silver residue and overeating angle. However, a wet etching process in which the etch failure is suppressed using the etchant composition according to the exemplary embodiments can be realized.

3 is a cross-sectional view illustrating a method of manufacturing a display substrate according to exemplary embodiments. For example, FIG. 3 shows a display substrate including a wiring and an electrode structure formed by the above-described conductive pattern forming method.

Referring to FIG. 3, 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 film 220, and a gate electrode 225.

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

The active layer 210 may be formed to include an oxide semiconductor such as polysilicon or, for example, indium gallium zinc oxide (IGZO). The gate insulating film 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 with 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.

The interlayer insulating film 230 covering the gate electrode 225 is formed on the gate insulating film 220 and then the source electrode 233 which is in contact with the active layer 210 through the interlayer insulating film 230 and the gate insulating film 220 And the drain electrode 237 can 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, or Ag.

A via insulating film 240 covering the source electrode 233 and the drain electrode 237 may be formed on the interlayer insulating film 230. The via insulating film 240 may be formed using an organic insulating material such as an acrylic type, a siloxane type resin, or the like.

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 contacts the drain electrode 237 through the via insulating layer 240. 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.

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

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

According to exemplary embodiments, the counter electrode 260 may be formed by sequentially laminating a first transparent conductive oxide film, a silver-containing film, and a second transparent conductive oxide film, and then patterning through a wet etching process using the above- .

Thus, the counter electrode 260 includes the first transparent conductive oxide film pattern 262, the silver-containing pattern 124 and the second transparent conductive oxide film pattern 262 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 TFT, the pixel electrode 245, the display layer 255, and the counter electrode 260 described above can 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 a first transparent conductive oxide film pattern 272, a silver-containing pattern 274 and a second transparent conductive oxide film pattern 276 which are sequentially stacked, for example, on the via insulating film 240, May be patterned using the etchant composition in accordance with the illustrative embodiments.

In one embodiment, the lines 270 may be formed together by a wet etch process that is substantially the same as the counter electrodes 260 on the display area I.

As described above, by forming the counter electrode 260 and / or the wiring 270 of the image display apparatus in a laminated structure including the first transparent conductive oxide film pattern-containing pattern-second transparent conductive oxide film pattern, While implementing resistance properties, mechanical / chemical stability and optical properties can be improved together. Further, when the above-described etching liquid composition is used, defects such as silver residue, side damage, tip developing, etc. can be suppressed.

In some embodiments, patterning of the gate electrode 225, the source electrode 233, the drain electrode 237, and the pixel electrode 245 may be performed utilizing the etching solution composition or the conductive pattern forming method described above.

In addition, the above-described etchant composition may be used to form various conductive patterns of a touch sensor included in an image display device in which the display substrate is employed. For example, sensing electrodes, traces, pads, etc. of the touch sensor may be formed using the etchant composition.

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. It will be apparent to those skilled in the art that various changes and modifications can be made to the embodiments within the spirit and scope of the appended claims.

Examples and Comparative Examples

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

Etching
Initiator
(Oxone) Inorganic acid
(nitric acid) Organic acid Metal salt
(Ferric nitrate) Close
Alcohol water pH The first organic acid
(Acetic acid) The second organic acid Example 1 5 9.5 15 3
(EDTA) 0.2 10 Balance 0.14 Example 2 5 9.5 15 3
(IDA) 0.2 10 Balance 0.56 Example 3 5 9.5 15 3
(Glycine) 0.2 10 Balance 0.87 Example 4 5 9.5 18 - 0.2 10 Balance 0.11 Example 5 5 9.5 15 3
(EDTA) - 10 Balance 0.12 Comparative Example 1 5 5 10 10 10 - Balance 2.1 Comparative Example 2 5 9.5 - - 0.2 10 Balance 2.5 Comparative Example 3 - 9.5 15 3
(EDTA) 0.2 10 Balance 1.5

Experimental Example

A triple film of ITO (100 Å) / Ag (1000 Å) / ITO (100 Å) was formed on a glass substrate, and a sample cut into a size of 10 cm × 10 cm was prepared using a diamond knife.

The metal film etching solution compositions of Examples and Comparative Examples were injected into a spray type etching equipment (ETCHER, K.C.Tech). When the temperature of the metal film etchant composition was set to 40 占 폚 and the temperature reached 40 占 0.1 占 폚, the metal film etchant composition was sprayed onto the sample and the etching process was performed for 85 seconds.

After the etching process was completed, the sample was rinsed with deionized water, dried using a hot air drying apparatus, and the photoresist was removed using a photoresist stripper (PR stripper).

(1) Evaluation of etch rate (ER)

The thickness of the etched sample was measured using a scanning electron microscope (SU-8010, manufactured by Hitachi), and the thickness of the etched sample was divided by the etch time to measure the longitudinal etch rate. Thereafter, the etching rate was evaluated according to the following criteria, and the results are shown in Table 2 below.

<Evaluation Criteria>

◎: longitudinal etching rate is over 30 Å / sec

?: Longitudinal etching rate of 20 to 30 A / sec

X: longitudinal etching rate is less than 20 Å / sec

(2) Side Etch Evaluation

The etched samples were measured for the average etch distance between the side etch of the conductive pattern formed by using an electronic scanning microscope (SU-8010, manufactured by Hitachi) and the upper and lower portions of the substrate.

The side etch (S / E) was calculated by the following equation (1) and evaluated as follows.

[Equation 1]

Side etch (S / E) = ((width of photoresist both ends) - (width of etched wiring width)) / 2

?: Excellent (0.5 占 퐉 or less)

?: Good (more than 0.5 占 퐉 and not more than 1.0 占 퐉)

X: defective (exceeding 1.0 占 퐉)

(3) Measurement of critical bias (CD bias)

The etched samples were cleaned and dried, and the substrate was cut, and the cross section was measured using an electron microscope (SEM; model: SU-8010, manufactured by Hitachi). The threshold value bias evaluation was performed by measuring the upper width of the wiring in contact with the photoresist pattern after completion of the etching. The evaluation criteria are as follows.

?: Width of the wiring in contact with the photoresist exceeds 31 占 퐉 to 34 占 퐉

?: Width of the wiring in contact with the photoresist exceeds 23 占 퐉 to 31 占 퐉

DELTA: Width of the wiring in contact with the photoresist is more than 9 mu m and not more than 23 mu m

X: Width of the wiring which is not etched or in contact with the photoresist is 9 占 퐉 or less

The evaluation results of the above-described experimental examples are shown together in Table 2 below.

division ER Evaluation Side Etch CD Bias Example 1 ◎ ◎ ◎ Example 2 ◎ ◎ ◎ Example 3 ◎ ◎ ◎ Example 4 ◎ ○ ○ Example 5 ○ ○ ○ Comparative Example 1 X X △ Comparative Example 2 X X X Comparative Example 3 X ○ △

Referring to Table 2, the etchant compositions of the Examples, including the pH ranges and components according to the exemplary embodiments, exhibited excellent etch characteristics overall. In particular, in Examples 1 to 3 including the metal salt and the second organic acid, excellent results were obtained in both the etching rate and the etching uniformity.

On the other hand, in the comparative examples in which the pH exceeded 2 or the components such as the etchant were omitted, the etching rate was lowered, and the side etch or CD bias also deteriorated together.

100, 200: substrate 110: lower insulating film
115: lower conductive pattern 120: metal film
120a: conductive pattern 121: first transparent conductive oxide film
122, 262, and 272: a first transparent conductive oxide film pattern
123: Silver-containing film 124, 264, 274: silver-containing pattern
125: second transparent conductive oxide film
126, 266, 276: a second transparent conductive oxide film pattern
210: active layer 210: gate electrode
233: source electrode 237: drain electrode
245: pixel electrode 260: opposing electrode
270: Wiring

Claims (19)

Etch initiators; Inorganic acids; Organic acids; Polyhydric alcohol series profile improvers; And an excess of water,
A metal film etchant composition having a pH of 2 or less.
The metal film etchant composition of claim 1, wherein the etch initiator comprises at least one selected from the group consisting of peroxide peroxide, hydrogen peroxide, persulfate and per nitrate.
The metal film etch composition of claim 2, wherein the etch initiator comprises oxone.
The metal film etchant composition of claim 1, wherein the inorganic acid comprises nitric acid.
The metal film etch composition according to claim 1, wherein the organic acid comprises a first organic acid and a second organic acid that is weaker than the first organic acid.
The method of claim 5, wherein the first organic acid comprises acetic acid,
The second organic acid may be selected from the group consisting of iminodiacetic acid (IDA), ethylenediaminetetraacetic acid (EDTA), glycine, salicylic acid, citric acid, formic acid, But are not limited to, oxalic acid, malonic acid, succinic acid, butyric acid, gluconic acid, glycolic acid and pentanic acid. And at least one selected.
The method according to claim 1, wherein the polyhydric alcohol-based profile improving agent is selected from the group consisting of glycerol, ethylene glycol, ethylene glycol, triethylene glycol, and polyethylene glycol And at least one selected.
The metal film etch composition according to claim 1, further comprising a metal salt.
9. The metal film etchant composition of claim 8, wherein the metal salt comprises at least one selected from the group consisting of ferric nitrate, sodium nitrate, and potassium nitrate.
The composition according to claim 1,
1 to 20% by weight of the etch initiator;
1 to 15% by weight of the inorganic acid;
0.1 to 20% by weight of the organic acid;
1 to 20% by weight of the polyhydric alcohol-based profile modifier; And
Wherein the metal film etchant composition comprises excess water.
The metal film etchant composition of claim 10, further comprising 0.1 to 5% by weight of a metal salt.
The metal film etchant composition according to claim 1, which does not contain a phosphoric acid or phosphoric acid-based compound.
Forming a metal film on the substrate; And
And etching the metal film using the metal film etchant composition of any one of claims 1 to 12.
14. The method of claim 13, wherein forming the metal film comprises forming a silver containing film.
15. The method of claim 14, wherein forming the metal film further comprises forming a transparent conductive oxide film.
16. The method of forming a conductive pattern according to claim 15, 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 therebetween.
16. The method of claim 15, wherein the transparent conductive oxide film is formed of a material selected 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) And at least one selected.
14. The method of claim 13,
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 film is formed on the display layer.
The conductive pattern forming method according to claim 18, wherein the conductive pattern is provided as a common electrode, a reflective electrode, or a wiring of an image display apparatus.

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