KR101391603B1 - Echant for silver pattern - Google Patents

Abstract

The present invention relates to an etchant used for wet etching a metal film in a manufacturing process of a flat panel display (FPD), and more particularly, to a single film made of Ag or Ag alloy, an alloy film of Ag and a dissimilar metal, Ag-palladium alloy film / transparent electrode triple film, particularly multilayer films made of transparent conductive metals such as indium tin oxide (IZO) and indium zinc oxide (IZO).

Description

ECHANT FOR SILVER PATTERN "

The present invention relates to an etchant used for wet etching a metal film in a manufacturing process of a flat panel display (FPD), and more particularly, to a single film made of Ag or Ag alloy, an alloy film of Ag and a dissimilar metal, Ag-palladium alloy film / transparent electrode triple film, particularly multilayer films made of transparent conductive metals such as indium tin oxide (IZO) and indium zinc oxide (IZO).

2. Description of the Related Art A liquid crystal display (LCD) is one of the most widely used flat panel displays, and is composed of two substrates on which electrodes are formed and a liquid crystal layer interposed therebetween. And rearranges the liquid crystal molecules in the liquid crystal layer to adjust the amount of light transmitted.

In recent years, Al reflectors have been mainly used for products. However, for the realization of low power consumption through improvement of brightness, Ag metal including low specific resistance and high luminance is included Alloy metal is a trend to apply. Ag, or Ag alloy and ITO, is applied to the color filter electrode TFT wiring and reflector of the flat panel display device, it is possible to realize the enlargement of the device, high resolution and low power consumption, and for this purpose, There is a tendency to make patterning of metal film.

Particularly, there is a need to develop an etchant that does not damage the top Mo / Al / Mo alloy film deposited thereon while etching the transparent electrode / Ag-palladium alloy film / transparent electrode triple film.

Although there are patents for etchant for etching Ag metal to date, most of them are not applicable to the mass production process including the environmentally harmful substances, or the etchant has a side etch length (loss of metal to be left under the photoresist) Not suitable for device manufacturing process. In addition, since silver has 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 of the wiring easily occurs There is a problem. For this reason, when the conventional etching solution is used, silver is excessively etched or unevenly etched, resulting in excessive defects in the profile of the wiring.

Korean Patent No. 10-0579421 (2006.05.08) discloses an etching solution used for etching a film containing silver, which comprises 1 to 10% by weight of nitric acid, 50 to 75% by weight of phosphoric acid 0.5 to 3% by weight of auxiliary oxide solubilizer, 0.001 to 0.01% by weight of a small carbon-based surfactant, and water to make the total weight of the entire composition 100% by weight, An Ag metal film or an etchant capable of etching multiple films including these alloys and Ag metal, particularly a transparent electrode / Ag / transparent electrode triple film including ITO or IZO. The present invention is a composition including phosphoric acid as a main component. When the alloy film is etched using the above composition, damage to the electrode may occur when Mo / Al / Mo usable as an electrode is exposed.

Korean Patent No. 10-0579421 (2006.05.08)

The present invention can selectively etch an alloy film containing silver or silver and provide an etchant that does not cause damage to a Mo / Al / Mo alloy film stacked on top of an alloy film containing silver or silver I want to.

The present invention also provides an etching solution excellent in storage stability and aging resistance.

The present inventors have conducted studies to provide an etchant excellent in the effect of etching and excellent in the change over time as a result of the study. As a result, it has been found that, by using a sulfate compound as an oxidant and particularly by using a specific sulfate compound, And the stability over time is excellent. Thus, the present invention has been completed.

The present invention relates to an etchant in a silver-containing pattern comprising nitric acid, oxalic acid, acetic acid, a sulfate based compound with an oxidizing agent and an azole-based compound as a corrosion inhibitor.

The etchant of the present invention may further comprise ammonium phosphate as a source / drain anti-damage agent.

The etching solution according to the present invention can selectively etch an alloy film containing silver or silver, has an excellent etching rate, does not generate a residue, and does not cause damage to molybdenum or aluminum that can be used as an electrode .

FIG. 1 is a SEM photograph of an a-ITO / Ag / ITO triple film etched using an etchant according to Example 3 of the present invention.

A first aspect of the present invention is an etchant in a silver-containing pattern comprising nitric acid, oxalic acid, acetic acid, a sulfate compound as an oxidizing agent, and an azole compound as a corrosion inhibitor.

More specifically, water is added so as to be 1 to 10 wt% of nitric acid, 0.1 to 5 wt% of oxalic acid, 5 to 15 wt% of acetic acid, 0.5 to 10 wt% of a sulfate compound, 0.01 to 1.0 wt% . ≪ / RTI >

A second embodiment of the present invention is an etchant of a silver containing pattern comprising nitrate, oxalic acid, acetic acid, a sulfate based compound with an oxidizing agent, an azole based compound as a corrosion inhibitor, and ammonium phosphate as a source / drain anti-

More specifically, it is preferable to use a solution containing 1 to 10 wt% of nitric acid, 0.1 to 5 wt% of oxalic acid, 5 to 15 wt% of acetic acid, 0.5 to 10 wt% of a sulfate compound, 0.01 to 1.0 wt% of an azole compound, 0.1 to 2 wt% The remainder may contain water to be 100% by weight.

A third embodiment of the present invention is a method for purifying sulfuric acid, which comprises using a nitric acid, oxalic acid, acetic acid, a triple salt containing potassium peroxymonosulphate, potassium perchlorate and potassium sulfate as an oxidizing agent, ammonium phosphate as a source / drain anti- ≪ / RTI > More specifically, 0.5 to 10% by weight of a tribasic salt containing 1 to 10% by weight of nitric acid, 0.1 to 5% by weight of oxalic acid, 5 to 15% by weight of acetic acid and potassium peroxymonosulfate, potassium and potassium sulfonates, ammonium phosphate 0.1 To 2% by weight, an azole compound in an amount of 0.01 to 1.0% by weight, and the balance of 100% by weight.

The first to third aspects are merely illustrative of the present invention, but the present invention is not limited thereto.

In one embodiment of the present invention, the sulfate compound may be any one or a mixture of two or more selected from the group consisting of potassium peroxymonosulfate, potassium trisulfate and potassium sulfate, trisodium salt, ammonium persulfate, and sodium persulfate.

In one embodiment of the present invention, the azole-based compound is selected from the group consisting of 1,2,3-triazole, 1,2,4-triazole, 3-amino-1,2,4- , 2,4-triazole, 5-amino-1H-tetrazole, benzotriazole, 1-hydroxybenzotriazole, 1-methylbenzotriazole, 2-methylbenzotriazole, (1) selected from the group consisting of benzotriazole, benzotriazole-5-carboxylic acid, nitrobenzotriazole and 2- (2H-benzotriazol-2-yl) -4,6-di- Or a mixture of two or more.

Hereinafter, each configuration of the present invention will be described in detail.

In the present invention, the nitric acid is used as a co-oxidant to oxidize and etch silver and indium oxide. In the present invention, 1 to 10 wt%, more preferably 5 to 8 wt%, is preferably used. In the case of using less than 1% by weight, the etch rate of the silver (Ag) film and the indium oxide (ITO) film is lowered to cause unevenness on the substrate, %, The etch length becomes longer for each film, and the etching rate becomes too fast, which makes it difficult to control.

In the present invention, the oxalic acid is used as an etching agent for the indium oxide film and an Ag chelating agent, and it is preferable to use 0.1 to 5 wt%, more preferably 1 to 2 wt%. In the case of using more than 5 wt%, etching can be performed, but the storage stability (elapsed time) of the etching solution may be lowered. When the amount is less than 0.1 wt%, the effect is insignificant.

In the present invention, the acetic acid is used as a co-oxidant of silver, and has a dielectric constant smaller than that of water. Thus, the wet etch process improves the wettability of the Ag etchant to the metal film, And at the same time inhibiting the corrosion of the indium oxide film. The content is preferably 5 to 15% by weight, more preferably 8 to 12% by weight, and more preferably 9 to 10% by weight. When it is less than 5% by weight, Ag residue is generated, and when it is more than 15% by weight, a large amount of bubbles are generated, which may cause stain generation problem.

In the present invention, the sulfate compound is a component used as a main oxidizing agent for silver (Ag), and specifically, for example, a triple salt (or oxone) containing potassium peroxymonosulfate, potassium sulfate and potassium sulfate, , Ammonium persulfate, and sodium persulfate may be used. The content thereof is preferably 0.5 to 10% by weight, more preferably 0.5 to 5% by weight. If it is used in an amount less than 0.5% by weight, oxidation ability may be deteriorated and an Ag residue may be formed after etching. In the case where potassium peroxymonoper sulfate is used as a main oxidizing agent, if it is used in an amount exceeding 10% by weight, etching may be possible but damage to other membranes used as an electrode may occur. In addition, there is a difficulty in control due to the high etching rate.

In the present invention, the azole compound plays a role of controlling the etching rate through inhibition of corrosion of the silver (Ag) compound. In the range of 0.01 to 1.0 wt% of the azole compound, not only the corrosion inhibition of silver, The speed can be controlled and the occurrence of residue can be improved. If it exceeds 1.0% by weight, the etching rate may be too slow to cause a residue.

The azole compound may be at least one selected from the group consisting of 1,2,3-triazole, 1,2,4-triazole, 3-amino-1,2,4-triazole, , 5-amino-1H-tetrazole, benzotriazole, 1-hydroxybenzotriazole, 1-methylbenzotriazole, 2-methylbenzotriazole, 5-methylbenzotriazole, tolyltriazole, (2H-benzotriazole-2-yl) -4,6-di-t-butylphenol is used as the organic solvent. And more preferably 5-amino-1H-tetrazole is used.

The present invention may further comprise ammonium phosphate as a source / drain anti-demagnetizer, if necessary, and is preferably used in an amount of 0.1 to 2 wt%, more preferably 0.1 to 0.5 wt%. If it is used in an amount exceeding 2% by weight, the etching ability of the indium oxide film may be lowered, and residue may be generated.

The etchant according to the present invention can satisfy the property that the stability over time is secured for 30 days or more and the etchability is maintained.

Hereinafter, the present invention will be described in more detail with reference to Examples.

However, the following examples are only illustrative of the present invention, and the present invention is not limited to the following examples.

The following physical properties were measured by the following measurement methods.

1) Etching

An organic insulating film was deposited on the substrate, and ITO / Ag / ITO triplet deposited thereon was cut into 5 × 5 cm using a diamond knife to prepare a test piece. The total composition shown in Table 1 was prepared so as to have an etching amount of 8 Kg as the composition ratio with respect to the total weight. The etchant was injected into the experimental equipment of the injection type etching system and the temperature was set at 35 ° C. Total etch time was 100, 200, 300, 400, and 500% over etch based on end point detection (EPD).

2) an eych profile

After the etched substrate was cleaned, it was dried, and the etching profile was confirmed using an electron microscope (Model: Hitachi, S-4300). During the profile confirmation, the side etching was observed from the end of the photoresist to the portion where the triple film remained, and the degree of occurrence of the etching residue was observed in the profile of the degree of occurrence of the residue remaining on the lower film. The etched samples were also evaluated by observing changes in the roughness of the top Mo of the electrodes exposed in the structure in the over-etched substrate samples to determine whether the damage occurred.

[Examples 1 to 6]

Oxone (OXONE, manufactured by DuPont) was used as the nitric acid, oxalic acid, acetic acid and the sulfate compound, 5-amino-1H-tetrazole was prepared as the azole compound in the contents shown in Table 1 below, Respectively. At this time, the content of each sulfate compound was changed as shown in Table 1 below. Table 2 shows the results of measuring the physical properties by the physical property measuring method.

Composition (% by weight) Sulfate system
compound
(Oxone) nitric acid Acetic acid Oxalic acid Azole Ammonium phosphate Example 1 0.0 10 10 2 0.01 - Example 2 0.5 10 10 2 0.01 - Example 3 1.0 10 10 2 0.01 - Example 4 3.0 10 10 2 0.01 - Example 5 5.0 10 10 2 0.01 - Example 6 10.0 10 10 2 0.01 -

Etching Etching profile Residue damage Aging change Example 1 Un-Etch Bad
(Agin-Etch) - Never Example 2 Etch Good Residual occurrence Never Example 3 Etch Good No residue Never Example 4 Etch Good No residue Occurred Example 5 Etch Good No residue Occurred Example 6 Etch Bad (control is difficult because the etching rate is too fast) No residue Occurred

As shown in Table 2, when the sulfate compound was not used, it was not etched, and it was found that the physical properties were excellent in the range of 0.5 to 1.0% by weight of the sulfate compound. When the content of the sulfate compound was more than 3% by weight, it was found that the etching was satisfactory and the residue did not occur but the damage occurred.

[Examples 7 to 12]

An etchant was prepared in the same manner as in Example 1 except that the contents of nitric acid were different as shown in Table 3 below, and physical properties were measured and shown in Table 4 below.

Composition (% by weight) Sulfate system
compound
(Oxone) nitric acid Acetic acid Oxalic acid Azole Ammonium phosphate Example 7 1.5 0.0 10 2 0.01 - Example 8 1.5 0.5 10 2 0.01 - Example 9 1.5 1.0 10 2 0.01 - Example 10 1.5 5.0 10 2 0.01 - Example 11 1.5 10.0 10 2 0.01 - Example 12 1.5 15.0 10 2 0.01 -

Etching Etching profile Residue damage Aging change Example 7 Un-Etch Bad (Agin-Etch) - - Example 8 Etch Bad (bottom film residue) Residual occurrence Never Example 9 Etch Good No residue Never Example 10 Etch Good No residue Never Example 11 Etch Good No residue Never Example 12 Etch Bad (control is difficult because the etching rate is too fast) No residue Never

As shown in Table 4, when nitric acid was not used, no etching occurred, and it was found that the etching was the most excellent in the range of nitric acid content of 1.0 to 10% by weight. At 15 wt%, the etching rate was too fast and the etching profile was bad.

[Examples 13 to 17]

The etchant was prepared in the same manner as in Example 1 except that each nitric acid content was varied as shown in Table 5, and physical properties were measured and shown in Table 6 below.

Composition (% by weight) Sulfate compound
(Oxone) nitric acid Acetic acid Oxalic acid Azole Ammonium phosphate Example 13 1.5 8 10 2 0.01 - Example 14 1.5 8 10 2 0.05 - Example 15 1.5 8 10 2 0.1 - Example 16 1.5 8 10 2 One - Example 17 1.5 8 10 2 1.5 -

Etching Etching profile Residue damage Aging change Example 13 Etch Good No residue Never Example 14 Etch Good No residue Never Example 15 Etch Good No residue Never Example 16 Etch Good No residue Never Example 17 Etch Bad (Ag etch rate too slow to generate residue) Residual occurrence Never

As shown in Table 6, it was found that the residues were not generated in the range of using 0.01 to 1% by weight of 5-amino-1H-tetrazole as an azole compound, and the etching was excellent.

[Examples 18 to 20]

An etchant was prepared in the same manner as in Example 1 except that each nitric acid content was varied as shown in Table 7 below, and physical properties were measured and shown in Table 8 below.

Composition (% by weight) Sulfate compound
(Oxone) nitric acid Acetic acid Oxalic acid Azole Ammonium phosphate Example 18 1.5 10 10 One 0.01 - Example 19 1.5 10 10 3 0.01 - Example 20 1.5 10 10 5 0.01 -

Etching Etching profile Residue damage Aging change Example 18 Etch Good No residue Never Example 19 Etch Good No residue Never Example 20 Etch Good No residue Never

As shown in Table 8, it was found that an excellent etching was exhibited in a range of using 1 to 5 wt% of oxalic acid. However, it was found that the stability over time was reduced.

[Examples 21 to 23]

The etchant was prepared in the same manner as in Example 1 except that each nitric acid content was varied as shown in Table 9 below, and physical properties were measured and shown in Table 10 below.

Composition (% by weight) Sulfate compound
(Oxone) nitric acid Acetic acid Oxalic acid Azole Ammonium phosphate Example 21 5.0 10.0 10.0 2 0.01 0 Example 22 5.0 10.0 10.0 2 0.01 0.5 Example 23 5.0 10.0 10.0 2 0.01 1.5

Etching Etching profile Residue damage Aging change Example 21 Good Good Never Occur Example 22 Good Good Never Never Example 23 Bad Residual occurrence Occur Never

[Examples 24 to 26]

An etching solution was prepared in the same manner as in Example 1 except that ammonium persulfate (APS) was used as a sulfate compound, and physical properties were measured and shown in Table 12 below.

Composition (% by weight) Sulfate compound
(APS) nitric acid Acetic acid Oxalic acid Azole Example 24 0 5 10 One 0.01 Example 25 1.0 5 10 One 0.01 Example 26 1.5 5 10 One 0.01 Example 27 2.0 5 10 One 0.01 Example 28 2.5 5 10 One 0.01 Example 29 3.0 5 10 One 0.01

Etching Etching profile Residue damage Aging change Example 24 Un-etch Bad (Agin-etch) - none Example 25 Etch Good Occurrence (trace) none Example 26 Etch Good No residue none Example 27 Etch Good No residue none Example 28 Etch Good No residue none Example 29 Etch Good No residue none

As shown in Table 12, when ammonium persulfate (APS) was used as a sulfate compound, it was found that an excellent etching was exhibited in a range of 1.5 wt% or more and 1.5-3 wt%.

Claims (6)

A sulfate compound which is a peroxide and a nitric acid, oxalic acid, acetic acid and an azole-based compound,
A pattern of silver-containing pattern for selectively etching an alloy film comprising silver or silver by applying it to a laminated film of an alloy film comprising silver or silver and a Mo / Al / Mo alloy film stacked thereon. The method according to claim 1,
Wherein the etchant further comprises ammonium phosphate as a source / drain anti-demagnetizer. The method according to claim 1,
The etchant is dissolved in water to a concentration of 1 to 10 wt% of nitric acid, 0.1 to 5 wt% of oxalic acid, 5 to 15 wt% of acetic acid, 0.5 to 10 wt% of a sulfate compound, 0.01 to 1.0 wt% Containing pattern. 3. The method of claim 2,
And the ammonium phosphate is contained in an amount of 0.1 to 2% by weight. The method according to claim 1,
Wherein the sulfate compound is any one or a mixture of two or more selected from trisodium salt, ammonium persulfate, and sodium persulfate including potassium peroxymonosulphate, potassium sulphurate and potassium sulphate. The method according to claim 1,
The azole compound may be at least one selected from the group consisting of 1,2,3-triazole, 1,2,4-triazole, 3-amino-1,2,4-triazole, , 5-amino-1H-tetrazole, benzotriazole, 1-hydroxybenzotriazole, 1-methylbenzotriazole, 2-methylbenzotriazole, 5-methylbenzotriazole, tolyltriazole, A mixture of at least one member selected from the group consisting of carboxylic acid, nitrobenzotriazole and 2- (2H-benzotriazol-2-yl) -4,6-di-t- Containing pattern.

Images