KR102362460B1 - Etchant composition - Google Patents

Abstract

The etchant composition according to the present invention includes persulfate; inorganic acids; cyclic amine compounds; organic acids; organic acid salts; sulfamic acid; glycine; and water, and with respect to 100% by weight of the total etchant composition, the sulfamic acid is included in 0.1 to 6% by weight, and the glycine is included in an amount of 0.1 to 5% by weight, and the etchant composition according to the present invention comprises The copper-based metal layer may be selectively etched.

Description

Etchant composition {ETCHANT COMPOSITION}

The present invention relates to an etchant composition capable of selectively etching a copper-based metal film.

A transparent pixel electrode, a gate electrode, a source electrode, and a drain electrode are used in a TFT (Thin Film Transistor) array for image realization of a flat panel display. In general, a transparent conductive film containing indium as a main component is used as a pixel electrode, and a single film or multiple films containing Cu, Cr, Mo, Ti, Al, etc. as a main component is used as a gate electrode, a source electrode, and a drain electrode.

Recently, in order to simplify the production process and increase production, a new data wire made of a copper-based metal film is being developed by depositing IZO (indium zinc oxide) as an indium-based transparent conductive film at the bottom of the gate wiring. At this time, in order to etch the gate wiring, it is necessary to selectively etch only the copper-based metal film on the lowermost IZO thin film without etching.

Korean Patent Application Laid-Open No. 2012-0138290 relates to an etchant composition and a method for forming a metal wiring and a thin film transistor substrate using the same, wherein 0.5 wt% to 20 wt% of persulfate, 0.01 wt% to 2 wt% based on the total weight of the etchant composition % by weight of a fluorine compound, 1% to 10% by weight of an inorganic acid, 0.5% to 5% by weight of a cyclic amine compound, 0.1% to 10.0% by weight of a sulfonic acid, 0.1% to 10% by weight of an organic acid and its Disclosed is an etchant composition comprising at least one of the salts, and water such that the total weight of the total composition is 100% by weight.

However, when the etchant composition of the above literature is used, it may be difficult to selectively etch only the copper-based metal film by damaging the IZO thin film due to the fluorine compound, and there is a problem in that the properties of the treatment medium are not good.

Republic of Korea Patent Publication No. 10-2012-0138290 (2012.12.26)

It is an object of the present invention to provide an etchant composition capable of selectively etching only a copper-based metal film without causing etching damage to the IZO thin film.

In addition, it is an object of the present invention to provide an etchant composition having improved properties of a treatment medium.

The etchant composition of the present invention for achieving the above object is persulfate; inorganic acids; cyclic amine compounds; organic acids; organic acid salts; sulfamic acid; glycine; and water, with respect to 100% by weight of the total etchant composition, the sulfamic acid is included in an amount of 0.1 to 6% by weight, and the glycine is included in an amount of 0.1 to 5% by weight.

The etchant composition according to the present invention does not include a component affecting the IZO thin film, so there is an advantage that only copper wiring can be selectively etched without causing etching damage to the IZO thin film.

In addition, the etchant composition according to the present invention has the advantage of being able to maintain a desired etching shape of the copper film for a longer process time because the properties of the treatment medium are improved than that of the conventional etchant by including a specific component.

1a and 1b are diagrams showing IZO single-layer damage test results according to Examples and Comparative Examples.
2 is a diagram illustrating a change in a taper angle according to the number of sheets to be processed.
3 is a diagram illustrating a side etching change according to the number of treatment sheets.

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

In the present invention, when a member is said to be located "on" another member, this includes not only a case in which a member is in contact with another member but also a case in which another member is present between the two members.

In the present invention, when a part "includes" a certain component, this means that other components may be further included, rather than excluding other components, unless otherwise stated.

< etchant composition>

One aspect of the present invention is persulfate; inorganic acids; cyclic amine compounds; organic acids; organic acid salts; sulfamic acid; glycine; and water, with respect to 100% by weight of the total etchant composition, the sulfamic acid is included in 0.1 to 6% by weight, and the glycine is included in the etchant composition in an amount of 0.1 to 5% by weight.

The etchant composition according to the present invention may further include additives such as an additional etch control agent, a surfactant, and a pH control agent in addition to the above components in a range that does not impair the effects of the present invention, but is not limited thereto.

In one embodiment of the present invention, based on 100% by weight of the total amount of the etchant composition, 0.5 to 20% by weight of the persulfate; 0.1 to 10% by weight of the inorganic acid; 0.1 to 5% by weight of the cyclic amine compound; 0.1 to 20% by weight of the organic acid; 0.1 to 10% by weight of the organic acid salt; 0.1 to 6% by weight of the sulfamic acid; 0.1 to 5% by weight of the glycine; and water balance.

The copper-based metal film of the present invention may be a single copper film composed of only copper, and together with copper, aluminum (Al), magnesium (Mg), manganese (Mn), beryllium (Be), hafnium (Hf), niobium (Nb), It may be a copper alloy film composed of a copper alloy containing at least one selected from the group consisting of tungsten (W) and vanadium (V).

The copper-based metal film may be included in a composite film in which an IZO thin film is provided at the bottom, and in this case, the composite film may additionally include a configuration in addition to the copper-based metal film.

However, in this case, it is preferable that components additionally included in addition to the copper-based metal film can be etched together with the copper-based metal film by the etchant composition according to the present invention.

persulfate

The etchant composition of the present invention includes a persulfate. The persulfate as a main oxidizing agent may serve to form a taper with respect to the copper-based metal layer during etching.

The persulfate may be included in an amount of 0.5 to 20% by weight, preferably 1 to 18% by weight, more preferably 5 to 15% by weight, based on 100% by weight of the total etchant composition, in which case the etching rate is preferable. have. When the persulfate is included below the above range, the etching rate may be slightly lowered and sufficient etching may not be performed. Problems can arise that can be overetched.

In another embodiment of the present invention, the persulfate is potassium persulfate (K ₂ S ₂ O ₈ ), sodium persulfate (Na ₂ S ₂ O ₈ ) and ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ) may include at least one selected from the group consisting of.

inorganic acid

The etchant composition of the present invention includes an inorganic acid. The inorganic acid may serve as an auxiliary oxidizing agent, and the etching rate may be controlled according to the content of the inorganic acid.

When the inorganic acid is included in the etchant composition, the inorganic acid may react with copper ions eluted in the copper-based metal film etching process, thereby preventing an increase in the copper ions, thereby reducing the etch rate or etch rate There are advantages to avoiding it.

The inorganic acid is 0.1 to 10% by weight, preferably 1 to 5% by weight, more preferably 2 to 4% by weight based on 100% by weight of the total weight of the etchant composition, in this case providing an etchant composition having an appropriate etching rate There are possible advantages.

When the inorganic acid is included below the above range, the etching rate may be slightly lowered and a sufficient etching rate may not be reached. This peeling phenomenon may occur. When the photosensitive film is cracked or the photosensitive film is peeled off, the copper-based metal film located on the lower portion of the photosensitive film may be excessively etched. desirable.

The inorganic acid may include, for example, nitric acid, sulfuric acid, phosphoric acid, or perchloric acid alone or in combination of two or more, but is not limited thereto.

annular amine compound

The etchant composition according to the present invention includes a cyclic amine compound. When the cyclic amine compound is included in the etchant composition, it serves to prevent corrosion and may serve to control the etching rate.

The cyclic amine compound may be included in an amount of 0.1 wt% to 5 wt%, preferably 0.3 to 3 wt%, more preferably 0.5 to 1 wt%, based on 100 wt% of the total etchant composition. When the cyclic amine compound is included below the above range, the etching rate of the copper-based metal film is slightly increased and there is a risk of over-etching. can

The cyclic amine compound is, for example, an aminotetrazole-based, imidazole-based, indole-based, purine-based, pyrazole-based, pyridine-based, pyrimidine-based compound. It may be one or more selected from the group consisting of (pyrimidine), pyrrole, pyrrolidine, and pyrroline. Specifically, the cyclic amine compound may be an aminotetrazole-based compound, more specifically, 5-aminotetrazole, but is not limited thereto.

organic acids and organic acid salt

The etchant composition according to the present invention may include an organic acid and an organic acid salt.

The organic acid and the organic acid salt serve to control the etching rate of the etchant composition according to the present invention. Specifically, the organic acid may increase the etching rate of the etchant composition as the content increases in the etchant composition, and the organic acid salt serves to lower the etch rate as the content increases in the etchant composition.

Although not wishing to be bound by theory, the organic acid salt acts as a chelate to form a complex with copper ions eluted during the etching process of the copper-based metal layer in the etching solution composition, thereby controlling the etching rate of the copper-based metal layer.

In short, in the etchant composition according to the present invention, the etching rate can be controlled by adjusting the amounts of the organic acid and the organic acid salt to an appropriate level.

The organic acid may be included in an amount of 0.1 wt% to 20 wt%, preferably 1 to 15 wt%, more preferably 1 to 5 wt%, based on 100 wt% of the total weight of the etchant composition. When the organic acid is included within the above range, an appropriate etching rate is exhibited and the taper angle of the copper-based metal layer can be easily controlled.

When the organic acid is included in less than the above range, the etch rate may be slightly lowered, and the taper angle of the copper-based metal layer may be lowered. When the organic acid is included in excess of the above range, the etching rate may be slightly increased, and a problem in that the taper angle becomes higher than the intended angle may occur.

The organic acid salt may be included in an amount of 0.1 to 10% by weight, preferably 0.5 to 5% by weight, more preferably 2 to 4% by weight, based on 100% by weight of the total amount of the etchant composition, in which case the number of treatment sheets increases There is this.

When the organic acid salt is included below the above range, overetching may occur because it is difficult to control the etching rate of the copper-based metal layer. , since the number of substrates to be treated may be reduced accordingly, it is preferable to include the organic acid and the organic acid salt in the above content.

The organic acid may be, for example, carboxylic acid, dicarboxylic acid, or tricarboxylic acid or tetracarboxylic acid, specifically acetic acid, butanoic acid, citric acid, formic acid, gluconic acid ( gluconic acid, glycolic acid, malonic acid, oxalic acid, pentanoic acid, sulfobenzoic acid, sulfosuccinic acid, sulfophthalic acid acid), salicylic acid, sulfosalicylic acid, benzoic acid, lactic acid, glyceric acid, succinic acid, malic acid, tartaric acid (tartaric acid), isocitric acid (isocitric acid), propenoic acid (propenoic acid), imminodiacetic acid (imminodiacetic acid), and ethylenediaminetetraacetic acid (EDTA) or a mixture of two or more thereof. .

The organic acid salt may include potassium salt, sodium salt or ammonium salt of the organic acids.

sulfamic acid

The etchant composition of the present invention may include sulfamic acid as an additive for preventing aging. The sulfamic acid may serve to maintain a desired taper angle. When the sulfamic acid is included in the etchant composition, copper solubility is improved to facilitate dissolution of copper ions eluted in the chemical solution when etching a copper-deposited substrate, that is, a copper-based metal film, and a larger amount of copper ions can be There is an advantage in that substrates can be etched.

The sulfamic acid may be included in an amount of 0.1 to 6% by weight, preferably 1 to 5% by weight, and more preferably 2 to 4% by weight, based on 100% by weight of the total amount of the etchant composition, in which case the number of treatments increases have.

When the sulfamic acid is included in less than the above range, the replacement cycle of the chemical solution, that is, the etching solution, may be shortened because it does not sufficiently perform a role of maintaining the etching shape. There is a problem that control may be difficult.

glycine

Glycine may be included in the etchant composition to maintain a desired amount of side etch. In addition, since the glycine does not change over time of the component itself, when included in the etchant composition, it can suppress the change over time of the etchant composition, and chelate the copper ions eluted in the chemical to stabilize the chemical. can be done

The glycine may be included in an amount of 0.1 to 5% by weight, preferably 0.1 to 3% by weight, more preferably 0.5 to 2.5% by weight, based on 100% by weight of the total etchant composition, and in this case, the amount of side etching is kept constant and , there is an advantage in that the number of processed sheets increases.

When the glycine is included in less than the above range, the chelating effect on the copper ions eluted from the copper-based metal film may be somewhat reduced, so that the stability of the chemical may be reduced. Since the etching rate is slightly lowered and the etching time may be slightly longer in the process, it is preferably included within the above range.

water

The etchant composition of the present invention contains 0.5 to 20% by weight of the persulfate, based on 100% by weight of the total; 0.1 to 10% by weight of the inorganic acid; 0.1 to 5% by weight of the cyclic amine compound; 0.1 to 20% by weight of the organic acid; 0.1 to 10% by weight of the organic acid salt; 0.1 to 6% by weight of the sulfamic acid; 0.1 to 5% by weight of the glycine; and the remainder of water.

The water may be appropriately adjusted in consideration of the content of the etchant composition, but is not limited thereto, but may include pure water, ultrapure water, deionized water, distilled water, etc., and is preferably deionized water, It is more preferable to use deionized water with a specific resistance value of 18 MΩ·cm or more, which shows the degree of removal of ions from the water.

In another embodiment of the present invention, the etchant composition is to provide an etchant composition that is an etchant composition of a film including a copper-based metal film.

The etchant composition according to the present invention includes persulfate; inorganic acids; cyclic amine compounds; organic acids; organic acid salts; sulfamic acid; glycine; and water. In particular, since glycine and sulfamic acid are included in specific amounts, the treatment medium characteristics are excellent, and the etched shape of the copper-based metal film can be maintained for a longer process time.

Further, in another embodiment of the present invention, the etchant composition is to provide an etchant composition that does not etch a film including an indium oxide film.

In short, since the etchant composition according to the present invention does not contain a fluorine compound, there is an advantage in that it does not damage the IZO thin film and can selectively etch only the copper-based metal film, and by including sulfamic acid and glycine together, taper angle and side etching ( There is an advantage that the amount of side etch) is maintained uniformly.

Hereinafter, examples will be given to describe the present specification in detail. However, the embodiments according to the present specification may be modified in various other forms, and the scope of the present specification is not to be construed as being limited to the embodiments described below. The embodiments of the present specification are provided to more completely explain the present specification to those of ordinary skill in the art. In addition, "%" and "part" indicating the content hereinafter are based on weight unless otherwise specified.

Example 1 to 3 and comparative example 1 to 8

10 kg of an etchant composition including the components and compositions (wt%) of Table 1 was prepared.

Persulfate ¹⁾ mineral acid ^{2 )} Cyclic amine compound ³⁾ organic acids ^{4 )} organic acid salt ⁵⁾ sulfamic acid ^{6 )} glycine fluoride IDA ¹⁰⁾ DI water Example 1 12 3.3 0.7 2 3.5 4 0.5 - - remaining amount Example 2 12 3.3 0.7 2 3.5 2 0.5 - - remaining amount Example 3 12 3.3 0.7 2 3.5 4 2.5 - - remaining amount Comparative Example 1 12 3.3 0.7 2 3.5 4 0.5 AF ⁷⁾ =0.1 - remaining amount Comparative Example 2 12 3.3 0.7 2 3.5 2 0.5 ABF ^{8 )} =0.1 - remaining amount Comparative Example 3 12 3.3 0.7 2 3.5 4 2.5 HF ⁹⁾ =0.1 - remaining amount Comparative Example 4 12 3.3 0.7 2 3.5 - 0.5 - - remaining amount Comparative Example 5 12 3.3 0.7 2 3.5 7 0.5 - - remaining amount Comparative Example 6 12 3.3 0.7 2 3.5 4 - - - remaining amount Comparative Example 7 12 3.3 0.7 2 3.5 4 5.5 - - remaining amount Comparative Example 8 12 3.3 0.7 2 3.5 4 - - One remaining amount 1) APS: Ammonium Persulfate (Ammonium Persulfate)
2) HNO ₃
3) ATZ: 5-aminotetrazole
4) AcOH: acetic acid
5) AA: Ammonium Acetate
6) SA: sulfamic acid
7) AF: Ammonium Fluoride
8) ABF: Ammonium Bifluoride
9) HF: hydrogen fluoride
10) IDA: iminodiacetic acid

Experimental example One : IZO single film damage Test

For the IZO single-layer damage test according to the presence or absence of fluoride, the etching process was performed using the etchant compositions of Examples 1 to 3 and Comparative Examples 1 to 3, respectively. For the etching process, experimental equipment (model name: ETCHER (TFT), SEMES Co., Ltd.) of the spray-type etching method was used, and the temperature of the etchant composition was maintained at 25° C. The test was carried out. At this time, the injection pressure was 0.1 MPa, and the exhaust pressure was maintained at 20 Pa.

The cross-section and surface profile of the IZO substrate subjected to the etching process were inspected using SEM (made by Hitachi, model name S-4700), which is shown in FIGS. 1A and 1B .

Referring to FIG. 1A , in the case of the PR (photosensitive film) photos of Examples 1 to 3, the longitudinal etch amount (depth) of IZO does not exist during the etching time of 60 seconds, and the PR (photosensitive film) on the IZO wiring is removed in a strip process It can be seen that no surface damage is observed even in the subsequent photograph.

On the other hand, in the case of Comparative Examples 1 to 3 of FIG. 1b, the degree of longitudinal etching (depth) is different depending on each type of fluoride, and in the case of a strip photograph, a step difference on the surface of the IZO thin film in the region with and without PR on the surface can be seen to exist. In the composition of Comparative Examples 1 to 3, regardless of the type of fluoride, even a very small amount causes damage to the IZO thin film. Therefore, in order to selectively etch only Cu in the IZO/Cu double film, fluoride is included as in Comparative Examples 1 to 3 It can be seen that the etchant composition is not preferred.

Experimental example 2: According to the number of processed taper Angle (T/A) change

The etchant compositions according to Examples 1 to 3 and Comparative Examples 4 and 5 were maintained at 25° C., respectively, and an etching test of the IZO/Cu = 550/4000 Å substrate was performed. The total etching time was doubled based on the Cu etching time to perform over etching, and the experimental equipment and exhaust conditions were the same as in Experimental Example 1, and the results are shown in Table 2 and FIG. 2 .

number of transactions
Cu ions (ppm) Example 1 Example 2 Example 3 Comparative Example 4 Comparative Example 5 0 34.4 33.5 35.6 35.3 37.6 1000 35.7 33.6 35.9 38.6 36.5 2000 35.6 33.2 36.2 41.0 39.2 3000 36.4 33.9 36.5 43.6 40.6 4000 36.5 34.6 36.8 46.1 42.8 5000 36.4 34.9 36.5 49.4 45.0 6000 36.2 36.1 37.9 - 47.2 7000 36.9 37.0 39.4 - 49.3 8000 37.7 36.8 38.4 - 51.0 9000 34.8 35.2 36.7 - -

Referring to Table 2 and FIG. 2, in the case of Examples 1 to 3, when the content of sulfamic acid satisfies the range of the content according to the present invention, more specifically, the range of the preferred content, the T/A change according to the number of treatments It can be seen that it is not large and stable.

However, it can be seen that, as in Comparative Examples 4 and 5, when sulfamic acid is not included or is outside the range of the content according to the present invention, the T/A change according to the number of treatment sheets is large.

Experimental example 3: Aspects according to the number of transactions etching (S/E) change

The etching test of the IZO/Cu = 550/4000 Å substrate was performed by maintaining the etching solution compositions according to Examples 1 to 3 and Comparative Examples 6 to 8 at 25°C, respectively. The total etching time was doubled based on the Cu etching time to perform over etching, and the experimental equipment and exhaust conditions were the same as in Experimental Example 1, and the results are shown in Table 3 and FIG. 3 .

number of transactions
Cu ions (ppm) Example 1 Example 2 Example 3 Comparative Example 6 Comparative Example 7 Comparative Example 8 0 0.82 0.70 1.05 1.02 1.11 0.88 1000 0.82 0.70 1.05 1.01 0.63 0.85 2000 0.83 0.71 1.06 1.03 0.20 0.86 3000 0.83 0.71 1.08 1.02 - 0.85 4000 0.82 0.70 1.10 1.01 - 0.81 5000 0.82 0.70 1.09 0.98 - 0.76 6000 0.80 0.69 1.08 0.95 - 0.63 7000 0.81 0.68 1.05 0.88 - - 8000 0.78 0.64 1.02 - - - 9000 0.74 0.58 0.98 - - -

Referring to Table 3 and Figure 3, when the content of glycine is included in the content range according to the present invention, more specifically, within the preferred content range, as in Examples 1 to 3, the change in S/E according to the number of treatment sheets is not large, It is stable, and it can be seen that, as in Comparative Examples 6 and 7, when glycine is not included or the content is out of an appropriate amount, the change in S/E according to the number of treatments is large.

In the case of Comparative Example 8, as an amine compound similar to that of glycine in Examples 1 to 3, iminodiacetic acid was included, but the S/E was rapidly reduced from 4000 ppm of Cu ions, so that the number of sheets to be treated was lower than in Examples 1 to 3. you can see it's not good.

That is, as in Examples 1 to 3, when sulfamic acid and glycine are present in an appropriate content in the composition, S/E and T/A are maintained as initially intended, and thus it can be seen that the number of treated properties is excellent.

Claims (7)

persulfate; inorganic acids; cyclic amine compounds; organic acids; organic acid salts; sulfamic acid; glycine; and water, and does not contain a fluorine compound,
With respect to 100% by weight of the total etchant composition,
The sulfamic acid is included in 1 to 5% by weight,
As an etchant composition composition comprising the glycine in an amount of 0.1 to 3% by weight,
The etchant composition is an etchant composition that does not etch a film including an indium oxide film. According to claim 1,
With respect to the total 100% by weight of the etchant composition,
0.5 to 20% by weight of the persulfate;
0.1 to 10% by weight of the inorganic acid;
0.1 to 5% by weight of the cyclic amine compound;
0.1 to 20% by weight of the organic acid;
0.1 to 10% by weight of the organic acid salt; and
The etchant composition to be included as the balance of water. delete delete According to claim 1,
The persulfate is an etchant composition comprising at least one selected from the group consisting of potassium persulfate, sodium persulfate and ammonium persulfate. According to claim 1,
The etchant composition is an etchant composition of a film including a copper-based metal film. delete

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