KR102494016B1 - Metal layer etchant composition - Google Patents

Abstract

The metal film etching composition according to the present invention includes hydrogen peroxide, an organic acid, a glycol-based polymer, and water, and has a pH range of 3.0 to 4.4. It has a high selectivity or infinite selectivity, excellent fruit water stability even in a relatively high pH range, and can continuously maintain excellent initial properties even if etching is repeatedly performed and reused many times. In addition, it is possible to implement a tape profile with excellent linearity during etching, and has excellent effects in reducing CD loss and suppressing residue generation. In addition, as the composition has high stability, it has improved storage stability that can continuously maintain excellent initial properties before or after use, does not generate precipitates during etching, and has effects of suppressing heat generation.

Description

Metal layer etchant composition and etching method using the same {Metal layer etchant composition}

The present invention relates to a metal film etching composition.

In general, a thin film transistor (TFT) is used as a circuit board for independently driving each pixel in a liquid crystal display or an organic electroluminescence (EL) display. The TFT includes a scan signal line or gate line that transmits a scan signal and an image signal line or data line that transmits an image signal, a thin film transistor connected to the gate line and the data line, and a pixel electrode connected to the thin film transistor. consists of, etc. The process of forming the wiring of such a TFT is generally a sputtering process for forming a metal film, a photoresist application, photoresist formation process of a desired pattern by exposure and development, an etching process for forming a wiring, and a photoresist that is not needed after wiring is formed. It consists of a peeling process to remove.

Although aluminum or aluminum alloy layers have been commonly used as wiring materials for gate and data line electrodes of TFTs to manufacture substrates for conventional semiconductor devices and TFT-LCDs, it is essential to reduce the resistance of wirings for electrodes to implement large-sized displays. To this end, copper and/or molybdenum, which are low-resistance metals, are used to form wires. Accordingly, research on etching compositions used for etching wires containing copper and/or molybdenum is being actively conducted.

In order to etch copper and/or molybdenum-containing wires, a composition of an etchant having strong oxidizing power is required. For example, KR10-2018-0077610A discloses a metal film etching composition including hydrogen peroxide, a fluorine-containing compound, a tetrazole-based compound, a water-soluble compound having a nitrogen atom and a carboxyl group in one molecule, a sulfate compound, and a polyhydric alcohol-type surfactant. has been

However, these conventional metal film etching compositions do not have a high selectivity to metal films such as copper and/or molybdenum. Therefore, there is a limit to causing corrosion of a lower layer such as a silicon layer or a transparent conductive layer located under the metal layer. Therefore, it is difficult to form a precise pattern, quality is deteriorated, and economical efficiency is reduced.

Accordingly, it is necessary to study a metal film etching composition having a high selectivity to a transition metal film such as copper and molybdenum, which can substantially prevent corrosion of a lower film such as a silicon film and a transparent conductive film.

KR10-2018-0077610A (2018.07.09)

An object of the present invention is to provide a metal film etching composition having a high selectivity or infinite selectivity for a metal film such as copper or molybdenum compared to an underlying film such as a silicon film or a transparent conductive film.

An object of the present invention is to provide a metal film etching composition having excellent overwater stability even in a relatively high pH range.

Another object of the present invention is to provide a metal film etching composition capable of maintaining excellent initial properties continuously even when etching is repeatedly performed and reused many times, and maintaining a low taper angle even when the number of treatments increases.

Another object of the present invention is to provide a metal film etching composition capable of implementing a tape profile with excellent linearity during etching, as well as excellent CD loss reduction and residue generation suppression properties.

Another object of the present invention is to provide a metal film etching composition having improved storage stability capable of continuously maintaining excellent initial properties before or after use as the composition has high stability.

Another object of the present invention is to provide a metal film etching composition that does not generate precipitates during etching and can suppress heat generation.

The metal film etching composition according to the present invention includes hydrogen peroxide, an organic acid, a glycol-based polymer, and water, and has a pH range of 3.0 to 4.4.

In one embodiment of the present invention, the organic acid may include iminodisuccinic acid.

In one embodiment of the present invention, the organic acid may further include any one or two or more selected from malonic acid, glycolic acid, acetic acid, formic acid, citric acid, oxalic acid, butanoic acid, pentanoic acid, propionic acid, tartaric acid, and gluconic acid. there is.

In one example of the present invention, the glycol-based polymer may include polyethylene glycol.

A metal film etching composition according to an example of the present invention may include 10 to 40 wt% of hydrogen peroxide, 0.1 to 10 wt% of an organic acid, 0.1 to 5 wt% of a glycol-based polymer, and a balance of water.

The metal film etching composition according to an embodiment of the present invention may further include any one or two or more ammonium-based compounds selected from ammonium phosphate, ammonium hydrogen phosphate, ammonium superphosphate, ammonium fluoride, and ammonium hydrogen fluoride.

The metal film etching composition according to one embodiment of the present invention may further include an azole-based compound.

The metal film etching composition according to an embodiment of the present invention may further include any one or two or more hydrostabilizers selected from cyclohexylamine, n-hexylamine, i-hexylamine, and neo-hexylamine.

The metal film etching composition according to an example of the present invention may further include one or more pH adjusting agents selected from sodium hydroxide and potassium hydroxide.

The metal film etching composition according to an embodiment of the present invention may include hydrogen peroxide, 5-aminotetrazole, cyclohexylamine, iminodisuccinic acid, iminodiacetic acid, ammonium phosphate, ammonium fluoride, and polyethylene glycol.

A metal film etching composition according to an embodiment of the present invention includes at least one silicon film selected from a silicon oxide film and a silicon nitride film; or any one or two or more indium-based oxide films selected from an indium zinc oxide film, an indium tin oxide film, and an indium gallium zinc oxide film; It can be selectively etched with a high selectivity or infinite selectivity;

In one example of the present invention, the silicon film may include at least one selected from a silicon oxide film and a silicon nitride film, and the metal film may include at least one selected from a copper metal film and a molybdenum metal film. there is.

The metal film etching method according to the present invention may include etching the metal film using the metal film etching composition.

The metal film etching composition according to the present invention has an effect of having a high selectivity or infinite selectivity for a metal film such as copper or molybdenum compared to a lower film such as a silicon film or a transparent conductive film.

The metal film etching composition according to the present invention has excellent water stability even in a relatively high pH range.

The metal film etching composition according to the present invention can continuously maintain excellent initial properties even if etching is repeatedly performed and reused many times, and has an effect of maintaining a low taper angle even if the number of treatments increases.

The metal film etching composition according to the present invention can implement a tape profile with excellent linearity during etching, and has excellent effects in reducing CD loss and inhibiting residue generation.

The metal film etching composition according to the present invention has an effect of having improved storage stability capable of continuously maintaining excellent initial properties before or after use as the composition has high stability.

The metal film etching composition according to the present invention does not generate precipitates during etching and has an effect of suppressing heat generation.

Even if the effects are not explicitly mentioned in the present invention, the effects described in the specification expected by the technical features of the present invention and the inherent effects thereof are treated as described in the specification of the present invention.

1 is a scanning electron microscope image of a specimen after etching using the etching composition of Example 1 according to the present invention.

Hereinafter, a metal film etching composition and an etching method using the same according to the present invention will be described in detail with reference to the accompanying drawings.

The drawings described in this specification are provided as examples to sufficiently convey the spirit of the present invention to those skilled in the art. Therefore, the present invention may be embodied in other forms without being limited to the drawings presented, and the drawings may be exaggerated to clarify the spirit of the present invention.

Unless otherwise defined, the technical and scientific terms used in this specification have meanings commonly understood by those of ordinary skill in the art to which this invention belongs, and the gist of the present invention in the following description and accompanying drawings Descriptions of known functions and configurations that may unnecessarily obscure are omitted.

Singular forms of terms used in this specification may be construed as including plural forms unless otherwise indicated.

In this specification, the unit of % used without particular notice means weight % unless otherwise defined.

In the present invention, by increasing the etching rate of transition metal films such as copper and molybdenum, and significantly reducing etching of films such as silicon films and transparent conductive films used as substrates or lower films, in particular, very high selectivity or substantial To provide a metal film etching composition having an infinite selectivity.

The present inventors have made extensive efforts to minimize etching of films such as silicon films and transparent conductive films. As a result, the etching rate for the film is significantly reduced when it has a specific composition within a specific pH range, and a maximum of 0 Å /s, it was found that etching can be substantially prevented from the source.

That is, even if the metal film etching composition according to the present invention satisfies the specific pH range described later, when the specific composition described later is not satisfied, the etching rate for a film such as a silicon film or a transparent conductive film greatly exceeds 0 Å/s, Corrosion of the membrane cannot be prevented to a significant level. In addition, the same applies when the composition does not satisfy the specific pH range even if the composition satisfies the specific composition.

Specifically, the metal film etching composition according to the present invention includes hydrogen peroxide, an organic acid, a glycol-based polymer, and water, and has a pH range of 3.0 to 4.4, thereby reducing metals such as copper and molybdenum compared to films such as silicon films and transparent conductive films. It has a high selectivity to the membrane.

The organic acid preferably includes iminodisuccinic acid (IDS). When this is satisfied, that is, when the pH in the above-mentioned range and the composition including iminodisuccinic acid are satisfied, high selection is made for metal films such as copper and molybdenum compared to films such as transparent conductive films containing indium, gallium, or zinc. have rain Specifically, when an organic acid containing iminodisuccinic acid and a glycol-based polymer are used together, adsorption of the composition to the surface of the lower film of the metal film is facilitated, and the surface protection effect is maximized, so that films such as silicon film and transparent conductive film It can have an infinite selectivity to metal films such as copper and molybdenum. That is, there is an effect of practically preventing corrosion of a film such as a transparent conductive film containing indium, gallium, zinc, or the like. Conversely, when iminodisuccinic acid is not included, even if a glycol-based polymer is used together, it cannot have an infinite selectivity for a metal film such as copper or molybdenum compared to a film such as the transparent conductive film. For example, among organic acids and glycol-based polymers including iminodisuccinic acid, when they are used alone, that is, when neither of them is used, the infinite selectivity effect does not appear, and only when they are used together, infinite Selectivity effect is realized. Here, "infinite selectivity" means that the etching rate of a film such as a silicon film or a transparent conductive film is 0 Å/s, which substantially prevents etching, and at the same time, the etching rate of a metal film such as copper or molybdenum has a significant value that can be substantially etched. means to have

As described above, the infinite selectivity effect that appears when a specific pH range and a specific composition is satisfied is that iminodisuccinic acid and glycol-based polymers having cations move onto the surface as the surface of the lower membrane is negatively charged in the pH range. It can be attributed to the fact that it becomes easy to perform the role of an etching inhibitor (inhibitor) smoothly.

The glycol-based polymer is preferably polyethylene glycol (PEG), and more preferably, having a hydroxyl group (-OH) at the terminal may be more preferable because the above-described effect can be further exerted. The polyethylene glycol may have a weight average molecular weight of 150 to 10,000 g/mol, preferably 180 to 2,000 g/mol, and may be in a liquid or solid state at room temperature (25° C.). It is possible to prevent a problem in which the protective effect of the lower layer due to the weight average molecular weight is lowered, and problems in non-uniform etching such as generation of layer separation of the etching composition and decrease in solubility due to an excessively high weight average molecular weight. When low-molecular glycol-based compounds such as ethylene glycol, propylene glycol, and diethylene glycol are used instead of the glycol-based polymers, the etching rate for transition metal films such as copper and molybdenum is significantly reduced, as well as generation of precipitates, heat generation, and storage Problems such as deterioration of stability may appear.

The metal film etching composition according to the present invention may further include other types of organic acids other than iminodisuccinic acid. For example, organic acids other than iminodisuccinic acid include any one or two or more selected from iminodiacetic acid, malonic acid, glycolic acid, acetic acid, formic acid, citric acid, oxalic acid, butanoic acid, pentanoic acid, propionic acid, tartaric acid, and gluconic acid. can do. As a specific example, it may be preferable to further use iminodiacetic acid as an organic acid other than iminodisuccinic acid in terms of etching and stability improvement through effective chelation. Further use of one or more organic acids selected from malonic acid and glycolic acid may be good in terms of etching and stability improvement due to effective etching and chelation of metals such as copper and molybdenum. However, this is only described as a preferred example, and since other organic acids may be further used, the present invention is not necessarily construed as being limited thereto.

The composition ratio of the metal film etching composition according to an example of the present invention may be appropriately adjusted as long as the above effect can be achieved, so it is not greatly limited. For example, hydrogen peroxide 10 to 40% by weight, organic acid 0.1 to 10% by weight, It may be preferable to include 0.1 to 5% by weight of glycol-based polymer and the balance of water, 15 to 35% by weight of hydrogen peroxide, 2 to 8% by weight of organic acid, 0.2 to 2% by weight of glycol-based polymer and the balance of water. may be more desirable. However, this is only described as a preferred example, and the present invention is not necessarily construed as being limited thereto.

In the composition according to the present invention, it may be better to use 0.1 to 3% by weight, more preferably 0.2 to 2% by weight of organic acids including iminodisuccinic acid among organic acids in terms of properly realizing the above-mentioned effects. there is.

In addition, in the composition according to the present invention, when an organic acid other than iminodisuccinic acid is further used, the organic acid may be used in an amount of 0.5 to 8% by weight, more preferably 1 to 5% by weight, based on the total weight of the composition. . However, this is only described as a preferred example, and the present invention is not necessarily construed as being limited thereto.

As a more preferable example, in the composition according to the present invention, the weight ratio of the organic acid containing iminodisuccinic acid and the glycol-based polymer may be 1:0.1 to 2, preferably 1:0.2 to 1.5.

The metal film etching composition according to an embodiment of the present invention may further include any one or two or more ammonium-based compounds selected from ammonium phosphate, ammonium hydrogen phosphate, ammonium superphosphate, ammonium fluoride, and ammonium hydrogen fluoride. If this is satisfied, the etching rate of metals such as copper, molybdenum, and molybdenum alloys may be improved, which may be preferable. In addition, when an ammonium-based compound is further used, it may be more preferable that two or more different types are used together. When an ammonium-based compound is used, it may be used in an amount of 0.3 to 6% by weight, more preferably 0.5 to 4% by weight, based on the total weight of the composition. At this time, when phosphoric acid compounds such as ammonium phosphate, ammonium hydrogen phosphate, and ammonium superphosphate and fluoride compounds such as ammonium fluoride and ammonium hydrogen fluoride are used together, 0.5 to 5% by weight of the phosphoric acid compound and 0.01 to 0.5% by weight of the fluorinated compound It can be good to use. However, this is only described as a preferred example, and the present invention is not necessarily construed as being limited thereto.

The metal film etching composition according to one embodiment of the present invention may further include an azole-based compound. The azole-based compound is not particularly limited as long as it suppresses the etching rate of the metal film to form a good etching profile and improves the etching inhibition property for films such as silicon films and transparent conductive films. For example, imidazole. , pyrazole, 1,2,3-triazole, 1,2,4-triazole, tetrazole, pentazole, oxazole, isoxazole, 1,2,3-oxadiazole, oxadiazole, Razan, 1,3,4-oxadiazole, thiazole, isothiazole, thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thia It may include any one or two or more selected from diazoles and their derivatives. Specifically, examples of the azole-based compound include 5-aminotetrazole, 5-methyltetrazole, tetrazole, pyrrole, imidazole, pyrazole, triazole, and pyrrolidine, and 5-aminotetrazole , 5-methyltetrazole, may be more preferably selected from tetrazole-based compounds such as tetrazole. When the azole-based compound is further included, in improving the etching profile of a metal film and preventing etching of a silicon film, a transparent conductive film, etc., even if the composition is used repeatedly, the initial anti-etching performance can be more stably maintained. can be good in The amount of the azole-based compound used may be 0.1 to 2% by weight, more preferably 0.2 to 1% by weight, based on the total weight of the composition. However, this is only described as a preferred example, and the present invention is not necessarily construed as being limited thereto.

The metal film etching composition according to an embodiment of the present invention may further include any one or two or more hydrostabilizers selected from cyclohexylamine, n-hexylamine, i-hexylamine, and neo-hexylamine. If this is satisfied, it may be good in terms of stabilizing hydrogen peroxide, which is the main component, to more stably maintain initial anti-etching performance, and to be stable even when used for a long time. When a water stabilizer is used, it may be used in an amount of 0.1 to 2% by weight, more preferably 0.2 to 1% by weight, based on the total weight of the composition. However, this is only described as a preferred example, and the present invention is not necessarily construed as being limited thereto.

The metal film etching composition according to an example of the present invention may further include one or more pH adjusting agents selected from sodium carbonate, ammonia, sodium hydroxide, and potassium hydroxide. This is used to satisfy the above-mentioned pH range, and the amount of the pH adjusting agent may be appropriately adjusted so as to be in the above-mentioned pH range. As a specific embodiment, the pH adjusting agent may be commonly used in an amount of 0.01 to 5% by weight, specifically, 0.1 to 2% by weight, based on the total weight of the composition, but the present invention is not limited thereto.

As described above, the metal film etching composition according to the present invention prevents etching of a film such as a silicon film or a transparent conductive film and is excellent in etching a metal film.

As a specific example, the etching rate for the metal film of the metal film etching composition according to the present invention may be 10 to 150 Å/sec. As a more specific example, the etching rate for copper may be 70 to 150 Å/sec, specifically 80 to 130 Å/sec, and the etching rate for molybdenum may be 10 to 40 Å/sec, specifically 12 to 30 Å/sec. can be sec.

The silicon film may be one or more selected from a silicon oxide film and a silicon nitride film. However, it goes without saying that an anti-etching effect for various silicon films may be exhibited.

The transparent conductive film is used in the art, and specifically, an indium zinc oxide (IZO) film, an indium tin oxide (ITO) film, and an indium gallium zinc oxide (Indium gallium zinc oxide, IGZO) film, etc., any one or two or more indium-based oxide films selected from the like may be exemplified. However, it goes without saying that an anti-etching effect for various transparent conductive films may be exhibited.

The metal film may be one or two or more selected from copper, molybdenum, titanium, indium, zinc, tin, tungsten, silver, gold, chromium, manganese, iron, cobalt, nickel, niobium, alloys thereof, and the like. More specifically, it may be a copper film, a copper/molybdenum film, a copper/titanium film, a copper/molybdenum alloy film, or a copper/indium alloy film, more preferably a copper/molybdenum film, a copper/molybdenum alloy film, and the like. . However, it goes without saying that an effect of improving etching characteristics for various transition metals may be exhibited.

As a specific example, the copper/molybdenum film or the copper/molybdenum alloy film may be a multilayer in which one or more copper (Cu) films and one or more molybdenum (Mo) films and/or molybdenum alloy films (Mo-alloy) are mutually stacked. The multilayer may include a Cu/Mo(Mo-alloy) double layer, a Cu/Mo(Mo-alloy)/Cu or a Mo(Mo-alloy)/Cu/Mo(alloy) triple layer. The order of the films may be appropriately adjusted according to the material and bonding properties of the substrate. However, this is only described as a specific example, and the present invention is not necessarily construed as being limited thereto.

As a specific example, the molybdenum alloy film is molybdenum-tungsten (Mo-W), molybdenum-titanium (Mo-Ti), molybdenum-niobinium (Mo-Nb), molybdenum-chromium (Mo-Cr) or molybdenum-tantalum ( Mo-Ta), the molybdenum film or molybdenum alloy film may be deposited to have a thickness of 100 to 500 Å, and the copper film to have a thickness of 1000 to 10,000 Å in order to efficiently etch without residue. However, this is only described as a preferred example, and the present invention is not necessarily construed as being limited thereto.

The metal film according to the present invention may be used in an etching process, and the etching process may include a conventional etching process, and may include, for example, etching the metal film using the metal film etching composition.

Specifically, the etching process may include depositing a metal film on a substrate; patterning after forming a photoresist film on the metal film; and etching the metal film on which the patterned photoresist film is formed using the metal film etching composition according to the present invention. At this time, the metal film formed on the substrate may be a single film, a double metal film, or a multi-metal film (multi-layer metal film), and in the case of a double metal film or a multi-metal film, the stacking order is not particularly limited.

As a more specific example, the etching process may include forming a semiconductor structure between the substrate and the metal film, that is, between the substrate and the copper film or between the substrate and the molybdenum film in the case of a copper/molybdenum film. The semiconductor structure may be a semiconductor structure for a display device such as a liquid crystal display device or a plasma display panel. Specifically, the semiconductor structure may include one or more layers of a film selected from a dielectric film, a conductive film, and an amorphous or polycrystalline silicon film, and these semiconductor structures may be manufactured according to a conventional method.

Hereinafter, the present invention will be described in detail through examples, but these are for explaining the present invention in more detail, and the scope of the present invention is not limited by the following examples.

The etching composition of Example 1 was prepared by mixing each component in the component content shown in Table 1 below.

[Examples 2 to 12]

Etching compositions of Examples 2 to 12 were prepared by mixing each component in the component content shown in Table 1 below.

[Comparative Example 1 to Comparative Example 11]

Etching compositions of Comparative Examples 1 to 11 were prepared by mixing each component according to the component contents shown in Table 1 below.

Ingredients (wt%) H ₂ O ₂ ATZ glycolic compounds organic acid Ammonium compounds fruit stabilizer pH modifier water pH PEG EG PG DEG IDS IDA MA GA AP AF AS CHA HxA NaOH KOH Example 1 20 0.5 0.5 - - - 0.5 3.0 1.0 - 1.8 0.06 - 0.6 - 0.50 - balance 3.5 Example 2 20 0.5 0.5 - - - 1.0 3.0 1.0 - 1.8 0.06 - 0.6 - 0.50 - balance 3.7 Example 3 20 0.5 1.0 - - - 0.5 3.0 1.0 - 1.8 0.06 - 0.6 - 0.50 - balance 3.5 Example 4 20 0.5 0.5 - - - 0.5 3.0 1.5 - 1.8 0.06 - 0.6 - 0.50 - balance 3.3 Example 5 20 0.5 0.5 - - - 0.5 2.5 1.0 - 1.8 0.06 - 0.6 - 0.50 - balance 3.7 Example 6 20 0.5 0.5 - - - 0.5 3.0 1.0 - 1.8 0.06 - 0.6 - 0.75 - balance 3.8 Example 7 20 0.5 0.5 - - - 0.5 3.0 1.0 - 1.8 0.06 - 0.6 - 0.30 - balance 3.2 Example 8 20 0.5 0.5 - - - 0.5 3.0 - One 1.8 0.06 - 0.6 - 0.50 - balance 3.5 Example 9 20 0.5 0.5 - - - 0.5 3.0 1.0 - 1.8 0.06 - - 0.6 0.50 - balance 3.5 Example 10 20 0.5 0.5 - - - 0.5 3.0 1.0 - 1.8 0.06 - 0.6 - - 0.5 balance 3.6 Example 11 20 0.5 0.5 - - - - 3.0 1.0 - 1.8 0.06 - 0.6 - 0.80 - balance 3.5 Example 12 20 0.5 1.5 - - - - 3.0 1.0 - 1.8 0.06 - 0.6 - 0.50 - balance 3.5 Comparative Example 1 20 0.5 - - - - - 3.0 1.0 - 1.8 0.06 - 0.6 - 0.80 - balance 3.5 Comparative Example 2 20 0.5 - - - - 0.5 3.0 1.0 - 1.8 0.06 - 0.6 - 0.50 - balance 3.5 Comparative Example 3 20 0.5 - - - - 1.5 3.0 1.0 - 1.8 0.06 - 0.6 - 0.20 - balance 3.5 Comparative Example 4 20 0.5 0.5 - - - 0.5 3.0 1.0 - - 0.06 1.8 0.6 - 0.50 - balance 2.5 Comparative Example 5 20 0.5 0.5 - - - 0.5 3.0 1.0 - - 0.06 2.5 0.6 - 0.50 - balance 2.5 Comparative Example 6 20 0.5 0.5 - - - 0.5 3.0 - - 1.8 0.06 - 0.6 - 0.50 - balance 4.5 Comparative Example 7 20 0.5 0.5 - - - 0.5 - 1.0 - 1.8 0.06 - 0.6 - 0.50 - balance 4.5 Comparative Example 8 20 0.5 0.5 - - - 0.5 3.0 1.0 - 1.8 0.06 - 0.6 - - - balance 2.6 Comparative Example 9 20 0.5 - 0.5 - - 0.5 - - - 1.8 0.06 - 0.6 - 0.50 - balance 5.0 Comparative Example 10 20 0.5 - - 0.5 - 1.0 - - - 1.8 0.06 - 0.6 - 0.50 - balance 5.2 Comparative Example 11 20 0.5 - - - 0.5 1.0 - - - 1.8 0.06 - 0.6 - 0.50 - balance 5.2 H ₂ O ₂ : hydrogen peroxide
ATZ: 5-aminotetrazole
PEG: Polyethyleneglycol (81150, SIGMA-ALDRICH)
EG: Ethylene glycol
PG: Propylene glycol
IDS: Iminodisuccinic acid
IDA: iminodiacetic acid
MA: malonic acid GA: Glycolic acid
AP: ammonium phosphate dibasic
AF: Ammonium fluoride
AS: Ammonium sulfate
CHA: Cyclohexylamine
HxA: Hexylamine
NaOH: sodium hydroxide
KOH: potassium hydroxide

[Experimental Example 1]

<Evaluation of precipitate generation, heat generation, etching performance, change over time of storage>

Precipitate generation, heat generation, etching performance (CD skew, taper), and storage characteristics of the etching compositions prepared in Examples 1 to 12 and Comparative Examples 1 to 10 were evaluated.

Specifically, a molybdenum alloy film is deposited to a thickness of 300 Å on each lower layer of a silicon oxide film, an indium zinc oxide film, an indium tin oxide film, and an indium gallium zinc oxide film, and a copper film is deposited thereon to a thickness of 6,500 Å. A photolithography process was performed to form a pattern to prepare a specimen. In addition, the characteristics of precipitate generation, heat generation, etching performance, and change with storage time were evaluated when the copper content of the etching composition was 3,000, 4,000, and 5,000 ppm during etching.

For the occurrence of precipitates, the case where precipitate fire occurred was evaluated as ○, and the case where it did not occur was evaluated as ×, and for the case of heat generation, the case where 5 ° C or more increased during etching was evaluated as ○, and the case where there was no temperature change was evaluated as ×. . Etching performance (CD skew, taper) was evaluated by using mini-etcher equipment to 50% OE of each specimen based on EPD. When less than, it was judged as a good level. In order to confirm the storage stability of the etching composition, the change over time in storage was checked by age through a mini-etcher evaluation and evaluated as good, bad, or very poor (change over time: 0 to 5 days).

The results thereof are shown in Table 2 and Table 3 below.

pH Cu Content
(ppm) Etch rate
(Å/sec) Precipitate occurrence Fever or not Etch performance change over storage Cu Mo Example 1 3.5 3,000 86 15 × × Good Good 4,000 86 15 × × Good 5,000 88 15 × × Good Example 2 3.7 3,000 84 14 × × Good Good 4,000 83 14 × × Good 5,000 84 14 × × Good Example 3 3.5 3,000 86 15 × × Good Good 4,000 87 15 × × Good 5,000 87 15 × × Good Example 4 3.3 3,000 92 15 × × Good Good 4,000 92 15 × × Good 5,000 92 15 × × Good Example 5 3.7 3,000 90 16 × × Good Good 4,000 90 16 × × Good 5,000 91 16 × × Good Example 6 3.8 3,000 82 17 × × Good Good 4,000 82 17 × × Good 5,000 81 17 × × Good Example 7 3.2 3,000 92 14 × × Good Good 4,000 92 14 × × Good 5,000 93 14 × × Good Example 8 3.5 3,000 85 15 × × Good Good 4,000 85 15 × × Good 5,000 86 15 × × Good Example 9 3.5 3,000 85 13 × × Good Good 4,000 85 13 × × Good 5,000 85 14 × × Good Example 10 3.6 3,000 86 15 × × Good Good 4,000 86 15 × × Good 5,000 87 15 × × Good Example 11 3.5 3,000 90 15 × × Good error 4,000 91 15 × × Good 5,000 90 15 ○ ○ error Example 12 3.5 3,000 90 15 × × Good error 4,000 92 15 × × Good 5,000 91 15 ○ ○ error

pH Cu Content
(ppm) Etch rate
(Å/sec) Precipitate occurrence Fever or not Etch performance change over storage Cu Mo Comparative Example 1 3.5 3,000 80 13 × × Good very bad 4,000 85 13 ○ ○ error 5,000 92 13 ○ ○ very bad Comparative Example 2 3.5 3,000 83 12 × × Good error 4,000 82 12 × × Good 5,000 92 13 ○ ○ error Comparative Example 3 3.5 3,000 85 11 × × Good error 4,000 86 11 × × Good 5,000 96 10 ○ ○ error Comparative Example 4 2.5 3,000 84 13 × × Good error 4,000 84 13 × × Good 5,000 85 13 × × Good Comparative Example 5 2.5 3,000 88 14 × × Good error 4,000 88 14 × × Good 5,000 88 15 × × Good Comparative Example 6 4.5 3,000 71 13 ○ ○ error very bad 4,000 68 13 ○ ○ error 5,000 61 12 ○ ○ very bad Comparative Example 7 4.5 3,000 71 14 ○ ○ error very bad 4,000 80 15 ○ ○ very bad 5,000 88 16 ○ ○ very bad Comparative Example 8 2.6 3,000 96 10 × × error error 4,000 96 10 × × error 5,000 101 10 × × error Comparative Example 9 5.0 3,000 59 13 ○ ○ very bad very bad 4,000 53 13 ○ ○ very bad 5,000 48 13 ○ ○ very bad Comparative Example 10 5.2 3,000 55 12 ○ ○ very bad very bad 4,000 50 12 ○ ○ very bad 5,000 44 12 ○ ○ very bad Comparative Example 11 5.2 3,000 57 13 ○ ○ very bad very bad 4,000 52 13 ○ ○ very bad 5,000 47 13 ○ ○ very bad

As can be seen from Table 2 and Table 3, Examples 1 to 10 did not generate precipitates, did not generate heat, had good etching performance, and had excellent long-term storage stability. On the other hand, it was confirmed that the comparative examples had precipitates, heat generation, poor etching performance, poor long-term storage stability, or a combination of two or more of these problems. In particular, from Comparative Examples 9 to 11, even if iminodisuccinic acid and a glycol-based compound are used, when the glycol-based compound is a low molecular weight compound such as ethylene glycol, propylene glycol, diethylene glycol, etc. rather than polyethylene glycol, it can be confirmed that the effect does not appear. there is.

[Experimental Example 2]

<Evaluation of the etching selectivity of the metal layer to the lower layer>

The etching selectivity of the metal layer to the lower layer of the etching compositions prepared in Examples 1 to 12 and Comparative Examples 1 to 8 was evaluated. In addition, the presence or absence of molybdenum alloy residues was also evaluated.

Specifically, the thickness of the specimen before etching was measured using an ellipsometer (J.A Woollam Co., M-2000U), which is a thin film thickness measuring device. An etching process was performed on the specimens using each of the etching compositions maintained at an etching temperature of 32° C. in a quartz bath. At this time, the etching time was controlled in the same way. After the etching was completed, the specimen was washed with ultrapure water, and then the residual etching composition was completely dried using a drying device, and the thickness was measured to evaluate the etching rate. In addition, the molybdenum alloy residue was analyzed through surface observation during SEM analysis.

pH Molybdenum alloy residue Etch rate (Å/s) SiO ₂ SiN _x IZO ITO IGZO Example 1 3.5 doesn't exist 0 0 0 0 0 Example 2 3.7 doesn't exist 0 0 0 0 0 Example 3 3.5 doesn't exist 0 0 0 0 0 Example 4 3.3 doesn't exist 0 0 0 0 0 Example 5 3.7 doesn't exist 0 0 0 0 0 Example 6 3.8 doesn't exist 0 0 0 0 0 Example 7 3.2 doesn't exist 0 0 0 0 0 Example 8 3.5 doesn't exist 0 0 0 0 0 Example 9 3.5 doesn't exist 0 0 0 0 0 Example 10 3.6 doesn't exist 0 0 0 0 0 Example 11 3.5 doesn't exist 1.50 1.20 4.00 3.50 4.30 Example 12 3.5 doesn't exist 1.00 0.80 3.30 2.80 3.85 Comparative Example 1 3.5 doesn't exist 3.00 2.50 5.00 4.00 5.00 Comparative Example 2 3.5 doesn't exist 2.50 2.30 3.00 2.50 4.50 Comparative Example 3 3.5 has exist 2.30 2.00 2.70 2.20 4.10 Comparative Example 4 2.5 has exist 2.00 1.50 1.50 1.30 1.60 Comparative Example 5 2.5 has exist 2.00 1.50 1.50 1.30 1.60 Comparative Example 8 2.6 has exist 1.80 1.30 1.30 1.10 1.40 IZO: Indium Zinc Oxide
ITO: Indium Tin Oxide
IGZO: Indium Gallium Zinc Oxide

As can be seen from Table 4, in Examples 1 to 8, the etching rate of the lower layer of the silicon oxide layer, the silicon nitride layer, the indium zinc oxide layer, the indium tin oxide layer, and the indium gallium zinc oxide layer was 0 Å/ As s, etching did not substantially proceed. On the other hand, as the Comparative Examples had an etching rate of at least 1 Å/s or more, it could be confirmed that the etching of the lower layer could not be completely blocked.

In particular, from Example 1, Example 11, Example 12, Comparative Example 2 and Comparative Example 3, when iminodisuccinic acid and polyethylene glycol are used alone, it is difficult to prevent etching of the lower film, and they must be used together to prevent the lower film from being etched. It can be confirmed that etching can be prevented at the source.

In addition, from Comparative Examples 4 to 6 and Comparative Example 8, even if iminodisuccinic acid and polyethylene glycol are used together, when the pH range does not satisfy 3.0 to 4.4, it can be confirmed that the source of etching of the lower film cannot be prevented. there is. It is thought that this is due to the iminodisuccinic acid and polyethylene glycol having cations moving to the surface as the membrane surface is positively charged in the above pH range and properly performing the role of an etching inhibitor.

Claims (11)

10 to 40% by weight of hydrogen peroxide, 0.1 to 10% by weight of organic acid, 0.1 to 5% by weight of polyethylene glycol and the balance of water,
The organic acid is any one or two or more selected from the group consisting of iminodisuccinic acid, iminodiacetic acid, malonic acid, glycolic acid, acetic acid, formic acid, citric acid, oxalic acid, butanoic acid, pentanoic acid, propionic acid, tartaric acid and gluconic acid. include,
A metal film etching composition, characterized in that the pH range is 3.0 to 4.4. delete delete delete delete According to claim 1,
The metal film etching composition further comprises any one or two or more ammonium-based compounds selected from the group consisting of ammonium phosphate, ammonium hydrogen phosphate, ammonium superphosphate, ammonium fluoride and ammonium hydrogen fluoride. According to claim 1,
The metal film etching composition further comprises an azole-based compound. According to claim 1,
The metal film etching composition further comprises any one or two or more hydrostabilizers selected from the group consisting of cyclohexylamine, n-hexylamine, i-hexylamine and neo-hexylamine. According to claim 1,
The metal film etching composition further comprises at least one pH adjusting agent selected from the group consisting of sodium hydroxide and potassium hydroxide. According to claim 1,
The metal film etching composition may include at least one silicon film selected from the group consisting of a silicon oxide film and a silicon nitride film; or any one or two or more indium-based oxide films selected from the group consisting of an indium zinc oxide film, an indium tin oxide film, and an indium gallium zinc oxide film; A metal film etching composition for selectively etching at least one metal film selected from the group consisting of a contrast copper metal film and a molybdenum metal film at an infinite selectivity ratio. A metal film etching method comprising the step of etching a metal film using the metal film etching composition of any one of claims 1 and 6 to 10.

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