Composition for removing metal residue

Abstract

The invention relates to a composition for removing metal residues. The composition for removing a metal residue according to the present invention comprises an alkali metal hydroxide, a chelating agent, a polar solvent, and a polyethylene glycol containing two or more hydroxyl groups and having a number average molecular weight (Mn) of 150 to 282.

Description

Technical Field

[0001] This invention relates to a composition for removing metal residues. Background Technology

[0002] In recent years, with society officially entering the information age, the display field, which processes and displays massive amounts of information, has developed rapidly. Correspondingly, various semiconductor devices have been developed and have attracted attention. Examples of such semiconductor devices include Liquid Crystal Display (LCD), Plasma Display Panel (PDP), Field Emission Display (FED), Electroluminescence Display (ELD), and Organic Light Emitting Diodes (OLEDs). Furthermore, due to their superior performance in terms of thinness, lightweight, and low power consumption, they are rapidly replacing basic cathode ray tubes. Therefore, the demand for high-resolution and low-power display panels continues to increase.

[0003] Against this backdrop, extensive research has been conducted on low-temperature polycrystalline silicon (LTPS) materials. This material, which can be formed using amorphous silicon at relatively low reaction temperatures, exhibits high electron mobility and can provide high-resolution and low-power display panels. LTPS can be manufactured using methods such as solid-state crystallization (SPC), metal-induced crystallization (MIC), and excimer laser thermal treatment (ELA). However, during the manufacturing of LTPS, various organic and inorganic contaminants adhere to the substrate surface during deposition and etching processes, particularly persistent and difficult-to-remove metal residues. Processing subsequent steps with these contaminants or metal residues can lead to pinholes or pits in the film, broken wires or bridging in the wiring, resulting in low product yield.

[0004] Therefore, a cleaning process is performed between each process to remove contaminants generated on the substrate surface during the aforementioned processes, and extensive research has been conducted on cleaning agent compositions for this purpose. Relatedly, Patent Documents 1 and 2 disclose a cleaning agent composition for a substrate of a semiconductor device. However, the cleaning agent compositions for semiconductor device substrates disclosed in these patent documents have the disadvantage of insufficient removal power for contaminants such as metal residues during the cleaning process.

[0005] Therefore, there is still a need for a cleaning agent composition that can not only effectively remove metal residues that occur on the substrate surface during the process, but also avoid damaging the object being cleaned.

[0006] Existing technical documents

[0007] Patent Literature

[0008] (Patent Document 1) Korean Patent Publication No. 10-0503231 (Patent Document 2) Korean Patent Publication No. 10-1166002 Summary of the Invention

[0009] (The problem to be solved)

[0010] According to one aspect of the present invention, a composition for removing metal residues is provided that can effectively remove metal residues.

[0011] According to another aspect of the present invention, a composition for removing metal residues is provided that does not cause damage to the object being cleaned and has a high metal residue cleaning power.

[0012] The subject matter of this invention is not limited to the above-described contents. Those skilled in the art will readily understand additional aspects of this invention from the entirety of this specification.

[0013] (Solution to the problem)

[0014] The composition for removing metal residues according to the present invention comprises an alkali metal hydroxide, a chelating agent, a polar solvent, and polyethylene glycol containing two or more hydroxyl groups and having a number average molecular weight (Mn) of 150 to 282.

[0015] According to one embodiment of the present invention, a composition for removing metal residues is provided, wherein the alkali metal hydroxide may be sodium hydroxide (NaOH) or potassium hydroxide (KOH).

[0016] A composition for removing metal residues according to one embodiment of the present invention, wherein the polar solvent may be a proton-polar organic solvent.

[0017] A composition for removing metal residues according to one embodiment of the present invention, wherein the polar solvent may be a diethylene glycol monoalkyl ether.

[0018] A composition for removing metal residues according to one embodiment of the present invention, wherein the chelating agent may be selected from polycarboxylic acids, polyphosphonic acids, and salts thereof.

[0019] According to one embodiment of the invention, a composition for removing metal residues may comprise, relative to the total weight of the composition for removing metal residues, 0.1 to 15 wt% of the alkali metal hydroxide, 0.02 to 10 wt% of the chelating agent, 1 to 80 wt% of the polar solvent, and 0.1 to 20 wt% of the polyethylene glycol and the balance being water.

[0020] According to one embodiment of the present invention, a composition for removing metal residues has a surface tension of 35 dyne / cm or more and a contact angle relative to a silicon substrate of 30° to 75°.

[0021] A composition for removing metal residues according to one embodiment of the present invention, wherein the composition for removing metal residues can satisfy the following formula 1,

[0022] [Formula 1]

[0023] [COOH] / [OH]≤3

[0024] (In Formula 1, [COOH] refers to the number of moles of carboxylic acid groups that bind to the compounds included in the composition for removing metal residues, and [OH] refers to the total number of moles of hydroxyl groups of the polar solvent and polyethylene glycol included in the composition for removing metal residues).

[0025] A composition for removing metal residues according to one embodiment of the present invention, wherein the hydrogen ion concentration index (pH) of the composition for removing metal residues can be from 11 to 14.

[0026] A composition for removing metal residue according to one embodiment of the present invention, wherein the metal residue may be selected from any one or more of the group consisting of aluminum, stainless steel and iron.

[0027] (The effect of the invention)

[0028] The composition for removing metal residues according to one aspect of the present invention can effectively remove metal residues.

[0029] Furthermore, the composition for removing metal residues according to one aspect of the present invention does not cause damage to the object being cleaned and has a high metal residue cleaning power. Detailed Implementation

[0030] Unless otherwise defined, the technical and scientific terms used in this specification have the meaning commonly understood by one of ordinary skill in the art to which this invention pertains, and descriptions of known functions and configurations that may unnecessarily obscure the spirit of the invention are omitted in the following description or in part.

[0031] Embodiments of the present invention are provided to describe the invention more completely to those skilled in the art. Therefore, the scope of the present invention is not limited to the embodiments described below.

[0032] The terminology used in the description of this invention is for describing embodiments of the invention only and should not be considered limiting. Unless otherwise expressly stated, singular expressions include the meaning of plural expressions.

[0033] The term "comprising" in this specification is an open-ended description that has an equivalent meaning to expressions such as "possessing," "containing," "having," or "characterized in," and does not exclude elements, materials, or processes not otherwise listed.

[0034] Unless otherwise specified, all units used in this specification are based on weight. As an example, % or percentage refers to weight % or weight ratio. Unless otherwise stated, weight % means the weight of any one component in the whole composition.

[0035] Furthermore, the numerical ranges used in this paper include the lower and upper limits, all values ​​within that range, increments logically derived from the shape and width of the defined range, all values ​​with dual definitions, and all possible combinations of the upper and lower limits of numerical ranges defined in different forms. Unless otherwise stated herein, values ​​outside the defined numerical range that may appear due to experimental errors or numerical rounding are also included within the defined numerical range.

[0036] In this specification, terms such as “upper,” “upper part,” “upper surface,” “lower,” “lower part,” “lower surface,” and “side surface” may vary depending on the orientation of the device or component.

[0037] Furthermore, throughout the specification, when one part is referred to as being "connected" to another part, this includes not only the case of "direct connection" but also the case of "indirect connection" in which other elements are placed in between.

[0038] In this specification, the invention has been described in detail through various embodiments, but the embodiments described herein should be considered not only as one embodiment, but also as combinations with other embodiments. Therefore, references to claims in the patent claims correspond only to one example and should not be construed as meaning that the technical concept of the invention is limited to combinations with the referenced claims; combinations with various claims are also included within the scope of the technical concept of the invention.

[0039] In this specification, the term "alkyl" refers to a monovalent substituent, including straight-chain or branched forms, and the number of carbon atoms in an alkyl group can range from 1 to 12, 1 to 8, or 1 to 6.

[0040] Additionally, the term "cleaning object" in this specification refers to a silicon-containing layer or substrate, and the silicon-containing layer has the same meaning as the silicon-containing underlayer film described later.

[0041] Existing alkaline compositions for removing metal residues offer corrosion protection to the metal layer but can corrode silicon-containing layers such as amorphous silicon. Therefore, to reduce corrosion of silicon-containing layers, compositions with a pH adjusted below 10 for removing metal residues have been proposed. However, in this case, the cleaning power for metal residues is low.

[0042] The present invention will now be described in detail.

[0043] A composition for removing metal residues according to one aspect of the present invention comprises an alkali metal hydroxide, a chelating agent, a polar solvent, and polyethylene glycol containing two or more hydroxyl groups and having a number average molecular weight (Mn) of 150 to 282.

[0044] The composition for removing metal residues is an alkaline composition. Compositions for removing metal residues having this composition have a cleaning power for metal residues, and thus the cleaning power may be significantly improved compared to cases without it.

[0045] Furthermore, the composition for removing metal residues can prevent corrosion or damage to the object being cleaned while improving the cleaning power of the metal residues.

[0046] There are no particular limitations on the cleaning target of the composition for removing metal residues, as long as it includes metal residues generated in existing semiconductor processes. Specifically, the composition for removing metal residues can be used to clean flexible substrates or substrates with a silicon-containing underlayer film.

[0047] According to one embodiment, the flexible substrate may be selected from flexible glass substrates, plastic substrates, etc. In this case, the plastic substrate may include, but is not limited to, one or more materials selected from polyimide, polycarbonate, polyphenylene sulfide, polyarylether sulfone, etc.

[0048] According to one embodiment, the substrate on which the silicon-containing lower film is formed may be a substrate including a silicon-containing lower film, which includes one or more materials selected from amorphous silicon, polycrystalline silicon, silicon oxide, silicon nitride, etc.

[0049] According to one embodiment, in the substrate on which the silicon-containing underlayer is formed, the substrate may not only be a flexible substrate as described above, but may also be a commonly used metal-containing substrate.

[0050] The composition for removing metal residues according to one aspect of the present invention does not substantially cause corrosion or damage to the object being cleaned. That is, the composition for removing metal residues selectively cleans metal residues and contaminants present on the object being cleaned without causing any corrosion or damage.

[0051] According to a non-limiting embodiment, the composition for removing metal residues can be applied to a substrate on which a silicon-containing lower film, including amorphous silicon, is formed on a flexible glass substrate. In this case, the etching rate of the silicon-containing lower film during the cleaning process using the composition for removing metal residues can be... Specifically, the following can be 0 to... or 0.0001 to Within the aforementioned range, the composition for removing metal residues will not cause corrosion or damage to the object being cleaned.

[0052] The composition for removing metal residues exhibits excellent cleaning power for metal residues such as aluminum, stainless steel, and iron. In particular, its cleaning power for aluminum residues is outstanding.

[0053] In addition, the composition for removing metal residues not only provides excellent cleaning power for the aforementioned metal residues, but also has excellent cleaning power for contaminants, i.e. grease, adhering to the substrate surface.

[0054] As an organic substance adhering to the substrate surface, grease can include various forms of inorganic or organic particles in mineral oil-based or synthetic oil-based lubricating oils. The grease adhering to the substrate surface can harden and solidify due to metal residues generated during the process, thus reducing both work efficiency and process yield. Therefore, the composition for removing metal residues can effectively improve process yield.

[0055] According to one embodiment, the alkali metal hydroxide can be lithium hydroxide (LiOH), sodium hydroxide (NaOH), potassium hydroxide (KOH), rubidium hydroxide (RbOH), or cesium hydroxide (CsOH). Specifically, when the alkali metal hydroxide is sodium hydroxide (NaOH) or potassium hydroxide (KOH), it can be more advantageous in terms of cleaning power.

[0056] The chelating agent can be selected from polycarboxylic acids, polyphosphonic acids, and their salts. Therefore, the composition for removing metal residues improves the solubility and stability of the cleaned metal residues and greases in the cleaning solution.

[0057] As a specific example, the polycarboxylic acid may be one or a combination of two or more selected from ethylenediaminetetraacetic acid, propylenediaminetetraacetic acid, butanediaminetetraacetic acid, diethylenetriaminepentaacetic acid, iminodiacetic acid, N-(2-hydroxyethyl)ethylenediaminetriacetic acid, ethylene glycol-bis(β-aminoethyl ether)-N,N,N',N'-tetraacetic acid, 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, nitrilotriacetic acid, cyclohexane-1,2-diaminetetraacetic acid, 1,3-diamino-2-hydroxypropane-N,N,N',N'-tetraacetic acid, and hexamethylenediamine-N,N,N',N'-tetraacetic acid.

[0058] As a specific example, the polyphosphonic acid may be one or a combination of two or more selected from hydroxyethylidene diphosphonic acid, nitrotri(methylenephosphonic acid), ethylenediaminetetra(methylenephosphonic acid), amino(trimethylenephosphonic acid), and diethylenetriaminepenta(methylenephosphonic acid).

[0059] According to one embodiment, the chelating agent may be a mixture of the polycarboxylic acid and the polyphosphonic acid. In this case, the mixture may include salts of these compounds. These salts may be alkali metal salts, etc.

[0060] According to one embodiment, the polar solvent can be a proton-polar organic solvent. Specifically, the proton-polar organic solvent can be an alkyl alcohol solvent or an alkylene glycol monoalkyl ether.

[0061] Preferably, the polar solvent can be an alkylene glycol monoalkyl ether, specifically a dialkylene glycol monoalkyl ether or a trialkylene glycol monoalkyl ether. The alkylene glycol monoalkyl ether can be, for example, a (C2-C3)alkylene glycol mono(C1-C4)alkyl ether, and the repeating unit of the alkylene glycol can be 1 to 4.

[0062] As a specific example, the alkyl alcohol solvent may be methanol, ethanol, propanol, isopropanol, butanol, isobutanol, tert-butanol, pentanol, hexanol, heptanol, or octanol, etc.

[0063] As a specific example, the alkylene glycol monoalkyl ethers include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monoisopropyl ether, triethylene glycol monobutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, or tripropylene glycol monomethyl ether.

[0064] As described above, polyethylene glycol contains two or more hydroxyl groups and has a number average molecular weight (Mn) of 150 to 282, specifically, it may contain two hydroxyl groups and have a number average molecular weight (Mn) of 180 to 220 or 190 to 210. According to a preferred embodiment, the polyethylene glycol may have a polydisperse molecular weight distribution. Therefore, the polyethylene glycol may be a composition comprising molecules having distinct ethylene glycol repeating units centered around a molecule with a molecular weight (Mn) of 185 to 210, specifically 190 to 210. Compositions for removing metal residues comprising the polyethylene glycol described above exhibit excellent cleaning performance for typical aluminum, stainless steel, and iron residues, particularly showing very high cleaning performance for aluminum residues compared to other cleaning agents.

[0065] The composition for removing metal residues may comprise, relative to its total weight, 0.1 to 15 wt% of the alkali metal hydroxide, 0.02 to 10 wt% of the chelating agent, 1 to 80 wt% of the polar solvent, 0.1 to 20 wt% of the polyethylene glycol, and the balance being water. Specifically, the composition for removing metal residues may comprise, relative to its total weight, 0.5 to 12 wt% of the alkali metal hydroxide, 0.1 to 7 wt% of the chelating agent, 5 to 60 wt% of the polar solvent, 0.5 to 15 wt% of the polyethylene glycol, and the balance being water. More specifically, the composition for removing metal residues may comprise, relative to its total weight, 3 to 7 wt% of the alkali metal hydroxide, 0.5 to 3 wt% of the chelating agent, 10 to 30 wt% of the polar solvent, 3 to 10 wt% of the polyethylene glycol, and the balance being water.

[0066] According to one embodiment, the weight ratio of the mixture of alkali metal hydroxide, polar solvent, and polyethylene glycol can be 1:1 to 10, 1:2 to 9, 1:3 to 8, or 1:4 to 7.

[0067] According to one embodiment, the polyethylene glycol may be included in 1 to 50 parts by weight, 10 to 40 parts by weight, or 20 to 30 parts by weight relative to 100 parts by weight of a polar solvent.

[0068] The composition for removing metal residues that meets the above content range dissolves in the solution and does not cause precipitation of the cleaned metal residues, and can prevent corrosion of the silicon-containing lower film.

[0069] The water contained in the composition for removing metal residues is not particularly limited, but it can specifically be deionized water, and more specifically, as deionized water for semiconductor processes, it can have a resistivity value of 18 MΩ·cm or higher.

[0070] The hydrogen ion concentration index (pH) of the composition for removing metal residues according to one aspect of the present invention can be 11 to 14, 12 to 14 or 13 to 14.

[0071] The surface tension of the composition for removing metal residues according to one aspect of the present invention can be 35 dyne / cm or more, 40 dyne / cm or more, 45 dyne / cm or more, 50 dyne / cm or more, or 55 dyne / cm or more, and can be less than 75 dyne / cm, less than 70 dyne / cm, or less than 65 dyne / cm. Specifically, it can be 35 to 75 dyne / cm, 40 to 70 dyne / cm, or 45 to 65 dyne / cm. In this case, the surface tension, as a force that minimizes the directional effect of the liquid substance on the surface, can be a value measured at room temperature (25 ± 5 °C) according to ISO 304 standard using a surface tension meter with a platinum ring.

[0072] According to one aspect of the present invention, the contact angle of the composition for removing metal residues with a silicon substrate can be 30° to 75°, 40° to 70°, 45° to 65°, or 48° to 62°. The contact angle can be the value of the angle formed between the droplet (the composition for removing metal residues) and the substrate after 3 μL of the composition for removing metal residues is dropped onto the silicon (SiO2) substrate using a contact angle measuring instrument.

[0073] The composition for removing metal residues according to one aspect of the present invention can satisfy the following formula 1.

[0074] [Formula 1]

[0075] [COOH] / [OH]≤3

[0076] In Formula 1, [COOH] refers to the number of moles of carboxylic acid groups that are combined with the compounds included in the composition for removing metal residues, and [OH] refers to the total number of moles of hydroxyl groups of the polar solvent and polyethylene glycol included in the composition for removing metal residues.

[0077] Specifically, in Equation 1, [COOH] / [OH] can be less than 3 and more than 0.5. More specifically, [COOH] / [OH] can be between 2.5 and 1.

[0078] In one embodiment of the invention, the composition for removing metal residues may not include an oxidizing agent. The oxidizing agent may be hydrogen peroxide.

[0079] The present invention will be described in detail below through embodiments. However, it should be noted that the embodiments described below are for illustrative and specific purposes only and are not intended to limit the scope of the invention. This is because the scope of the invention is determined by the matters recorded in the patent claims and matters reasonably inferred from them.

[0080] <Evaluation Methods>

[0081] 1. Cleaning power evaluation

[0082] The cleaning power against aluminum residue, stainless steel residue, iron residue and grease was evaluated using the compositions of the examples and comparative examples described in Table 1 below, and the results are recorded in Table 2 below.

[0083] Specifically, to prepare the contaminated samples, each contaminant was sprayed onto IPA (isopropanol) at a concentration of 500 ppm, and then coated onto three types of substrates (3 cm × 3 cm): amorphous silicon single film, silicon oxide single film, and silicon nitride film. After coating, the substrates were allowed to dry naturally.

[0084] Before evaluation, the quantity of contaminants (i.e., metal residue) on the manufactured contaminated sample was confirmed. Additionally, in the case of grease, the quantity of particulate contaminants present on the surface of the manufactured contaminated sample was confirmed. Then, the compositions of each example and comparative example were sprayed onto the manufactured contaminated sample. Spraying was performed for 1 minute at 25°C using a simple stripping device at a pressure of 0.1 MPa. A flat-type 1 / 8 MVVP5005 nozzle was used for spraying. The quantity of metal residue and particulate contaminants before and after evaluation was then compared, and the difference was converted into a percentage to assess the degree of cleaning power (refer to Formula 2 below). The closer the percentage is to 100%, the higher the cleaning power.

[0085] Furthermore, the cleaning power evaluated by Equation 2 below is preferably 90% or higher. In this case, if the cleaning power for at least one item cannot meet the evaluation range described above, i.e., a cleaning power of 90% or higher, it is not conducive to providing an advantage in process yield.

[0086] [Equation 2] Cleaning power (%) = [1 - {(number of contaminants after cleaning) / (number of contaminants before cleaning)}] × 100

[0087] 2. Number-average molecular weight (Mn): The number-average molecular weights of the PEG and TEG used were measured using a gas chromatograph (Agilent 7890B, MS) equipped with an RTX5 amine column. The analytical conditions were: oven temperature maintained at 100°C for 2 minutes, then increased to 300°C at a rate of 12°C / min and held at this temperature for 6 minutes. The ionization voltage was 70 eV, and the transport gas (He) was set at a rate of 1 mL / min in split mode (10:1 ratio).

[0088] Measurement results: The number-average molecular weights (Mn) of the PEG and TEG used are recorded in Table 1 below.

[0089] (Examples 1 to 13)

[0090] The components listed in Table 1 below are used to manufacture a composition for removing metal residues.

[0091] (Comparative Examples 1 to 5)

[0092] The components listed in Table 1 below are used to manufacture a composition for removing metal residues.

[0093] Table 1

[0094]

[0095]

[0096] Table 2

[0097]

[0098]

[0099] As shown in Table 2 above, it can be confirmed that the composition for removing metal residues according to the embodiments plays an excellent role in removing metal residues, such as aluminum residues, stainless steel residues, and iron residues. It can also be confirmed that its cleaning performance for grease, including particulate grease, is also excellent. Furthermore, in the embodiments, after cleaning, no precipitation of cleaned metal residues and grease or other contaminants in the solution, or their residues remaining on the substrate or being re-adsorbed, was observed visually. Conversely, in the comparative examples, it was visually confirmed that metal residues and grease or other contaminants were not removed and remained, or precipitated as residues after cleaning.

[0100] In addition, although the embodiments have significant cleaning performance for contaminants such as metal residues and grease, they do not cause corrosion or damage to the substrate with the silicon-containing lower film formed, nor do they damage the flexible glass substrate.

Claims

1. A composition for removing metal residues, comprising an alkali metal hydroxide, a chelating agent, a polar solvent, and polyethylene glycol containing two or more hydroxyl groups and having a number average molecular weight of 150 to 282.

2. The composition for removing metal residues according to claim 1, wherein, The alkali metal hydroxide is sodium hydroxide or potassium hydroxide.

3. The composition for removing metal residues according to claim 1, wherein, The polar solvent is a proton-polar organic solvent.

4. The composition for removing metal residues according to claim 1, wherein, The polar solvent is a diethylene glycol monoalkyl ether.

5. The composition for removing metal residues according to claim 1, wherein, The chelating agent is selected from polycarboxylic acids, polyphosphonic acids, and their salts.

6. The composition for removing metal residues according to claim 1, wherein, Relative to the total weight of the composition used to remove metal residue, It comprises 0.1 to 15% by weight of the alkali metal hydroxide, 0.02 to 10% by weight of the chelating agent, 1 to 80% by weight of the polar solvent, and 0.1 to 20% by weight of the polyethylene glycol and the balance being water.

7. The composition for removing metal residues according to claim 1, wherein, The composition for removing metal residues has a surface tension of 35 dyne / cm or higher and a contact angle of 30° to 75° relative to the silicon substrate.

8. The composition for removing metal residues according to claim 1, wherein, The composition used to remove metal residues satisfies the following formula 1. [Formula 1] [COOH] / [OH]≤3 In Formula 1, [COOH] refers to the number of moles of carboxylic acid groups that bind to the compounds included in the composition for removing metal residues, and [OH] refers to the total number of moles of polar solvents and hydroxyl groups of polyethylene glycol included in the composition for removing metal residues.

9. The composition for removing metal residues according to claim 1, wherein, The hydrogen ion concentration index of the composition used to remove metal residues is 11 to 14.

10. The composition for removing metal residues according to claim 1, wherein, The metal residue is selected from any one or more of the group consisting of aluminum, stainless steel and iron.

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