Washing composition

Abstract

The present disclosure relates to a composition for cleaning post-etching residues on a semiconductor substrate and a related cleaning method.

Description

Technical Field

[0001] The present disclosure relates to a cleaning composition for a semiconductor substrate and a method for cleaning a semiconductor substrate. More specifically, the present disclosure relates to a cleaning composition for a semiconductor substrate after etching (e.g., etching a metal layer or a dielectric material layer deposited on the substrate), and to the removal of residues remaining on the substrate after removing the bulk of the resist.

Background Art

[0002] *Cross-reference to related applications This application claims priority from U.S. Provisional Application No. 63 / 358,398, filed on July 5, 2022, the content of which is hereby incorporated by reference in its entirety into the present disclosure.

[0003] In the manufacture of integrated circuit devices, photoresist is used as an intermediate mask for transferring the original mask pattern of a reticle onto a wafer substrate by a series of photolithography steps and etching (e.g., plasma etching) steps. One of the essential steps in the integrated circuit device manufacturing process is the removal of the patterned photoresist film from the wafer substrate. Generally, this step can be performed by one of two methods.

[0004] One method involves a wet stripping step of contacting the substrate coated with photoresist with a photoresist stripping solution consisting mainly of an organic solvent and an amine. However, such stripping solutions generally cannot completely and reliably remove the photoresist film, especially when the photoresist film has been exposed to ultraviolet light and plasma treatment during the manufacturing process. Depending on the photoresist film, it becomes highly cross-linked by such treatment and more difficult to dissolve in the stripping solution. In addition, the chemicals used in these conventional wet stripping methods may not be effective in removing inorganic or organometallic residual materials formed during the plasma etching of metal or oxide layers using halogen-containing gases.

[0005] An alternative method of removing the photoresist film involves exposing a wafer coated with photoresist to an oxygen-based plasma to burn off the resist film from the substrate in a process known as plasma ashing. However, plasma ashing is also not entirely effective in removing the plasma etching by-products described above. Instead, removal of these plasma etching by-products is typically accomplished later by exposing the processed metal thin film and dielectric thin film to a specific cleaning solution.

[0006] Metal-containing substrates are generally susceptible to corrosion. For example, substrates containing materials such as aluminum, copper, aluminum-copper alloys, tungsten nitride, tungsten, cobalt, titanium oxide, and other metals and metal nitrides corrode easily. Further, dielectrics in integrated circuit devices (e.g., interlayer dielectrics or ultra-low-k dielectrics) can be etched by using conventional cleaning chemicals. Additionally, as device geometries are scaled down, the amount of corrosion tolerated by integrated circuit device manufacturers has become smaller.

[0007] As residues become more difficult to remove and corrosion has to be controlled to lower levels than before, the cleaning solution should be safe in use and environmentally friendly.

[0008] Accordingly, the cleaning solution should be effective in removing etching residues and / or ashing residues and should be substantially non-corrosive to all exposed substrate materials. SUMMARY OF THE INVENTION

[0009] The present disclosure is directed to cleaning compositions useful for removing residues (e.g., residues from plasma etching and / or plasma ashing) from a semiconductor substrate (e.g., an extreme ultraviolet (EUV) photomask) as an intermediate step in a multi-step manufacturing process. These residues include organic compounds such as residual photoresist; organometallic compounds; metal oxides such as aluminum oxide (AlOx), silicon oxide (SiOx), titanium oxide (TiOx), zirconium oxide (ZrOx), tantalum oxide (TaOx), and hafnium oxide (HfOx) (which may be formed as reaction by-products from exposed metals); metals such as aluminum (Al), aluminum / copper alloy, copper (Cu), titanium (Ti), tantalum (Ta), tungsten (W), chromium (Cr), ruthenium (Ru), molybdenum (Mo), and cobalt (Co); doped metals such as boron (B)-doped tungsten; metal nitrides such as aluminum nitride (AlN), aluminum oxynitride (AlOxNy), silicon nitride (SiN), silicon oxynitride (SiON), titanium nitride (TiN), tantalum nitride (TaN), tantalum oxynitride (TaON), ruthenium nitride (RuN), chromium nitride (CrN), and tungsten nitride (WN); their alloys; and various relatively insoluble mixtures of other materials. One advantage of the cleaning compositions described in the present disclosure is that they can clean a wide range of residues encountered and are generally non-corrosive to exposed substrate materials (e.g., exposed metal oxides (e.g., AlOx), metals (e.g., aluminum, aluminum / copper alloy, copper, titanium, tantalum, tungsten, and cobalt), metal nitrides (e.g., silicon nitride, titanium nitride, tantalum nitride, and tungsten nitride), and their alloys).

[0010] In one aspect, the present disclosure is directed to a cleaning method that includes treating a substrate with a cleaning composition to obtain a treated substrate, and sonicating the treated substrate in the presence of a first rinse solvent to obtain a cleaned substrate. The cleaning composition may include at least one reducing agent, at least one chelating agent, at least one organic solvent, at least one alkanolamine, and water.

[0011] In another aspect, the present disclosure is directed to a cleaning method that includes sonicating a substrate in the presence of a cleaning composition to obtain a cleaned substrate, wherein the cleaning composition may include at least one reducing agent, at least one chelating agent, at least one organic solvent, at least one alkanolamine, and water.

[0012] In yet another aspect, the present disclosure is directed to a cleaning method that includes treating a substrate with a first cleaning composition that includes sulfuric acid and hydrogen peroxide to obtain a treated substrate; and treating the treated substrate with a second cleaning composition to obtain a cleaned substrate, wherein the second cleaning composition includes at least one reducing agent, at least one chelating agent, at least one organic solvent, at least one alkanolamine, and water.

[0013] In still yet another aspect, the present disclosure is directed to a cleaning composition that includes at least one reducing agent, at least one chelating agent, at least one organic solvent, at least one alkanolamine that includes methyldiethanolamine, and water.

[0014] Details of one or more embodiments of the invention are set forth in the following description. Other features, objects, and advantages of the invention will be apparent from the specification and claims. DETAILED DESCRIPTION OF THE INVENTION

[0015] In the definitions in the present disclosure, unless otherwise specified, all percentage values described should be understood as weight percentage values based on the total weight of the cleaning composition. Unless otherwise specified, the environmental temperature is defined as being from about 16 degrees Celsius (°C) to about 27 degrees Celsius (°C), for example 25 °C.

[0016] As used in the present disclosure, the terms "layer" and "film" are used interchangeably. In the definitions in the present disclosure, a "water-soluble" substance (for example, a water-soluble alcohol, ketone, ester, or ether) refers to a substance having a solubility of 1% by weight or more in water at 25 °C.

[0017] Generally, the present disclosure is directed to a cleaning composition (for example, a non-corrosive cleaning composition) comprising 1) at least one reducing agent, 2) at least one chelating agent, 3) at least one organic solvent, 4) at least one alkanolamine, and 5) water.

[0018] In some embodiments, the cleaning composition of the present disclosure may comprise at least one (for example, two, three, or four) reducing agent, which is considered to assist in the dissolution of residues on the semiconductor surface, such as photoresist residues, metal residues, and metal oxide residues. As used in the present disclosure, the term "reducing agent" refers to a compound that can induce oxidation and / or reduction in a semiconductor cleaning process. An example of a suitable reducing agent is hydroxylamine. In some embodiments, the reducing agent or the cleaning composition described in the present disclosure does not contain a peroxide (for example, hydrogen peroxide).

[0019] In some embodiments, the at least one redox agent may be about 0.5 wt% or more (e.g., about 1 wt% or more, about 2 wt% or more, about 3 wt% or more, about 4 wt% or more, about 5 wt% or more, about 6 wt% or more, about 7 wt% or more, about 8 wt% or more, about 9 wt% or more, about 10 wt% or more, about 11 wt% or more, or about 12 wt% or more) and / or about 20 wt% or less (e.g., about 19 wt% or less, about 18 wt% or less, about 17 wt% or less, about 16 wt% or less, about 15 wt% or less, about 14 wt% or less, about 13 wt% or less, or about 12 wt% or less) based on the cleaning composition of the present disclosure.

[0020] In some embodiments, the cleaning composition of the present disclosure may include at least one (e.g., two, three, or four) chelating agent, and the chelating agent may be a polyaminopolycarboxylic acid. For the purposes of the present disclosure, polyaminopolycarboxylic acid refers to a compound having a plurality (e.g., two, three, or four) of amino groups and a plurality (e.g., two, three, or four) of carboxylic acid groups. Suitable classes of polyaminopolycarboxylic acid chelating agents include, but are not limited to, mono- or poly-alkylene polyamine polycarboxylic acids, polyaminoalkane polycarboxylic acids, polyaminoalkanol polycarboxylic acids, and hydroxyalkyl ether polyamine polycarboxylic acids.

[0021] Suitable polyaminopolycarboxylic acid chelating agents include, but are not limited to, butylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid (DTPA), ethylenediaminetetrapropionic acid, triethylenetetraminehexaacetic acid, 1,3-diamino-2-hydroxypropane-N,N,N’,N’-tetraacetic acid, propylenediaminetetraacetic acid, ethylenediaminetetraacetic acid (EDTA), trans-1,2-diaminocyclohexanetetraacetic acid, ethylenediaminediacetic acid, ethylenediaminedipropionic acid, 1,6-hexamethylenediamine-N,N,N’,N’-tetraacetic acid, N,N-bis(2-hydroxybenzyl)ethylenediamine-N,N-diacetic acid, diaminopropanetetraacetic acid, 1,4,7,10-tetraazacyclododecanetetraacetic acid, diaminopropanol tetraacetic acid, and (hydroxyethyl)ethylenediaminetriacetic acid.

[0022] In some embodiments, the at least one chelating agent may be about 0.01 wt% or more (e.g., about 0.02 wt% or more, about 0.04 wt% or more, about 0.05 wt% or more, about ০.06 wt% or more, about 0.08 wt% or more, about 0.1 wt% or more, about 0.12 wt% or more, about 0.14 wt% or more, about 0.15 wt% or more, about 0.16 wt% or more, about 0.18 wt% or more, or about 0.2 wt% or more) and / or about 1 wt% or less (e.g., about 0.9 wt% or less, about 0.8 wt% or less, about 0.7 wt% or less, about 0.6 wt% or less, about 0.5 wt% or less, about 0.4 wt% or less, about 0.3 wt% or less, or about 0.2 wt% or less) based on the cleaning composition of the present disclosure.

[0023] Without wishing to be bound by theory, it is believed that the chelating agent can facilitate the dissolution of residues on the semiconductor surface (e.g., post-etching residues such as photoresist residues, metal residues, and metal oxide residues).

[0024] In some embodiments, the cleaning composition of the present disclosure may include at least one (e.g., two, three, or four) organic solvents. In some embodiments, the organic solvent suitable for the cleaning composition of the present disclosure may be a water-soluble organic solvent, examples of which include water-soluble organic solvents selected from the group consisting of water-soluble alcohols, water-soluble ketones, water-soluble esters, water-soluble ethers (e.g., glycol diethers), and water-soluble sulfoxides (e.g., dimethyl sulfoxide).

[0025] Classes of water-soluble alcohols include, but are not limited to, alkanediols (including, but not limited to, alkylene glycols), glycols, alkoxy alcohols (including, but not limited to, glycol monoethers), saturated aliphatic monohydric alcohols, unsaturated non-aromatic monohydric alcohols, and low molecular weight alcohols containing a ring structure. Examples of water-soluble alkanediols include, but are not limited to, 2-methyl-1,3-propanediol, 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 2,3-butanediol, pinacol, and alkylene glycols. Examples of water-soluble alkylene glycols include, but are not limited to, ethylene glycol, propylene glycol, hexylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, and tetraethylene glycol.

[0026] Examples of water-soluble alkoxy alcohols include, but are not limited to, 3-methoxy-3-methyl-1-butanol, 3-methoxy-1-butanol, 1-methoxy-2-butanol, and water-soluble glycol monoethers. Examples of water-soluble glycol monoethers include, but are not limited to, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol monoisopropyl ether, ethylene glycol mono-n-butyl ether (also called ethylene glycol butyl ether), diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, 1-methoxy-2-propanol, 2-methoxy-1-propanol, 1-ethoxy-2-propanol, 2-ethoxy-1-propanol, propylene glycol mono-n-propyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, ethylene glycol monobenzyl ether, and diethylene glycol monobenzyl ether.

[0027] Examples of water-soluble saturated aliphatic monohydric alcohols include, but are not limited to, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, tert-butyl alcohol, 2-pentanol, t-pentyl alcohol, and 1-hexanol.

[0028] Examples of water-soluble unsaturated non-aromatic monohydric alcohols include, but are not limited to, allyl alcohol, propargyl alcohol, 2-butenyl alcohol, 3-butenyl alcohol, and 4-penten-2-ol.

[0029] Examples of water-soluble low molecular weight alcohols containing a cyclic structure include, but are not limited to, tetrahydrofurfuryl alcohol, furfuryl alcohol, and 1,3-cyclopentanediol.

[0030] Examples of water-soluble ketones include, but are not limited to, acetone, cyclobutanone, cyclopentanone, diacetone alcohol, 2-butanone, 2,5-hexanedione, 1,4-cyclohexanedione, 3-hydroxyacetophenone, 1,3-cyclohexanedione, and cyclohexanone.

[0031] Examples of water-soluble esters include, but are not limited to, ethyl acetate; glycol monoesters such as ethylene glycol monoacetate and diethylene glycol monoacetate; and glycol monoether monoesters such as propylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and ethylene glycol monoethyl ether acetate.

[0032] In some embodiments, the at least one organic solvent may be about 1 wt% or more (e.g., about 5 wt% or more, about 10 wt% or more, about 15 wt% or more, about 20 wt% or more, about 25 wt% or more, about 30 wt% or more, about 35 wt% or more, about 40 wt% or more, about 45 wt% or more, about 50 wt% or more, about 55 wt% or more, or about 60 wt% or more) and / or about 70 wt% or less (e.g., about 65 wt% or less, about 60 wt% or less, about 55 wt% or less, about 50 wt% or less, about 45 wt% or less, about 40 wt% or less, about 35 wt% or less, about 30 wt% or less, about 25 wt% or less, about 20 wt% or less, about 15 wt% or less, or about 10 wt% or less) based on the cleaning composition of the present disclosure.

[0033] In some embodiments, the cleaning composition of the present disclosure may include at least one (e.g., two, three, or four) alkanolamine. Examples of suitable alkanolamines include, but are not limited to, monoethanolamine (MEA), diethanolamine, methyldiethanolamine (MDEA), triethanolamine, and aminopropyldiethanolamine.

[0034] Without wishing to be bound by theory, the alkanolamines described in the present disclosure can adjust the pH of the cleaning composition, reduce the surface roughness of the semiconductor substrate treated with the cleaning composition, and reduce the etching rate of the cleaning composition on exposed substrate materials (e.g., exposed metal or dielectric materials) that are not intended to be removed during the cleaning process, thereby reducing the corrosive effect of the cleaning composition.

[0035] In some embodiments, the at least one alkanolamine may be about 0.05 wt% or more (e.g., about 0.1 wt% or more, about 0.2 wt% or more, about 0.4 wt% or more, about 0.5 wt% or more, about 0.6 wt% or more, about 0.8 wt% or more, about 1 wt% or more, about 1.5 wt% or more, about 2 wt% or more, about 2.5 wt% or more, about 3 wt% or more, about 3.5 wt% or more, about 4 wt% or more, about 4.5 wt% or more, or about 5 wt% or more) and / or about 10 wt% or less (e.g., about 9.5 wt% or less, about 9 wt% or less, about 8.5 wt% or less, about 8 wt% or less, about 7.5 wt% or less, about 7 wt% or less, about 6.5 wt% or less, about 6 wt% or less, about 5.5 wt% or less, about 5 wt% or less, about 4.5 wt% or less, or about 4 wt% or less) with respect to the cleaning composition of the present disclosure.

[0036] In some embodiments, the cleaning composition of the present disclosure may include water. In some embodiments, the water may be deionized and ultra-pure, may not contain organic contaminants, and may have a minimum resistivity of about 4 to about 17 megaohms. In some embodiments, the resistivity of the water is 17 megaohms or more.

[0037] In some embodiments, water may be about 10 wt% or more (e.g., about 12 wt% or more, about 14 wt% or more, about 15 wt% or more, about 16 wt% or more, about 18 wt% or more, about 20 wt% or more, about 22 wt% or more, about 24 wt% or more, about 25 wt% or more, about 26 wt% or more, about 28 wt% or more, or about 30 wt% or more) and / or 90 wt% or less (e.g., about 85 wt% or less, about 80 wt% or less, about 75 wt% or less, about 70 wt% or less, about 65 wt% or less, about 60 wt% or less, about 55 wt% or less, about 50 wt% or less, about 45 wt% or less, about 40 wt% or less, about 35 wt% or less, or about 30 wt% or less) with respect to the cleaning composition of the present disclosure.

[0038] In some embodiments, the cleaning composition of the present disclosure may optionally contain at least one (e.g., two, three, or four) quaternary ammonium compound (e.g., quaternary ammonium hydroxide or a salt thereof). Examples of suitable quaternary ammonium hydroxides include, but are not limited to, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, dimethyldiethylammonium hydroxide, choline, tetraethanolammonium hydroxide, benzyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide, and benzyltributylammonium hydroxide. Without wishing to be bound by theory, it is believed that quaternary ammonium compounds can facilitate the dissolution of residues on the semiconductor surface (e.g., post-etching residues such as photoresist residues, metal residues, and metal oxide residues).

[0039] In some embodiments, the at least one quaternary ammonium compound may be about 0.1 wt% or more (e.g., about 0.2 wt% or more, about 0.4 wt% or more, about 0.5 wt% or more, about 0.6 wt% or more, about 0.8 wt% or more, about 1 wt% or more, about 1.5 wt% or more, about 2 wt% or more, about 2.5 wt% or more, about 3 wt% or more, about 3.5 wt% or more, about 4 wt% or more, about 4.5 wt% or more, or about 5 wt% or more) and / or about 10 wt% or less (e.g., about 9.5 wt% or less, about 9 wt% or less, about 8.5 wt% or less, about 8 wt% or less, about 7.5 wt% or less, about 7 wt% or less, about 6.5 wt% or less, about 6 wt% or less, about 5.5 wt% or less, about 5 wt% or less, about 4.5 wt% or less, or about 4 wt% or less) based on the cleaning composition of the present disclosure.

[0040] In some embodiments, the cleaning composition of the present disclosure may optionally contain at least one (e.g., two, three, or four) rust inhibitor. In some embodiments, the rust inhibitor may be selected from substituted or unsubstituted benzotriazoles. Without wishing to be bound by theory, such cleaning compositions are believed to exhibit significantly improved compatibility with materials in a semiconductor substrate (e.g., EUV photomask) that should not be removed by the cleaning composition compared to cleaning compositions that do not contain a rust inhibitor.

[0041] Suitable classes of substituted benzotriazoles include, but are not limited to, benzotriazoles substituted by at least one substituent selected from the group consisting of an alkyl group, an aryl group, a halogen group, an amino group, a nitro group, an alkoxy group, and a hydroxyl group. Substituted benzotriazoles also include substituted benzotriazoles fused with one or more aryl (e.g., phenyl) or heteroaryl groups.

[0042] Examples of benzotriazoles suitable for use as rust inhibitors include, but are not limited to, benzotriazole (BTA), 1-hydroxybenzotriazole, 5-phenylthiol-benzotriazole, 5-chlorobenzotriazole, 4-chlorobenzotriazole, 5-bromobenzotriazole, 4-bromobenzotriazole, 5-fluorobenzotriazole, 4-fluorobenzotriazole, naphthotriazole, tolyltriazole, 5-phenyl-benzotriazole, 5-nitrobenzotriazole, 4-nitrobenzotriazole, 2-(5-amino-pentyl)-benzotriazole, 1-aminobenzotriazole, 5-methylbenzotriazole, benzotriazole-5-carboxylic acid, 4-methylbenzotriazole, 4-ethylbenzotriazole, 5-ethylbenzotriazole, 4-propylbenzotriazole, 5-propylbenzotriazole, 4-isopropylbenzotriazole, 5-isopropylbenzotriazole, 4-n-butylbenzotriazole, 5-n-butylbenzotriazole, 4-isobutylbenzotriazole, 5-isobutylbenzotriazole, 4-pentylbenzotriazole, 5-pentylbenzotriazole, 4-hexylbenzotriazole, 5-hexylbenzotriazole, 5-methoxybenzotriazole, 5-hydroxybenzotriazole, dihydroxypropylbenzotriazole, 1-[N,N-bis(2-ethylhexyl)aminomethyl]-benzotriazole, 5-t-butylbenzotriazole, 5-(1’,1’-dimethylpropyl)-benzotriazole, 5-(1’,1’,3’-trimethylbutyl)benzotriazole, 5-n-octylbenzotriazole, and 5-(1’,1’,3’,3’-tetramethylbutyl)benzotriazole.

[0043] In some embodiments, the at least one rust inhibitor may be about 0.01 wt% or more (e.g., about 0.02 wt% or more, about 0.04 wt% or more, about 0.05 wt% or more, about 0.06 wt% or more, about 0.08 wt% or more, about 0.1 wt% or more, about 0.12 wt% or more, about 0.14 wt% or more, about 0.15 wt% or more, about 0.16 wt% or more, about 0.18 wt% or more, or about 0.2 wt% or more) and / or about 1 wt% or less (e.g., about 0.9 wt% or less, about 0.8 wt% or less, about 0.7 wt% or less, about 0.6 wt% or less, about 0.5 wt% or less, about 0.4 wt % or less, about 0.3 wt% or less, about 0.2 wt% or less, about 0.1 wt% or less) with respect to the cleaning composition of the present disclosure.

[0044] In some embodiments, the cleaning composition of the present disclosure adjusts the pH to an appropriate level and may contain at least one (e.g., two, three, or four) pH adjuster (e.g., acid or base). In some embodiments, the cleaning composition of the present disclosure may have a pH of about 8 or more (e.g., about 8.5 or more, about 9 or more, about 9.5 or more, about 10 or more, about 10.5 or more, about 11 or more, about 11.5 or more, about 12 or more, about 12.5 or more, or about 13 or more) to about 14 or less (e.g., about 13.5 or less, about 13 or less, about 12.5 or less, about 12 or less, about 11.5 or less, about 11 or less, about 10.5 or less, about 10 or less, about 9.5 or less, or about 9 or less). Without wishing to be bound by theory, it is believed that a cleaning composition having a pH of less than 8 is not effective for removing residues on a semiconductor substrate (e.g., EUV photomask). Further, without wishing to be bound by theory, it is believed that a cleaning composition having a pH higher than 14 will cause excessive corrosion to a semiconductor substrate (e.g., EUV photomask). The effective pH may vary depending on the type and amount of components used in the cleaning composition described in the present disclosure.

[0045] In some embodiments, the pH adjuster is free of metal ions (except for trace amounts of metal ion impurities). Suitable metal ion-free pH adjusters include acids and bases. Suitable acids that can be used as pH adjusters include carboxylic acids. Exemplary carboxylic acids include, but are not limited to, monocarboxylic acids, dicarboxylic acids, tricarboxylic acids, α-hydroxy and β-hydroxy acids of monocarboxylic acids, α-hydroxy and β-hydroxy acids of dicarboxylic acids, or α-hydroxy and β-hydroxy acids of tricarboxylic acids. Examples of suitable carboxylic acids include, but are not limited to, citric acid, maleic acid, fumaric acid, lactic acid, glycolic acid, oxalic acid, tartaric acid, succinic acid, or benzoic acid.

[0046] Suitable bases that can be used as pH adjusters include ammonium hydroxide, quaternary ammonium hydroxides, monoamines (including alkanolamines), and amidines (e.g., cyclic amidines). Examples of suitable quaternary ammonium hydroxides include, but are not limited to, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, dimethyldiethylammonium hydroxide, choline, tetraethanolammonium hydroxide, benzyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide, and benzyltributylammonium hydroxide. Examples of suitable monoamines include, but are not limited to, triethylamine, tributylamine, tripentylamine, diethylamine, butylamine, dibutylamine, and benzylamine. Examples of suitable alkanolamines include, but are not limited to, monoethanolamine, diethanolamine, methyldiethanolamine, triethanolamine, and aminopropyldiethanolamine. Examples of suitable cyclic amidines include, but are not limited to, 1,8-diazabicyclo[5.4.0]-7-undecene (DBU) and 1,5-diazabicyclo[4.3.0]-5-nonene (DBN).

[0047] When present, the amount of pH adjuster required varies as a function of the concentration of other components (e.g., the redox agent, the chelating agent, and the alkanolamine) in the various formulations, and also as a function of the molecular weight of the particular pH adjuster used. In some embodiments, the pH adjuster is about 0.1 wt% or more (e.g., 0.2 wt% or more, about 0.4 wt% or more, about 0.5 wt% or more, about 0.6 wt% or more, about 0.8 wt% or more, about 1 wt% or more, about 1.2 wt% or more, about 1.4 wt% or more, or about 1.5 wt% or more) and / or about 3 wt% or less (e.g., about 2.8 wt% or less, about 2.6 wt% or less, about 2.5 wt% or less, about 2.4 wt% or less, about 2.2 wt% or less, about 2 wt% or less, or about 1.8 wt% or less) relative to the cleaning composition of the present disclosure.

[0048] In some embodiments, the cleaning composition of the present disclosure may contain hydroxylamine, diethylenetriaminepentaacetic acid, at least one organic solvent (e.g., ethylene glycol butyl ether, propylene glycol, and / or DMSO), at least one alkanolamine (e.g., MEA or MDEA), and water. In some embodiments, such a cleaning composition may further contain 5-methylbenzotriazole and / or TMAH.

[0049] In some embodiments, the cleaning composition of the present disclosure may include (1) hydroxylamine in an amount of about 0.5 wt% to about 20 wt% based on the composition, (2) diethylenetriaminepentaacetic acid in an amount of about 0.01 wt% to about 1 wt% based on the composition, (3) at least one organic solvent (e.g., ethylene glycol butyl ether, propylene glycol, and / or DMSO) in an amount of about 1 wt% to about 70 wt% based on the composition, (4) at least one alkanolamine (e.g., MEA or MDEA) in an amount of about 0.1 wt% to about 10 wt% based on the composition, and (5) water in an amount of about 10 wt% to about 90 wt% based on the composition, and the composition has a pH of about 8 to about 14. In some embodiments, such a cleaning composition may further include TMAH in an amount of about 0.1 wt% to about 10 wt% based on the composition and / or 5-methylbenzotriazole in an amount of about 0.01 wt% to about 1 wt% based on the composition.

[0050] In some embodiments, the cleaning composition of the present disclosure may optionally include additional additives, such as additional pH adjusters, additional rust inhibitors, additional organic solvents, surfactants, biocides, and defoamers.

[0051] In some embodiments, the cleaning composition of the present disclosure may be particularly free or substantially free of one or more of the additive components, and in the case of two or more, may be particularly free or substantially free in any combination. Such components include polymers, oxygen scavengers, quaternary ammonium compounds (e.g., salts or hydroxides), alkali bases (e.g., NaOH, KOH, LiOH, Mg(OH)2, and Ca(OH)2), surfactants (e.g., cationic, anionic, or nonionic surfactants), defoamers, fluorine-containing compounds (e.g., fluoride compounds or fluorinated compounds (e.g., fluorinated polymers / surfactants)), silicon-containing compounds such as silanes (e.g., alkoxysilanes), nitrogen-containing compounds (e.g., amino acids, amines, imines (e.g., 1,8-diazabicyclo[5.4.0]-7-undecene (DBU) and 1,5-diazabicyclo[4.3.0) amidines such as nona-5-ene (DBN), amides, or imides, abrasives (e.g., ceria abrasives, nonionic abrasives, surface-modified abrasives, negatively / positively charged abrasives, or ceramic abrasive composites), plasticizers, oxidizing agents (e.g., peroxides, hydrogen peroxide, ferric nitrate, potassium iodate, potassium permanganate, nitric acid, ammonium chlorite, ammonium chlorate, ammonium iodate, ammonium perborate, ammonium perchlorate, ammonium periodate, ammonium persulfate, tetramethylammonium chlorite, tetramethylammonium chlorate, tetramethylammonium iodate, tetramethylammonium perborate, tetramethylammonium perchlorate, tetramethylammonium periodate, tetramethylammonium persulfate, urea hydrogen peroxide, and peracetic acid), rust inhibitors (e.g., azole rust inhibitors or non-azole rust inhibitors), electrolytes (e.g., polymeric electrolytes), silicates, cyclic compounds (e.g., azoles (e.g., diazoles, triazoles, or tetrazoles), triazines, and cyclic compounds containing two or more rings, e.g., substituted or unsubstituted naphthalene, or substituted or unsubstituted biphenyl ether), chelating agents, buffers, acids such as organic acids (e.g., carboxylic acids, e.g., hydroxycarboxylic acids, polycarboxylic acids, and sulfonic acids) and inorganic acids (e.g., sulfuric acid, sulfurous acid, nitrous acid, nitric acid, phosphorous acid, and phosphoric acid), pyrrolidone, polyvinylpyrrolidone, salts (e.g., halide salts or metal salts), and catalysts (e.g., metal-containing catalysts). When used in the present disclosure, a component that is "substantially free" in the cleaning composition refers to a component that is not intentionally added to the cleaning composition. In some embodiments, the cleaning composition described in the present disclosure may have one or more of the above components that are substantially free in the cleaning composition at about 1000 ppm or less (e.g., about 500 ppm or less, about 250 ppm or less, about 100 ppm or less, about 50 ppm or less, about 10 ppm or less, or about 1 ppm or less). In some embodiments, the cleaning composition described in the present disclosure may be completely free of one or more of the above components.

[0052] The cleaning composition described in the present disclosure may be prepared by simply mixing the components, or by mixing two compositions in a kit.

[0053] In some embodiments, the cleaning composition of the present disclosure is not particularly designed to remove the bulk of the photoresist film from the semiconductor substrate. Instead, the cleaning composition of the present disclosure may be designed to remove all residues after removing the bulk of the photoresist by a dry or wet stripping method. Thus, in some embodiments, the cleaning composition of the present disclosure is preferably used after a dry or wet photoresist stripping process. This photoresist stripping process is generally performed after a pattern transfer process such as an etching process or an implant process, or is performed to correct a mask error before pattern transfer. The chemical makeup of the residue depends on one or more processes performed before the cleaning step.

[0054] Any suitable dry stripping process may be used to remove the bulk of the photoresist from the semiconductor substrate. Examples of suitable dry stripping processes include oxygen-based plasma ashing such as fluorine / oxygen plasma or N2 / H2 plasma; ozone gas phase treatment; fluorine plasma treatment, thermal H2 gas treatment (e.g., the thermal H2 gas treatment described in U.S. Patent No. 5,691,117, which is hereby incorporated by reference in its entirety), and the like. In addition, any conventional organic wet stripping solution known to those skilled in the art can be used to remove the bulk of the resist from the semiconductor substrate.

[0055] A preferred stripping process used in combination with the cleaning method of the present disclosure is a dry stripping process. Preferably, this dry stripping process is an oxygen-based plasma ashing process. This process removes most of the photoresist from the semiconductor substrate by applying a reactive oxygen atmosphere at elevated temperature (typically 250 °C) under vacuum conditions (i.e., 1 torr). Organic materials are oxidized in this process and removed with the process gas. However, this process generally does not remove all inorganic or organometallic contaminants from the semiconductor substrate. To remove those residues, it is typically necessary to subsequently clean the semiconductor substrate using the cleaning composition of the present disclosure.

[0056] In some embodiments, the present disclosure is directed to a method of cleaning (cleaning) residues (e.g., post-etch residues and / or post-ashing residues) from a semiconductor substrate. Such a method is performed, for example, by contacting a semiconductor substrate comprising post-etch residues and / or post-ashing residues with a cleaning composition described in the present disclosure. The method may further comprise rinsing the semiconductor substrate with a rinse solvent after the contacting step and / or drying the semiconductor substrate after the rinsing step.

[0057] In some embodiments, the semiconductor substrate may be an EUV photomask. In some embodiments, the EUV photomask may include a high-reflectivity multilayer coating (the multilayer coating may include alternating layers of silicon and molybdenum (e.g., alternating layers over 40 - 50 layers)) on a substrate (e.g., a low thermal expansion material such as glass), and the reflective multilayer coating may be subsequently overcoated with a patterned absorber layer (e.g., a layer containing TaN and / or TaON). In some embodiments, the EUV photomask may include at least one material (e.g., an exposed material) or a layer of the at least one material, where the material is selected from the group consisting of a low thermal expansion material (e.g., glass), TaON, TaN, Ru, RuN, Si, SiO2, SiON, Ti, TiN, Cr, CrN, or Mo. In some embodiments, the cleaning method of the present disclosure does not substantially remove the above materials on the EUV photomask exposed to the cleaning composition. For example, in some embodiments, the cleaning method of the present disclosure removes no more than about 5 wt% (e.g., about 3 wt% or less, about 1 wt% or less, about 0.5 wt% or less, or about 0.1 wt% or less) of any of the materials on the EUV photomask.

[0058] In some embodiments, the semiconductor substrate to be cleaned may be a photomask other than an EUV photomask, or any other suitable semiconductor substrate having post-etch residues and / or post-ashing residues. Examples of photomasks other than EUV photomasks include photomasks used for radiation with wavelengths of 365 nm, 248 nm, and 193 nm. In some embodiments, the cleaning composition described in the present disclosure is for a specific exposed material on such a semiconductor substrate, such as a metal (e.g., Co, Cu, W, or W doped with B), an oxide (e.g., aluminum oxide (AlO X or Al2O3)), silicon oxide (SiO X ), or zirconium oxide (ZrO X) Substantially do not remove nitrides (e.g., TiN or SiN), and poly-Si. For example, in some embodiments, the cleaning composition of the present disclosure removes no more than about 5 wt% (e.g., no more than about 3 wt%, no more than about 1 wt%, no more than about 0.5 wt%, or no more than about 0.1 wt%) of any of the materials in the semiconductor substrate.

[0059] In some embodiments, the semiconductor substrate (e.g., EUV photomasks and photomasks other than EUV photomasks) to be cleaned in the method may contain organic residues and organometallic residues, and additionally may contain various metal oxides that need to be removed. The semiconductor substrate is typically composed of silicon, silicon germanium, group III-V compounds such as GaAs, or any combination thereof. The semiconductor substrate may additionally include exposed integrated circuit structures such as interconnect features (e.g., metal lines and dielectric materials). Metals and metal alloys used for interconnect features include, but are not limited to, aluminum, aluminum alloyed with copper, copper, titanium, tantalum, cobalt, and silicon, titanium nitride, tantalum nitride, tungsten, and their alloys. The semiconductor substrate may include interlayer dielectrics, layers of silicon oxide, silicon nitride, silicon carbide, titanium oxide, and carbon-doped silicon oxide.

[0060] In some embodiments, the present disclosure is directed to a first cleaning method that includes treating a substrate (e.g., a semiconductor substrate such as an EUV photomask) with the cleaning composition described in the present disclosure to obtain a treated substrate (i.e., a cleaning step), and sonicating the treated substrate in the presence of a first rinse solvent to obtain a cleaned substrate (i.e., a sonicating rinse step or a sonicating step). In some embodiments, treating the substrate with the cleaning composition does not include sonicating the substrate in the cleaning composition.

[0061] The semiconductor substrate may be treated with the cleaning composition by any suitable method. Examples thereof include placing the cleaning composition in a tank and immersing and / or submerging the semiconductor substrate in the cleaning composition, spraying the cleaning composition onto the semiconductor substrate, streaming the cleaning composition over the semiconductor substrate, or any combination thereof. Preferably, the semiconductor substrate is immersed in the cleaning composition.

[0062] In some embodiments, the cleaning composition of the present disclosure can be effectively used to treat or clean a semiconductor substrate at room temperature (e.g., about 16°C to about 27°C, e.g., about 25°C), or at a high temperature of about 55°C or higher (e.g., about 60°C or higher, about 65°C or higher, or about 70°C or higher) to about 80°C or lower (e.g., about 75°C or lower, about 70°C or lower, about 65°C or lower, or about 60°C or lower).

[0063] Generally, the number of cleaning times can vary widely depending on the specific cleaning method and temperature used. For example, a suitable cleaning time can be from about 1 minute or more (e.g., about 3 minutes or more or about 5 minutes or more) to about 10 minutes or less (e.g., about 8 minutes or less or about 5 minutes or less).

[0064] In some embodiments, the cleaning method of the present disclosure (e.g., the first cleaning method described above) may be repeated for a plurality of cycles (e.g., 2 cycles, 3 cycles, or 4 cycles). In some embodiments, each cycle may include cleaning, rinsing, and optionally drying using the cleaning composition described in the present disclosure. In embodiments where the cleaning method of the present disclosure is repeated for a plurality of cycles, the cleaning time in each cycle may be relatively short, and may be about 1 minute to about 5 minutes. In embodiments where the cleaning method of the present disclosure is not repeated, the cleaning time may be relatively long, and may be about 5 minutes to about 10 minutes. Without wishing to be bound by theory, repeating the cleaning method described in the present disclosure for a plurality of cycles may reduce the cleaning time in each cycle while maintaining the cleaning efficiency, which is considered to be able to reduce the overall cleaning time.

[0065] In some embodiments, in order to further enhance the cleaning ability of the cleaning composition of the present disclosure, mechanical agitation means may be used when the semiconductor substrate is immersed in the cleaning composition. Examples of suitable agitation means include circulating the cleaning composition over the substrate, streaming or spraying the cleaning composition over the substrate, and ultrasonic agitation or megasonic agitation during the cleaning process. The orientation of the semiconductor substrate with respect to the ground may be at any angle. A horizontal orientation or a vertical orientation is preferred.

[0066] The cleaning composition of the present disclosure may be used with conventional cleaning tools known to those skilled in the art. A significant advantage of the cleaning composition of the present disclosure is that it wholly or partially contains relatively non-toxic, non-corrosive, and non-reactive components, whereby the cleaning composition is stable over a wide range of temperatures and process times. The cleaning composition of the present disclosure is chemically compatible with substantially all of the materials used to construct existing and proposed semiconductor wafer cleaning process tools for batch wafer cleaning and single wafer cleaning.

[0067] After cleaning, the semiconductor substrate may undergo a sonication rinse step of sonicating the substrate in the presence of a first rinse solvent to remove the cleaning composition or other residues on the substrate. In some embodiments, the semiconductor substrate is immersed in the first rinse solvent in this sonication rinse step. In some embodiments, the first rinse solvent may include water (e.g., deionized water). In some embodiments, this sonication rinse step may be performed at an elevated temperature, for example, from about 40 °C or higher (e.g., about 45 °C or higher or about 50 °C or higher) to about 60 °C or lower (e.g., about 55 °C or lower or about 50 °C or lower).

[0068] Generally, the sonication rinse step may be performed with any suitable sonicator known in the art. In some embodiments, the sonication rinse step may be performed at an appropriate ultrasonic frequency. For example, the sonication rinse step may be performed at an ultrasonic frequency of about 20 kHz or higher (e.g., about 30 kHz or higher or about 40 kHz or higher) and / or about 1 MHz or lower (e.g., about 80 kHz or lower, about 60 kHz or lower, or about 50 kHz or lower). Without wishing to be bound by theory, it is believed that performing the sonication rinse step at a relatively high ultrasonic frequency may facilitate the cleaning of the semiconductor substrate and may shorten the rinse time.

[0069] Generally, the rinse time can vary widely depending on the specific cleaning method and temperature used. For example, a suitable rinse time in the overall cleaning method or in each cycle of the cleaning method may be from about 10 seconds or longer (e.g., about 15 seconds or longer, about 30 seconds or longer, or about 1 minute or longer) to about 5 minutes or shorter (e.g., about 4 minutes or shorter or about 2 minutes or shorter).

[0070] In some embodiments, after the sonication rinse step, the semiconductor substrate may optionally be rinsed with a second rinse solvent. In some embodiments, the second rinse solvent may include isopropyl alcohol. In some embodiments, the rinsing of the semiconductor substrate with the second rinse solvent may be performed with or without sonication. In embodiments where the semiconductor substrate is rinsed with the second rinse solvent with sonication, this step may be performed in a manner similar to the sonication rinse step using the first rinse solvent. In some embodiments, the semiconductor substrate may be rinsed with the second rinse solvent at a temperature of 16°C to 27°C (e.g., 25°C) for a time of 10 seconds to 5 minutes.

[0071] In some embodiments, the first or second rinse solvent may be a suitable rinse solvent other than those described above. Examples of suitable rinse solvents include, but are not limited to, deionized (DI) water, methanol, ethanol, isopropyl alcohol, N-methylpyrrolidone, gamma-butyrolactone, dimethyl sulfoxide, ethyl lactate, and propylene glycol monomethyl ether acetate. Alternatively, an aqueous rinse at pH > 8 (e.g., a dilute aqueous ammonium hydroxide solution) may be used. The rinse solvent may be applied to the semiconductor substrate using a method similar to the method used to apply the cleaning composition described in the present disclosure. The cleaning composition may have been removed from the semiconductor substrate prior to the start of the rinse step, or may still be in contact with the semiconductor substrate at the start of the rinse step. In some embodiments, the rinsing with the first or second rinse solvent may be repeated a plurality of times (e.g., 2, 3, or 4 times) within each cycle consisting of cleaning, rinsing, and optionally drying using the cleaning composition.

[0072] Optionally, after one or more of the rinse steps, the semiconductor substrate is dried. Any suitable drying method known in the art can be used. Examples of suitable drying methods include spin drying, flowing a drying gas across the semiconductor substrate, or drying the semiconductor substrate using a heating device such as a hot plate or an infrared lamp, Marangoni drying, Rotagoni drying, IPA drying, or any combination thereof. The drying time depends on the particular method used but is typically on the order of 30 seconds to 5 minutes.

[0073] In some embodiments, the present disclosure is directed to a second cleaning method that includes sonicating a substrate (e.g., a semiconductor substrate such as an EUV photomask) in the presence of the cleaning composition described herein to obtain a cleaned substrate (i.e., a sonicating cleaning step). In some embodiments, the substrate is immersed in the cleaning composition during the sonicating cleaning step. In some embodiments, this sonicating cleaning step may be performed under the same or similar conditions as those used in the aforementioned sonicating rinse step. For example, the sonicating cleaning step may be performed at an ultrasonic frequency of about 20 kHz or more (e.g., about 30 kHz or more or about 40 kHz or more) and / or about 1 MHz or less (e.g., about 80 kHz or less, about 60 kHz or less, or about 50 kHz or less). In some embodiments, this sonicating cleaning step may be performed at a temperature of about 55 °C or more (e.g., about 60 °C or more, about 65 °C or more, or about 70 °C or more) to about 80 °C or less (e.g., about 75 °C or less, about 70 °C or less, about 65 °C or less, or about 60 °C or less). In some embodiments, a suitable sonication time can be from about 1 minute or more (e.g., about 3 minutes or more or about 5 minutes or more) to about 10 minutes or less (e.g., about 8 minutes or less or about 5 minutes or less).

[0074] After the sonicating cleaning step, the semiconductor substrate may undergo one or more rinse steps in which the substrate is rinsed with a suitable rinse solvent (e.g., the first or second rinse solvent described in this disclosure) to remove the cleaning composition or other residues on the substrate. For example, the substrate may be rinsed one or more times (e.g., twice) with a first rinse solvent containing isopropyl alcohol, and then rinsed one or more times (e.g., twice) with a second rinse solvent containing water.

[0075] In some embodiments, each rinse step may be performed under the same or similar conditions as those used for the rinse steps described above. For example, the semiconductor substrate may be rinsed with the first or second rinse solvent for a time of from about 10 seconds or more (e.g., about 15 seconds or more, about 30 seconds or more, or about 1 minute or more) to about 5 minutes or less (e.g., about 4 minutes or less or about 2 minutes or less) at 16°C to 27°C (e.g., 25°C). Generally, each rinse step after the sonicating cleaning step can be performed with or without sonication.

[0076] Optionally, the semiconductor substrate may be dried using the same drying method as described above after one or more of the rinse steps.

[0077] In some embodiments, the second cleaning method of the present disclosure may be repeated in a plurality of cycles (e.g., 2 cycles, 3 cycles, or 4 cycles), and each cycle may include cleaning by using a cleaning composition, rinsing by using the first or second rinse solvent, and optionally drying.

[0078] In some embodiments, the present disclosure includes treating a substrate (e.g., a semiconductor substrate such as an EUV photomask) with a first cleaning composition containing sulfuric acid and hydrogen peroxide to obtain a treated substrate (i.e., the first cleaning step); and treating the treated substrate with a second cleaning composition to obtain a cleaned substrate (i.e., the second cleaning step), wherein the second cleaning composition is the cleaning composition described in the present disclosure, and is directed to a third cleaning method. In some embodiments, the substrate is immersed in the first or second cleaning composition.

[0079] In some embodiments, the first cleaning composition contains sulfuric acid and hydrogen peroxide in a weight ratio of about 1:1 or more (e.g., about 2:1 or more, about 3:1 or more, or about 4:1 or more) and / or about 8:1 or less (e.g., about 7:1 or less, about 6:1 or less, or about 5:1).

[0080] Generally, the first or second cleaning step can be performed with or without sonication. In embodiments where sonication is used, the sonication can be performed in the same or a similar manner as the above-described sonication cleaning step.

[0081] In some embodiments, the first and second cleaning steps can be performed at an appropriate temperature. In some embodiments, the first cleaning step may be performed at a temperature of about 80°C or more (e.g., about 85°C or more, about 90°C or more, or about 95°C or more) to about 110°C or less (e.g., about 105°C or less, about 100°C or less, or about 95°C or less). In some embodiments, the second cleaning step may be performed at a temperature of about 55°C or more (e.g., about 60°C or more, about 65°C or more, or about 70°C or more) to about 80°C or less (e.g., about 75°C or less, about 70°C or less, about 65°C or less, or about 60°C or less).

[0082] In some embodiments, the first and second cleaning steps may be performed for an appropriate time. In some embodiments, a suitable cleaning time for the first or second cleaning step may be from about 1 minute or more (e.g., about 3 minutes or more or about 5 minutes or more) to about 10 minutes or less (e.g., about 8 minutes or less or about 5 minutes or less).

[0083] After the first or second cleaning step, the semiconductor substrate may undergo one or more rinse steps in which the substrate is rinsed with a suitable rinse solvent to remove the cleaning composition or other residues on the substrate. In some embodiments, the substrate may be rinsed one or more times (e.g., 2 times) with a first rinse solvent containing water (e.g., deionized water) after the first cleaning step. In some embodiments, the substrate may be rinsed one or more times (e.g., 2 times) with a second rinse solvent containing isopropyl alcohol after the second cleaning step, and may also be rinsed one or more times (e.g., 2 times) with a third rinse solvent containing water.

[0084] In some embodiments, each rinse step may be performed under the same or similar conditions as those used in the above-described rinse steps. For example, the semiconductor substrate may be rinsed with the first, second, or third rinse solvent for a time of from about 10 seconds or more (e.g., about 15 seconds or more, about 30 seconds or more, or about 1 minute or more) to about 5 minutes or less (e.g., about 4 minutes or less or about 2 minutes or less) at 16°C to 27°C (e.g., 25°C). Generally, each rinse step can be performed with or without sonication.

[0085] Optionally, the semiconductor substrate may be dried using the same drying method as described above after one or more of the rinse steps.

[0086] In some embodiments, the third cleaning method of the present disclosure may be repeated for a plurality of cycles (e.g., 2 cycles, 3 cycles, or 4 cycles), and each cycle may include cleaning by using the first and the second cleaning compositions, rinsing by using the first, second, or third rinsing solvent, and optionally drying.

[0087] In some embodiments, the above-described first, second, or third cleaning method may further include forming a semiconductor device (e.g., an integrated circuit device such as a semiconductor chip) from the semiconductor substrate obtained by the method.

[0088] In some embodiments, a method for manufacturing an EUV photomask using the cleaning composition described in the present disclosure may include the following steps. First, a layer of photoresist is applied to a semiconductor substrate. The resulting semiconductor substrate may then undergo a pattern transfer process such as an etching process or an implant process to form an EUV photomask. Most of the photoresist may be removed by a dry or wet stripping process (e.g., an oxygen-based plasma ashing process). The remaining residue on the EUV photomask may then be removed in the manner described above using the cleaning composition described in the present disclosure. The EUV photomask can then be used to form one or more integrated circuits on a substrate, which can be processed to form semiconductor chips, for example, by assembly (e.g., dicing and bonding) and packaging (e.g., chip sealing).

[0089] The contents of all publications (e.g., patents, patent application publications, and papers) cited in the present disclosure are hereby incorporated by reference in their entirety into the present disclosure.

Examples

[0090] The present disclosure will be illustrated in more detail with reference to the following examples, which are for illustrative purposes only and should not be construed as limiting the scope of the present disclosure. All percent values described are weight % (wt%) values unless otherwise specified. Controlled stirring during the tests was done by using a 1-inch stir bar at 400 rpm unless otherwise specified.

[0091] ● General Procedure 1 * Formulation Blend Samples of the cleaning composition were prepared by adding the remaining components in the formulation to the calculated amount of organic solvent with stirring. After a uniform solution was obtained, optional additives were added if used. ● General Procedure 2A * Evaluation of the First Cleaning Method in a Single Cycle The above-described first cleaning method in a single cycle was evaluated using the following procedure.

[0092] Cleaning of PER (post-etching residue) from an EUV photomask was performed with the cleaning composition described below using an EUV photomask coupon, where the EUV photomask coupon included a glass substrate sequentially coated with 40 - 50 alternating layers of silicon and molybdenum, a Ru-based layer, and an absorption layer containing TaN and TaON, which were patterned by lithography, etched in a plasma metal etching apparatus, and then subjected to oxygen plasma ashing, and the top layer of the photoresist was completely removed.

[0093] A 4-inch long plastic locking tweezer was used to hold the test coupon, and thereby the coupon could then be suspended in a 500 ml beaker containing approximately 200 milliliters of the cleaning composition of the present disclosure. Then, a cleaning test was conducted by placing the coupon held by the plastic tweezer into the cleaning composition such that the PER layer-containing surface of the coupon faced the stir bar. Under controlled agitation of the cleaning composition, the coupon was allowed to stand in the cleaning composition at 55 °C, 65 °C, or 75 °C for 5 minutes or 10 minutes. When the desired cleaning time was completed, the coupon was quickly removed from the cleaning composition.

[0094] The cleaned coupon was then placed into a Branson M3800H sonicator and immersed in 600 ml of deionized water heated to 50 °C. The coupon was rinsed by sonicating in deionized water at an ultrasonic frequency of 40 kHz for 1 minute. The rinsed coupon was then removed from the sonicator and given two  15-second rinses (by immersing the coupon in isopropyl alcohol) and dried with an N2 flow. ● General Procedure 2B * Evaluation of the First Cleaning Method in Multiple Cycles The above-described first cleaning method in multiple cycles was evaluated using the following procedure.

[0095] A 4-inch long plastic locking tweezer was used to hold the test coupon, and thereby the coupon could then be suspended in a 500 ml beaker containing approximately 200 milliliters of the cleaning composition of the present disclosure. Then, a cleaning test was conducted by placing the coupon held by the plastic tweezer into the cleaning composition such that the PER layer-containing surface of the coupon faced the stir bar. Under controlled agitation of the cleaning composition, the coupon was allowed to stand in the cleaning composition at 55 °C, 65 °C, or 75 °C for 1 minute, 3 minutes, or 5 minutes. When the desired cleaning time was completed, the coupon was quickly removed from the cleaning composition.

[0096] The washed coupons were then placed into a Branson M3800H sonicator and immersed in 600 ml of deionized water heated to 50 °C. The coupons were rinsed by sonicating in the deionized water at an ultrasonic frequency of 40 kHz for 1 minute. The rinsed coupons were then removed from the sonicator and given two 15-second rinses (by immersing the coupons in isopropyl alcohol). After repeating the above cleaning process and rinsing process four times, the coupons were dried with an N2 flow.

[0097] ● General Procedure 3 * Evaluation of the Second Cleaning Method The second cleaning method described above was evaluated using the following procedure. Test EUV photomask coupons were placed into a Branson M3800H sonicator and immersed in 200 ml of a cleaning composition heated to 75 °C. The coupons were cleaned by sonicating in the cleaning composition at an ultrasonic frequency of 40 kHz for 5 minutes. Once the desired cleaning time was complete, the coupons were quickly removed from the sonicator. The washed coupons were given two 15-second rinses with isopropyl alcohol, then a 15-second rinse with deionized water, and dried with an N2 flow. Rinsing was done by immersing the coupons in isopropyl alcohol or deionized water. The above process was repeated four times.

[0098] ● General Procedure 4 * Evaluation of the Third Cleaning Method The third cleaning method described above was evaluated using the following procedure. The test EUV photomask coupon was cleaned in a first cleaning composition at 90°C to 100°C containing sulfuric acid and hydrogen peroxide in a weight ratio of 4:1 using the same cleaning procedure as described in General Procedure 2. The cleaning was performed by immersing the coupon in the first cleaning composition with gentle stirring for 3 minutes. When the desired cleaning time was completed, the coupon was quickly removed from the first cleaning composition. The cleaned coupon was rinsed once with deionized water for 15 seconds.

[0099] The rinsed coupon obtained above was cleaned in a second cleaning composition (which is the cleaning composition of the present disclosure) at 65°C or 75°C for 5 minutes using the same cleaning procedure as described in General Procedure 2. When the desired cleaning time was completed, the coupon was quickly removed from the second cleaning composition. This cleaned coupon was rinsed successively with isopropyl alcohol for 15 seconds twice and deionized water for 15 seconds and dried with an N2 flow. All rinses described in this procedure were performed by immersing the coupon in isopropyl alcohol or deionized water.

[0100] ● Example 1 Formulation Examples 1 to 11 (FE-1 to FE-11) were prepared according to General Procedure 1 and evaluated according to General Procedures 2A to 4. The formulations are summarized in Table 1 and the cleaning results are summarized in Table 2.

Table 1

[0101]

Table 2

[0102] As shown in Tables 1 and 2, Formulations FE-1 to FE-11 were effective in removing all post-etch residues from the EUV photomask by using the first, second, or third cleaning method described in the present disclosure.

[0103] Other embodiments are within the scope of the following claims.

Claims

1. treating a substrate with a cleaning composition to obtain a treated substrate, wherein the cleaning composition comprises at least one redox agent, at least one chelating agent, at least one organic solvent, at least one alkanolamine, and water; and sonicating the treated substrate in the presence of a first rinse solvent to obtain a cleaned substrate; A cleaning method comprising:

2. The method of claim 1 , wherein the substrate is an EUV photomask.

3. The EUV photomask according to claim 2, comprising a low thermal expansion material, TaON, TaN, Ru, RuN, Si, SiO ２ , SiON, Ti, TiN, Cr, CrN, or Mo.

4. The method of claim 1, wherein the treating step is carried out at a temperature of from about 55°C to about 75°C.

5. The method of claim 1 , wherein the sonicating step comprises immersing the processed substrate in the first rinse solvent.

6. The method of claim 1 , wherein the first rinse solvent comprises water.

7. 10. The method of claim 1, wherein the sonication step is carried out at a temperature of about 40°C to about 60°C.

8. The method of claim 1 , further comprising sonicating the processed substrate in the presence of a second rinse solvent.

9. The method of claim 8 , wherein the second rinse solvent is isopropanol.

10. The method of claim 1 , further comprising drying the cleaned substrate.

11. sonicating a substrate in the presence of a cleaning composition to obtain a cleaned substrate, wherein the cleaning composition comprises at least one redox agent, at least one chelating agent, at least one organic solvent, at least one alkanolamine, and water; A cleaning method comprising:

12. The method of claim 11 , wherein the substrate is an EUV photomask.

13. The EUV photomask includes a low thermal expansion material, TaON, TaN, Ru, RuN, Si, SiO ２ , SiON, Ti, TiN, Cr, CrN, or Mo. The method according to claim 12.

14. 12. The method of claim 11, wherein the sonication step is carried out at a temperature of about 55°C to about 75°C.

15. 12. The method of claim 11, wherein the substrate is immersed in the cleaning composition during the sonicating step.

16. The method of claim 11 , further comprising rinsing the cleaned substrate with a first rinse solvent.

17. 17. The method of claim 16, wherein the first rinse solvent comprises isopropanol.

18. 17. The method of claim 16, further comprising rinsing the cleaned substrate with a second rinse solvent after rinsing the cleaned substrate with the first rinse solvent.

19. The method according to claim 18, wherein the second rinse solvent is water.

20. The method according to claim 11, further comprising drying the washed substrate.

21. Processing a substrate with a first cleaning composition containing sulfuric acid and hydrogen peroxide to obtain a processed substrate; and Processing the processed substrate with a second cleaning composition to obtain a washed substrate, wherein the second cleaning composition contains at least one reducing agent, at least one chelating agent, at least one organic solvent, at least one alkanolamine, and water. A cleaning method comprising the above.

22. The method according to claim 21, wherein the substrate is an EUV photomask.

23. The EUV photomask includes a low thermal expansion material, TaON, TaN, Ru, RuN, Si, SiO ２ , SiON, Ti, TiN, Cr, CrN, or Mo, the method according to claim 22.

24. The method according to claim 21, wherein the treatment with the second cleaning composition is performed at a temperature of about 55 °C to about 75 °C.

25. The method according to claim 21, wherein the substrate is immersed in the first or second cleaning composition.

26. The method according to claim 21, further comprising rinsing the processed substrate with a first rinse solvent before processing the processed substrate with the second cleaning composition.

27. The method according to claim 26, wherein the first rinse solvent contains water.

28. The method according to claim 26, further comprising rinsing the washed substrate with a second rinse solvent and a third rinse solvent.

29. The method according to claim 28, wherein the second rinse solvent is isopropanol and the third rinse solvent is water.

30. The method according to claim 21, further comprising drying the washed substrate.

31. At least one reducing agent; At least one chelating agent; At least one organic solvent; At least one alkanolamine containing methyldiethanolamine; and Water A cleaning composition comprising the above.

32. The composition according to claim 31, wherein the composition has a pH of about 8 to about 14.

33. The composition according to claim 31, wherein the at least one reducing agent contains hydroxylamine.

34. The composition according to claim 31, wherein the at least one reducing agent is about 0.5 wt% to about 20 wt% based on the composition.

35. The composition according to claim 31, wherein the at least one chelating agent contains polyaminopolycarboxylic acid.

36. The composition according to claim 35, wherein the polyaminopolycarboxylic acid is selected from the group consisting of mono- or poly-alkylene polyamine polycarboxylic acids, polyaminoalkane polycarboxylic acids, polyaminoalkanol polycarboxylic acids, and hydroxyalkyl ether polyamine polycarboxylic acids.

37. The composition according to claim 35, wherein the polyaminopolycarboxylic acid is diethylenetriaminepentaacetic acid.

38. The composition according to claim 31, wherein the at least one chelating agent is from about 0.01% to about 1% by weight based on the composition.

39. The composition according to claim 31, wherein the at least one organic solvent is selected from the group consisting of water-soluble alcohols, water-soluble ketones, water-soluble esters, and water-soluble ethers.

40. The composition according to claim 31, wherein the at least one organic solvent comprises ethylene glycol butyl ether, propylene glycol, or dimethyl sulfoxide.

41. The composition according to claim 31, wherein the at least one organic solvent is from about 1% to about 70% by weight based on the composition.

42. The composition according to claim 31, wherein the at least one alkanolamine is from about 0.05% to about 10% by weight based on the composition.

43. The composition according to claim 31, wherein the water is from about 10% to about 90% by weight based on the composition.

44. The composition according to claim 31, further comprising at least one quaternary ammonium compound.

45. The compound according to claim 44, wherein the at least one quaternary ammonium compound comprises tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, dimethyldiethylammonium hydroxide, choline, tetraethanolammonium hydroxide, benzyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide, and benzyltributylammonium hydroxide.

46. The composition according to claim 44, wherein the at least one quaternary ammonium compound is from about 0.1% to about 10% by weight based on the composition.

47. The composition according to claim 31, further comprising at least one metal rust inhibitor.

48. The composition according to claim 47, wherein the at least one metal rust inhibitor comprises benzotriazole optionally substituted by at least one substituent selected from the group consisting of an alkyl group, an aryl group, a halogen group, an amino group, a nitro group, an alkoxy group, and a hydroxyl group.

49. The composition according to claim 47, wherein the at least one metal rust inhibitor comprises 5-methylbenzotriazole.

50. The composition according to claim 47, wherein the at least one metal rust inhibitor is from about 0.01 wt% to about 1 wt% based on the composition.

51. The composition comprises hydroxylamine; diethylenetriaminepentaacetic acid; at least one organic solvent comprising ethylene glycol butyl ether, propylene glycol, or dimethyl sulfoxide; at least one alkanolamine comprising methyldiethanolamine; and water and is the composition according to claim 31.

Images