Chemical solution, method for treating material to be treated, and method for producing semiconductor device

Abstract

The present invention addresses the problem of providing a chemical solution capable of selectively removing a silicon-germanium-containing material from a material to be treated having a silicon-germanium-containing material and a silicon-containing material. The chemical solution according to the present invention is used for a material to be treated having a silicon-germanium-containing material and a silicon-containing material, removes at least a part of the silicon-germanium-containing material, and contains a fluoride ion source, an oxidizing agent, a heterocyclic compound, and a solvent.

Description

Chemical solution, method for treating object to be treated, and method for manufacturing semiconductor device

[0001] The present invention relates to a chemical solution, a method for treating an object to be treated, and a method for manufacturing a semiconductor device.

[0002] As semiconductor devices become increasingly miniaturized, there is an increasing demand for highly efficient and accurate chemical etching and cleaning processes during the semiconductor device manufacturing process. In particular, when multiple materials exist on a substrate, it is desirable to be able to selectively remove a specific material.

[0003] For example, Patent Document 1 discloses an etching solution containing periodic acid and fluoride as an etching solution for selectively etching silicon germanium relative to silicon, germanium, and oxides thereof.

[0004] Japanese Patent Application Laid-Open No. 2020-107724

[0005] As described above, depending on the application, there may be a need to selectively remove at least a portion of silicon-germanium (SiGe)-containing materials from a workpiece having both silicon-germanium (SiGe)-containing materials and silicon (Si)-containing materials. The present inventors have studied the composition specifically disclosed in Patent Document 1 and found that the selectivity of removal of SiGe-containing materials relative to removal of Si-containing materials is insufficient and that improvement is necessary.

[0006] Therefore, an object of the present invention is to provide a chemical solution capable of selectively removing SiGe-containing materials from a workpiece containing SiGe-containing materials and Si-containing materials, and also to provide a method for treating a workpiece using the chemical solution and a method for manufacturing a semiconductor device.

[0007] As a result of extensive research into solving the above problems, the present inventors have found that the problems can be solved by the following configuration.

[0008] [1] A chemical solution used for a silicon-germanium-containing material and a processing object having the silicon-containing material, for removing at least a portion of the silicon-germanium-containing material, the chemical solution comprising a fluoride ion source, an oxidizing agent, a heterocyclic compound, and a solvent. [2] The chemical solution according to [1], wherein the heterocyclic compound is a nitrogen-containing heterocyclic compound. [3] The chemical solution according to [1] or [2], wherein the solvent comprises a water-soluble organic solvent. [4] The polar term δP of the Hansen solubility parameter of the solvent is 11 MPa or less. １／２The chemical solution according to any one of [1] to [3], wherein the content of the water-soluble organic solvent is less than 90% by mass with respect to the total mass of the chemical solution. [5] The chemical solution according to [3] or [4], wherein the content of the water-soluble organic solvent is less than 90% by mass with respect to the total mass of the chemical solution. [6] The chemical solution according to [3] or [5], wherein the water-soluble organic solvent is selected from the group consisting of alcohol-based solvents, carboxylic acid-based solvents, ether-based solvents, and sulfoxide-based solvents. [7] The chemical solution according to any one of [3], [5], and [6], wherein the water-soluble organic solvent is a carboxylic acid-based solvent. [8] The chemical solution according to any one of [1] to [7], wherein the heterocyclic compound is an azole or a derivative thereof. [9] The chemical solution according to [8], wherein the azole or a derivative thereof is a triazole or a derivative thereof.

[10] The chemical solution according to [8] or [9], wherein the azole or a derivative thereof is 1,2,4-triazole.

[11] The chemical solution according to any one of [1] to

[10] , wherein the content of the heterocyclic compound is 0.5 mass% or more relative to the total mass of the chemical solution.

[12] The chemical solution according to any one of [1] to

[11] , wherein the standard oxidation-reduction potential of the oxidizing agent is 1.3 V or more.

[13] The chemical solution according to any one of [1] to

[12] , wherein the oxidizing agent is periodic acid.

[14] The chemical solution according to any one of [1] to

[13] , which is used on a workpiece having two silicon-germanium-containing materials with different germanium concentrations and a silicon-containing material, and which removes at least a portion of the silicon-germanium-containing material with a higher germanium concentration.

[15] A method for treating a workpiece, comprising contacting a silicon-germanium-containing material and a silicon-containing material with the chemical solution according to any one of [1] to

[14] , and removing at least a portion of the silicon-germanium-containing material.

[16] A method for manufacturing a semiconductor device, comprising the method for treating an object to be treated according to

[15] .

[0009] According to the present invention, a chemical solution capable of selectively removing SiGe-containing materials from a workpiece having Si-containing materials and Si-containing materials can be provided. The present invention also provides a method for treating a workpiece using the chemical solution and a method for manufacturing a semiconductor device.

[0010] 1 is a cross-sectional view showing an embodiment of an object to be treated, and FIG. 2 is an example of a cross-sectional view showing an object to be treated after being treated by a method for treating an object to be treated of the present invention.

[0011] The present invention will be described in detail below. The following description of the components may be based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0012] In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits. Furthermore, in this specification, when two or more types of a certain component are present, the "content" of that component means the total content of those two or more components. In this specification, in a numerical range described in stages, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in a numerical range described in this specification, the upper or lower limit value described in a certain numerical range may be replaced with a value shown in the Examples. In this specification, a combination of two or more preferred embodiments is a more preferred embodiment.

[0013] In this specification, the term "SiGe-containing material" refers to a material containing Si and Ge elements, and is preferably a material composed essentially of only Si and Ge elements. "Composed essentially of only Si and Ge elements" means that the total content of Si and Ge elements is 90 atomic % or more with respect to all atoms of the material. A material composed essentially of only Si and Ge elements may contain other elements (e.g., C, N, O, B, and P) as long as the total content of Si and Ge elements is within the above range. The total content of Si and Ge elements in the SiGe-containing material is preferably 90 to 100 mass %, more preferably 99 to 100 mass %, and even more preferably 99.9 to 100 mass %, with respect to the total mass of the SiGe-containing material. In the SiGe-containing material, the content of Ge element (Ge / (Si+Ge)) relative to the total content of Si element and Ge element is preferably 60 atomic % or less, more preferably 50 atomic % or less, and even more preferably 45 atomic % or less. The lower limit of the content of Ge element relative to the total content of Si element and Ge element is preferably 5 atomic % or more, more preferably 25 atomic % or more. In this specification, the term "Si-containing material" refers to a material containing Si element that is different from the above-mentioned SiGe-containing material and does not substantially contain Ge element. "Substantially not containing Ge element" means that the content of Ge element is less than 5 atomic % (preferably 0 atomic %) with respect to all atoms of the material. The Si-containing material is preferably a material composed substantially only of Si element. "Composed substantially only of Si element" means that the content of Si element is 90 atomic % or more with respect to all atoms of the material. In a material substantially composed of only Si element, other elements (e.g., C element, N element, O element, B element, P element, etc., excluding Ge element) may be contained as long as the content of Si element is within the above range.

[0014] In this specification, "ppm" means "parts-per-million (10 －６ ) and "ppb" stands for "parts-per-billion (10 －９ ) and "ppt" stands for "parts-per-trillion (10－１２ In this specification, 1 Å (angstrom) corresponds to 0.1 nm.

[0015] Unless otherwise specified, each component of the drug solution described in this specification may be ionized in the drug solution or may form a salt.

[0016] The chemical solution of the present invention is used for a workpiece having a SiGe-containing material and a Si-containing material, and removes at least a portion of the SiGe-containing material, and includes a fluoride ion source, an oxidizing agent, a heterocyclic compound, and a solvent.

[0017] Although the reason why the chemical solution having the above-described configuration can solve the problems of the present invention is not entirely clear, the inventors speculate as follows. The following speculation does not limit the mechanism by which the effect is obtained. In other words, even if the effect is obtained by a mechanism other than the one described below, it is still within the scope of the present invention. A chemical solution containing a fluoride ion source, an oxidizing agent, and a solvent can oxidize SiGe-containing materials, solubilize them in the solvent, and remove them from the workpiece. It is speculated that the heterocyclic compound contained in the chemical solution of the present invention forms a complex with a component derived from the SiGe-containing materials, thereby selectively promoting the solubilization of the SiGe-containing materials. As a result, when the chemical solution of the present invention is used on a workpiece containing SiGe-containing materials and Si-containing materials, it is believed that at least a portion of the SiGe-containing materials can be selectively removed. Hereinafter, the ability to more selectively remove SiGe-containing materials from a workpiece containing SiGe-containing materials and Si-containing materials is simply referred to as "the effect of the present invention being superior."

[0018] Depending on the application, the chemical solution of the present invention may also preferably have excellent high-Ge-concentration SiGe selective solubility. In this specification, "high-Ge-concentration SiGe selective solubility" refers to the ability to selectively remove the SiGe-containing material with a high Ge concentration when used on a workpiece having two SiGe-containing materials with different germanium (Ge) concentrations and a silicon-containing material. The chemical solution of the present invention is likely to exhibit excellent high-Ge-concentration SiGe selective solubility because the heterocyclic compound coordinates with components derived from the SiGe-containing material with a high Ge concentration to promote dissolution.

[0019] [Fluoride Ion Source] The chemical solution of the present invention contains a fluoride ion source. The fluoride ion source is a fluoride ion source that generates fluoride ions (F － ) or a compound capable of releasing a fluoride ion source. The fluoride ion source may be in the form of a fluoride ion or a fluorine-containing ion. Examples of fluorine-containing ions include bifluoride ions (HF ２ － ), SiF ６ ２－ , TiF ６ ２－ , ZrF ６ ２－ , P.F. ６ － , and BF ４ － The fluoride ion source is often a salt of a fluoride ion or a fluorine-containing ion with a cation. Cations preferably contained in the fluoride ion source include H ＋ , Li ＋ , Na ＋ , K. ＋ , and NH ４ ＋ are mentioned, and H ＋ is preferred.

[0020] Examples of fluoride ion sources include hydrofluoric acid (HF) and ammonium fluoride (NH ４ F), hexafluorosilicic acid and its salts (H ２ SiF ６ , Na ２ SiF ６ etc.), fluoroboric acid and its salts (HBF ４ , K.B.F. ４ , N.H. ４ BF ４ etc.), hexafluorotitanic acid and its salts (H ２ TiF ６ ), hexafluorozirconic acid and its salts (H ２ ZrF ６ ), and hexafluorophosphate and its salts (HPF ６ ) are exemplified, hydrofluoric acid or ammonium fluoride is preferred, and hydrofluoric acid is more preferred.

[0021] The fluoride ion source may be used alone or in combination of two or more. The content of the fluoride ion source is preferably 0.005 to 10.0 mass%, more preferably 0.01 to 5.0 mass%, and even more preferably 0.1 to 1.0 mass%, relative to the total mass of the chemical solution, in terms of more excellent effects of the present invention. A solution containing a fluoride ion source may be used as the fluoride ion source. When a solution containing a fluoride ion source is used as the fluoride ion source, the content of the fluoride ion source refers to the content of the fluoride ion source contained in the solution.

[0022] [Oxidizing Agent] The chemical solution of the present invention contains an oxidizing agent. The standard oxidation-reduction potential of the oxidizing agent is preferably 1.0 V or higher, more preferably 1.3 V or higher, and even more preferably 1.5 V or higher, in terms of achieving better effects of the present invention. The upper limit of the standard oxidation-reduction potential of the oxidizing agent is not particularly limited, but is preferably 4.0 V or lower, more preferably 2.5 V or lower. The standard oxidation-reduction potential is based on a standard hydrogen electrode.

[0023] Examples of the oxidizing agent include hydrogen peroxide, and peroxides such as peracetic acid, performic acid, perpropionic acid, and salts thereof; perhalogen acid compounds such as periodic acid, perchloric acid, and salts thereof; oxide halides such as iodic acid, chloric acid, hypochlorous acid, and salts thereof; nitric acid compounds such as nitric acid, cerium nitrate, and iron nitrate; persulfates, persulfates, persulfates, peroxodisulfate, and peroxodisulfate; persulfides; percarbonates; perboric acid and salts thereof; permanganates; isocyanuric acid compounds such as isocyanuric acid, trichloroisocyanuric acid, and salts thereof; cerium compounds; and ferricyanides such as potassium ferricyanide. Peroxides or perhalogen acid compounds are preferred, and perhalogen acid compounds are more preferred. The periodic acid may be metaperiodic acid (HIO ４ ), and orthoperiodic acid (H ５ IO ６) are included. Among them, the oxidizing agent is preferably periodic acid (standard oxidation-reduction potential 1.6 V), hydrogen peroxide (standard oxidation-reduction potential 1.8 V), peracetic acid (standard oxidation-reduction potential 1.4 V), performic acid, or perpropionic acid, with periodic acid being more preferred. Note that the chemical solution may contain a component resulting from a reaction between the oxidizing agent and a solvent described below. For example, when the chemical solution contains hydrogen peroxide, an acidic compound (e.g., sulfuric acid), and acetic acid, part of the hydrogen peroxide may react with the acetic acid to generate peracetic acid, and the peracetic acid may function as the oxidizing agent.

[0024] The oxidizing agent may be used alone or in combination of two or more. The content of the oxidizing agent is preferably 0.01 to 10 mass %, more preferably 0.1 to 5 mass %, and even more preferably 0.6 to 3 mass %, relative to the total mass of the chemical solution, in terms of more excellent effects of the present invention.

[0025] [Solvent] The chemical solution of the present invention contains a solvent. Examples of the solvent include water and an organic solvent. The organic solvent is preferably a water-soluble organic solvent. The water-soluble organic solvent refers to an organic solvent having a solubility in water (100 g) at 25°C of 20 g / 100 g or more. In terms of achieving better effects of the present invention, the solvent preferably contains a water-soluble organic solvent, and more preferably contains water and a water-soluble organic solvent.

[0026] Examples of the organic solvent include alcohol-based solvents, carboxylic acid-based solvents, ether-based solvents, sulfoxide-based solvents, ester-based solvents, ketone-based solvents, sulfone-based solvents, amide-based solvents, and nitrile-based solvents. The organic solvent is preferably selected from the group consisting of alcohol-based solvents, carboxylic acid-based solvents, ether-based solvents, and sulfoxide-based solvents, and more preferably a carboxylic acid-based solvent.

[0027] Examples of alcohol solvents include methanol, ethanol, 1-propanol, 2-propanol, t-butyl alcohol, 1-butanol, 2-butanol, isobutyl alcohol, 2-pentanol, t-pentyl alcohol, hexanol, 3-methoxy-3-methyl-1-butanol, 3-methoxy-1-butanol, 1-methoxy-2-butanol, allyl alcohol, propargyl alcohol, 2-butenyl alcohol, 3-butenyl alcohol, 4-penten-2-ol, tetrahydrofurfuryl alcohol, furfuryl alcohol, and benzyl alcohol, and polyols such as glycerin, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, tetraethylene glycol, 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, hexylene glycol, pinacol, and 1,3-cyclopentanediol.

[0028] Examples of carboxylic acid solvents include formic acid, acetic acid, and propionic acid.

[0029] Examples of ether solvents include dialkyl ethers such as diethyl ether, diisopropyl ether, dibutyl ether, t-butyl methyl ether, and cyclohexyl methyl ether; glycol ethers such as ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, tetraethylene glycol dimethyl ether, dipropylene glycol dimethyl ether, triethylene glycol diethyl ether, tetraethylene glycol diethyl ether, ethylene glycol dimethyl ether, triethylene glycol dimethyl ether, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monomethyl ether, diethylene glycol propyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, and triethylene glycol monobutyl ether; and cyclic ethers such as tetrahydrofuran and 1,4-dioxane.

[0030] An example of a sulfoxide solvent is dimethyl sulfoxide (DMSO).

[0031] Examples of ester solvents include chain esters such as ethyl acetate, butyl acetate, ethyl lactate, methyl 3-methoxypropanoate, propylene glycol monomethyl ether acetate, ethylene glycol monoacetate, diethylene glycol monoacetate, ethylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol diacetate, and propylene glycol diacetate, and cyclic esters such as propylene carbonate, ethylene carbonate, and diethyl carbonate.

[0032] Examples of solvents other than those mentioned above include ketone solvents such as acetone, dimethyl ketone (propanone), cyclobutanone, cyclopentanone, cyclohexanone, methyl ethyl ketone (2-butanone), 5-hexanedione, methyl isobutyl ketone, 1,4-cyclohexanedione, 1,3-cyclohexanedione, and cyclohexanone; amide solvents such as N-methyl-2-pyrrolidone, N,N-dimethylformamide, 1-methyl-2-pyrrolidone, 2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, formamide, N-methylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropanamide, and hexamethylphosphoric triamide; sulfone solvents such as sulfolane, 3-methylsulfolane, and 2,4-dimethylsulfolane; and nitrile solvents such as acetonitrile.

[0033] Among these, the water-soluble organic solvent preferably contains at least one selected from the group consisting of formic acid, acetic acid, propionic acid, and ethylene glycol monobutyl ether (EGBE), more preferably contains at least one selected from the group consisting of acetic acid, propionic acid, and EGBE, and even more preferably contains acetic acid.

[0034] The polarity term δP of the Hansen solubility parameter of the solvent (hereinafter also simply referred to as "polarity term δP") is 20 MPa, which is preferable in terms of the effects of the present invention and the selective solubility of high Ge concentration SiGe. １／２ Preferably, 17 MPa or less １／２ More preferably, 11 MPa or less １／２ The lower limit of the polarity parameter δP is not particularly limited, but is more preferably 2 MPa or less. １／２ In most cases, it is 5 MPa or more. １／２ The hydrogen bond term δH of the Hansen solubility parameter of the solvent is preferably 10 to 60 MPa. １／２ is preferable, and 15 to 35 MPa １／２ The dispersion term δD of the Hansen solubility parameter of the solvent is more preferably 5 to 30 MPa. １／２ is preferable, and 10 to 20 MPa１／２ is more preferred.

[0035] In this specification, the Hansen solubility parameter refers to the Hansen solubility parameter described in "Hansen Solubility Parameters: A Users Handbook, Second Edition" (page 1-310, CRC Press, published in 2007) and the like. In other words, the Hansen solubility parameter expresses solubility as a multidimensional vector (polarity term δP, hydrogen bond term δH, and dispersion term δD), and these three parameters also refer to the coordinates of a point in a three-dimensional space called Hansen space. In this specification, a known literature value can be used as the Hansen solubility parameter of a compound. If a known literature value does not exist, a calculated value obtained using commercially available software HSPiP (Hansen Solubility Parameter in Practice) may be used. When the solvent is a mixed solvent containing two or more solvents, the Hansen solubility parameter of the solvent is determined by calculating the weighted average value of the Hansen solubility parameter values ​​of each solvent and the mass ratio of the content of each solvent. For example, in the case of water (polarity term δP = 16 MPa), １／２ ) / acetic acid (polar term δP=8MPa １／２ The polarity term δP of the mixed solvent of (16 × 30 + 8 × 70) / (30 + 70) = 10.4 MPa １／２ The same applies to the hydrogen bond term δH and the dispersion term δD.

[0036] The solvent may be used alone or in combination of two or more. The content of the solvent is preferably 60% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, relative to the total mass of the chemical solution, from the viewpoint of more excellent effects of the present invention. The upper limit is less than 100% by mass, preferably 99.5% by mass or less, and more preferably 99% by mass or less. When the chemical solution of the present invention contains a water-soluble organic solvent, the content of the water-soluble organic solvent is preferably 30% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more, relative to the total mass of the chemical solution, from the viewpoint of more excellent effects of the present invention. Furthermore, the content of the water-soluble organic solvent is preferably 95% by mass or less, more preferably less than 90% by mass, and even more preferably 80% by mass or less, from the viewpoint of excellent selective solubility of high Ge concentration SiGe.

[0037] [Heterocyclic Compound] The chemical solution of the present invention contains a heterocyclic compound. The heterocyclic compound may be either an aromatic heterocyclic compound or an aliphatic heterocyclic compound, with an aromatic heterocyclic compound being preferred. The heterocyclic compound may be either monocyclic or polycyclic, with a monocyclic compound being preferred. The heterocyclic compound preferably has 4 to 20 ring atoms, more preferably 5 to 10, even more preferably 5 to 8, and particularly preferably 5. The heterocyclic compound may have a substituent. Examples of the substituent include a hydroxyl group, a carboxylic acid group, an amino group, an alkyl group, an aryl group, an alkoxy group, an acyl group, an alkyloxycarbonyl group, an alkylcarbonyloxy group, a mercapto group, and a halogen atom. If possible, the substituent may further have a hydroxyl group, a carboxylic acid group, an amino group, a mercapto group, and a halogen atom as a substituent. It is also preferred that the heterocyclic compound has no substituent, as this will enhance the effects of the present invention. The number of heteroatoms contained as ring members in the heterocyclic compound is 1 or more, preferably 2 or more, more preferably 2 to 4, and even more preferably 2 or 3, in terms of better effects of the present invention. The heterocyclic compound preferably contains a nitrogen atom, an oxygen atom, or a sulfur atom as a heteroatom, and more preferably contains a nitrogen atom. That is, the heterocyclic compound is preferably a nitrogen-containing heterocyclic compound. The nitrogen-containing heterocyclic compound may have a heteroatom other than a nitrogen atom as a ring member atom.

[0038] The nitrogen-containing heterocyclic compound is preferably an azole or a derivative thereof. An azole is a five-membered aromatic heterocyclic compound containing a nitrogen atom. The number of nitrogen atoms contained in the azole is preferably 1 to 4, and more preferably 1 to 3. Examples of the azole include pyrrole, in which one of the atoms constituting the azole ring is a nitrogen atom; imidazole and pyrazole, in which two of the atoms constituting the azole ring are nitrogen atoms; thiazole, in which one of the atoms constituting the azole ring is a nitrogen atom and the other is a sulfur atom; triazole, in which three of the atoms constituting the azole ring are nitrogen atoms; and tetrazole, in which four of the atoms constituting the azole ring are nitrogen atoms.

[0039] Examples of the azole derivative include azoles having a substituent. Examples of the substituent include a hydroxyl group, a carboxylic acid group, a mercapto group, an amino group, a halogen atom, an alkyl group (preferably having 1 to 6 carbon atoms), an aryl group (preferably a phenyl group), and a 2-imidazolyl group. The alkyl group and aryl group may further have the above-mentioned substituent as a substituent. When the azole has two or more substituents, the substituents may be bonded to each other to form a ring that may have a substituent. The ring may be either an aromatic ring or an aliphatic ring, with an aromatic ring being preferred. The ring may also be either a hydrocarbon ring or a heterocyclic ring. Preferred examples of the ring include a benzene ring, an azole ring, a thiophene ring, a furan ring, and a pyridine ring, with a benzene ring being more preferred. Examples of the substituent that the ring may have include the substituent that the azole derivative may have. In terms of achieving better effects of the present invention, it is also preferable that the substituents in the substituted azole do not bond to each other to form a ring.

[0040] Examples of imidazole and its derivatives include imidazole, 1-methylimidazole, 2-methylimidazole, 5-methylimidazole, 1,2-dimethylimidazole, 2-mercaptoimidazole, 4,5-dimethyl-2-mercaptoimidazole, 4-hydroxyimidazole, 2,2'-biimidazole, 4-imidazolecarboxylic acid, histamine, and benzimidazole, with imidazole being preferred. Examples of pyrazole and its derivatives include pyrazole, 2,4-dimethylpyrazole, 3,5-dimethylpyrazole, benzopyrazole, and 2-mercaptobenzopyrazole, with pyrazole being preferred. Examples of thiazole and its derivatives include 2,4-dimethylthiazole, benzothiazole, and 2-mercaptobenzothiazole, with thiazole being preferred. Examples of triazole and derivatives thereof include 1,2,4-triazole, 3-methyl-1,2,4-triazole, 3-amino-1,2,4-1H-triazole, 1,2,3-triazole, 1-methyl-1,2,3-triazole, benzotriazole, 1-hydroxybenzotriazole, 1-dihydroxypropylbenzotriazole, 2,3-dicarboxypropylbenzotriazole, 4-hydroxybenzotriazole, 4-carboxybenzotriazole, 5-methylbenzotriazole, and 2,2'-{[(5-methyl-1H-benzotriazol-1-yl)methyl]imino}diethanol, of which 1,2,4-triazole, 3-methyl-1,2,4-triazole, or 3-amino-1,2,4-1H-triazole is preferred, and 1,2,4-triazole is more preferred. Examples of tetrazole and its derivatives include 1H-tetrazole (1,2,3,4-tetrazole), 5-methyltetrazole, 5-aminotetrazole, 1,5-pentamethylenetetrazole, 1-phenyl-5-mercaptotetrazole, and 1-(2-dimethylaminoethyl)-5-mercaptotetrazole, with 5-aminotetrazole being preferred.

[0041] Of the azoles and derivatives thereof, imidazole, pyrazole, triazole, or derivatives thereof are preferred, triazole or derivatives thereof are more preferred, 1,2,4-triazole or derivatives thereof are even more preferred, and 1,2,4-triazole is particularly preferred.

[0042] Nitrogen-containing heterocyclic compounds also include pyridine and derivatives thereof (e.g., pyridine-2-carboxylic acid), piperidine and derivatives thereof, piperazine and derivatives thereof, piperazine and derivatives thereof, pyrimidine and derivatives thereof, pyridazine and derivatives thereof, triazine and derivatives thereof, pyrrolidine and derivatives thereof, pyrrole and derivatives thereof, morpholine and derivatives thereof, and oxazine and derivatives thereof.

[0043] The heterocyclic compound may be used alone or in combination of two or more. The content of the heterocyclic compound is preferably 0.01 to 10 mass %, more preferably 0.05 to 5 mass %, and even more preferably 0.5 to 2 mass %, relative to the total mass of the chemical solution, in terms of better effects of the present invention.

[0044] [Other Additives] The chemical solution may contain other additives in addition to those described above. Examples of other components include basic compounds, acidic compounds, surfactants, antifoaming agents, and unsaturated compounds. Note that all of these components are compounds different from the above-described fluoride ion source, oxidizing agent, solvent, and heterocyclic compound.

[0045] <Basic Compound> The chemical solution may contain a basic compound. Examples of the basic compound include organic basic compounds and inorganic basic compounds. Examples of the organic basic compound include amine compounds, quaternary ammonium salts, amine oxide compounds, nitro compounds, nitroso compounds, oxime compounds, ketoxime compounds, aldoxime compounds, lactam compounds, and isocyanide compounds. Note that the organic basic compound is a compound different from the heterocyclic compound described above. Examples of the inorganic basic compound include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkaline earth metal hydroxides, and ammonia or salts thereof.

[0046] The content of the basic compound is not particularly limited, but is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, based on the total mass of the chemical solution.

[0047] <Acidic Compound> The chemical solution may contain an acidic compound. Examples of the acidic compound include inorganic acidic compounds. Examples of the inorganic acidic compound include hydrochloric acid, sulfuric acid, phosphoric acid, boric acid, and phosphonic acid, and sulfuric acid is preferred.

[0048] The content of the acidic compound is not particularly limited, but is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass, based on the total mass of the chemical solution.

[0049] <Surfactant> The chemical solution may contain a surfactant. The surfactant is not particularly limited as long as it is a compound having a hydrophilic group and a hydrophobic group (lipophilic group) in one molecule, and examples thereof include nonionic surfactants, cationic surfactants, and anionic surfactants. The surfactant often has at least one hydrophobic group selected from the group consisting of an aliphatic hydrocarbon group, an aromatic hydrocarbon group, and a combination thereof. The total carbon number of the surfactant is preferably 16 to 100.

[0050] Examples of the nonionic surfactant include ester-type nonionic surfactants, ether-type nonionic surfactants, and ester-ether-type nonionic surfactants, and ether-type nonionic surfactants are preferred. Examples of the nonionic surfactant include the compounds exemplified in paragraph

[0126] of WO 2022 / 044893, the contents of which are incorporated herein by reference.

[0051] Examples of cationic surfactants include primary to tertiary alkylamine salts (e.g., monostearyl ammonium chloride, distearyl ammonium chloride, tristearyl ammonium chloride, etc.) and modified aliphatic polyamines (e.g., polyethylene polyamine, etc.).

[0052] Examples of anionic surfactants include sulfonic acid surfactants having a sulfonic acid group, sulfate ester surfactants having a sulfate ester group, and carboxylic acid surfactants having a carboxylic acid group. Examples of anionic surfactants include the compounds exemplified in paragraphs

[0116] to

[0123] of WO 2022 / 044893, the contents of which are incorporated herein by reference.

[0053] <Antifoaming agent> The chemical solution may contain an antifoaming agent. Surfactants may cause foaming depending on how they are used. Therefore, it is preferable that the chemical solution containing a surfactant contains an antifoaming agent that suppresses the generation of foaming, shortens the lifespan of the generated foam, and suppresses residual foam. The antifoaming agent is not particularly limited as long as it does not impair the effects of the present invention, and examples thereof include silicone-based antifoaming agents, acetylene diol-based antifoaming agents, fatty acid ester-based antifoaming agents, and long-chain aliphatic alcohol-based antifoaming agents. Among these, silicone-based antifoaming agents are preferred because of their superior effect of suppressing residual foam. It should be noted that the antifoaming agent does not include compounds contained in the above-mentioned surfactants.

[0054] <Unsaturated Compound> The chemical solution may contain an unsaturated compound. The unsaturated compound is a compound containing a carbon-carbon unsaturated bond, and is preferably a compound containing a carbon-carbon double bond. The unsaturated compound preferably has at least one structure selected from the group consisting of a carboxylic acid group, an amide group, a hydroxy group, an ester bond, and an ether bond, and more preferably has at least one structure selected from the group consisting of a carboxylic acid group and a polyalkylene glycol structure. Examples of unsaturated compounds include unsaturated fatty acids such as linoleic acid, oleic acid, and sorbic acid, polyalkylene glycol alkenylene ethers such as polyoxyethylene oleyl ether, polyalkylene glycol unsaturated fatty acid esters such as polyethylene glycol oleate and polyethylene glycol linoleate, sorbitol unsaturated fatty acid esters such as sorbitol tetraoleate, sorbitol trioleate, sorbitol dioleate, and sorbitol monooleate, sorbitan unsaturated fatty acid esters such as sorbitan monooleate and sorbitan trioleate, oleamide, ethylene glycol monoallyl ether, allyl methyl ether, glycerol α,α'-diallyl ether, pentaerythritol tetraallyl ether, ethylene glycol monovinyl ether, maleic acid, 3-phenyl-2-propen-1-ol, and 1,2-epoxy-5-hexene.

[0055] The content of the unsaturated compound is preferably 0.001 to 10% by mass, more preferably 0.005 to 5% by mass, based on the total mass of the chemical solution.

[0056] [Physical properties of chemical solution] <pH> The pH of the chemical solution is preferably 0.5 to 9, more preferably 1 to 7. The pH of the chemical solution can be measured using a known pH meter by a method in accordance with JIS Z8802-1984. The measurement temperature is 25°C.

[0057] <Metal Content> The content (measured as ion concentration) of metals (e.g., metal elements Fe, Co, Na, Cu, Mg, Mn, Li, Al, Cr, Ni, Zn, Sn, and Ag) contained as impurities in the chemical solution is preferably 5 mass ppm or less, more preferably 1 mass ppm or less. In particular, the metal content is more preferably a value lower than 1 mass ppm, that is, a mass ppb order or less, particularly preferably 100 mass ppb or less, and most preferably less than 10 mass ppb. The lower limit is preferably 0.

[0058] <Insoluble Particles> The drug solution of the present invention preferably does not substantially contain insoluble particles. The term "insoluble particles" refers to particles of inorganic solids or organic solids that do not dissolve in the drug solution and ultimately exist as particles. The term "substantially does not contain insoluble particles" refers to a measurement composition obtained by diluting the drug solution 10,000 times with a solvent contained in the drug solution, and the number of particles with a particle size of 50 nm or more contained in 1 mL of the measurement composition is 40,000 or less. The number of particles contained in the measurement composition can be measured in the liquid phase using a commercially available particle counter. Commercially available particle counters include those manufactured by Rion and PMS. A representative example of the former is the KS-19F, and a representative example of the latter is the Chem20. To measure larger particles, devices such as the KS-42 series and LiQuilaz II S series can be used. Examples of insoluble particles include particles of inorganic solids such as silica (including colloidal silica and fumed silica), alumina, zirconia, ceria, titania, germania, manganese oxide, and silicon carbide; and particles of organic solids such as polystyrene, polyacrylic resin, and polyvinyl chloride. Methods for removing insoluble particles from the chemical solution include, for example, purification treatments such as filtering. Furthermore, it is preferable that the chemical solution does not contain abrasive grains.

[0059] <Coarse particles> The chemical solution may contain coarse particles, but the content thereof is preferably low. Coarse particles refer to particles having a diameter (particle size) of 1 μm or more when the particle shape is considered to be a sphere. The coarse particles contained in the chemical solution include particles such as dust, dirt, organic solids, and inorganic solids contained as impurities in the raw material, as well as particles such as dust, dirt, organic solids, and inorganic solids brought in as contaminants during the preparation of the chemical solution, and which ultimately exist as particles without dissolving in the chemical solution.

[0060] The content of coarse particles in the chemical solution is preferably 100 or less, more preferably 50 or less, particles with a particle size of 1 μm or more per mL of the chemical solution. The lower limit is preferably 0 or more, more preferably 0.01 or more, per mL of the chemical solution. The content of coarse particles present in the chemical solution can be measured in the liquid phase using a commercially available measuring device that uses a light scattering liquid particle measuring method with a laser as a light source.

[0061] [Method for Producing the Chemical Solution] The chemical solution of the present invention can be produced by a known method. The method for producing the chemical solution of the present invention will be described in detail below.

[0062] <Solution Preparation Step> Examples of methods for preparing the chemical solution of the present invention include a method of mixing the above-mentioned components. The order and / or timing of mixing the above-mentioned components are not particularly limited, and examples include a method of sequentially adding a fluoride ion source, an oxidizing agent, a heterocyclic compound, and, if necessary, optional components to a container containing a solvent, and then stirring to mix. Alternatively, the solution may be prepared by adjusting the pH of the mixed solution by adding a pH adjuster. When adding the components to a container, they may be added all at once, or may be added in multiple divided portions.

[0063] The stirring device and stirring method used to prepare the chemical solution may be a known device such as a stirrer or disperser. Examples of the stirrer include an industrial mixer, a portable stirrer, a mechanical stirrer, and a magnetic stirrer. Examples of the disperser include an industrial disperser, a homogenizer, an ultrasonic disperser, and a bead mill.

[0064] The mixing of the components in the chemical solution preparation step, the purification treatment described below, and the storage of the produced chemical solution are preferably carried out at 40° C. or lower, more preferably at 30° C. or lower. The lower limit is preferably 5° C. or higher, more preferably 10° C. or higher. By preparing, treating, and / or storing the chemical solution within the above temperature range, the performance can be maintained stably for a long period of time.

[0065] The drug solution of the present invention may be prepared as a kit in which the raw materials are divided into a plurality of parts. When the drug solution of the present invention is prepared as a kit, the raw materials may be mixed in a predetermined ratio at the time of use or before use to obtain the drug solution of the present invention. The drug solution may also be prepared as a concentrated solution. In this case, the diluted solution obtained by diluting with a dilution liquid before use is used. In other words, the kit may include the drug solution in the form of a concentrated solution and the dilution liquid.

[0066] (Purification) It is preferable to perform a purification treatment in advance on one or more of the raw materials used to prepare the chemical solution. Furthermore, if necessary, the chemical solution may be subjected to a purification treatment. The degree of purification is preferably such that the raw material has a purity of 99% by mass or more, and more preferably such that the purity of the raw solution has a purity of 99.9% by mass or more. The upper limit is preferably 99.9999% by mass or less.

[0067] Examples of purification methods include passing the raw material through an ion exchange resin or a reverse osmosis membrane (RO) membrane, reprecipitation, distillation of the raw material, and filtering. Any filter conventionally used for filtration can be used without particular limitation. Examples of materials constituting the filter include filters made of fluororesins such as polytetrafluoroethylene (PTFE) and tetrafluoroethylene perfluoroalkyl vinyl ether copolymer (PFA), polyamide resins such as nylon, polyallylsulfone (PAS), and polyolefin resins (including high-density or ultra-high molecular weight) such as polyethylene and polypropylene (PP). Among these materials, materials selected from the group consisting of polyethylene, polypropylene (including high-density polypropylene), fluororesins (including PTFE and PFA), and polyamide resins (including nylon) are preferred, with fluororesin filters being more preferred. Filtering the raw material using a filter made of these materials can effectively remove highly polar foreign matter that is likely to cause defects.

[0068] The purification treatment may be carried out by combining two or more of the above purification methods, or may be carried out multiple times.

[0069] (Container) The container for containing the above-mentioned chemical solution, concentrated solution, or kit is not particularly limited, and any known container can be used as long as corrosiveness by the liquid is not a problem. Specific examples of the container include the "Clean Bottle" series manufactured by Aicello Chemical Co., Ltd. and the "Pure Bottle" manufactured by Kodama Resin Industry Co., Ltd. In addition, for the purpose of preventing impurities from being mixed (contaminated) into the raw materials and chemical solution, it is also preferable to use a multilayer container whose inner wall has a six-layer structure made of six types of resin, or a multilayer container whose inner wall has a seven-layer structure made of six types of resin. Examples of such containers include, but are not limited to, the containers described in JP 2015-123351 A. In addition, the containers exemplified in paragraphs

[0121] to

[0124] of WO 2022 / 004217 can also be used as containers, and the contents of these containers are incorporated herein by reference.

[0070] The interior of these containers is preferably washed before filling with the chemical solution. The liquid used for washing is preferably one that has a reduced amount of metal impurities. After production, the chemical solution may be bottled in a container such as a gallon bottle or a coated bottle, and then transported and stored.

[0071] To prevent changes in the components of the drug solution during storage, the inside of the container may be purged with an inert gas (such as nitrogen or argon) with a purity of 99.99995% by volume or higher. A gas with a low moisture content is particularly preferred. During transportation and storage, the drug solution may be stored at room temperature, or the temperature may be controlled within the range of -20°C to 20°C to prevent deterioration.

[0072] The method for producing the chemical solution may further include a static elimination step of eliminating static electricity from the chemical solution.

[0073] [Uses] The chemical solution of the present invention is used for treating semiconductor substrates. More specifically, it is preferably used for semiconductor devices. "For semiconductor devices" means that it is used during the manufacture of semiconductor devices. The chemical solution can be used in the manufacturing process of semiconductor devices, and can be used to treat, for example, SiGe-containing materials, Si-containing materials, insulating films, resist films, anti-reflective films, etching residues, and ashing residues (hereinafter simply referred to as "residues") present on a substrate. The chemical solution may also be used to treat semiconductor substrates after chemical mechanical polishing. The chemical solution of the present invention can be suitably used as a liquid (etchant) for removing at least a portion of the SiGe-containing materials from a workpiece containing SiGe-containing materials and Si-containing materials.

[0074] [Workpiece] The workpiece to be treated with the chemical solution of the present invention is a workpiece containing SiGe-containing materials and Si-containing materials. By using the chemical solution of the present invention on the workpiece, at least a portion of the SiGe-containing materials can be selectively removed relative to the Si-containing materials.

[0075] The workpiece is not particularly limited as long as it contains SiGe-containing and Si-containing materials. Typically, the SiGe-containing and Si-containing materials are disposed on a substrate. In this specification, "on a substrate" refers to the front, back, side, and grooves of the substrate. Furthermore, "a predetermined material is disposed on a substrate" refers to both a predetermined material being directly present on the surface of the substrate and a predetermined material being present on the substrate via another layer. Furthermore, "SiGe-containing and Si-containing materials are disposed on a substrate" refers to any form of presence of the SiGe-containing and Si-containing materials as long as they are present simultaneously on the substrate. For example, the SiGe-containing and Si-containing materials may be in contact with each other, or may be in contact with each other via another layer or member. Alternatively, the Si-containing and SiGe-containing materials may be present on the same substrate but not in contact with each other. The SiGe-containing and Si-containing materials on the substrate may be in the form of a film, wiring, plate, column, or particle. When the SiGe-containing and Si-containing materials are in the form of a film, their thickness is not particularly limited, and may be, for example, 1 to 50 nm. The SiGe-containing material and the Si-containing material may be disposed on only one or both of the principal surfaces of the substrate, or may be disposed over the entire principal surface of the substrate or over a portion of the principal surface of the substrate.

[0076] The workpiece may have a Si-containing material and two SiGe-containing materials with different Ge concentrations. In other words, the SiGe-containing material in the workpiece may include two SiGe-containing materials with different Ge concentrations. By using the chemical solution of the present invention on a workpiece having a Si-containing material and two SiGe-containing materials with different Ge concentrations, it is possible to selectively remove at least a portion of the SiGe-containing material with a high Ge concentration relative to the SiGe-containing material with a low Ge concentration. In the two SiGe-containing materials with different Ge concentrations, the content of the Ge element (Ge / (Si+Ge)) relative to the total content of the Si element and the Ge element in the SiGe-containing material with a high Ge concentration is preferably 25 to 60 atomic %, more preferably 35 to 50 atomic %. Furthermore, the content of the Ge element (Ge / (Si+Ge)) relative to the total content of the Si element and the Ge element in the SiGe-containing material with a low Ge concentration is preferably 5 to 35 atomic %, more preferably 10 to 30 atomic %. The difference between the Ge element content in the SiGe-containing material with a high Ge concentration and the Ge element content in the SiGe-containing material with a low Ge concentration is preferably 5 atomic % or more, more preferably 10 atomic % or more. The workpiece may have three or more SiGe-containing materials with different Ge concentrations.

[0077] The size, thickness, shape, and layer structure of the substrate are not particularly limited and can be appropriately selected as desired. The substrate may be either a single layer or a multilayer. Examples of the substrate include metal substrates, semiconductor substrates, conductive substrates other than metal, metal oxide substrates, glass substrates, and resin substrates, with semiconductor substrates being preferred. Examples of semiconductor substrates include semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for plasma displays, substrates for FEDs (Field Emission Displays), substrates for optical disks, substrates for magnetic disks, and substrates for magneto-optical disks. Examples of materials constituting the semiconductor substrate include silicon, germanium, and III-V group compounds such as GaAs, as well as combinations thereof.

[0078] The form of the workpiece may be, for example, a workpiece 200 including a substrate 202 and SiGe-containing materials 204 and Si-containing materials 206 alternately stacked on the substrate 202, as shown in FIG. 1 . While FIG. 1 illustrates an embodiment in which the workpiece 200 includes a plurality of SiGe-containing materials 204 and Si-containing materials 206, only one layer of either or both of the plurality of SiGe-containing materials 204 and the plurality of Si-containing materials 206 may be present. Although FIG. 1 illustrates portions on the substrate 202 in which neither the SiGe-containing materials 204 nor the Si-containing materials 206 are present, such portions may be covered with the SiGe-containing materials 204. While FIG. 1 illustrates the SiGe-containing materials 204 directly disposed on the substrate 202, they may be disposed via another layer. The Si-containing materials 206 may be supported by another material (not shown). Furthermore, the plurality of Si-containing materials 206 may each be in a different layer. Additionally, the plurality of SiGe-containing layers 204 may be layers of different compositions (eg, layers having different Ge concentrations).

[0079] The workpiece may include, in addition to the SiGe-containing and Si-containing materials, other layers and / or structures as desired. For example, the substrate may include one or more components selected from the group consisting of metal wiring, a metal hard mask, a gate electrode, a source electrode, a drain electrode, an insulating layer, a ferromagnetic layer, and a non-magnetic layer. The substrate may include an exposed integrated circuit structure. The integrated circuit structure may include, for example, interconnect mechanisms such as metal wiring and dielectric materials. Examples of metals and alloys used in the interconnect mechanisms include aluminum, copper-aluminum alloys, copper, nickel, nickel silicide, cobalt, cobalt silicide, ruthenium, platinum, gold, titanium, tantalum, tungsten, titanium nitride, and tantalum nitride. The substrate may include one or more layers of a material selected from the group consisting of silicon oxide, silicon nitride, silicon carbide, and carbon-doped silicon oxide.

[0080] The method for manufacturing the workpiece is not particularly limited. For example, the workpiece may be manufactured by forming an insulating film on a substrate, disposing a SiGe-containing material and / or a Si-containing material on the insulating film by a method such as a sputtering method, a chemical vapor deposition (CVD) method, or a molecular beam epitaxy (MBE) method, and then performing a planarization process such as CMP.

[0081] Examples of applications of the object to be treated include DRAM (Dynamic Random Access Memory), FRAM (registered trademark) (Ferroelectric Random Access Memory), MRAM (Magnetoresistive Random Access Memory), PRAM (Phase Change Random Access Memory), logic circuits, and processors. Among these, the object to be treated is preferably one used for manufacturing semiconductor elements. In other words, the chemical solution is preferably used in a process for manufacturing semiconductor elements. As an element obtained by applying a chemical solution to a workpiece, a field effect transistor (FET) is preferred, and a gate-all-around-FET (GAA-FET) is more preferred. That is, the workpiece is preferably one obtained during the manufacturing process of a GAA-FET.

[0082] [Method for Treating a Workpiece] A method for treating a workpiece using the chemical solution of the present invention can be a method of contacting the workpiece with the chemical solution of the present invention. By contacting the workpiece with the chemical solution, SiGe-containing materials in the workpiece are selectively removed (etched). Furthermore, when the workpiece has two SiGe-containing materials and a Si-containing material with different Ge concentrations, by appropriately adjusting the composition of the chemical solution, SiGe-containing materials with a high Ge concentration in the workpiece can also be selectively removed (etched).

[0083] Methods for contacting the workpiece with the chemical solution include, for example, immersing the workpiece in the chemical solution contained in a tank, spraying the chemical solution onto the workpiece, flowing the chemical solution over the workpiece, and combinations of these methods, and the method of immersing the workpiece in the chemical solution is preferred.

[0084] Furthermore, in order to further increase the treatment speed with the chemical solution, a mechanical stirring method may be used, such as a method of circulating the chemical solution above the workpiece, a method of passing or spraying the chemical solution above the workpiece, or a method of stirring the chemical solution by ultrasonic waves or megasonics.

[0085] The treatment time using the chemical solution can be adjusted as appropriate. The treatment time (contact time between the chemical solution and the object to be treated) is preferably 0.5 to 60 minutes, more preferably 1 to 20 minutes. The temperature of the chemical solution during treatment is preferably 10 to 100°C, more preferably 15 to 60°C.

[0086] When processing the workpiece, only a portion or all of the SiGe inclusions in the workpiece may be removed. Furthermore, a portion of the Si inclusions in the workpiece may be intentionally or unavoidably removed. The workpiece 200 shown in FIG. 2 is one form of the workpiece 200 shown in FIG. 1 after being processed by this processing method. In this case, the dissolution rate of the Si inclusions 206 is sufficiently lower than that of the SiGe inclusions 204, and a portion of the SiGe inclusions 204 is dissolved from the side, forming a recess.

[0087] The present processing method may include a rinsing step in which the object to be processed is rinsed with a rinsing liquid, as needed. For example, after the object to be processed is brought into contact with the chemical solution, a rinsing step may be further performed. Examples of the rinse liquid include water, hydrofluoric acid (preferably 0.001 to 1 mass% hydrofluoric acid), hydrochloric acid (preferably 0.001 to 1 mass% hydrochloric acid), hydrogen peroxide solution (preferably 0.5 to 31 mass% hydrogen peroxide solution, more preferably 3 to 15 mass% hydrogen peroxide solution), a mixture of hydrofluoric acid and hydrogen peroxide solution (FPM), a mixture of sulfuric acid and hydrogen peroxide solution (SPM), a mixture of ammonia water and hydrogen peroxide solution (APM), a mixture of ammonium hydroxide, hydrogen peroxide and water (SC-1), a mixture of hydrochloric acid and hydrogen peroxide solution (HPM), carbon dioxide water (preferably 10 to 60 mass ppm carbon dioxide water), ozone water (preferably 10 to 60 mass ppm ozone water), hydrogen water (preferably 10 to 20 mass ppm hydrogen water), a citric acid solution (preferably 0.01 to 10 mass% citric acid solution), sulfuric acid (preferably 1 to 10 % by mass aqueous sulfuric acid), ammonia water (preferably 0.01 to 10% by mass aqueous ammonia), isopropyl alcohol (IPA), hypochlorous acid aqueous solution (preferably 1 to 10% by mass aqueous hypochlorous acid), aqua regia (preferably aqua regia corresponding to a volume ratio of "37% by mass hydrochloric acid:60% by mass nitric acid" of "2.6:1.4" to "3.4:0.6"), ultrapure water, nitric acid (preferably 0.001 to 1% by mass nitric acid), perchloric acid (preferably 0.001 to 1% by mass perchloric acid), oxalic acid aqueous solution (preferably 0.01 to 10% by mass aqueous oxalic acid), acetic acid (preferably 0.01 to 10% by mass aqueous acetic acid or acetic acid stock solution), or periodic acid aqueous solution (preferably 0.5 to 10% by mass aqueous periodic acid. Examples of periodic acid include orthoperiodic acid and metaperiodic acid). Hydrofluoric acid, nitric acid, perchloric acid, and hydrochloric acid are referred to as HF, HNO ３ , HClO ４ HCl and ozone water are intended to be aqueous solutions in which ozone, carbon dioxide, and hydrogen ... ３ , CO ２ , and H ２ In the present invention, an aqueous solution of

[0088] The rinse treatment may be carried out by contacting the workpiece with a rinse liquid. The above-described method of contacting the workpiece with a chemical liquid may also be applied as the method of contacting the workpiece with the rinse liquid.

[0089] The rinsing step may be followed by a drying step, if necessary. The drying method is not particularly limited, and examples thereof include spin drying, flowing a dry gas over the substrate, heating the substrate with a heating means such as a hot plate or an infrared lamp, IPA (isopropyl alcohol) vapor drying, Marangoni drying, Rotagoni drying, and combinations thereof.

[0090] [Method for Manufacturing a Semiconductor Device] The method for processing a workpiece described above can be suitably applied to a method for manufacturing a semiconductor device. The method may be performed before or after other processes performed on the substrate. The cleaning method may be incorporated into other processes, or the cleaning method may be incorporated into other processes. Examples of other processes include processes for forming structures such as metal wiring, gate structures, source structures, drain structures, insulating films, ferromagnetic layers, and non-magnetic layers (e.g., layer formation, etching, chemical mechanical polishing, and modification), resist formation processes, exposure processes, removal processes, heat treatment processes, cleaning processes, and inspection processes.

[0091] The above processing method may be performed at any stage of a back end process (BEOL: Back end of the line), a middle process (MOL: Middle of the line), or a front end process (FEOL: Front end of the line), and is preferably performed in a front end process or a middle process.

[0092] The present invention will be described in more detail below with reference to the following examples. The materials, amounts used, ratios, treatment details, and treatment procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples. Furthermore, all of the components used in the examples and comparative examples were classified as semiconductor grade or equivalent high purity grade.

[0093] [Preparation of Chemical Solutions] The components (fluoride ion source, oxidizing agent, solvent, heterocyclic compound, and other optional components) shown in the table below were mixed so that the content of each component was the value shown in the table below, to prepare chemical solutions for each of the Examples and Comparative Examples. The components used in preparing the chemical solutions are as follows.

[0094] [Heterocyclic compounds] 1,2,4-triazole, imidazole, pyrazole, 3-amino-1H-1,2,4-triazole, pyridine-2-carboxylic acid

[0095] [Other ingredients] HF (hydrogen fluoride, fluoride ion source) Periodic acid (oxidizing agent, standard redox potential 1.6 V) Hydrogen peroxide (oxidizing agent, standard redox potential 1.8 V) Acetic acid (solvent) Propionic acid (solvent) Formic acid (solvent) EGBE (ethylene glycol monobutyl ether, solvent) Sulfuric acid (acidic compound)

[0096] [Evaluation] According to the procedure described below, the solubility of each chemical solution was measured for a SiGe-containing material with a high Ge concentration, a SiGe-containing material with a low Ge concentration, and a Si-containing material, and the etching selectivity was evaluated.

[0097] A substrate on which a SiGe-containing material with a high Ge concentration (SiGe40, Si / Ge = 60 / 40 (element ratio)) was laminated to a thickness of 20 nm, a substrate on which a SiGe-containing material with a low Ge concentration (SiGe25, Si / Ge = 75 / 25 (element ratio)) was laminated to a thickness of 30 nm, and a substrate on which a Si-containing polysilicon (Si) was laminated to a thickness of 100 nm were prepared. These substrates were each cut into 2 x 2 cm squares to prepare test specimens. The SiGe40 test specimen was immersed in the chemical solution (25°C) of the example or comparative example for 5 seconds. The SiGe25 test specimen was immersed in the chemical solution (25°C) of the example or comparative example for 20 seconds. The Si test specimen was immersed in the chemical solution (25°C) of the example or comparative example for 2 minutes. Before and after the immersion, the film thicknesses of SiGe40, SiGe25, and Si were measured using an optical film thickness meter, Ellipsometer M-2000 (manufactured by JA Woollam). From the measured change in film thickness before and after immersion, the dissolution rate (Å / min) of each film when using each chemical solution was calculated. From the calculated dissolution rate of each film, the solubility and etching selectivity of each chemical solution for each film were evaluated based on the following evaluation criteria.

[0098] (Etching property of SiGe 40) H: Dissolution rate is 800 Å / min or more M: Dissolution rate is 300 Å / min or more and less than 800 Å / min L: Dissolution rate is less than 300 Å / min

[0099] (SiGe25 Etching Properties) H: Dissolution rate is 500 Å / min or more M: Dissolution rate is 100 Å / min or more and less than 500 Å / min L: Dissolution rate is less than 100 Å / min

[0100] (Si etching ability) H: Dissolution rate is 20 Å / min or more M: Dissolution rate is 6 Å / min or more and less than 20 Å / min L: Dissolution rate is less than 6 Å / min

[0101] (Etching selectivity of SiGe 40 relative to Si) H: The ratio of the dissolution rate of SiGe 40 to the dissolution rate of Si is 180 or more M: The ratio of the dissolution rate of SiGe 40 to the dissolution rate of Si is 20 or more and less than 180 L: The ratio of the dissolution rate of SiGe 40 to the dissolution rate of Si is less than 20 In practice, the etching selectivity of SiGe 40 relative to Si is preferably M or H, and more preferably H.

[0102] (Etching selectivity of SiGe40 relative to SiGe25) H: The ratio of the dissolution rate of SiGe40 to the dissolution rate of SiGe25 is 15 or more. M: The ratio of the dissolution rate of SiGe40 to the dissolution rate of SiGe25 is 5 or more and less than 15. L: The ratio of the dissolution rate of SiGe40 to the dissolution rate of SiGe25 is less than 5. In terms of being able to selectively remove the SiGe-containing material with a higher Ge concentration from a processed object having two SiGe-containing materials with different Ge concentrations and a Si-containing material, the etching selectivity of SiGe40 relative to SiGe25 is preferably M or H, and more preferably H.

[0103] [Results] The composition of each chemical solution and the evaluation results are shown in the table below. In the table below, the "SiGe40 / SiGe25" column shows the evaluation results of etching selectivity of SiGe40 relative to SiGe25, and the "SiGe40 / Si" column shows the evaluation results of etching selectivity of SiGe40 relative to Si. In the table below, when a chemical solution contains multiple water-soluble organic solvents, for example, the description "A+B" in the type column and "a+b" in the content column means that the chemical solution contains a mass % of solvent A and b mass % of solvent B. In the table below, the columns "δD", "δP", and "δH" represent the dispersion term, polar term, and hydrogen bond term of the Hansen solubility parameter of the solvent, respectively, and are expressed in units of MPa. １／２ Table 2 is a continuation of Table 1. For example, the chemical solution of Example 12 contains 0.41 mass % of HF, 3 mass % of hydrogen peroxide, 1 mass % of 1,2,4-triazole, 70 mass % of acetic acid, and 1 mass % of sulfuric acid, with the remainder being water.

[0104]

[0105]

[0106] From the above table, it was confirmed that the chemical solution of the present invention can selectively remove SiGe-containing materials from a processing object having SiGe-containing materials and Si-containing materials.

[0107] From a comparison of Examples 2-3 and 5-6, the polarity term δP of the Hansen solubility parameter of the solvent is 11 MPa. １／２ It was confirmed that the effects of the present invention and the selective solubility of high Ge-concentration SiGe were better when the content of the heterocyclic compound was 0.5 mass% or more, relative to the total mass of the chemical solution. A comparison of Examples 2 and 7 confirmed that the effects of the present invention and the selective solubility of high Ge-concentration SiGe were better when the content of the water-soluble organic solvent was less than 90 mass%, relative to the total mass of the chemical solution. A comparison of Examples 3 and 8 to 11 confirmed that the selective solubility of high Ge-concentration SiGe was better when the heterocyclic compound was an azole compound, and that the effects of the present invention were better when the heterocyclic compound was 1,2,4-triazole. A comparison of Example 12 and Example 2 confirmed that the effects of the present invention and the selective solubility of high Ge-concentration SiGe were better when the oxidizing agent was periodic acid.

[0108] A test specimen containing both a SiGe40 layer and a Si layer was prepared, and the test specimen was immersed in the chemical solution (25°C) of the example or comparative example. The ratio of the dissolution rates of SiGe40 and Si was calculated according to the method described above. Results equivalent to those shown in the table above were obtained.

[0109] 200 Processed object 202 Substrate 204 SiGe-containing material 206 Si-containing material

Claims

1. A chemical solution used on a silicon-germanium-containing material and a workpiece having a silicon-containing material, for removing at least a portion of the silicon-germanium-containing material, the chemical solution comprising: a fluoride ion source; an oxidizing agent; a heterocyclic compound; and a solvent.

2. The pharmaceutical solution according to claim 1, wherein the heterocyclic compound is a nitrogen-containing heterocyclic compound.

3. The chemical solution according to claim 1 or 2, wherein the solvent comprises a water-soluble organic solvent.

4. The polarity term δP of the Hansen solubility parameter of the solvent is 11 MPa １／２ The drug solution according to claim 1 or 2, wherein:

5. The chemical solution according to claim 3, wherein the content of the water-soluble organic solvent is less than 90% by mass based on the total mass of the chemical solution.

6. The chemical solution according to claim 3, wherein the water-soluble organic solvent is selected from the group consisting of alcohol-based solvents, carboxylic acid-based solvents, ether-based solvents, and sulfoxide-based solvents.

7. The chemical solution according to claim 6, wherein the water-soluble organic solvent is a carboxylic acid solvent.

8. The medicinal solution according to claim 1 or 2, wherein the heterocyclic compound is an azole or a derivative thereof.

9. The medicinal solution according to claim 8, wherein the azole or its derivative is a triazole or its derivative.

10. The medicinal solution according to claim 8, wherein the azole or derivative thereof is 1,2,4-triazole.

11. The chemical solution according to claim 1 or 2, wherein the content of the heterocyclic compound is 0.5 mass % or more based on the total mass of the chemical solution.

12. The chemical solution according to claim 1 or 2, wherein the oxidizing agent has a standard oxidation-reduction potential of 1.3 V or higher.

13. The chemical solution according to claim 1 or 2, wherein the oxidizing agent is periodic acid.

14. The chemical solution according to claim 1 or 2, which is used on a workpiece having two silicon-germanium-containing materials with different germanium concentrations and a silicon-containing material, and which removes at least a portion of the silicon-germanium-containing material with a higher germanium concentration.

15. A method for treating a workpiece, comprising contacting a silicon-germanium-containing material and a workpiece having a silicon-containing material with the chemical solution according to claim 1 or 2, and removing at least a portion of the silicon-germanium-containing material.

16. A method for manufacturing a semiconductor device, comprising the method for processing an object according to claim 15.

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