Chemical liquid, method for treating object to be treated, and method for producing semiconductor device

Abstract

The present invention provides a chemical liquid: which has a high etching rate ratio for SiGe over an Si-containing substance when applied to an object to be treated that contains SiGe and an Si-containing substance other than SiGe; and which is unlikely to leave a residue on the Si-containing substance following application. The present invention also provides: a method for treating an object to be treated; and a method for producing a semiconductor device. The chemical liquid according to the present invention is applied to an object to be treated that contains SiGe and an Si-containing substance other than SiGe and removes at least a part of the SiGe contained in the object to be treated. The chemical liquid contains: a polymer containing a first repeating unit having at least one group selected from the group consisting of a primary amino group or a salt thereof, a secondary amino group or a salt thereof, a tertiary amino group or a salt thereof and a quaternary ammonium group and a second repeating unit selected from the group consisting of a repeating unit having an acid group and a repeating unit represented by -SO2-; a fluoride ion source; and an oxidizing agent.

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 etching, cleaning, and other processes using processing liquids during semiconductor device manufacturing processes. For example, Patent Document 1 discloses a "processing liquid containing a fluoride ion source, an oxidizing agent, and a predetermined additive" as a processing liquid that can improve the smoothness of a processed surface when etching SiGe (silicon germanium).

[0003] International Publication No. 2021 / 176913

[0004] The present inventors applied the processing solution described in Patent Document 1 to a workpiece containing SiGe and a Si-containing material other than SiGe in an attempt to selectively dissolve the SiGe. However, although selective dissolution of SiGe was possible, residues were likely to remain on the Si-containing material after application of the processing solution. In other words, they found that it was difficult to simultaneously increase the etching rate ratio of SiGe to the Si-containing material and reduce the residues on the Si-containing material.

[0005] Therefore, an object of the present invention is to provide a chemical solution that, when applied to a workpiece containing SiGe and a Si-containing material other than SiGe, has a high etching rate ratio of SiGe to the Si-containing material and is less likely to leave residue on the Si-containing material after application. Another object of the present invention is to provide a method for treating a workpiece and a method for manufacturing a semiconductor device using the chemical solution.

[0006] 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.

[0007] [1] A chemical solution used for a workpiece containing SiGe and a Si-containing substance other than SiGe, for removing at least a portion of the SiGe contained in the workpiece, the chemical solution comprising a first repeating unit having at least one group selected from the group consisting of a primary amino group or a salt thereof, a secondary amino group or a salt thereof, a tertiary amino group or a salt thereof, and a quaternary ammonium group, and a repeating unit having an acid group and -SO ２ - a chemical solution comprising: a polymer containing a second repeating unit selected from the group consisting of repeating units represented by the formula (I) -; a fluoride ion source; and an oxidizing agent. [2] The chemical solution according to [1], wherein the first repeating unit is a repeating unit having at least one group selected from the group consisting of a tertiary amino group or a salt thereof, and a quaternary ammonium group. [3] The chemical solution according to [1] or [2], wherein the first repeating unit is a repeating unit having a quaternary ammonium group. [4] The chemical solution according to any one of [1] to [3], wherein the acid group is a carboxylic acid group, a sulfonic acid group, or a phosphonic acid group. [5] The chemical solution according to any one of [1] to [4], wherein the polymer has a weight-average molecular weight of 5,000 to 30,000. [6] The chemical solution according to any one of [1] to [5], wherein the oxidizing agent is a compound selected from the group consisting of peroxides, perhalogen acid compounds, and nitric acid compounds. [7] The chemical solution according to any one of [1] to [6], wherein the oxidizing agent is a compound selected from the group consisting of hydrogen peroxide, peracetic acid, periodic acid or a salt thereof, and nitric acid. [8] The chemical solution according to any one of [1] to [7], further comprising an organic acid. [9] The chemical solution according to any one of [1] to [8], further comprising an inorganic acid.

[10] A method for treating an object to be treated, comprising a step of contacting the chemical solution according to any one of [1] to [9] with an object to be treated containing SiGe and a Si-containing substance other than SiGe, and removing at least a portion of the SiGe contained in the object to be treated.

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

[10] .

[0008] According to the present invention, it is possible to provide a chemical solution that, when applied to a workpiece containing SiGe and a Si-containing material other than SiGe, has a high etching rate ratio of SiGe to the Si-containing material and is less likely to leave residue on the Si-containing material after application.Furthermore, it is also possible to provide a method for treating a workpiece and a method for manufacturing a semiconductor device using the above chemical solution.

[0009] 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.

[0010] 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.

[0011] The meaning of each description in this specification is explained below. In this specification, a numerical range expressed using "to" means a range including the numerical values ​​before and after "to" as the lower and upper limits. The compounds described in this specification may contain structural isomers, optical isomers, and isotopes, unless otherwise specified. Furthermore, the structural isomers, optical isomers, and isotopes may be contained singly or in combination of two or more types. In this specification, the bonding direction of a divalent group (e.g., -COO-) is, unless otherwise specified, when Y in a compound represented by "X-Y-Z" is -COO-, the compound may be either "X-O-CO-Z" or "X-CO-O-Z". In this specification, "total solid content" means the total content of all components contained in a composition other than solvents such as water and organic solvents. In this specification, "ppm" means "parts-per-million (10 ppm)." －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.

[0012] In this specification, "room temperature" means "25° C." Unless otherwise specified, in this specification, when a molecular weight distribution is present, the molecular weight is the weight average molecular weight determined by gel permeation chromatography (GPC) in terms of polyethylene glycol.

[0013] The components of the drug solution referred to in this specification may be ionized in the drug solution or may form a salt. In addition, in the case of a component having a plurality of groups capable of forming a salt, such as a polymer, only some or all of the groups capable of forming a salt may form a salt.

[0014] [Chemical Solution] The chemical solution of the present invention is used for a workpiece containing SiGe and a Si-containing substance other than SiGe, and removes at least a portion of the SiGe contained in the workpiece, and contains a polymer (hereinafter also referred to as a "specific polymer") described below, a fluoride ion source, and an oxidizing agent.

[0015] Although the mechanism by which the chemical solution of the present invention can solve the problems of the present invention by adopting the above-described configuration is not necessarily clear, the inventors speculate that the specific polymer contained in the chemical solution of the present invention, which includes the first repeating unit and the second repeating unit described below, is more easily adsorbed by Si-containing substances other than SiGe in the workpiece and is more easily removed from the Si-containing substances, thereby solving the problems of the present invention. Note that the above speculation does not limit the mechanism by which the effects are obtained. In other words, even if the effects are obtained by a mechanism other than the above, they are included in the scope of the present invention. Hereinafter, when the chemical solution of the present invention is applied to a workpiece containing SiGe and Si-containing substances other than SiGe (hereinafter simply referred to as the "workpiece"), at least one of the effects of a high etching rate ratio of SiGe to the Si-containing substances and a low degree of residue remaining on the Si-containing substances after application is also referred to as "excellent effects of the present invention."

[0016] The components contained in the medicinal solution of the present invention will be described in detail below.

[0017] <Specific Polymer> The chemical solution of the present invention contains a specific polymer. The specific polymer includes a first repeating unit having at least one group (hereinafter also referred to as "specific group") selected from the group consisting of a primary amino group or a salt thereof, a secondary amino group or a salt thereof, a tertiary amino group or a salt thereof, and a quaternary ammonium group, and a repeating unit having an acid group and -SO ２ The polymer comprises a second repeating unit selected from the group consisting of repeating units represented by the formula: embedded image The first repeating unit and the second repeating unit will be described in detail below.

[0018] <<First Repeating Unit>> In the first repeating unit, the primary amino group is —NH ２ The secondary amino group is, for example, a group represented by *-NHR ２ (R ２ represents a monovalent substituent. ) or a group represented by *-NH-*, and a tertiary amino group is, for example, *-NR ３ ２ (R ３ each independently represents a monovalent substituent, or *-NR ３ - is a group represented by *, and the quaternary ammonium group is a group represented by the following formula (A1) or formula (A2), where * is a linking moiety to a carbon atom.

[0019]

[0020] In formula (A1) and formula (A2), R ４ A each independently represents a monovalent substituent. － represents a monovalent anion. * represents a bonding position.

[0021] R ２ ~R ４ The monovalent substituent represented by is not particularly limited, but is preferably a hydrocarbon group which may have a substituent, more preferably an aliphatic hydrocarbon group having 1 to 8 carbon atoms which may have a substituent, and even more preferably an alkyl group having 1 to 4 carbon atoms which may have a substituent. ３ may be the same or different, and multiple R ４ may be the same or different. －Examples of the cations include halogen ions (e.g., Cl － ), sulfate ion, nitrate ion, acetate ion, methyl sulfate ion, ethyl sulfate ion, and hydroxide ion.

[0022] Examples of the salt include salts formed between a primary amino group, a secondary amino group, or a tertiary amino group (hereinafter simply referred to as "amino group") and an acidic compound. In the specific polymer, some of the amino groups may form salts (some of the amino groups may be free), or all of them may form salts. The acidic compound may be either an inorganic acid or an organic acid. Examples of the acidic compound include hydrochloric acid, sulfuric acid, sulfurous acid, phosphoric acid, nitric acid, hydrobromic acid, amidosulfuric acid, acetic acid, propionic acid, methanesulfonic acid, ethanesulfonic acid, allylglycine, maleic acid, citraconic acid, fumaric acid, and itaconic acid. Preferred salts include hydrochloride, hydrobromide, acetate, sulfate, nitrate, sulfite, phosphate, amidosulfate, and methanesulfonate, and more preferred are hydrochloride, hydrobromide, and acetate.

[0023] In terms of achieving better effects of the present invention, the first repeating unit is preferably a repeating unit having at least one group selected from the group consisting of a tertiary amino group or a salt thereof and a quaternary ammonium group, and more preferably a repeating unit having a quaternary ammonium group. The number of specific groups contained in the first repeating unit is not particularly limited, but is preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 or 2.

[0024] Examples of monomers from which the first repeating unit is derived include diallylamine, alkyl diallylamine such as methyl diallylamine, dialkyl diallyl ammonium salts such as dimethyl diallyl ammonium salts (halide salts, hydroxide salts, nitrate salts, sulfate salts, etc.), allylamine, vinylamine, vinylpyrrolidone, acrylamide, hexadimethrine salts (halide salts, hydroxide salts, nitrate salts, sulfate salts, etc.), 4-vinylpyridine, ornithine, lysine, arginine, histidine, and vinylimidazole. Alternatively, a repeating unit consisting of dimethylamine and epihalohydrin (preferably epichlorohydrin) may be used as the first repeating unit.

[0025] The first repeating unit is preferably a repeating unit represented by general formula (1-a) or a repeating unit represented by general formula (1-b).

[0026]

[0027] In general formula (1-a), L １ａ and L ２ａ each independently represents a single bond or a methylene group. １ａ is a single bond, L ２ａ is a methylene group, and L １ａ is a methylene group, L ２ａ is a single bond. １ａ is preferably a single bond, and L ２ａ is preferably a methylene group.

[0028] In the general formula (1-a), X represents a group represented by the formula (X1) or a group represented by the formula (X2). * represents a bonding position. In the formulas (X1) and (X2), R １ａrepresents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may have a hydroxyl group, or an aralkyl group having 7 to 10 carbon atoms. The alkyl group having 1 to 10 carbon atoms which may have a hydroxyl group may be linear, branched, or cyclic, and examples thereof include alkyl groups having 1 to 4 carbon atoms which may have a hydroxyl group, of which methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 2-hydroxybutyl, 3-hydroxybutyl, 4-hydroxybutyl, or cyclohexyl groups are preferred. Examples of aralkyl groups having 7 to 10 carbon atoms include benzyl, methylbenzyl, naphthylmethyl, and phenethyl groups. R １ａ Among these, a hydrogen atom, a methyl group, an ethyl group, or a benzyl group is preferable as the aryl group.

[0029] D － represents a monovalent anion. － Examples of the monovalent anion represented by the formula (I) include a halide ion (e.g., a chloride ion), a sulfate ion, a nitrate ion, an acetate ion, a methyl sulfate ion, an ethyl sulfate ion, a sulfamate ion, and a hydroxide ion.

[0030] In general formula (1-b), L １ｂ and L ２ｂ each independently represents a single bond or a methylene group. １ｂ is a single bond, L ２ｂ is a methylene group, and L １ｂ is a methylene group, L ２ｂ is a single bond. １ｂ is preferably a single bond, and L ２ｂ is preferably a methylene group.

[0031] In general formula (1-b), R １ｂ and R ２ｂ each independently represents an alkyl group having 1 to 10 carbon atoms which may have a hydroxyl group, or an aralkyl group having 7 to 10 carbon atoms. Specific examples and preferred embodiments of the alkyl group having 1 to 10 carbon atoms which may have a hydroxyl group and the aralkyl group having 7 to 10 carbon atoms are１ａ These are the same as the specific examples and preferred embodiments of the alkyl group having 1 to 10 carbon atoms and the aralkyl group having 7 to 10 carbon atoms which may have a hydroxyl group, represented by the following formula:

[0032] In general formula (1-b), D － represents a monovalent anion. － Examples of the monovalent anion represented by the formula (1-a) include D － Examples of the monovalent anion include the ions exemplified above.

[0033] In general formula (1-b), R １ｂ , R ２ｂ and D － Examples of the combination of D are shown in Examples 1 to 5 below, and among them, Examples 1, 5, and 6 are preferred. － The chloride ion represented by the formula (I) may be replaced by an anion selected from bromide ion, iodide ion, methyl sulfate ion and ethyl sulfate ion.

[0034] Example 1: R １ｂ =R ２ｂ = methyl group, D － = chloride ion Example 2: R １ｂ =R ２ｂ = ethyl group, D － = chloride ion Example 3: R １ｂ =R ２ｂ = propyl group, D － = chloride ion Example 4: R １ｂ =R ２ｂ = butyl group, D － = chloride ion Example 5: R １ｂ = ethyl group, R ２ｂ = benzyl group, D － = chloride ion Example 6: R １ｂ = methyl group, R ２ｂ = ethyl group, D － = Ethyl sulfate ion

[0035] The first repeating unit may be a repeating unit represented by general formula (1-c).

[0036]

[0037] In the general formula (1-c), Y represents a group represented by formula (Y1) or a group represented by formula (Y2). * represents a bonding position. １ｃ and R ２ｃ each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may have a hydroxyl group, or an aralkyl group having 7 to 10 carbon atoms. Specific examples and preferred embodiments of the alkyl group having 1 to 10 carbon atoms which may have a hydroxyl group and the aralkyl group having 7 to 10 carbon atoms are １ａ These are the same as the specific examples and preferred embodiments of the alkyl group having 1 to 10 carbon atoms and the aralkyl group having 7 to 10 carbon atoms which may have a hydroxyl group, represented by the following formula: － represents a monovalent anion. － Examples of the monovalent anion represented by the formula (1-a) include D － Examples of the monovalent anion include the ions exemplified above.

[0038] The first repeating unit may have an acid group, but preferably does not have an acid group. When a repeating unit has a specific group and an acid group, the repeating unit is considered to be the first repeating unit.

[0039] The specific polymer may have only one type of first repeating unit, or may have two or more types. The content of the first repeating unit in the specific polymer is preferably 1 mol% or more, more preferably 10 mol% or more, even more preferably 25 mol% or more, and particularly preferably 50 mol% or more, based on the total repeating units of the specific polymer. The upper limit of the content of the first repeating unit is not particularly limited, but is preferably 99 mol% or less, more preferably 95 mol% or less, even more preferably 90 mol% or less, and particularly preferably 80 mol% or less, based on the total repeating units of the specific polymer. When the specific polymer has two or more types of first repeating units, it is preferable that the total content is within the above range.

[0040] <<Second Repeating Unit>> The acid group contained in the second repeating unit is not particularly limited, but examples include a carboxylic acid group, a sulfonic acid group, a phosphonic acid group, and a phenolic hydroxy group. In terms of achieving better effects of the present invention, a carboxylic acid group, a sulfonic acid group, or a phosphonic acid group is preferred. The number of acid groups contained in the second repeating unit is not particularly limited, but is preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 or 2.

[0041] An example of the second repeating unit is a repeating unit represented by the following formula (b).

[0042]

[0043] In formula (b), R ｂ１ , R ｂ２ and R ｂ３ each independently represents a functional group having a hydrogen atom, an alkyl group, or an acid group. ｂ represents a single bond or a (k+1)-valent linking group. A represents an acid group. k represents an integer of 1 to 4. When a plurality of acid groups are present in formula (b), the plurality of acid groups may be the same or different.

[0044] The alkyl group may be linear, branched, or cyclic. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 3. Examples of the functional group having an acid group include -L in formula (b). ｂ -(A) ｋ Examples of the group include a group represented by the following formula: ｂ , A and k will be described in detail later. ｂ１ , R ｂ２ and R ｂ３ is preferably a hydrogen atom, a methyl group, an ethyl group, or a carboxy group, and more preferably a hydrogen atom, a methyl group, or a carboxy group. ｂ１ , R ｂ２ and R ｂ３ It is preferred that one of represents a hydrogen atom, a methyl group or a carboxy group, and the remaining two each represent a hydrogen atom.

[0045] L ｂThe (k+1)-valent linking group represented by the formula (I) is not particularly limited as long as it is a group having a valence corresponding to the number of A, and examples thereof include an optionally substituted di- to pentavalent aliphatic hydrocarbon group, an optionally substituted di- to pentavalent aromatic hydrocarbon group, an optionally substituted di- to pentavalent aromatic heterocyclic group, -O-, -CO-, -SO ２ -, -NR Ｌ -, -N<, and groups formed by combining these. Ｌ represents a hydrogen atom or a monovalent organic group, preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. When k is 1, the divalent linking group may be a divalent aliphatic hydrocarbon group, a divalent aromatic hydrocarbon group, a divalent aromatic heterocyclic group, -O-, -CO-, or -SO ２ -, -NR Ｌ -, and groups formed by combining these. As the divalent aliphatic hydrocarbon group, an alkylene group having 1 to 6 carbon atoms (preferably 1 to 3 carbon atoms) is preferred. L ｂ is more preferably a single bond, a methylene group, or a phenylene group.

[0046] The preferred embodiments of the acid group represented by A are as described above. k is preferably an integer of 1 to 3, and more preferably 1 or 2.

[0047] The specific polymer may have only one type of second repeating unit, or may have two or more types. The content of the second repeating unit in the specific polymer is preferably 0.1 mol% or more, more preferably 10 mol% or more, even more preferably 20 mol% or more, and particularly preferably 30 mol% or more, based on the total repeating units of the specific polymer. The upper limit of the content of the second repeating unit is not particularly limited, but is preferably 99 mol% or less, more preferably 90 mol% or less, even more preferably 70 mol% or less, and particularly preferably 50 mol% or less, based on the total repeating units of the specific polymer. When the specific polymer has two or more types of second repeating units, it is preferable that the total content is within the above range.

[0048] In the specific polymer, the first repeating unit and the second repeating unit may be bonded randomly (so-called random copolymer), alternately (so-called alternating copolymer), or block-like (so-called block copolymer), but it is preferable that the first repeating unit and the second repeating unit are bonded alternately or block-like. In particular, when the second repeating unit is a repeating unit having the above-mentioned acid group, it is preferable that the first repeating unit and the second repeating unit (repeating unit having an acid group) are bonded block-like, and it is preferable that the second repeating unit is -SO ２ When the repeating unit is represented by -, the first repeating unit and the second repeating unit (-SO ２ It is preferable that the repeating units represented by the formula (a) and (b) are alternately bonded to each other.

[0049] The specific polymer may have a repeating unit different from both the first repeating unit and the second repeating unit. The content of the repeating unit different from both the first repeating unit and the second repeating unit in the specific polymer is preferably 20 mol % or less, more preferably 0 to 10 mol %, and even more preferably 0 to 5 mol %, based on the total repeating units in the specific polymer. It is preferable that the specific polymer does not have a repeating unit different from both the first repeating unit and the second repeating unit.

[0050] The weight average molecular weight (Mw) of the specific polymer is not particularly limited, but is preferably from 500 to 200,000, more preferably from 800 to 100,000, still more preferably from 1,000 to 50,000, and particularly preferably from 5,000 to 30,000.

[0051] The content of the specific polymer is preferably 1 ppm by mass to 10% by mass, more preferably 0.001 to 5% by mass, and even more preferably 0.01 to 3% by mass, relative to the total mass of the chemical solution. Only one type of specific polymer may be used, or two or more types may be used. When two or more types of specific polymers are used, it is preferable that the total amount thereof is within the above range.

[0052] <Fluoride Ion Source> The chemical solution of the present invention contains a fluoride ion source. The fluoride ion source is an ion containing fluorine atoms (F － and / or HF ２ － Fluoride ion sources include, for example, hydrofluoric acid (HF), ammonium fluoride (NH ４ F), fluoroborate (KBF ４ , N.H. ４ BF ４ etc.), fluoroboric acid, tetrabutylammonium tetrafluoroborate, aluminum hexafluoride, sodium fluoride, potassium fluoride, AlF ２ , LiF ４ , CaF ３ , NaHF ６ , N.H. ４ HF ２ , K.H.F. ２ , H ２ SiF ６ , and R １ｆ NR ２ｆ R ３ｆ R ４ｆ Examples of the compounds represented by the above R １ｆ NR ２ｆ R ３ｆ R ４ｆ F middle, R １ｆ , R ２ｆ , R ３ｆ and R ４ｆ R each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. １ｆ , R ２ｆ , R ３ｆ and R ４ｆ The total number of carbon atoms contained in R is preferably 1 to 12. １ｆ NR ２ｆ R ３ｆ R ４ｆ Examples of compounds represented by F include tetramethylammonium fluoride, tetraethylammonium fluoride, methyltriethylammonium fluoride, and tetrabutylammonium fluoride. The fluoride ion source is preferably hydrofluoric acid or ammonium fluoride.

[0053] The content of the fluoride ion source is not particularly limited, but is preferably 0.001 to 10 mass %, more preferably 0.01 to 5 mass %, and even more preferably 0.1 to 3 mass %, relative to the total mass of the chemical solution. Only one type of fluoride ion source may be used, or two or more types may be used. When two or more types of fluoride ion sources are used, the total amount thereof is preferably within the above range.

[0054] <Oxidizing Agent> The chemical solution of the present invention contains an oxidizing agent. Examples of oxidizing agents include peroxides, perhalogen acid compounds (such as periodic acid and its salts), oxide halides (such as iodic acid and its salts), nitric acid compounds, persulfides (such as monopersulfides and dipersulfides), and percarbonates. In terms of achieving superior effects of the present invention, compounds selected from the group consisting of peroxides, perhalogen acid compounds, and nitric acid compounds are preferred. The peroxide is a compound containing one or more peroxy groups (—O—O—) and may be a peroxyacid (such as peracetic acid, perbenzoic acid, and salts thereof). Other examples of oxidizing agents include perborate, perborate salts, permanganate salts, cerium compounds, and ferricyanides (such as potassium ferricyanide).

[0055] More specific examples of the oxidizing agent include hydrogen peroxide, peracetic acid, periodic acid, potassium iodate, potassium permanganate, ammonium persulfate, ammonium molybdate, nitric acid, ferric nitrate, potassium nitrate, and urea-hydrogen peroxide adduct. Of these, the oxidizing agent is preferably a compound selected from the group consisting of hydrogen peroxide, peracetic acid, periodic acid or a salt thereof, and nitric acid.

[0056] The content of the oxidizing agent is not particularly limited, but is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 5% by mass or more, relative to the total mass of the chemical solution. The upper limit of the content is preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less, and particularly preferably less than 10% by mass, relative to the total mass of the chemical solution. Only one type of oxidizing agent may be used, or two or more types may be used. When two or more types of oxidizing agents are used, it is preferable that the total amount is within the above range.

[0057] <Organic Acid or Inorganic Acid> The chemical solution of the present invention preferably further contains at least one of an organic acid and an inorganic acid. The organic acid and the inorganic acid may be at least one of a solvent and a pH adjuster in the chemical solution. Specific examples of organic acids and inorganic acids include at least one acid selected from the group consisting of methanesulfonic acid, trifluoromethanesulfonic acid, oxalic acid dihydrate, citric acid, tartaric acid, picolinic acid, succinic acid, acetic acid, lactic acid, sulfosuccinic acid, benzoic acid, propionic acid, formic acid, pyruvic acid, maleic acid, malonic acid, fumaric acid, malic acid, ascorbic acid, mandelic acid, heptanoic acid, butyric acid, valeric acid, glutaric acid, phthalic acid, hypophosphorous acid, salicylic acid, 5-sulfosalicylic acid, hydrochloric acid, ethanesulfonic acid, butanesulfonic acid, p-toluenesulfonic acid, dichloroacetic acid, difluoroacetic acid, monochloroacetic acid, monofluoroacetic acid, trichloroacetic acid, trifluoroacetic acid, hydrobromic acid, sulfuric acid, and etidronic acid. The organic acids and inorganic acids may also be salts. Examples of salts of organic acids and inorganic acids include ammonium acetate, sodium acetate, potassium acetate, tetraalkylammonium acetate such as tetramethylammonium acetate, phosphonium acetate, ammonium butyrate, ammonium trifluoroacetate, ammonium carbonate, ammonium chloride, ammonium sulfate, phosphoric acid, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, bis(tetramethylammonium) hydrogen phosphate, disodium hydrogen phosphate, sodium dihydrogen phosphate, dipotassium hydrogen phosphate, potassium dihydrogen phosphate, ditetraalkylammonium hydrogen phosphate, ditetraalkylammonium dihydrogen phosphate, diphosphonium hydrogen phosphate, phosphonium dihydrogen phosphate, ammonium phosphonate, tetraalkylammonium phosphonate, sodium phosphonate, potassium phosphonate, and phosphonium phosphonate. Of these, the organic acid and inorganic acid are preferably sulfuric acid or acetic acid.

[0058] The content of the organic acid and inorganic acid is not particularly limited, but is preferably 0.001 to 90 mass %, more preferably 0.01 to 80 mass %, and even more preferably 0.1 to 70 mass %, relative to the total mass of the chemical solution. Only one organic acid or inorganic acid may be used, or two or more types may be used. When two or more organic acids or inorganic acids are used, the total amount thereof is preferably within the above range.

[0059] <Organic Solvent> The chemical solution preferably contains an organic solvent. Examples of the organic solvent include alcohol-based solvents, ketone-based solvents, ester-based solvents, ether-based solvents (e.g., containing (poly)alkylene glycols substituted at both ends with alkyl groups or amino groups), sulfone-based solvents, sulfoxide-based solvents, nitrile-based solvents, and amide-based solvents. Examples of the alcohol-based solvent include alkanediols (e.g., containing alkylene glycols), alkoxyalcohols (e.g., containing glycol monoethers), saturated aliphatic monohydric alcohols, unsaturated non-aromatic monohydric alcohols, and low-molecular-weight alcohols containing a ring structure.

[0060] Examples of the organic solvent include acetic acid, ethylene glycol, propylene glycol, butyl diglycol, 1,4-butanediol, tripropylene glycol methyl ether, propylene glycol propyl ether, diethylene glycol n-butyl ether, hexyloxypropylamine, poly(oxyethylene)diamine, dimethyl sulfoxide, tetrahydrofurfuryl alcohol, glycerol, sulfolane, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monobenzyl ether, diethylene glycol dimethyl ether, diethylene glycol One or more selected from the group consisting of glycerol diethyl ether, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, polyethylene glycol monomethyl ether, diethylene glycol methyl ethyl ether, propylene glycol monomethyl ether, propylene glycol dimethyl ether, propylene glycol monobutyl ether, monopropyl ether, dipropylene glycol monomethyl ether (DPM), dipropylene glycol monoisopropyl ether, dipropylene monobutyl ether, dipropylene glycol diisopropyl ether, 1-methoxy-2-butanol, 2-methoxy-1-butanol, 2-methoxy-2-methylbutanol, 1,1-dimethoxyethane, 2-(2-butoxyethoxy)ethanol, methanol, ethanol, isopropanol, and 1-butanol are preferred, and one or more selected from the group consisting of acetic acid, propylene glycol, and sulfolane are more preferred.

[0061] The content of the organic solvent is not particularly limited, but is preferably 1 to 95 mass %, more preferably 10 to 80 mass %, and even more preferably 20 to 70 mass %, based on the total mass of the chemical solution. Only one organic solvent may be used, or two or more organic solvents may be used. When two or more organic solvents are used, the total amount thereof is preferably within the above range.

[0062] <Water> The chemical solution preferably contains water. The type of water used in the chemical solution may be any type that does not adversely affect the semiconductor substrate, and distilled water, deionized water (DI: De Ionized) water, and pure water (ultrapure water) can be used. Pure water (ultrapure water) is preferred because it contains almost no impurities and has less of an effect on the semiconductor substrate during the semiconductor substrate manufacturing process. The water content is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 10% by mass or more, relative to the total mass of the chemical solution. The upper limit of the water content is preferably 99.999% by mass or less, more preferably 99.99% by mass or less, and even more preferably 90.0% by mass or less, relative to the total mass of the chemical solution.

[0063] [Physical properties of chemical solution] <pH> The pH of the chemical solution is preferably 0.0 to 6.0, more preferably 0.1 to 4.0, and even more preferably 0.5 to 3.0. The pH of the chemical solution can be measured using a known pH meter by a method in accordance with JIS Z8802-1984. In this specification, the pH of the chemical solution is a value measured at room temperature (25°C) using an F-51 (trade name) manufactured by Horiba, Ltd.

[0064] <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 content of sodium atoms in the chemical solution is preferably 1 mass ppm or less relative to the total mass of the chemical solution. Since it is expected that even higher purity chemical solutions will be required in the manufacture of cutting-edge semiconductor devices, the content of the above metals is more preferably lower than 1 mass ppm, that is, more preferably on the order of ppb by mass or less, particularly preferably 100 mass ppb or less, and most preferably less than 10 mass ppb. The lower limit is preferably 0.

[0065] <Insoluble Particles> The chemical solution preferably contains substantially no insoluble particles. The term "insoluble particles" refers to particles of inorganic solids, organic solids, etc., that ultimately exist as particles without dissolving in the chemical solution. The term "substantially free of insoluble particles" refers to a measurement composition obtained by diluting the chemical solution 10,000 times with a solvent contained in the chemical solution, and the number of particles with a particle size of 40 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 counter devices include those manufactured by Rion Corporation and PMS. A representative example of the former is the KS-19F, and a representative example of the latter is the UltraChem 40. To measure larger coarse particles, devices such as the KS-42 series and the 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.

[0066] <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.

[0067] 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.

[0068] [Method for Producing Chemical Solution] The chemical solution can be produced by a known method, which will be described in detail below.

[0069] [Solution Preparation Step] The chemical solution can be produced, for example, by mixing the above-mentioned components. Examples of methods for preparing the chemical solution include a method in which a specific polymer, a fluoride ion source, an oxidizing agent, and, if necessary, optional components are sequentially added to a vessel containing a purified solvent, followed by stirring to mix, and, if necessary, adding a pH adjuster to adjust the pH of the mixed solution, thereby preparing the chemical solution. Furthermore, when adding each component to a vessel, they may be added all at once, or may be added in portions over multiple times.

[0070] 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.

[0071] <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 also 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.

[0072] 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. A combination of the above purification methods may be used as the purification method. Furthermore, the purification method may be performed multiple times.

[0073] <Container> The chemical solution (including the diluted chemical solution described below) can be filled into any container for storage, transportation, and use, as long as corrosiveness and other factors do not pose a problem.

[0074] As a container, a container with a high degree of cleanliness within the container for semiconductor applications and that suppresses the elution of impurities from the inner wall of the container's storage section into the chemical solution is preferred. Examples of such containers include various containers commercially available as containers for semiconductor chemical solutions, such as the "Clean Bottle" series manufactured by Aicello Chemical Co., Ltd. and the "Pure Bottle" manufactured by Kodama Resin Industry Co., Ltd., but are not limited to these. In addition, the containers exemplified in paragraphs

[0121] to

[0124] of International Publication No. 2022 / 004217 can also be used as containers, and the contents of these containers are incorporated herein.

[0075] The interior of these containers is preferably cleaned before filling with the chemical solution. The liquid used for cleaning is preferably one that has a reduced amount of metal impurities. After production, the chemical solution may be bottled in containers such as gallon bottles or quart bottles for transportation and storage.

[0076] In order 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 more. 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.

[0077] [Dilution Step] The chemical solution may be subjected to a dilution step in which the concentrated solution is diluted with a diluent such as water, and then the diluted chemical solution (diluted chemical solution) may be used to treat the object to be treated. In other words, the chemical solution may be diluted with a diluent containing water before use. Note that the concentrated solution and the diluted chemical solution are also forms of the chemical solution of the present invention as long as they satisfy the requirements of the present invention.

[0078] It is preferable to perform a purification treatment beforehand on the diluted solution used in the dilution step. It is also more preferable to perform a purification treatment on the diluted chemical solution obtained by the dilution step. Examples of the purification treatment include the ion component reduction treatment using an ion exchange resin or an RO membrane, etc., and the removal of foreign matter using filtering, which are described as purification treatments for the chemical solution above. It is preferable to perform any one of these treatments.

[0079] The dilution rate of the chemical solution in the dilution step may be adjusted as appropriate depending on the type and content of each component and the material to be treated, but the ratio of the diluted chemical solution to the chemical solution before dilution (dilution factor) is preferably 10 to 10,000 times, more preferably 10 to 1,000 times, and even more preferably 10 to 300 times in terms of mass ratio or volume ratio (volume ratio at 23°C). The dilution solution preferably contains water, and more preferably is water.

[0080] The change in pH before and after dilution (the difference between the pH of the chemical solution before dilution and the pH of the diluted chemical solution) is preferably 2.0 or less, more preferably 1.8 or less, and even more preferably 1.5 or less. The pH of the chemical solution before dilution and the pH of the diluted chemical solution are preferably in the preferred embodiments described above.

[0081] The specific method of the dilution step of diluting the chemical solution may be performed in accordance with the above-mentioned chemical solution preparation step. The stirring device and stirring method used in the dilution step may also be the same as those used in the above-mentioned chemical solution preparation step.

[0082] [Processing Method for Workpiece] The present invention also includes a processing method for a workpiece (hereinafter also simply referred to as "the processing method"). The processing method is a processing method for a workpiece, which includes a step of contacting the chemical solution of the present invention with a workpiece containing SiGe and a Si-containing substance other than SiGe, and removing (etching) at least a portion of the SiGe contained in the workpiece.

[0083] <Workpiece> SiGe is a material composed of a combination of silicon (Si) and germanium (Ge), and can preferably be used as a semiconductor material. SiGe may intentionally or unavoidably contain components other than silicon and germanium. The total content of silicon and germanium in SiGe is preferably 95 to 100 mass%, more preferably 99 to 100 mass%, and even more preferably 99.9 to 100 mass%, based on the total mass of SiGe. Furthermore, the element ratio of silicon (Si) to germanium (Ge) in SiGe (the ratio of the atom% occupied by Si atoms to the atom% occupied by Ge atoms in SiGe, Si:Ge) is preferably 99:1 to 30:70, more preferably 95:5 to 50:50, and even more preferably 85:15 to 65:35.

[0084] The Si-containing material different from SiGe is not particularly limited, but is preferably at least one material selected from the group consisting of silicon, silicon oxide, silicon nitride, silicon carbide, silicon carbonitride, silicon oxycarbide, and silicon oxycarbonitride.

[0085] Specific examples of silicon oxide include SiO ｙ (wherein y is preferably 0.5 to 2.0, more preferably 1.0 to 2.0). Examples of silicon oxycarbide include SiO ｚ C ｗ (wherein z is preferably 0.5 to 2.0, more preferably 1.0 to 2.0, and w is preferably 0.5 to 2.0, more preferably 1.0 to 2.0). ｙ and SiO ｚ C ｗThe material represented by the composition may further contain hydrogen. ｚ C ｗ Examples of the material represented by the composition include Si(OC ２ H ５ ) ４ (tetraethyl orthosilicate, TEOS).

[0086] The form of the workpiece may be, for example, a workpiece 200 including a substrate 202 and SiGe 204 and Si-containing materials other than SiGe 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 204 and a plurality of Si-containing materials other than SiGe 206, only one layer of either or both of the plurality of SiGe 204 and the plurality of Si-containing materials other than SiGe 206 may be present. Also, while FIG. 1 illustrates areas on the substrate 202 where neither SiGe 204 nor the Si-containing materials other than SiGe 206 are present, such areas may be covered with SiGe 204. While FIG. 1 illustrates the SiGe 204 being directly disposed on the substrate 202, it may be disposed via another layer. The Si-containing materials other than SiGe 206 may be supported by another material (not shown). Furthermore, the plurality of Si-containing materials 206 different from SiGe may be different layers.

[0087] The type of substrate included in the object to be treated is not particularly limited, and examples thereof include various substrates such as 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. The size, thickness, shape, layer structure, etc. of the substrate are not particularly limited and can be appropriately selected as desired.

[0088] Examples of wafers constituting semiconductor substrates include wafers made of silicon-based materials such as silicon (Si) wafers, silicon carbide (SiC) wafers, silicon-containing resin wafers (glass epoxy wafers), gallium nitride (GaN), gallium phosphide (GaP) wafers, gallium arsenide (GaAs) wafers, and indium phosphide (InP) wafers. Examples of silicon wafers include n-type silicon wafers doped with pentavalent atoms (e.g., phosphorus (P), arsenic (As), and antimony (Sb)), and p-type silicon wafers doped with trivalent atoms (e.g., boron (B) and gallium (Ga)). Examples of silicon in silicon wafers include amorphous silicon, single crystal silicon, polycrystalline silicon, and polysilicon. Among these, wafers made of silicon-based materials such as silicon wafers, silicon carbide wafers, and silicon-containing resin wafers (glass epoxy wafers) are preferred.

[0089] The workpiece may have a metal hard mask. For example, the workpiece 200 shown in FIG. 1 may further have a metal hard mask. Examples of the metal hard mask include Cu, Co, W, and AlO. ｘ , AlN, AlO ｘ N ｙ , W.O. ｘ , Ti, TiN, ZrO ｘ , HfO ｘ and TaO ｘ (Note that x is a number expressed by 1 to 3, and y is a number expressed by 1 to 2.) Metal hard masks include Cu, Co, W, AlO ｘ , AlN, AlO ｘ N ｙ , W.O. ｘ , Ti, TiN, ZrO ｘ , HfO ｘ and TaO ｘ The content of any one or more of the above is preferably 30 to 100% by mass, more preferably 60 to 100% by mass, and even more preferably 95 to 100% by mass, based on the total mass.

[0090] The form of the SiGe and Si-containing material other than SiGe contained in the workpiece is not particularly limited, and may be, for example, a film-like form, a wiring-like form, or a particulate form. When it is a film-like form, its thickness is not particularly limited and may be appropriately selected depending on the application, for example, 1 to 50 nm. The SiGe and Si-containing material other than SiGe may be disposed on only one main surface of the substrate, or on both main surfaces. Furthermore, they may be disposed over the entire main surface of the substrate, or may be disposed over a portion of the main surface of the substrate.

[0091] <Treatment method> In this treatment method, the method of bringing the object to be treated into contact with the chemical solution is not particularly limited, and examples thereof include a method of immersing the object to be treated in the chemical solution placed in a tank, a method of spraying the chemical solution onto the object to be treated, a method of flowing the chemical solution onto the object to be treated, and any combination thereof. Among these, the method of immersing the object to be treated in the chemical solution is preferred.

[0092] Furthermore, to further enhance the cleaning ability of the chemical solution, a mechanical stirring method may be used, such as circulating the chemical solution over the workpiece, flowing or spraying the chemical solution over the workpiece, or stirring the chemical solution with ultrasonic waves or megasonics.

[0093] The contact time between the object to be treated and the chemical solution can be adjusted as appropriate. The treatment time (contact time between the chemical solution and the object to be treated) is not particularly limited, but is preferably 0.25 to 20 minutes, more preferably 0.5 to 15 minutes. The temperature of the chemical solution during treatment is not particularly limited, but is preferably 20 to 75°C, more preferably 20 to 60°C.

[0094] In this processing method, the SiGe in the workpiece may be partially or entirely dissolved. 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-containing material 206, which is different from SiGe, is sufficiently slower than that of SiGe, and part of the SiGe 204 is dissolved from the side, forming a recess.

[0095] 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.

[0096] 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 aqueous solution (preferably 0.01 to 10 mass % citric acid aqueous solution), sulfuric acid (preferably 1 to 10% by mass aqueous sulfuric acid solution), 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 solution), 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 solution. 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 The term "ozone water," "carbon dioxide water," and "hydrogen water" refer to aqueous solutions in which ozone and HCl are dissolved in water. ３ , CO ２ , and H ２The term "rinse solution" refers to an aqueous solution obtained by dissolving the above in water. These rinse solutions may be mixed and used as long as the purpose of the rinsing step is not impaired. The rinse solution may also contain an organic solvent.

[0097] Specific examples of the rinsing step include contacting the workpiece with a rinse liquid, such as immersing the substrate in a rinse liquid contained in a tank, spraying the rinse liquid onto the substrate, or flowing the rinse liquid onto the substrate, or any combination thereof.

[0098] The treatment time (contact time between the rinse liquid and the object to be treated) is not particularly limited, but is, for example, 5 seconds to 5 minutes. The temperature of the rinse liquid during treatment is not particularly limited, but is generally, for example, preferably 16 to 60°C, and more preferably 18 to 40°C. When SPM is used as the rinse liquid, its temperature is preferably 16 to 250°C. When SC-1 is used as the rinse liquid, its temperature is preferably 16 to 250°C.

[0099] This processing method may also include a drying step, in which a drying process is performed after the rinsing step, if necessary. The drying method is not particularly limited, but examples 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, or a combination thereof. The drying time varies depending on the specific method used, but is typically about 30 seconds to several minutes.

[0100] [Method for Manufacturing a Semiconductor Device] The above-described method for processing a workpiece can be suitably applied to a method for manufacturing a semiconductor device. The above-described method for processing a workpiece can be performed before or after other processes performed on the substrate. The above-described cleaning method can be incorporated into other processes, or the above-described method can 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.

[0101] 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.

[0102] 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. In addition, in preparing and evaluating each of the chemical solutions shown below, handling of containers, preparation of the chemical solutions, filling, storage, and analytical measurements were all carried out in a clean room meeting ISO Class 2 or lower at 23°C.

[0103] [Preparation of Chemical Solutions] The components (fluoride ion source, oxidizing agent, organic solvent, additive, water, and specific polymer) shown in the table below were mixed so that the content of each component was the value shown in the table below to prepare each of the chemical solutions used in the following tests. High-purity semiconductor-grade raw materials were used for each component, and further purification treatment was performed as necessary. Unless otherwise specified, the content of each component shown in the table is based on mass.

[0104] [Tests and Evaluations] According to the procedures described below, the solubility (etching rate, ER) of the Si-containing material and SiGe in each chemical solution, and the residue (contact angle) on the Si-containing material were evaluated.

[0105] <Solubility> A substrate on which silicon germanium (Si:Ge = 75:25 (element ratio)) was laminated to a thickness of 50 nm, and a substrate on which silicon oxycarbonitride (SiOCN) was laminated to a thickness of 100 nm were prepared, and each of these substrates was cut into a 2 x 2 cm square to prepare a test specimen. The test specimen was immersed in the chemical solution (25 ° C) of the example or comparative example for 2 minutes. Before and after the immersion test, the film thickness of the SiGe film and the SiOCN film was measured using an optical film thickness meter Ellipsometer M-2000 (manufactured by JA Woollam). From the measured film thicknesses 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 of each film in each chemical solution was evaluated based on the following evaluation criteria. In all evaluation criteria, the closer to A, the better the evaluation.

[0106] (Evaluation criteria for solubility in SiGe film) A: Dissolution rate is 30 Å / min or more B: Dissolution rate is 5 Å / min or more but less than 30 Å / min C: Dissolution rate is less than 5 Å / min

[0107] (Evaluation criteria for solubility in SiOCN film) A: Dissolution rate is less than 0.1 Å / min. B: Dissolution rate is 0.1 Å / min or more and less than 0.5 Å / min. C: Dissolution rate is 0.5 Å / min or more.

[0108] <Contact Angle Measurement (Evaluation of Residue on SiOCN Film)> The amount of residue on the SiOCN film was evaluated by measuring the water contact angle of the SiOCN film after the above <Solubility> test. The water contact angle was measured three times using a contact angle meter (DropMaster 701, manufactured by Kyowa Interface Science Co., Ltd.) for a substrate on which SiOCN was laminated to a thickness of 100 nm, 500 milliseconds after a water droplet contacted the surface, and the average value was taken as the contact angle (°). The analysis was performed assuming a surface tension of water of 72.9 mN / m, and the measurement was performed in an environment of 23°C. From the obtained water contact angle, the amount of residue on the SiOCN film was evaluated based on the following evaluation criteria. The closer the value is to A, the less residue there is on the SiOCN film, and the better the evaluation.

[0109] (Evaluation criteria for water contact angle with SiOCN film) A: Contact angle is 10° or more and less than 35° B: Contact angle is 35° or more and less than 45° C: Contact angle is 45° or more

[0110] [Results] The formulations of the chemical solutions used in the above tests and the evaluation results are shown in Tables 1 and 2. In Tables 1 and 2, the content of each component is based on mass. In Tables 1 and 2, in the "Evaluation Results" column, the measured values ​​in each test are listed in the upper row, and the evaluations corresponding to the measured values ​​are listed in the lower row.

[0111]

[0112]

[0113]

[0114] As shown in Tables 1 and 2, when the chemical solution of the present invention was applied to a workpiece containing SiGe and a Si-containing material other than SiGe, it was confirmed that the etching rate ratio of SiGe to the Si-containing material was high and that residue was unlikely to remain on the Si-containing material after application (Examples 1 to 5). On the other hand, when the chemical solution did not contain a polymer (Comparative Example 1) or when the polymer did not have a second repeating unit and did not fall under the specific polymer (Comparative Examples 2 to 4), either of the effects was not satisfied. Furthermore, a comparison of Examples 1 to 3 confirmed that when the first repeating unit of the specific polymer was a repeating unit having at least one group selected from the group consisting of a tertiary amino group or a salt thereof, and a quaternary ammonium group, the etching rate of SiGe was superior (larger), and when the first repeating unit was a repeating unit having a quaternary ammonium group, the etching rate of SiOCN was superior (smaller).

[0115] In addition, instead of the substrate on which SiOCN was laminated, a substrate on which polysilicon (Si) was laminated to a thickness of 100 nm and a substrate on which silicon oxide (SiO ２ ) to a thickness of 100 nm was used, and the Si film and SiO ２ The solubility of the film was evaluated by measuring the contact angle of the Si film and the SiO ２ Amount of residue on the film (Si film and SiO ２ The water contact angle of the SiGe film was evaluated, and it was confirmed that the water contact angle of the SiGe film was similar to that of the SiOCN film. ２ Dissolution rate (ER) of the film, and the Si film and SiO ２ The evaluation results of the water contact angle of the film are shown in Table 3 below. In Table 3, the evaluation criteria for solubility in Si film and SiO ２ The evaluation criteria for solubility in each of the samples are shown below. In each evaluation criteria, the closer to A, the better the evaluation.

[0116] (Evaluation criteria for solubility in Si film) A: Dissolution rate is less than 7 Å / min. B: Dissolution rate is 7 Å / min or more and less than 15 Å / min. C: Dissolution rate is 15 Å / min or more.

[0117] (SiO ２ Evaluation criteria for solubility in film) A: Dissolution rate is less than 2 Å / min. B: Dissolution rate is 2 Å / min or more and less than 4 Å / min. C: Dissolution rate is 4 Å / min or more.

[0118] In addition, the evaluation criteria for the water contact angle with respect to the Si film and the SiO ２ The evaluation criteria for the water contact angle of the film are shown below. In any of the evaluation criteria, if the result is A or higher, it is considered that there is little residue on the film, and this is at a level that does not pose a problem in practical use.

[0119] (Si film and SiO ２ Evaluation criteria for water contact angle with film) A: Contact angle is 10° or more and less than 40° B: Contact angle is 40° or more

[0120] Table 3 is shown below.

[0121]

[0122] 200 Processed object 202 Substrate 204 SiGe 206 Si-containing material

Claims

1. A chemical solution used for a workpiece containing SiGe and a Si-containing material other than SiGe, for removing at least a portion of the SiGe contained in the workpiece, the chemical solution comprising a first repeating unit having at least one group selected from the group consisting of a primary amino group or a salt thereof, a secondary amino group or a salt thereof, a tertiary amino group or a salt thereof, and a quaternary ammonium group, and a repeating unit having an acid group and -SO ２ a polymer including a second repeating unit selected from the group consisting of repeating units represented by the formula: -; a fluoride ion source; and an oxidizing agent.

2. The drug solution according to claim 1, wherein the first repeating unit is a repeating unit having at least one group selected from the group consisting of a tertiary amino group or a salt thereof, and a quaternary ammonium group.

3. The chemical solution according to claim 1, wherein the first repeating unit is a repeating unit having a quaternary ammonium group.

4. The chemical solution according to claim 1, wherein the acid group is a carboxylic acid group, a sulfonic acid group, or a phosphonic acid group.

5. The drug solution according to claim 1, wherein the weight average molecular weight of the polymer is 5,000 to 30,000.

6. The chemical solution of claim 1, wherein the oxidizing agent is a compound selected from the group consisting of peroxides, perhalogen acid compounds, and nitric acid compounds.

7. The chemical solution according to claim 1, wherein the oxidizing agent is a compound selected from the group consisting of hydrogen peroxide, peracetic acid, periodic acid or a salt thereof, and nitric acid.

8. The pharmaceutical solution of claim 1, further comprising an organic acid.

9. The chemical solution of claim 1, further comprising an inorganic acid.

10. A method for treating a workpiece, comprising a step of contacting the workpiece containing SiGe and a Si-containing substance other than SiGe with the chemical solution according to any one of claims 1 to 9, and removing at least a portion of the SiGe contained in the workpiece.

11. A method for manufacturing a semiconductor device, comprising the method for treating an object according to claim 10.