JP6965144B2 - Cleaning liquid and method for manufacturing it - Google Patents

Description

The present invention relates to a cleaning solution and a method for producing the same.

A semiconductor device is formed by laminating a metal wiring layer, a low-dielectric layer, an insulating layer, etc. on a substrate, and such a semiconductor device is formed by a lithography method in which a resist pattern is used as a mask for etching. It is manufactured by processing each of the above layers.

The resist film, temporary laminated film (also referred to as sacrificial film) used in the above lithography method, and the residue derived from the metal wiring layer and the low dielectric layer generated in the etching process should not interfere with the next process. , It is removed using a cleaning solution so as not to interfere with the semiconductor device.

Conventionally, as a cleaning liquid used in such a semiconductor device manufacturing process, a cleaning liquid containing a hydroxylamine derivative has been proposed (see, for example, Patent Document 1). The cleaning solution containing such a hydroxylamine derivative has improved removal performance for various residues as compared with the cleaning solutions before that.

International Publication No. 2011/0277772

In recent years, with the increasing density and high integration of semiconductor devices, for example, a wiring forming method using the damascene method has been adopted. In such a wiring forming method, as the metal wiring material constituting the metal wiring layer of the semiconductor device, easily corrosive metals such as cobalt, copper, and tungsten are used alone or in the form of an alloy, or in the form of SiGe or the like, respectively. It is used as a metal wiring material in semiconductor devices. Silicide and other easily corrosive metals such as cobalt, copper, tungsten, and SiGe used as metal wiring materials have a problem that they are easily corroded by a cleaning liquid. Therefore, there is a demand for a cleaning liquid that does not easily corrode VDD and other easily corrosive metals such as cobalt, copper, tungsten, and SiGe when cleaning the substrate.

The present invention has been made in view of such conventional circumstances, and at least a cleaning liquid having an excellent corrosion suppressing function against tetrahydrofuran and other easily corrosive metals such as cobalt, copper, tungsten, and SiGe, and a cleaning liquid thereof. It is an object of the present invention to provide a method of manufacturing.

The present inventors have conducted extensive research to solve the above problems. As a result, they have found that the above problems can be solved by using a specific alkanolhydroxyamine and a basic compound in the cleaning liquid, and have completed the present invention. Specifically, the present invention provides the following.

The first aspect of the present invention is a cleaning solution containing an alkanol hydroxyamine represented by the following general formula (1) and a basic compound other than the alkanol hydroxyamine.

（式中、Ｒ^ａ１及びＲ^ａ２は、それぞれ独立して、ヒドロキシ基を１〜３個有する炭素原子数１〜１０のアルキル基又は水素原子を示す。但し、Ｒ^ａ１及びＲ^ａ２が同時に水素原子となることはない。）

(In the formula, R ^a1 and R ^a2 each independently represent an alkyl group or a hydrogen atom having 1 to 3 hydroxy groups and having 1 to 10 carbon atoms. However, R ^a1 and R ^a2 are hydrogen atoms at the same time. It will never be.)

A second aspect of the present invention is a method for producing a cleaning solution containing an alkanolhydroxyamine represented by the above general formula (1) and a basic compound other than the alkanolhydroxyamine. A method comprising a step of synthesizing the alkanolhydroxyamine by oxidizing an alkanolamine represented by the following general formula (2) and a step of blending the reaction product from the step with the basic compound. be.

（式中、Ｒ^ｂ１及びＲ^ｂ２は、それぞれ独立して、ヒドロキシ基を１〜３個有する炭素原子数１〜１０のアルキル基又は水素原子を示す。但し、Ｒ^ｂ１及びＲ^ｂ２が同時に水素原子となることはない。）

(In the formula, R ^b1 and R ^b2 each independently represent an alkyl group or a hydrogen atom having 1 to 3 hydroxy groups and having 1 to 10 carbon atoms. However, R ^b1 and R ^b2 are hydrogen atoms at the same time. It will never be.)

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a cleaning liquid having an excellent corrosion suppressing function against at least tetrahydrofuran and other easily corrosive metals such as cobalt, copper, tungsten and SiGe, and a method for producing the same.

<< Cleaning liquid >>
The cleaning solution of the present invention contains an alkanolhydroxyamine represented by the above general formula (1) (sometimes simply abbreviated as "alkanolhydroxyamine" in the present specification) and a basic compound other than the alkanolhydroxyamine. (In the present specification, it may be simply abbreviated as "basic compound".) The composition (typically, a liquid composition) is suitable as a cleaning liquid and an anticorrosive agent. ..

Further, in the cleaning liquid of the present embodiment, it is preferable that ^{Ra 1} and Ra ^{2 in the general formula (1) have the same group.}

Further, in the cleaning solution of the present embodiment, the basic compound comprises a quaternary ammonium hydroxide, an alkanolamine, a hydroxyamine compound other than the alkanolhydroxyamine represented by the general formula (1), an alkylamine, and ammonia. It is preferably at least one selected from the group.

Further, the cleaning solution of the present embodiment preferably has a pH of 8 or more, more preferably 9 or more. In such a pH range, the oxidation-reduction potential of javax and other easily corrosive metals such as cobalt, copper, tungsten, and SiGe, particularly cobalt, tends to decrease, and cobalt has been liable to corrode in the past. The cleaning liquid of the present embodiment can effectively remove the object to be cleaned while suppressing the corrosion of cobalt even at a pH corresponding to such a corrosion region of cobalt.

Such a cleaning liquid is suitable as a cleaning liquid for electronic components such as semiconductor devices and liquid crystal displays (LCDs). For example, in semiconductor manufacturing processes, FEOL (Front End of Line) processes such as lithography process, etching process, chemical mechanical polishing (CMP), BEOL (Back End of Line) process such as wiring formation process, and through silicon vias. It is suitable as a cleaning liquid used in a post-process such as an electrode (TSV) and a C4 method (Control Connection), and is preferably used for cleaning a substrate having a metal on its surface. A substrate having a metal on its surface means a substrate in which the metal is exposed on at least a part of the surface of the substrate. The metal is, for example, a metal formed as a metal wiring layer, a plug, or other metal structure in a substrate on which a semiconductor device is formed. Examples of the substrate include a substrate on which a metal wiring layer, a low dielectric layer, an insulating layer and the like are laminated on a substrate such as a silicon wafer to form a semiconductor device. Further, the substrate may be a substrate provided with a silicide layer containing germanium or the like. The cleaning liquid of this embodiment is suitable for cleaning in lithography or cleaning for lithography, and can be used as a cleaning liquid for lithography.

Examples of the metal include cobalt, which is an easily corrosive metal, and an alloy thereof. Examples of the alloy of cobalt include alloys with at least one of other transition elements and typical elements (for example, phosphorus, boron, silicon, etc.), and specifically, phosphorus and / or boron-containing alloys such as CoWPB and the like. , CoSi and the like, and examples thereof. Further, the metal may be another easily corrosive metal such as copper, tungsten, germanium or an alloy thereof, and the alloy may be at least one of copper and tungsten and other alloys. Examples thereof include alloys with at least one of a transition element and a typical element (for example, phosphorus, boron, silicon, etc.), and specifically, a phosphorus and / or boron-containing alloy such as CuPB, and VDD such as WSi and SiGe. Illustrated. When dialkanolhydroxyamine and dialkanolamine, which will be described later, are used, a corrosion suppressing effect can be easily obtained not only for cobalt but also for copper, dungsten, and SiGe. Hereinafter, in the present specification, "cobalt or its alloy", "copper or its alloy" and "tungsten or its alloy" may be simply abbreviated as "cobalt", "copper" and "tungsten", respectively.

By containing alkanolhydroxyamine and a basic compound other than the alkanolhydroxyamine, the cleaning solution of the present embodiment is excellent at least against VDD and other easily corrosive metals such as cobalt, copper, tungsten and SiGe. Has a corrosion suppression function. Therefore, even if the cleaning liquid comes into contact with the surface of the substrate such as Cobalt, Copper, Tungsten, SiGe or the like, or other easily corrosive metals when cleaning the substrate, the substrate surface is also free to corrode such as Cobalt, Copper, Tungsten, SiGe or the like. Corrosion of metal is well suppressed. Although the mechanism of action is not clear, it is presumed that the reducing action of alkanolhydroxyamine suppresses the corrosion of tetrahydrofuran and other easily corrosive metals such as cobalt, copper, tungsten and SiGe.

Further, since the alkanolhydroxyamine represented by the general formula (1) has a lower vapor pressure than the alkanolamine represented by the general formula (2), the cleaning liquid is heated to a predetermined temperature for cleaning. Even if it is used, the composition change is suppressed and it is useful as a cleaning liquid. For example, it is preferable to use an alkanolhydroxyamine having a vapor pressure of preferably 0.3 mmHg or less, more preferably 0.1 mmHg, and even more preferably 0.05 mmHg or less.

Further, since the alkanolhydroxyamine represented by the general formula (1) is more water-soluble than the alkanolamine represented by the general formula (2), use low-cost water as the solvent or solvent. In addition, the residue can be suppressed in washing with such an aqueous solution, which is useful as a cleaning liquid. For example, it is preferable to use an alkanolhydroxyamine having a LogP of preferably 0.5 or less.

The LogP value means an octanol / water partition coefficient and can be calculated by calculation using parameters of Ghose, Plitchet, Crippen et al. (See J. Comp. Chem., 9, 80 (1998)). This calculation can be performed using software such as CAChe 6.1 (manufactured by Fujitsu Limited).

Hereinafter, each component will be described.

<Alkanol hydroxyamine>
As the alkanol hydroxyamine, the alkanol hydroxyamine represented by the above general formula (1) is used. In the formula, R ^a1 and R ^a2 each independently represent an alkyl group or a hydrogen atom having 1 to 3 hydroxy groups and having 1 to 10 carbon atoms. However, ^Ra1 and ^Ra2 do not become hydrogen atoms at the same time.

As the alkanol hydroxyamine, dialkanol hydroxyamine, ^{which is an alkyl group in which Ra 1} and Ra ² have 1 to 3 hydroxy groups and have 1 to 10 carbon atoms, is preferable. It is preferable to use such an alkanol hydroxyamine because it can suppress corrosion not only on cobalt but also on VDD and other easily corrosive metals such as copper, tungsten and SiGe.

The ^{number of hydroxy groups in R a1} and R ^a2 may be one or two, respectively, and even if one is used, the effect of the present invention can be sufficiently exerted. Hydroxy group in R ^a1 and R ^a2 are, when the number of carbon atoms in each alkyl group in R ^a1 and R ^a2 are 3 may constitute the primary alcohol, or any secondary alcohol, also, When the ^{number of carbon atoms of each alkyl group in R a1} and R ^a2 is 4 to 10, it may be composed of a primary alcohol, a secondary alcohol, or a tertiary alcohol, but the secondary alcohol. It is preferable to configure.

The alkyl group having 1 to 10 carbon atoms in R ^a1 and Ra ² may be any linear, branched or cyclic alkyl group, for example, a methyl group, an ethyl group or an n-propyl group. , Isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, cyclobutyl group, n-pentyl group, isopentyl group, sec-pentyl group, tert-pentyl group, neopentyl group, 2-methylbutyl group , 1,2-dimethylpropyl group, 1-ethylpropyl group, cyclopentyl group, n-hexyl group, isohexyl group, sec-hexyl group, tert-hexyl group, neohexyl group, 2-methylpentyl group, 1,2-dimethyl Butyl group, 2,3-dimethylbutyl group, 1-ethylbutyl group, cyclohexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, etc. are mentioned, and the number of carbon atoms is 1 to 4. A linear or branched alkyl group is preferable, and an ethyl group, an n-propyl group, and an isopropyl group are particularly preferable.

Specific examples of the linear or branched alkyl group having 1 to 3 hydroxyl groups and 1 to 4 carbon atoms in R ^a1 and R ^{a2 include, for example, 1-hydroxyethyl group and 2-hydroxyethyl.} Group, 1,2-dihydroxyethyl group, 2,2-dihydroxyethyl group, 1-hydroxy-n-propyl group, 2-hydroxy-n-propyl group, 3-hydroxy-n-propyl group, 1,2-dihydroxy -N-propyl group, 1,3-dihydroxy-n-propyl group, 2,2-dihydroxy-n-propyl group, 2,3-dihydroxy-n-propyl group, 3,3-dihydroxy-n-propyl group, 1,2,3-trihydroxy-n-propyl group, 2,2,3-trihydroxy-n-propyl group, 2,3,3-trihydroxy-n-propyl group, 1-hydroxyisopropyl group, 2- Hydroxyisopropyl group, 1,1-dihydroxyisopropyl group, 1,2-dihydroxyisopropyl group, 1,3-dihydroxyisopropyl group, 1,2,3-trihydroxyisopropyl group, 1-hydroxy-n-butyl group, 2- Hydroxy-n-butyl group, 3-hydroxy-n-butyl group, 4-hydroxy-n-butyl group, 1,2-dihydroxy-n-butyl group, 1,3-dihydroxy-n-butyl group, 1,4 -Dihydroxy-n-butyl group, 2,2-dihydroxy-n-butyl group, 2,3-dihydroxy-n-butyl group, 2,4-dihydroxy-n-butyl group, 3,3-dihydroxy-n-butyl Group, 3,4-dihydroxy-n-butyl group, 4,4-dihydroxy-n-butyl group, 1,2,3-trihydroxy-n-butyl group, 1,2,4-trihydroxy-n-butyl Group, 1,3,4-trihydroxy-n-butyl group, 2,2,3-trihydroxy-n-butyl group, 2,2,4-trihydroxy-n-butyl group, 2,3,3- Trihydroxy-n-butyl group, 3,3,4-trihydroxy-n-butyl group, 2,4,4-trihydroxy-n-butyl group, 3,4,4-trihydroxy-n-butyl group, 2,3,4-trihydroxy-n-butyl group, 1-hydroxy-sec-butyl group, 2-hydroxy-sec-butyl group, 3-hydroxy-sec-butyl group, 4-hydroxy-sec-butyl group, 1,1-dihydroxy-sec-butyl group, 1,2-dihydroxy-sec-butyl group, 1,3-dihydroxy-sec-butyl group, 1,4-dihi Droxy-sec-butyl group, 2,3-dihydroxy-sec-butyl group, 2,4-dihydroxy-sec-butyl group, 3,3-dihydroxy-sec-butyl group, 3,4-dihydroxy-sec-butyl group , 4,4-Dihydroxy-sec-butyl group, 1-hydroxy-2-methyl-n-propyl group, 2-hydroxy-2-methyl-n-propyl group, 3-hydroxy-2-methyl-n-propyl group , 1,2-Dihydroxy-2-methyl-n-propyl group, 1,3-dihydroxy-2-methyl-n-propyl group, 2,3-dihydroxy-2-methyl-n-propyl group, 3,3- Dihydroxy-2-methyl-n-propyl group, 3-hydroxy-2-hydroxymethyl-n-propyl group, 1,2,3-trihydroxy-2-methyl-n-propyl group, 1,3,3-tri Hydroxy-2-methyl-n-propyl group, 2,3,3-trihydroxy-2-methyl-n-propyl group, 1,3-dihydroxy-2-hydroxymethyl-n-propyl group, 2,3-dihydroxy Examples thereof include -2-hydroxymethyl-n-propyl group, 1-hydroxy-2-methylisopropyl group, 1,3-dihydroxy-2-methylisopropyl group, 1,3-dihydroxy-2-hydroxymethylisopropyl group and the like. In particular, 2-dihydroxyethyl group, 2-hydroxy-n-propyl group and 2-hydroxyisopropyl group are preferable.

The content of alkanolhydroxyamine is preferably 0.001 to 10% by mass, more preferably 0.01 to 5% by mass, and 0.01 to 0.5% by mass with respect to the total amount of the cleaning liquid. It is more preferable to have. With such a content, it is possible to effectively remove the object to be cleaned while suppressing corrosion of easily corrosive metals, in particular, VDD of cobalt, copper, tungsten, SiGe and the like.

<Basic compound>
As the basic compound, at least one selected from the group consisting of a quaternary ammonium hydroxide, an alkanolamine, a hydroxyamine compound other than the alkanolhydroxyamine represented by the above general formula (1), an alkylamine, and ammonia. It is preferable to use one.

[Quaternary ammonium hydroxide]
As the quaternary ammonium hydroxide, a compound represented by the following general formula (3) is preferable.

In the above general formula (3), R ^{c1 to} R ^c4 are independently alkyl groups having 1 to 16 carbon atoms, aryl groups having 6 to 16 carbon atoms, aralkyl groups having 7 to 16 carbon atoms, or carbons. It shows a hydroxyalkyl group having 1 to 16 atoms.

Among the compounds represented by the above general formula (3), tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, methyltripropylammonium hydroxide Things, methyltributylammonium hydroxide, ethyltrimethylammonium hydroxide, dimethyldiethylammonium hydroxide, benzyltrimethylammonium hydroxide, hexadecyltrimethylammonium hydroxide, and (2-hydroxyethyl) trimethylammonium hydroxide It is particularly preferable from the viewpoint of availability that it is at least one selected from the group consisting of. Further, tetramethylammonium hydroxide and tetraethylammonium hydroxide are preferable because they have high solubility in the object to be cleaned and high cleaning performance.

[Inorganic base]
Further, as the basic compound, for example, an inorganic base may be used in combination with a quaternary ammonium hydroxide. As the inorganic base, hydroxides of alkali metals such as potassium hydroxide, sodium hydroxide and rubidium hydroxide are preferable, and potassium hydroxide is more preferable.

[Alkanolamine]
Examples of alkanolamines include triethanolamine, 2- (2-aminoethoxy) ethanol, N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-dibutylethanolamine, N-methylethanolamine, and N. -Ethylethanolamine, N-butylethanolamine, N-methyldiethanolamine, triisopropanolamine and the like can be mentioned. As the alkanolamine, an alkanolamine represented by the general formula (2) such as monoethanolamine, diethanolamine, monoisopropanolamine, and diisopropanolamine may also be used.

When a cleaning solution is produced by a method including the step of synthesizing alkanolhydroxyamine by using alkanolamine as a basic compound and oxidizing alkanolamine, the amount of alkanolamine remaining after synthesis is insufficient. , It is preferable to separately add a basic compound other than alkanolamine.

[Hydroxyamine compound]
Examples of the hydroxyamine compound other than the alkanol hydroxyamine represented by the general formula (1) include hydroxyamine (HO-NH ₂ ), N-methylhydroxyamine, N-ethylhydroxyamine, and N- (tert-). Monoalkylhydroxyamines such as butyl) hydroxyamines and N-propylhydroxyamines; dialkylhydroxyamines such as N, N-diethylhydroxyamines and N, N-dimethylhydroxyamines; and alkylhydroxyamines such as.

[Alkylamine]
Examples of the alkylamine include monoalkylamines such as N-methylamine, N-ethylamine, N- (tert-butyl) amine and N-propylamine; and dialkylamines such as N, N-diethylamine and N, N-dimethylamine; And so on.

[Other basic compounds]
Ammonia can also be used as the basic compound.

The content of the basic compound other than the alkanol hydroxyamine represented by the above general formula (1) varies depending on the basic strength of the compound, but is 0.5 to 30% by mass with respect to the total amount of the cleaning solution. Is preferable, and 1 to 20% by mass is more preferable. With such a content, it is possible to effectively remove the object to be cleaned while suppressing corrosion of easily corrosive metals, in particular, VDD of cobalt, copper, tungsten, SiGe and the like. When the inorganic base is used in combination with the quaternary ammonium hydroxide, the content of the inorganic base is preferably 0.1 mass ppm to 1 mass% with respect to the total amount of the cleaning liquid, and is preferably 1 mass ppm to 1000 mass. More preferably, it is ppm. With such a content, it is possible to effectively remove the object to be cleaned while suppressing the corrosion of easily corrosive metals, particularly VDD of cobalt, copper, tungsten, SiGe and the like. Further, as described above, when alkanolamine is used as the basic compound, it is preferable to use two or more basic compounds by using another basic compound in addition to the alkanolamine.

<Solvent>
Further, the cleaning liquid of the present invention may contain a solvent that dissolves the alkanolhydroxyamine represented by the general formula (1) and the basic compound. The solvent is not particularly limited as long as it can uniformly dissolve the components contained in the cleaning liquid, and any of water, an organic solvent, and an aqueous solution of an organic solvent can be used, and water is preferably contained. .. As the water, pure water, deionized water, ion-exchanged water and the like can be used. The organic solvent may be used alone or in combination of two or more.

The organic solvent may be a water-soluble organic solvent or a hydrophobic organic solvent, but a water-soluble organic solvent is preferable. When the organic solvent contained in the solvent is water-soluble, it is generally preferable because the alkanolhydroxyamine has high solubility and does not easily remain on the surface of the object to be cleaned. As the solvent, it is preferable to use water and an organic solvent in combination, and it is more preferable to use water and a water-soluble organic solvent in combination. When water and a water-soluble organic solvent are used in combination as a solvent, the content of water with respect to the total of water and the water-soluble organic solvent is preferably 1 to 99% by mass, more preferably 10 to 40% by mass, and 15 to 30%. Mass% is more preferred.

Examples of the water-soluble organic solvent include sulfoxides such as dimethyl sulfoxide; sulfones such as dimethyl sulfone, diethyl sulfone, bis (2-hydroxyethyl) sulfone and tetramethylene sulfone; N, N-dimethylformamide and N-methylformamide. , N, N-Dimethylacetamide, N-Methylacetamide, N, N-diethylacetamide and other amides; N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-hydroxymethyl-2-pyrrolidone, N Lactams such as −hydroxyethyl-2-pyrrolidone; lactones such as β-propiolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε-caprolactone; 1,3-dimethyl- Imidazolidinones such as 2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, 1,3-diisopropyl-2-imidazolidinone; ethylene glycol, propylene glycol, 1,2-butylene glycol, 1 , 3-butylene glycol, 2,3-butylene glycol, glycerin, diethylene glycol and other polyhydric alcohols; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monoallyl ether , Propropylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, 3-methoxy-3-methyl-1-butanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol Monobutyl ether, diethylene glycol monobenzyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol Glycol monoalkyl ethers such as monopropyl ether, triethylene glycol monobutyl ether, tripropylene glycol monobutyl ether, ethylene glycol dimethyl ether, Glycol ether solvents such as glycol dialkyl ethers such as diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether; ethylene glycol monoacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether Examples thereof include glycol ester solvents such as acetate and diethylene glycol monoacetate.

Of these, the preferred water-soluble organic solvents are dipropylene glycol monomethyl ether (DPM), propylene glycol (PG), 3-methoxy-3-methyl-1-butanol, dimethyl sulfoxide, propylene glycol monomethyl ether, and propylene glycol. At least one selected from the group consisting of monoethyl ether, propylene glycol monopropyl ether, diethylene glycol monoethyl ether (ethyl diglycol), and diethylene glycol monobutyl ether.

When the water-soluble organic solvent is contained, the content thereof is preferably 1 to 99% by mass, more preferably 10 to 85% by mass, and 30 to 80% by mass with respect to the total amount of the cleaning liquid. Is even more preferable. With such a content, it is possible to effectively remove the object to be cleaned while suppressing the corrosion of easily corrosive metals, particularly VDD of cobalt, copper, tungsten, SiGe and the like.

<Other ingredients>
Other components such as a surfactant may be added to the cleaning liquid of the present embodiment as long as the effects of the present invention are not impaired. The surfactant is not particularly limited, and examples thereof include a nonionic surfactant, an anionic surfactant, a cationic surfactant, and an amphoteric surfactant.

Further, the cleaning liquid of the present embodiment does not need to contain another anticorrosive agent as long as it contains the alkanolhydroxyamine represented by the above general formula (1) and a basic compound, but other anticorrosive agents. It may also contain an agent. Such other anticorrosive agents are not particularly limited, and are, for example, benzotriazole, aminotetrazole, 5-amino-1-phenyltetrazole, 5-amino-1- (1-naphthyl) tetrazole, 1-methyl-5-amino. Examples thereof include nitrogen-containing heterocyclic compounds such as tetrazole, 1,5-diaminotetrazole, imidazole, indol, purine, pyrazole, pyridine, pyrimidine, pyrrol, pyrrolidine and pyrrolin, as well as secondary amine compounds and amino acid compounds.

<< Anticorrosive agent >>
An anticorrosive agent containing an alkanol hydroxyamine represented by the general formula (1) and a basic compound other than the alkanol hydroxyamine is also one of the present inventions.
The anticorrosive agent of the present invention is a composition containing an alkanolhydroxyamine represented by the above general formula (1) and a basic compound other than the alkanolhydroxyamine, and the composition (typically a liquid composition). The thing) is suitable as an anticorrosive agent.

Further, in the anticorrosion agent of the present embodiment, the basic compound other than the alkanolhydroxyamine is a group consisting of a quaternary ammonium hydroxide, an alkanolamine, a hydroxyamine compound other than the alkanolhydroxyamine, an alkylamine, and ammonia. It is preferably at least one that is more selected. Further, in the anticorrosive agent of this embodiment, it is preferable that ^{Ra1 and Ra2 in the above general formula (1) are the same group.}

As described above, the anticorrosive agent of the present embodiment contains alkanolhydroxyamine and a basic compound other than the alkanolhydroxyamine, whereby metals such as cobalt, copper, tungsten, SiGe and the like are easily corroded. Corrosion of sex metals can be effectively suppressed.

<< Method of manufacturing cleaning liquid >>
The method for producing the cleaning solution of the present invention is a method for producing a cleaning solution containing an alkanolhydroxyamine represented by the above general formula (1) and a basic compound, and is represented by the above general formula (2). It is a method including a step of synthesizing the alkanol hydroxyamine by oxidizing the alkanolamine, and a step of blending a reaction product and a basic compound by the step. The method for producing the cleaning liquid of the present invention is suitable as the method for producing the cleaning liquid according to the first aspect of the present invention or the above-mentioned anticorrosive agent of the present invention.

In the general formula (2) representing an alkanolamine as a starting material, R ^b1 and R ^b2 are independently alkyl groups or hydrogen atoms having 1 to 3 hydroxy groups and 1 to 10 carbon atoms. However, R ^b1 and R ^b2 do not become hydrogen atoms at the same time.

As the alkanolamine, as described above, a dialkanolamine in which R ^b1 and R ^b2 are alkyl groups having 1 to 3 hydroxy groups and 1 to 10 carbon atoms is preferable. It is preferable to use such an alkanolamine because it can suppress corrosion not only on cobalt but also on copper and tungsten.

In the above reaction for oxidizing an alkanolamine, since it is not normally oxidized, R ^{b1 in the general formula (2) is the same group as Ra 1} in the general formula (1) ^{, and R b} 2 in the general formula (2) is ^{It has the same group as Ra 2} in the general formula (1), and is specifically as follows.

The hydroxy groups in R ^b1 and R ^b2 are the same as those described for the hydroxy groups in ^{R a1} and R ^a2 of the general formula (1), and the number of carbon atoms of each alkyl group in ^{R b1} and R ^{b2 is 3.} In some cases, and when the ^{number of carbon atoms of each alkyl group in R b1} and R ^b2 is 4 to 10, it is preferable to form a secondary alcohol.

Examples of the alkyl group having 1 to 10 carbon atoms in R ^b1 and R ^b2 include the same alkyl groups as those described in the general formula (1), and are linear or branched alkyl groups having 1 to 4 carbon atoms. The group is preferable, and the ethyl group and the n-propyl group are particularly preferable.

Specific examples of the linear or branched alkyl group having 1 to 3 hydroxyl groups and having 1 to 4 carbon atoms in R ^b1 and R ^{b2 are the same as those described in the general formula (1).} Those are mentioned, and a 2-hydroxyethyl group and a 2-hydroxy-n-propyl group are particularly preferable.

^{Similar to R a1} and R ^a2 in the general formula (1), it is preferable that ^{R b1} and R ^b2 in the general formula (2) have the same group. Further, ^{it is preferable that R a1} , R ^a2 , R ^b1 and R ^b2 are the same group.

Examples of the oxidizing agent that oxidizes the alkanolamine include hydrogen peroxide and the like.

The amount of the oxidizing agent added to the alkanolamine is preferably 30 to 100 mol%, more preferably 60 to 80 mol%, based on the molar amount of the alkanolamine. With such an addition amount, alkanolhydroxyamine can be produced from alkanolamine to obtain a mixed solution having a high anticorrosion effect.

The reaction temperature for oxidizing the alkanolamine is, for example, preferably 40 to 80 ° C, more preferably 50 to 70 ° C. The reaction time is preferably 20 to 120 minutes, more preferably 30 to 90 minutes. By carrying out the oxidation reaction under such conditions, alkanolhydroxyamine can be produced from alkanolamine to obtain a mixed solution having a high anticorrosion effect.

For example, as shown in the reaction formula below, _{by adding hydrogen peroxide solution (H 2} O ₂ ) to diethanolamine, which is an alkanolamine, and oxidizing it, the reaction product is 2,2', which is an alkanolhydroxyamine. -(Hydroxyimino) bisethanol can be obtained.

However, in the above reaction, it is difficult to oxidize the entire amount of diethanolamine, and the obtained reaction solution tends to be a mixture of diethanolamine and 2,2'-(hydroxyimino) bisethanol. The yield of 2,2'-(hydroxyimino) bisethanol, which is an alkanol hydroxyamine, is about 25% to 70%, although it depends on the reaction conditions.

In the method for producing a cleaning solution of the present invention, it is easy to obtain a mixture of alkanolamine as a starting material and alkanolhydroxyamine as a reaction product, and the mixture obtained after the oxidation reaction is used as it is, that is, alkanolamine or alkanolhydroxyamine. Can be used in the cleaning solution of the present embodiment without isolation and purification, and the production efficiency is high. Further, as compared with the case where alkanolamine or alkanolhydroxyamine is used alone as a cleaning liquid or an anticorrosive agent, a cleaning liquid or an anticorrosive agent having a high anticorrosive effect can be obtained. According to this method, alkanolamine becomes a basic compound and can exhibit a high anticorrosion effect.

<< Cleaning method >>
A cleaning method using the cleaning solution of the present invention is also one of the present inventions.
The cleaning method of the present invention is a method of cleaning a substrate using the above-mentioned cleaning liquid or the cleaning liquid produced by the above-mentioned method.

Cleaning of the substrate is suitable for cleaning the substrate in lithography.
For example, the cleaning method of the present embodiment is performed after the etching mask layer forming step of forming an etching mask layer of a predetermined pattern on the surface of the substrate and the etching step of etching the substrate exposed from the etching mask layer. This is a method for cleaning the etched substrate. The cleaning method of the present embodiment is suitable when at least a part of the surface of the substrate is made of tetrahydrofuran or other easily corrosive metal such as cobalt, copper, tungsten, or SiGe. At this time, at least a part of VDD and other easily corrosive metals such as cobalt, copper, tungsten, and SiGe are exposed on the surface of the substrate and come into contact with the cleaning liquid, but cobalt, copper, tungsten, SiGe, and the like are exposed. Corrosion of tetrahydrofuran and other easily corrosive metals is well suppressed. Therefore, by cleaning with the above-mentioned cleaning liquid, it is possible to effectively remove the object to be cleaned while suppressing the corrosion of VDD and other easily corrosive metals such as cobalt, copper, tungsten and SiGe.

As will be described later, according to the evaluation of the etching rate, the cleaning method of the present embodiment is 0.2 nm / min or less, preferably 0.1 nm / min or less, and more preferably 0.09 nm / min with respect to cobalt. It is as small as the following and has a large corrosion suppression effect. Similarly, according to the evaluation of the etching rate, it is possible to reduce the etching rate to 0.4 nm / min or less, preferably 0.2 nm / min or less, and more preferably 0.04 nm / min or less with respect to copper. Yes, it can be expected to have a corrosion suppression effect. Similarly, according to the evaluation of the etching rate, it is possible to reduce the etching rate to 0.2 nm / min or less, preferably 0.1 nm / min or less, and more preferably 0.01 nm / min or less with respect to tungsten. Yes, it can be expected to have a corrosion suppression effect. Similarly, according to the evaluation of the etching rate, it is possible to reduce the etching rate to 0.05 nm / min or less, preferably 0.01 nm / min or less with respect to SiGe, and a corrosion suppressing effect can be expected. When the above-mentioned dialkanolhydroxyamine and dialkanolamine are used, the corrosion suppressing effect can be easily obtained not only for cobalt but also for VDD and other easily corrosive metals such as copper, dungsten and SiGe.

The specific cleaning method is not particularly limited as long as it is a usual method. For example, the substrate is brought into contact with the above-mentioned cleaning liquid for 1 to 40 minutes by using a dipping method, a paddle method, a shower method, or the like. The cleaning is usually performed at room temperature, but the cleaning liquid may be heated to about 85 ° C. in order to enhance the cleaning effect.

<< Anticorrosion method >>
As described above, a method of corroding a corrosive metal by using the above-mentioned cleaning liquid, anticorrosive agent, or the cleaning liquid or anticorrosive agent produced by the above method is also one of the present inventions. The anticorrosive method includes, for example, contacting the porous metal such as cobalt, copper, tungsten, SiGe, or other easily corrosive metal (for example, a substrate on which the easily corrosive metal is exposed on the surface) with the cleaning liquid or the anticorrosive agent. Specifically, it can be carried out in the same manner as the above-mentioned cleaning method.

Further, in the method of corroding a corrosive metal by using the above-mentioned anticorrosive agent or the anticorrosive agent produced by the above method, the anticorrosive agent is added to a chemical solution for lithography such as a cleaning solution, a developing solution, a rinsing solution and a stripping solution. By including the chemical solution for lithography in the chemical solution for lithography, for example, the chemical solution for lithography can be used, for example, tetrahydrofuran or other easily corrosive metal such as cobalt, copper, tungsten, SiGe (for example, a substrate on which the easily corrosive metal is exposed on the surface). Including contact with. Such an anticorrosion method is, for example, a cleaning method usually used in a lithography method (for example, the above-mentioned cleaning method) depending on the type or application of a chemical solution for lithography such as a cleaning solution, a developing solution, a rinsing solution, and a stripping solution containing the anticorrosive agent. ), A developing method, a rinsing method, and a peeling method can be used. As the lithographic chemical solution containing the anticorrosive agent of the present embodiment, a cleaning solution and a developing solution are preferable. As the developing solution, for example, an alkaline developing solution such as a 2.38% aqueous solution of tetramethylammonium hydroxide (TMAH) can be used.

A lithographic chemical solution containing the anticorrosive agent of the present invention is also one of the present inventions. Examples of the chemical solution for lithography include a cleaning solution, a developing solution, a rinsing solution, a stripping solution, and the like, and a cleaning solution is preferable.

<< Method of manufacturing semiconductors >>
A method for manufacturing a semiconductor including using the cleaning method of the present invention is also one of the present inventions.
The method for manufacturing a semiconductor of the present invention is a method for manufacturing a semiconductor including a substrate, which comprises cleaning the substrate by using the cleaning method described above.

According to the method of this embodiment, as described above, even when at least a part of the surface of the substrate is made of VDD or other easily corrosive metal such as cobalt, copper, tungsten or SiGe, cobalt, copper, Semiconductors can be manufactured by suppressing corrosion of VDD and other easily corrosive metals such as tungsten and SiGe.

<< Lithography method >>
A lithography method including using the cleaning method of the present invention or the anticorrosion method of the present invention is also one of the present inventions. The anticorrosive method of the present invention may be a method of corroding a corrosive metal by using the above-mentioned cleaning liquid, anticorrosive agent, or the cleaning liquid or anticorrosive agent produced by the above method, or the anticorrosive agent may be used as a cleaning liquid. The above-mentioned description including contacting a corrosive metal (for example, a substrate on which the corrosive metal is exposed on the surface) with the lithographic chemical solution by impregnating the lithographic chemical solution such as a developing solution, a rinsing solution, and a stripping solution. It may be an anticorrosion method.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples.

[Control example]
As a control example, a solution consisting of 75.0% by mass of ethyldiglycol, 2.0% by mass of tetramethylammonium hydroxide TMAH) and 23.0% by mass of water (remaining portion) was prepared.

[Examples 1 to 4]
_{In the examples, hydrogen peroxide solution (H 2} O ₂ ) was stirred at 60 ° C. with alkanolamines (monoethanolamine, diethanolamine, monoisopropanolamine, diisopropanolamine) dissolved in water in the amounts shown in Table 1, respectively. It was added dropwise over 60 minutes. Then, after further reacting at 60 ° C. for 1 hour, the obtained reaction solution was added to 99.5 parts by mass of the solution as a control example so as to be 0.5 parts by mass, respectively, to prepare a washing solution.

For example, the composition of the washing liquid of Example 1 is 75.0 parts by mass of ethyldiglycol, 2.0 parts by mass of tetramethylammonium hydroxide (TMAH), 0.5 parts by mass of the above-mentioned reaction liquid, and water (remaining portion). ) 22.5 parts by mass.

As shown in Table 3, the reaction solution obtained by adding a hydrogen peroxide solution to alkanolamine in Examples 1 to 4 contains alkanolamine as a starting material and alkanolhydroxyamine as a product of an oxidation reaction. It was confirmed by liquid chromatography mass analysis (LC-MS) that it was a mixture with.

An example of the analysis result is shown. In the reaction solution obtained in Example 4, as a result of evaluation by liquid chromatography-mass spectrometry (LC-MS), peaks were observed at positions where the m / z values were 134.1172 and 150.1122. From this result, the reaction solution obtained in Example 4 is a mixture of diisopropanolamine, which is a starting material, and diisopropanolhydroxyamine, which is a product of an oxidation reaction in which one hydroxy group is bonded to a nitrogen atom. It turns out that there is. Further, as a result of evaluating the reaction solution of Example 4 by a nuclear magnetic resonance apparatus (NMR), it was confirmed that the molar ratio of starting material: reaction product = 59:41, and the yield of diisopropanol hydroxyamine was high. , 32.2%.

[Example 5]
As a cleaning solution, 1 of the reaction solution obtained in Example 4 was added to 100% by mass of a 2.38% aqueous solution of tetramethylammonium hydroxide (TMAH) (trade name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.). A cleaning solution was prepared by adding 0.0% by mass.

[Example 6]
As a cleaning liquid, it was obtained in Example 4 with respect to 100% by mass of an aqueous solution (trade name: NMD-W, manufactured by Tokyo Ohka Kogyo Co., Ltd.) containing 2.38% tetramethylammonium hydroxide (TMAH) and an activator. 1.0% by mass of the reaction solution was added to prepare a washing solution.

[Example 7]
As a cleaning liquid, a mixture consisting of 65% by mass of dipropylene glycol monomethyl ether (DPM), 5% by mass of propylene glycol (PG), 2.0% by mass of tetramethylammonium hydroxide (TMAH), and 28% by mass of water (remaining portion). 1.0% by mass of the reaction solution obtained in Example 4 was added to the solution to prepare a washing solution.

[Comparative Examples 1 to 6]
In Comparative Examples 1 to 6, as shown in Table 2, monoethanolamine, diethanolamine, diethylamine, monoisopropanolamine, diisopropanolamine, dipropylamine and water were mixed as comparative control compounds of the anticorrosive agent. 0.5 parts by mass of each of the mixtures was added to 99.5 parts by mass of the control solution to prepare a washing solution.

[Comparative Example 7]
_{In Comparative Example 7, hydrogen peroxide solution (H 2} O ₂ ) was added dropwise to dipropylamine dissolved in water at 60 ° C. over 60 minutes under stirring as a comparative control compound of the anticorrosive agent in the amount shown in Table 1. bottom. Then, after further reacting at 60 ° C. for 1 hour, the obtained reaction solution was added to 99.5 parts by mass of the solution as a control example so as to be 0.5 part by mass to prepare a washing solution. The reaction solution obtained in Comparative Example 7 was a mixture of dipropylamine and dipropylhydroxyamine, as shown in Table 4.

[Comparative Example 8]
A washing solution was prepared in the same manner as in Example 5 except that the reaction solution obtained in Example 4 was not added.

[Comparative Example 9]
A washing solution was prepared in the same manner as in Example 6 except that the reaction solution obtained in Example 4 was not added.

[Comparative Example 10]
A washing solution was prepared in the same manner as in Example 7 except that the reaction solution obtained in Example 4 was not added.

[Evaluation of etching rate for copper layer, tungsten layer, or cobalt layer]
Copper, tungsten, or cobalt was formed on a silicon substrate to obtain a silicon substrate having a copper layer, a tungsten layer, or a cobalt layer having a thickness of 100 nm. This silicon substrate was immersed in a cleaning solution heated to 60 ° C. for 60 minutes. After the immersion is completed, the silicon substrate is rinsed with pure water, the film thickness of the copper layer, the tungsten layer, or the cobalt layer is measured, and the etching rate of the copper layer, the tungsten layer, or the cobalt layer is determined from the difference in the film thickness before and after the immersion. Asked. The results are shown in Tables 3 and 4.

The evaluation of the etching rate in Tables 3 and 4 is based on the following criteria. The etching rate of the control example using the solution was 2.21 for the copper layer, 0.14 for the tungsten layer, and 0.35 for the cobalt layer. The unit for evaluating the etching rate is [nm / min].
・ Copper (Cu)
⊚: 0.2 or less, 〇: more than 0.2, 0.4 or less, ×: more than 0.4 ・ Tungsten (W)
⊚: 0.1 or less, 〇: more than 0.1, 0.2 or less, ×: more than 0.2 ・ Cobalt (Co)
⊚: 0.1 or less, 〇: more than 0.1, 0.2 or less, ×: more than 0.2

From the results in Tables 3 and 4, the cleaning solutions of Examples 1 to 4 containing a mixed solution of alkanol hydroxyamine and alkanolamine were all made of cobalt as compared with the cleaning solutions of Comparative Examples 1 to 7 containing no alkanol hydroxyamine. The etching rate was low and the corrosion suppression function was excellent. Of these, the cleaning solutions of Examples 2 and 4 containing a mixed solution of dialkanolhydroxyamine and dialkanolamine have a lower etching rate of copper and tungsten and an excellent corrosion suppressing function as compared with the cleaning solutions of Comparative Examples 1 to 7. Was there. It was confirmed that all of the alkanolhydroxyamines obtained in the examples had a larger LogP value, were excellent in water solubility, had a low vapor pressure, and were excellent in composition stability, as compared with the amines used in the comparative examples. ..

[Evaluation of etching rate for SiGe layer]
A silicon substrate provided with a SiGe layer having a thickness of 100 nm was immersed in the cleaning liquids (25 ° C.) of Examples 5 to 7 and Comparative Examples 8 to 10 for 10 minutes. After the completion of the immersion, the silicon substrate was rinsed with pure water, the film thickness of the SiGe layer was measured, and the etching rate of the SiGe layer was determined from the difference in the film thickness before and after the immersion. The results are shown in Table 5.

The evaluation of the etching rate in Table 5 is based on the following criteria. The unit for evaluating the etching rate is [nm / min].
・ SiGe
⊚: 0.01 or less, 〇: more than 0.01, 0.05 or less, ×: more than 0.05

From the results in Table 5, the washing solutions of Examples 5 to 7 using the reaction solution obtained in Example 4 containing a mixed solution of alkanol hydroxyamine and alkanolamine were all alkanol hydroxyamine (1,1'). It was confirmed that the etching rate of the SiGe layer was lower than that of the cleaning solutions of Comparative Examples 8 to 10 containing (hydroxyimino) bis (2-propanol)) and the corrosion suppressing function was excellent.

Claims (10)

Alkanol hydroxyamine represented by the following general formula (1) and
A cleaning solution containing a basic compound other than the alkanol hydroxyamine .
The content of the alkanol hydroxyamine is 0.001 to 10% by mass with respect to the total amount of the cleaning liquid.
A cleaning solution in which the content of the basic compound is 0.5 to 30% by mass with respect to the total amount of the cleaning solution .

(In the formula, R ^a1 and R ^a2 each independently represent an alkyl group or a hydrogen atom having 1 to 3 hydroxy groups and having 1 to 10 carbon atoms. However, R ^a1 and R ^a2 are hydrogen atoms at the same time. It will never be.) The basic compound is at least one selected from the group consisting of a quaternary ammonium hydroxide, an alkanolamine, a hydroxyamine compound other than the alkanolhydroxyamine, an alkylamine, and ammonia, according to claim 1. Cleaning solution. The cleaning solution according to claim 1 or 2, ^{wherein Ra1} and ^Ra2 in the general formula (1) are the same group. The cleaning solution according to any one of claims 1 to 3, wherein the content of the alkanol hydroxyamine is 0.001 to 1% by mass of the cleaning solution. The cleaning solution according to any one of claims 1 to 4, wherein the content of the basic compound is 1 to 20% by mass of the cleaning solution. The cleaning solution according to any one of claims 1 to 5, which has a pH of 8 or more. The cleaning solution according to any one of claims 1 to 6, which is a cleaning solution for lithography. Alkanol hydroxyamine represented by the following general formula (1) and
A cleaning solution containing a basic compound other than the alkanol hydroxyamine .
A method for producing a cleaning liquid, wherein the content of the alkanolhydroxyamine is 0.001 to 10% by mass and the content of the basic compound is 0.5 to 30% by mass with respect to the total amount of the cleaning liquid.
The method comprises a step of synthesizing the alkanolhydroxyamine by oxidizing an alkanolamine represented by the following general formula (2), and a step of synthesizing the alkanolhydroxyamine.
A method comprising the step of blending the reaction product from the above step with the basic compound.

(In the formula, R ^a1 and R ^a2 each independently represent an alkyl group or a hydrogen atom having 1 to 3 hydroxy groups and having 1 to 10 carbon atoms. However, R ^a1 and R ^a2 are hydrogen atoms at the same time. It will never be.)

(In the formula, R ^b1 and R ^b2 each independently represent an alkyl group or a hydrogen atom having 1 to 3 hydroxy groups and having 1 to 10 carbon atoms. However, R ^b1 and R ^b2 are hydrogen atoms at the same time. It will never be.) A method for cleaning a substrate using the cleaning solution according to any one of claims 1 to 7 or the cleaning solution produced by the method according to claim 8. A method for manufacturing a semiconductor including the substrate, which comprises cleaning the substrate by using the method according to claim 9.