JP2018109154A - Cleaning liquid and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning liquid having an excellent corrosion suppressing function and a method for producing the same. The cleaning solution 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. In the formula, Ra1 and Ra2 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. [Selection diagram] None

Description

  The present invention relates to a cleaning liquid 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. Such a semiconductor device is formed by a lithography method in which an etching process is performed using a resist pattern as a mask. It is manufactured by processing each of the above layers.

  Resist films, temporary laminated films (also referred to as sacrificial films) used in the above lithography method, and metal wiring layers and low dielectric layer-derived residues generated in the etching process do not interfere with the next process. It is removed using a cleaning solution so as not to hinder 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 liquid containing such a hydroxylamine derivative has improved removal performance with respect to various residues as compared to previous cleaning liquids.

International Publication No. 2011/027772

  In recent years, with the increase in density and integration of semiconductor devices, for example, a wiring formation method using a damascene method has been adopted. In such a wiring formation method, as a metal wiring material constituting a metal wiring layer of a semiconductor device, an easily corrosive metal, for example, cobalt, copper, tungsten are each in the form of a simple substance or an alloy, or a silicide such as SiGe, It is used as a metal wiring material in semiconductor devices. Silicides 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 the cleaning liquid. Therefore, there is a demand for a cleaning solution that hardly causes corrosion even for silicide and other easily corrosive metals such as cobalt, copper, tungsten, and SiGe during substrate cleaning.

  The present invention has been made in view of such a conventional situation, and a cleaning solution having an excellent anti-corrosion function against silicides and other easily corrosive metals such as cobalt, copper, tungsten, SiGe, and the like. The object is to provide a method of manufacturing.

  The inventors of the present invention have made extensive studies to solve the above problems. As a result, it has been found that the above problem can be solved by using a specific alkanolhydroxyamine and a basic compound in the cleaning liquid, and the present invention has been completed. Specifically, the present invention provides the following.

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

（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 represents an alkyl group having 1 to 10 carbon atoms or a hydrogen atom having 1 to 3 hydroxy groups, provided that R ^a1 and R ^a2 are simultaneously hydrogen atoms. It will never be.)

  A second aspect of the present invention is a method for producing a cleaning liquid containing an alkanolhydroxyamine represented by the general formula (1) and a basic compound other than the alkanolhydroxyamine, the method comprising: 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 of the step with the basic compound. is there.

（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 represents an alkyl group having 1 to 10 carbon atoms or a hydrogen atom having 1 to 3 hydroxy groups, provided that R ^b1 and R ^b2 are simultaneously hydrogen atoms. It will never be.)

  ADVANTAGE OF THE INVENTION According to this invention, the washing | cleaning liquid excellent in the corrosion inhibitory function with respect to silicide and other easily corrosive metals, such as cobalt, copper, tungsten, SiGe, and the method of manufacturing this can be provided.

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

In the cleaning liquid of this embodiment, R ^a1 and R ^a2 in the general formula (1) are preferably the same group.

  In the cleaning liquid of this embodiment, the basic compound is composed of 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.

  Furthermore, the cleaning liquid of this embodiment preferably has a pH of 8 or more, and more preferably 9 or more. In such a pH range, silicide and other easily corrosive metals such as cobalt, copper, tungsten, and SiGe, in particular, the tendency of the oxidation-reduction potential of cobalt to be lowered tends to decrease. The cleaning liquid of this embodiment can effectively remove the object to be cleaned while suppressing the corrosion of cobalt even at a pH corresponding to such a corrosive zone 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 a semiconductor manufacturing process, a lithography process, an etching process, a FEOL (Front End of Line) process such as chemical mechanical polishing (CMP), a BEOL (Back End of Line) process such as a wiring formation process, and silicon penetration It is suitable as a cleaning liquid used in a subsequent process such as an electrode (TSV) or a C4 construction method (Controlled Collapse Chip Connection), and is preferably used for cleaning a substrate having a metal on its surface. A substrate having a metal on the surface means a substrate in which the metal is exposed on at least a part of the substrate surface. The metal is, for example, a metal formed as a metal wiring layer, a plug, or other metal structure on the substrate on which the semiconductor device is formed. Examples of the substrate include a substrate in which a semiconductor device is formed by laminating a metal wiring layer, a low dielectric layer, an insulating layer, etc. on a substrate such as a silicon wafer. 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 a corrosive metal, or an alloy thereof. Examples of the cobalt alloy include alloys with at least one of other transition elements and typical elements (for example, phosphorus, boron, silicon, etc.). Specifically, phosphorus and / or boron-containing alloys such as CoWPB, And silicide such as CoSi. Further, the metal may be copper, tungsten, germanium, or any alloy thereof, which is another easily corrosive metal, and as the alloy, at least one of copper and tungsten, and other Examples include alloys with at least one of transition elements and typical elements (for example, phosphorus, boron, silicon, etc.). Specifically, phosphorus and / or boron-containing alloys such as CuPB, and silicides such as WSi and SiGe are used. Illustrated. When dialkanolhydroxyamine and dialkanolamine, which will be described later, are used, a corrosion inhibiting effect is easily obtained not only for cobalt but also for copper, dungsten, and SiGe. Hereinafter, in this specification, “cobalt or an alloy thereof”, “copper or an alloy thereof” and “tungsten or an alloy thereof” may be simply referred to as “cobalt”, “copper” and “tungsten”, respectively.

  The cleaning liquid of this embodiment is superior to at least silicides and other corrosive metals such as cobalt, copper, tungsten, and SiGe by containing an alkanolhydroxyamine and a basic compound other than the alkanolhydroxyamine. Has a corrosion inhibiting function. Therefore, even when the cleaning solution comes into contact with silicide or other corrosive metals such as cobalt, copper, tungsten, or SiGe on the surface of the substrate, the silicide or other easily corrosive metals such as cobalt, copper, tungsten, or SiGe may be used. Corrosion of metals is well controlled. Although the mechanism of action is not clear, it is presumed that corrosion of silicide and other easily corrosive metals such as cobalt, copper, tungsten and SiGe is suppressed by the reducing action of alkanolhydroxyamine.

  In addition, 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 does, a composition change is suppressed and it is useful as a washing | 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 still more preferably 0.05 mmHg or less.

  Furthermore, since the alkanolhydroxyamine represented by the general formula (1) is higher in water solubility than the alkanolamine represented by the general formula (2), water having a low cost is used as a solvent or a solvent. In addition, it is possible to suppress residues in the cleaning with such an aqueous solution, which is useful as a cleaning liquid. For example, it is suitable to use an alkanolhydroxyamine whose LogP is preferably 0.5 or less.

  The LogP value means an octanol / water partition coefficient, and can be calculated by calculation using parameters of Gose, Pritchett, 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 alkanolhydroxyamine, an alkanolhydroxyamine represented by the general formula (1) is used. In the formula, R ^a1 and R ^a2 each independently represent a C 1-10 alkyl group having 1 to 3 hydroxy groups or a hydrogen atom. However, R ^a1 and R ^a2 are not simultaneously hydrogen atoms.

As the alkanolhydroxyamine, dialkanolhydroxyamine in which R ^a1 and R ^a2 are alkyl groups having 1 to 10 carbon atoms and having 1 to 3 hydroxy groups is preferable. The use of such an alkanolhydroxyamine is preferable in that a corrosion inhibitory effect on not only cobalt but also silicide, such as copper, tungsten, SiGe, and other easily corrosive metals can be obtained.

The number of hydroxy groups in R ^a1 and R ^a2 may be one or two, respectively, and even if it is one, the effects 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 constitute any of primary alcohol, secondary alcohol, or tertiary alcohol, but secondary alcohol It is preferable to constitute.

The alkyl group having 1 to 10 carbon atoms in R ^a1 and R ^a2 may be any linear, branched or cyclic alkyl group, such as 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-o A til group, an n-nonyl group, an n-decyl group, and the like. A linear or branched alkyl group having 1 to 4 carbon atoms is preferable, and an ethyl group, an n-propyl group, an isopropyl group is particularly preferable. Is preferred.

Specific examples of the linear or branched alkyl group having 1 to 4 carbon atoms and having 1 to 3 hydroxyl groups in R ^a1 and R ^a2 include, for example, 1-hydroxyethyl group, 2-hydroxyethyl group 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-hydro Siisopropyl 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 group Ci-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 1,4-dihydride Xi-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-trihydroxy-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-2-hydroxymethyl-n-propyl group, 1-hydroxy-2-methylisopropyl group, 1,3-dihydroxy-2-methylisopropyl group, 1,3-dihydroxy-2-hydroxymethyl An isopropyl group etc. are mentioned, 2-dihydroxyethyl group, 2-hydroxy-n-propyl group, and 2-hydroxyisopropyl group are especially 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. More preferably it is. By setting it as such content, a to-be-cleaned object can be removed effectively, suppressing corrosion of silicides, such as a corrosive metal, especially cobalt, copper, tungsten, SiGe.

<Basic compound>
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 represented by the 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 general formula (3), R ^{c1 to} R ^c4 are each independently an alkyl group having 1 to 16 carbon atoms, an aryl group having 6 to 16 carbon atoms, an aralkyl group having 7 to 16 carbon atoms, or carbon. A hydroxyalkyl group having 1 to 16 atoms is shown.

  Among the compounds represented by the general formula (3), tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, methyltripropylammonium hydroxide , 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: Furthermore, tetramethylammonium hydroxide and tetraethylammonium hydroxide are preferable because they have high solubility in an object to be cleaned and high cleaning performance.

[Inorganic base]
Moreover, as a basic compound, you may use together an inorganic base with a quaternary ammonium hydroxide, for example. As the inorganic base, alkali metal hydroxides such as potassium hydroxide, sodium hydroxide and rubidium hydroxide are preferable, and potassium hydroxide is more preferable.

[Alkanolamine]
Examples of the alkanolamine include triethanolamine, 2- (2-aminoethoxy) ethanol, N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-dibutylethanolamine, N-methylethanolamine, 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, diisopropanolamine may be used.

  In addition, when a cleaning liquid is produced by a method including a 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 alkanolhydroxyamine represented by the general formula (1) include N-methylhydroxyamine, N-ethylhydroxyamine, N- (tert-) in addition to hydroxyamine (HO—NH ₂ ). Examples thereof include monoalkylhydroxyamines such as (butyl) hydroxyamine and N-propylhydroxyamine; dialkylhydroxyamines such as N, N-diethylhydroxyamine and N, N-dimethylhydroxyamine;

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

[Other basic compounds]
As the basic compound, ammonia can also be used.

  The content of the basic compound other than the alkanolhydroxyamine represented by the 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 liquid. Is preferable, and it is more preferable that it is 1-20 mass%. By setting it as such content, a to-be-cleaned object can be removed effectively, suppressing corrosion of silicides, such as a corrosive metal, especially cobalt, copper, tungsten, SiGe. In addition, when using an inorganic base together with a quaternary ammonium hydroxide, it is preferable that content of an inorganic base is 0.1 mass ppm-1 mass% with respect to the washing | cleaning liquid whole quantity, and 1 mass ppm-1000 mass. More preferably, it is ppm. By setting it as such content, a to-be-cleaned object can be removed effectively, suppressing corrosion of silicides, such as a corrosive metal, especially cobalt, copper, tungsten, SiGe. In addition, as described above, when alkanolamine is used as the basic compound, it is preferable to use two or more basic compounds separately using another basic compound in addition to alkanolamine.

<Solvent>
Moreover, the cleaning liquid of the present invention may contain a solvent for dissolving 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 the organic solvent can be used, and preferably contains water. . As water, pure water, deionized water, ion-exchanged water, or the like can be used. An organic solvent may be used independently and may be used in combination of 2 or more type.

  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 preferable in that the alkanolhydroxyamine is generally highly soluble and hardly remains 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 the solvent, the water content relative 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%. More preferred is mass%.

  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, N-methylformamide Amides such as N, N-dimethylacetamide, N-methylacetamide, N, N-diethylacetamide; 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- 2-Imidazolidinone, 1,3-diechi Imidazolidinones such as 2-imidazolidinone and 1,3-diisopropyl-2-imidazolidinone; ethylene glycol, propylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene Polyhydric alcohols such as glycol, glycerin and diethylene glycol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monoallyl ether, propylene 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, Glycol monoalkyl ethers such as triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monobutyl ether, tripropylene glycol monobutyl ether, ethylene glycol dimethyl ether, die Glycol ether solvents such as glycol dialkyl ethers such as tylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, and diethylene glycol diethyl ether; ethylene glycol monoacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl Examples include glycol ester solvents such as ether acetate and diethylene glycol monoacetate.

  Among them, preferable water-soluble organic solvents are selected from dipropylene glycol monomethyl ether (DPM), propylene glycol (PG), 3-methoxy-3-methyl-1-butanol, dimethyl sulfoxide, propylene glycol monomethyl ether, propylene glycol It is 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 more preferable. By setting it as such content, a to-be-cleaned object can be removed effectively, suppressing corrosion of silicides, such as a corrosive metal, especially cobalt, copper, tungsten, SiGe.

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

  In addition, the cleaning liquid of this embodiment does not need to contain other anticorrosive agents as long as it contains an alkanolhydroxyamine represented by the above general formula (1) and a basic compound, but other anticorrosive agents. An agent may also be contained. Examples of such other anticorrosive agents include, but are not limited to, benzotriazole, aminotetrazole, 5-amino-1-phenyltetrazole, 5-amino-1- (1-naphthyl) tetrazole, and 1-methyl-5-amino. In addition to nitrogen-containing heterocyclic compounds such as tetrazole, 1,5-diaminotetrazole, imidazole, indole, purine, pyrazole, pyridine, pyrimidine, pyrrole, pyrrolidine, and pyrroline, secondary amine compounds, amino acid compounds, and the like can be given.

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

In the anticorrosive agent of this 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 preferable that at least one is selected. In the anticorrosive agent of this embodiment, R ^a1 and R ^a2 in the general formula (1) are preferably the same group.

  As described above, the anticorrosive agent of the present embodiment contains an alkanolhydroxyamine and a basic compound other than the alkanolhydroxyamine, whereby a metal, particularly silicide such as cobalt, copper, tungsten, SiGe, and other easily corroded materials. Corrosion of the conductive metal can be effectively suppressed.

<< Method for Producing Cleaning Liquid >>
The method for producing the cleaning liquid of the present invention is a method for producing a cleaning liquid containing an alkanolhydroxyamine represented by the general formula (1) and a basic compound, and is represented by the general formula (2). The method comprises a step of synthesizing the alkanolhydroxyamine by oxidizing the alkanolamine, and a step of blending the reaction product of the step with a basic compound. The method for producing the cleaning liquid of the present invention is suitable as a method for producing the cleaning liquid of the first aspect of the present invention or the above-described anticorrosive agent of the present invention.

In the general formula (2) representing the starting alkanolamine, R ^b1 and R ^b2 each independently represent a C 1-10 alkyl group having 1 to 3 hydroxy groups or a hydrogen atom. However, R ^b1 and R ^b2 are not simultaneously hydrogen atoms.

The alkanolamine is preferably a dialkanolamine in which R ^b1 and R ^b2 are alkyl groups having 1 to 10 carbon atoms having 1 to 3 hydroxy groups as described above. Use of such an alkanolamine is preferable in that a corrosion inhibiting effect on not only cobalt but also copper or tungsten can be obtained.

In the above reaction for oxidizing alkanolamine, since it is not usually oxidized, R ^b1 in general formula (2) is the same group as R ^a1 in general formula (1), and R ^b2 in general formula (2) is It is the same group as R ^a2 in the general formula (1), specifically as follows.

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

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

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

Similarly to R ^a1 and R ^a2 in the general formula (1), R ^b1 and R ^b2 in the general formula (2) are preferably the same group. Further, R ^a1 , R ^a2 , R ^b1 and R ^b2 are preferably the same group.

  Hydrogen peroxide etc. are mentioned as an oxidizing agent which oxidizes alkanolamine.

  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. By setting it as such addition amount, the alkanolhydroxyamine can be produced | generated from alkanolamine, and the liquid mixture which has a high anticorrosion effect can be obtained.

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

For example, as shown in the following reaction formula, by adding hydrogen peroxide water (H ₂ O ₂ ) to diethanolamine, which is an alkanolamine, and oxidizing it, 2,2 ′, which is an alkanolhydroxyamine, is obtained as a reaction product. -(Hydroxyimino) bisethanol can be obtained.

  However, in the above reaction, it is difficult for the total amount of diethanolamine to be oxidized, and the resulting reaction solution tends to be a mixture of diethanolamine and 2,2 '-(hydroxyimino) bisethanol. The yield of 2,2 '-(hydroxyimino) bisethanol, which is an alkanolhydroxyamine, is about 25% to 70%, depending on the reaction conditions.

  In the method for producing the cleaning liquid 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 for the cleaning liquid of this embodiment without isolation and purification, and the production efficiency is good. Moreover, compared with the case where alkanolamine or alkanolhydroxyamine is used for a washing | cleaning liquid or an anticorrosion agent alone, the washing | cleaning liquid or anticorrosion agent which has a high anticorrosion effect can be obtained. In addition, according to this method, an alkanolamine becomes a basic compound and can exhibit a high anticorrosion effect.

<< Cleaning method >>
A cleaning method using the cleaning liquid of the present invention is also one aspect of the present invention.
The cleaning method of the present invention is a method for cleaning a substrate using the above-described cleaning liquid or the cleaning liquid manufactured by the above-described method.

The cleaning of the substrate is suitable as the cleaning of the substrate in lithography.
For example, the cleaning method of the present embodiment is performed in an etching mask layer forming process for forming an etching mask layer having a predetermined pattern on the surface of the substrate, and in a subsequent process of the etching process for etching the substrate exposed from the etching mask layer. In other words, this is a method of cleaning the etched substrate. The cleaning method of this embodiment is suitable when at least a part of the surface of the substrate is made of silicide or other easily corrosive metal such as cobalt, copper, tungsten, or SiGe. At this time, at least a part of the silicide or other easily corrosive metal such as cobalt, copper, tungsten, or SiGe is exposed on the surface of the substrate and is in contact with the cleaning solution. However, cobalt, copper, tungsten, SiGe, or the like is used. Corrosion of silicide and other easily corrosive metals is well suppressed. Therefore, by cleaning with the above-described cleaning liquid, it is possible to effectively remove the object to be cleaned while suppressing the corrosion of silicide 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 this embodiment is 0.2 nm / min or less, preferably 0.1 nm / min or less, more preferably 0.09 nm / min with respect to cobalt. The following is small and the corrosion inhibiting effect is large. Similarly, according to the evaluation of the etching rate, it can be reduced to 0.4 nm / min or less, preferably 0.2 nm / min or less, more preferably 0.04 nm / min or less for copper. Yes, anti-corrosion effect can be expected. Similarly, according to the evaluation of the etching rate, it can be reduced to 0.2 nm / min or less, preferably 0.1 nm / min or less, more preferably 0.01 nm / min or less for tungsten. Yes, anti-corrosion effect can be expected. Similarly, according to the evaluation of the etching rate, it can be reduced to 0.05 nm / min or less, preferably 0.01 nm / min or less with respect to SiGe, and a corrosion inhibiting effect can be expected. When the dialkanolhydroxyamine and dialkanolamine described above are used, it is easy to obtain a corrosion inhibiting effect not only on cobalt but also on silicide 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 commonly performed method. For example, using a dipping method, a paddle method, a shower method or the like, the substrate is brought into contact with the above-described cleaning liquid for 1 to 40 minutes. 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.

<< Anti-corrosion method >>
Thus, the method of anticorrosion of an easily corrosive metal using the washing | cleaning liquid mentioned above, anticorrosion agent, or the washing | cleaning liquid or anticorrosion agent manufactured by the said method is also one of this invention. The anticorrosion method includes, for example, contacting a silicide or other easily corrosive metal such as cobalt, copper, tungsten, or SiGe (for example, a substrate with the easily corroded metal exposed on the surface) with the cleaning liquid or the anticorrosive. Specifically, it can be performed in the same manner as the above-described cleaning method.

  Moreover, the method of anticorrosion of an easily corrosive metal using the anticorrosive agent mentioned above or the anticorrosive agent manufactured by the said method adds this anticorrosive agent to the chemical | medical solution for lithography, such as a washing | cleaning liquid, a developing solution, a rinse solution, and a peeling solution. Incorporating into the chemical solution for lithography, for example, a silicide or other easily corrosive metal such as cobalt, copper, tungsten, or SiGe (for example, a substrate having the easily corroded metal exposed on the surface) is added to the lithography solution. Including contacting with. Such an anticorrosion method is, for example, a cleaning method usually used in a lithography method (for example, the above-described cleaning method) depending on the type or use of a chemical solution for lithography such as a cleaning solution, a developer solution, a rinsing solution, or a stripping solution containing the anticorrosive agent. ), A developing method, a rinsing method, and a peeling method can be used. The lithographic chemical solution containing the anticorrosive agent of this embodiment is preferably a cleaning solution or a developer. As the developer, for example, an alkali developer 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 aspect of the present invention. Examples of the lithographic chemical solution include a cleaning solution, a developing solution, a rinsing solution, a stripping solution, and the like, and a cleaning solution is preferable.

<< Semiconductor Manufacturing Method >>
A method for manufacturing a semiconductor including using the cleaning method of the present invention is also one of the present invention.
The method for manufacturing a semiconductor of the present invention is a method for manufacturing a semiconductor including a substrate, which includes cleaning the substrate using the cleaning method described above.

  According to the method of the present embodiment, as described above, even when at least a part of the surface of the substrate is made of silicide or other easily corrosive metal such as cobalt, copper, tungsten, or SiGe, cobalt, copper, It is possible to manufacture a semiconductor while suppressing corrosion of silicide 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 aspect of the present invention. The anticorrosion method of the present invention may be the above-described cleaning solution, anticorrosive agent, or a method of anticorrosive metal anticorrosion using the cleaning solution or anticorrosive agent produced by the above method, or the anticorrosive agent as a cleaning solution, Including in a lithographic chemical solution such as a developer, a rinsing solution, a stripping solution, etc., and contacting an easily corrosive metal (for example, a substrate having the easily corroded metal exposed on the surface) with the lithographic chemical solution. An anticorrosion method may be used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples.

[Control example]
As a control example, a solution comprising 75.0% by mass of ethyl diglycol, 2.0% by mass of tetramethylammonium hydroxide TMAH, and 23.0% by mass of water (remainder) was prepared.

[Examples 1 to 4]
In Examples, hydrogen peroxide water (H ₂ O ₂ ) was stirred at 60 ° C. in alkanolamine (monoethanolamine, diethanolamine, monoisopropanolamine, diisopropanolamine) dissolved in water in the amounts shown in Table 1, respectively. It was dripped over 60 minutes. And after reacting further at 60 degreeC for 1 hour, the obtained reaction liquid was added so that it might become 0.5 mass part with respect to 99.5 mass parts of the solutions used as a control, respectively, and the washing | cleaning liquid was prepared.

  For example, the composition of the cleaning liquid of Example 1 is 75.0 parts by mass of ethyl diglycol, 2.0 parts by mass of tetramethylammonium hydroxide (TMAH), 0.5 parts by mass of the reaction liquid described above, and water (remainder). 22.5 parts by mass.

  The reaction liquid obtained by adding hydrogen peroxide to alkanolamine in Examples 1 to 4, as shown in Table 3, was alkanolamine as a starting material and alkanolhydroxyamine as a product of an oxidation reaction. All were confirmed by liquid chromatography mass spectrometry (LC-MS).

  An example of an 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 m / z values were 134.1172 and 150.1122. From this result, the reaction solution obtained in Example 4 is a mixture of diisopropanolamine as a starting material and diisopropanolhydroxyamine in which one hydroxy group is bonded to a nitrogen atom as a product of an oxidation reaction. I know that there is. Moreover, as a result of evaluating the reaction liquid of this Example 4 with a nuclear magnetic resonance apparatus (NMR), it was confirmed that it was a molar ratio of starting material: reaction product = 59: 41, and the yield of diisopropanolhydroxyamine was It was 32.2%.

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

[Example 6]
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 as a cleaning liquid. 1.0% by mass of the reaction solution was added to prepare a cleaning solution.

[Example 7]
As a cleaning liquid, a mixture comprising 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 (remainder) To the solution, 1.0% by mass of the reaction solution obtained in Example 4 was added to prepare a cleaning solution.

[Comparative Examples 1-6]
In Comparative Examples 1-6, as shown in Table 2, it was obtained by mixing monoethanolamine, diethanolamine, diethylamine, monoisopropanolamine, diisopropanolamine, dipropylamine and water as a comparative control compound of the anticorrosive. 0.5 parts by mass of each mixture was added to 99.5 parts by mass of a control solution to prepare a cleaning solution.

[Comparative Example 7]
In Comparative Example 7, hydrogen peroxide (H ₂ O ₂ ) was added dropwise at 60 ° C. over 60 minutes with stirring to dipropylamine dissolved in water as an anticorrosive comparative compound in the amounts shown in Table 1. did. And after reacting further at 60 degreeC for 1 hour, the obtained reaction liquid was added so that it might become 0.5 mass part with respect to 99.5 mass parts of solutions used as a control, and the washing | cleaning liquid was prepared. As shown in Table 4, the reaction solution obtained in Comparative Example 7 was a mixture of dipropylamine and dipropylhydroxyamine.

[Comparative Example 8]
A cleaning 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 cleaning 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 cleaning 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 over a silicon substrate to obtain a silicon substrate having a copper layer, tungsten layer, or cobalt layer with a thickness of 100 nm. This silicon substrate was immersed in a cleaning solution heated to 60 ° C. for 60 minutes. After immersion, rinse the silicon substrate with pure water, measure the film thickness of the copper layer, tungsten layer, or cobalt layer, and etch the copper layer, tungsten layer, or cobalt layer from the difference in film thickness before and after 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 with the control solution was 2.21 for the copper layer, 0.14 for the tungsten layer, and 0.35 for the cobalt layer. The unit of evaluation of the etching rate is [nm / min].
・ Copper (Cu)
A: 0.2 or less, ◯: more than 0.2, 0.4 or less, x: more than 0.4, tungsten (W)
◎: 0.1 or less, ○: more than 0.1 or less, 0.2, ×: more than 0.2 Cobalt (Co)
A: 0.1 or less, ○: more than 0.1 and less than 0.2, x: more than 0.2

  From the results of Tables 3 and 4, in the cleaning liquids of Examples 1 to 4 including a mixed liquid of alkanol hydroxyamine and alkanolamine, all of the cleaning liquids of Comparative Examples 1 to 7 not including alkanol hydroxyamine were compared with cobalt. The etching rate was small and the corrosion inhibition function was excellent. Among these, in the cleaning liquids of Examples 2 and 4 including a mixed liquid of dialkanolhydroxyamine and dialkanolamine, compared with the cleaning liquids of Comparative Examples 1 to 7, the etching rate of copper and tungsten is small and the corrosion inhibiting function is excellent. It was. In addition, it was confirmed that all the alkanolhydroxyamines obtained in the Examples had a large LogP value, excellent water solubility, low vapor pressure, and excellent composition stability, compared to the amines used in Comparative Examples. .

[Evaluation of etching rate for SiGe layer]
The silicon substrate provided with the 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 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 film thickness before and after 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 of evaluation of the etching rate is [nm / min].
・ SiGe
A: 0.01 or less, ○: more than 0.01 or less, 0.05 or less, ×: more than 0.05

  From the results of Table 5, all of the cleaning liquids of Examples 5 to 7 using the reaction liquid obtained in Example 4 containing a mixed liquid of alkanolhydroxyamine and alkanolamine are alkanolhydroxyamine (1,1 ′ Compared to the cleaning solutions of Comparative Examples 8 to 10 that do not contain (hydroxyimino) bis (2-propanol)), it was confirmed that the etching rate was small for the SiGe layer and the corrosion inhibition function was excellent.

Claims (10)

An alkanolhydroxyamine represented by the following general formula (1);
A cleaning liquid containing a basic compound other than the alkanolhydroxyamine.

(In the formula, R ^a1 and R ^a2 each independently represents an alkyl group having 1 to 10 carbon atoms or a hydrogen atom having 1 to 3 hydroxy groups, provided that R ^a1 and R ^a2 are simultaneously hydrogen atoms. It will never be.)   2. The basic compound according to claim 1, wherein 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. Cleaning liquid. The cleaning liquid according to claim 1 or 2, wherein R ^a1 and R ^a2 in the general formula (1) are the same group.   The cleaning liquid according to claim 1, wherein the content of the alkanolhydroxyamine is 0.001 to 1% by mass of the cleaning liquid.   The cleaning liquid 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 liquid.   The cleaning liquid according to any one of claims 1 to 5, wherein the pH is 8 or more.   The cleaning liquid according to claim 1, wherein the cleaning liquid is a lithography cleaning liquid. An alkanolhydroxyamine represented by the following general formula (1);
A method for producing a cleaning liquid containing a basic compound other than the alkanolhydroxyamine,
In the method, the step of synthesizing the alkanolhydroxyamine by oxidizing the alkanolamine represented by the following general formula (2); and
The method including the process of mix | blending the reaction product by the said process, and the said basic compound.

(In the formula, R ^a1 and R ^a2 each independently represents an alkyl group having 1 to 10 carbon atoms or a hydrogen atom having 1 to 3 hydroxy groups, provided that R ^a1 and R ^a2 are simultaneously hydrogen atoms. It will never be.)

(In the formula, R ^b1 and R ^b2 each independently represents an alkyl group having 1 to 10 carbon atoms or a hydrogen atom having 1 to 3 hydroxy groups, provided that R ^b1 and R ^b2 are simultaneously hydrogen atoms. It will never be.)   A method for cleaning a substrate using the cleaning liquid according to claim 1 or the cleaning liquid produced by the method according to claim 8.   A method of manufacturing a semiconductor comprising the substrate, comprising cleaning the substrate using the method of claim 9.