KR20180127908A - Etching fluid, replenishing fluid, and method for forming copper wiring - Google Patents

Abstract

The present invention provides an etching fluid having a side etching suppressing effect and being excellent in formation of a fine pattern of copper wiring. According to the present invention, an etching fluid for copper is an aqueous solution including acid, oxidant metal ions, and one or more kinds of compounds selected from a group consisting of 5-membered ring heteroaromatic (A), 5- or 6-membered ring heteroaromatic (B), and alkanolamine (B2). The 5-membered ring heteroaromatic (A) is a heteroaromatic compound not having a hydroxyalkyl group and having 1 or more nitrogen atoms as a hetero atom forming a ring. The 5- or 6-membered ring heteroaromatic (B) is a heteroaromatic compound having 1 or more nitrogen atoms as a hetero atom forming a ring, and substituted with a substituent group having a hydroxyalkyl group with 1 or more to 5 or less of carbon atoms. The alkanolamine (B2) is a compound represented by R^1 -N(R^2 )-R^3, wherein R^1 and R^2 is independently an alkyl group or a hydroxyalkyl group having 1 or more to 8 or less of carbon atoms, R^3 is a hydrogen atom, an alkyl group, or a hydroxyalkyl group having 1 or more to 8 or less of carbon atoms, and at least one of R^1 to R^3 is a hydroxyalkyl group.

Description

METHOD FOR FORMING ETCHING FLUIDS, METHODS FOR FORMING COPPER WIRING,

The present invention relates to a copper etching solution, a replenishing solution thereof, and a method for forming a copper wiring.

In the production of a printed wiring board, when a copper wiring pattern is formed by a photoetching method, a ferric chloride-based etching solution, a copper chloride-based etching solution, an alkaline etching solution, or the like is used as an etching solution. When these etchants are used, copper under the etching resist called side etching sometimes dissolves from the side surface of the wiring pattern. That is, by covering with the etching resist, a portion (that is, a copper wiring portion) which is not desired to be removed by the etching solution originally is removed by the etching solution, and the width Tapering phenomenon has occurred. Especially when the copper wiring pattern is fine, this side etching should be made as small as possible. In order to suppress this side etching, there has been proposed an etching solution in which an azole compound as a five-membered ring compound in a complex direction is compounded (Patent Documents 1 to 4)

Japanese Patent Application Laid-Open No. 2007-332430 Japanese Patent Application Laid-Open No. 2005-330572 Publication No. 2009-79284 Publication No. 2009-221596

In the etching solution disclosed in the above-mentioned patent documents, a certain effect of suppressing the side etching is expected. However, in the market, as the demand for miniaturization becomes strong, an etching solution excellent in the formation of a copper wiring fine pattern while having an effect of suppressing the side etching has been demanded.

The present invention has been made in view of the above-described circumstances, and provides a method of forming an etchant, a replenished solution thereof, and a copper wiring, which is excellent in suppressing the side etching and excellent in forming fine patterns of copper wiring.

The etching solution for copper of the present invention is characterized in that the etching solution comprises a complex aromatic compound (A) having an acid, an oxidizing metal ion and a 5-membered ring, a heteroaromatic compound (B1) (B2), wherein the heteroaromatic compound (A) having the five-membered ring has no hydroxyalkyl group and further has a nitrogen atom as a heteroatom constituting the ring And the heteroaromatic compound (B1) having 5 or 6-membered rings is a heteroaromatic compound having at least one nitrogen atom as a heteroatom constituting the ring and further having a hydroxyalkyl group having 1 to 5 carbon atoms (1): R ¹ -N (R ² ) -R ³ (in the general formula (1), R ¹ and R ² are each independently a substituted or unsubstituted aromatic compound, , Independently, an alkyl group or an alkyl group having 1 to 8 carbon atoms And R ³ represents a hydrogen atom, an alkyl group, or a hydroxyalkyl group having 1 to 8 carbon atoms, and at least one of R ¹ to R ³ is the above-mentioned hydroxyalkyl group) Which is a compound.

The replenishing liquid to be added to the etchant when the etchant is used continuously or repeatedly is characterized in that the replenishing liquid contains the complex aromatic compound (A) having the five-membered ring and the heteroaromatic compound having the 5- to 6- Which is an aqueous solution containing at least one compound selected from the group consisting of the compound (B1) and the alkanolamine (B2).

The present invention relates to a copper wiring forming method for etching a portion of a copper layer not covered with an etching resist, and a method of forming a copper wiring for etching using the etching liquid.

Further, in the present invention, " copper " may be made of copper or may be made of a copper alloy. In the present specification, "copper" refers to copper or a copper alloy.

The etching solution of the present invention is selected from the group consisting of an acid, an oxidizing metal ion, and a heteroaromatic compound (A) having a 5-membered ring, a heteroaromatic compound (B1) having a 5- to 6-membered ring, and alkanolamine (B2) ≪ / RTI > The at least one compound selected from the group consisting of the heteroaromatic compound (B1) having 5 to 6-membered rings and the alkanolamine (B2) is capable of capturing the cuprous ions generated simultaneously with the progress of the etching, It is possible to provide a method for forming an etchant, its replenishment liquid, and a copper wiring, which is superior in the effect of suppressing the side etching and is excellent in the formation of the copper wiring fine pattern.

1 is a cross-sectional view showing an example of a copper wiring after etching by the etching solution of the present invention.

<Copper etching solution>

The copper etching solution of the present invention is a copper etching solution comprising a complex aromatic compound (A) having an acid, an oxidizing metal ion and a five-membered ring, a heteroaromatic compound (B1) having a 5- to 6-membered ring, and an alkanolamine Is an aqueous solution comprising at least one compound selected. The heteroaromatic compound (A) having a five-membered ring is a heteroaromatic compound having no hydroxyalkyl group and having at least one nitrogen atom as a heteroatom constituting a ring. The heteroaromatic compound (B1) having 5 to 6 member rings is a heteroaromatic compound having at least one nitrogen atom as a hetero atom constituting a ring and substituted with a substituent having a hydroxyalkyl group having 1 to 5 carbon atoms . The alkanolamine (B2) and the general formula ^{(1): R 1 -N (} R 2) -R 3 ( formula (1) of, R ¹ and R ² are, independently, an alkyl group, or C 1 or higher And R ³ represents a hydrogen atom, an alkyl group, or a hydroxyalkyl group having 1 to 8 carbon atoms, and at least one of R ¹ to R ³ is the above hydroxyalkyl group. &Lt; / RTI &gt;

<Mountain>

The acid of the present invention can be appropriately selected from an inorganic acid and an organic acid. Examples of the inorganic acid include sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, and hydrobromic acid. Examples of the organic acid include formic acid, acetic acid, oxalic acid, maleic acid, benzoic acid and glycolic acid. Of these acids, hydrochloric acid is preferable from the viewpoints of the stability of the etching rate and the dissolution stability of copper. At least one of these acids may be used, or two or more of them may be used in combination.

The concentration of the acid is preferably 7 to 180 g / L, more preferably 18 to 110 g / L. When the concentration of the acid is 7 g / L or more, the etching rate is increased, so that it is possible to rapidly etch copper. When the acid concentration is 180 g / L or less, the dissolution stability of copper is maintained and the deterioration of the working environment can be suppressed.

 <Oxidizing metal ion>

The oxidizing metal ion of the present invention may be any metal ion capable of oxidizing metal copper, and examples thereof include cupric ion and ferric ion. From the viewpoint of suppressing the side etching and the stability of the etching rate, it is preferable to use a cupric ion as the oxidizing metal ion. At least one kind of oxidizing metal ions may be used, or two or more kinds of them may be used in combination.

The oxidizing metal ion can be contained in the etching liquid by blending an oxidizing metal ion source (source). For example, when a cupric ion source is used as the oxidizing metal ion source, specific examples thereof include copper oxide, copper sulfate, copper bromide, copper salt of organic acid, copper hydroxide and the like. For example, when a ferric ion source is used as the oxidizing metal ion source, specific examples thereof include iron chloride, iron bromide, iron iodide, iron sulfate, iron nitrate, and iron salts of organic acids.

The concentration of the oxidizing metal ion is preferably 10 to 300 g / L, more preferably 10 to 250 g / L, still more preferably 15 to 220 g / L, still more preferably 30 to 200 g / L Do. When the concentration of the oxidizing metal ion is 10 g / L or more, the etching rate is increased, and therefore it is possible to rapidly etch copper. When the concentration of the oxidizing metal ion is 300 g / L or less, the dissolution stability of copper is maintained.

<Complex aromatic compound (A) having a 5-membered ring>

The heteroaromatic compound (A) having a five-membered ring of the present invention is a heteroaromatic compound having no hydroxyalkyl group and having at least one nitrogen atom as a heteroatom constituting a ring. The above-mentioned aromatic aromatic compound (A) having a five-membered ring may be at least one kind, or two or more kinds thereof may be used in combination.

The aromatic aromatic compound (A) having the five-membered ring preferably has only nitrogen as the hetero atom constituting the ring from the viewpoint of structural stability and solubility in an acidic solution. Examples of the aromatic aromatic compound (A) having such a five-membered ring include imidazole compounds having an imidazole skeleton, pyrazole compounds having a pyrazole skeleton, triazole compounds having a triazole skeleton, tetrazoles having a tetrazole skeleton And an azole compound such as a sol compound.

Examples of the imidazole compound include imidazoles such as imidazole, 2-methylimidazole, 2-undecyl-4-methylimidazole and 2-phenylimidazole, benzoimidazole, 2- Benzoimidazoles such as methylbenzoimidazole, 2-undecylbenzimidazole, 2-phenylbenzoimidazole and 2-mercaptobenzimidazole. Of these, benzimidazole is preferred.

Examples of the pyrazole compounds include pyrazole compounds such as pyrazole, 3-methylpyrazole, 1-ethylpyrazole, 3-aminopyrazole, 3,5-dimethylpyrazole, 3-amino- -Chloropyrazole 1,3,5-trimethylpyrazole, and the like.

Examples of the triazole compound include 1,2,3-triazole, 1,2,4-triazole, 5-phenyl-1,2,4-triazole, -Triazole, benzotriazole, 1-methyl-benzotriazole, tolythriazole, and the like. Of these, benzotriazole is preferred.

As the tetrazole compound, for example, there can be mentioned 1H-tetrazole, 5-amine-1H-tetrazole, 5-methyl-1H- 1-phenyl-5-mercapto-1H-tetrazole, 1-cyclohexyl-5-mercapto-1H-tetrazole, 5,5'-non-1H-tetrazole and their ammonium salts or Na salts , Zn salts, Ca salts, K salts and the like.

Among the above azole compounds, tetrazole compounds are preferable from the viewpoint of high suppressing effect of undercut, and tetrazole compounds are preferred from the standpoints of 1H-tetrazole, 5-phenyl-1H-tetrazole, Tetrazole, 5'-non-1H-tetrazole, and ammonium salts or metal salts thereof are more preferable, and 1H-tetrazole, 5-amino-1H-tetrazole and ammonium salts or metal salts thereof are more preferable. It is presumed that these tetrazole compounds can form a thin and uniform protective film on the side surface from the top portion of the conductor pattern.

The concentration of the aromatic compound (A) having the five-membered ring is preferably 0.1 to 50 g / L, more preferably 0.1 to 15 g / L, and still more preferably 0.2 to 10 g / L. If the concentration of the aromatic compound (A) having the five-membered ring is 0.1 g / L or more, undercutting can be reliably suppressed. On the other hand, when the concentration of the complex aromatic compound (A) having the five-membered ring is 50 g / L or less, the etching rate can be prevented from lowering and the portion to be etched can be reliably etched. Can be prevented from occurring.

<Complex aromatic compound (B1) having a 5- to 6-membered ring>

The heteroaromatic compound (B1) having a 5- to 6-membered ring of the present invention is a heteroaromatic compound having at least one nitrogen atom as a heteroatom constituting a ring and having a heteroaromatic ring substituted with a substituent having a hydroxyalkyl group having 1 to 5 carbon atoms / RTI &gt; The above-mentioned heteroaromatic compound (B1) having 5 or 6-membered rings can be used in combination of two or more.

The substituent having a hydroxyalkyl group (hereinafter also referred to as a substituent having a hydroxyalkyl group) refers to one of a substituent consisting of a hydroxyalkyl group and a hydrocarbon derivative having 1 to 10 carbon atoms and having a hydroxyalkyl group. The hydrocarbon derivative having 1 to 10 carbon atoms means that some carbon or hydrogen in the hydrocarbon group may be substituted with another atom (for example, a sulfur atom, an oxygen atom, a fluorine atom, or the like) or a substituent. Examples of the hydrocarbon derivative include an alkyl group, a cycloalkyl group, an alkenyl group, a cycloalkenyl group, an alkynyl group, an amino group, an aminoalkyl group, an acetyl group and a phenyl group. Examples of the hydrocarbon derivative having 1 to 10 carbon atoms having a hydroxyalkyl group include those obtained by substituting one or two -H of the amino group with a hydroxyalkyl group as shown by the following general formula (2) equation (2): - XN (R 1) -R 2 ( formula (2), X is an alkynyl represents an alkylene with a carbon number of 1~10, R ¹ ~R ² is, independently, a hydrogen atom or a carbon number of 1 to At least one of R ¹ to R ² is a hydroxyalkyl group, and the alkylene group may have an ether bond, an ester bond, an amide bond, a urethane bond, etc.), and the like . The same applies to the hydrocarbon derivative and the hydroxyalkyl group-containing substituent.

From the viewpoint of structural stability and solubility in an acidic solution, the above-mentioned heteroaromatic compound (B1) having a 5- to 6-membered ring preferably has only nitrogen as the hetero atom constituting the ring or only nitrogen and sulfur as the heteroatom Do.

The compound (B1) having a 5- to 6-membered ring may be a compound (b1-0) having a hydroxyalkyl group-containing substituent and containing as a heterocyclic ring only a five-membered ring in the complex direction, (B1-1), a compound (b1-2) containing a condensed ring of a 6-membered ring in a complex direction and a 5-membered ring in a molecule, and a compound (b1-2) in which a 6-membered ring in a complex direction and a 5-membered ring in a complex direction are a single bond or a divalent linking group And at least one compound selected from the group consisting of compounds (b1-3) linked together.

The compound (b1-0) having only the five-membered ring in the complex direction in the molecule is not particularly limited as long as it is a compound substituted with a substituent having a hydroxyalkyl group. Examples thereof include imidazole compounds having an imidazole skeleton, Pyrazole compounds having a skeleton, triazole compounds having a triazole skeleton, and tetrazole compounds having a tetrazole skeleton. Specific examples include 2- (1-hydroxyethyl) benzimidazole, 4-hydroxymethyl-5-methylimidazole and 3,5-dimethyl-1-hydroxymethylpyrazole.

Examples of the compound (b1-1) containing only the complex direction six-membered ring in the molecule include a pyridine compound having a pyridine skeleton, a pyrimidine compound having a pyrimidine skeleton, a pyrazine compound having a pyrazine skeleton, Pyridazine compounds and the like.

The pyridine compound is not particularly limited as long as it is a compound having a pyridine skeleton substituted by a substituent having a hydroxyalkyl group, and for example, a pyridine compound represented by the following general formula (3) can be exemplified.

(In the general formula (3), R ¹ to R ⁵ independently represent a hydrocarbon derivative having 1 to 10 carbon atoms excluding a hydrogen atom, a hydroxyalkyl group-containing substituent or a hydroxyalkyl group-containing substituent, and R ¹ to R ⁵ , At least one of them represents a substituent group containing a hydroxyalkyl group.)

The hydrocarbon derivative having 1 to 10 carbon atoms in the hydrocarbon derivative having 1 to 10 carbon atoms excluding the hydroxyalkyl group-containing substituent is preferably a hydrocarbon derivative comprising carbon and hydrogen from the viewpoint of effectively suppressing the side etching. Containing hydrocarbyl group-containing substituent except for the following hydroxyalkyl group-containing substituent is the same.

Examples of the pyridine compound include 2-pyridine methanol, 3-pyridine methanol, 4-pyridine methanol, 2-pyridine ethanol, 3-pyridine ethanol, Methanol, 2-amino-3-pyridine methanol, pyridoxine hydrochloride, and the like.

The pyrimidine compound is not particularly limited as long as it is a compound having a pyrimidine skeleton substituted with a substituent having a hydroxyalkyl group, for example, a pyridine compound shown by the following general formula (4) can be exemplified.

(In the general formula (4), R ⁶ to R ⁹ independently represent a hydrogen atom, a hydroxyalkyl group-containing substituent or a hydrocarbon derivative having 1 to 10 carbon atoms excluding a hydroxyalkyl group-containing substituent group, and R ⁶ to R ⁹ , at least one of them represents a hydroxyalkyl group-containing substituent.)

Examples of the pyrimidine compound include 4-amino-2-methyl-5-pyrimidine methanol, 2-methyl-4-aminopyrimidine- -Phenylpyrimidine-2-ethanol, 5- (4-methoxyphenyl) pyrimidine-2-ethanol and the like.

The pyrazine compound is not particularly limited as long as it is a compound having a pyrazine skeleton substituted with a substituent having a hydroxyalkyl group, for example, a pyrazine compound represented by the following general formula (5) can be exemplified.

(In the general formula (5), R ¹⁰ to R ¹³ independently represent a hydrocarbon derivative having 1 to 10 carbon atoms excluding a hydrogen atom, a hydroxyalkyl group-containing substituent or a hydroxyalkyl group-containing substituent, and R ¹⁰ to R ¹³ , At least one of them represents a substituent group containing a hydroxyalkyl group.)

Examples of the pyrazine compound include 2-pyrazinemethanol, 5-methyl-2-pyrazinemethanol, 1- (3-fluorpyrazin-2-yl) ethanol and? -Phenyl-2-pyrazinethanol.

The pyridazine compound is not particularly limited as long as it is a compound having a pyridazine skeleton substituted with a substituent having a hydroxyalkyl group. For example, a pyridazine compound represented by the following formula (6) can be exemplified.

(In the general formula (6), R ¹⁴ to R ¹⁷ independently represent a hydrocarbon derivative having 1 to 10 carbon atoms excluding a hydrogen atom, a hydroxyalkyl group-containing substituent or a hydroxyalkyl group-containing substituent, and R ¹⁴ to R ¹⁷ , At least one of them represents a substituent group containing a hydroxyalkyl group.)

Examples of the pyridazine compound include? -Phenylpyridazine-3-methanol,? -Phenylpyridazine-4-methanol and the like.

Among the compounds (b1-1) containing only the complex direction six-membered ring in the molecule, the pyridine compound is preferable and the compound represented by the formula (2) is preferable from the viewpoint of obtaining an etching solution excellent in suppression of side etching and excellent in formation of a copper wiring fine pattern. Pyridine methanol, 3-pyridine methanol, 4-pyridine methanol, 2-pyridine ethanol, 3-pyridine ethanol and pyridoxine hydrochloride are more preferable.

The compound (b1-2) containing the condensed ring of the 6-membered ring in the complex direction and the 5-membered ring in the molecule may be a compound (b1-2) substituted with a substituent having a 6-membered ring in the complex direction and / or a hydroxyalkyl group substituted with a substituent having a hydroxyalkyl group (Hydroxymethyl) -1H-benzotriazole, 1- (2-hydroxyethyl) -1H-benzotriazole, and the like are preferable, as long as they are compounds containing a condensed ring having a complex five- Benzotriazole, 2,2 '- (methyl-1H-benzotriazol-1-ylmethylimino) bisethanol, and 9- (2-hydroxyethyl) adenine. Among them, 1- (hydroxymethyl) -1H-benzotriazole is preferable.

&Lt; alkanolamine (B2) >

The alkanolamine (B2) of the present invention is represented by the general formula (1): R ¹ -N (R ² ) -R ³

(Wherein R ¹ and R ² independently represent an alkyl group or a hydroxyalkyl group having 1 to 8 carbon atoms and R ³ represents a hydrogen atom, an alkyl group, or a hydrocarbon group having 1 to 8 carbon atoms A hydroxyalkyl group, and at least one of R ¹ to R ³ is the above hydroxyalkyl group. These alkanolamines (B2) can be used in combination of two or more.

Examples of the alkanolamine (B2) include monohydric alcohols such as dimethylamino ethanol, diethylamino ethanol, methylamino ethanol, ethylamino ethanol, dimethylaminopropanol, methylaminopropanol, diethylaminopropanol, Divalent hydroxy alcohol compounds such as hydroxy alcohol compounds, diethanol amine, ethyl diethanol amine and butyl diethanol amine, and trivalent hydroxy alcohol compounds such as triethanol amine. Of these, dimethylaminoethanol and diethylaminoethanol are preferred.

The concentration of the at least one compound selected from the group consisting of the above-mentioned heteroaromatic compound (B1) having 5 to 6 member rings and alkanolamine (B2) is 0.15 g / L or more, more preferably 0.2 g / L or more, still more preferably 0.3 g / L or more, and preferably 30 g / L or less, more preferably 20 g / L or less, and 10 g / L or less More preferable.

Further, the weight ratio of the above-mentioned complex aromatic compound (A) having the 5-member ring to at least one compound selected from the group consisting of the above-mentioned 5- and 6-membered heteroaromatic compound (B1) and alkanolamine (B2) A) / ((B1) + (B2))] is preferably 0.001 or more, more preferably 0.01 or more, further preferably 0.1 or more, from the viewpoint of forming a fine pattern of copper wiring, More preferably 30 or less, more preferably 20 or less, and still more preferably 15 or less.

In addition to the above-mentioned components, other components may be added to the etching solution of the present invention to such an extent as not to interfere with the effect of the present invention. Examples of the other components include aliphatic acyclic compounds such as diethylenetriamine, triethylenetetramine, tetraethylpentamine, and pentaethylenehexamine; Pyrrolidine compounds having a pyrrolidine skeleton, piperidine compounds having a piperidine skeleton, piperazine compounds having a piperazine skeleton, homopiperazine compounds having a homopiperazine skeleton, hexahydro-1,3,5 Aliphatic heterocyclic compounds such as hexahydro-1,3,5-triazine compounds having a triazine skeleton; Polycondensates containing a tertiary nitrogen and a quaternary nitrogen such as dicyandiamide diethylenetriamine polycondensate, dicyandiamide formaldehyde polycondensate, dicyandiamide triethylenetetram polycondensate and the like; Component stabilizers such as cationic surfactants, anionic surfactants, amphoteric surfactants, and glycols may be added. When the other components are added, the concentration thereof is usually about 0.01 to 5 g / L.

The etching solution can be easily prepared by dissolving each component in water. The water is preferably water from which ionic substances and impurities are removed, and for example, ion-exchanged water, pure water, and ultra-pure water are preferable.

The etching solution may be formulated so that each component has a predetermined concentration at the time of use, or may be diluted immediately before use with the concentrated solution prepared. The method of using the etching solution is not particularly limited, but in order to effectively suppress the side etching, it is preferable to perform etching using a spray as described later. The temperature of the etching solution during use is not particularly limited, but it is preferable to use the etching solution at 20 to 55 占 폚 in order to effectively suppress the side etching while maintaining high productivity.

The replenisher of the present invention is a replenisher to be added to the etchant when the etchant of the present invention is continuously or repeatedly used, wherein the complex aromatic compound (A) having the 5-member ring and the compound , An aromatic compound (B1), and the above alkanolamine (B2). Each component in the replenisher is the same as the component that can be compounded in the above-described etching solution of the present invention. By adding the replenishing liquid, the respective component ratios of the etchant are appropriately maintained, so that the effect of the above-described etchant of the present invention can be stably maintained.

In the replenishment solution of the present invention, acid such as hydrochloric acid may be contained within a range not exceeding 360 g / L. In addition, the replenishing liquid may contain chlorinated metal ions such as cupric chloride in a concentration not exceeding a concentration of 14 g / L at a cupric ion concentration. In addition to the above components, other components added to the etching solution may be mixed in the replenishing liquid. The components that may be contained in the above-mentioned replenishment liquid may be directly added to the etching solution of the present invention when the etching solution of the present invention is continuously or repeatedly used.

The concentration of each component in the replenishing liquid is appropriately set according to the concentration of each component in the etching solution. From the viewpoint of stably maintaining the effect of the etching solution of the present invention described above, the complex aromatic compound (A) having the five- (B1) having 5 to 6-membered rings, and at least one compound selected from the group consisting of alkanolamine (B2) is preferably 0.01 to 30 g / L.

The copper wiring forming method of the present invention is characterized in that etching is performed using the etching solution of the present invention in the copper wiring forming method for etching a portion of the copper layer not covered with the etching resist. As a result, as described above, the effect of suppressing the side etching is high, and the fine pendent of the copper wiring can be formed. When the etching solution of the present invention is used continuously or repeatedly in the copper wiring forming step employing the copper wiring forming method of the present invention, it is preferable to perform etching while adding the replenishing solution of the present invention described above. Since the respective component ratios of the etchant are appropriately maintained, the effect of the above-described etchant of the present invention can be stably maintained.

In the copper wiring forming method of the present invention, it is preferable that the etching solution is sprayed to a portion of the copper layer not covered with the etching resist by spraying. Side etching can be effectively suppressed. When spraying, the nozzle is not particularly limited, but a fan-shaped nozzle, a full-cone nozzle, a two-fluid nozzle, or the like can be used.

When spraying with a spray, the spray pressure is preferably 0.04 MPa or more, more preferably 0.08 MPa or more. If the spray pressure is 0.04 MPa or more, a protective coating can be formed on the side surface of the copper wiring with an appropriate thickness. As a result, the side etching can be effectively prevented. The spray pressure is preferably 0.30 MPa or less from the viewpoint of preventing breakage of the etching resist.

[Example]

Next, examples of the present invention will be described along with comparative examples. The present invention is not limited to the following examples.

Each of the etching solutions having the compositions shown in Tables 1 and 2 was prepared, etched under the conditions described below, and each item was evaluated by the following evaluation method. In the respective etching solutions of the compositions shown in Tables 1 and 2, the remaining portion is ion-exchanged water. The concentration of hydrochloric acid shown in Tables 1 and 2 is the concentration as hydrogen chloride.

(Test substrate used)

(Trade name: PI-38N-CCS-08EO) having a copper layer thickness of 8 占 퐉 was prepared, and a photolithography method (resist agent (Tokyo- P-RZ30 &quot;)). The etching resist pattern has a thickness of about 4 占 퐉, a 20 占 퐉 pitch pattern area of line / space = 13 占 퐉 / 7 占 퐉, and a 40 占 퐉 pitch pattern area of line / space = 22 占 퐉 / 18 占 퐉, did.

(Etching condition)

The etching was carried out under the conditions of a spraying pressure of 0.18 MPa and a treating temperature of 35 캜 by using a sectorial nozzle (trade name "ISVV9020" manufactured by Ikeuchi Co., Ltd.). The treatment time was set to a time at which the bottom width of the copper wiring was 8 to 15 占 퐉 at a pitch of 20 占 퐉. The treatment time at this time is as shown in Tables 1 and 2. In Comparative Example 8, however, the treatment was carried out at a spray pressure of 0.12 MPa. After the etching, the substrate was washed with water and dried, and the following evaluations were carried out.

(Evaluation of fine pattern)

Each of the test substrates subjected to the etching treatment was removed with a spray nozzle (ISVV9020, manufactured by Ikeuchi Co., Ltd.) using hydrochloric acid (hydrogen chloride concentration: 7 wt%) at a spray pressure of 0.15 MPa for 40 seconds, For 20 seconds (or a 3 wt% sodium hydroxide aqueous solution for 60 seconds) to remove the etching resist. Then, a part of each of the test substrates was cut, was planted in cold mounting resins, and a polishing process was carried out so that the cross section of the wiring could be observed. The cross-section of the wiring was photographed using an optical microscope, and measurement of the top width and the bottom width of the wiring was carried out. At this time, in the measurement, the top width and the bottom width of n = 2 or more were taken as average values. B-T in the table is the bottom width-top width of the copper wiring. In the comparative example, when the bottom was not etched and the bottom width could not be measured, it was indicated as &quot; - &quot;. The column of the fine pattern (fine Pt) in the table indicates that when the value of BT in a 20 占 퐉 pitch pattern area of line / space = 13 占 퐉 / 7 占 퐉 is less than 2 占 퐉 is?, When the value of BT is 2 占 퐉 or more, Or the case where the floor width can not be measured is evaluated as x.

Furtherance Amount of blending Processing time
(second) Upper: pitch 20 占 퐉 (L / S = 13/7 占 퐉), lower end: pitch 40 占 (22/18 占 퐉) Fine Pt
Sculpture T Width: T
(탆) Bottom width: B
(탆) IT
(탆) Example
One Cupric chloride · dihydrate 96 g / L
(35 g / L as cupric ion) 72 ○ 8.6 10.3 1.7 Hydrochloric acid 67g / L 5-Amino-1H-tetrazole 3g / L 17.4 19.0 1.6 2-pyridine Methanol 5g / L Example
2 Cupric chloride · dihydrate 96 g / L
(35 g / L as cupric ion) 72 ○ 9.0 10.9 1.9 Hydrochloric acid 67g / L 1H-tetrazole 1.5 g / L 17.4 19.8 2.4 3-pyridine Methanol 8g / L Example 3 Cupric chloride · dihydrate 96 g / L
(35 g / L as cupric ion) 72 ○ 7.8 8.2 0.4 Hydrochloric acid 67g / L 5-Amino-1H-tetrazole 3g / L 16.6 19.4 2.8 2-pyridine Methanol 2 g / L Example
4 Cupric chloride · dihydrate 96 g / L
(35 g / L as cupric ion) 72 ○ 8.8 9.0 0.2 Hydrochloric acid 67g / L 5-Amino-1H-tetrazole 3g / L 15.7 16.3 0.6 1-hydroxymethyl-1H-benzotriazole 0.3 g / L Example
5 Cupric chloride · dihydrate 96 g / L
(35 g / L as cupric ion) 72 ○ 8.4 9.7 1.3 Hydrochloric acid 67g / L 1H-tetrazole 1.5 g / L 16.6 19 2.4 Dimethylaminoethanol 8g / L Example
6 Cupric chloride · dihydrate 96 g / L
(35 g / L as cupric ion) 72 ○ 8.9 10.7 1.8 Hydrochloric acid 67g / L 5-Amino-1H-tetrazole 3g / L 16.9 19.8 2.9 Methylaminomethanol 20g / L Example
7 Cupric chloride · dihydrate 96 g / L
(35 g / L as cupric ion) 72 ○ 9.0 10.7 1.7 Hydrochloric acid 67g / L 1H-tetrazole 1.5 g / L 16.8 19.8 3.0 Pyridoxine hydrochloride 7g / L Example
8 Cupric chloride · dihydrate 96 g / L
(35 g / L as cupric ion) 72 ○ 8.7 9.8 1.1 Hydrochloric acid 67g / L 5-Amino-1H-tetrazole 3g / L 16.7 19.3 2.6 Dicyandiamide-formalin polycondensate 0.01 g / L Dimethylaminoethanol 8g / L Example
9 Cupric chloride · dihydrate 96 g / L
(35 g / L as cupric ion) 72 ○ 9.7 11.5 1.8 Hydrochloric acid 67g / L 1H-tetrazole 1.5 g / L 17.1 19.8 2.7 3- (dimethylamino) -1-propanol 15g / L Example
10 Cupric chloride · dihydrate 96 g / L
(35 g / L as cupric ion) 72 ○ 9.3 10.9 1.6 Hydrochloric acid 67g / L 5-Amino-1H-tetrazole 3g / L 16.8 19.6 2.7 2- (1-hydroxyethyl) benzoimidazole 12 g / L Example
11 Cupric chloride · dihydrate 96 g / L
(35 g / L as cupric ion) 72 ○ 8.9 10.8 1.9 Hydrochloric acid 67g / L 1H-tetrazole 1.5 g / L 16.9 19.9 3.0 9- (2-hydroxyethyl) adenine 5g / L Example
12 Cupric chloride · dihydrate 96 g / L
(35 g / L as cupric ion) 72 ○ 9.5 11.2 1.7 Hydrochloric acid 67g / L 5-Amino-1H-tetrazole 3g / L 17.8 20.9 3.1 4- (butylamino) -1-butanol 20g / L

Furtherance Amount of blending Processing time
(second) Upper: pitch 20 占 퐉 (L / S = 13/7 占 퐉)
Bottom: pitch 40 占 퐉 (22/18 占 퐉) Fine Pt
Sculpture T Width: T
(탆) Bottom width: B
(탆) IT
(탆) Comparative Example 1 Cupric chloride · dihydrate 96 g / L
(35 g / L as cupric ion) 72 × 7.7 - - Hydrochloric acid 67g / L 1H-tetrazole 1.5 g / L 17.9 21.3 3.4 Benzotriazole 0.5 g / L Comparative Example 2 Cupric chloride · dihydrate 96 g / L
(35 g / L as cupric ion) 72 × 9.0 12.5 3.5 Hydrochloric acid 67g / L 5-Amino-1H-tetrazole 3g / L 17.9 20.4 2.5 2- (Methylamino) pyridine 3g / L Comparative Example 3 Cupric chloride · dihydrate 96 g / L
(35 g / L as cupric ion) 72 × 9.0 - - Hydrochloric acid 67g / L 5-Amino-1H-tetrazole 3g / L 24.3 34.4 10.1 Adenine 0.4 g / L Comparative Example 4 Cupric chloride · dihydrate 96 g / L
(35 g / L as cupric ion) 72 × 9.0 - - Hydrochloric acid 67g / L 1H-tetrazole 1.5 g / L 17.7 22.9 5.2 Piperazine ethanol 0.5 g / L Comparative Example 5 Cupric chloride · dihydrate 96 g / L
(35 g / L as cupric ion) 72 × 8.6 14.7 6.1 Hydrochloric acid 67g / L 5-Amino-1H-tetrazole 3g / L 17.9 22.0 4.1 Pyrazole 5g / L Comparative Example 6 Cupric chloride · dihydrate 96 g / L
(35 g / L as cupric ion) 72 × 9.0 - - Hydrochloric acid 67g / L 1H-tetrazole 1.5 g / L 15.7 24.2 8.5 2-aminoethanol 3g / L Comparative Example 7 Cupric chloride · dihydrate 96 g / L
(35 g / L as cupric ion) 72 × 8.4 13.3 4.9 Hydrochloric acid 67g / L 1H-tetrazole 1.5 g / L 17.9 20.9 3.0 1-amino-2-propanol 3g / L Comparative Example 8 Cupric chloride · dihydrate 102g / L
(35 g / L as cupric ion) 140 × 8.5 10.8 2.3 Hydrochloric acid 50g / L 5-Amino-1H-tetrazole 2 g / L 16.1 17.7 1.6 Dicyandiamide-formalin polycondensate 0.1 g / L

In Tables 1 and 2, the dicyandiamide-formalin polycondensate represents the trade name &quot; Unisense KHF10P &quot;, manufactured by Senka.

As shown in Table 1, according to the embodiment of the present invention, it was found that the value of B-T was less than 2 占 퐉, and an excellent fine pattern could be formed. On the other hand, as shown in Table 2, the results of Comparative Examples were inferior to those of Examples. From these results, it was found that the etching solution obtained by the present invention has a high suppressing effect of the side etching and is excellent in the formation of the fine pattern of the copper wiring.

1: substrate
2: Copper wiring
3: Resist resin
T: Width of the top portion of the copper wiring
B: width of the bottom portion of the copper wiring

Claims (10)

In the copper etching solution,
Wherein the etching solution comprises a complex aromatic compound (A) having an acid, an oxidizing metal ion, and a 5-membered ring,
(B1) having 5 to 6 member rings, and alkanolamine (B2), and the compound
The heteroaromatic compound (A) having a five-membered ring is a heteroaromatic compound having no hydroxyalkyl group and having at least one nitrogen atom as a heteroatom constituting a ring,
The heteroaromatic compound (B1) having a 5- or 6-membered ring is a heteroaromatic compound having at least one nitrogen atom as a heteroatom constituting a ring and substituted with a substituent having a hydroxyalkyl group having 1 to 5 carbon atoms ,
The alkanolamine (B2) is a compound represented by the general formula (1): R ¹ -N (R ² ) -R ³
(Wherein R ¹ and R ² independently represent an alkyl group or a hydroxyalkyl group having 1 to 8 carbon atoms and R ³ represents a hydrogen atom, an alkyl group, or a hydrocarbon group having 1 to 8 carbon atoms And at least one of R ¹ to R ³ is the above-mentioned hydroxyalkyl group). The method according to claim 1,
Wherein the acid is hydrochloric acid. 3. The method according to claim 1 or 2,
Wherein the oxidizing metal ion is a cupric ion. 3. The method according to claim 1 or 2,
Wherein the complex aromatic compound (A) having a five-membered ring is at least one compound selected from the group consisting of an imidazole compound, a pyrazole compound, a triazole compound, and a tetrazole compound. 3. The method according to claim 1 or 2,
Wherein the heteroaromatic compound (B1) having 5 to 6 member rings has at least one nitrogen atom as a hetero atom constituting the ring. 3. The method according to claim 1 or 2,
(B1-0) in which only the five-membered ring in the complex direction is contained in the molecule as the heterocyclic ring, and the compound (b1-1) in which only the six-membered ring in the complex direction is contained in the molecule, A compound (b1-2) having a condensed ring of a 6-membered ring in a complex direction and a 5-membered ring in a molecule, and a compound (b1-3) in which a 6-membered ring in a complex direction and a 5-membered ring in a complex are linked by a single bond or a divalent linking group Wherein the etchant is at least one selected from the group consisting 3. The method according to claim 1 or 2,
Wherein the concentration of the at least one compound selected from the group consisting of the compound (B1) having a 5- to 6-membered ring and the alkanolamine (B2) is 0.15 g / L or more and 30 g / L or less. 3. The method according to claim 1 or 2,
(A) / (B), wherein the weight ratio of the compound (A) to the compound (A) selected from the group consisting of the complex aromatic compound (A) having the 5-membered ring and the heteroaromatic compound (B1) having 5 to 6 member rings and the alkanolamine ((B1) + (B2))] is 0.001 or more and 30 or less. A replenishment liquid to be added to the above etching solution when the etching solution according to claim 1 or 2 is used continuously or repeatedly,
Wherein the replenishing liquid comprises the complex aromatic compound (A) having the five-membered ring,
Wherein said compound is an aqueous solution containing at least one compound selected from the group consisting of said aromatic aromatic compound (B1) having 5 to 6 member rings and said alkanolamine (B2). A method for forming a copper wiring which etches a portion of a copper layer not covered with an etching resist,
A method of forming a copper wiring, characterized in that etching is performed using the etching solution described in claim 1 or 2.

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