TW202136581A - Etching solution, replenishing solution and method for forming copper wiring excellently forming a fine pattern in the fine pitch pattern area where the fine part and the rough part are mixed - Google Patents

Abstract

The present invention is an etching solution, which is an etching solution of copper, the etching fluid containing: an acid, an oxidizing metal ion, an aromatic heterocyclic compound (A) having a five-membered ring, and an aliphatic heterocyclic compound (B) having a five- to seven-membered ring, and a cationic polymer containing tertiary nitrogen or quaternary nitrogen in the molecule. The aromatic heterocyclic compound (A) having a five-membered ring is an aromatic heterocyclic compound having one or more nitrogen atoms as a ring-constituting heteroatom. The aliphatic heterocyclic compound (B) having a five- to seven-membered ring (B) is an aliphatic heterocyclic compound having one or more nitrogen atoms as a ring-constituting heteroatom. This etching solution can excellently form a fine pattern in the fine pitch pattern area where the fine portion and the rough portion are mixed.

Description

Method for forming etching liquid, replenishing liquid and copper wiring

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

In the manufacture of a printed wiring board, when a copper wiring pattern is formed by a photoetching method, the etching solution usually uses a ferric chloride-based etching solution, a copper chloride-based etching solution, an alkaline etching solution, or the like. If these etching solutions are used, the copper under the resist may dissolve from the side surface of the wiring pattern, and this is so-called side etching. That is, the part (that is, the copper wiring part) that was originally intended to be not removed by etching by covering the resist is removed by the etching solution, so that the width of the copper wiring gradually decreases from the bottom to the top. Especially when the copper wiring pattern is fine, it is necessary to minimize such side etching. In order to suppress this side etching, an etching solution is proposed in which an azole compound is blended, which is an aromatic heterocyclic compound having a five-membered ring (Patent Documents 1 to 4). In addition, in order to suppress side etching, an etching solution in which an aliphatic heterocyclic compound having a five- to seven-membered ring is blended has also been proposed (Patent Document 5). [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Application Publication No. 2005-330572 [Patent Document 2] JP 2009-221596 A [Patent Document 3] JP 2013-104104 A [Patent Document 4] Japanese Patent Application Publication No. 2018-193602 [Patent Document 5] JP 2014-224303 A

[Problems to be solved by the invention]

On the other hand, the etching solution is required on the market to have a side etching suppression effect and to excellently form a fine pattern of copper wiring. In the etching solution disclosed in the above-mentioned patent documents, a certain side etching suppression effect can be expected, but the etching solution disclosed in Patent Document 4, which is judged to be high performance, specifically discloses the following: success Ground line width/line space (line/space)=13 μm/7 μm 20 μm pitch pattern area (fine part) and line width/line pitch=22 μm/18 μm 40 μm pitch pattern area (rough part) ) A fine pattern is formed in the mixed pitch pattern; however, it cannot be formed in a finer (narrow) pitch pattern area.

The present invention has been completed in view of the above-mentioned actual situation, and its object is to provide an etching solution and its replenishing solution for forming a fine pattern in a fine-pitch pattern region where the fine portion and the rough portion are mixed, and a method for forming copper wiring. [Technical means to solve the problem]

The present invention relates to an etching solution, which is an etching solution of copper, the etching solution comprising: an acid, an oxidizing metal ion, an aromatic heterocyclic compound (A) having a five-membered ring, and an aliphatic heterocyclic compound having a five- to seven-membered ring A cyclic compound (B), and a cationic polymer containing tertiary nitrogen or quaternary nitrogen in the molecule, the five-membered aromatic heterocyclic compound (A) has one or more nitrogen atoms as heteroatoms constituting the ring The aliphatic heterocyclic compound (B) having a five- to seven-membered ring is an aliphatic heterocyclic compound having one or more nitrogen atoms as heteroatoms constituting the ring.

The present invention relates to a replenishing liquid, which is a replenishing liquid added to the etching liquid when the above-mentioned etching liquid is used continuously or repeatedly, and the replenishing liquid is an aqueous solution containing the following compound: an aromatic heterocyclic compound having a five-membered ring (A) , The aliphatic heterocyclic compound (B) with a five- to seven-membered ring, and a cationic polymer containing tertiary or quaternary nitrogen in the molecule, the five-membered aromatic heterocyclic compound (A) is An aromatic heterocyclic compound having more than one nitrogen atom as a heteroatom constituting a ring, and the aliphatic heterocyclic compound (B) having a five to seven membered ring is an aliphatic heterocyclic compound having more than one nitrogen atom as a heteroatom constituting the ring Cyclic compound.

The present invention relates to a method for forming copper wiring, which is to etch a portion of a copper layer that is not covered by a resist, and to perform etching using the above-mentioned etching solution. [Effects of the invention]

The etching solution of the present invention contains an acid, an oxidizing metal ion, an aromatic heterocyclic compound having a five-membered ring (A), an aliphatic heterocyclic compound having a five- to seven-membered ring (B), and a three-membered ring in the molecule. A cationic polymer of grade nitrogen or quaternary nitrogen, the five-membered aromatic heterocyclic compound (A) is an aromatic heterocyclic compound having one or more nitrogen atoms as heteroatoms constituting the ring, and the five to seven The ring-membered aliphatic heterocyclic compound (B) is an aliphatic heterocyclic compound having one or more nitrogen atoms as a hetero atom constituting the ring. The etching solution of the present invention forms a uniform coating in the fine-pitch pattern area where the fine part and the rough part are mixed, so that not only side etching can be suppressed, but also a fine pattern with excellent linearity can be formed. Therefore, the etching solution of the present invention can be used for the application of forming a copper wiring pattern on a copper surface provided with a resist.

In addition, the etching solution of the present invention can not only form a fine pattern excellently in the fine pitch pattern area where the fine portion and the rough portion are mixed, but also can form a rough pattern well. When the etching solution of the present invention contains glycol ethers and/or In the case of glycols, a rough pattern can be formed particularly excellently. Normally, since the flow rate of the etching liquid is different between the fine part and the rough part, there is a tendency that the film formation and the etching in the depth direction are likely to be different. For example, in a rough portion with a fast flow rate, the film is not easily formed to the bottom, and therefore shrinkage (inverted trapezoidal shape) is likely to occur at the bottom of the rough pattern. When the bottom is contracted, the bottom width cannot be observed from the top of the substrate. Therefore, there is a risk that product management is difficult, or when pressure is applied to the top during assembly, the corners of the top will be damaged, etc. The structure is abnormal or foreign objects are generated. Since the etching solution of the present invention has no difference in the etching properties of the fine portion and the rough portion (the shapes of the fine pattern and the rough pattern become approximately the same shape), the above-mentioned problems can be avoided, and the etching solution of the present invention is useful.

＜Copper etching solution＞ The copper etching solution of the present invention contains: an acid, an oxidizing metal ion, an aromatic heterocyclic compound having a five-membered ring (A), an aliphatic heterocyclic compound having a five- to seven-membered ring (B), and an intermolecular A cationic polymer containing tertiary nitrogen or quaternary nitrogen, the five-membered aromatic heterocyclic compound (A) is an aromatic heterocyclic compound having one or more nitrogen atoms as heteroatoms constituting the ring, and the five-membered aromatic heterocyclic compound The aliphatic heterocyclic compound (B) having a to seven-membered ring is an aliphatic heterocyclic compound having one or more nitrogen atoms as a hetero atom constituting the ring. In addition, the "copper" in the copper etching solution of the present invention may be composed of copper or a copper alloy.

＜Acid＞ The acid of the present invention can be appropriately selected from inorganic acids and organic acids. As this inorganic acid, sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, hydrobromic acid, etc. are mentioned, for example. As this organic acid, formic acid, acetic acid, oxalic acid, maleic acid, benzoic acid, glycolic acid, etc. are mentioned, for example. Among the above-mentioned acids, hydrochloric acid is preferred from the viewpoint of the stability of the etching rate and the dissolution stability of copper. At least one of the above-mentioned acids may be used, or two or more of them may be used in combination.

The concentration of the above acid is preferably 7 to 180 g/L, more preferably 18 to 110 g/L. When the acid concentration is 7 g/L or more, the etching rate becomes faster, so copper can be etched quickly. In addition, when the concentration of the acid is 180 g/L or less, the dissolution stability of copper can be maintained, and the deterioration of the working environment can be suppressed.

＜Oxidizing metal ions＞ The oxidizing metal ion of the present invention may be any metal ion capable of oxidizing metallic copper, and examples thereof include divalent copper ions, trivalent iron ions, and the like. From the viewpoint of suppressing side etching and the viewpoint of the stability of the etching rate, it is preferable to use divalent copper ion as the oxidizing metal ion. At least one of the above-mentioned oxidizing metal ions may be used, or two or more of them may be used in combination.

The above-mentioned oxidizing metal ion can be contained in the etching solution by blending an oxidizing metal ion source. For example, when a divalent copper ion source is used as an oxidizing metal ion source, specific examples thereof include copper chloride, copper sulfate, copper bromide, copper salts of organic acids, copper hydroxide, and the like. For example, when a trivalent iron ion source is used as an oxidizing metal ion source, specific examples thereof include iron chloride, iron bromide, iron iodide, iron sulfate, iron nitrate, iron salts of organic acids, and the like.

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, and still more preferably 20 to 200 g/L. When the concentration of oxidizing metal ions is 10 g/L or more, the etching rate becomes faster, so copper can be etched quickly. In addition, when the concentration of oxidizing metal ions is 300 g/L or less, the dissolution stability of copper can be maintained.

＜Aromatic heterocyclic compound with five-membered ring (A)＞ The five-membered aromatic heterocyclic compound (A) of the present invention is an aromatic heterocyclic compound having one or more nitrogen atoms as a hetero atom constituting the ring. At least one kind of the above-mentioned five-membered aromatic heterocyclic compound (A) may be used, or two or more kinds may be used in combination.

From the viewpoint of structural stability and solubility in acidic liquids, the above-mentioned five-membered aromatic heterocyclic compound (A) preferably has only nitrogen as a heteroatom constituting the ring. Examples of such five-membered aromatic heterocyclic compounds (A) include imidazole compounds having an imidazole skeleton, pyrazole compounds having a pyrazole skeleton, triazole compounds having a triazole skeleton, and those having a tetrazole skeleton. Azole compounds such as tetrazole compounds.

Examples of the imidazole compound include imidazoles such as imidazole, 2-methylimidazole, 2-undecyl-4-methylimidazole, and 2-phenylimidazole, benzimidazole, 2-methylbenzimidazole, Benzimidazoles such as 2-undecylbenzimidazole, 2-phenylbenzimidazole, 2-mercaptobenzimidazole, etc. Among them, benzimidazole is preferred.

Examples of the pyrazole compound include pyrazole, 3-methylpyrazole, 1-ethylpyrazole, 3-aminopyrazole, 3,5-dimethylpyrazole, 3-amino-1- Methylpyrazole, 4-chloropyrazole 1,3,5-trimethylpyrazole, etc.

Examples of the triazole compound include 1,2,3-triazole, 1,2,4-triazole, 5-phenyl-1,2,4-triazole, 5-amino-1,2, 4-triazole, benzotriazole, 1-methyl-benzotriazole, tolyltriazole, etc. Among them, benzotriazole is preferred.

Examples of the tetrazole compound include 1H-tetrazole, 5-amino-1H-tetrazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole, 5-mercapto-1H- Tetrazole, 1-phenyl-5-mercapto-1H-tetrazole, 1-cyclohexyl-5-mercapto-1H-tetrazole, 5,5'-bi-1H-tetrazole, and these ammonium salts or Metal salts such as Na salt, Zn salt, Ca salt, K salt, etc.

Among the above-mentioned azole compounds, tetrazole compounds are preferred from the viewpoint of high undercut suppression effect, and 1H-tetrazole, 5-methyl-1H-tetrazole, and 5-phenyl-tetrazole are more preferred. 1H-tetrazole, 5-amino-1H-tetrazole, 5,5'-bi-1H-tetrazole, and these ammonium or metal salts, etc., more preferably 1H-tetrazole, 5-methyl -1H-tetrazole, 5-amino-1H-tetrazole, and ammonium or metal salts thereof. It is inferred that these tetrazole compounds can thinly and uniformly form the protective film on the side surface from the top of the conductor pattern.

The concentration of the above-mentioned five-membered aromatic heterocyclic compound (A) is preferably 0.1-50 g/L, more preferably 0.1-15 g/L, and still more preferably 0.2-10 g/L. If the concentration of the five-membered aromatic heterocyclic compound (A) is 0.1 g/L or more, side etching (especially a decrease in the width of the top portion) can be reliably suppressed. On the other hand, when the concentration of the above-mentioned five-membered aromatic heterocyclic compound (A) is 50 g/L or less, it is possible to prevent a decrease in the etching rate, and it is possible to reliably etch the part to be etched. It can prevent short circuit (poor insulation).

<Aliphatic heterocyclic compound with five to seven membered ring (B)> The aliphatic heterocyclic compound (B) having a five- to seven-membered ring of the present invention is an aliphatic heterocyclic compound having one or more nitrogen as a hetero atom constituting the ring. At least one kind of aliphatic heterocyclic compound (B) having a five- to seven-membered ring may be used, or two or more kinds may be used in combination.

The above-mentioned aliphatic heterocyclic compound (B) having a five- to seven-membered ring preferably has only nitrogen as a heteroatom constituting the ring in order to suppress side etching without reducing the linearity of the copper wiring. In addition, from the viewpoint of stability in the etching solution, the aliphatic heterocyclic compound (B) having a five- to seven-membered ring is preferably an aliphatic heterocyclic compound having 3 or less nitrogen constituting the ring.

As specific examples of the aliphatic heterocyclic compound, for example, a tetrahydropyrrole compound having a tetrahydropyrrole skeleton, a piperidine compound having a piperidine skeleton, a piperidine compound having a piperidine skeleton, and a piperazine compound having a high piperazine (homopiperazine ) High piper compounds with a skeleton, hexahydro-1,3,5-tris compounds with a hexahydro-1,3,5-tris skeleton, etc. Among the above-listed compounds, aliphatic heterocycles can be substituted by amino, alkyl, aralkyl, aryl, nitro, nitroso, hydroxyl, carboxy, carbonyl, alkoxy, halo, azo, and cyano groups. Substituents such as group, imino group, phosphine group, thiol group, sulfo group, etc. are substituted.

（通式（I）中，R¹ ～R⁵ 分別獨立地表示氫、含胺基的取代基、或除含胺基的取代基以外的碳數1～10的烴衍生基。此等取代基可彼此鍵結而形成環結構）。The tetrahydropyrrole compound is not particularly limited as long as it is a compound having a tetrahydropyrrole skeleton. For example, a tetrahydropyrrole compound represented by the following formula (I) can be exemplified.

(In the general formula (I), R ¹ to R ⁵ each independently represent hydrogen, an amino group-containing substituent, or a C 1-10 hydrocarbon-derived group other than the amino group-containing substituent. These substituents Can be bonded to each other to form a ring structure).

The above-mentioned amine group represents _{any one of -NH 2} , -NHR, and -NRR', and the above-mentioned R and R'each independently represent a hydrocarbon-derived group having 1 to 10 carbon atoms, and R and R'may be bonded to each other to form a saturated ring structure. The above-mentioned amino group-containing substituent refers to any one of a substituent composed of an amino group and a substituent in which a part of hydrogen in a hydrocarbon-derived group having 1 to 10 carbon atoms is substituted with an amino group. From the viewpoint of effectively suppressing side etching and further improving the linearity of the copper wiring, a substituent composed of an amino group or an amino group-containing substituent composed of carbon, hydrogen, and nitrogen is preferred. The same applies to the following amino groups and amino group-containing substituents.

The above-mentioned hydrocarbon-derived group means that a part of carbon or hydrogen in the hydrocarbon group may be substituted with other atoms or substituents. Examples of hydrocarbon-derived groups include methyl, ethyl, propyl, butyl, hydroxymethyl, hydroxyethyl, hydroxypropyl, aryl, acetyl, phenyl, hydroxyethoxymethyl, and hydroxy. Ethoxyethyl, hydroxyethoxypropyl, etc. are preferably hydrocarbon-derived groups composed of carbon and hydrogen from the viewpoint of effectively suppressing side etching and further improving the straightness of copper wiring. The same applies to the following hydrocarbon-derived groups.

As specific examples of the above-mentioned tetrahydropyrrole compound, for example, tetrahydropyrrole, 1-(2-hydroxyethyl)tetrahydropyrrole, indoline, 1-isopropyl-3-hydroxytetrahydropyrrole, 1, 2-Cyclohexane dicarboximide, 1-butyltetrahydropyrrole, 1-ethyltetrahydropyrrole, 2-(2-hydroxyethyl)-1-methyltetrahydropyrrole, 2-methyltetrahydropyrrole Hydropyrrole, 1-(2-hydroxyethyl)tetrahydropyrrole, 1-(3-aminopropyl)tetrahydropyrrole, 1-(2-aminoethyl)tetrahydropyrrole, 3-aminotetrahydro Pyrrole, 2-aminomethyl-1-ethyltetrahydropyrrole, 2-(2-aminoethyl)-1-methyltetrahydropyrrole, 3-(dimethylamino)tetrahydropyrrole, 3- (Methylamino)tetrahydropyrrole, 1-(2-tetrahydropyrrolylmethyl)tetrahydropyrrole, 3-(diethylamino)tetrahydropyrrole, 1,1'-dimethyl-3-amino Tetrahydropyrrole, 3-(ethylamino)tetrahydropyrrole, 1-methyl-2-(1-N-piperidinomethyl)tetrahydropyrrole, 4-(1-tetrahydropyrrolyl) ) Piperidine, 3-(N-acetyl-N-methylamino) tetrahydropyrrole, 3-(N-acetyl-N-ethylamino) tetrahydropyrrole, 2-tetrahydropyrrole methamide , 3-tetrahydropyrrole carboxamide, 3-acetamide tetrahydropyrrole, 1-ethyl-2-tetrahydropyrrole carboxamide, 3-amino-1-(tertiary butoxycarbonyl) tetrahydro Pyrrole, 3-(tertiary butoxycarbonylamino)tetrahydropyrrole, 1-amino-2-(methoxymethyl)tetrahydropyrrole, 1-benzyl-3-aminotetrahydropyrrole, 1 -Benzyl-3-(dimethylamino)tetrahydropyrrole, 1-benzyl-3-(methylamino)tetrahydropyrrole, 1-benzyl-3-(ethylamino)tetrahydropyrrole, 3, 4-diamino-1-benzyltetrahydropyrrole, 1-benzyl-3-acetamide tetrahydropyrrole, (1s,6s)-2,8-diazabicyclo[4.3.0]nonane, etc. .

（通式（II）中，R⁶ ～R¹¹ 分別獨立地表示氫、含胺基的取代基、或除含胺基的取代基以外的碳數1～10的烴衍生基。此等取代基可彼此鍵結而形成環結構）。The piperidine compound is not particularly limited as long as it is a compound having a piperidine skeleton. For example, a piperidine compound represented by the following formula (II) can be exemplified.

(In the general formula (II), R ⁶ to R ¹¹ each independently represent hydrogen, an amino group-containing substituent, or a C 1-10 hydrocarbon-derived group other than the amino group-containing substituent. These substituents Can be bonded to each other to form a ring structure).

Specific examples of the piperidine compound include, for example, piperidine, 1-methylpiperidine, 2-methylpiperidine, 3-methylpiperidine, 4-methylpiperidine, and 4-methylpiperidine. , 3,5-dimethylpiperidine, 2-ethylpiperidine, 4-piperidine carboxylic acid, 1,2,3,4-tetrahydroquinoline, decahydroisoquinoline, 2,6-dimethyl Piperidine, 2-piperidine methanol, 3-piperidine methanol, 4-piperidine methanol, 2,2,6,6-tetramethylpiperidine, 4-aminopiperidine, 1-aminopiperidine, 3-aminopiperidine, 4-(aminomethyl)piperidine, 4-amino-1-methylpiperidine, 2-(aminomethyl)piperidine, 3-(aminomethyl)piper Pyridine, 4-piperidine carboxamide, 2-piperidine carboxamide, 1-(2-aminoethyl) piperidine, 4-acetamide piperidine, 3-acetamide piperidine, 4-amine 1-isopropylpiperidine, 1-(3-aminopropyl)-2-methylpiperidine, 4-amino-2,2,6,6-tetramethylpiperidine, 2,2 '-Bipiperidine, 4,4'-Bipiperidine, 4-N-hexahydropyridylpiperidine, 4-amino-1-piperidine carboxylate ethyl ester, 4-amino-1-benzylpiperidine Pyridine, 4-(2-aminoethyl)-1-benzylpiperidine, 4-acetamide-1-benzylpiperidine, etc.

（通式（III）中，R¹² ～R¹⁷ 分別獨立地表示氫、含胺基的取代基、或除含胺基的取代基以外的碳數1～10的烴衍生基。此等取代基可彼此鍵結而形成環結構）。The above-mentioned piper compound is not particularly limited as long as it is a compound having a piper skeleton. For example, a piper compound represented by the following formula (III) can be exemplified.

(In the general formula (III), R ¹² to R ¹⁷ each independently represent hydrogen, an amino group-containing substituent, or a C 1-10 hydrocarbon-derived group other than the amino group-containing substituent. These substituents Can be bonded to each other to form a ring structure).

Specific examples of the above-mentioned piper compound include piper, 1-methyl piper, 2-methyl piper, 1-allyl piper, 1-isobutyl piper, and 1-hydroxyethyl. Oxyethyl piper, 1-phenyl piper, 1-amino piper, 1-amino ethyl piper, N-(2-aminoethyl piper), 1-amino-4- Methyl piper, 1-ethyl piper, 1- piper, ethanol, 1- piper, ethyl carboxylate, 1-methyl piper, 1-propyl piper, 1-acetyl piper, 1-isopropyl piper, 1-cyclopentyl piper, 1-cyclohexyl piper, 1-(2-methoxyethyl) piper, 1-piperonyl piper, 1-(diphenyl) Methyl) piper, 2- piper, 1,4-dimethyl piper, 1-methyl-3-phenyl piper, 1,4-bis(3-aminopropyl) piper, 1-(2-Dimethylaminoethyl)-4-methylpiper, 1-(2-aminoethyl)piper, 1,4-bis(3-aminopropyl)piper, 2 ,5-Dimethylpiper, 2,6-Dimethylpiper, 1,4-Dimethylpiper, 1-(4-aminophenyl)-4-methylpiper, 1, 4-Diethyl-2,5-piperidinone, 1-methyl-4-(1,4'-bipiperidin-4-yl)piperidin, 1-(4-aminophenyl) -4-(4-Methoxyphenyl)piperidin, 1,4-dimethylpiperidin-2-one, 1,4-diethylpiperidin-2-one, 1,4-dimethyl Piperidine-2,3-dione, 2-piperidine carboxylic acid, triethylenediamine, etc.

（通式（IV）中，R^{1 8} ～R²⁴ 分別獨立地表示氫、含胺基的取代基、或除含胺基的取代基以外的碳數1～10的烴衍生基。此等取代基可彼此鍵結而形成環結構）。The above-mentioned high piperidine compound is not particularly limited as long as it is a compound having a high piper piper skeleton. For example, a high piperidine compound represented by the following formula (IV) can be exemplified.

In (Formula ^{(IV), R 1 8 ~} R 24 each independently represent a hydrogen, a substituted amine group containing, in addition to carbon atoms, or a substituted amino group-containing hydrocarbon group having 1 to 10 derivative. Such substituents The groups can be bonded to each other to form a ring structure).

Specific examples of the above-mentioned homopiperidin compounds include, for example, homopiperidin, 1-methyl homopiperidin, 1-methylaniline homopiperidin, 1,4-dimethyl homopiperidin, 4-methyl -1-High piperidine dithiocarboxylic acid, 1-acetyl group piperidine, 1-butyryl group piperidine, etc.

（通式（V）中，R²⁵ ～R³⁰ 分別獨立地表示氫、含胺基的取代基、或除含胺基的取代基以外的碳數1～10的烴衍生基。此等取代基可彼此鍵結而形成環結構）。The above-mentioned hexahydro-1,3,5-tri?? compound is not particularly limited as long as it is a compound having a hexahydro-1,3,5-tri?? -1,3,5-Three compounds.

(In the general formula (V), R ²⁵ to R ³⁰ each independently represent hydrogen, an amino group-containing substituent, or a C 1-10 hydrocarbon-derived group other than the amino group-containing substituent. These substituents Can be bonded to each other to form a ring structure).

Specific examples of the above-mentioned hexahydro-1,3,5-trimethyl compound include: hexahydro-1,3,5-trimethyl, hexahydro-1,3,5-trimethyl-1,3, 5-tris, hexahydro-2,4,6-trimethyl-1,3,5-tris, hexahydro-1,3,5-tris(3-dimethylaminopropyl)-1, 3,5-tris, hexahydro-1,3,5-tripropyl-1,3,5-tris, hexahydro-1,3,5-triethyl-1,3,5-tris , Hexahydro-1,3,5-triisopropyl-1.3.5-tris, hexahydro-1,3,5-tribenzyl-1,3,5-tris, hexahydro-1,3 ,5-Tris(2-hydroxyethyl)-1,3,5-tris, hexahydro-1,3,5-trinitro-1,3,5-tris, hexahydro-1,3, 5-trinitroso-1,3,5-tris, hexahydro-2,4,6-trimethyl-1,3,5-trinitro-1,3,5-tris, hexahydro- 1,3,5-Tripropenyl-1,3,5-tris, hexamethylenetetramine, etc.

From the viewpoint of improving the ability to form a fine pattern in the fine pitch pattern area where the fine part and the rough part are mixed, the concentration of the aliphatic heterocyclic compound (B) having a five- to seven-membered ring is preferably 0.01-10 g /L, more preferably 0.02-5 g/L, still more preferably 0.05-3 g/L.

＜Cationic polymer containing tertiary nitrogen or quaternary nitrogen＞ The cationic polymer containing tertiary nitrogen or quaternary nitrogen of the present invention can use well-known examples. Amine polycondensate, dicyandiamide-formaldehyde polycondensate, dicyandiamine-triethylenetetraamine polycondensate and other dicyandiamide-based cationic polymers; polyallylamine, allylamine-dimethylene Propylamine copolymer, diallyldimethylammonium chloride polycondensate, diallylamine acetate-sulfur dioxide copolymer, diallylmethylethylammonium ethylsulfate-sulfur dioxide copolymer, polyene Propylamine sulfate, allylamine acetate-diallylamine acetate copolymer, methyldiallylamine sulfate polymer, diallylamine sulfate-horse Polyallylamine cationic polymers such as acid copolymers; condensation polymers of aliphatic monoamines and epihalohydrin compounds such as dimethylamine-epichlorohydrin condensation products, etc. Among them, the cationic polymer containing tertiary nitrogen or quaternary nitrogen is preferably a dicyandiamide-diethylenetriamine polycondensate from the viewpoint of forming copper wiring with excellent linearity. Amine-polyalkylene polyamine polycondensate, dicyandiamine-formaldehyde polycondensate, dicyandiamine-triethylenetetramine polycondensate, diallyldimethylammonium chloride polycondensate. The cationic polymer containing tertiary nitrogen or quaternary nitrogen may be used at least one kind or in combination of two or more kinds.

From the viewpoint of improving the ability to form fine patterns in the fine-pitch pattern area where the fine part and the rough part are mixed, the concentration of the cationic polymer containing tertiary nitrogen or quaternary nitrogen is preferably 0.001-10 g/L , More preferably 0.005 to 5 g/L, still more preferably 0.01 to 2 g/L.

＜Glycol ethers and/or glycols＞ From the viewpoint of excellent formation of fine patterns in the fine-pitch pattern area where fine parts and rough parts are mixed, and excellent formation of rough patterns, the etching solution of the present invention preferably contains glycol ethers and/or glycols kind. The above-mentioned glycol ethers and/or glycols can be used in combination of two or more types.

As the above-mentioned glycol ethers, well-known glycol ethers can be used, for example, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, triethylene glycol monomethyl ether, Ethylene glycol monoisopropyl ether, diethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, triethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, diethyl Glycol monoisobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, propylene glycol monopropyl ether, dipropylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, Tripropylene glycol monobutyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether , Dipropylene glycol dimethyl ether, etc. Among them, diethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, and dipropylene glycol monomethyl ether are preferred.

As the above diols, well-known diols can be used, for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, methyl propylene glycol, dimethyl diethylene glycol, methyl ethyl diethylene glycol , Methyl dipropylene glycol, methyl tripropylene glycol, polyethylene glycol, polypropylene glycol, etc. Among them, diethylene glycol, methyl propylene glycol, methyl dipropylene glycol, and methyl ethyl diethylene glycol are preferred.

From the viewpoint of improving the ability to form fine patterns and rough patterns in the fine pitch pattern area where the fine part and the rough part are mixed, the concentration of the glycol ethers and/or glycols is preferably 0.01-30 g/L , More preferably 0.1-10 g/L, still more preferably 0.1-5 g/L.

In addition to the above-mentioned components, other components may be added to the etching solution of the present invention to the extent that the effects of the present invention are not hindered. As the above-mentioned other components, for example, aliphatic acyclic compounds such as diethylenetriamine, triethylenetetramine, tetraethylpentamine, and pentaethylenehexamine can be added; cationic surfactants, Anionic surfactants, amphoteric surfactants and other component stabilizers. In addition, when the above-mentioned other components are added, their concentration is usually about 0.001 to 5 g/L.

The above-mentioned etching solution can be easily prepared by dissolving the above-mentioned components in water. As the above-mentioned water, water from which ionic substances and impurities have been removed is preferable, and for example, ion exchange water, pure water, ultrapure water, etc. are preferable.

The above-mentioned etching solution may be blended with each component so as to have a predetermined concentration at the time of use, or a concentrated solution may be prepared in advance and diluted immediately before use for use. The method of using the above-mentioned etching solution is not particularly limited. In order to effectively suppress side etching, it is preferable to perform etching using a sprayer as described later. In addition, the temperature of the etching solution during use is not particularly limited, but in terms of maintaining high productivity, in order to effectively suppress side etching, it is preferable to use it at 20 to 55°C.

The replenishing liquid of the present invention is a replenishing liquid added to the above-mentioned etching liquid when the etching liquid of the present invention is used continuously or repeatedly, and the replenishing liquid is an aqueous solution containing the following compound: the above-mentioned five-membered aromatic heterocyclic compound (A) The above-mentioned aliphatic heterocyclic compound (B) having five to seven-membered rings, and the above-mentioned cationic polymer containing tertiary nitrogen or quaternary nitrogen in the molecule. The components in the above-mentioned replenishing liquid are the same as the components that can be blended into the above-mentioned etching liquid of the present invention. By adding the replenishing liquid, the component ratio of the etching liquid is maintained at an appropriate level, so that the effect of the etching liquid of the present invention can be stably maintained.

In addition, the replenishment solution of the present invention may contain an acid such as hydrochloric acid. In addition, the replenishing liquid may contain oxidizing metal ions such as copper dichloride. In addition to the above-mentioned components, other components added to the etching liquid may be blended with the above-mentioned replenishing liquid. In addition, the components that may be contained in the above-mentioned replenishing liquid may be directly added to the etching liquid of the present invention when the etching liquid of the present invention is used continuously or repeatedly, instead of being contained in the above-mentioned replenishing liquid.

The method of forming the copper wiring of the present invention is to etch the portion of the copper layer that is not covered by the resist, and is characterized in that the etching is performed using the above-mentioned etching solution of the present invention. Thereby, it is possible to form an excellent fine pattern of copper wiring in the fine pitch pattern area where the fine part and the rough part are mixed as described above. In addition, in the copper wiring formation step using the copper wiring formation method of the present invention, when the etching solution of the present invention is used continuously or repeatedly, it is preferable to perform etching while adding the above-mentioned replenishing solution of the present invention. The reason is to maintain the respective component ratios of the etching liquid at an appropriate level, and therefore it is possible to stably maintain the effects of the etching liquid of the present invention.

In the method for forming copper wiring of the present invention, it is preferable to spray the etching liquid on the portion of the copper layer that is not covered by the resist using a sprayer. The reason is that side etching can be effectively suppressed. When spraying, the nozzle is not particularly limited, and fan nozzles, dense cone nozzles, two-fluid nozzles, etc. can be used.

In the case of etching with a sprayer, 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 film with an appropriate thickness can be formed on the side surface of the copper wiring. This can effectively prevent side etching. In addition, from the viewpoint of preventing damage to the resist, the spray pressure is preferably 0.40 MPa or less. [Example]

Next, examples and comparative examples of the present invention will be described together. In addition, the present invention should not be limited to the following examples for explanation.

Each etching solution of the composition shown in Tables 1 to 2 was prepared, and etching was performed under the following conditions, and each item was evaluated by the following evaluation method. In addition, in each etching solution of the composition shown in Tables 1 to 2, the remainder is ion-exchanged water. In addition, the concentration of hydrochloric acid shown in Tables 1 to 2 is the concentration of hydrogen chloride.

(Test board used) Prepare a copper/polyimide laminate with a copper layer thickness of 8 μm (manufactured by Toray Films, trade name "PI-38N-CCS-08EO"), and use photolithography (resist (manufactured by Tokyo Ohka) "PMER-P-RZ30")) form a resist pattern on the copper layer. Regarding the resist pattern, a pattern area of 18 μm pitch (fine part) with a thickness of about 4 μm and line width/line pitch = 11 μm/7 μm and a 25 μm pitch with line width/line pitch = 16 μm/9 μm were produced A resist pattern in which the pattern area (roughness) is mixed.

(Etching conditions) The etching was performed using a fan nozzle (manufactured by Ikeuchi Co., Ltd., trade name "ISVV9020") under the conditions of a spray pressure of 0.20 MPa and a treatment temperature of 35°C. Regarding the processing time, when the pitch is 18 μm, it is assumed that the bottom width of the copper wiring becomes 8 to 15 μm. After etching, it was washed with water, dried, and evaluated as shown below.

(Evaluation of fine patterns) For each test substrate that was etched, hydrochloric acid (hydrogen chloride concentration: 7 wt%) was used, and the protective film was removed with a fan nozzle (manufactured by Ikeuchi, trade name: ISVV9020) at a spray pressure of 0.15 MPa and a treatment time of 40 seconds , And immersed in acetone for 20 seconds (or immersed in a 3 wt% sodium hydroxide aqueous solution for 60 seconds) to remove the resist. Subsequently, a part of each test substrate was cut, embedded in a cold embedding resin, and polished so that the cross section of the wiring could be observed, and a sample for cross-sectional observation was produced. In the cross-sectional observation of the wiring, an image is taken using an optical microscope, and the top width and bottom width of the wiring are measured. At this time, n=2 was measured more than once, and the top width and bottom width were averaged. In addition, B-T in the table is the value of the bottom width-the top width of the copper wiring. Regarding the column of fine part in the table, the case where the B-T value of the 18 μm pitch pattern area with line width/line pitch = 11 μm/7 μm is 0≦B-T≦2 μm is judged as ○, and the division Otherwise, it is judged as ×. Regarding the linearity of the fine part, the width of 50 bottoms was measured, the standard deviation was calculated, and the case of 0.50 or less was judged as ○ (a pass criterion of linearity), and the other cases were judged as ×. Regarding the column of roughness, from the viewpoint that the bottom of the rough pattern is less likely to shrink, as long as the B-T value of the pattern area with a 25 μm pitch of line width/line pitch = 19 μm/9 μm is 0 or more Better. In addition, the value obtained by subtracting the B-T of the fine part from the B-T of the rough part is defined as the density difference. The closer this value is to 0, the more it can be judged that there is no difference in the etching properties of the fine part and the rough part, so it is better to The density difference is close to zero.

[Table 1] composition Concentration (g/L) Fine part pitch l8 μm (L/S＝11/7 μm) Rough part pitch 25 μm (L/S=16/9 μm) Poor density (fine B-T-rough OL B-T) Top width (μm) Bottom width (μm) 0≦B－T≦2.0 (μm) Linearity≦0.50 B－T≧0 (μm) Example 1 Copper Dichloride Dihydrate 80 8.1 8.7 0.6 〇 0.40 〇 -0.3 0.9 hydrochloric acid 75 5-amino-1H-tetrazole 3 Dicyandiamine-diethylene triamine polycondensate 0.05 1-Dimethylaminoethyl-4methylpiperidine 0.2 Example 2 Copper Dichloride Dihydrate 80 7.6 9.5 1.9 〇 0.46 〇 0.6 1.3 hydrochloric acid 75 1H-tetrazole 1.5 Diallyl dimethyl ammonium chloride polycondensate 0.05 N-(2-aminoethyl)piperidine 0.1 Example 3 Copper Dichloride Dihydrate 80 7.4 7.9 0.5 〇 0.43 〇 -0.7 1.2 hydrochloric acid 75 5-methyl-1H-tetrazole 3 Dicyandiamine-polyalkylene polyamine polycondensate 0.05 1-aminopiper 0.1 Example 4 Copper Dichloride Dihydrate 80 7.5 8.0 0.5 〇 0.47 〇 -0.2 0.7 hydrochloric acid 75 1H-tetrazole 1.5 Dicyandiamine-diethylene triamine polycondensate 0.05 3-Methylaminotetrahydropyrrole 0.1 Example 5 Copper Dichloride Dihydrate 80 7.6 8.8 1.2 〇 0.45 〇 0.5 0.8 hydrochloric acid 75 5-amino-1H-tetrazole 3 Diallyl dimethyl ammonium chloride polycondensate 0.05 1-(2-aminoethyl)tetrahydropyrrole 0.2 Example 6 Copper Dichloride Dihydrate 80 7.4 7.7 0.3 〇 0.44 〇 -0.8 1.1 hydrochloric acid 75 1H-tetrazole 1.5 Dicyandiamine-polyalkylene polyamine polycondensate 0.05 4-aminopiperidine 0.1 Example 7 Copper Dichloride Dihydrate 80 7.4 8.0 0.6 〇 0.46 〇 -0.2 0.8 hydrochloric acid 75 5-methyl-1H-tetrazole 3 Dicyandiamine-diethylene triamine polycondensate 0.05 1-(2-aminoethyl)piperidine 0.2 Example 8 Copper Dichloride Dihydrate 80 7.4 8.2 0.8 〇 0.43 〇 0.6 0.2 hydrochloric acid 75 5-amino-1H-tetrazole 3 Dicyandiamine-diethylene triamine polycondensate 0.05 1-(2-aminoethyl)piperidine 0.2 Diethylene glycol 0.5 Example 9 Copper Dichloride Dihydrate 80 7.3 9.1 1.8 〇 0.45 〇 1.6 0.2 hydrochloric acid 75 1H-tetrazole 3 Diallyl dimethyl ammonium chloride polycondensate 0.05 4-aminopiperidine 0.1 Dipropylene glycol monomethyl ether 1 Example 10 Copper Dichloride Dihydrate 80 7.4 9.3 1.9 〇 0.47 〇 1.6 0.3 hydrochloric acid 75 5-methyl-1H-tetrazole 3 Dicyandiamine-polyalkylene polyamine polycondensate 0.05 1-aminopiper 0.1 Diethylene glycol dimethyl ether 0.5

[Table 2] composition Concentration (g/L) Fine part pitch 18 μm (L/S=11/7 μm) Top width (μm) Bottom width (μm) 0≦B－T≦2.0 (μm) Linearity≦0.50 Comparative example 1 Copper Dichloride Dihydrate 80 6.1 8.0 1.9 〇 0.64 X hydrochloric acid 75 5-amino-1H-tetrazole 3 Dicyandiamine-polyalkylene polyamine polycondensate 0.05 1-ethylpiper 0.2 Comparative example 2 Copper Dichloride Dihydrate 80 6.3 8.2 1.9 〇 0.58 X hydrochloric acid 75 1H-tetrazole 1.5 Diallyl dimethyl ammonium chloride polycondensate 0.05 1-methyltetrahydropyrrole 0.1 Comparative example 3 Copper Dichloride Dihydrate 80 6.4 8.8 2.4 X 0.61 X hydrochloric acid 75 5-amino-1H-tetrazole 3 Dicyandiamine-diethylene triamine polycondensate 0.05 4-piperidine carboxylic acid 0.2 Comparative example 4 Copper Dichloride Dihydrate 80 7.5 7.6 0.1 〇 0.70 X hydrochloric acid 75 1H-tetrazole 1.5 3-pyridine methanol 8 Comparative example 5 Copper Dichloride Dihydrate 80 7.5 10.7 3.2 X 0.58 X hydrochloric acid 75 1H-tetrazole 1.5 Diallyl dimethyl ammonium chloride polycondensate 0.05 Comparative example 6 Copper Dichloride Dihydrate 80 6.7 6.4 -0.3 X 0.50 〇 hydrochloric acid 75 5-amino-1H-tetrazole 3 Dimethylaminoethanol 8 Dicyandiamine-polyalkylene polyamine polycondensate 0.05

without

without

Claims (8)

An etching solution, which is an etching solution for copper, is characterized in that: The etching solution contains: acid, oxidizing metal ion, five-membered aromatic heterocyclic compound (A), five- to seven-membered aliphatic heterocyclic compound (B), and tertiary nitrogen in the molecule Or cationic polymer of quaternary nitrogen, The five-membered aromatic heterocyclic compound (A) is an aromatic heterocyclic compound having one or more nitrogen atoms as heteroatoms constituting the ring, The aliphatic heterocyclic compound (B) having a five- to seven-membered ring is an aliphatic heterocyclic compound having one or more nitrogen atoms as a heteroatom constituting the ring. Such as the etching solution of claim 1, wherein the acid is hydrochloric acid. According to the etching solution of claim 1 or 2, wherein the oxidizing metal ion is a divalent copper ion. The etching solution of claim 1 or 2, wherein the five-membered aromatic heterocyclic compound (A) is selected from the group consisting of imidazole compounds, pyrazole compounds, triazole compounds, and tetrazole compounds More than one compound. The etching solution of claim 1 or 2, wherein the aliphatic heterocyclic compound (B) with five to seven membered rings is selected from the group consisting of tetrahydropyrrole compounds, piperidine compounds, piperidine compounds, and homopiperazine Compounds, and one or more compounds in the group consisting of hexahydro-1,3,5-tris compounds. Such as the etching solution of claim 1 or 2, which contains glycol ethers and/or glycols. A replenishing liquid, which is a replenishing liquid added to the etching liquid when the etching liquid in any one of the requirements 1 to 6 is used continuously or repeatedly, The replenishment solution is an aqueous solution containing the following compounds: an aromatic heterocyclic compound having a five-membered ring (A), an aliphatic heterocyclic compound having a five- to seven-membered ring (B), and a tertiary nitrogen or four-membered ring in the molecule. Cationic polymer of grade nitrogen, The five-membered aromatic heterocyclic compound (A) is an aromatic heterocyclic compound having one or more nitrogen atoms as heteroatoms constituting the ring, The aliphatic heterocyclic compound (B) having a five- to seven-membered ring is an aliphatic heterocyclic compound having one or more nitrogen atoms as a heteroatom constituting the ring. A method for forming copper wiring, which is to etch the part of the copper layer that is not covered by the resist, and is characterized in that: Use the etching solution of any one of Claims 1 to 7 for etching.