JP6764845B2 - Stripping composition for resist - Google Patents

Description

The present invention relates to a stripping composition for resist.

As a method for forming a metal surface pattern of a thin film precision material of an electronic material such as a printed circuit board or an elastic surface wave filter, a photolithography method in which a photocurable photoresist is used, exposed in advance, developed, and further etched is generally used. Is used for It is necessary to peel off the remaining photoresist on the metal surface after etching, but conventionally, an inorganic alkaline aqueous solution such as sodium hydroxide has been generally used as these resist stripping solutions (see Patent Document 1).
In the case of an inorganic alkaline aqueous solution, when the photoresist is peeled off, the cured photoresist is peeled off from the metal surface in a film shape, and the peeled film-like photoresist adheres to the surface of the metal pattern and remains. Is occurring. In order to solve this problem, physical measures such as increasing the spray pressure at the time of peeling are taken, but secondary troubles such as causing deformation of the metal pattern by increasing the spray pressure are secondary problems. (See Patent Document 2). As a result of lowering the swelling of the resist material in order to respond to the miniaturization of the wiring pattern due to the miniaturization and high capacity of electronic components, the resist material itself has become difficult to peel off, and narrow wiring. Combined with the presence of the resist sandwiched between the patterns, it has become difficult to remove the resist with a conventional inorganic alkaline aqueous solution.

In order to solve such a problem, a resist stripping solution containing an organic alkaline compound such as a combination of monoethanolamine and tetramethylammonium hydroxide is effective (see Patent Document 3), and is widely used recently. It has come to be.

However, since the resist stripping agent containing tetramethylammonium hydroxide is highly toxic, there is a problem that a large amount of cost is required for safety equipment and environmental equipment from the viewpoint of safety and health and reduction of environmental emissions. Therefore, there is an increasing need for a resist stripping agent that does not contain tetramethylammonium hydroxide.

Japanese Unexamined Patent Publication No. 2003-140364 Japanese Unexamined Patent Publication No. 2002-62668 Japanese Unexamined Patent Publication No. 2001-5201

When the resist is peeled off using a conventional stripping solution, the resist film for forming wiring with a narrow pitch pattern has insufficient peelability, and a residue of the resist film can be seen on the substrate surface. Therefore, there is a problem that a long time is required to completely peel off the resist film on the substrate.
The present invention provides a resist release composition having good resist film peelability and leaving no residue of the resist film even between patterns with a narrow pitch. Further, it is an object of the present invention to provide a stripping composition for a resist, which does not contain tetramethylammonium hydroxide and therefore contributes to safety and health and cost reduction of waste liquid treatment.

The present inventors have arrived at the present invention as a result of diligent studies to solve the above problems. That is, the present invention is a stripping composition for a resist containing an amine (A), an inorganic alkaline compound (B) and water having a nucleophilic parameter N value of 12.7 to 23.5, as described in (A). ) Is a primary amine, and based on the weight of the stripping composition for resist, 3.0 to 6.0 % by weight of (A) is contained, and the pH of the stripping composition for resist is 12.8 to 13.7. It is a peeling composition for resist.

The peeling composition for resist of the present invention exhibits good peeling properties with respect to photosensitive materials such as photoresists and dry film resists. In particular, it is effective in removing all resist films between narrow-pitch wiring patterns. In addition, since it does not contain tetramethylammonium hydroxide, it contributes to safety and health and cost reduction of waste liquid treatment.

The stripping composition for resist of the present invention contains amine (A), an inorganic alkaline compound (B) and water having a nucleophilic parameter N value of 12.7 to 23.5.

The nucleophilic parameter N used for selection of amines is the nucleophilic parameter N of Swain-Scott (for CH ₃ I) (J. Am. Chem. Soc., Vol. 90, No. 17, p. 319, 1968). It is defined in. The amine used in this stripping solution is not particularly limited as long as the nucleophilic parameter N in water is 12.7 to 23.5.

The value of the nucleophilic parameter N is 12.7 to 23.5, preferably 12.7 to 20.0, and more preferably 13.0 to 17.2. If it is less than 12.7 or more than 23.5, it takes time to peel off the photoresist.
The stripping composition for resist of the present invention may contain at least one amine having a nucleophilic parameter N value of 12.7 to 23.5, and the nucleophilic parameter N value is 12 Amines less than 0.7 and amines with a nucleophilic parameter N greater than 23.5 can also be used together.

Examples of the amine (A) having a nucleophilic parameter N value of 12.7 to 23.5 include primary to tertiary amines having a nucleophilic parameter N value of 12.7 to 23.5.
Benzylamine (N = 13.4), n-propylamine (N = 13.3), n-butylamine (N) are examples of primary amines having a nucleophilic parameter N value of 12.7 to 23.5. = 15.3), 1,3-diaminopropane (N = 14.0), 2-phenylethyleneamine (N = 13.4), ethylenediamine (N = 13.3) and allylamine (N = 13.2) And so on.
Secondary amines with a nucleophilic parameter N value of 12.7 to 23.5 include diethylamine (N = 14.7), dimethylamine (N = 17.1), and methylamine (N = 13.9). ), Diethanolamine (N = 13.0), piperidine (N = 18.1), pyrrolidine (N = 17.2), piperazine (N = 17.2), perhydroazepine (N = 18.3) and morpholine. (N = 15.6) and the like.
Examples of the tertiary amine having a nucleophilic parameter N value of 12.7 to 23.5 include triethylenediamine (N = 18.8) and trimethylamine (N = 23.1).
These may be used alone or in combination of two or more.
When two or more kinds of amines are used in combination, the value of each nucleophilic parameter N of the amines contained in the resist stripping composition may be 12.7 to 23.5.
Of these, from the viewpoint of peeling speed, it is preferably a primary amine or a secondary amine or a mixture thereof, more preferably a primary amine or a mixture of a primary amine and a secondary amine, and particularly preferably a primary amine. Is.

Examples of the inorganic alkaline compound (B) include alkali metal hydroxides, alkali metal silicates, alkali metal hydroxides, alkali metal phosphates, alkali metal carbonates, ammonium phosphates, ammonium carbonates and the like. , Preferably an alkali metal hydroxide.
Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide and the like. Of these, lithium hydroxide, sodium hydroxide and potassium hydroxide are preferable, and sodium hydroxide and potassium hydroxide are more preferable, from the viewpoint of narrow-pitch peelability.
These may be used alone or in combination of two or more.

Examples of water include ultrapure water, ion-exchanged water, RO water, distilled water and the like, and ultrapure water and ion-exchanged water are preferable.

The weight of (A) is preferably 0.5 to 50% by weight, more preferably 1.0 to 30% by weight, and particularly preferably 3.0 to 10% by weight, based on the weight of the stripping composition for resist. %.
If it is 50% by weight or less, the resist peeling composition has a low viscosity and high permeability, and if it is 0.5% by weight or more, the narrow pitch peeling property is improved.

The weight of (B) is preferably 0.1 to 10% by weight, more preferably 0.2 to 7%, based on the weight of the resist peeling composition from the viewpoint of the peeling speed for peeling and removing the photoresist. It is% by weight, particularly preferably 0.3 to 5% by weight.

The stripping composition for resist of the present invention may further contain a solubilizing agent (C). The solubilizer (C) solubilizes the amine (A) having a nucleophile parameter N value of 12.7 to 23.5.
Examples of the solubilizing agent (C) include aromatic sulfonic acids, aromatic carboxylic acids, anionic surfactants, nonionic surfactants and the like.
Examples of the aromatic sulfonic acid include benzene sulfonic acid, p-toluene sulfonic acid, xylene sulfonic acid and p-phenol sulfonic acid.
Examples of the aromatic carboxylic acid include benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, mellitic acid and cinnamic acid.
Examples of the anionic surfactant include sodium octanate, sodium decanoate, sodium laurate, sodium myristate, sodium palmitate, sodium stearate, sodium dodecylbenzen sulfonate, sodium lauryl sulfate and the like.
Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, glycerin fatty acid ester, sorbitan fatty acid ester, sucrose fatty acid ester and the like.
Of these, aromatic sulfonic acids, anionic surfactants and nonionic surfactants are preferable from the viewpoint of solubility, and benzenesulfonic acid, p-toluenesulfonic acid, xylenesulfonic acid and p-phenolsulfonic acid are more preferable. Acids, sodium laurates and polyoxyethylene alkyl ethers.

The pH of the stripping composition for resist of the present invention is preferably 6.0 to 15.0, and more preferably 7.0 to 14.5.
If it is 15.0 or less, the metal on the substrate is difficult to form hydroxides and oxides, and if it is 6.0 or more, it is difficult to dissolve the metal on the substrate.
The pH of the stripping composition for resist of the present invention was measured at 25 ° C. using a pH meter without dilution.

Amine (A) having a nucleophile parameter N value of 12.7 to 23.5, an inorganic alkaline compound (B), a solubilizer (C), and an anticorrosive agent (D) described later so as to satisfy the above pH conditions. ), Dispersant (E) and activator (F) are appropriately adjusted in type and concentration.
Further, an acid may be separately added to these resist stripping solutions in order to adjust the pH.

Acids added to adjust the pH include hydrochloric acid, nitrate, sulfuric acid, phosphoric acid, acetic acid, citric acid, formic acid, gluconic acid, lactic acid, oxalic acid, tartaric acid, benzensulfonic acid, xylenesulfonic acid, p-phenol. Examples thereof include sulfonic acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, melitonic acid and silicic acid.

The stripping composition for resist of the present invention may further contain an anticorrosive agent (D).
Examples of the anticorrosive agent (D) include triazole, benzotriazole, 3-aminotriazole, 5-aminotetrazole, tetrahydrobenzotriazole, 5-methylbenzotriazole, imidazole, sodium nitrite, ammonium chromate, sorbitol, xylitol, sucrose, and mannitol. , Martitol, Lactitol and the like.

The stripping composition for resist of the present invention may further contain a dispersant (E).
Examples of the dispersant (E) include a polyethylene oxide adduct at both ends of propylene glycol, polyvinyl alcohol and a derivative thereof, a polyethylene glycol (meth) acrylic acid ester polymer and a polymer thereof, and (meth) acrylic represented by polyacrylic acid. Acid (salt) polymer and its copolymer, maleic acid (salt) polymer represented by sodium salt of styrene and maleic acid copolymer, sodium salt of diisobutylene and maleic acid copolymer and its copolymer , Polynaphthalene sulfonic acid (salt) represented by sodium salt of β-naphthalene sulfonic acid formarin condensate, polymelamine sulfonic acid (salt), sulfonated styrene (salt) polymer and its copolymer, (meth) acrylic. Polymers of (meth) acryloyloxyethyl phosphate typified by copolymers of acid and (meth) acryloyloxyethyl phosphate, polysaccharides having anionic groups typified by sodium alginate and carboxymethyl cellulose, and derivatives thereof, quaternary Polymers of ammonium monomers and their copolymers, polymers of (meth) acryloyloxyethyltrimethylammonium chlorides and their copolymers, hydrophilic group-modified polyvinyl alcohols typified by cation-modified and carboxyl-modified polyvinyl alcohols. , A polymer of a hydrophilic group monomer represented by an acrylamide / acrylic acid copolymer and a (meth) acrylic acid (salt), and a single amount of a hydrophilic group represented by an acrylic acid / dimethyldialylammonium chloride copolymer. Examples thereof include a polymer of a polymer and a quaternary ammonium monomer.
The notation of "(meth) acrylic acid" means acrylic acid or methacrylic acid. The notation "(meth) acryloyl" means acryloyl or methacryloyl.
Examples of the above (salt) include alkali metal salts (sodium salt, potassium salt, etc.), alkaline earth metal salts (calcium salt, magnesium salt, etc.), ammonium salts, amine salts, and quaternary ammonium salts.

The stripping composition for resist of the present invention may further contain an activator (F) (excluding the dispersant (E)).
The activator (F) may be any as long as it lowers the surface tension of water, and examples thereof include anionic surfactants, nonionic surfactants, cationic surfactants, and the like, and anionic surfactants are particularly preferable.
Examples of the anionic surfactant include fatty acids (salts), alkylbenzene sulfonic acids (salts), alkylnaphthalene sulfonic acids (salts), alkyl ether carboxylic acids (salts), alkyl sulfate esters (salts), alkyl ether sulfonic acids (salts), and the like. Examples thereof include alkyl phosphate (salt) and alkyl ether phosphate (salt).

A commercially available preservative, antifoaming agent, or the like may be further added to the resist peeling composition of the present invention.

Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Hereinafter, unless otherwise specified,% indicates a weight% and a part indicates a weight part. In the following, Examples 4 to 10, 12, 15 and 17 to 19 mean Reference Examples 1 to 12.

<Examples 1 to 17 and Comparative Examples 1 to 7>
The amine (A), alkali (B), solubilizer (C), anticorrosive agent (D), dispersant (E), activator (F) and water shown in Tables 1 and 2 are placed in a polypropylene container. To obtain a stripping solution for comparison with the stripping solution of the present invention.

<Measurement of pH>
The pH of the stripping composition for resist was measured at 25 ° C. using a pH meter (manufactured by Horiba Seisakusho).

As a performance evaluation, the peeling time and narrow pitch peeling property of the resist film were carried out by the following methods.

<Resist film peeling time>
The peeling time of the resist film was evaluated by measuring the time until the resist film was removed from the substrate by the following operation method.
(1) A copper wiring printed circuit board (copper-plated wiring width 30 μm / resist film width 20 μm on a copper seed layer) patterned with a resist film having a thickness of 50 μm was cut into a square of 10 mm square to prepare a test piece.
(2) The stripping solution was placed in a test tube, the temperature was adjusted to 50 ° C. in a water bath, and then the above test piece was immersed therein and allowed to stand.
(3) The test piece was visually observed after immersion, and the time (minutes) until the resist film disappeared from the substrate was measured. In the stripping solution used for this purpose, the disappearance time of the resist film is preferably less than 30 minutes, and the evaluation was made according to the following criteria.
◎ ◎: Less than 20 minutes ◎: 20 minutes or more and less than 30 minutes ○: 30 minutes or more and less than 45 minutes △: 45 minutes or more and less than 60 minutes ×: 60 minutes or more

<Narrow pitch peeling property>
The narrow pitch peelability was observed and evaluated by the following operation method.
(1) A copper wiring printed circuit board (copper-plated wiring width 30 μm / resist film width 20 μm on a copper seed layer) patterned with a resist film having a thickness of 50 μm was cut into a square of 10 mm square to prepare a test piece.
(2) The stripping solution was placed in a test tube, the temperature was adjusted to 50 ° C. in a water bath, and then the above test piece was immersed therein and allowed to stand.
(3) After the immersion, the test piece was visually observed, and the immersion was continued for another 5 minutes from the time when the resist film disappeared from the substrate, the test piece was pulled up with tweezers, and immediately washed with ion-exchanged water.
(4) Observe the patterning surface of the test piece after immersion with a digital microscope (VH-6300 manufactured by KEYENCE CORPORATION), and apply a resist film after immersion to the area of the resist film coated area of the total immersion area of the printed circuit board. The area ratio (%) of the coated (peeling residue) is calculated.
It was evaluated according to the following criteria.
⊚: less than 1% ○: 1% or more and less than 3% Δ: 3% or more and less than 10% ×: 10% or more

As is clear from Tables 1 and 2, it can be seen that Examples 1 to 17 of the present invention have a resist film peeling time of less than 30 minutes and a high narrow pitch peeling property as compared with Comparative Examples.

The resist peeling composition of the present invention has good peeling properties and is particularly effective for removing all resist films between narrow-pitch wiring patterns. Therefore, photosensitive materials such as photoresists and dry film resists are used. Can be used for.

Claims (3)

A stripping composition for a resist containing an amine (A) having a nucleophilic parameter N value of 12.7 to 23.5, an inorganic alkaline compound (B), and water, wherein the primary amine is (A). There is, based on the weight of the resist peeling composition, the resist peeling composition containing 3.0 to 6.0 % by weight of the above (A) and the pH of the resist stripping composition is 12.8 to 13.7. object. The stripping composition for resist according to claim 1, which contains 0.1 to 10% by weight of the above (B) based on the weight of the stripping composition for resist. The stripping composition for resist according to claim 1 or 2, wherein (B) is an alkali metal hydroxide.
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