WO2015056428A1 - Resist-stripping liquid - Google Patents

Resist-stripping liquid Download PDF

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Publication number
WO2015056428A1
WO2015056428A1 PCT/JP2014/005128 JP2014005128W WO2015056428A1 WO 2015056428 A1 WO2015056428 A1 WO 2015056428A1 JP 2014005128 W JP2014005128 W JP 2014005128W WO 2015056428 A1 WO2015056428 A1 WO 2015056428A1
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WIPO (PCT)
Prior art keywords
film
resist
mass
stripping solution
resist stripping
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PCT/JP2014/005128
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French (fr)
Japanese (ja)
Inventor
真一郎 淵上
坂田　俊彦
礼子 有冨
靖紀 鈴木
五十嵐　軌雄
明里 児玉
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パナソニックＩｐマネジメント株式会社
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Priority to CN201480057086.XA priority Critical patent/CN105659167A/en
Publication of WO2015056428A1 publication Critical patent/WO2015056428A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
    • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer
    • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having at least one potential-jump barrier or surface barrier, e.g. PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic System or AIIIBV compounds with or without impurities, e.g. doping materials
    • H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
    • H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
    • H01L21/3105—After-treatment
    • H01L21/311—Etching the insulating layers by chemical or physical means
    • H01L21/31127—Etching organic layers
    • H01L21/31133—Etching organic layers by chemical means
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/26—Processing photosensitive materials; Apparatus therefor
    • G03F7/42—Stripping or agents therefor
    • G03F7/422—Stripping or agents therefor using liquids only
    • G03F7/425—Stripping or agents therefor using liquids only containing mineral alkaline compounds; containing organic basic compounds, e.g. quaternary ammonium compounds; containing heterocyclic basic compounds containing nitrogen
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
    • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
    • G03F7/26—Processing photosensitive materials; Apparatus therefor
    • G03F7/42—Stripping or agents therefor
    • G03F7/422—Stripping or agents therefor using liquids only
    • G03F7/426—Stripping or agents therefor using liquids only containing organic halogen compounds; containing organic sulfonic acids or salts thereof; containing sulfoxides

Definitions

  • the present invention is a stripping solution for stripping a resist used in the manufacture of display devices and semiconductors such as liquid crystal and organic EL. More specifically, the resist film formed on a copper film can be completely stripped.
  • the present invention relates to a resist remover that can be used.
  • etching by photolithography is used to form not only semiconductor elements but also conductive wiring and insulating layers. Is used.
  • a photoresist film (hereinafter also simply referred to as “resist film”) is formed on the formed metal film.
  • the resist film is exposed through a pattern mask and developed, so that a pattern (or a negative pattern) to be left by etching remains on the film. Then, the exposed metal film is removed by wet etching using an etchant.
  • an insulating layer is formed on the conductive wiring.
  • a patterned resist film is formed on the insulating film formed on the conductive wiring, and unnecessary portions are removed by dry etching using plasma or the like. The resist film remaining after the etching is then stripped with a resist stripping solution.
  • conductive wiring has been mainly formed of aluminum (hereinafter also referred to as “Al”).
  • Al aluminum
  • Cu copper having a lower resistivity
  • a water-based positive photoresist stripping solution is generally a composition comprising alkanolamine, a polar solvent, and water, and is heated to about 40-50 ° C. in a resist stripping apparatus.
  • Alkanolamine is an essential component for solubilizing the carbonyl group of the alkali insolubilizing agent DNQ (diazonaphthoquinone) compound in the positive photoresist stripping solution in a polar solvent and water by nucleophilic action.
  • DNQ diazonaphthoquinone
  • amines are classified into primary, secondary, and tertiary depending on the number of substituents attached to nitrogen.
  • the smaller the series the stronger the basicity and the stronger the nucleophilicity.
  • the smaller the series the stronger the power to solubilize the alkali insolubilizing agent DNQ compound in the positive photoresist stripping solution in a polar solvent or water, and the stronger the resist stripping power (hereinafter referred to as “resist stripping power”).
  • resist stripping power hereinafter referred to as “resist stripping power”.
  • alkanolamine has a chelating action on copper and corrodes copper by forming a complex.
  • the chelating action on copper like basicity and nucleophilicity, is stronger as the series is smaller and corrodes copper. Therefore, when a copper film is used as the conductive wiring, a stripping solution using a tertiary alkanolamine having a low chelating action on copper has been proposed.
  • a dry etching process is used for etching the insulating film formed on the conductive wiring.
  • the resist film is exposed to plasma.
  • the resist film exposed to plasma changes in quality due to excessive polymerization and becomes difficult to peel off (Patent Document 1).
  • Patent Document 3 discloses a resist stripping solution for stripping a resist film on a copper film.
  • Patent Document 3 discloses a resist stripping solution containing an amine, a solvent, a strong alkali, and water. In Patent Document 3, it is assumed that corrosion of copper is prevented by using a resist stripping solution having these compositions in an environment where the oxygen concentration is a predetermined value or less.
  • tertiary alkanolamines have the advantage that the chelating action is weak and copper corrosion falls within an acceptable level range.
  • the basicity and nucleophilicity are weak, and there is a drawback that the resist stripping force is weak compared to a photoresist stripping solution using primary or secondary alkanolamine.
  • the DNQ compound remains on the surface of the copper film after the photoresist is peeled off, and the SiNx film (insulating film) formed on the upper layer of the conductive wiring patterned with the copper film is peeled off or damaged due to dry etching and altered.
  • the polymerization of the DNQ compound and the novolak resin has progressed excessively, causing problems such as poor peeling of the hard-to-peel altered resist on the altered a-Si (amorphous silicon) film. Street.
  • a base film such as molybdenum is formed on the substrate in order to increase the adhesion of the copper film.
  • the resist stripping solution in the case of using a copper film must not corrode not only the copper film itself but also the underlying film. This is because when the base film is corroded, the copper film itself on the base film is also peeled off.
  • Patent Document 1 is an invention relating to resist stripping in a state where aluminum and copper are simultaneously present.
  • an organic solvent having an alkylbenzene sulfonic acid as a proton-donating organic solvent and a stripping solution containing monoethanolamine as a proton-accepting organic solvent are merely disclosed, and no specific composition is disclosed.
  • Patent Document 3 discloses a resist stripping solution under strong alkali. However, under strong alkali, molybdenum in contact with copper is corroded by the galvanic potential. Patent Document 3 does not mention this point.
  • the present invention provides a stripping solution having a resist stripping force equal to or higher than that of a stripping solution for aluminum wiring using monoethanolamine and suppressing damage to copper wiring. .
  • the resist stripper according to the present invention is: It includes a tertiary alkanolamine, a polar solvent, water, a strong alkali agent, and a reducing agent, and has a pH of 12 or more.
  • the resist stripping solution according to the present invention can suitably strip the resist film on the copper film without corroding the copper film. Therefore, even if an insulating layer such as an amorphous silicon (a-Si) film is formed on the copper film, the insulating layer does not peel off. Further, even if a base layer such as molybdenum (hereinafter also referred to as “Mo”) is formed under the copper film, the base layer is not corroded.
  • Mo molybdenum
  • a resist film that has been altered through a dry etching process on an insulating film such as a SiNx film formed on a copper film can also be suitably peeled off.
  • the resist stripping solution according to the present invention does not need to be subjected to oxygen plasma ashing or the like before the stripping step. As a result, it can contribute greatly to productivity and cost reduction in the factory.
  • the resist film from which the resist stripper according to the present invention is peeled is assumed to be a positive resist.
  • the positive resist includes a novolac resin as a resin and a DNQ (diazonaphthoquinone) compound as a photosensitive agent.
  • a resist film is formed on a film formed on a substrate, and exposure is performed through a pattern.
  • the novolac resin originally has a property of being dissolved in an alkaline solution, but the melting point is protected by a DNQ compound.
  • the DNQ compound is altered by exposure and dissolved in water, so that the novolak resin is also dissolved. In this way, the resist film patterning is completed.
  • the substrate on which the patterning is completed with the resist film is subjected to wet etching processing or dry etching processing.
  • the dry etching process is a process performed in a vacuum, and the resist film remaining as a pattern is exposed to a high temperature and radical atmosphere. As a result, the novolak resins in the resist film are recombined with each other, and the composition is changed into a composition that hardly dissolves.
  • the resist film After etching, the resist film is no longer necessary, so strip off with a resist stripper. That is, the resist film from which the resist stripping solution is peeled is not only the resist film that has undergone the wet etching process but also the resist film that has undergone the dry etching process. Although the resist film remaining on the substrate has not undergone the exposure process, the entire resist film is exposed by being exposed to plasma or being left under a fluorescent lamp after the etching is completed. It is in the same state as
  • the situation where the resist stripping solution becomes a problem is as follows. As an example, a basic process for manufacturing a FET (Field Effect Transistor) will be described. On the substrate, wiring such as gates is patterned with copper or aluminum. This is a process of removing copper and aluminum by wet etching. At this time, the resist remaining on the copper or aluminum pattern is removed with a resist stripping solution. At this time, copper and aluminum are corroded by contact with the resist stripping solution.
  • FET Field Effect Transistor
  • a SiNx layer is formed as an insulating layer on the copper or aluminum pattern, and an a-Si (n +) / a-Si (amorphous silicon) layer serving as a semiconductor portion is formed on the SiNx layer.
  • the a-Si (n +) / a-Si layer is coated with a resist, exposed and developed, and the a-Si (n +) / a-Si layer is patterned by dry etching. Thereafter, the resist is removed with a resist stripping solution. The resist film exposed to the plasma during dry etching is altered as described above and becomes difficult to dissolve.
  • the resist film exposed to the plasma during dry etching is altered as described above and hardly dissolved. Therefore, a resist stripping solution that is strong enough to strip the altered resist film is used. However, the resist stripping solution having a strong resist stripping force corrodes the metal (copper) wiring after the wet etching. On the other hand, if the resist stripping solution has only a resist stripping force that does not corrode metal (copper) wiring, the altered resist film cannot be stripped.
  • the resist stripping solution for removing the resist film on the copper film should not corrode the molybdenum film which is the base film of the copper film.
  • the resist stripping solution according to the present invention can strip the resist film without corroding the underlying molybdenum film and the upper copper film, and also removes the resist film that has been altered by exposure to plasma. can do.
  • the resist stripping solution according to the present invention includes a tertiary alkanolamine, a polar solvent, water, a strong alkali agent, and a reducing agent, and has a pH of 12 or more.
  • Alkanolamine makes the carbonyl group (sulfonic acid ester moiety) of the DNQ compound, which is an alkali insolubilizing agent for positive photoresists, soluble in a polar solvent and water by nucleophilic action.
  • tertiary alkanolamines that can be suitably used include the following. Triethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-dibutylethanolamine, N-ethyldiethanolamine, N-butyldiethanolamine, N-methyldiethanolamine and the like. These may be used in combination of a plurality of types.
  • the polar solvent may be an organic solvent having an affinity for water. Moreover, it is more suitable if the mixing property with said tertiary alkanolamine is favorable.
  • water-soluble organic solvents examples include sulfoxides such as dimethyl sulfoxide; sulfones such as dimethyl sulfone, diethyl sulfone, bis (2-hydroxyethyl) sulfone, and tetramethylene sulfone; N, N-dimethylformamide, N-methyl Amides such as formamide, N, N-dimethylacetamide, N-methylacetamide, N, N-diethylacetamide; N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N -Lactams such as hydroxymethyl-2-pyrrolidone and N-hydroxyethyl-2-pyrrolidone; 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, 1,3-diisopropyl -2-Imidazolidinones such as imi
  • a mixture of at least one selected from dimethyl sulfoxide, N-methyl-2-pyrrolidone, and diethylene glycol monobutyl ether and at least one selected from ethylene glycol, diethylene glycol, and propylene glycol is preferable.
  • a desired result can be obtained by using a mixed liquid of diethylene glycol monobutyl ether (BDG) and propylene glycol (PG) as a polar solvent.
  • BDG diethylene glycol monobutyl ether
  • PG propylene glycol
  • a mixed solution of diethylene glycol monobutyl ether (BDG) and propylene glycol (PG) can be suitably used as a polar solvent.
  • BDG diethylene glycol monobutyl ether
  • PG propylene glycol
  • BDG diethylene glycol monobutyl ether
  • the strong alkali agent was selected from tetramethylammonium hydroxide, trimethyl-2-hydroxyethylammonium hydroxide, dimethylbis (2-hydroxyethyl) ammonium hydroxide, tetrabutylammonium hydroxide, alkylammonium hydride, and guanidine carbonate. Including at least one.
  • gallic acid gallic acid, pyrogallol and the like
  • tannic acid capable of generating these substances by hydrolysis in a strong alkaline solution
  • tannic acid may be said to be a substance having at least gallic acid as a basic skeleton.
  • at least the structure of the formula (1) is included.
  • the resist stripping solution of the present invention has a pH of 12 or more.
  • Resist stripping force after wet etching A silicon thermal oxide film having a thickness of 100 nm was formed on a silicon substrate, and a copper film having a thickness of 300 nm was formed on the silicon thermal oxide film by sputtering. A positive resist solution was applied onto the copper film by spin coating. After the resist film was dried, it was exposed using a wiring pattern mask. And the resist of the exposed part was peeled with the resist peeling liquid. This is called a copper film substrate. That is, the copper film substrate is in a state in which a portion where the resist film of the wiring pattern remains on the copper film and a portion where the copper film is exposed are formed.
  • the exposed copper film was removed by etching using an acid-based copper etchant.
  • the copper film substrate was immersed in a sample resist stripper for 10 minutes.
  • the temperature of the sample resist stripping solution is 30 to 40 ° C.
  • the copper film substrate was washed, and it was observed while interfering with an optical microscope whether or not the resist film remained on the copper film. It was also observed by SEM.
  • the remaining resist film was confirmed on the copper film, it was “x”, and when the remaining resist film was not confirmed, it was marked “ ⁇ ”.
  • a-Si (amorphous silicon) film having a thickness of 300 nm was formed on a silicon substrate.
  • a positive resist solution was applied onto the a-Si film by spin coating. After the resist film was dried, it was exposed using a wiring pattern mask. And the resist of the exposed part was peeled with the resist peeling liquid.
  • This is called an amorphous silicon substrate. That is, the amorphous silicon substrate is in a state in which a portion of the wiring pattern resist film remaining on the a-Si film and a portion of the a-Si film exposed are formed.
  • the exposed a-Si film was removed by dry etching using a reactive sputtering method in a vacuum chamber. Therefore, the resist film remaining on the a-Si film is exposed to plasma during sputtering.
  • the amorphous silicon substrate was immersed in a sample resist stripping solution for 10 minutes. The temperature of the sample resist stripping solution is 30 to 40 ° C.
  • the amorphous silicon substrate was washed, and it was observed while interfering with an optical microscope whether or not the resist film remained on the a-Si film. It was also observed by SEM.
  • the result is “X” when the remaining resist film is confirmed on the a-Si film, and “ ⁇ ” when the remaining resist film is not confirmed.
  • a molybdenum film having a thickness of 40 nm was formed on a glass substrate, and then a copper film was further laminated to a thickness of 300 nm. This is called a molybdenum substrate.
  • the molybdenum substrate was wet etched in the same manner as in “(1) Resist peeling force after wet etching”. By this wet etching, the copper film and the molybdenum film in a portion where the resist film is not formed are removed.
  • the etched molybdenum substrate was immersed in a sample resist stripper for 10 minutes.
  • the temperature of the sample resist stripping solution is 30 to 40 ° C. Thereafter, the molybdenum substrate was washed and dried.
  • FIG. 1 shows a schematic diagram of a cross section observed at this time.
  • a molybdenum film 12 is formed on the glass substrate 10, and a copper film 14 is formed thereon.
  • an undercut portion 20 is formed between the copper film 14 and the undercut portion 20.
  • ⁇ Contact angle> The copper film substrate from which the resist film was peeled and the copper film was exposed was immersed again in a resist stripping solution, then washed with pure water, and water droplets were blown with a blower. The contact angle on the copper film of this copper film substrate was measured. The indicator liquid used at this time is pure water. If this contact angle is large, even if the resist film can be sufficiently peeled off by SEM, the adhesion between the copper film and the insulating film formed on the upper layer of the copper film is weak, and the insulating film may peel off. .
  • the resist stripping solution in which the exposed resist component was powdered and mixed at a ratio of 2% by mass was also used as the resist stripping solution soaked again. That is, the resist stripping solution that has been immersed again is only the sample resist solution (indicated as “resist concentration 0%”), and when 2% by weight of the resist component powder exposed to the sample resist solution is mixed. Two types (“resist concentration 2%”) were prepared.
  • the resist stripping solution actually used is circulated, it contains stripped resist components.
  • the resist component contained in the resist stripping solution may sufficiently affect the surface condition on the copper film.
  • the sample resist solution having a resist concentration of 2% is a simulated reproduction of the resist stripping solution actually used.
  • sample resist stripping solution was prepared as follows. The composition ratio was adjusted by the amount of propylene glycol (PG).
  • Example 1 The sample resist stripping solution of Example 1 was prepared with the following composition ratio. N-methyldiethanolamine (MDEA) 5.0% by mass Propylene glycol (PG) 22.98% by mass Diethylene glycol monobutyl ether (BDG) 40.0% by mass 31.0% by weight of water Tetramethylammonium hydroxide (TMAH) 1.0 mass% Tannic acid 0.02% by mass The above was mixed and stirred to obtain the sample resist stripping solution of Example 1.
  • MDEA N-methyldiethanolamine
  • PG Propylene glycol
  • BDG Diethylene glycol monobutyl ether
  • TMAH Tetramethylammonium hydroxide
  • Example 2 In Example 2, the amount of strong alkali agent (TMAH) was increased from that in Example 1. N-methyldiethanolamine (MDEA) 5.0% by mass Propylene glycol (PG) 21.48% by mass Diethylene glycol monobutyl ether (BDG) 40.0% by mass 31.0% by weight of water Tetramethylammonium hydroxide (TMAH) 2.5% by mass Tannic acid 0.02% by mass The above was mixed and stirred to obtain the sample resist stripping solution of Example 2.
  • MDEA N-methyldiethanolamine
  • PG Propylene glycol
  • BDG Diethylene glycol monobutyl ether
  • TMAH Tetramethylammonium hydroxide
  • Example 3 In Example 3, the amount of tertiary alkanolamine was reduced compared to Example 1.
  • N-methyldiethanolamine (MDEA) 2.0% by mass Propylene glycol (PG) 25.98% by mass
  • Diethylene glycol monobutyl ether (BDG) 40.0% by mass 31.0% by weight of water
  • Tetramethylammonium hydroxide (TMAH) 1.0 mass% Tannic acid 0.02% by mass The above was mixed and stirred to obtain the sample resist stripping solution of Example 3.
  • MDEA N-methyldiethanolamine
  • PG Propylene glycol
  • BDG Diethylene glycol monobutyl ether
  • TMAH Tetramethylammonium hydroxide
  • Example 4 In Example 4, the amount of strong alkali agent (TMAH) was increased from Example 3. N-methyldiethanolamine (MDEA) 2.0% by mass Propylene glycol (PG) 24.48% by mass Diethylene glycol monobutyl ether (BDG) 40.0% by mass 31.0% by weight of water Tetramethylammonium hydroxide (TMAH) 2.5% by mass Tannic acid 0.02% by mass The above was mixed and stirred to obtain a sample resist stripping solution of Example 4.
  • MDEA N-methyldiethanolamine
  • PG Propylene glycol
  • BDG Diethylene glycol monobutyl ether
  • TMAH Tetramethylammonium hydroxide
  • Example 5 In Example 5, the type of the strong alkali agent in Example 2 was changed. N-methyldiethanolamine (MDEA) 5.0% by mass Propylene glycol (PG) 21.48% by mass Diethylene glycol monobutyl ether (BDG) 40.0% by mass 31.0% by weight of water Guanidine carbonate 2.5% by mass Tannic acid 0.02% by mass The above was mixed and stirred to obtain a sample resist stripping solution of Example 5.
  • MDEA N-methyldiethanolamine
  • PG Propylene glycol
  • BDG Diethylene glycol monobutyl ether
  • guanidine carbonate is represented by the following formula (Formula 2).
  • Example 6 In Example 6, the type of the strong alkali agent in Example 1 was changed. N-methyldiethanolamine (MDEA) 5.0% by mass Propylene glycol (PG) 22.98% by mass Diethylene glycol monobutyl ether (BDG) 40.0% by mass 31.0% by weight of water Choline 1.0% by mass Tannic acid 0.02% by mass The above was mixed and stirred to obtain a sample resist stripping solution of Example 6.
  • MDEA N-methyldiethanolamine
  • PG Propylene glycol
  • BDG Diethylene glycol monobutyl ether
  • choline (2-hydroxyethyltrimethylammonium hydroxide) is represented by the following formula (Formula 3).
  • Example 7 In Example 7, the type of the strong alkali agent in Example 1 was changed, and the amount was also reduced. N-methyldiethanolamine (MDEA) 5.0% by mass Propylene glycol (PG) 23.73% by mass Diethylene glycol monobutyl ether (BDG) 40.0% by mass 31.0% by weight of water AH212 0.25% by mass Tannic acid 0.02% by mass The above was mixed and stirred to obtain a sample resist stripping solution of Example 7.
  • MDEA N-methyldiethanolamine
  • PG Propylene glycol
  • BDG Diethylene glycol monobutyl ether
  • AH212 (2-hydroxyethylammonium hydroxide) is represented by the following formula (Formula 4).
  • Example 8 In Example 8, the type of the strong alkali agent in Example 1 was changed. N-methyldiethanolamine (MDEA) 5.0% by mass Propylene glycol (PG) 22.98% by mass Diethylene glycol monobutyl ether (BDG) 40.0% by mass 31.0% by weight of water NaOH 1.0% by mass Tannic acid 0.02% by mass The above was mixed and stirred to obtain a sample resist stripping solution of Example 8.
  • MDEA N-methyldiethanolamine
  • PG Propylene glycol
  • BDG Diethylene glycol monobutyl ether
  • Table 1 shows the compositions and evaluation results of Examples 1 to 4.
  • Table 2 shows the compositions and evaluation results of Examples 5 to 8.
  • Comparative Example 1 is a composition obtained by removing the strong alkali agent and reducing agent from Example 1. N-methyldiethanolamine (MDEA) 5.0% by mass Propylene glycol (PG) 24.0% by mass Diethylene glycol monobutyl ether (BDG) 40.0% by mass 31.0% by weight of water The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 1.
  • MDEA N-methyldiethanolamine
  • PG Propylene glycol
  • BDG Diethylene glycol monobutyl ether
  • Comparative Example 3 In Comparative Example 3, the type of amine of Comparative Example 1 was changed. There are no strong alkali agents and reducing agents. N, N-diethylethanolamine (N-DEEA) 5.0% by mass Propylene glycol (PG) 24.0% by mass Diethylene glycol monobutyl ether (BDG) 40.0% by mass 31.0% by weight of water The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 3.
  • N-DEEA N-diethylethanolamine
  • PG Propylene glycol
  • BDG Diethylene glycol monobutyl ether
  • Comparative Example 4 In Comparative Example 4, the type of amine of Comparative Example 1 was changed. There are no strong alkali agents and reducing agents. Secondary alkanolamines were used as amines. N-methylethanolamine (MMA) 5.0% by mass Propylene glycol (PG) 24.0% by mass Diethylene glycol monobutyl ether (BDG) 40.0% by mass 31.0% by weight of water The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 4.
  • MMA N-methylethanolamine
  • PG Propylene glycol
  • BDG Diethylene glycol monobutyl ether
  • Comparative Example 5 In Comparative Example 5, the type of amine of Comparative Example 1 was changed. There are no strong alkali agents and reducing agents. Primary alkanolamine was used as amines. Monoethanolamine (MEA) 5.0% by mass Propylene glycol (PG) 24.0% by mass Diethylene glycol monobutyl ether (BDG) 40.0% by mass 31.0% by weight of water The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 5.
  • MEA Monoethanolamine
  • PG Propylene glycol
  • BDG Diethylene glycol monobutyl ether
  • Table 3 shows the compositions and evaluation results of Comparative Examples 1 to 5.
  • Comparative Example 6 In Comparative Example 6, only a strong alkali agent was added to Comparative Example 1. N-methyldiethanolamine (MDEA) 5.0% by mass Propylene glycol (PG) 23.975 mass% Diethylene glycol monobutyl ether (BDG) 40.0% by mass 31.0% by weight of water Tetramethylammonium hydroxide (TMAH) 0.025% by mass The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 6.
  • MDEA N-methyldiethanolamine
  • PG Propylene glycol
  • BDG Diethylene glycol monobutyl ether
  • TMAH Tetramethylammonium hydroxide
  • Comparative Example 7 In Comparative Example 7, the amount of the strong alkali agent in Comparative Example 6 was increased. N-methyldiethanolamine (MDEA) 5.0% by mass Propylene glycol (PG) 23.75% by mass Diethylene glycol monobutyl ether (BDG) 40.0% by mass 31.0% by weight of water Tetramethylammonium hydroxide (TMAH) 0.25% by mass The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 7.
  • MDEA N-methyldiethanolamine
  • PG Propylene glycol
  • BDG Diethylene glycol monobutyl ether
  • TMAH Tetramethylammonium hydroxide
  • Comparative Example 8 In Comparative Example 8, the amount of the strong alkali agent in Comparative Example 6 was increased. N-methyldiethanolamine (MDEA) 5.0% by mass Propylene glycol (PG) 23.0% by mass Diethylene glycol monobutyl ether (BDG) 40.0% by mass 31.0% by weight of water Tetramethylammonium hydroxide (TMAH) 1.0 mass% The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 8.
  • MDEA N-methyldiethanolamine
  • PG Propylene glycol
  • BDG Diethylene glycol monobutyl ether
  • TMAH Tetramethylammonium hydroxide
  • Comparative Example 9 In Comparative Example 9, the amount of the strong alkali agent in Comparative Example 6 was increased. N-methyldiethanolamine (MDEA) 5.0% by mass Propylene glycol (PG) 21.5% by mass Diethylene glycol monobutyl ether (BDG) 40.0% by mass 31.0% by weight of water Tetramethylammonium hydroxide (TMAH) 2.5% by mass The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 9.
  • MDEA N-methyldiethanolamine
  • PG Propylene glycol
  • BDG Diethylene glycol monobutyl ether
  • TMAH Tetramethylammonium hydroxide
  • Comparative Example 10 The comparative example 10 changed the kind of strong alkali agent of the comparative example 7. N-methyldiethanolamine (MDEA) 5.0% by mass Propylene glycol (PG) 23.75% by mass Diethylene glycol monobutyl ether (BDG) 40.0% by mass 31.0% by weight of water NH 3 0.25% by mass The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 10.
  • MDEA N-methyldiethanolamine
  • PG Propylene glycol
  • BDG Diethylene glycol monobutyl ether
  • Comparative Example 11 In Comparative Example 11, the amount of the strong alkali agent in Comparative Example 10 was increased. N-methyldiethanolamine (MDEA) 5.0% by mass Propylene glycol (PG) 22.5% by mass Diethylene glycol monobutyl ether (BDG) 40.0% by mass 31.0% by weight of water NH 3 1.5% by mass The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 11.
  • MDEA N-methyldiethanolamine
  • PG Propylene glycol
  • BDG Diethylene glycol monobutyl ether
  • Table 4 shows the compositions and evaluation results of Comparative Examples 6 to 11.
  • Comparative Example 12 In Comparative Example 12, alkanolamine was removed from Comparative Example 6. Propylene glycol (PG) 28.975 mass% Diethylene glycol monobutyl ether (BDG) 40.0% by mass 31.0% by weight of water Tetramethylammonium hydroxide (TMAH) 0.025% by mass The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 12.
  • PG Propylene glycol
  • BDG Diethylene glycol monobutyl ether
  • TMAH Tetramethylammonium hydroxide
  • Table 5 shows the compositions and evaluation results of Comparative Examples 12 to 15.
  • Tables 1 to 5 show the compositions of the above sample resist stripping solutions and the results on “resist stripping power” and “corrosiveness to the base film”.
  • each sample resist stripping solution of Examples 1 to 8 was not only stripped of the resist film after wet etching, but also the a-Si film that was considered to be altered by exposure to plasma.
  • the resist film after the dry etching was sufficiently peeled off.
  • each of the sample resist stripping solutions of Examples 1 to 8 can strip the resist film without distinguishing between wet etching and dry etching, and does not corrode the molybdenum film serving as the base film.
  • each of the resist samples of Examples 1 to 8 had a low contact angle (15 to 17 degrees). This is judged that the substance which inhibits adhesion does not remain on the surface of the copper film even after using the stripping solution. Therefore, even if film formation is performed after the resist film is stripped with each of the sample resist stripping solutions of Examples 1 to 8, no adhesion failure occurs between the base film (here, the copper film). It was.
  • each sample resist stripping solution of Examples 1 to 8 has a resist stripping force equivalent to the stripping solution for aluminum wiring using monoethanolamine, and even if the base is a copper film, Even a copper film can be used without causing damage.
  • Comparative Examples 1 to 3 are sample resist stripping solutions that use a tertiary amine and do not contain any strong alkali agent. With these compositions, although the corrosion of the copper film and the base film (molybdenum film) was low, the resist film after dry etching could not be peeled off.
  • Comparative Examples 4 and 5 are obtained by reducing the series of amines and using secondary amines and primary amines. With these compositions, the resist film after dry etching can be removed. However, the copper film and the copper film on the molybdenum film were subjected to corrosion that could not be used as a product. That is, an amine having a smaller series has a stronger effect of stripping the resist film, and at the same time corrodes the copper film and the underlying molybdenum film. This is thought to be because a complex is formed between the amine and copper.
  • Comparative Examples 6 to 11 the amount of strong alkaline agent was examined in order to ensure the resist peeling force with respect to the resist film after dry etching while keeping the corrosion to the base film low.
  • the amount of TMAH increases, the resist film after dry etching can be peeled off.
  • the corrosion of the copper film and the molybdenum film also progressed.
  • Comparative Examples 10 and 11 are the results when ammonia was used as a strong alkali agent. Even if ammonia was contained in an amount of 0.25 to 1.5% by mass, the resist film after dry etching could not be peeled off. On the other hand, corrosion of copper film and molybdenum film occurred.
  • Comparative Examples 12 to 15 show the results in the case where only PG was increased from Comparative Examples 6 to 9 without containing an amine.
  • the resist film after wet etching was able to be peeled off without causing corrosion, whether it was a copper film or a molybdenum film. This indicates that the novolak resin is soluble in the alkali solution in the first place, which can be said to be the expected result of the novolak resin.
  • Comparative Examples 1 to 15 the resist film after dry etching was able to be peeled off in Comparative Examples 4 and 5 using a secondary amine and a primary amine as an amine, and a tertiary amine.
  • Comparative Examples 8 and 9 containing 1.0% by mass or more of TMAH.
  • Comparative Examples 8 and 9 were observed by the optical microscope so that neither the copper film nor the molybdenum film was significantly corroded. Therefore, in order to reduce the corrosion on the copper film and the molybdenum film of Comparative Examples 8 and 9, the composition ratio of the example is that a reducing agent is added.
  • Examples 5 to 8 are the results of changing the type of strong alkali agent.
  • the same results as in Examples 1 to 4 could be obtained with quaternary ammonium bases such as Choline and AH212, or strong guanidine-based alkaline agents.
  • the resist stripping solution of the present invention can be suitably used as a resist stripping solution when a positive photoresist is used.
  • This can be suitably used for general production of FPD such as a liquid crystal display, a plasma display, and an organic EL.

Abstract

　The present invention provides a stripping liquid capable of stripping, by using one composition, both a resist film on a copper film and a resist film changed in quality by exposure to plasma on an insulation film. The resist-stripping liquid, characterized in containing a tertiary alkanol amine, a polar solvent, water, a strong alkali agent, and a reducing agent, and having a pH of 12 or greater, can remove a resist film changed in quality by exposure to plasma, and does not corrode a copper film and a ground molybdenum layer. Tetraalkylammonium hydroxide (TMAH) and tannic acid can suitably be used for the strong alkali agent and the reducing agent, respectively.

Description

レジスト剥離液Resist stripper
　本発明は、液晶、有機ＥＬ等のディスプレイデバイスや半導体の製造時に用いるレジストを剥離するための剥離液であり、より詳しくは、銅膜上に形成される、レジスト膜を完全に剥離させることができるレジスト剥離液に関する。 The present invention is a stripping solution for stripping a resist used in the manufacture of display devices and semiconductors such as liquid crystal and organic EL. More specifically, the resist film formed on a copper film can be completely stripped. The present invention relates to a resist remover that can be used.
　液晶や有機ＥＬ（Ｅｌｅｃｔｒｏ－Ｌｕｍｉｎｅｓｃｅｎｃｅ）等のフラットパネルディスプレイ（ＦＰＤ）のＴＦＴ（Ｔｈｉｎ　Ｆｉｌｍ　Ｔｒａｎｓｉｓｔｏｒ）製造プロセスでは、半導体素子だけでなく、導電配線や絶縁層を形成するのにも、フォトリソグラフィによるエッチングが用いられる。 In the TFT (Thin Film Transistor) manufacturing process of flat panel displays (FPD) such as liquid crystal and organic EL (Electro-Luminescence), etching by photolithography is used to form not only semiconductor elements but also conductive wiring and insulating layers. Is used.
　このエッチングでは、例えば成膜された金属膜上にフォトレジスト膜（以後単に「レジスト膜」とも呼ぶ。）を形成する。レジスト膜は、パターンマスクを通して露光され、現像されることで、エッチングで残したいパターン（若しくはそのネガパターン）が膜上に残る。そして、露出した金属膜を、エッチャントを用いたウエットエッチングで除去する。 In this etching, for example, a photoresist film (hereinafter also simply referred to as “resist film”) is formed on the formed metal film. The resist film is exposed through a pattern mask and developed, so that a pattern (or a negative pattern) to be left by etching remains on the film. Then, the exposed metal film is removed by wet etching using an etchant.
　また、導電配線上には、絶縁層が形成される。絶縁層は、導電配線上に形成した絶縁膜に、パターン化したレジスト膜を形成し、プラズマ等を利用したドライエッチングで不要な部分を除去する。エッチング後に残ったレジスト膜は、その後レジスト剥離液で剥離される。 Also, an insulating layer is formed on the conductive wiring. As the insulating layer, a patterned resist film is formed on the insulating film formed on the conductive wiring, and unnecessary portions are removed by dry etching using plasma or the like. The resist film remaining after the etching is then stripped with a resist stripping solution.
　従来導電配線は、主としてアルミニウム（以後「Ａｌ」とも記載する。）で形成されていた。しかし、ＦＰＤの大型化によって、多くの電流を流す必要が生じ、より抵抗率の小さな銅（以後「Ｃｕ」とも記載する。）を導電配線として用いることが検討された。 Conventionally, conductive wiring has been mainly formed of aluminum (hereinafter also referred to as “Al”). However, with the increase in size of the FPD, it is necessary to pass a large amount of current, and it has been studied to use copper having a lower resistivity (hereinafter also referred to as “Cu”) as a conductive wiring.
　水系のポジ型フォトレジスト用剥離液は、一般的にアルカノールアミン、極性溶媒、水からなる組成物であり、レジスト剥離装置内で４０～５０℃程度に加温して使用される。アルカノールアミンは、求核作用によって、ポジ型フォトレジスト用剥離液中のアルカリ不溶化剤ＤＮＱ（ジアゾナフトキノン）化合物のカルボニル基を極性溶媒及び水に可溶化するために必須の成分である。 A water-based positive photoresist stripping solution is generally a composition comprising alkanolamine, a polar solvent, and water, and is heated to about 40-50 ° C. in a resist stripping apparatus. Alkanolamine is an essential component for solubilizing the carbonyl group of the alkali insolubilizing agent DNQ (diazonaphthoquinone) compound in the positive photoresist stripping solution in a polar solvent and water by nucleophilic action.
　一般にアミンは窒素に付いている置換基の数によって、一級、二級、三級に分類される。このうち、級数が小さいほど塩基性が強く、求核性も強いことが知られている。つまり、級数が小さなアルカノールアミンであるほど、ポジ型フォトレジスト用剥離液中のアルカリ不溶化剤ＤＮＱ化合物を極性溶媒や水に可溶化する力が強く、強力なフォトレジスト剥離力（以後「レジスト剥離力」とも呼ぶ。）を持つことになる。 Generally, amines are classified into primary, secondary, and tertiary depending on the number of substituents attached to nitrogen. Among these, it is known that the smaller the series, the stronger the basicity and the stronger the nucleophilicity. In other words, the smaller the series, the stronger the power to solubilize the alkali insolubilizing agent DNQ compound in the positive photoresist stripping solution in a polar solvent or water, and the stronger the resist stripping power (hereinafter referred to as “resist stripping power”). Will also be called.)
　しかし、アルカノールアミンは銅に対するキレート作用があり、錯体を作ることによって銅を腐食する。この銅へのキレート作用は塩基性や求核性と同様に、級数が小さいほど強く、銅を腐食する。そこで、導電配線として銅膜を使う場合は、銅に対するキレート作用の低い、三級アルカノールアミンを使う剥離液が提案されている。 However, alkanolamine has a chelating action on copper and corrodes copper by forming a complex. The chelating action on copper, like basicity and nucleophilicity, is stronger as the series is smaller and corrodes copper. Therefore, when a copper film is used as the conductive wiring, a stripping solution using a tertiary alkanolamine having a low chelating action on copper has been proposed.
　また、導電配線上に形成される絶縁膜のエッチングには、ドライエッチングプロセスが利用される。ドライエッチングプロセスでは、レジスト膜はプラズマに晒される。プラズマに晒されたレジスト膜は、重合が過剰に進むことで変質し、剥離しにくくなる（特許文献１）。 Also, a dry etching process is used for etching the insulating film formed on the conductive wiring. In the dry etching process, the resist film is exposed to plasma. The resist film exposed to plasma changes in quality due to excessive polymerization and becomes difficult to peel off (Patent Document 1).
　このような場合でも導電配線としてアルミニウム膜を用いる場合は、フォトレジスト用剥離液に強力なレジスト剥離力を持たせるために、一級アルカノールアミンであるモノエタノールアミンを用いたレジスト剥離液を使用するのが一般的である。アルミニウムは一級アルカノールアミンのモノエタノールアミンによる腐食作用をあまり受けないからである。 Even in such a case, when an aluminum film is used as the conductive wiring, a resist stripping solution using monoethanolamine, which is a primary alkanolamine, is used in order to give the resist stripping solution strong resist stripping power. Is common. This is because aluminum is not subject to the corrosive action of primary alkanolamine by monoethanolamine.
　しかし、導電配線として銅膜を用いる場合は、銅を腐食し難い代わりに、レジスト剥離力も弱い、三級アルカノールアミンを使用せざるを得ない。そこで、剥離工程の前に、酸素プラズマアッシング処理などを施して、重合が過剰に進んだレジスト膜を減ずるなどの処置を施すことで、変質したレジスト膜を何とか剥離しているのが現状である。しかし、工程数の増加とコスト増が課題となっている。 However, when a copper film is used as the conductive wiring, a tertiary alkanolamine having a weak resist peeling force must be used instead of being hard to corrode copper. Therefore, it is the current situation that the altered resist film is somehow removed by performing an oxygen plasma ashing process or the like before the peeling process to reduce the resist film that has undergone excessive polymerization. . However, an increase in the number of processes and an increase in cost are issues.
　また、特許文献３では、銅膜上のレジスト膜を剥離するレジスト剥離液が開示されている。特許文献３では、アミンと溶剤と強アルカリおよび水を含むレジスト剥離液が開示されている。特許文献３では、これらの組成のレジスト剥離液を酸素濃度が所定値以下の環境で使用することで、銅の腐食が防止されるとする。 Further, Patent Document 3 discloses a resist stripping solution for stripping a resist film on a copper film. Patent Document 3 discloses a resist stripping solution containing an amine, a solvent, a strong alkali, and water. In Patent Document 3, it is assumed that corrosion of copper is prevented by using a resist stripping solution having these compositions in an environment where the oxygen concentration is a predetermined value or less.
特開平０８－２６２７４６号公報Japanese Patent Application Laid-Open No. 08-262746 特開平０５－０４７６５４号公報Japanese Patent Laid-Open No. 05-047654 特開２００３－１４０３６４号公報JP 2003-140364 A
　上記で説明したように、三級のアルカノールアミンの場合はキレート作用が弱く、銅の腐食は許容レベル範囲内に収まるという利点がある。一方、塩基性や、求核性が弱く、一級や二級のアルカノールアミンを使用したフォトレジスト用剥離液と比較すると、レジスト剥離力が弱いという欠点がある。 As explained above, tertiary alkanolamines have the advantage that the chelating action is weak and copper corrosion falls within an acceptable level range. On the other hand, the basicity and nucleophilicity are weak, and there is a drawback that the resist stripping force is weak compared to a photoresist stripping solution using primary or secondary alkanolamine.
　このため、フォトレジスト剥離後の銅膜表面にＤＮＱ化合物が残留し、銅膜をパターンニングした導電配線の上層に成膜するＳｉＮｘ膜（絶縁膜）が剥がれたり、ドライエッチングによってダメージを受けて変質し、ＤＮＱ化合物とノボラック樹脂の重合が過剰に進み、変質したａ－Ｓｉ（アモルファスシリコン）膜上の難剥離変質レジストの剥離不良が発生したりするなどの課題が生じていたのは、上述の通りである。 For this reason, the DNQ compound remains on the surface of the copper film after the photoresist is peeled off, and the SiNx film (insulating film) formed on the upper layer of the conductive wiring patterned with the copper film is peeled off or damaged due to dry etching and altered. However, the polymerization of the DNQ compound and the novolak resin has progressed excessively, causing problems such as poor peeling of the hard-to-peel altered resist on the altered a-Si (amorphous silicon) film. Street.
　また、ガラス基板上に銅膜を形成する場合は、銅膜の付着力を高めるため、モリブデン等の下地膜を基板上に形成する。すなわち、銅膜を使った場合のレジスト剥離液は、銅膜自体だけでなく、この下地膜も腐食させてはいけない。下地膜が腐食されると、下地膜上の銅膜自体も剥がれてしまうからである。 Also, when a copper film is formed on a glass substrate, a base film such as molybdenum is formed on the substrate in order to increase the adhesion of the copper film. In other words, the resist stripping solution in the case of using a copper film must not corrode not only the copper film itself but also the underlying film. This is because when the base film is corroded, the copper film itself on the base film is also peeled off.
　この課題に対して、特許文献１は、アルミニウムと銅が同時に存在している状態でのレジスト剥離についての発明である。しかし、プロトン供与性の有機溶媒としてアルキルベンゼンスルホン酸を有する有機溶媒、またプロトン受容性の有機溶媒としてはモノエタノールアミンを含有する剥離液とされているだけで、具体的な組成の開示はない。 In response to this problem, Patent Document 1 is an invention relating to resist stripping in a state where aluminum and copper are simultaneously present. However, an organic solvent having an alkylbenzene sulfonic acid as a proton-donating organic solvent and a stripping solution containing monoethanolamine as a proton-accepting organic solvent are merely disclosed, and no specific composition is disclosed.
　また、特許文献３は、強アルカリの下でのレジスト剥離液を開示している。しかし、強アルカリ下では、ガルバニック電位によって、銅と接触しているモリブデンが腐食されてしまう。特許文献３は、この点についての言及はない。 Patent Document 3 discloses a resist stripping solution under strong alkali. However, under strong alkali, molybdenum in contact with copper is corroded by the galvanic potential. Patent Document 3 does not mention this point.
　したがって、銅膜上のレジスト膜を腐食させることなく、絶縁膜上でプラズマに曝され変質したレジスト膜の両方を剥離させることのできる剥離液は、未だ好適な組成が完成されていないものである。 Therefore, a stripping solution that can strip both resist films that have been exposed to plasma on an insulating film without corroding the resist film on the copper film has not yet been completed with a suitable composition. .
　本発明は、このような状況に鑑み、モノエタノールアミンを使用したアルミニウム配線用剥離液と同等若しくはそれ以上のレジスト剥離力を持ち、銅配線へのダメージを抑えた剥離液を提供するものである。 In view of such circumstances, the present invention provides a stripping solution having a resist stripping force equal to or higher than that of a stripping solution for aluminum wiring using monoethanolamine and suppressing damage to copper wiring. .
　より具体的に本発明に係るレジスト剥離液は、
　三級アルカノールアミンと、極性溶媒と、水と、強アルカリ剤と、還元剤を含み、ｐＨが１２以上であることを特徴とする。 More specifically, the resist stripper according to the present invention is:
It includes a tertiary alkanolamine, a polar solvent, water, a strong alkali agent, and a reducing agent, and has a pH of 12 or more.
　本発明に係るレジスト剥離液は、銅膜上のレジスト膜を、銅膜を腐食させることなく、好適に剥離させることができる。そのため、銅膜上にアモルファスシリコン（ａ－Ｓｉ）膜などの絶縁層を形成しても、絶縁層が剥離するといったことがない。また、銅膜の下層にモリブデン（以後「Ｍｏ」とも記載する。）等の下地層を形成していても、下地層を腐食することがない。 The resist stripping solution according to the present invention can suitably strip the resist film on the copper film without corroding the copper film. Therefore, even if an insulating layer such as an amorphous silicon (a-Si) film is formed on the copper film, the insulating layer does not peel off. Further, even if a base layer such as molybdenum (hereinafter also referred to as “Mo”) is formed under the copper film, the base layer is not corroded.
　さらに、銅膜上に形成したＳｉＮｘ膜といった絶縁膜上でドライエッチングのプロセスを経て変質したレジスト膜も、好適に剥離させることができる。 Furthermore, a resist film that has been altered through a dry etching process on an insulating film such as a SiNx film formed on a copper film can also be suitably peeled off.
　これらの効果を有するので、本発明に係るレジスト剥離液は、剥離工程の前に酸素プラズマアッシング処理などを施す必要がない。結果、工場での生産性およびコスト低減に高く寄与することができる。 Because of these effects, the resist stripping solution according to the present invention does not need to be subjected to oxygen plasma ashing or the like before the stripping step. As a result, it can contribute greatly to productivity and cost reduction in the factory.
エッチングの状態を示す図である。It is a figure which shows the state of an etching.
　以下本発明に係るレジスト剥離液について説明する。なお、以下の説明は本発明に係るフォトレジスト剥離液の一実施形態を示すものであり、本発明の趣旨を逸脱しない範囲で、以下の実施形態および実施例は改変されてもよい。 Hereinafter, the resist stripping solution according to the present invention will be described. The following description shows an embodiment of the photoresist stripping solution according to the present invention, and the following embodiments and examples may be modified without departing from the gist of the present invention.
　本発明に係るレジスト剥離液が剥離するレジスト膜は、ポジ型レジストを想定している。ポジ型レジストには、樹脂としてノボラック系の樹脂が含まれ、感光剤としてＤＮＱ（ジアゾナフトキノン）化合物が含まれる。エッチングを行う場合、基板上に作製された膜上にレジスト膜を形成し、パターンを介して露光を行う。 The resist film from which the resist stripper according to the present invention is peeled is assumed to be a positive resist. The positive resist includes a novolac resin as a resin and a DNQ (diazonaphthoquinone) compound as a photosensitive agent. In the case of performing etching, a resist film is formed on a film formed on a substrate, and exposure is performed through a pattern.
　この露光によってＤＮＱ化合物のスルホン酸エステル部分が強アルカリによるケン化作用で極性溶媒や水に可溶する。ノボラック系の樹脂は、もともとアルカリ溶液に溶解する性質を有するが、ＤＮＱ化合物によって溶解点をプロテクトされている。ＤＮＱ化合物が露光によって変質し、水中に溶け出すことで、ノボラック樹脂も溶け出す。このようにしてレジスト膜のパターンニングが完成する。 This exposure allows the sulfonic acid ester portion of the DNQ compound to be soluble in polar solvents and water by saponification with strong alkali. The novolac resin originally has a property of being dissolved in an alkaline solution, but the melting point is protected by a DNQ compound. The DNQ compound is altered by exposure and dissolved in water, so that the novolak resin is also dissolved. In this way, the resist film patterning is completed.
　レジスト膜によってパターンニングが完成した基板は、ウエットエッチング処理若しくは、ドライエッチング処理が施される。ドライエッチング処理は、真空中で行われる処理で、パターンとして残ったレジスト膜は、高温とラジカルな雰囲気に曝される。これによって、レジスト膜中のノボラック系の樹脂同士が再結合し、溶解しにくい組成に変質する。 The substrate on which the patterning is completed with the resist film is subjected to wet etching processing or dry etching processing. The dry etching process is a process performed in a vacuum, and the resist film remaining as a pattern is exposed to a high temperature and radical atmosphere. As a result, the novolak resins in the resist film are recombined with each other, and the composition is changed into a composition that hardly dissolves.
　エッチング後、レジスト膜は不要になるので、レジスト剥離液で剥離する。すなわち、レジスト剥離液が剥離するレジスト膜は、ウエットエッチングの工程を経たレジスト膜だけでなく、ドライエッチングの工程を経たレジスト膜も対象となる。なお、基板上に残ったレジスト膜は、露光の工程を経てはいないが、エッチングが終了した後、プラズマに曝されたり、蛍光灯の下で放置されるといったことで、レジスト膜全体が露光されたのと同じ状態になっている。 After etching, the resist film is no longer necessary, so strip off with a resist stripper. That is, the resist film from which the resist stripping solution is peeled is not only the resist film that has undergone the wet etching process but also the resist film that has undergone the dry etching process. Although the resist film remaining on the substrate has not undergone the exposure process, the entire resist film is exposed by being exposed to plasma or being left under a fluorescent lamp after the etching is completed. It is in the same state as
　レジスト剥離液が問題となる局面は以下のような局面である。例としてＦＥＴ（Ｆｉｅｌｄ　Ｅｆｆｅｃｔ　Ｔｒａｎｓｉｓｔｏｒ）を作製する基本的なプロセスで説明する。基板上には、銅やアルミニウムで、ゲート等の配線がパターンされる。これは銅やアルミニウムをウエットエッチングで除去する工程を経る。この時、銅やアルミニウムのパターン上に残ったレジストは、レジスト剥離液で除去する。この際に銅やアルミニウムはレジスト剥離液に接触することにより腐食される。 The situation where the resist stripping solution becomes a problem is as follows. As an example, a basic process for manufacturing a FET (Field Effect Transistor) will be described. On the substrate, wiring such as gates is patterned with copper or aluminum. This is a process of removing copper and aluminum by wet etching. At this time, the resist remaining on the copper or aluminum pattern is removed with a resist stripping solution. At this time, copper and aluminum are corroded by contact with the resist stripping solution.
　次に銅やアルミニウムのパターン上に絶縁層としてＳｉＮｘ層を成膜し、ＳｉＮｘ層の上に半導体部分となるａ－Ｓｉ（ｎ＋）／ａ－Ｓｉ（アモルファスシリコン）層を成膜する。ａ－Ｓｉ（ｎ＋）／ａ－Ｓｉ層はレジストが塗布、露光、現像され、ドライエッチングによってａ－Ｓｉ（ｎ＋）／ａ－Ｓｉ層のパターンニングが行われる。この後、レジスト剥離液でレジストが除去される。ドライエッチングを行う際のプラズマに曝されたレジスト膜は上記の説明のように変質し、溶解しにくくなる。 Next, a SiNx layer is formed as an insulating layer on the copper or aluminum pattern, and an a-Si (n +) / a-Si (amorphous silicon) layer serving as a semiconductor portion is formed on the SiNx layer. The a-Si (n +) / a-Si layer is coated with a resist, exposed and developed, and the a-Si (n +) / a-Si layer is patterned by dry etching. Thereafter, the resist is removed with a resist stripping solution. The resist film exposed to the plasma during dry etching is altered as described above and becomes difficult to dissolve.
　ドライエッチングを行う際のプラズマに曝されたレジスト膜は上記の説明のように変質し、溶解しにくい。そこで、変質したレジスト膜を剥離できるほど強力なレジスト剥離液を使用する。しかしレジスト剥離力の強いレジスト剥離液では、ウエットエッチング後の金属（銅）配線が腐食を受ける。一方、金属（銅）配線が腐食されない程度のレジスト剥離力しか持たないレジスト剥離液であると、変質したレジスト膜を剥離できない。 The resist film exposed to the plasma during dry etching is altered as described above and hardly dissolved. Therefore, a resist stripping solution that is strong enough to strip the altered resist film is used. However, the resist stripping solution having a strong resist stripping force corrodes the metal (copper) wiring after the wet etching. On the other hand, if the resist stripping solution has only a resist stripping force that does not corrode metal (copper) wiring, the altered resist film cannot be stripped.
　また、銅膜上のレジスト膜を除去するレジスト剥離液は、銅膜の下地膜であるモリブデン膜を腐食させてはいけない。本発明に係るレジスト剥離液は、下地膜であるモリブデン膜および、その上層である銅膜を腐食することなく、レジスト膜を剥離でき、尚且つ、プラズマに曝されて変質したレジスト膜をも除去することができる。 Also, the resist stripping solution for removing the resist film on the copper film should not corrode the molybdenum film which is the base film of the copper film. The resist stripping solution according to the present invention can strip the resist film without corroding the underlying molybdenum film and the upper copper film, and also removes the resist film that has been altered by exposure to plasma. can do.
　次に本発明に係るレジスト剥離膜の組成について詳しく説明する。本発明に係るレジスト剥離液は、三級アルカノールアミンと、極性溶媒と、水と、強アルカリ剤と還元剤を含み、ｐＨが１２以上であることを特徴とする。 Next, the composition of the resist release film according to the present invention will be described in detail. The resist stripping solution according to the present invention includes a tertiary alkanolamine, a polar solvent, water, a strong alkali agent, and a reducing agent, and has a pH of 12 or more.
　アルカノールアミンは、求核作用によって、ポジ型フォトレジストのアルカリ不溶化剤であるＤＮＱ化合物のカルボニル基（スルホン酸エステル部分）を極性溶媒および水に可溶にする。 Alkanolamine makes the carbonyl group (sulfonic acid ester moiety) of the DNQ compound, which is an alkali insolubilizing agent for positive photoresists, soluble in a polar solvent and water by nucleophilic action.
　三級アルカノールアミンとしては、具体的に以下のものが好適に利用できる。トリエタノールアミン、Ｎ，Ｎ－ジメチルエタノールアミン、Ｎ，Ｎ－ジエチルエタノールアミン、Ｎ，Ｎ－ジブチルエタノールアミン、Ｎ－エチルジエタノールアミン、Ｎ－ブチルジエタノールアミン、Ｎ－メチルジエタノールアミン等である。これらは、複数種類を混合して用いてもよい。 Specific examples of tertiary alkanolamines that can be suitably used include the following. Triethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-dibutylethanolamine, N-ethyldiethanolamine, N-butyldiethanolamine, N-methyldiethanolamine and the like. These may be used in combination of a plurality of types.
　極性溶媒としては、水と親和性のある有機溶媒であればよい。また上記の三級アルカノールアミンとの混合性が良好であればより好適である。 The polar solvent may be an organic solvent having an affinity for water. Moreover, it is more suitable if the mixing property with said tertiary alkanolamine is favorable.
　このような水溶性有機溶媒としては、ジメチルスルホキシド等のスルホキシド類；ジメチルスルホン、ジエチルスルホン、ビス（２－ヒドロキシエチル）スルホン、テトラメチレンスルホン等のスルホン類；Ｎ，Ｎ－ジメチルホルムアミド、Ｎ－メチルホルムアミド、Ｎ，Ｎ－ジメチルアセトアミド、Ｎ－メチルアセトアミド、Ｎ，Ｎ－ジエチルアセトアミド等のアミド類；Ｎ－メチル－２－ピロリドン、Ｎ－エチル－２－ピロリドン、Ｎ－プロピル－２－ピロリドン、Ｎ－ヒドロキシメチル－２－ピロリドン、Ｎ－ヒドロキシエチル－２－ピロリドン等のラクタム類；１，３－ジメチル－２－イミダゾリジノン、１，３－ジエチル－２－イミダゾリジノン、１，３－ジイソプロピル－２－イミダゾリジノン等のイミダゾリジノン類；エチレングリコール、エチレングリコールモノメチルエーテル、エチレングリコールモノエチルエーテル、エチレングリコールモノブチルエーテル、エチレングリコールモノメチルエーテルアセテート、エチレングリコールモノエチルエーテルアセテート、ジエチレングリコール、ジエチレングリコールモノメチルエーテル、ジエチレングリコールモノエチルエーテル、ジエチレングリコールモノプロピルエーテル、ジエチレングリコールモノブチルエーテルなどのジエチレングリコールモノアルキルエーテル、プロピレングリコール、プロピレングリコールモノメチルエーテル、プロピレングリコールモノエチルエーテル、プロピレングリコールモノプロピルエーテル、プロピレングリコールモノブチルエーテルなどのプロピレングリコールモノアルキルエーテル（アルキルは炭素原子数１～６の低級アルキル基）等の多価アルコール類、およびその誘導体が挙げられる。これらの中で、ジメチルスルホキシド、Ｎ－メチル－２－ピロリドン、ジエチレングリコールモノブチルエーテルの中から選ばれる少なくとも１種と、エチレングリコール、ジエチレングリコール、プロピレングリコールの中から選ばれる少なくとも１種の混合液が好適に利用できる。中でも、ポジ型レジストに対しては、ジエチレングリコールモノブチルエーテル（ＢＤＧ）と、プロピレングリコール（ＰＧ）との混合液を極性溶媒として利用すると、望ましい結果を得ることができる。 Examples of such water-soluble organic solvents include sulfoxides such as dimethyl sulfoxide; sulfones such as dimethyl sulfone, diethyl sulfone, bis (2-hydroxyethyl) sulfone, and tetramethylene sulfone; N, N-dimethylformamide, N-methyl Amides such as formamide, N, N-dimethylacetamide, N-methylacetamide, N, N-diethylacetamide; N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N-propyl-2-pyrrolidone, N -Lactams such as hydroxymethyl-2-pyrrolidone and N-hydroxyethyl-2-pyrrolidone; 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, 1,3-diisopropyl -2-Imidazolidinones such as imidazolidinone; Glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol mono Propylene glycol compounds such as diethylene glycol monoalkyl ether such as butyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether Alkyl ether (the alkyl is a lower alkyl group having 1 to 6 carbon atoms) are exemplified polyvalent alcohols, and derivatives thereof, and the like. Among these, a mixture of at least one selected from dimethyl sulfoxide, N-methyl-2-pyrrolidone, and diethylene glycol monobutyl ether and at least one selected from ethylene glycol, diethylene glycol, and propylene glycol is preferable. Available. In particular, for a positive resist, a desired result can be obtained by using a mixed liquid of diethylene glycol monobutyl ether (BDG) and propylene glycol (PG) as a polar solvent.
　なお、本発明に係るレジスト剥離液では、極性溶媒としてジエチレングリコールモノブチルエーテル（ＢＤＧ）とプロピレングリコール（ＰＧ）の混合液が好適に利用できる。これらの極性溶媒は、レジスト膜を溶解し、また溶解しやすくする。特にプロピレングリコール（ＰＧ）はレジスト膜を膨潤させ、ジエチレングリコールモノブチルエーテル（ＢＤＧ）は、レジスト膜を溶解する。したがって、少なくとも２液を含有する極性溶媒が効果的である。 In the resist stripping solution according to the present invention, a mixed solution of diethylene glycol monobutyl ether (BDG) and propylene glycol (PG) can be suitably used as a polar solvent. These polar solvents dissolve and facilitate dissolution of the resist film. In particular, propylene glycol (PG) swells the resist film, and diethylene glycol monobutyl ether (BDG) dissolves the resist film. Therefore, a polar solvent containing at least two liquids is effective.
　強アルカリ剤としては、テトラメチルアンモニウムヒドロキシド、トリメチル－２－ヒドロキシエチルアンモニウムヒドロキシド、ジメチルビス（２－ヒドロキシエチル）アンモニウムヒドロキシド、テトラブチルアンモニウムヒドロオキサイド、アルキルアンモニウムハイドライド、炭酸グアニジンから選ばれた少なくとも一種を含む。 The strong alkali agent was selected from tetramethylammonium hydroxide, trimethyl-2-hydroxyethylammonium hydroxide, dimethylbis (2-hydroxyethyl) ammonium hydroxide, tetrabutylammonium hydroxide, alkylammonium hydride, and guanidine carbonate. Including at least one.
　また、還元剤としては、没食子酸やピロガロール等が利用でき、強アルカリ溶液中で加水分解により、これらの物質を生成できるタンニン酸が好適に使用できる。ここでは、タンニン酸とは、少なくとも没食子酸を基本骨格とする物質と言ってもよい。なお、少なくとも（化１）式の構造物を含む。 Also, as the reducing agent, gallic acid, pyrogallol and the like can be used, and tannic acid capable of generating these substances by hydrolysis in a strong alkaline solution can be preferably used. Here, tannic acid may be said to be a substance having at least gallic acid as a basic skeleton. In addition, at least the structure of the formula (1) is included.
Figure JPOXMLDOC01-appb-C000001
 　　　　　　　　　　　　　　　・・・（化１）
Figure JPOXMLDOC01-appb-C000001
 ... (Chemical formula 1)
　特に、タンニン酸は、レジスト剥離液に含有させると、徐々に没食子酸に分解し、長い時間に渡って、還元作用を発揮する。したがって、レジスト剥離液としての、ライフを長くすることができる。つまり、レジスト剥離液のレジスト剥離力の経時劣化が少ないという効果を発揮させることができる。また、本発明のレジスト剥離液は、ｐＨが１２以上であることを特徴とする。 In particular, when tannic acid is contained in the resist stripping solution, it gradually decomposes into gallic acid and exhibits a reducing action over a long period of time. Therefore, the life as a resist stripping solution can be extended. That is, the effect that the resist stripping force of the resist stripping solution is less deteriorated with time can be exhibited. Moreover, the resist stripping solution of the present invention has a pH of 12 or more.
　以下に本発明に係るレジスト剥離液の実施例および比較例を示す。なお、評価項目について説明する。 Examples and comparative examples of resist stripping solutions according to the present invention are shown below. The evaluation items will be described.
　＜レジスト剥離力＞
　レジスト剥離力を以下の２つの観点で評価した。 <Resist stripping force>
The resist peeling force was evaluated from the following two viewpoints.
　（１）ウエットエッチング後のレジスト剥離力
　シリコン基板上に、シリコン熱酸化膜を１００ｎｍ成膜し、シリコン熱酸化膜上にスパッタ法で銅膜を３００ｎｍの厚みに形成した。その銅膜上にポジ型レジスト液をスピンコートで塗布した。レジスト膜が乾燥した後、配線パターンのマスクを用いて露光した。そしてレジスト剥離液で、感光した部分のレジストを剥離した。これを銅膜基板と呼ぶ。つまり、銅膜基板は、銅膜上に配線パターンのレジスト膜が残った部分と、銅膜が露出した部分が形成された状態になる。 (1) Resist stripping force after wet etching A silicon thermal oxide film having a thickness of 100 nm was formed on a silicon substrate, and a copper film having a thickness of 300 nm was formed on the silicon thermal oxide film by sputtering. A positive resist solution was applied onto the copper film by spin coating. After the resist film was dried, it was exposed using a wiring pattern mask. And the resist of the exposed part was peeled with the resist peeling liquid. This is called a copper film substrate. That is, the copper film substrate is in a state in which a portion where the resist film of the wiring pattern remains on the copper film and a portion where the copper film is exposed are formed.
　次に、酸系の銅のエッチャントを用いて、露出した銅膜をエッチングし除去した。銅膜のエッチングが終了した後、銅膜基板をサンプルレジスト剥離液に１０分間浸漬させた。サンプルレジスト剥離液の温度は３０～４０℃である。そして銅膜基板を洗浄し、銅膜上にレジスト膜が残留しているか否かを光学顕微鏡で干渉をかけながら観察した。また、ＳＥＭでも観察した。表では銅膜上にレジスト膜の残りが確認された場合は、「×」とし、レジスト膜の残りが確認されなかった場合は、「○」とした。 Next, the exposed copper film was removed by etching using an acid-based copper etchant. After the etching of the copper film was completed, the copper film substrate was immersed in a sample resist stripper for 10 minutes. The temperature of the sample resist stripping solution is 30 to 40 ° C. Then, the copper film substrate was washed, and it was observed while interfering with an optical microscope whether or not the resist film remained on the copper film. It was also observed by SEM. In the table, when the remaining resist film was confirmed on the copper film, it was “x”, and when the remaining resist film was not confirmed, it was marked “◯”.
　（２）ドライエッチング後のレジスト剥離力
　シリコン基板上に、ａ－Ｓｉ（アモルファスシリコン）膜を３００ｎｍの厚さで形成した。そのａ－Ｓｉ膜上にポジ型レジスト液をスピンコートで塗布した。レジスト膜が乾燥した後、配線パターンのマスクを用いて露光した。そしてレジスト剥離液で、感光した部分のレジストを剥離した。これをアモルファスシリコン基板と呼ぶ。つまり、アモルファスシリコン基板は、ａ－Ｓｉ膜上に配線パターンのレジスト膜が残った部分と、ａ－Ｓｉ膜が露出した部分が形成された状態になる。 (2) Resist stripping force after dry etching An a-Si (amorphous silicon) film having a thickness of 300 nm was formed on a silicon substrate. A positive resist solution was applied onto the a-Si film by spin coating. After the resist film was dried, it was exposed using a wiring pattern mask. And the resist of the exposed part was peeled with the resist peeling liquid. This is called an amorphous silicon substrate. That is, the amorphous silicon substrate is in a state in which a portion of the wiring pattern resist film remaining on the a-Si film and a portion of the a-Si film exposed are formed.
　次に、真空チャンバー中で反応性スパッタリング法を用いて、露出したａ－Ｓｉ膜をドライエッチングし除去した。したがって、ａ－Ｓｉ膜上に残っているレジスト膜は、スパッタリング中のプラズマに曝されたことになる。ａ－Ｓｉ膜のエッチングが終了した後、アモルファスシリコン基板をサンプルレジスト剥離液に１０分間浸漬させた。サンプルレジスト剥離液の温度は３０～４０℃である。 Next, the exposed a-Si film was removed by dry etching using a reactive sputtering method in a vacuum chamber. Therefore, the resist film remaining on the a-Si film is exposed to plasma during sputtering. After the etching of the a-Si film was completed, the amorphous silicon substrate was immersed in a sample resist stripping solution for 10 minutes. The temperature of the sample resist stripping solution is 30 to 40 ° C.
　そしてアモルファスシリコン基板を洗浄し、ａ－Ｓｉ膜上にレジスト膜が残留しているか否かを光学顕微鏡で干渉をかけながら観察した。また、ＳＥＭでも観察した。その結果を、表ではａ－Ｓｉ膜上にレジスト膜の残りが確認された場合は、「×」とし、レジスト膜の残りが確認されなかった場合は、「○」とした。 Then, the amorphous silicon substrate was washed, and it was observed while interfering with an optical microscope whether or not the resist film remained on the a-Si film. It was also observed by SEM. In the table, the result is “X” when the remaining resist film is confirmed on the a-Si film, and “◯” when the remaining resist film is not confirmed.
　＜下地膜の腐食性＞
　ガラス基板上にモリブデン膜を４０ｎｍの厚さで形成した後、さらに銅膜を３００ｎｍ積層したものを作製した。これをモリブデン基板と呼ぶ。モリブデン基板を「（１）ウエットエッチング後のレジスト剥離力」同様にウエットエッチングした。このウエットエッチングで、レジスト膜が形成されていない部分の銅膜とモリブデン膜は除去される。 <Corrosiveness of the underlying film>
A molybdenum film having a thickness of 40 nm was formed on a glass substrate, and then a copper film was further laminated to a thickness of 300 nm. This is called a molybdenum substrate. The molybdenum substrate was wet etched in the same manner as in “(1) Resist peeling force after wet etching”. By this wet etching, the copper film and the molybdenum film in a portion where the resist film is not formed are removed.
　エッチング後のモリブデン基板を、サンプルレジスト剥離液中に１０分間浸漬させた。サンプルレジスト剥離液の温度は、３０～４０℃である。その後、モリブデン基板を洗浄・乾燥した。 The etched molybdenum substrate was immersed in a sample resist stripper for 10 minutes. The temperature of the sample resist stripping solution is 30 to 40 ° C. Thereafter, the molybdenum substrate was washed and dried.
　次に、モリブデン基板をガラス基板ごと割断し、割断面のＳＥＭ観察を行った。図１にはこの時に観測される断面の模式図を示す。ガラス基板１０上にモリブデン膜１２が形成されその上に銅膜１４が形成されている。レジスト剥離液に浸漬されることによって、図１（ｂ）のように、モリブデン膜１２が腐食されている場合は、銅膜１４との間にアンダーカット部分２０が形成される。このような状態が観察されたら「×」とし、図１（ａ）のように、アンダーカット部分２０が生じなかった場合を「○」と判定した。 Next, the molybdenum substrate was cleaved together with the glass substrate, and the SEM observation of the cut section was performed. FIG. 1 shows a schematic diagram of a cross section observed at this time. A molybdenum film 12 is formed on the glass substrate 10, and a copper film 14 is formed thereon. When the molybdenum film 12 is corroded as shown in FIG. 1B by being immersed in the resist stripping solution, an undercut portion 20 is formed between the copper film 14 and the undercut portion 20. When such a state was observed, it was determined as “X”, and a case where the undercut portion 20 did not occur as shown in FIG.
　＜接触角＞
　レジスト膜を剥離し銅膜が露出した銅膜基板を、再度レジスト剥離液に浸漬させ、その後純水で洗浄し、ブロアで水滴を飛ばした。この銅膜基板の銅膜上の接触角を測定した。この時用いた指示液は純水である。この接触角が大きいと、たとえＳＥＭでレジスト膜の十分な剥離を確認できたとしても、銅膜と銅膜の上層に形成する絶縁膜の接着性が弱く、絶縁膜の剥離が生じる虞がある。 <Contact angle>
The copper film substrate from which the resist film was peeled and the copper film was exposed was immersed again in a resist stripping solution, then washed with pure water, and water droplets were blown with a blower. The contact angle on the copper film of this copper film substrate was measured. The indicator liquid used at this time is pure water. If this contact angle is large, even if the resist film can be sufficiently peeled off by SEM, the adhesion between the copper film and the insulating film formed on the upper layer of the copper film is weak, and the insulating film may peel off. .
　なお、再度浸漬させたレジスト剥離液は、露光させたレジスト成分を粉末にしたものを２質量％の割合で混ぜこんだレジスト剥離液も使った。すなわち、再度浸漬させたレジスト剥離液は、サンプルレジスト液だけの場合（「レジスト濃度０％」と表示した。）と、サンプルレジスト液に露光させたレジスト成分の粉末を２質量％混ぜ込んだ場合（「レジスト濃度２％」と表示した。）の２種類を用意した。 In addition, the resist stripping solution in which the exposed resist component was powdered and mixed at a ratio of 2% by mass was also used as the resist stripping solution soaked again. That is, the resist stripping solution that has been immersed again is only the sample resist solution (indicated as “resist concentration 0%”), and when 2% by weight of the resist component powder exposed to the sample resist solution is mixed. Two types ("resist concentration 2%") were prepared.
　実際に使われるレジスト剥離液は、循環使用されているので、剥離したレジスト成分を含有している。レジスト剥離液中に含まれるレジスト成分は、銅膜上の表面状態に影響を及ぼす虞も十分に考えられる。レジスト濃度２％のサンプルレジスト液は、このような実際に使用されている状態のレジスト剥離液を模擬的に再現したものである。 Since the resist stripping solution actually used is circulated, it contains stripped resist components. The resist component contained in the resist stripping solution may sufficiently affect the surface condition on the copper film. The sample resist solution having a resist concentration of 2% is a simulated reproduction of the resist stripping solution actually used.
　＜サンプルレジスト剥離液＞
　以下の要領でサンプルレジスト剥離液を調製した。なお、組成比の調整はプロピレングリコール（ＰＧ）の量で行った。 <Sample resist stripper>
A sample resist stripping solution was prepared as follows. The composition ratio was adjusted by the amount of propylene glycol (PG).
（１）実施例１
　実施例１のサンプルレジスト剥離液を以下の組成比で調製した。
　Ｎ－メチルジエタノールアミン（ＭＤＥＡ）　５．０質量％
　プロピレングリコール（ＰＧ）　２２．９８質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
　テトラメチルアンモニウムヒドロキシド（ＴＭＡＨ）　　１．０質量％
　タンニン酸　　　０．０２質量％
以上を混合攪拌して実施例１のサンプルレジスト剥離液とした。 (1) Example 1
The sample resist stripping solution of Example 1 was prepared with the following composition ratio.
N-methyldiethanolamine (MDEA) 5.0% by mass
Propylene glycol (PG) 22.98% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
Tetramethylammonium hydroxide (TMAH) 1.0 mass%
Tannic acid 0.02% by mass
The above was mixed and stirred to obtain the sample resist stripping solution of Example 1.
（２）実施例２
　実施例２は実施例１より強アルカリ剤（ＴＭＡＨ）の量を増やした。
　Ｎ－メチルジエタノールアミン（ＭＤＥＡ）　５．０質量％
　プロピレングリコール（ＰＧ）　２１．４８質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
　テトラメチルアンモニウムヒドロキシド（ＴＭＡＨ）　　２．５質量％
　タンニン酸　　　０．０２質量％
以上を混合攪拌して実施例２のサンプルレジスト剥離液とした。 (2) Example 2
In Example 2, the amount of strong alkali agent (TMAH) was increased from that in Example 1.
N-methyldiethanolamine (MDEA) 5.0% by mass
Propylene glycol (PG) 21.48% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
Tetramethylammonium hydroxide (TMAH) 2.5% by mass
Tannic acid 0.02% by mass
The above was mixed and stirred to obtain the sample resist stripping solution of Example 2.
（３）実施例３
　実施例３は実施例１より三級アルカノールアミンの量を減らした。
　Ｎ－メチルジエタノールアミン（ＭＤＥＡ）　２．０質量％
　プロピレングリコール（ＰＧ）　２５．９８質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
　テトラメチルアンモニウムヒドロキシド（ＴＭＡＨ）　　１．０質量％
　タンニン酸　　　０．０２質量％
以上を混合攪拌して実施例３のサンプルレジスト剥離液とした。 (3) Example 3
In Example 3, the amount of tertiary alkanolamine was reduced compared to Example 1.
N-methyldiethanolamine (MDEA) 2.0% by mass
Propylene glycol (PG) 25.98% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
Tetramethylammonium hydroxide (TMAH) 1.0 mass%
Tannic acid 0.02% by mass
The above was mixed and stirred to obtain the sample resist stripping solution of Example 3.
（４）実施例４
　実施例４は、実施例３から強アルカリ剤（ＴＭＡＨ）の量を増やした。
　Ｎ－メチルジエタノールアミン（ＭＤＥＡ）　２．０質量％
　プロピレングリコール（ＰＧ）　２４．４８質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
　テトラメチルアンモニウムヒドロキシド（ＴＭＡＨ）　　２．５質量％
　タンニン酸　　　０．０２質量％
以上を混合攪拌して実施例４のサンプルレジスト剥離液とした。 (4) Example 4
In Example 4, the amount of strong alkali agent (TMAH) was increased from Example 3.
N-methyldiethanolamine (MDEA) 2.0% by mass
Propylene glycol (PG) 24.48% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
Tetramethylammonium hydroxide (TMAH) 2.5% by mass
Tannic acid 0.02% by mass
The above was mixed and stirred to obtain a sample resist stripping solution of Example 4.
（５）実施例５
　実施例５は、実施例２の強アルカリ剤の種類を変更した。
　Ｎ－メチルジエタノールアミン（ＭＤＥＡ）　５．０質量％
　プロピレングリコール（ＰＧ）　２１．４８質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
　炭酸グアニジン　　２．５質量％
　タンニン酸　　　０．０２質量％
以上を混合攪拌して実施例５のサンプルレジスト剥離液とした。 (5) Example 5
In Example 5, the type of the strong alkali agent in Example 2 was changed.
N-methyldiethanolamine (MDEA) 5.0% by mass
Propylene glycol (PG) 21.48% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
Guanidine carbonate 2.5% by mass
Tannic acid 0.02% by mass
The above was mixed and stirred to obtain a sample resist stripping solution of Example 5.
　なお、炭酸グアニジンは以下の（化２）式で表される。 Note that guanidine carbonate is represented by the following formula (Formula 2).
Figure JPOXMLDOC01-appb-C000002
 　　　　　　　　　　　　　　　・・・（化２）
Figure JPOXMLDOC01-appb-C000002
 ... (Chemical formula 2)
（６）実施例６
　実施例６は、実施例１の強アルカリ剤の種類を変更した。
　Ｎ－メチルジエタノールアミン（ＭＤＥＡ）　５．０質量％
　プロピレングリコール（ＰＧ）　２２．９８質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
　コリン（Ｃｈｏｌｉｎｅ）　　１．０質量％
　タンニン酸　　　０．０２質量％
以上を混合攪拌して実施例６のサンプルレジスト剥離液とした。 (6) Example 6
In Example 6, the type of the strong alkali agent in Example 1 was changed.
N-methyldiethanolamine (MDEA) 5.0% by mass
Propylene glycol (PG) 22.98% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
Choline 1.0% by mass
Tannic acid 0.02% by mass
The above was mixed and stirred to obtain a sample resist stripping solution of Example 6.
　なお、コリン（Ｃｈｏｌｉｎｅ：２－ヒドロキシエチルトリメチルアンモニウムハイドロオキサイド）は以下の（化３）式で表される。 Note that choline (2-hydroxyethyltrimethylammonium hydroxide) is represented by the following formula (Formula 3).
Figure JPOXMLDOC01-appb-C000003
 　　　　　　　　　　　　　　　・・・（化３）
Figure JPOXMLDOC01-appb-C000003
 ... (Chemical formula 3)
（７）実施例７
　実施例７は、実施例１の強アルカリ剤の種類を変更し、量も減らした。
　Ｎ－メチルジエタノールアミン（ＭＤＥＡ）　５．０質量％
　プロピレングリコール（ＰＧ）　２３．７３質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
　ＡＨ２１２　　０．２５質量％
　タンニン酸　　　０．０２質量％
以上を混合攪拌して実施例７のサンプルレジスト剥離液とした。 (7) Example 7
In Example 7, the type of the strong alkali agent in Example 1 was changed, and the amount was also reduced.
N-methyldiethanolamine (MDEA) 5.0% by mass
Propylene glycol (PG) 23.73% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
AH212 0.25% by mass
Tannic acid 0.02% by mass
The above was mixed and stirred to obtain a sample resist stripping solution of Example 7.
　なお、ＡＨ２１２（２－ヒドロキシエチルアンモニウムヒドロキシド）は以下の（化４）式で表される。 AH212 (2-hydroxyethylammonium hydroxide) is represented by the following formula (Formula 4).
Figure JPOXMLDOC01-appb-C000004
 　　　　　　　　　　　　　　　・・・（化４）
Figure JPOXMLDOC01-appb-C000004
 ... (Chemical formula 4)
（８）実施例８
　実施例８は、実施例１の強アルカリ剤の種類を変更した。
　Ｎ－メチルジエタノールアミン（ＭＤＥＡ）　５．０質量％
　プロピレングリコール（ＰＧ）　２２．９８質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
　ＮａＯＨ　　１．０質量％
　タンニン酸　　　０．０２質量％
以上を混合攪拌して実施例８のサンプルレジスト剥離液とした。 (8) Example 8
In Example 8, the type of the strong alkali agent in Example 1 was changed.
N-methyldiethanolamine (MDEA) 5.0% by mass
Propylene glycol (PG) 22.98% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
NaOH 1.0% by mass
Tannic acid 0.02% by mass
The above was mixed and stirred to obtain a sample resist stripping solution of Example 8.
　実施例１乃至４の組成および評価結果を表１に示す。また、実施例５乃至８の組成および評価結果を表２に示す。 Table 1 shows the compositions and evaluation results of Examples 1 to 4. Table 2 shows the compositions and evaluation results of Examples 5 to 8.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
（９）比較例１
　比較例１は実施例１から強アルカリ剤および還元剤を抜いた組成である。
　Ｎ－メチルジエタノールアミン（ＭＤＥＡ）　５．０質量％
　プロピレングリコール（ＰＧ）　２４．０質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
以上を混合攪拌して比較例１のサンプルレジスト剥離液とした。 (9) Comparative Example 1
Comparative Example 1 is a composition obtained by removing the strong alkali agent and reducing agent from Example 1.
N-methyldiethanolamine (MDEA) 5.0% by mass
Propylene glycol (PG) 24.0% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 1.
（１０）比較例２
　比較例２は、比較例１のアミンの種類を変更した。強アルカリ剤および還元剤はない。
　Ｎ，Ｎ－ジメチルエタノールアミン（ＤＭＥＡ）　５．０質量％
　プロピレングリコール（ＰＧ）　２４．０質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
以上を混合攪拌して比較例２のサンプルレジスト剥離液とした。 (10) Comparative Example 2
In Comparative Example 2, the type of amine of Comparative Example 1 was changed. There are no strong alkali agents and reducing agents.
N, N-dimethylethanolamine (DMEA) 5.0% by mass
Propylene glycol (PG) 24.0% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 2.
（１１）比較例３
　比較例３は、比較例１のアミンの種類を変更した。強アルカリ剤および還元剤はない。
　Ｎ，Ｎ－ジエチルエタノールアミン（Ｎ－ＤＥＥＡ）　５．０質量％
　プロピレングリコール（ＰＧ）　２４．０質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
以上を混合攪拌して比較例３のサンプルレジスト剥離液とした。 (11) Comparative Example 3
In Comparative Example 3, the type of amine of Comparative Example 1 was changed. There are no strong alkali agents and reducing agents.
N, N-diethylethanolamine (N-DEEA) 5.0% by mass
Propylene glycol (PG) 24.0% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 3.
（１２）比較例４
　比較例４は、比較例１のアミンの種類を変更した。強アルカリ剤および還元剤はない。
　アミン類としてニ級アルカノールアミンを用いた。
　Ｎ－メチルエタノールアミン（ＭＭＡ）　５．０質量％
　プロピレングリコール（ＰＧ）　２４．０質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
以上を混合攪拌して比較例４のサンプルレジスト剥離液とした。 (12) Comparative Example 4
In Comparative Example 4, the type of amine of Comparative Example 1 was changed. There are no strong alkali agents and reducing agents.
Secondary alkanolamines were used as amines.
N-methylethanolamine (MMA) 5.0% by mass
Propylene glycol (PG) 24.0% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 4.
（１３）比較例５
　比較例５は、比較例１のアミンの種類を変更した。強アルカリ剤および還元剤はない。
　アミン類として一級アルカノールアミンを用いた。
　モノエタノールアミン（ＭＥＡ）　５．０質量％
　プロピレングリコール（ＰＧ）　２４．０質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
以上を混合攪拌して比較例５のサンプルレジスト剥離液とした。 (13) Comparative Example 5
In Comparative Example 5, the type of amine of Comparative Example 1 was changed. There are no strong alkali agents and reducing agents.
Primary alkanolamine was used as amines.
Monoethanolamine (MEA) 5.0% by mass
Propylene glycol (PG) 24.0% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 5.
　比較例１乃至５の組成および評価結果を表３に示す。 Table 3 shows the compositions and evaluation results of Comparative Examples 1 to 5.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
（１４）比較例６
　比較例６は、比較例１に強アルカリ剤だけを加えた。
　Ｎ－メチルジエタノールアミン（ＭＤＥＡ）　５．０質量％
　プロピレングリコール（ＰＧ）　２３．９７５質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
　テトラメチルアンモニウムヒドロキシド（ＴＭＡＨ）　　０．０２５質量％
以上を混合攪拌して比較例６のサンプルレジスト剥離液とした。 (14) Comparative Example 6
In Comparative Example 6, only a strong alkali agent was added to Comparative Example 1.
N-methyldiethanolamine (MDEA) 5.0% by mass
Propylene glycol (PG) 23.975 mass%
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
Tetramethylammonium hydroxide (TMAH) 0.025% by mass
The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 6.
（１５）比較例７
　比較例７は、比較例６の強アルカリ剤の量を増やした。
　Ｎ－メチルジエタノールアミン（ＭＤＥＡ）　５．０質量％
　プロピレングリコール（ＰＧ）　２３．７５質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
　テトラメチルアンモニウムヒドロキシド（ＴＭＡＨ）　　０．２５質量％
以上を混合攪拌して比較例７のサンプルレジスト剥離液とした。 (15) Comparative Example 7
In Comparative Example 7, the amount of the strong alkali agent in Comparative Example 6 was increased.
N-methyldiethanolamine (MDEA) 5.0% by mass
Propylene glycol (PG) 23.75% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
Tetramethylammonium hydroxide (TMAH) 0.25% by mass
The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 7.
（１６）比較例８
　比較例８は、比較例６の強アルカリ剤の量を増やした。
　Ｎ－メチルジエタノールアミン（ＭＤＥＡ）　５．０質量％
　プロピレングリコール（ＰＧ）　２３．０質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
　テトラメチルアンモニウムヒドロキシド（ＴＭＡＨ）　　１．０質量％
以上を混合攪拌して比較例８のサンプルレジスト剥離液とした。 (16) Comparative Example 8
In Comparative Example 8, the amount of the strong alkali agent in Comparative Example 6 was increased.
N-methyldiethanolamine (MDEA) 5.0% by mass
Propylene glycol (PG) 23.0% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
Tetramethylammonium hydroxide (TMAH) 1.0 mass%
The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 8.
（１７）比較例９
　比較例９は、比較例６の強アルカリ剤の量を増やした。
　Ｎ－メチルジエタノールアミン（ＭＤＥＡ）　５．０質量％
　プロピレングリコール（ＰＧ）　２１．５質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
　テトラメチルアンモニウムヒドロキシド（ＴＭＡＨ）　　２．５質量％
以上を混合攪拌して比較例９のサンプルレジスト剥離液とした。 (17) Comparative Example 9
In Comparative Example 9, the amount of the strong alkali agent in Comparative Example 6 was increased.
N-methyldiethanolamine (MDEA) 5.0% by mass
Propylene glycol (PG) 21.5% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
Tetramethylammonium hydroxide (TMAH) 2.5% by mass
The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 9.
（１８）比較例１０
　比較例１０は、比較例７の強アルカリ剤の種類を変更した。
　Ｎ－メチルジエタノールアミン（ＭＤＥＡ）　５．０質量％
　プロピレングリコール（ＰＧ）　２３．７５質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
　ＮＨ３　　０．２５質量％
以上を混合攪拌して比較例１０のサンプルレジスト剥離液とした。 (18) Comparative Example 10
The comparative example 10 changed the kind of strong alkali agent of the comparative example 7.
N-methyldiethanolamine (MDEA) 5.0% by mass
Propylene glycol (PG) 23.75% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
NH 3 0.25% by mass
The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 10.
（１９）比較例１１
　比較例１１は、比較例１０の強アルカリ剤の量を増やした。
　Ｎ－メチルジエタノールアミン（ＭＤＥＡ）　５．０質量％
　プロピレングリコール（ＰＧ）　２２．５質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
　ＮＨ３　　１．５質量％
以上を混合攪拌して比較例１１のサンプルレジスト剥離液とした。 (19) Comparative Example 11
In Comparative Example 11, the amount of the strong alkali agent in Comparative Example 10 was increased.
N-methyldiethanolamine (MDEA) 5.0% by mass
Propylene glycol (PG) 22.5% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
NH 3 1.5% by mass
The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 11.
　比較例６乃至１１までの組成および評価結果を表４に示す。 Table 4 shows the compositions and evaluation results of Comparative Examples 6 to 11.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
（２０）比較例１２
　比較例１２は、比較例６からアルカノールアミンを除いた。
　プロピレングリコール（ＰＧ）　２８．９７５質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
　テトラメチルアンモニウムヒドロキシド（ＴＭＡＨ）　　０．０２５質量％
以上を混合攪拌して比較例１２のサンプルレジスト剥離液とした。 (20) Comparative Example 12
In Comparative Example 12, alkanolamine was removed from Comparative Example 6.
Propylene glycol (PG) 28.975 mass%
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
Tetramethylammonium hydroxide (TMAH) 0.025% by mass
The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 12.
（２１）比較例１３
　比較例１３は、比較例７からアルカノールアミンを除いた。
　プロピレングリコール（ＰＧ）　２８．７５質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
　テトラメチルアンモニウムヒドロキシド（ＴＭＡＨ）　　０．２５質量％
以上を混合攪拌して比較例１３のサンプルレジスト剥離液とした。 (21) Comparative Example 13
In Comparative Example 13, alkanolamine was removed from Comparative Example 7.
Propylene glycol (PG) 28.75% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
Tetramethylammonium hydroxide (TMAH) 0.25% by mass
The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 13.
（２２）比較例１４
　比較例１４は、比較例８からアルカノールアミンを除いた。
　プロピレングリコール（ＰＧ）　２８．０質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
　テトラメチルアンモニウムヒドロキシド（ＴＭＡＨ）　　１．０質量％
以上を混合攪拌して比較例１４のサンプルレジスト剥離液とした。 (22) Comparative Example 14
In Comparative Example 14, alkanolamine was removed from Comparative Example 8.
Propylene glycol (PG) 28.0% by mass
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
Tetramethylammonium hydroxide (TMAH) 1.0 mass%
The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 14.
（２３）比較例１５
　比較例１５は、比較例９からアルカノールアミンを除いた。
　プロピレングリコール（ＰＧ）　２６．５０質量％
　ジエチレングリコールモノブチルエーテル（ＢＤＧ）　　４０．０質量％
　水　３１．０質量％
　テトラメチルアンモニウムヒドロキシド（ＴＭＡＨ）　　２．５質量％
以上を混合攪拌して比較例１５のサンプルレジスト剥離液とした。 (23) Comparative Example 15
In Comparative Example 15, alkanolamine was removed from Comparative Example 9.
Propylene glycol (PG) 26.50 mass%
Diethylene glycol monobutyl ether (BDG) 40.0% by mass
31.0% by weight of water
Tetramethylammonium hydroxide (TMAH) 2.5% by mass
The above was mixed and stirred to obtain a sample resist stripping solution of Comparative Example 15.
　比較例１２乃至１５の組成および評価結果を表５に示す。 Table 5 shows the compositions and evaluation results of Comparative Examples 12 to 15.
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
　以上の各サンプルレジスト剥離液の組成および、「レジスト剥離力」と「下地膜への腐食性」についての結果を表１乃至５に示した。 Tables 1 to 5 show the compositions of the above sample resist stripping solutions and the results on “resist stripping power” and “corrosiveness to the base film”.
　表１及び２を参照して、まず実施例１乃至８の各サンプルレジスト剥離液は、ウエットエッチング後のレジスト膜の剥離はもちろんのこと、プラズマに曝され変質したと考えられるａ－Ｓｉ膜上のドライエッチング後のレジスト膜も十分に剥離することができた。 Referring to Tables 1 and 2, each sample resist stripping solution of Examples 1 to 8 was not only stripped of the resist film after wet etching, but also the a-Si film that was considered to be altered by exposure to plasma. The resist film after the dry etching was sufficiently peeled off.
　また、下地膜（モリブデン膜）への腐食性については、１０分間の浸漬でも、腐食は認められなかった。すなわち、実施例１乃至８の各サンプルレジスト剥離液は、ウエットエッチング、ドライエッチングの区別なく、レジスト膜を剥離することができ、尚且つ、下地膜となるモリブデン膜を腐食することもなかった。 In addition, regarding the corrosiveness to the base film (molybdenum film), no corrosion was observed even after immersion for 10 minutes. That is, each of the sample resist stripping solutions of Examples 1 to 8 can strip the resist film without distinguishing between wet etching and dry etching, and does not corrode the molybdenum film serving as the base film.
　また、レジスト剥離液に接触した後の銅膜の表面状態を調べた接触角の結果を見ると、実施例１乃至８の各レジストサンプルは、接触角が低かった（１５～１７度）。これは、剥離液使用後も銅膜表面に接着を阻害する物質が残留していないと判断される。したがって、実施例１乃至８の各サンプルレジスト剥離液で、レジスト膜を剥離した後に、成膜を行っても、下地膜（ここでは銅膜）との間で接着不良が起こることはないと考えられた。 Further, when the results of contact angles obtained by examining the surface state of the copper film after contact with the resist stripping solution were observed, each of the resist samples of Examples 1 to 8 had a low contact angle (15 to 17 degrees). This is judged that the substance which inhibits adhesion does not remain on the surface of the copper film even after using the stripping solution. Therefore, even if film formation is performed after the resist film is stripped with each of the sample resist stripping solutions of Examples 1 to 8, no adhesion failure occurs between the base film (here, the copper film). It was.
　したがって、実施例１乃至８の各サンプルレジスト剥離液は、モノエタノールアミンを使用したアルミニウム配線用剥離液同等のレジスト剥離力を有し、尚且つ下地が銅膜であっても、モリブデン膜上の銅膜であっても、ダメージを与えることなく使用することができる。 Therefore, each sample resist stripping solution of Examples 1 to 8 has a resist stripping force equivalent to the stripping solution for aluminum wiring using monoethanolamine, and even if the base is a copper film, Even a copper film can be used without causing damage.
　比較例１乃至３は、三級アミンを用いて、強アルカリ剤が全く含まれていないサンプルレジスト剥離液である。これらの組成では、銅膜や下地膜（モリブデン膜）の腐食は低かったものの、ドライエッチング後のレジスト膜については剥離することができなかった。 Comparative Examples 1 to 3 are sample resist stripping solutions that use a tertiary amine and do not contain any strong alkali agent. With these compositions, although the corrosion of the copper film and the base film (molybdenum film) was low, the resist film after dry etching could not be peeled off.
　また、比較例１のウエットエッチング後の銅膜上の接触角を見ると、ＳＥＭ観察では、剥離できたように見えていても、接触角は４０度以上と高かった。これは、銅膜上に疎水性の膜が形成されていることが示唆されている。このような表面状態の銅膜上に他の膜（例えば絶縁膜等）を形成した場合には、銅膜とその上の膜との間の接着性が弱くなる虞が考えられた。 Further, when the contact angle on the copper film after the wet etching of Comparative Example 1 was observed, the contact angle was as high as 40 degrees or more in SEM observation even though it seemed to be peeled off. This suggests that a hydrophobic film is formed on the copper film. When another film (such as an insulating film) is formed on the copper film in such a surface state, there is a possibility that the adhesiveness between the copper film and the film thereon is weakened.
　比較例４、５は、アミンの級数を小さくしたもので、二級アミン、一級アミンを使用したものである。これらの組成では、ドライエッチング後のレジスト膜を剥離することができる。しかし、銅膜およびモリブデン膜上の銅膜は製品として使用できないほどの腐食を受けた。つまり、級数の少ないアミン程、レジスト膜を剥離する作用が強いもの、同時に銅膜および下地膜のモリブデン膜をも腐食する。これはアミンと銅の間で錯体が形成されるからと考えられている。 Comparative Examples 4 and 5 are obtained by reducing the series of amines and using secondary amines and primary amines. With these compositions, the resist film after dry etching can be removed. However, the copper film and the copper film on the molybdenum film were subjected to corrosion that could not be used as a product. That is, an amine having a smaller series has a stronger effect of stripping the resist film, and at the same time corrodes the copper film and the underlying molybdenum film. This is thought to be because a complex is formed between the amine and copper.
　比較例６乃至１１は、下地膜への腐食を低く抑えたままで、ドライエッチング後のレジスト膜に対するレジスト剥離力を確保するため、強アルカリ剤の量を検討したものである。比較例６乃至９を参照して、ＴＭＡＨの量が増加するにしたがい、ドライエッチング後のレジスト膜は、剥離できるようになる。しかし、ＴＭＡＨの量が増加するに従い、銅膜およびモリブデン膜の腐食も進んだ。 In Comparative Examples 6 to 11, the amount of strong alkaline agent was examined in order to ensure the resist peeling force with respect to the resist film after dry etching while keeping the corrosion to the base film low. With reference to Comparative Examples 6 to 9, as the amount of TMAH increases, the resist film after dry etching can be peeled off. However, as the amount of TMAH increased, the corrosion of the copper film and the molybdenum film also progressed.
　比較例１０および１１は、強アルカリ剤としてアンモニアを用いた場合の結果である。アンモニアは、０．２５～１．５質量％含有されていても、ドライエッチング後のレジスト膜を剥離することはできなかった。一方、銅膜やモリブデン膜の腐食は発生した。 Comparative Examples 10 and 11 are the results when ammonia was used as a strong alkali agent. Even if ammonia was contained in an amount of 0.25 to 1.5% by mass, the resist film after dry etching could not be peeled off. On the other hand, corrosion of copper film and molybdenum film occurred.
　比較例１２乃至１５は、アミンを含有させず、ＰＧだけを比較例６乃至９から増量した場合の結果を示す。ウエットエッチング後のレジスト膜に対しては、銅膜であっても、モリブデン膜であっても、腐食を起こすことなく、剥離することができた。これは、そもそもノボラック樹脂がアルカリ溶液に可溶になることを示しており、ノボラック樹脂の予定された結果とも言える。 Comparative Examples 12 to 15 show the results in the case where only PG was increased from Comparative Examples 6 to 9 without containing an amine. The resist film after wet etching was able to be peeled off without causing corrosion, whether it was a copper film or a molybdenum film. This indicates that the novolak resin is soluble in the alkali solution in the first place, which can be said to be the expected result of the novolak resin.
　しかし、ＴＭＡＨを２．５質量％加え、ｐＨが１４．０となっても（比較例１５）、ドライエッチング後のレジスト膜を剥離することはできなかった。すなわち、変質したレジスト膜は、ｐＨをアルカリにするだけでは溶解できず、アミンによる求核反応が必要であることがわかる。 However, even when 2.5% by mass of TMAH was added and the pH became 14.0 (Comparative Example 15), the resist film after dry etching could not be peeled off. That is, it can be seen that the altered resist film cannot be dissolved only by making the pH alkaline, and requires a nucleophilic reaction with an amine.
　比較例１乃至１５を参照すると、ドライエッチング後のレジスト膜を剥離することができたのは、アミンとして二級アミンおよび、一級アミンを用いた比較例４および５と、三級アミンであって、ＴＭＡＨが１．０質量％以上含まれた比較例８および９だけであった。特に、比較例８および９は、光学顕微鏡による観察では、銅膜もモリブデン膜も、大きな腐食を受けていないように観察された。そこで、比較例８および９の銅膜およびモリブデン膜への腐食を低減させるために、還元剤を添加したのが、実施例の組成比である。 Referring to Comparative Examples 1 to 15, the resist film after dry etching was able to be peeled off in Comparative Examples 4 and 5 using a secondary amine and a primary amine as an amine, and a tertiary amine. And Comparative Examples 8 and 9 containing 1.0% by mass or more of TMAH. In particular, Comparative Examples 8 and 9 were observed by the optical microscope so that neither the copper film nor the molybdenum film was significantly corroded. Therefore, in order to reduce the corrosion on the copper film and the molybdenum film of Comparative Examples 8 and 9, the composition ratio of the example is that a reducing agent is added.
　実施例１、２を参照すると、タンニン酸を添加することで、ドライエッチング後のレジスト膜を剥離することができ、尚且つ銅膜およびモリブデン膜の腐食が抑えられた。また、三級アミンであるＭＤＥＡの量を実施例１、２の半分以下である２．０質量％としても（実施例３、４）、同様の効果を得ることができた。 Referring to Examples 1 and 2, by adding tannic acid, the resist film after dry etching can be peeled off, and corrosion of the copper film and molybdenum film was suppressed. Moreover, even when the amount of MDEA, which is a tertiary amine, was 2.0% by mass, which is less than half that of Examples 1 and 2 (Examples 3 and 4), the same effect could be obtained.
　また、実施例５乃至８は、強アルカリ剤の種類を変えた結果である。コリン（Ｃｈｏｌｉｎｅ）やＡＨ２１２のような四級アンモニウム塩基や、グアニジン系の強アルカリ剤でも、実施例１乃至４と同じ結果を得ることができた。 Moreover, Examples 5 to 8 are the results of changing the type of strong alkali agent. The same results as in Examples 1 to 4 could be obtained with quaternary ammonium bases such as Choline and AH212, or strong guanidine-based alkaline agents.
　本発明のレジスト剥離液は、ポジ型フォトレジストを用いた場合のレジスト剥離液として好適に利用することができる。これは、液晶ディスプレイ、プラズマディスプレイ、有機ＥＬなどＦＰＤの製造一般に好適に利用することができる。 The resist stripping solution of the present invention can be suitably used as a resist stripping solution when a positive photoresist is used. This can be suitably used for general production of FPD such as a liquid crystal display, a plasma display, and an organic EL.
１０　ガラス基板
１２　モリブデン層（膜）
１４　銅膜
２０　アンダーカット部分 10 Glass substrate 12 Molybdenum layer (film)
14 Copper film 20 Undercut part

Claims (5)

  1. 　三級アルカノールアミンと、極性溶媒と、水と、強アルカリ剤と、還元剤を含み、ｐＨが１２以上であることを特徴とするレジスト剥離液。 A resist stripping solution comprising a tertiary alkanolamine, a polar solvent, water, a strong alkali agent, and a reducing agent, and having a pH of 12 or more.
  2. 　前記還元剤が、タンニン酸を含むことを特徴とする請求項１に記載されたレジスト剥離液。 The resist stripping solution according to claim 1, wherein the reducing agent contains tannic acid.
  3. 　前記強アルカリ剤は、テトラメチルアンモニウムヒドロキシド、トリメチル－２－ヒドロキシエチルアンモニウムヒドロキシド、ジメチルビス（２－ヒドロキシエチル）アンモニウムヒドロキシド、テトラブチルアンモニウムヒドロオキサイド、アルキルアンモニウムハイドライド、炭酸グアニジンから選ばれた少なくとも一種を含むことを特徴とする請求項１または２の何れかの請求項に記載されたレジスト剥離液。 The strong alkali agent is selected from tetramethylammonium hydroxide, trimethyl-2-hydroxyethylammonium hydroxide, dimethylbis (2-hydroxyethyl) ammonium hydroxide, tetrabutylammonium hydroxide, alkylammonium hydride, and guanidine carbonate. The resist stripping solution according to claim 1, comprising at least one kind.
  4. 　前記三級アルカノールアミンが、Ｎ－メチルジエタノールアミンであり、前記極性溶媒がジエチレングリコールモノブチルエーテルと、プロピレングリコールの混合溶媒であることを特徴とする請求項１または２の何れかの請求項に記載されたレジスト剥離液。 The tertiary alkanolamine is N-methyldiethanolamine, and the polar solvent is a mixed solvent of diethylene glycol monobutyl ether and propylene glycol, according to any one of claims 1 and 2. Resist stripper.
  5. 　前記三級アルカノールアミンは、２～９質量％であり、
    前記強アルカリ剤は、０．２５～５．０質量％であり、
    前記還元剤は、０．０２～３．０質量％であることを特徴とする請求項１乃至４の何れか１の請求項に記載されたレジスト剥離液。     The tertiary alkanolamine is 2-9% by mass,
    The strong alkali agent is 0.25 to 5.0% by mass,
    The resist stripping solution according to any one of claims 1 to 4, wherein the reducing agent is 0.02 to 3.0 mass%.
PCT/JP2014/005128 2013-10-18 2014-10-08 Resist-stripping liquid WO2015056428A1 (en)

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