KR20130069399A - Resist stripping solution and a method of stripping resist - Google Patents

Abstract

PURPOSE: A resist stripping liquid is provided to easily strip a negative type photo resist by including hydrocarbon-based solvent including plural types of naphtalenic compound having substituent and benzene sulfonic acid. CONSTITUTION: A resist stripping liquid comprises (a) 70-95 mass% of hydrocarbon-based solvent and (b) 5-30 mass% of benzene sulfonic acid. The hydrocarbon-based solvent includes 3 kinds or more of alkyl group substituted naphthalene, and the total content of those are 50 mass% or more. The benzene sulfonic acid is substituted to alkyl group and the total carbon number is 8 or more. The resist stripping liquid additionally comprises (c) carbon number 6 or more of 1-10 mass% of fatty acid ester. A negative type photo resist strip using the resist stripping liquid is perform in solution temperature at less than 60 degree Celsius. The negative type photo resist comprises polyisoprene compound.

Description

RESIST STRIPPING SOLUTION AND METHOD OF STRIPPING RESIST [0002]

The present invention relates to a resist stripping liquid and a resist stripping method.

BACKGROUND ART [0002] In a manufacturing process of a semiconductor device such as an IC or LSI or a liquid crystal display device, a substrate is etched using a photoresist pattern as a mask to form a fine pattern. Such a resist pattern may be formed by forming a thin film of a photoresist on a silicon substrate or a metal film substrate such as aluminum, molybdenum, or chromium, a glass substrate, or a metal oxide film substrate such as ITO (indium tin oxide) And irradiated with ultraviolet light or the like, followed by development.

In order to etch the substrate with high precision using such a photoresist, high adhesion between the resist pattern and the substrate is required. As a method for improving the adhesion between the resist pattern and the substrate, so-called post baking in which the pattern of the photoresist obtained by the development is baked (heat treatment) is proposed from the viewpoint of the process. Further, in the material aspect, a positive type photoresist such as benzoimidazoles or polybenzimidazoles is added to a positive photoresist (Patent Document 1), or benzotriazoles are incorporated into a negative type photoresist (Patent Document 2 ) Has been proposed to add an adhesion improver to a photoresist.

Japanese Patent Laid-Open No. 6-27657 Japanese Patent Laid-Open No. 8-339087 Japanese Patent Application Laid-Open No. 61-2152 Japanese Patent Application Laid-Open No. 62-35357

However, when post-baking is performed for improving the adhesion between the resist and the substrate, peeling becomes difficult especially in the case of a negative type photoresist. On the other hand, if the photoresist is peeled off at a high temperature, the removability tends to increase, but damage to other members (for example, SiO ₂ , SiOC, SiON) may occur and processing can be performed without excessively raising the temperature .

Further, in the positive type resist, generally, the photoresist dissolves in the dissolving liquid and is peeled off. On the other hand, in the negative type resist, the photoresist is usually swollen and peeled off as it is not dissolved. As described above, when the photoresist is peeled off as it is peeled off, the photoresist is reattached to the substrate to cause pattern defects. Therefore, there is a demand for a photoresist stripping solution capable of dissolving and / or peeling the photoresist more difficult to dissolve and peel off. Further, it is disclosed that arylsulfonic acid is applied to one type of naphthalene-based solvent to remove the post-baked resist, which is not specialized in the negative type resist (the above Patent Documents 3 and 4).

SUMMARY OF THE INVENTION In view of the above-identified problems in the art, the present invention provides a negative type photoresist used for forming a pattern on a substrate such as a silicon substrate, a glass substrate, a metal film substrate, The present invention also provides a peeling solution which can dissolve and peel off quickly and without excessive heating even after the peeling, and a peeling method using the peeling solution.

The above problem has been solved by the following means.

(1) A resist stripper for stripping a negative photoresist,

(a) 70 to 95% by mass of a hydrocarbon solvent containing three or more kinds of naphthalene substituted with an alkyl group and having a total content of 50% by mass or more thereof,

(b) 5 to 30% by mass of a benzenesulfonic acid having 8 or more carbon atoms and substituted with an alkyl group.

(2) The resist stripper according to (1), further comprising (c) 1 to 10% by mass of a fatty acid ester having 6 or more carbon atoms.

(3) The resist stripper according to (1) or (2), wherein the negative type photoresist is formed of a polyisoprene compound.

(4) The three-component alkyl naphthalene according to any one of (1) to (3), wherein at least three kinds of alkylnaphthalenes of different kinds are used in the following formulas (a) to (f) And removing the resist.

(a) the number of substituents (R < ^{1 >} )

(b) the number of atoms of the substituent (R ¹ )

(c) the substitution position of the substituent (R ¹ ) on the naphthalene ring

(d) Structure of substituent (R ¹ )

(e) the number of carbon atoms of the substituent (R ¹ )

(f) a combination of two or more of (a) to (e)

(Wherein R ¹ represents an alkyl group having 1 to 9 carbon atoms, the alkyl group may be straight-chain, branched or cyclic, and the alkyl group may further have a substituent, n 1 represents an integer of 1 to 8. R ² Represents a substituent other than an alkyl group, and n2 represents an integer of 0 to 7)

(5) A resist stripping method comprising stripping a negative-type photoresist using the resist stripper according to any one of (1) to (4).

(6) The resist stripping method described in (5), wherein the negative type photoresist is formed of a polyisoprene compound.

(7) The resist stripping method according to (5) or (6), wherein the resist stripping is performed at a liquid temperature of 60 ° C or lower.

(8) The resist stripping method according to any one of (5) to (7), wherein the developing solution used for forming the pattern after exposure of the negative type photoresist is an isoparaffin type solvent.

(9) The resist stripping method according to any one of (5) to (8), wherein the negative type photoresist is applied on indium tin oxide or a glass substrate.

(Effects of the Invention)

According to the present invention, a negative type photoresist used for forming a pattern on a substrate such as a silicon substrate, a glass substrate, a metal film substrate, and a metal oxide film substrate can be rapidly and accurately removed can do.

The present inventors have intensively studied and found that a negative type photoresist can be easily peeled off by coexisting a hydrocarbon solvent containing a plurality of naphthalene-based compounds having a substituent at a high ratio and a small amount of benzenesulfonic acid. Thereby completing the present invention. It has been found that the present invention is particularly effective when a negative type photoresist containing an isoprene type polymer compound is used. In addition, since the peeling effect is high, it is possible to realize a sufficiently high peeling property without causing excessive heating, and damage to other members can be prevented. Best Mode for Carrying Out the Invention Hereinafter, the present invention will be described focusing on preferred embodiments thereof.

[(a) Specific hydrocarbon solvent]

The naphthalene-containing hydrocarbon solvent substituted with an alkyl group suitably applied in the present invention is included in the category of solvent naphtha, heavy solvent naphtha, and coal tar naphtha by fractional distillation of, for example, gas diesel or petroleum. Among them, in the present invention, at least three kinds of naphthalene compounds (for example, methylnaphthalene, dimethylnaphthalene, dimethylmonoisopropylnaphthalene) having a total carbon number of 11 or more substituted with an alkyl group are contained in a high ratio (50 to 85 mass%) It is preferable to use a hydrocarbon solvent. The kind of the specific naphthalene compound is not limited to the atomic composition, but isomers such as structural isomers are also counted as one kind.

The term " total carbon number " includes the number of carbon atoms of the substituent group when it contains any substituent group other than the number of carbon atoms contained in the specific site. The content of each kind of naphthalene compound is not particularly limited, but it is preferable that the content of the naphthalene compound is sufficient for high effect, and it is preferable that one naphthalene compound is contained in 1% by mass or more of the solvent. It is preferable that the naphthalene compound is included in a range of 5 to 80 parts by mass and more preferably 10 to 60 parts by mass in terms of the minimum content with respect to 100 parts by mass of the maximum content among the three kinds. desirable. It is preferable that the second largest content is contained in an amount of 10 to 90 parts by mass, more preferably 20 to 70 parts by mass. The number of specific naphthalenes is not particularly limited as long as it is three or more, and the upper limit is not particularly limited, but it is practically 10 or less.

The substituted naphthalene compound has a total carbon number of 11 to 40, preferably 11 to 30, more preferably 11 to 20, and particularly preferably 11 to 15. It is particularly preferable that the content of the substituted naphthalene compound having a carbon number within this range is in a range described later. The naphthalene substituted with an alkyl may have a substituent (T) [an alkyl group (preferably having 1 to 6 carbon atoms), an alkoxy group (preferably having 1 to 6 carbon atoms), a hydroxyl group, a carboxyl group, A halogen atom, an acyl group (preferably having from 2 to 6 carbon atoms), or may have a structure in which an aromatic ring or a heterocyclic ring is hydrogenated.

The alkyl-substituted naphthalene is preferably represented by the following formula (N).

R ¹ represents an alkyl group having 1 to 9 carbon atoms. The alkyl group may be linear, branched or cyclic. The alkyl group may further have a substituent. Examples of the substituent which R ¹ may further have include the above substituent (T).

n1 represents an integer of 1 to 8;

R ² represents a substituent other than an alkyl group. Specific examples of R ² include the above substituent (T).

n2 represents an integer of 0 to 7;

The classification of the alkyl-substituted naphthalene is preferably according to the following conditions (a) to (f).

(a) the number of substituents (R < ^{1 >} )

(b) the number of atoms of the substituent (R ¹ )

(c) the substitution position of the substituent (R ¹ ) on the naphthalene ring

(d) Structure of substituent (R ¹ )

(e) the number of carbon atoms of the substituent (R ¹ )

(f) a combination of two or more of (a) to (e)

Hereinafter, it is confirmed that all of these solvents have three or more kinds of naphthalene compounds though specific examples are given (for example, 1-methylnaphthalene, 2-methylnaphthalene, 1,4-dimethylnaphthalene, 2,6- , 2,7-dimethylnaphthalene). Specific examples thereof include Cactus Solvent HP-MN (main component: methylnaphthalene 80%, manufactured by Nikkoseki Yukagaku K.K.), Cactus Solvent HP-DMN (main component: dimethylnaphthalene 80%, manufactured by Nikkoseki Yukagaku Kabushiki Kaisha), Cactus Solvent P- Cactus Solvent P-200 (a mixture of methylnaphthalene and dimethylnaphthalene, Nikkoseki Yukagaku Kabushiki Kaisha), Cactus Solvent P-220 (a mixture of methylnaphthalene and dimethylnaphthalene, manufactured by Nippon Sekiyu Kagaku Kabushiki Kaisha) (A mixture of dimethyl naphthalene and dimethyl naphthalene, Nikkoseki Yukagaku Co., Ltd.), Cactus Solvent PAD-1 (main component: dimethyl monoisopropyl naphthalene, Nikko Seki Yukagaku Kogyo Co., Ltd.), Solvesso 200 ULTRA LOW NAPHTHALENE AROMATIC 200 (aromatic hydrocarbon, mainly C11-14 alkyl naphthalene, Exxon Mobil Chemical Com commercially available products such as Solvesso 200ND (aromatic hydrocarbons, mainly C11-14 alkyl naphthalene, manufactured by Exxon Mobil Chemical Company) can be used.

The content of the substituted naphthalene compound in the hydrocarbon solvent is 50 to 85% by mass, preferably 55 to 80% by mass, and more preferably 55 to 70% by mass. The component other than the substituted naphthalene compound in the hydrocarbon-based solvent is not particularly limited, and any organic compound ordinarily contained in such a mixture may be used. For example, a mixture of an aromatic compound other than the specific naphthalene, and a mixture of 1,3,5-trimethylbenzene, 1,2,4-trimethylbenzene, and a xylene isomer. It is also possible to use phenol, o-cresol, m-cresol, p-cresol, 2,6-xylenol, 2,4-xylenol, 2,5-xylenol, 2,3- 5-xylenol, 3,4-xylenol, m-ethylphenol, p-ethylphenol and the like. By including the substituted naphthalene compound at the lower limit value or higher, it is possible to achieve a sufficient resist removal effect, which is preferable. The upper limit value may be appropriately set because the increase in the effect does not increase even if the upper limit value is exceeded.

The preferred range of the content of the hydrocarbon-based solvent containing the substituted naphthalene compound in the release liquid is 70 to 95 mass%. And more preferably 80 to 90% by mass.

In general, compounds having similar physical properties are attracted to each other and adsorbed or dissolved easily. In the present invention, it is effective that a plurality of alkyl-substituted naphthalenes are present because the photoresist having various hydrophilic structures, structures, and solubilities contains a plurality of naphthalene compounds, Respectively. Further, it is presumed that the substituent (hydrocarbon group) of the naphthalene and the hydrocarbon group of the isoprene-based photoresist have similar properties, so that dissolution and peeling can be facilitated.

[(b) Specific benzenesulfonic acid]

The benzenesulfonic acid having a total of at least 8 carbon atoms substituted with an alkyl group may contain benzenesulfonic acid having a different carbon number.

The specific benzenesulfonic acid preferably has 8 to 24 carbon atoms in total, more preferably 16 to 22 carbon atoms in total, and particularly preferably has 18 to 20 carbon atoms in total. The benzenesulfonic acid may have a specific substituent (alkyl group, alkoxy group, acyl group, phenoxy group, etc.) within the range of attaining the effect of the present invention, or may have a structure in which an aromatic ring or a heterocyclic ring is hydrogenated. The term " acid " as used herein means a salt or anion.

The preferred range of the substituted benzenesulfonic acid in the release liquid is 5 to 30 mass%, more preferably 5 to 20 mass%, and particularly preferably 10 to 15 mass%. By including the specific substituted benzenesulfonic acid at the lower limit value or more, the peeling property of the photoresist can be improved, which is preferable. On the other hand, it is preferable to keep the amount below the above upper limit so that the solubility of the photoresist can be maintained.

[(c) Specific Fatty Acid Esters]

The fatty acid ester may be any fatty acid ester having 6 or more carbon atoms. For example, sucrose fatty acid esters, glycerin fatty acid esters, higher fatty acid esters, and polyhydric alcohol fatty acid esters. Preferably, it is a higher fatty acid ester and more preferably ester-bonded with a fatty acid which is a main component of the branched alcohol and saturated fatty acid. As branched alcohols, 2-ethyl-hexyl alcohol is preferred. The fatty acid is preferably a fatty acid having 6 to 20 carbon atoms, more preferably 10 to 18 carbon atoms, and particularly preferably 12 to 16 carbon atoms. For example, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, capric acid, caprylic acid, caproic acid and the like are preferable. Mixtures of these are more preferred.

Specific examples thereof include palm oil fatty acid esters and palm oil fatty acid esters, and commercially available products can be obtained.

The content of the fatty acid ester in the peeling liquid is preferably 1 to 10% by mass, and more preferably 3 to 7% by mass. The inclusion of the specific fatty acid ester above the lower limit described above is preferable because both the peeling property and the solubility of the photoresist can be improved. On the other hand, it is preferable that the content be not more than the upper limit value because the viscosity can be suppressed (peelability is not lowered).

(Negative photoresist)

Examples of the radical polymerizable compound include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate and the like as a radical polymerizing composition, a photoacid generator, a basic compound and optionally optional additives. (Meth) acrylic acid alkyl esters; (Meth) acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; (Meth) acrylic acid aryl esters such as phenyl (meth) acrylate and benzyl (meth) acrylate; Dicarboxylic acid diesters such as diethyl maleate and dibutyl fumarate; Vinyl group-containing aromatic compounds such as styrene and? -Methylstyrene; Vinyl group-containing aliphatic compounds such as vinyl acetate; Conjugated diolefins such as butadiene and isoprene; Nitrile group-containing polymerizable compounds such as acrylonitrile and methacrylonitrile; Chlorine-containing polymerizable compounds such as vinyl chloride and vinylidene chloride; Amide bond-containing polymerizable compounds such as acrylamide, methacrylamide and the like. These may be used alone, or two or more of them may be used in combination. Of these, conjugated diolefins such as butadiene and isoprene are particularly preferable from the viewpoint of adhesion, and isoprene-based radical polymerization compositions are particularly preferable.

Examples of the negative type resist include negative type photoresist compositions (JP-A-6-167809) in which tetraphenylsilane, tetraphenoxysilane or derivatives thereof are added to rubber-based photoresists mainly comprising a cyclic rubber and a bisazide compound, (For example, HR-200 manufactured by FUJIFILM ELECTRONIC MATERIALS CO., LTD.), Alkaline-soluble novolak resins, alkoxymethylated melamine as a crosslinking agent, and halogenated triazine as an acid generator 5-303196).

The polyisoprene compound is preferably a compound having a cis-1,4 polyisoprene structure. Further, it is preferably a partially cyclized polyisoprene.

(Post baking)

In the present invention, it is preferable that the negative resist after the heat treatment (post baking) is peeled. The condition of the heat treatment is not particularly limited, but it is preferably 70 to 160 占 폚, more preferably 80 to 140 占 폚, in consideration of ordinary conditions of this type of resist. The heat treatment time is not particularly limited, but it is practically 30 seconds to 30 minutes (however, the recommended temperature and time may vary depending on the apparatus and the manufacturing source, and accordingly, it may be appropriately dealt with). The atmosphere condition in the heat treatment is not particularly limited.

(Peeling method)

The peeling liquid of the present invention may be used at any liquid temperature, but it is preferably performed at 20 to 90 ° C in view of damage to the member. Particularly, the present invention is excellent in that it can be peeled off even at 60 캜 or lower, and it is preferable to use it at 60 캜 or lower because damage to other members can be reduced.

The peeling time is not particularly limited, but is generally performed for 1 minute to 30 minutes. Preferably 1 minute to 20 minutes, and more preferably 2 minutes to 10 minutes.

Example

Next, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to these Examples.

(Example 1)

A commercially available negative type photoresist HR-200 (polyisoprene based on FUJIFILM ELECTRONIC MATERIALS) was spin-coated on a 4-inch glass substrate with an ITO film and baked on a hot plate at 100 DEG C for 90 seconds to form a 1.5- . Exposure was performed with a g line stepper (FPA-1550MIVW, NA = 0.54) manufactured by Canon Inc., and development was carried out for 60 seconds by a commercially available developer WNRD (Fuji Film Electronics Material Co.) to form a pattern. Subsequently, after post-baking at 130 占 폚 for 3 minutes, etching was performed with a mixed solution of hydrochloric acid and ferric chloride using the pattern thus obtained as a mask to form a pattern of ITO with resist on the silicon wafer. Here, the etching time was defined as the time for which the ITO substrate to which the resist was not applied was immersed in the etching solution and the ITO film was completely etched and removed, that is, the just etching time.

Thereafter, the wafer was immersed in the peeling solution described in Table 1 (stirred at 250 rpm by an agitator) heated in a beaker, and the peeling state of the resist was confirmed. In addition, it is a comparative example that the number of the peeling solution is represented by c **.

The results of the peeling treatment were evaluated separately as follows.

AA: Peel off within 3 minutes

A: Peeling within 3 minutes and within 5 minutes

B: Peeling within 10 minutes after 5 minutes

C: over 10 minutes, remaining

Also, at least three kinds of alkyl-substituted naphthalene compounds in the Cactus Solvent P-200, Cactus Solvent HP-MN, Solvesso 200, Solvesso 200ND, Cactus Solvent P-200 and ULTRA LOW NAPHTHALENE AROMATIC are contained in the hydrocarbon solvent in an amount of 50% I confirmed that it was included. Further, it was confirmed that, in the hydrocarbon solvent, each substituted naphthalene contained 1% by mass or more, and the lowest content component was contained in an amount of 5 parts by mass or more with respect to 100 parts by mass of the maximum content component with respect to the three components contained in large amounts.

* 1: Details of the abbreviation

P-200: Cactus Solvent P-200 (manufactured by Nikkoseki Yukagaku Kogyo Co., Ltd.)

HP-NM: Cactus Solvent HP-MN (manufactured by Nikkoseki Yukagaku Kogyo Co., Ltd.)

200: Solvesso 200 (manufactured by Exxon Kagaku K.K.)

200ND: Solvesso 200ND (manufactured by Exxon Kagaku K.K.)

ULNA: ULTRA LOW NAPHTHALENE AROMATIC 200 (Exxon Mobil Chemical Company)

B.A .: butyl acetate

DBS: Dodecylbenzenesulfonic acid (Kao Chemicals Schae Neopellex GS)

DMBS: 2,5-dimethylbenzenesulfonic acid dihydrate (manufactured by Alfa Aeser)

· Texaprint SKEH:

     Fatty acid ethylhexyl esters

     (Fatty acid 2-ethylhexyl ester manufactured by Cognis)

* 2: 2.36 mass% TMAH (tetramethylammonium hydroxide)

* 3: peeling treatment temperature, peeling treatment time

(Example 2)

Except that the resist SC270, HNR-120, and other negative photoresists prepared in accordance with the known information were coated in place of the negative resist HR-200 manufactured by Fuji Film Electronic Materials Co., Ltd., The resultant was treated with a peeling solution, and peeling could be performed in the same manner as in Example 1.

Claims (9)

As a resist stripping solution for stripping a negative type photoresist,
(a) 70 to 95% by mass of a hydrocarbon solvent containing three or more kinds of naphthalene substituted with an alkyl group and having a total content of 50% by mass or more thereof,
(b) 5 to 30% by mass of a benzenesulfonic acid having 8 or more carbon atoms and substituted with an alkyl group. The method according to claim 1,
(c) 1 to 10% by mass of a fatty acid ester having 6 or more carbon atoms. 3. The method according to claim 1 or 2,
Wherein the negative type photoresist is made of a polyisoprene compound. 4. The method according to any one of claims 1 to 3,
Wherein the three kinds of alkylnaphthalenes include three or more kinds of the different kinds of the alkyl naphthalenes under the following conditions (a) to (f) in the following formula (N).
(a) the number of substituents (R < ^{1 >} )
(b) the number of atoms of the substituent (R ¹ )
(c) the substitution position of the substituent (R ¹ ) on the naphthalene ring
(d) Structure of substituent (R ¹ )
(e) the number of carbon atoms of the substituent (R ¹ )
(f) a combination of two or more of (a) to (e)

(Wherein R ¹ represents an alkyl group having 1 to 9 carbon atoms, the alkyl group may be straight-chain, branched or cyclic, and the alkyl group may further have a substituent, n 1 represents an integer of 1 to 8. R ² Represents a substituent other than an alkyl group, and n2 represents an integer of 0 to 7) A resist stripping method comprising stripping a negative type photoresist using the resist stripping liquid according to any one of claims 1 to 4. 6. The method of claim 5,
Wherein the negative type photoresist is made of a polyisoprene compound. The method according to claim 5 or 6,
Wherein the resist stripping is performed at a liquid temperature of 60 占 폚 or less. 8. The method according to any one of claims 5 to 7,
Wherein the developing solution used for forming the pattern after exposure of the negative type photoresist is an isoparaffin type solvent. 9. The method according to any one of claims 5 to 8,
Wherein the negative type photoresist is applied on indium tin oxide or a glass substrate.