JPH11305438A - Positive photosensitive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photosensitive compsn. which has high sensitivity for ArF excimer laser light, which can form a resist pattern having excellent resolution and resist profile and good dry etching resistance without causing peeling from a substrate, and which has adaptability for a standard developer, by combining a photoacid producing agent and a resin containing a polymer having a specified structure as the structural unit. SOLUTION: This compsn. contains a compd. which produces an acid by irradiation of active rays or radiation and a resin having a bivalent polycyclic alicyclic unit expressed by the formula in the main chain of the polymer. In the formula, X is a bivalent bonding group selected from oxygen atom, sulfur atom, -NH- or -NHSO2 -, R1 , R2 are independently hydrogen atoms, alkyl groups. substd. alkyl groups, cyclic alkyl groups, substd. cyclic alkyl groups, groups which can be decomposed by the effect of an acid, or-Y-R3 , wherein Y is a single bond, alkyl group or bivalent group selected from ether groups or the like, R3 is -COOH, alkoxy group or the like, and n is 2 or 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive photosensitive composition used in a process for producing semiconductors such as ICs, a circuit substrate for liquid crystals and thermal heads, and other photofabrication processes. It is. More specifically, the present invention relates to a positive photosensitive composition suitably used for fine processing of a semiconductor device using light energy rays having a short wavelength such as far ultraviolet rays, X-rays, and electron beams, and particularly relates to a semiconductor device using an ArF excimer laser. The present invention relates to a positive photosensitive composition that can be suitably used for microfabrication.

[0002]

2. Description of the Related Art In recent years, high integration of semiconductor integrated circuits has progressed, and LSIs and VLSIs have been put into practical use, and the minimum pattern width of integrated circuits has reached a sub-half micron area.
Further miniaturization is progressing. Therefore, the demand for photolithography technology for forming a fine pattern is becoming more and more severe. As one of means for miniaturizing a pattern, it is known to shorten the wavelength of exposure light used when forming a resist pattern.

[0003] For example, DR with an integration degree of up to 64 Mbits
To date, the manufacture of AM has been based on the i-line (365
nm) has been used as a light source. 256 Mbit D
In the mass production process of RAM, a KrF excimer laser (248 nm) has been put to practical use as an exposure light source instead of i-line, and a light source with a shorter wavelength has been studied for the purpose of manufacturing a DRAM having an integration degree of 1 Gbit or more. I have. Examples of such a short wavelength light source include an ArF excimer laser (193 nm) and an F ₂ excimer laser (157 n).
m), the use of X-rays and electron beams is considered to be effective (Takumi Ueno et al., "Short Wavelength Photoresist Material-ULSI
Micromachining for ”, Bunshin Publishing, 1988).

In particular, an ArF excimer laser is positioned as a next-generation exposure technology, and development of a resist for ArF excimer laser exposure having high sensitivity, high resolution, and excellent dry etching resistance has been desired. Conventional i-line and K
As a resist material for rF excimer laser exposure,
To obtain high dry etching resistance, resists containing aromatic polymers are widely used, for example,
A novolak resin-based resist or a polyvinyl phenol-based chemically amplified resist is known. However, since the aromatic ring introduced for the purpose of imparting dry etching resistance hardly transmits light in the wavelength range of ArF excimer laser light, it is difficult to expose even the bottom of the resist film. A good pattern with no cross-sectional shape could not be obtained.

It is known that one of the solutions to the problem of resist transparency is to use an aliphatic polymer containing no aromatic ring, for example, polymethyl methacrylate (J. Vac. Sci. Technol., B9, 3357 (1991)). However, such a polymer cannot be practically used because sufficient dry etching resistance cannot be expected. As described above, in developing a resist material for ArF excimer laser exposure, it is the greatest challenge to achieve both improved transparency and high dry etching resistance. Therefore, the fact that a resist containing an alicyclic hydrocarbon group instead of an aromatic ring shows the same resistance to dry etching as an aromatic group and has a small absorption at 193 nm, Proc. SPIE,
1672, 66 (1992), and in recent years the use of this polymer has been energetically studied.

[0006] Originally, attempts to apply a polymer containing an alicyclic hydrocarbon group to a resist have been made for a long time. For example, Japanese Patent Application Laid-Open Nos. 60-195542, 1-217453 and 2-59751 have been proposed. Discloses a norbornene-based polymer, and JP-A-2-46045 discloses various alkali-soluble resins having a cyclic aliphatic hydrocarbon skeleton and a maleic anhydride unit. Further, JP-A-5-80515 discloses a copolymer of norbornene and an acrylic acid ester protected with an acid-decomposable group, and is disclosed in JP-A-4-39665, JP-A-5-265212, and JP-A-5-80515. And JP-A-7-234511
Discloses a copolymer having an adamantane skeleton in the side chain, and JP-A-7-252324 and JP-A-9-221526 disclose an aliphatic group having 7 to 12 carbon atoms having a bridged cyclic hydrocarbon group. cyclic hydrocarbon group, the compound linked to the side chain of the polymer, e.g., tricyclo [5,2,1,0 ^2,6] decane methylene group, a tricyclo [5,2,1,0 ^2,6] decanediyl Group,
A norbornanediyl group, a norbornanedimethyl group and an adamantanediyl group are disclosed, and JP-A-7-199467 discloses a tricyclodecanyl group, a dicyclopentenyl group, a dicyclopentenyloxyethyl group, a norbornyl group, and a cyclohexyl group on the polymer side. Each compound linked to the chain is disclosed.

Further, Japanese Patent Application Laid-Open No. 9-325498 discloses a polymer having a cyclohexane and isobornyl skeleton in the main chain, and further disclosed in JP-A-9-230595, JP-A-9-244247,
JP-A-10-10739, WO97-33198, EP794458, EP789278 disclose polymers in which various cyclic olefins such as dicycloolefin are introduced into the main chain, JP-A-8-82925,
JP-A-9-230597 discloses that a compound having a menthyl group or a menthyl derivative group among terpenoid skeletons is preferable. However, as an adverse effect of introducing an alicyclic hydrocarbon site, the system becomes extremely hydrophobic,
Conventionally, tetramethylammonium hydroxide (hereinafter referred to as TMAH) has been widely used as a developing solution for resist.
There are phenomena such as difficulty in developing with an aqueous solution and peeling of the resist from the substrate during development.

[0008] In order to cope with such hydrophobicity of the resist, studies have been made to mix an organic solvent such as isopropyl alcohol in a developing solution. Although some results have been obtained, there are concerns about swelling of the resist film and the process becomes complicated. The problem has not always been solved. In the approach of improving the resist itself, many measures have been taken to supplement hydrophobic alicyclic hydrocarbon sites by introducing a hydrophilic group.

In general, a measure has been taken in which a monomer having a carboxylic acid moiety such as acrylic acid or methacrylic acid is copolymerized with a monomer having an alicyclic hydrocarbon group. In addition, although there is a tendency to improve the substrate adhesion, there are many problems such as deterioration of dry etching resistance and further increase in resist film loss, and the above-mentioned problems have not been solved. Furthermore, in JP-A-7-234511, a monomer having a hydroxyl group or a cyano group in the molecule instead of a carboxylic acid group such as HEMA or acrylonitrile is referred to as a monomer having an alicyclic hydrocarbon group. The aim was to solve the developability by copolymerization, but the solution was not sufficiently satisfactory.

Recently, J. Photopolym. Sci., Tech.,
Vol. 9, 509 (1996) and J. Photopolym. Sci., Tech., Vol. 1
As described in U.S. Pat. No. 0,545 (1997), improvement of substrate adhesion has been studied by focusing on a lactone structure such as mevalonic lactone. However, in order to ensure the developability, an overcoat layer that complicates the process is required, and the developability is insufficient, and the substrate adhesion is also insufficient. In Japanese Patent Application Laid-Open No. 8-289626, a monomer having a carboxylic acid group and an alicyclic hydrocarbon moiety in a molecule at the same time is studied, and dry etching resistance, developability, and substrate adhesion are improved. Nevertheless, problems such as lack of substrate adhesion and suitability for a standard developer due to extremely high solubility of the developer have been encountered.

Similarly, Japanese Patent Application Laid-Open No. 9-325498 discusses a polymer having a cyclohexane skeleton or isobornyl skeleton in which an acidic substituent such as a carboxylic acid group or a sulfonic acid group is introduced into a side chain in a main chain. Although the properties have been improved, the adhesion to the substrate has not yet reached a satisfactory level. Also, J. Photopolym. Sci., Tech., Vo
As described in l. 10,561 (1997), improvements have been made by copolymerizing alicyclic hydrocarbon monomers having alcoholic hydroxyl groups, but they have not yet reached a satisfactory level. Absent.

Furthermore, a report has been made on introducing a hydroxyl group into the norbornene polymer main chain from the viewpoint of imparting substrate adhesion (J. Photop.
olym.Sci., Tech., Vol.10,529 (1997), J.Photopolym.Sc
i., Tech., Vol. 10, 521 (1997)), but satisfactory results have not been obtained in both developability and substrate adhesion. As described above, the photosensitivity has high transparency to deep ultraviolet rays of ArF excimer laser light, has high dry etching resistance, is uniformly dissolved in an alkali developing solution, and has excellent adhesion to a substrate. The composition has not yet been obtained.

[0013]

SUMMARY OF THE INVENTION The object of the present invention has been made in view of the above-mentioned problems, and has been made in consideration of the following problems.
In particular, it has high sensitivity to ArF excimer laser light, and has excellent resolution and resist profile.
It is an object of the present invention to provide a positive photosensitive composition having sufficient dry etching resistance and suitable for a standard developing solution (2.38% TMAH aqueous solution) capable of forming a resist pattern that does not peel off from a substrate.

[0014]

Means for Solving the Problems The present inventors have conducted intensive studies on the constituent materials of a positive-type chemically amplified resist composition, and as a result, have found that a resin containing a polymer containing a specific structure as a structural unit and a photoacid generator The inventors have found that the object can be achieved by a combination of agents, and have led to the present invention. That is, the present invention is achieved by a method having the following configuration. (1) (A) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and (B) a main chain of a polymer comprising a divalent polycyclic alicyclic unit represented by the following general formula (I): A positive photosensitive composition characterized by containing the resin contained in (1).

[0015]

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(In the above formula (I), X represents a divalent linking group selected from an oxygen atom, a sulfur atom, -NH- and -NHSO _2-. R ₁ and R ₂ are each independently Hydrogen atom, alkyl group, substituted alkyl group, cyclic alkyl group,
Substituted cyclic alkyl group, a group decomposable or -Y-R ₃ group, by the action of an acid. Y is a single bond, an alkylene group, a substituted alkylene group, an ether group, a carbonyl group, an ester group, an amide group, or a divalent group obtained by combining two or more groups selected from the group consisting of a sulfonamide group. Represent. R ₃ represents —COOH, —COOR ₄ , an alkoxy group, or a substituted alkoxy group. R ₄ represents an alkyl group, a substituted alkyl group, a cyclic alkyl group, or a substituted cyclic alkyl group. n represents 2 or 3. )

(2) The positive photosensitive composition as described in (1) above, wherein the resin is synthesized by a cyclization polymerization method and has a group that is decomposed by the action of an acid. (3) The above item (1) or comprising a low-molecular acid-decomposable dissolution inhibiting compound having a group decomposable by the action of an acid and having an alkali solubility increased by the action of an acid and having a molecular weight of 1,000 or less. The positive photosensitive composition according to (2). (4) The positive photosensitive composition as described in any one of (1) to (3) above, wherein far-ultraviolet light having a wavelength of 220 nm or less is used as an exposure light source.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the resin used in the present invention will be described in detail. In the general formula (I), examples of the group (also referred to as an acid-decomposable group) decomposed by the action of an acid in R ₁ include a tertiary alkyl group such as a t-butyl group and a t-amyl group, an isobornyl group, 1-ethoxyethyl, 1-butoxyethyl, 1-isobutoxyethyl, 1-cyclohexyloxyethyl, etc.
And alkoxymethyl groups such as -alkoxyethyl, 1-methoxymethyl group and 1-ethoxyethyl group, tetrahydropyranyl group, tetrahydrofuranyl group and the like.

The alkyl group for R ₁ , R ₂ and R ₄ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably a methyl group, an ethyl group,
Propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group and t-butyl group. R ₁ ,
Examples of the cyclic alkyl group for R ₂ and R ₄ include a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, an adamantyl group, a 2-methyl-2-adamantyl group, a norbornyl group, a boronyl group, an isobornyl group, a tricyclodecanyl group, and a dicyclodecanyl group. Examples thereof include a cyclopentenyl group, a nobornane epoxy group, a menthyl group, an isomenthyl group, a neomenthyl group, a neomenthyl group, and a tetracyclododecanyl group.

Examples of the alkoxy group for R ₃ include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group and a butoxy group. Further substituents in the above-mentioned alkyl group, cyclic alkyl group and alkoxy group include a hydroxyl group, a halogen atom, a carboxyl group, an alkoxy group, an acyl group, a cyano group, an acyloxy group and the like. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group and a butoxy group, and examples of the acyl group include a formyl group and an acetyl group.
Examples of the acyloxy group include an acetoxy group. Examples of the alkylene group and substituted alkylene group for Y include the groups shown below.

[0021] - [C (Ra) (Rb)] _p - in the above groups, R _a, R _b represents a hydrogen atom, an alkyl group, a substituted alkyl group, a halogen atom, a hydroxyl group, an alkoxy group, both identical Or may be different, and the alkyl group is preferably a lower alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group, and more preferably a methyl group, an ethyl group, a propyl group, and an isopropyl group. Represents a substituent selected from the group. Examples of the substituent of the substituted alkyl group include a hydroxyl group, a halogen atom and an alkoxy group. Examples of the alkoxy group include those having 1 to 4 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group and a butoxy group. P represents an integer of 1 to 10. In the general formula (I), X is preferably an oxygen atom.

The resin of the present invention is, for example, CSMarvel, eta
l .; J. Am. Chem. Soc. 79, 5771 (1957) and CSMarvel.etal .;
Soc. 81, 984 (1959) can be synthesized using the cyclopolymerization method described in J. Am. That is, as shown in the following Scheme 1, it can be easily obtained by polymerizing 1,5-pentadiene or 1,6-heptadiene substituted at the 2,6-position using a radical polymerization initiator. The polymerization is carried out using an organic solvent such as chloroform or benzene in a bulk, solution or emulsion system of the diolefin. After the reaction for a predetermined time, it is preferable to purify the resulting resin of the present invention by reacting with the unreacted monomer components, solvents, and the like by distillation under reduced pressure.

[0023]

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(In the scheme 1, n is 2 or 3,
m is an integer of 10 or more) The thus obtained resin of the present invention is measured by gel permeation chromatography equipped with a refractive index detector by comparing the retention time with that of a polystyrene having a known molecular weight and obtaining a weight average molecular weight. Ask for. The resin used in the present invention preferably has a weight average molecular weight in the range of 1500 to 100,000, more preferably in the range of 2000 to 70000, and particularly preferably in the range of 3000 to 50,000. If the weight average molecular weight is less than 1500, the dry etching resistance, heat resistance, and adhesion to the substrate tend to be insufficient. If the weight average molecular weight exceeds 100,000, the resist sensitivity tends to decrease. Also, the degree of dispersion (Mw / M
n) is preferably 1.0 to 6.0, more preferably 1.
0 to 4.0, and the smaller the value, the better the heat resistance and the image resist (resist profile, defocus latitude, etc.).

Japanese Patent Application Laid-Open No. 9-325498 discloses a polymer in which a cyclohexane skeleton having a carboxylic acid group is introduced into the main chain, and a cycloaliphatic hydrocarbon skeleton is bonded by a single bond. JP-A-9-244247 and EP-0789278 disclose resins obtained by subjecting a norbornene-substituted product to ring-opening polymerization and then performing a hydrogenation reaction.

However, in these resins, the developing property is improved.
Although good, the adhesion to the substrate is still insufficient
Minutes. On the other hand, the resin of the present invention
It is not clear whether the reason is that it is specifically excellent in developability and adhesion
However, the polymer of the present invention also has a cyclopentane ring in the main chain.
Or a cyclohexane ring, and a carbon atom on the main chain carbon.
Acid-derived groups (—CO—X—R ₁Etc.), and
Cycloaliphatic hydrocarbon backbone linked via methylene bond
Due to having the basic structural unit
It seems that it was expressed.

For the purpose of improving the performance of the resin of the present invention,
Another polymerizable monomer may be further copolymerized as long as the transparency of 220 nm or less and the dry etching resistance of the resin are not significantly impaired. Examples of the copolymerizable monomer that can be used include the following. For example, an addition-polymerizable polymer selected from acrylic acid, methacrylic acid, acrylic esters, acrylamides, methacrylic esters, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, styrenes, crotonic esters, and the like. There are a compound having one saturated bond, an acid anhydride such as maleic anhydride, maleimide, acrylonitrile, methacrylonitrile, and the like. Others
Generally, any addition-polymerizable unsaturated compound that can be copolymerized can be used.

Specific examples of copolymerizable monomers such as acrylates and methacrylates include alkyl acrylates having 1 to 8 carbon atoms, methyl acrylate, ethyl acrylate, propyl acrylate, and acrylic acid. t-butyl, amyl acrylate, cyclohexyl acrylate, 2-hydroxyethyl acrylate,
Phenyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, t-butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, adamantyl methacrylate, 2-hydroxyethyl methacrylate, phenyl methacrylate, naphthyl methacrylate, acrylic acid Tricyclodecanyl, tricyclodecyl acrylate, tetrahydropyranyl methacrylate, ethoxyethyl methacrylate, butoxyethyl methacrylate, methoxypropyl methacrylate, cyclohexylethyl methacrylate, adamantyl oxyethoxyethyl methacrylate, adamantyl carbonyloxyethoxy methacrylate Ethyl, 1-paramenthyl methacrylate, 3-oxocyclohexyl methacrylate, menthyl methacrylate and the like

Specific examples of acrylamide and methacrylamide include N, N-dimethylacrylamide, N, N-diethylacrylamide, N-methyl-
N-phenylacrylamide, N-hydroxyethyl-
N-methylacrylamide, N, N-dimethylmethacrylamide, N, N-diethylmethacrylamide, N-methyl-N-phenylmethacrylamide, N-hydroxyethyl-N-ethylmethacrylamide, N-cyclohexylmaleimide and the like can be mentioned. .

Specific examples of the allyl compound include allyl esters such as allyl acetate, allyl acetoacetate, allyl lactate and allyl benzoate. Specific examples of vinyl ethers include alkyl vinyl ethers such as ethylhexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, and hydroxyethyl vinyl ether; vinyl aryl ethers such as vinyl phenyl ether and vinyl naphthyl ether; vinyl butyrate and vinyl isobutyrate. , Vinyl valate, vinyl methoxy acetate, vinyl lactate, vinyl benzoate, vinyl salicylate, vinyl naphthoate and the like.

Specific examples of styrenes include styrene,
Examples include p-hydroxystyrene, carboxystyrene, methylstyrene, methoxystyrene, and acetoxystyrene. Specific examples of crotonic esters include butyl crotonate and hexyl crotonate. Other examples of the copolymerizable addition-polymerizable unsaturated compound include norbornene, 1,5-dimethyl-1,5-
Examples include alicyclic hydrocarbon compounds such as cyclooctadiene, 5,6-dihydrodicyclopentadiene, and 1,5-octadiene, and derivatives thereof. When these copolymerizable monomers do not contain an acid-decomposable group in the repeating unit represented by the general formula (I), the copolymerizable monomer preferably contains an acid-decomposable group.

In the resin of the present invention, the content of the repeating unit represented by the general formula (I) is preferably at least 10 mol%, more preferably at least 20 mol%, even more preferably in the repeating units of all monomers. 30 mol% or more. When the resin of the present invention contains an acid-decomposable group, the content of the acid-decomposable group-containing repeating unit is preferably from 10 to 90 mol%, more preferably from 15 to 90 mol%, based on the repeating units of all the monomers. ~ 85 mol%, more preferably 20 ~
80 mol%. Further, the content of the repeating unit of the other copolymer component is preferably at most 80 mol%, more preferably at most 70 mol%, further preferably at most 60 mol%, based on the repeating units of all the monomers. Hereinafter, (a-1) to (a-15) are shown as examples of the repeating unit represented by the general formula (I) constituting the resin of the present invention,
The present invention is not limited to these examples.

[0033]

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[0034]

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[0035]

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[0036]

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In the present invention, the addition amount of the above resin in the photosensitive composition (excluding the solvent) is 5 to the total solid content.
It is 0 to 99.7% by weight, preferably 70 to 99% by weight. Further, when the resin of the present invention contains an acid-decomposable group, it contains or does not contain a low-molecular acid-decomposable dissolution inhibiting compound having a molecular weight of which alkali solubility is increased by the action of an acid of 1000 or less. However, when it does not contain an acid-decomposable group, it preferably contains a low-molecular acid-decomposable dissolution inhibiting compound having a molecular weight of 1,000 or less, whose alkali solubility is increased by the action of an acid. That is, in order to increase the ratio of dissolution rate to alkali in the unexposed area and the exposed area and to obtain high resolution, it is effective to add a compound which increases the alkali solubility by the action of an acid.

Next, the photoacid generator in the positive photosensitive composition of the present invention will be described. Used in the present invention,
Examples of compounds that decompose upon irradiation with actinic rays or radiation to generate an acid include a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization, a photodecolorant for dyes, a photochromic agent, or an ultraviolet ray. , A micro-photoresist that generates acid by far ultraviolet rays, KrF excimer laser light, ArF excimer laser light, electron beam, X-ray, molecular beam or ion beam, and appropriately selects a known photoacid generator and a mixture thereof. Can be used.

Of these, preferred for use in the present invention are photoacid generators which generate an acid with light in the range of 220 nm or less, and the mixture of the resin with the above resin of the present invention is sufficiently dissolved in an organic solvent. Any photoacid generator may be used as long as the photoacid generator can be used. Further, they may be used alone or as a mixture of two or more kinds, or may be used in combination with an appropriate sensitizer. Examples of usable photoacid generators include, for example, J. Or
g.Chem.Vol.43, N0.15, 3055 (1978) Triphenylsulfonium salt derivatives and other onium salts described in Japanese Patent Application No. 9-279071 (sulfonium salts, iodonium salts, phosphonium salts, diazonium Salts, ammonium salts) can also be used.

Specific examples of the onium salt include diphenyliodonium triflate, diphenyliodonium pyrene sulfonate, diphenyliodonium, dodecylbenzenesulfonate, triphenylsulfonium triflate, triphenylsulfonium hexafluoroantimonate, diphenyliodonium hexafluoroantimonate, and triphenyliodonium hexafluoroantimonate. Examples include phenylsulfonium naphthalene sulfonate, triphenylsulfonium camphorsulfonium, (4-methoxyphenyl) phenyliodonium trifluoromethanesulfonate, and bis (t-butylphenyl) iodonium trifluoromethanesulfonate.

Also, JP-A-3-103854, JP-A-3-103856
Diazodisulfones and diazoketosulfones described in JP-A-4-210960, JP-A-64-18143, JP-A-2-24
Iminosulfonates described in 5756, JP-A-2-71
Disulfones described in No. 270 can also be suitably used. Further, USP 3849137, JP-A-63-26653, JP-A-62
-69263, JP-A-63-146038, JP-A-63-163452,
The compounds described in JP-A-62-153853 and JP-A-63-146029, in which a group capable of generating an acid by light is introduced into the main chain or side chain of the polymer, can also be used.

Further, Japanese Patent Application Laid-Open Nos. Hei 7-25846 and Hei 7-846
No. 28237, aliphatic alkylsulfonium salts having a 2-oxocyclohexyl group described in JP-A-7-92675 and JP-A-8-27120, and N-hydroxysuccinimide sulfonates, and further, J. Photopolym.Sci., Te
ch., Vol. 7, No. 3, 423 (1994), etc. can also be suitably used, and these photoacid generators can be suitably used alone or in combination of two or more. it can.

The amount of the compound which decomposes upon irradiation with actinic rays or radiation to generate an acid, which is variously mentioned above, is as follows:
It is usually in the range of 0.001 to 40% by weight, preferably 0.01 to 20% by weight, more preferably 0.1 to 5% by weight, based on the total weight of the photosensitive composition (excluding the coating solvent).
% By weight. 0.001 of photoacid generator added
If the amount is less than% by weight, the sensitivity decreases, and conversely,
If the addition amount exceeds 40% by weight, the light absorption of the resist becomes too high, and the profile is deteriorated and the process (especially baking) margin is unfavorably reduced. The positive photosensitive composition of the present invention may contain an acid-decomposable dissolution-inhibiting compound, an organic basic compound, and a compound that promotes solubility in a developer, if necessary.

As the low-molecular acid-decomposable dissolution-inhibiting compound used in the present invention, those which do not decrease the transmittance at 220 nm or less, dry etching resistance and heat resistance are preferred. These compounds include, for example, Proc. SPIE, 272
4,355 (1996) and JP-A-8-15865, US5310619, US537
Cholic acid derivatives, dehydrocholic acid derivatives, deoxycholic acid derivatives, lithocholic acid derivatives, ursocholic acid derivatives, and abietic acid derivatives protected with an acid-decomposable group as described in 2912 Such alicyclic compounds as described above can also be preferably used. Further, the low-molecular acid-decomposable dissolution-inhibiting compound described in JP-A-6-51519 can also be used in an addition range that does not deteriorate the transmittance at 220 nm,
1,2-Naphthoquinone diazide compounds can also be used.

When an acid-decomposable dissolution-inhibiting compound is used in the photosensitive composition of the present invention, the amount thereof is usually 1% based on the total weight of the photosensitive composition (excluding the coating solvent).
It is used in the range of -50% by weight, preferably in the range of 3-40% by weight, more preferably in the range of 5-30% by weight. Preferred organic basic compounds that can be used in the present invention include compounds that are more basic than phenol, and among them, nitrogen-containing basic compounds are more preferable.
The organic basic compound is mainly added for the purpose of improving the stability over time and the adhesion properties of the acid scavenger and the resist. For example, JP-A-63-149640, JP-A-5-249662, JP-A-6-149640
242605, JP-A-6-242606, JP-A-6-266100, JP-A-7-120929, JP-A-9-274312, and JP-T-7-508840 include these organic basic compounds. Those which do not vaporize or sublime are preferably used.

Among these organic basic compounds, 1,5-
Diazabicyclo [4,3,0] -5-nonene, 1,8-
Diazabicyclo [5,4,0] -7-undecene, 1,
4-diazabicyclo [2,2,2] octane, 4-dimethylaminopyridine, 1-naphthylamine, N-methylformamide, piperidine, hexamethylenetetramine, imidazoles are particularly preferably used. Also, JP-A-6-242606, JP-A-6-242605, basic ammonium salts and sulfonium salts described in JP-A-8-110635, etc.
Alternatively, an internal salt such as betaine can be used.

Of these, pyridinium p-toluenesulfonate, 2,4,6-trimethylpyridinium p-toluenesulfonate, tetramethylammonium p-toluenesulfonate, tetrabutylammonium lactate and the like are particularly preferably used. These nitrogen-containing basic compounds are used alone or in combination of two or more. The amount of the nitrogen-containing basic compound used is usually 0.1 to 100 parts by weight of the photosensitive composition (excluding the solvent).
001 to 10 parts by weight, preferably 0.01 to 5 parts by weight. If the amount is less than 0.001 part by weight, the effect of adding the nitrogen-containing basic compound cannot be obtained. On the other hand, if it exceeds 10 parts by weight, the sensitivity tends to decrease and the developability of the unexposed part tends to be remarkably deteriorated.

Examples of the compound capable of accelerating dissolution in a developer which can be used in the present invention include compounds having two or more phenolic hydroxyl groups described in JP-A-3-206458,
Naphthols such as naphthol, or JP-A-3-1793
No. 55, JP-A-5-181279, JP-A-9-6001, JP-A-9-27
No. 4,318, US Pat. No. 5,374,500, compounds having one or more carboxyl groups described in DE4214363, carboxylic anhydrides, low molecular weight compounds having a molecular weight of 1,000 or less such as sulfonamide compounds and sulfonylimide compounds described in Japanese Patent Application No. 9-279071. Can be mentioned. Of these, dissolution-promoting compounds that do not deteriorate the transmittance at 220 nm are preferable, and for example, steroids, norsteroids, and terpenoids are preferable, and adamantanecarboxylic acid, cholic acid, norcholanic acid, abietic acid, and agatendicarboxylic acid are particularly preferable. preferable.

The positive photosensitive composition of the present invention further contains, if necessary, an antihalation agent, a plasticizer, a surfactant, a photosensitizer, an adhesion aid, a crosslinking agent, a photobase generator and the like. can do. As a suitable antihalation agent, a compound that efficiently absorbs irradiation radiation is preferable, and fluorene, 9-fluorenone, substituted benzenes such as benzophenone, anthracene, and anthracene-9-
Examples thereof include polycyclic aromatic compounds such as methanol, anthracene-9-carboxyethyl, phenanthrene, perylene, and azylene. Of these, polycyclic aromatic compounds are particularly preferable.

These antihalation agents exhibit the effect of improving the standing wave by reducing the reflected light from the substrate and reducing the influence of multiple reflection in the resist film. In order to improve the acid generation rate by exposure, a photosensitizer as described below can be added. Suitable photosensitizers include, specifically, benzophenone, p-p'tetramethyldiaminobenzophenone, 2-chlorothioxanthone, anthrone, 9-ethoxyanthracene, pyrene, phenothiazine, benzyl, benzoflavin, acetophenone, phenanthrene, benzoquinone , Anthraquinone, 1,2-naphthoquinone and the like, but are not limited thereto.
These photosensitizers can also be used as the antihalation agent.

To the photosensitive composition of the present invention, the following surfactants can be added for the purpose of improving coating properties and developing properties. Examples of such surfactants include, for example, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate, and polyoxyethylene nonyl phenyl ether. Nonionic surfactants such as oxyethylene sorbitan monostearate and sorbitan monolaurate; F-Top EF301 and EF303 (manufactured by Shin-Akita Chemical Co., Ltd.); Florad FC43
0,431 (manufactured by Sumitomo 3M Limited), Mega Fuck F171, F
173, F176, F177P (Dai Nippon Ink Co., Ltd.), Surflon
S-382, SC101,102,103,104,105,106 (made by Asahi Glass Co., Ltd.)
And other fluorosurfactants, polysiloxane polymer KP-3
41 (manufactured by Shin-Etsu Chemical Co., Ltd.).

The amount of these surfactants is usually 2 parts by weight or less, preferably 1 part by weight or less, per 100 parts by weight of the solids in the composition of the present invention. These surfactants may be used alone, or may be added in plural combinations. The positive photosensitive composition of the present invention may further contain a plasticizer, an adhesion aid, a crosslinking agent, a photobase generator, an antifoaming agent, and the like, if necessary.

The photosensitive composition of the present invention is prepared as a solution by dissolving the above-mentioned components in a solvent capable of dissolving the above-mentioned components and then filtering the resulting solution with, for example, a filter having a pore size of about 0.05 μm to 0.2 μm. Is done. As the solvent used here, for example, ethylene glycol monoethyl ether acetate, cyclohexanone, 2-heptanone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether propionate,
Propylene glycol monoethyl ether acetate,
Methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl β-methoxyisobutyrate, ethyl butyrate, propyl butyrate, methyl isobutyl ketone, ethyl acetate, isoamyl acetate, ethyl lactate, toluene, xylene, cyclohexyl acetate, diacetone alcohol, N-
Methylpyrrolidone, N, N-dimethylformamide, γ
-Butyrolactone, N, N-dicylacetamide and the like.

These solvents are used alone or as a mixture. In addition, the selection of these solvents is important because it affects solubility in the composition, coatability to a substrate, storage stability, and the like, and water contained in the solvent also affects these performances and is possible. It is more preferable that the number is as small as possible. Further, the photosensitive composition of the present invention, when mixed with metal impurities such as metals and impurity components such as chlor ions,
When manufacturing a semiconductor device, an operation failure, a defect, and a decrease in yield occur, which is not preferable. For this reason, it is preferable to reduce the mixed concentration of these impurity components to 100 ppb or less.

The photosensitive composition prepared by satisfying the above-mentioned various conditions is coated on a substrate by a suitable coating means such as a spinner, a coater or the like, prebaked (pre-exposure heating), and passed through a predetermined mask to a wavelength of 220 nm or less. A good resist pattern can be obtained by exposing with the above exposure light, performing PEB (post-exposure bake), and developing. The substrate used here may be a substrate usually used in a semiconductor device or other manufacturing apparatus, and examples thereof include a silicon substrate, a glass substrate, and a non-magnetic ceramic substrate.

Further, if necessary, additional layers such as a silicon oxide layer, a metal layer for wiring,
An interlayer insulating film, a magnetic film, an antireflection film layer and the like may be present, and various wirings and circuits may be formed. Furthermore, these substrates may be subjected to a hydrophobic treatment according to a conventional method in order to enhance the adhesion of the resist film. Suitable hydrophobizing agents include, for example, 1,1,
1,3,3,3-hexamethyldisilazane (HMDS)
And the like.

The thickness of the resist applied on the substrate is preferably in the range of about 0.1 μm to 10 μm. In the case of ArF exposure, the thickness is preferably 0.1 μm to 1.5 μm. The resist film applied on the substrate is preferably pre-baked at a temperature of about 60 to 160 ° C. for about 30 to 300 seconds. If the pre-baking temperature is low and the time is short, the amount of residual solvent in the resist film becomes relatively large, and adverse effects such as deterioration of adhesion are caused, which is not preferable. On the other hand, if the prebaking temperature is high and the time is long, adverse effects such as decomposition of components such as the binder and the photoacid generator of the photosensitive composition occur, which is not preferable.

[0058] As apparatus for exposing a resist film after prebaking, a commercially available ultraviolet exposure apparatus, X-ray exposure apparatus, an electron beam exposure apparatus, KrF excimer exposure apparatus, ArF excimer exposure system, F ₂ excimer exposure device and the like are used Particularly, in the present invention, an apparatus using an ArF excimer laser as an exposure light source is preferable. The post-exposure bake is for the purpose of causing the elimination of the protecting group catalyzed by an acid or the purpose of eliminating the standing wave,
This is performed for the purpose of diffusing an acid generator or the like into the film. This post-exposure bake can be performed in the same manner as the previous pre-bake. For example, the baking temperature is about 60 to 160
° C, preferably about 90-150 ° C.

As the developer of the photosensitive composition of the present invention,
Sodium hydroxide, potassium hydroxide, sodium carbonate,
Inorganic alkalis such as sodium silicate and aqueous ammonia,
Primary amines such as ethylamine and n-propylamine;
Secondary amines such as diethylamine and di-n-butylamine; and tertiary amines such as triethylamine and methyldiethylamine.
Amines, alcoholamines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), trimethylhydroxymethylammonium hydroxide, triethylhydroxymethylammonium hydroxide, trimethylhydroxyethyl Quaternary ammonium salts such as ammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo- [5,
4,0] -7-undecene, 1,5-diazabicyclo-
An aqueous alkaline solution such as a cyclic amine such as [4,3,0] -5-nonane can be used.

Further, a suitable amount of a hydrophilic organic solvent such as alcohols or ketones, a nonionic or anionic surfactant, a cationic surfactant or an antifoaming agent may be added to the alkaline aqueous solution. Can be used. These additives not only improve the performance of the resist but also enhance the adhesion to the substrate, reduce the amount of the developing solution used, and reduce defects caused by bubbles during development. Play.

[0061]

The present invention will be described in more detail with reference to examples including synthesis examples, but the present invention is not limited thereto. Synthesis Example 1 Monomer a: Synthesis of diethyl α, α'-dimethylenepimelate Starting from tetraethyl 1,1,5,5-pentanetetracarboxylate, CSMarvel, et al .; J. Am. Ch.
79, 5771 (1957). Synthesis Example 2 Monomer b: Synthesis of dimethyl α, α'-dimethylenepimelate Starting from tetramethyl 1,1,5,5-pentanetetracarboxylate, CSMarvel, et al .; J. Am. Ch.
79, 5771 (1957). (B.p = 82 ° C.)

Synthesis Example 3 Monomer c: Synthesis of α, α′-dimethylenepimelic acid Diethyl α, α′-dimethylenepimelate obtained in Synthesis Example 1 was placed in an aqueous sodium hydroxide solution and stirred at room temperature for 36 hours. Neutralized with hydrochloric acid, cooled and the resulting powder was repeatedly recrystallized with water to obtain the desired product. Synthesis Example 4 Monomer d: Synthesis of di-t-butyl α, α′-dimethylenepimelate The tetraethyl 1,1,5,5-pentanetetracarboxylate of Synthesis Example 1 was converted to tetra-t-butyl 1,1, 5,
Other than changing to 5-pentanetetracarboxylate,
In the same manner as in Synthesis Example 1, monomer d was synthesized.

Synthesis Example 5 Monomer e: dimethyl α, α '
-Synthesis of dimethylene adipate acid It was synthesized according to the synthesis method described in CS Marvel, et al .; J. Am. Chem. Soc. Vol. 81, 984 (1959). Synthesis Example 6 Monomer f: Synthesis of α, α′-dimethyleneadipate Diethyl α, α′-dimethylenepimelate obtained in Synthesis Example 1 was placed in an aqueous sodium hydroxide solution, stirred at room temperature for 36 hours, and added with hydrochloric acid. Neutralized and cooled, the resulting powder was repeatedly recrystallized with water to obtain the desired product.

Synthesis Example 7 Synthesis of Polymer A (Invention) 3.2 g of monomer a and 2.0 g of monomer c were dissolved in 200 ml of ethanol, and 50 m of benzoyl peroxide was dissolved.
g was added and heated for 7 hours to reflux. After completion of the reaction, the reaction product was poured into water and crystallized. After dissolving with ethanol and crystallization with water twice about the obtained crystals, the crystallized product was filtered and dried under reduced pressure of 0.1 mmHg at 40 ° C. for 48 hours to obtain a polymer. 3 g of the obtained polymer was dissolved in 10 g of tetrahydrofuran, and 0.6 g of 3,4-dihydro-2H-pyran was used as a reaction reagent.
And coagulated using hexane to obtain a polymer A of the present invention. The weight average molecular weight determined by gel permeation chromatography was 7,980, and the degree of dispersion was 3.5.
Met.

Synthesis Example 8 Synthesis of Polymer B (Invention) 2.0 g of monomer b obtained in Synthesis Example 2 above, 0.7 g of monomer c obtained in Synthesis Example 3, and d2.
2 g was dissolved in 200 ml of ethanol, 50 mg of benzoyl peroxide was added, and the mixture was heated for 7 hours to reflux. After the completion of the reaction, the content was poured into water and crystallized. After repeating the dissolution of the crystals with ethanol and the crystallization with water twice, the obtained crystallized product was separated by filtration and dried at 40 ° C. for 48 hours to obtain a polymer B. The weight average molecular weight determined by gel permeation chromatography was 5,980, and the degree of dispersion was 3.0.

Synthesis Example 9 Synthesis of Polymer C (Invention) 1.8 g of monomer e, 1.0 g of monomer f, and 2.2 g of t-butyl methacrylate were dissolved in 200 ml of THF, 55 mg of benzoyl peroxide was added, and the mixture was heated for 7 hours. Then, it was refluxed. After the reaction, the contents were poured into water and crystallized. After two recrystallizations with water,
The crystallized product was filtered and dried at 40 ° C. under a reduced pressure of 0.1 mmHg for 48 hours to obtain a polymer C. The weight average molecular weight by gel permeation chromatography is 4980.
And the degree of dispersion was 2.8.

Synthesis Example 10 Synthesis of acid-decomposable low molecular weight compound a A mixture of 12.27 g (0.03 mol) of cholic acid and 12 ml of thionyl chloride was refluxed for 1 hour. Excess thionyl chloride is removed, the solid obtained is dissolved in 15 ml of tetrahydrofuran, 4 g (0.035 mol) of potassium tert-butoxide are slowly added, the reaction mixture is refluxed for 6 hours, cooled and then poured into water. did. The resulting solid was collected by filtration, washed with water and dried under reduced pressure.
The purified product was recrystallized from n-hexane to obtain tert-butyl cholate (the following formula) in a yield of 74%.

[0068]

Embedded image

Synthesis Example 11 Synthesis of Polymer D (Comparative Example) A copolymer of 1-cyclohexyl-3-carboxylic acid and t-butyl methacrylate was prepared according to the method described in Synthesis Example 1 disclosed in JP-A-9-325498. I got Synthesis Example 12 Synthesis of Polymer E (Comparative Example) A copolymer of norbornene dicarboxylic acid, t-butyl methacrylate and methyl acrylate was obtained by the method described in Synthesis Example 6 disclosed in JP-A-9-325498. Synthesis Example 13 Synthesis of Polymer F (Comparative Example) A polymer obtained by hydrogenating a ring-opening polymer of a norbornene derivative described in the fourth example disclosed in JP-A-9-244247 is referred to as E.
It was synthesized according to the method described in PO789278.

Example 1-4-A (Measurement of Optical Density) Polymers A to C obtained in Synthesis Examples 7, 8, and 9, Synthesis Example 10
Each of the acid-decomposable low-molecular compound a, the onium salt and the solvent obtained in the above was mixed and dissolved at the ratio shown in Table 1. Next, 0.1 (W / W)% of triethylamine was added to the solid content in the solution, and the fluorine-based surfactant F177 was used.
100 ppm of P (manufactured by Dainippon Ink and Chemicals, Inc.) was added and dissolved to prepare a resist solution. This was filtered through a 0.1 μm Teflon filter. This filtrate was uniformly applied on a quartz substrate using a spin coater,
Heat and dry on a hot plate for 0 seconds, 1.00 μm
Was formed. The optical absorption of this film was measured with an ultraviolet spectrophotometer. Table 2 shows the results. Each of the resists has an optical density at 193 nm of 0.5 or less, and the measured optical density of the resist using the resin of the present invention is smaller than the value of poly (hydroxystyrene) of Comparative Example 1 below. It was found to have sufficient permeability.

[0071]

[Table 1]

[0072]

[Table 2]

Example 1-4-B (Measurement of dry etching resistance) The photosensitive composition of the present invention of Example 1 in Table 1 was used in an amount of 0.1%.
The solution was filtered through a μm Teflon filter. The obtained filtrate was uniformly applied on a silicon substrate by using a spin coater, and dried by heating on a hot plate at 100 ° C. for 90 seconds to form a 0.70 μm resist film. The resist film formed above was subjected to CF _4/4 using a reactive ion etching apparatus (CSE-1110) manufactured by ULVAC.
The etching rate for O ₂ (8/2) gas was measured. The results are shown in Table-3. It has been found that the etching rate of the resist using the resin of the present invention is sufficiently smaller than the value of poly (methyl methacrylate) of Comparative Example 2 and has sufficient dry etching resistance.

[0074]

[Table 3]

Example 3 (Evaluation of Image) The photosensitive compositions of the present invention of Examples 1 to 4 in Table 1 were filtered with a 0.1 μm Teflon filter. This filtrate was uniformly coated on a silicon substrate treated with hexamethyldisilazane using a spin coater,
And dried on a hot plate for 90 seconds.
m of the resist film was formed. For this resist film,
Exposure to ArF excimer laser light through a mask, immediately after exposure, heating on a hot plate at 110 ° C. for 90 seconds, and development with a 2.38% aqueous tetramethylammonium hydroxide solution at 23 ° C. for 60 seconds, followed by pure water Rinsed for 30 seconds and dried.

The pattern obtained by the above treatment was observed with a scanning electron microscope, and the sensitivity, profile, critical resolution, and adhesion were examined. Table 4 shows the results. The sensitivity was represented by an exposure amount for reproducing a 0.3 μm mask pattern. The critical resolution was defined as the critical resolution at an exposure amount for reproducing a 0.3 μm mask pattern. The adhesion was examined for the adhesion of 30 dot patterns of 0.20 μm, and the number of peeling patterns was examined. As is evident from the results in Table 4, the resist composition using the resin of the present invention was excellent in sensitivity and resolution, and each had a rectangular profile formed. In addition, no peeling of the pattern was observed, and there was no problem in adhesion.

[0077]

[Table 4]

Comparative Example 1 Example 1-4 was repeated except that the polymer A of Example 1 was replaced with poly (hydroxystyrene) and a weight average molecular weight of 8,000.
A resist film was formed in the same manner as in -A. When the optical absorption of the obtained film was measured with an ultraviolet spectrophotometer, it was found to be 19
The optical density at 3 nm was 1.50 or more. Comparative Example 2 The polymer A of Example 1 was prepared by using poly (methyl methacrylate)
Example 1 was repeated except that the weight average molecular weight was changed to 12000.
A resist film was formed in the same manner as in -4-B, and the etching rate was measured. Etching rate is 1250 ° / min
Met.

Comparative Example 3 Using polymer D obtained in Synthesis Example 9, Example 1-4-B
A resist was prepared in the same manner as described above, and the dry etching resistance was examined. As shown in Table 3, the dry etching resistance was inferior to Examples 1-4 containing the resin of the present invention. When an image was evaluated using the polymer D in the same manner as described above, the resolution and adhesion of the resist were poor as shown in Table-4. Comparative Example 4 Using the polymer E obtained in Synthesis Example 11, Examples 1-4
A resist was prepared in the same manner as in -B, and the dry etching resistance was examined. As a result, as shown in Table 3, the dry etching resistance was inferior to Examples 1 to 4 containing the resin of the present invention. When an image was evaluated using the polymer E in the same manner as described above, the resolution and adhesion of the resist were poor.

Comparative Example 5 Using the polymer F obtained in Synthesis Example 12, Examples 1-4
A resist was prepared in the same manner as in -B, and the dry etching resistance was examined. The results are as shown in Table-4, although the dry etching resistance is superior as compared with Examples 1-4 containing the resin of the present invention as shown in Table-3. Thus, the resolution and adhesion of the resist were inferior.

[0081]

As is apparent from the above description, the positive photosensitive composition using the resin of the present invention has high transparency, particularly to far ultraviolet light of 220 nm or less.
And the dry etching resistance is good. In particular, when an ArF excimer laser beam is used as an exposure light source, it exhibits high sensitivity, high resolution, a good pattern profile, and excellent adhesion to a substrate. Therefore, it can be effectively used for forming a fine pattern required for manufacturing a semiconductor element, and the contribution to this kind of technology is extremely large.

Claims (4)

[Claims] 1. A compound which (A) generates an acid upon irradiation with actinic rays or radiation and (B) a divalent polycyclic alicyclic unit represented by the following general formula (I): A positive photosensitive composition comprising a resin having a main chain. Embedded image In (the general formula (I), X represents an oxygen atom, a sulfur _{atom, -NH -, - NHSO 2 -} .R 1, R 2 representing a divalent linking group selected from each independently represent a hydrogen atom, An alkyl group, a substituted alkyl group, a cyclic alkyl group, a substituted cyclic alkyl group, a group which decomposes under the action of an acid, or -YR ₃
Represents a group. Y is a single bond, an alkylene group, a substituted alkylene group, an ether group, a carbonyl group, an ester group, an amide group, or a divalent group obtained by combining two or more groups selected from the group consisting of a sulfonamide group. Represent. R ₃
Represents —COOH, —COOR ₄ , an alkoxy group, or a substituted alkoxy group. R ₄ is an alkyl group, a substituted alkyl group,
Represents a cyclic alkyl group or a substituted cyclic alkyl group. n represents 2 or 3. ) 2. The positive photosensitive composition according to claim 1, wherein the resin is synthesized by a cyclopolymerization method, and has a group that is decomposed by the action of an acid. 3. A compound having a group decomposable by the action of an acid and having a molecular weight of 100, whose alkali solubility is increased by the action of an acid.
The positive photosensitive composition according to claim 1, further comprising 0 or less of a low-molecular acid-decomposable dissolution inhibiting compound. 4. The positive photosensitive composition according to claim 1, wherein a far ultraviolet light having a wavelength of 220 nm or less is used as an exposure light source.