JP2000347410A - Positive type photosensitive composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a positive type photosensitive composition having good sensitivity, resolution and adhesion, giving a good resist pattern and exhibiting satisfactory dry etching resistance by incorporating a compound which generates an acid when irradiated with active light or radiation and a specified resin. SOLUTION: The photosensitive composition contains a compound which generates an acid when irradiated with active light or radiation and a resin having repeating structural units containing two or more hydroxyl substituted aliphatic groups and having a group which is decomposed by the action of the acid and increases the solubility of the resin in an alkali developing solution. The resin has repeating structural units of the formula, wherein R1 is H or a 1-8C alkyl, R2-R6 are mutually the same or different and each H, a halogen, 1-8C linear or branched alkyl or 3-7C cyclic alkyl, (n) is 0 or 1 and X is a combining group containing linear, branched or cyclic alkylene, -CO-, -COO-, -O-, -S- or two or more of these.

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. . More specifically, the present invention relates to a positive-type photosensitive composition suitable for using far ultraviolet rays having a wavelength of 250 nm or less as an exposure light source.

[0002]

2. Description of the Related Art When a conventional resist comprising a novolak and a naphthoquinonediazide compound is used for lithographic pattern formation using far ultraviolet light or excimer laser light, novolak and naphthoquinonediazide have a strong absorption in the far ultraviolet region. Light hardly reaches the bottom of the resist, and only a low-sensitivity, tapered pattern can be obtained.

One of the means for solving such a problem is as follows.
U.S. Pat. No. 4,491,628, EP 249,1
No. 39 or the like. The chemically amplified positive resist composition generates an acid in the exposed portion by irradiation with radiation such as far ultraviolet light, and the reaction using the acid as a catalyst dissolves the active radiation-irradiated portion and the non-irradiated portion in the developing solution. It is a pattern forming material that changes the properties and forms a pattern on a substrate.

Examples of such a combination include a combination of a compound capable of generating an acid by photolysis with an acetal or an O, N-acetal compound (Japanese Patent Laid-Open No. 48-89003), a combination of an orthoester or an amide acetal compound. (JP-A-51-120714), combination with a polymer having an acetal or ketal group in the main chain (JP-A-53-133429), combination with an enol ether compound (JP-A-55-12995) ), A combination with an N-acyliminocarbonate compound
126236), a combination with a polymer having an orthoester group in the main chain (JP-A-56-17345), a combination with a tertiary alkyl ester compound (JP-A-60-3625), a silyl ester Combination with a compound (JP-A-60-10247) and combination with a silyl ether compound (JP-A-60-37549)
And JP-A-60-112446). These have high photosensitivity because the quantum yield exceeds 1 in principle.

[0005] Similarly, a system which is decomposed by heating in the presence of an acid and solubilized in an alkali is disclosed in, for example,
-45439, JP-A-60-3625, JP-A-62
JP-A-229242, JP-A-63-27829, JP-A-63-36240, JP-A-63-250642, JP-A-5-181279, Polym.Eng.Sce., 23
Volume, 1012 (1983); ACS. Sym. 242, 11 (1984); S
emiconductor World 1987, November, p. 91; Macromole
cules, 21: 1475 (1988); SPIE, 920: 42 (198
8) and the like, a combination of a compound capable of generating an acid upon exposure to light and an ester or carbonate compound of a tertiary or secondary carbon (for example, t-butyl or 2-cyclohexenyl); No. 219775, 5-249682
And combinations with acetal compounds described in JP-A Nos. 6-65332 and 6-65232.
Nos. 8 and 6-65333, t.
And a combination system with a butyl ether compound.

Since these systems mainly use a resin having a poly (hydroxystyrene) basic skeleton having a small absorption in a 248 nm region as a main component, a high sensitivity is obtained when a KrF excimer laser is used as an exposure light source. A high-resolution and good pattern can be formed, and it can be a good system as compared with the conventional naphthoquinonediazide / novolak resin system.

However, when a light source having a shorter wavelength, for example, an ArF excimer laser (193 nm) is used as an exposure light source, the compound having an aromatic group essentially exhibits a large absorption in the 193 nm region. The system was not enough. Further, as a polymer having a small absorption in a wavelength region of 193 nm, the use of poly (meth) acrylate is described in J. Vac. Sci. Technol., B9, 3357 (199).
As described in 1), this polymer is generally resistant to dry etching performed in the semiconductor manufacturing process.
There was a problem that it was lower than that of a conventional phenol resin having an aromatic group.

On the other hand, the polymer having an alicyclic hydrocarbon group exhibits the same dry etching resistance as an aromatic group and has a small absorption in the 193 nm region.
SPIE, 1672, 66 (1992). In recent years, the use of this polymer has been vigorously studied. Specifically, JP-A-4-39665, JP-A-5-80515, and 5-2
No. 65212, No. 5-297591, No. 5-3466
No. 68, No. 6-289615, No. 6-324494
No. 7-49568, No. 7-185046, No. 7
191463, 7-199467, 7-23
Polymers described in JP-A Nos. 4511 and 7-252324 are exemplified. However, these polymers do not always have sufficient dry etching resistance,
Even though the dry etching resistance is good, film peeling due to insufficient adhesion to the substrate occurs, but the acid decomposability is insufficient, and the exposed discrimination-unexposed part dissolution discrimination is small,
As a result, the resolution was low.

Japanese Patent Application Laid-Open No. 10-83076 describes a resin having a hydroxyl group in a repeating structure in order to improve adhesion to a substrate. However, this resin has insufficient hydrophilicity. Although the sensitivity is low and the adhesion is improved when resolving a large pattern, the adhesion is insufficient when resolving a fine pattern, and there is a problem that film peeling occurs. Was.

[0010]

SUMMARY OF THE INVENTION The object of the present invention is to
An object of the present invention is to provide a positive photosensitive composition suitable for use with an exposure light source of 0 nm or less, particularly 220 nm or less. Another object of the present invention is to provide a positive photosensitive composition which gives good sensitivity, resolution, adhesion and a resist pattern when using an exposure light source having a wavelength of 250 nm or less, particularly 220 nm or less, and further exhibits a sufficient dry etching resistance. Is to provide.

[0011]

According to the present invention, the following positive photosensitive composition is provided to achieve the above object of the present invention.

(1) (A) a compound capable of generating an acid upon irradiation with actinic rays or radiation; and (B) a repeating structural unit containing two or more aliphatic groups substituted by a hydroxyl group, and A positive photosensitive composition containing a resin having a group which is decomposed by an action and acts to increase the solubility of the resin in an alkaline developer. (2) The repeating unit containing two or more aliphatic groups substituted with a hydroxyl group in the above (B), wherein the repeating unit contains at least one of a 1,2-diol structure and a 1,3-diol structure. The positive photosensitive resin composition according to the above (1), which is a structural unit. (3) The resin according to (1), wherein the resin (B) has a repeating structural unit represented by the following general formula (I).
Or the positive photosensitive composition according to (2).

[0013]

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In the general formula (I), R ₁ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. R _{2 to} R ₆ are the same or different and represent a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, or a cyclic alkyl group having 3 to 7 carbon atoms. These alkyl groups may be substituted with a hydroxyl group, an alkoxy group or a carboxyl group.
Further, two or more of R _{2 to} R ₆ may combine to form a single ring. n is 0 or 1. X is linear,
Branched or cyclic alkylene group, -CO-, -CO
O-, -O-, -S-, or a linking group containing a plurality of these. (4) The resin according to (1) to (1), wherein the resin (B) has at least one of a 1,2-diol structure and a 1,3-diol structure and an alicyclic hydrocarbon structure.
The positive photosensitive composition according to (3). (5) Further, (C) a molecular weight of 3000 having a group which is decomposed by the action of an acid to increase the solubility in an alkali developer.
The positive photosensitive composition according to any one of the above (1) to (4), comprising the following low molecular compound. (6) The positive photosensitive composition as described in any of (1) to (5) above, wherein far-ultraviolet light having a wavelength of 250 nm or less is used as an exposure light source. (7) The positive photosensitive composition as described in (6) above, wherein far-ultraviolet light having a wavelength of 220 nm or less is used as an exposure light source.

By introducing two or more hydroxyl groups into one repeating unit, high hydrophilicity can be obtained and high sensitivity can be achieved. Further, even if the amount of the alicyclic monomer having high hydrophobicity is increased in order to improve dry etching resistance, high hydrophilicity is maintained, and the film is not peeled off due to little decrease in sensitivity and deterioration in adhesion. Further, development defects are small due to high hydrophilicity. Further, a 1,2-diol structure having a hydroxyl group on an adjacent carbon, or a 1,3-diol structure has a higher hydrophilicity than a non-adjacent diol due to a synergistic effect of two adjacent hydroxyl groups, Demonstrate better effects.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the positive photosensitive composition of the present invention will be described in detail. First, (A) a compound that generates an acid upon irradiation with actinic rays or radiation (photoacid generator) will be described. The photoacid generator used in the present invention is a compound that generates an acid upon irradiation with actinic rays or radiation. Examples of the compound used in the present invention, which decomposes 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, and a photodiscoloration agent. Known light (ultraviolet light of 400 to 200 nm, far ultraviolet light, particularly preferably g-ray, h-ray, i-ray, KrF excimer laser light), ArF excimer laser light, electron beam , An X-ray, a molecular beam or an ion beam to generate an acid and a mixture thereof can be appropriately selected and used.

Other compounds which generate an acid upon irradiation with actinic rays or radiation used in the present invention include, for example, diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, arsonium salts and the like. Onium salts, organic halogen compounds, organometallic / organic halides, photoacid generators having an o-nitrobenzyl-type protecting group, compounds that generate sulfonic acid by photolysis represented by iminosulfonate, disulfone compounds , Diazoketosulfone and diazodisulfone compounds. Further, a group in which an acid is generated by such light or a compound in which a compound is introduced into a main chain or a side chain of a polymer can be used.

Further, VNRPillai, Synthesis, (1), 1 (198
0), A. Abad etal, Tetrahedron Lett., (47) 4555 (1971),
Compounds that generate an acid by light described in DHR Barton et al., J. Chem. Soc., (C), 329 (1970), U.S. Pat. No. 3,779,778, and EP 126,712 can also be used.

Among the compounds capable of decomposing upon irradiation with actinic rays or radiation to generate an acid, those which are used particularly effectively are described below. (1) The following general formula (PAG) substituted with a trihalomethyl group
The oxazole derivative represented by 1) or the general formula (PAG)
An S-triazine derivative represented by 2).

[0020]

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In the formula, R ²⁰¹ is a substituted or unsubstituted aryl group or alkenyl group, and R ²⁰² is a substituted or unsubstituted aryl group, alkenyl group, alkyl group, —C (Y) ₃
Is shown. Y represents a chlorine atom or a bromine atom. Specific examples include the following compounds, but the present invention is not limited thereto.

[0022]

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[0023]

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[0024]

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(2) An iodonium salt represented by the following formula (PAG3) or a sulfonium salt represented by the following formula (PAG4).

[0026]

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Here, the formulas Ar ¹ and Ar ² are the same or different and each represents a substituted or unsubstituted aryl group. Preferred substituents include an alkyl group, a haloalkyl group, a cycloalkyl group, an aryl group, an alkoxy group, a nitro group, a carboxyl group, an alkoxycarbonyl group, a hydroxy group, a mercapto group, and a halogen atom.

R ²⁰³ , R ²⁰⁴ and R ²⁰⁵ are the same or different and each represents a substituted or unsubstituted alkyl group or aryl group. Preferably, they are an aryl group having 6 to 14 carbon atoms, an alkyl group having 1 to 8 carbon atoms, and substituted derivatives thereof.
Preferred substituents are an alkoxy group having 1 to 8 carbon atoms, an alkyl group having 1 to 8 carbon atoms, a nitro group, a carboxyl group, a hydroxy group and a halogen atom for the aryl group, and a substituent for the alkyl group. It is an alkoxy group having 1 to 8 carbon atoms, a carboxyl group, or an alkoxycarbonyl group.

[0029] Z ^- represents a counter anion, for example BF ₄ ^{-,
_{AsF 6 -, PF 6 -,}} SbF 6 -, SiF 6 2-, ClO 4 -,
Alkanesulfonic acid which may be substituted, perfluoroalkanesulfonic acid, benzenesulfonic acid which may be substituted, naphthalenesulfonic acid, anthracenesulfonic acid,
Examples include but are not limited to camphor sulfonic acid. Preferred are alkanesulfonic acid, perfluoroalkanesulfonic acid, alkyl-substituted benzenesulfonic acid, and pentafluorobenzenesulfonic acid.

Further, two of R ²⁰³ , R ²⁰⁴ and R ²⁰⁵ and Ar ¹ and Ar ² may be bonded through a single bond or a substituent.

Specific examples include the following compounds, but are not limited thereto.

[0032]

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[0033]

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[0034]

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[0035]

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[0036]

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[0037]

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[0038]

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[0039]

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[0040]

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[0041]

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[0042]

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The above onium salts represented by the general formulas (PAG3) and (PAG4) are known, for example, JWKnapczyk
etal, J. Am. Chem. Soc., 91, 145 (1969), ALMaycok eta
l, J. Org. Chem., 35, 2532, (1970), E. Goethas et al., Bul
l.Soc.Chem.Belg., 73,546, (1964), HM Leicester, JA
me.Chem.Soc., 51,3587 (1929), JVCrivello etal, J.Po
Chem. Ed., 18,2677 (1980), U.S. Pat. Nos. 2,807,648 and 4,247,473, and JP-A-53-101,331.

(3) Disulfone derivatives represented by the following formula (PAG5) or iminosulfonate derivatives represented by the following formula (PAG6).

[0045]

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In the formula, Ar ³ and Ar ⁴ are the same or different and each represents a substituted or unsubstituted aryl group. R ²⁰⁶ represents a substituted or unsubstituted alkyl group or aryl group.
A represents a substituted or unsubstituted alkylene group, alkenylene group, or arylene group. Specific examples include the following compounds, but are not limited thereto.

[0047]

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[0048]

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[0049]

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[0050]

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[0051]

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[0052]

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(4) A diazodisulfone derivative represented by the following general formula (PAG7).

[0054]

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Here, R represents a linear, branched or cyclic alkyl group or an optionally substituted aryl group. Specific examples include the following compounds,
It is not limited to these.

[0056]

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The amount of the compound capable of decomposing upon irradiation with actinic rays or radiation to generate an acid is usually 0.03 to the solid content of the whole positive photosensitive composition of the present invention.
It is used in the range of 0.01 to 40% by weight, preferably 0.0
It is used in an amount of 1 to 20% by weight, more preferably 0.1 to 5% by weight. 0.001% by weight of a compound that is decomposed by irradiation with actinic rays or radiation to generate an acid.
If the amount is smaller, the sensitivity is lowered, and the addition amount is 40% by weight.
If it is larger, the light absorption of the resist becomes too high, and the profile is deteriorated and the process (especially, baking) margin is undesirably reduced.

Next, (B) a repeating unit having two or more aliphatic groups substituted by a hydroxyl group according to the present invention, preferably containing at least one of a 1,2-diol structure and a 1,3-diol structure A resin having a structural unit and having a group which is decomposed by the action of an acid and acts to increase the solubility of the resin in an alkaline developer (hereinafter, simply referred to as “(B) resin of the present invention” or “(B ) The acid-decomposable resin of the present invention) is also described.

(B) The resin of the present invention has at least two aliphatic groups substituted with hydroxyl groups, preferably at least one of a 1,2-diol structure and a 1,3-diol structure, Any resin can be used as long as it has a group which is decomposed by the action of and acts so as to increase the solubility of the resin in an alkaline developer. A group that is decomposed by the action of an acid and acts so as to increase the solubility of the resin in an alkaline developer is hereinafter simply referred to as an “acid-decomposable group”. (B) In the resin of the present invention, any of primary, secondary and tertiary hydroxyl groups can be used. However, since the tertiary hydroxyl group decreases the hydrophilicity of the hydroxyl group due to steric hindrance, 1 It preferably has one or more primary or secondary hydroxyl groups. More preferably, all the hydroxyl groups in the repeating unit are primary or secondary hydroxyl groups. In addition, the resin of the present invention preferably contains a repeating structural unit represented by the general formula (I). The repeating structural unit represented by the general formula (I) preferably has the above diol structure. It is further preferable that the resin has a monocyclic and / or polycyclic alicyclic hydrocarbon structure in order to improve dry etching resistance.
This monocyclic or polycyclic alicyclic hydrocarbon structure may be present in a repeating structural unit having a 1,2-diol structure and / or a 1,3-diol structure, or may be used as another copolymer component. It may be present in a repeating structural unit. In addition, from the viewpoint of hydrophilicity and production cost, it is preferable that it is present in another repeating structural unit as a copolymer component.

(B) In the resin of the present invention, the acid-decomposable group is present in an aliphatic group substituted with a hydroxyl group or in a repeating structural unit having a 1,2-diol structure and / or a 1,3-diol structure. Or may have a repeating structural unit having a monocyclic or polycyclic alicyclic hydrocarbon structure,
It may be present in the repeating structural unit or may be present in another repeating structural unit as a further copolymer component.

In formula (I), the number of carbon atoms in R ₁ is 1
Specific examples of the alkyl group of to 8 include methyl, ethyl,
n-propyl, iso-propyl, n-butyl, iso
-Butyl, sec-butyl, t-butyl and the like. Of these, methyl is preferred. Specific examples of the linear or branched alkyl group having 1 to 8 carbon atoms in R _{2 to} R ₆ include the same as the specific examples of the alkyl group of R ₁ . Examples of the cyclic alkyl group having 3 to 7 carbon atoms include cyclopropanyl, cyclobutanyl, cyclopentyl, cyclohexyl, and the like. R ₂
These alkyl groups to R ₆ may be substituted with a hydroxyl group, an alkoxy group or a carboxyl group. The alkoxy group preferably has 1 to 8 carbon atoms, and specific examples include methoxy, ethoxy, n-propoxy, iso-propoxy, cyclohexyloxy, n-octyloxy and the like. Examples of the halogen atom in R _{2 to} R ₆ include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and among them, a chlorine atom and a bromine atom are preferable.

Further, two or more of R _{2 to} R ₆ may combine to form a single ring. As the monocyclic ring, a 3- to 7-membered ring is preferable, and specifically, cyclohexyl, cyclopentyl,
Cyclobutanyl, cyclopropyl and the like can be mentioned.

X represents a linear, branched, or cyclic alkylene group, -CO-, -COO-, -O-, -S-, or a linking group containing a plurality thereof. Among them, an alkyne group is preferable. As the alkylene group, preferably methylene, which may have a substituent,
Examples thereof include those having 1 to 8 carbon atoms such as ethylene, propylene, butylene, hexylene, and octylene. The cyclic alkylene group preferably has 5 carbon atoms such as cyclopentylene and cyclohexylene which may have a substituent.
To 8 are mentioned. Preferred substituents on the alkylene group include a halogen atom, an alkoxy group, a hydroxyl group, a nitro group, a cyano group, a carboxy group and the like.

Preferred specific examples of the repeating structural unit represented by formula (I) are shown below, but it should not be construed that the invention is limited thereto.

[0065]

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(B) The content of the repeating structural unit having the structure represented by the above general formula (I) in the resin of the present invention is adjusted by the balance between dry etching resistance, alkali developability and the like. , 5 mol% or more, preferably 10 to 70 mol%, more preferably 20 to 60 mol%, based on all repeating structural units.
Range.

As described above, the acid-decomposable group in the present invention is a group which is decomposed by the action of an acid to increase the solubility in an alkaline developer. Examples of the acid-decomposable group include a group which is hydrolyzed by the action of an acid to form an acid, and a group which forms an acid by the elimination of a carbon cation by the action of an acid. Preferred are groups represented by the following formulas (XIII) and (XIV). Thereby, the stability over time becomes excellent.

[0068]

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Here, R₄₇~ R₄₉Are the same or different
An alkyl which may have a hydrogen atom or a substituent
Group, cycloalkyl group, or alkenyl group
You. However, R in the formula (XIII)₄₇~ R₄₉At least one of
One is a group other than a hydrogen atom. R ₅₀Has a substituent
Alkyl, cycloalkyl or alkenyl
Represents a hydroxyl group. In addition, R of the formula (XIII)₄₇~ R₄₉Two of the
Or R of the formula (XIV)₄₇~ R₄₈, R₅₀Two of the groups are bonded
To form a ring structure consisting of 3 to 8 carbon atoms and heteroatoms
It may be formed. Specifically, such rings are
Lopropyl group, cyclopentyl group, cyclohexyl group,
Cycloheptyl group, 1-cyclohexenyl group, 2-tetra
Lahydrofuranyl group, 2-tetrahydropyranyl group, etc.
No. Z₁~ Z_TwoAre the same or different
Represents a sulfur atom or a sulfur atom. As the alkyl group, preferred are
Preferably a methyl group, an ethyl group which may have a substituent
Group, propyl group, n-butyl group, sec-butyl group,
Such as xyl group, 2-ethylhexyl group, octyl group
Those having 1 to 8 carbon atoms are exemplified. The above cycloalkyl
As the alkyl group, which may have preferably a substituent,
Cyclopropyl group, cyclopentyl group, cyclohexyl
Examples thereof include those having 3 to 8 carbon atoms such as a group. Above
The alkenyl group preferably has a substituent
Good, vinyl, propenyl, allyl, butenyl
Group, pentenyl group, hexenyl group, cyclohexenyl group
And those having 2 to 6 carbon atoms such as

Further, as the further substituent in each of the above substituents, a hydroxyl group, a halogen atom (fluorine,
Chlorine, bromine, iodine), nitro group, cyano group, amide group, sulfonamide group, alkyl group, methoxy group, ethoxy group, hydroxyethoxy group, propoxy group, hydroxypropoxy group, alkoxy group such as butoxy group, methoxycarbonyl group And alkoxycarbonyl groups such as ethoxycarbonyl group; acyl groups such as formyl group, acetyl group and benzoyl group; acyloxy groups such as acetoxy group and butyryloxy group; and carboxy groups.

(B) The acid-decomposable resin of the present invention can further contain the following acid-decomposable group-containing repeating structural unit.

[0072]

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[0073]

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[0074]

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[0075]

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As described above, (B) the resin of the present invention
It is preferable to have a monocyclic and / or polycyclic alicyclic hydrocarbon structure in order to improve dry etching resistance. The monocyclic hydrocarbon structure is preferably an alicyclic group such as cyclopropane, cyclobutane, cyclopentane, cyclohexane or the like which may have a substituent and having 3 or more carbon atoms, and more preferably has a substituent. It is an alicyclic group having 3 to 8 carbon atoms which may be substituted. The polycyclic hydrocarbon structure is preferably an alicyclic group such as bicyclo, tricyclo, tetracyclo or the like having 5 or more carbon atoms which may have a substituent,
More preferably, it may have 6 to 3 carbon atoms which may have a substituent.
It is 0, more preferably a polycyclic alicyclic group having 7 to 25 carbon atoms which may have a substituent. Preferred substituents of the monocyclic or polycyclic alicyclic group include a hydroxyl group,
Halogen atom (fluorine, chlorine, bromine, iodine), nitro group, cyano group, amide group, sulfonamide group, alkyl group, methoxy group, ethoxy group, hydroxyethoxy group,
An alkoxy group having 1 to 8 carbon atoms such as a propoxy group, a hydroxypropoxy group, a butoxy group, an alkoxycarbonyl group such as a methoxycarbonyl group and an ethoxycarbonyl group, an acyl group such as a formyl group, an acetyl group and a benzoyl group, an acetoxy group and a butyryloxy group And an acyloxy group such as a group and a carboxy group. Note that the substituent may be an acid-decomposable group.

Representative examples of the above monocyclic or polycyclic alicyclic hydrocarbon structures include the following.

[0078]

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[0079]

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Representative examples of the repeating structural unit having an alicyclic hydrocarbon structure are shown below, but are not limited thereto.

[0081]

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[0082]

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[0083]

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[0084]

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[0085]

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[0086]

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[0087]

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[0088]

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These repeating structural units having an alicyclic hydrocarbon structure may be used alone or in combination of two or more kinds in the resin of the present invention (B). The content of the repeating structural unit having an alicyclic hydrocarbon structure is preferably from 20 to 80 mol%, more preferably from 30 to 70 mol%, of the total repeating structural units of the resin (B) of the present invention.

(B) The resin of the present invention may further contain a carboxyl group. The carboxyl group may be contained in a repeating structural unit having a group represented by the above general formula (I), or may be contained in another repeating structural unit other than these. Furthermore, these structural units may be included in a plurality of positions.

The content of all the repeating structural units having a carboxyl group in the positive photosensitive composition of the present invention is adjusted by the performance such as alkali developability, substrate adhesion, and sensitivity. It is preferably in the range of 0 to 60 mol%, more preferably 0 to 40 mol%, and still more preferably 0 to 20 mol%, based on the unit.
Specific examples of the repeating structural unit having a carboxyl group are shown below, but the present invention is not limited thereto.

[0092]

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[0093]

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(B) For the purpose of improving the performance of the resin of the present invention, another polymerizable monomer may be further copolymerized within a range that does not significantly impair the transmittance of the resin of 220 nm or less and the dry etching resistance. Good. Copolymerizable monomers that can be used include those shown below.
For example, it has one addition-polymerizable unsaturated bond selected from acrylates, acrylamides, methacrylates, methacrylamides, allyl compounds, vinyl ethers, vinyl esters, styrenes, crotonates, and the like. Compound.

Specifically, for example, acrylic esters such as alkyl (the alkyl group has 1 to 1 carbon atoms)
Acrylates (eg, methyl acrylate, ethyl acrylate, propyl acrylate, t-butyl acrylate, amyl acrylate, cyclohexyl acrylate, ethylhexyl acrylate, octyl acrylate, tert-octyl acrylate) , Chloroethyl acrylate, 2-hydroxyethyl acrylate 2,2
-Dimethylhydroxypropyl acrylate, 5-hydroxypentyl acrylate, trimethylolpropane monoacrylate, pentaerythritol monoacrylate, glycidyl acrylate, benzyl acrylate, methoxybenzyl acrylate, furfuryl acrylate, tetrahydrofurfuryl acrylate, etc.), aryl acrylate, methoxyethoxyethyl Acrylate;

Methacrylic esters such as alkyl (preferably having 1 to 10 carbon atoms in the alkyl group) methacrylate (eg, methyl methacrylate,
Ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, t-butyl methacrylate,
Amyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate,
Octyl methacrylate, 2-hydroxyethyl methacrylate, 4-hydroxybutyl methacrylate, 5-
Hydroxypentyl methacrylate, 2,2-dimethyl-3-hydroxypropyl methacrylate, trimethylolpropane monomethacrylate, pentaerythritol monomethacrylate, glycidyl methacrylate, furfuryl methacrylate, tetrahydrofurfuryl methacrylate, etc.), aryl methacrylate (for example, phenyl methacrylate, naphthyl) Methacrylate),
Methoxyethoxyethyl methacrylate; acrylamides, for example, acrylamide, N-alkylacrylamide, (the alkyl group having 1 to 10 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, a butyl group, a t-butyl group , Heptyl, octyl, cyclohexyl, benzyl, hydroxyethyl, benzyl, etc.), N-arylacrylamide,
N-dialkylacrylamide (as the alkyl group,
Examples thereof include those having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, a butyl group, an isobutyl group, an ethylhexyl group, and a cyclohexyl group. ), N, N-arylacrylamide, N-hydroxyethyl-N-methylacrylamide, N-2-acetamidoethyl-N-acetylacrylamide and the like; methacrylamides, for example, methacrylamide, N-alkylmethacrylamide (as an alkyl group) Has 1 to 10 carbon atoms, for example, a methyl group, an ethyl group, a t-butyl group, an ethylhexyl group, a hydroxyethyl group, a cyclohexyl group, etc.), N-
Aryl methacrylamide, N, N-dialkyl methacrylamide (alkyl groups include ethyl group, propyl group, butyl group, etc.), N-hydroxyethyl-N
-Methyl methacrylamide, N-methyl-N-phenyl methacrylamide, N-ethyl-N-phenyl methacrylamide and the like; allyl compounds such as allyl esters (for example, allyl acetate, allyl caproate, allyl caprylate, lauric acid) Allyl, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate,
Allyl lactate, etc.), allyloxyethanol, etc .;

Crotonic esters, for example, alkyl crotonates (for example, butyl crotonate, hexyl crotonate, glycerin monocrotonate, etc.); dialkyl itaconates (for example, dimethyl itaconate, diethyl itaconate, dibutyl itaconate, etc.) And dialkyl esters of maleic acid or fumaric acid (eg, dimethyl maleate, dibutyl fumarate, etc.), maleic anhydride, maleimide, acrylonitrile, methacrylonitrile, maleile nitrile, and the like. In addition, generally, any addition-polymerizable unsaturated compound that can be copolymerized may be used.

Among them, methoxyethoxyethyl methacrylate and methoxyethoxyethyl acrylate are particularly preferred. (B) The content of the repeating structural unit derived from another polymerizable monomer in the resin of the present invention is preferably 50 mol% or less based on all repeating structural units.
It is more preferably at most 30 mol%.

From the viewpoint of ensuring transparency to far ultraviolet rays, it is preferred that the resin of the present invention does not contain an aromatic ring. This is because if the transparency to far ultraviolet rays is reduced by the introduction of the aromatic ring, the exposure light hardly reaches the bottom of the resist film, resulting in a pattern profile called taper.

The positive photosensitive composition of the present invention comprises (C) a low molecular weight compound having a group which is decomposed by the action of an acid to increase the solubility in an alkaline developer and has a molecular weight of 3000 or less (hereinafter, referred to as “C”). "(C) Acid-decomposable dissolution inhibiting compound")
Is preferable. In particular, Proceeding of SPIE, 2724, 35
5 (1996), alicyclic or aliphatic compounds such as the cholic acid derivative are preferred as (C) acid-decomposable dissolution inhibiting compounds. (C) The amount of the acid-decomposable dissolution-inhibiting compound to be added is preferably 3 to 50% by weight, more preferably 5 to 4% by weight, based on the solid content of the whole positive photosensitive composition.
0% by weight, more preferably 10 to 35% by weight. Specific examples of the acid-decomposable dissolution inhibiting compound (C) are shown below.
It is not limited to these.

[0101]

Embedded image

(B) A repeating unit containing two or more aliphatic groups substituted by a hydroxyl group, preferably a repeating unit containing at least one of a 1,2-diol structure and a 1,3-diol structure And a resin having a group that is decomposed by the action of an acid and acts so as to increase the solubility of the resin in an alkali developer, has these structures, radicals of an unsaturated monomer having the group, a cation,
Alternatively, it is synthesized by anionic polymerization. More specifically, each monomer is blended based on the preferred composition described above, a polymerization catalyst is added in a suitable solvent at a monomer concentration of about 10 to 40% by weight, and the mixture is heated and polymerized as necessary. Synthesized.

(B) The molecular weight of the resin of the present invention is measured by a GPC method, and is preferably 2,000 or more, more preferably 3,000 to 1,000, in weight average (Mw: polystyrene standard).
1,000,000, more preferably 3,000-20
000, particularly preferably 4,000 to 100,00
It is in the range of 0, and as the value is larger, the heat resistance and the like are improved, while the developability and the like are reduced. The balance is adjusted to a preferable range. The degree of dispersion (Mw / Mn) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0.
0, and the smaller the value, the better the heat resistance and image performance (pattern profile, defocus latitude, etc.). In the positive photosensitive composition of the present invention, the amount of the resin added is 50 to 99.7% by weight, preferably 70 to 99% by weight, based on the total solid content.

The positive photosensitive composition of the present invention preferably contains a surfactant. Specifically, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether,
Polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether; polyoxyethylene alkyl allyl ethers such as polyoxyethylene octyl phenol ether and polyoxyethylene nonyl phenol ether; polyoxyethylene / polyoxypropylene block copolymers; sorbitan monolaurate ,
Sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, sorbitan tristearate and other sorbitan fatty acid esters, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxy Nonionic surfactants such as polyoxyethylene sorbitan fatty acid esters such as ethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate; F-Top EF301, EF303;
EF352 (manufactured by Shin-Akita Chemical Co., Ltd.), MegaFac F1
71, F173, F176, F189, R08 (manufactured by Dainippon Ink Co., Ltd.), Florad FC430, FC431
(Manufactured by Sumitomo 3M Limited), Asahi Guard AG71
0, Surflon S-382, SC101, SC102,
Fluorinated surfactants such as SC103, SC104, SC105, SC106 (manufactured by Asahi Glass Co., Ltd.), organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), and acrylic or methacrylic (co) polymerized polyflow No. 75, no. 95 (manufactured by Kyoeisha Yushi Kagaku Kogyo KK) and Troysol S-366 (manufactured by Troy Chemical Co., Ltd.). Among these surfactants, a fluorine-based or silicon-based surfactant is preferred from the viewpoints of coating properties and reducing development defects. The amount of the surfactant is usually 0.0001% by weight to 2% by weight, preferably 0.001% by weight, based on the solid content of the whole composition in the composition of the present invention.
% By weight to 1% by weight. These surfactants can be used alone or in combination of two or more.

The positive photosensitive composition of the present invention may further contain, if necessary, an acid-decomposable dissolution promoting compound, a dye, a plasticizer, a surfactant, a photosensitizer, an organic basic compound, and a developer. A compound that promotes solubility, an aliphatic carboxylic acid, and the like can be contained. Examples of the compound capable of accelerating dissolution in a developer that can be used in the present invention include phenolic OH.
It is a low molecular weight compound having a molecular weight of 1,000 or less and having two or more groups or one or more carboxy groups. When the compound has a carboxy group, an alicyclic or aliphatic compound is preferable for the same reason as described above. The preferred addition amount of these dissolution promoting compounds is (B) 2 to 50% by weight, more preferably 5 to 30% by weight, based on the resin of the present invention. An addition amount exceeding 50% by weight is not preferable because new development defects such as development residue deterioration and pattern deformation during development occur.

Such a phenol compound having a molecular weight of 1,000 or less can be prepared by, for example, referring to the methods described in JP-A-4-122938, JP-A-2-28531, US Pat. No. 4,916,210, EP 219294, and the like. ,
Those skilled in the art can easily synthesize.

Preferred organic basic compounds that can be used in the present invention are compounds that are more basic than phenol. Among them, a nitrogen-containing basic compound is preferable. Preferred chemical environments include the structures of the following formulas (A) to (E).

[0108]

Embedded image

Further preferred compounds are nitrogen-containing basic compounds having two or more nitrogen atoms having different chemical environments in one molecule, and particularly preferred is a ring structure containing a substituted or unsubstituted amino group and a nitrogen atom. Or a compound having an alkylamino group. Preferred specific examples include substituted or unsubstituted guanidine, substituted or unsubstituted aminopyridine, substituted or unsubstituted aminoalkylpyridine, substituted or unsubstituted aminopyrrolidine, substituted or unsubstituted indazol,
Substituted or unsubstituted pyrazole, substituted or unsubstituted pyrazine, substituted or unsubstituted pyrimidine, substituted or unsubstituted purine, substituted or unsubstituted imidazoline, substituted or unsubstituted pyrazoline, substituted or unsubstituted piperazine, substituted Or, unsubstituted aminomorpholine, substituted or unsubstituted aminoalkylmorpholine and the like can be mentioned. Preferred substituents are an amino group,
An aminoalkyl group, an alkylamino group, an aminoaryl group, an arylamino group, an alkyl group, an alkoxy group, an acyl group, an acyloxy group, an aryl group, an aryloxy group, a nitro group, a hydroxyl group, and a cyano group. As particularly preferred compounds, guanidine, 1,1-dimethylguanidine, 1,1,3,3-tetramethylguanidine, 2-
Aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-dimethylaminopyridine, 4-dimethylaminopyridine, 2-diethylaminopyridine, 2- (aminomethyl) pyridine, 2-amino-3-methylpyridine, 2-amino -4-methylpyridine, 2-amino-5
-Methylpyridine, 2-amino-6-methylpyridine,
3-aminoethylpyridine, 4-aminoethylpyridine, 3-aminopyrrolidine, piperazine, N- (2-aminoethyl) piperazine, N- (2-aminoethyl) piperidine, 4-amino-2,2,6,6 -Tetramethylpiperidine, 4-piperidinopiperidine, 2-iminopiperidine, 1- (2-aminoethyl) pyrrolidine, pyrazole, 3-amino-5-methylpyrazole, 5-amino-3-methyl-1-p- Tolylpyrazole, pyrazine, 2- (aminomethyl) -5-methylpyrazine, pyrimidine, 2,4-diaminopyrimidine, 4,6-dihydroxypyrimidine, 2-pyrazoline, 3-pyrazoline,
N-aminomorpholine, N- (2-aminoethyl) morpholine, 1,5-diazabicyclo [4,3,0] non-5-ene, 1,8-diazabicyclo [5.4.0]
Examples include, but are not limited to, undec-7-ene, 2,4,5-triphenylimidazole and the like. Among them, 1,5-diazabicyclo [4.3.0] non-5-ene and 1,8-diazabicyclo [5.4.0]
Undec-7-ene and 2,4,5-triphenylimidazole are preferred from the viewpoint of resolving power or suppressing a change in performance over time from exposure to post-heating.

These nitrogen-containing basic compounds are used alone or in combination of two or more. The amount of the nitrogen-containing basic compound to be used is generally 0.001 to 10% by weight, preferably 0.01 to 5% by weight, based on the total solid content of the positive photosensitive composition. If the amount is less than 0.001% by weight, the effect of the addition of the nitrogen-containing basic compound cannot be obtained.
On the other hand, if it exceeds 10% by weight, the sensitivity tends to decrease and the developability of the unexposed portion tends to deteriorate.

Suitable dyes include oil dyes and basic dyes. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink # 312, Oil Green BG, Oil Blue BOS, Oil Blue # 60
3. Oil black BY, oil black BS, oil black T-505 (all manufactured by Orient Chemical Co., Ltd.), crystal violet (CI42555), methyl violet (CI42535), rhodamine B
(CI45170B), malachite green (CI42
000), methylene blue (CI52015) and the like.

In order to improve the acid generation rate by exposure, a photosensitizer as described below can be further added. Examples of suitable photosensitizers include benzophenone, p, p'-tetramethyldiaminobenzophenone,
p, p'-tetraethylethylaminobenzophenone,
2-chlorothioxanthone, anthrone, 9-ethoxyanthracene, anthracene, pyrene, perylene, phenothiazine, benzyl, acridine orange, benzoflavin, setoflavin-T, 9,10-diphenylanthracene, 9-fluorenone, acetophenone, phenanthrene, 2-nitro Fluorene, 5-nitroacenaphthene, benzoquinone, 2-chloro-4-nitroaniline, N-acetyl-p-nitroaniline, p-nitroaniline, N-acetyl-4-nitro-1-naphthylamine, picramide, anthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone 1,2-benzanthraquinone, 3-methyl-1,3-diaza-
1,9-benzanthrone, dibenzalacetone, 1,
2-naphthoquinone, 3,3′-carbonyl-bis (5,
7-dimethoxycarbonylcoumarin) and coronene, but are not limited thereto. These photosensitizers can also be used as a light absorbing agent for far ultraviolet light as a light source. In this case, the light absorbing agent exerts 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.

Further, the positive photosensitive composition of the present invention includes:
An aliphatic carboxylic acid can be blended for improving the solubility in a developer. Examples of the aliphatic carboxylic acid include cyclopentyl acetic acid, cyclohexyl acetic acid, cyclohexane carboxylic acid, dicyclohexyl acetic acid, 1-adamantane carboxylic acid, 2-norbornane acetic acid, noradamantane carboxylic acid, 1,3-adamantane dicarboxylic acid,
Examples thereof include, but are not limited to, 3-adamantanediacetic acid, 1,4-cyclohexanedicarboxylic acid, and carboxylic acids having a steroid structure (cholic acid, deoisicholic acid, lithocholic acid, and the like).

The positive photosensitive composition of the present invention is dissolved in a solvent in which each of the above components is dissolved, and coated on a support. As the solvent used here, ethylene dichloride, cyclohexanone, cyclopentanone, 2-heptanone, γ
-Butyrolactone, methyl ethyl ketone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene, ethyl acetate, methyl lactate, ethyl lactate , Methyl methoxypropionate, ethyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, propyl pyruvate, N, N-
Dimethylformamide, dimethylsulfoxide, N-methylpyrrolidone, tetrahydrofuran and the like are preferable, and these solvents are used alone or in combination.

The positive photosensitive composition of the present invention can be used for a substrate (for example, silicon / silicon) which is used for manufacturing a dense integrated circuit device.
A good resist pattern can be obtained by applying a suitable coating method such as a spinner, a coater or the like on a silicon dioxide coating), exposing through a predetermined mask, baking and developing. Here, the exposure light is preferably far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less. Specifically, a KrF excimer laser (248 nm), an ArF excimer laser (193 nm), and an F ₂ excimer laser (157 n)
m), X-rays, electron beams and the like.

Examples of the developer for the positive photosensitive composition of the present invention include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, and n-propyl. Primary amines such as amines, diethylamine, di-n
Secondary amines such as -butylamine, triethylamine,
Tertiary amines such as methyldiethylamine, alcoholamines such as dimethylethanolamine and triethanolamine, quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide, and cyclic amines such as pyrrole and pichelidine. An alkaline aqueous solution can be used. Further, an appropriate amount of an alcohol or a surfactant may be added to the above alkaline aqueous solution.

[0117]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the contents of the present invention are not limited thereto.

Synthesis Example 1 (Repeating structural unit (a1) to
(Synthesis of Raw Material Monomer of (a10)) The raw material monomers of specific examples (a1) to (a10)
Alternatively, it can be synthesized by selectively protecting the 1,2- or 1,3-diol portion of the alcohol having a 1,3-diol structure, converting the (meth) acrylate, and then deprotecting.

Synthesis of Starting Monomer of Specific Example (a1) 30.0 g of 2,2-dimethyl-1,3-dioxolane-4-methanol (isomeric mixture) was added to tetrahydrofuran 20
0 ml, and triethylamine 37 g, N,
0.1 g of N-dimethylaminopyridine was added. To this solution was added methacrylic acid chloride over 30 minutes under ice cooling. After the temperature was raised to room temperature and reacted for 2 hours, ethyl acetate was added. This solution was washed with distilled water, dried and concentrated to obtain a crude product. This was purified by column chromatography to obtain 37 g of 2,2-dimethyl-1,3-dioxolan-4-methyl methacrylate. 36 g of the obtained 2,2-dimethyl-1,3-dioxolan-4-methyl methacrylate was dissolved in 500 ml of methanol, and 1.7 g of p-toluenesulfonic acid was added thereto, followed by stirring at room temperature for 3 hours. Water was added, the mixture was extracted with ethyl acetate, and the organic phase was washed with water, dried and concentrated to obtain a crude product. This was purified by column chromatography to obtain 23 g of a raw material monomer of the specific example (a1).

Synthesis of raw material monomers of specific examples (a2) to (a10) Synthesis of raw material monomers of specific example (a1) except that methacrylic chloride was changed to acrylic acid chloride in the synthesis of raw material monomers of specific example (a1) In the same manner as in the above, the raw material monomer of the specific example (a2) was obtained. By using the same method, the raw material monomers of the specific examples (a3) to (a10) were obtained.

Synthesis Example 2 (Resins (P1) to (P1
Synthesis of 0)) 2-methyl-2-adamantane methacrylate (5.0 g) in N, N-dimethylacetamide (8 g) heated to 60 ° C. under a nitrogen stream, and the starting monomer of specific example (a1) 3.42
g, polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) (manufactured by Wako Pure Chemical; V-65) 0.107
g, 0.157 g of mercaptoacetic acid as a chain transfer agent was added to N,
A solution dissolved in 25.7 g of N-dimethylacetamide was added dropwise over 4 hours. After further reacting at 60 ° C. for 2 hours, 0.06 g of V-65 was added and reacted for another 2 hours. The reaction liquid was poured into 1000 ml of ion-exchanged water, and the precipitated powder was collected by filtration. This was dissolved in THF, poured into 1500 ml of hexane, and the resulting powder was filtered and dried to obtain a resin (P1). The weight average molecular weight (Mw) of the obtained resin was 12,100, and the degree of dispersion (Mw / M
n) was 1.9. The weight average molecular weight and the degree of dispersion are measured by the GPC method, and are values in terms of polystyrene. The resins (P2) to (P10) of the present invention (B) described in Table 1 were synthesized by adjusting the amount of the polymerization initiator, the amount of the chain transfer agent, and the polymerization concentration using the same method.

[0122]

[Table 1]

Example 1 (Measurement of dry etching resistance) 1.0 g of the resin obtained in the above synthesis example was dissolved in 4.5 g of propylene glycol monomethyl ether acetate.
The solution was filtered through a 0.2 μm Teflon filter. Apply evenly on silicon substrate with spin coater, 100
Heat drying on a hot plate at 90 ° C for 90 seconds.
A 7 μm resist film was formed. The obtained membrane is ULV
AC reactive ion etching system (CSE-1)
110), the etching rate for CF ₄ / O ₂ (8/2) gas was measured. The result was as shown in Table 2 (etching conditions: Power = 500 W, P
response = 4.6 Pa, Gas Flow Ra
te = 10 sccm).

[0124]

[Table 2]

From the results shown in Table 2, in the case of the composition using the resin specified in the present invention, the etching rate was smaller than the values of the comparative poly (methyl methacrylate) and the comparative polymer (1), and the etching resistance was sufficient. It turns out that it has an etching property.

Example 2 (Evaluation of Image: Evaluation of KrF Exposure) 1.0 g of the resin of the present invention obtained in the above synthesis example, 0.03 g of triphenylsulfonium triflate salt and 1,5
-Diazabicyclo [4.3.0] non-5-ene 0.0
04g, Megafac R08 (Dai Nippon Ink Co., Ltd.)
0.00006 g was dissolved in 4.5 g of propylene glycol monomethyl ether acetate and filtered with a 0.2 μm Teflon filter. It was uniformly applied on a silicon substrate that had been subjected to hexamethyldisilazane treatment by a spin coater, and was dried by heating on a hot plate at 100 ° C. for 90 seconds to form a 0.4 μm resist film.
This resist film was subjected to pattern exposure using a KrF excimer laser stepper (NA = 0.42; 248 nm), and immediately after exposure, heated at 110 ° C. for 60 seconds on a hot plate. The film was further immersed and developed in a 2.38% aqueous solution of tetramethylammonium hydroxide at 23 ° C. for 60 seconds, rinsed with pure water for 30 seconds, and dried.
Here, the sensitivity was defined as an exposure amount for reproducing a 0.35 μm mask pattern. Resolution is 0.35μm
Is defined with a critical resolution at an exposure amount that reproduces the mask pattern of (1).

[0127]

[Table 3]

From the results shown in Table 3, the resist using the resin specified in the present invention has high sensitivity and good resolution.
Also, it can be seen that the pattern shape is good.

Example 3 (Evaluation of Image: Evaluation of ArF Exposure) For the resist film of 0.4 μm obtained in Example 2,
Pattern exposure was carried out using an rF excimer laser stepper (NA = 0.55).
Heated on hot plate for seconds. Furthermore, 2.38%
23 with aqueous solution of tetramethylammonium hydroxide
After immersion development at 60 ° C. for 60 seconds, rinsing with pure water for 30 seconds, and drying. As a result, a favorable positive pattern in which the exposed portions of the resist film were removed at the sensitivities and resolutions shown in Table 4 was formed. Here, the sensitivity was defined as an exposure amount for reproducing a mask pattern of 0.20 μm. The resolution was defined as a critical resolution at an exposure amount for reproducing a 0.20 μm mask pattern. The development defects were uniformly coated on a silicon substrate that had been subjected to hexamethyldisilazane treatment using a photosensitive resin composition by a spin coater,
Heating and drying on a hot plate at 90 ° C for 90 seconds,
A 0.50 μm resist film was formed. The film was further developed with a 2.38% by weight aqueous solution of tetramethylammonium hydroxide at 23 ° C. for 60 seconds, rinsed with pure water for 30 seconds, and dried. The sample on which the contact hole pattern thus obtained was formed was used as a KLA211.
The number of development defects was measured by two machines (manufactured by KLA Tencor Co., Ltd.) (Threshold 12, Pixcel Size = 0.39).

[0130]

[Table 4]

From the results shown in Table 4, it can be seen that the resist using the resin specified in the present invention shows good sensitivity and resolution to ArF excimer laser light and forms a good positive pattern. .

[0132]

The positive-working photosensitive composition of the present invention is particularly suitable for
Even when far ultraviolet light of 20 nm or less (especially ArF excimer laser light) is used as an exposure light source, it has high sensitivity, high resolution, shows a good pattern profile, and has sufficient dry etching resistance and adhesion. It can be effectively used for forming a fine pattern necessary for manufacturing a semiconductor element.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshiaki Aoi 4,000 Kawajiri, Yoshida-cho, Haibara-gun, Shizuoka Prefecture F-term in Fujisha Shin Film Co., Ltd. CB41 CB45 CC20

Claims (7)

[Claims] 1. An acid having (A) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and (B) a repeating structural unit containing at least two aliphatic groups substituted by a hydroxyl group, and the action of an acid. A positive photosensitive composition containing a resin having a group that acts to increase the solubility of the resin in an alkaline developer by being decomposed. 2. The repeating structural unit containing two or more aliphatic groups substituted with a hydroxyl group in (B) contains at least one of a 1,2-diol structure and a 1,3-diol structure. The positive photosensitive resin composition according to claim 1, which is a repeating structural unit. 3. The resin of the above (B) is represented by the following general formula (I)
The positive photosensitive composition according to claim 1, comprising a repeating structural unit represented by the formula: Embedded image In the general formula (I), R ₁ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. R _{2 to} R ₆ are the same or different and represent a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, or a cyclic alkyl group having 3 to 7 carbon atoms. These alkyl groups may be substituted with a hydroxyl group, an alkoxy group or a carboxyl group. Also, R ₂ ~
Two or more of R ₆ may combine to form a single ring. n is 0 or 1. X is a linear, branched or cyclic alkylene group, -CO-, -COO-, -O
-, -S-, or a linking group containing a plurality of these. 4. The resin according to claim 1, wherein the resin (B) has at least one of a 1,2-diol structure and a 1,3-diol structure and an alicyclic hydrocarbon structure. The positive photosensitive composition as described in the above. 5. The method according to claim 1, further comprising (C) a low molecular compound having a molecular weight of not more than 3000 and having a group which is decomposed by the action of an acid and has an increased solubility in an alkali developing solution. The positive photosensitive composition according to any one of the above. 6. The exposure light source according to claim 1, wherein deep ultraviolet light having a wavelength of 250 nm or less is used.
The positive photosensitive composition according to any one of the above. 7. The positive photosensitive composition according to claim 6, wherein far-ultraviolet light having a wavelength of 220 nm or less is used as an exposure light source.