JP2002006500A - Positive photoresist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a positive photoresist composition which ensures improved line edge roughness and is excellent also in various resist characteristics such as sensitivity, resolving power, resist shape and focal depth. SOLUTION: The positive photoresist composition contains (A) a compound which generates an acid when irradiated with active light or radiation, (B) an alkali-insoluble or slightly alkali-soluble resin which is made alkali-soluble by the action of the acid and (C) a specified tetraalkylammonium inner salt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a lithographic printing plate or an IC.
The present invention relates to a positive photosensitive composition used in a semiconductor manufacturing process such as the above, a circuit substrate such as a liquid crystal and a thermal head, and other photofabrication processes.
In particular, the positive photoresist composition of the present invention is acted upon by high-energy radiation such as deep ultraviolet rays (including excimer lasers), electron beams, X-rays, or emitted light, and is suitably used for manufacturing semiconductor integrated circuits. It is something that can be done.

[0002]

2. Description of the Related Art Conventionally, in the process of manufacturing semiconductor devices such as ICs and LSIs, fine processing by lithography using a photoresist composition has been performed.
2. Description of the Related Art In recent years, with the increase in the degree of integration of integrated circuits, formation of ultrafine patterns in a submicron region or a quarter-micron region has been required. Along with this, the exposure wavelength tends to be shortened, for example, from g-line to i-line, and further to KrF excimer laser light. At present, lithography using excimer laser light is an important processing technique in this field, and a chemically amplified resist is adopted as a resist suitable for such an excimer laser lithography process. The chemically amplified resist composition generates an acid in the exposed area by irradiation with radiation such as deep ultraviolet light, and the reaction using the acid as a catalyst reduces the solubility of the active radiation irradiated area and the non-irradiated area in the developing solution. It is a material that forms a pattern on a substrate by changing. Chemically amplified resists have the advantage that they have high sensitivity and resolution, and can form an image with a compound that generates an acid by a small amount of radiation (hereinafter, referred to as a “photoacid generator”).

As an example of a chemically amplified positive resist, a compound capable of generating an acid by photolysis, an acetal or O, N
-Combination with acetal compound (JP-A-48-8900)
No. 3), a combination with an orthoester or amide acetal compound (JP-A-51-120714), a combination with a polymer having an acetal or ketal group in the main chain (JP-A-53-133429), and an enol ether compound. (Japanese Unexamined Patent Publication (Kokai) No. 55-1295) and a combination with an N-acylimino carbonate compound (Japanese Unexamined Patent Publication (Kokai) No. 55-12623).
No. 6), 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).
No.), a combination with a silyl ester compound (JP-A-60-1985)
10247) and a combination with a silyl ether compound (JP-A-60-37549, JP-A-60-12144).
No. 6).

Similarly, systems which are stable under aging at room temperature, but are decomposed by heating in the presence of an acid and solubilized in alkali are disclosed in, for example, JP-A-59-45439, JP-A-60-3625, JP-A-62-229242, JP-A-63-27829, JP-A-63-36240, JP-A-63-250642, Polym. Eng. Sci., Vol. 23,
1012 (1983), ACS. Sym., 242, 11 (1984), Se
miconductor World 1987, November, 91, Macromolec
ules, vol. 21, p. 1475 (1988), SPIE, vol. 920, p. 42 (198)
8) and the like, and a combination system of a compound generating an acid upon exposure to light and an ester or carbonate compound of a tertiary or secondary carbon (for example, t-butyl, 2-cyclohexenyl). Since these systems also have high sensitivity and low absorption in the far ultraviolet region, they can be effective systems for shortening the light source wavelength capable of ultrafine processing.

The positive chemically amplified resist is decomposed by the reaction of a three-component system comprising an alkali-soluble resin, a photoacid generator and a compound having an acid-decomposable group and a dissolution inhibiting compound for the alkali-soluble resin, and decomposed by the reaction with an acid. A two-component system comprising a resin having a soluble group and a photoacid generator, a resin having a group which is decomposed by reacting with an acid and becoming alkali-soluble, a low-molecular dissolution inhibiting compound having an acid-decomposable group, and It can be broadly classified into a hybrid system composed of a photoacid generator. In these two-component, three-component, and hybrid-type positive chemically amplified resists, a resist pattern is obtained by heat treatment and development with an acid from a photoacid generator being exposed by exposure.

[0006] In lithography using a chemically amplified resist, sensitivity, resolution, profile,
Coating properties, heat resistance, dry etching resistance, adhesion, substrate dependence, environmental stability (eg, resist dimensional stability due to fluctuations in withdrawal time), and depth of focus (eg, pattern formation against defocus during radiation irradiation) Photoresist excellent in various properties such as properties) has been demanded, and many ideas for improving the performance by additives have been disclosed.
Due to its unique reaction mechanism, chemically amplified positive resist
Attempts have been made to prevent the diffusibility of the generated acid by adding an acid scavenger to improve the resist properties, especially the environmental stability. For example, JP-A-5-127369,
5-232706, 5-249662, 5-
Nos. 289322, 6-317902, 7-926
Nos. 78, 7-120929 and the like have been proposed to which an organic amine is added. However, when an amine is added, there is a problem that the resolution is improved but the sensitivity is lowered.

On the other hand, attempts have been made to add various compounds to a chemically amplified resist composition for the purpose of improving sensitivity, improving a resist pattern shape, and the like. For example, JP-A-5-181279, JP-A-7-92679, and JP-A-9-6
Nos. 001, 6-6002, 9-6003, U.S. Pat. Nos. 5,955,240, 5,948,589, and EP 679951 disclose the addition of a carboxylic acid. No. 4-
No. 217251, No. 7-181680, No. 8-211
597, U.S. Pat. Nos. 5,688,628 and 597,255.
No. 9 discloses the addition of an aromatic polyhydroxy compound, and is disclosed in JP-A-5-181263 and JP-A-7-181263.
No. 92680 discloses the addition of a sulfonamide compound.

[0008] Further, a device for improving resist characteristics such as resolution, exposure latitude, adhesion, and substrate dependence is disclosed. For example, JP-A-9-5987, U.S. Pat. No. 5,770,343, and EP-A-749044 disclose methods of preventing pattern collapse by adding formamide or acetamide compound.
No. 44950 discloses that the dependency on the substrate is improved by adding a nitrogen-containing compound such as succinimide or phthalimide. JP-A-5-232706,
No. 6-11835, No. 6-242606, No. 6-2
No. 66100, No. 7-333851, No. 7-3338
No. 44, U.S. Pat. No. 5,663,035, European Patent 6777
No. 88, a compound (photobase) whose basicity is reduced by exposure is added to provide environmental stability (for example,
There is disclosed a method for improving resist dimensional stability due to fluctuations in the withdrawal time, resolution, depth of focus, and the like.

Further, Japanese Patent Application Laid-Open No. 9-297396 discloses that
There is disclosed a device for improving resolution and depth of focus by adding a specific low-molecular acid-decomposable dissolution inhibiting compound to a component-based chemically amplified resist. JP-A-9-127700, U.S. Pat. No. 5,783,354, European Patent 762207, and European Patent 813113 disclose the addition of an ammonium salt such as tetra-n-butylammonium lactate. US Patent 56291
No. 34, U.S. Pat. No. 5,658,706 discloses adding a pyridinium salt and discloses a method for improving environmental stability.

However, even with the above-described techniques, the photoresist composition for exposure to far ultraviolet rays has many insufficiencies in line edge roughness performance, and improvement has been required. Here, the line edge roughness refers to the line pattern of the resist and the edge of the interface between the substrate and the edge of the resist that fluctuate irregularly in the direction perpendicular to the line direction due to the characteristics of the resist. The edge looks uneven. The unevenness is transferred by an etching process using a resist as a mask, and lowers the yield because the electrical characteristics are deteriorated. In particular, as the resist pattern size becomes smaller than quarter micron, there is an increasing demand for improvement in line edge roughness, but no guideline for improvement has been disclosed so far.

[0011]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a positive-type photo resist for exposure to deep ultraviolet light which has improved line edge roughness and further excellent resist characteristics such as sensitivity, resolution, resist shape and depth of focus. It is to provide a resist composition.

[0012]

Means for Solving the Problems The present inventors have conducted intensive studies on the constituent materials of a resist composition in a positive-type chemical amplification system. As a result, the object of the present invention has been achieved by using a specific low-molecular compound. This led to the present invention.
That is, the above object is achieved by the following constitutions. (1) (A) a compound which generates an acid upon irradiation with actinic rays or radiation, (B) a resin which is insoluble or hardly soluble in alkali and becomes alkali-soluble by the action of an acid, and
(C) A positive photoresist composition comprising a tetraalkylammonium internal salt represented by the following general formula (I) or (II).

[0013]

Embedded image

(In the general formulas (I) and (II), R ₁ , R ₂ ,
And R ₃ each independently represents an alkyl group having 1 to 6 carbon atoms. (2) The positive photoresist composition according to the above (1), wherein the resin (B) contains a repeating unit represented by the following general formulas (IV) and (V).

[0015]

Embedded image

(L represents a hydrogen atom, a substituted or unsubstituted linear, branched or cyclic alkyl group or an optionally substituted aralkyl group. Z represents a substituted or unsubstituted aralkyl group. Represents a chain, branched or cyclic alkyl group, or an optionally substituted aralkyl group, and Z and L may combine to form a 5- or 6-membered ring.

(3) The positive photoresist according to the above (1) or (2), wherein the positive photoresist composition further comprises (D) a nitrogen-containing basic compound as an acid scavenger. Resist composition.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the compounds used in the present invention will be described in detail. << (C) Low molecular weight compound >> Specific examples of the compound represented by the general formula (I) include compounds (C-1) to (C
-3) and specific examples of the compound represented by the general formula (II) include the following compounds (C-4) and (C-5), but are not limited thereto. is not.

[0019]

Embedded image

In the present invention, the amount of the compound (C) to be added is usually 0.001 based on the solid content in the composition.
Used in a range of from 40 to 40% by weight, preferably from 0.01 to 40% by weight.
It is used in an amount of 20% by weight, more preferably 0.05 to 15% by weight. When the addition amount of the compound (C) of the present invention is
If the amount is less than 0.001% by weight, the effect of improving the line edge roughness may not be sufficiently obtained. If the addition amount is more than 40% by weight, the profile of the resist deteriorates,
The process margin may be narrow, which is not preferable.
The method for synthesizing the compound (C) is known, and a commercially available method can be used.

{(A) Photoacid Generator} The photoacid generator (A) used in the present invention is a compound which generates an acid upon irradiation with actinic rays or radiation.

The photoacid generator used in the present invention includes:
Known light (400 to 200 n) used for a photoinitiator for photocationic polymerization, a photoinitiator for photoradical polymerization, a photodecolorant for dyes, a photochromic agent, or a micro resist.
m ultraviolet rays, far ultraviolet rays, particularly preferably g-rays, h-rays,
Compounds that generate an acid by i-ray, KrF excimer laser light), ArF excimer laser light, electron beam, X-ray, molecular beam or ion beam, and mixtures thereof can be appropriately selected and used.

Other photoacid generators used in the present invention include, for example, onium salts such as diazonium salts, ammonium salts, phosphonium salts, iodonium salts, sulfonium salts, selenonium salts, arsonium salts, and the like.
Organic halogen compound, organic metal / organic halide, o
A photoacid generator having a nitrobenzyl-type protecting group; a compound represented by photolysis such as iminosulfonate that generates sulfonic acid; a disulfone compound; a diazoketosulfone; and a diazodisulfone compound.

Further, a group that generates an acid by these lights,
Alternatively, a compound having a compound introduced into the main chain or side chain of a polymer can be used.

Further, VNR Pillai, Synthesis,
(1), 1 (1980), A. Abad et al., Tetrahedron Lett.,
(47) 4555 (1971), DHR Barton et al., J. Chem.
Soc., (C), 329 (1970), U.S. Pat. No. 3,779,778, EP 126,712, and the like, can also be used compounds that generate an acid by light.

Among the above-mentioned photoacid generators (A), those which can be used particularly effectively include the following <A-1> to <A-4>.
>. <A-1>: An oxazole derivative represented by the following general formula (PAG1) or an S-triazine derivative represented by the following general formula (PAG2) substituted by a trihalomethyl group.

[0027]

Embedded image

In the formula, R ²⁰¹ represents a substituted or unsubstituted aryl group or alkenyl group, and R ²⁰² represents a substituted or unsubstituted aryl group, alkenyl group, alkyl group, —C (Y)
_{Shows 3} . Y represents a chlorine atom or a bromine atom.

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

[0030]

Embedded image

<A-2>: The following general formula (PAG3)
Or an iodonium salt represented by the general formula (PAG4)
A sulfonium salt represented by the formula:

[0032]

Embedded image

In the formula, Ar ¹ and Ar ² each independently represent a substituted or unsubstituted aryl group. R ²⁰³ , R ²⁰⁴ , R
²⁰⁵ independently represents a substituted or unsubstituted alkyl group or aryl group.

Z ^- represents a counter anion, for example, B
F ₄ ⁻ , AsF ₆ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , SiF ₆ ²⁻ , Cl
_{^{O 4 -, CF 3 SO 3}} - or the like of the perfluoroalkane sulfonate anion, an alkyl sulfonate anions such as camphorsulfonic acid anion, pentafluorobenzenesulfonic acid anion, benzenesulfonic acid anion, triisopropyl benzenesulfonic acid aromatic anions such as Examples thereof include, but are not limited to, condensed polynuclear aromatic sulfonic acid anions such as aromatic sulfonic acid anions and naphthalene-1-sulfonic acid anions, anthraquinone sulfonic acid anions, and sulfonic acid group-containing dyes. Further, these anionic species may further have a substituent.

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.

[0037]

Embedded image

[0038]

Embedded image

[0039]

Embedded image

[0040]

Embedded image

[0041]

Embedded image

[0042]

Embedded image

[0043]

Embedded image

The above-mentioned onium salts represented by the general formulas (PAG3) and (PAG4) are known, for example, JW Knap
czyk et al., J. Am. Chem. Soc., 91, 145 (1969), A.
L. Maycok et al., J. Org.Chem., 35, 2532, (197
0), E. Goethas et al., Bull. Soc. Chem. Belg., 73,
546, (1964), HM Leicester, J. Ame. Chem. Soc., 5
1, 3587 (1929), JV Crivello et al., J. Polym. C
hem. Ed., 18, 2677 (1980), U.S. Pat. Nos. 2,807,648 and 4,247,473, and JP-A-53-101,331. <A-3>: Disulfone derivative represented by the following general formula (PAG5) or iminosulfonate derivative represented by the following general formula (PAG6).

[0045]

Embedded image

In the formula, Ar ³ and Ar ⁴ each independently represent 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.

[0048]

Embedded image

[0049]

Embedded image

[0050]

Embedded image

<A-4>: A diazodisulfone derivative represented by the following general formula (PAG7).

[0052]

Embedded image

In the formula, R represents a linear, branched or cyclic alkyl group or an optionally substituted aryl group.

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

[0055]

Embedded image

In the present invention, the amount of the photoacid generator (A) to be added is usually 0.03% based on the solid content in the composition.
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 10% by weight. When the amount of the photoacid generator is 0.001
If the amount is less than 10% by weight, the sensitivity is lowered, and the addition amount is 40%.
If the content is more than the weight percentage, the light absorption of the resist becomes too high, and the profile is deteriorated and the process margin is narrowed, which is not preferable.

{(B) Resin} The resin (B) used in the present invention is a resin which is insoluble or hardly soluble in alkali and becomes alkali-soluble by the action of an acid. As such a resin whose solubility in an alkali developing solution is increased by the action of an acid, a resin having a repeating unit corresponding to hydroxystyrene and decomposed by the action of an acid to increase the solubility in alkali is preferably used.

Here, the hydroxystyrene includes o
It may be any of-, m-, or p-hydroxystyrene, and may be partially hydrogenated. Further, it may have a substituent other than a hydroxyl group. Examples of such a substituent include an alkyl group, an alkoxy group, an aralkyl group, and an aryl group.

As the resin used in the positive chemically amplified resist of the present invention, which has a group that decomposes with an acid and increases the solubility in an alkaline developer (hereinafter referred to as an “acid-decomposable group”). Is a resin having an acid-decomposable group in the main chain or side chain of the resin, or in both the main chain and the side chain. Among them, a resin having a group which can be decomposed by an acid in a side chain is more preferable.

The group decomposable with an acid is preferably -C
OOA ⁰ and —O—B ⁰ groups. Examples of the group containing these are the groups represented by —R ⁰ —COOA ⁰ and —Ar—O—B ⁰ .

Here, A ⁰ is -C (R ⁰¹ ) (R ⁰² ) (R
^{03), - Si (R 01} ) (R 02) (R 0 3) or -C
It represents a (R ⁰⁴ ) (R ⁰⁵ ) -OR ⁰⁶ group. B ⁰ represents A ⁰ or a —CO—OA ⁰ group.

R ⁰¹ , R ⁰² , R ⁰³ , R ⁰⁴ and R ⁰⁵ are the same or different and represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkenyl group or an aryl group, and R ⁰⁶ represents an alkyl group or an aryl group. Show. However, R ^{01 to} R ⁰³
At least two are groups other than a hydrogen atom;
Two groups out of ^{01 to} R ⁰³ and R ^{04 to} R ⁰⁶ may combine to form a ring.

R ⁰ represents a divalent aliphatic or aromatic hydrocarbon group which may have a substituent, and -Ar- represents a divalent group which may have a monocyclic or polycyclic substituent. Represents an aromatic group.

The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group and a t-butyl group. Preferred are those having 3 to 10 carbon atoms such as cyclopropyl group, cyclobutyl group, cyclohexyl group and adamantyl group, and alkenyl groups having 2 to 2 carbon atoms such as vinyl group, propenyl group, allyl group and butenyl group. Preferably, the aryl group has 6 to 1 carbon atoms such as phenyl, xylyl, toluyl, cumenyl, naphthyl and anthracenyl.
Four are preferred.

These substituents include a hydroxyl group, a halogen atom (fluorine, chlorine, bromine, iodine), a nitro group, a cyano group, the above-mentioned alkyl group, methoxy group, ethoxy group, hydroxyethoxy group, propoxy group, hydroxy group and the like. Propoxy group, n-butoxy group, isobutoxy group, s
an alkoxy group such as an ec-butoxy group and a t-butoxy group,
Methoxycarbonyl group, alkoxycarbonyl group such as ethoxycarbonyl group, benzyl group, aralkyl group such as phenethyl group, cumyl group, aralkyloxy group, formyl group, acetyl group, butyryl group, benzoyl group, cyanyl group, acyl such as valeryl group Group, acyloxy group such as butyryloxy group, the above alkenyl group, vinyloxy group,
Examples thereof include an alkenyloxy group such as a propenyloxy group, an allyloxy group and a butenyloxy group, an aryloxy group such as the above-described aryl group and phenoxy group, and an aryloxycarbonyl group such as a benzoyloxy group.

An acid-decomposable group (—COOA ⁰ or —O—
B ⁰ ) is preferably a silyl ether group, a cumyl ester group, an acetal group, a tetrahydropyranyl ether group, an enol ether group, an enol ester group, a tertiary alkyl ether group, a tertiary alkyl ester group, or a tertiary alkyl ester group. And the like. More preferred are a tertiary alkyl ester group, a tertiary alkyl carbonate group, a cumyl ester group, an acetal group, and a tetrahydropyranyl ether group. Particularly preferred is an acetal group.

Next, when the group decomposable by the acid is bonded as a side chain, the base resin has a repeating unit corresponding to the above-mentioned hydroxystyrene and has -OH or -COOH, preferably- It is an alkali-soluble resin having a ^R0- COOH or -Ar-OH group.
For example, an alkali-soluble resin described below can be used.

From the viewpoint of achieving a rectangular profile, an alkali-soluble resin having a high transmittance to far ultraviolet light or excimer laser light is preferable. Preferably, the transmittance at a wavelength of 248 nm with a thickness of 1 μm is 20 to 90%.

From these viewpoints, particularly preferred alkali-soluble resins are o-, m-, p-poly (hydroxystyrene) and copolymers thereof, hydrogenated poly (hydroxystyrene), halogen- or alkyl-substituted poly (hydroxystyrene). Hydroxystyrene), partially O-alkylated or O-acylated poly (hydroxystyrene), styrene-
A hydroxystyrene copolymer, an α-methylstyrene-hydroxystyrene copolymer and a hydrogenated novolak resin.

The resin having an acid-decomposable group used in the present invention is disclosed in EP 254853, JP-A-2-25.
No. 850, No. 3-223860, No. 4-251259
As described in No. 2, the alkali-soluble resin is reacted with a precursor of an acid-decomposable group, or an alkali-soluble resin monomer having an acid-decomposable group bonded thereto is copolymerized with various monomers. Can be obtained.

Specific examples (1) to (18) of the resin (B) having a group which can be decomposed by an acid used in the present invention are shown below, but the present invention is not limited thereto. (1): pt-butoxystyrene / p-hydroxystyrene copolymer, (2): p- (t-butoxycarbonyloxy) styrene / p-hydroxystyrene copolymer, (3): p- (t -Butoxycarbonylmethyloxy)
Styrene / p-hydroxystyrene copolymer, (4): 4- (t-butoxycarbonylmethyloxy)
-3-methylstyrene / 4-hydroxy-3-methylstyrene copolymer, (5): p- (t-butoxycarbonylmethyloxy)
Styrene / p-hydroxystyrene (10% hydrogenated) copolymer, (6): m- (t-butoxycarbonylmethyloxy)
Styrene / m-hydroxystyrene copolymer, (7): o- (t-butoxycarbonylmethyloxy)
Styrene / o-hydroxystyrene copolymer, (8): p- (cumyloxycarbonylmethyloxy)
Styrene / p-hydroxystyrene copolymer, (9): p- (t-butoxycarbonylmethyloxy)
Styrene / p-hydroxystyrene / styrene copolymer, (10): pt-butoxystyrene / p-hydroxystyrene / fumaronitrile copolymer, (11): p-hydroxystyrene / t-butyl methacrylate copolymer, (12): styrene / p-hydroxystyrene / t-butyl methacrylate copolymer (13): p-hydroxystyrene / t-butyl acrylate copolymer, (14): styrene / p-hydroxystyrene / t-butyl acrylate Copolymer (15): p- (t-butoxycarbonylmethyloxy) styrene / p-hydroxystyrene / N-methylmaleimide copolymer, (16): p-hydroxystyrene / t-butyl acrylate / p- (t -Butoxycarbonyloxy) styrene copolymer, (17): p Hydroxystyrene / t-butyl acrylate / p-(t-butoxycarbonylmethyloxy)
Styrene copolymer, (18): p-hydroxystyrene / t-butyl acrylate / p-acetoxystyrene copolymer (see the following structural formula).

[0072]

Embedded image

In the present invention, the resin (B) having an acid-decomposable group is preferably a resin containing a repeating structural unit represented by the following general formulas (IV) and (V). Thereby, the effect of the present invention becomes more remarkable.

[0074]

Embedded image

[In the above formula, L represents a hydrogen atom, an optionally substituted linear, branched or cyclic alkyl group, or an optionally substituted aralkyl group. Z represents a linear, branched or cyclic alkyl group which may be substituted, or an aralkyl group which may be substituted.
Further, Z and L may combine to form a 5- or 6-membered ring. As the alkyl group of L and Z in the general formula (IV),
For example, a carbon number of 1 to 1 such as methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, pentyl group, cyclopentyl group, hexyl group, cyclohexyl group, octyl group and dodecyl group. 20
Straight, branched or cyclic ones.

Preferred substituents which the alkyl groups of L and Z may have are an alkyl group, an alkoxy group, a hydroxyl group,
Halogen atom, nitro group, acyl group, acyloxy group,
Acylamino group, a sulfonylamino group, an alkylthio group, an arylthio group, an aralkylthio group, a thiophenecarbonyloxy group, a thiophenemethylcarbonyloxy group, and a heterocyclic residue such as a pyrrolidone residue.
Preferably, it has 12 or less carbon atoms. As an alkyl group having a substituent, for example, cyclohexylethyl group, alkylcarbonyloxymethyl group, alkylcarbonyloxyethyl group, arylcarbonyloxyethyl group, aralkylcarbonyloxyethyl group, alkyloxymethyl group, aryloxymethyl group, aralkyloxymethyl Group, alkyloxyethyl group, aryloxyethyl group, aralkyloxyethyl group, alkylthiomethyl group, arylthiomethyl group, aralkylthiomethyl group,
Examples thereof include an alkylthioethyl group, an arylthioethyl group, and an aralkylthioethyl group. The alkyl in these groups is not particularly limited, but may be any of chain, cyclic, and branched, and may further have a substituent such as the above-described alkyl group and alkoxy group. Examples of the alkylcarbonyloxyethyl group include a cyclohexylcarbonyloxyethyl group, a t-butylcyclohexylcarbonyloxyethyl group, an n-butylcyclohexylcarbonyloxyethyl group, and the like. The aryl is not particularly limited, but is generally a phenyl group, a xylyl group,
Examples thereof include those having 6 to 14 carbon atoms such as a toluyl group, a cumenyl group, a naphthyl group, and an anthracenyl group, and may further have a substituent such as the above-described alkyl group and alkoxy group. Examples of the aryloxyethyl group include a phenyloxyethyl group and a cyclohexylphenyloxyethyl group. The aralkyl is not particularly limited, but examples thereof include a benzyl group. Examples of the aralkylcarbonyloxyethyl group include a benzylcarbonyloxyethyl group.

The aralkyl group of L and Z in the general formula (IV) includes, for example, a substituted or unsubstituted benzyl group,
Examples thereof include those having 7 to 15 carbon atoms such as a substituted or unsubstituted phenethyl group. Preferred substituents on the aralkyl group include an alkoxy group, a hydroxyl group, a halogen atom, a nitro group, an acyl group, an acylamino group, a sulfonylamino group, an alkylthio group, an arylthio group, an aralkylthio group, and the like. Examples thereof include an alkoxybenzyl group, a hydroxybenzyl group, and a phenylthiophenethyl group. The range of the carbon number of the substituent which the aralkyl group as L or Z may have is preferably 12 or less.

As described above, the introduction of a bulky group such as a phenyl group or a cyclohexyl group at the terminal of a substituted alkyl group or a substituted aralkyl group can further improve edge roughness.

5 or 6 formed by combining L and Z with each other
Examples of the member ring include a tetrahydropyran ring and a tetrahydrofuran ring.

The molar ratio of the repeating structural unit represented by the general formula (IV) to the repeating structural unit represented by the general formula (V) in the resin is preferably from 1/99 to 60/40, more preferably Is 5/95 to 50/50, more preferably 10/90 to 40/60.

The resin containing the repeating structural units represented by the general formulas (IV) and (V) may contain structural units derived from other monomers.

Other monomers include hydrogenated hydroxystyrene; halogen, alkoxy or alkyl-substituted hydroxystyrene; styrene; halogen, alkoxy, acyloxy or alkyl-substituted styrene; maleic anhydride; acrylic acid derivative; methacrylic acid derivative;
-Substituted maleimide and the like, but are not limited thereto.

The molar ratio of the structural units of the general formulas (IV) and (V) to the structural units of the other monomers is as follows:
[(IV) + (V)] / [other monomer components] = 100
/ 0 to 50/50, preferably 100/0 to 60/4
0, more preferably 100/0 to 70/30.

Specific examples of the resin containing a repeating structural unit represented by the above general formulas (IV) and (V) include:
The following are mentioned.

[0085]

Embedded image

[0086]

Embedded image

[0087]

Embedded image

[0088]

Embedded image

[0089]

Embedded image

[0090]

Embedded image

[0091]

Embedded image

[0092]

Embedded image

[0093]

Embedded image

[0094]

Embedded image

In the above specific examples, Me is a methyl group, E
t is an ethyl group, n-Bu is an n-butyl group, iso-Bu
Represents an isobutyl group, and t-Bu represents a t-butyl group.

When an acetal group is used as the acid-decomposable group, a polyhydroxy compound is added at the synthesis stage to adjust the alkali dissolution rate and improve heat resistance to introduce a cross-linking site connecting the polymer main chain with a polyfunctional acetal group. May be. The amount of the polyhydroxy compound to be added is 0.01 to 5 mol%, more preferably 0.05 to 4 mol%, based on the amount of hydroxyl groups of the resin. Examples of the polyhydroxy compound include those having 2 to 6 phenolic hydroxyl groups or alcoholic hydroxyl groups, preferably 2 to 4 hydroxyl groups, and more preferably 2 to 4 hydroxyl groups.
Or three.

Specific examples of the polyhydroxy compound are shown below, but it should not be construed that the invention is limited thereto.

[0098]

Embedded image

In the present invention, the content of the repeating unit having an acid-decomposable group in the resin (B) is preferably from 5 to 50 mol%, more preferably from 10 to 40 mol%, based on all repeating units. It is.

In the present invention, the content of the repeating unit corresponding to hydroxystyrene in the resin (B) is preferably from 5 to 95 mol%, more preferably from 10 to 85 mol%, based on all repeating units. is there.

The weight average molecular weight (Mw) of the resin having an acid-decomposable group is preferably in the range of 2,000 to 300,000. If it is less than 2,000, the film is greatly reduced due to the development of the unexposed portion. Here, the weight average molecular weight is defined as a polystyrene equivalent value of gel permeation chromatography.

The degree of dispersion (weight average molecular weight / number average molecular weight) of the resin having a group decomposable with an acid is 1.0 to 5.0.
Is preferable. If the degree of dispersion is more than 5.0, the resolving power is lowered and the resist pattern becomes tapered, which is not preferable.

The resin (B) of the photosensitive composition of the present invention
[That is, a resin having an acid-decomposable group] may be used as a mixture of two or more kinds. The amount of the resin (B) used is 40 to 40% based on the total weight of the photosensitive composition (excluding the solvent).
It is 99% by weight, preferably 60 to 98% by weight.

The positive photoresist composition of the present invention comprises:
After being dissolved in a solvent that dissolves each of the above components, the solution is usually adjusted, for example, by filtration through a filter having a pore size of about 0.05 μm to 0.2 μm to prepare a solution. Examples of the solvent used here include 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, and propylene glycol monoethyl ether acetate.
-Methyl 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-dimethylacetamide, propylene carbonate, ethylene carbonate and the like. These solvents are used alone or in combination. The choice of solvent is important because it affects the solubility in the positive photoresist composition of the present invention, the applicability to a substrate, the storage stability, and the like. It is preferable that the amount of water contained in the solvent be small because it affects various resist properties.

Further, in the positive photoresist composition of the present invention, it is preferable to reduce metal impurities such as metals and impurity components such as chloride ions to 100 ppb or less. The presence of many of these impurities is not preferable because it causes operation failure, defects, and reduced yield in manufacturing a semiconductor device.

The solid content of the positive photoresist composition is preferably dissolved in the solvent and dissolved in a solid concentration of 3 to 40% by weight . More preferably, it is 5 to 30% by weight, and still more preferably 7 to 20% by weight. << (D) Organic Basic Compound >> The positive photoresist composition of the present invention preferably further contains an organic basic compound as an acid scavenger.

As the organic basic compound used in the present invention, a compound having a higher basicity than phenol is preferable.

In particular, nitrogen-containing basic compounds having the following structures (A) to (E) are preferably used. By using this nitrogen-containing basic compound, there is an effect that a change in performance over time from exposure to post-heating can be reduced.

[0109]

Embedded image

Here, R ²⁵⁰ , R ²⁵¹ and R ²⁵² are the same or different and are a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aminoalkyl group having 1 to 6 carbon atoms, a hydroxyalkyl having 1 to 6 carbon atoms. Or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, wherein R ²⁵¹ and R ²⁵² may be bonded to each other to form a ring.

[0111]

Embedded image

Wherein R ²⁵³ , R ²⁵⁴ , R ²⁵⁵ and R ²⁵⁶
Are the same or different and represent an alkyl group having 1 to 6 carbon atoms.) Further preferred compounds are nitrogen-containing cyclic compounds or basic nitrogen-containing compounds having two or more nitrogen atoms having different chemical environments in one molecule. .

The nitrogen-containing cyclic compound more preferably has a polycyclic structure. Preferred specific examples of the nitrogen-containing polycyclic compound include a compound represented by the following general formula (VI).

[0114]

Embedded image

In the formula (VI), Y and W each independently represent a linear, branched or cyclic alkylene group which may contain a hetero atom and may be substituted.

Here, as the hetero atom, a nitrogen atom,
Examples include a sulfur atom and an oxygen atom. The alkylene group preferably has 2 to 10 carbon atoms, and more preferably has 2 to 2 carbon atoms.
There are five. Examples of the substituent of the alkylene group include an alkyl group having 1 to 6 carbon atoms, an aryl group, an alkenyl group, a halogen atom, and a halogen-substituted alkyl group.

Further, specific examples of the compound represented by the general formula (VI) include the following compounds.

[0118]

Embedded image

Among the above, 1,8-diazabicyclo [5.4.0] undec-7-ene and 1,5-diazabicyclo [4.3.0] non-5-ene are particularly preferred.

The basic nitrogen-containing compound having two or more nitrogen atoms having different chemical environments in one molecule is particularly preferably a compound containing both a substituted or unsubstituted amino group and a ring structure containing 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 indazole, 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 amino Morpholine, substituted or unsubstituted aminoalkylmorpholine and the like. Preferred substituents are an amino group, aminoalkyl group, alkylamino group, aminoaryl group, arylamino group, alkyl group, alkoxy group, acyl group, acyloxy group, aryl group, aryloxy group, nitro group, hydroxyl group, cyano group It is.

As particularly preferred compounds, guanidine,
1,1-dimethylguanidine, 1,1,3,3-tetramethylguanidine, 2-aminopyridine, 3-aminopyridine, 4-aminopyridine, 2-dimethylaminopyridine, 4-dimethylaminopyridine, 2-diethylamino Pyridine, 2- (aminomethyl) pyridine, 2-amino-3-methylpyridine, 2-amino-4-methylpyridine, 2-amino-5-methylpyridine, 2-amino-6-methylpyridine, 3-aminoethyl Pyridine, 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, trimethylimidazole, triphenylimidazole, methyldiphenylimidazole, and the like, but are not limited thereto.

The basic nitrogen-containing compounds used in the present invention can be used alone or in combination of two or more. The amount of the basic nitrogen-containing compound used is usually 0.001 to 10 parts by weight, based on the solid content of the photosensitive composition,
Preferably it is 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, sensitivity tends to decrease and developability of the unexposed portion tends to deteriorate. (E) Other additives etc. The positive resist composition of the present invention may further contain, if necessary, a surfactant, an acid-decomposable dissolution inhibiting compound, a dye, a plasticizer, a photosensitizer, and a crosslinking agent. A photobase generator, a thermal base generator, a spectral sensitizer, a compound that promotes solubility in a developer, a compound whose basicity is reduced by exposure (photobase), and the like.

As the surfactant that can be used in the positive photoresist composition of the present invention, a fluorine-based and / or silicon-based surfactant is suitably used, and a fluorine-based surfactant, a silicon-based surfactant and a fluorine atom And any one or more surfactants containing both silicon atoms.

As these surfactants, for example, those described in
62-36663, 61-226746, 61-226745, 62-170
950, 63-34540, JP-A-7-230165, 8-62834
Nos. 9-54432, 9-5988, U.S. Pat.No. 5,405,720, U.S. Pat.No. 5,360,692, U.S. Pat.
No. 0, US Pat. No. 5,436,098, US Pat. No. 5,576,143, US Pat. No. 5,294,511 and US Pat. No. 5,824,451. The following commercially available surfactants can be used as they are.

Examples of commercially available surfactants that can be used include, for example, F-Top EF301 and EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florado FC430 and 431 (manufactured by Sumitomo 3M Limited), Megafac F171, F173, and F176. F189, R08 (Dainippon Ink Co., Ltd.)
Manufactured), Surflon S-382, SC101, 102, 103, 104, 10
5, 106 (manufactured by Asahi Glass Co., Ltd.) and fluorinated surfactants such as Troysol S-366 (manufactured by Troy Chemical Co., Ltd.) or silicon-based surfactants. Also, polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can be used as a silicon-based surfactant.

The amount of these surfactants is usually 0.001% by weight based on the solid content in the composition of the present invention.
To 2% by weight, preferably 0.01% to 1% by weight. These surfactants may be added alone or in some combination.

Examples of the surfactant which can be used in addition to the above include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene oleyl ether and the like. Polyoxyethylene alkyl allyl ethers such as ethylene alkyl ethers, polyoxyethylene octyl phenol ether, polyoxyethylene nonyl phenol ether, polyoxyethylene / polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostea Sorbitan esters such as sorbitan monooleate, sorbitan trioleate, sorbitan tristearate, polyoxyethylene Nonionics such as fatty acid esters of polyoxyethylene sorbitan such as rubitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate Surfactants and the like.

The amount of these other 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.

Examples of the acid-decomposable dissolution-inhibiting compound that can be used in the positive photoresist composition of the present invention include low-molecular acid-decomposable, dissolution-inhibiting compounds described in JP-A-5-134415 and JP-A-6-51519. Compounds can be used.

Examples of the plasticizer that can be used in the positive photoresist composition of the present invention include JP-A-4-212960,
JP-A-8-262720, EP 735422,
Compounds described in EP 416873, EP 439371 and U.S. Pat. No. 5,846,690, specifically, di (2-ethylhexyl) adipate, n-hexyl benzoate, di-n-octyl phthalate, di-n-phthalate -Butyl, benzyl phthalate-n-butyl, dihydroabiethyl phthalate and the like.

Examples of the compound which can be used in the present invention and which promotes solubility in a developer include, for example, JP-A No. 4-13 / 1990.
No. 4345, JP-A-4-217251, JP-A-7-1
No. 81680, JP-A-8-212597, U.S. Pat.
And polyhydroxy compounds described in JP-A Nos. 688628 and 5972559. Examples thereof include 1,1-bis (4-hydroxyphenyl) cyclohexane, 4,4- (α-methylbenzylidene) bisphenol, and α, α ′, α ″ -tris. (4-hydroxyphenyl) -1,3,5-triisopropylbenzene, α, α ′, α ″ -tris (4-hydroxyphenyl) -1-ethyl-4-isopropylbenzene, 1,2,2-tris ( (Hydroxyphenyl) propane, 1,1,2-tris (3,5-dimethyl-4-hydroxyphenyl) propane, 2,2,5,5-tetrakis (4-hydroxyphenyl) hexane, 1,2-tetrakis (4 -Hydroxyphenyl) ethane, 1,1,3
Tris (hydroxyphenyl) butane, para [α,
Aromatic polyhydroxy compounds such as α, α ′, α′-tetrakis (4-hydroxyphenyl)]-xylene are preferably used. Also, salicylic acid, diphenolic acid,
Organic acids such as phenolphthalein can also be used, and JP-A Nos. 5-181263 and 7-92.
680, sulfonamide compounds described in JP-A-4-24
No. 8554, No. 5-181279, No. 7-92679
And carboxylic acid anhydrides described in JP-A No.
An alkali-soluble resin such as a polyhydroxystyrene resin described in 1-153869 can also be added.

Suitable dyes that can be used in the present invention include oily dyes and basic dyes. Specifically, Oil Yellow # 101, Oil Yellow # 103, Oil Pink #
312, oil green BG, oil blue BOS, oil blue # 603, oil black BY, oil black BS, oil black T-505 (all manufactured by Orient Chemical Industry Co., Ltd.), crystal violet (CI
42555), methyl violet (CI4253)
5), rhodamine B (CI45170B), malachite green (CI42000), methylene blue (CI5
2015).

Furthermore, the composition of the present invention contains
No. 28247, European Patent 616258, US Pat.
25443, JP-A-9-127700, European Patent 7
No. 62207 and the ammonium salts described in U.S. Pat. No. 5,783,354, specifically, tetramethylammonium hydroxide, tetra-n-butylammonium hydroxide, betaine and the like can be added.
No. 6, No. 6-11835, No. 6-242606, No. 6-266100, No. 7-338381, No. 7-3
No. 33844, US Pat. No. 5,663,035, European Patent No. 6
A compound (photobase) whose basicity is reduced by exposure described in 77788 can also be added.

Further, a spectral sensitizer as described below is added to sensitize the photosensitive composition of the present invention to a longer wavelength region than the deep ultraviolet where the photoacid generator used has no absorption. Sensitivity can be given to i-line or g-line. Suitable spectral sensitizers include, specifically, 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-nitrofluorene, 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), coronene and the like, but are not limited thereto.

These spectral sensitizers can also be used as a light absorbing agent for far ultraviolet light as a light source. In this case, the light absorbing agent can reduce the reflected light from the substrate and reduce the effect of multiple reflection in the resist film, thereby reducing the standing wave.

Examples of the photobase generator which can be added to the composition of the present invention include JP-A-4-151156 and JP-A-4-1620.
Nos. 40, 5-197148, 5-5995, 6-194834, 8-146608, and 10-
No. 83079 and EP 622682. Specific examples thereof include 2-nitrobenzyl carbamate, 2,5-dinitrobenzylcyclohexyl carbamate, N-cyclohexyl-4-methylphenylsulfonamide, and 1,1- Dimethyl-2-phenylethyl-
N-isopropyl carbamate and the like can be suitably used. These photobase generators are added for the purpose of improving the resist shape and the like.

Examples of the thermal base generator include, for example, those described in
No. 158242, No. 5-158239, U.S. Pat.
No. 76143.

Such a positive resist composition of the present invention is applied on a substrate to form a thin film. The thickness of this coating film is preferably from 0.2 to 4.0 μm.

In the present invention, if necessary, a commercially available inorganic or organic antireflection film can be used. Further, an antireflection film can be applied to the upper layer of the resist and used.

The antireflection film used as the lower layer of the resist may be any of an inorganic film type such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon and amorphous silicon, and an organic film type comprising a light absorbing agent and a polymer material. Can be used. The former is a vacuum evaporation system for film formation, C
Equipment such as VD equipment and sputtering equipment is required.
As the organic antireflection film, for example, Japanese Patent Publication No. 7-69611
US Pat. No. 5,294,680, comprising a condensate of a diphenylamine derivative and a formaldehyde-modified melamine resin, an alkali-soluble resin, and a light absorbing agent; a reaction product of a maleic anhydride copolymer and a diamine type light absorbing agent described in US Pat. JP-A-6-18631, containing a resin binder and a methylolmelamine-based thermal crosslinking agent
Acrylic resin type antireflection film having a carboxylic acid group, an epoxy group and a light absorbing group in the same molecule described in 18656, one comprising methylolmelamine and a benzophenone-based light absorbing agent described in JP-A-8-87115, and JP-A-8-17950
No. 9 obtained by adding a low-molecular-weight light absorbing agent to the polyvinyl alcohol resin.

Examples of the organic antireflection film include DUV30 series manufactured by Brewer Science and DUV-4.
0 series, Shipley AR-2, AR-3, AR
A commercially available organic antireflection film such as -5 can also be used.

The resist solution is applied on a substrate (eg, silicon / silicon dioxide coating) used for manufacturing precision integrated circuit devices (on a substrate provided with the antireflection film if necessary), a spinner, a coater, and the like. After coating by an appropriate coating method such as that described above, exposure through a predetermined mask, baking and development can provide a good resist pattern. Here, the exposure light is preferably 150
It is light having a wavelength of nm to 250 nm. Specifically, Kr
F excimer laser (248 nm), ArF excimer laser (193 nm), F2 excimer laser (157
nm), X-rays, electron beams and the like. In the present invention, an apparatus using a KrF excimer laser as an exposure light source is particularly preferably used.

Examples of the developer used in the composition of the present invention include inorganic alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine and the like. Primary amines, diethylamine, di-n-
Secondary amines such as butylamine, tertiary amines such as triethylamine and methyldiethylamine, alcoholamines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, trimethylhydroxyethylammonium hydroxide and the like And quaternary ammonium salts, and alkaline aqueous solutions of cyclic amines such as pyrrole and pyrhelidine.

Further, alcohols and surfactants can be added to the above-mentioned alkaline aqueous solution in appropriate amounts, and used. A commercially available developer to which a surfactant is added, for example, HPRD-402, -402Z manufactured by Fuji Film Ohlin Co., Ltd.
Etc. can be used.

Further, an appropriate amount of an anionic surfactant, a cationic surfactant, an antifoaming agent or the like may be added. These additives may be used to improve the performance of the resist, increase the adhesion to the substrate, reduce the amount of developer used, or reduce defects caused by bubbles during development. Added to the aqueous solution.

[0146]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to the following examples. [Synthesis of Resin] Resin can be synthesized by acetalization using either a method using vinyl ether or an acetal exchange method using alcohol and alkyl vinyl ether. Further, for efficient and stable synthesis, a dehydration azeotropic method as described below can be used. However, it is not limited to these synthesis methods.

Synthesis Example 1 (Resin R-1) 32.4 g (0.2 mol) of p-acetoxystyrene was dissolved in 120 ml of butyl acetate, and dissolved in a stream of nitrogen and stirred.
At 0 ° C., azobisisobutyronitrile (AIBN)
033 g was added three times every 2.5 hours, and finally another 5
The polymerization reaction was performed by continuing stirring for a time. The reaction solution was poured into 1200 ml of hexane to precipitate a white resin. After drying the obtained resin, methanol 150 ml
Was dissolved. 7.7 g of sodium hydroxide (0.1 g
(9 mol) / water (50 ml) was added, and the mixture was heated under reflux for 3 hours for hydrolysis. After that, 200m of water
The mixture was diluted with 1 and neutralized with hydrochloric acid to precipitate a white resin. This resin was separated by filtration, washed with water and dried. Further, the resultant was dissolved in 200 ml of tetrahydrofuran and dropped and reprecipitated in 5 liter of ultrapure water with vigorous stirring. This reprecipitation operation was repeated three times. The obtained resin was dried in a vacuum dryer at 120 ° C. for 12 hours to obtain a poly (p-hydroxystyrene) alkali-soluble resin R-1. The weight average molecular weight of the obtained resin was 12,000.

Synthesis Example 2 (Resin R-2) 35.25 g (0.2 mol) of a p-tert-butoxystyrene monomer and 5.21 g (0.2 mol) of a p-tert-butoxystyrene monomer dehydrated and purified by a conventional method. 0.05 mol) was dissolved in 100 ml of tetrahydrofuran. Under a nitrogen stream and stirring, at 80 ° C., 0.033 g of azobisisobutyronitrile (AIBN) was added three times every 2.5 hours, and finally, stirring was continued for another 5 hours to carry out a polymerization reaction. . The reaction solution was poured into 1200 ml of hexane to precipitate a white resin. After drying the obtained resin,
It was dissolved in 150 ml of tetrahydrofuran. This is 4N
Hydrochloric acid was added thereto, and the mixture was hydrolyzed by heating under reflux for 6 hours and then reprecipitated in 5 liters of ultrapure water. The resin was separated by filtration, washed with water and dried. Furthermore, tetrahydrofuran 20
It was dissolved in 0 ml and dropped and reprecipitated in 5 liter of ultrapure water with vigorous stirring. This reprecipitation operation was repeated three times. The obtained resin was dried in a vacuum dryer at 120 ° C. for 12 hours to obtain a poly (p-hydroxystyrene / t-butylstyrene) copolymer alkali-soluble resin R-2.
The weight average molecular weight of the obtained resin was 12,000.

Synthesis Example-3 (Resin R-3) Poly (p-hydroxystyrene) manufactured by Nippon Soda Co., Ltd.
(VP8000) was designated as alkali-soluble resin R-3.
The weight average molecular weight was 9,800.

Synthesis Example-4 (Resin R-4) Poly (p-hydroxystyrene) manufactured by Nippon Soda Co., Ltd.
(VP15000) was designated as alkali-soluble resin R-4. The weight average molecular weight was 17,000.

[Synthesis Example-5] Synthesis of Alkali-Soluble Resin B-1 20 g of alkali-soluble resin R-2 obtained in the above Synthesis Example 320 g of propylene glycol monomethyl ether acetate (PGMEA) was dissolved in a flask, and distillation under reduced pressure was performed. Done, water and PGME
A was distilled off azeotropically. After confirming that the water content was sufficiently low, 24 g of ethyl vinyl ether and 0.35 g of p-toluenesulfonic acid were added, and the mixture was stirred at room temperature for 1 hour.
Thereto was added 0.28 g of triethylamine to terminate the reaction. Ethyl acetate was added to the reaction solution, and after further washing with water, ethyl acetate, water and an azeotropic PGMEA were distilled off under reduced pressure to obtain a resin B protected with an acid-decomposable group according to the present invention.
-1 was obtained.

[Synthesis Example-6] Synthesis of alkali-soluble resin B-2 70 g of alkali-soluble resin R-3 obtained in the above Synthesis Example 320 g of PGMEA was dissolved in a flask, and distilled under reduced pressure to obtain water and PGME.
A was distilled off azeotropically. After confirming that the water content was sufficiently low, 28 g of benzyl alcohol, 26 g of t-butyl vinyl ether and 0.35 g of p-toluenesulfonic acid were added, and the mixture was stirred at room temperature for 1 hour. After adding 0.1 g of triethylamine and stirring at room temperature for 10 minutes to terminate the reaction, ethyl acetate was added to the reaction solution, followed by washing with water, followed by distillation under reduced pressure to remove ethyl acetate, water and an azeotropic PGMEA. Is removed, and the resin B protected with an acid-decomposable group according to the present invention is removed.
-2 was obtained.

[Synthesis Example-7] Synthesis of Alkali-Soluble Resin B-3 70 g PGMEA 320 g of the alkali-soluble resin R-2 obtained in the above Synthesis Example was dissolved in a flask, and distilled under reduced pressure to obtain water and PGME.
A was distilled off azeotropically. After confirming that the water content was sufficiently low, 20 g of cyclohexylethanol, 15.5 g of t-butyl vinyl ether and 0.1 g of p-toluenesulfonic acid were added.
35 g was added, and the mixture was stirred at room temperature for 1 hour. After adding 0.28 g of triethylamine and stirring at room temperature for 10 minutes to terminate the reaction, ethyl acetate was added to the reaction solution, followed by washing with water, followed by distillation under reduced pressure to remove ethyl acetate, water and an azeotropic PGMEA. Was distilled off to obtain a resin B-3 protected by an acid-decomposable group according to the present invention.

[Synthesis Example-8] Synthesis of Alkali-Soluble Resin B-4 70 g PGMEA 320 g of the alkali-soluble resin R-3 obtained in the above Synthesis Example was dissolved in a flask, and distilled under reduced pressure to obtain water and PGME.
A was distilled off azeotropically. After confirming that the water content was sufficiently low, 22 g of cyclohexylethanol, 17.5 g of t-butyl vinyl ether and 0.1 g of p-toluenesulfonic acid were added.
35 g was added, and the mixture was stirred at room temperature for 1 hour. After adding 0.28 g of triethylamine and stirring at room temperature for 10 minutes to terminate the reaction, ethyl acetate was added to the reaction solution, followed by washing with water, followed by distillation under reduced pressure to remove ethyl acetate, water and an azeotropic PGMEA. Was distilled off to obtain a resin B-4 protected by an acid-decomposable group according to the present invention.

[Synthesis Example-9] Synthesis of alkali-soluble resin B-5 20 g of alkali-soluble resin R-4 obtained in the above Synthesis Example 320 g of PGMEA was dissolved in a flask, and distilled under reduced pressure to obtain water and PGME.
A was distilled off azeotropically. After confirming that the water content was sufficiently low, 22.4 g of cyclohexylethanol, 17.5 g of t-butyl vinyl ether and 0.35 g of p-toluenesulfonic acid were added, and the mixture was stirred at room temperature for 1 hour. Then 5.5 g of pyridine and 5.9 g of acetic anhydride were added thereto, and the mixture was stirred at room temperature for 1 hour. Ethyl acetate was added to the reaction solution, and after further washing with water, ethyl acetate, water and an azeotropic PGMEA were distilled off under reduced pressure to obtain a resin B-5 protected by an acid-decomposable group according to the present invention. Was.

[Synthesis Example-10] Synthesis of Alkali-Soluble Resin B-6 20 g PGMEA 320 g of the alkali-soluble resin R-1 obtained in the above Synthesis Example was dissolved in a flask, and distilled under reduced pressure to obtain water and PGME.
A was distilled off azeotropically. After confirming that the water content was sufficiently low, 22.4 g of cyclohexylethanol, 17.5 g of t-butyl vinyl ether and 0.35 g of p-toluenesulfonic acid were added, and the mixture was stirred at room temperature for 1 hour. Then 5.5 g of pyridine and 5.9 g of acetic anhydride were added thereto, and the mixture was stirred at room temperature for 1 hour. Ethyl acetate was added to the reaction solution, and after further washing with water, ethyl acetate, water, and an azeotropic PGMEA were distilled off under reduced pressure to obtain a resin B-6 protected by an acid-decomposable group according to the present invention. Was.

Example 1 A photosensitive resin composition having the following composition was mixed at a solid content of about 12% by weight.
The solution was filtered through a 0.1 μm microfilter to prepare a positive photoresist. Composition: Resin: 96.37 parts by weight of resin (B-1) obtained in Synthesis Example 5 Acid generator: (A-1) 3.50 Compound of the present invention: (C-1) 0.10 Surface activity Agent: The following (W-2) 0.030 Solvent: The following (S-1) 733.33 The obtained positive photoresist solution was applied to a DUV manufactured by Brewer Science using a spin coater (Mark 8 manufactured by Tokyo Electron Limited). -42 is applied on a 6-inch silicon wafer coated at 60 nm, and is applied at 120 ° C. for 90 seconds.
Heat treatment with a vacuum adsorption type hot plate, about 0.4μ
m of the resist film was formed. Then, pattern exposure was carried out using a KrF excimer laser (FPA-3000EX5 manufactured by Canon Inc., wavelength: 248 nm, NA = 0.63). After exposure, a heat treatment (PEB) was performed at 100 ° C. for 90 seconds, immediately developed with a 2.38% by weight aqueous solution of tetramethylammonium hydroxide, subsequently rinsed with pure water, and then spin-dried to obtain a resist pattern.

[Example 2-8 and Comparative Example 1-5] Example 1
In the same manner as described above, a photosensitive resin composition having the following composition was mixed so that the solid content concentration was about 12% by weight, and 0.1 μm was obtained.
m, filtered through a Teflon (registered trademark) microfilter, and a positive photoresist was prepared to form a resist pattern.

Composition of photosensitive resin composition of Example 2: Resin: resin obtained in Synthesis Example 5 (B-1) 94.78 parts by weight Acid generator: (A-1) 2.50 Acid generator : (A-3) 2.50 Compound of the present invention: (C-1) 0.10 Acid scavenger: (D-1) 0.10 Surfactant: (W-2) 0.02 Solvent: the following (S-1) 513.33 The following (S-6) 220.00

Composition of photosensitive resin composition of Example 3: Resin: 94.24 parts by weight of resin (B-1) obtained in Synthesis Example 5 Acid generator: (A-2) 3.50 Acid generator : The following (A-3) 2.00 Compound of the present invention: the above (C-2) 0.20 Acid scavenger: the following (D-2) 0.05 Surfactant: the following (W-2) 0.01 Solvent: The following (S-1) 586.66 The following (S-3) 146.67

Composition of photosensitive resin composition of Example 4: Resin: 96.78 parts by weight of resin (B-2) obtained in Synthesis Example 6 Acid generator: (A-1) 3.00 The present invention Compound: The following (C-1) 0.20 Surfactant: The following (W-1) 0.20 Solvent: The following (S-1) 660.00 The following (S-5) 73.33

Composition of Photosensitive Resin Composition of Example 5: Resin: 92.08 parts by weight of resin (B-3) obtained in Synthesis Example 7 Acid generator: following (A-1) 4.50 following (A) -3) 3.0 Compound of the present invention: (C-1) 0.30 Acid scavenger: (D-2) 0.10 Surfactant: (W-2) 0.02 Solvent: ( S-1) 513.33 The following (S-4) 220.00

Composition of photosensitive resin composition of Example 6: Resin: 89.23 parts by weight of resin (B-4) obtained in Synthesis Example 8 Acid generator: (A-1) 2.50 -2) 2.50 Compound of the present invention: (C-4) 0.40 Surfactant: (W-1) 0.02 Solvent: (S-2) 733.33

Composition of Photosensitive Resin Composition of Example 7: Resin: 93.48 parts by weight of resin (B-5) obtained in Synthesis Example 9 Acid generator: (A-1) 6.0 Compound: (C-1) 0.30 Acid scavenger: (D-2) 0.20 Surfactant: (W-2) 0.02 Solvent: (S-1) 696.66 S-7) 36.67

Composition of Photosensitive Resin Composition of Example 8: Resin: 93.47 parts by weight of resin (B-6) obtained in Synthesis Example 10 Acid generator: (A-1) 3.00 -3) 3.00 Compound of the invention: (C-1) 0.50 Surfactant: (W-1) 0.03 Solvent: (S-1) 586.66 (S-3) 146.67

Composition of photosensitive resin composition of Comparative Example 1: Resin: 97.86 parts by weight of resin (B-1) obtained in Synthesis Example 5 Acid generator: (A-1) 2.00 Acid scavenger : (D-1) 0.100 Surfactant: (W-2) 0.04 Solvent: (S-1) 733.33

Composition of photosensitive resin composition of Comparative Example 2: Resin: 98.28 parts by weight of resin (B-4) obtained in Synthesis Example 8 Acid generator: (A-2) 1.50 Acid scavenger : (D-1) 0.200 Surfactant: (W-1) 0.02 Solvent: (S-1) 733.33

[Comparative Example 3] Using trimethylammonium butyrobetaine described in Examples of JP-A-9-127700 as an additive, a photosensitive resin composition having the following composition was adjusted to a solid content of about 12% by weight. The mixture was mixed to obtain a positive-type photoresist, and filtered through a 0.1 μm Teflon microfilter to form a resist pattern. Resin: Resin (B-1) obtained in Synthesis Example 5 96.68 parts by weight Acid generator: (A-1) 3.0 Trimethylammonium butyrobetaine 0.30 Surfactant: (W-1) 0.02 Solvent: 733.33 below (S-1)

[Comparative Example 4] JP-A-9-127700, European Patent 8
No. 13113, using a tetra-n-butylammonium lactate as an additive, a photosensitive resin composition having the following composition was mixed so as to have a solid concentration of about 12% by weight, and a 0.1 μm Teflon micro After filtering through a filter, a positive photoresist was prepared to form a resist pattern. Resin: 96.58 parts by weight of resin (B-1) obtained in Synthesis Example 5 Acid generator: (A-1) 3.0 Tetra-n-butylammonium lactate 0.30 Acid scavenger: (D- 1) 0.10 Surfactant: The following (W-2) 0.02 Solvent: The following (S-1) 733.33

[Comparative Example 5] Using a tetraethylammonium acetate described in Examples of JP-A-9-127700 as an additive, a photosensitive resin composition having the following composition has a solid content of about 12% by weight. And filtered with a 0.1 μm Teflon microfilter to prepare a positive photoresist to form a resist pattern. Resin: 96.48 parts by weight of resin (B-1) obtained in Synthesis Example 5 Acid generator: (A-3) 3.0 Tetraethylammonium acetate 0.50 Surfactant: (W-1) 02 solvent: the following (S-1) 733.33

The compounds of the present invention used above are shown below. As the compounds (C-1) and (C-2), those purchased as reagents from Tokyo Chemical Industry Co., Ltd. were used as they were. Compound (C-3) was used as purchased from Aldrich as a reagent.

The acid generators (A-1) to (A-
3) and acid scavengers (D-1) and (D-2) are shown below.

[0173]

Embedded image

The surfactants (W-1) and (W-2) used above are shown below. W-1: Megafac R08 (Dai Nippon Ink Co., Ltd.) W-2: Troysol S-366 (Troy Chemical Co., Ltd.)
The solvents (S-1) to (S-7) used are shown below. S-1: propylene glycol monomethyl ether acetate S-2: propylene glycol monomethyl ether propionate S-3: propylene glycol monomethyl ether S-4: ethoxyethyl propionate S-5: γ-butyrolactone S-6: ethyl lactate S-7: Propylene carbonate

The resulting resist pattern was evaluated for sensitivity, resolution, depth of focus, line edge roughness, and shape by the following methods. [Sensitivity] The minimum exposure amount for reproducing a 0.16 μm line pattern on the mask was shown. [Resolution] The width of a line pattern that can be resolved with the minimum exposure amount that reproduces the 0.16 μm line pattern of the mask
(μm), that is, the critical resolution. [Depth of focus] The focal point is moved up and down to expose a minimum exposure amount that reproduces a 0.16 μm line pattern on the mask.
4 shows an allowable focus range in which a 6 μm line pattern can be reproduced. [Line edge roughness] 0.16 μm in mask
5 μm in the longitudinal direction of a 0.16 μm line pattern obtained by the minimum exposure amount reproducing the line pattern
In the range of m, the distance from the reference line where the edge should be located was measured at 50 points by S-8840 manufactured by Hitachi, Ltd., the standard deviation was determined, and 3σ was calculated. The smaller the value, the better the performance. [Shape] The cross-sectional shape of the 0.16 μm line pattern obtained by the minimum exposure amount for reproducing the 0.16 μm line pattern on the mask was observed with a scanning electron microscope. A rectangular shape was indicated by ○, and a tapered shape was indicated by ×. A slightly tapered shape is indicated by a triangle.

[0176]

[Table 1]

As shown in Table 1, the resist composition of the present invention showed satisfactory results in all of sensitivity, resolution, depth of focus, line edge roughness, and shape. In particular, the line edge roughness is a remarkably good result.

[0178]

The present invention can provide a positive resist composition which is suitable for far ultraviolet light, particularly KrF excimer laser light, has improved line edge roughness, and is excellent in sensitivity, resolution, depth of focus and resist shape.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03F 7/004 501 G03F 7/004 501 H01L 21/027 H01L 21/30 502R F-term (Reference) 2H025 AA01 AA02 AA03 AB16 AC04 AD03 BE00 BE07 BE10 BF15 BG00 CB45 CC20 FA17 4J002 AA001 BC041 BC091 BC121 EN138 ER027 EU186 EU207 EU226 FD206 FD207 FD208 GP03

Claims (3)

[Claims] 1. A compound which generates an acid upon irradiation with actinic rays or radiation, (B) a resin which is insoluble or hardly soluble in alkali and becomes alkali-soluble by the action of an acid, and (C) A positive photoresist composition comprising a tetraalkylammonium internal salt represented by the following general formula (I) or (II). Embedded image (In the general formulas (I) and (II), R ₁ , R ₂ , and R
₃ each independently represents an alkyl group having 1 to 6 carbon atoms. ) 2. The resin of (B) has the following general formula (IV)
The positive photoresist composition according to claim 1, comprising a repeating unit represented by (V) or (V). Embedded image (L represents a hydrogen atom, an optionally substituted linear, branched or cyclic alkyl group, or an optionally substituted aralkyl group. Z represents an optionally substituted, linear or branched Or a cyclic alkyl group or an aralkyl group which may be substituted.
Alternatively, a 6-membered ring may be formed. ) 3. The positive photoresist composition according to claim 1, wherein the positive photoresist composition further comprises (D) a nitrogen-containing basic compound as an acid scavenger.