JP2003057815A - Chemical amplification type resist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemical amplification type positive resist composition suitable for lithography with an excimer laser such as ArF or KrF, having good various resist performances such as sensitivity and resolution and giving improved line edge roughness. SOLUTION: The chemical amplification type positive resist composition comprises a resin which is alkali-insoluble and is made alkali-soluble by the action of an acid, an acid generator and a biadamantane derivative such as a compound of formula (I) (where R1 and R2 are each H or an ester group).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a chemically amplified positive resist composition used for fine processing of semiconductors.

[0002]

2. Description of the Related Art A lithographic process using a resist composition is usually employed for fine processing of semiconductors.
In lithography, Rayleigh
As represented by the expression of the diffraction limit of h), in principle, the shorter the exposure wavelength, the higher the resolution can be. The exposure light source for lithography used for manufacturing semiconductors is a g-line with a wavelength of 436 nm, an i-line with a wavelength of 365 nm, and a wavelength of 248.
The wavelength of the KrF excimer laser of nm is becoming shorter year by year, and the ArF excimer laser of wavelength 193 nm is expected as a next-generation exposure light source.

Since the lens used in the ArF excimer laser exposure machine has a shorter life than that used in the conventional exposure light source, it is desirable that the exposure time to the ArF excimer laser light is as short as possible. For that purpose, since it is necessary to increase the sensitivity of the resist, a so-called chemically amplified resist containing a resin having a group that is cleaved by the acid by utilizing the catalytic action of an acid generated by exposure is used.

However, in the conventionally known chemically amplified resist composition, the line edge roughness, that is, the smoothness of the pattern side wall is lowered due to the generation of standing waves, etc.
There was a problem that the uniformity of the line width deteriorates.

[0005]

The object of the present invention is to provide Ar
A chemically amplified positive resist composition suitable for excimer laser lithography such as F and KrF, which has various resist performances such as sensitivity and resolution, and a positive resist composition that provides particularly improved line edge roughness. It is to provide a chemically amplified resist composition.

The inventors of the present invention have conducted extensive studies on a chemically amplified positive resist composition in order to improve line edge roughness, and as a result, have found that a chemically amplified positive resist containing a specific compound, a biadamantane derivative, is contained. The present inventors have completed the present invention by finding that the composition not only gives improved line edge roughness, but also has various resist performances.

[0007]

[Means for Solving the Problems] That is, the present invention provides a chemical composition containing a resin, an acid generator, and a biadamantane derivative, which is insoluble in an alkaline aqueous solution itself but becomes soluble in the alkaline aqueous solution by the action of an acid. The present invention relates to an amplified positive resist composition.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The chemically amplified positive type composition of the present invention is characterized by containing a specific compound called a biadamantane derivative. Examples of the biadamantane derivative include at least one selected from the compounds represented by the following formula (I). (I) (In the formula, R ₁ and R ₂ each independently represent hydrogen or an ester group.) Further, as the biadamantane derivative, preferably,
At least one selected from the compounds represented by the following formula (II) can be mentioned. (II) (In the formula, R ₃ and R ₄ independently represent an acid labile group which dissociates in the presence of an acid.) Here, the acid dissociated in the presence of an acid represented by R ₃ and R ₄ . As the unstable group, a group in which a quaternary carbon is bonded to an oxygen atom, such as tert-butyl, tert-butoxycarbonyl or tert-butoxycarbonylmethyl; tetrahydro-2-pyranyl, tetrahydro-2-furyl, 1-ethoxyethyl ,
1- (2-methylpropoxy) ethyl, 1- (2-methoxyethoxy) ethyl, 1- (2-acetoxyethoxy) ethyl, 1- [2- (1-adamantyloxy) ethoxy] ethyl or 1- [2- Acetal-type groups such as (1-adamantanecarbonyloxy) ethoxy] ethyl; 3-oxocyclohexyl, 4-methyltetrahydro-2-pyron-4-yl (derived from mevalonic lactone) or 2-methyl-2. -Adamantyl, 2-
Examples thereof include residues of non-aromatic cyclic compounds such as ethyl-2-adamantyl. Specific examples of the biadamantane derivative represented by the formula (II) include compounds represented by the following formula (III).

[0009] (III)

The chemically amplified resist composition of the present invention contains, in addition to the biadamantane derivative, a resin that is itself insoluble in an alkaline aqueous solution as a binder component, but becomes soluble in the alkaline aqueous solution by the action of an acid. It contains an active compound that generates an acid by the action of radiation as an acid generator, and utilizes the catalytic action of the acid generated from the acid generator in the irradiated area. In the chemically amplified positive resist, the acid generated in the radiation irradiation part is treated by the post heat treatment (post expos
By ure bake), the protective groups such as the resin are cleaved, and the acid is regenerated to solubilize the radiation irradiated part with an alkali.

In the chemically amplified positive resist composition, a resin which is insoluble in an alkaline aqueous solution itself but becomes soluble in the alkaline aqueous solution by the action of an acid is a protective agent having a dissolution inhibiting ability in the alkaline aqueous solution. Examples of the resin include a resin which has a group and becomes alkali-soluble after the protective group is cleaved by the action of an acid.

The resin which is insoluble in the alkaline aqueous solution itself but is soluble in the alkaline aqueous solution itself is, for example, a resin having a phenol skeleton or (meth).
Examples thereof include resins having an acrylate ester skeleton and having an alicyclic ring and a carboxyl group on the alcohol side of the ester. Specifically, polyvinylphenol resins, polyisopropenylphenol resins, resins in which some of the hydroxyl groups of these polyvinylphenol resins or polyisopropenylphenol resins have been alkyletherified, vinylphenol or isopropenylphenol and other polymerizable A copolymer resin with a saturated compound, a polymer of an alicyclic ester of (meth) acrylic acid, which has a carboxyl group in its alicyclic ring, a cycloaliphatic ester of (meth) acrylic acid and (meth ) Examples include copolymer resins with acrylic acid.

A protective group capable of inhibiting dissolution in an alkaline aqueous solution. As a protective group which is cleaved by the action of an acid, for example, tert-butyl, tert-butoxycarbonyl or tert-butoxy is used. A group in which a quaternary carbon is bonded to an oxygen atom, such as carbonylmethyl; tetrahydro-2-pyranyl, tetrahydro-2-furyl, 1-ethoxyethyl, 1- (2-methylpropoxy) ethyl, 1
Of-(2-methoxyethoxy) ethyl, 1- (2-acetoxyethoxy) ethyl, 1- [2- (1-adamantyloxy) ethoxy] ethyl or 1- [2- (1-adamantanecarbonyloxy) ethoxy] ethyl Acetal-type groups such as 3-oxocyclohexyl, 4-methyltetrahydro-2-pyron-4-yl (derived from mevalonic lactone) or 2-methyl-2-adamantyl, 2-ethyl-2-adamantyl Residues of such non-aromatic cyclic compounds are included, and these groups are replaced with hydrogen of a phenolic hydroxyl group or hydrogen of a carboxyl group. These protective groups can be introduced into an alkali-soluble resin having a phenolic hydroxyl group or a carboxyl group by a known protective group introduction reaction. Further, the above resin can be obtained by copolymerizing an unsaturated compound having such a group as one monomer.

The acid generator in the present invention can be various compounds that generate an acid by irradiating the substance itself or a resist composition containing the substance with radiation. Examples thereof include onium salts, halogenated alkyltriazine compounds, disulfone compounds, compounds having a diazomethanesulfonyl skeleton, and sulfonate compounds. Specific examples of such an acid generator are as follows.

Diphenyliodonium trifluoromethanesulfonate, 4-methoxyphenylphenyliodonium hexafluoroantimonate, 4-methoxyphenylphenyliodonium trifluoromethanesulfonate, bis (4-tert-butylphenyl) iodonium tetrafluoroborate, bis (4-tert-
Butylphenyl) iodonium hexafluorophosphate, bis (4-tert-butylphenyl) iodonium hexafluoroantimonate, bis (4-tert-
Butylphenyl) iodonium trifluoromethanesulfonate,

Triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium trifluoromethanesulfonate, 4-methoxyphenyldiphenylsulfonium hexafluoroantimonate, 4-methoxyphenyldiphenylsulfonium trifluoromethanesulfonate, p-tolyldiphenyl Sulfonium trifluoromethanesulfonate, p-
Tolyldiphenylsulfonium perfluorobutanesulfonate, p-tolyldiphenylsulfonium perfluorooctanesulfonate, 2,4,6-trimethylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-tert-butylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-
Phenylthiophenyldiphenylsulfonium hexafluorophosphate, 4-phenylthiophenyldiphenylsulfonium hexafluoroantimonate,
1- (2-naphthoylmethyl) thioranium hexafluoroantimonate, 1- (2-naphthoylmethyl)
Thioranium trifluoromethanesulfonate, 4-
Hydroxy-1-naphthyldimethylsulfonium hexafluoroantimonate, 4-hydroxy-1-naphthyldimethylsulfonium trifluoromethanesulfonate, cyclohexylmethyl (2-oxocyclohexyl) sulfonium trifluoromethanesulfonate, cyclohexylmethyl (2-oxocyclohexyl) sulfonium perfluorobutane Sulfonate,
Cyclohexylmethyl (2-oxocyclohexyl) sulfonium perfluorooctane sulfonate,

2-Methyl-4,6-bis (trichloromethyl) -1,3,5-triazine, 2,4,6-tris (trichloromethyl) -1,3,5-triazine, 2-
Phenyl-4,6-bis (trichloromethyl) -1,3
5-triazine, 2- (4-chlorophenyl) -4,6
-Bis (trichloromethyl) -1,3,5-triazine, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4
-Methoxy-1-naphthyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (benzo [d] [1,3] dioxolan-5-yl) -4,6-
Bis (trichloromethyl) -1,3,5-triazine,
2- (4-methoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (3
4,5-trimethoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (3
4-dimethoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (2,4-dimethoxystyryl) -4,6-bis (trichloromethyl) -1,3,5 -Triazine, 2- (2-methoxystyryl) -4,6-bis (trichloromethyl) -1,3
5-triazine, 2- (4-butoxystyryl) -4,
6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-pentyloxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine,

Diphenyl disulfone, di-p-tolyl disulfone, bis (phenylsulfonyl) diazomethane, bis (4-chlorophenylsulfonyl) diazomethane, bis (p-tolylsulfonyl) diazomethane, bis (4-tert-butylphenylsulfonyl) diazomethane, Bis (2,4-xylylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane,
(Benzoyl) (phenylsulfonyl) diazomethane,

1-benzoyl-1-phenylmethyl p
-Toluene sulfonate (common name benzoin tosylate), 2-benzoyl-2-hydroxy-2-phenylethyl p-toluene sulfonate (common name α-methylol benzoin tosylate), 1,2,3-benzenetriyl trismethane sulfonate, 2 , 6-dinitrobenzyl p-toluenesulfonate, 2-nitrobenzyl p-toluenesulfonate, 4-nitrobenzyl
p-toluenesulfonate,

N- (phenylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) succinimide, N- (trifluoromethylsulfonyloxy) phthalimide, N- (trifluoromethylsulfonyloxy) -5-norbornene-2, 3-dicarboximide, N- (trifluoromethylsulfonyloxy) naphthalimide, N- (10-camphorsulfonyloxy) naphthalimide and the like.

Further, in the chemically amplified positive resist composition of the present invention, a basic compound, particularly a basic nitrogen-containing organic compound such as amines is added as a quencher so that it can be retained after exposure. Performance deterioration due to acid deactivation can be improved. Specific examples of the basic compound used for the quencher include those represented by the following formulas.

[0022]

[0023]

In the formula, R ¹¹ , R ¹² and R ¹⁷ each independently represent hydrogen, alkyl, cycloalkyl, aryl or alkoxy. The alkyl, cycloalkyl, aryl or alkoxy may be each independently substituted with a hydroxyl group, an amino group or an alkoxy group having 1 to 6 carbon atoms. The amino group may be substituted with an alkyl group having 1 to 4 carbon atoms. The alkyl preferably has about 1 to 6 carbon atoms, the cycloalkyl preferably has about 5 to 10 carbon atoms, and the aryl has 6 to 1 carbon atoms.
About 0 is preferable, and the alkoxy preferably has about 1 to 6 carbon atoms. R ¹³ , R ¹⁴ and R ¹⁵ are each independently
Represents hydrogen, alkyl, cycloalkyl, aryl or alkoxy. The alkyl, cycloalkyl, aryl,
Alternatively, the alkoxy may be independently substituted with a hydroxyl group, an amino group, or an alkoxy group having 1 to 6 carbon atoms. The amino group may be substituted with an alkyl group having 1 to 4 carbon atoms. The alkyl has 1 carbon atom.
Is preferably about 6 and the cycloalkyl has 5 to 5 carbon atoms.
The aryl preferably has about 6 to 10 carbon atoms, and the alkoxy preferably has about 1 to 6 carbon atoms. R ¹⁶ represents alkyl or cycloalkyl.
The alkyl or cycloalkyl may be independently substituted with a hydroxyl group, an amino group or an alkoxy group having 1 to 6 carbon atoms. The amino group may be substituted with an alkyl group having 1 to 4 carbon atoms. Further, the alkyl is
It preferably has about 1 to 6 carbon atoms, and the cycloalkyl preferably has about 5 to 10 carbon atoms. A represents alkylene, carbonyl, imino, sulfide or disulfide.
The alkylene preferably has about 2 to 6 carbon atoms. Further, R ^{11 to} R ¹⁷ may have either a linear structure or a branched structure, and any of them may be used.

In the resist composition of the present invention, although it is insoluble in an alkaline aqueous solution itself, 0.1 to 20 parts by weight of an acid generator is added to 100 parts by weight of a resin which is soluble in the alkaline aqueous solution by the action of an acid. Parts by weight, 0.1 parts of biadamantane derivative
It is preferably contained in the range of 5 parts by weight. When using a basic compound as a quencher, 0.001 to 100 parts by weight of the resin of the resist composition is used.
The content is preferably in the range of 1 part by weight, more preferably 0.01 to 1 part by weight. The composition of the present invention may also contain a small amount of various additives such as a sensitizer, a dissolution inhibitor, another resin, a surfactant, a stabilizer and a dye, if necessary.

The resist composition of the present invention usually becomes a liquid resist composition in a state where each of the above components is dissolved in a solvent, and is applied onto a substrate such as a silicon wafer by a conventional method such as spin coating. . The solvent used here may be any solvent that dissolves each component, has an appropriate drying rate, and gives a uniform and smooth coating film after the solvent evaporates. Solvents generally used in this field are used. You can. For example, glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; esters such as ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate; acetone, methyl isobutyl ketone, 2-heptanone. And ketones such as cyclohexanone; cyclic esters such as γ-butyrolactone. These solvents may be used alone or in combination of two or more.

The resist film coated and dried on the substrate is subjected to an exposure treatment for patterning, then a heat treatment for promoting a deprotecting group reaction, and then developed with an alkali developing solution. It The alkaline developer used here can be various alkaline aqueous solutions used in this field, but in general, an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline) is used. Often used.

[0028]

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, the part indicating the amount used is based on weight unless otherwise specified. The weight average molecular weight is
It is a value obtained by gel permeation chromatography using polystyrene as a standard product.

Resin Synthesis Example 1 (Synthesis of Resin A1) 2-Ethyl-2-adamantyl methacrylate, 3-hydroxy-1-adamantyl methacrylate and α-methacryloyloxy-γ-butyrolactone were mixed at 5: 2.5. :
It was charged at a molar ratio of 2.5 (20.0 parts: 9.5 parts: 7.3 parts), and 2 parts by weight of methyl isobutyl ketone was added to all the monomers to obtain a solution. Azobisisobutyronitrile as an initiator was added thereto in an amount of 2 mol% based on the total amount of the monomers, and heated at 80 ° C. for about 8 hours. After that, the operation of pouring the reaction solution into a large amount of heptane to cause precipitation is performed 3 times,
Purified. As a result, a copolymer having a weight average molecular weight of about 9,200 was obtained. This copolymer has each unit represented by the following formula, and this is referred to as resin A1.

[0030]

Next, in addition to the resins obtained in the above resin synthesis examples, the following raw materials were used to prepare and evaluate resist compositions.

<Acid generator> B1: p-tolyldiphenylsulfonium perfluorooctane sulfonate, <quencher> C1: 2,6-diisopropylaniline, <additive> D1: 3,3′-carboxy (tert-butyl)- 1,1'-Via Damantan

Examples 1 and 2 and Comparative Example 1 The following components were mixed and dissolved, and the pore size was 0.2 μm.
To obtain a resist solution.

Resin (Type and amount are shown in Table 1) Acid generator (type and amount are listed in Table 1) Quencher (see table 1 for types and amounts) Solvent (type and amount are listed in Table 1)

An organic antireflective coating having a thickness of 780 Å was obtained by applying a composition for organic antireflective coating made by Brewer "ARC-25-8" to a silicon wafer and baking at 215 ° C. for 60 seconds. Was formed, and the above resist solution was spin-coated thereon so that the film thickness after drying was 0.39 μm. After applying the resist solution, it was prebaked on a direct hot plate at 130 ° C. for 60 seconds. An ArF excimer stepper [“NSR ArF” manufactured by Nikon Corporation, NA = 0.55, σ = 0.6] was used for each wafer on which the resist film was formed in this way, and the exposure amount was changed stepwise to form a line and space pattern. Exposed. After exposure, 6 on a hot plate at 130 ° C
Post exposure bake for 0 seconds, then 2.
Paddle development was performed for 60 seconds with a 38 wt% tetramethylammonium hydroxide aqueous solution. The bright field pattern after development on the organic antireflection film substrate was observed with a scanning electron microscope, and the results are shown in Table 2. The bright field pattern here means that the outer frame is a chrome layer (light-shielding layer), and the chrome layer (light-shielding layer) is formed in a line on the inside of the frame with the glass surface (light-transmitting portion) as a base. It is a pattern obtained by exposure and development through a reticle. Therefore, after exposure and development, the resist layer around the line-and-space pattern is removed, and the resist layer corresponding to the outer frame remains outside the pattern.

Effective sensitivity: A line-and-space pattern of 0.18 μm was displayed at an exposure dose of 1: 1. Resolution: The minimum size of the line-and-space pattern separated by the exposure amount of the effective sensitivity is displayed. Smoothness of the pattern wall surface: The wall surface of the isolated line pattern was observed with a scanning electron microscope, and one that was smoother than the comparative example was judged as ◯, and one that did not change was judged as x.

[0037]

[Table 1] ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example No. Resin Acid generator Quencher additive Solvent ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ Example 1 A1 / 10 part B1 / 0.2 part C1 / 0.0075 part D1 / 0.5 part E1 Example 2 A1 / 10 part B1 / 0.2 part C1 / 0.0075 part D1 / 1.0 part E1 ────────────────────────────────── Comparative Example 1 A1 / 10 part B1 / 0.2 part C1 / 0.0075 part − E1 ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

[0038]

[Table 2]

[0039]

Industrial Applicability The chemically amplified positive resist composition of the present invention provides a resist pattern with significantly improved line edge roughness, and has excellent resist performances such as sensitivity and resolution. Therefore, this composition
It is suitable for exposure using an excimer laser, an ArF excimer laser, or the like, thereby providing a resist pattern with high performance.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2H025 AA01 AA03 AB16 AC04 AC08                       AD03 BE00 BE10 BG00 CB41                       CC20 FA17

Claims (7)

[Claims] 1. A chemically amplified positive type which contains a resin, which is itself insoluble in an alkaline aqueous solution but is soluble in an alkaline aqueous solution by the action of an acid, an acid generator, and a biadamantane derivative. Resist composition. 2. A resin 100 which is itself insoluble in an alkaline aqueous solution but becomes soluble in the alkaline aqueous solution by the action of an acid.
The acid generator is contained in an amount of 0.1 to 20 parts by weight and the biadamantane derivative in an amount of 0.1 to 5 parts by weight based on parts by weight.
The composition as described. 3. A biadamantane derivative represented by the following formula (I): At least 1 selected from the compounds represented by formula (I) (wherein R ₁ and R ₂ independently represent hydrogen or an ester group).
The composition according to claim 1 or 2, which is a seed. 4. A biadamantane derivative represented by the following formula (II): (II) (wherein R ₃ and R ₄ each independently represent an acid labile group that dissociates in the presence of an acid), and at least one compound selected from the group consisting of The composition as described. 5. The biadamantane derivative is represented by the following formula (III): The composition according to claims 1 to 4, which is a compound represented by the formula (III). 6. The composition according to claim 1, further comprising a basic compound as a quencher. 7. A resin 100 which is itself insoluble in an alkaline aqueous solution but becomes soluble in the alkaline aqueous solution by the action of an acid.
The composition according to any one of claims 1 to 6, which contains 0.001 to 1 part by weight of the basic compound with respect to parts by weight.