TWI627508B - Resist underlayer film forming composition for euv lithography - Google Patents

Abstract

Provides improved resistance to resist and roughness of resist pattern The EUV uses a resist underlayer film to form a composition.

Included at the end is represented by the following formula (1) The lithography of the polymer and the organic solvent forms a composition with a resist underlayer film.

(wherein, X represents a phenyl group, a naphthyl group or a fluorenyl group substituted with at least one selected from the group consisting of a halogen atom, a hydroxyl group, and a linear or branched alkoxy group having 1 to 6 carbon atoms; , v means 0 or 1.)

Description

EUV lithography with resisting underlayer film forming composition

The present invention is a composition for forming a resistive underlayer film between a substrate and a resist film formed thereon in order to obtain a resist pattern of a desired shape in a lithography step of a process for fabricating a semiconductor device. . In particular, a composition of a resist underlayer film suitable for use in a lithography step of exposure to ultra-ultraviolet rays (hereinafter, abbreviated as EUV) having a wavelength of 13 nm to 14 nm is formed.

Currently, EUV lithography is required to increase the output of the EUV exposure source of the EUV exposure device. When the output of the exposure light source is low, the exposure time of the resist pattern for forming is increased, and the wafer processing time per unit time is also increased, so that the production efficiency of the manufacturing step is lowered. Therefore, it is required for the resist to form a target resist pattern with a low energy exposure.

In order to form a resist pattern for a low exposure amount, it is necessary to generate energy at a lower photochemical reaction by EUV light irradiation to the resist. Thus, in order to produce a photochemical agent with a low exposure amount The response must be highly responsive to EUV light. Therefore, the EUV lithography resist material is strongly required to increase the light responsiveness (sensitivity) of the resist.

In addition, when EUV lithography is formed, the formed line width is 32 nm or less. In order to accurately transfer the resist pattern to the base substrate, the line width of the scintillation indicator forming the resist pattern must be more strictly required. Roughness (LWR) and Line Edge Roughness (LER) indicating the scintillation index of the sidewall of the resist pattern. The formed resist pattern shape, when the skirt shape or the adjacent pattern is a shape that is not divided and joined together, or the formed resist pattern is caused to blink in a specific direction, when viewed from above the pattern The values of LWR and LER will become large, and will have an adverse effect on the control of the formed resist pattern. Therefore, the resist material used for EUV lithography is strongly required to reduce the flicker (roughness) of such a resist pattern.

Heretofore, as a material suitable for forming a lower layer film of a resist for EUV lithography, a resist underlayer film forming composition having reduced evacuation has been used (Patent Document 1). Further, although it is not a specific material for EUV exposure, a resist underlayer film forming composition containing a reaction product of a diglycidyl ester compound and an acid dianhydride is disclosed (Patent Document 2). However, such a resist underlayer film forming composition does not disclose that the resist underlayer film obtained by capping the end of the polymer forms a composition, and there is no description about the effect of improving the sensitivity or roughness of the resist.

[Previous Technical Literature] [Patent Literature] [Previous Technical Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2010/061774

[Patent Document 2] International Publication No. 2009/104685

As means for improving the sensitivity and roughness of the resist in EUV lithography, attempts have been made to optimize the chemical structure or additive composition of the resin contained in the resist material, and to expose the developing conditions and developing conditions during the formation of the resist. Most appropriate and so on. In addition, the method of controlling the chemical state of the interface between the resist and the underlayer film is also listed. That is, in the positive resist, when the chemical state of the interface between the resist and the underlayer of the resist is changed to the alkali state, the shape of the obtained resist pattern is easily changed into a skirt shape, and the roughness of the resist pattern is also easy. Become bigger. Therefore, in order to correct the shape of the skirt and form a resist pattern of the target method, the resist sensitivity will deteriorate due to the necessity of irradiating a higher exposure amount. On the other hand, when the chemical state of the interface between the resist and the underlayer film becomes acidic, the shape of the resist pattern suppresses the occurrence of the shape of the skirt, and the resist pattern can be formed with a lower exposure amount. Therefore, the sensitivity of the resist will increase.

Therefore, an object of the present invention is to provide a resist underlayer film forming composition which is characterized by an EUV lithography step to deteriorate the surface state of the resist underlayer film into an acidic state in order to improve the resist sensitivity and roughness.

According to a first aspect of the present invention, there is provided a composition for forming a lithographic resist underlayer film comprising a polymer having a structure represented by the following chemical formula (1) at the terminal and an organic solvent.

(wherein, X represents a phenyl group, a naphthyl group or a fluorenyl group substituted with at least one selected from the group consisting of a halogen atom, a hydroxyl group, and a linear or branched alkoxy group having 1 to 6 carbon atoms; , v is 0 or 1.)

X in the above formula (1) represents a group represented by, for example, the following formula (2).

(wherein R ₁ , R ₂ , R ₃ , R ₄ and R ₅ each independently represent a hydrogen atom, a halogen atom, a hydroxyl group or a linear or branched alkoxy group having 1 to 6 carbon atoms; .)

In addition to the structure represented by the above formula (1), the polymer may have at least one (for example, one or two) structural units represented by the following formula (3) in the main chain. .

(wherein A ₁ , A ₂ , A ₃ , A ₄ , A ₅ and A ₆ each independently represent a hydrogen atom, a methyl group or an ethyl group, Q ₁ represents a divalent organic group, and m ₁ and m ₂ represent 0. Or 1.)

In the above formula (3), Q ₁ is represented by, for example, a divalent organic group represented by the following formula (4).

(wherein Q ₂ represents at least one alkylene group having 1 to 10 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alicyclic hydrocarbon ring having 3 to 10 carbon atoms or a carbon number of 6 a divalent organic group of the aromatic hydrocarbon ring of ~14, wherein the divalent organic group may be selected from an alkyl group having 1 to 6 carbon atoms, a halogen atom, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, or a carbon atom. At least one selected from the group consisting of an alkoxycarbonyl group having 2 to 6 carbon atoms, a nitro group, a cyano group and an alkylthio group having 1 to 6 carbon atoms, and the divalent organic group having two kinds of stretching When an alkyl group, an alkenyl group, an alicyclic hydrocarbon ring or an aromatic hydrocarbon ring, the two kinds of alkylene groups, two kinds of alkenyl groups, two kinds of alicyclic hydrocarbon rings or two kinds of aromatic hydrocarbon rings By sulfonyl, disulfide, thioether, carbonyl, -C(=O)O-, -O-, -C(CH ₃ ) ₂ - and -C(CF ₃ ) ₂ - The linkage selected by the group formed by the group may form a bond, and n ₁ and n ₂ each independently represent 0 or 1.)

In the above formula (3), Q ₁ also represents a divalent organic group represented by the following formula (5).

(wherein Y is a divalent group represented by the following formula (6) or (7).)

(wherein R ₆ and R ₇ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 3 to 6 carbon atoms, a benzyl group or a phenyl group, and the phenyl group may be selected from carbon At least one substituted group selected from the group consisting of an alkyl group having 1 to 6 atoms, a halogen atom, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group and an alkylthio group having 1 to 6 carbon atoms; Or R ₆ and R ₇ may be bonded to each other, and together with the carbon atom to which R ₆ and R ₇ are bonded, form a ring having 3 to 6 carbon atoms.)

In the above formula (3), Q ₁ is a divalent organic group represented by the following formula (8).

(wherein R ₈ is an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 3 to 6 carbon atoms, a benzyl group or a phenyl group, and the phenyl group may be selected from an alkyl group having 1 to 6 carbon atoms. At least one of a group consisting of a halogen atom, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, and an alkylthio group having 1 to 6 carbon atoms is substituted.

The alkyl group may, for example, be a methyl group, an ethyl group or a propyl group. The halogen atom may, for example, be a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, and a butoxy group. Isobutoxy, sec-butoxy, tert-butoxy. Among these halogen atoms, a fluorine atom and an iodine atom and a methoxy group in the alkoxy group are preferable because they have excellent EUV absorption energy. The alkylene group may, for example, be a vinyl group, a vinyl group, a propenyl group or a butenyl group. The above-mentioned alkenyl group may, for example, be a -CH=CH- group. As the above alkenyl group, for example, an allyl group can be mentioned. The alicyclic hydrocarbon ring may, for example, be a cyclopropane ring, a cyclobutane ring, a cyclopentane ring or a cyclohexane ring. The aromatic hydrocarbon ring may, for example, be a benzene ring, a naphthalene ring or an anthracene ring. When the divalent organic group is a two alkyl group, an alkenyl group, an alicyclic hydrocarbon ring or an aromatic hydrocarbon ring, the two kinds of alkyl groups, two kinds of alkenyl groups, and two kinds of alicyclic groups The hydrocarbon ring or the two aromatic hydrocarbon rings are via a sulfonyl group, a disulfide group, a thioether group, a carbonyl group, a -C(=O)O- group, an -O- group, a -C(CH ₃ ) ₂ group. A linking group such as a -C group or a -C(CF ₃ ) ₂ - group may be bonded.

The resist underlayer film forming composition according to the first aspect of the present invention may further contain a crosslinking agent and a crosslinking catalyst.

According to a second aspect of the present invention, the resist underlayer film forming composition of the first aspect of the present invention is coated on a substrate having a film to be processed, and then baked, and a resist underlayer film is formed on the resist underlayer film. The upper resist is coated on the substrate covered by the resist, irradiated with ultra-ultraviolet rays, and then developed, and then formed into a resist pattern, the resist pattern is used as a mask, and the pattern is transferred by dry etching. A method of fabricating a semiconductor device onto the substrate.

The lithographic underlayer film forming composition of the present invention contains a polymer which is capped by a structure represented by the above formula (1) at the terminal. By suitably using such a resist underlayer film to form a composition in the EUV lithography process, the sensitivity or roughness of the resist can be effectively reduced.

[Best Practice for Carrying Out the Invention]

The lithographic resist underlayer film forming composition of the present invention is a polymer having a structure represented by the above formula (1) at the terminal. The The weight average molecular weight of the polymer is, for example, 2,000 to 50,000.

The monomer which forms the terminal of the above-mentioned polymer is, for example, a compound represented by the following formula (9-a) to formula (9-x).

The above polymer is, for example, obtained by reacting a polymer having an epoxy group at the terminal and a monomer having a reaction reaction with the epoxy group. As such a monomer, the compound represented by the above formula (9-a) to formula (9-x), that is, 4-fluorobenzoic acid, 4-chlorobenzoic acid, 4-bromobenzoic acid, iodide Benzoic acid, 1-chloro-4-fluorobenzoic acid, 2,4-dichlorobenzoic acid, 2,4,6-trichlorobenzoic acid, 2,3,4,5,6-pentafluorobenzoic acid, 4- Chlorosalicylic acid, 3,5-dichlorosalicylic acid, 3,5-dibromosalicylic acid, 3,5-diiodosalicylic acid, tetrachlorobenzoic anhydride, tetrabromobenzoic anhydride, 4-fluorophenol, 2,4,6-tetraiodophenol, 4-hydroxybenzoic acid, 4-methoxybenzoic acid, 4-ethoxybenzoic acid, 4-methoxyphenol, salicylic acid, 3-hydroxy-4-methyl The oxybenzoic acid, 3,5-dimethoxybenzoic acid, and 3,4,5-trimethoxybenzoic acid are not limited to these examples. Preferred among these compounds are 4-fluorobenzoic acid, 3,5-diiodosalicylic acid and 4-methoxybenzoic acid.

The monomer represented by the above formula (3) as a structural unit showing that m ₁ and m ₂ are represented by 1, for example, has two represented by the following formulas (10-a) to (10-k) Epoxy compound,

That is, 1,4-phthalic acid diglycidyl, 2,6-naphthalene dicarboxylic acid diglycidyl, 1,6-dihydroxynaphthalene diglycidyl, 1,2-cyclohexanedicarboxylic acid can be exemplified. Diglycidyl, 2,2-bis(4-hydroxyphenyl)propane diglycidyl, 2,2-bis(4-hydroxycyclohexane)propane diglycidyl, 1,4-butanediol diglycidyl , monopropenyl isocyanuric acid diglycidyl, monomethyl isocyanuric acid diglycidyl, 5,5-diethyl barbituric acid diglycidyl, 5,5-dimethylethene Urea diglycidyl, but is not limited thereto.

The monomer which forms the structural unit represented by the above formula (3) and wherein m ₁ and m ₂ are 0, for example, contains two compounds represented by the following formulas (11-a) to (11-s). a compound of a carboxyl group, a hydroxyphenyl group or a quinone imine group, and an acid dianhydride,

That is, examples thereof include isophthalic acid, 5-hydroxyisophthalic acid, 2,4-dihydroxybenzoic acid, 2,2-bis(4-hydroxyphenyl)succinic acid, succinic acid, and butyl. Aenedioic acid, tartaric acid, 3,3'-dithiobispropionic acid, 1,4-cyclohexanedicarboxylic acid, cyclobutanecarboxylic acid dianhydride, cyclopentane acid dianhydride, monopropylene isocyanocyanate Acid, 5,5-diethylbarbituric acid, bisglycolic acid, acetone dicarboxylic acid, 2,2'-thioglycolic acid, 4-hydroxybenzoic acid-4-hydroxyphenyl, 2,2- Bis(4-hydroxyphenyl)propane and 2,2-bis(4-hydroxyphenyl)hexafluoropropane, but are not limited to these examples.

The number of repetitions of the structural unit represented by the above formula (3) is, for example, in the range of 10 or more and 10,000 or less.

At least one structural unit represented by the above formula (3) is contained, and as the polymer having a structure represented by the above formula (1) at the terminal, the following formula (12-a) to formula (12) can be used. -d) is shown, but is not limited to these examples.

The structural unit represented by the above formula (12-a) and the polymer having a terminal are the compounds represented by the formula (9-1), A compound represented by the formula (10-h) and a raw material of the compound represented by the formula (11-j) are obtained by polymerization. The structural unit represented by the formula (12-d) and the polymer having a terminal are a compound represented by the formula (9-r) and a compound represented by the formula (10-h). The starting material of the compound represented by 11-j) is obtained by polymerization.

a unit structure represented by a of the formula (12-a), the formula (12-b), the formula (12-c), and the formula (12-d), and a unit structure represented by b and a unit represented by c The molar ratio of the structure satisfies the relationship of a:(b+(c/2))=1:1.

Regarding the aforementioned molar ratio a of the formula (12-a), the formula (12-b), the formula (12-c), and the formula (12-d): (b+(c/2))=1:1, b The molar ratio to c is expressed as b: (c/2) = (1-x): x. However, the molar ratio x is 0.01 to 0.8, more preferably 0.1 to 0.3.

The organic solvent contained in the underlayer film forming composition of the present invention may, for example, be propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA) or propylene glycol monoethyl ether. A mixture of two or more selected from the group consisting of propylene glycol monopropyl ether, methyl ethyl ketone, ethyl lactate, cyclohexanone, γ-butyrolactone, N-methylpyrrolidone, and the like. Further, the ratio of the organic solvent of the resist underlayer film forming composition of the present invention is, for example, 50% by mass or more and 99.9% by mass or less.

The polymer contained in the resist underlayer film forming composition of the present invention is, for example, 0.1% by mass to 50% by mass based on the resist underlayer film forming composition.

The resist underlayer film forming composition of the present invention may contain a crosslinkable catalyst which promotes a crosslinking agent and a compound which crosslinks, in addition to a polymer and an organic solvent. When a component from which the organic solvent is removed from the resist underlayer film forming composition of the present invention is defined as a solid component, the solid component contains an additive such as a polymer, a crosslinking agent to be added, and a crosslinking catalyst. The ratio of the additive is, for example, 0.1% by mass to 50% by mass, and more preferably 1% by mass to 30% by mass based on the solid content of the resist underlayer film forming composition of the present invention.

The crosslinking agent contained in any component of the underlayer film forming composition of the present invention may, for example, be hexamethoxymethyl melamine, tetramethoxymethyl benzoguanamine or 1,3,4,6-tetra. (Methoxymethyl) acetylene urea (POWDERLINK [registered trademark] 1174), 1,3,4,6-tetrakis(butoxymethyl)acetylene urea, 1,3,4,6-tetrakis (hydroxymethyl group Acetylene urea, 1,3-bis(hydroxymethyl) urea, 1,1,3,3-tetrakis(butoxymethyl)urea and 1,1,3,3-tetrakis(methoxymethyl) Urea. When the crosslinking agent is used, the content of the crosslinking agent is, for example, 1% by mass to 50% by mass, and more preferably 5% by mass to 30% by mass based on the polymer.

The crosslinking catalyst contained in any component of the underlayer film forming composition of the present invention may, for example, be p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium cation-p-toluenesulfonate or salicylate. Acid, camphorsulfonic acid, 5-sulfonic acid salicylic acid, 4-chlorobenzenesulfonic acid, 4-hydroxybenzenesulfonic acid, benzenesulfonic acid, 1-naphthalenesulfonic acid, citric acid, benzoic acid, hydroxybenzoic acid, etc. Sulfonated compounds and carboxy oxygen compounds. When the crosslinking catalyst is used, the content ratio of the crosslinking catalyst is, for example, 0.1% by mass to the crosslinking agent. 50% by mass, more preferably 1% by mass to 30% by mass.

The substrate used in the method for fabricating the semiconductor device of the second aspect of the present invention is represented by a germanium wafer, but an SOI (Silicon on Insulator) substrate, or gallium antimonide (GaAs), indium phosphide (InP), or A compound semiconductor wafer such as gallium phosphide (GaP). In the substrate, for example, a hafnium oxide film, a niobium oxide film containing nitrogen (SiON film), a hafnium oxide film containing carbon (SiOC film), and a hafnium oxide film containing fluorine (SiOF film) may be used. Insulation film. At this time, the resist underlayer film is formed on the film to be processed.

In the method of producing the semiconductor device of the present invention, the resist solution used for covering the resist film on the resist underlayer film may be either a positive type or a negative type, and a chemical amplification type resist for EUV sensitization may also be used. As the developing solution used for development after the EUV irradiation, an alkaline developing solution such as an aqueous solution of tetramethylammonium hydroxide (TMAH) can be used.

Hereinafter, the synthesis examples and examples of the present invention will be specifically described. However, the present invention is not limited to the description of the following synthesis examples and examples.

The weight average molecular weight of the polymer shown in the following Synthesis Examples 1 to 5 of the present specification is measured by gel permeation chromatography (hereinafter, abbreviated as GPC). In the measurement, a GPC apparatus manufactured by Tosoh Co., Ltd. was used, and measurement conditions and the like are as follows.

GPC pipe column: Shodex [registered trademark] ‧ Asahipak [registered trademark] (Showa Denko (share))

Column temperature: 40 ° C

Solvent: N,N-dimethylformamide (DMF)

Flow rate: 0.6ml/min

Standard sample: polystyrene (tosoh)

[Examples] <Synthesis Example 1>

1.38 g of monomethyl diglycidyl isocyanuric acid (product name: Me-DGIC, Shikoku Chemical Industry Co., Ltd.), 7.86 g of 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 5.51 g of 3,5-bisiodosalicylic acid, 0.54 g of benzyltriethylammonium chloride, and 104.89 g of propylene glycol monomethyl ether were mixed, and heated under reflux for 4 hours while stirring. In the obtained polymer solution, cation exchange resin (product name: Dowex [registered trademark] 550A, Muromachi Technos (share)) 26 g and anion exchange resin (product name: An Bailai [registered trademark] 15 JWET, Organo (share) )) 26 g, ion exchange treatment at room temperature for 4 hours. As a result of GPC analysis, the obtained polymer solution had a weight average molecular weight of 3,100 in terms of standard polystyrene.

<Synthesis Example 2>

2.70 g of monopropenyl diglycidyl isocyanuric acid (product name: MA-DGIC, Shikoku Chemical Industry Co., Ltd.), 2.71 g of 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 3,5-bisiodosalicylic acid 1.90 g, benzyltriethyl chloride 0.19 g of ammonium and 37.18 g of propylene glycol monomethyl ether were mixed, and heated under reflux for 4 hours while stirring. To the obtained polymer solution, cation exchange resin (product name: Dowex [registered trademark] 550A, Muromachi Technos (share)) 9 g and anion exchange resin (product name: An Bailai [registered trademark] 15 JWET, Organo (share) )) 9 g, ion exchange treatment at room temperature for 4 hours. As a result of GPC analysis, the obtained polymer solution had a weight average molecular weight of 3,100 in terms of standard polystyrene.

<Synthesis Example 3>

3.93 g of monomethyl diglycidyl isocyanuric acid (product name: Me-DGIC, Shikoku Chemicals Co., Ltd.), 3.33 g of 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 0.53 g of 4-fluorobenzoic acid, 0.21 g of benzyltriethylammonium chloride, and 35.99 g of propylene glycol monomethyl ether were mixed, and heated under reflux for 4 hours while stirring. To the obtained polymer solution, cation exchange resin (product name: Dowex [registered trademark] 550A, Muromachi Technos (share)) 26 g and anion exchange resin (product name: An Bailai [registered trademark] 10JWET, Organo (share) )) 10 g, ion exchange treatment at room temperature for 4 hours. As a result of GPC analysis, the obtained polymer solution had a weight average molecular weight of 4,500 in terms of standard polystyrene.

<Synthesis Example 4>

Monopropenyl diglycidyl isocyanuric acid (product name: MA- DGIC, Shikoku Chemical Industry Co., Ltd.) 5.50g, 1,2,3,4-cyclobutane tetracarboxylic dianhydride 3.31g, 4-methoxybenzoic acid 0.91g, benzyltriethylammonium chloride 0.23 g and 39.77 g of propylene glycol monomethyl ether were mixed, and the mixture was heated under reflux for 4 hours while stirring. To the obtained polymer solution, cation exchange resin (product name: Dowex [registered trademark] 550A, Muromachi Technos (share)) 10 g and anion exchange resin (product name: An Bailai [registered trademark] 15 JWET, Organo (share) )) 10 g, ion exchange treatment at room temperature for 4 hours. As a result of GPC analysis, the obtained polymer solution had a weight average molecular weight of 5,700 in terms of standard polystyrene.

<Synthesis Example 5>

Monopropenyl diglycidyl isocyanuric acid (product name: MA-DGIC, Shikoku Chemical Industry Co., Ltd.) 13.00 g, 5,5-diethyl barbituric acid 8.65 g, benzyl triethyl 0.53 g of ammonium chloride and 88.72 g of propylene glycol monomethyl ether were mixed, and heated under reflux for 4 hours while stirring. To the obtained polymer solution, cation exchange resin (product name: Dowex [registered trademark] 550A, Muromachi Technos (share)) 22 g and anion exchange resin (product name: An Bailai [registered trademark] 15 JWET, Organo (share) )) 22 g, ion exchange treatment at room temperature for 4 hours. As a result of GPC analysis, the obtained polymer solution had a weight average molecular weight of 8,000 in terms of standard polystyrene.

<Example 1>

2.50 g of the polymer solution obtained in the above Synthesis Example 1, and tetramethoxymethylacetylene urea (product name: POWDERLINK [registered trademark] 1174, manufactured by Nihon Cytec Industries Inc., Japan), 0.13 g, 0.01 g of toluenesulfonic acid hydrate, 19.33 g of propylene glycol monomethyl ether, and 45.11 g of propylene glycol monomethyl ether acetate were mixed to prepare a resist underlayer film-forming composition.

<Example 2>

2.2 g of the polymer solution obtained in the above Synthesis Example 2, tetramethoxymethylacetylene urea (product name: POWDERLINK [registered trademark] 1174, manufactured by Nihon Cytec Industries Inc., Japan), 0.12 g, 0.01 g of toluenesulfonic acid hydrate, 18.74 g of propylene glycol monomethyl ether, and 43.74 g of propylene glycol monomethyl ether acetate were mixed to prepare a resist underlayer film-forming composition.

<Example 3>

2.00 g of the polymer solution obtained in the above Synthesis Example 3, tetramethoxymethylacetylene urea (product name: POWDERLINK [registered trademark] 1174, manufactured by Nihon Cytec Industries Inc., Japan), 0.14 g, 0.01 g of toluenesulfonic acid hydrate, 20.57 g of propylene glycol monomethyl ether, and 48.00 g of propylene glycol monomethyl ether acetate were mixed to prepare a resist underlayer film-forming composition.

<Example 4>

2.00 g of the polymer solution obtained in the above Synthesis Example 4, tetramethoxymethylacetylene urea (product name: POWDERLINK [registered trademark] 1174, manufactured by Nihon Cytec Industries Inc., Japan), 0.14 g, 0.01 g of toluenesulfonic acid hydrate, 20.47 g of propylene glycol monomethyl ether, and 47.76 g of propylene glycol monomethyl ether acetate were mixed to prepare a resist underlayer film-forming composition.

<Comparative Example 1>

2.50 g of the polymer solution obtained in the above Synthesis Example 5, tetramethoxymethylacetylene urea (product name: POWDERLINK [registered trademark] 1174, manufactured by Nihon Cytec Industries Inc., Japan), 0.11 g, 5 0.01 g of sulfonic acid salicylic acid, 35.70 g of propylene glycol monomethyl ether, and 16.19 g of propylene glycol monomethyl ether acetate were mixed to prepare a resist underlayer film forming composition.

(Formation and evaluation of resist pattern)

On each of the wafers, the respective underlayer film forming compositions prepared in Examples 1 to 4 and Comparative Example 1 of the present specification were spin-coated at a film thickness of 5 nm, and heated at 205 ° C for 60 seconds. Forming a resist underlayer film. The EUV positive resist solution (methacrylate resin solution) was spin-coated and heated on the lower layer of the resist, and an EUV exposure apparatus (EUV Micro Exposure Lithography Tool, MS-13, manufactured by EXITECH Co., Ltd.) was used. Exposure was carried out under conditions of NA = 0.35, Quadrole illumination, and σ = 0.36/0.68. After exposure PEB, cooled on a cold plate ~ room temperature, and then developed and washed to form a resist pattern. The evaluation was judged by the most appropriate exposure amount (Eop) when the line width of 26 nm was formed, and the LWR value of the pattern viewed from above the pattern.

Eop was evaluated by using Critical Dimension Scanning Electron Microscopy (CD-SEM), and at the most appropriate focal length, the exposure amount when the line width of 26 nm was formed was taken as the Eop value. Moreover, since the smaller the Eop value, the more the resist pattern can be formed with less exposure energy, the resist sensitivity becomes higher.

The LWR was measured by using a CD-SEM to detect the position of the pattern from the upper part, and the positional deviation was quantified as LWR. Specifically, in the Eop in which the line width of 26 nm is formed, the line width of the formed resist pattern from the bottom portion of the pattern to 70% of the height of the pattern is measured by a CD-SEM. The 3 σ of these values is taken as the LWR value. Therefore, σ is the standard deviation. Further, the smaller the LWR value, the smaller the roughness of the formed resist, and the pattern transfer accuracy of the base substrate can be improved in the manufacturing process.

The results of measurement of Eop and LWR of the resist pattern of 26 nm line width are shown in Table 1 below. The smaller the Eop and LWR, the better the value.

When the resist underlayer film was formed using the resist underlayer film forming compositions of Examples 1 to 4 by using Table 1, when the resist underlayer film was formed using the resist underlayer film of Comparative Example 1, the resist underlayer film was formed. The Eop is smaller, and therefore, the sensitivity of the resist of the resist underlayer film forming composition can be improved. Further, when the resist underlayer film was formed using the resist underlayer film forming compositions of Examples 1 to 4, the LWR was further formed when the resist underlayer film was formed by using the resist underlayer film of Comparative Example 1 to form a resist underlayer film. Small, therefore, the resist underlayer film forming composition can reduce the roughness of the formed resist pattern. Namely, it was confirmed that the resist underlayer film forming compositions of Examples 1 to 4 exhibited a useful effect in order to improve the sensitivity and roughness of the resist in the formation of the resist pattern.

The embodiments of the present invention have been described above, and the technical scope of the present invention is not limited to the scope described in the above embodiments. In the above embodiments, various modifications or additions may be made.

Claims (6)

A lithographic underlayer film forming composition comprising a polymer having a structure represented by the following formula (1) and an organic solvent, wherein the polymer has a formula (3) in the main chain At least one structural unit shown, (wherein, X represents at least one substituted phenyl group, naphthyl group or the group selected from the group consisting of a halogen atom, a hydroxyl group, and a linear or branched alkoxy group having 1 to 6 carbon atoms;蒽 base, v is shown as 0 or 1) (wherein A ₁ , A ₂ , A ₃ , A ₄ , A ₅ and A ₆ each independently represent a hydrogen atom, a methyl group or an ethyl group, and Q ₁ represents a divalent organic group represented by the following formula (4); , m ₁ and m ₂ respectively represent 0 or 1) (wherein Q ₂ represents an alkylene group having 1 to 10 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alicyclic hydrocarbon ring having 3 to 10 carbon atoms or a carbon number of 6 to 14; a divalent organic group of at least one aromatic hydrocarbon ring, wherein the divalent organic group may be selected from an alkyl group having 1 to 6 carbon atoms, a halogen atom, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, or carbon. At least one of the group consisting of an alkoxycarbonyl group having 2 to 6 atoms, a nitro group, a cyano group and an alkylthio group having 1 to 6 carbon atoms, wherein the divalent organic group has 2 alkylene groups a base, an alkenyl group, an alicyclic hydrocarbon ring or an aromatic hydrocarbon ring, the two alkylene groups, two extended alkenyl groups, two alicyclic hydrocarbon rings or two aromatic hydrocarbon ring systems It may be a sulfonyl group, a disulfide group, a thioether group, a carbonyl group, a -C(=O)O- group, an -O- group, a -C(CH ₃ ) ₂ - group and a -C(CF ₃ ) _{2 group.} - The linkages selected by the group formed by the group are bonded, and n ₁ and n ₂ are independently shown as 0 or 1). A lithographic underlayer film forming composition comprising a polymer having a structure represented by the following formula (1) and an organic solvent, wherein the polymer has a formula (3) in the main chain At least one structural unit shown, (wherein, X represents at least one substituted phenyl group, naphthyl group or the group selected from the group consisting of a halogen atom, a hydroxyl group, and a linear or branched alkoxy group having 1 to 6 carbon atoms;蒽 base, v is shown as 0 or 1) (wherein A ₁ , A ₂ , A ₃ , A ₄ , A ₅ and A ₆ each independently represent a hydrogen atom, a methyl group or an ethyl group, and Q ₁ represents a divalent organic group represented by the following formula (5); , (wherein Y represents a divalent group represented by the following formula (6) or formula (7)), (wherein R ₆ and R ₇ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 3 to 6 carbon atoms, a benzyl group or a phenyl group, and the phenyl group may be selected from carbon At least one of the group consisting of an alkyl group having 1 to 6 atoms, a halogen atom, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, and an alkylthio group having 1 to 6 carbon atoms is substituted. Or R ₆ and R ₇ may be bonded to each other to form a ring having 3 to 6 carbon atoms together with the carbon atom to which R ₆ and R ₇ are bonded. A lithographic underlayer film forming composition comprising a polymer having a structure represented by the following formula (1) and an organic solvent, wherein the polymer has a formula (3) in the main chain At least one structural unit shown, (wherein, X represents at least one substituted phenyl group, naphthyl group or the group selected from the group consisting of a halogen atom, a hydroxyl group, and a linear or branched alkoxy group having 1 to 6 carbon atoms;蒽 base, v is shown as 0 or 1) (wherein A ₁ , A ₂ , A ₃ , A ₄ , A ₅ and A ₆ each independently represent a hydrogen atom, a methyl group or an ethyl group, and Q ₁ represents a divalent organic group represented by the following formula (8)) , (wherein R ₈ represents an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 3 to 6 carbon atoms, a benzyl group or a phenyl group, and the phenyl group may be selected from an alkyl group having 1 to 6 carbon atoms; At least one of a group consisting of a halogen atom, an alkoxy group having 1 to 6 carbon atoms, a nitro group, a cyano group, and an alkylthio group having 1 to 6 carbon atoms is substituted. The lithographic underlayer film forming composition according to any one of claims 1 to 3, wherein X in the above formula (1) is a group represented by the following formula (2), (wherein R ₁ , R ₂ , R ₃ , R ₄ and R ₅ each independently represent a hydrogen atom, a halogen atom, a hydroxyl group or a linear or branched alkoxy group having 1 to 6 carbon atoms). The lithographic underlayer film forming composition according to any one of Claims 1 to 3, which further comprises a crosslinking agent and a crosslinking catalyst. A method for producing a semiconductor element, which comprises applying a resist underlayer film forming composition according to any one of Claims 1 to 5 to a substrate having a film to be processed, and baking to form a resist underlayer film, The resist is coated on the underlayer film of the resist, and the substrate coated with the resist is irradiated with ultra-ultraviolet rays, and then developed to form a resist pattern, and the resist pattern is used as a mask, which is dry-etched. The pattern is transferred onto the aforementioned substrate.