WO2013100374A1

WO2013100374A1 - Composition for forming a photoresist underlayer, method for forming a pattern using same, and semiconductor integrated circuit device comprising the pattern

Info

Publication number: WO2013100374A1
Application number: PCT/KR2012/009980
Authority: WO
Inventors: 이성재; 조연진; 하광일; 이철호; 이충헌
Original assignee: 제일모직 주식회사
Priority date: 2011-12-30
Filing date: 2012-11-23
Publication date: 2013-07-04
Also published as: KR101354639B1; TW201331238A; TWI444393B; KR20130078758A

Abstract

The present invention relates to a composition for forming a photoresist underlayer, wherein the composition comprises a solvent and a copolymer which includes a recurring unit and is represent by formulas 1 to 4, relates to a method for forming a pattern using same, and also relates to a semiconductor integrated circuit device comprising the pattern formed by the method.

Description

【Specification】

[Name of invention]

A composition for forming a photoresist underlayer, a pattern forming method using the same, and a semiconductor integrated circuit device comprising the pattern. . _.

Technical Field

A composition for forming a photoresist underlayer. A pattern forming method using the same and a semiconductor integrated circuit device including the pattern.

Background Art

Recently, the semiconductor industry is focused on ultra-fine processing technology that has a pattern size of several tens of nanometers away from a pattern of several hundred nanometers.

Looking at the pattern formation method on a semiconductor wafer, cross-coating or depositing a film of organic and inorganic components on the semiconductor wafer, and then coating a photoresist for pattern formation. After exposure to moderate light, the solution is developed with basic solution. The pattern is formed using a suitable etching gas.

In the case of irradiating the active light having short wavelengths of 248 ^η ηι, 193ηηι and 13.5 대신 instead of the active light having a wavelength of 365 nm in order to form a fine pattern according to this pattern formation method. There is an increase and collapse of line width roughness (LWR) of the photoresist pattern.

In order to solve this problem, research is being conducted to apply a photoresist underlayer between the photoresist and the organic and inorganic components.

【Detailed Description of the Invention】 ^{^}

[Technical problem]

In one embodiment of the present invention is to provide a reduced and decay (col lapse) is not able to form a photoresist pattern a uniform ^thickness, for the photoresist agent under film-forming composition in the LWRUine width roughness).

Another embodiment of the present invention is to provide a pattern forming method using the composition for forming a photoresist underlayer.

Another embodiment of the present invention is to provide a semiconductor integrated circuit device including a pattern formed by the pattern forming method.

[Technical Solution]

One embodiment of the present invention is a copolymer comprising a repeating unit represented by the formula 1 to 4; And it provides a composition for forming a photoresist undercoat comprising a solvent. [Formula 1]

[Formula 4]

(In Chemical Formulas 1 to 4,

R. R, R and R ⁷ each independently represent a hydrogen atom. A substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group. A substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C3 to C20 cycloalkenyl group. A substituted or unsubstituted C3 to C20 cycloalkynyl group, or a substituted or unsubstituted C6 to C30 aryl group,

R ² is a lactone derivative group,

R ⁴ is substituted or unsubstituted C 1 to. A C20 alkane group or a substituted or unsubstituted C2 to C20 alkenol group,

R ⁶ is a single bond, a substituted or unsubstituted Cr to C20 alkylene group, a substituted or unsubstituted C2 to C20 alkenylene group, or a substituted or unsubstituted C2 to C20 alkynylene group Go. R is a substituted or unsubstituted C6 to C30 aral group.

1 ^ is substituted or unsubstituted C1 _. To C20 alkylene group. Substituted or unsubstituted C2 to C20 alkenylene group. A substituted or unsubstituted C2 to C20 alkynylene group, is a substituted or unsubstituted C6 to C30 arylene group, and R ⁹ is a fluorine atom. Or a C1 to C10 alkyl group substituted with at least one fluorine atom,

a + b + c + d = l and _. . 0.1 <a <0.5, 0.1 <b <0.5, 0.1 <c <0.5 and 0.01 <d <0.2

The copolymer is represented by the formula 5-1. And at least one selected from copolymers containing structural units represented by 5 to 5-4.

[Formula 5-1]

[Formula 5-2]

[Formula 5-4]

(In Chemical Formula 5—1 to 5 ′ 4,

a + b + c + d = l and 0.1 <a <0.5. 0.1 b <0.5, 0.1 <c ≦ 0.5 and 0.01 <d <0.2.

The copolymer is a + b + c + d = l in Chemical Formulas 1 to 4, and .0.2 <a <0.4, 0.3 <b 0..5..0.2 <c 0.4 and 0.05 <d <0.15 days have.

The weight average molecular weight of the copolymer may be about 1.000 g / mol to about 1,000,000 g / mol. . The copolymer may be included in an amount of about 0.1% by weight to about 10% by weight based on the total amount of the photoresist underlayer forming composition.

The composition for forming a photoresist underlayer may further include a crosslinking agent. The crosslinking agent is an amino resin. Glycoluril Compounds, Bisepoxy Compounds. And at least one selected from melamine compounds and melamine derivatives. The crosslinking agent may be included in an amount of about 0.01% by weight to about 1.0% by weight based on the total amount of the photoresist underlayer forming composition.

Another embodiment of the present invention includes providing a layer of material over a substrate; Forming a photoresist underlayer by applying the composition for forming a photoresist underlayer on the material layer; Forming a photoresist layer on the photoresist underlayer; Exposing and developing the photoresist charge to form a photoresist pattern; Selectively removing the photoresist underlayer using the photoresist pattern and exposing a portion of the material layer; And etching the exposed portion of the material layer.

The forming of the photoresist underlayer may be performed by a spin-on coating method.

The photoresist layer may have a thickness of about 70 nm or less.

Another _, one embodiment of the present invention is a plurality of tiles formed by the pattern forming method A semiconductor integrated circuit device comprising a turn is provided.

Other specific details of embodiments of the present invention are included in the following detailed description.

Advantageous Effects

It is possible to form a photoresist pattern having a uniform thickness without reduction and collapse of LWRCline width roughness.

BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is an NMR analysis graph of monomers prepared in Synthesis Example 1-1.

2 to 6 are scanning electron microscope (SEM) photographs showing the resolution of the photoresist pattern according to Examples 1 to 4 and Comparative Example 1, respectively.

[Best form for implementation of the invention]

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the subject matter may be embodied in many different forms and should not be construed as limited to the example set forth herein.

Unless otherwise defined herein, "substituted" means a hydrogen atom in the compound halogen atom (F, Br, G1, or I), hydroxy group, alkoxy group, nitro group, cyano group, amino group. Pottery, amidino and hydrazino. Hydrazono group, carbonyl group. Carbamyl / thiol groups, ester groups, carboxyl groups or salts thereof. Sulfonic acid groups or salts thereof, phosphoric acid or salts thereof, C1 to C20 alkyl groups, G2 to C20 alkenyl groups, C2 to C20 alkynyl groups, C6 to C30 aryl groups, C7 to C30. Arylalkyl groups, C1 to C4 alkoxy groups, C1 to C20 heteroalkyl groups, C3 to C20 heteroarylalkyl groups, C3. To C30 cycloalkyl groups. C3 to C15 cycloalkenyl group, C6 to C15 cycloalkynyl group. Substituted with a substituent selected from C2 to C20 heterocycloalkyl group and combinations thereof.

Also,. Unless otherwise defined herein, "hetero" means. N. 0. It means that it contains three heteroatoms of the heteroatoms selected from S and P.

Hereinafter, a composition for forming a photoresist underlayer according to one embodiment is described. The composition for forming a photoresist underlayer according to one embodiment is a copolymer comprising a repeating unit represented by the following Chemical Formulas 1 to 4. And solvents. . [Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

In Chemical Formulas 1 to 4 above. R ¹ , R ³ , R and R ⁷ are each independently a hydrogen atom. Substituted or unsubstituted C1 to C20 alkyl group substituted or unsubstituted C2 to G20 alkenyl group, substituted or unsubstituted C2 to C20 alkynyl group, substituted or unsubstituted C3 to C20 cycloalkyl group, substituted or unsubstituted C3 to C20 cycloalkenyl group, substituted or unsubstituted C3 to C20 cycloalkynyl group. Or a substituted or unsubstituted C6 to C30.aryl group. .

In Formulas 1 to 4, R ² may be a lactone derivative group.

The lactone derivative group rigs ^"tonal (butyrolactonyl), lock valerolactone tonil (valerolactonyl), 1.3- cycloalkyl carboxylic acid borak tonil (1,3- cyclohexanecarbolactonyl) butyronitrile in detail. 2, 6-norbornane carboxylic borak Rhone _5 At least one selected from -yl (2,6-norbornanecarbolacton-5-yl) and oxa-2,6 norbornanecarbolactone-5-yl (7-oxa—Se-norbornanecarbolacton-S-yl) . In Formulas 1 to 4, R may be a substituted or unsubstituted C1 to C20 alkanol group, or a substituted or unsubstituted C2 to C20 alkenol group. ^"Formula 1 to .4 R ⁶ is a single bond, a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted in ^the" unsubstituted C2 to C20 alkenylene group, or a substituted or unsubstituted C2 to C20 alkynylene gial Can and. R ¹⁰ may be a substituted or unsubstituted C6 to C30 aryl group. Of

In Formulas 1 to 4, R ⁸ is a substituted or unsubstituted C1 to C20 alkylene group or a substituted or unsubstituted C2 to C20 alkenylene group, a substituted or unsubstituted C2 to C20 alkynylene group. Or a substituted or unsubstituted C6 to C30 arylene group, and R ⁹ may be a fluorine atom or a C1 to C10 alkyl group substituted with at least one fluorine atom.

The copolymer may contain fluorine atoms as in the repeating unit represented by Chemical Formula 4, thereby controlling affinity with the photoresist to prevent collapse of the photoresist pattern. In addition, even if the acid generator component for crosslinking is not used separately, since it is contained in the copolymer, the acid generator component is uniformly distributed in the composition, thereby forming a thin, photoresist charge having high uniformity. have. In addition, the acid generated by deformation of the copolymer may reduce LWRGine width roughness of the photoresist pattern of the upper layer.

In Formulas 1 to 4 a, b. c and d represent the mole fraction of each repeating unit, and a + b + c + d = l. The molar fraction of each repeating unit may be 0.1 <a <0.5, 0.1 <b <0.5, 0.1 <c 0.δ and 0.01 <d ≦ 0.2, specifically 0.2 ≦ a ≦ 0.4, 0.3 <b <0.5, 0.2 <c <0.4 and 0.05 ≦ d <0.15. When the mole fraction of each repeating unit is within the above range, the lower photoresist film has no solubility and reactivity with the photoresist formed on the upper layer, has faster etching than the photoresist, and also has LW (line width roughness). ), There is no reduction and collapse, and a uniform photoresist pattern can be formed. .

Specifically, the copolymer may use at least one selected from a copolymer including structural units represented by the following Chemical Formulas 5-1 to 5-4. [Formula 5-1]

[Formula 5-2]

[Chemical Machining 5-3]

[Formula 5-4]

In Formulas 5-1 to 5-4, a + b + c + d = l, 0.1 ≦ a ≦ 0.5, 0.1 <b <0.5, 0, l <c <0.5, and 0.01 <(1 <0.2 days) have.

^'When forming a lower photoresist film using a composition comprising the copolymer, the line width roughness (LWR) of the photoresist pattern formed on the upper layer is reduced And prevent col lapse _. In addition, an acid generator component is contained in the copolymer so that it is uniformly distributed in the composition. Accordingly, it is possible to increase the photo resist lower layer cross-linking ^force. As a result, film uniformity is ensured even at a thin film thickness, and a uniform photoresist pattern can be formed even with a thin film of about 70 mW or less under exposure conditions of 248 kHz, 193 kHz and 13.5 kHz wavelengths.

The weight average molecular weight of the copolymer may be from about 1,000 g / mol to about 1,000,000 g / mol, specifically from about 3,000 g / mol to about 100,000 g / mol ᅳ also the degree of dispersion of the co-polymer (Mw / Mn) may be from about 1.2 to about 3.0. Specifically, about 1.3 to about 2.5. When the weight average molecular weight and the dispersion of the copolymer are within the above range, the film thickness uniformity of the lower photoresist layer is maintained, and appropriate hydrophilicity is provided to prevent the collapse of the photoresist pattern.

The copolymer may comprise from about 0.1% to about 10% by weight relative to the total composition for forming the lower photoresist film, ^it Specifically, it may be included as about 2% by weight if within about 0.2% by weight. When the copolymer is included within the above range, the copolymer may have a fast etching rate required for the photoresist underlayer.

The solvent is not particularly limited as long as it has sufficient solubility or dispersibility in the copolymer, and for example, propylene glycol, propylene glycol diacetate, mesopropyl propanediol, diethylene glycol, diethylene glycol butyl ether, tri ( Ethylene glycol) monocetyl ether. Propyleneglycol monomethylether, propyleneglycol monomethylether acetate, cyclonuxanone (or 'anone'), ethyl lactate. At least one selected from gamma butyrolactone and acetylacetone can be used.

. The solvent may be included as a _balance with respect to the total amount of the composition for forming a photoresist underlayer, and specifically, may be included as about 90% by weight to about .99.9% by weight ^< ¾. ^' ᅳ

The photoresist underlayer forming composition may further include a crosslinking agent. The crosslinking agent may crosslink the repeating unit in the polymer by heating, and may include an amino resin such as an etherified amino resin; Glycoluril compounds such as compounds represented by Formula A: Bisepoxy compounds such as compounds represented by the following formula (B); N-methoxymethyl melamine. Melamine compounds such as N-butoxymethyl melamine and the like; Melamine derivatives such as compounds represented by formula (C) below; Or combinations thereof. - ^. [Formula A]

[Formula B]

[Formula C]

The cross-linking ^"agents may be included to increase from about 0.01% to about 1.0% increase with respect to the photo resist lower layer total composition for forming, specifically, it may be included as about 0.02% to about 0.5% by weight. When the crosslinking agent is included in the above range, it is possible to secure crosslinkability without changing the optical properties of the composition for forming a photoresist underlayer.

The photoresist underlayer forming composition may further include a surfactant. ——

The surfactant is for example an alkylbenzenesulfonic acid salt. Alkylpyridinium salts, polyethylene glycol. A quaternary ammonium salt may be used, but is not limited thereto. Hereinafter, a method of forming and forming a pattern using the above-described composition for forming a photoresist underlayer will be described.

In one embodiment, a pattern forming method comprises providing a layer of material over a substrate. The group charge by applying a photo composition for resist lower film formation described above on the charge photoresist host substep of forming a film, comprising: forming a photoresist layer over the photo resist lower layer, exposing the ^photoresist, layer and developing Forming a photoresist pattern, selectively removing the photoresist underlayer using the photoresist pattern, exposing a portion of the material layer, and etching the exposed portion of the material layer. Include.

The substrate is for example a silicon wafer. It may be a glass substrate or a polymer substrate. The material filling is the material to be finally patterned, for example a metal layer such as aluminum, copper or the like. It may be a semiconductor layer such as silicon or an insulating layer such as silicon oxide, silicon nitride, or the like. The material layer can be formed, for example, by chemical vapor deposition.

The photoresist underlayer may be formed by coating the composition for forming a photoresist underlayer.

The photoresist underlayer forming composition is as described above.

The photoresist underlayer forming composition may be prepared in a solution form and applied by a spin-on coating method. Subsequently, the applied photoresist underlayer forming composition is heat-treated to form a photoresist underlayer.

At this time, the coating thickness, heat treatment conditions, etc. of the composition for forming a photoresist underlayer are not particularly limited. For example, about 90.8 A may be applied at a thickness of about 13 ^°, about 100 ^° C. and for example heat treated at about 100 ^° C. to about 300 ^° C. for about 10 seconds to about 10 minutes.

Subsequently, a photoresist charge is applied onto the photoresist underlayer. The photoresist charge may be a radiation-sensitive imaging charge that includes a photosensitive material.

The photoresist layer may have a thickness of about 70 kPa or less, and specifically, may be formed of about Ι ηηι to about 60 kPa. When the photoresist underlayer is formed using the above-described composition for forming a photoresist underlayer, the photoresist layer formed thereon may be formed as a thin thin film having high uniformity as in the above range. Subsequently, the photoresist layer is exposed and developed to form a photoresist pattern. In this case, the exposure may be performed using, for example, ArF, KrF, E-beam, or the like. In addition, the heat treatment may be performed at about 150 ^° C. to about 500 ^° C. after the exposure.

Subsequently, the photoresist underlayer is selectively removed using the photoresist pattern as a mask. At this time, if the additive auxiliary and / or the bottom anti-reflection layer is formed may be removed together. Depending on the length, a portion of the material layer below may be exposed.

The exposed portion of the material layer is then etched. In this case, the etching may be performed by dry etching using an etching gas, and the etching gas may be, for example, CHF ₃ , CF ₄ . CH ₄ .

Cl ₂ , BC 1 ₃ . These mixed gases can be used.

The photoresist underlayer and photoresist layer are then removed using a conventional stripper to form a plurality of patterns formed from the material fill. All. .

The plurality of patterns are metal patterns, semiconductors ^' patterns. Insulation pattern can be varied, and semiconductor integration _. There may be various patterns within the circuit device. When the pattern is included in a semiconductor integrated circuit device, for example, the semiconductor integrated circuit device may be an insulating layer including a metal wiring, a semiconductor pattern, a contact hole, a bias hole, a damascene trench, and the like.

[Mode for carrying out the invention]

. Through the following examples. Embodiments of the present invention described above will be described in more detail. However, the following examples are for illustrative purposes only and do not limit the scope of the present invention.

Monomer Synthesis

Synthesis Example 1-1

17.8 g (100 mmol) of 4-hydroxyphenyl methacrylate. Methylene chloride (178 ml) and triethylamine 20.¾ (20 () 睡 01) are placed in a 1 L flask and stirred by cooling to 0-5 ^° C. Thereafter, 2.92 g (10 麵 ol) of trifluoromethanesulphonic anhydride were added dropwise for 1 hour. After the reaction is stirred for 12 hours, the reaction is terminated by adding water 178ιιι1. The resulting organic layer was extracted and concentrated under reduced pressure to obtain 27.9 g of a monomer A in the reaction formula 1, ie, a colorless crystalline solid (yield .90%).

[Banungsik 1]

Monomer A The H NM analysis graph of the produced monomer A is shown in FIG. 1. Too _. 1 is an NMR analysis graph of the monomer prepared in Synthesis Example 1-1. The production of monomer A can be confirmed from the NMR analysis result of FIG. 1.

Synthesis Example 1-2

, Except ^{"4-hydroxy-eu} in the above Synthesis Example 1 1-phenyl methacrylate instead of 2-hydroxy ethyl methacrylate was used a ^{methacrylate.} Synthesis was carried out in the same manner as in Synthesis Example 1-1. This affords 27.9 g of the following monomer B (yield 78%).

Monomer B Synthesis Example 1-3

And is, to the synthesized in the same method as in Example 1-1 except that the monomers trifluoromethyl in the above Synthesis Example 1-1 with methane sulfonic anhydride instead na flu oro-butane sulfonic anhydride C 27.9 _g ( Yield 87%).

Monomer C Synthesis Example 1-4

Except that 2-hydroxyethyl methacrylate was used instead of 4-hydroxythoxyphenyl methacrylate in Synthesis Example 1-1 and nonafluorobutanesulphonic unhydride was used instead of trifluoromethanesulphonic anhydride. And. Synthesis was carried out in the same manner as in Synthesis Example 1-1 to obtain 27.9 g of the following monomer D (yield 76%). ^"

(Copolymer synthesis)

Synthesis Example 2-1

Butylrolactyl methacrylate 3 誦 01, hydroxyoxy propyl meth ¾ ¾ 40 mmol, ^' benzyl methacrylate 30 ^' ol, and monomer A lOmmol prepared in Chemical Formula 1-1 were added to a polar flask under a nitrogen atmosphere. It is dissolved in twice the amount of methyl ethyl ketone solvent of the above monomer total. A polymerization initiator to the solution dimethyl-2,2'-azobis (2-methylpropionate KV601. ^'Wako Chemicals Co., Ltd.), and then insert the lOmmol. At 80 ^° C _temperature. Combine for about 4 hours. Thereafter, the reaction solution is precipitated in n-nucleic acid and dried in vacuo to obtain a copolymer including a structural unit represented by the following Chemical Formula 5-1. At this time, the weight average molecular weight of the copolymer is 7.300 g / mol, dispersion degree (Mw / Mn) Is 1.9.

[Formula 5-1]

(In Formula 5-1, a = 0.3.b = 0.3.c = 0.3 and (1 = 0.1))

Synthesis Example 2-2

A structural unit represented by the following Chemical Formula 5-2 was synthesized in the same manner as in Synthesis Example 2-1, except that Monomer B prepared in Synthesis Example 1-2 was used instead of Monomer A in Synthesis Example 2-1. The copolymer containing is obtained. At this time, the weight average molecular weight of the copolymer is 6,800 g / mol, dispersion degree (Mw / Mn) is 1.88.

[Formula 5 ^' 2]

(In Formula 5-2, a = 0.3, b = 0.3. C = 0.3 and (K) .l)

Synthesis Example 2-3

Except for using monomer C prepared in Synthesis Example 1-3 instead of Monomer A in Synthesis Example 2-1. Synthesis was carried out in the same manner as in Synthesis Example 2-1 to obtain a copolymer including a structural unit represented by Chemical Formula 5-3 _. It is. At this time, the weight average molecular weight of the copolymer is 7,800 g / mol, dispersion degree (Mw / Mn) is 1.98. [Formula 5-3]

(In Formula 5-3, a = 0.3, b = 0.3, c = 0.3 and d = 0.1)

Hansung Example 2-4

Except for using monomer D prepared in Synthesis Example 1-4 instead of Monomer A in Synthesis Example 2-1. Synthesis was carried out in the same manner as in Synthesis Example 2-1 to obtain a copolymer including a structural unit represented by the following Chemical Formula 5-4. The weight average molecular weight of the copolymer was 7,100 g / mol, and the degree of dispersion (M \ v / Mn) is 1.92.

[Formula 5-4]

(In Formula 5-4, a = 0.3.b = 0.3.c = 0.3 and (1 = 0.1))

Comparative Synthesis Example 1

In a nitrogen atmosphere, butyrolactoneyl methacrylate 30 'iol, hydroxyisopropyl methacrylate 40' ol, and benzyl methacrylate 30 'ol were placed in a flask, which was twice the amount of methyl ethyl ketone solvent in the monomer. Dissolved in. To this solution was added 10 μl ol of a polymerization initiator, dimethyl _2, 2′-azobis (2-methylpropionate) (V601, manufactured by Wako Chemicals). Polymerize at 80 ^° C for about 4 hours. The reaction solution is then precipitated in n—nucleic acid and dried in vacuo to obtain a copolymer comprising a structural unit represented by the following formula (6). At this time, the weight average molecular weight of the copolymer is 6,900 g / mol, dispersion degree (Mw / Mn) is 1.83.

(In Formula 6, a = 0.3, b = 0.4, and c = 0.3)

(Formation of photoresist underlayer ^ production of composition)

Example 1

0.5 g of the copolymer obtained in Synthesis Example 2-1 and 0.125 g of the glycoluril derivative crosslinking agent (PD-1174) represented by Chemical Formula A were dissolved in 100 g of propylene glycol monomethyl ether acetate (PGMEA) to form a photoresist underlayer Was prepared.

{Formula A]

Example 2

Except for using the co-polymer obtained in Synthesis Example 2-2 instead of the copolymer obtained in Synthesis Example 2-1, a composition for forming a photoresist underlayer was prepared in the same manner as in Example 1.

Example 3

Except for using the co-polymer obtained in Synthesis Example 2-3 instead of the copolymer obtained in Synthesis Example 2-1. In the same manner as in Example 1, a composition for forming a photoresist underlayer was prepared. ^'

Example 4

Except for using the copolymer obtained in Synthesis Example 2-4 instead of the copolymer obtained in Synthesis Example 2-1. In the same manner as in Example 1, a composition for forming a photoresist underlayer was prepared.

Comparative Example 1

Comparative Synthesis Example 1 notary copolymer 0.5g, glycidyl # reel base derivative cross-linking agent (PD-1174) represented by the above formula (A) obtained _{in, _0.125g,.} And pyridinium p- represented by the following formula (7) 0.0125 g of toluenesulfonate was dissolved in propylene glycol monomethyl, ether ^' acetate (PGMEA) ioog to prepare a composition for forming a photoresist underlayer:

[Formula 7]

(Formation of photoresist underlayer and photoresist pattern)

Examples 1 to 4 and _{. On} the silacon wafer on which the silicon nitride layer is formed _. The composition for forming a photoresist underlayer formed in Comparative Example 1 was applied by a spin-silver coating method, and then heat-treated at 205 ^° C. for 60 seconds on a hot plate to form a photoresist underlayer having a thickness of lOnm.

The photoresist _. E-beam photoresist was applied on the lower layer to form a photoresist layer having a thickness of 60 nm. Then, the photoresist layer was heat-treated at 205 ^° C for 60 seconds, and then J-X-9300FS manufactured by JE0L, an E-beam exposure equipment, was used. The exposure was performed. It was then developed with a 2.38% by weight aqueous solution of tetramethylammonium hydroxide (TMAH) to form a photoresist pattern, i.e., a line & space of 40 kV resolution. A pattern was formed.

Evaluation 1: Determination of Contact Angle and Thickness Uniformity on Photoresist Substrate Surface

The contact angle of the surface of the lower photoresist film formed according to Examples 1 to 4 and Comparative Example 1 was measured using a contact angle meter, and the thickness uniformity of the surface was measured using a k-mac device, which is a thin film thickness meter. Measured. The results are shown in Table 1 below.

Table 1

In Table 1, the contact angle shows the affinity between the photoresist lower layer and the photoresist applied to the upper layer, and in Examples 1 to 4, it was found that the hydrophilicity was higher than that of Comparative Example 1. It can be seen that the collapse of the pattern can be prevented. ,

^In addition, in the case of Examples 1 to .4, the uniformity deviation of the thickness was smaller than that of Comparative Example 1. As it appears, it can be confirmed that thickness uniformity is more excellent.

Evaluation 2: Elution Experiment of Photoresist Solvent

Propylene glycol monomethyl ether acetate (PGMEA) as a solvent for the photoresist underlayer formed according to Examples 1 to 4 and Comparative Example 1. Propylene glycol monomethyl ether (PGME). It was immersed in an aqueous solution of Anone and 2.38 wt% tetramethylammonium hydroxide (TMAH), respectively. The thickness of the lower photoresist film before and after dipping was measured using k-niac equipment, and the results are shown in Table 2 below.

Table 2

The thickness difference (A) is the difference between the existing thickness and the thickness after immersion, and the change rate (%) represents the thickness difference as a percentage.

The thickness change rate shows the extent that the lower photoresist film is not dissolved in the solvent or the developer, and it can be confirmed that the photoresist lower films of Examples 1 to 4 and Comparative Example 1 are almost insoluble in the solvent or the developer.

Evaluation 3: resolution of photoresist pattern. LWR and Collapse Measurement Resolution of the photoresist pattern formed according to Examples 1 to 4 and Comparative Example 1,

LWR and collapse were measured by CD measurement SEM. The results are shown in FIGS. 2 to 6 and Table 3 below.

^"Figures 2 to 6, a photoresist pattern according to each of Examples 1 to 4 and Comparative Example 1 Scanning electron microscope (SEM) images showing the resolution of

TABLE 3

(X: no collapse occurs. 0: no collapse occurs.) Through Table 3 and FIGS. It can be seen that the photoresist pattern manufactured according to Examples 1 to 4 can realize a highly integrated semiconductor integrated circuit device with excellent resolution, and it is understood that the LWR value is small and no collapse occurs. Can be. On the other hand, in the case of Comparative Example 1, as shown in the SEM photograph of FIG. 6, the resolution was not good, and thus, the UR value itself was not measured, and it can be seen that collapsing occurred. In the case of Comparative Example 1 it can be seen that forming a uniform photoresist pattern without reduction and collapse of LWR.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of the present invention.

Claims

Claims Claim 1 A copolymer comprising a repeating unit represented by the following formulas (1) to (4); And a solvent. A composition for forming a photoresist underlayer.

[Formula 1]

[Formula 2]

[Formula 4]

(In the above Chemical Formulas 1 to 4,

R ¹ , R. R and R ⁷ each independently represent a hydrogen atom. A substituted or unsubstituted C1 to C20 alkyl group. Substituted or unsubstituted C2 to C20 alkenyl group. Substituted or unsubstituted C2 to C20 alkynyl group, Substituted or unsubstituted C3 to C20 cycloalkyl group, Substituted or unsubstituted C3 to C20 sarcloalkenyl group. A substituted or unsubstituted C3 to C20 cycloalkynyl group, or a substituted or unsubstituted C6 to C30 aryl group,

R ² is a lactone derivative group. R represents a substituted or unsubstituted C1 to C20 alkan. Or a substituted or unsubstituted C2 to C20 alkenol group,

R ⁶ is a single bond. Substituted or unsubstituted C1 to C20 alkylene group, substituted or unsubstituted C2 to C20 alkenylene group, or substituted or unsubstituted C2 to C20 alkynylene group, R ¹⁰ is substituted or unsubstituted C6 to 'C30 aryl Qi.

R ⁸ is a substituted or unsubstituted C1 to C20 alkylene group. A substituted or unsubstituted C2 to C20 alkenylene group, a substituted or unsubstituted C2 to C20 ^" alkynylene group, or a substituted or unsubstituted C6 to C30 arylene group, and ᅳ is an atom or is substituted with at least one fluorine atom α to cioalkyl group /

a + b + c + d = l and 0.1 <a <0.5. 0.1 <b <0.5. 0.1c <0.5. And 0.01 <cl <0.2 is ·). Claims 21

The method of claim 1,

The copolymer is a composition for forming a photoresist underlayer comprising at least one selected from copolymers comprising structural units represented by the following Chemical Formulas 5-1 to 5-4.

[Chemical Formula 5-2 _i]

[Formula 5-3]

(In Chemical Formulas 5-1 to 5-4.

a + b + c + d = l and 0.1 <a <0.5, 0.1 <b 0.5, 0.1 <c <0.5 and 0.01 <d <0.2.)

[Claim 3]

The method of claim 1

The copolymer is a. The composition for forming a photoresist underlayer, wherein b, c and d are respectively 0.2 ≦ a ≦ 0.4, 0.3 <b <0.5, 0.2 <c <0.4 and 0.05 d <0.15.

[Claim 4]

The method of claim 1,

The weight average molecular weight of the copolymer is 1.000 to 1,000,000 g / mol composition for forming a photoresist underlayer.

[Claim 5]

The method of claim 1.

The copolymer is a composition for forming a photoresist underlayer comprising 0.1 to 10% by weight relative to the total amount of the composition for forming a photoresist underlayer.

[6.] ^"

According to claim 1, ^''

. The composition for forming a photoresist underlayer further comprises a crosslinking agent.

[Claim 7]

The method of claim 6,

The crosslinking agent is a composition for forming a photoresist underlayer comprising at least one selected from an amino resin ᅳ, a glycoluril compound, a bisepoxy compound, a melamine compound and a melamine derivative. ᅳ

【Claim 8】,

The method of claim 6,

The crosslinking agent is a composition for forming a photoresist underlayer comprising 0.01 to 1.0% by weight relative to the total amount of the composition for forming a photoresist underlayer.

[Claim 9]

Providing a layer of material on the substrate;

Forming a photoresist underlayer by applying the composition for forming a photoresist underlayer according to any one of claims 1 to 8 on the material layer;

Forming a photoresist layer on the photoresist underlayer; . Exposing and developing the photoresist layer to form a photoresist pattern;

Selectively removing the photoresist underlayer using the photoresist pattern and exposing a portion of the material layer; And

Advancing the exposed portion of the material layer

Pattern forming method comprising a.

[Claim 10]

The method according to claim 9,

The forming of the photoresist underlayer is performed by a spin-on coating method.

[Claim 11]

The method of claim 9.

The thickness of the photoresist layer is 70nm or less pattern forming method.

[Claim 12]

A semiconductor integrated circuit device comprising a plurality of patterns formed by the pattern forming method according to claim 9.