KR101354639B1 - Composition for photoresist underlayer, method of forming patterns using the same, and semiconductor integrated circuit device including the patterns - Google Patents

Abstract

[화학식 2]

[화학식 3]

[화학식 4]

(상기 화학식 1 내지 4에서, 각 치환기는 명세서에 정의된 바와 같다.)The present invention relates to a composition for forming a photoresist underlayer comprising a copolymer including a repeating unit represented by Formulas 1 to 4 and a solvent, a pattern forming method using the same, and a semiconductor integrated circuit device including a pattern formed by the method. .
[Chemical Formula 1]

(2)

(3)

[Chemical Formula 4]

(Wherein each substituent is as defined in the above Chemical Formulas 1 to 4)

Description

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

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

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.

In the pattern formation method on the semiconductor wafer, the organic or inorganic component film is cross-coated or deposited on the semiconductor wafer, and then a photoresist is coated for pattern formation, exposed with a suitable light, and then a basic solution is applied. It develops and forms a pattern using a suitable etching gas.

In this pattern formation method, when the active light having short wavelengths of 248 nm, 193 nm and 13.5 nm is irradiated instead of the active light having a wavelength of 365 nm to form a fine pattern, the LWR (line width roughness) of the photoresist pattern There is a problem of increase and collapse.

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

One embodiment of the present invention is to provide a composition for forming a photoresist underlayer capable of forming a photoresist pattern having a uniform thickness without reduction and collapse of line width roughness (LWR).

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.

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]

(2)

(3)

[Chemical Formula 4]

(In the above Chemical Formulas 1 to 4,

R ¹ , R ³ , R ⁵ and R ⁷ are each independently 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 a substituted or unsubstituted C1 to C20 alkanol group, or a substituted or unsubstituted C2 to C20 alkenol group,

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

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 R ⁹ is a fluorine atom or a C1 to C10 alkyl group substituted with at least one fluorine atom,

a + b + c + d = 1, and 0.1 ≦ a ≦ 0.5, 0.1 ≦ b ≦ 0.5, 0.1 ≦ c ≦ 0.5 μs, and 0.01 ≦ d ≦ 0.2 μm.)

The copolymer may include at least one selected from copolymers including structural units represented by the following Chemical Formulas 5-1 to 5-4.

[Formula 5-1]

[Formula 5-2]

[Formula 5-3]

[Formula 5-4]

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

a + b + c + d = 1, and 0.1 ≦ a ≦ 0.5, 0.1 ≦ b ≦ 0.5, 0.1 ≦ c ≦ 0.5 μs, and 0.01 ≦ d ≦ 0.2 μm.)

The copolymer may be a + b + c + d = 1 in Formulas 1 to 4, 0.2 ≦ a ≦ 0.4, 0.3 ≦ b ≦ 0.5, 0.2 ≦ c ≦ 0.4 μs, and 0.05 ≦ d ≦ 0.15.

The weight average molecular weight of the copolymer may be about 1,000 g / mol to about 1,000,000 dl / mol.

The copolymer may be included in about 0.1% by weight to about 10% by weight relative to the total amount of the composition for forming a photoresist underlayer.

The photoresist underlayer forming composition may further include a crosslinking agent, and the crosslinking agent may include at least one selected from an amino resin, a glycoluryl compound, a bisepoxy compound, a melamine compound, and a melamine derivative, and the crosslinking agent The total amount of the photoresist underlayer forming composition may be included in an amount of about 0.01 wt% to about 1.0 wt%.

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 layer 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 embodiment of the present invention provides a semiconductor integrated circuit device including a plurality of patterns formed by the pattern forming method.

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

It is possible to form a photoresist pattern having a uniform thickness without reduction and collapse of line width roughness (LWR).

1 is a ¹ H NMR analysis graph of the monomer 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.

Hereinafter, exemplary embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Unless otherwise defined herein, 'substituted' means that a hydrogen atom in a compound is a halogen atom (F, Br, Cl, or I), a hydroxyl group, an alkoxy group, a nitro group, a cyano group, an amino group, an azido group, an amino group Dino group, hydrazino group, hydrazono group, carbonyl group, carbamyl group, thiol group, ester group, carboxyl group or salt thereof, sulfonic acid group or salt thereof, phosphoric acid or salt thereof,, C1 to C20 alkyl group, C2 to C20 alkenyl group, C2 To C20 alkynyl group, C6 to C30 aryl group, C7 to C30 arylalkyl group, C1 to C4 alkoxy group, C1 to C20 heteroalkyl group, C3 to C20 heteroarylalkyl group, C3 to C30 cycloalkyl group, C3 to C15 cycloalkenyl group, C6 To C15 cycloalkynyl group, C2 to C20 heterocycloalkyl group, and a combination thereof.

In addition, unless otherwise defined herein, "hetero" means containing 1 to 3 heteroatoms selected from N, O, 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 includes a copolymer including a repeating unit represented by the following Chemical Formulas 1 to 4, and a solvent.

[Formula 1]

(2)

(3)

[Chemical Formula 4]

R ¹ , R ³ , R ⁵ and R ⁷ in Formulas 1 to 4 are each independently 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 Substituted 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 substituted or unsubstituted C6 to It may be a C30 aryl group.

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

Specifically, the lactone derivative group is butyrolactonyl, valerolactonyl, 1,3-cyclohexanecarbolactonyl, 2,6-norbornanecaractone-5 At least one selected from (2,6-norbornanecarbolacton-5-yl) and 7-oxa-2,6-norbornanecarbolacton-5-yl (7-oxa-2,6-norbornanecarbolacton-5-yl) It can be one.

In Formulas 1 to 4, R ⁴ may be a substituted or unsubstituted C1 to C20 alkanol group, or a substituted or unsubstituted C2 to C20 alkenol group.

R ⁶ in Chemical Formulas 1 to 4 may be a single bond, a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C2 to C20 alkenylene group, or a substituted or unsubstituted C2 to C20 alkynylene group, R ¹⁰ may be a substituted or unsubstituted C6 to C30 aryl group.

In Formulas 1 to 4, 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 It may be a C6 to C30 arylene group, R ⁹ may be a fluorine atom, or a C1 to C10 alkyl group substituted with at least one fluorine atom.

The copolymer may include a fluorine atom as in the repeating unit represented by Formula 4, thereby controlling the affinity with the photoresist to prevent the collapse of the photoresist pattern. In addition, even if the acid generator component for crosslinking is not used separately, the acid generator component is uniformly distributed in the composition as it is contained in the copolymer, thereby forming a highly uniform thin photoresist layer. . In addition, the acid generated by deformation of the copolymer may reduce the line width roughness (LWR) of the photoresist pattern of the upper layer.

In Formulas 1 to 4, a, b, c, and d represent a mole fraction of each repeating unit, and a + b + c + d = 1. The molar fraction of each repeating unit may be 0.1 ≦ a ≦ 0.5, 0.1 ≦ b ≦ 0.5, 0.1 ≦ c ≦ 0.5 μs, and 0.01 ≦ d ≦ 0.2, specifically 0.2 ≦ a ≦ 0.4, 0.3 ≦ b ≦ 0.5, 0.2 ≦ c ≦ 0.4 μs and 0.05 ≦ d ≦ 0.15 μs. When the mole fraction of each repeating unit is in the above range, the photoresist underlayer has no solubility and reactivity with the photoresist formed on the upper layer, has faster etching than photoresist, and also reduces the line width roughness (LWR) and It is possible to form a photoresist pattern having no thickness and having a uniform thickness.

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

[Formula 5-1]

[Formula 5-2]

[Formula 5-3]

[Formula 5-4]

In Formulas 5-1 to 5-4, a + b + c + d = 1, and 0.1 ≦ a ≦ 0.5, 0.1 ≦ b ≦ 0.5, 0.1 ≦ c ≦ 0.5 μm, and 0.01 ≦ d ≦ 0.2 μm.

When forming the lower photoresist film using the composition comprising the copolymer, it is possible to reduce the line width roughness (LWR) of the photoresist pattern formed on the upper layer and to prevent collapse. In addition, the acid generator component is contained in the copolymer to be uniformly distributed in the composition, thereby increasing the crosslinking force of the photoresist underlayer. As a result, film thickness uniformity is ensured even at a thin film thickness, and a uniform photoresist pattern can be formed even at a thin thin film of about 70 nm or less under exposure conditions of 248 nm, 193 nm, and 13.5 nm wavelengths.

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

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 composition for forming a photoresist underlayer, and specifically, about 0.2% by weight to about 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, but for example, propylene glycol, propylene glycol diacetate, methoxy propanediol, diethylene glycol, diethylene glycol butyl ether, tri (ethylene glycol) At least one selected from monomethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone (or 'anone'), ethyl lactate, gamma-butyrolactone and acetylacetone have.

The solvent may be included in the remainder relative to the total amount of the composition for forming a photoresist underlayer, and specifically, about 90 wt% to about 99.9 wt%.

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; A glycoluril compound such as a compound represented by the following formula (A); Bisepoxy compounds, such as the compound represented by following formula (B); Melamine compounds such as N-methoxymethyl melamine, N-butoxymethyl melamine and the like; Melamine derivatives such as compounds represented by formula (C) below; Or a mixture thereof.

(A)

[Formula B]

≪ RTI ID = 0.0 &

The crosslinking agent may be included in an amount of about 0.01 wt% to about 1.0 wt% based on the total amount of the photoresist underlayer forming composition, and specifically, about 0.02 wt% to about 0.5 wt%. 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 may be, for example, an alkylbenzenesulfonate, an alkylpyridinium salt, a polyethylene glycol, or a quaternary ammonium salt, but is not limited thereto.

Hereinafter, a method of forming a pattern using the above-described composition for forming a photoresist underlayer will be described.

According to one or more exemplary embodiments, a method of forming a pattern includes: providing a material layer on a substrate, applying a composition for forming a photoresist underlayer on the material layer to form a photoresist underlayer, and forming a photoresist on the photoresist underlayer Forming a layer, 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 Etching the exposed portion of the material layer.

The substrate may be, for example, a silicon wafer, a glass substrate, or a polymer substrate.

The material layer is a material to be finally patterned and may be a metal layer such as aluminum, copper, or the like, 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 applying 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. It can be heat treated.

Subsequently, a photoresist layer is applied on the photoresist underlayer film. The photoresist layer may be a radiation-sensitive imaging layer comprising a photosensitive material.

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delete

The photoresist layer may have a thickness of about 70 nm or less, and specifically, about 10 nm to about 60 nm. 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.

The photoresist layer is then exposed and developed to form a photoresist pattern. The exposure may be performed using, for example, ArF, KrF, E-beam, or the like. In addition, a “heat treatment” process may be performed at about 150 ° C. to about 500 ° C. after exposure.

Subsequently, the photoresist underlayer is selectively removed using the photoresist pattern as a mask. In this case, when the auxiliary layer and / or the bottom anti-reflection layer are formed, these may be removed together. This may expose a portion of the underlying material layer.

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 , BCl ₃ , a mixed gas thereof, or the like.

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

The plurality of patterns may vary from metal patterns, semiconductor patterns, insulating patterns, and the like, and may be various patterns in the semiconductor integrated 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.

Hereinafter, embodiments of the present invention will be described in detail with reference to examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

(Monomer synthesis)

Synthetic example  1-1

17.8 g (100 mmol) of 4-hydroxyphenyl methacrylate, methylene chloride (178 ml) and 20.2 g (200 mmol) of triethylamine are placed in a 1 L flask and cooled to 0-5 ° C. and stirred. Thereafter, 2.92 g (100 mmol) of trifluoromethanesulphonic anhydride was added dropwise for 1 hour. The reaction is then stirred for 12 hours and 178 ml of water is added to terminate the reaction. The resulting organic layer was extracted and concentrated under reduced pressure to obtain 27.9 g (yield 90%) of monomer A in Scheme 1, that is, a colorless crystalline solid.

[Reaction Scheme 1]

¹ H NMR analysis graph of the resulting monomer A is shown in FIG. 1 is a ¹ H NMR analysis graph of the monomer prepared in Synthesis Example 1-1. The production of monomer A can be confirmed from the ¹ H NMR analysis result of FIG. 1.

Synthetic example  1-2

Except for using 2-hydroxyethyl methacrylate instead of 4-hydroxyphenyl methacrylate in Synthesis Example 1-1, and synthesized in the same manner as in Synthesis Example 1-1 to 27.9 g of the monomer B (yield 78 %)

Synthetic example  1-3

Synthesis Example 1-1 was synthesized in the same manner as in Synthesis Example 1-1, except that nonafluorobutanesulphonic anhydride was used instead of trifluoromethanesulphonic anhydride in Synthesis Example 1-1. Yield 87%).

Synthetic example  1-4

Except for using 2-hydroxyethyl methacrylate instead of 4-hydroxyphenyl methacrylate in Synthesis Example 1-1 and nonafluorobutanesulphonic anhydride instead of trifluoromethanesulphonic anhydride Then, it synthesize | combined by the method similar to the synthesis example 1-1, and obtains following monomer D 27.9g (yield 76%).

(Copolymer synthesis)

Synthetic example  2-1

30 mmol of γ-butyrolactyl methacrylate, 40 mmol of hydroxyisopropyl methacrylate, 30 mmol of benzyl methacrylate, and 10 mmol of the monomer A prepared in Chemical Formula 1-1 were placed in a flask, and the monomer was It is dissolved in twice the total amount of methyl ethyl ketone solvent. 10 mmol of dimethyl-2,2'-azobis (2-methylpropionate) (V601, manufactured by Wako Chemicals), a polymerization initiator, was added to the solution, followed by polymerization at 80 DEG C for about 4 hours. Thereafter, the reaction solution is precipitated in n-hexane and dried under vacuum 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 d = 0.1)

Synthetic example  2-2

Except for using the monomer B prepared in Synthesis Example 1-2 instead of the monomer A in Synthesis Example 2-1, and synthesized in the same manner as in Synthesis Example 2-1 to include a structural unit represented by the formula A copolymer 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 d = 0.1)

Synthetic example  2-3

Except for using the monomer C prepared in Synthesis Example 1-3 instead of the monomer A in Synthesis Example 2-1, and synthesized in the same manner as in Synthesis Example 2-1 to include a structural unit represented by the formula A copolymer is obtained. 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).

Synthetic example  2-4

Except for using the monomer D prepared in Synthesis Example 1-4 instead of the monomer A in Synthesis Example 2-1, and synthesized in the same manner as in Synthesis Example 2-1 to include a structural unit represented by the formula A copolymer is obtained. At this time, the weight average molecular weight of the copolymer is 7,100 g / mol, dispersion degree (Mw / Mn) is 1.92.

[Formula 5-4]

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

Comparative Synthetic Example  One

In a nitrogen atmosphere, 30 mmol of γ-butyrolactyl methacrylate, 40 mmol of hydroxyisopropyl methacrylate, and 30 mmol of benzyl methacrylate are placed in a flask, which is dissolved in twice the amount of methyl ethyl ketone solvent of the above monomer total. . 10 mmol of dimethyl-2,2'-azobis (2-methylpropionate) (V601, manufactured by Wako Chemicals), a polymerization initiator, was added to the solution, followed by polymerization at 80 DEG C for about 4 hours. Thereafter, the reaction solution is precipitated in n-hexane and dried under vacuum to obtain a copolymer including a structural unit represented by the following Chemical 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.

[Chemical Formula 6]

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

( Photoresist Bottom membrane  조 Preparation of Composition for Formation)

Example  One

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.

(A)

Example  2

Except for using the copolymer 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 copolymer obtained in Synthesis Example 2-3 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  4

Except for using the copolymer obtained in Synthesis Example 2-4 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.

Comparative Example  One

0.5 g of the copolymer obtained in Comparative Synthesis Example 1, 0.125 g of the glycoluril derivative crosslinking agent (PD-1174) represented by Formula A, and 0.0125 g of pyridinium p-toluenesulfonate represented by Formula 7, It was dissolved in 100 g of ether acetate (PGMEA) to prepare a composition for forming a photoresist underlayer.

[Formula 7]

( Photoresist Bottom membrane  And Photoresist  Pattern formation)

On the silicon wafer on which the silicon nitride layer is formed, the photoresist underlayer forming compositions prepared in Examples 1 to 4 and Comparative Example 1 were applied by spin-on coating, and then heat-treated at 205 ° C. for 60 seconds on a hot plate. To form a photoresist underlayer having a thickness of 10 nm.

E-beam photoresist is applied on the lower photoresist layer to form a photoresist layer having a thickness of 60 nm. Then, the photoresist layer is heat-treated at 205 ° C. for 60 seconds, and then JBX-9300FS manufactured by JEOL, an E-beam exposure equipment. The exposure was carried out using. It was then developed with a 2.38 wt% aqueous solution of tetramethylammonium hydroxide (TMAH) to form a photoresist pattern, ie a line & space pattern with 40 nm resolution.

Rating 1: Photoresist Bottom membrane  Surface Contact angle  And thickness uniformity measurements

The contact angles of the surface of the lower photoresist film formed according to Examples 1 to 4 and Comparative Example 1 were 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. It was. The results are shown in Table 1 below.

Contact Angle (°) Thickness uniformity Example 1 71 101.3 ± 4.2 Example 2 69 99.7 ± 3.7 Example 3 74 110.1 ± 2.7 Example 4 73 105.6 ± 3.9 Comparative Example 1 62 102.6 ± 9.9

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 can be prevented.

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

Evaluation 2: Photoresist  Elution Experiment of Solvent

The photoresist underlayer formed according to Examples 1 to 4 and Comparative Example 1 was prepared using solvents of propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), anone and 2.38 wt% tetramethylammonium hydroxide. It was immersed in the aqueous solution of the side (TMAH), respectively. The thickness of the photoresist underlayer film after immersion and after immersion was measured using a k-mac apparatus, and the results are shown in Table 2 below.

menstruum Existing Thickness Thickness after immersion Thickness difference Thickness change ratio (%) Example 1 PGMEA 91.2 90.9 0.3 0.33 PGME 90.8 90.7 0.1 0.11 Anone 90.9 100.1 0.2 0.22 TMAH 91.1 90.5 0.6 0.66 Example 2 PGMEA 103.2 102.6 0.6 0.58 PGME 103.6 103.1 0.5 0.49 Anone 102.3 102.1 0.2 0.20 TMAH 103.4 103.4 0 0 Example 3 PGMEA 106.8 106.2 0.6 0.56 PGME 107.2 107.0 0.2 0.19 Anone 106.9 107.2 0.7 0.65 TMAH 106.2 105.8 0.4 0.38 Example 4 PGMEA 99.2 99.1 0.1 0.10 PGME 100.1 100.0 0.1 0.10 Anone 101.3 100.6 0.3 0.30 TMAH 99.6 99.3 0.3 0.30 Comparative Example 1 PGMEA 101.2 100.5 0.7 0.70 PGME 102.1 101.4 0.7 0.69 Anone 100.9 100.8 0.1 0.10 TMAH 103.2 103.2 0 0

The thickness difference is the difference between the existing thickness and the thickness after immersion, and the thickness 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.

Rating 3: Photoresist  The resolution of the pattern, LWR  And collapse ( collapse ) Presence

The resolution, LWR, and collapse of the photoresist patterns formed according to Examples 1 to 4 and Comparative Example 1 were measured by CD measurement SEM. The results are shown in FIGS. 2 to 6 and Table 3 below.

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.

Resolution (nm) LWR (nm) Collapse Occurs Example 1 39.8 5.4 X Example 2 41.3 6.0 X Example 3 39.4 7.1 X Example 4 38.8 6.5 X Comparative Example 1 40.1 - O

(X: no collapse occurs O: no collapse occurs)

Through Tables 3 and 2 to 6, it can be seen that the photoresist pattern manufactured according to Examples 1 to 4 can implement a highly integrated semiconductor integrated circuit device with excellent resolution, and the LWR value is small and collapses. It can be seen that (collapse) does not occur. 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 LWR value measurement itself was not performed, and it can be seen that collapse occurred. Accordingly, in the case of Examples 1 to 4 it can be seen that forming a uniform photoresist pattern without reduction and collapse of LWR compared to Comparative Example 1.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, And falls within the scope of the invention.

Claims (12)

A copolymer including a repeating unit represented by Formulas 1 to 4; And
menstruum
Composition for forming a photoresist underlayer comprising a.
[Chemical Formula 1]

(2)

(3)

[Chemical Formula 4]

(In the above Chemical Formulas 1 to 4,
R ¹ , R ³ , R ⁵ and R ⁷ are each independently 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 a substituted or unsubstituted C1 to C20 alkanol group, or a substituted or unsubstituted C2 to C20 alkenol group,
R ⁶ is a single bond, a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C2 to C20 alkenylene group, or a substituted or unsubstituted C2 to C20 alkynylene group, and R ¹⁰ is substituted or unsubstituted C6 to C30 aryl group,
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 R ⁹ is a fluorine atom or a C1 to C10 alkyl group substituted with at least one fluorine atom,
a + b + c + d = 1, and 0.1 ≦ a ≦ 0.5, 0.1 ≦ b ≦ 0.5, 0.1 ≦ c ≦ 0.5, and 0.01 ≦ d ≦ 0.2.)
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.
[Formula 5-1]

[Formula 5-2]

[Formula 5-3]

[Formula 5-4]

(In Chemical Formulas 5-1 to 5-4,
a + b + c + d = 1, and 0.1 ≦ a ≦ 0.5, 0.1 ≦ b ≦ 0.5, 0.1 ≦ c ≦ 0.5, and 0.01 ≦ d ≦ 0.2.)
The method of claim 1,
The copolymer has a composition for forming a photoresist underlayer having a, b, c, and d in the general formulas 1 to 4, wherein 0.2 ≦ a ≦ 0.4, 0.3 ≦ b ≦ 0.5, 0.2 ≦ c ≦ 0.4, and 0.05 ≦ d ≦ 0.15, respectively. .
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.
The method of claim 1,
The copolymer is a composition for forming a photoresist underlayer comprising 0.1 to 10% by weight based on the total amount of the composition for forming a photoresist underlayer.
The method of claim 1,
The composition for forming a photoresist underlayer further comprises a crosslinking agent.
The method according to claim 6,
The crosslinking agent is a composition for forming a photoresist underlayer comprising at least one selected from an amino resin, a glycoluril compound, a bisepoxy compound, a melamine compound and a melamine derivative.
The method according to 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.
Providing a layer of material over 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
Etching the exposed portion of the material layer
≪ / RTI >
10. The method of claim 9,
The forming of the photoresist underlayer is performed by a spin-on coating method.
10. The method of claim 9,
And a thickness of the photoresist layer is 70 nm or less.
A semiconductor integrated circuit device comprising a plurality of patterns formed by the pattern forming method according to claim 9.

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