KR102402748B1 - Composition for hard mask - Google Patents

Abstract

Embodiments of the present invention include a polymer and a solvent of a first aromatic unit containing a plurality of aryl rings and a second aromatic unit containing a cyano group, and can form a hardmask with improved etch resistance and solubility together. A composition for a hard mask is provided.

Description

Composition for hard mask {COMPOSITION FOR HARD MASK}

The present invention relates to a composition for a hard mask. More particularly, the present invention relates to a composition for a hard mask comprising an aromatic unit.

For example, in the fields of semiconductor manufacturing, microelectronics, etc., the degree of integration of structures such as circuits, wirings, and insulating patterns is continuously improved. Accordingly, a photolithography process for fine patterning of the structures is being developed together.

In general, a photoresist layer is formed by coating a photoresist on an etch target layer, and a photoresist pattern is formed through exposure and development processes. Then, a predetermined pattern may be formed by partially removing the etch target layer using the photoresist pattern as an etch mask. After image transfer to the etch target layer is performed, the photoresist pattern may be removed through an ashing and/or strip process.

An anti-reflective coating (ARC) layer may be formed between the etch target layer and the photoresist layer in order to suppress resolution degradation due to light reflection during the exposure process. In this case, etching of the ARC layer is added, and accordingly, consumption or etching amount of the photoresist layer or the photoresist pattern may be increased. In addition, when the thickness of the etch target layer increases or the etching amount required to form a desired pattern increases, sufficient etch resistance of the required photoresist layer or photoresist pattern may not be secured.

Accordingly, a resist lower layer may be added between the target layer to be etched and the photoresist layer in order to secure the etch resistance and etch selectivity of the photoresist for forming a desired pattern.

The resist underlayer needs to have sufficient etch resistance (or etch resistance) and heat resistance to, for example, a high-temperature etching process, and also needs to be formed to a uniform thickness by, for example, a spin-on coating process. .

Korean Patent Application Laid-Open No. 10-2010-0082844 discloses an example of a composition for forming a resist underlayer.

Korean Patent Publication No. 10-2010-0082844

One object of the present invention is to provide a composition for a hard mask capable of forming a hard mask having excellent solubility and etch resistance.

1. A polymer of a first aromatic unit containing a plurality of aryl rings and a second aromatic unit containing a cyano group; and a solvent, a composition for a hard mask.

2. The composition for a hard mask according to the above 1, wherein the polymer comprises a repeating unit represented by the following formula (1):

[Formula 1]

(In Formula 1, Ar ₁ is an arylene group having 10 to 40 carbon atoms, and Ar ₂ is an arylene group having 6 to 40 carbon atoms).

3. The hard mask of 2 above, wherein Ar ₁ in Formula 1 represents the first aromatic unit, and is derived from at least one selected from the group consisting of compounds represented by Formulas 2-1 to 2-4 below. For composition:

[Formula 2-1]

[Formula 2-2]

(In Formula 2-2, X is -OH, -OR ¹ or -NR ² R ³ , and R ¹ , R ² and R ³ are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms)

[Formula 2-3]

(in Formula 2-3, Ar ₃ and Ar ₄ are each independently a phenylene group or a naphthylene group, and n ₁ and n ₂ are each independently an integer of 1 or 2)

[Formula 2-4]

(In Formula 2-4, Y is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, an alkynyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 25 carbon atoms).

4. The composition for a hard mask according to the above 3, wherein Ar ₁ is derived from at least one selected from the group consisting of compounds represented by the following Chemical Formulas 2-3-1 to 2-3-3:

[Formula 2-3-1]

[Formula 2-3-2]

[Formula 2-3-3]

.

.

5. The composition for a hard mask according to 2 above, wherein Ar ₂ in Formula 1 includes a phenylene group or a naphthylene group.

6. The composition for a hard mask according to the above 5, wherein the cyano group-containing second aromatic unit is derived from at least one of compounds represented by the following Chemical Formula 3-1 or Chemical Formula 3-2:

[Formula 3-1]

[Formula 3-2]

.

.

7. The composition for a hard mask according to 1 above, further comprising at least one of a crosslinking agent, a catalyst, or a surfactant.

By using the composition for a hard mask according to embodiments of the present invention, it is possible to form a hard mask having excellent solubility in a solvent and having improved etch resistance together.

The composition for a hard mask according to embodiments of the present invention may include a polymer prepared by using a cyano group-containing aromatic compound as a linker. As a cyano group having a high polarity is repeatedly included in the polymer, solubility in an organic solvent such as propylene glycol monomethyl ether acetate (PGMEA) can be significantly improved.

In addition, the etch resistance of the hard mask may be improved by using an aromatic compound having a high carbon content in the preparation of the polymer.

Accordingly, from the composition for a hard mask, a hard mask having a desired scale and shape with improved mechanical reliability can be formed. In addition, a high-resolution photolithography process may be implemented using the hard mask, and a target pattern having a desired fine line width may be formed.

Embodiments of the present invention include a polymer including a first aromatic unit and a second aromatic unit containing a cyano group, and thus provide a composition for a hard mask with improved solubility and etch resistance.

The composition for a hard mask may be applied between, for example, a photoresist layer and an etch target layer to form a hard mask layer used as a resist lower layer. The hard mask layer may be partially removed through a photoresist pattern to form a hard mask, and the hard mask may be used as an additional etching mask.

The hardmask layer or hardmask may be used as, for example, a spin-on hardmask (SOH).

Hereinafter, the composition for a hard mask according to embodiments of the present invention will be described in detail. When there is an isomer of the compound or resin represented by the formula used in the present application, the compound or resin represented by the formula means the representative formula including the isomer.

Hereinafter, specific embodiments of the present invention will be described. However, these are preferred examples, and the spirit and scope of the present invention are not necessarily limited thereto.

The composition for a hard mask according to embodiments of the present invention includes a polymer and a solvent, and may further include additional agents such as a crosslinking agent and a catalyst.

polymer

According to embodiments of the present invention, the composition for a hard mask includes a polymer in which a first aromatic unit and a second aromatic unit containing a cyano group are repeatedly polymerized together. The first aromatic unit may include a plurality of aryl rings.

As used herein, the term “aromatic unit” or “aromatic compound” is used to encompass not only a compound in which the unit or compound as a whole satisfies aromaticity, but also a compound in which some structures or groups of the compound satisfy aromaticity.

According to exemplary embodiments, the polymer may include a repeating unit represented by Formula 1 below.

[Formula 1]

In Formula 1, Ar ₁ may represent an arylene group having 10 to 40 carbon atoms, and Ar ₂ may represent an arylene group having 6 to 40 carbon atoms.

As used herein, the term “arylene group” may refer to the aforementioned aromatic unit or a divalent group derived from an aromatic compound.

In Formula 1, “Ar ₁ ” represents the first aromatic unit, and may be provided as a backbone unit or a basic unit that provides etch resistance of the polymer or hard mask.

Ar ₁ or the first aromatic unit may be derived from a high carbon content compound comprising a plurality of aryl rings. As used herein, the term “carbon content” may mean a ratio of the number of carbon masses to the total number of masses per molecule of a compound.

In example embodiments, Ar ₁ or the first aromatic unit may be derived from at least one of compounds represented by Chemical Formulas 2-1 to 2-4 below.

[Formula 2-1]

[Formula 2-2]

In Formula 2-2, X is -OH, -OR ¹ or -NR ² R ³ , and R ¹ , R ² and R ³ may each independently represent a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.

[Formula 2-3]

In Formula 2-3, Ar ₃ and Ar ₄ are each independently a phenylene group or a naphthylene group, and n ₁ and n ₂ are each independently an integer of 1 or 2.

[Formula 2-4]

In Formula 2-4, Y may represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 1 to 20 carbon atoms, an alkynyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 25 carbon atoms.

For example, the first aromatic unit may include a unit derived from a fluorene compound represented by Formula 2-3. Ar ₃ in fluorene base unit And as an additional aromatic group represented by Ar ₄ is included, the etch resistance of the hard mask may be further improved.

In some embodiments, the first aromatic unit may be derived from at least one of compounds represented by the following Chemical Formulas 2-3-1 to 2-3-3.

[Formula 2-3-1]

[Formula 2-3-2]

[Formula 2-3-3]

For example, in the case of the compound of Formula 2-3-1, the main chain of the polymer may be formed through two biphenylol groups. In this case, the linearity of the polymer may be improved, and the flexibility of the polymer may be improved through the rotatable structure of biphenylol. Accordingly, along with the improvement of the etch resistance of the polymer, film forming properties such as flatness can be improved.

For example, pyrenol may be mentioned as an example of the compound of Formula 2-2, and in this case, the effect of improving etch resistance through a high carbon content can be easily realized. On the other hand, the solubility is supplemented from the second aromatic unit containing a cyano group, which will be described later, so that a hard mask having excellent etch resistance can be implemented without excessive deterioration of film-forming properties.

In Formula 1, -Ar ₂ -CN may represent the cyano group-containing second aromatic unit. The cyano group-containing second aromatic unit may be included as a linker or pendant unit of the polymer, and may serve as a unit for enhancing solubility of the polymer.

In example embodiments, the cyano group-containing second aromatic unit may be derived from at least one of compounds represented by the following Chemical Formula 3-1 or Chemical Formula 3-2.

[Formula 3-1]

[Formula 3-2]

As the highly polar cyano group (-CN) is exposed out of the polymer main chain as a pendant as shown in Formula 3-1 or Formula 3-2, the solubility of the polymer in a solvent to be described later can be significantly improved. Since solubility may be secured by the cyano group, "Ar ₂ " may also be designed to include an aryl ring to improve etch resistance.

In some embodiments, the cyano group may be bonded to an aldehyde group at a para position. In this case, the possibility of exposure of the cyano group is increased and steric hindrance is reduced, so that the effect of improving solubility through the cyano group can be further enhanced.

In exemplary embodiments, the polymer may be substantially composed of the above-described first first aromatic unit and a second aromatic unit containing a cyano group. In this case, a synergistic effect of securing etch resistance through the first aromatic unit and securing solubility through the second aromatic unit may be efficiently implemented.

In one embodiment, the combination of other linkers or main chain units may be included within a range that does not impair the effect through the combination of the first aromatic unit and the second aromatic unit, and embodiments of the present invention necessarily exclude this. it is not

As represented by Chemical Formula 1, the length of the polymer may be extended while the first aromatic unit and the second aromatic unit are substantially alternately repeated with each other. However, Formula 1 indicates that the first aromatic unit and the second aromatic unit are included together, and the bonding order and position are not necessarily limited.

In one embodiment, the polydispersity index (PDI, Polydispersity index) [weight average molecular weight (Mw) / number average molecular weight (Mn)] of the polymer including the repeating unit represented by Formula 1 may be about 1.5 to 6.0. and preferably about 1.5 to 3.0. In the above range, film forming properties such as coatability and flatness may be improved together with desirable solubility and etch resistance.

The content of the polymer is not particularly limited, but may be, for example, about 5 to 60% by weight of the total weight of the composition for a hard mask, and in one embodiment, about 10 to 50% by weight.

menstruum

The solvent used in the composition for a hard mask according to embodiments of the present invention is not particularly limited, and may include an organic solvent having sufficient solubility in the aromatic compound described above. For example, the solvent is propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), cyclohexanone, ethyl lactate, gamma-butyrolactone. (γ-butyrolactone; GBL), acetyl acetone, and the like.

The content of the solvent is not particularly limited, and may be included in the remaining amount excluding the polymer of the aromatic compound and additional agents to be described later. For example, the solvent may be included in an amount of 30 to 90% by weight of the total weight of the composition for a hard mask.

<Additional Agents>

Optionally, the composition for a hard mask according to embodiments of the present invention may further include additional agents such as a crosslinking agent, a catalyst, and a surfactant to improve curing properties.

The crosslinking agent may be included to promote crosslinking of the repeating unit of the polymer of the aromatic compound, for example, may react with a hydroxyl group of the polymer.

Examples of the crosslinking agent include melamine, an amino resin, a glycoluryl compound, or a bisepoxy compound.

The crosslinking agent is, for example, an etherified amino resin, such as a methylated or butylated melamine (specifically N-methoxymethyl-melamine or N-butoxymethyl-melamine) and a methylated or butylated melamine urea resin (specific example, Cymel U-65 Resin or UFR 80 Resin), glycoluryl derivative (see Formula 4, specific example, Powderlink 1174), bis (hydroxymethyl)-p represented by Formula 5 -cresol compounds and the like may be included. In addition, a bis-epoxy compound represented by the following Chemical Formula 6 and a melamine-based compound represented by the following Chemical Formula 7 may be used as a crosslinking agent.

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

An acid catalyst or a basic catalyst may be used as the catalyst.

The acid catalyst may be a thermally activated acid catalyst. As an example of the acid catalyst, an organic acid such as p-toluene sulfonic acid can be used. As the acid catalyst, a compound of a thermal acid generator (TAG) system may be used. Examples of the thermal acid generator system catalyst include pyridinium p-toluene sulfonate, 2,4,4,6-tetrabromocyclohexadienone, benzointosylate, 2-nitrobenzyltosyl and alkyl esters of organic sulfonic acids.

As the basic catalyst, any one selected from ammonium hydroxide represented by NH ₄ OH or NR ₄ OH (R is an alkyl group) may be used.

When the crosslinking agent is included, the content of the crosslinking agent may be about 1 to 30 parts by weight, preferably about 5 to 20 parts by weight, more preferably about 5 to 10 parts by weight based on 100 parts by weight of the polymer of the aromatic compound. have. When the catalyst is included, the amount of the catalyst may be about 0.001 to 5 parts by weight, preferably about 0.1 to 2 parts by weight, and more preferably about 0.1 to 1 parts by weight based on 100 parts by weight of the polymer of the aromatic compound. It may be parts by weight.

Within the content range of the crosslinking agent and the catalyst, appropriate crosslinking properties may be obtained without deteriorating the etch resistance, heat resistance, and flatness of the polymer of the aromatic compound.

The composition for a hard mask according to embodiments of the present invention may further include a surfactant to improve surface properties and adhesion of the hard mask. The surfactant may include, but is not limited to, alkylbenzenesulfonate, alkylpyridinium salt, polyethylene glycol, quaternary ammonium salt, and the like. The content of the surfactant may be, for example, about 0.1 to 10 parts by weight based on 100 parts by weight of the polymer of the aromatic compound.

In addition, embodiments of the present invention provide a pattern forming method using the hard mask composition.

According to exemplary embodiments, an etch target layer may be formed on a substrate, and the hard mask composition may be coated and cured on the etch target layer to form a hard mask. A photoresist layer may be formed on the hard mask, and a photoresist pattern may be formed by selectively exposing and developing the photoresist layer. A hard mask pattern may be formed by selectively etching the hard mask using the photoresist pattern.

Thereafter, by selectively removing the etch target layer using the photoresist pattern and the hard mask pattern together as an etch mask, a predetermined target pattern may be formed.

For example, the substrate may include a semiconductor substrate manufactured from a silicon wafer or a germanium wafer. The etch target layer may include an insulating material such as silicon oxide or silicon nitride, a conductive material such as a metal or metal nitride, or a semiconductor material such as polysilicon.

Hereinafter, experimental examples including specific examples and comparative examples are presented to help the understanding of the present invention, but these are merely illustrative of the present invention and do not limit the appended claims, the scope and description of the present invention It is obvious to those skilled in the art that various changes and modifications to the embodiments are possible within the scope of the spirit, and it is natural that such variations and modifications fall within the scope of the appended claims.

Examples and Comparative Examples

A composition for a hard mask of the composition and content (% by weight) described in Table 1 was prepared. In Examples and Comparative Examples, para-toluenesulfonic acid (5 mol% relative to the monomer compound of the polymer) was used as an acid catalyst when forming the polymer (A).

division Polymer (A) Solvent (B) Crosslinking agent (C) Catalyst (D) Surfactants
(E) ingredient content ingredient content ingredient content ingredient content ingredient content Example 1 A-1 10 B-1 90 - - - - - - Example 2 A-2 10 B-1 90 - - - - - - Example 3 A-3 10 B-1 90 - - - - - - Example 4 A-4 10 B-1 90 - - - - - - Example 5 A-5 10 B-1 90 - - - - - - Example 6 A-6 10 B-1 90 - - - - - - Example 7 A-7 10 B-1 90 - - - - - - Example 8 A-8 10 B-1 90 - - - - - - Example 9 A-1 10 B-1 88 C-1 One D-1 One - - Example 10 A-1 10 B-1 89 - - - - E-1 One Comparative Example 1 A'-1 10 B-1 90 - - - - - - Comparative Example 2 A'-2 10 B-1 90 - - - - - - Comparative Example 3 A'-3 10 B-1 90 - - - - - - Comparative Example 4 A'-4 10 B-1 90 - - - - - - Comparative Example 5 A'-5 10 B-1 90 - - - - - - Comparative Example 6 A'-6 10 B-1 90

,

(1:1 몰비율)의 축합 중합을 통해 생성된 중합체(중량평균분자량: 4,500)A-1:

,

Polymer produced through condensation polymerization of (1:1 molar ratio) (weight average molecular weight: 4,500)

,

(1:1 몰비율)의 축합 중합을 통해 생성된 중합체(중량평균분자량: 4,500)A-2:

,

Polymer produced through condensation polymerization of (1:1 molar ratio) (weight average molecular weight: 4,500)

,

(1:1 몰비율)의 축합 중합을 통해 생성된 중합체(중량평균분자량: 4,700)A-3:

,

Polymer produced through condensation polymerization of (1:1 molar ratio) (weight average molecular weight: 4,700)

,

(1:1 몰비율)의 축합 중합을 통해 생성된 중합체(중량평균분자량: 4,100)A-4:

,

Polymer produced through condensation polymerization of (1:1 molar ratio) (weight average molecular weight: 4,100)

,

(1:1 몰비율)의 축합 중합을 통해 생성된 중합체(중량평균분자량: 3,800)A-5:

,

Polymer produced through condensation polymerization of (1:1 molar ratio) (weight average molecular weight: 3,800)

,

(1:1 몰비율)의 축합 중합을 통해 생성된 중합체(중량평균분자량: 4,200)A-6:

,

Polymer produced through condensation polymerization of (1:1 molar ratio) (weight average molecular weight: 4,200)

,

(1:1 몰비율)의 축합 중합을 통해 생성된 중합체(중량평균분자량: 4,600)A-7:

,

Polymer produced through condensation polymerization of (1:1 molar ratio) (weight average molecular weight: 4,600)

,

(1:1 몰비율)의 축합 중합을 통해 생성된 중합체(중량평균분자량: 4,800)A-8:

,

Polymer produced through condensation polymerization of (1:1 molar ratio) (weight average molecular weight: 4,800)

,

(1:1 몰비율)의 축합 중합을 통해 생성된 중합체(중량평균분자량: 4,450)A'-1:

,

Polymer produced through condensation polymerization of (1:1 molar ratio) (weight average molecular weight: 4,450)

,

(1:1 몰비율)의 축합 중합을 통해 생성된 중합체(중량평균분자량: 4,450)A'-2:

,

Polymer produced through condensation polymerization of (1:1 molar ratio) (weight average molecular weight: 4,450)

,

(1:1 몰비율)의 축합 중합을 통해 생성된 중합체(중량평균분자량: 4,600)A'-3:

,

Polymer produced through condensation polymerization of (1:1 molar ratio) (weight average molecular weight: 4,600)

,

(1:1 몰비율)의 축합 중합을 통해 생성된 중합체(중량평균분자량: 4,900)A'-4:

,

Polymer produced through condensation polymerization of (1:1 molar ratio) (weight average molecular weight: 4,900)

,

(1:1 몰비율)의 축합 중합을 통해 생성된 중합체(중량평균분자량: 4,400)A'-5:

,

Polymer produced through condensation polymerization of (1:1 molar ratio) (weight average molecular weight: 4,400)

,

(1:1 몰비율)의 축합 중합을 통해 생성된 중합체(중량평균분자량: 4,500)A'-6:

,

Polymer produced through condensation polymerization of (1:1 molar ratio) (weight average molecular weight: 4,500)

B-1: PGMEA

C-1: N-methoxymethyl-melamine resin

D-1: p-toluene sulfonic acid-pyridine salt

E-1: triethylene glycol

Experimental example

Solubility, coating properties, and etch resistance of the hard mask layer or hard mask formed of the compositions of Table 1 were evaluated through the evaluation method to be described later. The evaluation results are shown in Table 2 below.

(1) solubility

After stirring the compositions of Examples and Comparative Examples at 50° C. for 1 hour, 1) confirming the dissolved state of the polymer in a warm state (50° C.), cooling to room temperature, 2) at room temperature (25° C.) The dissolved state of the polymer was confirmed, and the mixture was further stirred at room temperature for 6 hours, and 3) the dissolved state of the polymer at room temperature was reconfirmed (25° C.), and solubility was measured.

<Solubility determination>

(double-circle): Undissolved polymer was not visually confirmed in the state left at room temperature.

○: Undissolved polymer was not visually confirmed at room temperature, but a small amount of undissolved polymer was visually confirmed when left at room temperature.

△: Undissolved polymer was not visually confirmed in a warm state, but undissolved polymer was visually confirmed in a room temperature state.

x: A small amount of undissolved polymer was visually confirmed in a heated state.

(2) Flatness evaluation

The compositions of Examples and Comparative Examples were coated on a SiO ₂ wafer substrate including a trench having a width of 10 μm and a depth of 0.50 μm) and dried to form a hard mask film, and the thickness difference between the trench portion and the non-trench portion was measured using a scanning electron microscope. (SEM) was observed to evaluate the flatness.

<Flatness judgment>

◎: thickness difference less than 150 nm

○: thickness difference 150 to 175 nm

△: thickness difference 175 to 200 nm

×: thickness difference greater than 200 nm

(3) Evaluation of etch resistance

The compositions according to Examples and Comparative Examples were coated on a silicon wafer by spin-coating, respectively, and baked at 200° C. for 60 seconds to form a hard mask layer having a thickness of 1500 Å. A photoresist for ArF is coated on each hard mask layer formed, and after baking at 110°C for 60 seconds, exposure is performed using ASML (XT:1450G, NA 0.93) exposure equipment, and then each is exposed with TMAH (2.38wt% aqueous solution). After development, a line-and-space pattern of 60 nm was obtained.

The photoresist pattern is further cured at 110° C. for 60 seconds, and dry etching is performed on the hard mask layer for 20 seconds using the photoresist pattern and CHF ₃ /CF ₄ mixed gas, respectively, and the cross section is cut with FE-SEM. Each was observed to measure the etching rate to determine the etch resistance to halogen plasma.

<Determination of etch resistance>

◎: Etching rate less than 10A/Sec

○: Etching rate 10A/Sec or more and less than 11A/Sec

△: Etching rate 11A/Sec or more and less than 12A/Sec

×: Etching rate 12A/Sec or more

division solubility flatness etch resistance Example 1 ◎ ◎ ○ Example 2 ◎ ◎ ○ Example 3 › › ◎ Example 4 ◎ ◎ ○ Example 5 › › ◎ Example 6 › › ◎ Example 7 › › ◎ Example 8 › › ○ Example 9 ◎ ◎ ○ Example 10 ◎ ◎ ○ Comparative Example 1 △ ○ ○ Comparative Example 2 ◎ ◎ × Comparative Example 3 △ △ ○ Comparative Example 4 △ △ ◎ Comparative Example 5 △ × ◎ Comparative Example 6 △ △ ◎

Referring to Table 2, in the case of Examples including a cyano group-containing linker unit solubility, coating properties and etch resistance overall improved results. However, in Comparative Examples in which the aldehyde compounds in which the cyano group is omitted were used, solubility and flatness were significantly lowered as compared to the Examples. In the case of Comparative Example 2, solubility and flatness were increased due to a decrease in carbon content compared to Comparative Example 1, but etch resistance was excessively decreased.

In the case of Examples 1 to 4 in which a fluorene-based compound was used as the first aromatic unit, excellent solubility and coating properties were obtained while maintaining adequate etch resistance. In Examples 5 and 6 in which a carbazole or pyrenol compound was used as the first aromatic unit, etch resistance was significantly improved.

On the other hand, in the case of Example 8 including three aryl rings of the cyano group-containing second aromatic unit, solubility and flatness were somewhat decreased compared to Example 1.

Claims (7)

a polymer of a first aromatic unit containing a plurality of aryl rings and a second aromatic unit containing a cyano group; and
containing a solvent;
The polymer comprises a repeating unit represented by the following formula (1), a composition for a hard mask:
[Formula 1]

(In Formula 1, Ar ₁ represents the first aromatic unit, and is derived from at least one selected from the group consisting of Formula 2-1, Formula 2-2, and Formula 2-3-1,
Ar ₂ is an arylene group having 6 to 40 carbon atoms)
[Formula 2-1]

[Formula 2-2]

(In Formula 2-2, X is -OH, -OR ¹ or -NR ² R ³ , and R ¹ , R ² and R ³ are each independently a hydrogen atom or an alkyl group having 1 to 20 carbon atoms)
[Formula 2-3-1]

.
delete delete delete The composition for a hard mask according to claim 1, wherein Ar ₂ in Formula 1 comprises a phenylene group or a naphthylene group.
The composition for a hard mask according to claim 5, wherein the cyano group-containing second aromatic unit is derived from at least one of compounds represented by the following Chemical Formula 3-1 or Chemical Formula 3-2:
[Formula 3-1]

[Formula 3-2]

.
The composition for a hard mask according to claim 1, further comprising at least one of a crosslinking agent, a catalyst, and a surfactant.