KR102349972B1 - Composition for hard mask and method of forming pattern using the same - Google Patents

Abstract

화학식 1 중, Ar1은 다중 방향족 고리 구조를 갖는 탄소수 10 내지 30의 아릴렌기이며, Ar2는 다중 방향족 고리 구조를 갖는 탄소수 10 내지 30의 아릴기이며, X는 산-분해성 또는 열-분해성 보호기이다.The composition for a hard mask of the present invention includes a polycondensate including a repeating unit structure represented by the following Chemical Formula 1 and a solvent.
[Formula 1-1]

In Formula 1, Ar1 is an arylene group having 10 to 30 carbon atoms having a multiple aromatic ring structure, Ar2 is an aryl group having 10 to 30 carbon atoms having a multiple aromatic ring structure, and X is an acid-decomposable or thermal-decomposable protecting group.

Description

A composition for a hard mask and a pattern forming method using the same

The present invention relates to a composition for a hard mask and a pattern forming method using the same. More particularly, it relates to a composition for a hard mask comprising a polycondensate of an aromatic compound and a pattern forming method using the same.

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 has, for example, sufficient etch resistance (or etch resistance) and heat resistance to a high-temperature etching process, and also satisfies the characteristics for being formed to a uniform thickness by, for example, a spin-on coating process. desirable.

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 chemical and film-forming properties.

One object of the present invention is to provide a pattern forming method utilizing the composition for a hard mask.

1. A polycondensate comprising a repeating unit structure represented by the following formula (1); And a composition for a hard mask comprising a solvent:

[Formula 1-1]

(In Formula 1, Ar1 is an arylene group having 10 to 30 carbon atoms having a multiple aromatic ring structure, Ar2 is an aryl group having 10 to 30 carbon atoms having a multiple aromatic ring structure, and X is an acid-decomposable or thermal-decomposable protecting group ).

2. The composition for a hard mask according to the above 1, wherein X comprises a structure of the following Chemical Formula 2 or Chemical Formula 3:

[Formula 2]

[Formula 3]

(In Formulas 2 and 3, R ₁ is a tertiary hydrocarbon group, R ₂ is an aliphatic hydrocarbon group having 2 to 10 carbon atoms or a silane group, and R ₃ and R ₄ are each independently hydrogen or 1 to 4 carbon atoms. is an aliphatic hydrocarbon group of ).

3. The composition for a hard mask according to the above 2, wherein the structure of Formula 2 is derived from a compound of Formula 2-1:

[Formula 2-1]

(In Formula 2-1, Ra and Rb are each independently a tertiary alkyl group having 4 to 10 carbon atoms)

4. The composition for a hard mask according to 2 above, wherein the structure of Chemical Formula 3 is derived from any one of the compounds of Chemical Formulas 3-1 to 3-20:

.

.

5. The composition for a hard mask according to the above 1, wherein Ar1 is derived from pyrenol or naphthol.

6. The composition for a hard mask according to 1 above, wherein Ar2 is derived from naphthyl aldehyde or pyrene aldehyde:

7. The composition for a hard mask according to the above 1, wherein the polycondensate comprises a structural unit represented by the following formula (8):

[Formula 8]

(In Formula 8, m and n represent the molar ratio of each unit indicated by square brackets, and m and n are each 20 to 80 mol%)

8. The composition for a hard mask according to 1 above, comprising 5 to 30% by weight of the polymer and 70 to 95% by weight of the solvent based on the total weight of the composition.

9. forming an etch target layer on the substrate; forming a preliminary hard mask layer by applying the composition for a hard mask of any one of 1 to 8 above on the etch target layer; heat-treating the preliminary hard mask layer to form a hard mask layer in which the protecting group included in the polycondensate is deprotected; forming a photoresist pattern on the hardmask layer; and etching the hard mask layer and the etch target layer using the photoresist pattern.

10. The method according to 9 above, wherein the site of the polycondensate deprotected by the protecting group is substituted with a hydroxyl group.

By using the composition for a hard mask according to embodiments of the present invention, a hard mask having excellent etch resistance and improved film-forming properties such as solubility and coating property may be formed.

The polycondensate included in the composition for a hard mask according to embodiments of the present invention may include a protecting group bonded to a multiple aromatic ring structure in the main chain. The protecting group may enhance the solubility of the polycondensate in a solvent to improve the solubility of the composition for a hard mask. Accordingly, the coatability of the composition can also be improved to obtain uniform film uniformity and flatness.

The protecting group may be acid-decomposable or thermal-decomposable, and may be removed in a baking process after coating the composition to be converted into, for example, a hydroxyl group. Therefore, after curing, the polycondensate may maintain high carbon content characteristics derived from the multi-aromatic ring structure to implement high etch resistance.

A high-resolution photolithography process can be implemented using the hardmask formed from the hardmask composition, and a target pattern having a desired fine line width can be formed.

1 to 5 are schematic cross-sectional views for explaining a pattern forming method according to example embodiments.

Embodiments of the present invention include a polycondensate containing a multi-aromatic ring structure substituted with a protecting group, and thus provide a composition for a hard mask with significantly improved solubility and etch resistance.

Using the hardmask composition, for example, a hardmask film used as a resist lower film may be formed by being applied between the photoresist layer and the etch target film. 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.

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.

As used herein, the term “polycyclic aromatic” may include a structure in which a plurality of aromatic rings are fused while maintaining aromaticity.

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

polycondensate

According to embodiments of the present invention, the composition for a hard mask may include a repeating unit structure represented by Chemical Formula 1 below.

[Formula 1]

In Formula 1, Ar1 may represent an arylene group having 10 to 30 carbon atoms and having a multiple aromatic ring structure. Ar2 may represent an aryl group having 10 to 30 carbon atoms having a multiple aromatic ring structure.

X represents a protecting group, and may have a structure represented by the following Chemical Formula 2 or Chemical Formula 3.

[Formula 2]

[Formula 3]

In Formulas 2 and 3, the wavy mark indicates a bonding site with the oxygen atom (O) shown in Formula 1.

In Formulas 2 and 3, R ₁ represents a tertiary hydrocarbon group (eg, a tertiary alkyl group), R ₂ represents an aliphatic hydrocarbon group having 2 to 10 carbon atoms or a silane group, and R ₃ and R ₄ are Each may independently represent hydrogen or an aliphatic hydrocarbon group having 1 to 4 carbon atoms (eg, an alkyl group).

R ₂ may include, for example, an aliphatic hydrocarbon group connected by an ether bond or a carbonyl bond, and at least one hydrogen atom may be substituted with a hydroxyl group or a halogen atom. R ₃ and R ₄ may also be substituted with at least one hydrogen atom with a hydroxyl group, a halogen atom, a cyano group, a nitro group, or the like.

In exemplary embodiments, Ar1 may be derived from pyrenol (Formula 4) or naphthol (Formula 5).

[Formula 4]

[Formula 5]

In a preferred embodiment, pyrenol having a high carbon content may be used to improve the etch resistance of the hard mask.

For example, when X has the structure of Formula 2, it may be derived from a compound of Formula 2-1 below.

[Formula 2-1]

In Formula 2-1, Ra and Rb may each independently represent a tertiary alkyl group having 4 to 10 carbon atoms.

For example, the compound of Formula 2-1 may include a compound of Formula 2-1-1 or 2-1-2 below.

[Formula 2-1-1]

[Formula 2-1-2]

In some embodiments, when the compound of Formula 2-1 is used as pyrenol and a compound providing a protecting group, a hydroxyl group of pyrenol may nucleophilically attack one carbonyl carbon included in Formula 2-1. The protecting group (X) may be bound by the mechanism of Scheme 1 below.

[Scheme 1]

For example, when X has the structure of Formula 3, it may be derived from compounds of Formulas 3-1 to 3-20.

In some embodiments, when the compound of Formula 3-1 is used as pyrenol and a compound providing a protecting group, the hydroxyl group of pyrenol reacts with the double bond carbon included in Formula 3-1 to form a compound of Scheme 2 below The protecting group (X) may be bound by a mechanism.

[Scheme 2]

In exemplary embodiments, Ar2 may be derived from a polycyclic aromatic aldehyde or a synthetic equivalent thereof. In preferred embodiments, Ar2 may be derived from naphthyl aldehyde (Formula 6) or pyrene aldehyde (Formula 7).

[Formula 6]

[Formula 7]

In a preferred embodiment, naphthyl aldehyde may be used in consideration of film uniformity such as solubility and coating properties. However, even when pyrene aldehyde is used, sufficient solubility and flatness may be realized by the protecting group (X), which will be described later.

In one embodiment, a high carbon content is hardmasked by designing both the main chain unit (eg Ar1) and the linker unit (or pendant) (eg Ar2) of the polycondensate to contain a polycyclic aromatic structure. of the etch resistance can be significantly improved.

However, as the carbon content increases, the solubility of the polycondensate may decrease and thus the film uniformity may decrease. Therefore, the solubility may be supplemented by bonding a protecting group to Ar1. The protecting group may include a rotatable hydrophilic group or a polar group such as an ether bond in the functional group, and may improve solubility and flexibility of the polycondensate.

According to exemplary embodiments, the protecting group (X) may be provided as an acid-decomposable or thermally-decomposable functional group. Accordingly, for example, after the hard mask composition is applied, the protecting group (X) is released during a baking or curing process, and the substituent bonded to Ar1 may be restored to a hydroxyl group.

Therefore, since the high carbon content structure of the polycondensate is maintained in the hard mask state, an improved etch resistance effect can be realized.

According to some embodiments, a plurality of Ar1 groups are present in the polycondensate, some of the plurality of Ar1 groups are substituted with a protecting group (X), and some of the hydroxyl groups may remain bonded to Ar1. have.

For example, the polycondensate may include a structural unit according to Formula 8 below.

[Formula 8]

In Formula 8, m and n represent molar ratios of units indicated by square brackets. In one embodiment, m and n may each be about 20 to 80 mole %.

In one embodiment, the weight average molecular weight of the polymer may be in the range of, for example, about 1,000 to 10,000, and desirable heat resistance, etch resistance, solubility, and flatness may be secured together in the above range.

In one embodiment, the polydispersity index (PDI, Polydispersity index) [weight average molecular weight (Mw) / number average molecular weight (Mn)] of the polycondensate may be about 1.5 to 6.0, preferably about 1.5 to 4.0 can be 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 30% by weight of the total weight of the composition for a hard mask, and in one embodiment, about 10 to 30% 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 polycondensate 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 polycondensate and additional agents to be described later. For example, the solvent may be included in an amount of about 70 to 95% by weight of the total weight of the composition for a hard mask.

additional formulation

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

The crosslinking agent is capable of crosslinking the repeating units included in the polymer with each other, and may react with, for example, a hydroxyl group included in the polymer. By the crosslinking agent, the curing characteristics of the composition for a hard mask may be further strengthened.

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 9, specific example, Powderlink 1174), bis (hydroxymethyl)-p represented by Formula 10 -cresol compounds and the like may be included. In addition, a bisepoxy-based compound represented by the following Chemical Formula 11 and a melamine-based compound represented by the following Chemical Formula 12 may also be used as a crosslinking agent.

[Formula 9]

[Formula 10]

[Formula 11]

[Formula 12]

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 polycondensate.

When the catalyst is included, the content 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 part by weight based on 100 parts by weight of the polycondensate. can

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

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 polycondensate.

1 to 5 are schematic cross-sectional views for explaining a pattern forming method according to example embodiments. 1 to 5 provide a pattern forming method using the hard mask composition according to the above-described embodiments of the present invention.

Referring to FIG. 1 , an etch target layer 110 may be formed on a substrate 100 . The substrate 100 may be, for example, a semiconductor substrate including single crystal silicon or single crystal germanium.

The etching target layer 110 may include a conductive material such as a metal or metal nitride, an insulating material such as silicon oxide or silicon nitride, or a semiconductor material such as polysilicon, depending on the use of the target pattern.

Referring to FIG. 2 , the preliminary hardmask layer 120 may be formed by applying the above-described hardmask composition on the etch target layer 110 through, for example, a spin coating process.

As described above, the composition for a hard mask may include a multi-aromatic ring structure substituted with a protecting group, and may include a polycondensate having improved solubility through the protecting group. Accordingly, the preliminary hardmask film 120 having a uniform profile with improved coatability and flatness may be formed.

Referring to FIG. 3 , the hardmask layer 125 may be formed by heat-treating the preliminary hardmask layer 120 . The heat treatment may include, for example, a baking process performed at a temperature of about 100 to 400°C.

The protecting group includes an acid-decomposable or thermally-decomposable functional group, and the protecting group may be released or deprotected by the heat treatment. The site from which the protecting group is released may be restored to a hydroxyl group. Accordingly, as the carbon content of the multi-aromatic ring increases, the hardmask layer 125 having increased etch resistance may be formed. A photoresist layer 130 may be formed on the hard mask layer 125 .

Referring to FIG. 4 , the photoresist layer 130 may be selectively exposed and developed to form a photoresist pattern 135 .

Referring to FIG. 5 , the hard mask layer 125 may be selectively etched using the photoresist pattern 130 to form a hard mask pattern 127 .

Thereafter, the target layer 110 may be selectively removed using the photoresist pattern 130 and the hard mask pattern 127 together as an etch mask, thereby forming a predetermined target pattern 115 .

Since the hard mask pattern 127 has high etch resistance through the polycondensate, etch damage from, for example, an etching gas used in a dry etching process may be prevented. Accordingly, a rigid etch mask structure is maintained during the etching process, and a target pattern 115 having a desired pattern profile may be formed.

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 polycondensate) was used as an acid catalyst when forming the polymer (A).

division Polycondensate (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-1 10 B-1 88 C-1 One D-1 One - - Example 6 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 - - - - - -

,

,

(1:0.5:1 몰비율)의 축합반응으로 생성된 아래 화학식 13 구조의 공중합체(중량평균분자량: 4,300)A-1:

,

,

(1:0.5:1 molar ratio) a copolymer of the following formula 13 produced by a condensation reaction (weight average molecular weight: 4,300)

[Formula 13]

,

,

(1:0.5:1 몰비율)의 축합반응으로 생성된 아래 화학식 14 구조의 공중합체(중량평균분자량: 4,100)A-2:

,

,

(1:0.5:1 molar ratio) a copolymer of the following formula (14) produced by a condensation reaction (weight average molecular weight: 4,100)

[Formula 14]

,

,

(1:0.7:1 몰비율)의 축합반응으로 생성된 아래 화학식 15 구조의 공중합체(중량평균분자량: 5,700)A-3:

,

,

(1:0.7:1 molar ratio) a copolymer of the following formula 15 produced by a condensation reaction (weight average molecular weight: 5,700)

[Formula 15]

,

,

(1:0.5:1 몰비율)의 축합반응으로 생성된 아래 화학식 16 구조의 공중합체(중량평균분자량: 3,950)A-4:

,

,

(1:0.5:1 molar ratio) a copolymer of the following formula (16) produced by a condensation reaction (weight average molecular weight: 3,950)

[Formula 16]

,

(1:1 몰비율)의 축합반응으로 생성된 공중합체(중량평균분자량: 3,300)A'-1:

,

(1:1 molar ratio) of the copolymer produced by the condensation reaction (weight average molecular weight: 3,300)

,

(1:1 몰비율)의 축합반응으로 생성된 공중합체(중량평균분자량: 3,800)A'-2:

,

(1:1 molar ratio) of the copolymer produced by the condensation reaction (weight average molecular weight: 3,800)

,

(1:1 몰비율)의 축합반응으로 생성된 공중합체(중량평균분자량: 3,300)A'-3:

,

(1:1 molar ratio) of the copolymer produced by the condensation reaction (weight average molecular weight: 3,300)

B: PGMEA

C: N-methoxymethyl-melamine resin

D: p-toluene sulfonic acid-pyridine salt

E: triethylene glycol

Experimental example

Etching resistance, solubility, and flatness of the hard mask layer or hard mask formed of the compositions of Table 1 were evaluated through an evaluation method to be described later. The evaluation results are shown in Table 2 below.

(1) 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

(2) solubility

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

(3) 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

Δ: thickness difference 175 to 200 nm

×: thickness difference greater than 200 nm

division etch resistance solubility flatness Example 1 ○ ◎ ◎ Example 2 ○ ◎ ◎ Example 3 ◎ ◎ ◎ Example 4 ○ ◎ ◎ Example 5 ○ ◎ ◎ Example 6 ○ ◎ ◎ Comparative Example 1 ○ △ △ Comparative Example 2 ◎ × × Comparative Example 3 ○ △ △

Referring to Table 2, in the case of the hard mask including the polycondensate substituted with the protecting group according to the embodiments of the present invention, solubility and flatness were improved while maintaining etch resistance.

On the other hand, in the case of Comparative Examples in which the application of the protecting group was omitted, both solubility and flatness were lowered by the introduction of the polycyclic aromatic ring.

100: substrate 110: etch target film
115: target pattern 120: preliminary hard mask film
125: hard mask film 127: hard mask pattern
130: photoresist film 135: photoresist pattern

Claims (10)

a polycondensate comprising a repeating unit structure represented by the following formula (1); and
A composition for a hard mask comprising a solvent:
[Formula 1]

(In Formula 1, Ar1 is an arylene group having 10 to 30 carbon atoms having a multiple aromatic ring structure, Ar2 is an aryl group having 10 to 30 carbon atoms having a multiple aromatic ring structure, and X is an acid-decomposable or thermal-decomposable protecting group ).
The composition for a hard mask according to claim 1, wherein X comprises a structure of Formula 2 or Formula 3 below:
[Formula 2]

[Formula 3]

(In Formulas 2 and 3, R ₁ is a tertiary hydrocarbon group, R ₂ is an aliphatic hydrocarbon group having 2 to 10 carbon atoms or a silane group, and R ₃ and R ₄ are each independently hydrogen or 1 to 4 carbon atoms. is an aliphatic hydrocarbon group of ).
The composition for a hard mask according to claim 2, wherein the structure of Formula 2 is derived from a compound of Formula 2-1:
[Formula 2-1]

(In Formula 2-1, Ra and Rb are each independently a tertiary alkyl group having 4 to 10 carbon atoms)
The composition for a hard mask according to claim 2, wherein the structure of Formula 3 is derived from any one of the following compounds of Formulas 3-1 to 3-20:

.
The composition for a hard mask according to claim 1, wherein Ar1 is derived from pyrenol or naphthol.
The composition for a hard mask according to claim 1, wherein Ar2 is derived from naphthyl aldehyde or pyrene aldehyde:
The composition for a hard mask according to claim 1, wherein the polycondensate comprises a structural unit represented by the following Chemical Formula 8:
[Formula 8]

(In Formula 8, m and n represent the molar ratio of each unit indicated by square brackets, and m and n are each 20 to 80 mol%)
The composition for a hard mask according to claim 1, comprising 5 to 30% by weight of the polymer, and 70 to 95% by weight of the solvent based on the total weight of the composition.
forming an etch target layer on a substrate;
forming a preliminary hard mask layer by applying the composition for a hard mask of any one of claims 1 to 8 on the etch target layer;
heat-treating the preliminary hard mask layer to form a hard mask layer in which the protecting group included in the polycondensate is deprotected;
forming a photoresist pattern on the hardmask layer; and
and etching the hardmask layer and the etch target layer using the photoresist pattern.
The method according to claim 9, wherein the site of the polycondensate deprotected by the protecting group is substituted with a hydroxyl group.

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