KR20170104270A - Composition for hard mask - Google Patents

Abstract

The present invention relates to a composition for a hard mask, and more particularly, to a composition for a hard mask which exhibits excellent heat resistance without deteriorating optical properties and mechanical properties by containing compounds and solvents represented by specific chemical formulas. Additionally, the composition can form a resist underlayer film (hard mask) which simultaneously satisfies the gap-fill characteristics required in the front-end-of-the-line (FEOL) field.

Description

COMPOSITION FOR HARD MASK [0001]

The present invention relates to a composition for a hard mask.

BACKGROUND OF THE INVENTION In the industrial field, such as the microelectronics industry and micro-scopic structures (e.g., micromachines, magnetoresist heads, etc.), there is a continuing need to reduce the size of structural features. There is also a need in the microelectronics industry to reduce the size of microelectronic devices and to provide a greater amount of circuitry for a given chip size.

Effective lithographic techniques are essential to reduce geometry size.

In a typical lithographic process, first, a resist is applied to a lower layer material, and then exposed to radiation to form a resist layer. The resist layer is then developed with a developer to form a patterned resist layer, and the material in the openings of the patterned resist layer is etched to transfer the pattern to the underlying material. After the transfer is completed, a patterned resist layer is exposed by patterning to form a patterned resist layer. The image is then developed by contacting the exposed resist layer with any material (typically an aqueous alkali developer). The pattern is then transferred to the underlying material by etching the material within the openings of the patterned resist layer. After the transfer is completed, the remaining resist layer is removed.

Most of the lithographic processes use an anti-refractive coating (ARC) to minimize the reflectivity between the resist layer and underlying material. However, in the process of etching the antireflective coating after patterning, a large amount of resist layer may also be consumed, which may require additional patterning during subsequent etching steps.

In other words, in some lithographic imaging processes, the resist used may not have sufficient resistance to the etching step to such an extent that it can effectively transfer a predetermined pattern to the underlying material. Therefore, when an ultra-thin resist layer using an extremely thin resist material is required, a substrate to be etched is thick, a deep etching depth is required, or a specific etchant is required for a predetermined lower layer material A resist underlayer film has been used.

The resist underlayer film serves as an intermediate layer between the resist layer and the underlying layer material that can be patterned by transfer from the patterned resist, the underlayer resist layer containing a pattern from the patterned resist layer and transferring the pattern to the underlying layer material To withstand the etching process necessary to achieve the required etching process.

Many materials have been studied to form these undercoat films, but there is still a continuing need for improved undercoat compositions.

Conventionally, the materials for forming the undercoat layer are difficult to apply to the substrate. For example, chemical or physical vapor deposition, special solvent, or high temperature baking is used, but these are costly. In recent years, studies on a lower layer film composition that can be applied by a spin-on coating technique have been conducted without necessity of high temperature firing.

It is also possible to selectively etch selectively using the resist layer formed on the upper layer, and at the same time, the lower layer film composition which is resistant to the etching process necessary for patterning the lower layer using the lower layer film as a mask Research is underway.

Korean Patent Laid-Open No. 10-2010-0082844 discloses a technique relating to a resist underlayer film forming composition.

Korean Patent Publication No. 10-2010-0082844

The present invention relates to a resist underlayer film (hard mask) which exhibits excellent heat resistance without compromising optical and mechanical properties and simultaneously satisfies the gap-fill characteristics required in the front-end-of-the-line And to provide a composition for a hard mask capable of forming a hard mask.

1. A composition for a hard mask, comprising a compound represented by the following formula (1) and a solvent:

[Chemical Formula 1]

,

또는

이고,(Wherein L =

,

or

ego,

이고,R ₁ to R ₁₂ independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an aryl group having 6 to 12 carbon atoms, or

ego,

Ar ₁ and Ar ₃ are each independently an arylene group having 6 to 18 carbon atoms,

Ar ₂ And Ar ₄ are each independently a polycyclic aromatic group having 10 to 22 carbon atoms,

n is an integer of 2 or 3).

2. The hard mask composition according to 1 above, wherein Ar ₁ in the formula ( ₁₎ is at least one selected from the group consisting of the following formulas (2) and (3)

(2)

(3)

.

.

3. The hard mask composition according to item 1, wherein Ar < ₂ > in the formula (1)

[Chemical Formula 4]

.

.

4. The composition for hard mask according to 1 above, wherein the compound represented by the formula (1) is at least one of compounds represented by the following formulas (5) to (9).

[Chemical Formula 5]

[Chemical Formula 6]

(7)

[Chemical Formula 8]

또는

임).(R ₁ to R ₁₂ independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group,

or

being).

5. The hard mask composition according to 1 above, wherein the composition contains 10 to 50% by weight of the compound represented by the formula (1) and 50 to 90% by weight of the solvent.

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

The composition for a hard mask of the present invention forms a resist underlayer film (hard mask) having excellent optical properties, mechanical properties, heat resistance properties and Gap-fill properties.

The composition for a hard mask of the present invention is a composition for a hard mask which exhibits excellent heat resistance without deteriorating optical and mechanical properties and which simultaneously satisfies the gap-fill characteristic required in the front-end-of-the-line To form a film (hard mask).

The composition for a hard mask according to an embodiment of the present invention can obtain appropriate crosslinking properties without changing the optical characteristics of the underlayer film to be formed.

An embodiment of the present invention includes a compound represented by the following formula (1) and a solvent, thereby exhibiting excellent heat resistance without deteriorating the optical and mechanical properties, and being required in the front-end-of-the-line (Hard mask) capable of simultaneously satisfying the gap-fill characteristics of the hard mask.

In the present invention, when the compound represented by the formula or the isomer of the resin is present, the compound represented by the formula or the resin means a representative formula including the isomer thereof.

<Composition for hard mask>

The composition for a hard mask of the present invention comprises a compound (A) represented by the following formula (1) and a solvent (B).

The compound (A) represented by the general formula (1)

[Chemical Formula 1]

,

또는

이고,(Wherein L =

,

or

ego,

이고,R ₁ to R ₁₂ independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an aryl group having 6 to 12 carbon atoms, or

ego,

Ar ₁ and Ar ₃ are each independently an arylene group having 6 to 18 carbon atoms,

Ar ₂ and Ar ₄ are each independently a polycyclic aromatic group having 10 to 22 carbon atoms,

n is an integer of 2 or 3).

By including the compound (A) represented by the above formula (1), the hard mask layer formed of the hard mask composition of the present invention can exhibit excellent heat resistance and coating property at the same time. Specifically, when the compound (A) represented by formula (1) according to the present invention is used, excellent heat resistance is exhibited without deteriorating the optical properties and mechanical properties, and since it is not a polymer, its molecular weight is small, -Line (FEOL) field simultaneously.

In this respect, Ar ₁ of the formula (1) according to an embodiment of the present invention may be at least one selected from the group consisting of the following formulas 2 and 3:

(2)

(3)

.

.

From the viewpoint of improving the heat resistance, Ar ₂ in the formula (1) according to an embodiment of the present invention may be represented by the following formula 4:

[Chemical Formula 4]

.

.

Specific examples of the compound represented by the formula (1) may be at least one of the compounds represented by the following formulas (5) to (8).

[Chemical Formula 5]

[Chemical Formula 6]

(7)

[Chemical Formula 8]

또는

임).(R ₁ to R ₁₂ independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group,

or

being).

The compounds represented by the above formulas (5) to (8) can be, for example, the following formulas (9) to (13)

[Chemical Formula 9]

[Chemical formula 10]

(11)

[Chemical Formula 12]

[Chemical Formula 13]

.

.

The content of the compound (A) represented by the general formula (1) according to an embodiment of the present invention is not particularly limited as long as the object of the present invention can be achieved. For example, it may be 10 to 50% When the above range is satisfied, the effect of the present invention described above can be exhibited to the best. When the content of the compound (A) represented by the general formula (1) is less than 10% by weight or exceeds 50% by weight in the total weight of the composition, the gap fill characteristic may be lowered.

Solvent (B)

The solvent according to an embodiment of the present invention is not particularly limited as long as it is an organic solvent having sufficient solubility for the compound represented by the formula (1), for example, propylene glycol monomethyl ether acetate (PGMEA) Propylene glycol monomethyl ether (PGME), cyclohexanone, ethyl lactate, gamma -butyrolactone (GBL), and acetyl acetone. Propylene glycol monomethyl ether acetate (PGMEA).

The content of the solvent (B) according to one embodiment of the present invention is not particularly limited as long as the object of the present invention can be achieved. In the composition according to the present invention, the amount of the solvent (B) . For example, when only the compound of Chemical Formula 1 is used in the composition, the solvent may be 50 to 90% by weight of the total weight of the composition. When the above range is satisfied, the effects of the present invention described above can be effectively exhibited.

Cross-linking agent (C) and the catalyst (D)

In addition, if necessary, the composition for a hard mask according to an embodiment of the present invention may further include at least one of a crosslinking agent and a catalyst.

The crosslinking agent is capable of crosslinking the repeating units of the polymer by heating in a reaction catalyzed by the generated acid and can be reacted with the hydroxyl group of the compound (A) in such a manner as to be catalyzed by the resulting acid The crosslinking agent is not particularly limited. Representative examples of such a crosslinking agent include any one selected from the group consisting of melamine, amino resin, glycoluril compound and bisepoxy compound.

By further including the crosslinking agent, the curing property of the composition for a hard mask can be further enhanced.

Specific examples of the cross-linking agent include etherified amino resins such as methylated or butylated melamine (specific examples include N-methoxymethyl-melamine or N-butoxymethyl-melamine) and methylated or butylated Urea resin (specific examples of which are Cymel U-65 Resin or UFR 80 Resin), glycoluril derivatives represented by the following formula (31) (specific examples include Powderlink 1174), bis (hydroxymethyl) p-cresol compound), and the like. The bis-epoxy compound represented by the following formula (33) and the melamine compound represented by the following formula (34) may also be used as the crosslinking agent.

(31)

(32)

(33)

(34)

As the catalyst, an acid catalyst or a basic catalyst may be used.

The acid catalyst may be a thermally activated acid catalyst. Examples of the acid catalyst include an organic acid such as p-toluene sulfonic acid monohydrate, and a TAG (thermal acid generator) based compound which ensures storage stability. Thermal acid generators are acid generator compounds which are intended to release acid upon thermal treatment, for example pyridinium p-toluene sulfonate, 2,4,4,6-tetrabromocyclohexa Dienone, benzoin tosylate, 2-nitrobenzyl tosylate, and alkyl esters of organic sulfonic acids.

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

Other photosensitive catalysts known in the art of resist technology can also be used as long as they are compatible with the other components of the antireflective composition.

When the cross-linking agent is included, the content of the cross-linking agent may be 1 part by weight to 30 parts by weight, preferably 5 parts by weight to 20 parts by weight, more preferably 5 parts by weight, based on 100 parts by weight of the compound (A) To 10 parts by weight. When the catalyst is included, the content of the catalyst may be 0.001 to 5 parts by weight, preferably 0.1 to 2 parts by weight, more preferably 0.1 to 5 parts by weight, relative to 100 parts by weight of the compound (A) Parts by weight to 1 part by weight.

When the crosslinking agent is included in the above range, appropriate crosslinking properties can be obtained without changing the optical properties of the lower layer film to be formed.

In addition, when the catalyst content falls within the above range, appropriate crosslinking properties can be obtained and the acidity affecting the storage stability can be appropriately maintained.

Additive (E)

If necessary, the composition for a hard mask of the present invention may further comprise additives such as a surfactant. Examples of the surfactant include, but are not limited to, alkylbenzenesulfonates, alkylpyridinium salts, polyethylene glycols, and quaternary ammonium salts. In this case, the content of the surfactant may be 0.1 part by weight to 10 parts by weight based on 100 parts by weight of the compound (A). When the content of the surfactant is within the above range, appropriate crosslinking properties can be obtained without changing the optical properties of the lower layer film to be formed.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to be illustrative of the invention and are not intended to limit the scope of the claims. It will be apparent to those skilled in the art that such variations and modifications are within the scope of the appended claims.

Examples and Comparative Examples

A composition for a hard mask of the composition and the content (% by weight) shown in the following Tables 1 and 2 was prepared.

division The compound (A) Solvent (B) The crosslinking agent (C) The catalyst (D) Additive (E) ingredient content ingredient content ingredient content ingredient content ingredient content Example 1 A-1 20 B-1 80 - - - - - - Example 2 A-1 10 B-1 90 - - - - - - Example 3 A-1 30 B-1 70 - - - - - - Example 4 A-2 20 B-1 80 - - - - - - Example 5 A-3 20 B-1 80 - - - - - - Example 6 A-4 20 B-1 80 - - - - - - Example 7 A-5 20 B-1 80 - - - - - - Example 8 A-1 55 B-1 45 - - - - - - Example 9 A-1 20 B-1 78 C-1 One D-1 One - - Example 10 A-1 20 B-1 79 - - - - E-1 One

division The compound (A ') Solvent (B) The crosslinking agent (C) The catalyst (D) Additive (E) ingredient content ingredient content ingredient ingredient content ingredient content ingredient Comparative Example 1 A'-1 20 B-1 80 - - - - - - Comparative Example 2 A'-2 20 B-1 80 - - - - - - Comparative Example 3 A'-3 20 B-1 80 - - - - - - Comparative Example 4 A'-4 20 B-1 80 - - - - - - Comparative Example 5 A'-1 20 B-1 78 C-1 One D-1 One - - Comparative Example 6 A'-1 20 B-1 79 - - - - E-1 One

A-1:

A-2:

A-3:

A-4:

A-5:

A'-1:

A'-2:

A'-3:

: 중량평균분자량:3000 (1-파이레놀과 1,4-자일레놀의 공중합체)A'-4:

: Weight average molecular weight: 3000 (copolymer of 1-pyrenol and 1,4-xylenol)

B-1: Propylene glycol monomethyl ether acetate (PGMEA)

C-1: (N-methoxymethyl-melamine)

D-1: p-toluenesulfonic acid-pyridine salt

E-1: Triethylene glycol

Experimental Example

1. Evaluation of heat resistance

The composition was vacuum dried to remove the solvent, and a portion of the sample was taken and the mass loss rate was measured while elevating the temperature to 800 DEG C using TGA (thermogravimetric analysis) under nitrogen.

Mass loss rate = {(mass at initial mass-800 degrees) / initial mass} x 100%

&Lt; Determination of heat resistance &

○: Mass loss rate less than 40%

DELTA: Mass loss rate: 40% or more to less than 50%

×: mass loss rate of 50% or more

2. Gap-fill characterization

<Evaluation method>

Each of the sample solutions prepared in Examples 1 to 10 and Comparative Examples 1 to 6 was coated on a silicon wafer by spin coating on a silicon substrate having a pattern of 600 nm deep and 100 nm wide and baked at 200 캜 for 60 seconds, Film was formed, and cross-sectional SEM was measured to evaluate the gap-fill characteristic.

&Lt; Gap-fill characteristic determination >

◎: Unfilled space is not confirmed in the cross-sectional photograph, and unevenness of coating surface is not visually confirmed.

○: The unevenness of the coating surface is not visually confirmed, but the unfilled space is confirmed in the cross-sectional photograph.

△: The unfilled space was not confirmed in the cross-sectional photograph, but the unevenness of the coating surface was visually confirmed.

×: The unfilled space is confirmed in the cross-sectional photograph, and the unevenness of the coating surface is visually confirmed.

division Heat resistance
(Mass loss rate at 800 ° C) Gap-fill characteristics 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 3, the heat resistance and the gap-fill characteristics are excellent in the Examples, but the Comparative Examples are not excellent in all of these properties. However, the coating uniformity of the liquid phase was slightly lowered in Example 8 due to an increase in viscosity.

Claims (6)

A composition for a hard mask, comprising a compound represented by the following formula (1) and a solvent:
[Chemical Formula 1]

(Wherein L =

,

or

ego,
R ₁ to R ₁₂ independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or an aryl group having 6 to 12 carbon atoms, or

ego,
Ar ₁ and Ar ₃ are each independently an arylene group having 6 to 18 carbon atoms,
Ar ₂ and Ar ₄ are each independently a polycyclic aromatic group having 10 to 22 carbon atoms,
n is an integer of 2 or 3). The composition for a hard mask according to claim 1, wherein Ar ₁ in the formula ( ₁₎ is at least one selected from the group consisting of the following formulas (2) and (3)
(2)

(3)

. The composition for a hard mask according to claim 1, wherein Ar &lt; ₂ &gt; in the formula (1)
[Chemical Formula 4]

. The composition for a hard mask according to claim 1, wherein the compound represented by the formula (1) is at least one compound represented by the following formulas (5) to (9).
[Chemical Formula 5]

[Chemical Formula 6]

(7)

[Chemical Formula 8]

(R ₁ to R ₁₂ independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a phenyl group,

or

being). The hard mask composition according to claim 1, which comprises 10 to 50% by weight of the compound represented by the formula (1) and 50 to 90% by weight of the solvent in the total weight of the composition. The composition of claim 1, further comprising at least one of a crosslinking agent and a catalyst.