KR102539890B1 - Composition for hard mask - Google Patents

Abstract

The present invention relates to a composition for a hard mask, and more particularly, to a carbazole-based compound containing at least one of an aldehyde compound having 1 to 25 carbon atoms, a diol compound having 1 to 25 carbon atoms, and a diol compound having 1 to 25 carbon atoms and an acetylene group, A resist underlayer film (hard mask) having excellent heat resistance, high temperature resistance and coating uniformity can be formed by including a polymer and a solvent produced by a condensation reaction.

Description

Composition for hard mask {COMPOSITION FOR HARD MASK}

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

In industries such as the microelectronics industry and microscopic structures (eg, micromachines, magnetoresist heads, etc.), there is a continuing desire to reduce the size of structural features. There is also a desire in the microelectronics industry to reduce the size of microelectronic devices, thereby providing a greater amount of circuitry in a given chip size.

To reduce feature size, effective lithographic techniques are essential.

A typical lithographic process first applies a resist to the underlying material and then exposes it 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 complete, a patterned resist layer is formed by exposing the photosensitive resist in a pattern-wise manner. The image is then developed by contacting the exposed resist layer with a material (typically an aqueous alkaline 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 complete, the remaining resist layer is removed.

Most of the lithographic processes use an anti-refractive coating (ARC) to increase resolution in order to minimize reflectivity between a resist layer and an underlying material. However, in the process of etching the anti-reflection coating after patterning, the resist layer is also highly consumed, and additional patterning may be required during the subsequent etching step.

In other words, for some lithographic imaging processes, the resist used may not be sufficiently resistant to the etching step to effectively transfer the desired pattern to the underlying material. Therefore, when an ultra-thin resist layer using an extremely thin resist material is required, when a substrate to be etched is thick, when a deep etching depth is required, or when it is necessary to use a specific etchant for a given lower layer material. etc., a resist underlayer film has been used.

The resist underlayer film serves as an intermediate layer between the resist layer and the underlayer material that can be patterned by transfer from the patterned resist, the resist underlayer film receiving the pattern from the patterned resist layer and transferring the pattern to the underlayer material. It must be able to withstand the etching process required to

Although many materials have been tried to form such an underlayer film, there is still a need for an improved underlayer film composition.

Since conventional materials for forming an underlayer film are difficult to apply to a substrate, for example, chemical or physical vapor deposition, special solvents, or high-temperature firing are used, but they are costly. Accordingly, research on an underlayer film composition that can be applied by a spin-on coating technique without the need for high-temperature baking has recently been conducted.

In addition, it can be selectively and easily etched using the resist layer formed thereon as a mask, and at the same time is resistant to the etching process required for patterning the lower layer using the lower layer as a mask, especially when the lower layer is a metal layer. Research is ongoing.

Korean Patent Publication No. 10-2010-0082844 discloses a technique for forming a resist underlayer film.

Korean Patent Publication No. 10-2010-0082844

An object of the present invention is to provide a composition for a hard mask capable of forming a resist underlayer film (hard mask) having excellent heat resistance, high temperature heat resistance and coating uniformity.

1. A hard mask composition comprising a polymer prepared by a condensation reaction of at least one of an aldehyde compound having 1 to 25 carbon atoms and a diol compound having 1 to 25 carbon atoms and a carbazole-based compound containing an acetylene group, and a solvent.

2. The hard mask composition according to 1 above, wherein the carbazole-based compound containing an acetylene group is represented by Formula 1 below:

[Formula 1]

(In the formula, n is an integer from 1 to 3).

3. The hard mask composition according to 1 above, wherein the diol compound is a compound represented by Formula 2 below:

[Formula 2]

(Wherein, Ar is an arylene group of 6 to 20, and R ₁ and R ₂ are each independently a hydrogen atom, a methyl group or an ethyl group).

4. The hard mask composition according to 1 above, wherein the polymer has a weight average molecular weight of 1000 to 15000.

5. The hard mask composition according to 1 above, comprising 10 to 50% by weight of the polymer and 50 to 90% by weight of the solvent based on the total weight of the composition.

6. The hard mask composition 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 can form a polymer for a resist underlayer film having excellent heat resistance.

The composition for a hard mask of the present invention can form additional crosslinking at a high temperature.

One embodiment of the present invention is a polymer and solvent prepared by condensation of at least one of a C1-25 aldehyde compound, a C1-25 diol, and a C1-25 diol compound and a carbazole-based compound containing an acetylene group It relates to a composition for a hard mask capable of forming a resist underlayer film (hard mask) having excellent heat resistance, high temperature heat resistance and coating uniformity by including.

Hereinafter, specific embodiments of the present invention will be described. However, this is only an example and the present invention is not limited thereto.

In the present invention, when there are isomers of a compound or resin represented by a formula, the compound or resin represented by the formula means a representative formula including the isomer.

< for hard mask Composition>

The hard mask composition of the present invention is prepared by a condensation reaction of at least one of an aldehyde compound (a1) having 1 to 25 carbon atoms and a diol compound (a2) having 1 to 25 carbon atoms and a carbazole-based compound (a3) containing an acetylene group. It contains polymer (A) and solvent (B).

Polymer (A)

The polymer (A) is prepared by a condensation reaction between at least one of an aldehyde compound (a1) and a diol compound (a2) and a carbazole-based compound (a3) containing an acetylene group.

In the present invention, by including the polymer (A), a hard mask formed from the composition for a hard mask of the present invention can exhibit excellent heat resistance and coating properties at the same time. Specifically, when forming a hard mask with the hard mask composition according to the present invention, the hard mask formed by including the polymer (A) exhibits excellent heat resistance, high temperature heat resistance, and coating uniformity without deterioration in optical and mechanical properties.

carbazole type Compound (a3)

The carbazole-based compound (a3) may still contain an acetylene group even after forming one repeating unit of the polymer (A). Therefore, when a hard mask is formed using the composition for a hard mask of the present invention, when a high temperature heat treatment is performed, an additional crosslinking reaction may occur with the polymer or other polymers containing the acetylene group. This additional crosslinking reaction allows the hard mask formed from the hard mask composition of the present invention to exhibit excellent heat resistance. The temperature range of the high-temperature heat treatment is not particularly limited as long as the object of the present invention can be achieved, and may vary depending on the individual physical properties of the repeating units constituting the polymer (A), but, for example, 350 to 600 ° C., preferably may be 400 to 500 ° C.

In terms of producing a hard mask having excellent heat resistance according to an additional crosslinking reaction, preferably, the carbazole-based compound (a3) containing an acetylene group according to an embodiment of the present invention is, for example, represented by the following formula (1) can be a compound:

[Formula 1]

(In the formula, n is an integer from 1 to 3).

Aldehyde compound (a1)

As the aldehyde compound (a1) undergoing a condensation reaction with the carbazole-based compound (a3) containing an acetylene group, any aldehyde known in the art may be used without particular limitation, but, for example, formaldehyde, paraformaldehyde, acetaldehyde, Propylaldehyde, butylaldehyde, isobutylaldehyde, valeraldehyde, capronaldehyde, 2-methylbutylaldehyde, hexylaldehyde, undecanealdehyde, 7-methoxy-3, 7-dimethyloctylaldehyde, cyclohexanaldehyde, 3-methyl Saturated aliphatic aldehydes such as 2-butylaldehyde, glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, glutaraldehyde, adipinaldehyde, and thiophenaldehyde, unsaturated aliphatic aldehydes such as acrolein and methacrolein, fur Heterocyclic aldehydes such as fural pyridinaldehyde, benzaldehyde, naphthaldehyde, anthracene carboxaldehyde, phenylbenzaldehyde, anisaldehyde, terephthalaldehyde, phenanthrylaldehyde, salicylaldehyde, phenylacetaldehyde, 3-phenylpropionaldehyde, trilaldehyde, aromatic aldehydes such as (N,N-dimethylamino)benzaldehyde and acetoxybenzaldehyde, and the like, preferably aromatic aldehydes.

Dior Compound (a2)

In the present invention, the diol compound (a2) undergoing a condensation reaction with the carbazole-based compound (a3) containing an acetylene group is at least one selected from the group consisting of aliphatic diols, derivatives of the aliphatic diols, aromatic diols, and derivatives of the above aromatic diols. is a concept that includes In the present specification, a diol derivative may be a case in which hydrogen of at least one hydroxyl group is substituted with an alkyl group having 1 to 2 carbon atoms.

The diol compound (a2) may be a diol compound (a2) known in the art without particular limitation, but may be, for example, a compound represented by the following formula (2):

[Formula 2]

(Wherein, Ar is an arylene group of 6 to 20, R ₁ and R ₂ are each independently a hydrogen atom, a methyl group or an ethyl group, preferably the arylene group is a phenylene group, naphthalenediyl group, anthracenediyl group, biphenyl It may be at least one selected from the group consisting of a diyl group and a stilbendiyl group).

The content of the polymer (A) according to an embodiment of the present invention is not particularly limited as long as the object of the present invention can be achieved, but may be, for example, 10 to 50% by weight of the total weight of the composition, and the above range When satisfied, the heat resistance is the best and the coating uniformity can be the best.

In addition, the weight average molecular weight of the polymer (A) according to an embodiment of the present invention is not particularly limited as long as the object of the present invention can be achieved, but may be, for example, 1000 to 15000, and when the above range is satisfied The effect of the present invention described above may be most excellent.

Polydispersity index (PDI) [weight average molecular weight (Mw) / number average molecular weight (Mn)] of the polymer according to the present invention is preferably 1.5 to 6.0, more preferably 1.8 to 4.0. When the polydispersity index [weight average molecular weight (Mw) / number average molecular weight (Mn)] is within the above range, it is preferable because the effect due to the above-mentioned polymer (A) is excellent.

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 Formula 1, but, for example, propylene glycol monomethyl ether acetate (PGMEA) , propylene glycol monomethyl ether (PGME), cyclohexanone, ethyl lactate, gamma-butyrolactone (GBL), acetyl acetone, and the like, preferably It may be propylene glycol monomethyl ether acetate (PGMEA).

The content of the solvent (B) according to an embodiment of the present invention is not particularly limited as long as the object of the present invention can be achieved, and the remaining amount except for the reaction component and other additives including the polymer (A) in the composition according to the present invention can be included For example, when only the polymer (A) is used in the composition, the solvent may be 50 to 90% by weight of the total weight of the composition, and when the above range is satisfied, the above-described effects of the present invention may be effectively exhibited.

cross-linking agent and catalyst

Also, 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 is capable of reacting with the polymer (A) in a manner capable of being catalyzed by the generated acid. ramen is not particularly limited. As a representative example of such a crosslinking agent, any one selected from the group consisting of melamine, amino resins, glycoluril compounds and bis-epoxy compounds may be used.

By further including the crosslinking agent, curing characteristics of the hard mask composition may be further enhanced.

Specific examples of the crosslinking 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 melamine. A urea resin (specific examples, Cymel U-65 Resin or UFR 80 Resin), a glycoluril derivative represented by Formula 11 (specific examples, Powderlink 1174), bis(hydroxymethyl) represented by Formula 12 -p-cresol compound) and the like. In addition, a bisepoxy-based compound represented by the following formula (13) and a melamine-based compound represented by the following formula (14) can also be used as a crosslinking agent.

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

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

As the acid catalyst, a thermally activated acid catalyst may be used. As an example of the acid catalyst, an organic acid such as p-toluene sulfonic acid monohydrate may be used, and a TAG (thermal acid generator)-based compound with storage stability may be used. Thermal acid generators are acid generator compounds designed to release acid upon heat treatment, for example pyridinium p-toluene sulfonate, 2,4,4,6-tetrabromocyclohexa Dienone, benzoin tosylate, 2-nitrobenzyl tosylate, alkyl ester of organic sulfonic acid, etc. can be used.

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.

In addition, other photosensitive catalysts known in the art of resist may also be used as long as they are compatible with the other components of the antireflective composition.

When the crosslinking agent is included, the content of the crosslinking 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 polymer (A). to 10 parts by weight. In addition, when the catalyst is included, the content of the catalyst may be 0.001 part by weight to 5 parts by weight, preferably 0.1 part by weight to 2 parts by weight, more preferably 0.1 part by weight based on 100 parts by weight of the polymer (A). It may be part by weight or 1 part by weight.

When the crosslinking agent is included within the above range, appropriate crosslinking characteristics may be obtained without changing the optical characteristics of the formed underlayer film.

In addition, when the content of the catalyst is within the above range, appropriate crosslinking properties may be obtained, and acidity, which affects storage stability, may be appropriately maintained.

additive

If necessary, the hard mask composition of the present invention may further include an additive such as a surfactant. Alkylbenzenesulfonic acid salts, alkylpyridinium salts, polyethylene glycols, quaternary ammonium salts, etc. may be used as the surfactant, but are not limited thereto. 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 polymer (A). When the content of the surfactant is within the above range, appropriate crosslinking properties may be obtained without changing the optical properties of the formed underlayer film.

Hereinafter, preferred embodiments are presented to aid understanding of the present invention, but these embodiments are only illustrative of the present invention and do not limit the scope of the appended claims, and embodiments within the scope and spirit of the present invention It is obvious to those skilled in the art that various changes and modifications to the are possible, and it is natural that these variations and modifications fall within the scope of the appended claims.

Example and comparative example

Compositions for hard masks having the compositions and contents (wt%) described in Tables 1 and 2 below were prepared.

division Polymer (A) Solvent (B) Crosslinking agent (C) 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 15 B-1 85 - - - - - - Example 3 A-1 40 B-1 60 - - - - - - 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-6 20 B-1 80 - - - - - - Example 9 A-1 5 B-1 95 - - - - - - Example 10 A-1 55 B-1 45 - - - - - - Example 11 A-1 20 B-1 78 C-1 One D-1 One - - Example 12 A-1 20 B-1 79 - - - - E-1 One

division Polymer (A') Solvent (B) Crosslinking agent (C) Catalyst (D) Additive (E) ingredient content ingredient content ingredient content ingredient content ingredient content Comparative Example 1 A'-1 20 B-1 80 - - - - - - Comparative Example 2 A'-2 20 B-1 80 - - - - - - Comparative Example 3 A'-1 20 B-1 78 C-1 One D-1 One - - Comparative Example 4 A'-1 20 B-1 79 - - - - E-1 One

의 축합반응으로 생성된 중합체(중량평균분자량:3500)A-1:

Polymer produced by the condensation reaction of (weight average molecular weight: 3500)

의 축합반응으로 생성된 중합체(중량평균분자량:4200)A-2:

Polymer produced by the condensation reaction of (weight average molecular weight: 4200)

의 축합반응으로 생성된 중합체(중량평균분자량:3700)A-3:

Polymer produced by the condensation reaction of (weight average molecular weight: 3700)

의 축합반응으로 생성된 중합체(중량평균분자량:3900)A-4:

Polymer produced by the condensation reaction of (weight average molecular weight: 3900)

의 축합반응으로 생성된 중합체(중량평균분자량:900)A-5:

A polymer produced by the condensation reaction of (weight average molecular weight: 900)

의 축합반응으로 생성된 중합체(중량평균분자량:12000)A-6:

Polymer produced by the condensation reaction of (weight average molecular weight: 12000)

의 축합반응으로 생성된 중합체(중량평균분자량:3500)A'-1:

Polymer produced by the condensation reaction of (weight average molecular weight: 3500)

의 축합반응으로 생성된 중합체(중량평균분자량:4500)A'-2:

Polymer produced by the condensation reaction of (weight average molecular weight: 4500)

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

C-1: N-methoxymethyl-melamine

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

E-1: triethylene glycol

Experimental example

1. Heat resistance evaluation

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 the temperature was raised to 400° C. using TGA (thermogravimetric analysis) under nitrogen.

Mass loss rate = {(initial mass - mass at 400°C)/initial mass} x 100%

<Heat resistance determination>

◎: Mass loss rate less than 10%

○: Mass loss rate of 10% or more to less than 15%

△: mass loss rate of 15% or more to less than 25%

×: mass loss rate of 25% or more

2. High-temperature heat resistance evaluation

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

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

<Heat resistance determination>

○: Mass loss rate less than 40%

△: mass loss rate of 40% or more to less than 50%

×: mass loss rate of 50% or more

3. Coating uniformity

After drying, the composition was spin-coated to a thickness of 5 μm, dried in a hot air dryer at 100° C. for 3 minutes, and the surface was visually confirmed.

<Determination of coating uniformity>

○: Non-uniformity of the coating surface was not confirmed visually.

(triangle|delta): Local non-uniformity was visually confirmed.

x: Non-uniformity was confirmed visually from the entire surface.

division heat resistance
(400℃ mass loss rate) high temperature resistance
(800℃ mass loss rate) coating uniformity Example 1 ○ ○ ○ Example 2 ○ ○ ○ Example 3 ○ ○ ○ Example 4 ○ ○ ○ Example 5 ○ ○ ○ Example 6 ○ ○ ○ Example 7 △ △ ○ Example 8 ◎ ○ △ Example 9 ○ △ ○ Example 10 ○ ○ △ Example 11 ○ ○ ○ Example 12 ○ ○ ○ Comparative Example 1 ○ × ○ Comparative Example 2 ○ × ○ Comparative Example 3 ○ × ○ Comparative Example 4 ○ × ○

Referring to Table 3, it was confirmed that the examples showed excellent heat resistance, high temperature heat resistance, and coating uniformity, but the comparative examples were not excellent.

Claims (6)

A hard mask composition comprising a polymer prepared by a condensation reaction of at least one of an aldehyde compound having 1 to 25 carbon atoms and a diol compound having 1 to 25 carbon atoms and a carbazole-based compound containing an acetylene group, and a solvent.
The hard mask composition of claim 1, wherein the carbazole-based compound containing an acetylene group is represented by Formula 1 below:
[Formula 1]

(In the formula, n is an integer from 1 to 3).
The hard mask composition of claim 1, wherein the diol compound is a compound represented by Formula 2 below:
[Formula 2]

(Wherein, Ar is an arylene group of 6 to 20, and R ₁ and R ₂ are each independently a hydrogen atom, a methyl group or an ethyl group).
The hard mask composition of claim 1 , wherein the polymer has a weight average molecular weight of 1000 to 15000.
The composition for a hard mask according to claim 1, comprising 10 to 50% by weight of the polymer and 50 to 90% by weight of the solvent in the total weight of the composition.
The composition for a hard mask according to claim 1 , further comprising at least one of a crosslinking agent and a catalyst.