KR102252677B1 - A composition of anti-reflective hardmask - Google Patents

Abstract

The present invention provides an anti-reflective hard mask composition comprising (a) a copolymer or a copolymer mixture (blend) comprising bisindole compounds represented by chemical formula 1 below, and (b) an organic solvent.

Description

Anti-reflection hard mask composition {A COMPOSITION OF ANTI-REFLECTIVE HARDMASK}

The present invention relates to a hardmask composition having antireflection properties useful in a lithographic process, and to a polymer containing a bisindole-based aromatic ring having strong absorption in an ultraviolet wavelength region, and a hardmask composition comprising the same. .

In recent years, as the semiconductor industry increasingly requires a micronization process, an effective lithographic process is essential in order to realize such ultra-fine technology. In particular, there is an increasing demand for a new material for a hardmask process, which is very essential in the etching process.

In general, the hardmask film quality serves as an interlayer that transfers a fine pattern of a photoresist to a lower substrate layer through a selective etching process. Therefore, the hardmask layer is required to have properties such as chemical resistance, heat resistance, and etching resistance to withstand multiple etching processes. The existing hard mask film quality was made of an amorphous carbon layer (ACL) film made by chemical vapor deposition (CVD). The disadvantages of this are high cost equipment investment and particles generated during the process, and film quality is opaque. There were many very inconvenient points to use due to photo alignment problems, etc.

Recently, instead of the chemical vapor deposition method, a spin-on hardmask method formed by a spin-on coating method has been introduced. In the spin-on coating method, a hardmask composition is formed using an organic polymer material having solubility in a solvent, and the most important characteristic is that an organic polymer coating film having both etching resistance must be formed.

However, the characteristics of solubility and etching resistance, which are two properties required for such an organic hardmask layer, are in conflict with each other, so a hardmask composition capable of satisfying all of them was required. While satisfying the characteristics of these organic hardmask materials, materials introduced into the semiconductor lithographic process have been recently introduced (Publication Patent 10-2009-0120827, Publication 10-2008-0107210, Patent WO 2013100365 A1), which is These were hard mask materials using a copolymer having an appropriate high molecular weight synthesized by the conventional phenol resin manufacturing method using ren (hydroxypyrene).

However, as the recent semiconductor lithographic process goes through a further refinement process, in the case of such an organic hardmask material, it is difficult to sufficiently perform the role of a mask due to the lack of etching selectivity in the etching process compared to the conventional inorganic hardmask material. Came to pass. Therefore, there is an urgent need to introduce an organic hardmask material that is more optimized for the etching process.

Patent Document 1: KR 10-2009-0120827 A Patent Document 2: KR 10-2008-0107210 A Patent Document 3: WO 2013/100365 A1

An object of the present invention is to provide a hardmask polymer having excellent polymer solubility, high etching selectivity, and sufficient resistance to multi-etching, and a composition comprising the same.

An object of the present invention is to provide a novel hardmask polymer that can be used to perform a lithographic technique, and a composition comprising the same, since reflectivity between a resist and a back layer can be minimized.

The object of the present invention can be achieved by a copolymer comprising bisindole compounds represented by the following formula (1).

[Formula 1]

In the above formula, R1 and R2 are each independently hydrogen; C1-C20 alkyl group; C2-C20 alkenyl group; C6-C30 aryl group; An aryl group including a C6-C30 hetero atom; Or a C6 ~ C30 aryl group substituted with one or more substituents selected from the group consisting of hydroxyl groups, fluorine, nitro and nitrile groups; and R1 and R2 include an ether bond, a ketone bond, an ester bond, and a combination thereof It may include one or more selected from (except when R1 and R2 are hydrogen), R1 and R2 may be the same as or different from each other, and R1 and R2 may be bonded to each other to form a ring with each other. However, the fluorene structure is excluded from the compound structure constituting the ring.

The weight average molecular weight of the copolymer may be 1,000 to 30,000.

R1 and R2 of the bisindole-based compound represented by Formula 1 are specifically, R1 is hydrogen, and R2 is a phenyl derivative, a naphthyl derivative, a quinoline derivative, a biphenyl derivative, a diphenyl ether derivative, 1 It may be an anthracene derivative, a carbazole derivative, an indole derivative, a phenanthrene derivative, a pyrene derivative, a triphenylene derivative, or a perylene derivative.

In addition, R1 is benzene, R2 is a phenyl derivative, a naphthyl derivative, a quinoline derivative, a biphenyl derivative, a diphenyl ether derivative, an anthracene derivative, a carbazole derivative, an indole derivative, a phenanthrene derivative, It may be a pyrene-based derivative, a triphenylene-based derivative, or a perylene-based derivative.

In addition, the R1 and R2 may be bonded to each other to have a compound structure having a cyclic structure, wherein the compound structure having the cyclic structure may be a dibenzoshuberenone-based compound, etc., and in the compound structure having the cyclic structure, fluorene Structure is excluded.

The bisindole-based compound represented by Formula 1 may be more specifically selected from the group consisting of the following compounds, in which R 1 is hydrogen; C1-C20 alkyl group; C2-C20 alkenyl group; C6-C30 aryl group; An aryl group including a C6-C30 hetero atom; Or a C6 ~ C30 aryl group substituted with one or more substituents selected from the group consisting of hydroxyl groups, fluorine, nitro and nitrile groups; wherein R1 is selected from the group consisting of ether bonds, ketone bonds, ester bonds, and combinations thereof It may contain more than one (except when R1 is hydrogen).

Substituents R3, R4, and R5 of the following compounds may each independently be hydrogen, hydroxy, alkoxy, halogen, an amino group, a C1-C20 alkyl group, a C2-C20 alkenyl group, or a C6-C30 aryl group.

In addition, an object of the present invention is (a) a copolymer comprising bisindole compounds represented by the following formula (2) or a mixture of these copolymers; And (b) can be achieved by an anti-reflective hardmask composition comprising an organic solvent:

[Formula 2]

In the above formula, R1, R2, R6, and R7 are each independently hydrogen; C1-C20 alkyl group; C2-C20 alkenyl group; C6-C30 aryl group; An aryl group including a C6-C30 hetero atom; Or a C6 ~ C30 aryl group substituted with one or more substituents selected from the group consisting of a hydroxyl group, fluorine, nitro, and nitrile group; wherein R1, R2, R6, R7 are each an ether bond, a ketone bond, an ester bond, or these May contain a combination of (except when R1, R2, R6, and R7 are hydrogen), and R1 and R2, and R6 and R7 are the same as or different from each other, and R1 and R2, and R6 and R7 are each other. It may be a structure that combines to form a ring. However, the fluorene structure is excluded from the ring structure formed by bonding of R1 and R2 to each other.

The weight average molecular weight of the copolymer may be 1,000 to 30,000.

In the copolymer of Formula 2 included in the antireflective hardmask composition, R1 is hydrogen and R2 is a phenyl derivative, a naphthyl derivative, a quinoline derivative, a biphenyl derivative, a diphenyl ether derivative, an anthracene derivative. It may be a derivative, a carbazole derivative, an indole derivative, a phenanthrene derivative, a pyrene derivative, a triphenylene derivative, or a perylene derivative.

In addition, in the copolymer of Formula 2 included in the antireflection hardmask composition, R1 is benzene, R2 is a phenyl derivative, a naphthyl derivative, a quinoline derivative, a biphenyl derivative, a diphenyl ether derivative, It may be an anthracene derivative, a carbazole derivative, an indole derivative, a phenanthrene derivative, a pyrene derivative, a triphenylene derivative, or a perylene derivative.

In the anti-reflective hardmask composition, R1 and R2, and R6 and R7 may each be bonded to each other to have a compound structure having a cyclic structure. Flurene is excluded from the structure of a compound having a ring structure by bonding of R1 and R2 to each other.

If necessary, the hard mask composition may include a crosslinking agent; An acid catalyst component; Other additives including at least one compatible material such as an antifoaming agent, a leveling agent, and a surfactant; may also be included.

The hardmask composition comprises (a) 1 to 30% by weight of a polymer containing the bisindole compound or a blend of these polymers; (c) 0 to 10% by weight of a crosslinking agent component; (d) 0 to 1.0% by weight of an acid catalyst; And (b) using an organic solvent as the remaining component may be made of a total of 100% by weight.

In addition, (e) other additives may be used in an amount of 0 to 3,000 ppm based on the weight of the (a) polymer or a mixture of these polymers in addition to the total 100% by weight of the hardmask composition.

The crosslinking agent is methoxymethylated glycoluril, butoxymethylglycoluril, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, methoxymethylated urea, butoxymethylated urea, me It may be selected from the group consisting of oxymethylated thiourea compounds.

The acid catalyst is 　p-toluenesulfonic acid monohydrate, pyridinium p-toluene sulfonate, 2,4,4,6-tetrabromocyclohexadienone, benzo Phosphorus tosylate, 2-nitrobenzyl tosylate and alkyl esters of organic sulfonic acids.

The other additives may be those widely known in the art.

The organic solvent is not particularly limited as long as it has sufficient solubility in the aromatic ring-containing polymer, for example, propylene glycol monomethyl ether acetate (PGMEA), cyclohexanone, gamma butyrolactone, ethyl lactate. And the like.

The hardmask composition based on the bisindole-based copolymer according to the present invention has a very high carbon content in the polymer, so the value of the Ohnishi Parameter predicting the etch resistance is very low, so it is a very advantageous structure for etch resistance. In terms of the polymer structure, the packing density is very high, so when a thin film is formed, the film density increases and the etching resistance is very excellent. Accordingly, since the etching selectivity is high compared to the existing organic hard mask, the resistance to multiple etching is sufficient, and a lithographic structure having excellent pattern evaluation results can be provided.

In addition, the copolymer containing the bisindole-based compound has the advantage of forming a thin film having a thickness of 0.5 μm or more because the solubility of the polymer is good and the average molecular weight of the polymer can be increased.

The hard mask composition based on the bisindole-based polymer according to the embodiments of the present invention is an antireflection film in the Deep UV region such as ArF (193 nm) and KrF (248 nm) when forming a film, and has a useful range of refractive index and absorption, The reflectivity between the and the back layer can be minimized.

According to the present invention, a copolymer containing a bisindole derivative compound represented by the following formula (1) is provided.

[Formula 1]

In the above formula, R1 and R2 are each independently hydrogen; C1-C20 alkyl group; C2-C20 alkenyl group; C6-C30 aryl group; An aryl group including a C6-C30 hetero atom; Or a C6 ~ C30 aryl group substituted with one or more substituents selected from the group consisting of hydroxyl groups, fluorine, nitro and nitrile groups; and R1 and R2 include an ether bond, a ketone bond, an ester bond, and a combination thereof It may include one or more selected from (except when R1 and R2 are hydrogen), R1 and R2 may be the same as or different from each other, and R1 and R2 may be bonded to each other to form a ring with each other. However, the fluorene structure is excluded from the compound structure constituting the ring.

The present invention has such a bisindole structure, and thus polymer solubility is significantly increased compared to the conventional single carbazole or indole type compound, and shows an advantage of forming a hard mask thin film having a relatively high thickness.

The weight average molecular weight of the copolymers has a range of 1,000 to 30,000, and preferably has a range of 2,000 to 30,000. More preferably, it can have a weight average molecular weight of 4,000 to 15,000, so it has the effect of forming a thick thin film compared to the existing hard mask material.

Here, the bisindole-based derivative compound of Formula 1 may preferably be in any one of the following forms.

Here, R1 is hydrogen; C1-C20 alkyl group; C2-C20 alkenyl group; C6-C30 aryl group; An aryl group including a C6-C30 hetero atom; Or a C6-C30 aryl group which may be substituted with a hydroxyl group, fluorine, nitro, or nitrile group. Further, R1 may contain an ether bond, a ketone bond, an ester bond, or a combination thereof (except when R1 is hydrogen).

Each of R3, R4, and R5 may be hydrogen, hydroxy, alkoxy, halogen, amino group, C1~C20 alkyl group, C2~C20 alkenyl group, or C6~C30 aryl group.

In particular, in Formula 1, R1 is hydrogen, and R2 is a phenyl derivative, a naphthyl derivative, a quinoline derivative, a biphenyl derivative, a diphenyl ether, an anthracene derivative, a carbazole derivative, an indole derivative, a phenanthrene derivative , Pyrene-based derivatives, triphenylene-based derivatives, and perylene-based derivatives, the carbon content of the copolymer containing a compound selected from the group consisting of the biindole structure and the corresponding R2 substituent structure increases, so that the inherent etch resistance characteristics of the hardmask are improved. There is an improvement effect.

In particular, a copolymer having a structure in which R2 is a naphthalene derivative, carbazole, anthracene derivative, pyrene derivative, or perylene derivative is preferable. In this case, it acts as a more sufficient mask when etching CF4 due to an increase in carbon content in the polymer. There is an effect that can be done.

In addition, according to the present invention, (a) a copolymer including bisindole compounds represented by the following formula (2) or a mixture of these copolymers; And (b) there is provided an anti-reflection hardmask composition comprising an organic solvent.

[Formula 2]

In the above formula, R1, R2, R6, and R7 are each independently hydrogen; C1-C20 alkyl group; C2-C20 alkenyl group; C6-C30 aryl group; An aryl group including a C6-C30 hetero atom; Or a C6 ~ C30 aryl group substituted with one or more substituents selected from the group consisting of a hydroxyl group, fluorine, nitro, and nitrile group; wherein R1, R2, R6, R7 are each an ether bond, a ketone bond, an ester bond, or these May contain a combination of (except when R1, R2, R6, and R7 are hydrogen), and R1 and R2, and R6 and R7 are the same as or different from each other, and R1 and R2, and R6 and R7 are each other. It may be a structure that combines to form a ring. However, the fluorene structure is excluded from the ring structure formed by bonding of R1 and R2 to each other.

The copolymer having the structure of Formula 2 may have, for example, the following forms of (Chemical Formula 2-1) to (Chemical Formula 5-3).

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

The polymers may be used in combination with a novolac resin or aromatic C6 to C20 novolac polymers having a hydroxyl group in order to improve the dissolution and coating properties or curing properties of the entire hardmask composition. Compared to 1 to 30% by weight may be included.

On the other hand, in order to make a hardmask composition, the (a) copolymer containing the bisindole derivative compound is preferably used in an amount of 1 to 30% by weight based on the total hardmask composition. When the copolymer containing the (a) bisindole derivative compound is less than 1% by weight or exceeds 30% by weight, it becomes less than or exceeds the desired coating thickness, making it difficult to accurately match the coating thickness.

And the organic solvent is not particularly limited as long as it has sufficient solubility in the above aromatic ring-containing polymer. For example, propylene glycol monomethyl ether acetate (PGMEA), cyclohexanone, gamma butyrolactone, ethyllac Tate, etc. are mentioned.

In addition, the antireflection hardmask composition of the present invention additionally contains at least one compatible material such as (c) a crosslinking agent component, (d) an acid catalyst, (e) an antifoaming agent, a leveling agent, and a surfactant. Other additives may be further included.

The (c) crosslinking agent component used in the hardmask composition of the present invention is preferably capable of crosslinking the repeating units of the polymer by heating in a catalytic reaction by the generated acid, and the (d) acid catalyst is thermally activated. It is preferable that it is an acid catalyst, and the (e) other additives are sufficient as long as they have compatibility well known in the art.

The (c) crosslinking agent component used in the hardmask composition of the present invention is not particularly limited as long as it is a crosslinking agent capable of reacting with the aromatic ring-containing polymer in a manner that can be catalytically functionalized by the produced acid. Examples of the crosslinking agent include melamine-based, substituted urea-based, or polymers thereof. Preferably, it is a crosslinking agent having at least two crosslinking substituents, methoxymethylated glycoluril, butoxymethylglycoluril, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, These are compounds such as methoxymethylated urea, butoxymethylated urea, and methoxymethylated thiourea.

Further, a crosslinking agent having high heat resistance can be used as the crosslinking agent, but a compound containing a crosslinking substituent having an aromatic ring in the molecule can be preferably used. These compounds may exemplify compounds in the form of the following structural formula.

As the (d) acid catalyst used in the hardmask composition of the present invention, an organic acid such as p-toluenesulfonic acid monohydrate may be used, and TAG (Thermal Acid Generator) having storage stability A system compound can also be used as a catalyst. TAG is an acid generator compound designed to release an acid during heat treatment. For example, pyridinium P-toluene sulfonate, 2,4,4,6-tetrabromocyclohexadienone, It is preferable to use benzoin tosylate, 2-nitrobenzyl tosylate, and alkyl esters of organic sulfonic acids.

The (e) other additives used in the hardmask composition of the present invention are antifoaming agents, leveling agents, and surfactant materials well known in the art.

When the hardmask composition of the present invention further comprises (c) a crosslinking agent component and (d) an acid catalyst, the hardmask composition of the present invention comprises (a) a bisindole-based aerial having strong absorption properties in the ultraviolet region. 1 to 30% by weight, more preferably 3 to 15% by weight, (c) 0.1 to 10% by weight of a crosslinking agent component, more preferably 0.5 to 5% by weight, (d) The acid catalyst may be 0.01 to 1.0% by weight, more preferably 0.05 to 0.5% by weight, and (b) a total of 100% by weight using an organic solvent as the remaining component.

In addition, when the hardmask composition of the present invention further comprises (c) a crosslinking agent component, (d) an acid catalyst, and (e) other additives, the hardmask composition of the present invention (a) exhibits strong absorption properties in the ultraviolet region. Having a bisindole-based copolymer or a blend of these copolymers 1 to 30% by weight, more preferably 3 to 15% by weight, (b) 0.1 to 10% by weight of a crosslinking agent component, more preferably 0.5 to 5% by weight, (c) 0.01 to 1.0% by weight of the acid catalyst, more preferably 0.05 to 0.5% by weight, and (b) may be made of a total of 100% by weight using an organic solvent as the remaining component, (e) other The additive is used by adding 10 to 3000 ppm, more preferably 100 to 1,000 ppm, based on the weight of the (a) copolymer or a mixture of these copolymers, to 100% by weight, which is the total amount of the composition.

Here, when the amount of the bisindole-based aromatic ring-containing polymer is less than 1% by weight or exceeds 30% by weight, it becomes less than or exceeds the desired coating thickness, making it difficult to accurately match the coating thickness.

In addition, when the crosslinking agent component exceeds 10% by weight, the optical properties of the coating film may be changed due to excessive injection.

In addition, when the amount of the acid catalyst exceeds 1% by weight, storage stability may be affected due to an increase in acidity due to excessive injection.

When the additive exceeds 3000 ppm, it may cause problems such as coating properties and etch properties in an organic solvent due to excessive injection.

Hereinafter, the present invention will be described in more detail through examples, but the following examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

(Monomer synthesis)

2 equivalents of indole and 1 equivalent of aldehyde or ketone compound were reacted for about 4 hours at a temperature of 80°C using a solvent glycerol in the presence of iron (III) phosphate (5 mol %) as a catalyst, and then treated with an excess of ethyl acetate solvent. The produced catalyst is removed.

Subsequently, after removing the excess solvent, the resulting crude can be recrystallized in ethanol to obtain a desired bisindole compound in a yield of 85 to 90%.

(Copolymer synthesis)

The bisindole compounds synthesized in the above monomer synthesis and aldehyde or ketone comonomers were mixed with a solvent gamma butyrolactone under an acid catalyst such as paratoluene sulfonic acid or methane sulfonic acid, at a temperature of 110 to 130 degrees. It is polymerized for about 10 to 20 hours under conditions.

After the polymerization is completed, the reaction product is precipitated with an excess of methanol/water co-solvent and then neutralized with triethylamine. The resulting precipitate is filtered, washed several times with an excess of methanol solvent, and then the final filtered precipitate is dried in a vacuum oven at 60° C. for 24 hours to obtain copolymers. At this time, the obtained polymer weight average molecular weight (Mw) has a range of about 4,000 to 15,000.

Hereinafter, the following copolymers can be obtained through specific examples.

(Example-1)

In a 125 mL round flask, 11.2 g (25 mmol) of bisindole compound, 3.2 g (30 mmol) of benzaldehyde, and 0.25 g of methanesulfonic acid were dissolved in 43 g of gamma butyrolactone, followed by a temperature of 120 degrees. Polymerization was carried out for 10 hours.

After the polymerization is over, the reaction product is precipitated in an excess of methanol/water (8:2) solvent and then neutralized with triethylamine. The resulting precipitate was filtered, washed twice with a methanol solvent, and then filtered and dried in a vacuum oven at 60° C. for 24 hours to obtain a polymer of Formula 2-2.

High molecular weight average molecular weight (Mw) 6,500, polydispersity (Mw/Mn) 1.86 results were obtained.

Hereinafter, the following copolymers could be synthesized in the same manner as in Example-1.

(Example-2)

11.2 g (25 mmol) of a bisindole compound, 4.7 g (30 mmol) of naphthylaldehyde, and 0.25 g of methanesulphonic acid were dissolved in 48 g of gamma butyrolactone, and then a polymer was synthesized in the same manner as in Example 1. The synthesized polymer obtained a weight average molecular weight (Mw) of 5,100 and a polydispersity (Mw/Mn) of 1.88.

(Example-3)

After dissolving 11.2 g (25 mmol) of a bisindole compound, 6.2 g (30 mmol) of anthracenealdehyde, and 0.25 g of methanesulphonic acid in 52 g of gamma butyrolactone, a polymer was synthesized in the same manner as in Example 1. The synthesized polymer obtained a weight average molecular weight (Mw) of 5,300 and a polydispersity (Mw/Mn) of 1.90.

(Example-4)

Bisindole compound 11.2g (25mmol), pyrenealdehyde 6.9g (30mmol), and methane sulfonic acid 0.25g was dissolved in gamma butyrolactone 54g, a polymer was synthesized in the same manner as in Example 1. The synthesized polymer obtained a weight average molecular weight (Mw) of 4,800 and a polydispersity (Mw/Mn) of 1.79.

(Example-5)

Bisindole compound 11.2g (25mmol), flurenone 5.4g (30mmol), and methane sulfonic acid 0.25g was dissolved in gamma butyrolactone 54g, a polymer was synthesized in the same manner as in Example 1. The synthesized polymer had a weight average molecular weight (Mw) of 6,900 and a polydispersity (Mw/Mn) of 1.87.

(Example-6)

Bisindole compound 10.6g (25mmol), benzaldehyde 3.2g (30mmol), and methane sulfonic acid 0.25g was dissolved in gamma butyrolactone 42g, a polymer was synthesized in the same manner as in Example 1. The synthesized polymer had a weight average molecular weight (Mw) of 6,200 and a polydispersity (Mw/Mn) of 1.89.

(Example-7)

10.6 g (25 mmol) of a bisindole compound, 4.7 g (30 mmol) of naphthylaldehyde, and 0.25 g of methanesulphonic acid were dissolved in 46 g of gamma butyrolactone, and a polymer was synthesized in the same manner as in Example 1. The synthesized polymer obtained a weight average molecular weight (Mw) of 5,700 and a polydispersity (Mw/Mn) of 1.86.

(Example-8)

10.6 g (25 mmol) of a bisindole compound, 6.2 g (30 mmol) of anthracenealdehyde, and 0.25 g of methanesulphonic acid were dissolved in 50 g of gamma butyrolactone, and a polymer was synthesized in the same manner as in Example 1. The synthesized polymer obtained a weight average molecular weight (Mw) of 4,600 and a polydispersity (Mw/Mn) of 1.88.

(Example-9)

10.6 g (25 mmol) of a bisindole compound, 6.9 g (30 mmol) of pyrenealdehyde, and 0.25 g of methanesulphonic acid were dissolved in 53 g of gamma butyrolactone, and a polymer was synthesized in the same manner as in Example 1. The synthesized polymer obtained a weight average molecular weight (Mw) of 5,200 and a polydispersity (Mw/Mn) of 1.88.

(Example-10)

Bisindole compound 10.6g (25mmol), flurenone 5.4g (30mmol), and methane sulfonic acid 0.25g was dissolved in gamma butyrolactone 48g, a polymer was synthesized in the same manner as in Example 1. The synthesized polymer had a weight average molecular weight (Mw) of 6,500 and a polydispersity (Mw/Mn) of 1.91.

(Example-11)

Bisindole compound 11.2g (25mmol), benzaldehyde 3.2g (30mmol), and methane sulfonic acid 0.25g was dissolved in gamma butyrolactone 43g, a polymer was synthesized in the same manner as in Example 1. The synthesized polymer had a weight average molecular weight (Mw) of 6,300 and a polydispersity (Mw/Mn) of 1.88.

(Example-12)

11.2 g (25 mmol) of a bisindole compound, 4.7 g (30 mmol) of naphthylaldehyde, and 0.25 g of methanesulphonic acid were dissolved in 48 g of gamma butyrolactone, and a polymer was synthesized in the same manner as in Example 1. The synthesized polymer obtained a weight average molecular weight (Mw) of 5,100 and a polydispersity (Mw/Mn) of 1.85.

(Example-13)

After dissolving 11.2 g (25 mmol) of a bisindole compound, 6.2 g (30 mmol) of anthracenealdehyde, and 0.25 g of methanesulphonic acid in 52 g of gamma butyrolactone, a polymer was synthesized in the same manner as in Example 1. The synthesized polymer obtained a weight average molecular weight (Mw) of 4,300 and a polydispersity (Mw/Mn) of 1.90.

(Example-14)

Bisindole compound 11.2g (25mmol), pyrenealdehyde 6.9g (30mmol), and methane sulfonic acid 0.25g was dissolved in gamma butyrolactone 54g, a polymer was synthesized in the same manner as in Example 1. The synthesized polymer obtained a weight average molecular weight (Mw) of 5,300 and a polydispersity (Mw/Mn) of 1.97.

(Example-15)

After dissolving bisindole compound 11.2g (25mmol), fluorenone 5.4g (30mmol), and methanesulphonic acid 0.25g in gamma butyrolactone 50g, a polymer was synthesized in the same manner as in Example 1. The synthesized polymer had a weight average molecular weight (Mw) of 7,100, and a polydispersity (Mw/Mn) of 1.91.

(Example-16)

After dissolving bisindole compound 12.4g (25mmol), fluorenone 5.4g (30mmol), and methanesulphonic acid 0.25g in gamma butyrolactone 53g, a polymer was synthesized in the same manner as in Example 1. The synthesized polymer obtained a weight average molecular weight (Mw) of 5,900 and a polydispersity (Mw/Mn) of 1.95.

(Example-17)

After dissolving bisindole compound 12.2g (25mmol), flurenone 5.4g (30mmol), and methanesulphonic acid 0.25g in gamma butyrolactone 53g, a polymer was synthesized in the same manner as in Example 1. The synthesized polymer had a weight average molecular weight (Mw) of 6,700 and a polydispersity (Mw/Mn) of 1.98.

(Comparative Example) Synthesis of Phenol-Based Polymer

After dissolving 35 g (100 mmol) of 9,9-bishydroxyphenylfluorene and 11.7 g (110 mmol) of benzaldehyde in 109 g of PGMEA, 1 g of concentrated sulfuric acid is added thereto. After polymerization in the same manner as in Example-1, the polymer was purified and dried in a vacuum oven to obtain a polymer having a weight average molecular weight (Mw) of 3,500.

The weight average molecular weight results of the synthesized copolymers are shown in Table 1 below.

As can be seen from the molecular weight results, it was found that the bisindole-based copolymers had a larger weight average molecular weight than the phenolic copolymer synthesized in Comparative Example.

Copolymer Weight average molecular weight (Mw) Polydispersity (Mw/Mn) Example-1 6,500 1.86 Example-2 5,100 1.88 Example-3 5,300 1.90 Example-4 4,800 1.79 Example-5 6,900 1.87 Example-6 6,200 1.89 Example-7 5,700 1.86 Example-8 4,600 1.88 Example-9 5,200 1.88 Example-10 6,500 1.91 Example-11 6,300 1.88 Example-12 5,100 1.85 Example-13 4,300 1.90 Example-14 5,300 1.97 Example-15 7,100 1.91 Example-16 5,900 1.95 Example 17 6,700 1.98 Comparative Example 3,500 1.90

Preparation of hard mask composition

1 g of the polymer and 300 ppm of the surfactant prepared in Examples 1 to 17 and Comparative Examples were completely dissolved in 7 g of propylene glycol monomethyl ether acetate (PGMEA) and 2 g of cyclohexanone, and then filtered using a 0.2 um melbrain filter. Thus, the sample solutions of Examples 1 to 17 and Comparative Examples were prepared, respectively.

The sample solutions prepared according to Examples 1 to 17 and Comparative Examples were spin-coated on a silicon wafer and baked at 240° C. for 60 seconds to form a film having a thickness of 3500 Å.

At this time, the refractive index n and the extinction coefficient k of the formed films were obtained, respectively. The device used was Ellipsometer (J. A. Woollam), and the measurement results are shown in Table 2.

As a result of the evaluation, it was confirmed that there is a refractive index and absorbance that can be used as an antireflection film at the wavelengths of ArF (193 nm) and KrF (248 nm). Typically, the refractive index range of the material used as the semiconductor antireflection film is about 1.4 to 1.8, and the important thing is the extinction coefficient, and the higher the absorbance, the better. It can be seen that the hardmask composition according to the embodiments can be used as an antireflection film.

Sample type Optical characteristics (193nm) Optical characteristics (248nm) Refractive index (n) Extinction coefficient (k) Refractive index (n) Extinction coefficient (k) Example 1 1.48 0.58 1.70 0.51 Example 2 1.50 0.60 1.75 0.53 Example 3 1.49 0.63 1.72 0.52 Example 5 1.52 0.61 1.74 0.55 Example 7 1.54 0.65 1.73 0.57 Example 10 1.53 0.71 1.75 0.58 Example 11 1.52 0.69 1.75 0.57 Example 12 1.54 0.65 1.73 0.54 Example 15 1.55 0.67 1.75 0.56 Comparative Example 1.48 0.68 1.95 0.35

Lithographic evaluation of anti-reflective hardmask composition

The sample solutions prepared in Examples 1, 5, 7, 10, 11, 15 and Comparative Examples were spin-coated on a silicon wafer coated with aluminum, respectively, and baked at 240° C. for 60 seconds to form a coating film having a thickness of 3000 Å.

After coating a photoresist for KrF on each of the formed coating films, bake at 110°C for 60 seconds, perform exposure using ASML (XT:1400, NA 0.93) exposure equipment, and then use TMAH (tetramethyl ammonium hydroxide) 2.38wt% aqueous solution. Each was developed for 60 seconds. Then, as a result of examining each of the 90 nm line and space patterns using V-SEM, the results shown in Table 3 were obtained. The exposure latitude (EL) margin according to the change of the exposure amount and the depth of focus (DoF) margin according to the change in distance from the light source were considered and recorded in Table 3. As a result of pattern evaluation, good results were confirmed in terms of profile and margin, and it was found that the EL margin and DoF margin required in the litho pattern evaluation were satisfied.

Sample type Pattern characteristics EL margin
(△mJ/energy mJ) DoF margin
(㎛) Pattern shape Example 1 0.4 0.4 cubic Example 5 0.3 0.3 cubic Example 7 0.4 0.3 cubic Example 10 0.3 0.3 cubic Example 11 0.3 0.3 cubic Example 15 0.3 0.3 cubic Comparative Production Example 0.2 0.2 undercut

Evaluation of etching characteristics for antireflective hardmask composition

In Examples 5, 7, 10, 15 and Comparative Examples, respectively, the patterned specimens were subjected to dry etching of the lower SiON antireflection film (BARC) _{with CHF 3} /CF _{4 mixed gas using PR as a mask, followed by O 2} /N ₂ Dry etching of this hard mask was performed again using the SiON antireflection film as a mask with the mixed gas. Afterwards, dry etching the silicon nitride (SiN) film quality by using the hard mask as a mask with _{CHF 3} /CF _{4 mixed gas, and then O 2} ashing and wet stripping process for the remaining hard mask and organic matter. Proceeded.

Immediately after hard mask etching and silicon nitride etching, the cross-sections of each specimen were examined with V-SEM, and the results are listed in Table 4. As a result of the etch evaluation, the pattern shape after hard mask etching and silicon nitride etching in each case did not show any bowing phenomenon, and both had good resistance due to the etching process, so that the etching process of the silicon nitride film was performed well. Confirmed.

Sample type Pattern shape (after hard mask etching) Pattern shape (after SiN etching) Example 5 Vertical shape Vertical shape Example 7 Vertical shape Vertical shape Example 10 Vertical shape Vertical shape Example 15 Vertical shape Vertical shape Comparative Example Slightly boeing Boeing

Claims (16)

A copolymer comprising bisindole compounds represented by the following formula (1):
[Formula 1]

In the above formula, R1 and R2 are each independently a C1-C20 alkyl group; C2-C20 alkenyl group; C6-C30 aryl group; An aryl group including a C6-C30 hetero atom; Or a C6 ~ C30 aryl group substituted with one or more substituents selected from the group consisting of hydroxyl groups, fluorine, nitro and nitrile groups; and R1 and R2 include an ether bond, a ketone bond, an ester bond, and a combination thereof It may include one or more selected from, R1 and R2 may be the same as or different from each other, and R1 and R2 may be a compound structure that forms a ring by bonding to each other. However, the fluorene structure is excluded from the compound structure constituting the ring. The copolymer according to claim 1, wherein the copolymer has a weight average molecular weight of 1,000 to 30,000. delete The method of claim 1, wherein R1 is benzene, and R2 is a phenyl derivative, a naphthyl derivative, a quinoline derivative, a biphenyl derivative, a diphenyl ether derivative, an anthracene derivative, a carbazole derivative, an indole derivative, and A copolymer characterized in that it is a nanthrene derivative, a pyrene derivative, a triphenylene derivative, or a perylene derivative. The copolymer according to claim 1, wherein R1 and R2 are bonded to each other to have a compound structure having a cyclic structure, provided that fluorene is excluded from the compound structure having a cyclic structure. The copolymer according to claim 1, wherein the bisindole-based compound represented by Formula 1 is at least one selected from the group consisting of the following compounds.

In the above compounds, R1 is a C1-C20 alkyl group ; C2-C20 alkenyl group; C6-C30 aryl group; An aryl group including a C6-C30 hetero atom; Or a C6 ~ C30 aryl group substituted with one or more substituents selected from the group consisting of hydroxyl groups, fluorine, nitro and nitrile groups; And, R1 is from the group consisting of ether bonds, ketone bonds, ester bonds, and combinations thereof It may contain one or more selected , and the substituents R3, R4, and R5 of the compounds are each independently hydrogen, hydroxy, alkoxy, halogen, amino group, C1 ~ C20 alkyl group, C2 ~ C20 alkenyl group, or C6 It may be an aryl group of ~C30. (a) a copolymer including bisindole compounds represented by the following formula (2) or a mixture of these copolymers; And
(b) organic solvent
Anti-reflection hard mask composition comprising:
[Formula 2]

In the above formula, R1, R2, R6, and R7 are each independently a C1-C20 alkyl group; C2-C20 alkenyl group; C6-C30 aryl group; An aryl group including a C6-C30 hetero atom; Or a C6 ~ C30 aryl group substituted with one or more substituents selected from the group consisting of a hydroxyl group, fluorine, nitro, and nitrile group; wherein R1, R2, R6, R7 are each an ether bond, a ketone bond, an ester bond, or these can be in included in the combination, and may also be a structure of R1 and R2, and R6 and R7 are the same or different from each other, R1 and R2, and R6 and R7 are bonded to each other to form a ring. However, the fluorene structure is excluded from the ring structure formed by bonding of R1 and R2 to each other. [8] The antireflection hardmask composition of claim 7, wherein the copolymer has a weight average molecular weight of 1,000 to 30,000. delete The method of claim 7, wherein R1 is benzene, R2 is a phenyl derivative, a naphthyl derivative, a quinoline derivative, a biphenyl derivative, a diphenyl ether derivative, a monoanthracene derivative, a carbazole derivative, an indole derivative, A phenanthrene derivative, a pyrene derivative, a triphenylene derivative, or a perylene derivative. The method of claim 7, wherein R1 and R2, and R6 and R7 are a compound structure having a cyclic structure by bonding to each other, provided that fluorene is excluded among the compounds having a cyclic structure by bonding of R1 and R2. That, anti-reflection hard mask composition. The antireflection according to claim 7, wherein the copolymer represented by Formula 2 is at least one copolymer selected from the group consisting of copolymers of the following (Chemical Formula 2-1) to (Chemical Formula 2-7) Hardmask composition:
[Formula 2]

The method of claim 7, wherein the hard mask composition is a crosslinking agent; An acid catalyst component; And other additives; characterized in that it can be made by further comprising one or more components selected from the group consisting of, anti-reflection hard mask composition. The method of claim 13, wherein the hard mask composition,
(a) 1 to 30% by weight of a copolymer containing the bisindole-based compound or a blend of these copolymers;
(c) 0 to 10% by weight of the crosslinking agent component
(d) 0 to 1% by weight of an acid catalyst, and
(b) 100% by weight of an organic solvent is used as the remaining component, and (e) other additives are used in addition to the total 100% by weight of 0 to 3000 ppm based on the weight of the polymer or a mixture of these polymers, provided that the above Any one or more of (c), (d), (e) is characterized in that it is essentially included, anti-reflection hard mask composition. The method of claim 13 or 14, wherein the crosslinking agent is methoxymethylated glycoluril, butoxymethylglycoluril, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, methoxymethylated benzoguanamine Antireflection hardmask composition that is any one selected from the group consisting of oxymethylated urea, butoxymethylated urea, and methoxymethylated thiourea compounds. The method of claim 13 or 14, wherein the acid catalyst is p-toluenesulfonic acid monohydrate, pyridinium p-toluene sulfonate, 2,4,4,6 -An anti-reflection hardmask composition that is any one selected from the group consisting of tetrabromocyclo hexadienone, benzoin tosylate, 2-nitrobenzyl tosylate, and alkyl esters of organic sulfonic acids.