KR102215333B1 - Resist underlayer composition, and method of forming patterns using the composition - Google Patents

Abstract

[화학식 2]

상기 화학식 1 및 화학식 2의 정의는 명세서 내에 기재한 바와 같다.A composition for a resist underlayer film comprising a moiety represented by the following Formula 1 or a polymer including a moiety represented by the following Formula 2, and a solvent, and a pattern formation method using the composition for a resist underlayer film are provided.
[Formula 1]

[Formula 2]

The definitions of Formula 1 and Formula 2 are as described in the specification.

Description

Resist underlayer composition and pattern formation method using the same {RESIST UNDERLAYER COMPOSITION, AND METHOD OF FORMING PATTERNS USING THE COMPOSITION}

The present description relates to a composition for a resist underlayer film, and a pattern forming method using the same.

Recently, the semiconductor industry is developing from a pattern of several hundred nanometers to an ultra-fine technology having a pattern of several to tens of nanometers. Effective lithographic techniques are essential to realize such ultra-fine technology.

In the lithographic technique, a photoresist film is coated on a semiconductor substrate such as a silicon wafer, exposed and developed to form a thin film, and activated radiation such as ultraviolet rays is irradiated through a mask pattern on which the device pattern is drawn, and developed. , A processing method of forming a fine pattern corresponding to the pattern on the surface of the substrate by etching the substrate using the obtained photoresist pattern as a protective film.

As ultra-fine pattern manufacturing technology is required, short wavelengths such as i-line (365 nm), KrF excimer laser (wavelength 248 nm), and ArF excimer laser (wavelength 193 nm) are also used for the exposure of photoresist. Accordingly, in order to solve the problems caused by the diffuse reflection or standing wave from the semiconductor substrate of the activated radiation, many studies have been made to solve the problem by interposing a resist underlayer having an optimized reflectance between the resist and the semiconductor substrate. have

On the other hand, as a light source for fine pattern manufacturing in addition to the activated radiation, a method of using high energy rays such as EUV (Extreme ultraviolet; wavelength 13.5 nm) and E-Beam (electron beam) is also performed. Although there is no reflection, studies on improving the adhesion between the resist and the lower film are also being widely studied in order to improve the collapse of the pattern formed as the pattern is refined. In addition, studies to improve etch selectivity and chemical resistance in addition to studies to reduce the problems caused by the light source as described above are also widely studied.

In addition, attempts to improve the etch selectivity, chemical resistance, and adhesion to the resist, along with studies to reduce the problems caused by the light source as described above, have been continued.

One embodiment provides a composition for a resist underlayer film capable of improving coating uniformity, reducing surface roughness, and improving adhesion to a photoresist even when the thickness is formed to be thin.

Another embodiment provides a pattern forming method using the resist underlayer composition.

According to one embodiment, there is provided a composition for a resist underlayer film comprising a moiety represented by the following Formula 1 or a polymer including a moiety represented by the following Formula 2, and a solvent.

[Formula 1]

A is a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C3 to C10 cycloalkylene group, a substituted or unsubstituted C2 to C10 heterocycloalkylene group, a substituted or unsubstituted C6 to C30 arylene group , A substituted or unsubstituted C2 to C30 heteroarylene group, or a combination thereof,

R ² is any one of a C5 to C30 alkyl group, a C3 to C30 cycloalkyl group, and a C6 to C30 aryl group,

L ³ to L ⁶ are each independently a single bond, a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof,

X ² and X ³ are each independently a single bond, -O-, -S-, -S(=O)-, -S(=O) ₂ -, -C(=O) -, substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C3 to C10 cycloalkylene group, a substituted or unsubstituted A C2 to C10 heterocycloalkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof,

d to i are each independently an integer of 0 to 10,

* Is the connection point,

[Formula 2]

In Chemical Formula 2,

A is a substituted C1 to C20 alkylene group, a substituted C3 to C10 cycloalkylene group, a substituted C2 to C10 heterocycloalkylene group, a substituted C6 to C30 arylene group, a substituted C2 to C30 heteroarylene group, or these Wherein the substituent of A includes at least one of a C5 to C30 alkyl group, a C3 to C30 cycloalkyl group, and a C6 to C30 aryl group,

L ⁹ to L ¹² are each independently a single bond, a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof,

X ⁵ and X ⁶ are each independently a single bond, -O-, -S-, -S(=O)-, -S(=O) ₂ -, -C(=O)-, substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C3 to C10 cycloalkylene group, a substituted or unsubstituted A C2 to C10 heterocycloalkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof,

m to r are each independently an integer of 0 to 10,

* Is the connection point.

According to another embodiment, the steps of forming an etching target layer on a substrate, forming a resist underlayer layer by applying the composition for a resist underlayer film according to an embodiment on the etching target layer, forming a photoresist pattern on the resist underlayer layer And it provides a pattern forming method comprising the step of sequentially etching the resist underlayer layer and the etching target layer using the photoresist pattern using an etching mask.

The composition for a resist underlayer film according to an embodiment may provide a resist underlayer film capable of improving coating uniformity and reducing a possibility of occurrence of defects.

1 to 5 are cross-sectional views illustrating a method of forming a pattern using a composition for a resist underlayer film according to an embodiment.

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily implement the present invention. However, the present invention may be implemented in various different forms, and is not limited to the embodiments described herein.

In the drawings, the thicknesses are enlarged to clearly express various layers and regions, and the same reference numerals are attached to similar parts throughout the specification. When a part of a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the case where the other part is "directly above", but also the case where there is another part in the middle. Conversely, when one part is "directly above" another part, it means that there is no other part in the middle.

Unless otherwise defined in the specification, the term'substituted' means that the hydrogen atom in the compound is a halogen atom (F, Br, Cl, or I), a hydroxy group, an alkoxy group, a nitro group, a cyano group, an amino group, an azido group, or an amino group. Dino group, hydrazino group, hydrazono group, carbonyl group, carbamyl group, thiol group, ester group, carboxyl group or salt thereof, sulfonic acid group or salt thereof, phosphoric acid or salt thereof, vinyl group, C1 to C20 alkyl group, C2 to C20 alke Nyl group, C2 to C20 alkynyl group, C6 to C30 aryl group, C7 to C30 arylalkyl group, C6 to C30 allyl group, C1 to C30 alkoxy group, C1 to C20 heteroalkyl group, C3 to C20 heteroarylalkyl group, C3 to C30 cycloalkyl group , C3 to C15 cycloalkenyl group, C6 to C15 cycloalkynyl group, C3 to C30 heterocycloalkyl group, and a combination thereof.

In addition, unless otherwise defined in the specification,'hetero' means containing 1 to 3 heteroatoms selected from N, O, S, and P.

In addition, unless otherwise defined in the specification,'*' refers to a connection point of a compound or a compound moiety.

Hereinafter, a composition for a resist underlayer film according to an embodiment will be described.

The composition for a resist underlayer film according to an embodiment includes a polymer including a moiety represented by the following Formula 1 or a moiety represented by the following Formula 2, and a solvent.

[Formula 1]

A is a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C3 to C10 cycloalkylene group, a substituted or unsubstituted C2 to C10 heterocycloalkylene group, a substituted or unsubstituted C6 to C30 arylene group , A substituted or unsubstituted C2 to C30 heteroarylene group, or a combination thereof,

R ² is any one of a C5 to C30 alkyl group, a C3 to C30 cycloalkyl group, and a C6 to C30 aryl group,

L ³ to L ⁶ are each independently a single bond, a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof,

X ² and X ³ are each independently a single bond, -O-, -S-, -S(=O)-, -S(=O) ₂ -, -C(=O) -, substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C3 to C10 cycloalkylene group, a substituted or unsubstituted A C2 to C10 heterocycloalkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof,

d to i are each independently an integer of 0 to 10,

* Is the connection point,

[Formula 2]

In Chemical Formula 2,

A is a substituted C1 to C20 alkylene group, a substituted C3 to C10 cycloalkylene group, a substituted C2 to C10 heterocycloalkylene group, a substituted C6 to C30 arylene group, a substituted C2 to C30 heteroarylene group, or these Wherein the substituent of A includes at least one of a C5 to C30 alkyl group, a C3 to C30 cycloalkyl group, and a C6 to C30 aryl group,

L ⁹ to L ¹² are each independently a single bond, a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof,

X ⁵ and X ⁶ are each independently a single bond, -O-, -S-, -S(=O)-, -S(=O) ₂ -, -C(=O)-, substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C3 to C10 cycloalkylene group, a substituted or unsubstituted A C2 to C10 heterocycloalkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof,

m to r are each independently an integer of 0 to 10,

* Is the connection point.

For example, in Formula 1,

A may be a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C3 to C10 cycloalkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof.

In another example, in Chemical Formula 1,

X ² and X ³ are each independently a single bond, -O-, or -S-,

L ³ and L ⁵ are each independently a substituted or unsubstituted C6 to C30 arylene group,

L ⁴ and L ⁶ may each independently be a single bond, a substituted or unsubstituted C1 to C20 alkylene group.

For example, X ² and X ^{3 in} Formula 1, and X ⁵ and X ⁶ in Formula 2 may each independently be represented by Formula 3 below.

[Formula 3]

In Chemical Formula 3,

R ^a to R ^c are each independently a substituted or unsubstituted C1 to C5 alkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof,

X ^a and X ^b are each independently -O- or -S-,

na to ne are each independently an integer of 0 to 5,

Here, "substituted" means that a hydrogen atom is substituted with a C1 to C5 alkyl group, a hydroxy group, or a thiol group.

As another example, Formula 1 and Formula 2 may be represented by Formula 1-1 and Formula 2-1, respectively.

[Formula 1-1]

In Formula 1,

R ¹ is any ^one of a C5 to C30 alkyl group, a C3 to C30 cycloalkyl group, and a C6 to C30 aryl group,

R ² is hydrogen, deuterium, -F (fluoro group), -Cl (chloro group), -Br (bromo group), -I (iodo group), hydroxyl group, cyano group, nitro group, amino group, amidino Group, carboxyl group or salt thereof, sulfonic acid group or salt thereof, phosphoric acid group or salt thereof, substituted or unsubstituted C1 to C30 alkyl group, substituted or unsubstituted C2 to C30 alkenyl group, substituted or unsubstituted C2 to C30 Alkynyl group, substituted or unsubstituted C1 to C10 alkoxy group, substituted or unsubstituted C3 to C10 cycloalkyl group, substituted or unsubstituted C2 to C10 heterocycloalkyl group, substituted or unsubstituted C6 to C30 aryl A group, a substituted or unsubstituted C6 to C30 aryloxy group, a substituted or unsubstituted C6 to C30 arylthio group, or a combination thereof,

L ¹ to L ⁶ are each independently a single bond, a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof,

X ¹ to X ³ are each independently a single bond, -O-, -S-, -S(=O)-, -S(=O) ₂ -, -C(=O) -, substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C3 to C10 cycloalkylene group, a substituted or unsubstituted A C2 to C10 heterocycloalkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof,

a to i are each independently an integer of 0 to 10,

* Is the connection point,

[Formula 2-1]

R ³ is any one of a C5 to C30 alkyl group, a C3 to C30 cycloalkyl group, and a C6 to C30 aryl group,

L ⁷ to L ¹² are each independently a single bond, a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof,

X ⁴ to X ⁶ are each independently a single bond, -O-, -S-, -S(=O)-, -S(=O) ₂ -, -C(=O)-, substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C3 to C10 cycloalkylene group, a substituted or unsubstituted A C2 to C10 heterocycloalkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof,

j to r are each independently an integer of 0 to 10,

* Is the connection point.

The moiety represented by Formula 1 or Formula 2 has a cyanuric acid skeleton at the center. With such a structure, it is possible to have a relatively high refractive index (n) and a low extinction coefficient (k) for light transmitted from a light source used in the photoresist.

Specifically, when the moiety represented by Formula 1 or Formula 2 has a cyanuric acid skeleton in the center, the activation irradiation degree i-line (365 nm), KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), etc. It is possible to have a high refractive index and a low extinction coefficient for light having a high energy wavelength such as EUV (Extreme ultraviolet; wavelength 13.5 nm) and E-Beam (electron beam), as well as light having a short wavelength of.

Accordingly, when a composition containing the polymer containing the moiety is used as a material for a photoresist underlayer film, for example, the light interference effect can be suppressed by having an optimized reflectance for the light source from the film to be etched, In the etching process, it can have a high etch selectivity with the photoresist layer, and can have excellent flatness.

The polymer including the moiety according to Formula 1 or the moiety according to Formula 2 may contain one or more sulfur (S) in the main chain. The polymer including one or more sulfur atoms in the main chain may have a high refractive index and a fast etch rate.

According to an embodiment, R ¹ in Formula ¹ is a C5 to C30 alkyl group,

R ² is hydrogen, deuterium, -F, -Cl, a hydroxyl group, a cyano group, a nitro group, an amino group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, or a substituted or unsubstituted C3 to C30 Is an alkyl group of,

At least one of X ¹ to X ³ is each independently -O- or -S-,

L ¹ to L ⁶ are each independently a single bond, or a substituted or unsubstituted C1 to C20 alkylene group,

Each of a to i may independently be an integer of 0 to 5.

For example, R ¹ in Formula 1 may be a C5 to C30 long-chain alkyl group. Accordingly, in a polymer having a high molecular weight, since the substituent substituted in the central skeleton of Formula 1 is hydrophobic, the solubility in the solvent may be excellent, and accordingly, the coatability and adhesion to the photoresist may be improved. .

Likewise, according to one embodiment, R ³ in Formula 2 is a C5 to C30 alkyl group,

At least one of X ⁴ to X ⁶ is each independently -O- or -S-,

L ⁷ to L ¹² are each independently a single bond or a substituted or unsubstituted C1 to C20 alkylene group,

j to r may each independently be an integer of 0 to 5.

Formula 2 also, like the general formula 1 R ³ may be a sheet-chain alkyl group of C5 to C30. Also, since the substituent substituted in the central skeleton of Formula 2 is hydrophobic, the solubility in the solvent can be excellent even when a polymer having a high molecular weight is formed, and thus, coating properties and adhesion to the photoresist can be improved. have.

Specifically, the polymer has excellent solubility and can form a resist underlayer film having excellent coating uniformity. When the polymer is used as a material for a resist underlayer film, the formation or thickness of pin-holes and voids during the baking process A uniform thin film can be formed without deterioration of dispersion, and excellent gap-fill and planarization properties can be provided when there is a step difference in a lower substrate or film, or when a pattern is formed.

In one embodiment, R ¹ in Formula 1 may be a C5 to C30 chain alkyl group,

R ² is hydrogen, -F, -Cl, a hydroxyl group, a cyano group, a nitro group, an amino group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, or a substituted or unsubstituted C3 to C30 alkyl group Can be,

At least one of X ¹ to X ³ may be -S-,

L ¹ to L ⁶ may each independently be a single bond, or a substituted or unsubstituted C1 to C20 alkylene group,

a to i may each independently be an integer of 0 to 5,

R ³ in Formula 2 may be a C5 to C30 chain alkyl group,

At least one of X ⁴ to X ⁶ may be -S-,

L ⁷ to L ¹² may each independently be a single bond, or a substituted or unsubstituted C1 to C20 alkylene group,

j to r may each independently be an integer of 0 to 5.

As described above, each of the moieties according to Formula 1 or Formula 2 may have a cyanuric acid skeleton at the center to have a relatively high refractive index and a low extinction coefficient. Therefore, when the composition containing the polymer is used as, for example, a photoresist underlayer material, the light interference effect can be suppressed by having an optimized reflectance for the light source from the film to be etched, and the photoresist layer and the photoresist layer in the etching process It can have a high etch selectivity of, and can have excellent flatness.

Further, since the moiety according to Formula 1 or the polymer including the moiety according to Formula 2 contains sulfur (S) in the main chain, a high refractive index may be realized and a fast etch rate may be obtained.

In one embodiment, the polymer may include a first moiety represented by Formula 1 or Formula 2, and a second moiety represented by Formula 2 and including A different from the first moiety. have.

For example, the second moiety is in Formula 2,

Includes A different from the first moiety, wherein A is a substituted C1 to C20 alkylene group, a substituted C3 to C10 cycloalkylene group, a substituted C2 to C10 heterocycloalkylene group, a substituted C6 to C30 arylene group , A substituted C2 to C30 heteroarylene group, or a combination thereof, wherein the substituent of A includes at least one of a C5 to C30 alkyl group, a C3 to C30 cycloalkyl group, and a C6 to C30 aryl group,

L ⁹ to L ¹² are each independently a single bond, a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof,

X ⁵ and X ⁶ are each independently -O-, or -S-,

m to r may each independently be an integer of 0 to 5.

For example, when the polymer includes a first moiety and a second moiety that are different from each other, the first moiety and the second moiety are X ² and X ³ represented by Formula 3, and X of Formula 2 One or more of ⁵ and X ⁶ may further each be different.

Alternatively, the polymer may further include a third moiety represented by Formula 2 and including A different from the first moiety and the second moiety.

More specifically, the polymer may include one or more of the moieties represented by the following Chemical Formulas 4 to 7.

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

The polymer may have a weight average molecular weight of 1,000 to 100,000. Specifically, it may have a weight average molecular weight of 1,000 to 50,000, more specifically 1,000 to 20,000. By having a weight average molecular weight in the above range, the carbon content of the composition for a resist underlayer film containing the polymer and the solubility in a solvent can be adjusted to optimize.

The polymer may be included in an amount of 0.1 to 50% by weight, 0.1 to 30% by weight, or 0.1 to 15% by weight based on the total content of the composition for the resist underlayer film. By being included in the above range, the thickness, surface roughness, and degree of planarization of the resist underlayer film can be adjusted.

In addition, the resist underlayer composition may further include a crosslinking agent.

The crosslinking agent may be, for example, melamine-based, substituted urea-based, or these polymers. Preferably, a crosslinking agent having at least two crosslinking substituents, for example, methoxymethylated glycoruryl, butoxymethylated glycoruryl, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxy Compounds such as methylated benzoguanamine, methoxymethylated urea, butoxymethylated urea, methoxymethylated thiourea, or butoxymethylated thiourea may be used.

As the crosslinking agent, a crosslinking agent having high heat resistance may be used, and for example, a compound containing a crosslinking substituent having an aromatic ring (eg, a benzene ring or a naphthalene ring) in the molecule may be used. The crosslinking agent may, for example, have two or more crosslinking sites.

In addition, the composition for the resist underlayer film is an acrylic resin, an epoxy resin, a novolac resin, a glucouril resin, and a melamine resin in addition to the polymer containing the moiety represented by Formula 1 or the moiety represented by Formula 2. One or more other polymers of the resin may be further included, but the present invention is not limited thereto.

The composition for the resist underlayer film may further include an additive of a surfactant, a thermal acid generator, a plasticizer, or a combination thereof.

The surfactant may be, for example, an alkylbenzene sulfonic acid salt, an alkylpyridinium salt, a polyethylene glycol, a quaternary ammonium salt, or the like, but is not limited thereto.

The thermal acid generator is an acidic compound such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluenesulfonic acid, salicylic acid, sulfosalicylic acid, citric acid, benzoic acid, hydroxybenzoic acid, naphthalenecarboxylic acid, etc. ,4,6-tetrabromocyclohexadienone, benzointosylate, 2-nitrobenzyltosylate, and other organic fonate alkyl esters may be used, but the present invention is not limited thereto.

The additive may be included in an amount of 0.001 to 40 parts by weight based on 100 parts by weight of the resist underlayer composition. By including it in the above range, the solubility can be improved without changing the optical properties of the composition for a resist underlayer film.

The solvent is not particularly limited as long as it has sufficient solubility or dispersibility in the polymer, for example, propylene glycol, propylene glycol diacetate, methoxy propanediol, diethylene glycol, diethylene glycol butyl ether, tri(ethylene glycol) mono Methyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, ethyl lactate, gamma-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, methylpyrrolidone , Methylpyrrolidinone, acetylacetone, and ethyl 3-ethoxypropionate.

As described above, since the polymer according to an embodiment has improved solubility and is stable against an organic solvent, when a composition for a resist underlayer film containing the polymer is used as a material for a photoresist underlayer film, for example, a photoresist pattern is used. During the formation process, it is possible to minimize the generation of by-products due to peeling by a solvent or generation of chemical substances, and a loss of thickness due to the upper photoresist solvent.

The composition for a resist underlayer film according to an embodiment has excellent coating uniformity, excellent stability, can implement a high refractive index, and has a high etch rate, so that high energy rays such as EUV (Extreme Ultraviolet) or Beam (electron beam) can be used. It can be applied to the lithographic process used. The lithography process using high-energy rays is a lithography technology that uses EUV light of a very short wavelength such as 10 nm to 20 nm, for example, 13.5 nm, or light corresponding to the electron beam region, and uses ultra-fine patterns having a width of 20 nm or less. It is a process that can be formed.

In the case of the patterning process in which ultra-fine patterns are formed using high-energy rays such as EUV and E-Beam, not only the problem of reflection from the substrate but also the collapse of the pattern due to the miniaturization of the pattern, and the roughness of the sidewall of the photoresist pattern ) There may be a problem such as occurrence.

When the underlayer film is formed by the composition for a resist underlayer film including a polymer according to an embodiment, the solubility in a solvent is excellent, so that coating uniformity is improved, and surface roughness may be minimized. In addition, as the underlayer film formed of the composition for a resist underlayer film according to an embodiment has an optimized reflectance for the light source from the film to be etched, not only can the light interference effect be suppressed, but also the flatness is improved, resulting in the same problems as described above. Can be prevented.

Meanwhile, according to another embodiment, a resist underlayer film manufactured using the above-described composition for a resist underlayer film is provided. The resist underlayer film may be a form obtained by coating the above-described composition for a resist underlayer film, for example, on a substrate and then curing through a heat treatment process. The resist underlayer film may be, for example, an antireflection film.

Hereinafter, a method of forming a pattern using the above-described composition for a resist underlayer film will be described with reference to FIGS. 1 to 5.

1 to 5 are cross-sectional views illustrating a method of forming a pattern using the composition for a resist underlayer film according to the present invention.

Referring to FIG. 1, first, an object to be etched is prepared. An example of the object to be etched may be a thin film 102 formed on the semiconductor substrate 100. Hereinafter, only the case where the object to be etched is the thin film 102 will be described. The surface of the thin film is pre-cleaned to remove contaminants, etc. remaining on the thin film 102. The thin film 102 may be, for example, a silicon nitride film, a polysilicon film, or a silicon oxide film.

Subsequently, a composition for a resist underlayer film including a polymer and a solvent having a moiety represented by Formula 1 or a moiety represented by Formula 2 is coated on the surface of the cleaned thin film 102 by applying a spin coating method.

Thereafter, drying and baking processes are performed to form a resist underlayer layer 104 on the thin film. The baking treatment may be performed at 100 to 500, for example, 100 to 300. Since a more detailed description of the composition for a resist underlayer film has been described in detail above, it will be omitted to avoid redundancy.

Referring to FIG. 2, a photoresist layer 106 is formed by coating a photoresist on the resist underlayer layer 104.

Examples of the photoresist include a positive photoresist containing a naphthoquinone diazide compound and a novolac resin, an acid generator capable of dissociating an acid by exposure, and decomposition in the presence of an acid to increase solubility in an aqueous alkaline solution. Quantification of chemically amplified type photoresist containing alkali-soluble resin, chemically amplified type containing alkali-soluble resin with groups capable of imparting a resin that increases solubility in aqueous alkali solution by decomposition in the presence of an acid generator and acid Type photoresist, etc. are mentioned.

Subsequently, a first baking process of heating the substrate 100 on which the photoresist film 106 is formed is performed. The first baking process may be performed at a temperature of 90 to 120.

3, the photoresist layer 106 is selectively exposed.

When an exposure process for exposing the photoresist film 106 is described as an example, an exposure mask having a predetermined pattern formed on a mask stage of an exposure apparatus is positioned, and the exposure mask ( 110). Subsequently, by irradiating light to the mask 110, a predetermined portion of the photoresist film 106 formed on the substrate 100 selectively reacts with the light transmitted through the exposure mask.

As an example, examples of light that can be used in the exposure process include not only light having a short wavelength such as an activated irradiation i-line (365 nm), a KrF excimer laser (wavelength 248 nm), and an ArF excimer laser (wavelength 193 nm), but also EUV (Extreme and light having a high energy wavelength such as ultraviolet; wavelength 13.5 nm) and E-Beam (electron beam).

The photoresist film 106b at the exposed portion has a relatively hydrophilicity compared to the photoresist film 106a at the unexposed portion. Accordingly, the photoresist film of the exposed portion 106b and the non-exposed portion 106a has different solubility.

Subsequently, a second baking process is performed on the substrate 100. The second baking process may be performed at a temperature of 90 to 150. By performing the second baking process, the photoresist film corresponding to the exposed region is easily dissolved in a specific solvent.

Referring to FIG. 4, a photoresist pattern 108 is formed by dissolving and removing the photoresist film 106b corresponding to the exposed area using a developer. Specifically, the photoresist pattern 108 is completed by dissolving and removing the photoresist film corresponding to the exposed region using a developer such as tetra-methyl ammonium hydroxide (TMAH).

Next, the resist underlayer is etched using the photoresist pattern 108 as an etching mask. The organic layer pattern 112 is formed by the above etching process. The etching may be performed by dry etching using, for example, an etching gas, and the etching gas may be CHF ₃ , CF ₄ , Cl ₂ , BCl _3, and a mixed gas thereof. As described above, since the resist underlayer film formed by the resist underlayer composition according to an embodiment has a fast etching rate, a smooth etching process can be performed within a short time.

Referring to FIG. 5, the exposed thin film 102 is etched by applying the photoresist pattern 108 as an etching mask. As a result, the thin film is formed as a thin film pattern 114. In the exposure process performed previously, the thin film pattern 114 formed by the exposure process performed using an ArF light source may have a width of several tens to several hundred nm, and a thin film formed by the exposure process performed using an EUV light source. The pattern 114 may have a width of 20 nm or less.

Hereinafter, the present invention will be described in more detail through examples of the synthesis of the above-described polymer and the preparation of a composition for a resist underlayer film comprising the same. However, the technical limitations of the present invention are not limited by the following examples.

Synthesis example

Synthesis Example 1

1,3-diallyl-5-(2-hydroxyethyl)-isocyanurate (6.33 g, 0.025 mol), 1,3-diallyl-5-pentyl-isocyanurate (6.98 g, 0.025 mol), 1 in a 100 mL round flask equipped with a condenser. ,2-Ethanedithiol (3.77g, 0.04mol), AIBN (Azobisisobutyronitrile) (0.66g, 0.004mol), and 30g of N,N-dimethylformamide (DMF) were added, and the mixture was stirred using a magnetic bar and the temperature was raised to 80℃. The polymerization reaction proceeded. After the reaction for 4 hours, 1-Mercaptohexane (2.96.025 mol) and AIBN (0.33 g, 0.002 mol) were added and reacted for an additional 2 hours to produce a polymerization reaction product including the structural unit of Formula 7. After completion of the reaction, lower the temperature to room temperature (23℃~25℃), dilute with 80 g of tetrahydrofuran (THF), and purify 4 times using toluene and IPA (Isopropyl alcohol) to remove low molecules and catalyst. A polymer containing the structural unit of Formula 4 (molecular weight (Mw) = 8,000) was obtained.

[Formula 4]

Synthesis Example 2

1,3-diallyl-5-(2-hydroxyethyl)-isocyanurate (12.7g, 0.05mol), Biphenyl-4,4'-dithiol (8.73g, 0.04mol), AIBN (0.66g) in a 250mL round flask equipped with a condenser. , 0.004mol) and 57g of DMF were added, and the temperature was raised while stirring using a magnetic bar, and the polymerization reaction proceeded to 80°C. After the reaction for 8 hours, 1-Mercaptohexane (2.96.025 mol) and AIBN (0.33 g, 0.002 mol) were added and reacted for an additional 3 hours to produce a polymerization reaction product including the structural unit of Formula 8. After completion of the reaction, lower the temperature to room temperature (23℃~25℃), dilute with THF 80g, and purify 4 times with toluene and IPA (Isopropyl alcohol) to remove low molecules and catalysts. Finally, the structural unit of formula 5 A polymer containing (molecular weight (Mw) = 3,500) was obtained.

[Formula 5]

Synthesis example 3

1,3-diallyl-5-methyl-isocyanurate (11.2 g, 0.05 mol), 1,4-Dithioerythritol (6.17 g, 0.04 mol), AIBN (0.66 g, 0.004 mol), and DMF 30 g in a 100 mL round flask equipped with a condenser. After putting in, the temperature was raised while stirring using a magnetic bar, and the polymerization reaction proceeded to 80°C. After the reaction for 4 hours, 1-Mercaptohexane (2.96.025 mol) and AIBN (0.33 g, 0.002 mol) were added and reacted for an additional 2 hours to produce a polymerization reaction product including the structural unit of Formula 9. After completion of the reaction, lower the temperature to room temperature (23℃~25℃), dilute with THF 80g, and purify 4 times with toluene and IPA (Isopropyl alcohol) to remove low molecules and catalysts. Finally, the structural unit of formula 6 A polymer containing (molecular weight (Mw) = 7,000) was obtained.

[Formula 6]

Synthesis Example 4

Bisphenol A diallyl ether (15.4g, 0.05mol), 1,4-Dithioerythritol (6.17g, 0.04mol), AIBN (0.66g, 0.004mol), and 56g of DMF were added to a 250mL round flask equipped with a condenser, and then using a magnetic bar. The temperature was raised while stirring, and the polymerization reaction proceeded to 80°C. After the reaction for 4 hours, 1-Mercaptobutane (2.25.025 mol) and AIBN (0.33 g, 0.002 mol) were added and reacted for an additional 2 hours to produce a polymerization reaction product including the structural unit of Formula 10. After completion of the reaction, lower the temperature to room temperature (23℃~25℃), dilute with THF 80g, and purify 4 times with toluene and IPA (Isopropyl alcohol) to remove low molecules and catalysts. Finally, the structural unit of formula 7 A polymer containing (molecular weight (Mw) = 6,500) was obtained.

[Formula 7]

Comparative synthesis example

Methyl methacrylate (40g), 2-hydroxyacrylate (52.1g), Benzyl acrylate (70.4g), AIBN (2g), and Dioxane (306g) were added to a 500ml 2-neck round flask, and a condenser was connected. The temperature was raised to 80° C., and after reaction for 2.5 hours, the reaction solution was cooled to room temperature. The reaction solution was transferred to a 3 L light bulb and washed with hexane. The obtained resin was dried in a vacuum oven at 30° C. to remove the residual solvent, thereby finally obtaining a polymer (Mw = 12,000) containing a moiety represented by the following formula (12).

[Formula 12]

Preparation of composition for resist underlayer film

Example 1

After dissolving the polymer prepared from Synthesis Example 1 and Pyridinium p-toluenesulfonate (1 part by weight relative to 100 parts by weight of the polymer) in a mixed solvent of propylene glycol monomethyl ether and ethyl lactate (mixed weight ratio = 1:1), for 6 hours By stirring, a composition for a resist underlayer film was prepared.

The amount of the mixed solvent used was 1% by weight based on the total content of the composition for a resist underlayer film in which the polymer solid content was prepared.

Example 2

It was carried out in the same manner as in Example 1, except that the polymer of Synthesis Example 2 was used.

Example 3

It was carried out in the same manner as in Example 1, except that the polymer of Synthesis Example 3 was used.

Example 4

It was carried out in the same manner as in Example 1, except that the polymer of Synthesis Example 4 was used.

Comparative Example 1

It was carried out in the same manner as in Example 1, except that the polymer of Comparative Synthesis Example 1 was used.

evaluation

Evaluation 1: Coating uniformity

2 ml of each of the compositions prepared from Examples 1 to 4 and Comparative Example 1 were each applied onto an 8-inch wafer, and then spin-coated at a main spin speed of 1,500 rpm using an auto track (TEL ACT-8) for 20 seconds. After proceeding, curing at 210° C. for 90 seconds to form a 300 nm-thick thin film. The thickness of 51 points was measured along the horizontal axis to compare coating uniformity, and the results are shown in Table 1 below.

The smaller the coating uniformity (%) value, the better the coating uniformity.

Coating uniformity(%) Example 1 1.5 Example 2 2.1 Example 3 1.9 Example 4 1.8 Comparative Example 1 3.3

Evaluation 2: Contact angle

2 ml each of the compositions prepared from Examples 1 to 4 and Comparative Example 1 were each applied onto a 4-inch wafer, and then spin-coated at 1,500 rpm for 20 seconds using a spin coater (Mikasa). Thereafter, curing was performed at 210° C. for 90 seconds to form a thin film, and the contact angle when distilled water (DIW) was dropped on the surface was measured. The measured contact angle is as described in Table 2 below.

It can be seen that the greater the contact angle, the better the adhesion to the resist.

Contact angle (°) Example 1 72 Example 2 69 Example 3 69 Example 4 68 Comparative Example 1 62

In the above, although specific embodiments of the present invention have been described and illustrated, the present invention is not limited to the described embodiments, and various modifications and variations can be made without departing from the spirit and scope of the present invention. It is self-evident to those who have. Therefore, such modifications or variations should not be individually understood from the technical spirit or point of view of the present invention, and the modified embodiments should be said to belong to the claims of the present invention.

100: substrate 102: thin film
104: resist underlayer film 106: photoresist film
108: photoresist pattern 110: mask
112: organic layer pattern 114: thin film pattern

Claims (17)

A polymer comprising a moiety represented by the following formula (1) or a moiety represented by the following formula (2); And a composition for a resist underlayer film containing a solvent:
[Formula 1]

A is a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C3 to C10 cycloalkylene group, a substituted or unsubstituted C2 to C10 heterocycloalkylene group, a substituted or unsubstituted C6 to C30 arylene group , A substituted or unsubstituted C2 to C30 heteroarylene group, or a combination thereof,
R ² is any one of a C5 to C30 alkyl group, a C3 to C30 cycloalkyl group, and a C6 to C30 aryl group,
L ³ to L ⁶ are each independently a single bond, a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof,
X ² and X ³ are each independently a single bond, -S-, -S(=O)-, -S(=O) ₂ -, a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, substituted or unsubstituted C2 to C10 alkynylene group, substituted or unsubstituted C3 to C10 cycloalkylene group, substituted or unsubstituted C2 to C10 heterocycloalkylene group, substituted or It is an unsubstituted C6 to C30 arylene group, or a combination thereof,
d to i are each independently an integer of 0 to 10,
* Is the connection point,
[Formula 2]

In Chemical Formula 2,
A is a substituted C1 to C20 alkylene group, a substituted C3 to C10 cycloalkylene group, a substituted C2 to C10 heterocycloalkylene group, a substituted C6 to C30 arylene group, a substituted C2 to C30 heteroarylene group, or these Wherein the substituent of A includes at least one of a C5 to C30 alkyl group, a C3 to C30 cycloalkyl group, and a C6 to C30 aryl group,
L ⁹ to L ¹² are each independently a single bond, a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof,
X ⁵ and X ⁶ are each independently a single bond, -S-, -S(=O)-, -S(=O) ₂ -, a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, substituted or unsubstituted C2 to C10 alkynylene group, substituted or unsubstituted C3 to C10 cycloalkylene group, substituted or unsubstituted C2 to C10 heterocycloalkylene group, substituted or It is an unsubstituted C6 to C30 arylene group, or a combination thereof,
m to r are each independently an integer of 0 to 10,
* Is the connection point. In claim 1,
In Formula 1,
A is a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C3 to C10 cycloalkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof, a composition for a resist underlayer film. In claim 1,
In Formula 1,
X ² and X ³ are each independently a single bond or -S-,
L ³ and L ⁵ are each independently a substituted or unsubstituted C6 to C30 arylene group,
L ⁴ and L ⁶ are each independently a single bond, a substituted or unsubstituted C1 to C20 alkylene group, a composition for a resist underlayer film. In claim 1,
Formula 1 and Formula 2 are each represented by the following Formula 1-1 and Formula 2-1, a composition for a resist underlayer film:
[Formula 1-1]

[Formula 2-1]

In Formula 1 and Formula 2,
R ¹ is hydrogen, deuterium, -F (fluoro group), -Cl (chloro group), -Br (bromo group), -I (iodo group), hydroxyl group, cyano group, nitro group, amino group, amidino Group, carboxyl group or salt thereof, sulfonic acid group or salt thereof, phosphoric acid group or salt thereof, substituted or unsubstituted C1 to C30 alkyl group, substituted or unsubstituted C2 to C30 alkenyl group, substituted or unsubstituted C2 to C30 Alkynyl group, substituted or unsubstituted C1 to C10 alkoxy group, substituted or unsubstituted C3 to C10 cycloalkyl group, substituted or unsubstituted C2 to C10 heterocycloalkyl group, substituted or unsubstituted C6 to C30 aryl A group, a substituted or unsubstituted C6 to C30 aryloxy group, a substituted or unsubstituted C6 to C30 arylthio group, or a combination thereof,
R ² and R ³ are each independently any one of a C5 to C30 alkyl group, a C3 to C30 cycloalkyl group, and a C6 to C30 aryl group,
L ¹ to L ¹² are each independently a single bond, a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof,
X ¹ to X ⁶ are each independently a single bond, -S-, -S(=O)-, -S(=O) ₂ -, a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, substituted or unsubstituted C2 to C10 alkynylene group, substituted or unsubstituted C3 to C10 cycloalkylene group, substituted or unsubstituted C2 to C10 heterocycloalkylene group, substituted or It is an unsubstituted C6 to C30 arylene group, or a combination thereof,
a to r are each independently an integer of 0 to 10,
* Is the connection point. In claim 4,
In Formula 1-1,
R ¹ is hydrogen, deuterium, -F, -Cl, a hydroxyl group, a cyano group, a nitro group, an amino group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, or a substituted or unsubstituted C3 to C30 Is an alkyl group of,
R ² in Formula 1 is a C5 to C30 alkyl group,
At least one of X ¹ to X ³ is -S-,
L ¹ to L ⁶ are each independently a single bond, or a substituted or unsubstituted C1 to C20 alkylene group,
a to i are each independently an integer of 0 to 5, the composition for a resist underlayer film. In claim 4,
R ³ in Formula 2-1 is a C5 to C30 alkyl group,
At least one of X ⁴ to X ⁶ is -S-,
L ⁷ to L ¹² are each independently a single bond or a substituted or unsubstituted C1 to C20 alkylene group,
j to r are each independently an integer of 0 to 5, the composition for a resist underlayer film. In claim 1,
A composition for a resist underlayer film comprising a first moiety represented by Formula 1 or Formula 2, and a second moiety represented by Formula 2 and comprising A different from the first moiety. In clause 7,
The second moiety is in Formula 2,
A is a substituted C1 to C20 alkylene group, a substituted C3 to C10 cycloalkylene group, a substituted C2 to C10 heterocycloalkylene group, a substituted C6 to C30 arylene group, a substituted C2 to C30 heteroarylene group, or these Wherein the substituent of A includes at least one of a C5 to C30 alkyl group, a C3 to C30 cycloalkyl group, and a C6 to C30 aryl group,
L ⁹ to L ¹² are each independently a single bond, a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof,
X ⁵ and X ⁶ are each independently -S-,
m to r are each independently an integer of 0 to 5, the composition for a resist underlayer film. In claim 1,
X ² and X ³ of Formula 1, and X ⁵ and X ⁶ of Formula 2 are each independently a composition for a resist underlayer film represented by the following Formula 3:
[Formula 3]

In Chemical Formula 3,
R ^a to R ^c are each independently a substituted or unsubstituted C1 to C5 alkylene group, a substituted or unsubstituted C6 to C30 arylene group, or a combination thereof,
X ^a and X ^b are each independently -S-,
na to ne are each independently an integer of 0 to 5,
Here, "substituted" means that a hydrogen atom is substituted with a C1 to C5 alkyl group, a hydroxy group, or a thiol group. The method of claim 1,
The polymer is a composition for a resist underlayer film comprising at least one of the moieties represented by the following Formulas 4 to 7:
[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

. The method of claim 1,
A composition for a resist underlayer film having a weight average molecular weight of 1,000 to 100,000 of the polymer. The method of claim 1,
The polymer is 0.1 to 50% by weight, based on the total content of the composition, the resist underlayer composition containing. The method of claim 1,
The composition further comprises a crosslinking agent having two or more crosslinking sites for a resist underlayer film. The method of claim 1,
The composition is a composition for a resist underlayer film further comprising a surfactant, a thermal acid generator, a plasticizer, or an additive of a combination thereof. Forming a layer to be etched on the substrate,
Forming a resist underlayer film by applying the composition for a resist underlayer film according to any one of claims 1 to 14 on the etching target film,
Forming a photoresist pattern on the resist underlayer film, and
And sequentially etching the resist underlayer layer and the etching target layer by using the photoresist pattern as an etching mask. The method of claim 15,
The step of forming the photoresist pattern
Forming a photoresist film on the resist underlayer film,
Exposing the photoresist film, and
And developing the photoresist film. The method of claim 15,
The step of forming the resist underlayer film further comprises performing heat treatment at a temperature of 100°C to 500°C after coating the composition for the resist underlayer film.

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