KR20230020811A - Resist underlayer composition, and method of forming patterns using the composition - Google Patents

Abstract

The invention relates to a composition for a resist underlayer film and a method for forming a pattern using the composition for a resist underlayer film, comprising: a polymer A including a heterocycle containing at least two nitrogen atoms; a compound B comprising at least a single ring, a fused ring in which two or more single rings are fused, and a non-fused ring in which two or more single rings are connected by a single bond, substituted or unsubstituted C1 to C5 alkylene group, O or C(O), wherein the single ring is a substituted or unsubstituted C6 to C30 aromatic ring or a substituted or unsubstituted C2 to C30 heteroaromatic ring, and includes at least 5 such single rings in a structural unit; and a solvent. Accordingly, the present invention can be advantageously used in forming fine patterns of photoresist using a high-energy light source.

Description

Composition for resist underlayer film and pattern formation method using the same {RESIST UNDERLAYER COMPOSITION, AND METHOD OF FORMING PATTERNS USING THE COMPOSITION}

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

In recent years, the semiconductor industry has been developing from hundreds of nanometer-sized patterns to ultra-fine technologies having several to several tens of nanometer-sized patterns. Effective lithographic techniques are essential to realize these ultra-fine technologies.

The lithographic technique coats a photoresist film on a semiconductor substrate such as a silicon wafer to form a thin film, irradiates activating radiation such as ultraviolet rays through a mask pattern on which a device pattern is drawn, and then develops the obtained photoresist pattern. It is a processing method of forming a fine pattern corresponding to the pattern on the surface of the substrate by etching the substrate as a protective film.

An exposure process performed in the photoresist pattern forming step is one of the important factors for obtaining a high-resolution photoresist image.

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 used as activating radiation used for photoresist exposure. Accordingly, in order to solve problems caused by diffuse reflection or standing waves of activating radiation from a semiconductor substrate, a resist underlayer having an optimized reflectance between the resist and the semiconductor substrate is interposed to solve many studies. there is.

On the other hand, in addition to the activation radiation, a method of using high-energy rays such as EUV (Extreme ultraviolet; wavelength 13.5 nm) and E-Beam (electron beam) as a light source for fine pattern production has also been made, and in the case of the light source, reflection from the substrate has been made. Although there is little, the thickness of the resist underlayer film has to be further thinned according to pattern refinement, and research on improving the adhesion between the resist and the underlayer film has been widely reviewed to improve the collapse of the formed pattern. In addition, in order to maximize the efficiency of the light source, research on improving sensitivity through an underlayer film is being reviewed.

Provided is a composition for a resist underlayer film that does not cause pattern collapse of the resist even in a fine patterning process, is formed into a thin film, can shorten an etching process time, and improves patterning performance and efficiency by improving sensitivity to an exposure light source.

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

One embodiment, Polymer A including a hetero ring containing at least two nitrogen atoms; At least one of a single ring, a fused ring in which two or more single rings are fused, and an unfused ring in which two or more single rings are connected by a single bond, a substituted or unsubstituted C1 to C5 alkylene group, O or C(O) Compound B, wherein the single ring is a substituted or unsubstituted C6 to C30 aromatic ring or a substituted or unsubstituted C2 to C30 heteroaromatic ring, and includes at least 5 of the single rings in a structural unit; and a solvent for a resist underlayer film.

The polymer A may include at least one structural unit represented by Chemical Formulas 1 to 5 below.

[Formula 1]

[Formula 2]

[Formula 3] [Formula 4]

[Formula 5]

In Formulas 1 to 5,

Ring A is a heterocycle containing at least 2 nitrogen atoms,

R ¹ to R ⁶ are each independently hydrogen, heavy hydrogen, a halogen group, a hydroxyl group, a cyano group, a nitro group, an amino group, an epoxy group, a vinyl group, an allyl group, a (meth)acrylate group, an oxetane group, and a thiol group. , Carboxyl group, substituted or unsubstituted C1 to C10 alkyl group, substituted or unsubstituted C2 to C10 alkenyl group, substituted or unsubstituted C2 to C10 alkynyl group, substituted or unsubstituted C1 to C10 heteroalkyl group, substituted or unsubstituted a substituted or unsubstituted C1 to C10 heteroalkenyl group, a substituted or unsubstituted C1 to C10 heteroalkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 heterocycloalkyl group, a substituted or unsubstituted C6 to C20 heterocycloalkyl group, A C20 aryl group, a substituted or unsubstituted C1 to C20 heteroaryl group, or a combination thereof;

L ¹ to L ¹² are each independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C1 to C10 cycloalkylene group, An unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, a substituted or unsubstituted C1 to C20 heteroarylene group, or a combination thereof,

X ¹ to X ⁸ are each independently -O-, -S-, -S(O)-, -S(O) ₂ -, -C(O)-, -(CO)O-, -O( CO), -O(CO)O-, -NR'- (where R”” is hydrogen, deuterium, or a C1 to C10 alkyl group), or a combination thereof,

Y ¹ and Y ² are each independently a halogen group, a hydroxyl group, a cyano group, a nitro group, an amino group, an epoxy group, a vinyl group, an allyl group, a (meth)acrylate group, an oxetane group, a thiol group, a carboxyl group, or is a combination of these

* is a connection point.

Wherein R ¹ to R ⁶ are each independently hydrogen, a hydroxyl group, an epoxy group, a vinyl group, an allyl group, a (meth)acrylate group, an oxetane group, a thiol group, a carboxyl group, a substituted or unsubstituted C1 to C10 alkyl group , A substituted or unsubstituted C1 to C10 heteroalkyl group, or a combination thereof,

Wherein L ¹ to L ¹² are each independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, or a combination thereof;

The X ¹ to X ⁸ may each independently be -O-, -S-, -C(O)-, -(CO)O-, -O(CO), or a combination thereof.

The heterocycle including at least two nitrogen atoms may be at least one of structures represented by Formulas A-1 to A-8 below.

[Formula A-1] [Formula A-2] [Formula A-3] [Formula A-4]

[Formula A-5] [Formula A-6] [Formula A-7] [Formula A-8]

In Formula A-1 to Formula A-8,

R ^a , R ^b , R ^x and R ^y are each independently hydrogen, heavy hydrogen, a halogen group, a hydroxy group, a cyano group, a nitro group, an amino group, an epoxy group, a vinyl group, a (meth)acrylate group, an oxetane group , Thiol group, carboxyl group, 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 an unsubstituted C1 to C30 thioalkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C6 to C30 aryloxy group, a substituted or unsubstituted A C6 to C30 thioaryl group, a substituted or unsubstituted C2 to C30 heteroaryl group, or a combination thereof;

L ^a and L ^b are each independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C1 to C10 cycloalkylene group, An unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, a substituted or unsubstituted C1 to C20 heteroarylene group, or a combination thereof,

* is a linkage point within the polymer, respectively.

Wherein R ^a and R ^b are each independently hydrogen, a hydroxyl group, an epoxy group, a vinyl group, an allyl group, a (meth)acrylate group, an oxetane group, a thiol group, a carboxyl group, a substituted or unsubstituted C1 to C10 alkyl group , A substituted or unsubstituted C1 to C10 heteroalkyl group, or a combination thereof,

Wherein R ^x and R ^y are each independently hydrogen, a hydroxyl group, an epoxy group, a vinyl group, an allyl group, a (meth)acrylate group, an oxetane group, a thiol group, a carboxyl group, a substituted or unsubstituted C1 to C10 alkyl group , A substituted or unsubstituted C1 to C10 heteroalkyl group, or a combination thereof,

L ^a and L ^b may each independently be a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, or a combination thereof.

The polymer A may include at least one structural unit represented by Chemical Formulas 6 to 11 below.

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

[Formula 10]

[Formula 11]

In Formulas 6 to 11,

* is a point connected to the main chain, side chain or terminal group of the polymer.

The polymer A may include at least one structural unit represented by Chemical Formulas 12 to 16, and the weight average molecular weight of the polymer A may be 2,000 g/mol to 300,000 g/mol.

[Formula 12]

[Formula 13]

[Formula 14] [Formula 15]

[Formula 16]

In Formulas 12 to 16,

* is a point connected to the main chain, side chain or terminal group of the polymer.

The single ring, fused ring, and non-fused ring may include at least one structure listed in Group I below.

[Group I]

In Group I,

Z ¹ is a single bond, a substituted or unsubstituted C1 to C5 alkylene group, O or C(O);

Z ³ to Z ¹⁸ are each independently C(O), NR ^c , O, S, CR ^d R ^e or a combination thereof;

R ^c to R ^e are each independently hydrogen, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C2 to C20 heteroaryl group, a halogen atom, or a halogen-containing group. , or a combination thereof.

The single ring, the fused ring, and the non-fused ring may be at least one of structures represented by Chemical Formulas B-1 to Chemical Formulas B-5.

[Formula B-1]

[Formula B-2]

[Formula B-3]

[Formula B-4]

[Formula B-5]

In Formula B-1 to Formula B-5,

R ^f is hydrogen, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C2 to C20 heteroaryl group, or a combination thereof;

* is a connection point.

The compound B may include at least one structural unit represented by Chemical Formulas 17 to 19 below.

[Formula 17]

[Formula 18]

[Formula 19]

In Formulas 17 to 19,

L ¹³ to L ¹⁸ are each independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C1 to C10 cycloalkylene group, An unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, a substituted or unsubstituted C1 to C20 heteroarylene group, or a combination thereof,

* is a point connected to the main chain, side chain or terminal group of the compound.

The compound B may be any one of a single molecule, an oligomer, and a polymer including at least one structural unit represented by any one of Formulas 20 to 22 below.

[Formula 20]

[Formula 21]

[Formula 22]

In Formulas 20 to 22,

* is a point connected to the main chain, side chain or terminal group.

The compound B may be a single molecule or an oligomer, and may have a molecular weight of 300 to 3,000 g/mol.

The compound B is a polymer, and may have a weight average molecular weight of 1,000 g/mol to 50,000 g/mol.

The composition may include the polymer A and the compound B in a weight ratio of 90:10 to 10:90.

A total weight of the polymer A and the compound B may be included in an amount of 0.1 wt% to 50 wt% based on the total weight of the resist underlayer composition.

The composition may further include one or more polymers selected from acrylic resins, epoxy resins, novolak-based resins, glycoluril-based resins, and melamine-based resins.

The composition may further include an additive including a surfactant, a thermal acid generator, a plasticizer, or a combination thereof.

In another embodiment, forming a film to be etched on a substrate, forming a resist underlayer film by applying the composition for a resist underlayer film according to an embodiment onto the film to be etched, forming a photoresist pattern on the resist underlayer film and sequentially etching the resist underlayer layer and the etch target layer using the photoresist pattern as an etching mask.

The forming of the photoresist pattern may include forming a photoresist layer on the resist underlayer, exposing the photoresist layer, and developing the photoresist layer.

The forming of the resist underlayer film may further include heat treatment at a temperature of 100° C. to 500° C. after coating the composition for the resist underlayer film.

The composition for a resist underlayer film according to an embodiment is capable of forming an ultra-thin film for a predetermined wavelength such as EUV, and has excellent coating properties, planarization properties, and adhesion to a photoresist, and is suitable for solutions used during a lithography process. A resist underlayer film having excellent chemical resistance and a fast etch rate can be provided. Therefore, the composition for a resist underlayer film according to one embodiment or a resist underlayer film prepared therefrom may be advantageously used for forming a fine pattern of a photoresist using a high-energy light source such as EUV.

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 skilled in the art can easily implement the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments set forth herein.

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

Unless otherwise defined herein, 'substituted' means that a hydrogen atom in a 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, an amino group A dino group, a hydrazino group, a hydrazono group, a carbonyl group, a carbamyl group, a thiol group, an ester group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a vinyl group, a C1 to C20 alkyl group, a C2 to C20 alkene 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 means substituted with a substituent selected from combinations thereof.

In addition, unless otherwise defined herein, 'hetero' means containing 1 to 10 heteroatoms each independently selected from N, O, S and P.

Unless otherwise specified in the present specification, the weight average molecular weight is measured by dissolving the powder sample in tetrahydrofuran (THF) and then using Agilent Technologies' 1200 series Gel Permeation Chromatography (GPC) (column is Shodex). company LF-804, standard sample used Shodex polystyrene).

In addition, unless otherwise defined herein, '*' indicates a structural unit of a compound or a connecting point of a compound moiety.

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

The present invention prevents the collapse of the resist pattern during the micro-pattern formation process of photolithography using a short-wavelength light source such as an ArF excimer laser (wavelength 193 nm) or a high-energy ray such as EUV (Extreme ultraviolet; wavelength 13.5 nm), and is coated with an ultra-thin film The present invention relates to a composition for a resist underlayer film capable of reducing an etching process time and improving photoresist patterning by improving sensitivity to an exposure light source, and a method of forming a photoresist pattern using such an underlayer film.

Specifically, a composition for a resist underlayer film according to an embodiment includes a polymer A including a heterocycle containing at least 2 nitrogen atoms; At least one of a single ring, a fused ring in which two or more single rings are fused, and an unfused ring in which two or more single rings are connected by a single bond, a substituted or unsubstituted C1 to C5 alkylene group, O or C(O) Compound B, wherein the single ring is a substituted or unsubstituted C6 to C30 aromatic ring or a substituted or unsubstituted C2 to C30 heteroaromatic ring, and includes at least 5 of the single rings in a structural unit; and a solvent.

By applying the composition according to one embodiment to the lower part of the photoresist to form a film, the adhesion between the film and the photoresist is improved, and the collapse of the resist pattern can be prevented even during the fine petering process, and sensitivity to exposure light sources As is improved, it is possible to improve the patterning performance and efficiency of the photoresist. In addition, since an ultra-thin lower layer film can be formed using the composition, there is an advantage in that the time of the etching process can be shortened.

Among the components included in the composition, compound B has a polycyclic structure including at least 5 single rings in a structural unit, thereby improving film density. Specifically, due to the polycyclic structure, the electron density increases, and accordingly, the density of the thin film can be improved to realize an ultra-thin film form with a dense structure, and high-voltage Energy efficiency can be improved upon pattern formation after exposure using energy rays.

Among the components included in the composition, polymer A has an excellent etch selectivity as it includes a heterocycle containing at least two nitrogen atoms, such as an isocyanurate backbone or a triazine backbone, and the film density of the resist underlayer film And it can help with ultra-thin coating properties.

Therefore, when the resist underlayer film composition according to one embodiment is used, it is possible to form a resist underlayer film with improved adhesion and chemical resistance and reduced thickness, and through this, a faster etching effect can be expected compared to the upper photoresist, and It is possible to improve the patterning performance by improving the light absorption efficiency.

For example, the polymer A may include at least one structural unit represented by Chemical Formulas 1 to 5 below.

[Formula 1]

[Formula 2]

[Formula 3] [Formula 4]

[Formula 5]

In Formulas 1 to 5,

Ring A is a heterocycle containing at least 2 nitrogen atoms,

R ¹ to R ⁶ are each independently hydrogen, heavy hydrogen, a halogen group, a hydroxyl group, a cyano group, a nitro group, an amino group, an epoxy group, a vinyl group, an allyl group, a (meth)acrylate group, an oxetane group, and a thiol group. , Carboxyl group, substituted or unsubstituted C1 to C10 alkyl group, substituted or unsubstituted C2 to C10 alkenyl group, substituted or unsubstituted C2 to C10 alkynyl group, substituted or unsubstituted C1 to C10 heteroalkyl group, substituted or unsubstituted a substituted or unsubstituted C1 to C10 heteroalkenyl group, a substituted or unsubstituted C1 to C10 heteroalkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 heterocycloalkyl group, a substituted or unsubstituted C6 to C20 heterocycloalkyl group, A C20 aryl group, a substituted or unsubstituted C1 to C20 heteroaryl group, or a combination thereof;

L ¹ to L ¹² are each independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C1 to C10 cycloalkylene group, An unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, a substituted or unsubstituted C1 to C20 heteroarylene group, or a combination thereof,

X ¹ to X ⁸ are each independently -O-, -S-, -S(O)-, -S(O) ₂ -, -C(O)-, -(CO)O-, -O( CO), -O(CO)O-, -NR'- (where R”” is hydrogen, deuterium, or a C1 to C10 alkyl group), or a combination thereof,

Y ¹ and Y ² are each independently a halogen group, a hydroxyl group, a cyano group, a nitro group, an amino group, an epoxy group, a vinyl group, an allyl group, a (meth)acrylate group, an oxetane group, a thiol group, a carboxyl group, or is a combination of these

* is a connection point.

In one embodiment, R ¹ to R ⁶ of Formulas 1 to 5 are each independently selected from hydrogen, a hydroxyl group, an epoxy group, a vinyl group, an allyl group, a (meth)acrylate group, an oxetane group, a thiol group, and a carboxyl group. , A substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C1 to C10 heteroalkyl group, or a combination thereof,

L ¹ to L ¹² are each independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, or a combination thereof;

X ¹ to X ⁸ may each independently be -O-, -S-, -C(O)-, -(CO)O-, -O(CO), or a combination thereof.

In a specific embodiment, R ¹ to R ⁶ in Formulas 1 to 5 are each independently hydrogen, a hydroxyl group, a (meth)acrylate group, a thiol group, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or An unsubstituted C1 to C10 thioalkyl group, or a combination thereof;

L ¹ to L ¹² are each independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, or a combination thereof;

X ¹ to X ⁸ may each independently be -O-, -S-, -C(O)-, -(CO)O-, -O(CO), or a combination thereof.

For example, the heterocycle including at least two nitrogen atoms may be at least one of structures represented by Formulas A-1 to A-8 below.

[Formula A-1] [Formula A-2] [Formula A-3] [Formula A-4]

[Formula A-5] [Formula A-6] [Formula A-7] [Formula A-8]

In Formula A-1 to Formula A-8,

R ^a , R ^b , R ^x and R ^y are each independently hydrogen, heavy hydrogen, a halogen group, a hydroxy group, a cyano group, a nitro group, an amino group, an epoxy group, a vinyl group, a (meth)acrylate group, an oxetane group , Thiol group, carboxyl group, 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 an unsubstituted C1 to C30 thioalkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C6 to C30 aryloxy group, a substituted or unsubstituted A C6 to C30 thioaryl group, a substituted or unsubstituted C2 to C30 heteroaryl group, or a combination thereof;

L ^a and L ^b are each independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C1 to C10 cycloalkylene group, An unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, a substituted or unsubstituted C1 to C20 heteroarylene group, or a combination thereof,

* is a linkage point within the polymer, respectively.

In one embodiment, R ^a and R ^b in Chemical Formulas A-1 to Chemical Formulas A-8 are each independently selected from hydrogen, a hydroxyl group, an epoxy group, a vinyl group, an allyl group, a (meth)acrylate group, and an oxetane group. , A thiol group, a carboxyl group, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C2 to C10 alkynyl group, a substituted or unsubstituted C1 to C10 heteroalkyl group, or is a combination of these

R ^x and R ^y are each independently hydrogen, a hydroxyl group, an epoxy group, a vinyl group, an allyl group, a (meth)acrylate group, an oxetane group, a thiol group, a carboxyl group, a substituted or unsubstituted C1 to C10 alkyl group, A substituted or unsubstituted C1 to C10 heteroalkyl group, or a combination thereof;

L ^a and L ^b may each independently be a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, or a combination thereof.

In a specific embodiment, R ^a and R ^b in Formulas A-1 to Formula A-8 are each independently a hydroxyl group, an epoxy group, an allyl group, a substituted or unsubstituted C1 to C10 alkyl group, or a substituted or unsubstituted is a C2 to C10 alkenyl group,

R ^x and R ^y are each independently a substituted or unsubstituted C1 to C10 alkyl group,

L ^a and L ^b may each independently be a substituted or unsubstituted C1 to C10 alkylene group.

For example, the polymer A may include at least one structural unit represented by Chemical Formulas 6 to 11 below.

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

[Formula 10]

[Formula 11]

In Formulas 6 to 11,

* is a point connected to the main chain, side chain or terminal group of the polymer.

For example, the polymer A may include at least one structural unit represented by Chemical Formulas 12 to 16, and the weight average molecular weight of the polymer A may be 2,000 g/mol to 300,000 g/mol.

[Formula 12]

[Formula 13]

[Formula 14] [Formula 15]

[Formula 16]

In Formulas 12 to 16,

* is a point connected to the main chain, side chain or terminal group of the polymer.

More specifically, the polymer A is 3,000 g/mol to 300,000 g/mol, such as 3,000 g/mol to 200,000 g/mol, such as 3,000 g/mol to 100,000 g/mol, such as 3,000 g/mol to 90,000 g/mol, such as 3,000 g/mol to 70,000 g/mol, such as 3,000 g/mol to 70,000 g/mol, such as 3,000 g/mol to 50,000 g/mol, such as 5,000 g / mol to 50,000 g / mol, for example, may have a weight average molecular weight of 5,000 g / mol to 30,000 g / mol, but is not limited thereto. When the weight average molecular weight of the polymer A is within the above range, it may be optimized by adjusting the carbon content of the composition for a resist underlayer film including the polymer A and the solubility in a solvent.

For example, the single ring, the fused ring, and the non-fused ring may include at least one structure listed in Group I below.

[Group I]

In Group I,

Z ¹ is a single bond, a substituted or unsubstituted C1 to C5 alkylene group, O or C(O);

Z ³ to Z ¹⁸ are each independently C(O), NR ^c , O, S, CR ^d R ^e or a combination thereof;

R ^c to R ^e are each independently hydrogen, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C2 to C20 heteroaryl group, a halogen atom, or a halogen-containing group. , or a combination thereof.

As a specific example, the single ring, the fused ring, and the non-fused ring may be at least one of structures represented by Chemical Formulas B-1 to Chemical Formulas B-5.

[Formula B-1]

[Formula B-2]

[Formula B-3]

[Formula B-4]

[Formula B-5]

In Formula B-1 to Formula B-5,

R ^f is hydrogen, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C2 to C20 heteroaryl group, or a combination thereof;

* is a connection point.

For example, the compound B may include at least one structural unit represented by Chemical Formulas 17 to 19 below.

[Formula 17]

[Formula 18]

[Formula 19]

In Formulas 17 to 19,

L ¹³ to L ¹⁸ are each independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C1 to C10 cycloalkylene group, An unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, a substituted or unsubstituted C1 to C20 heteroarylene group, or a combination thereof,

* is a point connected to the main chain, side chain or terminal group of the compound.

In one embodiment, the compound B may be any one of a single molecule, an oligomer, and a polymer including at least one structural unit represented by any one of Formulas 20 to 22 below.

[Formula 20]

[Formula 21]

[Formula 22]

In Formulas 20 to 22,

* is a point connected to the main chain, side chain or terminal group.

For example, the compound B may be a single molecule or an oligomer, and may have a molecular weight of 300 to 3,000 g/mol.

For example, the compound B is a polymer and may have a weight average molecular weight of 1,000 g/mol to 50,000 g/mol.

When the compound B is a single molecule or an oligomer, the molecular weight may be more specifically 500 to 3000 g/mol, for example, 500 to 2000 g/mol, and when the compound B is a polymer, the weight average molecular weight is more specifically 1,000 g/mol to 30,000 g/mol, such as 1,000 g/mol to 20,000 g/mol, such as 1,000 g/mol to 10,000 g/mol. When the molecular weight or weight average molecular weight of the compound B is within the above range, the film density of the resist underlayer film to be prepared is improved, so that the photoresist pattern may be prevented from being damaged or collapsed during the patterning process.

Meanwhile, the composition may include the polymer A and the compound B in a weight ratio of 90:10 to 10:90, for example 80:20 to 20:80, for example 75:25 to 25:75, For example, it may be included in a weight ratio of 70:30 to 30:70, for example 65:35 to 35:65, for example 60:40 to 40:60, for example 55:45 to 45:55 , but not limited to these.

By including the polymer A and the compound B in the above weight ratio, the composition for a resist underlayer film according to an embodiment can provide a resist underlayer film of excellent quality by improving adhesion to a photoresist and film density.

A total weight of the polymer A and the compound B may be included in an amount of 0.1 wt % to 50 wt % based on the total weight of the resist underlayer composition. By being included within the above range, the thickness, surface roughness and flatness of the resist underlayer film can be adjusted.

In addition, the composition for a resist underlayer film may further include one or more other polymers selected from acrylic resins, epoxy resins, novolac resins, glycoluril resins, and melamine resins, in addition to the above-mentioned polymers, but is not limited thereto no.

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

As the surfactant, for example, alkylbenzenesulfonic acid salts, alkylpyridinium salts, polyethylene glycol, quaternary ammonium salts, etc. may be used, but are not limited thereto.

The thermal acid generator is, for example, 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, or/and benzointosyl rate, 2-nitrobenzyl tosylate, and other organic sulfonic acid alkyl esters may be used, but are 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 composition for a resist underlayer film. By including it within the above range, solubility can be improved without changing the optical properties of the resist underlayer film composition.

The solvent is not particularly limited as long as it has sufficient solubility or dispersibility for the polymer, but examples include 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 , At least one selected from methylpyrrolidinone, methyl 2-hydroxyisobutyrate, acetylacetone, and ethyl 3-ethoxypropionate.

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

The crosslinking agent may include, for example, melamine-based, substituted urea-based, or these polymer-based. Preferably, a crosslinking agent having at least two cross-linking substituents, for example methoxymethylated glycoluril, butoxymethylated glycoluril, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxy Compounds such as methylated benzoguanamine, methoxymethylated urea, butoxymethylated urea, methoxymethylated thiourea, or butoxymethylated thiourea can 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 a molecule may be used. The crosslinking agent may have, for example, two or more crosslinking sites.

According to another embodiment, a resist underlayer film prepared using the above-described composition for a resist underlayer film is provided. The resist underlayer film may be cured through a heat treatment process after coating the above-described composition for a resist underlayer film on, for example, a substrate.

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 for explaining a pattern forming method using a 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 the 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. In order to remove contaminants remaining on the thin film 102, the surface of the thin film is pre-cleaned. The thin film 102 may be, for example, a silicon nitride film, a polysilicon film, or a silicon oxide film.

Subsequently, the composition for a resist underlayer film according to the present invention is coated on the surface of the cleaned thin film 102 by applying a spin coating method.

Thereafter, a resist underlayer film 104 is formed on the thin film by performing a drying and baking process. The baking treatment may be performed at 100 °C to 500 °C, for example, at 100 °C to 300 °C. Since a more specific 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 film 106 is formed by coating a photoresist on the resist underlayer film 104 .

Examples of the photoresist include a positive type photoresist containing a naphthoquinonediazide compound and a novolac resin, an acid generator capable of dissociating an acid by exposure, a compound and Chemically amplified positive-type photoresist containing an alkali-soluble resin, chemically-amplified positive-type photoresist containing an alkali-soluble resin having a group capable of imparting a resin having increased solubility in an aqueous alkali solution by decomposition in the presence of an acid generator and an acid A mold 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 °C to 120 °C.

Referring to FIG. 3 , the photoresist film 106 is selectively exposed.

Describing an exposure process for exposing the photoresist film 106 as an example, an exposure mask having a predetermined pattern is placed on a mask stage of an exposure apparatus, and the exposure mask ( 110) are sorted. Then, by irradiating the mask 110 with light, a predetermined portion of the photoresist film 106 formed on the substrate 100 selectively reacts with the light transmitted through the exposure mask.

For example, examples of light usable in the exposure process include short-wavelength light such as i-line activating radiation having a wavelength of 365 nm, KrF excimer laser having a wavelength of 248 nm, and ArF excimer laser having a wavelength of 193 nm. In addition, EUV (Extreme ultraviolet) having a wavelength of 13.5 nm corresponding to extreme ultraviolet light may be mentioned.

The photoresist layer 106b of the exposed portion has relatively hydrophilicity compared to the photoresist layer 106a of the unexposed portion. Accordingly, the photoresist films of the exposed portion 106b and the unexposed portion 106a have different solubilities.

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

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

Then, the resist underlayer is etched using the photoresist pattern 108 as an etching mask. The organic layer pattern 112 is formed through the above etching process. The etching may be performed by, for example, dry etching using an etching gas, and the etching gas may be, for example, CHF ₃ , CF ₄ , Cl ₂ , O ₂ or a mixed gas thereof. As described above, since the resist underlayer film formed by the resist underlayer film 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 into a thin film pattern 114 . In the previously performed exposure process, the thin film pattern (114 ) may have a width of several tens of nm to several hundred nm, and the thin film pattern 114 formed by an exposure process performed using an EUV light source may have a width of 20 nm or less.

Hereinafter, the present invention will be described in more detail through examples related to the synthesis of the above-described polymer A and compound B and the preparation of a composition for a resist underlayer film containing the same. However, the present invention is not technically limited by the following examples.

synthesis example

Synthesis of Polymer A

Synthesis Example 1

146.6 of 1,3-diallyl-5-(2-hydroxyethyl)isocyanurate, 68.1 g of 1,3 propanedithiol, 3.3 g of 2,2'-azobisisobutyronitrile, and 350 g of N,N-dimethylformamide were added to a 1L two-neck round flask and a condenser was placed. connected. After raising the temperature to 80 °C and reacting for 12 hours, the reaction solution was cooled to room temperature (23 °C). Thereafter, the reaction solution was transferred to a 1 L wide mouth bottle, washed three times with hexane, and then washed with ultrapure water. After completely dissolving the obtained resin in a gum state using 80 g of THF, it was slowly added dropwise to 700 g of toluene under stirring. Thereafter, by removing the solvent, a polymer (Mw = 10,500 g/mol) including a structural unit represented by Chemical Formula 1aa was finally obtained.

[Formula 1aa]

In Formula 1aa, * is a linking point.

Synthesis Example 2

In a 1 L two-necked round flask, 124.6 g of 1,3-diallyl-5-(2-hydroxyethyl)isocyanurate, 132.17 g of 1,3-Diallyl-5,5-diethylbarbituric acid, 47.1 g of 1,2-ethanedithiol, 2, 2' -6.5 g of azobisisobutyronitrile and 400 g of N,N-dimethylformamide were added and a condenser was connected. After raising the temperature to 80 °C and reacting for 4.5 hours, the reaction solution was cooled to room temperature (23 °C). Thereafter, the reaction solution was transferred to a 1 L wide mouth bottle, washed three times with hexane, and then washed with ultrapure water. After completely dissolving the obtained resin in a gum state using 80 g of THF, it was slowly added dropwise to 700 g of toluene under stirring. Thereafter, by removing the solvent, a polymer (Mw = 8,200 g/mol) including a structural unit represented by Chemical Formula 2aa was finally obtained.

[Formula 2aa]

In Formula 2aa, * is a linking point.

Synthesis Example 3

124.6 g of 1,3,5-triallyl isocyanurate, 58.5 g of 2-mercaptoethanol, 3.3 g of 2,2'-azobisisobutyronitrile, and 450 g of N,N-dimethylformamide were added to a 1L two-neck round flask and a condenser was connected. After raising the temperature to 80 °C and reacting for 2.5 hours, the reaction solution was cooled to room temperature (23 °C). Thereafter, the reaction solution was transferred to a 1 L wide mouth bottle, washed three times with hexane, and then washed with ultrapure water. After completely dissolving the obtained resin in a gum state using 80 g of THF, it was slowly added dropwise to 700 g of toluene under stirring. Thereafter, by removing the solvent, a polymer (Mw = 9,700 g/mol) including a structural unit represented by Chemical Formula 3aa and a structural unit represented by Chemical Formula 4aa was finally obtained.

[Formula 3aa] [Formula 4aa]

In Chemical Formulas 3aa and 4aa, * denotes a connection point.

Synthesis Example 4

1,3,5-triglycidyl isocyanurate (148.6 g, 0.5 mol), 2,2'-Thiodiacetic acid (60.0 g, 0.4 mol), benzyl triethyl ammonium chloride (9.1 g) and N,N- 350 g of dimethylformamide was added and a condenser was connected. After raising the temperature to 100 °C and reacting for 8 hours, the reaction solution was cooled to room temperature (23 °C). Thereafter, the reaction solution was transferred to a 1 L wide mouth bottle, washed three times with hexane, and then washed sequentially with purified water. After completely dissolving the obtained resin in a gum state using 80 g of THF, it was slowly added dropwise to 700 g of toluene under stirring. Thereafter, by removing the solvent, a polymer (Mw = 9,100 g/mol) including a structural unit represented by Chemical Formula 5aa was finally obtained.

[Formula 5aa]

In Formula 5aa, * is a linking point.

Synthesis of Compound B

Synthesis Example 5

8-propoxybenzopyrene (31.0 g, 0.1 mol), 1,4-bis(methoxymethyl)-benzene (16.6 g, 0.1 mol), diethyl sulfate (1.5 g, 0.1 mol), and PGMEA (250 g) were added to the flask. The mixture was stirred at 100 °C for 8 hours. When the reaction was completed, it was precipitated in 400 g of hexane, and the precipitate formed by adding methanol and water was filtered, and the remaining monomer was removed using methanol to obtain a compound containing a structural unit represented by the following formula 1bb (weight average molecular weight (Mw) = 1,300).

[Formula 1bb]

In Formula 1bb, * is a linking point.

Synthesis Example 6

9,9'-bis-(2-Naphthol)fluorine (45.0 g, 0.1 mol), Benzo-[ghi]perylene (27.6 g, 0.1 mol), 4,4'-Oxybis[(methoxymethyl)benzene]( After adding 51.6 g, 0.2 mol), diethyl sulfate (3.0 g, 0.2 mol), and PGMEA (190 g), the mixture was stirred at 100 °C for 8 hours. When the reaction was completed, it was precipitated in 200 g of hexane, and the precipitate formed by adding methanol and water was filtered, and the remaining monomer was removed using methanol to obtain a compound containing a structural unit represented by the following formula (2bb) (weight average molecular weight (Mw) = 2,100).

[Formula 2bb]

In Formula 2bb, * is a linking point.

Preparation of composition for resist underlayer film

Examples 1 to 8, Comparative Examples 1 and 2

0.5 g of polymer A prepared from Synthesis Examples 1 to 4 and Compound B prepared from Synthesis Examples 5 and 6 were added in the ratio shown in Table 1 below, PD1174 (TCI Corporation; curing agent) 0.125 g, and pyridinium para-toluene Resists according to Examples 1 to 8 and Comparative Examples 1 and 2 by completely dissolving 0.01 g of sulfonate (PPTS) in a mixed solvent of propylene glycol monomethyl ether and ethyl lactate (mixing volume ratio = 7:3) Compositions for underlayer films were prepared respectively.

polymer A compound B weight ratio Example 1 Synthesis Example 1 Synthesis Example 5 20:80 Example 2 Synthesis Example 2 Synthesis Example 5 70:30 Example 3 Synthesis Example 3 Synthesis Example 5 70:30 Example 4 Synthesis Example 4 Synthesis Example 5 80:20 Example 5 Synthesis Example 1 Synthesis Example 6 50:50 Example 6 Synthesis Example 2 Synthesis Example 6 30:70 Example 7 Synthesis Example 3 Synthesis Example 6 50:50 Example 8 Synthesis Example 4 Synthesis Example 6 50:50 Comparative Example 1 Synthesis Example 1 - - Comparative Example 2 - Synthesis Example 5 -

Evaluation of coating uniformity

2 ml each of the compositions prepared in Examples 1 to 8 and Comparative Examples 1 and 2 were taken and applied on an 8-inch wafer, respectively, and then using an auto track (TEL ACT-8) at a main spin speed of 1,500 rpm for 20 seconds After the spin coating, a thin film having a thickness of 250 Å was formed by curing at 210° C. for 90 seconds.

In addition, after further diluting the composition for a lower layer film prepared above, an ultra-thin film having a thickness of 50 Å was formed by spin-coating and curing as described above.

Coating uniformity was measured by measuring the thickness of 51 points along the horizontal axis, and the results are shown in Table 2 below. For coating uniformity, the difference (Å) between the maximum and minimum values of the 51-point thickness measurements was indicated, and the smaller the value, the better the coating uniformity.

Coating uniformity (maximum-minimum value (Å)) @ 250 Å film @ 50 Å film Example 1 5.2 2.3 Example 2 4.5 1.8 Example 3 4.3 1.5 Example 4 4.7 1.9 Example 5 5.5 2.3 Example 6 5.0 2.0 Example 7 5.6 2.4 Example 8 5.2 2.2 Comparative Example 1 6.3 3.7 Comparative Example 2 8.0 4.2

Referring to Table 2, it can be confirmed that the compositions for a resist underlayer film according to Examples 1 to 8 have superior coating uniformity compared to the compositions for a resist underlayer film according to Comparative Examples 1 and 2.

Membrane density evaluation

After applying the composition for a resist underlayer film according to Examples 1 to 8 and Comparative Examples 1 and 2 on a silicon substrate by a spin-on coating method, heat treatment was performed on a hot plate at 210 ° C. for 90 seconds to form a resist underlayer with a thickness of about 100 nm A film was formed.

Subsequently, the density of the resist underlayer film was measured, and the results are shown in Table 3. The density of the resist underlayer was measured using an X-Ray Diffractometer (Model: X'Pert PRO MPD, manufactured by Panalytical (Netherlands)).

Membrane Density (g/cm ³ ) Example 1 1.38 Example 2 1.39 Example 3 1.39 Example 4 1.40 Example 5 1.37 Example 6 1.37 Example 7 1.38 Example 8 1.38 Comparative Example 1 1.36 Comparative Example 2 1.34

Referring to Table 3, it can be seen that the films formed using the composition for a resist underlayer film according to Examples 1 to 8 have a higher density than the films formed using the composition for a resist underlayer film according to Comparative Examples 1 and 2. It is presumed that this is because the film density was improved by the compound B contained in the compositions for resist underlayer films according to Examples 1 to 8.

From the results of Table 3, it can be seen that when the resist underlayer film composition according to Examples 1 to 8 was used, a film having a more dense structure than Comparative Examples 1 and 2 could be formed.

Exposure characteristics evaluation

The compositions prepared in Examples 1 to 8 and Comparative Examples 1 and 2 were applied by a spin-on coating method, respectively, and then heat-treated on a hot plate at 210 ° C. for 90 seconds to form a resist underlayer film having a thickness of about 10 nm.

Thereafter, a photoresist solution was applied on the photoresist underlayer film by a spin-on coating method, and heat treatment was performed on a hot plate at 110° C. for 1 minute to form a photoresist layer. The photoresist layer was exposed to light with an accelerating voltage of 100 keV using an e-beam exposure machine (manufactured by Elionix), and then heat-treated at 110 °C for 60 seconds. Subsequently, the photoresist layer was developed with a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) at 23° C., and then rinsed in pure water for 15 seconds to form a line and space (L/S) photoresist pattern. was formed.

Next, the optimal exposure amount of the photoresist pattern was evaluated, and the results are shown in Table 4. Here, the exposure amount for resolving the line and space of 100 nm by 1:1 is referred to as the optimum energy (Eop, μC/cm 2 ), and the values in the table below are expressed as relative values compared to the Eop of Comparative Example 2.

Eop (μC/cm2) Example 1 0.90 Example 2 0.85 Example 3 0.85 Example 4 0.90 Example 5 0.95 Example 6 0.95 Example 7 0.95 Example 8 0.95 Comparative Example 1 1.20 Comparative Example 2 1.00

Referring to Table 4, when the resist underlayer film was formed using the composition for a photoresist underlayer film according to Examples 1 to 8, it could be confirmed that the optimal exposure amount of the photoresist pattern was excellent compared to Comparative Examples 1 and 2.

Therefore, from the results of Table 4, it can be seen that when using the composition for a resist underlayer film according to Examples 1 to 8, photoresist patterns having more excellent sensitivity compared to Comparative Examples 1 and 2 can be formed.

In the foregoing, although specific embodiments of the present invention have been described and shown, the present invention is not limited to the described embodiments, and it is common knowledge in the art that 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 viewpoint of the present invention, and modified embodiments should fall within the scope of the claims of the present invention.

100: substrate 102: thin film
104: resist underlayer film 106: photoresist film
106a: photoresist film of non-exposed area
106b: photoresist film of exposed area
108: photoresist pattern 110: mask
112: organic film pattern 114: thin film pattern

Claims (20)

Polymer A containing a heterocycle containing at least 2 nitrogen atoms;
At least one of a single ring, a fused ring in which two or more single rings are fused, and an unfused ring in which two or more single rings are connected by a single bond, a substituted or unsubstituted C1 to C5 alkylene group, O or C(O) including,
The single ring is a substituted or unsubstituted C6 to C30 aromatic ring or a substituted or unsubstituted C2 to C30 heteroaromatic ring,
Compound B containing at least 5 of the above single rings in the structural unit; and
A composition for a resist underlayer film containing a solvent. In paragraph 1,
A composition for a resist underlayer film, wherein the polymer A includes at least one structural unit represented by the following formulas 1 to 5:
[Formula 1]

[Formula 2]

[Formula 3] [Formula 4]

[Formula 5]

In Formulas 1 to 5,
Ring A is a heterocycle containing at least 2 nitrogen atoms,
R ¹ to R ⁶ are each independently hydrogen, heavy hydrogen, a halogen group, a hydroxyl group, a cyano group, a nitro group, an amino group, an epoxy group, a vinyl group, an allyl group, a (meth)acrylate group, an oxetane group, and a thiol group. , Carboxyl group, substituted or unsubstituted C1 to C10 alkyl group, substituted or unsubstituted C2 to C10 alkenyl group, substituted or unsubstituted C2 to C10 alkynyl group, substituted or unsubstituted C1 to C10 heteroalkyl group, substituted or unsubstituted a substituted or unsubstituted C1 to C10 heteroalkenyl group, a substituted or unsubstituted C1 to C10 heteroalkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 heterocycloalkyl group, a substituted or unsubstituted C6 to C20 heterocycloalkyl group, A C20 aryl group, a substituted or unsubstituted C1 to C20 heteroaryl group, or a combination thereof;
L ¹ to L ¹² are each independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C1 to C10 cycloalkylene group, An unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, a substituted or unsubstituted C1 to C20 heteroarylene group, or a combination thereof;
X ¹ to X ⁸ are each independently -O-, -S-, -S(O)-, -S(O) ₂ -, -C(O)-, -(CO)O-, -O( CO), -O(CO)O-, -NR'- (where R”” is hydrogen, deuterium, or a C1 to C10 alkyl group), or a combination thereof,
Y ¹ and Y ² are each independently a halogen group, a hydroxyl group, a cyano group, a nitro group, an amino group, an epoxy group, a vinyl group, an allyl group, a (meth)acrylate group, an oxetane group, a thiol group, a carboxyl group, or is a combination of these
* is a connection point. In paragraph 2,
Wherein R ¹ to R ⁶ are each independently hydrogen, a hydroxyl group, an epoxy group, a vinyl group, an allyl group, a (meth)acrylate group, an oxetane group, a thiol group, a carboxyl group, a substituted or unsubstituted C1 to C10 alkyl group , A substituted or unsubstituted C1 to C10 heteroalkyl group, or a combination thereof,
Wherein L ¹ to L ¹² are each independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, or a combination thereof;
Wherein X ¹ to X ⁸ are each independently -O-, -S-, -C(O)-, -(CO)O-, -O(CO), or a combination thereof. In paragraph 1,
A composition for a resist underlayer film, wherein the heterocycle containing at least two nitrogen atoms is at least one of structures represented by the following formulas A-1 to A-8:
[Formula A-1] [Formula A-2] [Formula A-3] [Formula A-4]

[Formula A-5] [Formula A-6] [Formula A-7] [Formula A-8]

In Formula A-1 to Formula A-8,
R ^a , R ^b , R ^x and R ^y are each independently hydrogen, heavy hydrogen, a halogen group, a hydroxy group, a cyano group, a nitro group, an amino group, an epoxy group, a vinyl group, a (meth)acrylate group, an oxetane group , Thiol group, carboxyl group, 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 an unsubstituted C1 to C30 thioalkyl group, a substituted or unsubstituted C3 to C30 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C6 to C30 aryloxy group, a substituted or unsubstituted A C6 to C30 thioaryl group, a substituted or unsubstituted C2 to C30 heteroaryl group, or a combination thereof;
L ^a and L ^b are each independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C1 to C10 cycloalkylene group, An unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, a substituted or unsubstituted C1 to C20 heteroarylene group, or a combination thereof;
* is a linkage point within the polymer, respectively. In paragraph 4,
Wherein R ^a and R ^b are each independently hydrogen, a hydroxyl group, an epoxy group, a vinyl group, an allyl group, a (meth)acrylate group, an oxetane group, a thiol group, a carboxyl group, a substituted or unsubstituted C1 to C10 alkyl group , A substituted or unsubstituted C1 to C10 heteroalkyl group, or a combination thereof,
Wherein R ^x and R ^y are each independently hydrogen, a hydroxyl group, an epoxy group, a vinyl group, an allyl group, a (meth)acrylate group, an oxetane group, a thiol group, a carboxyl group, a substituted or unsubstituted C1 to C10 alkyl group , A substituted or unsubstituted C1 to C10 heteroalkyl group, or a combination thereof,
Wherein L ^a and L ^b are each independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, or a combination thereof. In paragraph 1,
A composition for a resist underlayer film, wherein the polymer A includes at least one structural unit represented by Formulas 6 to 11 below:
[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

[Formula 10]

[Formula 11]

In Formulas 6 to 11,
* is a point connected to the main chain, side chain or terminal group of the polymer. In paragraph 1,
The polymer A includes at least one structural unit represented by Formulas 12 to 16 below,
The weight average molecular weight of the polymer A is 2,000 g / mol to 300,000 g / mol, a composition for a resist underlayer film:
[Formula 12]

[Formula 13]

[Formula 14] [Formula 15]

[Formula 16]

In Formulas 12 to 16,
* is a point connected to the main chain, side chain or terminal group of the polymer. In paragraph 1,
A composition for a resist underlayer film, wherein the single ring, the fused ring, and the non-fused ring contain at least one structure listed in Group I below:
[Group I]

In Group I,
Z ¹ is a single bond, a substituted or unsubstituted C1 to C5 alkylene group, O or C(O);
Z ³ to Z ¹⁸ are each independently C(O), NR ^c , O, S, CR ^d R ^e or a combination thereof;
R ^c to R ^e are each independently hydrogen, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C2 to C20 heteroaryl group, a halogen atom, or a halogen-containing group. , or a combination thereof. In paragraph 1,
A composition for a resist underlayer film, wherein the single ring, the fused ring, and the unfused ring are at least one of structures represented by the following formulas (B-1) to (B-5):
[Formula B-1]

[Formula B-2]

[Formula B-3]

[Formula B-4]

[Formula B-5]

In Formula B-1 to Formula B-5,
R ^f is hydrogen, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C2 to C20 heteroaryl group, or a combination thereof;
* is a connection point. In paragraph 1,
A composition for a resist underlayer film, wherein the compound B includes at least one structural unit represented by the following formulas 17 to 19:
[Formula 17]

[Formula 18]

[Formula 19]

In Formulas 17 to 19,
L ¹³ to L ¹⁸ are each independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C1 to C10 cycloalkylene group, An unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, a substituted or unsubstituted C1 to C20 heteroarylene group, or a combination thereof,
* is a point connected to the main chain, side chain or terminal group of the compound. In paragraph 1,
The compound B is any one of a single molecule, an oligomer and a polymer including at least one structural unit represented by any one of Formulas 20 to 22 below, a composition for a resist underlayer film:
[Formula 20]

[Formula 21]

[Formula 22]

In Formulas 20 to 22,
* is a point connected to the main chain, side chain or terminal group. In paragraph 11,
The compound B is a monomolecular or oligomer, and the molecular weight is 300 to 3,000 g / mol composition for a resist underlayer film. In paragraph 11,
The compound B is a polymer, and the weight average molecular weight is 1,000 g / mol to 50,000 g / mol composition for a resist underlayer film. In paragraph 1,
A composition for a resist underlayer film comprising the polymer A and compound B in a weight ratio of 90:10 to 10:90. In paragraph 1,
A composition for a resist underlayer film comprising a total weight of the polymer A and the compound B in an amount of 0.1% to 50% by weight based on the total weight of the composition for a resist underlayer film. In paragraph 1,
A composition for a resist underlayer film, further comprising at least one polymer selected from acrylic resins, epoxy resins, novolac resins, glycoluril resins, and melamine resins. In paragraph 1,
A composition for a resist underlayer film, further comprising an additive including a surfactant, a thermal acid generator, a plasticizer, or a combination thereof. Forming a film to be etched on a substrate;
Forming a resist underlayer film by applying the composition for a resist underlayer film according to any one of claims 1 to 17 on the etch target film;
forming a photoresist pattern on the resist underlayer film; and
sequentially etching the resist underlayer layer and the etch target layer using the photoresist pattern as an etching mask;
Pattern forming method comprising a. In paragraph 18,
Forming the photoresist pattern
Forming a photoresist film on the resist underlayer film;
Exposing the photoresist film to light; and
A pattern forming method comprising the step of developing the photoresist film. In paragraph 18,
The forming of the resist underlayer film further comprises heat treatment at a temperature of 100° C. to 500° C. after coating the composition for the resist underlayer film.

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