TW201839030A - Resist underlayer composition and method of forming patterns using the resist underlayer composition - Google Patents

Abstract

Disclosed are a resist underlayer composition and a method of forming a pattern using the same. The resist underlayer composition includes a polymer having a moiety represented by Chemical Formula 1 and a solvent. Definitions of the substituents in Chemical Formula 1 are the same as the descriptions in the specification.

Description

Resist primer composition and pattern forming method using resist underlayer composition

The present invention relates to a resist underlayer composition and a method of forming a pattern using the resist underlayer composition. More specifically, the present invention relates to a photoresist underlayer composition formed between a semiconductor substrate and a photoresist layer and a method of forming a photoresist pattern using the underlayer.

Recently, the semiconductor industry has developed ultra-fine technology with patterns ranging in size from several nanometers to tens of nanometers. This ultra-fine technology basically requires effective lithography.

The lithography technique includes coating a photoresist layer on a semiconductor substrate such as a germanium wafer, exposing and developing it to form a thin layer, and illuminating an activation such as ultraviolet light (UV) while providing a mask pattern having a pattern of elements. Radiation, the product is developed to obtain a photoresist pattern, and the substrate is etched using the photoresist pattern as a protective layer to form a fine pattern corresponding to the pattern on the surface of the substrate.

When it is necessary to fabricate ultra-fine patterns, it will have short wavelengths such as i-line (365 nm), KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm) and the like. Activating radiation is used for exposure of the photoresist. Therefore, research has been conducted to solve the problem of activating radiation due to diffuse reflection, standing wave or the like from a semiconductor substrate by inserting a resist underlayer having an optimum reflectance between the photoresist and the semiconductor substrate.

On the other hand, in addition to activating radiation, high-energy rays such as extreme ultraviolet light (EUV; wavelength 13.5 nm), electron beam (E-beam), and the like have been used as a light source for manufacturing a fine pattern, and Extensive research has been conducted to improve the adhesion of the resist to the underlying layer to improve the collapse of the pattern without reflection from the substrate. Further, in addition to reducing the problems caused by the light source, extensive research has been conducted in improving the etching selectivity and chemical resistance of the resist underlayer.

Further, in addition to reducing the problems caused by the light source, attempts have been made to improve the adhesion of the resist underlayer to the resist as well as the etching selectivity and chemical resistance.

The present invention relates to a resist underlayer composition which has an optimum reflectance at a specific wavelength while having improved coating properties, planarization characteristics, adhesion to photoresist, and rapid etching rate.

The invention also relates to a method of forming a pattern using the resist underlayer composition.

According to an embodiment, the resist underlayer composition includes a polymer including a portion represented by Chemical Formula 1 and a solvent.

[Chemical Formula 1]

In Chemical Formula 1, a is an integer of 0 to 3, and when a is 0, R ¹ is hydrogen, halogen, substituted or unsubstituted C1 to C30 alkyl, substituted or unsubstituted C6 to C30 aromatic A substituted or unsubstituted C1 to C30 heteroalkyl group, a substituted or unsubstituted C1 to C30 heteroalkenyl group, a substituted or unsubstituted C2 to C30 heteroaryl group, substituted or unsubstituted The C1 to C30 alkenyl group, the substituted or unsubstituted C1 to C30 alkynyl group or a combination thereof, when a is an integer of 1 to 3, R ¹ is a point of attachment (*), and R ⁰ is substituted or not Substituted C1 to C30 alkylene, substituted or unsubstituted C6 to C30 extended aryl, substituted or unsubstituted C1 to C30 heteroalkyl, substituted or unsubstituted C1 to C30 Alkenyl, substituted or unsubstituted C2 to C30 heteroaryl, substituted or unsubstituted C1 to C30 alkenyl, substituted or unsubstituted C1 to C30 alkynyl, ester (-COO) -), ether (-CO-), -CS-, or a combination thereof, R ² and R ^{3 are} independently substituted or unsubstituted C1 to C30 alkyl, substituted or unsubstituted C6 to C30 Extended aryl, substituted or unsubstituted C1 to C30 Heteroalkyl, substituted or unsubstituted C1 to C30 heterocycloalkenyl, substituted or unsubstituted C2 to C30 heteroaryl, substituted or unsubstituted C1 to C30 extended alkenyl, substituted Or unsubstituted C1 to C30 alkynyl, ester (-COO-), ether (-CO-), -CS- or a combination thereof, b and c are independently an integer from 0 to 3, and * is a point of attachment .

According to an embodiment, in Chemical Formula 1, R ² and R ³ may independently include at least one ester (-COO-), ether (-CO-) or -CS- in its structure, or at least one substituted or not Substituted C1 to C30 alkyl or substituted or unsubstituted C1 to C30 heteroalkyl is in its structure.

According to an embodiment, in Chemical Formula 1, when a is 0, R ¹ may be a C1 to C30 alkyl group, a C1 to C30 alkyl group substituted with at least one hydroxyl group, a C1 to C30 heteroalkyl group, substituted with at least one hydroxyl group. a C1 to C30 heteroalkyl group or a combination thereof, and in the chemical formula 1, when a is 1, R ⁰ may include at least one ester (-COO-), ether (-CO-) or -CS- in its structure Or a substituted or unsubstituted C1 to C30 alkyl group comprising at least one substituted or unsubstituted C1 to C30 alkylene group, including a substituted or unsubstituted C1 to C30 heteroalkyl group, At least one hydroxy-substituted C1 to C30 alkyl group or a C1 to C30 heteroalkyl group.

According to an embodiment, the polymer may have a weight average molecular weight of 1,000 to 100,000.

According to an embodiment, the composition may further comprise a crosslinking agent having at least two crosslinking sites.

According to an embodiment, the composition may further comprise an additive of a surfactant, a thermal acid generator, a plasticizer, or a combination thereof.

In accordance with another embodiment, a method of forming a pattern includes: forming an etched body layer on a substrate, applying a resist underlayer composition on the etched body layer to form a resist underlayer, and forming a photoresist pattern on the resist underlayer The resist underlayer and the etched body layer are sequentially etched using the photoresist pattern as an etch mask.

According to an embodiment, the step of forming the photoresist pattern may include forming a photoresist layer on the resist underlayer, exposing the photoresist layer, and developing the photoresist layer.

According to an embodiment, the step of forming a resist underlayer may further include heat-treating the coated resist underlayer composition at a temperature of from 100 ° C to 500 ° C.

Based on the above, the present invention provides a resist underlayer composition having an optimized reflectance at a predetermined wavelength while having improved coating properties, planarization characteristics, and rapid etch rate. The present invention also provides a method of forming a pattern using the resist underlayer composition.

The illustrative embodiments of the present disclosure are described in detail below, and can be readily made by those of ordinary skill in the art. However, the disclosure may be embodied in many different forms and is not construed as being limited to the illustrative embodiments set forth herein.

In the drawings, the thickness of layers, films, sheets, regions, and the like are exaggerated for clarity, and the same reference numerals are used throughout the description. It will be understood that when an element such as a layer, a film, a region or a substrate is referred to as being "on" another element, it may be directly on the other element or the intermediate element may be present. In contrast, when an element is referred to as being "directly on" another element, there is no intermediate element.

As used herein, when a definition is not otherwise provided, "substituted" means replacing a hydrogen atom in a compound by a substituent selected from a halogen atom (F, Br, Cl or I), a hydroxyl group, an alkoxy group. Base, nitro, cyano, amine, azide, sulfhydryl, decyl, fluorenylene, carbonyl, amine carbaryl, thiol, ester, carboxyl or a salt thereof, sulfonic acid group or salt thereof , phosphoric acid or its salt, vinyl, C1 to C20 alkyl, C2 to C20 alkenyl, C2 to C20 alkynyl, C6 to C30 aryl, C7 to C30 aralkyl, C6 to C30 allyl, C1 to C30 Alkoxy, C1 to C20 heteroalkyl, C3 to C20 heteroarylalkyl, C3 to C30 cycloalkyl, C3 to C15 cycloalkenyl, C6 to C15 cycloalkynyl, C3 to C30 heterocycloalkyl, and combination.

As used herein, when nothing is otherwise provided, "hetero" refers to 1 to 10 heteroatoms selected from N, O, S, and P.

As used herein, when no definition is provided, "*" refers to the point of attachment of a compound or moiety of a compound.

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

The resist underlayer composition according to the embodiment includes a polymer including a portion represented by Chemical Formula 1 and a solvent.

[Chemical Formula 1]

In Chemical Formula 1, a is an integer of 0 to 3, and when a is 0, R ¹ is hydrogen, halogen, substituted or unsubstituted C1 to C30 alkyl, substituted or unsubstituted C6 to C30 aromatic A substituted or unsubstituted C1 to C30 heteroalkyl group, a substituted or unsubstituted C1 to C30 heteroalkenyl group, a substituted or unsubstituted C2 to C30 heteroaryl group, substituted or unsubstituted The C1 to C30 alkenyl group, the substituted or unsubstituted C1 to C30 alkynyl group or a combination thereof, when a is an integer of 1 to 3, R ¹ is a point of attachment (*), and R ⁰ is substituted or not Substituted C1 to C30 alkylene, substituted or unsubstituted C6 to C30 extended aryl, substituted or unsubstituted C1 to C30 heteroalkyl, substituted or unsubstituted C1 to C30 Alkenyl, substituted or unsubstituted C2 to C30 heteroaryl, substituted or unsubstituted C1 to C30 alkenyl, substituted or unsubstituted C1 to C30 alkynyl, ester (-COO) -), ether (-CO-), -CS- or a combination thereof, R ² and R ^{3 are} independently substituted or unsubstituted C1 to C30 alkyl, substituted or unsubstituted C6 to C30 Aryl, substituted or unsubstituted C1 to C30 Alkyl, substituted or unsubstituted C1 to C30 heteroalkenyl, substituted or unsubstituted C2 to C30 heteroaryl, substituted or unsubstituted C1 to C30 alkenyl, substituted or substituted Unsubstituted C1 to C30 alkynyl, ester (-COO-), ether (-CO-), -CS- or a combination thereof, b and c are independently an integer from 0 to 3, and * is a point of attachment.

The moiety represented by Chemical Formula 1 has a structure of a triazine skeleton at the core and three oxygen atoms attached to the triazine. The portion has this structure and thus has a relatively high refractive index (n) and a low extinction coefficient (k) with respect to the ArF excimer laser (wavelength of 193 nm). Thus, when a composition comprising the polymer is used, for example, as a photoresist underlayer material, the photoresist underlayer material can have an optimum reflectance from the etch layer to the light source, and thus suppress optical interference effects, and during the etching process It also has high etch selectivity and improved flatness with the photoresist layer.

The portion represented by Chemical Formula 1 may contain at least one hydroxyl group, and further uniformity of coating is ensured by this structure.

For example, in Chemical Formula 1, when a is 0, R ¹ may be a C1 to C30 alkyl group, a C1 to C30 alkyl group substituted with at least one hydroxyl group, a C1 to C30 heteroalkyl group, substituted with at least one hydroxyl group. C1 to C30 heteroalkyl or a combination thereof, but is not limited thereto. Further, for example, in Chemical Formula 1, when a is 1, R ⁰ may be a substituted or unsubstituted C1 to C30 alkyl group, a C1 to C30 alkyl group substituted with at least one hydroxyl group, and C1 to C30 is a heteroalkyl group, a C1 to C30 heteroalkyl group substituted by at least one hydroxyl group, or a combination thereof, but is not limited thereto.

For example, in Chemical Formula 1, when a is 0, R ¹ may be a linear or branched C1 to C30 alkyl group in which at least one hydrogen is replaced by a hydroxyl group. For example, R ¹ can be a linear or branched C1 to C30 heteroalkyl group in which at least one hydrogen is replaced by a hydroxy group. Here, a hetero atom in a heteroalkyl group may be present at any position of the heteroalkyl group.

Further, in Chemical Formula 1, R ² and R ³ may independently include at least one of an ester (-COO-), an ether (-CO-), and -CS- in its structure, or may independently include at least one Substituted or unsubstituted C1 to C30 alkyl or substituted or unsubstituted C1 to C30 heteroalkyl is in its structure.

Since the polymer is stable and thermally stable in an organic solvent, when a resist underlayer composition including the polymer is used, for example, as a photoresist underlayer material, a resist underlayer formed thereon forms a photoresist pattern The delamination caused by solvent or heat may be minimized during the process, or the generation of by-products such as chemicals and the like may be minimized with the thickness loss caused by the photoresist solvent thereon. Furthermore, the compounds have improved solubility and thus can form a resist underlayer with improved coating uniformity.

Further, the polymer may be a copolymer comprising, in addition to the portion, at least one second moiety derived from a different single molecule.

The polymer may have a weight average molecular weight of 1,000 to 100,000. Specifically, the polymer may have a weight average molecular weight of 1,000 to 50,000, and more specifically, a weight average molecular weight of 1,000 to 20,000. When the weight average molecular weight of the polymer is within the above range, the amount of carbon of the resist underlayer composition including the polymer and the solubility in a solvent can be optimized.

When the polymer is used as a material for a resist underlayer, not only a uniform thin layer can be obtained during the baking process without forming pinholes or voids that break the thickness distribution, when the underlying substrate (or layer) has steps or Improved gap fill and planarization characteristics are also achieved when patterning.

The solvent may be any solvent having sufficient solubility or dispersibility for the polymer, and may include, for example, one selected from the group consisting of propylene glycol, propylene glycol diacetate, methoxypropylene glycol, diethylene glycol, diethylene glycol butyl ether, and the like. (ethylene glycol) monomethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, ethyl lactate, γ-butyrolactone, N,N-dimethylformamide, N,N At least one of dimethylacetamide, methyl pyrrolidone, methyl pyrrolidinone, acetamidine acetone and ethyl 3-ethoxypropionate.

The polymer may be included in an amount of 0.1 to 50 wt%, 0.1 to 30 wt%, or 0.1 to 15 wt%, based on the total of the resist underlayer composition. When the polymer is included in the above range, the thickness, surface roughness, and planarization of the formed thin layer can be controlled.

The resist underlayer composition may further include a crosslinking agent.

The crosslinking agent may be, for example, a melamine-based, substituted urea-based or polymer-based crosslinking agent. Preferably, the crosslinking agent may be a crosslinking agent having at least two substituents forming a crosslinking, such as, for example, the following compounds: methoxymethylated acetylene urea, butoxymethylated acetylene urea, Methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, methoxymethylated urea, butoxymethylation Urea, methoxymethylated thiourea or butoxymethylated thiourea and the like.

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

Further, in addition to the compound including the structural unit represented by Chemical Formula 1, the resist underlayer composition may further include at least one polymerization of at least one acrylic resin, epoxy resin, novolak resin, acetylene urea resin, and melamine resin. Things, but not limited to them.

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

The surfactant may include, for example, but not limited to, an alkyl benzenesulfonate, an alkyl pyridinium salt, a polyethylene glycol, a quaternary ammonium salt, a fluoroalkyl compound, and the like.

The thermal acid generator may, for example, be an acidic compound such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluenesulfonate, salicylic acid, sulfinic acid, citric acid, benzoic acid, hydroxybenzoic acid, naphthaleneic acid, and the like. And / or 2,4,4,6-tetrabromocyclohexadienone, benzoin tosylate, 2-nitrobenzyl tosylate, other alkyl sulfonates and the like, but not Limited to this.

The additive may be present in an amount of 0.001 to 40 parts by weight based on 100 parts by weight of the resist underlayer composition. Within the above range, the solubility can be improved without changing the optical properties of the resist underlayer composition.

According to another embodiment, a resist underlayer fabricated using the resist underlayer composition is provided. The resist underlayer may be cured by heat treatment after coating the resist underlayer composition on, for example, a substrate, and may include, for example, an organic thin layer such as a planarization layer, an anti-reflective coating layer, a sacrificial layer, a filler, and the like. Similar in electronic components.

Hereinafter, a method of forming a pattern using a resist underlayer composition will be described with reference to FIGS. 1 through 5.

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

Referring to Figure 1, a body for etching is prepared. The etched body can be a thin layer 102 formed on a substrate 100, such as a semiconductor substrate. In the following, the etched body is limited to the thin layer 102. The entire surface of the thin layer 102 is cleaned to remove impurities and the like remaining thereon. The thin layer 102 can be, for example, a tantalum nitride layer, a polysilicon layer, or a hafnium oxide layer.

Subsequently, a resist underlayer composition including a polymer having a structural unit represented by Chemical Formula 1 and a solvent is spin-coated on the surface of the cleaned thin layer 102.

The coated composition is then dried and baked to form a resist underlayer 104 on the thin layer 102. Baking can be carried out at 100 ° C to 500 ° C. For example, baking can be carried out at 100 ° C to 300 ° C. Specifically, the resist underlayer composition has been described in detail above, and thus detailed description thereof will be omitted.

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

Examples of the photoresist may be a positive photoresist containing a naphthoquinonediazide compound and a novolac resin, a chemically amplified positive photoresist containing an acid generator capable of dissociating an acid by exposure, decomposed in the presence of an acid, and an alkaline aqueous solution. Compounds having an increased solubility and an alkali-soluble resin, and an alkali-soluble resin containing a resin can be used to increase the solubility of a chemically amplified positive-type photoresist in an aqueous alkaline solution and the like.

Subsequently, the substrate 100 having the photoresist layer 106 thereon is subjected to initial baking. The initial baking can be carried out at a temperature of from about 90 °C to about 120 °C.

Referring to Figure 3, the photoresist layer 106 is selectively exposed.

Exposure of the photoresist layer 106 can be performed, for example, by placing an exposure mask having a predetermined pattern on a mask stage of the exposure apparatus and aligning the exposure mask 110 on the photoresist layer 106. Subsequently, light is irradiated into the exposure mask 110, and a predetermined region of the photoresist layer 106 formed on the substrate 100 selectively reacts with light passing through the exposure mask 110. Examples of the light used during the exposure may be an ArF laser (ArF laser) having wavelengths of 193 nm and 248 nm, EUV (extreme ultraviolet light) having a wavelength of 13.5 nm, and the like.

The exposed regions 106b of the photoresist layer 106 can be relatively hydrophilic compared to the non-exposed regions 106a of the photoresist layer 106. Therefore, the exposed region 106b and the non-exposed region 106a of the photoresist layer 106 may have different solubility from each other.

Subsequently, the substrate 100 is baked twice. The secondary baking can be carried out at a temperature of from about 90 °C to about 150 °C. Because of the secondary baking, the exposed region 106b of the photoresist layer 106 becomes easily dissolved with respect to the predetermined solvent.

Referring to FIG. 4, the exposed region 106b of the photoresist layer 106 is dissolved and removed by the developer to form a photoresist pattern 108. Specifically, the photoresist pattern 108 is completed by dissolving and removing the exposed region 106b of the photoresist layer 106 using a developing solution such as tetramethylammonium hydroxide (TMAH) and the like.

Subsequently, the photoresist pattern 108 is used as an etch mask to etch the resist underlayer 104. The organic layer pattern 112 is formed by etching.

The etching may be, for example, dry etching using an etching gas, which may be, for example, CHF ₃ , CF ₄ , Cl ₂ , BCl _{3 ,} and a mixed gas thereof.

Referring to Figure 5, the photoresist pattern 108 acts as an etch mask to etch the exposed thin layer 102. As a result, the thin layer is formed into a thin layer pattern 114.

Hereinafter, the present invention will be described in more detail by way of examples regarding the synthesis of a polymer and the preparation of a resist underlayer composition including the polymer. However, the present invention is not technically limited by the following exemplified embodiments. Synthesis Example Synthesis Example 1

16.46 g (0.05 mol) of 2,2'-((6-(oxiran-2-ylmethoxy)-1,3,5-triazine-2,4-diyl) bis(oxygen) Base)) diacetic acid, 3.1 g (0.05 mol) of ethylene glycol, 0.1.33 g (7 mmol) of p-toluenesulfonic acid and 13 g of anisole in a 100 mL round bottom flask equipped with a condenser Then, the mixture was stirred with a magnetic bar while heating to 150 ° C to carry out a polymerization reaction. After the reaction was carried out for 20 hours, the polymerization reaction solution was cooled to room temperature (23 ° C to 25 ° C), diluted with 30 g of HBM (methyl 2-hydroxyisobutyrate), and then added to 500 g of isopropanol. (IPA). After the mixture was stirred and allowed to stand, the supernatant was removed. Subsequently, the purified resin layer was further diluted with HBM (methyl 2-hydroxyisobutyrate), 500 g of isopropyl alcohol was added thereto, the resulting mixture was stirred, and the purification process was allowed to stand for four times to remove Low molecular weight and catalyst. Finally, a polymer (molecular weight (Mw) = 5,700) including the structural unit represented by Chemical Formula 1-1 was obtained.

[Chemical Formula 1-1] Synthesis Example 2

15.7 g (0.06 mol) of 2,2',2''-((1,3,5-triazine-2,4,6-triyl) stilbene (oxy)) triethanol, 5.9 g (0.05 Mol) succinic acid, 0.1.33 g (7 mmol) of p-toluenesulfonic acid and 15 g of anisole were placed in a 100 mL round bottom flask equipped with a condenser and stirred while heating at 150 °C The polymerization was carried out. After the reaction was carried out for 38 hours, the polymerization reaction solution was cooled to room temperature (23 ° C to 25 ° C), diluted with 30 g of HBM (methyl 2-hydroxyisobutyrate), and then added to 500 g of isopropanol. in. After the mixture was stirred and allowed to stand, the supernatant was removed. Subsequently, the purified resin layer was further diluted with HBM (methyl 2-hydroxyisobutyrate), 500 g of isopropyl alcohol was added thereto, the resulting mixture was stirred, and the purification process was allowed to stand for four times to remove Low molecular weight and catalyst. Finally, a polymer (molecular weight (Mw) = 8,100) including the structural unit represented by Chemical Formula 1-2 was obtained.

[Chemical Formula 1-2] Synthesis Example 3

15.7 g (0.06 mol) of 2,2',2''-((1,3,5-triazine-2,4,6-triyl) stilbene (oxy))triethanol, 12.96 g (0.05 Mol) 2,2'-((6-methoxy-1,3,5-triazine-2,4-diyl)bis(oxy))diacetic acid, 0.1.33 g (7 mmol) p-Toluenesulfonic acid and 20 g of anisole were placed in a 100 mL round bottom flask equipped with a condenser, and then stirred using a magnetic bar while heating to 150 ° C to carry out polymerization. After the reaction was carried out for 22 hours, the polymerization reaction solution was cooled to room temperature (23 ° C to 25 ° C), diluted with 30 g of HBM (methyl 2-hydroxyisobutyrate), and then added to 500 g of isopropanol. in. After the mixture was stirred and allowed to stand, the supernatant was removed. The purification process in which the purified resin layer was again diluted with HBM (methyl 2-hydroxyisobutyrate), 500 g of isopropyl alcohol was added thereto, the resulting mixture was stirred, and allowed to stand for a total of four times to remove low Molecules and catalysts. Finally, a polymer (molecular weight (Mw) = 4,500) including the structural unit represented by Chemical Formula 1-3 was obtained.

[Chemical Formula 1-3] Synthesis Example 4

14.96 g (0.06 mol) of 2,4,6-triallyloxy-1,3,5-triazine, 3.77 g (0.04 mol) of 1,2-ethanedithiol, 7.81 g (0.1 Mol) 2-indole ethanol, 0.13 g (8 mmol) of AIBN and 107 g of dimethylformamide (DMF) were placed in a 100 mL two-necked round bottom flask equipped with a condenser, then at 80 °C Next, by using a magnetic bar to mix. After the reaction was carried out for 6 hours, the reaction was cooled to room temperature (23 ° C to 25 ° C) and added to an excess of hexane. After the mixture was stirred and allowed to stand, the supernatant was removed. Subsequently, the reactant solution was added to toluene, and after the resulting mixture was stirred and allowed to stand, the supernatant was removed. As a result, after the removal of the low molecule and the catalyst, the obtained reactant was purified to obtain a polymer (molecular weight (Mw) = 3,800) including the structural unit represented by Chemical Formula 1-4.

[Chemical Formula 1-4] Synthesis Example 5

3.6 g (20 mmol) of 2,4-dichloro-6-methoxy-1,3,5-triazine was placed in a 250 mL round bottom flask equipped with a condenser, and 20 mL of CH was added thereto. ₂ Cl ₂ to dissolve it. Subsequently, 2.4 g (60 mmol) of NaOH dissolved in 20 mL of water was added to the reaction vessel. 20 mg of TBAB and PTC were placed in a reaction vessel, and then reacted at room temperature (23 ° C to 25 ° C) for 8 hours. The organic layer was extracted only from the reaction solution, then dried and concentrated to give a white solid. This solid was washed several times with hexane and dried to finally obtain a polymer (molecular weight (Mw) = 3,200) including the structural unit represented by Chemical Formula 1-5.

[Chemical Formula 1-5] (Me is a methyl group) Synthesis Example 6

4.95 g (126 mmol) of NaOH, 3.7 g (60 mmol) of ethylene glycol and 80 mL of water were placed in a 250 mL round bottom flask equipped with a condenser. 0.0036 mmol of BnMe ₃ NCl dissolved in 70 mL of water and PTC were added thereto. Subsequently, 7.38 g (40 mmol) of cyanuric chloride was dissolved in 100 mL of CH ₂ Cl ₂ , and the solution was added to the reaction vessel at 2 °C. The reaction was carried out at the same temperature for about 2 hours, and then the reaction temperature was raised to 15 ° C for 1 hour and the temperature was raised to room temperature (23 ° C to 25 ° C) for 5 hours. An additional amount (3.7 g, 60 mmol) of ethylene glycol was added to it. After the mixture was stirred for 2 hours, the organic layer was separated from the aqueous layer, then dried and solvent was removed. The residual viscous material was dried at 35 ° C for 2 days and washed with water and methanol. The obtained product was dissolved in acetone, the solution was precipitated in water and methanol, and the precipitate was dried to obtain a polymer (molecular weight (Mw) = 2,800) including the structural unit represented by Chemical Formula 1-6.

[Chemical Formula 1-6] Synthesis Example 7

4.95 g (126 mmol) of NaOH, 5.4 g (60 mmol) of butanediol and 80 mL of water were placed in a 250 mL flask equipped with a condenser. Subsequently, 0.0036 mmol of BnMe ₃ NCl with PTC was dissolved in 70 mL of water, and the solution was added to the reaction solution. Then, 7.38 g (40 mmol) of cyanuric chloride was dissolved in 100 mL of CH ₂ Cl ₂ , and the resulting solution was added to the reaction vessel at 2 °C. The reaction was carried out at the same temperature for about 2 hours, and then the reaction temperature was raised to 15 ° C for 1 hour and the temperature was raised to room temperature (23 ° C to 25 ° C) for 5 hours. 5.4 g (60 mmol) of butanediol was added thereto. The resulting mixture was further stirred for 2 hours, the organic layer was separated from the aqueous layer and dried, and the solvent was removed. The residual viscous material was washed with water and methanol at 35 ° C for 2 days. The obtained material was dissolved in acetone, the solution was precipitated in water and methanol, and the precipitate therein was dried to finally obtain a polymer (molecular weight (Mw) = 5,600) including the structural unit represented by Chemical Formula 1-7.

[Chemical Formula 1-7] Comparative Synthesis Example 1

5.54 g of 2-thiomethyl-4,6-diol-1,3,5-triazine, 10.00 g of monoallyl diglycidyl isocyanuric acid and 0.40 g as a catalyst Benzyltriethylammonium chloride was added to 63.77 g of propylene glycol monomethyl ether, and the mixture was reacted under reflux for 24 hours to obtain a polymer solution including: a polymer including a structural unit represented by Chemical Formula 2 (molecular weight ( Mw) = 4,300).

[Chemical Formula 2] Preparation Examples The resist underlayer composition 1

The polymer prepared in Synthesis Example 1, PD1174 (TCI Inc.; hardener) (15 parts by weight, based on 100 parts by weight of the polymer) and pyridinium p-toluenesulfonate (1 part by weight, in 100 parts by weight) The polymer was dissolved in a mixed solvent of propylene glycol monomethyl ether and ethyl lactate (weight ratio = 1:1), and the solution was stirred for 6 hours to prepare a resist underlayer composition.

The amount of the mixed solvent is controlled so that the polymer accounts for 2 wt% of the solid content based on the total weight of the resist underlayer composition. Examples 2 to 7

Each of the resist underlayer compositions was prepared in the same manner as in Example 1 except that each of the polymers according to Synthesis Examples 2 to 7 was used. Comparative example 1

A resist underlayer composition was prepared in the same manner as in Example 1 except that the polymer according to Comparative Synthesis Example 1 was used. Evaluation 1 : Optical properties

2 ml of the compositions according to Examples 1 to 7 and Comparative Example 1 were respectively taken, applied to a 4 Å wafer, and spin-coated at 1,500 rpm by using a spin coater (Mikasa Co., Ltd.). second. Subsequently, the coated composition was cured at 230 ° C for 90 seconds to form a thin layer of 30 nm thick, respectively. The refractive index (n) and the extinction coefficient (k) of each thin layer were measured under a condition of 800 A using a VASE ellipsometer (J.A. Woollam Co.).

The results are shown in Table 1.

(Table 1)

Referring to Table 1, the refractive index and extinction coefficient of the resist underlayer composition according to Examples 1 to 7 can be used as a resist underlayer at ArF wavelengths (193 nm and 248 nm), thus confirming the resist of the present invention The underlying composition has an improved reflectivity. Evaluation 2 : Coating uniformity

2 ml of each of the compositions according to Examples 1, 4, 6 and 7 and Comparative Example 1 were respectively taken and applied on an 8 Å wafer, and then the automatic track (ACT-8, TEL) was used at 1,500 rpm. The speed was spin coated for 20 seconds and cured at 230 ° C for 90 seconds to form a thin layer of 300 nm thick, respectively. The thickness of the thin layer was measured at 51 points to compare the uniformity.

The results are shown in Table 2.

In Table 2, the smaller the coating uniformity (%), the greater the degree of improvement.

(Table 2)

Referring to Table 2, the resist underlayer compositions according to Examples 1, 4 and 6 showed improved coating uniformity as compared with the resist underlayer composition according to Comparative Example 1.

Although the present invention has been described in connection with what is presently considered to be illustrative embodiments of the invention, it is understood that the invention is not limited to the disclosed embodiments. Various modifications and equal arrangements are included.

100‧‧‧Base

102‧‧‧ Thin layer

104‧‧‧Resist primer

106‧‧‧Photoresist layer

106a‧‧‧Unexposure zone

106b‧‧‧Exposure zone

110‧‧‧Exposure mask

108‧‧‧resist pattern

112‧‧‧Organic layer pattern

114‧‧‧ Thin layer pattern

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

Claims (9)

A resist underlayer composition comprising: a polymer including a portion represented by Chemical Formula 1; and a solvent, [Chemical Formula 1] Wherein, in Chemical Formula 1, a is an integer of 0 to 3, and when a is 0, R ¹ is hydrogen, halogen, substituted or unsubstituted C1 to C30 alkyl, substituted or unsubstituted C6 to C30 aryl, substituted or unsubstituted C1 to C30 heteroalkyl, substituted or unsubstituted C1 to C30 heteroalkenyl, substituted or unsubstituted C2 to C30 heteroaryl, substituted or not Substituted C1 to C30 alkenyl, substituted or unsubstituted C1 to C30 alkynyl or a combination thereof, when a is an integer from 1 to 3, R ¹ is a point of attachment (*), and R ⁰ is substituted or Unsubstituted C1 to C30 alkylene, substituted or unsubstituted C6 to C30 extended aryl, substituted or unsubstituted C1 to C30 heteroalkyl, substituted or unsubstituted C1 to C30 Heteroalkenyl, substituted or unsubstituted C2 to C30 heteroaryl, substituted or unsubstituted C1 to C30 alkenyl, substituted or unsubstituted C1 to C30 alkynyl, ester ( -COO-), ether (-CO-), -CS- or a combination thereof, R ² and R ^{3 are} independently substituted or unsubstituted C1 to C30 alkyl, substituted or unsubstituted C6 to C30 extended aryl, substituted or unsubstituted C1 to C30 heteroalkyl, substituted or unsubstituted C1 to C30 heteroalkenyl, substituted or unsubstituted C2 to C30 heteroaryl, substituted or unsubstituted C1 to C30 alkenyl, Substituted or unsubstituted C1 to C30 alkynyl, ester (-COO-), ether (-CO-), -CS- or a combination thereof, b and c are independently an integer from 0 to 3, and * is Junction. The resist underlayer composition according to claim 1, wherein in Chemical Formula 1, R ² and R ³ independently include at least one ester (-COO-), ether (-CO-) or -CS-. In the structure, it may include at least one substituted or unsubstituted C1 to C30 alkyl group or a substituted or unsubstituted C1 to C30 heteroalkyl group in its structure. The resist underlayer composition according to claim 1, wherein, in the chemical formula 1, when a is 0, R ¹ is a C1 to C30 alkyl group, and a C1 to C30 alkyl group substituted with at least one hydroxyl group. a C1 to C30 heteroalkyl group, a C1 to C30 heteroalkyl group substituted by at least one hydroxyl group, or a combination thereof, and in the chemical formula 1, when a is 1, R ⁰ includes at least one ester (-COO-), an ether ( -CO-) or -CS- in its structure, or including at least one substituted or unsubstituted C1 to C30 alkylene group, including a substituted or unsubstituted C1 to C30 heteroalkyl group or Unsubstituted C1 to C30 alkylene group, C1 to C30 alkyl group substituted by at least one hydroxyl group or C1 to C30 heteroalkyl group. The resist underlayer composition according to claim 1, wherein the polymer has a weight average molecular weight of 1,000 to 100,000. The resist underlayer composition of claim 1, wherein the composition further comprises a crosslinking agent having at least two crosslinking sites. The resist underlayer composition of claim 1, wherein the composition further comprises an additive of a surfactant, a thermal acid generator, a plasticizer, or a combination thereof. A method of forming a pattern, comprising: forming an etched underlayer on a substrate; applying a resist underlayer composition as described in claim 1 to the etched body layer to form a resist underlayer; Forming a photoresist pattern on the resist underlayer; and sequentially etching the resist underlayer and the etched body layer using the photoresist pattern as an etch mask. The method of forming a pattern according to claim 7, wherein the forming the photoresist pattern comprises: forming a photoresist layer on the resist underlayer; exposing the photoresist layer; and developing the Photoresist layer. The method of forming a pattern according to claim 7, wherein the step of forming the resist underlayer further comprises heat-treating the coated underlayer of the resist at a temperature of 100 ° C to 500 ° C. Things.