KR102101275B1 - Novel polymer and resist underlayer film composition containing the same - Google Patents

Abstract

The present invention relates to a core material of a resist underlayer film composition used in a semiconductor and display manufacturing process, and having excellent etching resistance, thermal stability, surface planarization, gap fill properties, and mechanical properties of a pattern; and a resist underlayer film composition comprising the same.

Description

A novel polymer and a resist underlayer film composition for semiconductor production comprising the same {NOVEL POLYMER AND RESIST UNDERLAYER FILM COMPOSITION CONTAINING THE SAME}

The present invention is a core material of a resist underlayer film composition used in a semiconductor and display manufacturing process having excellent etching resistance, thermal stability, surface planarity, gap fill characteristics, and mechanical properties of a pattern, and a resist underlayer film containing the same Regarding the composition, more specifically, when a polymer containing a repeating unit having a specific structure is included as a resin in a lower layer film composition, excellent thermal stability, surface planarization, gap fill properties, and remarkably improved etch resistance Since it exhibits the mechanical properties of the pattern, it can be used as a hard mask in semiconductor multi-layer lithography processes.

Recently, the semiconductor industry has developed from a pattern of hundreds of nanometers to a very fine technology having a pattern of several to several tens of nanometers. An effective lithography process is essential to realize this ultrafine technology.

A typical lithography process includes forming a material layer on a semiconductor substrate, coating a photoresist layer thereon, exposing and developing to form a photoresist pattern, and then etching the material layer using the photoresist pattern as a mask. .

However, as the size of the pattern to be formed recently decreases, it is difficult to form a fine pattern with a good profile due to high integration of a large scale integrated circuit (LSI) with the typical lithography process described above, and the limitations with existing process materials have.

In particular, in the case of a photoresist used for a patterning process of 40 nm node or less, the higher the resolution, the disadvantages such as roughness of the edge of the pattern and collapse of the pattern occurred. In order to obtain the target pattern resolution, the improvement of the resist resolution due to the high integration of LSI leads to a decrease in the thickness of the resist pattern, and a hard mask performing an etching process impossible with only the resist using an organic film and an inorganic film having high etching resistance in dry etching. Additional processes such as processes have been required. In addition, the decrease in the thickness of the pattern film has a disadvantage in that it does not function as a mask to sufficiently etch the underlying film in the etching process.

In the related art, an organic film and an inorganic film are additionally made under the resist, and then a method of etching the final film is used. However, the organic film has high thermal stability to make the upper inorganic film by chemical vapor deposition (CVD), flattening property to minimize bending of the wafer surface, crack resistance of the film after coating, resistance to dry etching, and maintaining the pattern shape after etching Mechanical properties and the like are required.

In addition, in the conventional process of 40 nm node or more, an amorphous carbon film by a CVD method was used rather than an introduction of an organic film by coating. The amorphous carbon film has excellent dry etching resistance, but has a disadvantage in that it is difficult to flatten the curvature of the wafer surface, and it takes a lot of processing time. To compensate for this, the organic film made by spin coating with the resin-containing composition replaced the role of the amorphous carbon film performed by the CVD method. However, the organic film produced by spin coating is superior to the conventional amorphous carbon film, but has the disadvantage of poor etching resistance and poor thermal stability on the wafer surface. As described above, as the etching resistance decreases, the thickness of the coating film must increase, and the thickness of the coating film increases the defect rate of the process, and also causes a problem of deteriorating the stability of the pattern after pattern formation.

In general, etching resistance increases when the carbon content is high among all the constituent elements of the compound forming the organic film. However, as the carbon content increases, solubility in the organic solvent decreases, and if the molecular weight of the resin is decreased to increase the solubility, the coating film has mechanical mechanical properties.

Since the compounds developed so far have limitations in replacing the amorphous carbon film, there is still a need for an underlayer film material having high etching resistance to replace the amorphous carbon film as well as excellent surface planarity, etching resistance, and properties such as gap fill. .

KR 10-1700150 B1

In order to solve the above problems, the present inventors prepared a polymer including a repeating unit having a specific structure in which two heteroaromatic ring moieties were connected through methylene substituted with an aromatic or heteroaromatic ring, and formed a resist underlayer film. When the solvent composition contains it, it was confirmed that it exhibits significantly improved etching resistance and the present invention was completed.

An object of the present invention is to provide a polymer containing a repeating unit having a specific structure capable of improving mechanical properties of a coating film while having excellent etching resistance and solubility in an organic solvent.

An object of the present invention is to provide a polymer comprising a repeating unit of a specific structure having excellent etching resistance as well as excellent planarization, thermal stability, and gap fill properties.

The present invention provides a resist underlayer film composition for semiconductor production by improving the heat resistance, thermal stability, surface planarity, pattern edge uniformity, and pattern mechanical properties by containing a polymer containing a repeating unit having a specific structure. It is aimed at providing.

In order to achieve the above object, the present invention provides a polymer comprising a repeating unit represented by Chemical Formula 1:

[Formula 1]

또는

이고;A and B are each independently

or

ego;

X and Y are each independently O or NR;

R is hydrogen, allyl, C ₁ -C ₂₀ alkyl or C ₆ -C ₂₀ aryl;

R ₁ is hydrogen, substituted or unsubstituted C ₆ -C ₂₀ aryl or substituted or unsubstituted C ₃ -C ₂₀ heteroaryl;

R ₂ to R ₅ are each independently hydrogen, hydroxy, C ₁ -C ₂₀ alkyl or C ₆ -C ₂₀ aryl;

또는

이고;W is

or

ego;

Ar ₁ is substituted or unsubstituted C ₆ -C ₂₀ aryl or substituted or unsubstituted C ₃ -C ₂₀ heteroaryl;

L ₁ is C ₆ -C ₂₀ arylene or C ₃ -C ₂₀ heteroarylene.

The polymer may include repeating repeats of the following Chemical Formula 2 or Chemical Formula 3:

[Formula 2]

[Formula 3]

In Formulas 2 and 3, R ₁ and W are the same as defined in Formula 1;

X ₁ , X ₂ , Y ₁ and Y ₂ are each independently O or NR;

R is hydrogen, allyl, C ₁ -C ₂₀ alkyl or C ₆ -C ₂₀ aryl;

R _3a , R _3b , R _5a and R _5b are each independently hydrogen, hydroxy, C ₁ -C ₂₀ alkyl or C ₆ -C ₂₀ aryl.

The polymer may include repeating sites specifically selected from the following structures:

In the above, R ₁ is C ₆ -C ₁₂ aryl or C ₃ -C ₁₂ heteroaryl;

R _3a , R _3b , R _5a and R _5b are each independently hydrogen, hydroxy, C ₁ -C ₁₀ alkyl or C ₆ -C ₁₂ aryl;

R _6a , R _6b , R _6c and R _6d are each independently hydrogen, allyl, C ₁ -C ₁₀ alkyl or C ₆ -C ₁₂ aryl;

Ar ₁ is C ₆ -C ₁₂ aryl or C ₃ -C ₂₀ heteroaryl;

L ₁ is C ₆ -C ₁₂ arylene or C ₃ -C ₁₂ heteroarylene.

The weight average molecular weight of the polymer may be 1,000 g / mol or more.

The present invention provides a resist underlayer film composition comprising the polymer.

The underlayer film composition may include the polymer in an amount of 0.5 to 50% by weight based on the total resist underlayer film composition. In the case of having the above-mentioned content range, it is preferable because it has excellent etching resistance and can express thermal stability, coating uniformity, gap fill properties, and excellent solubility in an organic solvent.

The underlayer film composition may further include one or more selected from crosslinking agents, crosslinking catalysts, organic solvents, and surfactants, but is not limited thereto.

The crosslinking agent is not limited, and may specifically include any one or two or more selected from compounds represented by Formulas A to C below.

[Formula A]

[Formula B]

[Formula C]

In the above formulas A to C,

R ^a1 to R ^a4 and R ^b1 to R ^b6 are each independently hydrogen, methyl or butyl;

이고;R ^d1 to R ^d3 are each independently hydrogen, C ₁ -C ₂₀ alkyl, or

ego;

R ^c1 to R ^c3 and R ^e1 to R ^e3 are each independently hydrogen or methyl.

The crosslinking catalyst is not limited, but may be specifically a compound represented by the following Chemical Formula D.

[Formula D]

In the above formula D,

R 'is H, C ₁ -C ₂₀ alkyl, C ₃ -C ₂₀ cycloalkyl, C ₆ -C ₂₀ aryl or C ₃ -C ₂₀ heteroaryl, or an onium ion containing a hydrocarbon group;

The cycloalkyl, aryl or heteroaryl of R 'is C ₁ -C ₂₀ alkyl, halogen, cyano, hydroxy, C ₃ -C ₂₀ cycloalkyl, C ₁ -C ₂₀ alkoxy, C ₆ -C ₂₀ aryloxy, C ₆ -C ₂₀ aryl and C ₃ -C ₂₀ heteroaryl may be further substituted with one or more selected from the group consisting of.

In one embodiment of the present invention, the onium ion containing the hydrocarbon group is a tetraC ₁ -C ₂₀ alkylammonium cation, pyrrolidinium cation, morpholinium cation, imidazolium cation, tetrahydropyrimidium cation, piperage It may be a nium cation, a piperidinium cation, a pyridinium cation, or a tetraC ₁ -C ₂₀ alkylphosphonium cation.

The novel polymer according to the present invention can be used as a core material of the underlayer composition. The resist underlayer film composition comprising the polymer according to the present invention not only exhibits significantly improved etching resistance by containing a polymer containing a repeating unit of a specific structure, but also has increased heat resistance, thermal stability, surface planarization, pattern edge It is possible to form a resist underlayer film having excellent uniformity and mechanical properties of a pattern.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art to which the present invention pertains can easily practice. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein.

Also, unless defined otherwise, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terms used in the description of the present invention are only for effectively describing a specific embodiment and are not intended to limit the present invention.

Also, the singular form used in the specification and the appended claims may be intended to include the plural form unless otherwise indicated in the context.

Unless otherwise defined herein, 'substituted' means that the hydrogen atom in the compound is a halogen atom (F, Br, Cl, or I), carboxyl, cyano, nitro, oxo (= 0), thio (= S) ), C1-C20 alkyl, halo C1-C20 alkoxy, C2-C20 alkenyl, C2-C20 alkynyl, C6-C20 aryl, C6-C20 aryloxy, C1-C20 alkoxycarbonyl, C1-C20 alkylcarbonyloxy , C2-C20 alkenylcarbonyloxy, C2-C20 alkynylcarbonyloxy, aminocarbonyl, C1-C20 alkylcarbonylamino, C2-C20 alkenylcarbonylamino, C2-C20 alkylcarbonylamino, C2- C20 alkenylcarbonylamino, C2-C20alkynylcarbonylamino, SR ', NR''R' '' (R 'to R' '' are each independently hydrogen, C1-C20 alkyl, C2-C20 alkenyl , C2-C20 alkynyl, C3-C20 cycloalkyl or C6-C20 aryl), C1-C20alkylsilyl, C2-C20alkenylsilyl, C2-C20alkynylsilyl, C6-C20arylsilyl, C6-C20arylC1 -C20 alkyl, C6-C20 aryl C2-C20 alkenyl, C6-C20 aryl C2-C20 alkynyl, C3-C20 cycloalkyl, C3-C20 cycloalkyl C1-C20 al Kill, C3-C20 cycloalkenyl, C6-C20 heteroaryl, C3-C20 heterocycloalkyl, and C3-C20 heteroaryl C1-C20 alkyl.

As used herein, "alkyl" refers to a monovalent straight chain or ground saturated hydrocarbon radical consisting of only carbon and hydrogen atoms, examples of such alkyl radicals being methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, Pentyl, hexyl, octyl, nonyl, and the like.

As used herein, "aryl" is an organic radical derived from an aromatic hydrocarbon by removal of one hydrogen, and is preferably a single or fused ring system comprising 4 to 7, preferably 5 or 6 ring atoms in each ring. It includes, and includes a form in which a plurality of aryls are connected by a single bond. The fused ring system can include an aliphatic ring, such as a saturated or partially saturated ring, and necessarily contains one or more aromatic rings. In addition, the aliphatic ring may include nitrogen, oxygen, sulfur, carbonyl, and the like in the ring. Specific examples of the aryl radical include phenyl, naphthyl, biphenyl, indenyl, fluorenyl, phenanthrenyl, anthracenyl, triphenylenyl, pyrenyl, chrysenyl, naphthacenyl, 9,10-dihydro And anthracenyl.

“Arylalkyl” as used herein refers to an alkyl radical substituted with an aryl radical as defined above. Examples of such arylalkyl radicals include, but are not limited to, benzyl and the like.

“Cycloalkyl” as used herein refers to a monocyclic, bicyclic, or tricyclic ring system. Monocyclic ring systems are exemplified by saturated cyclic hydrocarbon groups containing 3 to 8 carbon atoms. Examples of monocyclic ring systems include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl. Bicyclic ring systems are also exemplified by a bridged monocyclic ring system in which two nonadjacent carbon atoms of a monocyclic ring are linked by an alkylene bridge between one and three additional carbon atoms. Examples of bicyclic ring systems include bicyclo [3.1.1] heptane, bicyclo [2.2.1] heptane, bicyclo [2.2.2] octane, bicyclo [3.2.2] nonane, bicyclo [3.3.1 ] Nonane and bicyclo [4.2.1] nonane. Tricyclic ring systems are also exemplified by bicyclic ring systems in which two nonadjacent carbon atoms of a bicyclic ring are linked or linked by an alkylene bridge between 1 and 3 carbon atoms. Representative examples of tricyclic ring systems include, but are not limited to, tricyclo [3.3.1.03,7] nonane and tricyclo [3.3.1.13,7] decane (adamantane).

As used herein, "heteroaryl" includes 1 to 4 heteroatoms selected from B, N, O, S, P (= O), Si and P as aromatic ring skeleton atoms, and the remaining aromatic ring skeleton atoms are carbon. Aryl group means a 5- to 6-membered monocyclic heteroaryl, and a polycyclic heteroaryl condensed with one or more benzene rings, and may be partially saturated. In addition, heteroaryl in the present invention also includes a form in which one or more heteroaryls are connected by a single bond.

In the present specification, “alkoxy” and “aryloxy” refer to a -O-alkyl radical and a -O-aryl radical, respectively, where “alkyl” and “aryl” are as defined above.

Hereinafter, the present invention will be described in more detail.

The present invention provides a polymer comprising a repeating unit represented by the following formula (1) as a core material useful for forming an underlayer film having excellent etching resistance.

[Formula 1]

또는

이고;A and B are each independently

or

ego;

X and Y are each independently O or NR;

R is hydrogen, allyl, C ₁ -C ₂₀ alkyl or C ₆ -C ₂₀ aryl;

R ₁ is hydrogen, substituted or unsubstituted C ₆ -C ₂₀ aryl or substituted or unsubstituted C ₃ -C ₂₀ heteroaryl;

R ₂ to R ₅ are each independently hydrogen, hydroxy, C ₁ -C ₂₀ alkyl or C ₆ -C ₂₀ aryl;

또는

이고;W is

or

ego;

Ar ₁ is substituted or unsubstituted C ₆ -C ₂₀ aryl or substituted or unsubstituted C ₃ -C ₂₀ heteroaryl;

L ₁ is C ₆ -C ₂₀ arylene or C ₃ -C ₂₀ heteroarylene.

The polymer according to one embodiment not only exhibits significantly improved etching resistance, but also has excellent coating uniformity and thermal stability, and has high solubility in an organic solvent to effectively form a resist underlayer film by a spin-on coating method. In addition, when formed by a spin-on coating method on a lower layer having a predetermined pattern, gap-fill characteristics and planarization characteristics that can fill gaps between patterns are also excellent, and are hard masks for semiconductor multi-layer lithography processes. It can be used.

Specifically, the polymer according to an embodiment may be a polymer comprising a repeating unit represented by the following Chemical Formula 2 or Chemical Formula 3:

[Formula 2]

[Formula 3]

In Formulas 2 and 3, R ₁ and W are the same as defined in Formula 1;

X ₁ , X ₂ , Y ₁ and Y ₂ are each independently O or NR;

R is hydrogen, allyl, C ₁ -C ₂₀ alkyl or C ₆ -C ₂₀ aryl;

R _3a , R _3b , R _5a and R _5b are each independently hydrogen, hydroxy, C ₁ -C ₂₀ alkyl or C ₆ -C ₂₀ aryl.

The polymer according to an embodiment may preferably include at least one repeating unit selected from the following structures.

In the above, R ₁ is C ₆ -C ₁₂ aryl or C ₃ -C ₁₂ heteroaryl;

R _3a , R _3b , R _5a and R _5b are each independently hydrogen, hydroxy, C ₁ -C ₁₀ alkyl or C ₆ -C ₁₂ aryl;

R _6a , R _6b , R _6c and R _6d are each independently hydrogen, allyl, C ₁ -C ₁₀ alkyl or C ₆ -C ₁₂ aryl;

Ar ₁ is C ₆ -C ₁₂ aryl or C ₃ -C ₂₀ heteroaryl;

L ₁ is C ₆ -C ₁₂ arylene or C ₃ -C ₁₂ heteroarylene.

In one embodiment, R _3a , R _3b , R _5a and R _5b are each independently hydrogen, hydroxy or C ₁ -C ₄ alkyl; R ₁ and Ar ₁ are each independently C ₆ -C ₁₂ aryl; R _6a , R _6b , R _6c and R _6d are each independently hydrogen, allyl or C ₁ -C ₄ alkyl; L ₁ may be C ₆ -C ₁₂ arylene.

The polymer according to an embodiment may more preferably include at least one repeating unit selected from the following structures, but is not limited thereto.

In one embodiment, the weight average molecular weight (Mw) in terms of polystyrene by gel permeation chromatography (GPC) of the polymer is 1,000 g / mol or more, preferably 1,500 g / mol or more in terms of solubility in an organic solvent, 1,500 to 40,000 g / mol, and more preferably 2,000 to 20,000 g / mol. When the weight average molecular weight of the polymer is less than 1,000 g / mol, not only coating properties are deteriorated, but a large amount of fumes may be generated when baking at a high temperature. Within the above weight average molecular weight range, solubility in an organic solvent is excellent, and coating uniformity can be improved.

The polymer according to an embodiment may be synthesized through a known polymerization reaction, and polymerize at least one second monomer selected from the following first monomers of Formula M-1 and M-2 to M-4 below. It can be prepared by reaction, but is not limited thereto.

[Formula M-1]

[Formula M-2]

[Formula M-3]

[Formula M-4]

In the above formulas M-1 to M-4,

A, B, R ₁ , Ar ₁ and L ₁ are the same as defined in Formula 1 above;

R ₁₁ and R ₁₂ are each independently C ₁ -C ₂₀ alkyl or C ₆ -C ₂₀ aryl;

R ₁₃ and R ₁₄ are each independently hydroxy or C ₁ -C ₂₀ alkoxy.

The first monomer may be specifically represented by the following formula M-1a or formula M-1b:

[Formula M-1a]

[Formula M-1b]

In Formulas M-1a and M-1b, R ₁ is as defined in Formula 1;

X ₁ , X ₂ , Y ₁ and Y ₂ are each independently O or NR;

R is hydrogen, allyl, C ₁ -C ₂₀ alkyl or C ₆ -C ₂₀ aryl;

R _2a , R _2b , R _3a , R _3b , R _4a , R _4b , R _5a and R _5b are each independently hydrogen, hydroxy, C ₁ -C ₂₀ alkyl or C ₆ -C ₂₀ aryl.

The polymerization reaction may be performed in the presence of an acid catalyst, and any acid catalyst may be used in the case of a strong acid such as toluenesulfonic acid, sulfuric acid, dialkyl sulfate, hydrochloric acid, and the like. The amount of the acid catalyst used may be variously selected depending on the type of acid used.

The amount of the second monomer used is not particularly limited, but may be 0.5 to 5 moles, preferably 1 to 2 moles, per 1 mole of the first monomer.

The polymerization reaction temperature is possible in the range of 90 to 170 ° C, but when the temperature is low, there is a disadvantage that the polymerization time is increased, and if the reaction temperature is too high, a lot of side products are generated and solubility is lowered. The most suitable temperature may be about 120 ~ 140 ℃.

A solvent may be used in the polymerization reaction, and any of ketones, esters, ethers, and aromatic solvents may be used, and aromatic solvents, ketones, or esters may be considered in consideration of the dissolution characteristics of raw materials or product dissolution properties. The solvent may be preferred. The amount of these solvents used can be appropriately set depending on the type of raw material used and the type of catalyst used, furthermore, reaction conditions, etc., and is not particularly limited. In addition, after completion of the reaction, the compound may be obtained by precipitating in hexane, which is a non-polar solvent, and filtering and then vacuum drying to obtain the compound.

In addition, the present invention provides a resist underlayer film composition comprising a polymer comprising a repeating unit represented by Chemical Formula 1.

The resist underlayer film composition according to an embodiment may form a lower layer film on a substrate such as a silicon wafer by spin coating, spin on carbon, and the like, and is repeated from polymerization of the specific monomers. Since it contains a polymer containing a unit, it is possible to express significantly improved etching resistance. In addition, since the polymer has excellent thermal stability, coating uniformity, gap fill properties, and solubility in an organic solvent, when included in a resist underlayer composition, in addition to etching resistance, thermal stability, surface planarization, uniformity of pattern edges And since the mechanical properties of the pattern are excellent, it can be applied to a hard mask process or a process for making the wafer surface flat, and it can be used for gap filling and double patterning, and thus has various advantages.

In particular, the resist underlayer film composition comprising a polymer containing the repeating unit of Formula 1 as a resin exhibits significantly improved etching resistance, and thus can be used as a hard mask in a semiconductor multi-layer lithography process because it can manufacture a uniform underlayer film. have.

The resist underlayer film composition according to an embodiment may include a polymer and an organic solvent including the repeating unit of Chemical Formula 1.

In one embodiment, the polymer may be included in an amount of 0.5 to 50% by weight relative to the entire resist underlayer composition, and in an aspect for excellent etching resistance, 1 to 30% by weight, preferably 5 to 20% by weight have. In the above content range, the solubility of the resist underlayer film composition and the coatability at the time of film formation may be excellent, and the etching resistance may be significantly improved later.

The resist underlayer film composition according to an embodiment may include 0.5 to 50% by weight of the polymer including the repeating unit of Chemical Formula 5 and the residual amount of the organic solvent with respect to the entire resist underlayer film composition.

The resist underlayer film composition according to an embodiment may further include one or more selected from a crosslinking agent, a crosslinking catalyst, and a surfactant, but is not limited thereto.

In one embodiment, the resist underlayer film composition may be prepared by dissolving the polymer alone in an organic solvent, or by adding an additive such as a crosslinking agent, a crosslinking catalyst, or a surfactant. That is, the above components can be blended in a conventional manner to prepare a resist underlayer film composition. For example, after dissolving the polymer, crosslinking agent, and crosslinking catalyst of the present invention in an organic solvent, the particulate impurities are completely removed through a filtration process. By doing so, a resist underlayer film composition can be prepared.

In one embodiment, the crosslinking agent is for inducing a crosslinking reaction to further cure the underlayer film, and any compound that crosslinks at high temperature such as melamine derivatives, glycoluryl derivatives, methylol derivatives, and epoxy derivatives can be used without particular limitation. It is possible.

Among the specific examples of the crosslinking agent, specific examples of the epoxy derivative include tris (2,3-epoxypropyl) isocyanurate, trimethylolmethanetriglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglyceride. Cidyl ether and the like, and specific examples of the melamine derivatives include 1 to 6 methylol groups of hexamethylolmelamine, hexamethoxymethylmelamine, and hexamethylolmelamine which are methoxymethylated or mixtures thereof, hexa Methoxyethylmelamine, hexaacyloxymethylmelamine, and 1 to 6 acyloxymethylated compounds of methylol groups of hexamethylolmelamine or mixtures thereof, and the like, and specific examples of the glycouryl derivatives are tetramethylolglycol Compounds in which 1 to 4 of the methylol groups of ruryl, tetramethoxyglycoluril, tetramethoxymethylglycoluril, and tetramethylolglycolyl are methoxymethylated, or mixtures thereof, te La methyl may be mentioned 1 to 4 dogs acyloxy methylated compound or a mixture of the methylol group of the all-glycoside ruril.

The crosslinking agent according to an embodiment may specifically include any one or two or more selected from compounds represented by Formulas A to C below.

[Formula A]

[Formula B]

[Formula C]

In the above formulas A to C,

R ^a1 to R ^a4 and R ^b1 to R ^b6 are each independently hydrogen, methyl or butyl;

이고;R ^d1 to R ^d3 are each independently hydrogen, C ₁ -C ₂₀ alkyl, or

ego;

R ^c1 to R ^c3 and R ^e1 to R ^e3 are each independently hydrogen or methyl.

The structure of a crosslinking agent that can be preferably used according to one embodiment is described below, but is not limited thereto.

In one embodiment, the amount of the crosslinking agent is not particularly limited, but may be 1 to 30 parts by weight, preferably 3 to 15 parts by weight with respect to 100 parts by weight of the polymer. By inducing a sufficient crosslinking reaction in the above content range, it is possible to prevent the disadvantage of melting in a solvent in the upper organic film coating process, and to prevent the generation of fumes of residual crosslinking agent after crosslinking, thereby improving the stability of the resist.

In one embodiment, the crosslinking catalyst is intended to further promote a crosslinking reaction, and an acid catalyst or an acid generator may be used. As the acid generator, a thermal acid generator that generates acid by thermal decomposition may be used for light irradiation. It is possible to use both acid generators that generate acids.

In one embodiment, the acid catalyst or acid generator is not particularly limited, but may be specifically a compound represented by the following formula (D).

[Formula D]

In the above formula D,

R 'is hydrogen, C ₁ -C ₂₀ alkyl, C ₃ -C ₂₀ cycloalkyl, C ₆ -C ₂₀ aryl or C ₃ -C ₂₀ heteroaryl, or an onium ion containing a hydrocarbon group, specifically, tetraC _1- C ₂₀ alkylammonium cation, pyrrolidinium cation, morpholinium cation, imidazolium cation, tetrahydropyrimidium cation, piperazinium cation, piperidinium cation, pyridinium cation or tetraC ₁ -C ₂₀ alkylphosphonium Cations;

The cycloalkyl, aryl or heteroaryl of R 'is C ₁ -C ₂₀ alkyl, halogen, cyano, hydroxy, C ₃ -C ₂₀ cycloalkyl, C ₁ -C ₂₀ alkoxy, C ₆ -C ₂₀ aryloxy, C ₆ -C ₂₀ aryl and C ₃ -C ₂₀ heteroaryl may be further substituted with one or more selected from the group consisting of.

Specifically, an organic acid such as p-toluene sulfonic acid monohydrate may be used as the acid generator, and a thermal acid generator (TAG) for storage stability may be used. The thermal acid generator is an acid generator that releases acid upon heat treatment, such as pyridinium p-toluene sulfonate, 2,4,4,6-tetrabromocyclohexadioneone, benzointosylate, 2-nitro Benzyl tosylate, alkyl esters of organic sulfonic acid, and the like.

The acid catalyst or acid generator is not limited, and may be, for example, one or two or more compounds selected from the following structures.

In one embodiment, the amount of the crosslinking catalyst is not particularly limited, but may be included in an amount of 0.05 to 10 parts by weight, preferably 0.3 to 5 parts by weight based on 100 parts by weight of the polymer. When using a crosslinking catalyst in the above content range, it may have an appropriate curing rate and improved physical properties of the cured product.

In one embodiment, the organic solvent that can be used is any matter as long as it dissolves the polymer, crosslinking agent, and crosslinking catalyst of the present invention, but it is generally preferable to use an organic solvent used in the semiconductor manufacturing process. Specific examples of the organic solvent include cyclopentanone, cyclohexanone, 2-heptanone, 3-heptanone, 4-heptanone, ethyl lactate, gamma-butyrolactone, toluene, xylene, methyl ethyl ketone, Methyl isopropyl ketone, methyl butyl ketone, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, Diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, 3-ethoxy Ethyl cypropionate, tert-butyl acetate, tert-butyl propionate, propylene glycol monomethyl ether acetate, propylene glycol mono tert-butyl ether acetate, dimethyl sulfoxide, N, N-dimethylformamide, N-methylacetamide, N, And N-dimethylacetamide, N-methylpyrrolidone, and the like, but are not particularly limited to these. These solvents can be used alone or in combination of two or more. Among the organic solvents, cyclohexanone, 2-heptanone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, gamma-butyrolactone, ethyl lactate, dimethyl sulfoxide, N, N-dimethylacetamide, N It is preferred to use -methylpyrrolidone and mixtures thereof.

The amount of the organic solvent can be appropriately adjusted according to the physical properties of the organic solvent, that is, volatility, viscosity, and the like, so that a uniform resist underlayer film can be formed.

In one embodiment, when forming a resist underlayer film, a surfactant may be further included to improve coating uniformity. Examples of the surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, and polyoxyethylene oleyl ether, and polyoxyethylene octylphenyl ether. , Polyoxyethylene alkylaryl ethers such as polyoxyethylene nonylphenyl ether, polyoxyethylene-polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan mono Sorbitan fatty acid esters such as oleate, sorbitan trioleate, sorbitan tristearate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, poly Oxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate, etc. Nonionic surfactants, such as polyoxyethylene sorbitan fatty acid esters, EFTOP EF301, EFTOP EF303, EFTOPEF352 (Mitsubishi Materials Electronic Chemicals Co., Ltd.), MEGAFAC F171, MEGAFAC F173, MEGAFAC R-30, MEGAFAC R- 30N, MEGAFAC R-40, MEGAFAC R-40-LM (manufactured by DIC corporation), FLUORAD FC430, FLUORADFC431 (manufactured by Sumitomo 3M Limited), Asahi Guard AG710, SURFLON S-382, SURFLON SC101, SURFLON SC102, SURFLON SC103, SURFLON SC104 , SURFLON SC105, SURFLON SC106 (manufactured by Asahi Glass Co., Ltd.), a fluorine-based surfactant, organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.) It can be used, but is not limited thereto. In the case of using the surfactant, the content of the surfactant is 0.01 to 1 part by weight, preferably 0.01 to 0.5 part by weight, with respect to 100 parts by weight of the entire resist underlayer film composition for good resist film quality, but is not limited thereto. .

The resist underlayer film composition according to an embodiment has a film-forming property capable of forming a film by conventional spin coating.

The resist underlayer film composition according to an embodiment may be coated on a substrate by spin coating, and then a complete film may be formed through a baking process. The baking process may be performed at 200 to 450 ° C. for 30 to 180 seconds, but is not limited thereto. When the baking process within the above range, a lower layer film of a uniform thickness can be formed by sufficient crosslinking reaction. In addition, although the thickness of the underlayer film is appropriately selected, it is preferable to be 30 to 20,000 nm, particularly 50 to 15,000 nm. The coating process, the thickness of the underlayer film, the heating temperature and time are not limited to the above range, and may be manufactured in various different forms depending on the purpose.

In addition, the present invention provides a method of forming a pattern using the resist underlayer film composition, wherein the pattern forming method of the present invention comprises the steps of applying and heating the underlayer film resist composition on a substrate to form a resist underlayer film; Exposing the resist underlayer film; And developing using a developer.

When explaining the pattern forming method of the present invention in detail as follows.

First, as a step of applying the resist composition on a previously prepared substrate, the substrate is not particularly limited, and for example, may be arbitrarily selected from a silicon wafer, a glass substrate, and a flexible substrate. The method of applying the resist composition in the pattern forming method of the present invention may be arbitrarily selected from spin coating, dipping, spraying, transfer, spill coating, roll coating, and the like, but is not limited.

Next, the resist composition coated on the substrate is irradiated with light or heat is applied to evaporate the solvent of the resist composition to form a resist film. At this time, the curing of the resist film may proceed somewhat.

Next, the formed resist film is selectively exposed. Here, selectively exposing means exposing to form a desired resist pattern, and for example, a mask for forming a desired photoresist pattern when selectively exposing may be used. The light source at the time of exposure may be arbitrarily selected according to the type of the acid generator from among the ultraviolet ray I-ray, far ultraviolet ray KrF excimer laser, ArF excimer laser, F2 excimer laser, X-ray, and charged particle beam electron beam. For exposure, the exposed photoresist film may be cured as necessary.

Next, a pattern is formed by developing the exposed photoresist film using a developer. The developer may be any of those commonly used, but for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium methanesilicate, ammonia water, ethylamine, n-propylamine, triethylamine, tetramethylammonium hydroxide , Tetraethylammonium hydroxide or the like may be used alone or in combination of two or more kinds, preferably, an aqueous solution containing tetramethylammonium hydroxide can be used.

Hereinafter, the present invention will be described in more detail through specific examples and comparative examples. The following examples are intended to illustrate the invention, but the invention is not limited by the following examples.

[Method of measuring properties]

1) Weight average molecular weight (Mw)

GPC column: TSKgel SuperMultipore Hz-N (Tosoh Corporation)

Column temperature: 40 ℃

Solvent: Tetrahydrofuran (THF)

Flow rate: 1 ml / min

Standard sample: Polystyrene (Tosoh Corporation)

2) degree of crosslinking

In order to confirm the crosslinking ability of the prepared lower layer film, after the heating process was performed, the thickness of the lower layer film was measured, and the wafer on which the lower layer film was formed was immersed in an ethyl lactate solution for 1 minute, and distilled water was used to completely remove ethyl lactate. And washed for 10 seconds on a hot plate at 100 ° C., and again measured the thickness of the lower layer film to confirm the solubility of the lower layer film.

3) Surface uniformity / cracking

The solution of the lower layer film composition was applied on a SiO ₂ wafer substrate with a spin coater to a thickness of 300 nm, and fired on a hot plate at 400 ° C. for 1 minute to form a lower layer film. Using a scanning electron microscope (SEM), the cross-sectional shape of the SiO ₂ wafer substrate on which the underlayer film composition was applied was observed, and surface uniformity of the pattern by the underlayer film was evaluated.

4) Presence or absence of crack (gap fill property)

The cross section of the pattern was observed using an FE-SEM (electrospinning electron microscope) to determine the presence or absence of voids.

5) fume generation

Each of the lower layer film forming compositions was applied onto a silicon wafer using a spin coater. The coated wafer was baked on a hot plate at 400 ° C. for 1 minute to form a lower layer film. These lower layer films were scraped off from the silicon wafer to obtain a powder. The thermogravimetric phenomenon at 400 ° C of the obtained powder was measured by TG / DTA (TG-DTA2010SR manufactured by BRUKER).

6) Etch resistance

After spin-coating the composition for forming each of the lower layer films of Examples and Comparative Examples on a silicon wafer having an diameter of 8 inches, heating was performed at 180 ° C for 60 seconds in a hot plate having an oxygen concentration of 20% by volume, and then continued at 400 ° C for 60 seconds. Heating to form a lower layer film having a film thickness of 0.3 µm, and the lower layer film was CF ₄ / Ar / O ₂ (CF ₄ : 40 mL / min, Ar: 20 mL) using an etching apparatus “EXAM” (manufactured by Shinko Seiki). / min, O ₂ : 5 ml / min; pressure: 20 Pa; RF power: 200 W; treatment time: 40 seconds; temperature: 15 ° C) was etched. Then, the film thickness before and after the etching treatment was measured to calculate the etching rate (nm / min), and the etching resistance was evaluated based on the following criteria.

"◎": When the etching rate is less than 130nm / min

"○": When the etching rate is 130 nm / min or more and less than 150 nm / min

"△": when the etching rate is 150 to 200nm / min

"×": When the etching rate exceeds 200 nm / min

[Example 1] Preparation of polymer A

The flask was charged with 37.2 g (0.1 mol) of bis (3-indolyl) naphthylmethane, 11.7 g (0.11 mol) of benzaldehyde, and 0.5 g (0.003 mol) of p-toluenesulfonic acid, and 100 g of o-dichlorobenzene as a solvent. After adding 50 g of toluene, the reaction temperature was raised to 130 ° C. and stirred. After 4 hours of heating, the reaction was measured by GPC, and when the weight average molecular weight in terms of polystyrene reached 3,500, the reaction temperature was cooled to room temperature. The reaction mixture was neutralized with pyridine and then washed with distilled water. The organic layer was separated and precipitated in excess n-heptane. The solid was filtered and dried to obtain 28 g of Polymer A.

[Example 2] Preparation of polymer B

26 g of polymer B was obtained by reacting in the same manner as in Example 1, except that 17.2 g (0.11 mol) of naphthylaldehyde was used instead of 11.7 g (0.11 mol) of benzaldehyde of Example 1.

[Example 3] Preparation of polymer C

Polymer C was reacted in the same manner as in Example 1, except that 18.3 g (0.11 mol) of 1,4-bis (methoxymethyl) benzene was used instead of 11.7 g (0.11 mol) of benzaldehyde of Example 1 above. 26g was obtained.

[Example 4] Preparation of polymer D

Example 1 except that bis (3-carbazolyl) naphthylmethane 47.2 g (0.11 mol) was used instead of 37.2 g (0.1 mol) of bis (3-indolyl) naphthylmethane of Example 1. Reaction was conducted in the same manner to obtain 41 g of Polymer D.

[Comparative Example 1] Preparation of polymer E

The same method as in Example 2 except that 35 g (0.1 mol) of bis (hydroxyphenyl) fluorene was used instead of 37.2 g (0.1 mol) of bis (3-indolyl) naphthylmethane of Example 2 above. It reacted with and obtained 45g of polymer E.

[Examples 5 to 8 and Comparative Example 2]

A lower layer film composition was prepared according to the composition of Table 1 below. Resin was used to select the polymers A to D prepared in Examples 1 to 4, 1,3,4,6-tetrakis (methoxymethyl) glycoluril was used as a crosslinking agent, and pyrilysis was used as a crosslinking catalyst. Dinium toluene sulfonate was used, and cyclohexanone was used as a solvent. After dissolving the resin, the crosslinking agent, and the crosslinking catalyst in 90.5 g of the components and contents in Table 1, particulate impurities were completely removed using a 0.05 μm filter.

Polymer E prepared in Comparative Example 1 was used to examine the difference in effect due to the resin. The compositions of Examples and Comparative Examples are summarized in Table 1 below.

Resin Crosslinker Bridge
catalyst Kinds usage Example 5

(중합체 A)

(Polymer A) 9 g 0.45 g 0.045 g Example 6

(Polymer B) 9 g 0.45 g 0.045 g Example 7

(Polymer C) 9 g 0.45 g 0.045 g Example 8

(Polymer D) 9 g 0.45 g 0.045 g Comparative Example 2

(Polymer E) 9 g 0.45 g 0.045 g

[Physical property evaluation]

After spin-coating the compositions of Examples and Comparative Examples on a wafer, baking at 400 ° C. for 60 seconds, the surface was observed using a naked eye or a scanning electron microscope (SEM). Through surface observation, the degree of crosslinking, surface uniformity, cracks, pattern roughness, fume generation (400 ° C) and etching resistance were evaluated as ◎: very good, ○: good, △: medium, ×: not good, The results are shown in Table 2 below.

Bridge
Degree surface
Uniformity crack
The presence or absence Fume generation
(400 ℃) Etch resistance Example 5 ◎ ◎ ◎ ◎ ◎ Example 6 ◎ ◎ ◎ ◎ ◎ Example 7 ◎ ◎ ◎ ◎ ◎ Example 8 ◎ ◎ ◎ ◎ ◎ Comparative Example 2 ○ ○ ◎ ○ Δ

As shown in Table 2, when confirming the crosslinking degree, surface uniformity, etching resistance, fume generation degree, and presence or absence of cracks, Examples of the present invention were confirmed to have superior properties compared to Comparative Examples.

Particularly, Examples 5 to 8 of the present invention exhibited significantly superior etching resistance compared to Comparative Example 2 using a conventionally known resin.

The present invention uses a polymer having a specific structure in which two indole or carbazole moieties are linked through methylene substituted by an aromatic ring with a resin, and thus, a polymer E in which two aromatic rings, benzene rings, are linked by fluorene. Compared to Example 2, it was confirmed that it has a markedly etched etching resistance, from which it can be seen that the etching resistance is affected by the structure of the parent nucleus of the resin.

That is, the resist underlayer film composition of the present invention comprising a polymer of a specific structure as a resin has an advantage of excellent crosslinking degree and surface uniformity with excellent etching resistance and excellent heat resistance, thereby preventing fume generation and crack formation. Was confirmed.

As described above, in the present invention, a novel polymer and a composition for forming a resist underlayer film including the same have been described through specific matters and limited examples, but this is provided only to help a more comprehensive understanding of the present invention. It is not limited to the above embodiment, and those skilled in the art to which the present invention pertains can make various modifications and variations from these descriptions.

Accordingly, the spirit of the present invention should not be limited to the described embodiments, and should not be determined, and all claims that are equivalent or equivalent to the scope of the claims as well as the claims described below belong to the scope of the spirit of the invention. .

Claims (9)

delete Polymer comprising a repeating unit of the formula (2):
[Formula 2]

In Chemical Formula 2,
R ₁ is C ₆ -C ₂₀ aryl or C ₃ -C ₂₀ heteroaryl;
X ₁ and X ₂ are each independently O or NR;
R is hydrogen, allyl, C ₁ -C ₂₀ alkyl or C ₆ -C ₂₀ aryl;
R _3a and R _3b are each independently hydrogen, hydroxy, C ₁ -C ₂₀ alkyl or C ₆ -C ₂₀ aryl;
W is

or

ego;
Ar ₁ is C ₆ -C ₂₀ aryl or C ₃ -C ₂₀ heteroaryl;
L ₁ is C ₆ -C ₂₀ arylene or C ₃ -C ₂₀ heteroarylene. According to claim 2,
The polymer comprising a repeating unit selected from the following structure:

In the above, R ₁ is C ₆ -C ₁₂ aryl or C ₃ -C ₁₂ heteroaryl;
R _3a and R _3b are each independently hydrogen, hydroxy, C ₁ -C ₁₀ alkyl or C ₆ -C ₁₂ aryl;
R _6a and R _6b are each independently hydrogen, allyl, C ₁ -C ₁₀ alkyl or C ₆ -C ₁₂ aryl;
Ar ₁ is C ₆ -C ₁₂ aryl or C ₃ -C ₂₀ heteroaryl;
L ₁ is C ₆ -C ₁₂ arylene or C ₃ -C ₁₂ heteroarylene. According to claim 2,
The polymer has a weight average molecular weight of 1,000 g / mol or more. A resist underlayer film composition comprising the polymer of any one of claims 2 to 4. The method of claim 5,
The polymer is contained in 0.5 to 50% by weight relative to the total resist underlayer composition, resist underlayer composition. The method of claim 5,
A resist underlayer film composition further comprising one or more selected from crosslinking agents, crosslinking catalysts, organic solvents, and surfactants. The method of claim 7,
The crosslinking agent is selected from compounds represented by the following formulas A to C, resist underlayer film composition.
[Formula A]

[Formula B]

[Formula C]

In the above formulas A to C,
R ^a1 to R ^a4 and R ^b1 to R ^b6 are each independently hydrogen, methyl or butyl;
R ^d1 to R ^d3 are each independently hydrogen, C ₁ -C ₂₀ alkyl, or

ego;
R ^c1 to R ^c3 and R ^e1 to R ^e3 are each independently hydrogen or methyl. The method of claim 7,
The crosslinking catalyst is a compound represented by the following formula (D), a resist underlayer film composition.
[Formula D]

In the above formula D,
R 'is H, C ₁ -C ₂₀ alkyl, C ₃ -C ₂₀ cycloalkyl, C ₆ -C ₂₀ aryl or C ₃ -C ₂₀ heteroaryl, or an onium ion containing a hydrocarbon group;
The cycloalkyl, aryl or heteroaryl of R 'is C ₁ -C ₂₀ alkyl, halogen, cyano, hydroxy, C ₃ -C ₂₀ cycloalkyl, C ₁ -C ₂₀ alkoxy, C ₆ -C ₂₀ aryloxy, C ₆ -C ₂₀ aryl and C ₃ -C ₂₀ heteroaryl may be further substituted with one or more selected from the group consisting of.