KR102678333B1 - Semiconductor photoresist composition and method of forming patterns using the composition - Google Patents

Abstract

It relates to a composition for semiconductor photoresist containing an organometallic compound and a solvent represented by Chemical Formula 1, and a method of forming a pattern using the same.
Specific details about Formula 1 are the same as defined in the specification.

Description

Composition for semiconductor photoresist and method of forming a pattern using the same {SEMICONDUCTOR PHOTORESIST COMPOSITION AND METHOD OF FORMING PATTERNS USING THE COMPOSITION}

This disclosure relates to a composition for semiconductor photoresist and a method of forming a pattern using the same.

As one of the essential technologies for manufacturing next-generation semiconductor devices, EUV (extreme ultraviolet light) lithography is attracting attention. EUV lithography is a pattern formation technology that uses EUV light with a wavelength of 13.5 nm as an exposure light source. It has been demonstrated that EUV lithography can form extremely fine patterns (for example, 20 nm or less) in the exposure process of the semiconductor device manufacturing process.

Implementation of extreme ultraviolet (EUV) lithography requires the development of compatible photoresists that can perform at spatial resolutions of 16 nm or less. Currently, traditional chemically amplified (CA) photoresists have poor performance in resolution, photospeed, and feature roughness, or line edge roughness (LER), for next-generation devices. We are working hard to meet specifications.

Intrinsic image blur due to the acid catalyzed reactions that occur in these polymer photoresists limits resolution at small feature sizes, which limits the resolution of e-beam This has been known for a long time in lithography. Chemically amplified (CA) photoresists are designed for high sensitivity, but their typical elemental makeup lowers the photoresist's absorbance at a wavelength of 13.5 nm, thereby reducing sensitivity, in part. may experience more difficulties under EUV exposure.

CA photoresists can also suffer from roughness issues at small feature sizes and, due in part to the nature of acid-catalyzed processes, line edge roughness (LER) decreases as photospeed decreases. Experiments have shown that increases. Due to the drawbacks and problems of CA photoresists, there is a need in the semiconductor industry for new types of high-performance photoresists.

In order to overcome the disadvantages of the chemically amplified organic photosensitive composition described above, inorganic photosensitive compositions have been studied. In the case of inorganic photosensitive compositions, they are mainly used for negative tone patterning that is resistant to removal by a developer composition due to chemical modification through a non-chemical amplification mechanism. In the case of inorganic compositions, they contain inorganic elements with a higher EUV absorption rate than hydrocarbons, so sensitivity can be secured even through non-chemical amplification mechanisms, and they are less sensitive to stochastic effects, so they are known to have less line edge roughness and fewer defects. .

Inorganic photoresists based on tungsten and peroxopolyacids of tungsten mixed with niobium, titanium, and/or tantalum are radiation sensitive materials for patterning. It has been reported for (US5061599,; H. Okamoto, T. Iwayanagi, K. Mochiji, H. Umezaki, T. Kudo, Applied Physics Letters, 49(5), 298-300, 1986).

These materials have been effective in patterning large features in a bilayer configuration with deep UV, x-ray, and electron beam sources. More recently, cationic hafnium metal oxide sulfate (HfSOx) material was used with a peroxo complexing agent to image 15 nm half-pitch (HP) by projection EUV lithography. showed impressive performance when using (US2011-0045406,; J. K. Stowers, A. Telecky, M. Kocsis, B. L. Clark, D. A. Keszler, A. Grenville, C. N. Anderson, P. P. Naulleau, Proc. SPIE, 7969, 796915, 2011 ). This system demonstrated the best performance of non-CA photoresist, with optical velocities approaching the requirements for a viable EUV photoresist. However, hafnium metal oxide sulfate materials with peroxo complexing agents have some practical drawbacks. First, these materials are coated in a highly corrosive sulfuric acid/hydrogen peroxide mixture and have poor shelf-life stability. Second, as it is a complex mixture, it is not easy to change the structure to improve performance. Third, it must be developed in an extremely high concentration of TMAH (tetramethylammonium hydroxide) solution, such as about 25 wt%.

Recently, active research has been conducted as it has become known that molecules containing tin have excellent absorption of extreme ultraviolet rays. In the case of organotin polymer, which is one of them, the alkyl ligand is dissociated due to light absorption or secondary electrons generated thereby, and negative tone patterning that is not removed by organic developer is possible through crosslinking through oxo bonds with surrounding chains. Such organotin polymers have shown dramatic improvement in sensitivity while maintaining resolution and line edge roughness, but additional improvement in patterning characteristics is required for commercialization.

One embodiment provides a composition for a semiconductor photoresist with excellent sensitivity and storage stability.

Another embodiment provides a method of forming a pattern using the composition for semiconductor photoresist.

A composition for a semiconductor photoresist according to one embodiment includes an organometallic compound and a solvent represented by the following Chemical Formula 1.

[Formula 1]

In Formula 1,

R ^a , R ^b , R ^c and R ^d are each independently hydrogen, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or an unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof,

At least one of R ^a , R ^b , R ^c and R ^d is a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or It is an unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof.

Wherein R ^a , R ^b , R ^c and R ^d are each independently hydrogen, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, A substituted or unsubstituted C2 to C10 alkynyl group, a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof,

At least one of R ^a , R ^b , R ^c and R ^d is a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or It may be an unsubstituted C2 to C10 alkynyl group, a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof.

Wherein R ^a , R ^b , R ^c and R ^d are each independently hydrogen, methyl group, ethyl group, propyl group, butyl group, isopropyl group, tert-butyl group, 2,2-dimethylpropyl group, cyclopropyl group, cyclopropyl group, Butyl group, cyclopentyl group, cyclohexyl group, ethenyl group, propenyl group, butenyl group, ethynyl group, propynyl group, butynyl group, phenyl group, tolyl group, xylene group, benzyl group, or a combination thereof,

At least one of the R ^a , R ^b , R ^c and R ^d is a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, a tert-butyl group, a 2,2-dimethylpropyl group, a cyclopropyl group, and a cyclobutyl group. , cyclopentyl group, cyclohexyl group, ethenyl group, propenyl group, butenyl group, ethynyl group, propynyl group, butynyl group, phenyl group, tolyl group, xylene group, benzyl group, or a combination thereof.

The organometallic compound may include any one or a combination of compounds represented by the following formulas (a) to (d).

[Formula a]

[Formula b]

[Formula c]

[Formula d]

In the above formulas (a) to (d), R ^a , R ^b , R ^c and R ^d are each independently a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, or a substituted or unsubstituted C2 to C20 alkenyl group, substituted or unsubstituted C2 to C20 alkynyl group, substituted or unsubstituted C6 to C30 aryl group, or a combination thereof.

For example, in the above formulas (a) to (d), R ^a , R ^b , R ^c and R ^d are each independently a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, or a substituted or unsubstituted C1 to C10 cycloalkyl group. It may be a C2 to C10 alkenyl group, a substituted or unsubstituted C2 to C10 alkynyl group, a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof.

As a specific example, in the above formulas (a) to (d), R ^a , R ^b , R ^c and R ^d are each independently methyl group, ethyl group, propyl group, butyl group, isopropyl group, tert-butyl group, 2,2-dimethyl Propyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, ethenyl group, propenyl group, butenyl group, ethynyl group, propynyl group, butynyl group, phenyl group, tolyl group, xylene group, benzyl group, or It could be a combination of these.

The organometallic compound may include any one or a combination of the compounds listed in Group 1 below.

[Group 1]

[Formula 2] [Formula 3] [Formula 4]

[Formula 5] [Formula 6]

The composition for a semiconductor photoresist may include 1% to 30% by weight of the organometallic compound represented by Chemical Formula 1, based on 100% by weight of the composition for a semiconductor photoresist.

The composition for semiconductor photoresist may further include additives such as a surfactant, a cross-linking agent, a leveling agent, or a combination thereof.

A pattern forming method according to another embodiment includes forming a film to be etched on a substrate, forming a photoresist film by applying the composition for a semiconductor photoresist described above on the film to be etched, patterning the photoresist film to form a photoresist pattern. It includes forming and etching the etch target layer using the photoresist pattern as an etch mask.

The step of forming the photoresist pattern may use light with a wavelength of 5 nm to 150 nm.

The pattern forming method may further include providing a resist underlayer formed between the substrate and the photoresist film.

The photoresist pattern may have a width of 5 nm to 100 nm.

A composition for a semiconductor photoresist according to one embodiment has relatively excellent sensitivity and storage stability, and can provide a photoresist pattern that does not collapse even if it has a high aspect ratio.

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

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. However, in explaining this description, descriptions of already known functions or configurations will be omitted to make the gist of this description clear.

In order to clearly explain this description, parts that are not related to the description have been omitted, and identical or similar components are given the same reference numerals throughout the specification. In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, so this description is not necessarily limited to what is shown.

In the drawing, the thickness is enlarged to clearly express various layers and regions. Also, in the drawing, the thickness of some layers and regions is exaggerated for convenience of explanation. When a part of a layer, membrane, region, plate, etc. is said to be “on” or “on” another part, this includes not only cases where it is “directly above” another part, but also cases where there is another part in between.

In this description, “substitution” means that the hydrogen atom is deuterium, halogen group, hydroxy group, cyano group, nitro group, -NRR' (where R and R' are each independently hydrogen, substituted or unsubstituted C1 to C30 saturated or an unsaturated aliphatic hydrocarbon group, a substituted or unsubstituted C3 to C30 saturated or unsaturated alicyclic hydrocarbon group, or a substituted or unsubstituted C6 to C30 aromatic hydrocarbon group), -SiRR'R" (where R, R', and R” are each independently hydrogen, a substituted or unsubstituted C1 to C30 saturated or unsaturated aliphatic hydrocarbon group, a substituted or unsubstituted C3 to C30 saturated or unsaturated alicyclic hydrocarbon group, or a substituted or unsubstituted C6 to C30 saturated or unsaturated aliphatic hydrocarbon group. C30 aromatic hydrocarbon group), C1 to C30 alkyl group, C1 to C10 haloalkyl group, C1 to C10 alkylsilyl group, C3 to C30 cycloalkyl group, C6 to C30 aryl group, C1 to C20 alkoxy group, or a combination thereof. means that “Unsubstituted” means that a hydrogen atom remains a hydrogen atom without being substituted with another substituent.

In this specification, “alkyl group” means a straight-chain or branched-chain aliphatic hydrocarbon group, unless otherwise defined. The alkyl group may be a “saturated alkyl group” that does not contain any double or triple bonds.

The alkyl group may be a C1 to C10 alkyl group. For example, the alkyl group may be a C1 to C8 alkyl group, a C1 to C7 alkyl group, a C1 to C6 alkyl group, a C1 to C5 alkyl group, or a C1 to C4 alkyl group. For example, the C1 to C4 alkyl group may be methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, or tert-butyl or 2,2-dimethylpropyl.

In this description, unless otherwise defined, “cycloalkyl group” refers to a monovalent cyclic aliphatic saturated hydrocarbon group.

The cycloalkyl group may be a C3 to C10 cycloalkyl group, for example, a C3 to C8 cycloalkyl group, a C3 to C7 cycloalkyl group, a C3 to C6 cycloalkyl group, a C3 to C5 cycloalkyl group, or a C3 to C4 cycloalkyl group. For example, the cycloalkyl group may be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, or a cyclohexyl group, but is not limited thereto.

In this specification, “aryl group” refers to a substituent in which all elements of a cyclic substituent have p-orbitals, and these p-orbitals form conjugation, and are monocyclic or fused. Contains ring polycyclic (i.e. rings splitting adjacent pairs of carbon atoms) functional groups.

In this specification, unless otherwise defined, “alkenyl group” refers to a straight-chain or branched aliphatic hydrocarbon group and an aliphatic unsaturated alkenyl group containing one or more double bonds. do.

In this specification, unless otherwise defined, “alkynyl group” refers to a straight-chain or branched aliphatic hydrocarbon group and an aliphatic unsaturated alkynyl group containing one or more triple bonds. do.

In the chemical formulas described herein, S refers to the sulfur (S) element.

Hereinafter, a composition for a semiconductor photoresist according to one embodiment will be described.

A composition for a semiconductor photoresist according to an embodiment of the present invention includes an organometallic compound and a solvent, and the organometallic compound is represented by the following formula (1).

[Formula 1]

In Formula 1,

R ^a , R ^b , R ^c and R ^d are each independently hydrogen, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or an unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof,

At least one of R ^a , R ^b , R ^c and R ^d is a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or It is an unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof.

The compound represented by Formula 1 is an organic tin compound, and tin strongly absorbs extreme ultraviolet light at 13.5 nm and may have excellent sensitivity to high-energy light. Therefore, the organotin compound according to one embodiment can exhibit superior stability and sensitivity compared to conventional organic and/or inorganic resists.

The organometallic compound represented by Formula 1 essentially contains a -S(C=O)R group substituted for Sn. The Sn-S bond formed at this time has a stronger bond than the Sn-O bond, The organometallic compound may have high stability in water. In addition, the Sn-S bond has a lower bond dissociation energy when exposed to extreme ultraviolet rays than Sn-O, so the sensitivity characteristics of the organometallic compound may be excellent. Therefore, the composition for semiconductor photoresist containing the organometallic compound containing the Sn-S bond can be easily handled, storage stability can be improved, and sensitivity can be excellent.

Meanwhile, the compound represented by Formula 1 is hydrolyzed and dehydrated and condensed by heat treatment under an acidic, basic, or neutral catalyst, or without heat treatment, to form Sn-S-Sn bonds between organotin compounds, thereby forming Formula 1 It forms an organotin sulfoxide polymer derived from an organometallic compound represented by .

In particular, the bond between Sn-S has a strong bond strength, so the organometallic compound of the present invention containing the Sn-S bond can have improved stability against water, and storage of the composition for semiconductor photoresist containing it Stability can be improved.

For example, R ^a , R ^b , R ^c and R ^d are each independently hydrogen, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, or a substituted or unsubstituted C2 to C10 alkenyl group, substituted or unsubstituted C2 to C10 alkynyl group, substituted or unsubstituted C6 to C20 aryl group, or a combination thereof,

At least one of R ^a , R ^b , R ^c and R ^d is a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or It may be an unsubstituted C2 to C10 alkynyl group, a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof.

For example, R ^a , R ^b , R ^c and R ^d are each independently hydrogen, methyl group, ethyl group, propyl group, butyl group, isopropyl group, tert-butyl group, 2,2-dimethylpropyl group, Cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, ethenyl group, propenyl group, butenyl group, ethynyl group, propynyl group, butynyl group, phenyl group, tolyl group, xylene group, benzyl group, or a combination thereof ego,

At least one of the R ^a , R ^b , R ^c and R ^d is a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, a tert-butyl group, a 2,2-dimethylpropyl group, a cyclopropyl group, and a cyclobutyl group. , cyclopentyl group, cyclohexyl group, ethenyl group, propenyl group, butenyl group, ethynyl group, propynyl group, butynyl group, phenyl group, tolyl group, xylene group, benzyl group, or a combination thereof.

The organometallic compound may include any one or a combination of compounds represented by the following formulas (a) to (d).

[Formula a]

[Formula b]

[Formula c]

[Formula d]

In the above formulas (a) to (d),

R ^a , R ^b , R ^c and R ^d are each independently hydrogen, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted Or an unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof.

For example, in the above formula (a), R ^a is a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, or a substituted or unsubstituted C2 to C10 alkenyl group. It may be an alkynyl group, a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof.

For example, in the above formula (b), R ^a and R ^b are each independently a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or It may be an unsubstituted C2 to C10 alkynyl group, a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof.

R ^a and R ^b may each be the same or different.

As an example, in the above formula c, R ^a , R ^b and R ^c are each independently a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, or a substituted or unsubstituted C2 to C10 alkenyl group. , a substituted or unsubstituted C2 to C10 alkynyl group, a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof.

R ^a , R ^b and R ^c may each be the same or different.

For example, in the above formula (d), R ^a , R ^b , R ^c and R ^d are each independently a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, or a substituted or unsubstituted C2 to C10 cycloalkyl group. It may be a C10 alkenyl group, a substituted or unsubstituted C2 to C10 alkynyl group, a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof.

R ^a , R ^b , R ^c and R ^d may each be the same or different.

As a specific example, in the above formula (a), R ^a is methyl group, ethyl group, propyl group, butyl group, isopropyl group, tert-butyl group, 2,2-dimethylpropyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, It may be a cyclohexyl group, ethenyl group, propenyl group, butenyl group, ethynyl group, propynyl group, butynyl group, phenyl group, tolyl group, xylene group, benzyl group, or a combination thereof.

As a specific example, in the above formula (b), R ^a and R ^b are each independently methyl group, ethyl group, propyl group, butyl group, isopropyl group, tert-butyl group, 2,2-dimethylpropyl group, cyclopropyl group, cyclobutyl group. group, cyclopentyl group, cyclohexyl group, ethenyl group, propenyl group, butenyl group, ethynyl group, propynyl group, butynyl group, phenyl group, tolyl group, xylene group, benzyl group, or a combination thereof.

R ^a and R ^b may each be the same or different.

As a specific example, in the above formula c, R ^a , R ^b and R ^c are each independently methyl group, ethyl group, propyl group, butyl group, isopropyl group, tert-butyl group, 2,2-dimethylpropyl group, and cyclopropyl group. , cyclobutyl group, cyclopentyl group, cyclohexyl group, ethenyl group, propenyl group, butenyl group, ethynyl group, propynyl group, butynyl group, phenyl group, tolyl group, xylene group, benzyl group, or a combination thereof. .

R ^a , R ^b and R ^c may each be the same or different.

As a specific example, in the above formula (d), R ^a , R ^b , R ^c and R ^d are each independently methyl group, ethyl group, propyl group, butyl group, isopropyl group, tert-butyl group, 2,2-dimethylpropyl group, Cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, ethenyl group, propenyl group, butenyl group, ethynyl group, propynyl group, butynyl group, phenyl group, tolyl group, xylene group, benzyl group, or a combination thereof It can be.

R ^a , R ^b , R ^c and R ^d may each be the same or different.

For example, the organometallic compound may include any one or a combination of the compounds listed in Group 1 below.

[Group 1]

[Formula 2] [Formula 3] [Formula 4]

[Formula 5] [Formula 6]

In the case of commonly used organic resists, there is a risk of pattern collapse at high aspect ratios due to lack of etch resistance.

Meanwhile, in the case of conventional inorganic resists (e.g., metal oxide compounds), a highly corrosive mixture of sulfuric acid and hydrogen peroxide is used, making handling difficult and storage stability poor. As a composite mixture, it is relatively difficult to change the structure to improve performance. A highly concentrated developer must be used.

On the other hand, in the composition for a semiconductor photoresist according to one embodiment, as described above, the organometallic compound includes a structural unit in which an organic group derived from -S(C=O)R is bonded to a central metal atom, and thus, existing organic and /Or, it has relatively excellent etch resistance, sensitivity, and resolution compared to inorganic resist, and is easy to handle.

In the semiconductor photoresist composition according to one embodiment, the organometallic compound represented by Formula 1 is present in an amount of 1% to 30% by weight, for example, 1% to 25% by weight, for example, based on the total weight of the composition. For example, it may be comprised in an amount of 1% to 20% by weight, such as 1% to 15% by weight, such as 1% to 10% by weight, such as 1% to 5% by weight. possible, and is not limited to these. When the organometallic compound represented by Formula 1 is included in the above range, the storage stability and etch resistance of the composition for semiconductor photoresist are improved, and the resolution characteristics are improved.

The solvent included in the semiconductor resist composition according to one embodiment may be an organic solvent, for example, aromatic compounds (e.g., xylene, toluene), alcohols (e.g., 4-methyl-2-pentanol) , 4-methyl-2-propanol, 1-butanol, methanol, isopropyl alcohol, 1-propanol), ethers (e.g., anisole, tetrahydrofuran), esters (n-butyl acetate, propylene glycol mono) It may include, but is not limited to, methyl ether acetate, ethyl acetate, ethyl lactate), ketones (e.g., methyl ethyl ketone, 2-heptanone), and mixtures thereof.

In one embodiment, the semiconductor resist composition may further include a resin in addition to the above-described organometallic compound and solvent.

The resin may be a phenolic resin containing at least one aromatic moiety listed in Group 2 below.

[Group 2]

The resin may have a weight average molecular weight of 500 to 20,000.

The resin may be included in an amount of 0.1% by weight to 50% by weight based on the total content of the semiconductor resist composition.

When the resin is contained within the above content range, it can have excellent etching resistance and heat resistance.

Meanwhile, the composition for semiconductor resist according to one embodiment is preferably composed of the above-described organometallic compound, solvent, and resin. However, the composition for semiconductor resist according to the above-described embodiment may further include additives in some cases. Examples of the additives include surfactants, cross-linking agents, leveling agents, organic acids, quenchers, or combinations thereof.

The surfactant may be, for example, an alkylbenzenesulfonic acid salt, an alkylpyridinium salt, polyethylene glycol, a quaternary ammonium salt, or a combination thereof, but is not limited thereto.

The crosslinking agent may include, for example, a melamine-based crosslinking agent, a substituted urea-based crosslinking agent, an acrylic-based crosslinking agent, an epoxy-based crosslinking agent, or a polymer-based crosslinking agent, but is not limited thereto. A crosslinking agent having at least two crosslinking substituents, for example, methoxymethylated glycoluryl, butoxymethylated glycoluryl, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine. , 4-hydroxybutyl acrylate, acrylic acid, urethane acrylate, acrylic methacrylate, 1,4-butanediol diclicidyl ether, glycidol, diglycidyl 1,2-cyclohexane dicrboxylate, Compounds such as trimethylpropane triglycidyl ether, 1,3-bis(glycidoxypropyl_)tetramethyldisiloxane, methoxymethylated urea, butoxymethylated urea, or methoxymethylated thiourea can be used.

The leveling agent is intended to improve coating flatness during printing, and known leveling agents available commercially can be used.

Organic acids include p-toluenesulfonic acid, benzenesulfonic acid, p-dodecylbenzenesulfonic acid, 1,4-naphthalenedisulfonic acid, methanesulfonic acid, sulfonium fluoride salt, malonic acid, citric acid, propionic acid, methacrylic acid, oxalic acid, It may be lactic acid, glycolic acid, succinic acid, or a combination thereof, but is not limited thereto.

The quencher may be diphenyl (p-tryl) amine, methyl diphenyl amine, triphenyl amine, phenylenediamine, naphthylamine, diaminonaphthalene, or a combination thereof.

The amount of these additives used can be easily adjusted depending on the desired physical properties, and may be omitted.

In addition, the composition for semiconductor resist may further use a silane coupling agent as an additive as an adhesion promoter to improve adhesion to the substrate (for example, to improve the adhesion of the composition for semiconductor resist to the substrate). The silane coupling agent includes, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyl trichlorosilane, vinyltris(β-methoxyethoxy)silane; or 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, p-styryl trimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldi. ethoxysilane; Silane compounds containing carbon-carbon unsaturated bonds such as trimethoxy[3-(phenylamino)propyl]silane may be used, but are not limited thereto.

The composition for semiconductor photoresist may not cause pattern collapse even if a pattern having a high aspect ratio is formed. Therefore, for example, a micropattern with a width of 5 nm to 100 nm, for example, a micropattern with a width of 5 nm to 80 nm, for example, a micropattern with a width of 5 nm to 70 nm, e.g. A micropattern having a width of 5 nm to 50 nm, for example a micro pattern having a width of 5 nm to 40 nm, for example a micro pattern having a width of 5 nm to 30 nm, for example a micro pattern having a width of 5 nm to 20 nm. To form a pattern, a photoresist process using light with a wavelength of 5 nm to 150 nm, e.g., a photoresist process using light with a wavelength of 5 nm to 100 nm, e.g., a photoresist process using light with a wavelength of 5 nm to 80 nm. A resist process, for example a photoresist process using light with a wavelength of 5 nm to 50 nm, for example a photoresist process using light with a wavelength of 5 nm to 30 nm, for example a photoresist process using light with a wavelength of 5 nm to 20 nm. It can be used in the photoresist process. Therefore, by using the composition for semiconductor photoresist according to one embodiment, extreme ultraviolet lithography using an EUV light source with a wavelength of about 13.5 nm can be implemented.

Meanwhile, according to another embodiment, a method of forming a pattern using the above-described composition for semiconductor photoresist may be provided. As an example, the manufactured pattern may be a photoresist pattern.

Another pattern forming method in one embodiment includes forming a film to be etched on a substrate, forming a photoresist film by applying the composition for a semiconductor photoresist described above on the film to be etched, and patterning the photoresist film to form a photoresist pattern. It includes forming and etching the etch target layer using the photoresist pattern as an etch mask.

Hereinafter, a method of forming a pattern using the above-described composition for semiconductor photoresist will be described with reference to FIGS. 1 to 5. 1 to 5 are cross-sectional views illustrating a method of forming a pattern using a composition for semiconductor photoresist according to the present invention.

Referring to Figure 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 etching object is the thin film 102 will be described. The surface of the thin film 102 is cleaned to remove contaminants remaining on the thin film 102. The thin film 102 may be, for example, a silicon nitride film, a polysilicon film, or a silicon oxide film.

Next, a composition for forming a resist underlayer film 104 is coated on the surface of the cleaned thin film 102 using a spin coating method. However, one embodiment is not necessarily limited to this, and various known coating methods such as spray coating, dip coating, knife edge coating, and printing methods such as inkjet printing and screen printing may be used.

The resist underlayer coating process can be omitted, and the case of coating the resist underlayer film will be described below.

Afterwards, a drying and baking process is performed to form a resist underlayer film 104 on the thin film 102. The baking treatment may be performed at about 100 to about 500°C, for example, about 100°C to about 300°C.

The resist underlayer 104 is formed between the substrate 100 and the photoresist film 106, so that radiation reflected from the interface between the substrate 100 and the photoresist film 106 or from the interlayer hardmask is not intended. In the case of scattering into an unapplied photoresist area, non-uniformity of the photoresist linewidth and interference with pattern formation can be prevented.

Referring to Figure 2, the photoresist film 106 is formed by coating the above-described semiconductor photoresist composition on the resist underlayer film 104. The photoresist film 106 may be formed by coating the above-described semiconductor photoresist composition on the thin film 102 formed on the substrate 100 and then curing it through a heat treatment process.

More specifically, the step of forming a pattern using a semiconductor photoresist composition involves applying the above-described semiconductor resist composition to the substrate 100 on which the thin film 102 is formed by spin coating, slit coating, inkjet printing, etc. It may include a process of forming a photoresist film 106 by drying the applied semiconductor photoresist composition.

Since the composition for semiconductor photoresist has already been described in detail, redundant description will be omitted.

Next, a first baking process is performed to heat the substrate 100 on which the photoresist film 106 is formed. The first baking process may be performed at a temperature of about 80°C to about 120°C.

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

For example, examples of light that can be used in the exposure process include light with a short wavelength such as activating radiation i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), and ArF excimer laser (wavelength 193 nm), as well as EUV (wavelength 193 nm). Examples include light with high energy wavelengths such as Extreme UltraViolet (wavelength: 13.5 nm) and E-Beam (electron beam).

More specifically, the exposure light according to one embodiment may be short-wavelength light having a wavelength range of 5 nm to 150 nm, and may be light having a high-energy wavelength such as EUV (Extreme UltraViolet; wavelength 13.5 nm) or E-Beam (electron beam). You can.

The exposed area 106b of the photoresist film 106 has a different solubility from the unexposed area 106a of the photoresist film 106 as a polymer is formed through a crosslinking reaction such as condensation between organometallic compounds. .

Next, a second baking process is performed on the substrate 100. The second baking process may be performed at a temperature of about 90°C to about 200°C. By performing the second baking process, the exposed area 106b of the photoresist film 106 becomes difficult to dissolve in the developer.

FIG. 4 shows a photoresist pattern 108 formed by dissolving and removing the photoresist film 106a corresponding to the unexposed area using a developer. Specifically, the photoresist film 106a corresponding to the unexposed area is dissolved and then removed using an organic solvent such as 2-heptanone, thereby forming a photoresist pattern corresponding to the negative tone image ( 108) is completed.

As described above, the developer used in the pattern forming method according to one embodiment may be an organic solvent. Examples of organic solvents used in the pattern forming method according to one embodiment include ketones such as methyl ethyl ketone, acetone, cyclohexanone, and 2-heptanone, 4-methyl-2-propanol, 1-butanol, isopropanol, 1 -Alcohols such as propanol and methanol, esters such as propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate, n-butyl acetate, butyrolactone, aromatic compounds such as benzene, xylene, and toluene, or these There are combinations.

However, the photoresist pattern according to one embodiment is not necessarily limited to being formed as a negative tone image, and may be formed to have a positive tone image. In this case, the developer that can be used to form a positive tone image is a quaternary ammonium hydroxide composition such as tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, or a combination thereof. I can hear it.

As previously explained, not only light with wavelengths such as i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), and ArF excimer laser (wavelength 193 nm), but also EUV (Extreme UltraViolet; wavelength 13.5 nm), The photoresist pattern 108 formed by exposure to high-energy light such as an E-Beam may have a width of 5 nm to 100 nm thick. For example, the photoresist pattern 108 is 5 nm to 90 nm, 5 nm to 80 nm, 5 nm to 70 nm, 5 nm to 60 nm, 5 nm to 50 nm, 5 nm to 40 nm, 5 nm. It can be formed to have a width of 30 nm to 5 nm and a thickness of 5 nm to 20 nm.

Meanwhile, the photoresist pattern 108 has a half-pitch of about 50 nm or less, for example, 40 nm or less, for example, 30 nm or less, for example, 20 nm or less, for example, 15 nm or less. And, it may have a pitch having a line width roughness of about 10 nm or less, about 5 nm or less, about 3 nm or less, and about 2 nm or less.

Next, the resist underlayer 104 is etched using the photoresist pattern 108 as an etch mask. The organic layer pattern 112 is formed through the etching process described above. The formed organic layer pattern 112 may also have a width corresponding to the photoresist pattern 108 .

Referring to FIG. 5, the photoresist pattern 108 is applied as an etch mask to etch the exposed thin film 102. As a result, the thin film is formed as a thin film pattern 114.

The etching of the thin film 102 may be performed, for example, by dry etching using an etching gas. The etching gas may be, for example, CHF ₃ , CF ₄ , Cl ₂ , BCl ₃ , or a mixture thereof.

In the previously performed exposure process, the thin film pattern 114 formed using the photoresist pattern 108 formed by the exposure process performed using an EUV light source may have a width corresponding to the photoresist pattern 108. . As an example, it may have a width of 5 nm to 100 nm, the same as the photoresist pattern 108. For example, the thin film pattern 114 formed by an exposure process performed using an EUV light source has 5 nm to 90 nm, 5 nm to 80 nm, 5 nm to 70 nm, 5 nm, like the photoresist pattern 108. It may have a width of 5 nm to 60 nm, 5 nm to 50 nm, 5 nm to 40 nm, 5 nm to 30 nm, or 5 nm to 20 nm, and more specifically, may have a width of 20 nm or less.

Hereinafter, the present invention will be described in more detail through examples related to the production of the above-described composition for semiconductor photoresist. However, the technical features of the present invention are not limited to the following examples.

Example

Synthesis Example 1: Synthesis of an organotin compound represented by Formula 2

15 g of tetraphenyl tin and 50 ml of thiopropionic acid were added to a 250 mL two-neck round bottom flask at room temperature, heated at 120°C, and heated to reflux for 24 hours. Afterwards, unreacted thiopropionic acid was removed under reduced pressure to obtain an organometallic compound represented by the following formula (2) with a yield of 94%.

[Formula 2]

Synthesis Example 2: Synthesis of an organotin compound represented by Formula 3

5 g of Tetraphenyl tin and 50 ml of toluene were added to a 250 mL two-neck round bottom flask, then 9 ml (10 eq.) of Thioacetic acid was slowly added, and the mixture was heated and refluxed at 70°C for 24 hours. Afterwards, unreacted thioacetic acid and residual solvent were removed under reduced pressure to obtain an organometallic compound represented by the following formula (3) with a yield of 93%.

[Formula 3]

Synthesis Example 3: Synthesis of an organotin compound represented by Chemical Formula 4

By synthesizing in the same manner as in Synthesis Example 2, except that thiobutyric acid was used instead of thioacetic acid in Synthesis Example 2, a compound represented by the following formula (4) was obtained with a yield of 92%.

[Formula 4]

Synthesis Example 4: Synthesis of an organotin compound represented by Chemical Formula 5

By synthesizing in the same manner as in Synthesis Example 2, except that Thiopivalic acid was used instead of Thioacetic acid in Synthesis Example 2, the compound represented by the following Chemical Formula 5 was obtained with a yield of 95%.

[Formula 5]

Synthesis Example 5: Synthesis of organotin compound with Chemical Formula 6

By synthesizing in the same manner as Synthesis Example 2, except that Benzenecarbothioic acid was used instead of Thioacetic acid in Synthesis Example 2, the compound represented by the following formula (6) was obtained with a yield of 95%.

[Formula 6]

Comparative Synthesis Example 1

Benzyltin trichloride (5 g, 13.8 mmol) was added to a 100 mL round bottom flask and dissolved in pentane. Diethylamine (3.29 g, 45.5 mmol) was diluted in pentane and slowly added, followed by ethanol (3.4 g, 45.5 mmol). ) was slowly added and stirred at room temperature for 4 hours. Afterwards, the solid was removed by filtration through a filter, and the solvent was dried to obtain a compound represented by the following formula (7) with a yield of 45%.

[Formula 7]

Comparative Synthesis Example 2

Comparative Synthesis Example 1 was synthesized in the same manner except that butyltin trichloride was used instead of benzyltin trichloride, and the compound represented by the following formula 8 was obtained with a yield of 40%.

[Formula 8]

Examples 1 to 5

The compounds represented by Chemical Formulas 2 to 6 obtained in Synthesis Examples 1 to 5 were dissolved in 4-methyl-2-pentanol at 2 wt% and filtered through a 0.1 ㎛ PTFE syringe filter to form a photoresist. A composition was prepared. A 4-inch diameter circular silicon wafer with a native-oxide surface was used as a substrate for thin film deposition. Before depositing the resist thin film, the wafer is treated in a UV ozone cleaning system for 10 minutes, the resist composition is spin-coated on the wafer at 1500 rpm for 30 seconds, and baked at 100° C. for 120 seconds to form a thin film. Afterwards, the thickness of the film after coating and firing was measured using ellipsometry and was found to be 20 nm.

Comparative Examples 1 and 2

Comparative synthesis examples 1 and 2, except that the compounds represented by formulas 7 and 8 were dissolved in 4-methyl-2-pentanol at a concentration of 2 wt%. In the same manner as the example, the composition for semiconductor photoresist according to Comparative Examples 1 and 2 and a photoresist thin film containing the same were prepared. The thickness of the film after coating and baking was approximately 15 nm.

Evaluation 1: Sensitivity and line edge roughness (LER) evaluation

A linear array of 50 circular pads with a diameter of 500㎛ was projected onto a wafer coated with the photoresist composition of Examples 1 to 5 and Comparative Examples 1 and 2 using EUV light (Lawrence Berkeley National Laboratory Micro Exposure Tool, MET). did. Pad exposure time was adjusted to ensure that increased EUV dose was applied to each pad.

Afterwards, the resist and the substrate were exposed and baked (post-exposure bake, PEB) on a hotplate at 160°C for 120 seconds. The fired film was immersed in a developer (2-heptanone) for 30 seconds each, and then washed with the same developer for an additional 10 seconds to form a negative tone image, that is, to remove the unexposed portion of the coating. Finally, hot plate baking was performed at 150°C for 2 minutes to complete the process.

The residual resist thickness of the exposed pad was measured using an ellipsometer. The remaining thickness was measured for each exposure amount and graphed as a function of the exposure amount. Dg (energy level at which development is completed) for each type of resist was evaluated in two stages according to the following criteria and is shown in Table 1.

After measuring the line edge roughness (LER) of the formed line confirmed from the FE-SEM image, the line edge roughness was evaluated in three stages according to the following criteria and is shown in Table 1.

[Sensitivity]

- A: less than 16 mJ/cm ²

- B: 16 mJ/cm ² or more

[Line Edge Roughness (LER)]

- ○: 4nm or less

- △: More than 4nm and less than 7nm

- X: greater than 7nm

Evaluation 2: Storage stability

With respect to the photoresist compositions for semiconductors according to Examples 1 to 5 and Comparative Examples 1 and 2, the storage stability of the compositions was evaluated based on the following criteria, and are shown in Table 1 below.

[Storage stability]

The degree of precipitation occurring when left for a certain period of time under 25°C (room temperature) conditions was visually observed, set as a standard for storage, and evaluated in the following three steps.

○: Can be stored for more than 1 month

△: Can be stored for 1 week to less than 1 month

X: Can be stored for less than 1 week

Sensitivity LER Storage stability Example 1 A ○ ○ Example 2 A ○ △ Example 3 A ○ ○ Example 4 A ○ ○ Example 5 A ○ ○ Comparative Example 1 B △ △ Comparative Example 2 B △ X

(*HP: based on half pitch) From the results in Table 1, the semiconductor photoresist compositions according to Examples 1 to 5 exhibit excellent storage stability compared to Comparative Examples 1 and 2, and the patterns formed using them also showed Comparative Examples 1 and 2. It can be seen that the sensitivity is excellent compared to the others, and the line edge roughness is reduced.

Although specific embodiments of the present invention have been described and shown above, it is known in the art that the present invention is not limited to the described embodiments, and that various modifications and changes can be made without departing from the spirit and scope of the present invention. This is self-evident to those who have it. Accordingly, such modifications or variations should not be understood individually from the technical idea or viewpoint of the present invention, and the modified embodiments should be regarded as falling within the scope of the claims of the present invention.

100: substrate 102: thin film
104: resist underlayer film 106: photoresist film
106a: unexposed area 106b: exposed area
108: Photoresist pattern 112: Organic film pattern
114: thin film pattern

Claims (13)

A composition for semiconductor photoresist containing an organometallic compound and a solvent represented by the following formula (1):
[Formula 1]

In Formula 1,
R ^a , R ^b , R ^c and R ^d are each independently hydrogen, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or an unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof,
At least one of R ^a , R ^b , R ^c and R ^d is a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or It is an unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof. In paragraph 1:
Wherein R ^a , R ^b , R ^c and R ^d are each independently hydrogen, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, A substituted or unsubstituted C2 to C10 alkynyl group, a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof,
At least one of R ^a , R ^b , R ^c and R ^d is a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or A composition for a semiconductor photoresist comprising an unsubstituted C2 to C10 alkynyl group, a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof. In paragraph 1:
Wherein R ^a , R ^b , R ^c and R ^d are each independently hydrogen, methyl group, ethyl group, propyl group, butyl group, isopropyl group, tert-butyl group, 2,2-dimethylpropyl group, cyclopropyl group, cyclopropyl group, Butyl group, cyclopentyl group, cyclohexyl group, ethenyl group, propenyl group, butenyl group, ethynyl group, propynyl group, butynyl group, phenyl group, tolyl group, xylene group, benzyl group, or a combination thereof,
At least one of the R ^a , R ^b , R ^c and R ^d is a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, a tert-butyl group, a 2,2-dimethylpropyl group, a cyclopropyl group, and a cyclobutyl group. , cyclopentyl group, cyclohexyl group, ethenyl group, propenyl group, butenyl group, ethynyl group, propynyl group, butynyl group, phenyl group, tolyl group, xylene group, benzyl group, or a composition for a semiconductor photoresist. In paragraph 1:
The organometallic compound is a composition for a semiconductor photoresist comprising any one or a combination of compounds represented by the following formulas (a) to (d):
[Formula a]

[Formula b]

[Formula c]

[Formula d]

In the above formulas (a) to (d),
R ^a , R ^b , R ^c and R ^d are each independently a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, substituted or unsubstituted It is a substituted C2 to C20 alkynyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof. In paragraph 4,
Wherein R ^a , R ^b , R ^c and R ^d are each independently a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or A composition for a semiconductor photoresist comprising an unsubstituted C2 to C10 alkynyl group, a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof. In paragraph 4,
The R ^a , R ^b , R ^c and R ^d are each independently a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, a tert-butyl group, a 2,2-dimethylpropyl group, a cyclopropyl group, and a cyclobutyl group. , cyclopentyl group, cyclohexyl group, ethenyl group, propenyl group, butenyl group, ethynyl group, propynyl group, butynyl group, phenyl group, tolyl group, xylene group, benzyl group, or a composition for a semiconductor photoresist. In paragraph 1:
The organometallic compound is a composition for semiconductor photoresist comprising any one or a combination of compounds listed in Group 1 below:
[Group 1]
[Formula 2] [Formula 3] [Formula 4]

[Formula 5] [Formula 6]
In paragraph 1:
A composition for a semiconductor photoresist comprising 1% to 30% by weight of an organic metal compound represented by Chemical Formula 1, based on 100% by weight of the composition for a semiconductor photoresist. In paragraph 1:
The composition for a semiconductor photoresist further includes an additive such as a surfactant, a cross-linking agent, a leveling agent, or a combination thereof. Forming a film to be etched on a substrate;
forming a photoresist film by applying the composition for a semiconductor photoresist according to any one of claims 1 to 9 on the etching target film;
patterning the photoresist film to form a photoresist pattern; and
A pattern forming method comprising etching the etch target layer using the photoresist pattern as an etch mask. In paragraph 10:
The step of forming the photoresist pattern is a pattern forming method using light with a wavelength of 5 nm to 150 nm. In paragraph 10:
A pattern forming method further comprising providing a resist underlayer formed between the substrate and the photoresist film. In paragraph 10:
The photoresist pattern has a width of 5 nm to 100 nm.