Composition for semiconductor photoresist and method for forming pattern using the same

Abstract

To provide a composition for semiconductor photoresist with improved storage stability and coatability.SOLUTION: The present invention provides a composition for semiconductor photoresist that comprises an organotin compound represented by the formula 1 and a solvent, and a patterning method using the same.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a semiconductor photoresist composition and a pattern forming method using the same. [Background technology]

[0002] Extreme ultraviolet (EUV) lithography has been attracting attention as one of the elemental technologies for manufacturing next-generation semiconductor devices. EUV lithography is a pattern formation technology that uses EUV light with a wavelength of 13.5 nm as the exposure light source. It has been demonstrated that EUV lithography can form extremely fine patterns (e.g., 20 nm or less) in the exposure step of the semiconductor device manufacturing process.

[0003] The realization of extreme ultraviolet lithography requires the development of compatible photoresists capable of performing at sub-16 nm spatial resolution. Currently, traditional chemically amplified (CA) photoresists are being continuously developed to meet the specifications for resolution, photospeed, and feature roughness (feature roughness) and line edge roughness (line edge roughness or LER) for next generation devices.

[0004] These chemically amplified photoresists, which generally contain organic polymers, have an inherent image blur caused by acid-catalyzed reactions that limit resolution at small feature sizes, a fact that has long been known in electron beam lithography. Chemically amplified (CA) photoresists were designed for high sensitivity, but their typical elemental composition can reduce the absorbance of the photoresist at 13.5 nm wavelengths, resulting in lower sensitivity and in part creating additional difficulties under EUV exposure.

[0005] CA photoresists can also suffer from roughness issues at small feature sizes, and experiments have shown that line edge roughness (LER) increases as light speed decreases, due in part to the nature of the acid-catalyzed process. Due to the shortcomings and problems of CA photoresists, there is a demand in the semiconductor industry for a new class of high performance photoresists.

[0006] In order to overcome the problems of the chemically amplified organic photoresists described above, inorganic photosensitive compositions have been researched. Inorganic photosensitive compositions are mainly used for negative tone patterning, which is chemically modified by a non-chemically amplified mechanism and is resistant to removal by developer compositions. Inorganic photosensitive compositions contain inorganic elements with higher EUV absorption rates than hydrocarbons, and are known to be able to ensure sensitivity by a non-chemically amplified mechanism, are not sensitive to stochastic variations, and have low line edge roughness and number of defects.

[0007] Inorganic photoresists based on peroxopolyacids of tungsten and tungsten mixed with niobium, titanium, and / or tantalum have been reported for patterning radiation sensitive materials (Patent Document 1 and Non-Patent Document 1).

[0008] These materials have been effective in patterning large features in bilayer configurations at deep UV, x-ray, and electron beam sources. More recently, cationic hafnium metal oxide sulfate (HfSO) with a peroxo complexing agent has been used to develop a 15 nm half pitch by projection EUV exposure. x) materials have been reported to have shown impressive performance (Patent Document 2 and Non-Patent Document 2). This system has shown top-of-the-line performance in non-CA photoresists, with light speeds approaching the requirements for viable EUV photoresists. However, hafnium metal oxide sulfate materials with peroxo complexing agents have some practical drawbacks. First, these materials are coated with a highly corrosive sulfuric acid / hydrogen peroxide mixture and have poor storage stability. Second, as a complex mixture, it is not easy to modify the structure to improve performance. Third, they must be developed with extremely high concentrations, such as tetramethylammonium hydroxide (TMAH) solutions at around 25% by weight.

[0009] Recently, active research has been conducted on molecules containing tin, as they are known to have excellent absorption of extreme ultraviolet rays. One of these, organotin polymers, enables negative tone patterning that is not removed by organic developers through crosslinking with surrounding polymer chains by oxo bonds as organic ligands are dissociated by light absorption or secondary electrons generated by it. Although such organotin polymers have been shown to dramatically improve sensitivity while maintaining resolution and line edge roughness, further improvement of the patterning properties as mentioned above is required for commercialization. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] U.S. Pat. No. 5,061,599 [Patent Document 2] US Patent Application Publication No. 2011 / 0045406 [Non-patent literature]

[0011] [Non-Patent Document 1] H. Okamoto, T. Iwayanagi, K. Mochiji, H. Umezaki, T. Kudo, Applied Physics Letters, 49(5), 298-300, 1986 [Non-Patent Document 2] JKStowers, A.Telecky, M.Kocsis, BLClark, DAKEszler, A.Grenville, CNAnderson, PPNaulleau, Proc.SPIE, 7969, 796915, 2011 Summary of the Invention [Problem to be solved by the invention]

[0012] An object of the present invention is to provide a semiconductor photoresist composition having improved storage stability and coating properties.

[0013] Another object of the present invention is to provide a pattern forming method using the above semiconductor photoresist composition. [Means for solving the problem]

[0014] The composition for semiconductor photoresist according to the present invention contains an organotin compound represented by the following Chemical Formula 1, and a solvent.

[0015] [ka]

[0016] In the above Chemical Formula 1, X is -OR 2 , -SR 3 , -C(O)-L 2 -OR 4 , - or C(O)-L 3 -SR 5 and At this time, L 2 and L 3 each independently represents a single bond or a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, R 2 and R 3 each independently represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a combination thereof; R 4 and R 5 each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a combination thereof; L 1 represents a single bond or a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, R 1 is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted cycloalkenyl group having 3 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted cycloalkynyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a combination thereof; m and n are each independently an integer, and 2≦m+n≦6.

[0017] R in X in the above chemical formula 1 2 ~R 5 may each independently be a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a combination thereof.

[0018] R in X in the above chemical formula 1 2~R 5 may each independently be methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, iso-propyl, iso-butyl, iso-pentyl, iso-hexyl, iso-heptyl, iso-octyl, iso-nonyl, iso-decyl, sec-butyl, sec-pentyl, sec-hexyl, sec-heptyl, sec-octyl, tert-butyl, tert-pentyl, tert-hexyl, tert-heptyl, tert-octyl, tert-nonyl, or tert-decyl.

[0019] R in the above Chemical Formula 1 1 may be a substituted or unsubstituted branched alkyl group having 3 to 20 carbon atoms.

[0020] R in the above Chemical Formula 1 1 may be iso-propyl, iso-butyl, iso-pentyl, iso-hexyl, iso-heptyl, iso-octyl, iso-nonyl, iso-decyl, sec-butyl, sec-pentyl, sec-hexyl, sec-heptyl, sec-octyl, tert-butyl, tert-pentyl, tert-hexyl, tert-heptyl, tert-octyl, tert-nonyl, or tert-decyl.

[0021] L in the above chemical formula 1 1 may be a single bond, or a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms.

[0022] In the above Chemical Formula 1, m and n may be 4≦m+n≦6.

[0023] In the above Chemical Formula 1, m and n are such that m+n=4, and the above m may be an integer of 0-2, and the above n may be an integer of 2-4.

[0024] The organotin compound may be at least one selected from the group consisting of the compounds listed in Group 1 below.

[0025] [ka]

[0026] The content of the organotin compound may be 1% by mass to 30% by mass, based on 100% by mass of the total mass of the composition for semiconductor photoresist.

[0027] The semiconductor photoresist composition may further include an additive such as a surfactant, a crosslinking agent, a leveling agent, or a combination thereof.

[0028] A method for forming a pattern according to another embodiment of the present invention includes the steps of forming a film to be etched on a substrate, applying the above-described semiconductor photoresist composition on the film to be etched to form a photoresist film, patterning the photoresist film to form a photoresist pattern, and etching the film to be etched using the photoresist pattern as an etching mask.

[0029] The step of forming the photoresist pattern may use light having a wavelength of 5 nm to 150 nm.

[0030] The method for forming a pattern may further include forming a resist underlayer film between the substrate and the photoresist film.

[0031] The photoresist pattern may have a width of 5 nm to 100 nm. Effect of the Invention

[0032] According to the present invention, there is provided a semiconductor photoresist composition which is capable of realizing a pattern with significantly improved sensitivity while maintaining line edge roughness. [Brief description of the drawings]

[0033] [Figure 1] 1 is a schematic cross-sectional view illustrating a method for forming a pattern using a semiconductor photoresist composition according to an embodiment of the present invention. [Diagram 2] 1 is a schematic cross-sectional view illustrating a method for forming a pattern using a semiconductor photoresist composition according to an embodiment of the present invention. [Diagram 3] 1 is a schematic cross-sectional view illustrating a method for forming a pattern using a semiconductor photoresist composition according to an embodiment of the present invention. [Figure 4] 1 is a schematic cross-sectional view illustrating a method for forming a pattern using a semiconductor photoresist composition according to an embodiment of the present invention. [Diagram 5] 1 is a schematic cross-sectional view illustrating a method for forming a pattern using a semiconductor photoresist composition according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in the description of the present invention, the description of the already known functions or configurations will be omitted in order to clarify the gist of the present invention.

[0035] In order to clearly explain the present invention, parts unnecessary for the explanation are omitted, and the same 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 the convenience of explanation, so the present invention is not necessarily limited to those shown in the drawings.

[0036] In the drawings, the thicknesses of various layers and regions are exaggerated to clearly show the layers and regions. Also, in the drawings, the thicknesses of some layers and regions are exaggerated for the convenience of explanation. When a layer, film, region, plate, or other part is described as being "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part therebetween or there is another part therebetween.

[0037] In this specification, "substituted" means that a hydrogen atom is not substituted with a deuterium atom, a halogen atom, a hydroxy group, a cyano group, a nitro group, -NRR' (wherein R and R' are each independently a hydrogen atom, a substituted or unsubstituted saturated or unsaturated aliphatic hydrocarbon group having 1 to 30 carbon atoms, a substituted or unsubstituted saturated or unsaturated alicyclic hydrocarbon group having 3 to 30 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 carbon atoms), -SiRR'R" (wherein R, R', and R" are each independently a hydrogen atom). "Unsubstituted" means that the hydrogen atom is not substituted with another substituent, but remains as a hydrogen atom.

[0038] In this specification, unless otherwise specified, the term "alkyl group" refers to a straight-chain or branched aliphatic hydrocarbon group. The alkyl group may be a "saturated alkyl group" that does not contain any double bonds or triple bonds.

[0039] The alkyl group may be an alkyl group having 1 to 10 carbon atoms. For example, the alkyl group may be an alkyl group having 1 to 8 carbon atoms, an alkyl group having 1 to 7 carbon atoms, an alkyl group having 1 to 6 carbon atoms, or an alkyl group having 1 to 5 carbon atoms. For example, the alkyl group having 1 to 5 carbon atoms may be a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, or a 2,2-dimethylpropyl group.

[0040] In this specification, unless otherwise defined, the term "cycloalkyl group" refers to a monovalent cyclic aliphatic saturated hydrocarbon group.

[0041] The cycloalkyl group may be a cycloalkyl group having 3 to 10 carbon atoms, for example, a cycloalkyl group having 3 to 8 carbon atoms, a cycloalkyl group having 3 to 7 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, a cycloalkyl group having 3 to 5 carbon atoms, or a cycloalkyl group having 3 to 4 carbon atoms. For example, the cycloalkyl group may be, but is not limited to, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, or a cyclohexyl group.

[0042] As used herein, an "aryl group" refers to a substituent in which all elements of the cyclic substituent have p-orbitals and these p-orbitals form conjugation, including monocyclic or fused polycyclic (i.e., rings which share adjacent pairs of carbon atoms) functional groups.

[0043] As used herein, unless otherwise defined, the term "alkenyl group" refers to a straight-chain or branched aliphatic hydrocarbon group and an aliphatic unsaturated alkenyl group containing at least one double bond.

[0044] As used herein, unless otherwise defined, the term "alkynyl group" refers to a straight-chain or branched aliphatic hydrocarbon group and an aliphatic unsaturated alkynyl group containing at least one triple bond.

[0045] In the formulae depicted herein, t-Bu refers to a tert-butyl group.

[0046] Hereinafter, a semiconductor photoresist composition according to one embodiment of the present invention will be described.

[0047] A composition for semiconductor photoresist according to one embodiment of the present invention includes an organotin compound represented by the following Chemical Formula 1, and a solvent.

[0048] [ka]

[0049] In the above Chemical Formula 1, X is -OR 2 , -SR 3 , -C(O)-L 2 -OR 4 , or -C(O)-L 3 -SR 5 and At this time, L 2 and L 3 each independently represents a single bond or a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, R 2 and R 3 each independently represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a combination thereof; R 4 and R 5 each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a combination thereof; L 1 represents a single bond or a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, R 1 is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted cycloalkenyl group having 3 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted cycloalkynyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a combination thereof; m and n are each independently an integer, and 2≦m+n≦6.

[0050] In the above organotin compounds, in addition to S that is directly bonded to Sn, the functional group represented by X containing at least one of -O-, -S-, and -C(O)- provides an additional coordinate bond site for the central metal Sn. Therefore, the unshared electron pair of O or S induces not only intermolecular bonds but also intramolecular coordinate bonds, which is advantageous for the formation of a matrix.

[0051] In particular, compared to the general monomolecular form with 4-coordination, the coordination number of Sn is filled by additional coordination bonds, and the Sn atom is structurally blocked, improving moisture stability and preventing aggregation caused by condensation reaction after hydrolysis, which increases long-term storage stability. This effectively reduces defects during the coating process and also affects coating stability.

[0052] In addition, the adhesion to the substrate is improved by strengthening the bond, and the thin film stability is also improved.

[0053] Furthermore, since the aggregation phenomenon is prevented, the material can be coated in an amorphous state during spin coating without using any additives, thereby improving sensitivity and coatability.

[0054] As an example, R in X in the above chemical formula 1 2 ~R 5may each independently be a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a combination thereof.

[0055] As a specific example, R in X in the above formula 1 2 ~R 5 may each independently be methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, iso-propyl, iso-butyl, iso-pentyl, iso-hexyl, iso-heptyl, iso-octyl, iso-nonyl, iso-decyl, sec-butyl, sec-pentyl, sec-hexyl, sec-heptyl, sec-octyl, tert-butyl, tert-pentyl, tert-hexyl, tert-heptyl, tert-octyl, tert-nonyl, or tert-decyl.

[0056] As an example, R 1 may be a substituted or unsubstituted branched alkyl group having 3 to 20 carbon atoms, which means that the carbon atom bonded to the metal is in the form of a secondary carbon, a tertiary carbon, or a quaternary carbon.

[0057] In this specification, a branched alkyl group may be, for example, an iso-propyl group, an iso-butyl group, an iso-pentyl group, an iso-hexyl group, an iso-heptyl group, an iso-octyl group, an iso-nonyl group, an iso-decyl group, a sec-butyl group, a sec-pentyl group, a sec-hexyl group, a sec-heptyl group, a sec-octyl group, a tert-butyl group, a tert-pentyl group, a tert-hexyl group, a tert-heptyl group, a tert-octyl group, a tert-nonyl group, or a tert-decyl group.

[0058] As an example, L in the above formula 1 1may be a single bond, or a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms.

[0059] In one embodiment of the present invention, L in the above formula 1 1 may be a single bond, a substituted or unsubstituted methylene group, a substituted or unsubstituted ethylene group, a substituted or unsubstituted propylene group, or a substituted or unsubstituted trimethylene group.

[0060] As an example, m and n in the above Chemical Formula 1 may be 4≦m+n≦6.

[0061] As a specific example, m and n in the above Chemical Formula 1 are m+n=4, where m is an integer of 0-2, and n is an integer of 2-4.

[0062] More specific examples of the organotin compound include at least one selected from the group consisting of the compounds listed in Group 1 below.

[0063] [ka]

[0064] The organotin compound can be synthesized by appropriately referring to a conventionally known synthesis method. More specifically, a person skilled in the art can easily synthesize the organotin compound by referring to the synthesis methods described in the Examples.

[0065] The above organotin compound strongly absorbs extreme ultraviolet rays with a wavelength of 13.5 nm and has excellent sensitivity to light having high energy.

[0066] In the semiconductor photoresist composition according to one embodiment of the present invention, the organotin compound is contained in an amount of 1% by mass to 30% by mass, for example, 1% by mass to 25% by mass, for example, 1% by mass to 20% by mass, for example, 1% by mass to 15% by mass, for example, 1% by mass to 10% by mass, for example, 1% by mass to 5% by mass, but is not limited thereto. When the organotin compound is contained in an amount within the above range, the storage stability and etching resistance of the semiconductor photoresist composition are improved, and the resolution characteristics are improved.

[0067] The composition for semiconductor photoresist according to one embodiment of the present invention includes the organotin compound described above, and thus can provide a composition for semiconductor photoresist having excellent sensitivity and pattern formability.

[0068] The solvent contained in the semiconductor photoresist composition according to one embodiment of the present invention may be an organic solvent, and examples of the organic solvent may include, but are not limited to, aromatic compounds (e.g., xylene, toluene, etc.), alcohols (e.g., 4-methyl-2-pentanol, 4-methyl-2-propanol, 1-butanol, methanol, isopropyl alcohol, 1-propanol, etc.), ethers (e.g., anisole, tetrahydrofuran, etc.), esters (n-butyl acetate, propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate, etc.), ketones (e.g., methyl ethyl ketone, 2-heptanone, etc.), or mixtures thereof.

[0069] In one embodiment of the present invention, the semiconductor photoresist composition may further include a resin in addition to the organotin compound and a solvent.

[0070] The resin may be a phenolic resin containing at least one aromatic moiety listed in Group 2 below.

[0071] [ka]

[0072] The resin may have a weight average molecular weight of 500 to 20,000. The weight average molecular weight of the resin can be measured by gel permeation chromatography (GPC).

[0073] The resin is contained in an amount of 0.1% by mass to 50% by mass relative to the total mass of the composition for semiconductor photoresist.

[0074] When the resin is contained within the above content range, excellent etching resistance and heat resistance can be obtained.

[0075] The semiconductor photoresist composition according to an embodiment preferably comprises the above-mentioned organotin compound, solvent, and resin. However, the semiconductor photoresist composition according to the above-mentioned embodiment may further include additives, if necessary. Examples of the additives include a surfactant, a crosslinking agent, a leveling agent, an organic acid, a quencher, or a combination thereof.

[0076] The surfactant may be, for example, but is not limited to, an alkylbenzenesulfonate, an alkylpyridinium salt, a polyethylene glycol, a quaternary ammonium salt, or a combination thereof.

[0077] Examples of the crosslinking agent include, but are not limited to, melamine-based crosslinking agents, substituted urea-based crosslinking agents, acrylic-based crosslinking agents, epoxy-based crosslinking agents, or polymer-based crosslinking agents. Preferred crosslinking agents have at least two crosslinking-forming substituents, and can be, for example, compounds such as methoxymethylated glycoluril, butoxymethylated glycoluril, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, 4-hydroxybutyl acrylate, acrylic acid, urethane acrylate, acrylic methacrylate, 1,4-butanediol diglycidyl ether, glycidol, diglycidyl 1,2-cyclohexanedicarboxylate, trimethylpropane triglycidyl ether, 1,3-bis(glycidoxypropyl)tetramethyldisiloxane, methoxymethylated urea, butoxymethylated urea, or methoxymethylated thiourea.

[0078] The leveling agent is used to improve the coating flatness during printing, and any known leveling agent that is commercially available can be used.

[0079] The organic acid may be, but is not limited to, p-toluenesulfonic acid, benzenesulfonic acid, p-dodecylbenzenesulfonic acid, 1,4-naphthalenedisulfonic acid, methanesulfonic acid, sulfonium fluorides, malonic acid, citric acid, propionic acid, methacrylic acid, oxalic acid, lactic acid, glycolic acid, succinic acid, or combinations thereof.

[0080] The quencher may be diphenyl(p-tolyl)amine, methyldiphenylamine, triphenylamine, phenylenediamine, naphthylamine, diaminonaphthalene, or combinations thereof.

[0081] The amount of these additives used can be easily adjusted depending on the desired physical properties, and they may not be added at all.

[0082] In addition, the semiconductor photoresist composition can further use a silane coupling agent as an adhesion improver to improve adhesion to the substrate (for example, to improve adhesion of the semiconductor photoresist composition to the substrate). Examples of the silane coupling agent include, but are not limited to, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltris(β-methoxyethoxy)silane; or 3-methacryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, p-styryltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane; and carbon-carbon unsaturated bond-containing silane compounds such as trimethoxy[3-(phenylamino)propyl]silane.

[0083] The semiconductor photoresist composition does not cause pattern collapse or hardly occurs even when a pattern having a high aspect ratio is formed. Therefore, in order to form a fine pattern having a width of, for example, 5 nm to 100 nm, for example, a fine pattern having a width of, for example, 5 nm to 80 nm, for example, a fine pattern having a width of, for example, 5 nm to 70 nm, for example, a fine pattern having a width of, for example, 5 nm to 50 nm, for example, a fine pattern having a width of, for example, 5 nm to 40 nm, for example, a fine pattern having a width of, for example, 5 nm to 30 nm, for example, a fine pattern having a width of, for example, 5 nm to 20 nm, for example, a fine pattern having a width of, for example, 5 nm to 10 nm, the composition can be used in a photoresist process using light with a wavelength of, for example, 5 nm to 150 nm, for example, a photoresist process using light with a wavelength of, for example, 5 nm to 100 nm, for example, a photoresist process using light with a wavelength of, for example, 5 nm to 80 nm, for example, a photoresist process using light with a wavelength of, for example, 5 nm to 50 nm, for example, a photoresist process using light with a wavelength of, for example, 5 nm to 30 nm, for example, a photoresist process using light with a wavelength of, for example, 5 nm to 20 nm. Therefore, by using the semiconductor photoresist composition according to one embodiment of the present invention, extreme ultraviolet lithography using an EUV light source with a wavelength of 13.5 nm can be realized.

[0084] Meanwhile, according to another embodiment of the present invention, there is provided a method for forming a pattern using the above-mentioned semiconductor photoresist composition. For example, the pattern formed may be a photoresist pattern.

[0085] A method for forming a pattern according to an embodiment of the present invention includes the steps of forming a film to be etched on a substrate, applying the above-described semiconductor photoresist composition onto the film to be etched to form a photoresist film, patterning the photoresist film to form a photoresist pattern, and etching the film to be etched using the photoresist pattern as an etching mask.

[0086] A method for forming a pattern using the above-mentioned semiconductor photoresist composition will be described below with reference to Figures 1 to 5. Figures 1 to 5 are schematic cross-sectional views for explaining the method for forming a pattern using the semiconductor photoresist composition according to the present invention.

[0087] Referring to FIG. 1, first, an object to be etched is prepared. An example of the object to be etched may be a thin film 102 formed on a semiconductor substrate 100. The following description will be limited to the case where the object to be etched is the thin film 102. 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.

[0088] Next, a composition for forming a resist underlayer film for forming a resist underlayer film 104 is coated on the surface of the cleaned thin film 102 by applying a spin coating method. However, the present invention is not necessarily limited to this, and various known coating methods, for example, spray coating, dip coating, knife edge coating, and printing methods such as inkjet printing and screen printing, can also be used.

[0089] Although the step of coating the resist underlayer film can be omitted, the case of coating the resist underlayer film will be described below.

[0090] Thereafter, drying and baking steps are performed to form a resist underlayer film 104 on the thin film 102. The baking process can be performed at 100 to 500°C, for example, 100 to 300°C.

[0091] The resist underlayer film 104 is formed between the substrate 100 and the photoresist film 106 to prevent the occurrence of non-uniformity in the photoresist line width and the disruption of pattern formability when radiation reflected from the interface between the substrate 100 and the photoresist film 106 or from the interlayer hard mask is scattered into unintended photoresist regions.

[0092] 2, the above-described semiconductor photoresist composition is coated on a resist underlayer film 104 to form a photoresist film 106. The photoresist film 106 may be formed by coating the above-described semiconductor photoresist composition on a thin film 102 formed on a substrate 100 and then curing the composition through a heat treatment process.

[0093] More specifically, the step of forming a pattern using the semiconductor photoresist composition may include a step of applying the above-mentioned semiconductor photoresist composition onto the substrate 100 on which the thin film 102 is formed by a method such as spin coating, slit coating, inkjet printing, etc., and a step of drying the applied semiconductor photoresist composition to form a photoresist film 106.

[0094] The semiconductor photoresist composition has already been described in detail, so a duplicated description will be omitted.

[0095] Next, a first baking step is performed to heat the substrate 100 on which the photoresist film 106 is formed. The first baking step can be performed at a temperature of 80°C to 120°C.

[0096] Referring to FIG. 3, the photoresist film 106 is selectively exposed to light.

[0097] Examples of light that can be used in the exposure process include light with short wavelengths such as i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), and ArF excimer laser (wavelength 193 nm), as well as light with high-energy wavelengths such as EUV (Extreme UltraViolet; wavelength 13.5 nm) and E-Beam (electron beam).

[0098] More specifically, the light for exposure in one embodiment may be short-wavelength light having a wavelength range of 5 nm to 150 nm, or may be light having a high-energy wavelength such as EUV (Extreme UltraViolet; wavelength 13.5 nm) or E-Beam (electron beam).

[0099] The exposed regions 106b of the photoresist film 106 have a different solubility from the unexposed regions 106a of the photoresist film 106 by forming a polymer through a crosslinking reaction such as condensation between organometallic compounds.

[0100] Next, a second baking step is performed on the substrate 100. The second baking step can be performed at a temperature of 90° C. to 200° C. By performing the second baking step, the exposed region 106b of the photoresist film 106 becomes less soluble in a developer.

[0101] 4 shows a photoresist pattern 108 formed by dissolving and removing the photoresist film 106a corresponding to the unexposed region using a developer. Specifically, the photoresist film 106a corresponding to the unexposed region is dissolved and then removed using an organic solvent such as 2-heptanone, thereby completing the photoresist pattern 108 corresponding to a negative tone image.

[0102] As described above, the developer used in the pattern formation method according to one embodiment of the present invention may be an organic solvent. Examples of the organic solvent used in the pattern formation method according to one embodiment of the present invention include ketones such as methyl ethyl ketone, acetone, cyclohexanone, and 2-heptanone, alcohols such as 4-methyl-2-propanol, 1-butanol, iso-propanol, 1-propanol, and methanol, esters such as propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate, n-butyl acetate, and γ-butyrolactone, aromatic compounds such as benzene, xylene, and toluene, or combinations thereof.

[0103] However, the photoresist pattern is not necessarily limited to being formed as a negative tone image, but may be formed to have a positive tone image, in which case, examples of developers that can be used to form a positive tone image include quaternary ammonium hydroxides such as tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, or combinations thereof.

[0104] As described above, the photoresist pattern 108 formed by exposure to light having a wavelength such as i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), as well as high-energy light such as EUV (Extreme UltraViolet; wavelength 13.5 nm) and E-Beam (electron beam) can have a width of 5 nm to 100 nm. As an example, the photoresist pattern 108 is formed to a width of 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 to 30 nm, 5 nm to 20 nm, or 5 nm to 10 nm.

[0105] On the other hand, the photoresist pattern 108 may have a half pitch of 50 nm or less, such as 40 nm or less, such as 30 nm or less, such as 20 nm or less, such as 10 nm or less, and a line width roughness of 5 nm or less, 3 nm or less, 2 nm or less, 1 nm or less.

[0106] Next, the resist underlayer film 104 is etched using the photoresist pattern as an etching mask. Through this etching process, an organic layer pattern 112 is formed. The formed organic layer pattern 112 may also have a width corresponding to the photoresist pattern .

[0107] 5, the photoresist pattern 108 is applied as an etching mask to etch the exposed thin film 102. As a result, the thin film 102 is formed into a thin film pattern 114.

[0108] The thin film 102 can be etched by, for example, dry etching using an etching gas, and the etching gas that can be used is, for example, CHF3, CF4, Cl2, BCl3, or a mixture of these.

[0109] The thin film pattern 114 formed using the photoresist pattern 108 formed in the exposure process performed using the 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, similar to the photoresist pattern 108. For example, the thin film pattern 114 formed by the exposure process performed using the EUV light source may have a width of 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 to 30 nm, or 5 nm to 20 nm, similar to the photoresist pattern 108, and more specifically, is formed to a width of 20 nm or less. EXAMPLES

[0110] The present invention will be described in more detail with reference to the following examples of the preparation of the above-mentioned semiconductor photoresist composition, but the technical features of the present invention are not limited to the following examples.

[0111] (Synthesis of organotin compounds) (Synthesis Example 1) 10 g of an organotin compound represented by the following chemical formula A was dissolved in 30 ml of toluene, and then 8 g of 2-methoxythioacetic acid was slowly added and stirred at room temperature (20±5°C) for 6 hours. The toluene and dissociated propionic acid were then removed by vacuum distillation to obtain a compound represented by the following chemical formula 1a-1.

[0112] [ka]

[0113] (Synthesis Example 2) The same procedure as in Synthesis Example 1 was carried out except that 9.2 g of 2-(methylthio)thioacetic acid was used instead of 2-methoxythioacetic acid, to obtain the compound represented by 1a-2 below.

[0114] [ka]

[0115] (Synthesis Example 3) The same procedure as in Synthesis Example 1 was carried out except that 8 g of methyl 2-mercaptoacetate was used instead of 2-methoxythioacetic acid, to obtain a compound represented by the following chemical formula 1b-1.

[0116] [ka]

[0117] (Synthesis Example 4) The compound represented by the following chemical formula 1b-2 was obtained by carrying out the same procedure as in Synthesis Example 1, except that 9.2 g of S-methyl 2-mercaptothioacetate was used instead of 2-methoxythioacetic acid.

[0118] [ka]

[0119] (Synthesis Example 5) 10 g of an organotin compound represented by the following chemical formula B was dissolved in 30 ml of toluene, and then 6.9 g of 2-methoxyethane-1-thiol was slowly added and stirred at room temperature for 6 hours. Toluene and dissociated diethylamine were then removed by vacuum distillation to obtain a compound represented by the following chemical formula 1c-1.

[0120] [ka]

[0121] (Synthesis Example 6) The compound represented by the following chemical formula 1c-2 was obtained by carrying out the same procedure as in Synthesis Example 5, except that 8.2 g of 2-(methylthio)ethane-1-thiol was used instead of 2-methoxyethane-1-thiol.

[0122] [ka]

[0123] (Synthesis Example 7) 10 g of an organotin compound represented by the following formula C was dissolved in 30 ml of toluene, and then 10.3 g of 2-methoxythioacetic acid was slowly added and stirred at room temperature for 6 hours. Then, the toluene and dissociated propionic acid were removed by vacuum distillation to obtain a compound represented by the following formula 1d-1.

[0124] [ka]

[0125] (Synthesis Example 8) The compound represented by the following chemical formula 1d-2 was obtained by carrying out the same procedure as in Synthesis Example 7, except that 11.9 g of 2-(methylthio)thioacetic acid was used instead of 2-methoxythioacetic acid.

[0126] [ka]

[0127] (Synthesis Example 9) The compound represented by the following chemical formula 1e-1 was obtained by carrying out the same procedure as in Synthesis Example 7, except that 10.3 g of methyl 2-mercaptoacetate was used instead of 2-methoxythioacetic acid.

[0128] [ka]

[0129] (Synthesis Example 10) The compound represented by the following chemical formula 1e-2 was obtained by the same method as in Synthesis Example 7, except that 11.9 g of S-methyl 2-mercaptothioacetate was used instead of 2-methoxythioacetic acid.

[0130] [ka]

[0131] (Synthesis Example 11) 10 g of an organotin compound represented by the following chemical formula D was dissolved in 30 ml of toluene, and then 9 g of 2-methoxyethane-1-thiol was slowly added and stirred at room temperature for 6 hours. Toluene and dissociated diethylamine were then removed by vacuum distillation to obtain a compound represented by the following chemical formula 1f-1.

[0132] [ka]

[0133] (Synthesis Example 12) The compound represented by 1f-2 below was obtained by carrying out the same method as in Synthesis Example 11, except that 10.6 g of 2-(methylthio)ethane-1-thiol was used instead of 2-methoxyethane-1-thiol.

[0134] [ka]

[0135] (Synthesis Example 13) 10 g of an organotin compound represented by the following chemical formula E was dissolved in 30 ml of toluene, and then 5.6 g of 2-methoxythioacetic acid was slowly added and stirred at room temperature for 6 hours. The toluene and dissociated propionic acid were then removed by vacuum distillation to obtain a compound represented by the following chemical formula 1g.

[0136] [ka]

[0137] (Synthesis Example 14) 10 g of an organotin compound represented by the following chemical formula F was dissolved in 30 ml of toluene, and then 5.7 g of 2-(methylthio)ethane-1-thiol was slowly added and stirred at room temperature for 6 hours. Toluene and dissociated diethylamine were then removed by vacuum distillation to obtain a compound represented by the following chemical formula 1h.

[0138] [ka]

[0139] (Comparative Synthesis Example 1) The same procedure as in Synthesis Example 1 was carried out except that 5.8 g of thioacetic acid was used instead of 2-methoxythioacetic acid, to obtain a compound represented by the following chemical formula C1.

[0140] [ka]

[0141] (Comparative Synthesis Example 2) The same procedure as in Synthesis Example 13 was carried out except that 4 g of thioacetic acid was used instead of 2-methoxythioacetic acid, to obtain a compound represented by the following chemical formula C2.

[0142] [ka]

[0143] (Production of semiconductor photoresist composition) (Examples 1 to 14 and Comparative Examples 1 to 2) The compounds represented by chemical formulas 1a-1 to 1h obtained in Synthesis Examples 1 to 14, and the compounds represented by chemical formulas C1 and C2 obtained in Comparative Synthesis Examples 1 and 2 were each dissolved in propylene glycol monomethyl ether acetate (PGMEA) to a concentration of 3 mass % and filtered through a 0.1 μm PTFE syringe filter to produce semiconductor photoresist compositions.

[0144] (Rating 1: Storage stability) The storage stability of the semiconductor photoresist compositions used in Examples 1 to 14 and Comparative Examples 1 and 2 was evaluated according to the following criteria, and the results are shown in Table 1 below.

[0145] The semiconductor photoresist compositions according to Examples 1 to 14 and Comparative Examples 1 and 2 were left to stand for a specific period of time under room temperature (20±5°C) conditions, and the extent of precipitation was observed with the naked eye and evaluated on a two-level scale according to the following storage standards.

[0146] *Evaluation criteria -○: Can be stored for 3 months or more -×: Can be stored for 1 month or more but less than 3 months

[0147] (Evaluation 2: Coating uniformity) The semiconductor photoresist compositions of Examples 1 to 14 and Comparative Examples 1 and 2 were spin-coated at 1500 rpm for 30 seconds onto a 4-inch diameter circular silicon wafer having a native oxide surface, and the coated wafer was baked on a hot plate at 160°C for 120 seconds to form a thin film. Then, 10 points across the center of the wafer were arbitrarily selected and surface analyzed with an atomic force microscope (AFM) to determine the surface roughness (Rq value, root-mean-square roughness) (an Rq value of 0.3 or less can be judged to be excellent in coating uniformity).

[0148] [Table 1]

[0149] From the results in Table 1, it can be seen that the patterns formed using the semiconductor photoresist compositions of Examples 1 to 14 have superior storage stability and coating uniformity compared to Comparative Examples 1 and 2.

[0150] Although specific embodiments of the present invention have been described and illustrated above, it is obvious to those skilled in the art that the present invention is not limited to the described embodiments, and that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, such modifications or variations should not be understood individually from the technical spirit and perspective of the present invention, and the modified embodiments belong to the scope of the claims of the present invention. [Explanation of symbols]

[0151] 100 boards, 102 Thin Films, 104 Resist underlayer film, 106 Photoresist film, 106a unexposed area, 106b exposed area; 108 Photoresist pattern, 112 Organic film pattern, 110 Hard Mask 114 Thin film pattern.

Claims

1. An organotin compound represented by the following chemical formula 1: solvent A composition for a semiconductor photoresist comprising: 【Chemistry 1】 In the above Chemical Formula 1, X is -OR ２ , -SR ３ , -C(O)-L ２ -OR ４ or -C(O)-L ３ -SR ５ and At this time, L ２ and L ３ each independently represents a single bond or a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, R ２ and R ３ each independently represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a combination thereof; R ４ and R ５ each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a combination thereof; L １ is a single bond or a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, R １ is a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted cycloalkenyl group having 3 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted cycloalkynyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a combination thereof; m and n are each independently an integer, 2≦m+n≦6, and n≧1.

2. R in X in Formula 1 ２ ~R ５ wherein each independently represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a combination thereof.

3. R in X in Formula 1 ２ ~R ５ are each independently a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an n-heptyl group, an n-octyl group, an n-nonyl group, an n-decyl group, an isopropyl group, an isobutyl group, an isopentyl group, an isohexyl group, an isoheptyl group, an isooctyl group, an isononyl group, an isodecyl group, a sec-butyl group, a sec-pentyl group, a sec-hexyl group, a sec-heptyl group, a sec-octyl group, a tert-butyl group, a tert-pentyl group, a tert-hexyl group, a tert-heptyl group, a tert-octyl group, a tert-nonyl group, or a tert-decyl group.

4. R in Formula 1 １ 2. The semiconductor photoresist composition according to claim 1, wherein is a substituted or unsubstituted branched alkyl group having 3 to 20 carbon atoms.

5. R in Formula 1 １ is an isopropyl group, an isobutyl group, an isopentyl group, an isohexyl group, an isoheptyl group, an isooctyl group, an isononyl group, an isodecyl group, a sec-butyl group, a sec-pentyl group, a sec-hexyl group, a sec-heptyl group, a sec-octyl group, a tert-butyl group, a tert-pentyl group, a tert-hexyl group, a tert-heptyl group, a tert-octyl group, a tert-nonyl group, or a tert-decyl group.

6. L in Formula 1 １ 2. The semiconductor photoresist composition according to claim 1, wherein is a single bond, or a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms.

7. 2. The composition for semiconductor photoresist of claim 1, wherein m and n in Formula 1 satisfy the condition 4≦m+n≦6.

8. In the formula 1, m and n are each equal to 4; The m is an integer of 0 to 2, 2. The semiconductor photoresist composition according to claim 1, wherein said n is an integer of 2 to 4.

9. 2. The semiconductor photoresist composition according to claim 1, wherein the organotin compound is at least one selected from the group consisting of the compounds listed in Group 1 below: 【Chemistry 2】

10. 2. The semiconductor photoresist composition according to claim 1, wherein the content of the organotin compound is 1% by mass to 30% by mass, based on 100% by mass of the total mass of the semiconductor photoresist composition.

11. 10. The semiconductor photoresist composition of claim 1, further comprising an additive that is a surfactant, a crosslinking agent, a leveling agent, or a combination thereof.

12. forming a film to be etched on a substrate; A step of forming a photoresist film by applying the composition for a semiconductor photoresist according to any one of claims 1 to 12 onto the film to be etched; patterning the photoresist film to form a photoresist pattern; and Etching the layer to be etched using the photoresist pattern as an etching mask.

13. 13. The method of claim 12, wherein the forming of the photoresist pattern uses light having a wavelength of 5 nm to 150 nm.

14. The pattern forming method according to claim 12, further comprising forming a resist underlayer film between the substrate and the photoresist film.

15. The pattern forming method according to claim 12, wherein the photoresist pattern has a width of 5 nm to 100 nm.

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