Semiconductor photoresist composition, method of making and method of forming a pattern

Abstract

A semiconductor photoresist composition comprising an organotin compound represented by Chemical Formula 1 and a solvent; a method for preparing the same; and a method for forming a pattern using the same. The semiconductor photoresist composition has excellent sensitivity, resolution, and storage stability. Specific details of Chemical Formula 1 are defined in the specification.[Chemical Formula 1]

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2020-0178616, filed on December 18, 2020, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes. Technical Field

[0003] This disclosure relates to a semiconductor photoresist composition, a method for preparing the same, and a method for forming patterns using the photoresist composition. Background Technology

[0004] Extreme ultraviolet (EUV) lithography has attracted attention as a fundamental technology for manufacturing next-generation semiconductor devices. EUV lithography is a patterning technique that uses EUV rays with a wavelength of 13.5 nanometers as the exposure source. It is well known that, according to EUV lithography, extremely fine patterns (e.g., less than or equal to 20 nanometers) can be formed in the exposure process during the manufacturing of semiconductor devices.

[0005] Extreme ultraviolet (EUV) lithography is achieved through the development of compatible photoresists, which can be performed at a spatial resolution of 16 nanometers or less. Currently, efforts are underway to meet the insufficient specifications of conventional chemically amplified (CA) photoresists for next-generation devices, such as resolution, photosensitivity, and feature roughness (or line edge roughness or LER).

[0006] The inherent image blurring caused by acid-catalyzed reactions in these polymeric photoresists limits resolution at small feature sizes, a fact long known in electron beam (e-beam) lithography. Chemically amplified (CA) photoresists are designed for high sensitivity, but their sensitivity is reduced due to their typically lower elemental composition, which decreases absorbance at a wavelength of 13.5 nm. Therefore, CA photoresists may present additional challenges under EUV exposure.

[0007] Furthermore, CA photoresists may present difficulties with small feature sizes due to roughness issues, and the line edge roughness (LER) of CA photoresists has been experimentally shown to increase due to the inherent properties of the acid catalyst process, which partially reduces the photosensitivity. Therefore, due to these defects and problems of CA photoresists, a new type of high-performance photoresist is needed in the semiconductor industry.

[0008] To overcome the foregoing disadvantages of the chemically amplified (CA) organic photosensitive compositions, inorganic photosensitive compositions have been studied. The inorganic photosensitive compositions are mainly used for negative tone patterning, which has resistance to removal by a developer composition due to chemical modification by a non-chemically amplified mechanism. The inorganic compositions contain inorganic elements having a higher EUV absorption rate than hydrocarbons, and thus sensitivity can be ensured by a non-chemically amplified mechanism, and in addition, are less sensitive to stochastic effects, and thus are known to have low line edge roughness and a small number of defects.

[0009] It has been reported that inorganic photoresists based on peroxopolyacids of tungsten mixed with tungsten, niobium, titanium and / or tantalum have been used for patterned radiation-sensitive materials (US 5061599A; H. Okamoto, T. Iwayanagi, K. Mochiji, H. Umezaki, T. Kudo, Applied Physics Letters, 49(5), 298-300, 1986).

[0010] These materials are effective for large-pitch, bilayer configuration patterning as extreme ultraviolet (deep UV), X-ray, and electron beam sources. Recently, cationic metal oxide hafnium sulfate (HfSOx) materials with peroxide complexing agents have been used to image 15 nanometer half-pitch (HP) by projection EUV exposure with impressive performance. (US 2011-0045406A1; 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 presents the highest performance of a non-CA photoresist and has an achievable photospeed close to the requirements of EUV photoresists. However, the metal oxide hafnium sulfate materials with peroxide complexing agents have several practical disadvantages. First, these materials are coated in a corrosive mixture of sulfuric acid / hydrogen peroxide, which has insufficient shelf stability. Second, as a complex mixture, it is not easy to change its structure for improved performance. Third, development should be developed in a very high concentration of tetramethylammonium hydroxide (TMAH) solution, such as 25 wt%. SUMMARY

[0011] One embodiment provides a semiconductor photoresist composition having excellent sensitivity, resolution, and storage stability.

[0012] Another embodiment provides a pattern forming method using the semiconductor photoresist composition.

[0013] The semiconductor photoresist composition according to the embodiment includes an organic tin compound represented by Chemical Formula 1 and a solvent.

[0014] [Chemical Formula 1]

[0015]

[0016] In Chemical Formula 1,

[0017] R 1 to R 3 are each independently a substituted or unsubstituted C1 to C20 alkyl, and

[0018] R a , R b , and R c are each independently a substituted or unsubstituted C1 to C20 alkyl, a substituted or unsubstituted C3 to C20 cycloalkyl, a substituted or unsubstituted C2 to C20 alkenyl, a substituted or unsubstituted C2 to C20 alkynyl, a substituted or unsubstituted C6 to C30 aryl, or a combination thereof.

[0019] R 1 to R 3 may each independently be at least one selected from the group consisting of a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, and a t-butyl group.

[0020] R a , R b , and R c may each independently be at least one selected from the group consisting of a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, and a t-butyl group.

[0021] The semiconductor photoresist composition can further include an additive of a surfactant, a crosslinking agent, a leveling agent, or a combination thereof.

[0022] In another embodiment, a method of preparing a composition for a semiconductor photoresist is provided. The semiconductor photoresist composition can be prepared by reacting an organic tin compound represented by Chemical Formula 2 with an organic compound represented by Chemical Formula 3 in an organic solvent to prepare an organic tin compound represented by Chemical Formula 1, and mixing the prepared organic tin compound with a solvent.

[0023] [Chemical Formula 2] [Chemical Formula 3]

[0024]

[0025] In Chemical Formula 2 and Chemical Formula 3,

[0026] R 1 to R 3 each independently is a substituted or unsubstituted C1to C20alkyl,

[0027] R 4 to R 9 each independently is a substituted or unsubstituted C1to C20alkyl, a substituted or unsubstituted C3to C20cycloalkyl, a substituted or unsubstituted C2to C20alkenyl, a substituted or unsubstituted C2to C20alkynyl, a substituted or unsubstituted C6to C30aryl, or a combination thereof, and

[0028] R d is hydrogen, a substituted or unsubstituted C1to C20alkyl, a substituted or unsubstituted C3to C20cycloalkyl, a substituted or unsubstituted C2to C20alkenyl, a substituted or unsubstituted C2to C20alkynyl, a substituted or unsubstituted C6to C30aryl, or a combination thereof;

[0029] [Chemical Formula 1]

[0030]

[0031] wherein, in Chemical Formula 1,

[0032] R 1 to R 3 each independently is a substituted or unsubstituted C1to C20alkyl, and

[0033] R a , R b , and R c each independently is a substituted or unsubstituted C1to C20alkyl, a substituted or unsubstituted C3to C20cycloalkyl, a substituted or unsubstituted C2to C20alkenyl, a substituted or unsubstituted C2to C20alkynyl, a substituted or unsubstituted C6to C30aryl, or a combination thereof.

[0034] After dissolving the organotin compound represented by Chemical Formula 2 in an organic solvent, the organic compound represented by Chemical Formula 3 can be added dropwise thereto at about -78°C to about 60°C, followed by reacting for about 2 hours to about 24 hours to prepare the organotin compound represented by Chemical Formula 1.

[0035] R 1 to R 3may each independently be at least one selected from the group consisting of methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, and t-butyl.

[0036] R of Chemical Formula 2 4 to R 9 may each independently be at least one selected from the group consisting of substituted or unsubstituted C1 to C10 alkyl, substituted or unsubstituted C2 to C8 alkenyl, and substituted or unsubstituted C2 to C8 alkynyl.

[0037] R of Chemical Formula 3 d may be at least one selected from the group consisting of hydrogen, methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, and t-butyl.

[0038] The method for preparing a semiconductor photoresist composition can further include mixing an additive of a surfactant, a crosslinking agent, a leveling agent, or a combination thereof.

[0039] The method of forming a pattern according to another embodiment includes forming an etching target layer on a substrate; applying a semiconductor photoresist composition on the etching target layer to form a photoresist layer; patterning the photoresist layer to form a photoresist pattern; and etching the etching target layer using the photoresist pattern as an etching mask.

[0040] Light having a wavelength of about 5 nm to about 150 nm can be used to form the photoresist pattern.

[0041] The method of forming a pattern can further include providing a resist underlayer formed between the substrate and the photoresist layer.

[0042] The photoresist pattern can have a width of about 5 nm to about 100 nm.

[0043] The semiconductor photoresist composition according to the embodiment has excellent sensitivity, resolution, and storage stability, and by using the semiconductor photoresist composition, a photoresist pattern that does not collapse even with a high aspect ratio can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figures 1 to 5 is a cross-sectional view for explaining a method of forming a pattern using a semiconductor photoresist composition according to the embodiment.

[0045] [EXPLANATION OF REFERENCE NUMERALS]

[0046] 100: substrate;

[0047] 102: thin film;

[0048] 104: resist underlayer;

[0049] 106: photoresist layer;

[0050] 106a: exposed area;

[0051] 106b: non-exposed area;

[0052] 108: photoresist pattern;

[0053] 112: organic layer pattern;

[0054] 114: thin film pattern DETAILED DESCRIPTION

[0055] Hereinafter, embodiments of the present application will be described in detail with reference to the accompanying drawings. In the following description of the present application, well-known functions or constructions will not be described in detail so as to clarify the present application.

[0056] For the sake of clear illustration, the description and relationship are omitted, and throughout the present disclosure, the same or similar configuration elements are denoted by the same reference numerals. Also, since the size and thickness of each configuration in the drawings are arbitrarily illustrated for better understanding and easy description, the present application is not necessarily limited thereto.

[0057] In the drawings, the thickness of layers, films, panels, regions, and the like is exaggerated for clarity. In the drawings, the thickness of a portion of a layer or region and the like is exaggerated for clarity. It will be understood that when an element such as a layer, film, region or substrate is referred to as being "on" another element, it can be directly on the other element, or intervening elements can also be present.

[0058] As used herein, "substituted" means that a hydrogen atom is replaced by a deuterium, a halogen, a hydroxyl, an amino, a substituted or unsubstituted C1 to C30 amine group, a nitro group, a substituted or unsubstituted C1 to C40 silyl group, a C1 to C30 alkyl group, a C1 to C10 haloalkyl group, a C1 to C10 alkylsilyl group, a C3 to C30 cycloalkyl group, a C6 to C30 aryl group, a C1 to C20 alkoxy group, or a cyano group. "Unsubstituted" means that a hydrogen atom is not replaced by another substituent and the hydrogen atom is retained.

[0059] As used herein, "alkyl" means a straight chain or branched chain aliphatic hydrocarbon group when not otherwise defined. Alkyl groups can be "saturated alkyl groups" having no double or triple bonds.

[0060] Alkyl groups can be C1 to C20 alkyl groups. More specifically, alkyl groups can be C1 to C10 alkyl groups or C1 to C6 alkyl groups. For example, C1 to C4 alkyl groups mean that an alkyl chain contains 1 to 4 carbon atoms, and can be selected from the group consisting of methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and t-butyl.

[0061] Specific examples of alkyl groups can include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the like.

[0062] As used herein, "cycloalkyl" means a monovalent cyclic aliphatic hydrocarbon group when not otherwise defined.

[0063] As used herein, "alkenyl" is a straight-chain or branched aliphatic hydrocarbon group that refers to aliphatic unsaturated alkene groups containing at least one double bond when not otherwise defined.

[0064] As used herein, "alkynyl" is a straight-chain or branched aliphatic hydrocarbon group that refers to aliphatic unsaturated alkynyl groups containing at least one triple bond when not otherwise defined.

[0065] As used herein, "aryl" refers to a substituent in which all atoms in the cyclic substituent have a p orbital and these p orbitals are conjugated, which can include a monocyclic or fused ring polycyclic functional group (i.e., sharing pairs of adjacent carbon atom pairs of rings).

[0066] Hereinafter, a semiconductor photoresist composition according to an embodiment is described.

[0067] The semiconductor photoresist composition according to an embodiment of the present application includes an organotin compound and a solvent, wherein the organotin compound is represented by Chemical Formula 1.

[0068] [Chemical Formula 1]

[0069]

[0070] In Chemical Formula 1,

[0071] R 1 to R 3 are each independently a substituted or unsubstituted C1 to C20 alkyl group,

[0072] R a , R b , and R c 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, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof.

[0073] The organotin compound included in the semiconductor photoresist composition according to an embodiment of the present application is a C1 to C20 alkyl group, R 1 to R 3 are each a substituted or unsubstituted C1 to C20 alkyl group, in which case the organotin compound itself is stable, and penetration of external moisture can be reduced.

[0074] Therefore, even for active solvents, particularly solvents having high water reactivity, such as alcohol-based, ester-based, and ketone-based solvents, it exhibits excellent storage stability. Furthermore, for solvents having a relatively large amount of moisture in these solvents, it is also possible to maintain excellent storage stability.

[0075] Therefore, the storage stability of the semiconductor photoresist composition containing the organotin compound represented by Chemical Formula 1 can be improved.

[0076] Furthermore, when R 1 to R 3 are each independently a substituted or unsubstituted C1 to C20 alkyl group, the dissociation energy of the bond between the carbon of the alkyl group and the tin is low, making it possible to improve the sensitivity of exposure.

[0077] Therefore, a pattern can be formed even by low-energy exposure, and thus the sensitivity of the semiconductor photoresist composition containing the organotin compound represented by Chemical Formula 1 can be improved.

[0078] For example, R 1 to R 3 may each independently be a substituted or unsubstituted C1 to C10 alkyl group.

[0079] As a specific example, R 1 to R 3 may each independently be at least one selected from the group consisting of a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, and a t-butyl group.

[0080] For example, R 1 to R 3 may be the same or different.

[0081] For example, in Chemical Formula 1, R a , R b , and R c may each independently be at least one selected from the group consisting of a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C8 alkenyl group, and a substituted or unsubstituted C2 to C8 alkynyl group.

[0082] As a specific example, R a , R b , and R c may each independently be at least one selected from the group consisting of a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, and a t-butyl group.

[0083] For example, R a , R b , and R ceach of which can be identical or different.

[0084] In the case of a photoresist composition commonly used, etch resistance can be insufficient and a pattern can collapse at a high aspect ratio.

[0085] In contrast, the semiconductor photoresist composition according to the embodiment desirably includes the aforementioned organic tin compound and a solvent.

[0086] The solvent included in the semiconductor photoresist composition according to one embodiment can be an organic solvent such as an aromatic compound (e.g., xylene, toluene), an alcohol (e.g., 4-methyl-2-pentenol, 4-methyl-2-propanol, 1-butanol, methanol, isopropyl alcohol, or 1-propanol), an ether (e.g., anisole, tetrahydrofuran), an ester (n-butyl acetate, propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate), a ketone (e.g., methyl ethyl ketone, 2-heptanone), a mixture thereof, or the like, but is not limited thereto.

[0087] The semiconductor photoresist composition according to one embodiment can further include an additive in some cases. Examples of the additive include a surfactant, a crosslinking agent, a leveling agent, or a combination thereof.

[0088] The surfactant can be, for example, an alkylbenzenesulfonate, an alkylpyridinium salt, a polyethylene glycol, a quaternary ammonium salt, or a combination thereof, but is not limited thereto.

[0089] The crosslinking agent can be, for example, a melamine-based crosslinking agent, a substituted urea-based crosslinking agent, an acryl-based crosslinking agent, an epoxy-based crosslinking agent, or a polymer-based crosslinking agent, but is not limited thereto. It can be a crosslinking agent having at least two crosslinking-forming substituents, for example, a compound such as methoxymethylated glycoluril, butoxymethylated glycoluril, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, 4-hydroxybutyl acrylate, acrylic acid, acrylamidocaproate, acryloyl methacrylate, 1,4-butanediol diglycidyl ether, glycidol, diglycidyl 1,2-cyclohexanedicarboxylate, trimethylpropane triglycidyl ether, 1,3-bis(glycidyloxypropyl)tetramethyldisiloxane, methoxymethylated urea, butoxymethylated urea, or methoxymethylated thiourea, or the like.

[0090] The leveling agent can be used to improve the coating flatness during printing, and can be a known leveling agent commercially available.

[0091] The amount of the additive can be controlled according to the desired properties.

[0092] Further, the semiconductor photoresist composition can further include a silane coupling agent as an adhesion enhancer in order to improve the force of close contact with the substrate (e.g., in order to improve the adhesion of the semiconductor photoresist composition to the substrate). The silane coupling agent can be, for example, a silane compound including a carbon-carbon unsaturated bond such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltris(β-methoxyethoxy)silane; or 3-methacryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, p-styryltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane; trimethoxy[3-(phenylamino)propyl]silane, or the like, but is not limited thereto.

[0093] The semiconductor photoresist composition can be formed into a pattern having a high aspect ratio without collapse. Thus, in order to form a fine pattern having a width of, for example, about 5 nm to about 100 nm, about 5 nm to about 80 nm, about 5 nm to about 70 nm, about 5 nm to about 50 nm, about 5 nm to about 40 nm, about 5 nm to about 30 nm, or about 5 nm to about 20 nm, the semiconductor photoresist composition can be used in a photoresist process using light having a wavelength ranging from about 5 nm to about 150 nm (e.g., about 5 nm to about 100 nm, about 5 nm to about 80 nm, about 5 nm to about 50 nm, about 5 nm to about 30 nm, or about 5 nm to about 20 nm). Thus, the semiconductor photoresist composition according to an embodiment can be used to implement extreme ultraviolet lithography using an EUV light source having a wavelength of about 13.5 nm.

[0094] According to another embodiment, a method for preparing the aforementioned semiconductor photoresist composition can be provided.

[0095] The semiconductor photoresist composition according to one embodiment is prepared by reacting an organic tin compound represented by Chemical Formula 2 with an organic compound represented by Chemical Formula 3 in an organic solvent to prepare an organic tin compound represented by Chemical Formula 1, and by mixing the organic tin compound represented by Chemical Formula 1 with a solvent.

[0096] The organic tin compound represented by Chemical Formula 2 and the organic compound represented by Chemical Formula 3 are as follows, and the organic tin compound represented by Chemical Formula 1 is the same as described above.

[0097] [Chemical Formula 2] [Chemical Formula 3]

[0098]

[0099] In Chemical Formula 2 and Chemical Formula 3,

[0100] R 1 to R 3each independently is substituted or unsubstituted C1to C20alkyl,

[0101] R 4 to R 9 each independently is substituted or unsubstituted C1to C20alkyl, substituted or unsubstituted C3to C20cycloalkyl, substituted or unsubstituted C2to C20alkenyl, substituted or unsubstituted C2to C20alkynyl, substituted or unsubstituted C6to C30aryl, or a combination thereof, and

[0102] R d is hydrogen, substituted or unsubstituted C1to C20alkyl, substituted or unsubstituted C3to C20cycloalkyl, substituted or unsubstituted C2to C20alkenyl, substituted or unsubstituted C2to C20alkynyl, substituted or unsubstituted C6to C30aryl, or a combination thereof.

[0103] After dissolving the organotin compound represented by Chemical Formula 2 in an organic solvent, the organic compound represented by Chemical Formula 3 can be added dropwise at about -78°C to about 60°C, followed by reacting for about 2 hours to about 24 hours to prepare the organotin compound represented by Chemical Formula 1.

[0104] For example, the reaction temperature can be about -50°C to about 30°C, more specifically, about -20°C to about 0°C.

[0105] For example, the reaction time can be about 4 hours to about 16 hours, more specifically, about 4 hours to about 8 hours.

[0106] R 1 to R 3 may each independently be substituted or unsubstituted C1to C10alkyl.

[0107] For example, R 1 to R 3 may each independently be at least one selected from the group consisting of methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, and t-butyl.

[0108] For example, R 1 to R 3 may be the same or different.

[0109] For example, R 1 to R 3 may be the same or different.

[0110] R 1 to R 3 may be derived from R 1 to R 3.

[0111] In Chemical Formula 2, R 4 to R 9 may each independently be at least one selected from the group consisting of a substituted or unsubstituted C1to C10alkyl, a substituted or unsubstituted C2to C8alkenyl, and a substituted or unsubstituted C2to C8alkynyl.

[0112] For example, R 4 to R 9 in Chemical Formula 2 may each independently be a substituted or unsubstituted C1to C10alkyl.

[0113] For example, R 4 to R 9 in Chemical Formula 2 may each independently be at least one selected from the group consisting of a methyl, an ethyl, an n-propyl, an i-propyl, an n-butyl, an i-butyl, a sec-butyl, and a t-butyl.

[0114] For example, R 4 to R 9 in Chemical Formula 2 may be the same or different.

[0115] R d of Chemical Formula 3 can be at least one selected from the group consisting of a hydrogen, a substituted or unsubstituted C1to C10alkyl, a substituted or unsubstituted C2to C8alkenyl, and a substituted or unsubstituted C2to C8alkynyl.

[0116] For example, R d of Chemical Formula 3 can be at least one selected from the group consisting of a hydrogen, a methyl, an ethyl, an n-propyl, an i-propyl, an n-butyl, an i-butyl, a sec-butyl, and a t-butyl.

[0117] For example, R d of Chemical Formula 3 can be at least one selected from the group consisting of a methyl, an ethyl, an n-propyl, an i-propyl, an n-butyl, an i-butyl, a sec-butyl, and a t-butyl.

[0118] For example, R a , R b , and R c in Chemical Formula 1 can be the same as or different from each other.

[0119] For example, each of R a , R b , and R c in Chemical Formula 1 can be the same.

[0120] For example, R a , R b , and R c of Chemical Formula 1 can be derived from R d of Chemical Formula 3.

[0121] For example, the organic compound represented by Chemical Formula 3 can be one of acetic acid, propionic acid, butyric acid, isobutyric acid, but is not limited thereto.

[0122] The method for preparing the aforementioned semiconductor photoresist composition can further include mixing an additive of a surfactant, a crosslinking agent, a leveling agent, or a combination thereof.

[0123] Meanwhile, according to another embodiment, a method of forming a pattern using the aforementioned semiconductor photoresist composition is provided. For example, the pattern manufactured can be a photoresist pattern. More specifically, it can be a negative photoresist pattern.

[0124] The method of forming a pattern according to one embodiment includes forming an etching target layer on a substrate; applying a semiconductor photoresist composition on the etching target layer to form a photoresist layer; patterning the photoresist layer to form a photoresist pattern; and etching the etching target layer using the photoresist pattern as an etching mask.

[0125] Hereinafter, reference is made to Figures 1 to 5 A method of forming a pattern using a semiconductor photoresist composition is described. Figures 1 to 5 is a cross-sectional view for explaining a method of forming a pattern using a semiconductor photoresist composition according to one embodiment.

[0126] Reference is made to Figure 1 An object for etching is prepared. The object for etching can be a thin film 102 formed on a semiconductor substrate 100. Hereinafter, the object for etching is limited to the thin film 102. The entire surface of the thin film 102 is washed to remove impurities and the like remaining thereon. The thin film 102 can be, for example, a silicon nitride layer, a polysilicon layer, or a silicon oxide layer.

[0127] Subsequently, a resist underlayer composition for forming a resist underlayer 104 is spin-coated on the surface of the washed thin film 102. However, the embodiment is not limited thereto, and various coating methods known in the art, such as spraying, dipping, knife coating, printing methods (e.g., inkjet printing and screen printing), and the like, can be used.

[0128] The coating process of the resist underlayer can be omitted, and hereinafter, a process including coating of the resist underlayer is described.

[0129] Subsequently, the coated composition is dried and baked to form the resist underlayer 104 on the thin film 102. The baking can be performed at about 100°C to about 500°C, for example, about 100°C to about 300°C.

[0130] The resist underlayer 104 is formed between the substrate 100 and the photoresist layer 106, and thus, when the rays reflected from the interface between the substrate 100 and the photoresist layer 106 or the hard mask between the layers are scattered into unintended photoresist regions, it is possible to prevent non-uniformity of the photoresist line width and the pattern formation capability.

[0131] Reference Figure 2 The photoresist layer 106 is formed by applying the semiconductor photoresist composition on the resist underlayer 104. The photoresist layer 106 is obtained by applying the aforementioned semiconductor photoresist composition on the thin film 102 formed on the substrate 100, and then curing the photoresist layer 106 by heat treatment.

[0132] More specifically, the formation of the pattern by using the semiconductor photoresist composition can include applying the semiconductor photoresist composition on the substrate 100 having the thin film 102 by spin coating, slot coating, inkjet printing, or the like, and then drying the semiconductor photoresist composition to form the photoresist layer 106.

[0133] The semiconductor photoresist composition has been described in detail, and thus, further description will not be given.

[0134] Subsequently, the substrate 100 having the photoresist layer 106 is subjected to a first baking process. The first baking process can be performed at about 80°C to about 120°C.

[0135] Reference Figure 3 The photoresist layer 106 can be selectively exposed.

[0136] For example, the exposure can use light having a high-energy wavelength such as extreme ultraviolet (EUV; wavelength of about 13.5 nm), E-beam (electron beam), and the like, and light of a short wavelength such as i-line (wavelength of 365 nm), KrF excimer laser (wavelength of 248 nm), ArF excimer laser (wavelength of 193 nm), and the like.

[0137] More specifically, the light used for the exposure according to the embodiment can have a short wavelength and a high-energy wavelength in the range of about 5 nm to about 150 nm, for example, extreme ultraviolet (EUV; wavelength of about 13.5 nm), E-beam (electron beam), and the like.

[0138] In forming the photoresist pattern, a negative pattern can be formed.

[0139] The exposed region 106a of the photoresist layer 106 has a different solubility from the non-exposed region 106b of the photoresist layer 106 by the cross-linking reaction such as condensation between organic metal compounds to form a polymer.

[0140] Subsequently, the substrate 100 is subjected to a second baking process. The second baking process can be performed at a temperature of about 90°C to about 200°C. The exposed regions 106a of the photoresist layer 106 become less soluble in a developer due to the second baking process.

[0141] In Figure 4 The non-exposed regions 106b of the photoresist layer are dissolved and removed using a developer to form a photoresist pattern 108. Specifically, the non-exposed regions 106b of the photoresist layer are dissolved and removed by using an organic solvent such as 2-heptanone and the like to complete the photoresist pattern 108 corresponding to a negative image.

[0142] As described above, the developer used in the method of forming a pattern according to one embodiment can be an organic solvent. The organic solvent used in the method of forming a pattern according to one embodiment can be, for example, a ketone such as methyl ethyl ketone, acetone, cyclohexanone, 2-heptanone, and the like; an alcohol such as 4-methyl-2-propanol, 1-butanol, isopropyl alcohol, 1-propanol, methanol, and the like; an ester such as propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate, n-butyl acetate, butyrolactone, and the like; an aromatic compound such as benzene, xylene, toluene, and the like, or a combination thereof.

[0143] As described above, exposure to light having high energy such as extreme ultraviolet (EUV; wavelength of about 13.5 nanometers), E-beam (electron beam), and the like, and light having a short wavelength such as i-line (wavelength of about 365 nanometers), KrF excimer laser (wavelength of about 248 nanometers), ArF excimer laser (wavelength of about 193 nanometers), and the like, can provide a photoresist pattern 108 having a width of about 5 nanometers to about 100 nanometers in thickness. For example, the photoresist pattern 108 can have a width of about 5 nanometers to about 90 nanometers, about 5 nanometers to about 80 nanometers, about 5 nanometers to about 70 nanometers, about 5 nanometers to about 60 nanometers, about 5 nanometers to about 50 nanometers, about 5 nanometers to about 40 nanometers, about 5 nanometers to about 30 nanometers, or about 5 nanometers to about 20 nanometers in thickness.

[0144] On the other hand, the photoresist pattern 108 can have a half-pitch of less than or equal to about 50 nanometers, for example, less than or equal to about 40 nanometers, for example, less than or equal to about 30 nanometers, for example, less than or equal to about 20 nanometers, for example, less than or equal to about 15 nanometers, and a line width roughness of less than or equal to about 10 nanometers, less than or equal to about 5 nanometers, less than or equal to about 3 nanometers, or less than or equal to about 2 nanometers.

[0145] Subsequently, the photoresist pattern 108 is used as an etching mask to etch the resist underlayer 104. Through this etching process, an organic layer pattern 112 is formed. The width of the organic layer pattern 112 can also correspond to the width of the photoresist pattern 108.

[0146] ReferringFigure 5 The exposed thin film 102 is etched using the photoresist pattern 108 as an etching mask. Accordingly, the thin film is formed as a thin film pattern 114.

[0147] The etching of the thin film 102 can be dry etching using an etching gas, for example, CHF3, CF4, Cl2, BCl3, and a mixed gas thereof.

[0148] The width of the thin film pattern 114 of the photoresist pattern 108 formed by the exposure process performed using the EUV light source can correspond to the width of the photoresist pattern 108. For example, the thin film pattern 114 can have a width of about 5 nm to about 100 nm, which is equal to the width of the photoresist pattern 108. For example, the width of the thin film pattern 114 of the photoresist pattern 108 formed by the exposure process performed using the EUV light source can be about 5 nm to about 90 nm, about 5 nm to about 80 nm, about 5 nm to about 70 nm, about 5 nm to about 60 nm, about 5 nm to about 50 nm, about 5 nm to about 40 nm, about 5 nm to about 30 nm, or about 5 nm to about 20 nm, and more particularly, the width is less than or equal to 20 nm, as the width of the photoresist pattern 108.

[0149] Hereinafter, the present application will be described in more detail by Examples of preparation of the aforementioned semiconductor photoresist composition. However, the present application is not technically limited by the following Examples.

[0150] Example

[0151] Synthesis Example 1: Synthesis of Organic Tin Compound 1

[0152] The organic tin compound represented by Chemical Formula 2-1 (10 g, 26.4 mmol) was dissolved in 30 mL of anhydrous toluene, and then 4.8 g of acetic acid was slowly added dropwise at 0°C, followed by stirring for 6 hours.

[0153] Subsequently, after the temperature was raised to room temperature, the toluene was removed by vacuum distillation, and the remaining filtrate was fractionally distilled to obtain the organic tin compound 1 represented by Chemical Formula 1-1.

[0154] [Chemical Formula 2-1][Chemical Formula 1-1]

[0155]

[0156] Synthesis Example 2: Synthesis of Organic Tin Compound 2

[0157] The compound represented by Chemical Formula 2-2 (10 g, 31.0 mmol) was dissolved in 30 mL of anhydrous toluene, and then 8.3 g of isobutyric acid was slowly added dropwise at 0°C, followed by stirring for 6 hours.

[0158] Subsequently, after the temperature is raised to room temperature, toluene is removed by vacuum distillation, and the remaining filtrate is fractionally distilled to obtain an organotin compound 2 represented by Chemical Formula 1-2.

[0159] [Chemical Formula 2-2] [Chemical Formula 1-2]

[0160]

[0161] Synthesis Example 3: Synthesis of an organotin compound 3

[0162] The organotin compound represented by Chemical Formula 2-2 (10 g, 31.0 mmol) is dissolved in 30 mL of anhydrous toluene, and then 7.0 g of propionic acid is slowly added dropwise at 0°C, followed by stirring for 6 hours.

[0163] Subsequently, after the temperature is raised to room temperature, toluene is removed by vacuum distillation, and the remaining filtrate is fractionally distilled to obtain an organotin compound 3 represented by Chemical Formula 1-3.

[0164] [Chemical Formula 1-3]

[0165]

[0166] Synthesis Example 4: Synthesis of an organotin compound 4

[0167] The organotin compound represented by Chemical Formula 2-3 (10 g, 25.5 mmol) is dissolved in 30 mL of anhydrous toluene, and then 6.0 g of propionic acid is slowly added dropwise at 0°C, followed by stirring for 6 hours.

[0168] Subsequently, after the temperature is raised to room temperature, toluene is removed by vacuum distillation, and the remaining filtrate is fractionally distilled to obtain an organotin compound 4 represented by Chemical Formula 1-4.

[0169] [Chemical Formula 2-3] [Chemical Formula 1-4]

[0170]

[0171] Synthesis Example 5: Synthesis of an organotin compound 5

[0172] The organotin compound represented by Chemical Formula 2-3 (10 g, 25.5 mmol) is dissolved in 30 mL of anhydrous toluene, and then 6.9 g of isobutyric acid is slowly added dropwise at 0°C, followed by stirring for 6 hours.

[0173] Subsequently, after the temperature is raised to room temperature, toluene is removed by vacuum distillation, and the remaining filtrate is fractionally distilled to obtain an organotin compound 5 represented by Chemical Formula 1-5.

[0174] [Chemical Formula 1-5]

[0175]

[0176] Comparative Synthesis Example 1: Synthesis of organotin compound A

[0177] 25 ml of acetic acid was slowly added dropwise to the organotin compound represented by Chemical Formula A-1 (10.0 g, 25.6 mmol) at room temperature, followed by heating at 110°C under reflux for 24 hours.

[0178] Subsequently, after lowering the temperature to room temperature, acetic acid was vacuum distilled to obtain the organotin compound A represented by Chemical Formula a.

[0179] [Chemical Formula A-1] [Chemical Formula a]

[0180]

[0181] Comparative Synthesis Example 2: Synthesis of organotin compound B

[0182] 25 ml of propionic acid was slowly added dropwise to the organotin compound represented by Chemical Formula B-1 (10.0 g, 24.6 mmol) at room temperature, followed by heating at 110°C under reflux for 24 hours.

[0183] Subsequently, after lowering the temperature to room temperature, propionic acid was vacuum distilled to obtain the organotin compound B represented by Chemical Formula b.

[0184] [Chemical Formula B-1] [Chemical Formula b]

[0185]

[0186] Synthesis Examples 1 to 5 and Comparative Synthesis Examples 1 to 2

[0187] The organotin compounds 1 to 5 and the organotin compounds A and B obtained in Synthesis Example 1 to Synthesis Example 5 and Comparative Synthesis Example 1 and Comparative Synthesis Example 2 were dissolved in propylene glycol methyl ether acetate (PGMEA) at a concentration of 3.0 wt%, and then filtered with a 0.1 micron PTFE syringe filter to prepare a photoresist composition of Synthesis Example 1 to Synthesis Example 5 and Comparative Synthesis Example 1 and Comparative Synthesis Example 2. A circular silicon wafer having a diameter of 4 inches with a native oxide surface was used as a substrate for thin film deposition. The resist thin film was treated in a UV ozone cleaning system for 10 minutes before deposition, and each photoresist composition was spin-coated on the substrate at a speed of 2000 rpm for 30 seconds, and baked at 120°C for 120 seconds. The film thickness after coating and baking was measured by ellipsometry, and the result was about 20 nm.

[0188] Evaluation 1: Evaluation of sensitivity and line edge roughness (LER)

[0189] A film was prepared by coating the photoresist compositions according to Example 1 to Example 5 and Comparative Example 1 and Comparative Example 2 on a circular silicon wafer according to the coating method described above. The formed film was exposed to extreme ultraviolet radiation (E-beam) under an acceleration voltage of 100 kilovolts to form a 40 nm half-pitch nanoline pattern. The exposed film was exposed at 160°C for 60 seconds and immersed in a Petri dish containing 2-heptanone for 30 seconds, and then washed with the same solvent for 10 seconds. Finally, the washed film was baked at 150°C for 180 seconds, and a pattern image was obtained by field emission scanning electron microscopy (FE-SEM). The formed pattern line was measured according to the critical dimension (CD) size and line edge roughness (LER), and confirmed by the FE-SEM image, and then the sensitivity and line edge roughness of the film were evaluated according to the following criteria, and subsequently shown in Table 1.

[0190] Evaluation criteria

[0191] (1) Sensitivity

[0192] The CD size measured at an energy of 1000 microcoulomb / square centimeter was evaluated according to the following criteria, and the result is shown in Table 1.

[0193] - : greater than or equal to 40 nm

[0194] - : greater than or equal to 35 nm and less than 40 nm

[0195] - X: greater than 7 nm

[0196] - X: not confirmed pattern

[0197] (2) Line edge roughness (LER)

[0198] - O: less than or equal to 5 nm

[0199] - Δ: greater than or equal to 5 nm and less than or equal to 7 nm

[0200] - X: greater than 7 nm

[0201] Evaluation 2: Evaluation of storage stability

[0202] On the other hand, the semiconductor photoresist compositions according to Examples 1 to 5 and Comparative Examples 1 and 2 were evaluated in terms of storage stability, and the results are shown in Table 1.

[0203] [Storage stability]

[0204] The photoresist compositions according to Examples 1 to 5 and Comparative Examples 1 and 2 were allowed to stand at room temperature (20 ± 5°C) for a predetermined period of time, and then, the degree of precipitation was visually inspected, and evaluated as Level 2 according to the following storage property criteria.

[0205] ※ Evaluation criteria

[0206] - O: storable for greater than or equal to 6 months

[0207] - Δ: storable for greater than or equal to 3 months and less than 6 months

[0208] - X: storable for less than 3 months

[0209] (Table 1)

[0210] Sensitivity LER (nm) Storage stability Example 1 ◎ ○ ○ Example 2 ◎ ○ ○ Example 3 ◎ ○ ○ Example 4 ◎ ○ ○ Example 5 ◎ ○ ○ Comparative Example 1 △ X X Comparative Example 2 △ X X

[0211] Referring to Table 1, the semiconductor photoresist compositions according to Examples 1 to 5 exhibited more excellent storage stability than the semiconductor photoresist compositions according to Comparative Examples 1 and 2, and in addition, the patterns formed from the semiconductor photoresist compositions according to Examples 1 to 5 exhibited more excellent sensitivity and line edge roughness (LER) than the patterns formed from the semiconductor photoresist compositions according to Comparative Examples 1 and 2.

[0212] While the embodiments of the present application have been described above, the present application is not limited to the above-described embodiments, and various changes, modifications, and alterations can be made thereto without departing from the scope of the present application, which will be apparent to those skilled in the art. Therefore, the modified or changed embodiments cannot be interpreted as being outside the technical idea and scope of the present application, and the modified embodiments are within the scope of the claims of the present application.

Claims

1. A semiconductor photoresist composition, comprising: an organic tin compound represented by Chemical Formula 1, and a solvent: [Chemical Formula 1] wherein, in the Chemical Formula 1, R 1 to R 3 each independently is substituted or unsubstituted C1to C20alkyl, and R a , R b , and R c each independently is substituted or unsubstituted C1to C10alkyl, substituted or unsubstituted C2to C8alkenyl, substituted or unsubstituted C2to C8alkynyl, or a combination thereof.

2. The semiconductor photoresist composition of claim 1, wherein R 1 to R 3 each independently is at least one selected from the group consisting of methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, and t-butyl.

3. The semiconductor photoresist composition of claim 1, wherein R a , R b , and R c are each independently at least one selected from the group consisting of methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, and t-butyl. 4.The semiconductor photoresist composition of claim 1, wherein the semiconductor photoresist composition further comprises an additive of a surfactant, a crosslinking agent, a leveling agent, or a combination thereof. 5.A method for preparing a semiconductor photoresist composition, comprising preparing an organic tin compound represented by Chemical Formula 1 by reacting an organic tin compound represented by Chemical Formula 2 with an organic compound represented by Chemical Formula 3 in an organic solvent, and mixing the prepared organic tin compound represented by Chemical Formula 1 with a solvent: wherein in the Chemical Formula 2 and the Chemical Formula 3, R 1 to R 3 each independently is substituted or unsubstituted C1to C20alkyl, R 4 to R 9 each independently is substituted or unsubstituted C1to C20alkyl, substituted or unsubstituted C3to C20cycloalkyl, substituted or unsubstituted C2to C20alkenyl, substituted or unsubstituted C2to C20alkynyl, substituted or unsubstituted C6to C30aryl, or a combination thereof, and R d is hydrogen, substituted or unsubstituted C1to C10alkyl, substituted or unsubstituted C2to C8alkenyl, substituted or unsubstituted C2to C8alkynyl, or a combination thereof; [Chemical Formula 1] wherein, in the Chemical Formula 1, R 1 to R 3 each independently is substituted or unsubstituted C1to C20alkyl, and R a , R b , and R c each independently is substituted or unsubstituted Ci to C10alkyl, substituted or unsubstituted C2to C8alkenyl, substituted or unsubstituted C2to C8alkynyl, or a combination thereof. 6.The method for preparing a semiconductor photoresist composition of claim 5, wherein after dissolving the organic tin compound represented by Chemical Formula 2 in an organic solvent, the organic compound represented by Chemical Formula 3 is added dropwise thereto at -78 ℃ to 60 ℃, followed by a reaction for 2 hours to 24 hours to prepare the organic tin compound represented by Chemical Formula 1.

7. The method for preparing a semiconductor photoresist composition according to claim 5, wherein R 1 to R 3 each independently is at least one selected from the group consisting of methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, and t-butyl.

8. The method for producing a semiconductor photoresist composition according to claim 5, wherein R 4 to R 9 each independently is at least one selected from the group consisting of substituted or unsubstituted C1to C10alkyl, substituted or unsubstituted C2to C8alkenyl, and substituted or unsubstituted C2to C8alkynyl.

9. The method for preparing a semiconductor photoresist composition according to claim 5, wherein R d is at least one selected from the group consisting of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl. 10.The method for preparing a semiconductor photoresist composition of claim 5, comprising further adding an additive of a surfactant, a crosslinking agent, a leveling agent, or a combination thereof. 11.A method of forming a pattern, comprising: forming an etching target layer on a substrate; coating the semiconductor photoresist composition according to any one of claims 1 to 4 or the semiconductor photoresist composition prepared by the method according to any one of claims 5 to 10 on the etching target layer to form a photoresist layer; patterning the photoresist layer to form a photoresist pattern; and etching the etching target layer using the photoresist pattern as an etching mask. 12.The method of forming a pattern of claim 11, wherein the photoresist pattern is formed using light having a wavelength of 5 nm to 150 nm. 13.The method of forming a pattern of claim 11, wherein the method of forming a pattern further comprises providing a resist underlayer formed between the substrate and the photoresist layer. 14.The method of forming a pattern of claim 11, wherein the photoresist pattern has a width of 5 nm to 100 nm.

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