Semiconductor photoresist composition and method for forming pattern using the composition

Abstract

The present invention discloses a semiconductor photoresist composition and a method for forming a pattern using the semiconductor photoresist composition, wherein the semiconductor photoresist composition comprises a condensation product produced by a condensation reaction between an organic tin compound represented by Chemical Formula 1 and at least one organic acid compound; and a solvent, wherein the at least one organic acid compound is selected from a substituted organic acid, an organic acid including at least two acid functional groups, and a substituted or unsubstituted sulfonic acid. The semiconductor photoresist composition has excellent storage stability and sensitivity characteristics. The specific details of Chemical Formula 1 are as defined in the specification. [Chemical Formula 1].

Description

[0001] CROSS REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2020-0178620 filed in the Korean Intellectual Property Office on December 18, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a semiconductor photoresist composition and a method of forming a pattern using the semiconductor photoresist composition. Background Art

[0004] Extreme ultraviolet (EUV) lithography has attracted attention as a basic technology for manufacturing next-generation semiconductor devices. EUV lithography is a pattern forming technology that uses EUV rays with a wavelength of 13.5 nanometers as an exposure light source. According to EUV lithography, it is known that extremely fine patterns (for example, less than or equal to 20 nanometers) can be formed in an exposure process during the manufacture of semiconductor devices.

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

[0006] Intrinsic image blurring due to acid-catalyzed reactions in these polymer-based photoresists limits resolution in small feature sizes, which has long been known in electron beam (e-beam) lithography. Chemically amplified (CA) photoresists are designed for high sensitivity, but may have more difficulty under EUV exposure in part because their typical elemental composition reduces the absorbance of the photoresist at a wavelength of 13.5 nanometers and therefore reduces its sensitivity.

[0007] In addition, CA photoresists may have difficulty with small feature sizes due to roughness issues, and experimentally, the line edge roughness (LER) of CA photoresists increases because the photospeed is reduced due in part to the nature of the acid catalyst process. Therefore, due to these defects and problems of CA photoresists, new high performance photoresists are needed in the semiconductor industry.

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

[0009] Inorganic photoresists based on peroxopolyacids of tungsten mixed with tungsten, niobium, titanium and / or tantalum have been reported as radiation-sensitive materials for patterning ( US 5061599 ; H. Okamoto, T. Iwayanagi, K. Mochiji, H. Umezaki, T. Kudo, Applied Physics Letters, 495, 298-300, 1986 ).

[0010] These materials are effectively patterned for large spacings in dual layer configurations, such as extreme ultraviolet (deep UV), X-ray, and electron beam sources. Recently, impressive performance has been achieved in the case of using cationic metal oxide hafnium sulfate (HfSOx) materials with peroxide complexing agents for imaging 15 nanometer half-pitch (HP) by projection EUV exposure (US2011-0045406; JK Stowers, A. Telecky, M. Kocsis, BL Clark, DA Keszler, A. Grenville, CN Anderson, PP Naulleau, Proc. SPIE, 7969, 796915, 2011). This system presents the highest performance of non-CA photoresists and has a feasible photosensitivity close to the requirements of EUV photoresists. However, metal oxide hafnium sulfate materials with peroxo complexing agents have several practical disadvantages. First, these materials are coated in a corrosive sulfuric acid / hydrogen peroxide mixture and have insufficient shelf life stability. Second, as a complex mixture, it is not easy to change the structure for performance improvement. Third, it should be developed in a tetramethylammonium hydroxide (TMAH) solution at very high concentrations such as 25 wt%.

[0011] Recently, since it is known that molecules containing tin have excellent extreme ultraviolet absorption ability, active research has been conducted. For the organotin polymer therein, the alkyl ligand dissociates by light absorption or secondary electrons generated thereby, and crosslinks with adjacent chains through oxo bonds, thereby achieving negative patterning that may not be removed by organic developer.

[0012] However, such organotin-based photoresists have the disadvantage of being sensitive to moisture. Summary of the invention

[0013] The embodiment provides a semiconductor photoresist composition having excellent sensitivity and storage stability.

[0014] Another embodiment provides a method of forming a pattern using a semiconductor photoresist composition.

[0015] The semiconductor photoresist composition according to the embodiment comprises a condensation product produced by a condensation reaction between an organic tin compound represented by Chemical Formula 1 and at least one organic acid compound, at least one of the organic acid compounds being selected from a substituted organic acid, an organic acid including at least two acid functional groups, and a substituted or unsubstituted sulfonic acid; and a solvent.

[0016] [Chemical formula 1]

[0017]

[0018] In Chemical Formula 1,

[0019] R 1 is substituted or unsubstituted C1 to C20 alkyl, substituted or unsubstituted C3 to C20 cycloalkyl, substituted or unsubstituted C2 to C20 alkenyl, substituted or unsubstituted C2 to C20 alkynyl, substituted or unsubstituted C6 to C30 aryl, or -LOR d ,

[0020] 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,

[0021] L is a single bond, or a substituted or unsubstituted C1 to C20 alkylene group, and

[0022] R d It is a substituted or unsubstituted C1 to C20 alkyl group.

[0023] The weight ratio of the organotin compound to the organic acid compound is about 85:15 to about 99:1.

[0024] The substituted organic acid may be substituted by at least one of a heteroatom, an atomic group containing a heteroatom, and a combination thereof, and the heteroatom may be at least one of sulfur (S), nitrogen (N), oxygen (O), phosphorus (P), and fluorine (F), and the atomic group containing a heteroatom may be -OH, -SH, -NH 2 , -S-, and -SS-.

[0025] The organic acid compound may be at least one of glycolic acid, malonic acid, succinic acid, 1,2,3,4-butanetetracarboxylic acid, citric acid, tartaric acid, triacylglycerol, lactic acid, thioglycolic acid, dithiodiacetic acid, thiodiacetic acid, phthalic acid, maleic acid, L-aspartic acid, p-toluenesulfonic acid, methanesulfonic acid, and benzenesulfonic acid.

[0026] The organic acid compound may have a pKa of less than or equal to about 5.

[0027] The condensation product may be at least one of an oligomer, a polymer, and a combination thereof.

[0028] The condensation product may comprise a hydrolysis condensation product.

[0029] The semiconductor photoresist composition may further include a surfactant, a crosslinking agent, a leveling agent or a combination thereof.

[0030] The method of forming a pattern according to an embodiment includes: forming an etch target layer on a substrate; coating a semiconductor photoresist composition on the etch target layer to form a photoresist layer; patterning the photoresist layer to form a photoresist pattern; and etching the etch target layer using the photoresist pattern as an etch mask.

[0031] The photoresist pattern may be formed using light having a wavelength of about 5 nanometers to about 150 nanometers.

[0032] The method of forming a pattern may further include providing a resist bottom layer formed between the substrate and the photoresist layer.

[0033] The photoresist pattern may have a width of about 5 nanometers to about 100 nanometers.

[0034] The semiconductor photoresist composition according to the embodiment has excellent storage stability and sensitivity characteristics, and by using the semiconductor photoresist composition, it is possible to provide a photoresist pattern having excellent sensitivity and a high aspect ratio without pattern collapse. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figures 1 to 5 is a cross-sectional view for explaining a method of forming a pattern using a semiconductor photoresist composition according to an embodiment.

[0036] Description of Figure Numbers

[0037] 100: substrate;

[0038] 102: Film;

[0039] 104: resist bottom layer;

[0040] 106: photoresist layer;

[0041] 106a: exposure area;

[0042] 106b: non-exposed area;

[0043] 108: photoresist pattern;

[0044] 112: organic layer pattern;

[0045] 114: Thin film pattern DETAILED DESCRIPTION

[0046] Hereinafter, embodiments of the present invention are described in detail with reference to the accompanying drawings. In the following description of the present invention, well-known functions or constructions will not be described in order to clarify the present invention.

[0047] In order to clearly illustrate the present disclosure, description and relationship are omitted, and throughout the present disclosure, the same or similar configuration elements are designated by the same reference numerals. In addition, since the size and thickness of each configuration shown in the drawings are arbitrarily shown for better understanding and ease of description, the present invention is not necessarily limited thereto.

[0048] In the drawings, the thickness of a layer, film, panel, region, etc. is exaggerated for clarity. In the drawings, the thickness of a portion of a layer or region, etc. is exaggerated for clarity. It should 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 may also be present.

[0049] As used herein, "substituted" means replacing a hydrogen atom with deuterium, halogen, hydroxyl, amino, substituted or unsubstituted C1 to C30 amine, nitro, substituted or unsubstituted C1 to C40 silyl (e.g., C1 to C10 alkylsilyl), C1 to C30 alkyl, C1 to C10 haloalkyl, C3 to C30 cycloalkyl, C6 to C30 aryl, C1 to C20 alkoxy, or cyano. "Unsubstituted" means that a hydrogen atom is not replaced by another substituent and the hydrogen atom remains.

[0050] As used herein, when no definition is otherwise provided, "alkyl" refers to a straight or branched aliphatic hydrocarbon group. The alkyl group may be a "saturated alkyl group" not having any double or triple bonds.

[0051] The alkyl group may be a C1 to C20 alkyl group. More specifically, the alkyl group may be a C1 to C10 alkyl group or a C1 to C6 alkyl group. For example, a C1 to C4 alkyl group means that the alkyl chain contains 1 to 4 carbon atoms and may be selected from the following: methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl.

[0052] Specific examples of the alkyl group may include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like.

[0053] As used herein, when a definition is not otherwise provided, "cycloalkyl" refers to a monovalent cyclic aliphatic hydrocarbon group.

[0054] As used herein, when a definition is not otherwise provided, "alkenyl" refers to an aliphatic unsaturated alkenyl group containing at least one double bond as a straight or branched aliphatic hydrocarbon group.

[0055] As used herein, when a definition is not otherwise provided, "alkynyl" refers to an aliphatic unsaturated alkynyl group containing at least one triple bond as a straight or branched aliphatic hydrocarbon group.

[0056] As used herein, "aryl" refers to a substituent in which all atoms in the cyclic substituent have p-orbitals and these p-orbitals are conjugated and may contain monocyclic or fused-ring polycyclic functional groups (ie, rings that share adjacent pairs of carbon atoms) functional groups.

[0057] Hereinafter, a semiconductor photoresist composition according to an embodiment is described.

[0058] The semiconductor photoresist composition according to an embodiment of the present invention includes a condensation product and a solvent, wherein the condensation product is formed by a condensation reaction of an organic tin compound represented by Chemical Formula 1 and at least one organic acid compound selected from a substituted organic acid, an organic acid including at least two acid functional groups, and a substituted or unsubstituted sulfonic acid.

[0059] [Chemical formula 1]

[0060]

[0061] In Chemical Formula 1,

[0062] R 1 is substituted or unsubstituted C1 to C20 alkyl, substituted or unsubstituted C3 to C20 cycloalkyl, substituted or unsubstituted C2 to C20 alkenyl, substituted or unsubstituted C2 to C20 alkynyl, substituted or unsubstituted C6 to C30 aryl, or -LOR d ,

[0063] R a , Rb 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,

[0064] L is a single bond, or a substituted or unsubstituted C1 to C20 alkylene group, and

[0065] R d It is a substituted or unsubstituted C1 to C20 alkyl group.

[0066] As used herein, the term "condensation product" refers to a product resulting from a condensation reaction. A condensation reaction refers to a reaction in which at least two organic compound molecules combine with an active (e.g., reactive) atom or group of atoms as a center to release a single molecule such as water, ammonia, hydrogen chloride, and / or the like. Compounds resulting from the simple combination of two molecules (without releasing any single molecule) are also intended to be included in the category of condensation products herein.

[0067] The condensation products may comprise monomers, oligomers, polymers, and combinations thereof.

[0068] For example, R in Formula 1 1 It may be a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, or a combination thereof.

[0069] As a specific example, R of Chemical Formula 1 1 It may be a substituted or unsubstituted C3 to C20 alkyl group.

[0070] For example, R in Formula 1 1 It may be isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl or a combination thereof.

[0071] For example, R in Formula 1 a , R b and R c Each may independently be a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, or a combination thereof.

[0072] For example, R a , R b and R c Each of them can be independently methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, vinyl or a combination thereof.

[0073] R a , Rb and R c Each of may be the same or different.

[0074] For example, the substituted organic acid may be substituted by at least one of a heteroatom, an atom group containing a heteroatom, and a combination thereof.

[0075] The heteroatom may be at least one of sulfur (S), nitrogen (N), oxygen (O), phosphorus (P) and fluorine (F), and

[0076] The atomic group containing heteroatoms can be -OH, -SH, -NH 2 , -S-, and -SS-.

[0077] In the present specification, the substituted organic acid may, for example, mean that at least one of carbon atoms and hydrogen atoms included in a hydrocarbon chain linked to an acid functional group is substituted by at least one of a heteroatom, an atom group including a heteroatom, and a combination thereof while containing one acid functional group.

[0078] For example, the substituted organic acid may include at least one of the carbon atom and hydrogen atom at the end of the hydrocarbon chain to which the acid functional group is linked, at least one of the carbon atom and hydrogen atom in the middle of the hydrocarbon chain, and a combination thereof may be substituted by at least one of a heteroatom, an atomic group containing heteroatoms, and a combination thereof. For example, the substituted organic acid may include at least one carbon atom and / or hydrogen atom in the main chain and / or at the end of the hydrocarbon chain (to which the acid functional group is linked), and the substituted organic acid is substituted by a heteroatom, an atomic group containing heteroatoms, or a combination thereof.

[0079] Examples of substituted organic acids include glycolic acid, lactic acid, thioglycolic acid, and L-aspartic acid.

[0080] In the present specification, the acid functional group may be, for example, a carboxyl group.

[0081] The organic acid containing at least two acid functional groups may be, for example, an organic acid containing 2 to 4 acid functional groups and examples of the organic acid may include malonic acid, succinic acid, 1,2,3,4-butanetetracarboxylic acid, citric acid, tartaric acid, trisalicylic acid, dithiodiacetic acid, thiodiacetic acid, phthalic acid and maleic acid.

[0082] Meanwhile, in the present specification, a substituted or unsubstituted sulfonic acid means a sulfonic acid containing at least one -S(O) 2 OH group of organic acids.

[0083] Examples of the substituted or unsubstituted sulfonic acid may include p-toluenesulfonic acid, methanesulfonic acid, and benzenesulfonic acid.

[0084] Meanwhile, the organic acid compound may have a pKa of about 5 or less, for example, about 4 or less.

[0085] pKa is the molecular mass of an acid (HA) when it dissociates into H + When A-, it is the value obtained by taking the negative logarithm (-log) of the acid dissociation constant, and the larger the pKa value, the weaker the acid. When there are two or more acid dissociation functional groups in an organic acid molecule, the pKa value of the molecule is determined to be the value of the functional group with the lowest pKa.

[0086] When the pKa value of the organic acid compound is within the above range, a condensation product with the organic tin compound is easily formed. Since the condensation product is formed of an oligomer or a higher polymer, the penetration of external moisture can be reduced.

[0087] Therefore, the storage stability of the semiconductor photoresist composition including the condensation product formed by the condensation reaction of the organic tin compound represented by Chemical Formula 1 and the organic acid compound may be improved.

[0088] In the condensation product formed by the condensation reaction of the organic tin compound represented by Chemical Formula 1 and the organic acid compound, the group derived from the organic acid compound acts as a ligand and links the organic tin compound, and thus the condensation product as a final product may be at least one of an oligomer, a polymer, and a combination thereof.

[0089] For example, the condensation product may comprise a hydrolysis condensation product.

[0090] The condensation product may include the organic tin compound and the organic acid compound in a weight ratio of about 85:15 to about 99:1, and when it is within the above range, it may be more advantageous in terms of film forming properties, solubility, refractive index, and dissolution rate in a developer.

[0091] For example, the condensation product may include the organic tin compound and the organic acid compound in a weight ratio of about 90:10 to about 99:1, and specifically, about 90:10 to about 97:3.

[0092] In addition, the condensation product may have a weight average molecular weight (Mw) of about 1,000 g / mol to about 30,000 g / mol, for example, about 1,000 g / mol to about 20,000 g / mol, and in another embodiment, about 1,000 g / mol to about 10,000 g / mol. When it is within the above range, it may be more advantageous in terms of film formation characteristics in the developer, solubility, refractive index, and dissolution rate.

[0093] The conditions for obtaining the condensation product are not particularly limited.

[0094] For example, the organic tin compound and the organic acid compound represented by Chemical Formula 1 are diluted in a solvent such as propylene glycol monomethyl etheracetate (PGMEA), ethanol, 2-propanol, acetone, and butyl acetate. If necessary, the desired condensation product can be obtained by adding water and an acid (hydrochloric acid, acetic acid, nitric acid, etc.) as a reaction catalyst, followed by stirring to complete the polymerization reaction.

[0095] The type or amount of solvent, acid or base catalyst used herein can be selected arbitrarily without restriction. Required reaction times depends on the type, concentration, reaction temperature etc. of reactant and is different, but usually needs about 15 minutes to about 30 days. However, the reaction times is not limited to this scope.

[0096] In the case of commonly used photoresist compositions, etching resistance may be insufficient and patterns may collapse at high aspect ratios.

[0097] On the other hand, it is desirable that the semiconductor photoresist composition according to the embodiment consists of the aforementioned condensation product and a solvent.

[0098] The solvent included in the semiconductor photoresist composition according to the embodiment may 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, isopropanol, 1-propanol propylene glycol monomethyl ether), 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, etc., but is not limited thereto.

[0099] In some cases, the semiconductor photoresist composition according to the embodiment may further include an additive, and examples of the additive include a surfactant, a crosslinking agent, a leveling agent, or a combination thereof.

[0100] The surfactant may be, for example, alkylbenzene sulfonate, alkylpyridinium salt, polyethylene glycol, quaternary ammonium salt, or a combination thereof, but is not limited thereto.

[0101] The crosslinking agent may be, for example, a melamine crosslinking agent, a substituted urea crosslinking agent, an acryl crosslinking agent, an epoxy crosslinking agent or a polymer crosslinking agent, but is not limited thereto. It may be a crosslinking agent having at least two crosslinking substituents, for example, a compound such as methoxymethylated glycoluril, butoxymethylated glycoluril, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, 4-hydroxybutyl acrylate, acrylic acid, acrylic acid carbamate, methacrylate acrylate, 1,4-butanediol diglycidyl ether, glycidol, diglycidyl 1,2-cyclohexane dicarboxylate, trimethylpropane triglycidyl ether, 1,3-bis(glycidyloxypropyl)tetramethyldisiloxane, methoxymethylated urea, butoxymethylated urea or methoxymethylated thiourea, etc.

[0102] The leveling agent may be used to improve the flatness of the coating during printing, and may be a known leveling agent that is commercially available.

[0103] The amount of additives used can be controlled depending on the desired properties.

[0104] In addition, the semiconductor photoresist composition may further include a silane coupling agent as an adhesion enhancer to improve the close contact force with the substrate (for example, to improve the adhesion of the semiconductor photoresist composition to the substrate). The silane coupling agent may be, for example, a silane compound containing a carbon-carbon unsaturated bond, such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltri(β-methoxyethoxy)silane; or 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, p-phenylyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane; trimethoxy[3-(phenylamino)propyl]silane, etc., but are not limited thereto.

[0105] Semiconductor photoresist composition can be formed into a pattern with high aspect ratio without collapse. Therefore, in order to form a fine pattern with a width of, for example, about 5 nanometers to about 100 nanometers, about 5 nanometers to about 80 nanometers, about 5 nanometers to about 70 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, semiconductor photoresist composition can be used for the photoresist process of light with a wavelength in the range of about 5 nanometers to about 150 nanometers (for example, about 5 nanometers to about 100 nanometers, about 5 nanometers to about 80 nanometers, about 5 nanometers to about 50 nanometers, about 5 nanometers to about 30 nanometers or about 5 nanometers to about 20 nanometers). Therefore, semiconductor photoresist composition according to an embodiment can be used for realizing extreme ultraviolet lithography using an EUV light source with a wavelength of about 13.5 nanometers.

[0106] According to another embodiment, a method for forming a pattern using the aforementioned semiconductor photoresist composition is provided. For example, the pattern produced can be a photoresist pattern. More specifically, it can be a negative photoresist pattern.

[0107] The method of forming a pattern according to an embodiment includes: forming an etch target layer on a substrate; coating a semiconductor photoresist composition on the etch target layer to form a photoresist layer; patterning the photoresist layer to form a photoresist pattern; and etching the etch target layer using the photoresist pattern as an etch mask.

[0108] In the following, reference Figures 1 to 5 Methods of forming patterns using semiconductor photoresist compositions are 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 an embodiment.

[0109] refer to Figure 1 , an object for etching is prepared. The object for etching may 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 may be, for example, a silicon nitride layer, a polysilicon layer, or a silicon oxide layer.

[0110] Subsequently, a resist base layer composition for forming a resist base layer 104 is spin-coated on the surface of the washed thin film 102. However, the embodiment is not limited thereto, and various known coating methods such as spray coating, dip coating, knife edge coating, printing methods (e.g., inkjet printing and screen printing) and the like may be used.

[0111] The coating process of the resist underlayer may be omitted, and hereinafter, a process including coating of the resist underlayer is described.

[0112] Subsequently, the applied composition is dried and baked to form a resist bottom layer 104 on the thin film 102. The baking may be performed at about 100°C to about 500°C, for example, about 100°C to about 300°C.

[0113] The resist bottom layer 104 is formed between the substrate 100 and the photoresist layer 106 and thus prevents non-uniformity of photoresist line width and patterning capability when radiation reflected from an interface between the substrate 100 and the photoresist layer 106 or a hard mask between layers is scattered into an unintended photoresist area.

[0114] refer to Figure 2 The photoresist layer 106 is formed by coating a semiconductor photoresist composition on the resist base layer 104. The photoresist layer 106 is obtained by coating the aforementioned semiconductor photoresist composition on the thin film 102 formed on the substrate 100 and then curing it by heat treatment.

[0115] More specifically, forming a pattern by using a semiconductor photoresist composition may include coating the semiconductor photoresist composition on the substrate 100 having the thin film 102 by spin coating, slit coating, inkjet printing, etc., and then drying the semiconductor photoresist composition to form a photoresist layer 106 .

[0116] The semiconductor photoresist composition has been described in detail and will not be described again.

[0117] Subsequently, the substrate 100 having the photoresist layer 106 is subjected to a first baking process. The first baking process may be performed at about 80°C to about 120°C.

[0118] refer to Figure 3 , the photoresist layer 106 can be selectively exposed.

[0119] For example, exposure can use activating radiation with high energy wavelengths such as extreme ultraviolet (EUV; wavelength of 13.5 nanometers), E beam (electron beam), and short wavelength light such as i line (wavelength of 365 nanometers), KrF excimer laser (wavelength of 248 nanometers), ArF excimer laser (wavelength of 193 nanometers).

[0120] More specifically, light for exposure according to an embodiment may have a short wavelength and a high energy wavelength in a range of about 5 nm to about 150 nm, such as extreme ultraviolet (EUV; wavelength of about 13.5 nm), E beam (electron beam), or the like.

[0121] When forming the photoresist pattern, a negative pattern may be formed.

[0122] The exposed region 106 a of the photoresist layer 106 has a different solubility from the non-exposed region 106 b of the photoresist layer 106 by forming a polymer through a cross-linking reaction such as condensation between organic metal compounds.

[0123] Subsequently, the substrate 100 is subjected to a second baking process. The second baking process may be performed at a temperature of about 90° C. to about 200° C. The exposed area 106 a of the photoresist layer 106 becomes easily insoluble in the developer due to the second baking process. That is, after the second baking process, the exposed area 106 a of the photoresist layer 106 becomes insoluble in the developer.

[0124] exist Figure 4 In the process, the non-exposed area 106b of the photoresist layer is dissolved and removed using a developer to form a photoresist pattern 108. Specifically, the non-exposed area 106b of the photoresist layer is dissolved and removed using an organic solvent such as propylene glycol monomethyl ether acetate (PGMEA) to complete the photoresist pattern 108 corresponding to the negative image.

[0125] As described above, the developer used in the method for forming a pattern according to the embodiment may be an organic solvent. The organic solvent used in the method for forming a pattern according to the embodiment may be, for example: ketones such as methyl ethyl ketone, acetone, cyclohexanone, 2-heptanone, etc.; alcohols such as 4-methyl-2-propanol, 1-butanol, isopropanol, 1-propanol, methanol, etc.; esters such as propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate, n-butyl acetate, butyrolactone, etc.; aromatic compounds such as benzene, xylene, toluene, etc., or a combination thereof.

[0126] As described above, exposure to light having high energy such as extreme ultraviolet (EUV; having a wavelength of about 13.5 nanometers), E-beam (electron beam), and / or the like, and light having a wavelength such as i-line (a wavelength of about 365 nanometers), KrF excimer laser (a wavelength of about 248 nanometers), ArF excimer laser (a wavelength of about 193 nanometers), and / or the like can provide a photoresist pattern 108 having a width of about 5 nanometers to about 100 nanometers. 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.

[0127] On the other hand, the photoresist pattern 108 may have a half pitch of less than or equal to about 50 nanometers (e.g., less than or equal to about 40 nanometers; e.g., less than or equal to about 30 nanometers; e.g., less than or equal to about 20 nanometers; e.g., less than or equal to about 15 nanometers) and a pitch with 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.

[0128] Subsequently, the resist bottom layer 104 is etched using the photoresist pattern 108 as an etching mask. Through this etching process, an organic layer pattern 112 is formed. The organic layer pattern 112 may also have a width corresponding to the width of the photoresist pattern 108.

[0129] refer to Figure 5 , the exposed thin film 102 is etched by applying the photoresist pattern 108 as an etching mask. Thus, the thin film is formed into a thin film pattern 114.

[0130] The etching of the thin film 102 may be, for example, dry etching using an etching gas, and the etching gas may be, for example, CHF 3 CF 4 , Cl 2 , BCl 3 and their mixed gases.

[0131] In the exposure process, the thin film pattern 114 formed by using the photoresist pattern 108 formed by the exposure process performed by using the EUV light source may have a width corresponding to the width of the photoresist pattern 108. For example, the thin film pattern 114 may have a width of 5 nanometers to 100 nanometers, which is equal to the width of the photoresist pattern 108. For example, the thin film pattern 114 formed by using the photoresist pattern 108 formed by the exposure process performed by using the EUV light source may 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, and more specifically, have a width less than or equal to 20 nanometers, like the width of the photoresist pattern 108.

[0132] Hereinafter, the present invention will be described in more detail by way of an example of the preparation of the aforementioned semiconductor photoresist composition. However, the present invention is not technically limited to the following examples.

[0133] Examples

[0134] Synthesis Example 1: Synthesis of Organotin Compound 1

[0135] 25 mL of acetic acid was slowly added to the compound represented by Chemical Formula A-1 (10 g, 25.6 mmol) in a dropwise manner at room temperature, and then heated under reflux at 110° C. for 24 hours.

[0136] Subsequently, after the temperature was lowered to room temperature, acetic acid was vacuum distilled to obtain an organotin compound 1 represented by Chemical Formula B-1 (yield: 90%).

[0137] [Chemical formula A-1]

[0138]

[0139] [Chemical formula B-1]

[0140]

[0141] Synthesis Example 2: Synthesis of Organotin Compound 2

[0142] 25 mL of acrylic acid was slowly added to the compound represented by Chemical Formula A-2 (10 g, 25.4 mmol) in a dropwise manner at room temperature, and then heated under reflux at 110° C. for 24 hours.

[0143] Subsequently, after the temperature was lowered to room temperature, acrylic acid was vacuum distilled to obtain an organotin compound 2 represented by Chemical Formula B-2 (yield: 50%).

[0144] [Chemical formula A-2]

[0145]

[0146] [Chemical formula B-2]

[0147]

[0148] Synthesis Example 3: Synthesis of Organotin Compound 3

[0149] 25 mL of propionic acid was slowly added to the compound represented by Chemical Formula A-3 (10 g, 23.7 mmol) in a dropwise manner at room temperature, and then heated under reflux at 110° C. for 24 hours.

[0150] Subsequently, after the temperature was lowered to room temperature, propionic acid was vacuum distilled to obtain an organotin compound 3 represented by Chemical Formula B-3 (yield: 95%).

[0151] [Chemical formula A-3]

[0152]

[0153] [Chemical formula B-3]

[0154]

[0155] Synthesis Example 4: Synthesis of Organotin Compound 4

[0156] 25 mL of isobutyric acid was slowly added to the compound represented by Chemical Formula A-2 of Synthesis Example 2 (10 g, 25.4 mmol) in a dropwise manner at room temperature, and then heated under reflux at 110° C. for 24 hours.

[0157] Subsequently, after the temperature was lowered to room temperature, isobutyric acid was vacuum distilled to obtain an organotin compound 4 represented by Chemical Formula B-4 (yield: 95%).

[0158] [Chemical formula B-4]

[0159]

[0160] Synthesis Example 5: Synthesis of Organotin Compound 5

[0161] 25 mL of propionic acid was slowly added to the compound represented by Chemical Formula A-4 (10 g, 24.6 mmol) in a dropwise manner at room temperature, and then heated under reflux at 110° C. for 24 hours.

[0162] Subsequently, after the temperature was lowered to room temperature, propionic acid was vacuum distilled to obtain an organotin compound 5 represented by Chemical Formula B-5 (yield: 90%).

[0163] [Chemical formula A-4]

[0164]

[0165] [Chemical formula B-5]

[0166]

[0167] Example 1 to Example 7

[0168] Each of the organotin compounds according to Synthesis Examples 1 to 5 was mixed with an organic acid compound as shown in Table 1, and then added to propylene glycol methyl ether acetate (PGMEA, containing 5 wt % of deionized water (DIW)) to prepare a solution containing a solid concentration of 20 wt %.

[0169] The solutions were stirred at 80° C. for 24 hours and cooled to room temperature, and then the solutions were diluted to 3 wt % solids by using additional PGMEA solution to prepare condensate-containing solutions according to Examples 1 to 7, and then the prepared solutions were filtered with 0.1 μm polytetrafluoroethylene (PTFE) syringe filters, respectively, to prepare photoresist compositions.

[0170] (Table 1)

[0171]

[0172] Comparative Examples 1 to 5

[0173] The organotin compounds according to Synthesis Example 1 to Synthesis Example 5 were respectively dissolved in PGMEA at a solid concentration of 3 wt %, and then filtered with a 0.1 μm polytetrafluoroethylene (PTFE) syringe filter, thereby preparing a photoresist composition.

[0174] Evaluation 1: Evaluation of sensitivity and line edge roughness (LER)

[0175] The photoresist compositions of Examples 1 to 7 and Comparative Examples 1 to 5 were spin-coated on circular silicon wafers to form films at 1500rpm for 30 seconds. Each film was exposed to extreme ultraviolet radiation (E beam) at an accelerating voltage of 100 kV to form a 40 nm half-pitch nanowire pattern. The exposed film was exposed to 170°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 pattern images were obtained by field emission scanning electron microscopy (FE-SEM). The pattern lines formed by the FE-SEM images were measured according to the critical dimension (CD) size and line edge roughness (LER), and the sensitivity and line edge roughness of the film were then evaluated according to the following criteria, and are then shown in Table 2.

[0176] ※Evaluation Criteria

[0177] (1) Sensitivity

[0178] The CD size measured at 1000 microcoulombs / cm2 energy was evaluated according to the following criteria and the results are shown in Table 2.

[0179] -◎: greater than or equal to 40 nanometers

[0180] -○: greater than or equal to 35 nanometers and less than 40 nanometers

[0181] -△: less than 35 nanometers

[0182] -X: Unconfirmed pattern.

[0183] (2) Line edge roughness (LER)

[0184] -○: less than or equal to 4 nanometers

[0185] -△: greater than 4 nanometers and less than or equal to 7 nanometers

[0186] -X: larger than 7 nanometers

[0187] Assessment 2: Assessing storage stability

[0188] On the other hand, the photoresist compositions according to Example 1 to Example 7 and Comparative Example 1 to Comparative Example 5 were evaluated with respect to storage stability, and the results are shown in Table 2.

[0189] [Storage stability]

[0190] The photoresist compositions according to Examples 1 to 7 and Comparative Examples 1 to 5 were allowed to stand at room temperature (20±5° C.) for a predetermined period of time, and then visually inspected for the degree of precipitation and evaluated into 2 grades according to the following preservability criteria.

[0191] ※Evaluation Criteria

[0192] -○: Storage period is greater than or equal to 6 months

[0193] -△: can be stored for less than 6 months and greater than or equal to 3 months

[0194] -X: can be stored for less than 3 months

[0195] (Table 2)

[0196] Sensitivity LER(Nano) Storage stability Example 1 ◎ ○ ○ Example 2 ◎ ○ ○ Example 3 ◎ ○ ○ Example 4 ◎ ○ ○ Example 5 ◎ ○ ○ Example 6 ◎ ○ ○ Example 7 ◎ ○ ○ Comparative Example 1 ○ △ X Comparative Example 2 ◎ X X Comparative Example 3 ○ △ X Comparative Example 4 ○ △ △ Comparative Example 5 ○ △ X

[0197] Referring to Table 2, the semiconductor photoresist compositions according to Examples 1 to 7 exhibit better storage stability than the semiconductor photoresist compositions according to Comparative Examples 1 to 5, and in addition, the patterns formed by the semiconductor photoresist compositions according to Examples 1 to 7 exhibit better sensitivity and line edge roughness (LER) than the patterns formed by the semiconductor photoresist compositions according to Comparative Examples 1 to 5.

[0198] In the above, certain embodiments of the present invention have been described and illustrated, however, it is obvious to those skilled in the art that the present invention is not limited to the embodiments as described, and various modifications and conversions may be made without departing from the spirit and scope of the present invention. Therefore, the modified or converted embodiments may not be understood solely from the technical concepts and aspects of the present invention, and the modified embodiments are within the scope of the claims of the present invention.

Claims

1. A semiconductor photoresist composition comprising: at least one product produced by the reaction between the organotin compound represented by Chemical Formula 1 and the organic acid compound, the product being a polymer, the organic acid compound having a pKa of less than or equal to 5, the organic acid compound being selected from the group consisting of a substituted organic acid, an organic acid including at least two acid functional groups, and a substituted or unsubstituted sulfonic acid, The substituted organic acid is substituted by at least one of a heteroatom, an atom group containing a heteroatom, and a combination thereof, and The heteroatom is at least one of sulfur, nitrogen, oxygen, phosphorus and fluorine, and The atomic group including the heteroatom is at least one of -OH, -SH, -NH2, -S- and -SS-; and Solvent: [Chemical formula 1] Wherein, in Chemical Formula 1, R 1 is substituted or unsubstituted C1 to C20 alkyl, substituted or unsubstituted C3 to C20 cycloalkyl, substituted or unsubstituted C2 to C20 alkenyl, substituted or unsubstituted C2 to C20 alkynyl, substituted or unsubstituted C6 to C30 aryl, or -LOR d , 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, L is a single bond, or a substituted or unsubstituted C1 to C20 alkylene group, and R d It is a substituted or unsubstituted C1 to C20 alkyl group. 2 . The semiconductor photoresist composition according to claim 1 , wherein a weight ratio of the organic tin compound to the organic acid compound is 85:15 to 99:

1.

3. The semiconductor photoresist composition according to claim 1, wherein the organic acid compound comprises at least one of glycolic acid, malonic acid, succinic acid, 1,2,3,4-butanetetracarboxylic acid, citric acid, tartaric acid, trisaccharic acid, lactic acid, thioglycolic acid, dithiodiacetic acid, thiodiacetic acid, phthalic acid, maleic acid, L-aspartic acid, p-toluenesulfonic acid, methanesulfonic acid and benzenesulfonic acid. 4 . The semiconductor photoresist composition according to claim 1 , wherein the semiconductor photoresist composition further comprises a surfactant, a cross-linking agent, a leveling agent or a combination thereof.

5. A method for forming a pattern, comprising: forming an etching target layer on a substrate; applying the semiconductor photoresist composition according to any one of claims 1 to 4 on the etching target layer to form a photoresist layer; patterning the photoresist layer to form a photoresist pattern; as well as The etch target layer is etched using the photoresist pattern as an etch mask. 6 . The method of forming a pattern according to claim 5 , wherein the photoresist pattern is formed using light having a wavelength of 5 nm to 150 nm.

7. The method of forming a pattern according to claim 5, wherein the method of forming the pattern further comprises providing a resist bottom layer formed between the substrate and the photoresist layer. 8 . The method of forming a pattern according to claim 5 , wherein the photoresist pattern has a width of 5 nm to 100 nm.

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