Pattern forming method and photoresist film

Abstract

To provide a pattern forming method capable of improving sensitivity and a photoresist film obtained by the same.SOLUTION: The pattern forming method includes the steps of: applying a semiconductor photoresist composition containing an organotin compound on a substrate; forming a photoresist film by drying and heating; and exposing and developing the photoresist film. The organotin compound has at least one organic ligand containing an Sn-C bond, and at least one organic carbonyloxy group. The photoresist film contains a compound represented by (R1Sn)xOy(OAR2)z before or after exposure. There is also provided a photoresist film containing a compound represented by (R1Sn)xOy(OAR2)z.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] This description relates to a pattern formation method and a photoresist film used for forming a pattern.

Background Art

[0002] As one of the elemental technologies for manufacturing next-generation semiconductor devices, EUV (extreme ultraviolet light) lithography has attracted attention. EUV lithography is a pattern formation technology that uses EUV light with a wavelength of 13.5 nm as an exposure light source. According to EUV lithography, it has been demonstrated that extremely fine patterns (for example, 20 nm or less) can be formed in the exposure process of the semiconductor device manufacturing process.

[0003] The realization of extreme ultraviolet (EUV) lithography requires the development of compatible photoresists that can be performed with spatial resolutions of 16 nm or less. Currently, traditional chemically amplified (CA) photoresists are striving to meet the specifications for resolution, photospeed, and feature roughness, line edge roughness (or LER) for next-generation devices.

[0004] The intrinsic image blur caused by acid catalyzed reactions in these polymeric photoresists limits resolution at small feature sizes, a fact that has been known for a long time in e-beam lithography. Chemically amplified (CA) photoresists are designed for high sensitivity, but their typical elemental makeup reduces the absorbance of the photoresist at a wavelength of 13.5 nm, and as a result, they may experience additional difficulties under EUV exposure, in part because it reduces sensitivity.

[0005] CA photoresists also experience difficulties due to roughness issues at small feature sizes, and it has been experimentally shown that line edge roughness (LER) increases as photospeed decreases, partly due to the nature of the acid catalysis process. Due to the drawbacks and problems of CA photoresists, there is a need in the semiconductor industry for new types of high-performance photoresists.

[0006] To overcome the shortcomings of the chemically amplified organic photosensitive compositions described above, inorganic photosensitive compositions have been studied. In the case of inorganic photosensitive compositions, they are mainly used for negative tone patterning that has resistance to removal by a developer composition through chemical modification by a non-chemically amplified mechanism. In the case of inorganic compositions, they contain inorganic elements that have a higher EUV absorption rate compared to hydrocarbons, and it is known that sensitivity can be ensured even with a non-chemically amplified mechanism, they are less sensitive to the stochastic effect, and the number of line edge roughness and defects is also small.

[0007] Inorganic photoresists based on tungsten, and peroxopolyacids of tungsten mixed with niobium, titanium, and / or tantalum have been reported for use as radiation sensitive materials for patterning (US5061599,; H. Okamoto, T. Iwayanagi, K. Mochiji, H. Umezaki, T. Kudo, Applied Physics Letters, 49(5), 298 - 300, 1986).

[0008] These materials are deep UV, x-ray, and electron beam sources that were effective in patterning large features in a bilayer configuration. More recently, when using a cationic hafnium metal oxide sulfate (HfSOx) material with a peroxo complexing agent to image a 15 nm half-pitch (HP) by projection EUV lithography, impressive performance was shown (US2011-0045406,; J.K. Stowers, A. Telecky, M. Kocsis, B.L. Clark, D.A. Keszler, A. Grenville, C.N. Anderson, P.P. Naulleau, Proc. SPIE, 7969, 796915, 2011). This system shows the best performance of non-CA photoresists and has a photospeed approaching the requirements for a viable EUV photoresist. However, hafnium metal oxide sulfate materials with peroxo complexing agents have several practical drawbacks. First, these materials are coated with a highly corrosive sulfuric acid / hydrogen peroxide mixture and do not have good shelf-life stability. Second, it is not easy to make structural changes for performance improvement as a composite mixture. Third, they must be developed with a very high concentration of about 25 wt% tetramethylammonium hydroxide (TMAH) solution or the like.

[0009] Recently, with the discovery that molecules containing tin exhibit excellent extreme ultraviolet absorption, active research has been conducted. In the case of organotin polymers, one such example, negative-tone patterning that cannot be removed with an organic developer solution is possible through crosslinking by oxo bonds with peripheral chains while alkyl ligands dissociate due to light absorption or secondary electrons generated thereby. Such organotin polymers have shown a dramatic improvement in sensitivity while maintaining resolution and line-edge roughness. However, for commercialization, further improvement of the patterning characteristics is required.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] A patterning method according to one embodiment provides a pattern with improved sensitivity.

[0011] Another embodiment relates to a photoresist film formed in a patterning method.

MEANS FOR SOLVING THE PROBLEMS

[0012] A patterning method according to one embodiment includes applying a composition for a semiconductor photoresist containing an organotin compound onto a substrate; drying and heating to form a photoresist film; and exposing and developing the photoresist film. The organotin compound has at least one organic ligand containing an Sn-C bond and at least one organic carbonyloxy group. The photoresist film has, before or after exposure, (R 1 Sn) x O y (OAR 2 ) z (where x, y, and z are each independently 0.1 to 0.9, x + y + z = 1, A is a single bond or C=O, and R 1is a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C6-C30 arylalkyl group, and L a -O-R a (wherein L a is a substituted or unsubstituted C1-C20 alkylene group, and R a is a substituted or unsubstituted C1-C20 alkyl group), and is selected from among R 2 is hydrogen, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, a substituted or unsubstituted C6-C30 aryl group, or a combination thereof). The compound represented by

[0013] The photoresist film according to another embodiment contains a compound represented by (R 1 Sn) x O y (OAR 2 ) z . [Advantages of the Invention]

[0014] By using the patterning method according to one embodiment, the sensitivity can be improved. [Brief Description of the Drawings]

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in the description of this specification, descriptions of already known functions or configurations are omitted for the sake of clarity of the gist of this specification.

[0017] For the sake of clear description, parts unnecessary for explanation are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification. Also, the sizes and thicknesses of the respective configurations shown in the drawings are arbitrarily shown for convenience of explanation, so this description is not necessarily limited to the illustration.

[0018] In the drawings, the thicknesses are enlarged to clearly show various layers and regions. And in the drawings, for convenience of explanation, the thicknesses of some layers and regions are exaggerated. When a part such as a layer, a film, a region, or a plate is said to be “above” another part, this includes not only the case where it is directly above the other part but also the case where there are other parts in between.

[0019] In this description, "substituted" means that a hydrogen atom is deuterium, a halogen group, a hydroxy group, a thiol group, a cyano group, a nitro group, -NRR' (where R and R' are each independently hydrogen, a substituted or unsubstituted C1-C30 saturated or unsaturated aliphatic hydrocarbon group, a substituted or unsubstituted C3-C30 saturated or unsaturated alicyclic hydrocarbon group, or a substituted or unsubstituted C6-C30 aromatic hydrocarbon group), -SiRR'R" (where R, R', and R" are each independently hydrogen, a substituted or unsubstituted C1-C30 saturated or unsaturated aliphatic hydrocarbon group, a substituted or unsubstituted C3-C30 saturated or unsaturated alicyclic hydrocarbon group, or a substituted or unsubstituted C6-C30 aromatic hydrocarbon group), a C1-C30 alkyl group, a C1-C10 haloalkyl group, a C1-C10 alkylsilyl group, a C3-C30 cycloalkyl group, a C6-C30 aryl group, a C1-C20 alkoxy group, a C1-C20 sulfide group, or a combination thereof. "Unsubstituted" means that the hydrogen atom is not substituted by another substituent and remains as a hydrogen atom.

[0020] In this specification, the term "alkyl group" means a linear or branched aliphatic hydrocarbon group unless otherwise defined. The alkyl group may be a "saturated alkyl group" that does not contain any double or triple bonds.

[0021] The alkyl group may be a C1-C8 alkyl group. For example, the alkyl group may be a C1-C7 alkyl group, a C1-C6 alkyl group, or a C1-C5 alkyl group. For example, the C1-C5 alkyl group may be a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, or a tert-butyl group, or a 2,2-dimethylpropyl group.

[0022] In this description, the term "cycloalkyl group" means a monovalent cyclic aliphatic saturated hydrocarbon group unless otherwise defined.

[0023] The cycloalkyl group may be a C3-C8 cycloalkyl group, for example, a C3-C7 cycloalkyl group, a C3-C6 cycloalkyl group, a C3-C5 cycloalkyl group, or a C3-C4 cycloalkyl group. For example, the cycloalkyl group may be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, etc., and is not limited thereto.

[0024] As used herein, the "aliphatic unsaturated organic group" means a hydrocarbon group in which the bond between carbon and carbon atoms in the molecule contains a double bond, a triple bond, or a combination of these bonds.

[0025] The aliphatic unsaturated organic group may be a C2-C8 aliphatic unsaturated organic group. For example, the aliphatic unsaturated organic group may be a C2-C7 aliphatic unsaturated organic group, a C2-C6 aliphatic unsaturated organic group, a C2-C5 aliphatic unsaturated organic group, or a C2-C4 aliphatic unsaturated organic group. For example, the C2-C4 aliphatic unsaturated organic group may be a vinyl group, an ethynyl group, an allyl group, a 1-propenyl group, a 1-methyl-1-propenyl group, a 2-propenyl group, a 2-methyl-2-propenyl group, a 1-propynyl group, a 1-methyl-1-propynyl group, a 2-propynyl group, a 2-methyl-2-propynyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group, a 1-butynyl group, a 2-butynyl group, or a 3-butynyl group.

[0026] As used herein, the "aryl group" means a substituent in which all elements of the cyclic substituent have p-orbitals and these p-orbitals form conjugation, and includes a monocyclic or fused-ring polycyclic (i.e., rings that share adjacent pairs of carbon atoms) functional group.

[0027] As used herein, the term "heteroaryl group" means a group containing at least one heteroatom selected from the group consisting of N, O, S, P, and Si within an aryl group. Two or more heteroaryl groups may be directly linked by a sigma bond, or when the heteroaryl group contains two or more rings, the two or more rings may be fused to each other. When the heteroaryl group is a fused ring, each ring may contain 1 to 3 of the heteroatoms.

[0028] As used herein, the term "alkenyl group" means a straight-chain or branched-chain aliphatic hydrocarbon group, which is an aliphatic unsaturated alkenyl group containing one or more double bonds, unless otherwise defined.

[0029] As used herein, the term "alkynyl group" means a straight-chain or branched-chain aliphatic hydrocarbon group, which is an aliphatic unsaturated alkynyl group containing one or more triple bonds, unless otherwise defined.

[0030] The organometallic compound may contain at least one of an organic oxy group and an organic carbonyloxy group.

[0031] The organometallic compound is represented by the following Chemical Formula 1. [Chemical Formula] In Chemical Formula 1, R 3 is a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C6-C30 arylalkyl group, and L a -O-R a (where L a is a substituted or unsubstituted C1-C20 alkylene group, and R ais selected from (a substituted or unsubstituted C1-C20 alkyl group), R 4 ~R 6 are each independently a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C6-C30 arylalkyl group, -OR b and -OC(=O)R c and are selected from among, R 4 ~R 6 at least one of which is -OR b and -OC(=O)R c and is selected from among, R b is a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, a substituted or unsubstituted C6-C30 aryl group, or a combination thereof, R c is hydrogen, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, a substituted or unsubstituted C6-C30 aryl group, or a combination thereof.

[0032] As an example, R 4 ~R 6 is selected from -OR b and -OC(=O)R c among them.

[0033] On the other hand, the compound represented by the above Chemical Formula 1 can exhibit excellent limit resolution in a pattern formed using a semiconductor photoresist composition containing -OR b or -OC(=O)R c by including the same.

[0034] Also, -OR b or -OC(=O)R c The ligand can determine the solubility of the compound represented by the chemical formula 1 in a solvent.

[0035] Said R 3 is a substituted or unsubstituted C1-C8 alkyl group, a substituted or unsubstituted C3-C8 cycloalkyl group, a substituted or unsubstituted C2-C8 aliphatic unsaturated organic group containing one or more double bonds or triple bonds, a substituted or unsubstituted C6-C20 aryl group, a substituted or unsubstituted C4-C20 heteroaryl group, a carbonyl group, an ethoxy group, a propoxy group, or a combination thereof, R b is a substituted or unsubstituted C1-C8 alkyl group, a substituted or unsubstituted C3-C8 cycloalkyl group, a substituted or unsubstituted C2-C8 alkenyl group, a substituted or unsubstituted C2-C8 alkynyl group, a substituted or unsubstituted C6-C20 aryl group, or a combination thereof, R c may be hydrogen, a substituted or unsubstituted C1-C8 alkyl group, a substituted or unsubstituted C3-C8 cycloalkyl group, a substituted or unsubstituted C2-C8 alkenyl group, a substituted or unsubstituted C2-C8 alkynyl group, a substituted or unsubstituted C6-C20 aryl group, or a combination thereof.

[0036] Said R 3 is a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, a tert-butyl group, a 2,2-dimethylpropyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, an ethenyl group, a propenyl group, a butenyl group, an ethynyl group, a propynyl group, a butynyl group, a phenyl group, a tolyl group, a xylyl group, a benzyl group, a formyl group, an acetyl group, a propanoyl group, a butanoyl group, a pentanoyl group, an ethoxy group, a propoxy group, or a combination thereof, R bis an ethyl group, propyl group, butyl group, isopropyl group, tert-butyl group, 2,2-dimethylpropyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, ethenyl group, propenyl group, butenyl group, ethynyl group, propynyl group, butynyl group, phenyl group, tolyl group, xylyl group, benzyl group, or a combination thereof, R c may be hydrogen, an ethyl group, propyl group, butyl group, isopropyl group, tert-butyl group, 2,2-dimethylpropyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, ethenyl group, propenyl group, butenyl group, ethynyl group, propynyl group, butynyl group, phenyl group, tolyl group, xylyl group, benzyl group, or a combination thereof.

[0037] The composition for semiconductor photoresist does not cause pattern collapse even when forming a pattern having a high aspect ratio. Therefore, for example, a photoresist process using light with a wavelength of 5 nm to 150 nm, for example, a photoresist process using light with a wavelength of 5 nm to 100 nm, for example, a photoresist process using light with a wavelength of 5 nm to 80 nm, for example, a photoresist process using light with a wavelength of 5 nm to 50 nm, for example, a photoresist process using light with a wavelength of 5 nm to 30 nm, for example, a photoresist process using light with a wavelength of 5 nm to 20 nm, can be used to form a fine pattern having a width of 5 nm to 100 nm, for example, a fine pattern having a width of 5 nm to 80 nm, for example, a fine pattern having a width of 5 nm to 70 nm, for example, a fine pattern having a width of 5 nm to 50 nm, for example, a fine pattern having a width of 5 nm to 40 nm, for example, a fine pattern having a width of 5 nm to 30 nm, for example, a fine pattern having a width of 5 nm to 20 nm. Therefore, when using the composition for semiconductor photoresist according to one embodiment, extreme ultraviolet lithography using an EUV light source with a wavelength of about 13.5 nm can be realized.

[0038] A pattern formation method according to an embodiment includes the steps of applying a composition for a semiconductor photoresist containing an organotin compound on a substrate; drying and heating to form a photoresist film; and exposing and developing the photoresist film. The organotin compound has at least one organic ligand containing an Sn-C bond and at least one organic carbonyloxy group. The photoresist film contains, before or after exposure, a compound represented by (R 1 Sn) x O y (OAR 2 ) z (where x, y, and z are each independently 0.1 to 0.9, x + y + z = 1, A is a single bond or C=O, R 1 is a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C6-C30 arylalkyl group, and L a -O-R a (where L a is a substituted or unsubstituted C1-C20 alkylene group and R a is a substituted or unsubstituted C1-C20 alkyl group), and is selected from among these, and R 2 is hydrogen, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, a substituted or unsubstituted C6-C30 aryl group, or a combination thereof).

[0039] As an example, the produced pattern may be a photoresist pattern.

[0040] The photoresist film can contain Sn-OAR 2 bonds, Sn-O-Sn bonds, and Sn-C bonds.

[0041] Before exposure, the content of the compound represented by (R 1 Sn) x O y (OAR 2 ) z may be 5 to 95% by weight based on 100% by weight of the semiconductor photoresist composition.

[0042] After exposure and development, the content of the compound represented by (R 1 Sn) x O y (OAR 2 ) z may be 5 to 95% by weight based on 100% by weight of the semiconductor photoresist composition.

[0043] As a specific example, the R 1 is a substituted or unsubstituted C1-C8 alkyl group, a substituted or unsubstituted C3-C8 cycloalkyl group, a substituted or unsubstituted C2-C8 aliphatic unsaturated organic group containing one or more double bonds or triple bonds, a substituted or unsubstituted C6-C20 aryl group, a substituted or unsubstituted C4-C20 heteroaryl group, a carbonyl group, an ethoxy group, a propoxy group, or a combination thereof, the R 2 is hydrogen, a substituted or unsubstituted C1-C8 alkyl group, a substituted or unsubstituted C3-C8 cycloalkyl group, a substituted or unsubstituted C2-C8 alkenyl group, a substituted or unsubstituted C2-C8 alkynyl group, a substituted or unsubstituted C6-C20 aryl group, or a combination thereof.

[0044] As a more specific example, the R 1is a methyl group, ethyl group, propyl group, butyl group, isopropyl group, tert-butyl group, 2,2-dimethylpropyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, ethenyl group, propenyl group, butenyl group, ethynyl group, propynyl group, butynyl group, phenyl group, tolyl group, xylyl group, benzyl group, formyl group, acetyl group, propanoyl group, butanoyl group, pentanoyl group, ethoxy group, propoxy group, or a combination thereof, wherein R 2 is hydrogen, an ethyl group, propyl group, butyl group, isopropyl group, tert-butyl group, 2,2-dimethylpropyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, ethenyl group, propenyl group, butenyl group, ethynyl group, propynyl group, butynyl group, phenyl group, tolyl group, xylyl group, benzyl group, or a combination thereof.

[0045] Hereinafter, a method for forming a pattern using a composition for a semiconductor photoresist will be described with reference to FIGS. 1 to 5. FIGS. 1 to 5 are cross-sectional views for explaining a pattern formation method using the composition for a semiconductor photoresist according to the present invention.

[0046] Referring to FIG. 1, first, an object to be etched is provided. As an example of the object to be etched, it may be a thin film 102 formed on a semiconductor substrate 100. Hereinafter, the description will be made only when the object to be etched is the thin film 102. In order to remove contaminants and the like remaining on the surface of the thin film 102, the surface of the thin film 102 is cleaned. The thin film 102 may be, for example, a silicon nitride film, a polysilicon film, or a silicon oxide film.

[0047] Next, a composition for forming a resist underlayer film for forming a resist underlayer film 104 is coated on the surface of the washed thin film 102 by applying a spin coating method. However, one embodiment is not necessarily limited to this, and various known coating methods, for example, spray coating, dip coating, knife edge coating, printing methods such as inkjet printing and screen printing, etc. may be used.

[0048] The coating process of the resist underlayer film can be omitted. Hereinafter, the case of coating the resist underlayer film will be described.

[0049] Thereafter, a drying and baking process is performed to form a resist underlayer film 104 on the thin film 102. The baking treatment is performed at about 100 to about 500 ° C, and for example, it can be performed at about 100 ° C to about 300 ° C.

[0050] The resist underlayer film 104 is formed between the substrate 100 and the photoresist film 106, and when the irradiation line reflected from the interface or the interlayer hardmask between the substrate 100 and the photoresist film 106 scatters into an unintended photoresist region, it can prevent the non-uniformity of the photoresist linewidth and the pattern formability.

[0051] Referring to FIG. 2, a semiconductor photoresist composition is applied on the resist underlayer film 104 to form a photoresist film 106. The photoresist film 106 may be in a form cured by a heat treatment process after coating a semiconductor photoresist composition on a thin film 102 formed on a substrate 100.

[0052] More specifically, the step of applying the semiconductor photoresist composition may be performed by a vapor deposition method selected from chemical vapor deposition (CVD) or physical vapor deposition (PVD), and a coating method selected from spin coating, slit coating, or inkjet printing, on the substrate 100 on which the thin film 102 is formed, and may include a step of drying the applied semiconductor photoresist composition to form a photoresist film 106.

[0053] The semiconductor photoresist composition contains an organotin compound having at least one organic ligand containing an Sn-C bond and at least one organic carbonyloxy group.

[0054] The semiconductor photoresist composition according to one embodiment may contain the organotin compound and a solvent, and may further contain a resin additionally.

[0055] The solvent contained in the semiconductor photoresist composition may be an organic solvent, and for example, may include aromatic compounds (e.g., xylene, toluene), alcohols (e.g., 4-methyl-2-pentanol, 4-methyl-2-propanol, 1-butanol, methanol, isopropyl alcohol, 1-propanol), ethers (e.g., anisole, tetrahydrofuran), esters (n-butyl acetate, propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate), ketones (e.g., methyl ethyl ketone, 2-heptanone), mixtures thereof, etc., but is not limited thereto.

[0056] The resin may be a phenolic resin containing at least one aromatic moiety listed in Group 1 below.

Chemical formula

[0057] The resin is contained in an amount of 0.1% by weight to 50% by weight based on the total content of the composition for semiconductor photoresist.

[0058] When the resin is contained within the above content range, excellent etching resistance and heat resistance can be achieved.

[0059] On the other hand, the composition for semiconductor photoresist preferably consists of the above-described organometallic compound, solvent, and resin.

[0060] The composition for semiconductor photoresist may optionally further contain additives. Examples of the additives include surfactants, crosslinking agents, leveling agents, organic acids, quenchers, or combinations thereof.

[0061] As the surfactant, for example, alkylbenzene sulfonates, alkylpyridinium salts, polyethylene glycols, quaternary ammonium salts, or combinations thereof can be used, but are not limited thereto.

[0062] Examples of the crosslinking agent include, but are not limited to, melamine-based crosslinking agents, substituted iodine-based crosslinking agents, acrylic-based crosslinking agents, epoxy-based crosslinking agents, or polymer-based crosslinking agents. As crosslinking agents having at least two crosslinking-forming substituents, for example, compounds such as methoxymethylated glycoluril, butoxymethylated glycoluril, methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, 4-hydroxybutyl acrylate, acrylic acid, urethane acrylate, acrylmethacrylate, 1,4-butanediol diglycidyl ether, glycidol, diglycidyl 1,2-cyclohexanedicarboxylate, trimethylpropane triglycidyl ether, 1,3-bis(glycidoxypropyl)tetramethyldisiloxane, methoxymethylated iodine, butoxymethylated iodine, or methoxymethylated thioiodine can be used.

[0063] The leveling agent is for improving the coating flatness during printing, and known leveling agents available by commercial methods can be used.

[0064] The organic acid may be, but is not limited to, p-toluenesulfonic acid, benzenesulfonic acid, p-dodecylbenzenesulfonic acid, 1,4-naphthalenedisulfonic acid, methanesulfonic acid, fluorinated sulfonium salt, malonic acid, citric acid, propionic acid, methacrylic acid, oxalic acid, lactic acid, glycolic acid, succinic acid, or a combination thereof.

[0065] The inhibitor may be diphenyl(p-tolyl)amine, methyldiphenylamine, triphenylamine, phenylenediamine, naphthylamine, diaminonaphthalene, or a combination thereof.

[0066] The usage amounts of these additives can be easily adjusted according to the desired physical properties and may be omitted.

[0067] In addition, for the composition for semiconductor photoresist, in order to improve the adhesion to the substrate, etc. (for example, for improving the adhesion between the composition for semiconductor photoresist and the substrate), a silane coupling agent can be further used as an additive as an adhesion promoter. The silane coupling agent can be, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltris(β-methoxyethoxy)silane; or 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane; carbon-carbon unsaturated bond-containing silane compounds such as trimethoxy[3-(phenylamino)propyl]silane, etc., but is not limited thereto.

[0068] Next, a first baking process of heating the substrate 100 on which the photoresist film 106 is formed is performed. The first baking process can be performed at a temperature of about 80°C to about 120°C.

[0069] Referring to FIG. 3, the photoresist film 106 is selectively exposed using the patterned mask 110.

[0070] As an example, examples of the light that can be used in the exposure process include not only light having a short wavelength such as activation irradiation line i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), but also light having a high energy wavelength such as EUV (Extreme UltraViolet; wavelength 13.5 nm), E-Beam (electron beam), and the like.

[0071] More specifically, the exposure light according to one embodiment may be short-wavelength light having a wavelength range of 5 nm to 150 nm, or may be light having a high energy wavelength such as EUV (Extreme UltraViolet; wavelength 13.5 nm), E-Beam (electron beam), and the like.

[0072] The exposed region 106a in the photoresist film 106 has a different solubility from the unexposed region 106b of the photoresist film 106 by forming a polymer by a crosslinking reaction such as condensation between organometallic compounds.

[0073] Next, a second baking process is performed on the substrate 100. The second baking process can be performed at a temperature of about 90°C to about 200°C. By performing the second baking process, the exposed region 106a of the photoresist film 106 becomes less soluble in the developer.

[0074] FIG. 4 shows a photoresist pattern 108 formed by dissolving and removing the photoresist film 106b corresponding to the unexposed region using a developer. Specifically, after dissolving the photoresist film 106b corresponding to the unexposed region using an organic solvent such as 2 - heptanone and then removing it, the photoresist pattern 108 corresponding to the negative - tone image is completed.

[0075] As described above, the developer used in the pattern - forming method according to an embodiment may be an organic solvent. Examples of the organic solvent used in the pattern - forming method according to an embodiment include ketones such as methyl ethyl ketone, acetone, cyclohexanone, 2 - heptanone; alcohols such as 4 - methyl - 2 - propanol, 1 - butanol, isopropanol, 1 - propanol, methanol; esters such as propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate, n - butyl acetate, butyrolactone; aromatic compounds such as benzene, xylene, toluene; or combinations thereof.

[0076] However, the photoresist pattern according to an embodiment is not necessarily limited to the formation of a negative - tone image, and it may be formed to have a positive - tone image. In this case, examples of the developer that can be used for positive - tone image formation include quaternary ammonium hydroxide compositions such as tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, or combinations thereof.

[0077] As described above, the photoresist pattern 108 formed by exposure with light having wavelengths such as i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), etc., and also light having high energy such as EUV (Extreme UltraViolet; wavelength 13.5 nm), E-Beam (electron beam), etc., can have a width with a thickness of 5 nm to 100 nm. As an example, the photoresist pattern 108 is formed with a width of thickness of 5 nm to 90 nm, 5 nm to 80 nm, 5 nm to 70 nm, 5 nm to 60 nm, 5 nm to 50 nm, 5 nm to 40 nm, 5 nm to 30 nm, 5 nm to 20 nm.

[0078] On the other hand, the photoresist pattern 108 can have a pitch with a half-pitch of about 50 nm or less, for example 40 nm or less, for example 30 nm or less, for example 20 nm or less, for example 15 nm or less, and a line width roughness of about 10 nm or less, about 5 nm or less, about 3 nm or less, about 2 nm or less.

[0079] Next, the resist underlayer film 104 is etched using the photoresist pattern 108 as an etching mask. In such an etching process, an organic film pattern 112 is formed. The formed organic film pattern 112 can also have a width corresponding to the photoresist pattern 108.

[0080] Referring to FIG. 5, the thin film 102 exposed by applying the photoresist pattern 108 as an etching mask is etched. As a result, the thin film is formed into a thin film pattern 114.

[0081] The etching of the thin film 102 can be performed, for example, by dry etching using an etching gas, and the etching gas can be, for example, CHF3, CF4, Cl2, BCl3, and a mixed gas thereof.

[0082] In the previously performed exposure process, the thin film pattern 114 formed using the photoresist pattern 108 formed by the exposure process performed using an EUV light source can have a width corresponding to the photoresist pattern 108. As an example, it can have the same width as the photoresist pattern 108, which can be from 5 nm to 100 nm. For example, the thin film pattern 114 formed by the exposure process performed using an EUV light source can have widths such as 5 nm to 90 nm, 5 nm to 80 nm, 5 nm to 70 nm, 5 nm to 60 nm, 5 nm to 50 nm, 5 nm to 40 nm, 5 nm to 30 nm, 5 nm to 20 nm, similar to the photoresist pattern 108, and more specifically, it may be formed with a width of 20 nm or less.

[0083] According to another embodiment, a photoresist film formed in the above-described pattern forming method is provided.

[0084] The photoresist film according to one embodiment is (R 1 Sn) x O y (OAR 2 ) z (where x, y, and z are each independently from 0.1 to 0.9, x + y + z = 1, A is a single bond or C=O, R 1 is a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C6-C30 arylalkyl group, and L a -O-R a (where L a is a substituted or unsubstituted C1-C20 alkylene group, and R a is a substituted or unsubstituted C1-C20 alkyl group), and is selected from among them, R 2It can contain a compound represented by (hydrogen, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, a substituted or unsubstituted C6-C30 aryl group, or a combination thereof).

[0085] The photoresist film can have a thickness of 5 nm to 100 nm.

Example

[0086] Hereinafter, the present invention will be described in more detail through examples related to the production of the above-described composition for semiconductor photoresist. However, the technical features of the present invention are not limited by the following examples.

[0087] Synthesis of organometallic compounds Synthesis Example 1 40.7 g of t-butylSnPh3 and 300 g of propionic acid are placed in a 250 ml two-necked round-bottom flask and heated under reflux for 24 hours.

[0088] Unreacted propionic acid is removed under reduced pressure to obtain a compound represented by the following Chemical Formula 2.

Chemical formula

[0089] Synthesis Example 2 The same procedure as in Synthesis Example 1 is carried out except that butyric acid is applied instead of propionic acid to obtain a compound represented by the following Chemical Formula 3.

Chemical formula

[0090] Synthesis Example 3 The compound represented by the following Chemical Formula 4 is obtained by carrying out the procedure in the same manner as in Synthesis Example 1, except that t-amylSnPh3 is applied instead of t-butylSnPh3. [Chemical Formula]

[0091] Synthesis Example 4 The compound represented by the following Chemical Formula 5 is obtained by carrying out the procedure in the same manner as in Synthesis Example 1, except that t-amylSnPh3 is applied instead of t-butylSnPh3 and butyric acid is applied instead of propionic acid. [Chemical Formula]

[0092] Synthesis Example 5 30 mL of anhydrous pentane is added to 10 g of t-AmylSnCl3, and after maintaining the temperature at 0°C, 7.4 g of diethylamine and 6.1 g of ethanol are added, followed by stirring at room temperature for 1 hour. After completion of the reaction, filtration is carried out, and concentration and vacuum drying are performed to obtain the compound represented by the following Chemical Formula 6. [Chemical Formula]

[0093] Production of Composition for Semiconductor Photoresist Examples 1 to 14 and Comparative Examples 1 to 9 The compounds represented by Chemical Formulas 2 to 6 obtained in Synthesis Examples 1 to 5 and the compounds represented by the following Chemical Formulas 7 to 9 (Sigma-Aldrich) are dissolved in a solvent at a concentration of 3 wt% according to the composition shown in Table 1 below and filtered through a 0.1 μm PTFE (polytetrafluoroethylene) syringe filter to produce a composition for semiconductor photoresist. [Chemical Formula] [Chemical Formula] [Chemical]

[0094] [Table 1]

[0095] *PGMEA: Propylene glycol monomethyl ether acetate *PGME: Propylene glycol methyl ether *MIBC: 4 - Methyl - 2 - pentanol

[0096] Evaluation: Sensitivity, LER, Resolution Limit On a 200 - mm circular silicon wafer, the composition for photoresist is spin - coated at 1500 rpm for 30 seconds, baked at 110°C for 60 seconds, and then left standing at room temperature for 30 seconds. Subsequently, the exposure dose is split with an EUV light source (Lawrence Berkeley National Laboratory Micro Exposure Tool) to pattern the wafer into various L / S (1 / 1) sizes to form a photoresist thin film. After exposure, it is baked at 170°C for 60 seconds, and then developed with a PGMEA solvent. Finally, after baking at 150°C for 60 seconds, it is analyzed using SEM (Scanning electron microscopy).

[0097] [Evaluation Criteria for Sensitivity] - A: Less than 100 mJ / cm 2 Less than - B: 100 mJ / cm or more 2 or more

[0098] [Evaluation Criteria for LER] - ○: 2 nm or less - △: More than 2 nm and 5 nm or less - X: More than 5 nm

[0099] [Evaluation Criteria for Resolution Limit] -A: CD less than 10 nm -B: CD 10 nm or more

[0100]

Table 2

[0101] From the results in Table 2, it can be confirmed that the patterns formed using the semiconductor photoresist compositions according to Examples 1 to 14 exhibit excellent sensitivity, LER, and resolution characteristics compared to Comparative Examples 1 to 9.

[0102] As described above, specific embodiments of the present invention have been described and illustrated. However, the present invention is not limited to the described embodiments, and it is obvious to those with ordinary knowledge in this technical field that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, such modified examples or variations should not be individually understood from the technical idea or perspective of the present invention, and the modified embodiments belong to the scope of the claims of the present invention.

Explanation of Reference Numerals

[0103] 100... Substrate, 102... Thin film, 104... Underlying resist film, 106... Photoresist film, 106a... Exposed region, 106b... Unexposed region, 108... Photoresist pattern, 112... Organic film pattern, 110... Patterned mask, 114... Thin film pattern.

Claims

1. Applying a composition for a semiconductor photoresist containing an organotin compound onto a substrate; Drying and heating to form a photoresist film; and Exposing and developing the photoresist film, wherein the organotin compound has at least one organic ligand containing an Sn—C bond and at least one organic carbonyloxy group, The photoresist film contains, before or after exposure, a compound represented by (R １ Sn) ｘ O ｙ (OAR ２ ) ｚ (where x, y, and z are each independently 0.1 to 0.9, x + y + z = 1, A is a single bond or C=O, R １ is a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C6-C30 arylalkyl group, and L ａ -O-R ａ (where L ａ is a substituted or unsubstituted C1-C20 alkylene group and R ａ is a substituted or unsubstituted C1-C20 alkyl group), and is selected from among them, and R ２ is hydrogen, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, a substituted or unsubstituted C6-C30 aryl group, or a combination thereof).

2. The photoresist film is Sn-OAR ２ The pattern forming method according to claim 1, which contains Sn-OAR bonding, Sn-O-Sn bonding, and Sn-C bonding.

3. Before exposure, the content of the compound represented by (R １ Sn) ｘ O ｙ (OAR ２ ) ｚ is 5 to 95% by weight based on 100% by weight of the composition for semiconductor photoresist. The pattern forming method according to claim 1.

4. After exposure and development, the content of the compound represented by the formula (R １ Sn) ｘ O ｙ (OAR ２ ) ｚ is 5 to 95% by weight based on 100% by weight of the composition for semiconductor photoresist. The pattern forming method according to claim 1.

5. The step of applying a composition for a semiconductor photoresist containing an organotin compound onto the substrate is performed by at least one method of a deposition method selected from chemical vapor deposition (CVD) or physical vapor deposition (PVD), and a coating method selected from spin coating, slit coating, or inkjet printing. The pattern formation method according to Claim 1.

6. The step of exposing the photoresist film is performed using light having a wavelength of 5 nm to 150 nm. The pattern formation method according to Claim 1.

7. Said R １ is a substituted or unsubstituted C1-C8 alkyl group, a substituted or unsubstituted C3-C8 cycloalkyl group, a substituted or unsubstituted C2-C8 aliphatic unsaturated organic group containing one or more double bonds or triple bonds, a substituted or unsubstituted C6-C20 aryl group, a substituted or unsubstituted C4-C20 heteroaryl group, a carbonyl group, an ethoxy group, a propoxy group, or a combination thereof, Said R ２ is a hydrogen, a substituted or unsubstituted C1-C8 alkyl group, a substituted or unsubstituted C3-C8 cycloalkyl group, a substituted or unsubstituted C2-C8 alkenyl group, a substituted or unsubstituted C2-C8 alkynyl group, a substituted or unsubstituted C6-C20 aryl group, or a combination thereof, the pattern forming method according to claim 1.

8. Said R １ is a methyl group, ethyl group, propyl group, butyl group, isopropyl group, tert-butyl group, 2,2-dimethylpropyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, ethenyl group, propenyl group, butenyl group, ethynyl group, propynyl group, butynyl group, phenyl group, tolyl group, xylyl group, benzyl group, formyl group, acetyl group, propanoyl group, butanoyl group, pentanoyl group, ethoxy group, propoxy group, or a combination thereof, Said R ２ is a hydrogen, ethyl group, propyl group, butyl group, isopropyl group, tert-butyl group, 2,2-dimethylpropyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, ethenyl group, propenyl group, butenyl group, ethynyl group, propynyl group, butynyl group, phenyl group, tolyl group, xylene group, benzyl group, or a combination thereof, the pattern forming method according to claim 1.

9. The composition for a semiconductor photoresist further contains an additive of a surfactant, a crosslinking agent, a leveling agent, an organic acid, a quencher, or a combination thereof. The pattern formation method according to Claim 1.

10. (R １ Sn) ｘ O ｙ (OAR ２ ) ｚ (where x, y, and z are each independently from 0.1 to 0.9, x + y + z = 1, A is a single bond or C=O, R １ is a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C6-C30 arylalkyl group, and L ａ -O-R ａ (where L ａ is a substituted or unsubstituted C1-C20 alkylene group and R ａ is a substituted or unsubstituted C1-C20 alkyl group), and is selected from among these, and R ２ is hydrogen, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C2-20 alkenyl group, a substituted or unsubstituted C2-C20 alkynyl group, a substituted or unsubstituted C6-C30 aryl group, or a combination thereof) and a photoresist film containing the compound represented thereby.

11. The photoresist film has a thickness of 5 nm to 100 nm. The photoresist film according to Claim 10.

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