Pattern forming method

Abstract

To provide a pattern forming method using a semiconductor photoresist composition which achieves excellent resolution.SOLUTION: The pattern forming method includes: a step of applying a metal-containing resist composition onto a substrate by a spin coater at a speed of 100-1,500 rpm for 60-120 seconds; a step of performing a heat treatment at 90-200°C for 30-120 seconds in order to form a metal-containing resist film on the substrate; a step of exposing the metal-containing resist film to extreme ultraviolet light or light having a wavelength of 5-150 nm by using a pattern mask; and a development step of removing an unexposed region to form a resist pattern by applying a developer. The surface roughness of the metal-containing resist film having undergone the heat treatment step is a root mean square roughness (Rq) of 1.5 nm or less, an average roughness (Ra) of 1.0 nm or less, and a maximum roughness (Rmax) of 20 nm or less.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] This description relates to a patterning method using a semiconductor photoresist composition. [Background technology]

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

[0003] The implementation of extreme ultraviolet (EUV) lithography requires the development of compatible photoresists capable of performing spatial resolutions of 16 nm or less. Currently, traditional chemically amplified (CA) photoresists struggle to meet the specifications for resolution, photospeed, feature roughness, and line edge roughness (LER) for next generation devices.

[0004] Intrinsic image blur due to acid catalyzed reactions occurring in these polymeric photoresists limits resolution at small feature sizes, a fact that has long been known in e-beam lithography. Chemically amplified (CA) photoresists, designed for high sensitivity, are even more challenging under EUV exposure, in part because their typical elemental makeup reduces the absorbance of the photoresist at 13.5 nm wavelengths, thereby reducing sensitivity.

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

[0006] In order to overcome the disadvantages of the above-mentioned chemically amplified organic photosensitive compositions, inorganic photosensitive compositions have been researched. Inorganic photosensitive compositions are mainly used for negative tone patterning, which is resistant to removal by developer compositions due to chemical modification by non-chemically amplified substrates. Inorganic compositions contain inorganic elements with higher EUV absorption than hydrocarbons, so they can ensure sensitivity even with non-chemically amplified substrates, and are not sensitive to stochastic effects, so they are known to have low line edge roughness and low number of defects.

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

[0008] These materials have been effective in patterning large pitchers in a bilayer configuration with deep UV, x-ray, and electron beam sources. More recently, impressive performance has been shown when using cationic hafnium metal oxide sulfate (HfSOx) materials with peroxo complexing agents to image 15 nm half-pitch (HP) by projection EUV exposure (US2011-0045406; JK Towers, A. Telecky, M. Kocsis, BL Clark, DA Keszler, A. Grenville, CN Anderson, PP Naulleau, Proc. SPIE, 7969, 796915, 2011). This system shows the best performance of a non-CA photoresist and has a light speed approaching the requirements for a viable EUV photoresist. However, hafnium metal oxide sulfate materials with bar-oxo complexing agents have several practical drawbacks. First, the materials are coated with a highly corrosive sulfuric acid / hydrogen peroxide mixture, which results in poor shelf-life stability. Second, as a complex mixture, it is not easy to modify the structure to improve performance. Third, they must be developed with a very high concentration of TMAH (tetramethylammonium hydroxide) solution, such as 25 wt%.

[0009] Recently, it has been reported that molecules containing tin have excellent extreme ultraviolet absorption, and active research is being conducted on these molecules. In the case of organotin polymers, one of these, alkyl ligands are dissociated by light absorption or secondary electrons generated by the absorption, and negative tone patterning that is not removed by organic developers is possible through crosslinking with peripheral chains by iodine bonds. These organotin polymers have been shown to dramatically improve sensitivity while maintaining resolution and line edge roughness, but further improvement of the patterning properties is required for commercialization. Summary of the Invention

[0010] An embodiment provides a method for forming a pattern using a semiconductor photoresist composition, which can achieve excellent resolution.

[0011] According to an embodiment, the method for forming a pattern includes the steps of: applying a metal-containing resist composition on a substrate; drying and heating the substrate to form a metal-containing resist film on the substrate; exposing the metal-containing resist film using a patterned mask; and applying a developer composition to remove unexposed areas to form a resist pattern. The step of applying the metal-containing resist composition may be performed by applying the metal-containing resist composition with a spin coater at a speed of 100 to 1,500 rpm for 60 to 120 seconds, the heat treatment step may be performed at a temperature of 90 to 200° C. for 30 to 120 seconds, and the step of exposing the metal-containing resist film may be performed by irradiating extreme ultraviolet light or light having a wavelength of 5 nm to 150 nm. The surface roughness of the metal-containing resist film after the heat treatment step may be a root mean square roughness (Rq) of 1.5 nm or less, an average roughness (Ra) of 1.0 nm or less, and a maximum roughness (Rmax: peak to peak height) of 20 nm or less.

[0012] The root mean square roughness Rq may be between 0.1 nm and 1.5 nm.

[0013] The average roughness Ra may be between 0.1 nm and 1.0 nm.

[0014] The maximum roughness Rmax may be between 1 nm and 20 nm.

[0015] The metal compound contained in the metal-containing resist composition may include at least one of an organic oxy group-containing tin compound and an organic carbonyloxy group-containing tin compound.

[0016] The metal compound contained in the metal-containing resist composition is represented by the following Chemical Formula 1.

[0017] [ka] In the above Chemical Formula 1, R 1 is a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C7 to C30 arylalkyl group, and -L a -OR a (Here, L a is a substituted or unsubstituted C1 to C20 alkylene group, R a is a substituted or unsubstituted C1 to C20 alkyl group; R 2 ~R 4 are each independently -OR b and -OC(=O)R c is selected from among R b is a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof; R c is hydrogen, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof.

[0018] R 1 is a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C2 to C10 alkynyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C7 to C20 arylalkyl group, and -L a -OR a (Here, L a is a substituted or unsubstituted C1 to C10 alkylene group, R a is a substituted or unsubstituted C1 to C10 alkyl group.

[0019] R 1 may be 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 xylene 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.

[0020] The metal compound may be included in an amount of 1 to 30 wt % based on 100 wt % of the metal-containing resist composition.

[0021] The metal-containing resist composition may further include additives such as a surfactant, a crosslinking agent, a leveling agent, an organic acid, a quencher, or a combination thereof.

[0022] The method may further include providing a resist underlayer film formed between the substrate and the metal-containing resist film.

[0023] The photoresist pattern may have a width of 5 nm to 100 nm.

[0024] The resist pattern manufactured by the pattern forming method according to an embodiment may have excellent resolution. [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 is a cross-sectional view illustrating a method for forming a pattern using a metal-containing resist composition according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view illustrating a method for forming a pattern using a metal-containing resist composition according to an embodiment. [Diagram 3] FIG. 3 is a cross-sectional view illustrating a method for forming a pattern using a metal-containing resist composition according to an embodiment. [Figure 4] FIG. 4 is a cross-sectional view illustrating a method for forming a pattern using a metal-containing resist composition according to an embodiment. [Diagram 5] FIG. 5 is a cross-sectional view illustrating a method for forming a pattern using a metal-containing resist composition according to an embodiment. [Figure 6] FIG. 6 shows SEM photographs of the thin resist films according to the example and the comparative example. [Figure 7] FIG. 7 shows SEM photographs of the thin resist films according to the example and the comparative example. [Figure 8] FIG. 8 shows SEM photographs of the thin resist films according to the example and the comparative example. [Figure 9] FIG. 9 shows SEM photographs of the thin resist films according to the example and the comparative example. [Figure 10] FIG. 10 shows SEM photographs of the thin resist films according to the example and the comparative example. [Figure 11]FIG. 11 shows SEM photographs of the thin resist films according to the example and the comparative example. [Figure 12] FIG. 12 shows SEM photographs of the thin resist films according to the example and the comparative example. [Figure 13] FIG. 13 shows SEM photographs of the thin resist films according to the example and the comparative example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, in the description, the description of the already known functions or configurations will be omitted in order to clarify the gist of the description.

[0027] In order to clearly explain the present description, parts not related to the description will be omitted, and the same or similar components will be given the same reference numerals throughout the specification. In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for the convenience of explanation, so the present description is not necessarily limited to those shown in the drawings.

[0028] In the drawings, the thicknesses of various layers and regions are exaggerated to clearly show the layers and regions. Also, in the drawings, the thicknesses of some layers and regions are exaggerated for the convenience of explanation. When a part such as a layer, film, region, plate, etc. is described as being "on" or "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part therebetween.

[0029] In this description, "substituted" means that a hydrogen atom is substituted with deuterium, a halogen group, a hydroxy group, a thiol group, a cyano group, a nitro group, a carbonyl group, -NRR' (wherein R and R' are each independently hydrogen, a substituted or unsubstituted C1 to C30 saturated or unsaturated aliphatic hydrocarbon group, a substituted or unsubstituted C3 to C30 saturated or unsaturated alicyclic hydrocarbon group, or a substituted or unsubstituted C6 to C30 aromatic hydrocarbon group), -SiRR'R" (wherein R, R', and R" are each independently hydrogen, It means that the group is substituted with a substituted or unsubstituted C1 to C30 saturated or unsaturated aliphatic hydrocarbon group, a substituted or unsubstituted C3 to C30 saturated or unsaturated alicyclic hydrocarbon group, or a substituted or unsubstituted C6 to C30 aromatic hydrocarbon group), a C1 to C30 alkyl group, a C1 to C10 haloalkyl group, a C1 to C10 alkylsilyl group, a C3 to C30 cycloalkyl group, a C6C30 aryl group, a C1 to C20 alkoxy group, a C1 to C20 sulfide group, or a combination thereof. "Unsubstituted" means that the hydrogen atom is not replaced with another substituent and remains as a hydrogen atom.

[0030] As used herein, unless otherwise specified, the term "alkyl group" refers to a straight-chain or branched-chain aliphatic hydrocarbon group. The alkyl group may be a "saturated alkyl group" that does not contain any double or triple bonds.

[0031] The alkyl group may be a C1 to C10 alkyl group. For example, the alkyl group may be a C1 to C8 alkyl group, a C1 to C7 alkyl group, a C1 to C6 alkyl group, or a C1 to C5 alkyl group. For example, the C1 to 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, a tert-butyl group, or a 2,2-dimethylpropyl group.

[0032] In this description, unless otherwise defined, a "cycloalkyl group" refers to a monovalent cyclic aliphatic saturated hydrocarbon group.

[0033] The cycloalkyl group may be a C3 to C10 cycloalkyl group, such as a C3 to C8 cycloalkyl group, a C3 to C7 cycloalkyl group, or a C3 to C6 cycloalkyl group. For example, the cycloalkyl group may be, but is not limited to, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, or a cyclohexyl group.

[0034] As used herein, an "aryl group" refers to a substituent in which all elements of the cyclic substituent have p-orbitals that form conjugation, and includes monocyclic or fused-ring polycyclic (i.e., rings that share adjacent pairs of carbon atoms) functional groups.

[0035] As used herein, unless otherwise defined, an "alkenyl group" refers to a straight-chain or branched-chain aliphatic hydrocarbon group that is an aliphatic unsaturated alkenyl group containing one or more double bonds.

[0036] As used herein, unless otherwise defined, an "alkynyl group" refers to a straight-chain or branched-chain aliphatic hydrocarbon group that is an aliphatic unsaturated alkynyl group containing one or more triple bonds.

[0037] In the formulae depicted herein, t-Bu refers to a tert-butyl group.

[0038] Hereinafter, a method for forming a pattern according to an embodiment will be described.

[0039] A method for forming a pattern according to an embodiment of the present invention includes the steps of: applying a metal-containing resist composition on a substrate; drying and heating the composition to form a metal-containing resist film on the substrate; exposing the metal-containing resist film using a patterned mask; and applying a developer composition to remove unexposed areas to form a resist pattern. The step of applying the metal-containing resist composition is carried out by applying the metal-containing resist composition with a spin coater at a speed of 100 to 1,500 rpm for 60 to 120 seconds, the heat treatment step is carried out at a temperature of 90 to 200° C. for 30 to 120 seconds, and the step of exposing the metal-containing resist film is carried out by irradiating extreme ultraviolet light or light having a wavelength of 5 nm to 150 nm, The surface roughness of the metal-containing resist film after the heat treatment step may be such that the root mean square roughness (Rq) is 1.5 nm or less, the average roughness (Ra) is 1.0 nm or less, and the maximum roughness (Rmax: peak to peak height) is 20 nm or less.

[0040] The method for forming a pattern according to the present invention is a method for forming a film when a metal-containing resist composition containing a metal compound containing a metal, for example tin, an additive, and a solvent is applied to a substrate surface, and then patterning the film. The resist film formed from the metal-containing resist composition can be confirmed by AFM (Atomic Force Microscope) analysis for surface roughness values, and it has been confirmed that the film has excellent resolution during a photoresist process when Rq is 1.5 nm or less, Ra is 1.0 nm or less, and Rmax is 20 nm or less.

[0041] The surface roughness may be measured by using a surface roughness measuring device, for example, an optical profiler, using a photograph of the metal-containing resist film taken by an atomic force microscopy (AFM) or the like.

[0042] Among surface roughness, the root mean square roughness (R q ;root mean square roughness) means the root mean square (rms) of the vertical values ​​within the sampling length of the roughness profile. a The average roughness (R ) is also called the center line average roughness, and refers to the arithmetic mean of the absolute value of the ordinate (the length from the center line to the peak) within the reference length of the roughness profile. max (peak to peak height; maximum roughness depth) means the vertical distance between the highest peak and the lowest valley within the reference length of the roughness profile. For such surface roughness, the parameter definition and measurement method defined in KS B 0601 or ISO 4287 / 1 can be referred to.

[0043] The root mean square roughness Rq may be between 0.1 nm and 1.5 nm.

[0044] By way of example, the root mean square roughness Rq may be between 0.2 nm and 1.5 nm, such as between 0.3 nm and 1.5 nm, between 0.4 nm and 1.5 nm, or between 0.5 nm and 1.5 nm.

[0045] In one embodiment, the root mean square roughness Rq may be between 0.5 nm and 1.4 nm.

[0046] The average roughness Ra may be between 0.1 nm and 1.0 nm.

[0047] As an example, the average roughness Ra may be between 0.2 nm and 1.0 nm, for example between 0.3 nm and 1.0 nm, between 0.4 nm and 1.0 nm, or between 0.5 nm and 1.0 nm.

[0048] In one embodiment, the average roughness Ra may be between 0.5 nm and 0.9 nm.

[0049] The maximum roughness Rmax may be between 1 nm and 20 nm.

[0050] As an example, the maximum roughness Rmax may be between 1 nm and 20 nm, for example between 2 nm and 20 nm, between 3 nm and 20 nm, or between 4 nm and 20 nm.

[0051] In one embodiment, the maximum roughness Rmax may be between 5 nm and 20 nm.

[0052] A method for forming a pattern will be described below with reference to Figures 1 to 5. Figures 1 to 5 are cross-sectional views for explaining a method for forming a pattern using a metal-containing resist composition according to the present invention.

[0053] Referring to FIG. 1, first, an object to be etched is provided. An example of the object to be etched may be a thin film 102 formed on a semiconductor substrate 100. Hereinafter, only the case where the object to be etched is the thin film 102 will be described. The surface of the thin film 102 is cleaned to remove contaminants remaining on the thin film 102. The thin film 102 may be, for example, a silicon nitride film, a polysilicon film, or a silicon oxide film.

[0054] Then, a composition for forming a resist underlayer film is coated by spin coating on the surface of the cleaned thin film 102 to provide a resist underlayer film 104. However, an embodiment is not necessarily limited thereto, and various known coating methods, for example, spray coating, dip coating, knife edge coating, and printing methods, for example, inkjet printing and screen printing, may also be used.

[0055] The resist underlayer coating process may be omitted, and the following description will be made on the case where the resist underlayer is coated.

[0056] Then, a drying and baking process is performed to form a resist underlayer film 104 on the thin film 102. The baking process may be performed at about 100 to about 500°C, for example, about 100 to about 300°C.

[0057] The resist underlayer film 104 is formed between the substrate 100 and the photoresist film 106, and can prevent non-uniformity of the photoresist linewidth and disruption of pattern formability when radiation reflected from the interface between the substrate 100 and the photoresist film 106 or from an interlayer hard mask is scattered into unintended photoresist regions.

[0058] 2, a metal-containing resist composition is coated on the resist underlayer film 104 to form a photoresist film 106. The photoresist film 106 may be formed by coating a metal-containing resist composition on a thin film 102 formed on a substrate 100 and then curing the metal-containing resist composition through a heat treatment process.

[0059] More specifically, the step of forming a pattern using the metal-containing resist composition may include a step of applying the metal-containing resist composition onto the substrate 100 on which the thin film 102 is formed by spin coating, slit coating, inkjet printing, or the like, and a step of heat-treating the applied metal-containing resist composition to form a photoresist film 106.

[0060] The metal-containing resist composition may include a tin-based compound. For example, the tin-based compound may include at least one of an organic oxy group-containing tin compound and an organic carbonyloxy group-containing tin compound.

[0061] As an example, the metal compound contained in the metal-containing resist composition is represented by the following Chemical Formula 1:

[0062] [ka]

[0063] In the above Chemical Formula 1, R 1 is a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C7 to C30 arylalkyl group, and -L a -OR a (Here, L a is a substituted or unsubstituted C1 to C20 alkylene group, R a is a substituted or unsubstituted C1 to C20 alkyl group; R 2 ~R 4 are each independently -OR b and -OC(=O)R c is selected from among R b is a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof; R c is hydrogen, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof.

[0064] As an example, the above-mentioned R 1 is a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C2 to C10 alkynyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C7 to C20 arylalkyl group, and -L a -OR a(Here, L a is a substituted or unsubstituted C1 to C10 alkylene group, R a is a substituted or unsubstituted C1 to C10 alkyl group.

[0065] For example, the above R 1 may be 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 xylene 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.

[0066] As an example, the above-mentioned R b and R c may each independently be a substituted or unsubstituted C1 to C20 alkyl group.

[0067] Next, a heat treatment step is performed to heat the substrate 100 on which the photoresist film 106 is formed, at a temperature of about 90° C. to about 200° C. for 30 to 120 seconds.

[0068] In the metal-containing resist composition according to an embodiment, the metal-containing compound may be included in an amount of 1 wt % to 30 wt %, for example, 1 wt % to 25 wt %, for example, 1 wt % to 20 wt %, for example, 1 wt % to 15 wt %, for example, 1 wt % to 10 wt %, for example, 1 wt % to 5 wt %, based on 100 wt % of the metal-containing resist composition, but is not limited thereto.

[0069] The metal-containing resist composition according to an embodiment may include a solvent. The solvent may be an organic solvent, and examples thereof include, but are not limited to, 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), and mixtures thereof.

[0070] In an embodiment, the metal-containing resist composition may further include a resin in addition to the metal compound and the solvent.

[0071] The resin may be a phenolic resin containing at least one aromatic moiety listed in Group 1 below.

[0072] [ka] The resin may have a weight average molecular weight of 500 to 20,000.

[0073] The resin may be included in an amount of 0.1% by weight to 50% by weight based on the total content of the metal-containing resist composition.

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

[0075] Meanwhile, the metal-containing resist composition is preferably composed of the above-mentioned metal-containing compound, a solvent, and a resin. However, the metal-containing resist composition according to the above-mentioned embodiment may further include an additive, if necessary. Examples of the additive include a surfactant, a crosslinking agent, a leveling agent, an organic acid, a quencher, or a combination thereof.

[0076] Surfactants may be used, for example but not limited to, alkylbenzenesulfonates, alkylpyridinium salts, polyethylene glycols, quaternary ammonium salts, or combinations thereof.

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

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

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

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

[0081] The amount of these additives used can be easily adjusted depending on the desired physical properties, or can be omitted.

[0082] In addition, the metal-containing resist composition may further use a silane coupling agent as an additive to enhance adhesion to a substrate (for example, to improve the adhesive strength of a semiconductor resist composition to a substrate). The silane coupling agent may be, for example, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrichlorosilane, vinyltris(β-methoxyethoxy)silane; or 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane; or a carbon-carbon unsaturated bond-containing silane compound such as trimethoxy[3-(phenylamino)propyl]silane, but is not limited thereto.

[0083] Referring to FIG. 3, the photoresist film 106 is selectively exposed to light using a patterned mask 110 .

[0084] For example, light that can be used in the exposure process may be short-wavelength light having a wavelength range of 5 nm to 150 nm, or light having a high-energy wavelength such as EUV (Extreme UltraViolet; wavelength 13.5 nm) or E-Beam (electron beam).

[0085] The exposed regions 106b of the photoresist film 106 form polymers through cross-linking reactions such as condensation between organometallic compounds, and thus have a different solubility from the unexposed regions 106a of the photoresist film 106.

[0086] Next, a baking process is performed on the substrate 100. The baking process may be performed at a temperature of about 90° C. to about 200° C. By performing the baking process, the exposed region 106b of the photoresist film 106 becomes less soluble in a developer.

[0087] 4 shows a photoresist pattern 108 formed by dissolving and removing the photoresist film 106a corresponding to the unexposed region using a developer. Specifically, the photoresist film 106a corresponding to the unexposed region is dissolved and removed using an organic solvent such as 2-heptanone, thereby completing the photoresist pattern 108 corresponding to the negative tone image.

[0088] As described above, the developer used in the pattern formation method according to an embodiment may be an organic solvent. Examples of the organic solvent used in the pattern formation method according to an embodiment include ketones such as methyl ethyl ketone, acetone, cyclohexanone, and 2-heptanone, alcohols such as 4-methyl-2-propanol, 1-butanol, isopropanol, 1-propanol, and methanol, esters such as propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate, n-butyl acetate, and butyrolactone, aromatic compounds such as benzene, xylene, and toluene, and combinations thereof.

[0089] However, the photoresist pattern according to an embodiment is not limited to being formed as a negative tone image, and may be formed to have a positive tone image. In this case, examples of developers that can be used to form a positive tone image include quaternary ammonium hydroxide compositions such as tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, or combinations thereof.

[0090] As described above, the photoresist pattern 108 formed by exposure to light having a wavelength such as i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), as well as high-energy light such as EUV (Extreme UltraViolet; wavelength 13.5 nm) and E-Beam (electron beam) may have a thickness width of 5 nm to 100 nm. As an example, the photoresist pattern 108 may be formed with a width of 5 nm to 90 nm, 5 nm to 80 nm, 5 nm to 70 nm, 5 nm to 60 nm, 5 nm to 50 nm, 5 nm to 40 nm, 5 nm to 30 nm, 5 nm to 20 nm, or 5 nm to 10 nm.

[0091] Meanwhile, the photoresist pattern 108 may have a half-pitch of about 50 nm or less, e.g., 40 nm or less, e.g., 30 nm or less, e.g., 20 nm or less, e.g., 10 nm or less, and a line width roughness of about 5 nm or less, about 3 nm or less, about 2 nm or less, or about 1 nm or less.

[0092] Then, the resist underlayer film 104 is etched using the photoresist pattern 108 as an etching mask. Through this etching process, an organic layer pattern 112 is formed. The formed organic layer pattern 112 may also have a width corresponding to that of the photoresist pattern 108.

[0093] 5, the photoresist pattern 108 is applied as an etching mask to etch the exposed thin film 102. As a result, the thin film is formed into a thin film pattern 114.

[0094] The etching of the thin film 102 may be performed by dry etching using an etching gas, for example, CHF3, CF4, Cl2, BCl3, or a mixture thereof.

[0095] The thin film pattern 114 formed using the photoresist pattern 108 formed by the exposure process performed using an EUV light source in the previous exposure process may have a width corresponding to the photoresist pattern 108. For example, the thin film pattern 114 may have a width of 5 nm to 100 nm, similar to the photoresist pattern 108. For example, the thin film pattern 114 formed by the exposure process performed using an EUV light source may have a width of 5 nm to 90 nm, 5 nm to 80 nm, 5 nm to 70 nm, 5 nm to 60 nm, 5 nm to 50 nm, 5 nm to 40 nm, 5 nm to 30 nm, 5 nm to 20 nm, similar to the photoresist pattern 108, and more specifically may be formed with a width of 20 nm or less. EXAMPLES

[0096] The present invention will be described in more detail with reference to the following examples of the pattern forming method, but the technical features of the present invention are not limited to the following examples.

[0097] (Synthesis of metal-containing organic compounds) Synthesis Example 1 An organotin compound (10 g, 25.5 mmol) represented by the following formula A is dissolved in 30 ml of anhydrous toluene, and then 6.0 g of propionic acid is slowly added dropwise at 0° C. and stirred for 6 hours. After that, the temperature is raised to room temperature (23° C.), and the toluene is removed by vacuum distillation, and the remaining filtrate is fractionally distilled to obtain an organotin compound represented by the following formula 2.

[0098] [ka]

[0099] Synthesis Example 2 An organotin compound (10 g, 27.3 mmol) represented by the following formula B is dissolved in 30 ml of anhydrous toluene, and then 6.2 g of propionic acid is slowly added dropwise at 0° C. and stirred for 6 hours. After that, the temperature is raised to room temperature, and the toluene is removed by vacuum distillation, and the remaining filtrate is fractionally distilled to obtain an organotin compound represented by the following formula 3.

[0100] [ka]

[0101] Synthesis Example 3 An organotin compound (10 g, 31.0 mmol) represented by the following formula C is dissolved in 30 ml of anhydrous toluene, and then 7.0 g of propionic acid is slowly added dropwise at 0° C. and stirred for 6 hours. After that, the temperature is raised to room temperature, and the toluene is removed by vacuum distillation, and the remaining filtrate is fractionally distilled to obtain an organotin compound represented by the following formula 4.

[0102] [ka]

[0103] (Production of semiconductor photoresist composition) Examples 1 to 6, Comparative Examples 1 and 2 The compounds represented by Formulae 2 to 4 obtained in Synthesis Examples 1 to 3 and additives were dissolved in 1-methoxy-2-propyl acetate according to the compositions shown in Table 1 below, and filtered through a 0.1 μm PTFE syringe filter to prepare photoresist compositions.

[0104] A circular silicon wafer having a diameter of 8 inches and a native oxide surface was used as a substrate for thin film deposition. The resist composition was spin-coated on the wafer at 1500 rpm for 60 seconds and baked at 110° C. for 60 seconds to form a thin film. The thickness of the film after coating and baking was measured by ellipsometry and found to be 25 nm in Examples 1 to 6 and 24 nm in Comparative Examples 1 and 2.

[0105] [Table 1]

[0106] *Additive 1: Propionic acid (TCI) *Additive 2: Admantanecarboxylic acid (Sigma-Aldrich) *Additive 3: Glycolic acid (DAEJUNG CHEMICALS & METALS) *Additive 4: 1-Methylcyclohexanecarboxylic acid (Sigma-Aldrich)

[0107] Evaluation 1: Surface roughness The resist compositions according to Examples 1 to 6 and Comparative Examples 1 and 2 were spin-coated on a wafer at 1500 rpm for 60 seconds and baked at 110° C. for 60 seconds to form a thin film. The images were then measured using a scanning electron microscope and shown in FIGS. 6 to 13. The surface roughness of the thin film was measured from the images using software and the results are shown in Table 1 below.

[0108] Evaluation 2: Pattern formability A linear array of 50 circular pads with a diameter of 500 μm was projected using EUV light (Lawrence Berkeley National Laboratory Micro Exposure Tool, MET) onto wafers coated with the photoresist compositions of Examples 1 to 6 and Comparative Examples 1 and 2. Pad exposure times were adjusted so that an incremental EUV dose was applied to each pad.

[0109] The resist and substrate were then exposed on a hotplate at 160°C for 120 seconds and post-exposure baked (PEB). The baked films were then immersed in a developer (2-heptanone) for 30 seconds each and then washed in the same developer for an additional 10 seconds to form a negative tone image, i.e., remove the unexposed parts of the coating. A final hotplate bake at 150°C for 2 minutes completed the process.

[0110] After the process was completed, the presence or absence of L / S pattern formation was confirmed using a microscope. The results are shown in Table 2.

[0111] [Table 2]

[0112] From the results in Table 2, it can be seen that the patterns formed by the pattern forming methods according to the examples have excellent resolution.

[0113] Although specific embodiments of the present invention have been described and illustrated above, it is obvious to those skilled in the art that the present invention is not limited to the described embodiments, and that various modifications and variations are possible without departing from the spirit and scope of the present invention. Therefore, such modifications or variations should not be understood individually from the technical spirit and perspective of the present invention, and the modified embodiments should belong to the scope of the claims of the present invention. [Explanation of symbols]

[0114] 100...substrate, 102...thin film, 104...resist underlayer film, 106...photoresist film, 106a...unexposed area, 106b...exposed area, 108...photoresist pattern, 112...organic film pattern, 110...patterned mask, 114...thin film pattern.

Claims

1. applying a metal-containing resist composition onto a substrate; a heat treatment step of drying and heating to form a metal-containing resist film on the substrate; exposing the metal-containing resist film using a patterned mask; and a developing step of applying a developer composition to remove the unexposed areas to form a resist pattern. The step of applying the metal-containing resist composition is carried out by applying the metal-containing resist composition with a spin coater at a speed of 100 to 1,500 rpm for 60 to 120 seconds; The heat treatment step is carried out at a temperature of 90 to 200° C. for 30 to 120 seconds; The step of exposing the metal-containing resist film is carried out by irradiating the metal-containing resist film with extreme ultraviolet light or light having a wavelength of 5 nm to 150 nm; The surface roughness of the metal-containing resist film after the heat treatment step is such that the root mean square roughness (Rq) is 1.5 nm or less, the average roughness (Ra) is 1.0 nm or less, and the maximum roughness (Rmax: peak to peak height) is 20 nm or less.

2. The pattern formation method according to claim 1 , wherein the root mean square roughness Rq is 0.1 nm to 1.5 nm.

3. The pattern formation method according to claim 1 , wherein the average roughness Ra is 0.1 nm to 1.0 nm.

4. The pattern formation method according to claim 1 , wherein the maximum roughness Rmax is 1 nm to 20 nm.

5. 2. The pattern formation method according to claim 1, wherein the metal compound contained in the metal-containing resist composition includes at least one of an organic oxy group-containing tin compound and an organic carbonyloxy group-containing tin compound.

6. 2. The pattern forming method according to claim 1, wherein the metal compound contained in the metal-containing resist composition is represented by the following chemical formula 1: 【Chemistry 1】 In the above Chemical Formula 1, R １ is a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C7 to C30 arylalkyl group, and -L ａ -O-R ａ (Here, L ａ is a substituted or unsubstituted C1 to C20 alkylene group, R ａ is a substituted or unsubstituted C1 to C20 alkyl group; R ２ ~R ４ Each independently represents -OR ｂ and -OC(=O)R ｃ is selected from among R ｂ is a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof; R ｃ is hydrogen, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof.

7. The R １ is a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C2 to C10 alkynyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C7 to C20 arylalkyl group, and -L ａ -O-R ａ (Here, L ａ is a substituted or unsubstituted C1 to C10 alkylene group, R ａ The pattern formation method according to claim 1 , wherein R is a substituted or unsubstituted C1 to C10 alkyl group.

8. The R １ 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 xylene 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.

9. 2. The method of claim 1, wherein the metal compound is contained in an amount of 1 to 30 wt % based on 100 wt % of the metal-containing resist composition.

10. 2. The method of claim 1, wherein the metal-containing resist composition further comprises an additive selected from the group consisting of a surfactant, a crosslinking agent, a leveling agent, an organic acid, a quencher, and combinations thereof.

11. The pattern forming method according to claim 1 , further comprising the step of providing a resist underlayer film formed between the substrate and the metal-containing resist film.

12. 2. The pattern forming method according to claim 1, wherein the resist pattern has a width of 5 nm to 100 nm.

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