Method for forming an extremely ultraviolet light-reactive photoresist thin film and the photoresist thin film formed thereby

Abstract

The object of the present invention is to provide a method for forming a photoresist thin film that has improved photon absorption rate in extreme ultraviolet light and excellent etching resistance, and a photoresist thin film formed by this method. [Solution] One embodiment of the present invention provides a method for forming a hydrophobic photoresist thin film, comprising the steps of: introducing a first precursor and an oxygen source into a chamber in which a substrate is located to form a thin film containing hydrophilic groups; and introducing a second precursor to modify the thin film containing the hydrophilic groups to form a modified layer. The photoresist thin film formed through this method does not contain hydroxyl groups and therefore exhibits hydrophobicity.

Description

[Technical Field]

[0001] The present invention relates to a method for forming a photoresist thin film and a photoresist thin film formed thereby, and more particularly to a thin film formation method and a photoresist thin film formed thereby, which includes the step of forming a thin film containing hydrophilic groups using two types of precursors, and then modifying the thin film to form a modified layer. [Background technology]

[0002] Photoresist (PR) is a chemical substance whose properties change in response to light. In displays, it is used in the photolithography process to form fine circuits on thin-film transistors (TFTs).

[0003] Photoresists change their chemical properties when exposed to light. Depending on the type, they may harden or become more easily soluble when exposed to light. Photolithography is a method that utilizes these changes in the properties of photoresists to selectively remove only the weakened parts, thereby separating the parts to be used in the circuit from the parts that are not, and creating fine circuit patterns three-dimensionally, much like a print.

[0004] Photolithography is a core process in thin-film transistor manufacturing, where a thin layer of photoresist is applied to the thin-film transistor substrate. Subsequently, after placing it on a photomask that separates the area to be printed with the electronic circuit pattern from the rest of the substrate, light is shone on it, causing the properties of the photoresist to change between the areas that receive light and those that do not. At this point, the difference in solubility between the two areas with altered properties is used to remove the easily dissolvable photoresist through a development process.

[0005] The deposited material remaining in the area where the photoresist has disappeared is removed through the etching process, while the remaining deposited material beneath the photoresist is retained under the protection of the photoresist.

[0006] As it has become impossible to form fine patterns of 50 nm or less with krypton fluoride (248 nm) and argon fluoride (193 nm) light sources and conventional photoresists, lithography processes have recently been developed that use short-wavelength light sources and chemically amplified deep ultraviolet (DUV) photoresists that react to these short wavelengths to integrate more circuits into a smaller area.

[0007] Among the short-wavelength light sources that have emerged are extreme ultraviolet (EUV) (13 nm) light sources, ion beams, and X-rays. When using the extreme ultraviolet light source, it is expected that it will be possible to manufacture semiconductors at a speed 100 times faster and with 100 times more capacity compared to currently used processes, as this will enable circuit design of 0.1 μm or less.

[0008] While chemically amplified resists (CARs), which are representative photoresists, have been used as standard materials up to the argon fluoride generation, the introduction of extreme ultraviolet light and process miniaturization have led to problems such as (1) considerably poor photon absorption efficiency for photons in the extreme ultraviolet wavelength band due to the low cross-section of carbon and oxygen, the main components of CARs; (2) deterioration of uniformity and roughness characteristics due to acid diffusion; and (3) pattern collapse during the development process due to the low mechanical strength of organic-based photoresists. As a result, the need has emerged for the development of new inorganic photoresists that (1) have high photon absorbance in the extreme ultraviolet wavelength band, and (2) have excellent mechanical strength and etching resistance, satisfying the RLS (Resolution, LER / LWR, Sensitivity) characteristics.

[0009] Recently, inorganic photoresists using coating methods based on liquid-phase and gas-phase chemical reactions have been recognized as alternative technologies for ultra-fine pattern formation worldwide. However, the source technology development of related materials / processes / equipment is insufficient. Therefore, in order to preempt the next-generation extreme ultraviolet patterning technology and secure technological competitiveness, the development of inorganic photoresist materials and processes must be essentially carried out.

Summary of the Invention

Problems to be Solved by the Invention

[0010] The technical objective to be achieved by the present invention is to provide a method for forming a photoresist thin film with improved photon absorption rate of extreme ultraviolet rays and excellent etch resistance, and a photoresist thin film formed through this method.

[0011] The technical problems to be solved by the present invention are not limited to the technical problems mentioned above. Another technical problem not mentioned should be clearly understood by those with ordinary knowledge in the technical field to which the present invention belongs from the following description.

Means for Solving the Problems

[0012] In order to achieve the above technical problems, an embodiment of the present invention provides a method for forming a hydrophobic photoresist thin film, comprising the steps of: introducing a first precursor and an oxygen source into a chamber where a substrate is located to form a thin film containing hydrophilic groups; and introducing a second precursor to modify the thin film containing hydrophilic groups to form a modified layer.

[0013] After forming the thin film containing hydrophilic groups, the method further comprises the step of supplying a purge gas to the chamber to remove the unreacted oxygen source.

[0014] After forming the modified layer, the method further comprises the step of supplying a purge gas to the chamber to remove the unreacted second precursor.

[0015] The step of forming the modification layer does not include a reactant.

[0016] The thin film containing the hydrophilic group contains a hydroxy group.

[0017] In an embodiment of the present invention, the first precursor includes the structure of Chemical Formula 1 below.

[0018] [Chemical Formula 1] (R1)a‐M‐(L) d (Here, 0 ≦ a ≦ 5, 0 ≦ d ≦ 5, 0 < a + d < 5, a and d are integers, M is a Group 5 metal, R1 is selected from a linear, branched or cyclic alkyl group, a linear, branched or cyclic alkenyl group, and an aryl group, and L is a hydrolyzable ligand.)

[0019] In an embodiment of the present invention, the M is any one metal selected from Te, Sb, Sn, and In.

[0020] In an embodiment of the present invention, the L is selected from an ester group, an amine group, an amide group, an alkoxy group, a carbonyl group, and an aldehyde group.

[0021] In an embodiment of the present invention, the second precursor includes the structure of Chemical Formula 2 below.

[0022] [Chemical Formula 2] (R2) b -M * -(L1) e (Here, 1 ≦ b ≦ 5, 0 ≦ e ≦ 5, 1 ≦ b + e ≦ 5, b and e are integers, M * is a Group 5 metal, R2 is selected from a linear, branched or cyclic alkyl group, a linear, branched or cyclic alkenyl group, and an aryl group, and L1 is a hydrolyzable ligand.)

[0023] In an embodiment of the present invention, the M *is any one metal selected from Te, Sb, Sn, and In.

[0024] The L1 is selected from an ester group, an amine group, an amide group, an alkoxy group, a carbonyl group, and an aldehyde group. In an embodiment of the present invention, the oxygen source is one selected from water (H2O), oxygen (O2), ozone (O3), and hydrogen peroxide (H2O2).

[0025] The M and M * Among them, at least one may contain Te.

[0026] The M and M * may all be Te.

[0027] To achieve the above technical problem, another embodiment of the present invention provides a photoresist thin film formed by the above method.

[0028] In an embodiment of the present invention, it includes the structure of the following Chemical Formula 3.

[0029] [Chemical Formula 3] [(M) a’ O b’ [[ID=...]]] x O c’ (M * ) d’ (R2) e’ Here, M and M * are each independently a Group 5 metal, R2 is selected from a linear, branched or cyclic alkyl group, a linear, branched or cyclic alkenyl group, and an aryl group, and a' ≧ 4, b' ≧ 8, c' ≧ 4, d' ≧ 8, e' ≧ 8, x ≧ 1.

[0030] The M and M * Among them, at least one may contain Te.

[0031] The M and M * may all be Te.

[0032] The R2 may include a branched alkyl group or a halogenated alkyl group.

[0033] In the embodiment of the present invention, the contact angle with water is 60° or more.

[0034] In the embodiment of the present invention, when infrared spectroscopy is performed, the measurement is 3200-3400 cm- 1 The key difference is the absence of a hydroxyl peak. [Effects of the Invention]

[0035] According to embodiments of the present invention, a method for forming a photoresist thin film with increased photon absorption rate in extreme ultraviolet light and excellent etching resistance can be provided.

[0036] The desired thin film thickness can be formed via the first precursor.

[0037] Because the first and second precursors are deposited in sequence, and there is no direct bonding between the metal and hydroxyl groups within the thin film, hydrophobicity can be achieved.

[0038] The effects of the present invention are not limited to those described above, but should be understood to include all effects that can be inferred from the detailed description of the present invention or the configuration of the invention as described in the claims. [Brief explanation of the drawing]

[0039] [Figure 1] This is a schematic diagram of the photoresist thin film formation method according to the present invention. [Figure 2] This invention provides an infrared spectroscopy (IR) analysis graph within the hydroxyl group (OH) peak range. [Modes for carrying out the invention]

[0040] The present invention will be described below with reference to the attached drawings. However, the present invention may be carried out in various different forms and is therefore not limited to the embodiments described herein. In order to clearly illustrate the present invention in the drawings, parts unrelated to the description have been omitted, and similar parts throughout the specification are denoted by similar reference numerals.

[0041] Throughout the specification, when a part is described as being "connected (linked, in contact with, or joined)" to another part, this includes not only cases where it is "directly connected" but also cases where it is "indirectly connected" with other components in between. Furthermore, when a part is described as "containing" a component, this does not exclude other components unless otherwise stated, but rather means that it may contain other components.

[0042] The terms used herein are used solely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates a different meaning. In this specification, terms such as “includes” or “having” are intended to specify the existence of features, figures, stages, operations, components, parts, or combinations thereof described in the specification, and should be understood not to preemptively exclude the existence or possibility of adding one or more other features, figures, stages, operations, components, parts, or combinations thereof.

[0043] The embodiments of the present invention will be described in detail below with reference to the attached drawings.

[0044] In this specification, the term "substituted or unsubstituted" means a material that is substituted or unsubstituted with one or more substituents selected from the group consisting of deuterium, halogens, cyano groups, nitro groups, hydroxyl groups, carbonyl groups, ester groups, imide groups, amide groups, amino groups, carboxyl groups, sulfonic acid groups, sulfonamide groups, phosphine oxide groups, alkoxy groups, alkylcarbonyl groups, alkoxycarbonyl groups, sulfonyloxy groups, aryloxy groups, alkylthiooxy groups, arylthiooxy groups, alkylsulfoxy groups, arylsulfoxy groups, silyl groups, boron groups, aryl groups, and heteroaryl groups, or a material that is substituted or unsubstituted with two or more substituents linked together from the substituents shown as examples above.

[0045] In this specification, examples of halogens include fluorine, chlorine, bromine, or iodine.

[0046] In this specification, the oxygen of the ester group may be substituted with a linear, branched, or cyclic alkyl group having 1 to 25 carbon atoms or an aryl group having 6 to 25 carbon atoms.

[0047] In this specification, specific examples of alkyl groups include methyl, ethyl, propyl, n-propyl, isopropyl (iPr), butyl, n-butyl, isobutyl, tert-butyl (tBu), sec-butyl, 1-methyl-butyl, 1-ethylbutyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, and 3,3-dimethylbutyl Examples include, but are not limited to, 2-ethylbutyl, heptyl, n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl, 2-methylpentyl, 4-methylhexyl, and 5-methylhexyl. The alkyl groups may be substituted or unsubstituted, and if substituted, examples of substituents are as described above.

[0048] In this specification, an alkoxy group is a working group in which the aforementioned alkyl group is bonded to one end of an ethel group (-O-), and the description of alkyl groups described above can be applied, except that these are working groups bonded to an ethel group (-O-). For example, the alkyl group may be linear, branched, or cyclic. The number of carbon atoms in the alkoxy group is not particularly limited, but may be 1 to 20. Specifically, examples include, but are not limited to, methoxy, ethoxy, n-propoxy, isopropoxy, i-propyloxy, n-butoxy, isobutoxy, tert-butoxy, sec-butoxy, n-pentyloxy, neopentyloxy, isopentyloxy, n-hexyloxy, 3,3-dimethylbutyloxy, 2-ethylbutyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, cycloheptoxy, benzyloxy, and p-methylbenzyloxy. The alkoxy group may be substituted or unsubstituted, and if substituted, examples of substituents are as described above.

[0049] In this specification, the amine group may be selected from the group consisting of -NH2, monoalkylamine group, dialkylamine group, N-alkylarylamine group, monoarylamine group, diarylamine group, N-arylheteroarylamine group, N-alkylheteroarylamine group, monoheteroarylamine group, and diheteroarylamine group, and the number of carbon atoms is not particularly limited but may be 1 to 30. Specific examples of amine groups include, but are not limited to, methylamine group, dimethylamine group, ethylamine group, diethylamine group, phenylamine group, naphthylamine group, biphenylamine group, anthracenylamine group, 9-methyl-anthracenylamine group, diphenylamine group, ditolylamine group, N-phenylbiphenylamine group, N-phenylnaphthylamine group, N-biphenylnaphthylamine group, ditolylamine group, N-phenyltolylamine group, triphenylamine group, N-naphthylfluorenylamine group, N-phenylphenantrenylamine group, N-biphenylphenantrenylamine group, N-phenylfluorenylamine group, N-phenyltophenylamine group, N-phenantrenylfluorenylamine group, and N-biphenylfluorenylamine group. The amine groups may be substituted or unsubstituted, and examples of substituents in the case of substitution are as described above.

[0050] In this specification, the amide group may have hydrogen, a linear alkyl group having 1 to 30 carbon atoms, a branched alkyl group having 3 to 30 carbon atoms, a cyclic alkyl group having 3 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or a combination thereof bonded to the nitrogen of the amide group.

[0051] Figure 1 is a schematic diagram of the photoresist thin film formation method according to the present invention.

[0052] Referring to Figure 1, the method for forming a hydrophobic photoresist thin film according to an embodiment of the present invention will be described below.

[0053] According to an embodiment of the present invention, a method for forming a hydrophobic photoresist thin film includes forming a thin film containing a hydrophilic group by introducing a first precursor and an oxygen source into a chamber in which a substrate is located, and introducing a second precursor to modify the thin film containing the hydrophilic group to form a modified layer. The first step is to introduce a first precursor and an oxygen source into the chamber in which the substrate is located to form a thin film containing a hydrophilic group.

[0054] After forming the thin film containing the hydrophilic group, further comprising supplying a purge gas to the chamber to remove the unreacted oxygen source.

[0055] The thin film containing the hydrophilic group contains a hydroxy group.

[0056] The first precursor has a structure represented by the following Chemical Formula 1 and is represented by the following Chemical Formula 1.

[0057] [Chemical Formula 1] (R1) a -M-(L) d Here, a and d are integers, satisfying 0 ≦ a ≦ 5, 0 ≦ d ≦ 5, 0 < a + d < 5, M is a Group 5 metal, R1 is selected from linear, branched or cyclic alkenyl groups and aryl groups, and L is a hydrolyzable ligand.

[0058] More specifically, a is an integer from 0 to 4, and d can be an integer from 0 to 4. Specifically, when a + d = 4, more specifically when a = 0, d = 4, and when a = 1, d = 3.

[0059] Specifically, the M can be any one of the Group 5 metals selected from Te, Sb, Sn, and In. More specifically, the M can be Te or Sn. In a photoresist, the higher the absorbance, the better the sensitivity. From this aspect, ln, Sn, Sb, Te may be excellent in this order.

[0060] <0R1 may be selected from linear, branched, or cyclic alkyl groups, linear, branched, or cyclic alkenyl groups, and aryl groups.

[0061] Specifically, R1 is selected from hydrogen, a substituted or unsubstituted linear alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted branched alkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted cyclic alkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms.

[0062] Alkyl and aryl groups can be halogenated. In this case, the precursor is -(CH2) n CF3, -(CH2) n I, -(CH2) m It has active groups such as CHCH2, but this is just an example and not limited to this.

[0063] Alkyl alkyl groups have the advantage of favorable bonding with metals during extreme ultraviolet exposure. In this case, branched alkyl groups offer even greater favorable bonding with metals, potentially leading to improved sensitivity. When R1 is absent, they exhibit excellent reactivity with water, which may be advantageous in the formation of metal oxide films.

[0064] In other words, if R1 is not substituted, the more branched the alkyl group, the more favorable the bonding with the metal during EUV exposure, resulting in superior sensitivity. Specifically, isopropyl and tert-butyl exhibit superior sensitivity, and more specifically, tert-butyl exhibits superior sensitivity.

[0065] The alkenyl group refers to an aliphatic unsaturated alkenyl group that contains one or more double bonds as a linear or branched aliphatic hydrocarbon group.

[0066] The aryl group refers to a substituent in which all elements of the cyclic substituent have p-orbitals, and these p-orbitals form a conjugation, and can include monocyclic or fusion-ring polycyclic (i.e., rings that share adjacent pairs of carbon atoms) active groups.

[0067] In the case of aryl groups, the effect may be similar to that of linear alkyl groups.

[0068] L is a hydrolyzable ligand and can be selected from ester groups, amine groups, amide groups, alkoxy groups, carbonyl groups, and aldehyde groups.

[0069] Specifically, the ester group can be selected from a formate group, an acetyl group, a propionate group, and a phenylacetate group.

[0070] Specifically, the amine group may be a dialkylamine group. More specifically, the amine group may be a dimethylamine group.

[0071] In this case, the amine group exhibits the best reactivity with water.

[0072] The oxygen source may be one selected from water, oxygen, ozone, and hydrogen peroxide.

[0073] The first precursor deposition is carried out through the Chemical Vapor Deposition (CVD) process. This process is further divided into heat, plasma, and light depending on the external energy used in the CVD process. In this process, a wafer is placed in a vacuum chamber isolated from the outside, and a gas containing the raw materials for the thin film to be formed is supplied to deposit the thin film without altering the properties of the substrate through plasma, heat, etc.

[0074] During the deposition of the first precursor, oxide particles are formed at intervals and adsorbed physically or chemically.

[0075] The first precursor can be used to adjust the thickness of the photoresist thin film.

[0076] After the above step, a purging step can be performed, which is a step of supplying a purging gas to the chamber to remove the unreacted oxygen source.

[0077] The next step is to introduce a second precursor and modify the thin film containing the hydrophilic groups to form a modified layer. After forming the modified layer, the process further includes supplying a purging gas to the chamber to remove any unreacted second precursor.

[0078] The step of forming the modified layer does not involve reactants.

[0079] The aforementioned second precursor has the structure shown in chemical formula 2 below and is represented by chemical formula 2 below.

[0080] [Chemical formula 2] (R2) b -M * -(L1) Here, 1≦b≦5, 0≦e≦5, 1≦b+e≦5, b and e are integers, and M * R1 is a periodic metal, R2 is selected from linear, branched, or cyclic alkyl groups, linear, branched, or cyclic alkenyl groups, and aryl groups, and L1 is a hydrolyzable ligand.

[0081] Specifically, if b is an integer between 0 and 4, then e can be an integer between 0 and 4. More specifically, b+e=4 is possible. When b=3, e=1 is possible. Also, b+e=2 is possible. When b=1, e=1 is possible.

[0082] Said M *This can be any one of the metals selected from Te, Sb, Sn, and In among the 5 periodic metals. More specifically, the above M * This can be Sn and Te.

[0083] The aforementioned M and M * These may be the same or different. The aforementioned M and M * At least one of these may include Sn. The above M and M * At least one of them may include Te. The above M and M * All of these can be Te. Specifically, when M is Sn, M * It can be Te. When M is Te, M * It can be Sn. When M is Te, M * It can be Te. When M is Sn, M * This could be Sn. In photoresists, the higher the absorbance, the better the sensitivity, and from this perspective, the order of performance is In, Sn, Sb, and Te.

[0084] In photoresists, higher absorbance generally leads to better sensitivity, and from this perspective, In, Sn, Sb, and Te may perform best in that order.

[0085] The R2 can be selected from linear, branched, or cyclic alkyl groups, linear, branched, or cyclic alkenyl groups, and aryl groups. Furthermore, when R2 includes a halogenated alkyl group or a branched alkyl group, the sensitivity is excellent.

[0086] Specifically, R2 is selected from hydrogen, a substituted or unsubstituted linear alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted branched alkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted cyclic alkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms.

[0087] Specifically, R2 may include a branched alkyl group or a halogenated alkyl group.

[0088] More specifically, R2 may contain tert-butyl or -CH2CH2I.

[0089] Alkyl groups have the advantage of favoring bonding with metals during extreme ultraviolet exposure. In this case, branched alkyl groups are more favorable for bonding with metals than linear or cyclic alkyl groups.

[0090] The alkenyl group refers to an aliphatic unsaturated alkenyl group that contains one or more double bonds as a linear or branched aliphatic hydrocarbon.

[0091] The aryl group refers to a substituent in which all elements of the cyclic substituent have p-orbitals, and these p-orbitals form a conjugation, and can include monocyclic or fusion-ring polycyclic (i.e., rings that share adjacent pairs of carbon atoms) active groups.

[0092] In the case of aryl groups, the effect may be similar to that of linear alkyl groups.

[0093] L1 is a hydrolyzable ligand and can be selected from ester groups, amine groups, amide groups, alkoxy groups, carbonyl groups, and aldehyde groups.

[0094] Specifically, the ester group can be selected from a formate group, an acetyl group, a propionate group, and a phenylacetate group.

[0095] Specifically, the amine group may be a dialkylamine group. More specifically, the amine group may be a dimethylamine group.

[0096] L1 is removed during thin film formation due to hydrolysis.

[0097] In the step of depositing the second precursor, the second precursor may penetrate into the aforementioned gap, remove the hydroxo portion, and form a side chain.

[0098] The second precursor may retain oxo and remove hydroxo. As a result, the final thin film will exhibit hydrophobicity.

[0099] The ALD (Atomic Layer Deposition) process involves a deposition process that includes precursor supply, purging, reactant supply, and purging. However, the present invention does not involve reactants and only performs the precursor supply and purging steps. Such a process may offer even greater sensitivity and storage stability.

[0100] In such cases, that is, when the reactants are added and the purging process is carried out further, a metal oxide film is formed.

[0101] According to the present invention, a first cycle is defined as the process of introducing a first precursor and an oxygen source into a chamber where a substrate is located to form a thin film containing hydrophilic groups, purging, introducing a second precursor to modify the thin film containing the hydrophilic groups to form a modified layer, and purging. This cycle can be repeated 5 to 300 times. In the case of a hydrophobic photoresist thin film deposited in this way, the thickness can be formed within the range of 10 to 600 nm. When adjusting the thickness of the thin film to be thin, it can be used not only as a photoresist thin film but also as an underlayer film.

[0102] A photoresist thin film according to one embodiment of the present invention may be formed by the above-described formation method, or it may be formed by another method in addition to the above-described formation method.

[0103] The aforementioned photoresist thin film contains and is represented by the following chemical formula 3.

[0104] [Chemical formula 3] JPEG2026518036000002.jpg6170 Here, M and M *Each of the elements is independently a periodic metal of the 5th period, and R2 is selected from linear, branched, or cyclic alkyl groups, linear, branched, or cyclic alkenyl groups, and aryl groups, with a' ≥ 4, b' ≥ 8, c' ≥ 4, d' ≥ 8, e' ≥ 8, and x ≥ 1.

[0105] The aforementioned M and M * Each of these metals can independently be one of the five periodic metals selected from Te, Sb, Sn, and In. In photoresists, higher absorbance indicates better sensitivity, and from this perspective, ln, Sn, Sb, and Te are superior in that order.

[0106] Specifically, when M is selected from Sn and Te, * This can be selected from Sn and Te.

[0107] The aforementioned M and M * This may include at least Te.

[0108] More specifically, when M is Sn, * When M is Sn, * is Te, and when M is Te, M * is Te, and when M is Te, M * It can be Sn.

[0109] The R2 can be selected from linear, branched, or cyclic alkyl groups, linear, branched, or cyclic alkenyl groups, and aryl groups.

[0110] R2 is selected from hydrogen, a substituted or unsubstituted linear alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted branched alkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted cyclic alkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms.

[0111] Specifically, R2 may include a branched alkyl group or a halogenated alkyl group.

[0112] More specifically, R2 may contain a tert-butyl group (tBu) or -CH2CH2I.

[0113] a' ≧ 4, b' ≧ 8, c' ≧ 4, d' ≧ 8, e' ≧ 8, x ≧ 1.

[0114] Specifically, it is possible that a' ≥ 12, b' ≥ 24, c' ≥ 12, d' ≥ 24, e' ≥ 24, and x ≥ 3.

[0115] More specifically, the following are possible: 12≦a'≦80, 24≦b'≦160, 12≦c'≦80, 24≦d'≦160, 24≦e'≦480, 3 ≦ x ≦ 20.

[0116] The aforementioned [Chemical Formula 3] may have repeating units such as the following [Chemical Formula 4], for example.

[0117] [Chemical formula 4] JPEG2026518036000003.jpg71170

[0118] In this case, b is an integer between 1 and 3.

[0119] The repeating unit of [Chemical Formula 4] can grow in the lateral direction, the lateral direction, or both directions.

[0120] [Chemical Formula 5], [Chemical Formula 6], [Chemical Formula 7], and [Chemical Formula 8] below are shown as examples of thin film structures when x=1, x=2, x=3, and x=4, respectively. The form in which the thin film grows is not limited to these, and various modifications are possible. The bond angles for each atom can be different.

[0121] [Chemical formula 5] JPEG2026518036000004.jpg90149

[0122] [Chemical formula 6] JPEG2026518036000005.jpg110149

[0123] [Chemical formula 7] JPEG2026518036000006.jpg134158

[0124] [Chemical formula 8] JPEG2026518036000007.jpg106170

[0125] The photoresist thickness of the present invention may be 5 nm to 30 nm (50 Å to 300 Å). In [Chemical Formula 3], when a'=4, b'=4, c'=8, d'=8, e'=8 or 16 or 24, it may be represented in the form of [Chemical Formula 4]. When X=1, the length of the unit may be 1.6 nm to 2.0 nm.

[0126] The contact angle between the photoresist thin film and water may be 60° or greater. R2 must be present for the extreme ultraviolet light reaction. The contact angle refers to the angle between the water droplet and the solid interface when water is dropped onto a solid. A small contact angle indicates high wettability and hydrophilicity, while a large contact angle indicates low wettability and hydrophobicity.

[0127] Generally, the contact angle of a metal oxide film is hydrophilic and less than 50°. However, the thin film according to the present invention exhibits hydrophobicity, with a contact angle of 60° or higher and low wettability.

[0128] In the case of the photoresist thin film according to the present invention, since there is no direct bond between the metal and the hydroxyl group, when measured by infrared spectroscopy, the range is 3200-3400 cm⁻¹. -1 Therefore, there is a possibility that a hydroxyl peak is absent. This indicates that the photoresist thin film according to the present invention exhibits hydrophobicity.

[0129] The following describes in detail embodiments and experimental examples of the present invention. However, the following embodiments are for illustrative purposes only and do not limit the invention to them.

[0130] <Example 1> The first precursor (MeSn(OCOEt)3) and water were simultaneously introduced into the chamber containing the silicon wafer substrate at a temperature of 50°C to 100°C (preferably 75°C) and purged for 15 seconds. Subsequently, the second precursor (Me2(tBu)Sn(NMe2)) was introduced and purged for 20 seconds. This process was carried out for 300 cycles.

[0131] <Example 2> The first precursor (MeSn(OCOEt)3) and water were simultaneously added to the chamber containing the silicon wear substrate at a temperature of 50°C to 100°C (preferably 75°C) and purged for 15 seconds. Subsequently, the second precursor (Me2(CH2CH2I)Sn(NMe2)) was added and purged for 20 seconds. This process was carried out for 300 cycles.

[0132] <Example 3> The first precursor (MeSn(OCOEt)3) and water were simultaneously introduced into the chamber containing the silicon wafer substrate at a temperature of 50°C to 100°C (preferably 75°C) and purged for 15 seconds. Subsequently, the second precursor ((nBu)3Sn(NMe2)) was introduced and purged for 20 seconds. This process was carried out for 300 cycles.

[0133] <Example 4> The first precursor (MeSn(OCOEt)3) and water were simultaneously introduced into the chamber containing the silicon wafer substrate at a temperature of 50°C to 100°C (preferably 75°C) and purged for 15 seconds. Subsequently, the second precursor ((nBu)2(CH2CH2I)Sn(NMe2)) was introduced and purged for 20 seconds. This process was carried out for 300 cycles.

[0134] <Example 5> The first precursor (MeSn(OCOEt)3) and water were simultaneously introduced into the chamber containing the silicon wafer substrate at a temperature of 50°C to 100°C (preferably 75°C) and purged for 15 seconds. Subsequently, the second precursor (tBuSn(NMe2)) was introduced for 20 seconds and purged. This process was carried out for 300 cycles.

[0135] <Example 6> The first precursor (iPrSn(OCOEt)3) and water were simultaneously introduced into the chamber containing the silicon wafer substrate at a temperature of 50°C to 100°C (preferably 75°C) and purged for 15 seconds. Subsequently, the second precursor (Me2(tBu)Sn(NMe2)) was introduced and purged for 20 seconds. This process was carried out for 300 cycles.

[0136] <Example 7> The silicon wafer substrate was placed in a chamber where a first precursor (tBuSn(OCOEt)3) and water were simultaneously introduced at a temperature of 50°C to 100°C (preferably 75°C) and purged for 15 seconds. Subsequently, a second precursor (Me2(tBu)Sn(NMe2)) was introduced for 20 seconds and purged. This process was carried out for 300 cycles.

[0137] <Example 8> The first precursor (C3H4Sn(OCOEt)3) and water were simultaneously introduced into the chamber containing the silicon wafer substrate at a temperature of 50°C to 100°C (preferably 75°C) and purged for 15 seconds. Subsequently, the second precursor (Me2(tBu)Sn(NMe2)) was introduced and purged for 20 seconds. This process was carried out for 300 cycles.

[0138] <Example 9> The first precursor (C7H7Sn(OCOEt)3) and water were simultaneously introduced into the chamber containing the silicon wafer substrate at a temperature of 50°C to 100°C (preferably 75°C) and purged for 15 seconds. Subsequently, the second precursor (Me2(tBu)Sn(NMe2)) was introduced and purged for 20 seconds. This process was carried out for 300 cycles.

[0139] <Example 10> The silicon wafer substrate was placed in a chamber where a first precursor (tBuSn(OC(CH3)2Et)3) and water were simultaneously introduced at a temperature of 50°C to 100°C (preferably 75°C) and purged for 15 seconds. Subsequently, a second precursor (Me2(tBu)Sn(NMe2)) was introduced for 20 seconds and purged. This process was carried out for 300 cycles.

[0140] <Example 11> The first precursor (MeSn(NH2)3) and water were simultaneously introduced into the chamber containing the silicon wafer substrate at a temperature of 50°C to 100°C (preferably 75°C) and purged for 15 seconds. Subsequently, the second precursor (Me2(tBu)Sn(NMe2)) was introduced and purged for 20 seconds. This process was carried out for 300 cycles.

[0141] <Example 12> The first precursor (MeTe(OCOEt)3) and water were simultaneously introduced into the chamber containing the silicon wafer substrate at a temperature of 50°C to 100°C (preferably 75°C) and purged for 15 seconds. Subsequently, the second precursor (Me2(tBu)Sn(NMe2)) was introduced and purged for 20 seconds. This process was carried out for 300 cycles.

[0142] <Example 13> A first precursor (MeSn(OCOEt)3) and water were simultaneously introduced into the interior of the silicon wafer substrate at a temperature of 50°C to 100°C (preferably 75°C) for 15 seconds and then purged. Subsequently, a second precursor (Me2(tBu)Te(NMe2)) was introduced for 20 seconds and then purged. This process was carried out for 300 cycles.

[0143] <Example 14> The first precursor (MeTe(OCOEt)3) and water were simultaneously introduced into the chamber containing the silicon wafer at 50°C to 100°C (preferably 75°C) for 15 seconds and then purged. Subsequently, the second precursor (Me2(tBu)Te(NMe2)) was introduced for 20 seconds and then purged. This process was carried out for 300 cycles.

[0144] <Example 15> The first precursor (Sn(NH2)4) and water were simultaneously introduced into the chamber containing the silicon wafer substrate at a temperature of 50°C to 100°C (preferably 75°C) and purged for 15 seconds. Subsequently, the second precursor (Me2(tBu)Sn(NMe2)) was introduced and purged for 20 seconds. This process was carried out for 300 cycles.

[0145] <Comparative Example 1> The process of adding the second precursor was carried out in a step that included a reactant, unlike the example step that did not include a reactant, but all other conditions were the same as in Example 1.

[0146] <Comparative Example 2> The first precursor (MeSn(OCOEt)3) was used as a single precursor without the second precursor, and the other conditions were the same as in Example 1.

[0147] <Comparative Example 3> The process of adding the second precursor was carried out in a step containing a reactant, unlike the example step which does not contain a reactant, but all other conditions were the same as in Example 13.

[0148] <Example of experiment> The evaluation results of the experimental examples of the present invention are shown in Table 1 below.

[0149] [Table 1]

[0150] <Experimental Example 1> Thin Film Thickness Measurement The thickness of the photoresist thin films produced by carrying out the processes of Examples 1 to 15 and Comparative Examples 1 to 3 was measured using a polarization analyzer (Elipsometer), and the measured thickness was approximately 20 to 30 nm.

[0151] <Experimental Example 2> Water contact angle Generally, the contact angle of metal oxide films is lower than 50°. However, the photoresist thin film according to the present invention has a contact angle of 60° or higher. Because the hydroxo is removed and alkyl chains are present in the side chain portion of the thin film according to the present invention, it exhibits relatively hydrophobicity compared to the case of metal oxide films.

[0152] <Experimental Example 3> Coating properties and sensitivity The photoresist thin films produced by carrying out the processes of Examples 1-15 and Comparative Examples 1-3 were exposed to EUV radiation. After exposure, post-exposure baking (PEB) was performed at 170°C for 120 seconds. The post-exposure baked thin films were immersed in a developer solution and washed to form a negative tone image. The residual resist thickness was measured using an episometer, and the sensitivity (dose to gel) for each type of resist is shown in Table 1. Referring to Table 1, Examples 1-15 showed superior sensitivity compared to Comparative Example 2, in which only a single precursor was used in the CVD process.

[0153] Example 15 showed superior sensitivity compared to Comparative Example 3, which included reactants during the formation of the modified layer, because it did not contain reactants during that stage.

[0154] In photoresists, higher absorbance indicates superior sensitivity. From this perspective, ln, Sn, Sb, and Te are superior in this order. Therefore, Examples 12-14, which contain Te, showed superior sensitivity compared to Example 1, which contains only Sn.

[0155] In Comparative Examples 1 and 3, carrying out the reaction with the reactant resulted in the formation of a metal oxide film without photoreactive alkyl groups, making sensitivity evaluation impossible.

[0156] <Experimental Example 4> Infrared Spectroscopy (IR) Analysis Table 1 and Figure 2 show the results of infrared spectroscopy (IR) analysis performed at room temperature (generally 15-25°C) using a Bruker Vertex 70 system on the photoresist thin films produced by carrying out the processes of Examples 1-15 and Comparative Examples 1-3.

[0157] Examples 1-15 use 3200 cm- 1 ~3400cm- 1 The hydroxyl peak was not observed in comparative examples 1-3, as shown in Table 1 below.

[0158] Figure 2 shows the IR analysis graphs for Example 1 and Comparative Example 2. The hydroxo peak is 3232.36 cm⁻¹. 1 In this example, Example 1 is represented by a solid line, and Comparative Example 2 is represented by a dotted line. Example 1 used a first precursor (MeSn(OCOEt)3) and a second precursor (Me2(tBu)Sn(NMe2)), while Comparative Example 2 used the first precursor (MeSn(OCOEt)3) as a single precursor without the second precursor.

[0159] Referring to Figure 2, the IR analysis results show that in the case of the photoresist thin film according to the present invention, the hydroxyl peak range is (wavelength 3232.36 cm). -1 It can be confirmed that no peak appears within the ) range. This indicates that the hydroxyl group has been removed.

[0160] The above description of the present invention is for illustrative purposes only, and a person with ordinary skill in the art to which the present invention pertains will understand that it can be easily modified into other specific forms without altering the technical idea or essential features of the present invention. Therefore, the embodiments described above should be understood to be illustrative in all respects and not limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

[0161] The scope of the present invention is defined by the claims described below, and all modifications or alterations derived from the meaning and scope of the claims and the concept of equivalents thereof should be interpreted as being included within the scope of the present invention.

Claims

1. The process involves introducing a first precursor and an oxygen source into a chamber in which the substrate is located to form a thin film containing hydrophilic groups on the substrate, The process includes the step of adding a second precursor to modify the thin film containing the hydrophilic group and form a modified layer, A method for forming a hydrophobic photoresist thin film.

2. The further step includes forming a thin film containing the hydrophilic group, and then supplying a purging gas to the chamber to remove the unreacted oxygen source. The method for forming a hydrophobic photoresist thin film according to claim 1.

3. The further step includes, after forming the reformed layer, supplying a purging gas to the chamber to remove unreacted second precursors. The method for forming a hydrophobic photoresist thin film according to claim 1.

4. The step of forming the modified layer does not include reactants. The method for forming a hydrophobic photoresist thin film according to claim 1.

5. The thin film containing the hydrophilic group contains a hydroxyl group. The method for forming a hydrophobic photoresist thin film according to claim 1.

6. The first precursor includes the structure of the following chemical formula 1, The method for forming a hydrophobic photoresist thin film according to claim 1. [Chemical formula 1] (R １ ) ａ -M-(L) ｄ (Here, 0≦a≦5, 0≦d≦5, 0<a+d<5, a and d are integers, M is a 5-period metal, R １ (L is selected from linear, branched, or cyclic alkyl groups, linear, branched, or cyclic alkenyl groups, and aryl groups, and L is a ligand that can be independently hydrolyzed.)

7. The aforementioned M is one metal selected from Te, Sb, Sn, and In. The method for forming a hydrophobic photoresist thin film according to claim 6.

8. The aforementioned L is selected from ester groups, amine groups, amide groups, alkoxy groups, carbonyl groups, and aldehyde groups. The method for forming a hydrophobic photoresist thin film according to claim 6.

9. The aforementioned R １ However, containing branched alkyl groups, The method for forming a hydrophobic photoresist thin film according to claim 6.

10. The second precursor has the structure of the following chemical formula 2, The method for forming a hydrophobic photoresist thin film according to claim 1. [Chemical formula 2] (R ２ ) ｂ -M ＊ -(L １ )e (Here, 1≦b≦5, 0≦e≦5, 1≦b+e≦5, b and e are integers, M ＊ It is a metal in the 5th period, R 2 L is selected from linear, branched, or cyclic alkyl groups, linear, branched, or cyclic alkenyl groups, and aryl groups. １ It is a hydrolyzable ligand.

11. Said M * is one of the metals selected from Te, Sb, Sn, and In. The method for forming a hydrophobic photoresist thin film according to claim 10.

12. Said L １ This is selected from ester groups, amine groups, amide groups, alkoxy groups, carbonyl groups, and aldehyde groups. The method for forming a hydrophobic photoresist thin film according to claim 10.

13. The oxygen source is one selected from water, oxygen, ozone, and hydrogen peroxide. The method for forming a hydrophobic photoresist thin film according to claim 1.

14. The aforementioned M and M ＊ At least one of them contains Te, A method for forming a hydrophobic photoresist thin film according to claim 6 or claim 10.

15. The aforementioned M and M ＊ They are all Te. The method for forming a hydrophobic photoresist thin film according to claim 14.

16. The structure includes the chemical formula 3 shown below, Hydrophobic photoresist thin film. [Chemical formula 3] (Here, M and M ＊ These are each independently 5-period metals, R ２ (The group is selected from linear, branched, or cyclic alkyl groups, linear, branched, or cyclic alkenyl groups, and aryl groups, where a'≧4, b'≧8, c'≧4, d'≧8, e'≧8, and x≧1.)

17. The contact angle with water is 60° or greater. The hydrophobic photoresist thin film according to claim 16.

18. During infrared spectroscopy measurements, 3200-3400 cm- １ Therefore, there is no hydroxyl peak. The hydrophobic photoresist thin film according to claim 16.

19. The aforementioned R ２ is a tert-butyl group or -CH ２ CH ２ I, The hydrophobic photoresist thin film according to claim 16.

20. The aforementioned M and M ＊ At least one of them contains Te, The hydrophobic photoresist thin film according to claim 16.

21. The aforementioned M and M ＊ They are all Te. The hydrophobic photoresist thin film according to claim 20.

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