Coating compositions for forming resist underlayers for EUV lithography processes

Abstract

A coating composition for forming a resist bottom film for an EUV lithography process. A monomer represented by chemical formula (1) is provided: wherein X, Y, and Z are the same as described in the specification, and a polymer comprising repeating units derived from the monomer.

Description

Technical Field

[0001] This disclosure generally relates to undercoating compositions for use with photoresist compositions. Specifically, this disclosure provides coating compositions for forming photoresist undercoating films for far-ultraviolet (“EUV”) lithography. Background Technology

[0002] EUV lithography is one of the leading technology options to replace optical lithography for the manufacture of volumetric semiconductors with feature sizes of a few nanometers. Currently, EUV lithography has become the preferred patterning technology for immersion processes exceeding 193 nm for high-volume manufacturing of product nodes below 10 nm.

[0003] As is well known, the number of photons in the exposed area of ​​EUV lithography is much smaller than that in ArF lithography. Due to the lack of photons and the reduced pattern pitch, shot noise has a more significant impact on the pattern profile. As a result, new problems have emerged in recent EUV lithography techniques that were not observed in ArF lithography. The most serious problem has been reported as nano-bridging defects at line-to-space patterns with a 3x nm pitch. These defects lead to fatal bridging defects after the entire pattern has been transferred through the etching process.

[0004] It has been found that nanobridge defects are caused by an inherent lack of acid at the base of the photoresist via EUV patterning. Therefore, a chemical approach is needed to mitigate this defect. New materials capable of mitigating nanobridge defects in photoresists are still required. Summary of the Invention

[0005] It has been found that certain underlayer compositions providing additional acid to the interface between the newly designed polymer structure and the photoacid generator with high EUV absorption improve the light velocity and scum / foot profile of EUV photoresist. The compositions described in this application significantly reduce nanobridge defects compared to photoresist on CVD hard mask stacks.

[0006] One embodiment provides a monomer represented by chemical formula (1): (1) in, X is a straight-chain or branched C1 to C10 hydrocarbon group, C1 to C10 alkoxycarbonyl group, C1 to C10 alkanoyloxy group, carboxylic acid group, or a straight-chain or branched C1 to C10 hydroxyalkyl group optionally substituted with a C1 to C5 alkoxycarbonyl group or an alkoxy group substituted with a C1 to C5 group. Y is hydrogen, a straight-chain or branched C1 to C10 hydrocarbon group, a C1 to C10 alkoxycarbonyl group, or a C1 to C10 alkanoyloxy group, a carboxylic acid group, or a straight-chain or branched C1 to C10 hydroxyalkyl group optionally substituted with a C1 to C5 alkoxycarbonyl group or a C1 to C5 alkoxy group; and Z is a straight-chain or branched C1 to C10 hydrocarbon group, C1 to C10 alkoxycarbonyl group, C1 to C10 alkanoyloxy group, carboxylic acid group, or a straight-chain or branched C1 to C10 hydroxyalkyl group optionally substituted with a C1 to C5 alkoxycarbonyl group or a C1 to C5 alkoxy group. Each of the C1 to C10 hydrocarbon group, the C1 to C10 alkoxycarbonyl group, the C1 to C10 alkylyl group, and the C1 to C10 hydroxyalkyl group is optionally substituted with at least one of the following groups: fluorine, chlorine, bromine, iodine, hydroxyl, thiol, carboxylic acid group, C1 to C5 alkyl, C3 to C8 cycloalkyl, C2 to C5 alkenyl, C1 to C5 alkoxy, C2 to C5 alkenyl, C6 to C10 aryl, C6 to C10 aryloxy, C7 to C10 alkylaryl, and C7 to C10 alkylaryloxy.

[0007] Another embodiment provides a polymer comprising repeating units derived from the monomer.

[0008] In another embodiment, a base coat composition is provided, the base coat composition comprising a polymer, a crosslinking agent, and a solvent. The composition may further comprise a photoacid generator.

[0009] Another embodiment provides a method for forming an electronic device, the method comprising: (a) Applying a layer of the underlying coating composition to a substrate; (b) Curing the undercoat composition to form an undercoat film; (c) Applying a layer of the photoresist composition onto the underlying film to form a photoresist layer; (d) exposing the photoresist layer to radiation in a patterned manner; and (e) Develop the exposed photoresist layer to provide a photoresist relief image. Detailed Implementation

[0010] Reference will now be made in detail to exemplary embodiments, examples of which are shown in this specification. In this respect, these exemplary embodiments may take different forms and should not be construed as limiting to the description shown herein. Therefore, exemplary embodiments are described below to explain various aspects of this specification. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. When a statement such as “at least one of…” precedes the list of elements, it modifies the entire list of elements and does not modify any individual element in the list.

[0011] What will be understood is that when an element is referred to as being "on top of" another element, it can be in direct contact with that other element or an inserting element that may exist between them. Conversely, when an element is referred to as being "directly on top of" another element, there is no inserting element.

[0012] It will be understood that although the terms first, second, third, etc., may be used herein to describe different elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are used only to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Therefore, the first element, component, region, layer, or portion discussed below may be referred to as the second element, component, region, layer, or portion without departing from the teachings of this embodiment.

[0013] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a / an” and “the” as used herein are also intended to include the plural forms.

[0014] It will be further understood that, when used in this specification, the terms “comprises” and / or “comprising”, or “includes” and / or “including”, specify the presence of the said features, regions, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components and / or groups thereof.

[0015] Given the measurements discussed and the errors associated with the measurement of a particular quantity (i.e., the limits of the measurement system), the term “about” as used herein includes a specified value and means within an acceptable deviation of a particular value as determined by one of ordinary skill in the art. For example, “about” may mean within one or more standard deviations, or within ±30%, 20%, 10%, or 5% of the specified value.

[0016] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It will be further understood that terms (such as those defined in common dictionaries) shall be interpreted as having the same meaning as they have in the relevant field and in the context of this disclosure, and shall not be construed as having an idealized or overly formal meaning unless expressly defined herein.

[0017] As used herein, unless otherwise defined, the term "hydrocarbon group" refers to an organic compound having at least one carbon atom and at least one hydrogen atom, which is optionally substituted by one or more substituents indicated therein.

[0018] As used herein, unless otherwise defined, the term "alkyl" refers to a group derived from a straight-chain or branched saturated aliphatic hydrocarbon having a specified number of carbon atoms and a valence of at least 1.

[0019] As used herein, unless otherwise defined, the term "hydroxyalkyl" refers to an alkyl group substituted with at least one hydroxyl group (-OH).

[0020] As used herein, unless otherwise defined, the term “alkoxy” means “alkyl-O-”, where the term “alkyl” has the same meaning as “alkyl” above.

[0021] As used herein, unless otherwise defined, the term "alkyloxy" refers to a group having the formula "alkyl-C(=O)-O-", where "alkyl" has the same meaning as "alkyl" as described above.

[0022] As used herein, unless otherwise defined, the term "alkoxycarbonyl" refers to a group having the formula "alkyl-OC(=O)-", where "alkyl" has the same meaning as "alkyl" as described above.

[0023] As used herein, unless otherwise defined, the term "carboxylic acid group" refers to a group having the formula "-C(=O)-OH".

[0024] As used herein, unless otherwise defined, the term "cycloalkyl" refers to a monovalent group having one or more saturated rings, wherein all ring members are carbon.

[0025] As used herein, unless otherwise defined, the term "alkenyl" refers to a straight-chain or branched monovalent hydrocarbon group having at least one carbon-carbon double bond.

[0026] As used herein, unless otherwise defined, the term “alkenoxy” means “alkenyl-O-”, where the term “alkenyl” has the same meaning as “alkenyl” as described above.

[0027] As used herein, unless otherwise defined, the term "aryl" alone or in combination means an aromatic or heteroaromatic hydrocarbon containing at least one ring and having a specified number of carbon atoms. The term "aryl" can be interpreted as comprising a group having an aromatic or heteroaromatic ring fused to at least one cycloalkyl or heterocycloalkyl ring. "Aryl" can include one or more heteroatoms independently selected from nitrogen (N), oxygen (O), phosphorus (P), and sulfur (S).

[0028] As used herein, unless otherwise defined, the term “aryloxy” means “aryl-O-”, where the term “aryl” has the same meaning as “aryl” above.

[0029] As used herein, unless otherwise defined, the term "alkylaryl" refers to an alkyl group covalently linked to a substituted or unsubstituted aryl group connected to the compound.

[0030] As used herein, unless otherwise defined, the term “alkylaryloxy” means “alkylaryl-O-”, where the term “alkylaryl” has the same meaning as “alkylaryl” above.

[0031] monomer

[0032] In one embodiment, a monomer represented by chemical formula (1) is provided: (1).

[0033] In chemical formula (1), X can be a straight-chain or branched C1 to C10 hydrocarbon group, C1 to C10 alkoxy carbonyl group, C1 to C10 alkanoyloxy group, carboxylic acid group, or a straight-chain or branched C1 to C10 hydroxyalkyl group that can be substituted by a C1 to C5 alkoxy carbonyl group or an alkoxy group substituted by a C1 to C5 substituted group.

[0034] In chemical formula (1), Y can be hydrogen, a straight-chain or branched C1 to C10 hydrocarbon group, a C1 to C10 alkoxy carbonyl group, a C1 to C10 alkanoyloxy group, a carboxylic acid group, or a straight-chain or branched C1 to C10 hydroxyalkyl group that can be substituted by a C1 to C5 alkoxy carbonyl group or a C1 to C5 alkoxy group.

[0035] In chemical formula (1), Z can be a straight-chain or branched C1 to C10 hydrocarbon group, C1 to C10 alkoxy carbonyl group, C1 to C10 alkanoyloxy group, carboxylic acid group, or a straight-chain or branched C1 to C10 hydroxyalkyl group that can be replaced by a C1 to C5 alkoxy carbonyl group or a C1 to C5 alkoxy group.

[0036] Groups X, Y, and Z may further include substituents. In some embodiments, each of the C1 to C10 hydrocarbon group, C1 to C10 alkoxycarbonyl group, C1 to C10 alkyloxy group, and C1 to C10 hydroxyalkyl group constituting X, Y, and Z in formula (1) may be substituted with at least one of the following: fluorine, chlorine, bromine, iodine, hydroxyl, C1 to C5 alkyl, C3 to C8 cycloalkyl, C2 to C5 alkenyl, C1 to C5 alkoxy, C2 to C5 alkenyl, C6 to C10 aryl, C6 to C10 aryloxy, C7 to C10 alkylaryl, and C7 to C10 alkylaryloxy.

[0037] In some embodiments, the substituents may be hydroxyl groups. That is, each of X, Y, and Z may include 1, 2, 3, 4, or 5 hydroxyl groups. In other embodiments, the substituents may be carboxylic acid groups. That is, each of X, Y, and Z may include 1, 2, 3, 4, or 5 carboxylic acid groups.

[0038] When Y is hydrogen, the monomer represented by chemical formula (1) can be a secondary alcohol. When Y is a group other than hydrogen, the monomer represented by chemical formula (1) can be a tertiary alcohol.

[0039] Non-limiting examples of monomers represented by chemical formula (1) include the following compounds:

[0040] polymer

[0041] In another embodiment, a polymer is provided comprising repeating units derived from the monomers described above. The characteristics of the polymer can be understood by referring to the aforementioned characteristics of the monomers. In the polymer, at least one selected from X, Y, and Z may comprise a carboxylic acid group.

[0042] Based on the total number of repeating units in the polymer, the amount of repeating units derived from the monomer represented by chemical formula (1) can be 5-30 mol%, for example 10-20 mol.

[0043] The polymer may further comprise repeating units derived from monomers represented by chemical formula (2): (2).

[0044] Non-limiting examples of monomers represented by chemical formula (2) include the following compounds:

[0045] Based on the total number of repeating units in the polymer, the amount of repeating units derived from the monomer represented by chemical formula (2) can be 10-40 mol%, for example 15-30 mol.

[0046] In chemical formula (2), A, B, C, D, E and F can each be independently hydrogen, halogen, hydroxyl, carboxylic acid group, C1 to C10 alkoxy carbonyl, C1 to C10 alkoxy, straight-chain or branched C1 to C10 hydrocarbon group, C1 to C10 alkoxy carbonyl, or C1 to C10 alkyl oxy.

[0047] Each of the C1 to C10 alkoxycarbonyl, C1 to C10 alkoxy, C1 to C10 hydrocarbon, C1 to C10 alkoxycarbonyl, and C1 to C10 alkylyloxy groups constituting A, B, C, D, E, and F may be substituted with at least one of the following groups: fluorine, chlorine, bromine, iodine, C1 to C5 alkyl, C3 to C8 cycloalkyl, C2 to C5 alkenyl, C1 to C5 alkoxy, C2 to C5 alkenyloxy, C6 to C10 aryl, C6 to C10 aryloxy, C7 to C10 alkylaryl, and C7 to C10 alkylaryloxy.

[0048] In chemical formula (2), at least one of A, B, C, D, E and F may contain a hydroxyl group. The number of hydroxyl groups may be 1, 2, 3, 4 or 5, but is not limited thereto.

[0049] In chemical formula (2), at least one of A, B, C, D, E, and F may contain one or more iodine atoms. The number of iodine atoms may be 1, 2, 3, 4, or 5, but is not limited thereto.

[0050] In chemical formula (2), at least one of A, B, C, D, E and F may contain one or more carboxylic acid groups. The number of carboxylic acid groups may be 1, 2, 3, 4 or 5, but is not limited thereto.

[0051] The polymer may further comprise repeating units derived from monomers represented by chemical formula (3): (3).

[0052] In chemical formula (3), K, L, and M may each be independently a straight-chain or branched C1 to C10 hydrocarbon group, C1 to C10 alkoxycarbonyl group, or C1 to C10 alkanoyloxy group, wherein each of these groups may be substituted with a carboxylic acid group. K, L, and M may each be independently a straight-chain or branched C1 to C10 hydroxyalkyl group, which may be substituted with a C1 to C5 alkoxycarbonyl group or a C1 to C5 substituted alkoxy group. At least one of K, L, and M may contain a halogen atom selected from the group consisting of fluorine, chlorine, bromine, and iodine, hydroxyl, carboxyl, or combinations thereof.

[0053] In chemical formula (3), at least one of K, L and M may contain one or more halogen atoms. The number of halogen atoms may be 1, 2, 3, 4 or 5, but is not limited thereto.

[0054] In chemical formula (3), at least one of K, L and M may contain a hydroxyalkyl group. The number of hydroxyl groups in the compound may be 1, 2, 3, 4 or 5, but is not limited thereto.

[0055] In chemical formula (3), at least one of K, L and M may contain one or more carboxylic acid groups. The number of carboxylic acid groups may be 1, 2, 3, 4 or 5, but is not limited thereto.

[0056] Based on the total number of repeating units in the polymer, the amount of repeating units derived from the monomer represented by chemical formula (3) can be 10 to 60 mol%, for example 30 to 50 mol.

[0057] Undercoat composition and film

[0058] Another embodiment provides an undercoating composition comprising a polymer, a crosslinking agent, and a solvent.

[0059] The undercoating composition can be a cross-linked organic film, which can have a significantly reduced thickness. In some embodiments, the dried thickness of the undercoating composition film layer can be about 200 Å or less, about 150 Å or less, about 100 Å or less, about 90 Å or less, about 80 Å or less, about 70 Å or less, about 60 Å or less, or about 50 Å or less. In an exemplary embodiment, the applied undercoating composition can suitably have a thickness of 50 Å or less.

[0060] The method of applying the primer coating composition to the substrate is not particularly limited to methods commonly used in the relevant art. Exemplary methods may include, but are not limited to, dipping, spraying, or spin coating. For example, the primer coating composition may be spin-coated onto the substrate. Alternatively, the coating composition may be spin-coated onto the substrate and then heat-treated to provide a coating composition layer that is at least substantially free of pinholes.

[0061] In some embodiments, the underlying coating composition layer may be suitably heat-treated to remove solvent and to provide a heat-treated coating composition layer having a thickness of 100 Å or less, or 60 Å or 50 Å or less. The heat treatment may be performed under various conditions, such as at a temperature of about 160°C or greater, or about 180°C or greater, or about 200°C or greater, for 30 to 90 seconds.

[0062] The solvent component of the primer composition may be a single solvent or may include a mixture of two or more different solvents. Suitablely, each of the multiple solvents may be miscible with each other.

[0063] The polymer component of the undercoat composition may have a weight-average molecular weight (Mw) of about 1,000 to about 10,000,000 Daltons, for example, about 2,000 to about 10,000 Daltons, and a number-average molecular weight (Mn) of about 500 to about 1,000,000 Daltons, for example, about 2,000 to about 10,000 Daltons. The molecular weight (Mw or Mn) of the polymer in the composition may be suitably determined by gel permeation chromatography.

[0064] In several embodiments, the polymer component may be the major solids component of the undercoating composition. For example, the polymer may suitably be present in an amount of 50 to 99.9% by weight based on the total solids content of the coating composition, such as 80 or 85 to 95% by weight, 98% by weight, or greater than 99 (or even 100) by weight based on the total solids content of the coating composition. As used herein, “solids content” of a coating composition refers to all materials of the coating composition other than the solvent carrier.

[0065] Suitable polymers and polymer films for use in the underlying coating compositions of the present invention can be readily prepared based on the procedures described in the examples of this application and by analogy with the procedures described in the examples of this application, as will be readily understood by those skilled in the art.

[0066] As discussed above, in some embodiments, in addition to or as a component of the resin, the coating composition may contain a crosslinking agent. For example, the coating composition may contain amine-based crosslinking agents, such as melamine materials, including melamine resins manufactured by Cytec Industries and sold under the trade names Cymel 300, 301, 303, 350, 370, 380, 1116, and 1130; glycoureas, including those glycoureas available from Cytec Industries; and phenylmelamine and urea-based materials, including resins such as phenylmelamine resins available from Cytec Industries under the names Cymel 1123 and 1125, and urea resins available from Cytec Industries under the names Powderlink 1174 and 1196. In addition to being commercially available, such amine-based crosslinking agents can be prepared, for example, by reacting acrylamide or methacrylamide copolymers with formaldehyde in a solution containing alcohol, or alternatively by copolymerizing N-alkoxymethacrylamide or methacrylamide with other suitable monomers.

[0067] The undercoat composition may also contain additional dye compounds that absorb radiation used to expose the photoresist layer on the outer coating.

[0068] The undercoat composition may further contain other materials, such as one or more acid generators, including one or more thermal acid generators and / or photoacid generators. Suitable photoacid generators used in the undercoat composition include those disclosed herein for use in photoresist compositions for top coating. For a discussion of this use of photoacid generators in undercoat compositions, see U.S. Patent 6,261,743.

[0069] To prepare a liquid undercoat composition, the components of the composition can be dissolved in a suitable solvent, such as one or more oxyisobutyrates, particularly methyl-2-hydroxyisobutyrate, ethyl lactate, or glycol ethers, such as 2-methoxyethyl ether (diethylene glycol dimethyl ether), ethylene glycol monomethyl ether, and propylene glycol monomethyl ether; solvents having both ether and hydroxyl moieties, such as methoxybutanol, ethoxybutanol, methoxypropanol, and ethoxypropanol; methyl 2-hydroxyisobutyrate; esters, such as methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and other solvents, such as diesters, propylene carbonate, and γ-butyrolactone.

[0070] As discussed, the solvent component may contain one or more solvents having a boiling point of 200°C or greater. In some embodiments, solvents having a boiling point greater than 200°C include γ-butyrolactone, N-methylpyrrolidone, and benzyl benzoate.

[0071] As also discussed, a base coat composition is provided comprising at least 0.5 or 1% by weight of one or more solvents having a boiling point of 200°C or greater, such as one or more of the following: γ-butyrolactone; N-methylpyrrolidone; and / or benzyl benzoate. In some aspects, the base coat composition will contain no more than 70, 60, 50, 40, 30, 20, or 10% of one or more solvents having a boiling point of 200°C or greater (such as γ-butyrolactone; N-methylpyrrolidone; and / or benzyl benzoate), based on the total weight of the solvents present in the coating composition.

[0072] The concentration of the dry component in the solvent will depend on several factors, such as the application method. Typically, the solids content of the undercoat composition varies from about 0.1 to 20% by weight of the total weight of the coating composition, preferably from about 0.1 to 10% by weight of the coating composition.

[0073] The undercoat composition can be formulated with one or more photoacid generators. Suitable photoacid generators for use in the undercoat composition include those disclosed herein for use in photoresist compositions for top coating. For a discussion of this use of photoacid generators in undercoat compositions, see U.S. Patent 6,261,743. For example, the photoacid generator can be a small molecule compound having chemical formula (IV): Chemical formula (IV) G + Z - Wherein G has the chemical formula (V): Chemical formula (V) .

[0074] In the chemical formula (V), X can be either S or I. Each R 0 Attached to X and can be C independently 1-30 Alkyl; polycyclic or monocyclic C 3-30 Cycloalkyl; polycyclic or monocyclic C 6-30 Aryl; or a combination of at least one of the foregoing. r5 can be 2 or 3, provided that r5 is 2 when X is I, and 2 or 3 when X is S. In formula (IV), Z can include the anion of sulfonic acid, sulfonamide, or sulfonamide.

[0075] For example, cation G + It can have chemical formulas (VI), (VII), or (VIII):

[0076] in

[0077] X is either I or S. R h R i R j and R k It is either unsubstituted or substituted and each independently is a hydroxyl group, nitrile, halogen, or C. 1-30 Alkyl, C 1-30 fluoroalkyl, C 3-30 cycloalkyl, C 1-30 Fluorocycloalkyl, C 1-30 Alkoxy, C 3-30 alkoxycarbonylalkyl, C 3-30 Alkoxycarbonylalkoxy, C 3-30 Cycloalkoxy, C 5-30 Cycloalkoxycarbonylalkyl, C 5-30 Cycloalkoxycarbonylalkoxy, C 1-30 fluoroalkoxy, C 3-30 fluoroalkoxycarbonylalkyl, C 3-30 Fluoroalkoxycarbonylalkoxy, C 3-30 Fluorocycloalkoxy, C 5-30 Fluorocycloalkoxycarbonylalkyl, C 5-30 Fluorocycloalkoxycarbonylalkoxy, C 6-30 Aryl, C 6-30 Fluoroaryl, C 6-30 aryloxy group, or C 6-30 Fluoroaryloxy groups, each of which is either unsubstituted or substituted; Ar 1 and Ar 2 C is independent 10-30 Fused or single-bonded polycyclic aryl groups; R l It is a lone pair of electrons, where X is I or C. 6-20 Aryl, where X is S; p is an integer of 2 or 3, where p is 2 when X is 1 and p is 3 when X is S. q and r are each independent integers from 0 to 5, and s and t are each independent integers from 0 to 4.

[0078] In chemical formulas (VI), (VII), and (VIII), R h R i R j and R k At least one of them can be an acid-cleavable group. In one embodiment, the acid-cleavable group can be (i) tert-C 1-30 Alkoxy (e.g., tert-butoxy), tert-C 3-30Cycloalkoxy, tertiary C 1-30 fluoroalkoxy, (ii) tertiary C 3-30 Alkoxycarbonylalkyl, tert-C 5-30 Cycloalkoxycarbonylalkyl, tertiary C 3-30 fluoroalkoxycarbonylalkyl, (iii) tertiary C 3-30 Alkoxycarbonylalkoxy, tertiary C 5-30 Cycloalkoxycarbonylalkoxy, tertiary C 3-30 Fluoroalkoxycarbonylalkoxy, or (iv) including part-OC(R) 11 R 12 )-O- of C 2-30 acetal group (where R) 11 R 12 Each is independently either hydrogen or C. 1-30 alkyl).

[0079] Non-limiting examples of photoacid generators include the following compounds: .

[0080] The amount of photoacid generator can be 1-15% by weight, for example 4-10% by weight, based on the total weight of the composition.

[0081] Other components of photoresist may include solvents and surfactants.

[0082] Solvents typically suitable for dissolving, dispensing, and coating components may include anisole, alcohols (including ethyl lactate, methyl 2-hydroxybutyrate (HBM), 1-methoxy-2-propanol (also known as propylene glycol methyl ether, PGME), and 1-ethoxy-2-propanol), esters (including n-butyl acetate, 1-methoxy-2-propyl acetate (also known as propylene glycol methyl ether acetate, PGMEA), methoxyethoxypropionate, ethoxyethoxypropionate, and γ-butyrolactone), ketones (including cyclohexanone and 2-heptanone), and combinations comprising at least one of the foregoing solvents.

[0083] Coated substrate

[0084] The undercoating compositions disclosed herein can be used to form films comprising the undercoating compositions, wherein the films on a substrate constitute a coated substrate. Such a coated substrate may include: (a) a substrate having one or more layers to be patterned on its surface; (b) a layer of the undercoating composition disposed on the substrate; and (c) a layer of photoresist composition disposed on the layer of the undercoating composition or on one or more layers to be patterned. For example, patterning can be performed using ultraviolet radiation at wavelengths less than 248 nm, and particularly 193 nm, or by using EUV. The patternable film may therefore include a photoacid generator.

[0085] Methods of forming electronic devices

[0086] Therefore, a method of forming an electronic device may include: (a) coating a substrate with a layer of the undercoating composition; (b) curing the undercoating composition to form an undercoating film; (c) applying a layer of photoresist composition onto the undercoating film to form a photoresist layer; (d) exposing the photoresist layer to radiation in a patterned manner; and (e) developing the exposed photoresist layer to provide a photoresist relief image.

[0087] The substrate can have any size and shape, and can be, for example, those suitable for photolithography, such as silicon, silicon dioxide, silicon on insulator (SOI), strained silicon, gallium arsenide, coated substrates including those coated with silicon nitride, silicon oxynitride, titanium nitride, tantalum nitride, ultrathin gate oxides (such as hafnium oxide), metallic or metal-coated substrates including those coated with titanium, tantalum, copper, aluminum, tungsten and their alloys, and combinations thereof. For example, the surface of the substrate herein includes a critical dimension layer to be patterned, including one or more gate layers or other critical dimension layers on a substrate, for example, for semiconductor manufacturing. Such substrates can, for example, include silicon, SOI, strained silicon and other such substrate materials, formed into circular wafers having dimensions such as 200 mm, 300 mm or larger diameters, or other sizes suitable for wafer manufacturing production.

[0088] The resist undercoat composition according to embodiments of the present invention provides additional acid to the interface through a novel polymer structure and photoacid with high EUV absorption, thereby improving the light velocity and scum / foot profile of the EUV photoresist. Through the same mechanism, nanobridge defects observed after all pattern transfers can be significantly reduced compared to photoresists on CVD hard mask stacks.

[0089] The present disclosure is illustrated in more detail below with reference to examples. However, these examples are exemplary and the present disclosure is not limited thereto.

[0090] Example

[0091] Polymer Synthesis

[0092] Polymer Example 1

[0093] A 250 mL three-necked round-bottom flask was charged with tris(hydroxyethyl) isocyanurate (15.24 g), tris(carboxyethyl) isocyanurate (14.26 g), citric acid (11.21 g), 1,2-propanediol (5.33 g), propylene glycol monomethyl ether (10.0 g), anisole (50.0 g), and p-toluenesulfonic acid (0.44 g). The flask was connected to a condenser equipped with a Dean-Stark water separator and thermometer to measure and control the solution temperature throughout the polymerization. The flask was placed in a silicone oil bath equipped with a magnetic stirrer. The reactor temperature was set at 150°C and maintained for 4 hours. Thereafter, the reactor was cooled to room temperature while stirring. The polymer solution was precipitated in a tenfold excess of isopropanol, and the polymer was recovered by filtration and vacuum drying at 40°C for 24 hours. The dried powder was redissolved in tetrahydrofuran and then precipitated from a tenfold excess of isopropanol. The white product was filtered and dried in a vacuum oven at 40°C for 24 hours.

[0094] Polymer Example 2

[0095] A 250 mL three-necked round-bottom flask was charged with tris(hydroxyethyl) isocyanurate (14.28 g), tris(carboxyethyl) isocyanurate (18.88 g), 1,2-propanediol (9.25 g), 2-hydroxyisobutyric acid (7.59 g), anisole (50.0 g), and p-toluenesulfonic acid (0.58 g). The flask was connected to a condenser equipped with a Dean-Stark water separator and thermometer to measure and control the solution temperature throughout the polymerization. The flask was placed in a silicone oil bath equipped with a magnetic stirrer. The reactor temperature was set at 150°C and maintained for 4 hours. After this time, the reactor was cooled to room temperature while stirring. The polymer solution was precipitated in a tenfold excess of isopropanol, and the polymer was recovered by filtration and vacuum drying at 40°C for 24 hours. The dried powder was redissolved in tetrahydrofuran and then precipitated from a tenfold excess of isopropanol. The dried powder was redissolved in tetrahydrofuran and precipitated from a tenfold excess of isopropanol. The white product was filtered and dried in a vacuum oven at 40°C for 24 hours.

[0096] Polymer Example 3

[0097] To a 250 mL three-necked round-bottom flask, add tris(hydroxyethyl) isocyanurate (29.26 g), dimethyl-5-hydroxyisophthalate (10.10 g), 2-hydroxyisobutyric acid (10.00 g), anisole (44.61 g), and p-toluenesulfonic acid (0.99 g). Connect the flask to a condenser equipped with a Dean-Stark water separator and thermometer to measure and control the solution temperature throughout the polymerization. Place the flask in a silicone oil bath equipped with a magnetic stirrer. Set the reactor temperature to 150°C and maintain it for 8 hours. After this time, cool the reactor to 40°C while stirring. Dilute the resulting mixture by adding methyl 2-hydroxyisobutyrate (approximately 20% by weight).

[0098] A 250 mL three-necked round-bottom flask was charged with the reaction mixture (131.80 g), tetramethoxymethyl glycourea (6.49 g), and p-toluenesulfonic acid (the free p-toluenesulfonic acid content in the reaction mixture was analyzed prior to the reaction and then adjusted to 75 ppm based on solution weight). The flask was equipped with a nitrogen inlet, a water-cooled condenser, and a thermometer to measure and control the solution temperature throughout the polymerization. The flask was placed in a silicone oil bath equipped with a magnetic stirrer. The reactor temperature was set at 70°C and maintained for 5 hours. After the reaction was complete, the reactor was cooled to room temperature while stirring. The polymer solution was precipitated in a tenfold excess of isopropanol, and the polymer was recovered by filtration and vacuum drying at 50°C for 24 hours.

[0099] Polymer Example 4

[0100] A 250 mL three-necked round-bottom flask was charged with tris(hydroxyethyl) isocyanurate (11.37 g), tris(carboxyethyl) isocyanurate (15.03 g), diiodosalicylic acid (16.98 g), 1,2-propanediol (6.63 g), propylene glycol monomethyl ether (10.0 g), anisole (50.0 g), and p-toluenesulfonic acid (0.41 g). The flask was connected to a condenser equipped with a Dean-Stark water separator and thermometer to measure and control the solution temperature throughout the polymerization. The flask was placed in a silicone oil bath equipped with a magnetic stirrer. The reactor temperature was set at 150°C and maintained for 3 hours. After this time, the reactor was cooled to room temperature while stirring. The polymer solution was precipitated in a ten-fold excess of isopropanol, and the polymer was recovered by filtration and vacuum drying at 40°C for 24 hours. The dried powder was redissolved in tetrahydrofuran and then precipitated from a tenfold excess of isopropanol. The white product was filtered and dried in a vacuum oven at 40°C for 24 hours.

[0101] Polymer Example 5

[0102] A 250 mL three-necked round-bottom flask was charged with tris(hydroxyethyl) isocyanurate (15.24 g), citric acid (11.21 g), diiodosalicylic acid (18.21 g), 1,2-propanediol (5.33 g), propylene glycol monomethyl ether (10.0 g), anisole (50.0 g), and p-toluenesulfonic acid (0.44 g). The flask was connected to a condenser equipped with a Dean-Stark water separator and thermometer to measure and control the solution temperature throughout the polymerization. The flask was placed in a silicone oil bath equipped with a magnetic stirrer. The reactor temperature was set at 150°C and maintained for 3 hours. After this time, the reactor was allowed to cool to room temperature while stirring. The polymer solution was precipitated in a tenfold excess of isopropanol, and the polymer was recovered by filtration and vacuum drying at 40°C for 24 hours. The dried powder was redissolved in tetrahydrofuran and then precipitated from a tenfold excess of isopropanol. The dried powder was redissolved in tetrahydrofuran and then precipitated from a tenfold excess of isopropanol. The white product was filtered and dried in a vacuum oven at 40°C for 24 hours.

[0103] Polymer Example 6

[0104] Add glycerol (5.41 g), tris(carboxymethyl)isocyanurate (35.64 g), 1,2-propanediol (8.95 g), anisole (50.0 g), and p-toluenesulfonic acid (0.56 g) to a 250 mL three-necked round-bottom flask. Connect the flask to a condenser equipped with a Dean-Stark water separator and thermometer to measure and control the solution temperature throughout the polymerization. Place the flask in a silicone oil bath equipped with a magnetic stirrer. Set the reactor temperature to 150°C and maintain it for 2 hours. After this time, allow the reactor to cool to room temperature while stirring. Precipitate the polymer solution in a tenfold excess of isopropanol and recover the polymer by filtration and vacuum drying at 40°C for 24 hours. Redissolve the dried powder in tetrahydrofuran and then precipitate it from a tenfold excess of isopropanol. The white product was filtered and dried in a vacuum oven at 40°C for 24 hours.

[0105] Comparative Polymer Example 1

[0106] A 3-necked 100 mL round-bottom flask was equipped with a thermocouple, a Dean-Stark water separator, a condenser, and a heated oil bath. Tris(2-hydroxyethyl) isocyanurate (30.4 g), tris(2-carboxyethyl) isocyanurate (20.1 g, 58.2 mmol), n-butanol (20.0 g, 270.0 mmol), p-toluenesulfonic acid (0.5 g, 2.8 mmol), and 34 g anisole were weighed into the flask. The reaction mixture was heated to 150°C for 3 hours with stirring, cooled to room temperature, and the solution was precipitated with isopropanol / heptane, filtered, and dried under vacuum at 40°C for 24 hours.

[0107] Preparation of photoacid generator (PAG)

[0108] PAG Synthesis Example 1

[0109] A solution of bis(4-tert-butylphenyl)iodonium chloride (1.000 g, 2.332 mmol) in dichloromethane (10 mL) and another solution of lithium nonafluoro-1-butanesulfonate (1.142 g, 3.732 mmol) in H₂O (10 mL) were added to a clean 100 mL round-bottom flask equipped with a stir bar. The reaction mixture was stirred overnight at room temperature. The organic layer was separated and washed three times with 5 mL H₂O. The solvent was evaporated under reduced pressure and the resulting solid was dried in a vacuum oven. 1.425 g (88%) of the product as a white solid was obtained. 1 H NMR (600 MHz, DMSO- d 6) δ (ppm) = 8.16 (dt,4H), 7.55 (dt, 4H), 1.26 (s, 18H). 19 F NMR (564.686 MHz, DMSO- d 6) δ (ppm) = -80.42 (t, 3F), -114.82 (t, 2F), -121.37 (q, 2F), -125.66 (t, 2F).

[0110] PAG Synthesis Example 2

[0111] A solution of diphenyliodonium trifluoromethane sulfate (1.024 g, 2.380 mmol) in dichloromethane (10 mL) and another solution of lithium nonafluoro-1-butane sulfate (1.093 g, 3.571 mmol) in H₂O (10 mL) were added to a clean 100 mL round-bottom flask equipped with a stir bar. The reaction mixture was stirred overnight at room temperature. The organic layer was separated and washed three times with 5 mL H₂O. The solvent was evaporated under reduced pressure and the resulting solid was dried in a vacuum oven. 1.100 g (80%) of the product as a white solid was obtained. 1 H NMR (600 MHz, DMSO- d 6) δ (ppm) = 8.26-8.24(m, 4H), 7.67 (tt, 2H), 7.54 (tt, 4H). 19 F NMR (565 MHz, DMSO- d 6) δ (ppm) = -80.42 (t, 3F), -114.82 (t, 2F), -121.37 (q, 2F), -125.66 (t, 2F).

[0112] PAG Synthesis Example 3

[0113] A solution of bis(4-fluorophenyl)iodonium trifluoromethane sulfate (1.000 g, 2.145 mmol) in dichloromethane (10 mL) and another solution of lithium nonafluoro-1-butane sulfate (1.050 g, 3.432 mmol) in H₂O (10 mL) were added to a clean 100 mL round-bottom flask equipped with a stir bar. The reaction mixture was stirred overnight at room temperature. The organic layer was separated and washed three times with 5 mL H₂O. The solvent was evaporated under reduced pressure and the resulting solid was dried in a vacuum oven. 1.144 g (87%) of the product as a white solid was obtained. 1 H NMR (600 MHz, DMSO- d 6) δ (ppm) = 8.35-8.32(m, 4H), 7.45-7.41 (m, 4H). 19 F NMR (565 MHz, DMSO- d 6) δ (ppm) = -80.41 (t,3F), -106.63 (t, 2F), -114.82 (t, 2F), -121.37 (q, 2F), -125.66 (t, 2F).

[0114] PAG Synthesis Example 4

[0115] A solution of bis(4-tert-butylphenyl)iodonium chloride (20.000 g, 46.644 mmol) in dichloromethane (250 mL) and another solution of Na-AdOHDFMS (25.350 g, 69.966 mmol) in H₂O (250 mL) were added to a clean 1 L round-bottom flask equipped with a stir bar. The reaction mixture was stirred overnight at room temperature. The organic layer was separated and washed three times with 150 mL H₂O. The solvent was evaporated under reduced pressure and the resulting solid was dried in a vacuum oven. 30.305 g (89%) of the product as a white solid was obtained. 1 H NMR (600 MHz, DMSO- d 6) δ (ppm) = 8.15 (dt,4H), 7.55 (dt, 4H), 4.42 (s, 1H), 3.86 (s, 2H), 2.09 (m, 2H), 1.53-1.36 (m,12H), 1.27 (s, 18H).

[0116] PAG Synthesis Example 5

[0117] Add a solution of bis(4-fluorophenyl)iodonium trifluoromethanesulfonate (3.19 g, 6.83 mmol) in dichloromethane (100 mL) and another solution of sodium 1,1-difluoro-2-(((1r,3s,5R,7S)-3-hydroxyadamantane-1-yl)methoxy)-2-oxoethane-1-sulfonate (2.338 g, 10.26 mmol) in deionized water to a clean 250 mL round-bottom flask equipped with a stir bar. After stirring at room temperature for 16 hours, remove the H₂O layer. Take the crude NMR spectrum of the intermediate to check the reaction progress. Add more solution containing sodium 1,1-difluoro-2-(((1r,3s,5R,7S)-3-hydroxyadamantane-1-yl)methoxy)-2-oxoethane-1-sulfonate (1.6 g, 5.1 mmol). After stirring at room temperature for 16 hours, 0.31 g of sodium 1,1-difluoro-2-(((1r,3s,5R,7S)-3-hydroxyadamantane-1-yl)methoxy)-2-oxoethane-1-sulfonate was added. The aqueous and organic phases were separated. The organic phase was washed three times with water (15 mL) and the solvent was removed under reduced pressure. A product as a solid – 3.9 g (86%) was obtained. 1 HNMR (600 MHz, DMSO-d6): δ (ppm) 8.32(m, 4H), 7.42(m, 4H), 4.43(s, 1H), 3.86(s, 2H), 2.09(m, 2H), 1.53-1.38(m, 12H).19 F NMR (564 MHz, DMSO-d6): δ (ppm) -106.66(s, 2H), -109.00(s, 2H).

[0118] PAG Synthesis Example 6

[0119] A solution of diphenyliodonium trifluoromethanesulfonate (1 g, 2.34 mmol) in dichloromethane (30 mL) and another solution of sodium 1,1-difluoro-2-(((1r,3s,5R,7S)-3-hydroxyadamantane-1-yl)methoxy)-2-oxoethane-1-sulfonate (1.7 g, 4.69 mmol) in deionized water (15 mL) were added to a clean 100 mL round-bottom flask equipped with a stir bar. After stirring at room temperature for 16 hours, the H₂O layer was removed. The reaction progress was examined using a crude NMR spectrum of the intermediate. Further solution containing sodium 1,1-difluoro-2-(((1R,3S,5R,7S)-3-hydroxyadamantane-1-yl)methoxy)-2-oxoethane-1-sulfonate (0.43 g, 1.17 mmol) was added. After stirring at room temperature for 16 hours, the aqueous and organic phases were separated. The organic phase was washed eight times with water (7 mL) and the solvent was removed under reduced pressure. A product in solid form was obtained – 0.8 g (55%). 1 H NMR (600 MHz, DMSO-d6): δ (ppm) 8.24(m, 4H), 7.67(m, 2H), 7.54(m, 4H), 4.42(s, 1H), 3.86(s,2H), 2.09(m, 2H), 1.55-1.38(m, 12H). 19 F NMR (564 MHz, DMSO-d6): δ (ppm) -109.00 (s, 2H).

[0120] Reduction potential measurement of PAG

[0121] Electrochemical experiments were performed using a BASi Epsilon potentiostat equipped with a platinum working electrode, a platinum wire auxiliary electrode, and an Ag / AgCl reference electrode. All instruments (electrodes, analytical chamber, and stir bar) were cleaned with acetone before each use. The electrolyte solution consisted of 0.1 M tetrabutylammonium hexafluorophosphate (TBAH) in anhydrous acetonitrile. After purging, baseline readings were obtained before adding 10⁻³ M of the analyte (PAG in this case) to the solution. Measurements were taken across an electrochemical potential window of 0 to -2.0 V relative to Ag / AgCl. The potential scan rate was 0.1 V / s with a step size of 0.01 V. The results are summarized in Table 1.

[0122] Table 1

[0123] Preparation of primer coating composition

[0124] Composition Example 1

[0125] 0.24 g of the polymer from Example 1, 0.02 g of tetramethoxymethylglycolurea as a crosslinking agent, and 0.003 g of 2,4,6-trimethylpyridinium p-toluenesulfonate were dissolved in a mixture of 27.9 g of methyl-2-hydroxyisobutyrate, 69.8 g of propylene glycol monomethyl ether acetate, and 2 g of γ-butyrolactone solvent to obtain a solution. The solution was then filtered through a PTFE 0.45 micron membrane filter.

[0126] Composition Example 2

[0127] 0.20 g of the polymer from Example 2, 0.02 g of tetramethoxymethylglycolurea as a crosslinking agent, and 0.003 g of 2,4,6-trimethylpyridinium p-toluenesulfonate were dissolved in a mixture of 27.9 g of methyl-2-hydroxyisobutyrate, 69.8 g of propylene glycol monomethyl ether acetate, and 2 g of γ-butyrolactone solvent to obtain a solution. The solution was then filtered through a PTFE 0.45 micron membrane filter.

[0128] Composition Example 3

[0129] 0.20 g of the polymer from Example 3, 0.02 g of tetramethoxymethylglycolurea as a crosslinking agent, and 0.003 g of 2,4,6-trimethylpyridinium p-toluenesulfonate were dissolved in a mixture of 27.9 g of methyl-2-hydroxyisobutyrate, 69.8 g of propylene glycol monomethyl ether acetate, and 2 g of γ-butyrolactone solvent to obtain a solution. The solution was then filtered through a PTFE 0.45 micron membrane filter.

[0130] Composition Example 4

[0131] 0.20 g of the polymer from Example 3, 0.02 g of tetramethoxymethylglycolurea as a crosslinking agent, 0.003 g of 2,4,6-trimethylpyridinium p-toluenesulfonate, and 0.03 g of PAG 1 were dissolved in a mixture of 27.9 g of methyl-2-hydroxyisobutyrate, 69.8 g of propylene glycol monomethyl ether acetate, and 2 g of γ-butyrolactone solvent to obtain a solution. The solution was then filtered through a PTFE 0.45 micron membrane filter.

[0132] Comparative Composition Example 1

[0133] 0.15 g of the comparative polymer of Example 1, 0.01 g of tetramethoxymethylglycolurea as a crosslinking agent, and 0.002 g of 2,4,6-trimethylpyridinium p-toluenesulfonate were dissolved in a mixture of 97.8 g of methyl-2-hydroxyisobutyrate and 2 g of γ-butyrolactone solvent to obtain a solution. The solution was then filtered through a PTFE 0.45 micron membrane filter.

[0134] Resist pattern formation test

[0135] All prepared compositions were spin-coated onto a silicon wafer at 1,500 rpm using a spinner, and the wafer was heated on a hot plate at 205°C for 1 minute to form a thin film (5 nm thick) for electron beam lithography. A resist solution (a positive-type chemically amplified electron beam resist based on methacrylate) was applied to the resist underlayer for electron beam lithography using a spinner, and the wafer was heated on a hot plate to form a resist film (40 nm thick). The operating dose of the 40 nm patterned resist on the underlayer was evaluated by direct electron beam writing using an electron beam lithography tool (JBX 9300FS, 100 keV, JOEL, Japan).

[0136] Table 2

[0137] The examples in this invention demonstrate E that is significantly faster than conventional underlying systems (comparative examples). op This demonstrates the additional acid generation concept through specific functional portions of the polymer and PAG in this invention. Electron beam lithography was used as the testing method because the patterning mechanism of CAR in an electron beam is the same as that in EUV lithography. The top-view profile also verifies the advantages of this invention. The working example of this invention does not show slag and bridging, while the photoresist on the comparative example exhibits severe bridging on the L / S pattern.

[0138] While this disclosure has been described in conjunction with exemplary embodiments now considered to be practical, it should be understood that the invention is not limited to the disclosed embodiments, but rather is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A base coat composition for EUV lithography, comprising: A polymer comprising repeating units, wherein the repeating units are composed of the following: Derived from the repeating unit of the monomer represented by chemical formula (1): (1) in, X is a straight-chain or branched C1 to C10 hydrocarbon group, carboxylic acid group, or a straight-chain or branched C1 to C10 hydroxyalkyl group; Y is hydrogen, a straight-chain or branched C1 to C10 hydrocarbon group, a carboxylic acid group, or a straight-chain or branched C1 to C10 hydroxyalkyl group; and Z is a straight-chain or branched C1 to C10 hydrocarbon group, carboxylic acid group, or a straight-chain or branched C1 to C10 hydroxyalkyl group. Each of the C1 to C10 hydrocarbon groups and the C1 to C10 hydroxyalkyl groups is optionally substituted with at least one of the following groups: hydroxyl, carboxylic acid groups, C1 to C5 alkyl groups, and C3 to C8 cycloalkyl groups. The prerequisite is that at least one of X, Y, and Z is: A straight-chain or branched C1 to C10 hydrocarbon group substituted with at least one of the following groups: hydroxyl and carboxylic acid groups. Carboxylic acid group, or Straight-chain or branched C1 to C10 hydroxyalkyl groups; Derived from the repeating unit of the monomer represented by chemical formula (2): (2) in, A, B, C, D, E, and F are each independently hydrogen, halogen, hydroxyl, carboxylic acid group, C1 to C10 alkoxy group, straight-chain or branched C1 to C10 hydrocarbon group, C1 to C10 alkoxycarbonyl group, or C1 to C10 alkyloxy group. Each of the C1 to C10 alkoxy, the C1 to C10 hydrocarbon, the C1 to C10 alkoxycarbonyl, and the C1 to C10 alkanoyloxy is optionally substituted with at least one of the following: fluorine, chlorine, bromine, iodine, C1 to C5 alkyl, and C3 to C8 cycloalkyl. The prerequisite is that at least one of the choices A, B, C, D, E, and F is a hydroxyl group, and At least two items selected from A, B, C, D, E, and F are independently selected from the following group: hydroxyl, Carboxylic acid group, A straight-chain or branched C1 to C10 hydrocarbon group substituted with at least one of the following groups: C2 to C5 alkenyl, C1 to C5 alkoxy, and C2 to C5 alkenyloxy. C1 to C10 alkoxycarbonyl groups, and C1 to C10 alkyl acyloxy groups; Derived from the repeating unit of the monomer represented by chemical formula (3): (3) in, K, L, and M are each independently a straight-chain or branched C1 to C10 hydrocarbon group, a C1 to C10 alkoxycarbonyl group, a C1 to C10 alkanoyloxy group, or a straight-chain or branched C1 to C10 hydroxyalkyl group optionally substituted with a C1 to C5 alkoxycarbonyl group or a C1 to C5 substituted alkoxy group, each of which is optionally substituted with a carboxylic acid group. Each of the C1 to C10 hydrocarbon group, the C1 to C10 alkoxycarbonyl group, the C1 to C10 alkanoyloxy group, and the C1 to C10 hydroxyalkyl group is optionally substituted with at least one of the following: fluorine, chlorine, bromine, iodine, C1 to C5 alkyl, and C3 to C8 cycloalkyl. Of these, at least two of the selections from K, L, and M are independently selected from the following group: A straight-chain or branched C1 to C10 hydrocarbon group substituted with at least one of the following groups: carboxylic acid group, C2 to C5 alkenyl group, C1 to C5 alkoxy group, and C2 to C5 alkenyl group. C1 to C10 alkoxycarbonyl groups optionally substituted with carboxylic acid groups C1 to C10 alkanoyloxy groups optionally substituted with carboxylic acid groups, and Straight-chain or branched C1 to C10 hydroxyalkyl groups optionally substituted with C1 to C5 alkoxycarbonyl groups or C1 to C5 substituted alkoxy groups; and Based on the total solids content of the undercoat composition, 4 to 15% by weight of a photoacid generator containing iodonium cations.

2. The primer coating composition as described in claim 1, wherein, In chemical formula (2), at least one of A, B, C, D, E and F contains iodine.

3. The primer coating composition as described in claim 1, wherein, In chemical formula (3), at least one of K, L and M contains a hydroxyalkyl group.

4. The primer coating composition as claimed in claim 1, wherein, Photoacid generators contain iodonium cations, wherein the iodonium cations are selected from the group consisting of: and .

5. The primer composition as claimed in claim 1, wherein, The photoacid generator is selected from at least one of the following substances: 。 6. A coated substrate comprising: A layer of the undercoating composition as described in claim 1 disposed on a substrate, and A photoresist layer disposed on the layer of the underlying coating composition.

7. A method of forming an electronic device, the method comprising: (a) Applying a layer of the undercoating composition as described in claim 1 onto a substrate; (b) Curing the undercoat composition to form an undercoat film; (c) Applying a layer of the photoresist composition onto the underlying film to form a photoresist layer; (d) exposing the photoresist layer to radiation in a patterned manner; and (e) Develop the exposed photoresist layer to provide a photoresist relief image.

8. A method of forming an electronic device, the method comprising: (a) Apply a layer of the primer coating composition to the substrate; (b) Curing the undercoat composition to form an undercoat film with a thickness of 200 angstroms or less; (c) Applying a layer of the photoresist composition onto the underlying film to form a photoresist layer; (d) Expose the photoresist layer to EUV radiation in a patterned manner; as well as (e) Develop the exposed photoresist layer to provide a photoresist relief image. The underlying coating composition comprises: A polymer comprising repeating units, wherein the repeating units are composed of the following: Derived from the repeating unit of the monomer represented by chemical formula (1): (1) in, X is a straight-chain or branched C1 to C10 hydrocarbon group, carboxylic acid group, or a straight-chain or branched C1 to C10 hydroxyalkyl group; Y is hydrogen, a straight-chain or branched C1 to C10 hydrocarbon group, a carboxylic acid group, or a straight-chain or branched C1 to C10 hydroxyalkyl group; and Z is a straight-chain or branched C1 to C10 hydrocarbon group, carboxylic acid group, or a straight-chain or branched C1 to C10 hydroxyalkyl group. Each of the C1 to C10 hydrocarbon groups and the C1 to C10 hydroxyalkyl groups is optionally substituted with at least one of the following groups: hydroxyl, carboxylic acid group, C1 to C5 alkyl, and C3 to C8 cycloalkyl. The prerequisite is that at least one of X, Y, and Z is: A straight-chain or branched C1 to C10 hydrocarbon group substituted with at least one of the following groups: hydroxyl group, and carboxylic acid group. Carboxylic acid group, or Straight-chain or branched C1 to C10 hydroxyalkyl groups; Derived from the repeating unit of the monomer represented by chemical formula (2): (2) in, A, B, C, D, E, and F are each independently hydrogen, halogen, hydroxyl, carboxylic acid group, C1 to C10 alkoxy group, straight-chain or branched C1 to C10 hydrocarbon group, C1 to C10 alkoxycarbonyl group, or C1 to C10 alkyloxy group. Each of the C1 to C10 alkoxy, the C1 to C10 hydrocarbon, the C1 to C10 alkoxycarbonyl, and the C1 to C10 alkanoyloxy is optionally substituted with at least one of the following: fluorine, chlorine, bromine, iodine, C1 to C5 alkyl, and C3 to C8 cycloalkyl. The prerequisite is that at least one of the choices A, B, C, D, E, and F is a hydroxyl group, and At least two items selected from A, B, C, D, E, and F are independently selected from the following group: hydroxyl, Carboxylic acid group, A straight-chain or branched C1 to C10 hydrocarbon group substituted with at least one of the following groups: C2 to C5 alkenyl, C1 to C5 alkoxy, and C2 to C5 alkenyloxy. C1 to C10 alkoxycarbonyl groups, and C1 to C10 alkyl acyloxy groups; Derived from the repeating unit of the monomer represented by chemical formula (3): (3) in, K, L, and M are each independently a straight-chain or branched C1 to C10 hydrocarbon group, a C1 to C10 alkoxycarbonyl group, a C1 to C10 alkanoyloxy group, or a straight-chain or branched C1 to C10 hydroxyalkyl group optionally substituted with a C1 to C5 alkoxycarbonyl group or a C1 to C5 substituted alkoxy group, each of which is optionally substituted with a carboxylic acid group. Each of the C1 to C10 hydrocarbon group, the C1 to C10 alkoxycarbonyl group, the C1 to C10 alkanoyloxy group, and the C1 to C10 hydroxyalkyl group is optionally substituted with at least one of the following: fluorine, chlorine, bromine, iodine, C1 to C5 alkyl, and C3 to C8 cycloalkyl. Of these, at least two of the selections from K, L, and M are independently selected from the following group: A straight-chain or branched C1 to C10 hydrocarbon group substituted with at least one of the following groups: carboxylic acid group, C2 to C5 alkenyl group, C1 to C5 alkoxy group, and C2 to C5 alkenyl group. C1 to C10 alkoxycarbonyl groups optionally substituted with carboxylic acid groups C1 to C10 alkanoyloxy groups optionally substituted with carboxylic acid groups, and Straight-chain or branched C1 to C10 hydroxyalkyl groups optionally substituted with C1 to C5 alkoxycarbonyl groups or C1 to C5 substituted alkoxy groups; and Photoacid generator containing iodonium cations.

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