Photoacid generator, photoresist composition and pattern forming method

Abstract

To provide photoacid generators, photoresist compositions, and pattern formation methods.SOLUTION: A photoacid generator includes: an organic cation; and an anion including an anionic core, wherein the anionic core includes a cyclopentadienide group, wherein the cyclopentadienide group is substituted with an organic group including a semi-metal element, and wherein the anion is substituted with one or more electron withdrawing groups.

Description

[Technical Field]

[0001] PHOTOACID GENERATORS AND PHOTORESIST COMPOSITIONS FIELD OF THE INVENTION The present invention relates to photoacid generators, their use in photoresist compositions, and patterning methods using such photoresist compositions. The present invention finds particular applicability in lithography applications in the semiconductor manufacturing industry. [Background technology]

[0002] Photoresist materials are photosensitive compositions typically used to transfer images to one or more underlying layers, such as metal, semiconductor, or dielectric layers, disposed on a semiconductor substrate. To increase the integration density of semiconductor devices and enable the formation of structures with dimensions in the nanometer range, photoresists and photolithography processing tools with high resolution capabilities have been and continue to be developed.

[0003] Positive-tone chemically amplified photoresists are traditionally used for high-resolution processing. Such resists typically utilize a polymer with acid-labile groups and a photoacid generator. Patternwise exposure to activating radiation through a photomask causes the acid generator to form an acid, which, during post-exposure baking, causes cleavage of the acid-labile groups in the exposed areas of the polymer. This results in a difference in solubility characteristics between the exposed and unexposed areas of the resist in a developer. In a positive-tone development (PTD) process, the exposed areas of the photoresist layer become soluble in the developer and are removed from the substrate surface, while the unexposed areas, which are insoluble in the developer, remain after development, forming a positive image. The resulting relief image allows for selective processing of the substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 8,431,325 [Patent Document 2] U.S. Patent No. 4,189,323 Summary of the Invention [Problem to be solved by the invention]

[0005] There is a continuing need for photoresist compositions and patterning methods using such photoresist compositions that improve multiple aspects of lithographic performance, such as photospeed, line width roughness (LWR), and resolution. [Means for solving the problem]

[0006] One embodiment is directed to a photoacid generator comprising an organic cation and an anion comprising an anionic core comprising a cyclopentadienide group, wherein the cyclopentadienide group is substituted with an organic group comprising a metalloid element, and the anion is substituted with one or more electron-withdrawing groups.

[0007] Another aspect is directed to a photoresist composition that includes a polymer, a photoacid generator, optionally part of the polymer, and a solvent.

[0008] Yet another aspect is directed to a method for forming a pattern that includes forming a photoresist layer on a substrate from a photoresist composition, patternwise exposing the photoresist layer to activating radiation, and developing the exposed photoresist layer to provide a resist relief image. DETAILED DESCRIPTION OF THE INVENTION

[0009] Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in this description. In this regard, the exemplary embodiments may have different forms and should not be construed as limited to the description set forth herein. Accordingly, exemplary embodiments are described below by reference to the figures only to illustrate aspects of the present description. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Phrases such as "at least one of," when preceding a list of elements, modify the entire list of elements and not each individual element of the list.

[0010] As used herein, the terms "a," "an," and "the" do not denote quantitative limitations and should be construed to include both the singular and the plural unless otherwise indicated herein or clearly contradicted by context. "Or" means "and / or" unless expressly stated otherwise. The modifier "about," used in connection with a quantity, is inclusive of the stated value and has the meaning dictated by the context (e.g., including the degree of error associated with measurement of the particular quantity). All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independent and inclusive of each other. The suffix "(s)" is intended to include both the singular and the plural of the term it modifies, thereby including at least one of that term. "Optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes instances when the event occurs and instances when the event does not occur. The terms "first," "second," etc., as used herein, do not denote order, quantity, or importance, but rather are used to distinguish one element from another. When an element is said to be "on" another element, it may be in direct contact with the other element, or intervening elements may be present between them. In contrast, when an element is said to be "directly on" another element, there are no intervening elements present. It should be understood that the described components, elements, limitations, and / or features of the embodiments may be combined in any suitable manner in the various embodiments.

[0011] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted to have a meaning consistent with their meaning in the context of the relevant technical field and this disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0012] In this disclosure, "actinic rays" or "radiation" refers to, for example, the emission line spectrum of a mercury lamp, far ultraviolet rays typified by excimer lasers, extreme ultraviolet rays (EUV light), X-rays, and particle rays such as electron beams and ion beams. Furthermore, in this invention, "light" refers to actinic rays or radiation. Krypton fluoride lasers (KrF lasers) are a specific type of excimer laser and are sometimes called exciplex lasers. "Excimer" stands for "excimer dimer," and "exciplex" stands for "exciplex." Excimer lasers use a mixture of a rare gas (argon, krypton, or xenon) and a halogen gas (fluorine or chlorine) to emit coherent stimulated radiation (laser light) in the ultraviolet range under appropriate conditions of electrical stimulation and high pressure. Furthermore, unless otherwise specified, "exposure" in this specification includes not only exposure using far ultraviolet light such as that from a mercury lamp or an excimer laser, X-rays, extreme ultraviolet light (EUV light), etc., but also writing using particle beams such as electron beams and ion beams.

[0013] As used herein, the term "hydrocarbon" refers to an organic compound having at least one carbon atom and at least one hydrogen atom; "alkyl" refers to a straight- or branched-chain saturated hydrocarbon group having the specified number of carbon atoms and having a valence of one; "alkylene" refers to an alkyl group having a valence of two; "hydroxyalkyl" refers to an alkyl group substituted with at least one hydroxyl group (-OH); "alkoxy" refers to "alkyl-O-"; "carboxyl" and "carboxylic" are also used. "Cycloalkyl" refers to a monovalent group having one or more saturated rings in which all ring members are carbon; "cycloalkylene" refers to a cycloalkyl group having a valence of two; "alkenyl" refers to a straight- or branched-chain monovalent hydrocarbon group having at least one carbon-carbon double bond; "alkenoxy" refers to "alkenyl-O-"; "alkenylene" refers to an alkenyl group having a valence of two; "cycloalkenyl" refers to a group having at least one carbon- "alkynyl" refers to a monovalent hydrocarbon group having at least three carbon atoms and a carbon-carbon double bond; "aromatic group" refers to a monocyclic or polycyclic aromatic ring system that satisfies the Huckel rule (4n + 2π electrons) and contains carbon atoms in the ring; "heteroaromatic group" refers to an aromatic group that contains one or more heteroatoms (e.g., 1 to 4 heteroatoms) selected from N, O, and S in place of a carbon atom in the ring; "aromatic group" refers to a monovalent hydrocarbon group having at least three carbon atoms and a carbon-carbon double bond; "aromatic group" refers to a monovalent hydrocarbon group having at least one carbon atom and a carbon-carbon double bond; "aromatic group" refers to a monocyclic or polycyclic aromatic ring system that satisfies the Huckel rule (4n + 2π electrons) and contains carbon atoms in the ring; "heteroaromatic group" refers to an aromatic group that contains one or more heteroatoms (e.g., 1 to 4 heteroatoms) selected from N, O, and S in place of a carbon atom in the ring; "Aryl" refers to a monovalent monocyclic or polycyclic aromatic ring system in which all ring members are carbon and can include groups having an aromatic ring fused to at least one cycloalkyl or heterocycloalkyl ring; "arylene" refers to an aryl group having a valence of two; "alkylaryl" refers to an aryl group substituted with an alkyl group; "arylalkyl" refers to an alkyl group substituted with an aryl group; "aryloxy" refers to "aryl-O-"; and "arylthio" refers to "aryl-S-".

[0014] The prefix "hetero" means that the compound or group contains at least one ring member that is a heteroatom (e.g., 1, 2, 3, or 4 or more heteroatoms) in place of a carbon atom, where each heteroatom is independently N, O, S, Si, or P; a "heteroatom-containing group" refers to a substituent that contains at least one heteroatom; a "heteroalkyl" refers to an alkyl group having at least one heteroatom in place of a carbon; and a "heterocycloalkyl" refers to a group having 1 to 4 heteroatoms as ring members in place of carbon. "Heterocycloalkylene" refers to a divalent heterocycloalkyl group; "heteroaryl" refers to an aromatic 4-8-membered monocyclic, 8-12-membered bicyclic, or 11-14-membered tricyclic ring system having 1-4 heteroatoms (monocyclic), 1-6 heteroatoms (bicyclic), or 1-9 heteroatoms (tricyclic), each independently selected from N, O, S, Si, or P (e.g., carbon atoms and 1-3, 1-6, or 1-9 N, O, or S heteroatoms, respectively, in the monocyclic, bicyclic, or tricyclic ring systems). Examples of heteroaryl groups include pyridyl, furyl (furyl or furanyl), imidazolyl, benzimidazolyl, pyrimidinyl, thiophenyl or thienyl, quinolinyl, indolyl, thiazolyl, and the like; "heteroarylene" refers to a divalent heteroaryl group.

[0015] The term "halogen" refers to a monovalent substituent that is fluorine (fluoro), chlorine (chloro), bromine (bromo), or iodine (iodo). The prefix "halo" refers to a group that contains one or more fluoro, chloro, bromo, or iodo substituents in place of a hydrogen atom. Combinations of halo groups (e.g., bromo and fluoro) or only fluoro groups can be present. For example, the term "haloalkyl" refers to an alkyl group substituted with one or more halogens. As used herein, "substituted C1-8 haloalkyl" refers to a C1-8 alkyl group substituted with at least one halogen, which is further substituted with one or more other substituents other than halogen. It should be understood that because halogen atoms do not replace carbon atoms, substitution of a group with a halogen atom is not considered a heteroatom-containing group.

[0016] Unless expressly stated otherwise, each of the above substituents can be optionally substituted. The term "optionally substituted" refers to substituted or unsubstituted. "Substituted" means that at least one hydrogen atom of a chemical structure or group has been replaced with another terminal substituent, which is typically monovalent, provided that the normal valence of the designated atom is not exceeded. When a substituent is oxo (i.e., =0), two geminal hydrogen atoms on the carbon atom are replaced with terminal oxo groups. It is further noted that an oxo group is attached to a carbon through a double bond to form a carbonyl (C=0), and a carbonyl group is represented herein as -C(O)-. Combinations of substituents or variables are permissible. Exemplary substituents that may be present at a "substituted" position include nitro (-NO), cyano (-CN), hydroxyl (-OH), oxo (O), amino (-NH), mono- or di-(C 1~6 ) alkylamino, alkanoyl (acyl, etc. C 2~6 alkanoyl group, etc.), formyl (-C(O)H), carboxylic acid or its alkali metal salt or ammonium salt;C 2~6 Alkyl esters (-C(O)O-alkyl or -OC(O)-alkyl), C 7~13 Esters (including acrylates, methacrylates and lactones), such as aryl esters (-C(O)O-aryl or -OC(O)-aryl); amides (-C(O)NR, where R is hydrogen or C 1~6 alkyl), carboxamide (-CHC(O)NR, where R is hydrogen or C 1~6 alkyl), halogen, thiol (-SH), C 1~6 Alkylthio (-S-alkyl), thiocyano (-SCN), C 1~6 Alkyl, C 2~6 Alkenyl, C 2~6 Alkynyl, C 1~6 Haloalkyl, C 1~9 Alkoxy, C 1~6 Haloalkoxy, C 3~12 Cycloalkyl, C 5~18 Cycloalkenyl, C2~18 Heterocycloalkenyl, C having at least one aromatic ring (e.g., phenyl, biphenyl, naphthyl, etc., each ring being substituted or unsubstituted aromatic). 6~12 Aryl, C having 1 to 3 separate or fused rings and 6 to 18 ring carbon atoms 7~19 Arylalkyl, arylalkoxy having 1 to 3 separate or fused rings and 6 to 18 ring carbon atoms, C 7~12 Alkylaryl, C 3~12 Heterocycloalkyl, C 3~12 Heteroaryl, C 1~6 Alkylsulfonyl (-S(O)2-alkyl), C 6~12 Examples of alkyl groups include, but are not limited to, arylsulfonyl (-S(O)-aryl) or tosyl (CHCHSO-). If a group is substituted, the indicated number of carbon atoms is the total number of carbon atoms in the group, excluding carbon atoms of any substituents. For example, the group -CHCHCN is a C alkyl group substituted with a cyano group.

[0017] Unless otherwise defined herein, a "divalent linking group" is any of -O-, -S-, -Te-, -Se-, -C(O)-, -N(R ’ )-, C(O)N(R ’ )-, -S(O)-, -S(O)2-, -C(S)-, -C(Te)-, -C(Se)-, substituted or unsubstituted C 1~30 Alkylene, substituted or unsubstituted C 3~30 Cycloalkylene, substituted or unsubstituted C 3~30 Heterocycloalkylene, substituted or unsubstituted C 6~30 Arylene, substituted or unsubstituted C 3~30 refers to a divalent group containing one or more of: heteroarylene; heteroarylene; or combinations thereof; and each R ’ are independently hydrogen, substituted or unsubstituted C 1~20 Alkyl, substituted or unsubstituted C 1~20 Heteroalkyl, substituted or unsubstituted C 6~30 Aryl or substituted or unsubstituted C 3~30Typically, the divalent linking group is -O-, -S-, -C(O)-, -N(R')-, -S(O)-, -S(O)2-, substituted or unsubstituted C 1~30 Alkylene, substituted or unsubstituted C 3~30 Cycloalkylene, substituted or unsubstituted C 3~30 Heterocycloalkylene, substituted or unsubstituted C 6~30 Arylene, substituted or unsubstituted C 3~30 R' is hydrogen, substituted or unsubstituted C 1~20 Alkyl, substituted or unsubstituted C 1~20 Heteroalkyl, substituted or unsubstituted C 6~30 Aryl or substituted or unsubstituted C 3~30 More typically, the divalent linking group is -O-, -S-, -C(O)-, -C(O)O-, -N(R ’ )-, -C(O)N(R')-, substituted or unsubstituted C 1~10 Alkylene, substituted or unsubstituted C 3~10 Cycloalkylene, substituted or unsubstituted C 3~10 Heterocycloalkylene, substituted or unsubstituted C 6~10 Arylene, substituted or unsubstituted C 3~10 R is hydrogen, substituted or unsubstituted C 1~10 Alkyl, substituted or unsubstituted C 1~10 Heteroalkyl, substituted or unsubstituted C 6~10 Aryl or substituted or unsubstituted C 3~10 It is heteroaryl.

[0018] As used herein, "acid labile group" refers to a group formed on a polymer that undergoes bond cleavage, optionally and typically with thermal treatment, through the catalytic action of an acid, resulting in the formation of a polar group, such as a carboxylic acid group or an alcohol group. The moiety linked to the cleaved bond is then separated from the polymer, optionally and typically. In another system, a non-polymeric compound can contain an acid labile group that can be cleaved by the action of an acid, resulting in the formation of a polar group, such as a carboxylic acid group or an alcohol group, at the cleaved portion of the non-polymeric compound. Such acids are typically photogenerated acids, in which bond cleavage occurs during post-exposure bake (PEB). However, embodiments are not limited thereto. For example, such acids can be thermally generated. Suitable acid labile groups include, for example, tertiary alkyl ester groups, secondary or tertiary aryl ester groups, secondary or tertiary ester groups having a combination of alkyl and aryl groups, tertiary alkoxy groups, acetal groups, or ketal groups. Acid labile groups are also commonly referred to in the art as "acid cleavable groups," "acid cleavable protecting groups," "acid labile protecting groups," "acid leaving groups," "acid decomposable groups," and "acid sensitive groups."

[0019] The present inventors have discovered photoacid generators (PAGs) comprising an anionic core containing a cyclopentadienide group (also known as a cyclopentadienyl group) linked to one or more metalloid atoms, such as boron (B), silicon (Si), germanium (Ge), arsenic (As), selenium (Se), tellurium (Te), or antimony (Sb). The metalloid atoms are neutral in the PAG and covalently bonded to adjacent atoms, which should be understood to mean that the metalloid atoms are uncharged and do not carry a positive or negative charge. When used in photoresist compositions, PAGs according to the present invention can provide improved resolution and linewidth roughness (LWR) characteristics.

[0020] Provided is a photoacid generator comprising an organic cation and an anion comprising an anionic core. The anionic core comprises a cyclopentadienide group substituted with an organic group. The organic group comprises a metalloid element (e.g., B, Si, Ge, As, Se, Te, Sb, or a combination thereof). In the photoacid generator, the anion is substituted with one or more electron-withdrawing groups. In some embodiments, the anion of the photoacid generator does not contain or is free of -F, -CF3, or -CF2- groups. It should be understood that "free of -F, -CF3, or -CF2- groups" means that the anion of the photoacid generator excludes groups such as -CH2CF3 and -CH2CF2CH3. In yet other embodiments, the anion of the photoacid generator is free of fluorine (i.e., it does not contain a fluorine atom and is not substituted with a fluorine-containing group). In some embodiments, the photoacid generator is fluorine-free (ie, both the organic cation and the anion are fluorine-free).

[0021] The anionic core comprises a cyclopentadienide group. The cyclopentadienide anionic group may optionally be fused to one or two phenyl groups. In some embodiments, the anionic core comprises a cyclopentadienide group fused to one or two C aryl groups. It should be understood that when a cyclopentadienide group is fused to one C aryl group, the resulting fused ring contains nine carbon ring atoms, and when a cyclopentadienide group is fused to two C aryl groups, the resulting fused ring contains 13 carbon ring atoms.

[0022] Suitable anions include those whose conjugate acids have a pKa of -15 to 10. If a stronger photoacid is desired, the conjugate acid of the anion can have a pKa of, for example, -15 to 1 or -15 to -2. If a weaker photoacid is desired, the conjugate acid of the anion can have a pKa of, for example, -1 to 6 or 0 to 4.

[0023] The PAG may be in a non-polymeric form or in a polymeric form, present as part of a repeating unit of a polymer. For example, the PAG may be in the form of a polymerizable PAG monomer, or may be a polymer derived from such a monomer. When the PAG is in a polymeric form, it may be included as a group pendant to the polymer backbone, or it may be included as part of the polymer backbone.

[0024] In some embodiments, the anions comprising the anionic core may be represented by one or more of formulas (1)-(3). [ka]

[0025] In formulas (1) to (3), E 1 , E 2 , E 3 , E 4 and E 5 are each independently an electron-withdrawing group. An electron-withdrawing group (EWG) is a group that draws electron density from adjacent atoms toward itself by resonance effects, inductive effects, hyperconjugation effects, or a combination thereof. An EWG can be a weak electron-withdrawing group, such as a halogen, a moderate electron-withdrawing group, such as an aldehyde (-CHO), a ketone (-COR), a carboxylic acid (-COH), a carboxylic acid ester (-COR), or an amide (-CONH), or a strong electron-withdrawing group, such as a trihalide (-CF, CCl), a cyano (-CN), a sulfone (-SOR), a sulfonate (-OSOR), or a nitro (-NO). In some embodiments, each electron-withdrawing group is independently a halogen, a substituted or unsubstituted C 1~20 Haloalkyl, substituted or unsubstituted C 6~20 Aryl, substituted or unsubstituted C 3~20 Heteroaryl, -OR 6 , -SR 7 , -NO2, -CN, -C(O)R 8 , -C(O)OR 9 , -C(O)NR 10 R 11 , -S(O)2OR 12, -S(O)R 13 , -S(O)2R 14 , -OS(O)2R 15 or a combination thereof. 6 ~R 12 are each independently hydrogen, substituted or unsubstituted C 1~20 Alkyl, substituted or unsubstituted C 3~20 Cycloalkyl, substituted or unsubstituted C 3~20 Heterocycloalkyl, substituted or unsubstituted C 6~20 Aryl, substituted or unsubstituted C 7~20 Alkylaryl, substituted or unsubstituted C 7~20 Aryl alkyl, substituted or unsubstituted C 3~20 Heteroaryl, substituted or unsubstituted C 4~20 alkylheteroaryl or substituted or unsubstituted C 4~20 Heteroarylalkyl. R 13 ~R 15 are each independently a substituted or unsubstituted C 1~20 Alkyl, substituted or unsubstituted C 3~20 Cycloalkyl, substituted or unsubstituted C 3~20 Heterocycloalkyl, substituted or unsubstituted C 6~20 Aryl, substituted or unsubstituted C 7~20 Alkylaryl, substituted or unsubstituted C 7~20 Aryl alkyl, substituted or unsubstituted C 3~20 Heteroaryl, substituted or unsubstituted C 4~20 alkylheteroaryl or substituted or unsubstituted C 4~20 In some embodiments, E is heteroarylalkyl. 1 , E 2 , E 3 , E 4 and E 5 are each independently -CN, -C(O)R 8 , -C(O)OR 9 , -S(O)R 13 or -S(O)2R 14 and R 8 , R 9 , R 13 and R 14is as defined herein. In some embodiments, E 1 ~E 5 Each of the formulas is fluorine-free.

[0026] In formula (1), n1 is an integer of 1 to 4. Preferably, n1 can be 3 or 4, and typically, n1 can be 4. In some embodiments, n1 can be an integer of 3 or greater.

[0027] In formula (2), n2 is an integer from 0 to 4, and n3 is an integer from 0 to 2, provided that at least one of n2 and n3 is not 0. In other words, formula (2) requires at least one of E2 or E3 as a ring group substituent. Preferably, n2 can be 3 or 4, and n3 can be 1 or 2, and typically, n2 can be 4, and n3 can be 2. In some embodiments, the sum of n2 and n3 can be an integer of 3 or greater.

[0028] In formula (3), n4 and n5 each independently represent an integer of 0 to 4, provided that at least one of n4 and n5 is not 0. In other words, formula (3) does not include E as a ring group substituent. 4 or E 5 Preferably, n4 is 3 or 4, and n5 is 3 or 4, and typically, n4 and n5 are each 4. In some embodiments, the sum of n4 and n5 can be an integer greater than or equal to 3.

[0029] In one or more embodiments, n1 may be an integer greater than or equal to 3, the sum of n2+n3 may be an integer greater than or equal to 3, and n4+n5 may be an integer greater than or equal to 3.

[0030] In formula (1), m1 is an integer of 0 to 3. Preferably, m1 is 0 or 1, and typically, m1 is 0. When m1 is 0, it should be understood that a hydrogen atom is present.

[0031] In formula (1), the anion is substituted with one or more electron-withdrawing groups, so that the sum of n1+m1 is at least 1. In some embodiments, the sum of n1+m1 can be an integer from 1 to 4. Preferably, the sum of n1+m1 is 3 or 4, and typically, the sum of n1+m1 is 4.

[0032] In formula (2), m2 is an integer of 0 to 4, and m3 is an integer of 0 to 2. Preferably, m2 is 0 or 1, and m3 is 0 or 1, and typically, m2 and m3 are both 0. It should be understood that when the sum of n2 and m2 is less than 4, a hydrogen atom is present, and when m3 is 0, a hydrogen atom is present.

[0033] In formula (2), the anion is substituted with one or more electron-withdrawing groups, so that the sum of n1 + n2 + m1 + m2 is at least 1. In some embodiments, the sum of n2 + m2 can be an integer from 0 to 4. Preferably, the sum of n2 + m2 is 3 or 4, and typically, the sum of n2 + m2 is 4. In some embodiments, the sum of n3 + m3 can be an integer from 0 to 2. Preferably, the sum of n3 + m3 is 1 or 2, and typically, the sum of n3 + m3 is 2.

[0034] In formula (3), m4 and m5 are each independently an integer of 0 to 4. Preferably, m4 and m5 are each independently 0 or 1, and typically, m4 and m5 are each 0. It should be understood that when the sum of n4 and m4 is less than 4, a hydrogen atom is present, and when the sum of n5 and m5 is less than 4, a hydrogen atom is present. In some embodiments, the sum of n4 and m4 may be 4, and the sum of n5 and m5 may be 4.

[0035] In formula (3), the anion is substituted with one or more electron-withdrawing groups, so that the sum of n4 + n5 + m4 + m5 is at least 1. In some embodiments, the sum of n4 + m4 can be an integer from 0 to 4. Preferably, the sum of n4 + m4 is 3 or 4, and typically, the sum of n4 + m4 is 4. In some embodiments, the sum of n5 + m5 can be an integer from 0 to 4. Preferably, the sum of n5 + m5 is 3 or 4, and typically, the sum of n5 + m5 is 4.

[0036] In formulas (1) to (3), R 1 , R 2 , R 3 , R 4 and R 5 are each independently a substituted or unsubstituted C 1~30 Alkyl, substituted or unsubstituted C 1~30 Heteroalkyl, substituted or unsubstituted C 4~30 Cycloalkyl, substituted or unsubstituted C 3~20 Heterocycloalkyl, substituted or unsubstituted C 6~30 Aryl, substituted or unsubstituted C 7~30 Aryl alkyl, substituted or unsubstituted C 7~30 Alkylaryl, substituted or unsubstituted C 3~30 Heteroaryl, substituted or unsubstituted C 4~30 Heteroarylalkyl or substituted or unsubstituted C 4~30 alkylheteroaryl. Preferably, R 1 , R 2 , R 3 , R 4 and R 5 are each independently a substituted or unsubstituted C 1~10 Alkyl, substituted or unsubstituted C 4~8 Cycloalkyl, substituted or unsubstituted C 3~10 Heterocycloalkyl, substituted or unsubstituted C 6~14 Aryl, substituted or unsubstituted C 7~15 Aryl alkyl, substituted or unsubstituted C 7~15 Alkylaryl, substituted or unsubstituted C 3~10 Heteroaryl, substituted or unsubstituted C4~11 Heteroarylalkyl or substituted or unsubstituted C 4~11 It can be alkylheteroaryl.

[0037] R 1 , R 2 , R 3 , R 4 and R 5 Each of optionally further comprises one or both of a divalent linking group or a polymerizable group as part of its structure. Exemplary polymerizable groups are those that contain an ethylenically unsaturated double bond, such as substituted or unsubstituted C 2~20 It may be alkenyl or substituted or unsubstituted norbornyl, preferably (meth)acrylate or C2 alkenyl.

[0038] In formula (1), two or more adjacent R 1 The groups together optionally form a ring that optionally further includes one or more divalent linking groups as part of its structure, each of the one or more divalent linking groups being substituted or unsubstituted, and the ring being substituted or unsubstituted. In some embodiments, two or more R 1 The groups do not join together to form a ring.

[0039] In formula (2), two or more adjacent R 2 The groups together optionally form a ring that optionally further includes one or more divalent linking groups as part of its structure, each of the one or more divalent linking groups being substituted or unsubstituted, and the ring being substituted or unsubstituted. In some embodiments, two or more R 2 In formula (2), two or more adjacent R groups do not form a ring. 3 The groups together optionally form a ring that optionally further includes one or more divalent linking groups as part of its structure, each of the one or more divalent linking groups being substituted or unsubstituted, and the ring being substituted or unsubstituted. In some embodiments, two or more R 3 In formula (2), two or more adjacent R groups do not form a ring. 2 and R3 The groups together optionally form a ring that optionally further includes one or more divalent linking groups as part of its structure, each of which is substituted or unsubstituted, and the ring is substituted or unsubstituted. 2 and R 3 do not form a ring together.

[0040] In formula (3), two or more adjacent R 4 The groups together optionally form a ring that optionally further includes one or more divalent linking groups as part of its structure, each of the one or more divalent linking groups being substituted or unsubstituted, and the ring being substituted or unsubstituted. In some embodiments, two or more R 4 In formula (3), two or more adjacent R groups do not form a ring. 5 The groups together optionally form a ring that optionally further includes one or more divalent linking groups as part of its structure, each of the one or more divalent linking groups being substituted or unsubstituted, and the ring being substituted or unsubstituted. In some embodiments, two or more R 5 In formula (3), two or more adjacent R groups do not form a ring. 4 and R 5 The groups together optionally form a ring that optionally further includes one or more divalent linking groups as part of its structure, each of which is substituted or unsubstituted, and the ring is substituted or unsubstituted. 4 and R 5 do not form a ring together.

[0041] In formulas (1), (2) and (3), L 1 , L 2 and L 3 may each independently be a single bond or a divalent linking group. Exemplary divalent linking groups include substituted or unsubstituted C 1~30 Alkylene, substituted or unsubstituted C 4~30 Cycloalkylene, substituted or unsubstituted C3~30 Heterocycloalkylene, substituted or unsubstituted C 6~30 Arylene, substituted or unsubstituted C 7~30 Aryl alkylene, substituted or unsubstituted C 3~30 Heteroarylene, substituted or unsubstituted divalent C 4~30 Heteroaryl alkylene, including one or more of -O-, -C(O)- and / or -C(O)O-. Preferably, L 1 , L 2 and L 3 are each independently a single bond or a substituted or unsubstituted C 1~10 is a divalent linking group selected from one or more of alkylene, -O-, -C(O)-, and / or -C(O)O-. In some embodiments, L 1 , L 2 and L 3 does not include a fluorine atom or a group substituted with a fluorine atom.

[0042] In formula (1), one or more R 1 Groups and L 1 optionally form together a ring that optionally further includes one or more divalent linking groups as part of its structure, each of the one or more divalent linking groups being substituted or unsubstituted, and the ring being substituted or unsubstituted. 1 and L 1 do not form a ring together.

[0043] In formula (2), one or more R 2 Groups and L 2 optionally form together a ring that optionally further includes one or more divalent linking groups as part of its structure, each of the one or more divalent linking groups being substituted or unsubstituted, and the ring being substituted or unsubstituted. 2 and L 2 do not form a ring together. In formula (2), one or more R 3 Groups and L 2optionally form together a ring that optionally further includes one or more divalent linking groups as part of its structure, each of the one or more divalent linking groups being substituted or unsubstituted, and the ring being substituted or unsubstituted. 3 and L 2 do not form a ring together.

[0044] In formula (3), one or more R 4 Groups and L 3 optionally form together a ring that optionally further includes one or more divalent linking groups as part of its structure, each of the one or more divalent linking groups being substituted or unsubstituted, and the ring being substituted or unsubstituted. 4 and L 3 do not form a ring together. In formula (3), one or more R 5 Groups and L 3 optionally form together a ring that optionally further includes one or more divalent linking groups as part of its structure, each of the one or more divalent linking groups being substituted or unsubstituted, and the ring being substituted or unsubstituted. 5 and L 3 do not form a ring together.

[0045] In formulas (1), (2) and (3), Y 1 , Y 2 and Y 3 are each independently an organic group comprising a metalloid element, which may be selected from B, Si, Ge, As, Se, Te, Sb, or a combination thereof, or preferably selected from B, Si, or Ge. In some embodiments, the organic group Y 1 , Y 2 and / or Y 3 may include one or more metalloid elements selected from B, Si, Ge, or combinations thereof.

[0046] In some embodiments, Y 1 , Y 2 and Y3 are each independently expressed by formulas (4) to (6): [ka] wherein each * is Y 1 About L 1 Binding site for Y 2 About L 2 Binding site to Y 3 About L 3 Each represents a binding site for

[0047] In equation (4), Z 1 may be selenium (Se), tellurium (Te), Se—Se, or Te—Te. Preferably, Z 1 is Te.

[0048] In equation (5), Z 2 may be boron (B), arsenic (As), arsenic oxide (AsO), antimony (Sb) or antimony oxide (SbO). 2 is boron (B). As used herein, arsenic oxide is of the formula As(=O) and antimony oxide is of the formula Sb(=O).

[0049] In equation (6), Z 3 can be silicon (Si), germanium (Ge) or tellurium (Te). 3 is silicon (Si) or germanium (Ge).

[0050] In equation (4), R 19 is cyano, substituted or unsubstituted C 1~20 Alkyl, substituted or unsubstituted C 1~20 Alkoxy, substituted or unsubstituted C 4~20 Cycloalkyl, substituted or unsubstituted C 2~20 Alkenyl, substituted or unsubstituted C 6~30 Aryl, substituted or unsubstituted C 6~30 Aryloxy, substituted or unsubstituted C3~30 Heteroaryl, substituted or unsubstituted C 3~30 Heteroaryloxy, substituted or unsubstituted C 7~20 Aryl alkyl or substituted or unsubstituted C 4~20 may be heteroarylalkyl, R 19 optionally further comprises a divalent linking group as part of its structure. Preferably, R 19 is a substituted or unsubstituted C 1~10 Alkyl, substituted or unsubstituted C 1~10 Alkoxy or substituted or unsubstituted C 6~14 Aryl. R 19 may optionally further include a divalent linking group as part of its structure. For example, R 19 may further include a heteroatom-containing linking group selected from -O-, -C(O)-, -C(O)O-, and combinations thereof.

[0051] In equation (5), R 20 and R 21 are each independently hydrogen, halogen, cyano, substituted or unsubstituted C 1~20 Alkyl, substituted or unsubstituted C 1~20 Alkoxy, substituted or unsubstituted C 4~20 Cycloalkyl, substituted or unsubstituted C 2~20 Alkenyl, substituted or unsubstituted C 2~20 Alkynyl, substituted or unsubstituted C 6~30 Aryl, substituted or unsubstituted C 6~30 Aryloxy, substituted or unsubstituted C 3~30 Heteroaryl, substituted or unsubstituted C 3~30 Heteroaryloxy, substituted or unsubstituted C 7~20 Aryl alkyl or substituted or unsubstituted C 4~20 It may be heteroarylalkyl. Preferably, R 20 and R 21 are each independently a substituted or unsubstituted C 1~10 Alkyl, substituted or unsubstituted C 1~10 Alkoxy or substituted or unsubstituted C 6~14 It is aryl.

[0052] In equation (5), R 20 and R 21 At least one of is an organic group (eg, a substituent that is not hydrogen or halogen).

[0053] In equation (5), R 20 and R 21 may each optionally further include a divalent linking group as part of its structure. For example, R 20 and R 21 may each further comprise a heteroatom-containing linking group selected from -O-, -C(O)-, -C(O)O-, and combinations thereof.

[0054] In equation (5), R 20 and R 21 can be optionally linked to each other via a single bond or one or more divalent linking groups to form a ring, which can be substituted or unsubstituted. For example, R 20 and R 21 is a group of the formula -O-(C a1 R 25 R 26 )-(C a2 R 27 R 28 )-O- divalent linking group, R 25 ~R 28 are each independently hydrogen or substituted or unsubstituted C 1~10 alkyl, C a1 and C a2 together optionally form a ring, which may be substituted or unsubstituted.

[0055] In equation (6), R 22 ~R 24 are each independently hydrogen, halogen, cyano, substituted or unsubstituted C 1~20 Alkyl, substituted or unsubstituted C 1~20 Alkoxy, substituted or unsubstituted C 4~20 Cycloalkyl, substituted or unsubstituted C 2~20 Alkenyl, substituted or unsubstituted C 2~20Alkynyl, substituted or unsubstituted C 6~30 Aryl, substituted or unsubstituted C 6~30 Aryloxy, substituted or unsubstituted C 3~30 Heteroaryl, substituted or unsubstituted C 3~30 Heteroaryloxy, substituted or unsubstituted C 7~20 Aryl alkyl or substituted or unsubstituted C 4~20 It may be heteroarylalkyl. Preferably, R 22 ~R 24 are each independently hydrogen, substituted or unsubstituted C 1~10 Alkyl, substituted or unsubstituted C 1~10 Alkoxy or substituted or unsubstituted C 6~14 It is aryl.

[0056] In equation (6), R 22 ~R 24 At least one of is an organic group (eg, a substituent that is not hydrogen or halogen).

[0057] R 22 and R 24 may each optionally further include a divalent linking group as part of its structure. For example, R 22 ~R 24 may each further comprise a heteroatom-containing linking group selected from -O-, -C(O)-, -C(O)O-, and combinations thereof.

[0058] R 22 ~R 24 can be optionally linked to each other via a single bond or one or more divalent linking groups to form a ring, which can be substituted or unsubstituted.

[0059] In one or more embodiments, the anion may include one or more -CN groups and at least one Si atom. In some embodiments, the anion may include two or more -CN groups and at least one Si atom. In some embodiments, the anion may include three or more -CN groups and at least one Si atom. In still other embodiments, the anion may include four or more -CN groups and at least one Si atom.

[0060] In some embodiments, the anion of the photoacid generator has formula (1a), (2a), or (3a): [ka] may be represented by one or more of:

[0061] In formulas (1a), (2a) and (3a), M 1 may be B, Si, Ge, As, AsO, Se, Se-Se, Te, Te-Te, Sb or SbO. Preferably, M 1 is B or Si.

[0062] In formulas (1a), (2a) and (3a), x and y are each 0 or 1. For example, M 1 When M is Se, Te, Se-Se, or Te-Te, x and y are both 0. For example, M 1 When M is B, As, AsO, Sb, or SbO, x is 1 and y is 0 (or x is 0 and y is 1). For example, M 1 is Si, Ge, or Te, then x and y are both 1.

[0063] In formulas (1a), (2a) and (3a), E 1 , E 2 , E 3 , E 4 and E 5 are each independently an electron-withdrawing group as defined for formulas (1) to (3).

[0064] In formulas (1a), (2a), and (3a), n1 to n5 and m1 to m5 are as defined for formulas (1) to (3). In formulas (1a), (2a), and (3a), the anion of the photoacid generator contains at least one EWG.

[0065] In formulas (1a), (2a) and (3a), R 1 , R 2 , R 3 , R 4 and R 5 are each independently as defined in formulas (1) to (3). 1 The groups together optionally form a ring that optionally further includes one or more divalent linking groups as part of its structure, each of which is substituted or unsubstituted, and the ring is substituted or unsubstituted. 2 The groups together optionally form a ring that optionally further includes one or more divalent linking groups as part of its structure, each of which is substituted or unsubstituted, and the ring is substituted or unsubstituted. 3 The groups together optionally form a ring that optionally further includes one or more divalent linking groups as part of its structure, each of which is substituted or unsubstituted, and the ring is substituted or unsubstituted. 2 and R 3 The groups together optionally form a ring that optionally further includes one or more divalent linking groups as part of its structure, each of which is substituted or unsubstituted, and the ring is substituted or unsubstituted. 4 The groups together optionally form a ring that optionally further includes one or more divalent linking groups as part of its structure, each of which is substituted or unsubstituted, and the ring is substituted or unsubstituted. 5The groups together optionally form a ring that optionally further includes one or more divalent linking groups as part of its structure, each of which is substituted or unsubstituted, and the ring is substituted or unsubstituted. 4 and R 5 The groups together optionally form a ring that optionally further includes one or more divalent linking groups as part of its structure, each of the one or more divalent linking groups being substituted or unsubstituted, and the ring being substituted or unsubstituted.

[0066] In formulas (1a), (2a) and (3a), R 22a and R 23a are each independently hydrogen, halogen, cyano, substituted or unsubstituted C 1~10 Alkyl, substituted or unsubstituted C 1~10 Alkoxy, substituted or unsubstituted C 2~20 Alkynyl, substituted or unsubstituted C 6~14 It may be aryl. Preferably, R 22a and R 23a are each independently substituted or unsubstituted C 1~5 It is alkyl.

[0067] In formulas (1a), (2a) and (3a), R 24a is cyano, substituted or unsubstituted C 1~10 Alkyl, substituted or unsubstituted C 1~10 Alkoxy, substituted or unsubstituted C 2~20 Alkynyl, substituted or unsubstituted C 6~14 It may be aryl. Preferably, R 24a are each independently substituted or unsubstituted C 1~5 It is alkyl.

[0068] In formulas (1a), (2a) and (3a), L 4 can be a single bond or a divalent linking group. Exemplary divalent linking groups are substituted or unsubstituted C 1~30 Alkylene, substituted or unsubstituted C 4~30 Cycloalkylene, substituted or unsubstituted C3~30 Heterocycloalkylene, substituted or unsubstituted C 6~30 Arylene, substituted or unsubstituted C 7~30 Aryl alkylene, substituted or unsubstituted C 3~30 Heteroarylene, substituted or unsubstituted divalent C 4~30 Heteroaryl alkylene, including one or more of -O-, -C(O)- and / or -C(O)O-. Preferably, L 4 is a single bond or a substituted or unsubstituted C 1~10 is a divalent linking group selected from one or more of alkylene, -O-, -C(O)-, and / or -C(O)O-. In some embodiments, L 4 does not include a fluorine atom or a group substituted with a fluorine atom.

[0069] In some embodiments, the anion of the photoacid generator has formula (1b), (1c), (2b), or (3b): [ka] may be represented by one or more of:

[0070] In formulas (1b), (1c), (2b) and (3b), M 1 can be B, Si, Ge, As, AsO, Se, Se—Se, Te, Te—Te, Sb, or SbO.

[0071] In formulas (1b), (1c), (2b) and (3b), x and y are each 0 or 1. For example, M 1 When M is Se, Te, Se-Se, or Te-Te, x and y are both 0. For example, M 1 When M is B, As, AsO, Sb, or SbO, x is 1 and y is 0 (or x is 0 and y is 1). For example, M 1 is Si, Ge, or Te, then x and y are both 1.

[0072] In formulas (1b), (1c), (2b) and (3b), R 22a~R 24a are as defined for formulas (1a), (2a) and (3a), respectively.

[0073] In formulas (1b), (1c), (2b) and (3b), each A 1 are independently hydrogen, substituted or unsubstituted C 1~10 It may be an alkyl or oxo group (=O). Preferably, each A 1 are independently hydrogen or an oxo group.

[0074] In formulas (1b) and (3b), each A 2 are independently hydrogen, -CN, -C(O)R 8a , -C(O)OR 9a , -S(O)R 13a or -S(O)2R 14a R 8a and R 9a are each independently hydrogen, substituted or unsubstituted C 1~10 Alkyl, substituted or unsubstituted C 4~8 Cycloalkyl, substituted or unsubstituted C 3~20 Heterocycloalkyl, substituted or unsubstituted C 6~14 Aryl or substituted or unsubstituted C 3~20 heteroaryl, and R 13a and R 14a are each independently a substituted or unsubstituted C 1~10 Alkyl, substituted or unsubstituted C 4~8 Cycloalkyl, substituted or unsubstituted C 3~20 Heterocycloalkyl, substituted or unsubstituted C 6~14 Aryl or substituted or unsubstituted C 3~20 Preferably, each A is heteroaryl. 2 are independently hydrogen, -CN, -C(O)R 8a , -C(O)OR 9a , -S(O)R 13a or -S(O)2R 14a and R 8a and R 9a are each independently hydrogen, substituted or unsubstituted C 1~5 Alkyl or substituted or unsubstituted C6~14 aryl, and R 13a and R 14a are each independently a substituted or unsubstituted C 1~5 Alkyl or substituted or unsubstituted C 6~14 It is aryl.

[0075] In formulas (2b) and (3b), each A 3 ~A 8 are independently hydrogen, -CN, -C(O)R 8b , -C(O)OR 9b , -S(O)R 13b or -S(O)2R 14b R 8b and R 9b are each independently hydrogen, substituted or unsubstituted C 1~10 Alkyl, substituted or unsubstituted C 4~8 Cycloalkyl, substituted or unsubstituted C 3~20 Heterocycloalkyl, substituted or unsubstituted C 6~14 Aryl or substituted or unsubstituted C 3~20 heteroaryl, and R 13b and R 14b are each independently a substituted or unsubstituted C 1~10 Alkyl, substituted or unsubstituted C 4~8 Cycloalkyl, substituted or unsubstituted C 3~20 Heterocycloalkyl, substituted or unsubstituted C 6~14 Aryl or substituted or unsubstituted C 3~20 Heteroaryl. Preferably, A 3 ~A 8 are each independently -CN, -C(O)R 8b , -C(O)OR 9b , -S(O)R 13b or -S(O)2R 14b and R 8b and R 9b are each independently hydrogen, substituted or unsubstituted C 1~5 Alkyl or substituted or unsubstituted C 6~14 aryl, and R 13b and R 14b are each independently a substituted or unsubstituted C1~5 Alkyl or substituted or unsubstituted C 6~14 It is aryl.

[0076] Non-limiting examples of anions of formulas (1)-(3) include: [ka] [ka] [ka] [ka]

[0077] The photoacid generator further comprises an organic cation. In some embodiments, the organic cation comprises a polymerizable group, such as a polymerizable group comprising an ethylenically unsaturated double bond, such as a substituted or unsubstituted C 2~20 It may comprise alkenyl or substituted or unsubstituted norbornyl, preferably (meth)acrylate or C2 alkenyl.

[0078] In some embodiments, the organic cation can be a sulfonium cation or an iodonium cation. In some embodiments, the organic cation can be a sulfonium cation of formula (6a) or an iodonium cation of formula (6b). [ka]

[0079] In formulas (6a) and (6b), R 30 ~R 34 are each independently a substituted or unsubstituted C 1~20 Alkyl, substituted or unsubstituted C 4~20 Cycloalkyl, substituted or unsubstituted C 2~20 Alkenyl, substituted or unsubstituted C 6~30Aryl, substituted or unsubstituted C 3~30 Heteroaryl, substituted or unsubstituted C 7~20 Aryl alkyl or substituted or unsubstituted C 4~20 heteroarylalkyl or a combination thereof. 30 ~R 34 each independently or linked to another group R via a single bond or a divalent linking group 30 ~R 34 can be linked to form a ring. 30 ~R 34 Each of R may optionally include a divalent linking group as part of its structure. 30 ~R 34 may each independently optionally include an acid labile group selected from, for example, a tertiary alkyl ester group, a secondary or tertiary aryl ester group, a secondary or tertiary ester group having a combination of alkyl and aryl groups, a tertiary alkoxy group, an acetal group, or a ketal group.

[0080] Exemplary sulfonium cations of formula (6a) are: [ka] [ka] may include one or more of:

[0081] Exemplary iodonium cations of formula (6b) are: [ka] may include one or more of:

[0082] Suitable photoacid generators include those derived from any combination of the above anions and cations. In some embodiments, the photoacid generator may be a zwitterion. For example, in Formulas (1)-(3), R 1 ~R 5 -S + R15 R 16 or -I + R 15 wherein R 15 and R 16 is as defined above, which provides a cationic substituent on the anion. Suitable zwitterionic photoacid generators include, for example: [ka] [ka]

[0083] Photoacid generators can be prepared by methods known in the art and as exemplified in the examples disclosed in more detail below.

[0084] Also provided is a photoresist composition comprising a polymer, a photoacid generator described herein, and a solvent.

[0085] The polymer of the photoresist composition can be a homopolymer or a copolymer containing two or more structurally distinct repeat units. For example, the polymer can contain one or more repeat units containing a functional group selected from a hydroxyaryl group, an acid-labile group, a base-solubilizing group, a lactone-containing group, a sultone-containing group, a polar group, a crosslinkable group, a crosslinking group, or the like, or a combination thereof.

[0086] In one or more embodiments, the polymer may include repeat units formed from monomers that include acid labile groups. Suitable acid labile groups include, for example, tertiary ester, acetal, ketal, and tertiary ether groups. [ka] [ka] [ka] In the formula, R d is hydrogen, halogen (e.g., F, Cl, Br, I), substituted or unsubstituted C 1~6 Alkyl or substituted or unsubstituted C 3~6 It is cycloalkyl.

[0087] When repeat units having acid labile groups are present in the polymer, they are typically present in an amount of from 25 to 75 mol %, more typically from 25 to 50 mol %, and even more typically from 30 to 50 mol %, based on the total repeat units in the polymer.

[0088] In some embodiments, the polymer may include repeat units derived from one or more lactone-containing monomers. Suitable lactone-containing monomers include, for example: [ka] wherein R d is hydrogen, halogen (e.g., F, Cl, Br, I), substituted or unsubstituted C 1~6 Alkyl or substituted or unsubstituted C 3~6 It is cycloalkyl.

[0089] In some embodiments, the polymer may include repeat units having base-solubilizing groups and / or having a pKa of less than or equal to 12. Exemplary base-solubilizing groups may include fluoroalcohol groups, carboxylic acid groups, carboximide groups, sulfonamide groups, or sulfonimide groups.

[0090] Non-limiting examples of monomers containing base solubilizing groups include: [ka] [ka] wherein R iis hydrogen, halogen (e.g., F, Cl, Br, I), substituted or unsubstituted C 1~6 Alkyl or substituted or unsubstituted C 3~6 It is cycloalkyl.

[0091] The polymer may optionally further comprise one or more additional repeating units. The additional repeating structural units may be, for example, one or more additional units for the purpose of adjusting the properties of the photoresist composition, such as etch rate and solubility. Exemplary additional units may include those derived from one or more of (meth)acrylate, vinyl aromatic, vinyl ether, vinyl ketone, and / or vinyl ester monomers. When present in the first and / or second polymer, the one or more additional repeating units may be used in an amount of up to 50 mol %, typically 3 to 50 mol %, based on the total repeating units of the polymer.

[0092] Non-limiting exemplary polymers of the present invention include: [ka] where a, b, and c represent the mole fractions for each repeat unit of the polymer, and a+b+c=1.

[0093] The polymers typically have a weight average molecular weight (M) of 1,000 to 50,000 Daltons (Da), preferably 2,000 to 30,000 Da, more preferably 3,000 to 20,000 Da, and even more preferably 4,000 to 15,000 Da. w The polydispersity index (PDI) of the first polymer (M w and number average molecular weight (M n The ratio of ) to ) is typically 1.1 to 3, more typically 1.1 to 2. Molecular weight values ​​are determined by gel permeation chromatography (GPC) using polystyrene standards.

[0094] The polymer can be prepared by any suitable method in the art. For example, one or more monomers corresponding to the repeating units described herein can be combined or separately fed using a suitable solvent and initiator and polymerized in a reactor. For example, the polymer can be obtained by polymerization of each monomer under any suitable conditions, such as heating at an effective temperature, irradiating with actinic radiation at an effective wavelength, or a combination thereof.

[0095] In some embodiments, the photoresist composition may further comprise one or more additional photoacid generators (PAGs). The PAG may be in ionic or non-ionic form. The PAG may be in polymeric or non-polymeric form. In the polymeric form, the PAG may be present as part of a repeat unit of a polymer derived from a polymerizable PAG monomer.

[0096] Further suitable PAG compounds are of formula G + A - wherein G + is a photoactive cation, and A - is an anion capable of generating a photoacid. The photoactive cation is preferably selected from onium cations, preferably iodonium or sulfonium cations, such as those described above with respect to the PAGs of the invention (e.g., those of formulas (6a) and (6b)). Particularly suitable anions include those whose conjugate acids have pKas of -15 to 10. The anion is typically an organic anion having a sulfonate or non-sulfonate-type group, such as a sulfonamidate, sulfonimidate, methide, or borate.

[0097] Exemplary organic anions having a sulfonate group are: [ka] Includes one or more of the following.

[0098] Exemplary non-sulfonated anions are: [ka] Includes one or more of the following.

[0099] Commonly used onium salts include, for example, triphenylsulfonium trifluoromethanesulfonate, (p-tert-butoxyphenyl)diphenylsulfonium trifluoromethanesulfonate, tris(p-tert-butoxyphenyl)sulfonium trifluoromethanesulfonate, triphenylsulfonium p-toluenesulfonate; di-t-butylphenyliodonium perfluorobutanesulfonate, and di-t-butylphenyliodonium camphorsulfonate. Other useful PAG compounds are known in the chemically amplified photoresist art, such as nonionic sulfonyl compounds, such as 2-nitrobenzyl-p-toluenesulfonate, 2,6-dinitrobenzyl-p-toluenesulfonate, and 2,4-dinitrobenzyl-p-toluenesulfonate; sulfonate esters, such as 1,2,3-tris(methanesulfonyloxy)benzene, 1,2,3-tris(trifluoromethanesulfonyloxy)benzene, and 1,2,3-tris(p-toluenesulfonyloxy)benzene; diazomethane derivatives, such as bis(benzenesulfonyl)diazomethane, bis(p-toluenesulfonyl) ) diazomethane; glyoxime derivatives such as bis-O-(p-toluenesulfonyl)-α-dimethylglyoxime and bis-O-(n-butanesulfonyl)-α-dimethylglyoxime; sulfonate derivatives of N-hydroxyimide compounds such as N-hydroxysuccinimide methanesulfonate and N-hydroxysuccinimide trifluoromethanesulfonate; and halogen-containing triazine compounds such as 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine and 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-1,3,5-triazine. Suitable photoacid generators are further described in U.S. Pat. No. 5,619,499 and U.S. Pat. No. 5,619,499.

[0100] Typically, when the photoresist composition includes an additional non-polymeric PAG, the PAG is present in the photoresist composition in an amount of from 0.1 to 55 wt %, more typically from 1 to 25 wt %, based on total solids of the photoresist composition. When present in polymeric form, the additional PAG is typically included in the polymer in an amount of from 1 to 25 mol %, more typically from 1 to 8 mol % or 2 to 6 mol %, based on the total repeat units in the polymer.

[0101] The photoresist composition further comprises a solvent for dissolving the components of the composition and facilitating its coating on a substrate. Preferably, the solvent is an organic solvent conventionally used in the manufacture of electronic devices. Suitable solvents include, for example, aliphatic hydrocarbons such as hexane and heptane; aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as dichloromethane, 1,2-dichloroethane, and 1-chlorohexane; alcohols such as methanol, ethanol, 1-propanol, isopropanol, tert-butanol, 2-methyl-2-butanol, 4-methyl-2-pentanol, and diacetone alcohol (4-hydroxy-4-methyl-2-pentanone) (DAA); propylene glycol monomethyl ether (PGME); ethers such as diethyl ether, tetrahydrofuran, 1,4-dioxane, and anisole; acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-heptane, and the like. Examples of suitable solvents include ketones such as ethanol and cyclohexanone (CHO); esters such as ethyl acetate, n-butyl acetate, propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate (EL), hydroxyisobutyrate methyl ester (HBM), and ethyl acetoacetate; lactones such as γ-butyrolactone (GBL) and ε-caprolactone; lactams such as N-methylpyrrolidone; nitriles such as acetonitrile and propionitrile; cyclic or acyclic carbonates such as propylene carbonate, dimethyl carbonate, ethylene carbonate, propylene carbonate, diphenyl carbonate, and propylene carbonate; polar aprotic solvents such as dimethyl sulfoxide and dimethylformamide; water; and combinations thereof. Among these, preferred solvents are PGME, PGMEA, EL, GBL, HBM, CHO, DAA, and combinations thereof.

[0102] The total solvent content (i.e., the cumulative solvent content of all solvents) in a photoresist composition is typically 40 to 99 wt %, for example 60 to 99 wt %, or 85 to 99 wt %, based on the total solids content of the photoresist composition. The desired solvent content will depend, for example, on the desired thickness of the coated photoresist layer and the coating conditions.

[0103] In the photoresist compositions of the invention, the polymer is typically present in the photoresist composition in an amount of from 10 to 99.9 weight percent, typically from 25 to 99 weight percent, and more typically from 50 to 95 weight percent, combined, based on the total solids of the photoresist composition, where total solids will be understood to include the polymer, PAG, and other non-solvent components.

[0104] In some embodiments, the photoresist composition may further comprise a material containing one or more base-labile groups ("base-labile material"). As referred to herein, a base-labile group is a functional group that can undergo a cleavage reaction in the presence of an aqueous alkaline developer after the exposure and post-exposure bake steps to provide a polar group such as a hydroxyl, carboxylic acid, sulfonic acid, or the like. The base-labile group will not significantly react (e.g., will not undergo a bond-breaking reaction) before the development step of a photoresist composition containing the base-labile group. Thus, for example, the base-labile group will be substantially inert during the pre-exposure soft bake, exposure, and post-exposure bake steps. "Substantially inert" means that 5% or less, typically 1% or less, of the base-labile groups (or sites) decompose, cleave, or react during the pre-exposure soft bake, exposure, and post-exposure bake steps. The base-labile group reacts under typical photoresist development conditions, for example, using an aqueous alkaline photoresist developer such as an aqueous solution of 0.26N tetramethylammonium hydroxide (TMAH). For example, a 0.26N aqueous solution of TMAH can be used for single puddle development or dynamic development, where the 0.26N TMAH developer is dispensed onto the imaged photoresist layer for a suitable time, such as 10 to 120 seconds (s). An exemplary base-labile group is an ester group, typically a fluorinated ester group. Preferably, the base-labile material is substantially immiscible with the first and / or second polymers and other solid components of the photoresist composition and has a lower surface energy than the first and / or second polymers and other solid components of the photoresist composition. When coated onto a substrate, the base-labile material can thereby separate from the other solid components of the photoresist composition to the top surface of the formed photoresist layer.

[0105] In some embodiments, the base-labile material can be a polymeric material, also referred to herein as a base-labile polymer, which can include one or more repeating units containing one or more base-labile groups. For example, the base-labile polymer can include repeating units containing two or more base-labile groups, which can be the same or different. Preferred base-labile polymers include at least one repeating unit containing two or more base-labile groups, for example, repeating units containing two or three base-labile groups.

[0106] The base-labile polymer can be prepared using any suitable method in the art, including those described herein for the first and second polymers. For example, the base-labile polymer can be obtained by polymerization of the respective monomers under any suitable conditions, such as heating at an effective temperature, irradiating with actinic radiation at an effective wavelength, or a combination thereof. Additionally or alternatively, one or more base-labile groups can be grafted onto the backbone of the polymer using a suitable method.

[0107] In some embodiments, the base-labile substance is a single molecule containing one or more base-labile ester groups, preferably one or more fluorinated ester groups. Single-molecule base-labile substances typically have an M in the range of 50 to 1,500 Da. W It has.

[0108] If present, the base-labile material is typically present in a photoresist composition in an amount of from 0.01 to 10 weight percent, typically from 1 to 5 weight percent, based on the total solids content of the photoresist composition.

[0109] In addition to or instead of the base-labile polymer, the photoresist composition can further include one or more polymers in addition to and different from the polymers described above. For example, the photoresist composition can be as described above but include an additional polymer having a different composition. Additionally or alternatively, the one or more additional polymers can include those well known in the photoresist art, such as those selected from polyacrylates, polyvinyl ethers, polyesters, polynorbornenes, polyacetals, polyethylene glycols, polyamides, polyacrylamides, polyphenols, novolacs, styrenic polymers, polyvinyl alcohols, or combinations thereof.

[0110] The photoresist composition may further comprise one or more additional optional additives. For example, optional additives may include actinic and contrast dyes, antistriation agents, plasticizers, rate enhancers, sensitizers, photolytic quenchers (PDQs) (also known as photolytic bases), base quenchers, thermal acid generators, surfactants, and the like, or combinations thereof. When present, optional additives are typically present in the photoresist composition in an amount of 0.01 to 10 wt %, based on the total solids content of the photoresist composition.

[0111] PDQ generates a weak acid upon irradiation. The acid generated from the photolytic deactivator is not strong enough to react quickly with acid labile groups present in the resist matrix. Exemplary photolytic deactivators include, for example, photolytic cations, preferably C 1~20 Carboxylic acid or C 1~20 Also included are those useful for preparing strong acid generator compounds paired with anions of weak acids (pKa > 1), such as anions of sulfonic acids. Exemplary carboxylic acids include formic acid, acetic acid, propionic acid, tartaric acid, succinic acid, cyclohexanecarboxylic acid, benzoic acid, salicylic acid, and the like. Exemplary sulfonic acids include p-toluenesulfonic acid, camphorsulfonic acid, and the like. In a preferred embodiment, the photolytic quencher is a photolytic organic zwitterionic compound, such as diphenyliodonium-2-carboxylate.

[0112] The photodegradable deactivator may be in a non-polymeric form or a polymer-bound form. When in a polymeric form, the photodegradable deactivator is present in polymerized units on the first polymer or the second polymer. The polymerized units containing the photodegradable deactivator are typically present in an amount of 0.1 to 30 mol %, preferably 1 to 10 mol %, and more preferably 1 to 2 mol %, based on the total repeat units of the polymer.

[0113] Exemplary basic quenching agents include, for example, straight-chain aliphatic amines such as tributylamine, trioctylamine, triisopropanolamine, tetrakis(2-hydroxypropyl)ethylenediamine, n-tert-butyldiethanolamine, tris(2-acetoxy-ethyl)amine, 2,2′,2″,2′′-(ethane-1,2-diylbis(azanetriyl))tetraethanol, 2-(dibutylamino)ethanol, and 2,2′,2″-nitrilotriethanol; Cycloaliphatic amines such as N-(2-acetoxyethyl)morpholine, N,N-bis(2-hydroxyethyl)pivalamide, N,N-diethylacetamide, N,N-bis(2-hydroxyethyl)pival ... 1 , N 1 , N 3 , N 3linear and cyclic amides and derivatives thereof, such as tetrabutylmalonamide, 1-methylazepan-2-one, 1-allylazepan-2-one, and tert-butyl 1,3-dihydroxy-2-(hydroxymethyl)propan-2-ylcarbamate; ammonium salts, such as quaternary ammonium salts of sulfonates, sulfamates, carboxylates, and phosphonates; imines, such as primary and secondary aldimines and ketimines; optionally substituted diazines, such as pyrazines, piperazines, and phenazines; optionally substituted diazoles, such as pyrazoles, thiadiazoles, and imidazoles; and optionally substituted pyrrolidones, such as 2-pyrrolidone and cyclohexylpyrrolidine.

[0114] The basic quenching agent may be in a non-polymeric form or a polymer-bound form. When in a polymeric form, the quenching agent may be contained in the repeating units of the polymer. The polymerized units containing the quenching agent are typically present in an amount of 0.1 to 30 mol %, preferably 1 to 10 mol %, more preferably 1 to 2 mol %, based on the total repeating units of the polymer.

[0115] Exemplary surfactants include fluorinated and non-fluorinated surfactants, and may be ionic or non-ionic, with non-ionic surfactants being preferred. Exemplary fluorinated non-ionic surfactants include perfluoro C4 surfactants such as FC-4430 and FC-4432 surfactants available from 3M Corporation, and fluorodiols such as POLYFOX PF-636, PF-6320, PF-656 and PF-6520 fluorosurfactants from Omnova. In one embodiment, the photoresist composition further comprises a surfactant polymer comprising a fluorine-containing repeating unit.

[0116] A pattern formation method using the photoresist composition of the present invention is described. Suitable substrates onto which the photoresist composition can be coated include electronic device substrates. A variety of electronic device substrates, such as semiconductor wafers, polycrystalline silicon substrates, packaging substrates such as multichip modules, flat panel display substrates, and substrates for light-emitting diodes (LEDs) such as organic light-emitting diodes (OLEDs), can be used in the present invention, with semiconductor wafers being typical. Such substrates are typically composed of one or more of silicon, polysilicon, silicon oxide, silicon nitride, silicon oxynitride, silicon germanium, gallium arsenide, aluminum, sapphire, tungsten, titanium, titanium-tungsten, nickel, copper, and gold. Suitable substrates can be in the form of wafers, such as those used in the manufacture of integrated circuits, optical sensors, flat panel displays, integrated optical circuits, and LEDs. Such substrates can be of any suitable size. Typical wafer substrate diameters are 200 to 300 millimeters (mm), although wafers with smaller and larger diameters can be suitably used in accordance with the present invention. The substrate can optionally include one or more layers or structures that may comprise active or operational portions of the device being formed.

[0117] Typically, one or more lithographic layers, such as a hardmask layer, e.g., a spin-on carbon (SOC), amorphous carbon, or metal hardmask layer, a CVD layer, such as a silicon nitride (SiN), silicon oxide (SiO), or silicon oxynitride (SiON) layer, an organic or inorganic underlayer, or a combination thereof, are provided on the upper surface of the substrate before coating the photoresist composition of the invention. Such layers, together with an overcoated photoresist layer, form a lithographic material stack.

[0118] Optionally, a layer of adhesion promoter can be applied to the substrate surface before coating with the photoresist composition. If an adhesion promoter is desired, any suitable adhesion promoter for polymer films can be used, such as silanes, typically organosilanes such as trimethoxyvinylsilane, triethoxyvinylsilane, and hexamethyldisilazane, and aminosilane coupling agents such as gamma-aminopropyltriethoxysilane. Particularly suitable adhesion promoters include those sold under the names AP™ 3000, AP™ 8000, and AP™ 9000S, available from DuPont Electronics & Industrial (Marlborough, Massachusetts).

[0119] The photoresist composition can be coated onto a substrate by any suitable method, such as spin coating, spray coating, dip coating, doctor blading, etc. For example, application of a layer of photoresist can be achieved by spin-coating the photoresist in a solvent using a coating truck, in which the photoresist is dispensed onto a rotating wafer. During dispensing, the wafer is typically spun at a speed of up to 4,000 revolutions per minute (rpm), e.g., 200 to 3,000 rpm, e.g., 1,000 to 2,500 rpm, for a period of 15 to 120 seconds, resulting in a layer of photoresist composition on the substrate. Those skilled in the art will understand that the thickness of the coated layer can be adjusted by varying the spin speed and / or the total solids content of the composition. Photoresist composition layers formed from the compositions of the present invention typically have a dry layer thickness of 3 to 30 micrometers (μm), preferably greater than 5 to 30 μm, and more preferably 6 to 25 μm.

[0120] The photoresist composition is typically then soft-baked to minimize the solvent content in the layer, thereby forming a tack-free coating and improving adhesion of the layer to the substrate. Soft-baking is typically performed on a hot plate or in an oven, with a hot plate being typical. The soft-baking temperature and time depend, for example, on the photoresist composition and thickness. The soft-baking temperature is typically 80 to 170°C, more typically 90 to 150°C. The soft-baking time is typically 10 seconds to 20 minutes, more typically 1 minute to 10 minutes, and even more typically 1 minute to 2 minutes. The heating time can be easily determined by one skilled in the art based on the components of the composition.

[0121] The photoresist layer is then patternwise exposed to activating radiation to create a solubility differential between exposed and unexposed regions. References herein to exposing a photoresist composition to radiation activating the composition refer to the radiation being capable of forming a latent image in the photoresist composition. Exposure is typically carried out through a patterned photomask having optically transparent and optically opaque regions corresponding to the exposed and unexposed regions of the resist layer, respectively. Alternatively, such exposure can be carried out without a photomask, as in the direct-write process typically used for electron beam lithography. The activating radiation typically has a wavelength of less than 400 nm, less than 300 nm, or less than 200 nm, with 248 nm (KrF), 193 nm (ArF), 13.5 nm (EUV), or electron beam lithography being preferred. Preferably, the activating radiation is 248 nm radiation. This method is utilized in immersion or dry (non-immersion) lithography techniques. Exposure energies are typically between 1 and 200 millijoules per square centimeter (mJ / cm), depending on the exposure tool and the components of the photoresist composition. 2 ), preferably 10 to 100 mJ / cm 2 , more preferably 20 to 50 mJ / cm 2 is.

[0122] After the photoresist layer is exposed, a post-exposure bake (PEB) of the exposed photoresist layer is performed. PEB can be performed, for example, on a hot plate or in an oven, with a hot plate being typical. PEB conditions depend, for example, on the photoresist composition and layer thickness. PEB is typically performed at a temperature of 70 to 150°C, preferably 75 to 120°C, for 30 to 120 seconds. A latent image is formed in the photoresist, defined by regions where the polarity has been switched (exposed regions) and regions where the polarity has not been switched (unexposed regions).

[0123] The exposed photoresist layer is then developed with a suitable developer to selectively remove areas of the layer that are soluble in the developer, while the remaining insoluble areas form a resulting photoresist pattern relief image. In a positive-tone development (PTD) process, the exposed areas of the photoresist layer are removed during development, leaving behind the unexposed areas. Conversely, in a negative-tone development (NTD) process, the exposed areas of the photoresist layer remain, while the unexposed areas are removed during development. Application of the developer can be accomplished by any suitable method, such as those described above with respect to application of the photoresist composition, with spin coating being typical. The development time is effective to remove the soluble areas of the photoresist, typically between 5 and 60 seconds. Development is typically performed at room temperature.

[0124] Suitable developers for the PTD process include aqueous base developers, such as quaternary ammonium hydroxide solutions such as tetramethylammonium hydroxide (TMAH), preferably 0.26N TMAH, tetraethylammonium hydroxide, tetrabutylammonium hydroxide, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, etc. Developers suitable for the NTD process are organic solvent-based, meaning that the cumulative content of organic solvent in the developer is 50% by weight or more, typically 95% by weight or more, 98% by weight or more, or 100% by weight, based on the total weight of the developer. Suitable organic solvents for NTD developers include, for example, those selected from ketones, esters, ethers, hydrocarbons, and mixtures thereof. The developer is typically 2-heptanone or n-butyl acetate.

[0125] Coated substrates can be formed from the photoresist compositions of the present invention. Such coated substrates include (a) a substrate having one or more layers to be patterned on its surface, and (b) a layer of a photoresist composition over the one or more layers to be patterned.

[0126] The photoresist pattern can be used, for example, as an etch mask, allowing the pattern to be transferred to one or more subsequent underlying layers by known etching techniques, typically dry etching such as reactive ion etching. The photoresist pattern can be used, for example, for pattern transfer to an underlying hard mask layer, which is then used as an etch mask for pattern transfer to one or more layers below the hard mask layer. If the photoresist pattern is not consumed during pattern transfer, it can be removed from the substrate by known techniques, such as oxygen plasma ashing. When used in one or more such pattern formation processes, the photoresist composition can be used to manufacture semiconductor devices such as memory devices, processor chips (CPUs), graphics chips, optoelectronic chips, LEDs, OLEDs, and other electronic devices.

[0127] The present invention is further illustrated by the following non-limiting examples. [Example]

[0128] Synthesis of compound i-1 [ka] To a stirred solution of sodium cyanide (10.0 grams (g), 204.04 millimoles (mmol)) in dimethylformamide (DMF, 120 milliliters (mL)) was added CS2 (15.5 g, 204.04 mmol) dropwise over 45 minutes under an argon atmosphere, and the reaction mixture was then stirred at room temperature for 3 hours. The reaction mixture was then poured into 600 mL of deionized (DI) water, and the resulting mixture was allowed to stand for 12 hours. The resulting sulfur precipitate was removed by filtration, and the filtrate was transferred to a round-bottom flask. A solution of ammonium persulfate (46.5 g, 204.04 mmol) in deionized water (93 mL) was added dropwise to the filtrate over 30 minutes, and the reaction mixture was then stirred at room temperature for 15 minutes. The resulting precipitate, containing the tetracyano product, was collected by filtration, washed with deionized water (200 mL), and dried under vacuum. The precipitate was suspended in CH3CN (600 mL) and filtered. The filtrate was concentrated to give 10.5 g of crude product as a light brown solid. After purification, tetracyanodithiin (i-1) was isolated as a yellow solid (8.5 g, 19% yield) with a purity of 99.95% by ultra-performance liquid chromatography (UPLC). Carbon-13 nuclear magnetic resonance ( 13 C-NMR spectroscopy (100 megahertz (MHz), dimethyl sulfoxide-d6 (DMSO-d6)): chemical shifts (delta, δ): 125.5 parts per million (ppm) and 112.4 ppm.

[0129] Synthesis of compound i-2 [ka] A solution of tetracyanodithiine (i-1) (5.0 g, 23.12 mmol) in 1,2-dichlorobenzene (25 mL) was purged with argon gas for 10 minutes and then heated to 180-200 °C with stirring for 1 hour. The reaction mixture was then cooled to room temperature. The crude solid product was obtained by filtration, washed with hexane (100 mL), and subsequently stirred in ethanol (50 mL) for 30 minutes. The solid was then isolated by filtration and dried. The crude product was dissolved in tetrahydrofuran (THF, 25 mL), 150 mg of activated carbon was added thereto, and the resulting mixture was heated to 50 °C with stirring for 15 minutes. After this time, the mixture was filtered through a pad of diatomaceous earth and rinsed with THF (25 mL). The resulting filtrate was concentrated to provide 1.2 g of compound i-2 as a light brown solid with a purity of 97% by UPLC. 13 C-NMR spectroscopy (100 MHz, DMSO-d): δ: 125.0 ppm, 120.7 ppm, and 110.0 ppm.

[0130] Synthesis of compound i-3 [ka] In a three-necked round-bottom flask, (3-bromopropoxy)(tert-butyl)dimethylsilane (20.0 g, 78.97 mmol), sodium trifluoromethanesulfinate (16.0 g, 102.66 mmol), and DMF (200 mL) were combined under an argon atmosphere. The reaction mixture was heated to 120 °C and stirred under an argon atmosphere for 12 hours. The reaction was then allowed to cool to room temperature. The crude product was collected, dissolved in ethyl acetate (100 mL), washed with deionized water (2 × 40 mL) and brine (1 × 20 mL), and the organic layer was then separated, dried over anhydrous NaSO, filtered, and concentrated under reduced pressure to give 25 g of crude product as a light brown liquid. The crude product was purified by column chromatography using silica gel and 6% by volume dichloromethane in petroleum ether as the eluent. Compound i-3 (10.8 g) was obtained as a colorless liquid in 45% yield with a purity of 89% by gas chromatography-mass spectrometry (GC-MS).1 H-NMR) spectroscopy (400MHz, CDCl3), δ:3.75ppm(t,2H),3.33-3.38ppm(m,2H),2.08-2.15ppm(m,2H),0.91ppm(s,9H),0.07ppm(s,6H).

[0131] Synthesis of i-4 [ka] A solution of compound i-3 (2.0 g, 6.53 mmol) in THF (18 mL) was added dropwise to a stirred solution of 60 wt% NaH (783 mg, 19.57 mmol) in THF (8 mL) and DMF (4 mL) at 0 °C under an argon atmosphere. The resulting reaction mixture was stirred at 0 °C for 1 hour and then cooled to -40 °C. A solution of compound i-2 (1.32 g, 7.18 mmol) in THF (18 mL) was added thereto, and the reaction mixture was stirred at -40 °C for 2 hours. The reaction mixture was quenched with deionized water (40 mL) and then extracted with ethyl acetate (2 × 40 mL), and the product was then washed with brine (20 mL). The organic layer was separated and dried over anhydrous NaSO, and the resulting product was evaporated under reduced pressure to give 2.2 g of crude compound as a dark brown liquid. The crude compound was purified by column chromatography using silica and gradually eluting with 10-40% CH3CN in DCM. Yield 800 mg (35%). 1 H-NMR (400MHz, CDCl3), δ:3.70ppm(t,2H),2.71ppm(t,2H),0.84ppm(s,9H),-0.1ppm(s,6H).

[0132] Synthesis of PAG-1 [ka] In a 100 mL round-bottom flask equipped with a stir bar and a rubber septum, compound i-4 (0.346 g, 1.0 mmol) and triphenylsulfonium bromide (0.342 g, 1.0 mmol) were dissolved in a mixture of dichloromethane (10 mL) and deionized water (10 mL). The reaction mixture was stirred at room temperature for 2 h. The organic layer was separated and washed with deionized water (2 × 10 mL). The organic solvent was partially removed under reduced pressure (80% of the volume), and the concentrated solution was slowly poured into a vessel containing 25 mL of methyl t-butyl ether (MTBE), expected to produce PAG-1 as a solid, which was then filtered and dried.

[0133] Preparation of the photoresist composition A positive photoresist composition is prepared by first combining 7.73 g of polymer solution (10 wt % polymer P1 in PGMEA), 10.8 g of PAG-1 solution (1 wt % in methyl-2-hydroxyisobutyrate (HBM)), and 2.2 g of tert-butyl (1,3-dihydroxy-2-(hydroxymethyl)propan-2-yl)carbamate solution (1 wt % in PGMEA). 2.97 g of PGMEA and 6.10 g of HBM are added to the mixture. The resulting mixture is then filtered through a 0.2 μm PTFE filter to provide the photoresist composition. [ka]

[0134] Lithography Testing The above photoresist composition is spin-coated onto an 80 nm AR™ 40 underlayer (DuPont Electronics & Industrial) on a 300 mm silicon wafer, followed by a soft bake at 90°C for 60 seconds to a dry thickness of 90 nm. The resist coating layer is exposed to 193 nm radiation through a patterned mask. The exposed wafer is baked at 100°C for 60 seconds, and the resist layer is developed in a 0.26 N TMAH solution. A patterned photoresist layer is expected.

[0135] While the present disclosure has been described in connection with what are presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. an organic cation which is a sulfonium cation or an iodonium cation; an anion containing an anionic core containing a cyclopentadienide group; A photoacid generator comprising: the cyclopentadienide group is substituted with an organic group containing a metalloid element; the anion is substituted with one or more electron-withdrawing groups; The anion is represented by the formulas (1) to (3): 【Chemistry 1】 and In formulas (1) to (3), E 1 , E 2 , E 3 , E 4 and E 5 are each independently an electron-withdrawing group; n1 is an integer from 1 to 4, n2 is an integer from 0 to 4, and n3 is an integer from 0 to 2, provided that at least one of n2 and n3 is not 0; n4 and n5 each independently represent an integer of 0 to 4, provided that at least one of n4 and n5 is not 0; m1 is an integer from 0 to 3, m2 is an integer from 0 to 4, and m3 is an integer from 0 to 2; m4 and m5 each independently represent an integer of 0 to 4, R 1 , R 2 , R 3 , R 4 and R 5 are each independently substituted or unsubstituted C 1-30 alkyl, substituted or unsubstituted C 1-30 heteroalkyl, substituted or unsubstituted C 4-30 cycloalkyl, substituted or unsubstituted C 3-20 heterocycloalkyl, substituted or unsubstituted C 6-30 aryl, substituted or unsubstituted C 7-30 arylalkyl, substituted or unsubstituted C 7-30 alkylaryl, substituted or unsubstituted C 3-30 heteroaryl, substituted or unsubstituted C 4-30 heteroarylalkyl or substituted or unsubstituted C 4-30 alkylheteroaryl; each of R 1 , R 2 , R 3 , R 4 and R 5 optionally further includes one or both of a divalent linking group or a polymerizable group as part of its structure; L 1 , L 2 and L 3 are each independently a single bond or a divalent linking group; and Y 1 , Y 2 and Y 3 are each independently the organic group containing the metalloid element; the metalloid element is selected from B, Si, Ge, As, Te, Sb, Se, or a combination thereof; each electron withdrawing group is independently selected from halogen, substituted or unsubstituted C 1-20 haloalkyl, substituted or unsubstituted C 6-20 aryl, substituted or unsubstituted C 3-20 heteroaryl, —OR 6 , —SR 7 , —NO 2 , —CN, —C(O)R 8 , —C(O)OR 9 , —C(O)NR 10 R 11 , —S(O) 2 OR 12 , —S(O) 2 R 13 , —OS(O) 2 R 14 or combinations thereof; R 6 to R 12 are each independently hydrogen, substituted or unsubstituted C 1-20 alkyl, substituted or unsubstituted C 3-20 cycloalkyl, substituted or unsubstituted C 3-20 heterocycloalkyl, substituted or unsubstituted C 6-20 aryl, substituted or unsubstituted C 7-20 alkylaryl, substituted or unsubstituted C 7-20 arylalkyl, substituted or unsubstituted C 3-20 heteroaryl, substituted or unsubstituted C 4-20 alkylheteroaryl, or substituted or unsubstituted C 4-20 heteroarylalkyl; R 13 and R 14 are each independently substituted or unsubstituted C 1-20 alkyl, substituted or unsubstituted C 4-20 cycloalkyl, substituted or unsubstituted C 3-20 heterocycloalkyl, substituted or unsubstituted C 6-20 aryl, substituted or unsubstituted C 7-20 alkylaryl, substituted or unsubstituted C 7-20 arylalkyl, substituted or unsubstituted C 3-20 heteroaryl, substituted or unsubstituted C 4-20 alkylheteroaryl, or substituted or unsubstituted C 4-20 heteroarylalkyl; A photoacid generator in which none of E 1 to E 5 contains fluorine.

2. Y １ , Y ２ and Y ３ are each independently represented by formulas (4) to (6): 【Chemistry 2】 and in formulas (4) to (6), Z １ is Se, Te, Se—Se, or Te—Te, Z ２ is B, As, AsO, Sb or SbO, Z ３ is Si, Ge or Te, R １９ is cyano, substituted or unsubstituted C １～２０ Alkyl, substituted or unsubstituted C １～２０ Alkoxy, substituted or unsubstituted C ４～２０ Cycloalkyl, substituted or unsubstituted C ２～２０ Alkenyl, substituted or unsubstituted C ６～３０ Aryl, substituted or unsubstituted C ６～３０ Aryloxy, substituted or unsubstituted C ３～３０ Heteroaryl, substituted or unsubstituted C ３～３０ Heteroaryloxy, substituted or unsubstituted C ７～２０ Arylalkyl or substituted or unsubstituted C ４～２０ heteroarylalkyl, and R １９ optionally further includes a divalent linking group as part of its structure; R ２０ and R ２１ are each independently hydrogen, halogen, cyano, substituted or unsubstituted C １～２０ Alkyl, substituted or unsubstituted C １～２０ Alkoxy, substituted or unsubstituted C ４～２０ Cycloalkyl, substituted or unsubstituted C ２～２０ Alkenyl, substituted or unsubstituted C ２～２０ Alkynyl, substituted or unsubstituted C ６～３０ Aryl, substituted or unsubstituted C ６～３０ Aryloxy, substituted or unsubstituted C ３～３０ Heteroaryl, substituted or unsubstituted C ３～３０ Heteroaryloxy, substituted or unsubstituted C ７～２０ Arylalkyl or substituted or unsubstituted C ４～２０ heteroarylalkyl, and R ２０ and R ２１ each optionally further includes a divalent linking group as part of its structure; However, R ２０ and R ２１ at least one of is an organic group; R ２０ and R ２１ are optionally linked to each other via a single bond or a divalent linking group to form a ring, said ring being substituted or unsubstituted; R ２２ ~R ２４ are each independently hydrogen, halogen, cyano, substituted or unsubstituted C 1～２０ Alkyl, substituted or unsubstituted C １～２０ Alkoxy, substituted or unsubstituted C ４～２０ Cycloalkyl, substituted or unsubstituted C ２～２０ Alkenyl, substituted or unsubstituted C ２～２０ Alkynyl, substituted or unsubstituted C ６～３０ Aryl, substituted or unsubstituted C ６～３０ Aryloxy, substituted or unsubstituted C ３～３０ Heteroaryl, substituted or unsubstituted C ３～３０ Heteroaryloxy, substituted or unsubstituted C ７～２０ Arylalkyl or substituted or unsubstituted C ４～２０ heteroarylalkyl, However, R ２２ ~R ２４ at least one of is an organic group; R ２２ ~R ２４ each optionally further includes a divalent linking group as part of its structure; R ２２ ~R ２４ are optionally linked to each other via a single bond or a divalent linking group to form a ring, said ring being substituted or unsubstituted; and ＊ Is Y １ About L １ Binding site to Y ２ About L ２ Binding site to Y ３ About L ３ 2. The photoacid generator of claim 1, wherein the photoacid generator exhibits a binding site to

3. 3. The photoacid generator according to claim 1, wherein the anion comprises three or more --CN groups and at least one Si atom.

4. n1 is an integer of 3 or more, n2+n3 is an integer greater than or equal to 3, and 4. The photoacid generator according to claim 1, wherein n4+n5 is an integer of 3 or more.

5. 5. The photoacid generator according to claim 1, wherein the electron-withdrawing group is —CN.

6. The photoacid generator according to any one of claims 1 to 5, which is in the form of (i) a monomer containing a polymerizable double bond, or (ii) a polymer.

7. A polymer; A photoacid generator according to any one of claims 1 to 6, optionally being part of the polymer; Solvent and A photoresist composition comprising:

8. 1. A method of forming a pattern, comprising: (a) forming a photoresist layer on a substrate from the photoresist composition of claim 7; (b) patternwise exposing the photoresist layer to activating radiation; (c) developing the exposed photoresist layer to provide a resist relief image.

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