Photoacid generators, photoresist compositions, and pattern formation methods

Abstract

To provide photoacid generators, photoresist compositions, and pattern formation methods.SOLUTION: Provided is a photoacid generator comprising an organic cation and an anion having an anionic core that includes a cyclopentadienide group, wherein the cyclopentadienide group is substituted with an organic group containing a metalloid element, and the anion is substituted with one or more electron-withdrawing groups.SELECTED DRAWING: None

Description

[Technical field]

[0001] PHOTOACID GENERATORS AND METHODS OF PATTERNING USING SUCH PHOTORESIST COMPOSITIONS FIELD OF THEINVENTION 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 having 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 employ 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 to form a positive image. The resulting relief image allows 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. Pat. 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 that includes an organic cation and an anion that includes an anionic core that includes a cyclopentadienide group, where the cyclopentadienide group is substituted with an organic group that includes 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 PREFERRED EMBODIMENTS

[0009] Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the present description. In this regard, the exemplary embodiments may have different forms and should not be construed as being limited to the description set forth herein. Accordingly, exemplary embodiments are described below by reference to the figures only to explain 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. A phrase such as "at least one of," when preceding a list of elements, modifies the entire list of elements and does not modify each individual element of the list.

[0010] As used herein, the terms "a," "an," and "the" do not denote a limitation on quantity 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 otherwise indicated. The modifier "about," used in connection with a quantity, is inclusive of the stated value and has the meaning dictated by the context, including, for example, the degree of error associated with measurement of the particular quantity. All ranges disclosed herein are inclusive of the endpoints, which are independent and combinable with 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 event or circumstance described thereafter 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 an 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 there may be intervening elements 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 those skilled in the art to which the present 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 be further understood not to be interpreted in an ideal or overly formal sense unless expressly defined in this specification.

[0012] In this disclosure, "actinic rays" or "radiation" refers to, for example, the emission line spectrum of a mercury lamp, far ultraviolet light represented by an excimer laser, extreme ultraviolet light (EUV light), X-rays, particle rays such as electron beams and ion beams, etc. Furthermore, in the present 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" is an abbreviation for "excimer dimer" and "exciplex" is an abbreviation for "excimer complex". Excimer lasers use a mixture of rare gases (argon, krypton, or xenon) and halogen gases (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 to far ultraviolet light represented by a mercury lamp or an excimer laser, X-rays, extreme ultraviolet light (EUV light), and the like, but also writing with 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 "carboxyl" are examples of alkyl groups that are substituted with at least one hydroxyl group (-OH); "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 linear or branched 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 an alkyl 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; the term "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; the term "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 carbon atoms in the ring; "aryl" refers to a cyclic or polycyclic aromatic group that contains at least one heteroatom (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 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 (for monocyclic), 1-6 heteroatoms (for bicyclic), or 1-9 heteroatoms (for 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, for monocyclic, bicyclic, or tricyclic rings). 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 of a fluoro, chloro, bromo, or iodo substituent 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 by one or more halogens. As used herein, "substituted C 1~8 "Haloalkyl" means a C substituted with at least one halogen. 1~8It refers to an alkyl group, which is further substituted with one or more other substituents other than halogen. It should be understood that the substitution of a group with a halogen atom is not considered a heteroatom-containing group because a halogen atom does not replace a carbon atom.

[0016] Unless expressly provided otherwise, each of the above substituents may 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 is 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., =O), two geminal hydrogen atoms on a carbon atom are replaced with terminal oxo groups. It is further noted that an oxo group is bonded to a carbon through a double bond to form a carbonyl (C=O), and the carbonyl group is represented herein as -C(O)-. Combinations of substituents or variables are permitted. Exemplary substituents that may be present at the "substituted" position include nitro (-NO 2 ), cyano (-CN), hydroxyl (-OH), oxo (O), amino (-NH 2 ), mono- or di-(C 1~6 ) Alkylamino, alkanoyl (acyl, etc.) 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 2 where R is hydrogen or C 1~6 alkyl), carboxamide (-CH 2 C(O)NR 2 where R is hydrogen or C 1~6 alkyl), halogen, thiol (-SH), C 1~6 Alkylthio (-S-alkyl), thiocyano (-SCN), C1~6 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, C 2~18 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 1-3 separate or fused rings and 6-18 ring carbon atoms 7~19 Arylalkyl, arylalkoxy having 1-3 separate or fused rings and 6-18 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 Arylsulfonyl, (-S(O) 2 -aryl) or tosyl (CH 3 C 6 H 4 SO 2 -). If a group is substituted, the indicated number of carbon atoms is the total number of carbon atoms in the group, excluding the carbon atoms of any substituents. For example, the group -CH 2 CH 2 CN is a C substituted with a cyano group. 2 It is an alkyl 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 3~30Cycloalkylene, substituted or unsubstituted C 3~30 Heterocycloalkylene, substituted or unsubstituted C 6~30 Arylene, substituted or unsubstituted C 3~30 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 3~30 Typically, 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 at least one of 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 C3~10 It is heteroaryl.

[0018] As used herein, "acid labile group" refers to a group that, under the catalysis of an acid, optionally and typically with thermal treatment, undergoes bond cleavage, resulting in the formation of a polar group, such as a carboxylic acid group or an alcohol group, formed on a polymer, and optionally and typically the moiety connected to the cleaved bond is detached from the polymer. In another system, a non-polymeric compound can contain an acid labile group that can be cleaved by the action of an acid, and a polar group, such as a carboxylic acid group or an alcohol group, is formed on 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, and 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 with 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 cleavable groups" and "acid sensitive groups".

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

[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 combinations 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 is selected from the group consisting of -F, -CF 3 or -CF 2 - does not contain a - group. 3 or -CF 2 "Does not contain a -CH group" means that the anion of the photoacid generator is -CH 2 CF 3 and -CH 2 CF 2 CH 3 It should be understood that this is meant to exclude groups such as. In yet other embodiments, the anion of the photoacid generator is non-fluorine-containing (i.e., does not contain a fluorine atom and is not substituted with a fluorine-containing group). In some embodiments, the photoacid generator is non-fluorine-containing (i.e., both the organic cation and the anion are non-fluorine-containing).

[0021] The anionic core comprises a cyclopentadienide group. The cyclopentadienide anionic group can be optionally fused to one or two phenyl groups. In some embodiments, the anionic core comprises a cyclopentadienide group fused to one or two C6 aryl groups. It should be understood that when a cyclopentadienide group is fused to one C6 aryl group, the resulting fused ring contains 9 carbon ring atoms, and when a cyclopentadienide group is fused to two C6 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] PAG can be in a non-polymeric form or in a polymeric form, present as part of a repeat unit of a polymer.For example, PAG can be in the form of a polymerizable PAG monomer, or as a polymer derived from such a monomer.When PAG is in a polymeric form, it can be included as a group that is pendant to the polymer backbone, or it can 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. EWGs are weak electron withdrawing groups such as halogens, and moderate electron withdrawing groups such as aldehydes (-CHO), ketones (-COR), carboxylic acids (-CO 2 H), carboxylate esters (-CO 2 R) or amide (-CONH 2 ) or strong electron withdrawing groups such as trihalides (-CF 3 , CCl 3 ), cyano (-CN), sulfone (-SO 2 R), sulfonate (-OSO 2 R) or nitro (-NO 2In some embodiments, each electron withdrawing group can be 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 , -NO 2 , -CN, -C(O)R 8 , -C(O)OR 9 , -C(O)NR 10 R 11 , -S(O) 2 OR 12 , -S(O)R 13 , -S(O) 2 R 14 , -OS(O) 2 R 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 C4~20 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)R 14 and R 8 , R 9 , R 13 and R 14 is as defined herein. In some embodiments, E 1 ~E 5 Each of the above is non-fluorine containing.

[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 of 0 to 4, and n3 is an integer of 0 to 2, with the proviso that at least one of n2 and n3 is not 0. In other words, formula (2) does not include E as a ring group substituent. 2 Or E 3 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+n3 can be an integer equal to or greater than 3.

[0028] In formula (3), n4 and n5 are each independently 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 5Preferably, 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+n5 can be an integer equal to or greater than 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. It should be understood that when m1 is 0, 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, 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 can be 4, and the sum of n5 and m5 can 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 R5 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 C 4~11 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 the 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 Alkenyl or substituted or unsubstituted norbornyl, preferably (meth)acrylate or C 2 It may be 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 which is substituted or unsubstituted, and the ring is substituted or unsubstituted. 1 The groups do not join together to form a ring.

[0039] In formula (2), two or more adjacent R 2The 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 In formula (2), two or more adjacent 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. 3 In formula (2), two or more adjacent R 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. 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 which is substituted or unsubstituted, and the ring is substituted or unsubstituted. 4 In formula (3), two or more adjacent 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. 5 In formula (3), two or more adjacent R 4 and R 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 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 are substituted or unsubstituted C 1~30 Alkylene, substituted or unsubstituted C 4~30 Cycloalkylene, substituted or unsubstituted C 3~30 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 each independently represents a single bond or a substituted or unsubstituted C 1~10 In some embodiments, L is a divalent linking group selected from one or more of alkylene, -O-, -C(O)-, and / or -C(O)O-. 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 Group 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 which is substituted or unsubstituted, and the ring is substituted or unsubstituted.1 and L 1 do not form a ring together.

[0043] In formula (2), one or more R 2 Group 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 which is substituted or unsubstituted, and the ring is substituted or unsubstituted. 2 and L 2 do not form a ring together. In formula (2), one or more R 3 Group 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 which is substituted or unsubstituted, and the ring is substituted or unsubstituted. 3 and L 2 do not form a ring together.

[0044] In formula (3), one or more R 4 Group 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 which is substituted or unsubstituted, and the ring is substituted or unsubstituted. 4 and L 3 do not form a ring together. In formula (3), one or more R 5 Group 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 which is substituted or unsubstituted, and the ring is 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 Y 3 are each independently represented 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 of them represents a binding site for

[0047] In formula (4), Z 1 may be selenium (Se), tellurium (Te), Se-Se or Te-Te. 1 is Te.

[0048] In formula (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 formula (6), Z 3can be silicon (Si), germanium (Ge) or tellurium (Te). 3 is silicon (Si) or germanium (Ge).

[0050] In formula (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 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, R 19 optionally further comprises a divalent linking group as part of its structure. 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 formula (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 C6~30 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 is preferred. 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 formula (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 formula (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 formula (5), R 20 and R 21 may be optionally linked to each other via a single bond or one or more divalent linking groups to form a ring, which may be substituted or unsubstituted. For example, R 20 and R 21 is represented by 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 a substituted or unsubstituted C1~10 Alkyl, C a1 and C a2 taken together optionally form a ring, which can be substituted or unsubstituted.

[0055] In formula (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 2~20 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 is preferred. 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 formula (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 Two or more of may be optionally linked to each other via a single bond or one or more divalent linking groups to form a ring, which may 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 yet 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] It may be represented by one or more of:

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

[0062] In formulae (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, When it is Ge or Te, 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)-(3).

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

[0065] In formulae (1a), (2a) and (3a), R 1 , R 2 , R 3 , R 4 and R 5 are each independently as defined for formulae (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 3The 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. 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 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.

[0066] In formulae (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 an alkyl.

[0067] In formulae (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 C2 ~20 Alkynyl, substituted or unsubstituted C6~14 It may be aryl. Preferably, R 24a are each independently substituted or unsubstituted C 1~5 It is an 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 C 3~30 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 In some embodiments, L is a divalent linking group selected from one or more of alkylene, -O-, -C(O)-, and / or -C(O)O-. 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] It may be represented by one or more of:

[0070] In formulae (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 formulae (1b), (1c), (2b) and (3b), x and y are each 0 or 1. For example, M 1When 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 When is Si, Ge, or Te, x and y are both 1.

[0072] In formulae (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). 1 is 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) 2 R 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, 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 C6~14 Aryl or substituted or unsubstituted C 3~20 Preferably, each A is 2 are independently hydrogen, -CN, -C(O)R 8a , -C(O)OR 9a , -S(O)R 13a Or -S(O) 2 R 14a and R 8a and R 9a are each independently hydrogen, substituted or unsubstituted C 1~5 Alkyl or substituted or unsubstituted C 6~14 aryl, 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) 2 R 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, 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, A3 ~A 8 are each independently -CN, -C(O)R 8b , -C(O)OR 9b , -S(O)R 13b Or -S(O) 2 R 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, R 13b and R 14b are each independently a substituted or unsubstituted C 1~5 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 that includes an ethylenically unsaturated double bond, such as a substituted or unsubstituted C 2~20 Alkenyl or substituted or unsubstituted norbornyl, preferably (meth)acrylate or C 2 It may contain 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 6~30 Aryl, substituted or unsubstituted C 3~30 Heteroaryl, substituted or unsubstituted C 7~20 Arylalkyl or substituted or unsubstituted C 4~20 heteroarylalkyl or a combination thereof. 30 ~R 34 Each of R is independently or is linked to another group R via a single bond or a divalent linking group. 30 ~R 34 may 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 Each of may optionally include acid labile groups independently 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 + R 15 R 16 OR -I + R 15 where R 15 and R 16 is as defined above, which provides a cationic substituent on the anion. Suitable zwitterionic photoacid generators include, for example, the following: [ka] [ka]

[0083] The 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 that contain 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, and 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 a repeat unit having an acid labile group is present in the polymer, it is 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 that have base-solubilizing groups and / or have 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 are: [ka] [ka] wherein R i is hydrogen, halogen (e.g., F, Cl, Br, I), substituted or unsubstituted C 1~6 Alkyl or substituted or unsubstituted C 1~6 It is cycloalkyl.

[0091] The polymer may optionally further comprise one or more additional repeat units. The additional repeat 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 repeat units may be used in an amount of 50 mol % or less, typically 3 to 50 mol %, based on the total repeat 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 polymer typically has a weight average molecular weight (Mw) 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. The polydispersity index (PDI) of the first polymer, which is the ratio of Mw to number average molecular weight (Mn), 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 such as those described above with respect to the PAGs of the invention (e.g., those of formulas (6a) and (6b)), preferably iodonium or sulfonium cations. Particularly suitable anions include those whose conjugate acids have a pKa 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; sulfonic acid 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, 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 (Patent Document 1) and (Patent Document 2).

[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 weight percent, more typically from 1 to 25 weight percent, 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, methyl ethyl ketone ... Examples of suitable solvents include ketones such as tetrahydrofuran 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 dimethylsulfoxide 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 in a photoresist composition (i.e., the cumulative solvent content for all solvents) is typically 40 to 99% by weight, such as 60 to 99% by weight or 85 to 99% by weight, 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 photoresist compositions of the invention, the polymer is typically present in the photoresist composition in an amount of from 10 to 99.9%, typically from 25 to 99%, more typically from 50 to 95% by weight combined, based on the total solids content of the photoresist composition, it being understood that total solids includes the polymer, PAG and other non-solvent components.

[0104] In some embodiments, the photoresist composition may further comprise a material that comprises 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, etc. The base labile group will not significantly react (e.g., will not undergo a bond scission reaction) prior to the development step of the photoresist composition that comprises 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. By "substantially inert" it is meant 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 groups react under typical photoresist development conditions using, for example, an aqueous alkaline photoresist developer such as an aqueous solution of 0.26 normal (N) tetramethylammonium hydroxide (TMAH). For example, a 0.26N aqueous solution of TMAH can be used for single puddle development or dynamic development, e.g., 0.26N TMAH developer is dispensed into the imaged photoresist layer for a suitable time, such as 10-120 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 polymer and other solid components of the photoresist composition, and has a lower surface energy than the first and / or second polymer and other solid components of the photoresist composition. When coated onto a substrate, the base labile material may 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, and the base labile polymer can include one or more repeat units that include one or more base labile groups. For example, the base labile polymer can include repeat units that include two or more base labile groups, which can be the same or different. A preferred base labile polymer includes at least one repeat unit that includes two or more base labile groups, for example, a repeat unit that includes two or three base labile groups.

[0106] The base labile polymer can be prepared by 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.In addition or alternatively, one or more base labile groups can be grafted onto the backbone of the polymer by a suitable method.

[0107] In some embodiments, the base labile material is a single molecule that includes one or more base labile ester groups, preferably one or more fluorinated ester groups. Single molecule base labile materials typically have a MW in the range of 50 to 1,500 Da.

[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 may further comprise one or more polymers in addition to and different from the above-mentioned polymers.For example, the photoresist composition may comprise an additional polymer as described above, but with a different composition.In addition or instead, the one or more additional polymers may include those well known in the photoresist technology, such as those selected from polyacrylates, polyvinyl ethers, polyesters, polynorbornenes, polyacetals, polyethylene glycols, polyamides, polyacrylamides, polyphenols, novolacs, styrene-based polymers, polyvinyl alcohols, or combinations thereof.

[0110] The photoresist composition may further include one or more additional optional additives. For example, the optional additives may include actinic and contrast dyes, anti-striation 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, the 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 when irradiated. 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, cyclohexane carboxylic 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 in a polymer-bound form. When in a polymeric form, the photodegradable deactivator is present in a polymerized unit on the first polymer or the second polymer. The polymerized unit containing the photodegradable deactivator is 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 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-acetoxy-ethyl)morpholine, N,N-bis(2-hydroxyethyl)pivalamide, N,N-diethylacetamide, N,N-bis(2-hydroxyethyl)pyridine ... 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 in a polymer-bound form. When in a polymeric form, the quenching agent may be included in the repeating unit of the polymer. The polymerized unit containing the quenching agent is 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 unit of the polymer.

[0115] Exemplary surfactants include fluorinated and non-fluorinated surfactants, and can 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 that comprises a fluorine-containing repeat unit.

[0116] A method of forming a pattern using the photoresist composition of the present invention is described. Suitable substrates on 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; substrates for light emitting diodes (LEDs) such as organic light emitting diodes (OLEDs), and the like, 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, optical integrated circuits, and LEDs. Such substrates can be of any suitable size. A typical wafer substrate has a diameter of 200-300 millimeters (mm), although wafers having 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 include 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 prior to 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 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, hexamethyldisilazane, aminosilane coupling agents such as gamma-aminopropyltriethoxysilane, etc. 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 may be coated on the substrate by any suitable method, such as spin coating, spray coating, dip coating, doctor blading, and the like. For example, application of a layer of photoresist may be accomplished by spin coating the photoresist in a solvent using a coating track, where 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), such as 200-3,000 rpm, e.g., 1,000-2,500 rpm, for a period of 15-120 seconds, resulting in a layer of photoresist composition on the substrate. It will be understood by those skilled in the art that the thickness of the coated layer may be adjusted by varying the spin speed and / or the total solids content of the composition. The photoresist composition layer formed from the composition of the present invention typically has a dry layer thickness of 3-30 micrometers (μm), preferably greater than 5-30 μm, more preferably 6-25 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 the adhesion of the layer to the substrate. The soft bake is performed, for example, on a hot plate or in an oven, with a hot plate being typical. The temperature and time of the soft bake depend, for example, on the photoresist composition and thickness. The soft bake temperature is typically 80 to 170°C, more typically 90 to 150°C. The soft bake 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 readily determined by one of ordinary skill 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 difference between exposed and unexposed regions. Reference herein to exposing the photoresist composition to radiation activating for the composition refers to the radiation being capable of forming a latent image in the photoresist composition. Exposure is typically performed 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 performed without a photomask, as in direct write processes 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, and is preferably 248 nm (KrF), 193 nm (ArF), 13.5 nm (EUV), or electron beam lithography. 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 It is.

[0122] After exposure of the photoresist layer, 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. The PEB conditions depend, for example, on the photoresist composition and the thickness of the layer. PEB is typically performed at a temperature of 70-150°C, preferably 75-120°C, for 30-120 seconds. A latent image is formed in the photoresist, defined by areas where the polarity has been switched (exposed areas) and areas where the polarity has not been switched (unexposed areas).

[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 resultant photoresist pattern relief image. In a positive tone development (PTD) process, the exposed areas of the photoresist layer are removed during development, while the unexposed areas remain. 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 an amount of time effective to remove the soluble areas of the photoresist, with times of 5 to 60 seconds being typical. 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 0.26 normal (N) 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] A coated substrate can be formed from the photoresist composition of the invention. Such a coated substrate comprises (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, thereby allowing the pattern to be transferred to one or more successive 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, for example oxygen plasma ashing. When the photoresist composition is used in one or more such patterning processes, it can be used to manufacture semiconductor devices such as memory devices, processor chips (CPUs), graphic chips, optoelectronic chips, LEDs, OLEDs, and other electronic devices.

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

[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)), CS2 (15.5 g, 204.04 mmol) was added dropwise over 45 minutes under 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 sulfur precipitate thus formed was removed by filtration, and the filtrate was transferred into 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 collected by filtration and washed with DI water (200 mL) and dried under vacuum. 3 The mixture was suspended in CN (600 mL) and filtered. The filtrate was concentrated to give 10.5 g of crude product as a light brown solid. After purification, tetracyanodithiine (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), dimethylsulfoxide-d 6 (DMSO-d 6 )): 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 min and then heated to 180-200 °C with stirring for 1 h. The reaction mixture was then cooled to room temperature. The crude solid product was obtained by filtration, washed with hexane (100 mL), followed by stirring in ethanol (50 mL) for 30 min, then the solid was isolated by filtration and dried. The crude product was dissolved in tetrahydrofuran (THF, 25 mL), 150 mg of activated charcoal was added thereto, and the thus obtained mixture was heated to 50 °C with stirring for 15 min. After this time, the mixture was filtered through a pad of diatomaceous earth and rinsed with THF (25 mL). The obtained 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-d6): δ: 125.0 ppm, 120.7 ppm and 110.0 ppm.

[0130] Synthesis of compound i-3 [ka] In a three-neck 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 for 12 hours under an argon atmosphere. 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), then the organic layer was separated and washed with anhydrous Na 2 SO 4The mixture was dried over 1000 ml, 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 of 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). Proton nuclear magnetic resonance ( 1 H-NMR) spectroscopy (400MHz, CDCl 3 ), 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 argon atmosphere. The reaction mixture thus obtained was stirred at 0° C. for 1 h 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 h. 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 washed with anhydrous Na 2 SO 4 The product thus obtained was dried under reduced pressure to give 2.2 g of crude compound as a dark brown liquid. The crude compound was purified by elution using silica and 10-40% CH in DCM. 3 Purified by column chromatography slowly eluting with CN. Yield 800 mg (35%). 1 H-NMR (400MHz, CDCl 3 ), 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) are dissolved in a mixture of dichloromethane (10 mL) and deionized water (10 mL). The reaction mixture is stirred at room temperature for 2 h. The organic layer is separated and washed with deionized water (2 x 10 mL). The organic solvent is partially removed under reduced pressure (80% of the volume) and the concentrated solution is slowly poured into a vessel containing 25 mL of methyl t-butyl ether (MTBE) with the expectation of producing PAG-1 as a solid, which is 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 % of 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 a 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 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 comprising an anionic core containing a cyclopentadienide group; A photoacid generator comprising: the cyclopentadienide group is substituted with an organic group containing a metalloid element; A photoacid generator, wherein the anion is substituted with one or more electron-withdrawing groups.

2. The anion has the formula (1) to (3): 【Chemistry 1】 In the 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, with the proviso that at least one of n2 and n3 is not 0; n4 and n5 each independently represent an integer from 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; R １ , R ２ , R ３ , R ４ and R ５ each optionally further comprises as part of its structure one or both of a divalent linking group or a polymerizable group; 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, 2. The photoacid generator of claim 1, wherein the metalloid element is selected from B, Si, Ge, As, Te, Sb, Se, or a combination thereof.

3. Each electron withdrawing group is 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 , -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 ~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, However, E １ ~E ５ 3. The photoacid generator according to claim 1, wherein none of the above groups contains fluorine.

4. Y １ , Y ２ and Y ３ are each independently represented by formulas (4) to (6): 【Chemistry 2】 In the 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, 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, 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 for Y ２ About L ２ Binding site to Y ３ About L ３ 4. The photoacid generator of claim 2 or 3, wherein the photoacid generator exhibits a binding site to

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

6. n1 is an integer of 3 or more, n2+n3 is an integer equal to or greater than 3; and 6. The photoacid generator according to claim 1, wherein n4+n5 is an integer of 3 or more.

7. The photoacid generator according to any one of claims 1 to 6, wherein the electron-withdrawing group is -CN.

8. The photoacid generator according to any one of claims 1 to 7, which is in the form of (i) a monomer containing a polymerizable double bond, or (ii) a polymer.

9. A polymer; A photoacid generator according to any one of claims 1 to 8, optionally part of the polymer; Solvent and 1. A photoresist composition comprising:

10. 1. A method of forming a pattern, comprising the steps of: (a) forming a photoresist layer on a substrate from the photoresist composition of claim 9; (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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