Receptor-substituted EUV PAG with high electron affinity

Abstract

Compounds having the structure (I) wherein R1, R2, R1a and R2a are independently selected from the group consisting of H, nitro, cyano and alkylsulfonyl, wherein at least two of R1, R2, R1a and R2a are independently selected from nitro, cyano and alkylsulfonyl, and X <-> is not halide ion, toluenesulfonate radical, trifluoromethanesulfonate radical, tetrafluoroborate radical, aryl substituted borate radical, hexafluorophosphate radical, hexafluoroarsenate radical, acetate radical, trifluoroacetate radical, methanesulfonate radical, C-2 to C-20 straight-chain unsubstituted alkyl sulfonate radical, and X <-> is not halide ion, toluenesulfonate radical, trifluoromethanesulfonate radical, tetrafluoroborate radical, aryl substituted borate radical, hexafluorophosphate radical, hexafluoroarsenate radical, acetate radical, trifluoroacetate radical, methanesulfonate radical or C-2 to C-20 straight-chain unsubstituted alkyl sulfonate radical. And naphthalenesulfonic acid radicals and camphorsulfonic acid radicals. Also described are EUV negative and positive chemically amplified photoresist compositions containing the compounds and methods of patterning substrates using these photoresists.

Description

Technical Field

[0001] The disclosed and claimed subject matter relates to chemically amplified organic resist materials and methods of use containing a class of photoacid generators (PAGs) designed to enhance sensitivity for high-resolution patterning using electron beam or EUV radiation at a wavelength of 13.5 nm. Background Art

[0002] Chemically amplified resists are the main type of resist used in 248nm, 193nm, and 193nm immersion lithography. In these chemically amplified photoresists, the solubility change of the resist is divided into two reactions. The first step is a photoreaction in which photons are absorbed by a photoacid generator (PAG), which decomposes to form photoacids. The photoacids then catalyze a chemical reaction that causes a change in the solubility of the photoresist, for example, in the case of positive-tone photoresists, making the exposed areas more soluble in the developer. The solubility change may be caused by a deprotection reaction of the polymer backbone side groups (e.g., acetal-protected phenols or tertiary alcohol esters of carboxylic acids), which results in the formation of phenolic OH groups or carboxylic acids, making the polymer soluble in aqueous alkaline developers or insoluble in organic solvent developers. These reactions typically occur during the post-exposure bake (PEB) step. Since the photoacid acts only as a catalyst and is not consumed in the reaction, it can catalyze multiple such reactions: the original photoevent is amplified by the number of reactions catalyzed by each acid, hence the term chemical amplification.

[0003] Commonly used PAGs include triphenylsulfonium and diphenyliodonium salts of strong acids, including but not limited to perfluoroalkylsulfonic acids and their derivatives. For the UV wavelengths mentioned above, photoacid formation occurs via absorption of a photon in one of the PAG's absorption bands, converting it into an unstable excited state that decomposes into free radicals and radical cations. The radical cations further react to produce the protons required to form the catalytic species. This mechanism has been described in considerable detail in the literature [John L. Dektar and Nigel P. Hacker, J. Am. Chem. Soc. 1990, 112, 6004-6015].

[0004] The use of chemically amplified photoresists has been extended to extreme ultraviolet (EUV) light with a wavelength of 13.5 nm, or a photon energy of 91.6 eV. At this wavelength, the absorption of a photon produces a primary ionization event, in which an electron is ejected from an atom at high energy. This electron then collides with other atoms, leading to further ionization events and the generation of secondary electrons. In this electron cascade, the energy of the original photon is dissipated in a confined region surrounding the original absorption event in the form of electrons and positively charged species ("holes"), as well as electronic and thermal excitations. The size of this region is limited by the path length of the primary and secondary electrons, which is estimated to be approximately 2 to 3 nanometers.

[0005] At lower energy UV lithography wavelengths (i.e., 248 and 193 nm), the polymer components of the resist are essentially transparent at the exposure wavelength, and absorption is primarily performed by the PAGs. However, at EUV energies, all species absorb. Specifically, photon absorption and subsequent ionization can occur in any atom that constitutes the photoresist, not just in the PAGs. This absorption occurs essentially independently of the chemical environment of the ionized atoms: instead, it depends solely on the atomic composition of the photoresist. The absorbance of EUV resists can be calculated directly from the absorption cross sections of individual atoms and the film density, without considering the chemical environment of the atoms. [Roberto Fallica, Jarich Haitjema, Lianjia Wu, Sonia Castellanos, Albert M. Brouwer, Yasin Ekinci, J. Micro / Nanolith. MEMS MOEMS 17(2), 023505 (2018), Digital Object Identifier: 10.1117 / 1.JMM.17.2.023505]

[0006] This results in a key difference in the acid generation mechanism between EUV and longer UV lithography wavelengths: in EUV, direct absorption of photons by PAGs is no longer the primary photoacid generation mechanism. During exposure, EUV photon absorption generates stable electrons and holes, with the electrons losing energy in successive collisions until they reach an energy close to thermal equilibrium or recombine with holes. The PAGs function again at lower energies in the electron cascade when their cations can capture electrons, leading to the formation of free radicals. These free radicals are unstable and decompose into uncharged reaction products, as shown in Eq. (1) for the parent triphenylsulfonium and diphenyliodonium cations.

[0007]

[0008] Due to electron capture, electrons are removed from the electron / hole equilibrium formed during exposure, leaving behind holes. The cationic species corresponding to these holes then react further to produce the necessary protons to form the catalytic species (i.e., dissociated or undissociated photoacid). The kinetics of this process have been studied in the literature, and the acid formation rate predicted by kinetic models is in good agreement with experiment. [Craig D. Higgins, Charles R. Szmanda1, Alin Antohe, Greg Denbeaux, Jacque Georger2, and Robert L. Brainard, Japanese Journal of Applied Physics 50 (2011) 036504, 10.1143 / JJAP.50.036504, Digital Object Identifier: 10.1143 / JJAP.50.036504]

[0009] In the kinetic model mentioned above, the hole species R + The concentration of is increased from the steady-state concentration F[R by acid formation or by recombination with electrons according to Eq. (2) + ,e - ]reduce.

[0010]

[0011] From the perspective of acid formation, electron / hole recombination is a parasitic process that reduces the efficiency of acid formation. Removing electrons from the steady state through electron capture by the PAG can reduce the number of recombination events. Each electron capture event leaves behind a hole, which is free to further react to form photoacid. The higher the electron capture efficiency, the higher the acid yield.

[0012] One parameter that one might expect to use to predict the efficiency of electron capture by a PAG is the energy balance of electron capture, also known as its electron affinity. According to the widely accepted generalization of Koopman's theorem [Tjalling Koopmans, Physica. 1(1-6): 104-113. Digital Object Identifier: 10.1016 / S0031-8914(34)90011-2.], the electron affinity can be estimated by the LUMO energy obtained from quantum chemical calculations within the limits of a single electron self-consistent field (SCF) model. Table 1 lists the calculated LUMO values ​​for various sulfonium and iodonium PAGs. Inspection of the table confirms that iodonium salts generally have higher electron affinities than sulfonium salts.

[0013] The calculations summarized in Table 1 indicate that iodonium salts can have significantly higher electron affinities than sulfonium salts. Another advantage of iodonium salts is the higher EUV absorption cross-section of the iodine atom. While this may only be of minor importance in improving the overall EUV absorbance of the photoresist film, as the PAG only accounts for a small fraction of its total mass, it may contribute to a certain degree of photospeed improvement due to the direct absorption of the initial photon by the PAG.

[0014] In the kinetic studies mentioned above [Higgins et al.], the acid formation efficiencies of two PAGs (bis(4-(tert-butyl)phenyl)iodonium nonafluorobutane sulfonate and triphenylsulfonium nonafluorobutane sulfonate) were determined to be 5.6 and 4.6 units of acid per absorbed photon, respectively. This is consistent with other studies demonstrating that diphenyliodonium salts produce higher EUV speeds than triphenylsulfonium salts: [Martin Glodde, Dario L. Goldfarb, David R. Medeiros, Gregory M. Wallraff, and Gregory P. Denbeaux, Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures Processes sing, Measurement, and Phenomena 25, 2496 (2007); Digital Object Identifier: 10.1116 / 1.2779045], [Dario L. Goldfarb, Ali Afzali-Ardakani, Martin Glodde, Proc. SPIE 9779, Advances in Patterning Materials and Processes XXXIII,97790A (March 25, 2016); Digital Object Identifier: 10.1117 / 12.2218457], which is consistent with the EA values ​​seen in Table 1.

[0015] Table 1: LUMO energies of sulfonium and iodonium cations calculated by the PM3 method. All geometries were optimized by the Polak-Ribiere conjugate gradient method. RMS gradient

[0016]

[0017]

[0018] In one of the studies mentioned above, Goldfarb et al., the electron affinity (EA) and electrochemical reduction potential (Ep) of PAGs were investigated as predictors of EUV speed. A highly linear correlation was found between the EA values, determined from the LUMO values, and the experimentally determined Ep values. However, not all PAG speeds could be correctly predicted using either the EA or Ep values. The authors concluded, "Although no correlation could be established between this fundamental study and actual EUV speed, a significant improvement in EUV sensitivity was detected for PAGs with photoelectron-trapping properties compared to their DUV performance." Therefore, based on the hypothesized electron-trapping mechanism of acid formation by PAGs during EUV exposure and the available literature, it was concluded that electron affinity can provide a guide for selecting efficient EUV PAGs, but other factors also influence PAG performance.

[0019] Detailed description with accompanying drawings

[0020] Figure 1 are examples of specific compounds having structures (I), (Ia), (Ib), and (Ic).

[0021] Figure 2 are examples of specific compounds having structures (I), (Ia), (Ib), and (Ic). SUMMARY OF THE INVENTION

[0023] The present invention relates to a compound having structure (I), wherein R1, R2, R 1a and R 2a are independently selected from H, nitro, cyano and alkylsulfonyl, wherein R1, R2, R 1a and R 2a At least two of are independently selected from nitro, cyano and alkylsulfonyl, and X - The compound is not a halide, toluenesulfonate, trifluoromethanesulfonate, tetrafluoroborate, aryl-substituted borate, hexafluorophosphate, hexafluoroarsenate, acetate, trifluoroacetate, methanesulfonate, C-2 to C-20 linear unsubstituted alkylsulfonate, naphthalenesulfonate, and / or camphorsulfonate. Other aspects of the present invention are EUV negative-tone and positive-tone chemically amplified photoresist compositions containing the compound and methods for patterning substrates using the photoresists.

[0024]

[0025] The present invention describes PAGs with higher acid formation efficiency under ionizing radiation exposure, which higher efficiency results from the increased electron affinity exhibited by these PAGs due to acceptor substitution of the PAG cation. The formation of a higher number of catalytic acids per EUV photon or electron impact is desirable because it will increase photoresist sensitivity, result in higher throughput, and reduce stochastic effects on line width roughness. Another aspect of the invention is the use of the compounds of structure (I) disclosed herein and any embodiments thereof as photoacid generators. Yet another aspect of the invention is the use of any of the compositions disclosed herein as a photoresist on a substrate.

[0026] Detailed description

[0027] It should be understood that both the foregoing general description and the following detailed description are illustrative and explanatory and are not restrictive of the subject matter claimed. In this application, the use of the singular includes the plural, the word "a" or "an" means "at least one", and the use of "or" means "and / or", unless otherwise specifically stated. In addition, the use of the term "including" and other forms such as "includes" and "included" is not restrictive. In addition, terms such as "element" or "component" cover both elements and components comprising one unit and elements or components comprising more than one unit, unless otherwise specifically stated. As used herein, the conjunction "and" is intended to be inclusive and the conjunction "or" is not intended to be exclusive, unless otherwise stated. For example, the phrase "or, alternatively" is intended to be exclusive. As used herein, the term "and / or" refers to any combination of the aforementioned elements, including the use of a single element.

[0028] The term C-1 to C-4 alkyl includes methyl and C-2 to C-4 straight-chain alkyl groups, as well as C-3 to C-4 branched-chain alkyl moieties, such as the following: methyl (-CH3), ethyl (-CH2-CH3), n-propyl (-CH2-CH2-CH3), isopropyl (-CH(CH3)2), n-butyl (-CH2-CH2-CH2-CH3), tert-butyl (-C(CH3)3), isobutyl (CH2-CH(CH3)2, 2-butyl (-CH(CH3)CH2-CH3). Similarly, the term C-1 to C-8 includes methyl, C-2 to C-8 straight-chain alkyl, C-3 to C-8 branched-chain alkyl, C-4 to C-8 cycloalkyl (e.g., cyclopentyl, cyclohexyl, etc.) or C-5-C-8 alkylenecycloalkyl (e.g., -CH2-cyclohexyl, CH2-CH2-cyclopentyl, etc.).

[0029] The term C-2 to C-8 alkylene includes C-2 to C-8 straight chain alkylene moieties (e.g., ethylene, propylene, etc.) and C-3 to C-8 branched chain alkylene moieties (e.g., -CH(CH3)-, -CH(CH3)-CH2-, etc.).

[0030] The term C-2 to C-4 alkylene includes C-2 to C-4 straight chain alkylene moieties and C-3 to C-4 branched chain alkylene moieties.

[0031] The term C-2 to C-8 perfluoroalkylene includes C-2 to C-8 linear perfluoroalkylene moieties and C-3 to C-8 branched perfluoroalkylene moieties.

[0032] The term C-2 to C-4 perfluoroalkylene includes C-2 to C-4 straight-chain perfluoroalkylene moieties and C-3 to C-4 branched perfluoroalkylene moieties.

[0033] Unless otherwise indicated, the term alkylsulfonyl encompasses C-1 to C-8 alkyl moieties, which in turn encompass C-1 to C-8 straight-chain alkyl groups, C-3 to C-8 branched-chain alkyl groups, C-3 to C-8 cyclic alkyl groups, and C-4 to C-8 alicyclic alkyl groups attached to a sulfonyl group.

[0034] Phrase X - pK a Anions of acids with a pK less than 0, as used herein, do not include a Acids with a relative carbonyl group (e.g., HI, HCl, HBr, HF) that have a relative carbonyl group (e.g., HI, HCl, HBr, HF) but with a corresponding nucleophilic anion. These nucleophilic anions attack the intermediate carbon cation to form a stable compound (e.g., an alkyl halide, such as tert-butyl halide), thereby terminating the chemical amplification chain reaction and preventing the generation of further catalytic protons (H + The following references discuss chemical amplification mechanisms (Polymers for Microelectronics ACS Symposium Series ACS, (1993), Chapter 1 Chemically Amplification Mechanisms for Microlithography, E. Reichmanis et al., page 3), (Chemical Amplification Resists for Microlithography Adv Polymer Sci, Hiroshi Ito (2005) 172, page 37). Examples of suitable non-nucleophilic anions are described below.

[0035] The present invention relates to PAGs designed for and exhibiting high photospeed to ionizing radiation (such as x-rays, EUV, particle beams, or electron beams), which, due to its energy dissipation mechanism, generates electrons that can be captured by iodonium salts. Ionium derivatives selectively substituted with acceptor substituents enhance their electron capture efficiency by increasing their electron affinity above that of the parent compound (i.e., lacking the acceptor substituent).

[0036] Among these acceptor substituents, nitro, cyano, and alkylsulfonyl substituents at the 3- and 4-positions were found to be particularly effective. However, not only the nature of the substituent but also its position is important. A nitro substituent at the 2-position results in lower calculated EA values ​​and slower photospeeds. The (2-nitrophenyl)phenyliodonium ion has a lower electron affinity than the parent diphenyliodonium ion, and despite being substituted with two strong acceptors, the electron affinity of the 2,2'-dinitrophenyl derivative is very close to that of the parent. The n-butylsulfonyl group, which acts as a weak electron donor at the 3- and 4-positions, is a strong electron donor at the 2-position. This "ortho effect" is presumably due to the negative charge of the oxygen atom in the nitro or sulfonyl group, which is in close proximity to the central iodonium, donating electron density to it, thereby reducing the latter's positive charge and, consequently, its electron affinity. Ortho effects can also contribute to the electron affinity of 2,2'-dicyano derivatives, but in this case, some of the negative charge is further removed from the central iodonium, and there are no interactions with the lone electron pair. Notably, 3- and 4-acceptor substitutions result in nearly equal increases in electron affinity, which is not generally expected given the typical substituent effects seen in aromatic systems. The n-butylsulfonyl substituent, chosen here as a universal replacement for all alkylsulfonyl substituents, reduces electron affinity in monosubstitution (Table 1) but yields a high electron affinity when located at the 4-position and combined with a 4'-nitro substituent. Alkylsulfonyl substituents are of interest because the solubility properties of iodonium salts can be modified by selecting the appropriate alkyl chain length. The trifluoromethyl CF3 substituent acts as a strong acceptor at the 3- and 4-positions, but also leads to a significant increase in electron affinity when present at the 2-position: as a "hard" substituent (i.e., a substituent with low polarizability), it is much less affected by ortho effects.

[0037] Table 1 contains several compounds whose EA is not a valid predictor of observed EUV speed. References report testing of bis(2,4,6-trifluorophenyl)iodonium PAGs, finding them to have very low EUV speeds. [Goldfarb et al.] in the same reference found that PAGs 1, 2, 3, and 5 had speeds lower than or comparable to those of the parent compound, yet calculated EAs were significantly higher.

[0038] EUV PAG components

[0039] Ionium ions combine with suitable counter anions to form iodonium salts. For the purpose of high-resolution photolithography, these anions must be strong, non-nucleophilic acids that also have low diffusivity and volatility. In terms of acidity, the pK of the photoacid is 1,2-dichloroethane on the acidity scale. a Should be -1 or less [Eno Paenurk, Karl Kaupmees, Daniel Himmel, Agnes Kütt, Ivari Kaljurand, Ilmar A. Koppel, Ingo Krossing and Ivo Leito, Chem. Sci., 2017, 8, 6964]. Sulfonic acid is preferred because it exhibits low nucleophilicity and does not react with cationic intermediates formed during the solubility change reaction. The absence of these side reactions is important because adding an acid anion to a cationic species produces a neutral molecule, i.e., the acid catalyst is consumed and the chemical amplification chain reaction ends.

[0040] Early chemically amplified photoresists used antimony hexafluoride, arsenic hexafluoride, or hexafluorophosphate anions. - Because phosphorus is undesirable as a dopant, and AsF6 - This is undesirable due to the high toxicity of arsenic.

[0041] For high-resolution applications, it is also desirable that the acid not exhibit high diffusivity. For example, trifluoromethanesulfonic acid is a strong catalyst with low nucleophilicity, but it has strong diffusivity and also a high vapor pressure, which can cause the acid to redeposit from highly exposed areas to areas that are not intended to be exposed [Thomas Wallow, Marina Plat, Zhanping Zhang, Brian MacDonald, Joffre Bernard, Jeremias Romero, Bruno La Fontaine, Harry J. Levinson, Proc. SPIE 6519, Advances in Resist Materials and Processing Technology XXIV, 65190T, 2007; Digital Object Identifier: 10.1117 / 12.712338]. Therefore, trifluoromethanesulfonic acid is not a good candidate for high-resolution resists.

[0042] In one embodiment of the PAGs, compositions, and methods of the present invention, suitable counter anions include, but are not limited to:

[0043] Antimony hexafluoride; perfluoro and polyfluoroalkane sulfonates (including but not limited to perfluorobutanesulfonate (PFBS), hexafluoropropanesulfonate) or oxygen-substituted derivatives (including but not limited to 1,1,2-trifluoro-2-(trifluoromethoxy)ethanesulfonate (TTES); anions of methyl and imide superacids, such as tris(perfluoroalkylsulfonyl)methyl anions (especially tris[(trifluoromethyl)sulfonyl]methyl anions (C1) and tris[(nonafluoro-n-butyl)sulfonyl]methyl anions (C4)), bis(perfluoroalkylsulfonyl)imide anions (especially bis(trifluoromethanesulfonyl)imide anions (N1), bis(nonafluoro-n-butanesulfonyl)imide anions (N4)) and cyclic 4,4,5,5,6,6-hexafluorodihydro-1,1,3,3-tetraoxide-4H-1,3,2-dithiazine (NC3).

[0044]

[0045] In another aspect of this embodiment, other suitable counter anions are acid anions containing fluorinated aromatic systems, including but not limited to fully and partially substituted benzenesulfonates with fluorine and trifluoromethyl substituents.

[0046] In another aspect of this embodiment, other suitable counter anions are polymer-bound acids in which the sulfonate anion is attached to the polymer backbone via a linker group that does not contain a direct bond to the SO3 - In a preferred embodiment, the linking group comprises a CF group on a carbon atom adjacent to the sulfonate radical. In another preferred embodiment, the pendant acid anion is a bissulfonylimide anion having a perfluoroalkyl substituent (most preferably CF or C4F9) and a linking group bonding it to the polymer backbone, wherein the linking group contains optionally also perfluorinated or polyfluorinated carbon atoms.

[0047] Non-PFAS anions such as polycyano-substituted cyclopentadienyl anions, in particular pentacyano, tetracyano-monocarboxylates and tetracyanomethoxycyclopentadienyl anions [Martin Glodde, Sen Liu and Pushkara Rao Varnasi, J. Photopol. Sci. Techn. 23(2), 173-184 (2010) and US 7,655,379 B2] or acceptor-substituted thiophenesulfonates as described in Liu et al. [Sen Liu, Martin Glodde and Pushkara Varanasi, Proc. SPIE 7639, 76390D (2010); Digital Object Identifier: 10.1117 / 12.846600], US2009181319A1 and US 8,617,791 B2.

[0048] In another aspect of this embodiment, other suitable counter anions are described in WO 2009 / 087027 A2, which discloses compounds having the formula P + A - PAG, where A - The groups include pentacyanocyclopentadienyl ions and various tetracyanocarboxylates, and wherein P + is an onium salt, in particular an iodonium salt which may be optionally substituted with a nitro group. However, WO 2009 / 087027 A2 does not teach or suggest the combination of the cations of the present invention with these anions, since it lists a nitro group as a P + The present invention unexpectedly discovered that only nitro substitution at the 3- and 4-positions, and especially nitro disubstitution, resulted in higher electron affinity and thus higher acid yields for such PAGs, whereas 2-substitution was actually detrimental and 2,2′ disubstitution was ineffective.

[0049] As described herein, when discussing pK a range, these pK a Values ​​are obtained through ACD / PK for Microsoft Windows a Software version 4.0 (Advanced Chemistry Development Inc 8 King Street East, Suite 107, Toronto, Ontario Canada) predictions.

[0050] One aspect of the present invention is a compound having structure (I), wherein R1, R2, R 1a and R 2aare independently selected from H, nitro, cyano and alkylsulfonyl, wherein R1, R2, R 1a and R 2a At least two of are independently selected from nitro, cyano and alkylsulfonyl, and X - It is not a halide, toluenesulfonate, trifluoromethylsulfonate, tetrafluoroborate, aryl-substituted borate, hexafluorophosphate, hexafluoroarsenate, acetate, trifluoroacetate, methanesulfonate, C-2 to C-20 straight-chain unsubstituted alkylsulfonate, naphthalenesulfonate, and / or camphorsulfonate.

[0051]

[0052] Another aspect of the present invention is a compound having structure (I), wherein R1 and R 1a , R2 and R 2a 、R 1a and R2, or R1 and R 2a are independently selected from nitro, cyano and alkylsulfonyl, and X - It is not a halide, toluenesulfonate, trifluoromethylsulfonate, tetrafluoroborate, aryl-substituted borate, hexafluorophosphate, hexafluoroarsenate, acetate, trifluoroacetate, methanesulfonate, C-2 to C-20 straight-chain unsubstituted alkylsulfonate, naphthalenesulfonate, and / or camphorsulfonate.

[0053]

[0054] In one aspect of the compounds of the invention described above having structure (I), more specifically, they have structure (Ia). In one aspect of this embodiment, R1 and R 1a In another aspect of this embodiment, R1 and R 1a In another aspect of this embodiment, R1 and R 1a In another aspect of this embodiment, R1 is nitro and R 1a In another aspect of this embodiment, R1 is nitro and R 1a In another aspect of this embodiment, R1 is alkylsulfonyl and R 1a It is a cyano group.

[0055]

[0056] In one aspect of the compounds of the invention described above having structure (I), more specifically they have structure (Ib). In one aspect of this embodiment, R2 and R 2a In another aspect of this embodiment, R2 and R 2aIn another aspect of this embodiment, R2 and R 2a In another aspect of this embodiment, R2 is nitro and R 2a In another aspect of this embodiment, R2 is nitro and R 2a In another aspect of this embodiment, R2 is alkylsulfonyl and R 2a It is a cyano group.

[0057]

[0058] In one aspect of the compounds of the invention described above having structure (I), more specifically, they have structure (Ic). In one aspect of this embodiment, R1 and R 2a In another aspect of this embodiment, R1 and R 2a In another aspect of this embodiment, R1 and R 2a In another aspect of this embodiment, R1 is nitro and R 2a In another aspect of this embodiment, R1 is nitro and R 2a In another aspect of this embodiment, R1 is alkylsulfonyl and R 2a It is a cyano group.

[0059]

[0060] In another aspect of the compounds of the present invention having any one of structures (I), (Ia), (Ib) and (Ic), X - pK a In another aspect of this embodiment, X - pK a The anion of an acid with a molar ratio of less than 1.

[0061] In another aspect of the compounds of structures (I), (Ia), (Ib) and (Ic) of the present invention, X - is an anion of a fully or partially fluorinated alkylsulfonate having more than 3 carbon atoms, wherein the alkyl group is a linear, branched, or cyclic alkyl group. - The anion is a perfluorinated or partially fluorinated alkylsulfonate having more than 3 carbon atoms, wherein the alkyl group is a linear, branched or cyclic alkyl group containing a heteroatom group selected from -O-, -C(=O)- and -S(=O)2-.

[0062] In another aspect of the compounds of the present invention having any one of structures (I), (Ia), (Ib) and (Ic), X- It is antimony hexafluoride.

[0063] In another aspect of the compounds of the present invention having any one of structures (I), (Ia), (Ib) and (Ic), X - is an anion of a methide or imide perfluorinated superacid. In one aspect of this embodiment, it is an anion of a methide perfluorinated superacid. In another aspect of this embodiment, it is an anion of an imide perfluorinated superacid.

[0064] In another aspect of the compounds of the present invention having any one of structures (I), (Ia), (Ib) and (Ic), X - It is perfluorobutane sulfonate (PFBS) or hexafluoropropane sulfonate.

[0065] In another aspect of the compounds of the present invention having any one of structures (I), (Ia), (Ib) and (Ic), X - It is a tris(perfluoroalkylsulfonyl)methyl anion.

[0066] In another aspect of the compounds of the present invention having any one of structures (I), (Ia), (Ib) and (Ic), X - The anion is selected from the group consisting of tris[(trifluoromethyl)sulfonyl]methyl anion (C1) and tris[(nonafluoro-n-butyl)sulfonyl]methyl anion (C4), bis(perfluoroalkylsulfonyl)imide anion (especially bis(trifluoromethanesulfonyl)imide anion (N1), bis(nonafluoro-n-butanesulfonyl)imide anion (N4)) and cyclic 4,4,5,5,6,6-hexafluorodihydro-1,1,3,3-tetraoxide-4H-1,3,2-dithiazine (NC3).

[0067]

[0068] In another aspect of the compounds of the present invention having any one of structures (I), (Ia), (Ib) and (Ic), X - is a fluorinated arylsulfonate which is partially or fully substituted with a substituent selected from fluorine or perfluoroalkyl.

[0069] In another aspect of the compounds of the present invention having any one of structures (I), (Ia), (Ib) and (Ic), X - is a sulfonate moiety (-SO3) connected to the polymer backbone via a linker group. - ), the linking group does not contain a direct bond to the -SO3 - In another aspect of this embodiment, the -SO3 -The moiety is directly connected to the polymer backbone through a C-1 to C-8 straight chain perfluoroalkylene linking group. In another aspect of this embodiment, the perfluoroalkylene linking group is selected from the group consisting of: difluoromethylene (-CF2-), tetrafluoroethylene (-CF2-CF2-) and hexafluoropropylene (-CF2-CF2-CF2-). In another aspect of this embodiment, the linking group is a group in which the methylene moiety is directly connected to the sulfonate moiety, and the sulfonate moiety is connected to the polymer at its other end directly or through a C-1 to C-4 perfluoroalkylene moiety.

[0070] In another aspect of the compounds of the present invention having any one of structures (I), (Ia), (Ib) and (Ic), X - is a perfluoroalkylamide anion moiety (-N(perfluoroalkyl)) attached directly or via a linker to the polymer backbone - ), the linking group is selected from the group consisting of: C-1 to C-8 alkylene, C-1 to C-8 perfluorinated alkylene, C-1 to C-8 partially fluorinated alkylene.

[0071] In another aspect of the compounds of the present invention having any one of structures (I), (Ia), (Ib) and (Ic), X - is a diperfluoroalkyl carbon anion portion (-C(perfluoroalkyl)2) connected directly or through a linking group to the polymer backbone - ), the linking group is selected from the group consisting of C-1 to C-8 alkylene, C-1 to C-8 perfluorinated alkylene and C-1 to C-8 partially fluorinated alkylene.

[0072] In another aspect of the compounds of the present invention having any one of structures (I), (Ia), (Ib) and (Ic), X - In another aspect of this embodiment, the polycyano-substituted cyclopentadienyl anion is selected from the group consisting of a pentacyanocyclopentadienyl anion, a tetracyanomonocarboxylic acid cyclopentadienyl anion, and a tetracyanomethoxycyclopentadienyl anion. Figure 1 and Figure 2 Non-limiting examples of specific compounds having structures (I), (Ia), (Ib), and (Ic) are shown.

[0073] Resin components suitable for EUV

[0074] Polymer resins for photoresists

[0075] The photoresist compositions of the present invention described herein comprise an acid-sensitive imaging polymer and an acceptor-substituted photoacid generator as described above. The imaging polymer is preferably capable of undergoing a chemical transformation upon exposure of the photoresist composition to ionizing radiation, thereby resulting in different solubility of the polymer in exposed and unexposed areas. That is, the base polymers used in the present invention include any acid-sensitive polymer having acid-sensitive side chains that are catalytically cleaved in the presence of an acid generated by the photoacid generator of the present invention. The imaging polymer can be a positive-working imaging polymer or a negative-working imaging polymer. In such polymers, acid sensitivity is present due to the presence of acid-sensitive side chains bonded to the polymer backbone. Such acid-sensitive polymers comprising acid-sensitive side chains are conventional and well known in the art. Preferably, the imaging polymer is a polymer suitable for 13.4 nm (EUV) photolithography. When developed with an aqueous base developer, a photoresist composition that acts in a positive-working manner can be used as a negative-working photoresist when developed with a solvent (a non-limiting example of which is n-butyl acetate).

[0076] In some embodiments of these compositions of the present invention, the acid-sensitive side chains of the acid-sensitive polymer are protected with various acid-labile protecting groups well known to those skilled in the art. For example, the acid-sensitive side chains can be protected with high activation energy protecting groups (such as tert-butyl esters or tert-butyl carbonyls), low activation energy protecting groups (such as acetals, ketals, or silyl ethers of phenolic substances), or a combination of low and high activation energy protecting groups can also be used. Most preferably, the imaging polymers of the present invention contain a lactone moiety, more preferably a pendant lactone moiety. Examples of imaging polymers containing lactone moieties are well known in the art. See, for example, U.S. Published Patent Application No. 20060216643A1 and U.S. Patents Nos. 7,087,356, 7,063,931, 6,902,874, 6,730,452, 6,627,391, 6,635,401, and 6,756,180. Some preferred lactone-containing monomeric units for inclusion in the imaging polymer are:

[0077]

[0078] In one embodiment of these compositions of the present invention, the imaging polymer preferably contains at least about 5 mole % lactone-containing monomeric units, more preferably about 10 to 50 mole %, and most preferably 15 to 35 mole %, based on the total amount of monomeric units in the imaging polymer.

[0079] The imaging polymer may also contain adamantyl methacrylate or a mono- or poly-hydroxy substituted derivative of adamantyl acrylate.

[0080] Negative Molecular Glass Photoresist Resin

[0081] In another embodiment of these compositions of the present invention, these compositions can be based on a recently reported class of EUV photoresists, namely, negative molecular glass photoresists based on single-molecule epoxide crosslinks [C. Popescu, G. O'Callaghan, A. McClelland, J. Roth, T. Lada, T. Kudo, R. Dammel, M. Moinpour, Y. Cao, APG Robinson, Proc. SPIE 11612, Advances in Patterning Materials and Processes XXXVIII, 116120K (April 5, 2021); Digital Object Identifier: 10.1117 / 12.2583888], [Richard A. Lawson, Clifford L. Henderson, Journal of Micro / Nanolithography, MEMS, and MOEMS, Vol. 9, No. 1, 013016 (January 2010). Digital Object Identifier: 10.1117 / 1.3358383], [RA Lawson, CTLee, CL Henderson, R. Whetsell, L. Tolbert and Y. Wang, J. Vac. Sci. Technol. B, 25(6), 2140 - 2144 (2007). Digital Object Identifier 10.1116 / 1.2801885]. In these photoresist systems, a strong acid (typically hexafluoroantimonic acid generated upon exposure of the PAG) catalyzes the crosslinking of difunctional, trifunctional, or higher-functional monomolecular epoxides. The higher acid yield of the acceptor-substituted PAGs of the present invention for EUV exposure allows for higher photospeeds in this type of photoresist.

[0082] Acid quencher

[0083] Suitable acid quenchers include, but are not limited to, acid quenchers having a boiling point above 100°C at atmospheric pressure and a pK a A basic material or material combination of at least 1, such as an amine compound or a mixture of amine compounds. The acid quencher includes, but is not limited to, an amine compound having structures (XIIa), (XIIb), (XIIc), (XIId), (XIIe), (XIIf), (XIIg), (XIIh), (XIIi), (XIIj), (XIIk) and (XIII), or a mixture of compounds from the group; wherein R b1 is a C-1 to C-20 saturated alkyl chain or a C-2 to C-20 unsaturated alkyl chain; R b2 、R b3 、R b4、R b5 、R b6 、R b7 、R b8 、R b9 、R b10 、R b11 、R b12 , and R b13 Independently selected from the group consisting of H and C-1 to C-20 alkyl groups as shown below:

[0084]

[0085] Other suitable acid quenchers are tetraalkylammonium or trialkylammonium salts of carboxylic acids. Specific non-limiting examples are mono(tetraalkylammonium), di(tetraalkylammonium) salts of dicarboxylic acids, mono(trialkylammonium) or di(trialkylammonium) salts of dicarboxylic acids. Non-limiting examples of suitable dicarboxylic acids for these salts are oxalic acid, maleic acid, malonic acid, fumaric acid, phthalic acid, and the like. Structures (XIIma) to (XIImd) give the general structures of such materials, wherein Rqa to Rqd are independently C-4 to C-8 alkyl, and Rqe is a valence bond, an arylene moiety, a C-1 to C-4 alkylene moiety, an alkenyl moiety (-C(Rqf)=C(Rqg)-, wherein Rqf and Rqg are independently H or C-1 to C-4 alkyl). Structure (XIIme) gives a specific example of such a material.

[0086]

[0087]

[0088] Organic spin coating solvents

[0089] Organic spin-coating solvents suitable for dissolving the EUV composition described above include glycol ether derivatives such as ethyl cellosolve, methyl cellosolve, propylene glycol monomethyl ether (PGME), diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, dipropylene glycol dimethyl ether, propylene glycol n-propyl ether, or diethylene glycol dimethyl ether; glycol ether ester derivatives such as ethyl cellosolve acetate, methyl cellosolve acetate, or propylene glycol monomethyl ether acetate (PGMEA); carboxylic acid esters such as ethyl acetate, n-butyl acetate, and amyl acetate; carboxylic acid esters of dibasic acids such as diethyl oxalate and diethyl malonate; dicarboxylic acid esters of glycols such as ethylene glycol diacetate and propylene glycol diacetate; and Hydroxycarboxylates such as methyl lactate, ethyl lactate (EL), ethyl glycolate, and ethyl 3-hydroxypropionate; ketoesters such as methyl pyruvate or ethyl pyruvate; alkoxycarboxylates such as methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 2-hydroxy-2-methylpropionate, or methyl ethoxypropionate; ketone derivatives such as methyl ethyl ketone, acetylacetone, cyclopentanone, cyclohexanone, or 2-heptanone; ketoether derivatives such as diacetone alcohol methyl ether; ketoalcohol derivatives such as acetol or diacetone alcohol; ketals or acetals such as 1,3-dioxolane and diethoxypropane; lactones such as butyrolactone; amide derivatives such as dimethylacetamide or dimethylformamide; anisole; and mixtures thereof. In addition, these solvents can be used as "organic solvent developers" in some methods using the photoresists of the present invention when exposed to electron beam or EUV radiation as described below.

[0090] Optional cross-linking component

[0091] The EUV and electron beam compositions described herein, which are intended for negative-tone development with organic solvents, may further contain a crosslinking agent as an optional component. These materials are multifunctional compounds containing moieties that form crosslinks in the photoresist film under the influence of photogenerated acid. Examples of such components are multifunctional alkyl and aryl epoxides that form crosslinks by ring opening of the epoxide, or N-methoxymethylated melamine crosslinker derivatives, benzyl alcohol derivatives, or vinyl cyclic acetal derivatives that form crosslinks by forming reactive carbocations (Polymers for Microelectronics ACS Symposium Series ACS, (1993), Chapter 1 Chemically Amplification Mechanisms for Microlithography, E. Reichmanis et al., p. 3) and (Chemical Amplification Resists for Microlithography Adv Polymer Sci, Hiroshi Ito (2005) 172, p. 37).

[0092] Other optional components

[0093] In addition, the EUV and electron beam compositions described herein may further include additives selected from the group consisting of surfactants, inorganic-containing polymers; additives including small molecules, inorganic-containing molecules, surfactants, other photoacid generators, thermal acid generators, hardeners, crosslinkers, chain extenders, etc.; and combinations comprising at least one of the foregoing.

[0094] Positive chemically amplified photoresist and treatment thereof

[0095] Positive chemically amplified photoresist composition

[0096] By using such materials as described herein, another aspect of the present invention is a positive chemically amplified EUV or e-beam photoresist composition comprising

[0097] 1) any of the compounds of structures (I), (Ia), (Ib) and (Ic) of the present invention described herein,

[0098] 2) a photoresist resin as described above which undergoes chemically amplified deprotection catalyzed by photogenerated acid to release a resin soluble in aqueous base,

[0099] 3) an optional acid quencher component,

[0100] 4) Organic spin coating solvent.

[0101] In yet another aspect of this embodiment, an optional acid quencher component is present and can be selected from suitable materials described herein.In yet another aspect of this embodiment, the organic spin coating solvent can be selected from any one of the organic spin coating solvents described herein or a mixture of at least two such solvents.

[0102] By using such materials as described herein, another aspect of the present invention is a positive chemically amplified EUV or e-beam photoresist composition comprising

[0103] 1a) A compound having structure (I) wherein

[0104] R1, R2, R 1a and R 2a are independently selected from H, nitro, cyano and alkylsulfonyl, wherein R1, R2, R 1a and R 2a At least two of are independently selected from nitro, cyano and alkylsulfonyl, and X - pK a The anion of the acid is less than 0,

[0105]

[0106] 2a) a photoresist resin that undergoes chemically amplified deprotection catalyzed by photogenerated acid to release a resin that is soluble in aqueous base,

[0107] 3a) an optional acid quencher component,

[0108] 4a) Organic spin coating solvent.

[0109] In yet another aspect of this embodiment, an optional acid quencher component is present and can be selected from suitable materials described herein.

[0110] In yet another aspect of this embodiment, the organic spin-coating solvent can be selected from any one of the organic spin-coating solvents described herein or a mixture of at least two such solvents.

[0111] By using such materials as described herein, another aspect of the present invention is a positive chemically amplified EUV or e-beam photoresist composition comprising

[0112] 1b) A compound having structure (I) wherein

[0113] R1 and R 1a , R2 and R 2a 、R 1a and R2 or R1 and R 2a are independently selected from nitro, cyano and alkylsulfonyl, and X - is not a halide, toluenesulfonate, trifluoromethylsulfonate, tetrafluoroborate, aryl-substituted borate, hexafluorophosphate, hexafluoroarsenate, acetate, trifluoroacetate, methanesulfonate, C-2 to C-20 straight-chain unsubstituted alkylsulfonate, naphthalenesulfonate, and / or camphorsulfonate, and X - pK a The anion of the acid is less than 0,

[0114]

[0115] 2b) a photoresist resin that undergoes chemically amplified deprotection catalyzed by a photogenerated acid to release a resin that is soluble in aqueous base,

[0116] 3b) an optional acid quencher component,

[0117] 4b) Organic spin coating solvents.

[0118] In other aspects of this embodiment, the positive photoresist resins described herein are specifically employed.

[0119] In yet another aspect of this embodiment, an optional acid quencher component is present and can be selected from suitable materials described herein.In yet another aspect of this embodiment, the organic spin coating solvent can be selected from any one of the organic spin coating solvents described herein or a mixture of at least two such solvents.

[0120] Method using positive chemically amplified photoresist

[0121] Another aspect of the present invention is a method of forming a positive image in a substrate using a positive chemically amplified photoresist by EUV or e-beam exposure, comprising steps i) to iv);

[0122] i) coating a positive chemically amplified EUV or electron beam photoresist composition of any one of the positive chemically amplified photoresists of the present invention described above on a substrate to form a coating film,

[0123] ii) baking the coating film to form a baked coating film,

[0124] iii) exposing and baking the respective areas of the coating film with EUV or electron beam radiation through a mask to form exposed areas and unexposed areas,

[0125] iv) an optional post-exposure bake step,

[0126] v) developing away the exposed areas with an aqueous alkaline developer to form a positive image pattern in the coated photoresist on the substrate,

[0127] vi) Using the positive image pattern as a mask, the substrate is etched with plasma or chemical etchant to form a positive image in the substrate.

[0128] In one aspect of this embodiment, process step iv) is not optional. In one aspect of this embodiment, the aqueous alkaline developer in step v) is 0.26 NTMAH at room temperature.

[0129] Method for forming negative images using positive chemically amplified photoresist

[0130] Another aspect of the present invention is a method for forming a negative image in a substrate using a positive chemically amplified photoresist by EUV or electron beam exposure, comprising steps ia) to via);

[0131] ia) applying a positive chemically amplified EUV or electron beam photoresist composition of any one of the positive chemically amplified photoresists of the present invention described above on a substrate to form a coating film,

[0132] iia) baking the coating film to form a baked coating film,

[0133] iiia) exposing and baking the respective areas of the coating film with EUV or electron beam radiation through a mask to form exposed areas and unexposed areas,

[0134] iva) an optional post-exposure bake step,

[0135] va) developing with an organic solvent developer to remove unexposed areas and form a negative image pattern in the coated photoresist on the substrate,

[0136] The negative image pattern is used as a mask to etch the substrate using plasma or a chemical etchant to form a negative image in the substrate.

[0137] In one aspect of this embodiment, process step iva) is not optional. In another aspect of this embodiment, the organic solvent developer in step va) is n-butyl acetate at room temperature.

[0138] Negative chemically amplified photoresist composition

[0139] By using such materials described herein, another aspect of the present invention is a negative-tone chemically amplified EUV or e-beam photoresist composition comprising

[0140] 1c) any one of the compounds of structure (I), (Ia), (Ib) and (Ic) of the present invention described herein,

[0141] 2c) a photoresist resin which is soluble in aqueous base and undergoes chemical amplification crosslinking in the presence of a photogenerated acid,

[0142] 3c) an optional cross-linking component,

[0143] 4c) an optional acid quencher component,

[0144] 5c) Organic spin coating solvent.

[0145] In yet another aspect of this embodiment, an optional acid quencher component is present and can be selected from suitable materials described herein.In yet another aspect of this embodiment, the organic spin coating solvent can be selected from any one of the organic spin coating solvents described herein or a mixture of at least two such solvents.

[0146] By using such materials described herein, another aspect of the present invention is a negative-tone chemically amplified EUV or e-beam photoresist composition comprising

[0147] 1d) A compound having structure (I) wherein

[0148] R1, R2, R 1a and R 2aare independently selected from H, nitro, cyano and alkylsulfonyl, wherein R1, R2, R 1a and R 2a At least two of are independently selected from nitro, cyano and alkylsulfonyl, and X - pK a The anion of the acid is less than 0,

[0149]

[0150] 2d) a photoresist resin which is soluble in aqueous base and undergoes chemical amplification crosslinking in the presence of a photogenerated acid,

[0151] 3d) an optional cross-linking component,

[0152] 4d) an optional acid quencher component,

[0153] 5d) Organic spin coating solvent.

[0154] In yet another aspect of this embodiment, an optional acid quencher component is present and can be selected from suitable materials described herein.In yet another aspect of this embodiment, the organic spin coating solvent can be selected from any one of the organic spin coating solvents described herein or a mixture of at least two such solvents.

[0155] By using such materials described herein, another aspect of the present invention is a negative-tone chemically amplified EUV or e-beam photoresist composition comprising

[0156] 1e) A compound having structure (I), wherein

[0157] R1, R2, R 1a and R 2a are independently selected from H, nitro, cyano and alkylsulfonyl, wherein R1, R2, R 1a and R 2a At least two of are independently selected from nitro, cyano and alkylsulfonyl, and X - pK a The anion of the acid is less than 0,

[0158]

[0159] 2e) a photoresist resin which is soluble in aqueous base and undergoes chemical amplification crosslinking in the presence of a photogenerated acid,

[0160] 3e) a cross-linking component,

[0161] 4e) an optional acid quencher component,

[0162] 5e) Organic spin coating solvent.

[0163] In yet another aspect of this embodiment, an optional acid quencher component is present and can be selected from suitable materials described herein.In yet another aspect of this embodiment, the organic spin coating solvent can be selected from any one of the organic spin coating solvents described herein or a mixture of at least two such solvents.

[0164] By using such materials described herein, another aspect of the present invention is a negative-tone chemically amplified EUV or e-beam photoresist composition comprising

[0165] 1f) A compound having structure (I) wherein

[0166] R1 and R 1a , R2 and R 2a 、R 1a and R2 or R1 and R 2a are independently selected from nitro, cyano and alkylsulfonyl, and X - is not a halide, toluenesulfonate, trifluoromethylsulfonate, tetrafluoroborate, aryl-substituted borate, hexafluorophosphate, hexafluoroarsenate, acetate, trifluoroacetate, methanesulfonate, C-2 to C-20 straight-chain unsubstituted alkylsulfonate, naphthalenesulfonate and / or camphorsulfonate,

[0167]

[0168] 2f) a photoresist resin which is soluble in aqueous base and undergoes chemical amplification crosslinking in the presence of a photogenerated acid,

[0169] 3f) an optional cross-linking component,

[0170] 4f) an optional acid quencher component,

[0171] 5f) Organic spin coating solvent.

[0172] In yet another aspect of this embodiment, an optional acid quencher component is present and can be selected from suitable materials described herein.In yet another aspect of this embodiment, the organic spin coating solvent can be selected from any one of the organic spin coating solvents described herein or a mixture of at least two such solvents.

[0173] Method using negative-tone chemically amplified photoresist

[0174] Another aspect of the present invention is a method for forming a negative image in a substrate using a negative chemically amplified photoresist by EUV or electron beam exposure, comprising steps ib) to vib)

[0175] ib) coating a negative chemically amplified EUV photoresist composition of any one of the negative chemically amplified photoresists of the present invention described above on a substrate to form a coating film,

[0176] iib) baking the coating film to form a baked coating film,

[0177] iiib) exposing and baking the respective areas of the coating film with EUV or electron beam radiation through a mask to form exposed areas and unexposed areas,

[0178] ivb) an optional post-exposure bake step,

[0179] vb) developing with an aqueous alkaline or organic solvent developer to remove the unexposed areas and form a negative image pattern in the coated photoresist on the substrate,

[0180] vib) using the negative image pattern as a mask, etching the substrate with plasma or chemical etchant to form a negative image in the substrate.

[0181] In one embodiment of this method, step ivb) is not optional. In one embodiment of the method steps, in step vb), the developer is an aqueous base; in another aspect of this embodiment, the developer is 0.26N TMAH at room temperature. In another embodiment of this method, in step vb), the developer is an organic solvent; in another aspect of this embodiment, the developer is n-butyl acetate at room temperature.

[0182] Compositions containing cross-linkable molecular glasses

[0183] Another aspect of the present invention is a negative-tone chemically amplified EUV or electron beam photoresist composition comprising

[0184] 1g) A compound having structure (I) wherein

[0185] R1, R2, R 1a and R 2a are independently selected from H, nitro, cyano and alkylsulfonyl, wherein R1, R2, R 1a and R 2a At least two of are independently selected from nitro, cyano and alkylsulfonyl, and X - pK a The anion of the acid is less than 0,

[0186]

[0187] 2g) a molecular glass compound comprising 3 to 5 crosslinking moieties selected from oxirane, oxetane or mixtures thereof, which crosslink under the influence of the acid formed by irradiation with component 1a),

[0188] 3g) an optional acid quencher component,

[0189] 4g) Organic spin coating solvent.

[0190] In one aspect of this embodiment, the molecular glass compound has structure (II)

[0191]

[0192] Method using negatively cross-linkable molecular glass

[0193] Another aspect of the present invention is a method for forming a negative image with a negative photoresist by EUV or electron beam exposure, which comprises steps ic) to vic) using the composition containing the molecular glass compound described above.

[0194] ic) coating the negative chemically amplified EUV photoresist or electron beam composition containing the molecular glass compound described above on a substrate to form a coating film,

[0195] iic) baking the coating film to form a baked coating film,

[0196] iiic) exposing and baking the respective areas of the coating film with EUV or electron beam radiation through a mask to form exposed areas and unexposed areas,

[0197] ivc) an optional post-exposure bake step,

[0198] vc) developing with an organic solvent developer to remove the unexposed areas and form a negative image pattern in the coated molecular glass on the substrate,

[0199] vic) using the negative image pattern as a mask, etching the substrate with plasma or chemical etchant to form a negative image in the substrate.

[0200] In addition, the EUV composition described above may further include an additive selected from the group consisting of surfactants, inorganic-containing polymers; additives including small molecules, inorganic-containing molecules, surfactants, other photoacid generators, thermal acid generators, quenchers, hardeners, crosslinkers, chain extenders, etc.; and combinations comprising at least one of the foregoing. Example

[0201] Chemicals and Characterization

[0202] Unless otherwise indicated, all chemicals were purchased from Sigma Aldrich (3050 Spruce St., St. Louis, MO 63103) of the highest commercial grade and used as received unless otherwise noted.

[0203] Characterization methods

[0204] NMR spectra were recorded on a 400 MHz or 500 MHz Bruker Advance II+ spectrometer using deuterated solvents from Sigma-Aldrich (Merck). Chemical shifts are reported as d values ​​(ppm) and are calibrated against the internal standard Si(OMe)4 (0.00 ppm).

[0205] Table 2: List of iodonium salt synthesis examples

[0206]

[0207]

[0208]

[0209] *: alternative synthesis of Example 1; **: alternative synthesis of Example 9; ***: alternative synthesis of Example 10; ****: alternative synthesis of Example 4; *****: alternative synthesis of Example 2.

[0210] Synthesis Example 1: Synthesis of bis(4-nitrophenyl)iodonium tetrafluoroborate (PAG-1)

[0211]

[0212] Meta-chloroperbenzoic acid (mCPBA, CAS: 937-14-4, 3.8 g, 22 mmol) was dissolved in 100 mL of DCM and treated with 1-iodo-4-nitrobenzene (CAS: 636-98-6, 5.1 g, 20 mmol). Boron trifluoride etherate (CAS: 109-63-7, 7.1 g, 50 mmol) was added dropwise, and the mixture was stirred at room temperature for 1 h. The mixture was then cooled to 0°C, 4-nitrophenylboronic acid (CAS: 24067-17-2, 3.7 g, 22 mmol) was added portionwise, stirred at room temperature for 2 h, and purified using a silica plug. Impurities were first eluted with DCM, followed by elution with DCM / methanol (20:1) to isolate the crude product. The product fractions were concentrated and precipitated by adding tert-butyl methyl ether (MTBE). The solid was washed twice with MTBE and then dried in vacuo to afford bis(4-nitrophenyl)iodonium tetrafluoroborate in 36% yield (3.3 g).

[0213] 1 H-NMR (500MHz, DMSO-d6): δ = 8.55 (d, J = 9.0 Hz, 4H), 8.34 (d, J = 9.0, 4H) ppm. 13C-NMR (126MHz, DMSO-d6): δ = 150.1, 137.3, 126.9, 123.4, 49.1ppm. 19 F-NMR (377MHz, DMSO-d6): δ = -100.0, -146.2, -148.3ppm.

[0214] Synthesis Example 2: Synthesis of Bis(4-nitrophenyl)iodonium 4,4,5,5,6,6-hexafluoro-1,3,2-dithiazinane-2-salt 1,1,3,3-tetraoxide (PAG-2)

[0215]

[0216] Bis(4-nitrophenyl)iodonium tetrafluoroborate (1 g, 2.1 mmol) was dissolved in 150 mL of ethyl acetate and treated with 1,1,2,2,3,3-hexafluoropropane-1,3-disulfonylimide potassium salt (abcr, CAS: 588668-97-7, 0.87 g, 2.6 mmol) and stirred at room temperature for 2 h. The reaction mixture was washed with water (3 x 100 mL), dried over Na2SO4, filtered and reduced in vacuo to afford 1.2 g (84%) of the product as a white solid.

[0217] 1 H-NMR (500MHz, DMSO-d6): δ = 8.55 (d, J = 9.0 Hz, 4H), 8.34 (d, J = 9.0, 4H) ppm.

[0218] 19 F-NMR (377MHz, DMSO-d6): δ = -119.5, -125.8ppm.

[0219] Synthesis Example 3: Synthesis of bis(3-nitrophenyl)iodonium tetrafluoroborate (PAG-3)

[0220]

[0221] The same procedure as in Synthesis Example 1 was followed, using 1-iodo-3-nitrobenzene (CAS: 645-00-1) and 3-nitrophenylboronic acid (CAS: 13331-27-6). Yield: 25% (white solid). 1 H-NMR (500MHz, DMSO-d6): δ = 9.29 (t, J = 1.9 Hz, 2H), 8.74 (dt, J = 8.1, 1.1 Hz 2H), 8.48 (ddd, J = 8.3, 2.3, 0.9 Hz, 2H), 7.85 (t, J = 8.1 Hz, 2H) ppm.

[0222] Synthesis Example 4: Synthesis of bis(3-nitrophenyl)iodonium 4,4,5,5,6,6-hexafluoro-1,3,2-dithiazinane-2-salt 1,1,3,3-tetraoxide

[0223]

[0224] The same procedure was followed as in Synthesis Example 2. Yield: 95% (white solid). 1 H-NMR (500MHz, DMSO-d6): δ = 9.29 (t, J = 1.9 Hz, 2H), 8.73 (dt, J = 8.0, 1.3 Hz 2H), 8.48 (ddd, J = 8.3, 2.3, 0.9 Hz, 2H), 7.85 (t, J = 8.1 Hz, 2H) ppm. 13 C-NMR (126MHz, DMSO-d6): δ = 148.9, 141.8, 133.4, 130.6, 127.5, 117.3ppm. 19 F-NMR (377MHz, DMSO-d6): δ = -119.5, -125.8ppm.

[0225] Synthesis Example 5: Synthesis of bis(2-nitrophenyl)iodonium tetrafluoroborate (PAG-5)

[0226]

[0227] The same procedure as in Synthesis Example 1 was followed, using 1-iodo-2-nitrobenzene (CAS: 609-73-4) and 2-nitrophenylboronic acid (CAS: 5570-19-4). Yield: 28% (white solid). 1 H-NMR (500MHz, DMSO-d6): δ = 8.55 (dd, J = 8.1, 1.6 Hz, 2H), 8.29 ( dd, J = 8.1, 1.3 Hz 2H), 8.02 ( td, J = 7.7, 1.3 Hz, 2H), 7.93 ( td, J = 7.7, 1.6 Hz, 2H) ppm.

[0228] Synthesis Example 6: Synthesis of Bis(2-nitrophenyl)iodonium 4,4,5,5,6,6-hexafluoro-1,3,2-dithiazinane-2-salt 1,1,3,3-tetraoxide (PAG-6)

[0229]

[0230] The same procedure was followed as in Synthesis Example 2. Yield: 98% (white solid). 1H-NMR (500MHz, DMSO-d6): δ = 8.55 (dd, J = 8.1, 1.5 Hz, 2H), 8.29 ( dd, J = 7.9, 1.3 Hz 2H), 8.02 ( td, J = 7.8, 1.2 Hz, 2H), 7.93 ( td, J = 7.7, 1.6 Hz, 2H) ppm. 13 C-NMR (126MHz, DMSO-d6): δ=147.6, 138.0, 134.6, 127.9, 110.1ppm. 19 F-NMR (377MHz, DMSO-d6): δ = -119.5, -125.8ppm.

[0231] Synthesis Example 7: Synthesis of (3-nitrophenyl)(4-nitrophenyl)iodonium tetrafluoroborate PAG-7

[0232]

[0233] The same procedure as in Synthesis Example 1 was followed, using 1-iodo-4-nitrobenzene (CAS: 636-98-6) and 3-nitrophenylboronic acid (CAS: 13331-27-6). Yield: 29% (white solid). 1 H-NMR (500MHz, DMSO-d6): δ = 9.28 (t, J = 2.01H), 8.72 (ddd, J = 8.0, 1.7, 0.9Hz1H), 8.60–8. 54(m,2H),8.48(ddd,J=8.3,2.3,0.9Hz,1H),8.37–8.31(m,2H),7.85(t,J=8.2Hz,1H)ppm.

[0234] Synthesis Example 8: Synthesis of (3-nitrophenyl)(4-nitrophenyl)iodonium 4,4,5,5,6,6-hexafluoro-1,3,2-dithiazinane-2-salt 1,1,3,3-tetraoxide (PAG-8)

[0235]

[0236] The same procedure was followed as in Synthesis Example 2. Yield: 99% (white solid). 1 H-NMR (500MHz, DMSO-d6): δ = 9.28 (t, J = 1.81H), 8.72 (dt, J = 8.1, 1.3Hz1H), 8.59–8 .53(m,2H),8.52–8.44(m,1H),8.36–8.30(m,2H),7.85(td,J=8.2,1.1Hz,1H)ppm. 13C-NMR (126MHz, DMSO-d6): δ = 150.0, 149.0, 141.9, 137.2, 133.4, 130.7, 127.6, 126.9, 123.6, 117.2ppm. 19 F-NMR (377MHz, DMSO-d6): δ = -119.5, -125.8ppm.

[0237] Synthesis Example 9: Synthesis of bis(4-cyanophenyl)iodonium tetrafluoroborate (PAG-9)

[0238]

[0239] The same procedure as in Synthesis Example 1 was followed, using 4-iodobenzonitrile (CAS: 3058-39-7) and (4-cyanophenyl)boronic acid (CAS: 126747-14-6). Yield: 30% (white solid). 1 H-NMR (500MHz, DMSO-d6): δ=8.50–8.44(m,4H),8.07–8.01(m,4H)ppm.

[0240] Synthesis Example 10: Synthesis of bis(4-cyanophenyl)iodonium 4,4,5,5,6,6-hexafluoro-1,3,2-dithiazinane-2-salt 1,1,3,3-tetraoxide

[0241]

[0242] The same procedure was followed as in Synthesis Example 2. Yield: 99% (white solid). 1 H-NMR (500MHz, DMSO-d6): δ=8.50–8.45(m,4H),8.07–7.97(m,4H)ppm. 13 C-NMR (126MHz, DMSO-d6): δ = 136.5, 135.7, 122.0, 117.9, 115.5ppm. 19 F-NMR (377MHz, DMSO-d6): δ = -119.5, -125.8ppm.

[0243] Synthesis Example 11: Synthesis of Bis(2-methyl-5-nitrophenyl)iodonium Bromide (PAG-11) (Scheme 1)

[0244]

[0245] Solution 1

[0246] 4-Nitrotoluene (7.70g, 55.6 mmol, 2.6 equivalents; 30% excess) was dissolved in 30ml of concentrated sulfuric acid (98%), and the stirred mixture was slowly warmed to 55°C. Sodium metaperiodate (4.62g, 21.4 mmol, 1.0 equivalent) was added portionwise over a 2-hour period while stirring and maintaining the given temperature. Stirring was continued for another 2 hours while maintaining the temperature substantially at 55°C and subsequently cooled to room temperature. The reaction was quenched by pouring the cooled final reaction mixture into crushed ice in a beaker (400ml). Any precipitate was filtered out and discarded, and the cold filtrate was extracted three times with diethyl ether to remove unreacted 4-nitrotoluene (3×125ml, discarding the ether extract). Under stirring, potassium bromide salt (6.36g, excess) was added to the remaining aqueous solution. The precipitated bis(2-methyl-5-nitrophenyl)iodonium bromide (C-1), which was slightly soluble in water, was collected by filtration, washed thoroughly with cold water until the filtrate was neutral, and air-dried in the dark to obtain a pale yellow powder (7.85 g, 76.6% yield); mp = 159°C (decomposition); 1 HNMR (400 MHz, DMSO)

[0247] δ=9.37,8.36,8.35,7.84,7.82,2.74; 13 C NMR (101 MHz, DMSO)

[0248] δ=148.78,146.54,132.26,131.93,127.25,120.79,25.29.

[0249] Synthesis Example 12: Synthesis of tris(trifluoromethanesulfonyl)methylbis(2-methyl-5-nitrophenyl)iodonium (PAG-12) (Scheme 2)

[0250]

[0251] Option 2

[0252] The compound obtained in Example 11 (6.03 g, 12.6 mmol, 1.0 equivalent) was added to 400 mL of nitromethane and 100 mL of water. 6.23 g (13.8 mmol, 1.1 equivalent) of tris(trifluoromethanesulfonyl)methyl potassium was added, and the mixture was stirred at room temperature overnight. The water was then separated, and the organic solution was dried over anhydrous sodium sulfate. Finally, the nitromethane was removed in vacuo at 50° C. to obtain the desired product, tris(trifluoromethanesulfonyl)methylbis(2-methyl-5-nitrophenyl)iodonium (8.11 g, 79.5% yield): mp = 165° C. 1H NMR (400MHz, MeOD) δ = 9.27, 9.26, 8.44, 8.42, 7.84, 7.82, 2.81; 19 F NMR (377MHz, MeOD) δ = -78.22; 13 C NMR (101MHz, MeOD) δ = 149.99, 148.27, 133.79, 133.02, 128.77, 126.17, 122.94, 119.69, 119.46, 116.46, 83.83, 25.81.

[0253] Synthesis Example 13: Synthesis of Bis(3-nitrophenyl)iodonium Bromide (PAG-13) (Scheme 3)

[0254]

[0255] Option 3

[0256] Nitrobenzene (14.20 g, 115.3 mmol, 2.6 eq; 30% excess) was dissolved in 60 ml of concentrated sulfuric acid (98%) and the stirred mixture was slowly warmed to 55°C. Sodium metaperiodate (9.59 g, 44.4 mmol, 1 eq) was added portionwise over 2 hours while stirring and maintaining the given temperature. Stirring was continued for several more hours while maintaining the temperature at 55°C and then cooled to room temperature. The reaction was quenched by pouring the cooled final reaction mixture into a pile of crushed ice in a beaker (600 ml). Any precipitate was filtered off and discarded, and the cold filtrate was extracted three times with diethyl ether to remove unreacted nitrobenzene (3 x 150 ml, discarding the ether extracts). Potassium bromide salt (13.2 g, excess) was added to the remaining aqueous solution with stirring. The precipitated bis(3-nitrophenyl)iodonium bromide (C-2) was collected by filtration, washed thoroughly with cold water until the filtrate was neutral, and air-dried in the dark to obtain a light yellow powder (15.82 g, yield 79.1%); 1 H NMR (400MHz, DMSO) δ = 9.21, 8.68, 8.66, 8.41, 8.38, 7.78, 7.76, 7.74; 13 C NMR (101 MHz, DMSO) δ = 148.59, 141.42, 132.81, 130.20, 126.72, 120.15.

[0257] Synthesis Example 14: Synthesis of tris(trifluoromethanesulfonyl)methylbis(3-nitrophenyl)iodonium (PAG-14) (Scheme 4)

[0258]

[0259] Option 4

[0260] The compound obtained in Synthesis Example 13 (5.30 g, 11.8 mmol, 1.0 equivalent) was added to 400 mL of nitromethane and 100 mL of water, to which 6.35 g (14.1 mmol, 1.2 equivalents) of tris(trifluoromethanesulfonyl)methyl potassium was added, and the mixture was stirred at room temperature overnight. Subsequently, the water was separated, and the organic solution was dried over anhydrous sodium sulfate. Finally, the nitromethane was removed in vacuo at 50°C to obtain the target product, tris(trifluoromethanesulfonyl)methylbis(3-nitrophenyl)iodonium (8.23 g, 89.5% yield); mp = 205°C (decomposition); 1 H NMR (400MHz, MeOD) δ = 9.20, 8.63, 8.61, 8.54, 8.52, 7.83, 7.81, 7.79; 19 FNMR(377MHz,MeOD)δ=-78.14; 13 C NMR (101MHz, MeOD) δ = 140.99, 132.70, 124.73, 122.01, 119.11, 116.87, 113.63, 110.40, 107.16, 106.39.

[0261] Synthesis Example 15: Synthesis of bis(4-nitrophenyl)iodonium tetrafluoroborate (Alternative Synthesis of PAG-1) (Scheme 5)

[0262]

[0263] Option 5

[0264] In a 400 mL EasyMax automated reactor, meta-chloroperbenzoic acid (m-CPBA)>70% (16.95 g, 68.8 mmol, 1.1 equivalents) was dissolved in 200 mL of dichloromethane and subsequently 1-iodo-4-nitrobenzene (15.89 g, 62.52 mmol, 1.0 equivalents) was added, causing the solution to turn red. After stirring at room temperature for 30 minutes, boron trifluoride etherate BF3·Et2O (20.7 mL, 23.81 g, 164.4 mmol, 2.6 equivalents) was added to the reaction mixture using a syringe, forming some precipitate inside the reactor glass wall. The solution was then stirred vigorously for 2 hours, then cooled to 0°C and held for approximately 30 minutes. 4-Nitrophenylboronic acid (12.08 g, 68.8 mmol, 1.1 equivalents) was added to the cold reaction mixture, stirred at 0°C for 6 hours, and then equilibrated to room temperature overnight. The crude mixture was filtered and the crude product was washed three times with dichloromethane and five times with diethyl ether until TLC analysis showed no trace of reactants. The product was filtered and dried in a fume hood with flowing air for two days to obtain bis(4-nitrophenyl)iodonium tetrafluoroborate as a gray powder (13.94 g, 48.7% yield); mp = 134 ° C. 1 H NMR (400MHz, DMSO) δ = 8.56, 8.54, 8.34, 8.32; 19 F NMR (377MHz, DMSO) δ = -148.17; 13 CNMR (101 MHz, DMSO) δ = 149.72, 136.69, 126.58, 123.16.

[0265] Synthesis Example 16: Synthesis of tris(trifluoromethanesulfonyl)methylbis(4-nitrophenyl)iodonium (PAG-15) (Scheme 6)

[0266]

[0267] Option 6

[0268] The compound obtained in Synthesis Example 15 (8.01 g, 17.5 mmol, 1.0 equivalent) was added to 400 mL of nitromethane and 100 mL of water. 9.45 g (21.0 mmol, 1.2 equivalents) of tris(trifluoromethanesulfonyl)methyl potassium was added, and the mixture was stirred at room temperature overnight. Subsequently, the water was separated, and the organic solution was dried over anhydrous sodium sulfate. Finally, the nitromethane was removed in vacuo at 50° C. to obtain the target product, tris(trifluoromethanesulfonyl)methylbis(4-nitrophenyl)iodonium (9.51 g, 69.5% yield); mp = 205° C. (decomposition). 1 H NMR (400MHz, MeOD) δ = 8.48, 8.46, 8.35, 8.32;19 F NMR (377MHz, MeOD) δ = -78.21; 13 C NMR (101MHz, MeOD) δ = 151.68, 138.05, 127.71, 126.38, 123.14, 121.91, 119.90, 116.66, 84.16.

[0269] Synthesis Example 17: Synthesis of bis(4-cyanophenyl)iodonium tetrafluoroborate (Alternative Synthesis of PAG-9) (Scheme 7)

[0270]

[0271] Option 7

[0272] In a 140 mL EasyMax automated reactor, meta-chloroperbenzoic acid (m-CPBA) >70% (12.99 g, 52.69 mmol, 1.1 eq) was dissolved in 100 mL of dichloromethane, followed by the addition of 4-iodobenzonitrile (11.31 g, 47.90 mmol, 1.0 eq). The solution immediately turned red. After stirring at room temperature for 30 minutes, boron trifluoride etherate (BF3·Et2O) (15.9 mL, 18.25 g, 125.98 mmol, 2.63 eq) was added to the reaction mixture using a syringe, forming some precipitate on the inside of the reactor glass wall. The solution was then stirred vigorously for 2 hours, then cooled to 0°C and held for approximately 30 minutes. (4-Cyanophenyl)boronic acid (8.15 g, 52.69 mmol, 1.1 eq) was added to the cold reaction mixture, stirred at 0°C for 6 hours, and then equilibrated to room temperature overnight. The crude mixture was filtered off, and the crude product was washed three times with dichloromethane and five times with diethyl ether until TLC test showed no trace of reactants. The final product was dried in a fume hood with flowing air for two days to obtain bis(4-cyanophenyl)iodonium tetrafluoroborate (7.02 g, 35.1% yield) as a gray powder; 1 H NMR (400MHz, MeOD) δ = 8.42, 8.40, 7.90, 7.88; 19 F NMR (377MHz, MeOD) δ=-153.33.

[0273] Synthesis Example 18: Synthesis of tris(trifluoromethanesulfonyl)methylbis(4-cyanophenyl)iodonium (PAG-16) (Scheme 8)

[0274]

[0275] Option 8

[0276] The compound obtained in Synthesis Example 17 (3.55 g, 8.5 mmol, 1.0 equivalent) was added to 100 mL of nitromethane and 25 mL of water, to which 4.21 g (9.3 mmol, 1.1 equivalent) of tris(trifluoromethanesulfonyl)methyl potassium was added, and the mixture was stirred at room temperature overnight. Subsequently, the water was separated, and the organic solution was dried over anhydrous sodium sulfate. Finally, the nitromethane was removed in vacuo at 50°C to obtain the target product, tris(trifluoromethanesulfonyl)methylbis(4-cyanophenyl)iodonium (6.23 g, 98.8% yield); mp = 166°C; 1 H NMR (400MHz, MeOD) δ = 8.37, 8.35, 7.88, 7.86; 19 F NMR (377MHz, MeOD) δ = -78.04; 13 CNMR(101MHz,MeOD)δ=137.37,136.39,126.32,123.08,120.28,119.84,117.86,117.72,116.60,84.04.

[0277] Synthesis Example 19: Synthesis of bis(4-cyanophenyl)iodonium 4,4,5,5,6,6-hexafluoro-1,3,2-dithiazinane-2-salt 1,1,3,3-tetraoxide (alternative synthesis of PAG-10) (Scheme 9)

[0278]

[0279] Option 9

[0280] The compound obtained in Synthesis Example 18 (3.54 g, 8.47 mmol, 1.00 equivalent) was added to 100 mL of nitromethane and 25 mL of water, to which 3.15 g (9.52 mmol, 1.12 equivalents) of potassium cyclohexafluoropropane-1,3-bis(sulfonyl)imide was added, and the mixture was stirred at room temperature overnight. Subsequently, the water was separated, and the organic solution was dried over anhydrous sodium sulfate. Finally, the nitromethane was removed in vacuo at 50°C to obtain the target product, bis(4-cyanophenyl)iodonium cyclohexafluoropropane-1,3-bis(sulfonyl)imide (4.20 g, 79.6% yield); mp = 220°C; 1 H NMR (400MHz, DMSO) δ = 8.44, 8.42, 7.98, 7.96; 19 F NMR(377MHz,)δ=-119.61,-125.81; 13C NMR (101MHz, DMSO) δ = 136.31, 135.36, 121.62, 117.60, 115.65, 115.30, 112.69, 109.57, 106.86.

[0281] Synthesis Example 20: Synthesis of Bis(3-nitrophenyl)iodonium 4,4,5,5,6,6-hexafluoro-1,3,2-dithiazinane-2-salt 1,1,3,3-tetraoxide (Alternative Synthesis of PAG-4) (Scheme 10)

[0282]

[0283] Plan 10

[0284] The compound obtained in Synthesis Example 14 (5.00 g, 11.09 mmol, 1.00 equivalent) was added to 400 mL of nitromethane and 100 mL of water, to which was added 4.13 g (9.52 mmol, 1.12 equivalents) of potassium cyclohexafluoropropane-1,3-bis(sulfonyl)imide, and the mixture was stirred at room temperature overnight. Subsequently, the water was separated, and the organic solution was dried over anhydrous sodium sulfate. Finally, the nitromethane was removed in vacuo at 50°C to obtain the target product, bis(3-nitrophenyl)iodonium cyclohexafluoropropane-1,3-bis(sulfonyl)imide (7.25 g, 98.6% yield); mp = 175°C; 1 H NMR (400MHz, MeOD) δ = 9.20, 8.65, 8.63, 8.53, 8.50, 7.83, 7.81, 7.79; 19 F NMR (377MHz, MeOD) δ = -120.99, -127.50; 13 C NMR (101MHz, MeOD) δ = 150.41, 142.29, 134.21, 131.52, 128.55, 117.16, 115.74, 114.22, 110.93, 108.21.

[0285] Synthesis Example 21: Synthesis of Bis(4-nitrophenyl)iodonium 4,4,5,5,6,6-hexafluoro-1,3,2-dithiazinane-2-salt 1,1,3,3-tetraoxide (Alternative Synthesis of Example 2) (Scheme 11)

[0286]

[0287] Plan 11

[0288] The obtained compound C-3 (3.80 g, 8.30 mmol, 1.00 equivalent) was added to 200 mL of nitromethane and 50 mL of water, to which 3.09 g (9.33 mmol, 1.12 equivalents) of potassium cyclohexafluoropropane-1,3-bis(sulfonyl)imide was added, and the mixture was stirred at room temperature overnight. Subsequently, the water was separated, and the organic solution was dried over anhydrous sodium sulfate. Finally, the nitromethane was removed in vacuo at 50°C to obtain the target product bis(4-nitrophenyl)iodonium cyclohexafluoropropane-1,3-bis(sulfonyl)imide (4.40 g, yield 79.9%); mp = 231°C; 1 H NMR (400MHz, DMSO) δ = 8.56, 8.54, 8.33, 8.31; 19 F NMR (377MHz, DMSO) δ = -119.55, -125.84; 13 C NMR (101 MHz, DMSO) δ = 149.65, 136.86, 126.48, 123.05, 115.45, 112.48, 109.39, 106.67.

[0289] Photolithography Example 1: Electron Beam Contrast Curve of Negative Molecular Glass Resist

[0290] The PAGs of Synthetic Examples 1, 8, and 10 were formulated into photoresists along with the parent iodonium salt, diphenyliodonium 4,4,5,5,6,6-hexafluoro-1,3,2-dithiazinane-2-salt 1,1,3,3-tetraoxide (prepared similarly to Synthetic Example 2 from diphenyliodonium tetrafluoroborate) and the trifunctional epoxide 2,2′,2″-[methylenetris(4,1-phenyleneoxymethylene)]tri[oxirane](II) (prepared as described in Shou Zhao, Xiangning Huang, Andrew J. Whelton, and Mahdi M. Abu-Omar, ACS Sustainable Chem. Eng. 2018, 6, 7600-7608; Digital Object Identifier: 10.1021 / acssuschemeng.8b00443).

[0291]

[0292] 2,2′,2″-[Methylenetris(4,1-phenyleneoxymethylene)]tri[ethylene oxide]

[0293] 4 g of epoxide was dissolved in 100 ml of ethyl lactate. 0.0536 g of PAG was dissolved in 4 ml of ethyl lactate and mixed with the epoxide solution, followed by stirring for at least 2 hours. The solution was then filtered through a 20 nm PTFE syringe filter to obtain a resist formulation. 3 ml of the resist formulation was deposited on a 4" silicon wafer and spun at 1,000 rpm using a Sus s Microtech spin coater to obtain a film of approximately 30 nm thickness after soft baking at 75°C for 300 sec. After scratching the photoresist film, the initial film thickness was measured on a DECTAC profiler. The wafer was exposed on a Tescan SEM MIRA with an accelerating voltage of 20 keV and a beam intensity set to 8. The exposed film was developed by immersing in n-butyl acetate for 3 min and dried using a nitrogen flow. The remaining film thickness in areas exposed to different doses was measured using the same profiler and a comparative curve was determined. 50% film retention (E 1 / 2 ) are as follows (Table 3). This table shows that PAGs of the present invention with specific electron-withdrawing substitutions exhibit unexpected sensitivity to e-beam, and therefore also to EUV exposure, because in both cases, acid formation of the PAG proceeds by electron capture and both EUV and e-beam generate secondary electrons capable of such capture:

[0294] Table 3

[0295] Ionium derivatives <![CDATA[E 1 / 2 [μC / cm 2 ]]> 4,4'-Dinitro 17.8 3,4'-Dinitro 41.7 4,4'-dicyano 59.9 maternal body 86.1

[0296] Photolithography Example 2: Electron Beam Contrast Curve of Positive Chemically Amplified Photoresist

[0297] 130.8 mmol of PAG (cyclohexafluoropropane-1,3-bis(sulfonyl)imide salt of the iodonium cation described in Table 4) and 0.39 g of 0.1N triethanolamine in PGMEA were added to a 50% w / w solids PGME solution of 5 g of a terpolymer of hydroxystyrene, styrene, and tert-butyl acrylate with a molecular weight of approximately 10,000 Daltons, wherein the monomer ratio in the terpolymer was 6:2:2. This solution was diluted with PGMEA to a total concentration of 9.12% w / w solids (approximately 28.3 g of PGMEA). The bottle containing the solution was placed on a roller overnight and then filtered through a 20 nm PTFE syringe filter to obtain a resist formulation. 3 ml of the resist formulation was deposited on a 4" silicon wafer and spun at 1,000 rpm using a Suss Microtech spin coater. After soft baking at 110°C for 90 seconds, a film with a thickness of 346 nm to 388 nm was obtained. After scratching the photoresist film, the initial film thickness was measured on a DECTAC profilometer. The wafer was exposed on a Tescan SEM MIRA with an accelerating voltage of 20 keV and a beam intensity setting of 8. After exposure, the wafer was baked at a temperature of 130°C for 90 seconds. The baked film was developed by immersion in a 2.38% w / w TMAH solution, rinsed with water, and dried using a nitrogen flow. The remaining film thickness in areas exposed to different doses was measured using the same profilometer and a comparative curve was determined. The open point dose E0 is as follows (Table 4):

[0298] Table 4

[0299] Ionium derivatives <![CDATA[E0[μC / cm 2 ]]]> 4,4'-Dinitro 4 3,4'-Dinitro 7 4,4'-dicyano 3 2,2'-Dinitro 5

[0300] The above results demonstrate that the PAG of the present invention imparts unexpected sensitivity to positive-tone chemically amplified photoresists in both e-beam and extended EUV.

[0301] While the disclosed and claimed subject matter has been described and illustrated with a certain degree of particularity, it is to be understood that this disclosure is made by way of example only and that those skilled in the art may make numerous changes in conditions and sequence of steps without departing from the spirit and scope of the disclosed and claimed subject matter.

Claims

1. A compound having structure (I), wherein R1, R2, R 1a and R 2a are independently selected from H, nitro, cyano and alkylsulfonyl, wherein R1, R2, R 1a and R 2a At least two of are independently selected from nitro, cyano and alkylsulfonyl, and X - is not a halide, toluenesulfonate, trifluoromethylsulfonate, tetrafluoroborate, aryl-substituted borate, hexafluorophosphate, hexafluoroarsenate, acetate, trifluoroacetate, methanesulfonate, C-2 to C-20 straight-chain unsubstituted alkylsulfonate, naphthalenesulfonate and / or camphorsulfonate, 2. A compound having structure (I), wherein R1 and R 1a , R2 and R 2a 、R 1a and R2 or R1 and R 2a are independently selected from nitro, cyano and alkylsulfonyl, and X - is not a halide, toluenesulfonate, trifluoromethylsulfonate, tetrafluoroborate, aryl-substituted borate, hexafluorophosphate, hexafluoroarsenate, acetate, trifluoroacetate, methanesulfonate, C-2 to C-20 straight-chain unsubstituted alkylsulfonate, naphthalenesulfonate and / or camphorsulfonate, 3. The compound according to claim 1 or 2, having structure (Ia), 4. The compound according to claim 3, wherein R1 and R 1a Both are nitro.

5. The compound according to claim 3, wherein R1 and R 1a Both are cyano groups.

6. The compound according to claim 3, wherein R1 and R 1a Both are alkylsulfonyl groups.

7. The compound according to claim 3, wherein R1 is nitro and R 1a It is a cyano group.

8. The compound according to claim 3, wherein R1 is nitro and R 1a It is an alkylsulfonyl group.

9. The compound according to claim 3, wherein R1 is an alkylsulfonyl group and R 1a It is a cyano group.

10. The compound according to claim 1 or 2, having structure (Ib), 11. The compound according to claim 10, wherein R2 and R 2a Both are nitro.

12. The compound according to claim 10, wherein R2 and R 2a Both are cyano groups.

13. The compound according to claim 10, wherein R2 and R 2a Both are alkylsulfonyl groups.

14. The compound according to claim 10, wherein R2 is nitro and R 2a It is a cyano group.

15. The compound according to claim 10, wherein R2 is nitro and R 2a It is an alkylsulfonyl group.

16. The compound according to claim 10, wherein R2 is an alkylsulfonyl group and R 2a It is a cyano group.

17. The compound according to claim 1 or 2, having structure (Ic), 18. The compound according to claim 17, wherein R1 and R 2a Both are nitro.

19. The compound according to claim 17, wherein R1 and R 2a Both are cyano groups.

20. The compound according to claim 17, wherein R1 and R 2a Both are alkylsulfonyl groups.

21. The compound according to claim 17, wherein R1 is nitro and R 2a It is a cyano group.

22. The compound according to claim 17, wherein R1 is nitro and R 2a It is an alkylsulfonyl group.

23. The compound according to claim 17, wherein R1 is alkylsulfonyl and R 2a It is a cyano group.

24. A compound according to any one of claims 1 to 23, wherein X - pK a The anion of an acid with a pH less than 0.

25. A compound according to any one of claims 1 to 23, wherein X - pK a The anion of an acid with a molar ratio of less than 1.

26. A compound according to any one of claims 1 to 23, wherein X - The anion is a perfluorinated or partially fluorinated alkyl sulfonate having more than 3 carbon atoms, wherein the alkyl group is a linear, branched or cyclic alkyl group; or the anion is a perfluorinated or partially fluorinated alkyl sulfonate having more than 3 carbon atoms, wherein the alkyl group is a linear, branched or cyclic alkyl group containing a heteroatom group selected from -O-, -C(=O)- and -S(=O)2-.

27. A compound according to any one of claims 1 to 23, wherein X - It is antimony hexafluoride.

28. A compound according to any one of claims 1 to 23, wherein X - It is a perfluorinated superacid of methyl anion or iminium anion.

29. A compound according to any one of claims 1 to 23, wherein X - It is perfluorobutane sulfonate (PFBS) or hexafluoropropane sulfonate.

30. A compound according to any one of claims 1 to 23, wherein X - It is a tris(perfluoroalkylsulfonyl)methyl anion.

31. A compound according to any one of claims 1 to 23, wherein X - It is a bis(perfluoroalkylsulfonyl)imide anion.

32. A compound according to any one of claims 1 to 23, wherein X - is an anion selected from the group consisting of tris[(trifluoromethyl)sulfonyl]methyl anion (C1), tris[(nonafluoro-n-butyl)sulfonyl]methyl anion (C4), bis(trifluoromethanesulfonyl)imide anion (N1), bis(nonafluoro-n-butanesulfonyl)imide anion (N4) and cyclic 4,4,5,5,6,6-hexafluorodihydro-1,1,3,3-tetraoxide-4H-1,3,2-dithiazine (NC3); 33. A compound according to any one of claims 1 to 23, wherein X - is a fluorinated arylsulfonate which is partially or fully substituted with a substituent selected from fluorine or perfluoroalkyl.

34. A compound according to any one of claims 1 to 23, wherein X - is a sulfonate moiety (-SO3) connected to the polymer backbone via a linker group. - ), the linking group does not contain a direct bond to the -SO3 - Part of the aromatic ring.

35. The compound according to claim 34, wherein said -SO3 - The moiety is directly attached to the polymer backbone through a C-1 to C-8 linear perfluoroalkylene linking group.

36. The compound according to claim 35, wherein the perfluoroalkylene linking group is selected from the group consisting of difluoromethylene (-CF2-), tetrafluoroethylene (-CF2-CF2-), and hexafluoropropylene (-CF2-CF2-CF2-).

37. The compound according to claim 36, wherein the linking group is a methylene moiety directly linked to the sulfonate moiety, which is linked at its other end to the polymer directly or through a C-1 to C-4 perfluoroalkylene moiety.

38. A compound according to any one of claims 1 to 23, wherein X - is a perfluoroalkylamide anion moiety (-N(perfluoroalkyl)) attached directly or via a linker to the polymer backbone - ), wherein the linking group is selected from the group consisting of C-1 to C-8 alkylene, C-1 to C-8 perfluorinated alkylene, and C-1 to C-8 partially fluorinated alkylene.

39. A compound according to any one of claims 1 to 23, wherein X - is a diperfluoroalkyl carbon anion portion (-C(perfluoroalkyl)2) connected directly or through a linking group to the polymer backbone - ), wherein the linking group is selected from the group consisting of C-1 to C-8 alkylene, C-1 to C-8 perfluorinated alkylene, and C-1 to C-8 partially fluorinated alkylene.

40. A compound according to any one of claims 1 to 23, wherein X - It is a polycyano-substituted cyclopentadienyl anion.

41. The compound according to claim 40, wherein the polycyano-substituted cyclopentadienyl anion is selected from the group consisting of a pentacyanocyclopentadienyl anion, a tetracyanomonocarboxylic acid cyclopentadienyl anion, and a tetracyanomethoxycyclopentadienyl anion.

42. A positive chemically amplified EUV or electron beam photoresist composition comprising 1) A compound according to any one of claims 1 to 41, 2) photoresist resins that undergo chemically amplified deprotection catalyzed by photogenerated acid to release a resin that is soluble in aqueous base, 3) an optional acid quencher component, 4) Organic spin coating solvent.

43. A positive chemically amplified EUV or electron beam photoresist composition comprising 1a) A compound having structure (I) wherein R1, R2, R 1a and R 2a are independently selected from H, nitro, cyano and alkylsulfonyl, wherein R1, R2, R 1a and R 2a At least two of are independently selected from nitro, cyano and alkylsulfonyl, and X - pK a The anion of the acid is less than 0, 2a) a photoresist resin that undergoes chemically amplified deprotection catalyzed by photogenerated acid to release a resin that is soluble in aqueous base, 3a) an optional acid quencher component, 4a) Organic spin coating solvent.

44. A positive-tone chemically amplified EUV or electron beam photoresist composition comprising 1b) a compound having structure (I), wherein R1 and R 1a , R2 and R 2a 、R 1a and R2 or R1 and R 2a are independently selected from nitro, cyano and alkylsulfonyl, and X - is not a halide, toluenesulfonate, trifluoromethylsulfonate, tetrafluoroborate, aryl-substituted borate, hexafluorophosphate, hexafluoroarsenate, acetate, trifluoroacetate, methanesulfonate, C-2 to C-20 straight-chain unsubstituted alkylsulfonate, naphthalenesulfonate, and / or camphorsulfonate, and X - pK a The anion of the acid is less than 0, 2b) a photoresist resin that undergoes chemically amplified deprotection catalyzed by a photogenerated acid to release a resin that is soluble in aqueous base, 3b) an optional acid quencher component, 4b) Organic spin coating solvents.

45. A method of forming a positive image using a positive chemically amplified photoresist by EUV or e-beam exposure, comprising steps i) to iv); i) applying the positive chemically amplified EUV or electron beam photoresist composition according to any one of claims 42 to 44 on a substrate to form a coating film, ii) baking the coating film to form a baked coating film, iii) exposing regions of the baked coating film to EUV or electron beam radiation through a mask to form exposed regions and unexposed regions, iv) an optional post-exposure bake step, v) developing with an aqueous alkaline developer to remove the exposed area and form a positive image pattern in the coated photoresist on the substrate, vi) using the positive image pattern as a mask, etching the substrate with plasma or chemical etchant to form a positive image in the substrate.

46. ​​A method of forming a negative image using a positive chemically amplified photoresist by EUV or e-beam exposure, comprising steps ia) to via); ia) applying the positive chemically amplified EUV or electron beam photoresist composition according to any one of claims 42 to 44 on a substrate to form a coating film, iia) baking the coating film to form a baked coating film, iiia) exposing regions of the baked coating film to EUV or electron beam radiation through a mask to form exposed and unexposed regions, iva) an optional post-exposure bake step, va) developing with an organic solvent developer to remove the unexposed area, thereby forming a negative image pattern in the coated photoresist on the substrate, via) using the negative image pattern as a mask, etching the substrate with plasma or a chemical etchant to form a negative image in the substrate.

47. A negative-tone chemically amplified EUV or e-beam photoresist composition comprising 1c) a compound according to any one of claims 1 to 41, 2c) a photoresist resin which is soluble in aqueous base and undergoes chemical amplification crosslinking in the presence of a photogenerated acid, 3c) an optional cross-linking component, 4c) an optional acid quencher component, 5c) Organic spin coating solvent.

48. A negative-tone chemically amplified EUV or electron beam photoresist composition comprising 1d) a compound having structure (I), wherein R1, R2, R 1a and R 2a are independently selected from H, nitro, cyano and alkylsulfonyl, wherein R1, R2, R 1a and R 2a At least two of are independently selected from nitro, cyano and alkylsulfonyl, and X - pK a The anion of the acid is less than 0, 2d) a photoresist resin which is soluble in aqueous base and undergoes chemical amplification crosslinking in the presence of a photogenerated acid, 3d) an optional cross-linking component, 4d) an optional acid quencher component, 5d) Organic spin coating solvent.

49. A negative-tone chemically amplified EUV or electron beam photoresist composition comprising 1e) a compound having structure (I), wherein R1, R2, R 1a and R 2a are independently selected from H, nitro, cyano and alkylsulfonyl, wherein R1, R2, R 1a and R 2a At least two of are independently selected from nitro, cyano and alkylsulfonyl, and X - pK a The anion of the acid is less than 0, 2e) a photoresist resin which is soluble in aqueous base and undergoes chemical amplification crosslinking in the presence of a photogenerated acid, 3e) a cross-linking component, 4e) an optional acid quencher component, 5e) Organic spin coating solvent.

50. A negative-tone chemically amplified EUV or electron beam photoresist composition comprising 1f) a compound having structure (I), wherein R1 and R 1a , R2 and R 2a 、R 1a and R2 or R1 and R 2a are independently selected from nitro, cyano and alkylsulfonyl, and X - is not a halide, toluenesulfonate, trifluoromethylsulfonate, tetrafluoroborate, aryl-substituted borate, hexafluorophosphate, hexafluoroarsenate, acetate, trifluoroacetate, methanesulfonate, C-2 to C-20 straight-chain unsubstituted alkylsulfonate, naphthalenesulfonate and / or camphorsulfonate, 2f) a photoresist resin which is soluble in aqueous base and undergoes chemical amplification crosslinking in the presence of a photogenerated acid, 3f) an optional cross-linking component, 4f) an optional acid quencher component, 5f) Organic spin coating solvent.

51. A method for forming a negative image using a negative photoresist by EUV or electron beam exposure, comprising steps ib) to vib) ib) applying the negative chemically amplified EUV or electron beam photoresist composition according to any one of claims 47 to 50 on a substrate to form a coating film, iib) baking the coating film to form a baked coating film, iiib) exposing regions of the baked coating film to EUV or electron beam radiation through a mask to form exposed and unexposed regions, ivb) an optional post-exposure bake step, vb) developing with an aqueous alkaline or organic solvent developer to remove the unexposed areas, thereby forming a negative image pattern in the coated photoresist on the substrate, vib) using the negative image pattern as a mask, etching the substrate with plasma or a chemical etchant to form a negative image in the substrate.

52. A negative-tone chemically amplified EUV or electron beam photoresist composition comprising 1g) a compound having structure (I), wherein R1, R2, R 1a and R 2a are independently selected from H, nitro, cyano and alkylsulfonyl, wherein R1, R2, R 1a and R 2a At least two of are independently selected from nitro, cyano and alkylsulfonyl, and X - pK a The anion of the acid is less than 0, 2g) a molecular glass compound comprising 3 to 5 crosslinking moieties selected from oxirane, oxetane or mixtures thereof, said crosslinking moieties being crosslinked under the influence of the acid formed by irradiation with component 1a), 3g) an optional acid quencher component, 4g) Organic spin coating solvent.

53. The composition according to claim 52, wherein the molecular glass compound has structure (II), 54. A method of forming a negative image using a negative photoresist by EUV or electron beam exposure, comprising steps ic) to vic) ic) applying the negative chemically amplified EUV photoresist or the electron beam composition according to claim 52 or 53 on a substrate to form a coating film, iic) baking the coating film to form a baked coating film, iiic) exposing regions of the baked coating film to EUV or electron beam radiation through a mask to form exposed regions and unexposed regions, ivc) an optional post-exposure bake step, vc) developing with an organic solvent developer to remove the unexposed areas and form a negative image pattern in the coated molecular glass on the substrate, and etching the substrate using plasma or a chemical etchant using the negative image pattern as a mask to form a negative image in the substrate.

55. Use of a compound according to any one of claims 1 to 41 as a photoacid generator.

56. Use of a composition according to any one of claims 42 to 44, 47 to 50, 52 or 53 as a photoresist on a substrate.

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