Enhanced EUV photoresist and use method thereof

Abstract

Disclosed and claimed herein are novel non-polymeric aromatic-based core molecules containing oxygen-containing, acid or base-reactive cross-linking functional groups with improved sensitivity (photosensitivity speed), resolution (line width roughness), or both when formulated in EUV photoresists. Formulations made from the disclosed molecules and methods are also disclosed.

Description

Technical Field

[0001] The present patent application discloses non-polymeric aromatic core molecules containing oxygen-containing, acid- or base-reactive crosslinking functional groups, which have improved sensitivity (photospeed), resolution (line width roughness), or both when formulated in EUV photoresists. Also disclosed are formulations made from the disclosed molecules. Background Art

[0002] Extreme ultraviolet lithography (EUVL) is one of the leading technology options to replace optical lithography for volume semiconductor manufacturing with feature sizes <20nm. The extremely short wavelength (13.4nm) is a key enabler for achieving the high resolution required for multiple technology generations. In addition, the overall system concept (scanning exposure, projection optics, mask format and photoresist technology) is very similar to that used by current optical technologies. As with previous generations of lithography, EUVL consists of photoresist technology, exposure tool technology and mask technology. The main challenges are EUV source power and throughput. Any improvement in EUV power will directly impact the current stringent photoresist sensitivity specifications. In fact, a major issue with EUVL imaging is the photoresist sensitivity, the lower the sensitivity, the greater the required source power or the longer the exposure time required to fully expose the photoresist. The lower the power level, the greater the impact of noise on the line width roughness (LWR) of the printed line and line edge growth in negative photoresists or line edge recession in positive photoresists. As the features of the photoresist size are reduced to the wavelength of the imaging radiation, it is very difficult to obtain a pattern with an acceptable LWR.

[0003] Various attempts have been made to modify the composition of EUV photoresist compositions to improve the performance of functional properties. Electronic device manufacturers continually seek to increase the resolution of patterned photoresist images. It is desirable to have new photoresist compositions that can provide enhanced imaging capabilities, including new photoresist compositions that can be used for EUVL.

[0004] As is well known, the manufacturing process of various electronic devices or semiconductor devices such as IC, LSI, etc. involves fine patterning of a photoresist layer on the surface of a substrate material such as a semiconductor silicon wafer. This fine patterning process is traditionally carried out by a photolithography method, wherein the substrate surface is uniformly coated with a positive or negative photosensitive composition to form a thin layer, and selectively irradiated with actinic rays (such as ultraviolet rays (UV), deep UV, vacuum UV, extreme UV, X-rays, electron beams and ion beams) via a transmission mask or a reflection mask, and then developed to selectively dissolve the coated photosensitive layer in the region exposed to or not exposed to the actinic rays, thereby leaving a patterned photoresist layer on the substrate surface. The patterned photoresist layer thus obtained can be used as a mask in subsequent treatments (such as etching) on ​​the substrate surface. The manufacture of nanometer-scale size structures is a field of great concern because it can realize electronic devices and optical devices that utilize novel phenomena such as quantum confinement effects, and also allows greater component packaging density. Therefore, it is required that the photoresist pattern has an increasing fineness, which can be achieved by using actinic rays with a wavelength shorter than conventional ultraviolet light. Therefore, the situation now is that, instead of conventional ultraviolet light, electron beam (e-beam), excimer laser beam, EUV, BEUV and X-ray are used as short wavelength actinic rays. Needless to say, the minimum size that can be obtained is determined in part by the properties of the photoresist material and in part by the wavelength of the actinic ray. Various materials have been proposed as suitable photoresist materials. For example, in the case of negative photoresists based on polymer crosslinking, there is an inherent resolution limit of about 10nm, which is the approximate radius of a single polymer molecule.

[0005] It is also known to apply a technique called "chemical amplification" to photoresist materials. Chemically amplified photoresist materials are typically multi-component preparations, wherein there is a matrix material, typically a major polymer component, such as a polyhydroxystyrene (PHOST) resin protected by an acid-labile group and a photoacid generator (PAG), and one or more additional components that impart desired properties to the photoresist. The matrix material contributes to improved properties such as etch resistance and mechanical stability. By definition, chemical amplification occurs through a catalytic process involving PAGs, which results in a single irradiation event causing the transformation of multiple photoresist molecules. The acid produced by the PAG catalyzes a reaction with the polymer, causing it to lose a functional group, or alternatively causing a cross-linking event. For example, the speed of the reaction can be driven by heating the photoresist film. In this way, the sensitivity of the material to actinic radiation is greatly increased, because a small amount of irradiation events causes a large number of solubility change events. As described above, chemically amplified photoresists can be positive or negative.

[0006] Without being bound by theory, it is believed that the improved sensitivity results in improved structural integrity of the photopattern of the photoresist. This may be due to a reduction in stray, diffracted, or diffuse radiation. In addition, in systems where cross-linking and ultimately photochemically enhanced polymerization are key processes for generating the photopattern, it is believed that controlling cross-linking and / or polymerization can improve the accuracy of the desired pattern, such as eliminating or reducing such unwanted problems as LWR (line width roughness), line growth, and line sharpening.

[0007] It is also generally believed that in negative working photoresist systems based on a curing mechanism that relies on cross-linking and / or polymerization reactions, reactions occur with little control due to the chain reaction that hardens the photoresist. In a typical photoresist, underexposure will result in under-curing of the photo pattern, while overexposure will result in a broadening of the photo pattern. In almost all negative working photoresist processes, a post-exposure bake (PEB) is required to harden the photoresist to a point where it can withstand development processes including high pH developers as well as solvent and semi-aqueous developers. Maintaining the desired photo pattern is difficult when the exposed photoresist is exposed to the high temperatures of standard photoresist processes.

[0008] The patent literature is replete with photoresist formulations that contain epoxy materials as crosslinkers used in acid catalyzed curing processes. The patent literature describes a wide variety of compounds that can be used in photoresists, suggesting that each compound is as good as another, but only very few are supported in experimental and process results. Many materials are disclosed in a list of all possible variations, but without supporting data. The photoresist patterning literature does not describe any novelty, uniqueness, or improvement in crosslinkers, especially crosslinking solutions for increasing photoresist photospeed and / or reducing LWR. We have conducted intensive studies to determine the equivalent effectiveness of all crosslinking compounds in providing sensitivity and fine line photopatterning, and have surprisingly found that several unique new crosslinkers do in fact provide significant improvements in the generation of photopatterns produced by EUV actinic radiation.

[0009] This patent application discloses and claims novel crosslinking agents based on tris(triphenyl)methane as a core functional group and novel crosslinking agents based on 1,4-bis-(diphenylmethyl)benzene as a core functional group. The unexpected findings disclosed in this application are not limited to tris(triphenyl)methane or 1,4-bis-(diphenylmethyl)benzene, and can be expected to be applicable to other aromatic systems acting as crosslinking agents, including, for example, polynuclear aromatic compounds, aromatic heterocycles, biphenyl compounds, monoaromatic compounds, etc.

[0010] It is also proposed that these unique and novel cross-linkers can be used in conventional photoresist exposure processes, such as, for example, 365 nm, 248 nm, and 193 nm exposure schemes. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The molecular structures of the reference compounds used in the present disclosure and the molecular structures of the novel cross-linking agents 1 to 5 proposed in the present disclosure are shown.

[0012] Figure 2 The molecular structures of the novel cross-linking agents 6 to 11 proposed in the present disclosure are shown.

[0013] Figure 3 The molecular structures of the novel cross-linking agents 12 to 16 proposed in the present disclosure are shown.

[0014] Figure 4 The molecular structures of the novel cross-linking agents 17 to 21 proposed in the present disclosure are shown.

[0015] Figure 5 The molecular structure of the novel crosslinker 22 is shown, showing ortho, para, para substitution of the oxygen groups on the phenyl group.

[0016] Figures 6 to 9 Shown is a SEM image of 22 nm lines and spaces obtained by processing a photoresist containing the novel cross-linker presented in this disclosure. DETAILED DESCRIPTION

[0017] In a first embodiment, disclosed and claimed herein is an acid-sensitive cross-linking agent or a base-sensitive cross-linking agent comprising a core tris(4-hydroxyphenyl)methane group having structure I:

[0018]

[0019] Wherein -O-R1 to -O-R3 are respectively located at the ortho, meta or para position of the methane atom, and R1 to R3 are the same or different and are composed of at least one epoxy-ether cross-linking functional group, cycloepoxy-ether cross-linking functional group and / or oxetane-ether cross-linking functional group.

[0020] In a second embodiment, disclosed and claimed herein is an acid-sensitive crosslinker or a base-sensitive crosslinker comprising a core 1,4-(bis-4'-hydroxydiphenylmethyl)benzene core having structure II:

[0021]

[0022] wherein -O-R1 to -O-R4 are respectively located at the ortho, meta or para position of the methane atom, and R1 to R4 are the same or different and are composed of at least one epoxy-ether cross-linking functional group, cycloepoxy-ether cross-linking functional group and / or oxetane-ether cross-linking functional group.

[0023] In a third embodiment, disclosed and claimed herein is an acid-sensitive crosslinker or a base-sensitive crosslinker of any of the above embodiments, wherein R1 to R4 may be the same or different and comprise a glycidyl ether, 1,2-epoxy 4-butyl ether, 1,2-epoxycyclohexane-4-methyl ether or an oxetane ether group.

[0024] In a fourth embodiment, disclosed and claimed herein is an acid-sensitive cross-linker or a base-sensitive cross-linker of any of the above embodiments, wherein at least one of the hydrogens on at least one of the hydroxyphenyl groups is replaced with an iodide, a fluoride, or a fluoride-containing group, or a combination thereof.

[0025] In a fifth embodiment, disclosed and claimed herein is a photosensitive composition comprising at least one epoxy ether having a structure selected from the following I or II:

[0026]

[0027] At least one photoacid generator or photobase generator; optionally, a zwitterionic component; and at least one solvent, wherein -O-R1 to -O-R4 are respectively located at the ortho, meta or para position of the methane atom, and R1 to R4 are the same or different, and contain epoxy-ether crosslinking functional groups and / or oxetane-ether crosslinking functional groups.

[0028] In a sixth embodiment, disclosed and claimed herein is the composition of the above embodiment, wherein R1 to R4 may be the same or different and comprise glycidyl ether, 1,2-epoxy 4-butyl ether, 1,2-epoxycyclohexane-4-methyl ether or oxetane ether groups.

[0029] In a seventh embodiment, disclosed and claimed herein is the composition of the above embodiment, wherein any of the phenyl groups is substituted with an iodide, fluoride or fluoride-containing group, or a combination thereof.

[0030] In an eighth embodiment, disclosed and claimed herein is the composition of the above embodiment, further comprising a nucleophilic quencher, wherein the nucleophilic quencher is triphenylsulfonium triflate or triphenylsulfonium tosylate.

[0031] In a ninth embodiment, disclosed herein and claimed is the composition of the above embodiment, wherein at least one photoacid generator is selected from sulfonium salts, iodonium salts, sulfonyl imides, halogen-containing compounds, sulfone compounds, ester sulfonate compounds, diazomethane compounds, dicarboxyimidosulfonates, iminooxysulfonates, sulfanyl-diazomethanes, or mixtures thereof, and wherein the at least one solvent comprises an ester, an ether, an ether-ester, a ketone, a cyclic ketone, a halide solvent, an alkyl aryl ether, an alcohol, or combinations thereof.

[0032] As used herein, the terms ortho, meta, and para are located on the core aromatic ring relative to the methane carbon to which the aromatic group is bonded.

[0033] As used herein, the conjunction "and" is intended to be inclusive, and the conjunction "or" is not intended to be exclusive unless otherwise indicated. For example, the phrase "or alternatively" is intended to be exclusive.

[0034] As used herein, the terms "having," "containing," "including," "comprising," and the like are open-ended terms that indicate the presence of stated elements or features, but do not exclude additional elements or features. The articles "a," "an," and "the" are intended to include the plural as well as the singular, unless the context clearly indicates otherwise.

[0035] As used herein, the term PHOTOSPEED refers to the EUV dose required to obtain a 22 nm line when processed by the formulation test described below.

[0036] As used herein, the term "blend" refers to a mixture of at least two cross-linking agents that may differ in basic structure, substituents and / or isomers.

[0037] The novel crosslinking agent disclosed herein contains a tri(4-hydroxyphenyl)methane core or a l,4-(bis-4'-hydroxydiphenylmethyl)benzene core. The oxygen substituents are located on the three core phenyl groups of structure I, ortho, meta or para to the methyl atoms of the core structure. The three oxygen substituents can be positioned differently, wherein one oxygen substituent can be para, while another oxygen substituent can be meta, and the third oxygen substituent can be ortho, meta or para. The oxygen substituents are located on four core phenyl groups in the core phenyl groups, which are bonded to the central core phenyl group on structure II, ortho, meta or para to the methyl atoms of the core structure. The oxygen substituents can be positioned differently, wherein one oxygen substituent can be para, while another oxygen substituent can be meta, and the third oxygen substituent can be ortho, meta or para.

[0038] The zwitterionic component of the photosensitive composition of the present disclosure may be:

[0039]

[0040] Experimental synthesis of materials

[0041] The following is a general procedure for synthesizing representative novel cross-linking agents of the present disclosure:

[0042] A) Condensation of selected aldehydes with phenol to form a trityl core:

[0043] Under argon atmosphere, aldehyde (1.00 eq.), phenol (4.0 eq.), PTSA (20 mol%) and zinc chloride (20 mol%) were placed in a flask of appropriate size. The reaction mixture was heated to 50°C and stirred overnight. Water (25 mL) was added and the reaction mixture was extracted with EtOAc (3×25 mL). The combined organic fractions were washed with water (3×15 mL) and brine (15 mL), dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure to give a crude residue which was purified by automated flash column chromatography (0-100% Hx / EtOAc).

[0044] B) Synthesis of selected epoxides:

[0045] The trityl core from A) (1.0 eq.) was dissolved in epichlorohydrin (30.0 eq.) under argon atmosphere. Tetraethylammonium iodide (20 mol%) was added and the mixture was heated to 80°C overnight. An aqueous solution of NaOH (50%, w / w, 4.5 eq.) was added and the reaction was stirred for an additional 3 h. Once cooled to room temperature, the mixture was stirred through cotton wool and the filtrate was collected. Water (25 mL) was added and the reaction mixture was extracted with EtOAc (2×25 mL). The combined organic fractions were washed with water (3×15 mL) and brine (15 mL), dried over anhydrous MgSO4, filtered and concentrated under reduced pressure to give a crude residue which was purified by automated flash column chromatography (0-100% Hx / EtOAc).

[0046] C) Dealkylation reaction (if necessary)

[0047] Under argon atmosphere, boron tribromide (1.0M heptane solution, 4.5 equivalents) was added dropwise to a cooling solution of the selected triphenylmethane core (1.0 equivalent) in anhydrous dichloromethane (0.2M) at 0°C. The resulting solution was allowed to warm to room temperature and stirred overnight. Water (25mL) was added, and the reaction mixture was extracted with EtOAc (3×25mL). The combined organic fractions were washed with water (3×15mL) and brine (15mL), dried over anhydrous MgSO4, filtered and concentrated under reduced pressure to give a crude residue, which was purified by automated flash column chromatography (0-100% Hx / EtOAc).

[0048] D) Iodination (if necessary)

[0049] Under argon atmosphere, the selected triphenylmethane core (1.0 equivalent), NaOH (3.3 equivalents) and KI (3.3 equivalents) were dissolved in water / ethanol (75:25, v / v) solution. The solution was cooled to 0 ° C, and I2 (3.3 equivalents) was added. The resulting mixture was covered with aluminum foil and allowed to warm to room temperature and stirred overnight. HCl aqueous solution (4.0M, 40mL) was added, and the mixture was extracted with EtOAc (1×400mL). The combined organic fractions were washed with saturated sodium thiosulfate solution (1×100mL), brine (1×100mL), dried over anhydrous MgSO4, filtered and concentrated under reduced pressure to give a crude product, which was purified by automated flash column chromatography (0-100% Hx / EtOAc).

[0050] Synthesis of compound 19

[0051] Synthesis of 4,4'-((4-ethoxyphenyl)methylene)biphenol 7

[0052] The compound was prepared from 4-ethoxybenzaldehyde according to the general condensation procedure at a scale of 13.35 mmol to afford 7 as an off-white solid in 58% yield (2.470 g; 58%).

[0053] Synthesis of 4,4'-((4-ethoxyphenyl)methylene)bis(2,6-diiodophenol)8

[0054] Procedure adapted from literature. 2 4,4'-((4-ethoxyphenyl)methylene)biphenol 7 (2.470 g, 7.71 mmol) was dissolved in a solution of KOH (3.24 g, 57.82 mmol) in MeOH (39.0 mL). I2 (7.830 g, 30.84 mmol) was added to the solution in one go, and the reaction mixture was stirred under argon for about 10 min. Aqueous HCl (4.0 M, 20 mL) was added until the pH reached 4 to 5, so the mixture was extracted with EtOAc (3 × 25 mL). The combined organic fractions were washed with brine (25 mL), dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure to give a crude product, which was purified by automated flash column chromatography (0-100% Hx / EtOAc). The title compound (2.80 g; 44%) was obtained as a dark solid.

[0055] Synthesis of 4,4'-((4-hydroxyphenyl)methylene)bis(2,6-diiodophenol)9

[0056] The compound was prepared from 8 according to the general dealkylation procedure at a scale of 2.38 mmol. 9 (1.80 g; 95

[0057] Synthesis of ((((((4-(oxiran-2-ylmethoxy)phenyl)methylene)bis(2,6-diiodo-4,1-phenylene))bis(oxy))bis(methylene))bis(oxetane-3,3-diyl))dimethanol

[0058] 9 (1.70 g, 2.14 mmol) was dissolved in MeCN (7.1 mL) and K2CO3 (0.82 g, 5.99 mmol) was added to the resulting solution followed by (3-(bromomethyl)oxetan-3-yl)methanol (1.07 g, 5.88 mmol). The mixture was stirred at 60 °C overnight, at which time another portion of potassium carbonate (0.41 g, 2.99 mmol) was added followed by epichlorohydrin (0.24 g, 2.57 mmol). After an additional 16 h, water (10 mL) was added and the mixture was extracted with EtOAc (3 x 25 mL). The combined organic fractions were washed with brine (25 mL), dried over anhydrous MgSO4, filtered and concentrated under reduced pressure. The crude residue obtained was purified by automated flash column chromatography (0-100% Hx / EtOAc). CL 2134 (0.20 g; 9%) was obtained as a white solid.

[0059] Synthesis of compound 5

[0060] Synthesis of 4,4'-((3-fluoro-4-methoxyphenyl)methylene)biphenol 15

[0061] Under nitrogen, a mixture of 2-fluoro-p-methoxybenzaldehyde (4.00 g; 25.97 mmol), phenol (12.21 g; 129.87 mmol), ZnCl2 (0.32 g; 2.34 mmol) and PTSA (0.49 g; 2.6 mmol) was stirred at room temperature for 1 h, after which a viscous slurry was formed. It was heated to 45 ° C and left for 24 h. The reaction was cooled to room temperature. Ethyl acetate (40 mL) was added and washed with water (2×10 mL). The organic phase was dried over MgSO4 and evaporated to dryness in vacuo. The solid was further purified by column chromatography (silica; 80% hexane: 20% ethyl acetate) to give 15 (5.90 g; 65%) as a light yellow solid.

[0062] Synthesis of 4,4'-((3-fluoro-4-methoxyphenyl)methylene)bis(2,6-diiodophenol)16

[0063] Under nitrogen, a solution of 15 (0.70 g; 2.16 mmol), NaOH (0.52 g; 12.96 mmol) and KI (1.98 g; 11.88 mmol) in water / ethanol (1:1, 50 mL) was cooled to 0 °C. Iodine (3.02 g; 11.88 mmol) was added and the reaction was covered with foil and warmed to room temperature. After 24 h, HCl (6 M; 10 mL) was added. The precipitate was filtered, washed with water (3×20 mL) and then with hexane (10 mL). The precipitate was further purified by column chromatography (silica; 60% n-hexane: 40% ethyl acetate) to give 16 (0.90 g; 50%) as a white solid.

[0064] Synthesis of 4,4'-((3-fluoro-4-hydroxyphenyl)methylene)bis(2,6-diiodophenol)17

[0065] Under nitrogen, a degassed dichloromethane (5 mL) solution of 16 (0.33 g; 0.40 mmol) was cooled to -78 ° C. BBr (1 M in dichloromethane; 1.32 mL) was added within 5 minutes. The solution was warmed to room temperature. After 20 h, the reaction was quenched with ice (3 g). After the ice had melted, ethyl acetate (20 mL) was added. The mixture was washed with water (10 mL), followed by brine (10 mL), and then dried over MgSO. The organic phase was evaporated to dryness in vacuo to give 17 (0.27 g; 83%) as a white solid. No further purification was required. 1 H NMR:4I3FOH F1 otter10 / 12 / 20

[0066] Synthesis of 2,2'-(((((3-fluoro-4-(oxiran-2-ylmethoxy)phenyl)methylene)bis(2,6-diiodo-4,1-phenylene))bis(oxy))bis(methylene))bis(oxirane)

[0067] Under nitrogen, a solution of 17 (170 mg; 0.21 mmol) and tetraethylammonium iodide (20 mg, 0.06 mmol) in epichlorohydrin (5 mL) was heated and maintained at 80 ° C for 20 h. Sodium hydroxide (50% w / w aqueous solution; 0.94 mmol) was added to the reaction and left for another 3 h. The reaction was cooled to room temperature and then gravity filtered. The precipitate was washed with ethyl acetate (2×10 mL). The washings were combined with the filtrate. The filtrate was washed with water (3×20 mL), dried over MgSO4 and evaporated to dryness in vacuo. The solid was further purified by recrystallization using ethyl acetate: hexane (1:5) and column chromatography (silica; 30% n-hexane: 70% ethyl acetate) to give compound 5 (30 mg; 15) as a white solid. Synthesis of Representative Novel Compounds of the Disclosure

[0068]

[0069] Molecular weight: 1032.11

[0070] Synthesis of 4,4'-((4-methoxy-3-(trifluoromethyl)phenyl)methylene)biphenol 20

[0071] The compound was prepared according to the general condensation procedure from 19 on a scale of 4.9 mmol to give 20 (1.7 g; 93%) as a light red solid.

[0072] Synthesis of 4,4'-((4-methoxy-3-(trifluoromethyl)phenyl)methylene)bis(2,6-diiodophenol)21

[0073] Compound 21 was prepared from 20 at scale 2.14 mmol following the General Iodination Procedure - Method I. 21 was obtained as an orange / red solid (0.77 g; 41% yield).

[0074] Synthesis of 4,4'-((4-hydroxy-3-(trifluoromethyl)phenyl)methylene)bis(2,6-diiodophenol)22

[0075] Compound 22 was prepared from 21 according to the general dealkylation procedure at a scale of 0.88 mmol. 22 (0.32 g; 42

[0076] Synthesis of 2,2'-(((((4-(Oxiran-2-ylmethoxy)-3-(trifluoromethyl)phenyl)methylene)bis(2,6-diiodo-4,1-phenylene))bis(oxy))bis(methylene))bis(oxirane) CL 2103

[0077] This compound was prepared according to the general procedure Epoxide Appendix from 22 on a scale of 0.37 mmol. CL 2103 (0.17 g; 51%) was obtained as a white solid.

[0078] Synthesis of compound 16

[0079] Synthesis of 4,4',4",4"'-(1,4-phenylenebis(methanetriyl))tetraphenol 25

[0080] The compound was prepared from terephthalaldehyde according to the general condensation procedure at a scale of 7.46 mmol. Phenol was used at 9 molar equivalents. The amount of ZnCl2 and PTSA used was 0.2 molar equivalents. 25 (1.7 g; 48%) was obtained as a white solid.

[0081] 1,4-Bis(bis(4-(oxiran-2-ylmethoxy)phenyl)methyl)benzene

[0082] Compound 16 was prepared according to the General Procedure Epoxide Appendix from 25 at scale 1.54 mmol. Epichlorohydrin was used at 100 molar equivalents and Et4NI was used at 0.4 molar equivalents.

[0083] Synthesis of compound 14

[0084] Synthesis of 4,4',4",4"'-((perfluoro-1,4-phenylene)bis(methanetriyl))tetraphenol 26

[0085] The compound was prepared from tetrafluoroterephthalaldehyde according to the general condensation procedure at a scale of 9.7 mmol. Phenol was used in 9 molar equivalents. The amount of ZnCl2 and PTSA used was 0.2 molar equivalents. 26 (5.04 g; 95%) was obtained as a pale yellow solid. Synthesis of 2,2',2",2"'-(((((perfluoro-1,4-phenylene)bis(methanetriyl))tetra(benzene-4,1-diyl))tetra(oxy))tetra(methylene))tetra(ethylene oxide) CL 2122

[0086] Compound 14 was prepared from 26 in the general procedure Epoxide Appendix at a scale of 4.85 mmol. Epichlorohydrin was used at 100 molar equivalents and Et4NI was used at 0.4 molar equivalents to give a light yellow solid (0.95 g; 25

[0087] Synthesis of compound 10

[0088] Synthesis of (3-((4-(bis(4-(oxiran-2-ylmethoxy)phenyl)methyl)phenoxy)methyl)oxetan-3-yl)methanol

[0089] A solution of 4,4,4-trihydroxyphenylmethane (1 g; 3.42 mmol), NaH (82 mg; 3.42 mmol) in DMF (10 mL) was stirred for 5 min under nitrogen, then (3-(bromomethyl)oxetan-3-yl)methanol (1.24 g; 6.84 mmol) was added. The reaction mixture was heated to 50 °C for 16 h. Epichlorohydrin (5 mL; 64 mmol) was added, followed by Et4NI (260 mg; 1 mmol) and the mixture was heated to 80 °C for another 16 h. A solution of NaOH 50% w / w in water (0.82 mL) was added to the reaction mixture, and the reaction was maintained for another 3 h. The reaction mixture was cooled to room temperature and filtered through cotton. The mixture was washed with EtOAc (2×10 mL) and then with water (15 mL). The organic phase was washed with brine (15 mL) and dried over MgSO4. The organic phase was evaporated to dryness under reduced pressure. The solid was further purified by column chromatography (silica; 90% dichloromethane:10% ethyl acetate).

[0090] Synthesis of compound 15

[0091] Synthesis of 4,4'-((4-methoxy-2-(trifluoromethyl)phenyl)methylene)biphenol 27

[0092] The compound was prepared from 4-methoxy-2-(trifluoromethyl)benzaldehyde according to the general condensation procedure at a scale of 4.9 mmol. 27 (1.7 g; 93

[0093] Synthesis of 4,4'-((4-hydroxy-2-(trifluoromethyl)phenyl)methylene)biphenol 28

[0094] Compound 28 was prepared from 27 according to the general dealkylation procedure at a scale of 4.8 mmol. 28 (1.1 g; 63

[0095] Synthesis of 2,2'-(((((4-(Oxiran-2-ylmethoxy)-2-(trifluoromethyl)phenyl)methylene)bis(4,1-phenylene))bis(oxy))bis(methylene))bis(oxirane)

[0096] Compound 15 was prepared according to the General Procedure Epoxide Appendix from 28 on a scale of 3.05 mmol. CL 2128 (0.7 g; 44%) was obtained as a colorless solid.

[0097] Synthesis of compound 22

[0098] Synthesis of 4,4'-((2-hydroxy-3,5-diiodophenyl)methylene)bis(2,6-diiodophenol)32

[0099] Procedure adapted from literature. 1 KI (4.70 g, 28.32 mmol) was added in batches to a solution of 4,4'-((2-hydroxyphenyl)methylene)biphenol 13 (synthesized as shown in Scheme 7, 1.38 g, 4.72 mmol), NaIO4 (6.06 g, 28.32 mmol) and NaCl (3.31 g, 56.65 mmol) in AcOH / water (9:1, v / v, 16 mL). The resulting mixture was stirred at room temperature until complete consumption of the starting material was observed on TLC. Water (30 mL) was added and the mixture was extracted with EtOAc (3×25 mL). The combined organic fractions were washed with brine (35 mL), dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The obtained crude residue was purified by automated flash column chromatography (0-50% Hx / EtOAc). The title compound was obtained as a dark red solid with a yield of 9% (0.430 g, 0.41 mmol).

[0100] Synthesis of 2,2'-(((((3,5-diiodo-2-(oxiran-2-ylmethoxy)phenyl)methylene)bis(2,6-diiodo-4,1-phenylene))bis(oxy))bis(methylene))bis(oxiran) compound 22

[0101] Compound was prepared according to the General Procedure Epoxide Appendix from 4,4'-((2-hydroxy-3,5-diiodophenyl)methylene)bis(2,6-diiodophenol) 32 on a scale of 0.41 mmol. The title compound was obtained as a clear viscous oil in 40% yield (0.200 g, 0.16 mmol).

[0102] 1. C. Ge, H. Wang, B. Zhang, J. Yao, X. Li, W. Feng, P. Zhou, Y. Wang and J. Fang, Chem. Commun., 2015, 51, 14913-14916.

[0103] 2. K. Omura, J. Org. Chem., 1984, 49, 3046-3050.

[0104] 3. AAKelkar, N.M. Patil and RV Chaudhari, Tetrahedron Lett., 2002, 43, 7143-7146. 4. T. Dohi, N. Yamaoka and Y. Kita, Tetrahedron, 2010, 66, 5775-5785.

[0105] formula

[0106] General formulation: Since each of the novel crosslinkers has a different molecular weight, the formulation is described in terms of molar ratios. The crosslinker containing the high opacity crosslinker (compounds 1 to 7 and 9 to 15) is formulated at a different molar equivalent (Formula B below) than the non-high opacity crosslinker (compounds 8 and 16) (Formulas A1 to A2 below).

[0107] Formula A1: 1 molar equivalent of the new cross-linker, 0.461 molar equivalent of PAG and 0.090 molar equivalent of the nucleophilic quencher were added to ethyl acetate to obtain 16.5 g / L.

[0108] Formula A2: To ethyl acetate, 0.128 molar equivalent of EX2, 1 molar equivalent of a novel cross-linking agent,

[0109] 0.461 molar equivalents of PAG and 0.090 molar equivalents of nucleophilic quencher, giving 16.5 g / L.

[0110] Formula B1: To ethyl acetate were added 1 molar equivalent of the novel cross-linker, 0.455 molar equivalent of PAG, and 0.077 molar equivalent of the nucleophilic quencher.

[0111] Formula B2: To ethyl acetate, 0.063 molar equivalent of EX2, 1 molar equivalent of a novel cross-linking agent,

[0112] 0.455 molar equivalent of PAG and 0.077 molar equivalent of nucleophilic quencher.

[0113] It has also been discovered that two or more crosslinking agents, including different isomers of the present disclosure, can be combined in various ratios to obtain compositions that form blends of the properties of those blended crosslinking agents.

[0114] The solids percentage in the formulation can be varied to obtain a film thickness of 20 nm when spun and dried.

[0115] Formulation Testing Note: Formulations were prepared at such concentrations to obtain a film thickness of 20 nm when spun at 1500-2500 rpm and dried. Film thickness was measured using ellipsometry optical techniques.

[0116] Silicon wafers were spin coated at 2000 rpm using Brewer Science Optistack AL 212 primer and baked at 205°C for 30 sec. The photoresist formulation was dispensed onto the wafer using a pipette and spun at the spin speed required to achieve a 20 nm film thickness target (typically 1200 rpm to 2300 rpm). The wafer was baked at 60°C for 3 minutes and the film was checked to see if it was still suitable for exposure (e.g., no dewetting).

[0117] The wafers were exposed using a PSI synchrotron through a non-contact mask containing a pattern of 44nm line spacing, and many dies were exposed on one wafer with increasing dose. The wafers may optionally be post-exposure baked for 1 to 2 minutes, typically at 60°C to 80°C. The wafers were immersion developed in nBA (n-butyl acetate) for 30 to 60 seconds, and then optionally rinsed in MIBC (methyl isobutyl carbinol) for 15 seconds.

[0118] The patterns were then examined using an SEM and images were taken by dose. Line width and line width roughness were measured using a software package called SMILE.

[0119] Line width and LWR were plotted against dose, a trend line was calculated, and from this plot the dose required to achieve a 22nm line was calculated; and the LWR of the 22nm line was also recorded.

[0120] result

[0121] Figures 4 to 8 Shown are scanning electron microscope images of formulations using the novel cross-linking agents specified in the present disclosure.

[0122] Note: In some SEMs, such as those for compounds 6 and 7, there are no acceptable resist structures, but the photospeed is very high and perhaps a lower dose can make the pattern more acceptable.

[0123] The results show that a variety of very specific acid-sensitive epoxy and oxetane crosslinkers exhibit significant improvements in line width roughness or photospeed, or both, when used in EUV photoresists compared to commercial oxygen-containing crosslinkers or other classes of oxygen-containing crosslinkers. Also noteworthy are the improvements in the results as they relate to crosslinkers containing highly EUV absorbing iodide substituents as well as fluoride substituents and combinations thereof at various positions throughout the molecule.

[0124] Line width roughness improvement

[0125] As can be seen from Table 1 below, the addition of a methylene group between the oxygen functional group and the epoxy functional group of the phenol portion of Compound 1 improves the line width roughness by 30% compared to the commercial control.

[0126]

[0127]

[0128] Table 1

[0129] Also in Table 1, when the epoxy group is located on the cyclohexane structure, compound 2 shows a 7.7% improvement in line width roughness. Also in Table 1, when the epoxy group is replaced with an oxetane group (compounds 3 and 4), improvements in line width roughness are obtained, 21% and 18%, respectively. In Table 1, compound 5 has the core of compound 1, but both iodide and fluoride are substituted on the benzene ring, which improves line width roughness by 15%.

[0130] Speed ​​enhancement

[0131] When formulated into EUV photoresists, the crosslinking compounds of Tables 2, 3, and 4 provide improvements in photospeed compared to commercial crosslinkers. Without being bound by theory, it is believed that the increased freedom provided by extending the reactive epoxy or oxetane groups further away from the core structure, as in compounds 1 and 2, provides an easier crosslinking pathway. Interestingly, it was surprisingly found that the oxetane group of compound 3 provided an increase in photospeed, but not as great as compounds 1 or 2. It is believed that the epoxy group has greater strain than the oxetane and is therefore more reactive.

[0132] Compounds 1 and 6 differ in that the compounds contain 3 iodides substituted on the aromatic ring. Surprisingly, the non-iodine compound shows very high speeds. Compound 7, which differs from the control and compound 6 in that the epoxy chain contains another methylene group, thus moving the reactive epoxy away from the core molecule, also shows very high photospeeds.

[0133]

[0134] Table 2

[0135] Other variations of the novel cross-linking agents proposed in the present disclosure are shown in Tables 3 and 4 below:

[0136] As shown in Table 3, compounds 8, 9 and 2 are all members of the epoxycyclohexane crosslinking functional group. It can be seen that the photospeed is improved compared to the commercial control, but despite the change in the molecule or the isomer mixture, they have essentially equal photospeeds. Compound 10 has 2 epoxy groups and 1 oxetane on the molecule. The photospeed is essentially the same as the all-epoxy molecule and is essentially the same photospeed, that is, greatly improved over the commercial control.

[0137] Compound 11 contains six trifluoromethyl groups substituted on the methylene groups alpha to the phenol oxygen.

[0138] Compared to commercial crosslinkers, the photospeed is again greatly increased.

[0139]

[0140] Table 3

[0141] Table 4 discloses other novel crosslinkers of the present application. Compound 12 shows a member of the fluorinated molecule of the present disclosure. Here, three trifluoromethyl groups are substituted onto the benzene ring. The photospeed is worse than the control, but not as fast as some of the other novel crosslinkers. Although the increase in photospeed is not as high as some of the other crosslinkers described herein, the presence of the fluorinated group presents other advantages, such as solubility.

[0142] Compound 13 is similar to compound 12 but has an additional methylene group at the alpha position to the phenolic oxygen, thus extending the ether chain and moving the reactive epoxy group away from the core molecule. It can be seen that the photospeed is greatly improved by chain extension to about 7 times. Compound 15 is similar to compound 12 but only 1 trifluoromethyl group is substituted on the phenyl group. The photospeed is improved compared to the trisubstituted crosslinker.

[0143] Compounds 14 and 16 contain a pentaaryl basic core structure (Structure II): 1,4-bis-(diphenylmethyl)benzene. The epoxy group is a glycidyl ether, while compound 14 contains four fluorinated substituted on the central benzene ring. It can be seen that the photospeed of compound 14 is greatly improved, while the non-fluorinated compound 16 shows only a slight improvement in photospeed.

[0144]

Claims

1. Acid-sensitive crosslinkers or base-sensitive crosslinkers containing a core tris(4-hydroxyphenyl)methane group having structure I: Wherein R1 to R3 are the same or different and consist of at least one epoxy-ether crosslinking functional group, cycloepoxy-ether crosslinking functional group and / or oxetane-ether crosslinking functional group.

2. The crosslinking agent according to claim 1, wherein R1 to R3 may be the same or different and comprise at least one of glycidyl ether, 1,2-epoxy 4-butyl ether, 1,2-epoxycyclohexane-4-methyl ether or oxetane ether groups.

3. An acid-sensitive crosslinker or base-sensitive crosslinker comprising a core tris(4-hydroxyphenyl)methane group having the following structure: wherein R1 to R3 are the same or different and consist of at least one of an epoxy ether crosslinking functional group, a cycloepoxy-ether crosslinking functional group and / or an oxetane-ether crosslinking functional group, and wherein at least one of the hydrogens on at least one of the hydroxyphenyl groups is substituted with an iodide, a fluoride or a fluoride-containing group or a combination thereof.

4. The crosslinking agent according to claim 3, wherein R1 to R3 may be the same or different and comprise at least one of glycidyl ether, 1,2-epoxy 4-butyl ether, 1,2-epoxycyclohexane-4-methyl ether or oxetane ether groups.

5. An acid-sensitive crosslinker or base-sensitive crosslinker comprising a core 1,4-(bis-4'-hydroxydiphenylmethyl)benzene core having structure II: wherein R1 to R4 are the same or different and consist of at least one epoxy-ether crosslinking functional group, cycloepoxy-ether crosslinking functional group and / or oxetane-ether crosslinking functional group.

6. The crosslinking agent according to claim 5, wherein R1 to R4 may be the same or different and comprise a glycidyl ether, 1,2-epoxy 4-butyl ether, 1,2-epoxycyclohexane-4-methyl ether or oxetane ether group.

7. Acid-sensitive crosslinkers or base-sensitive crosslinkers containing a core tris(4-hydroxyphenyl)methane group having structure II: wherein R1 to R3 are the same or different and consist of epoxy-ether crosslinking functional groups, cycloepoxy-ether crosslinking functional groups and / or oxetane-ether crosslinking functional groups, and wherein at least one of the hydrogens on at least one of the hydroxyphenyl groups is substituted with an iodide, a fluoride or a fluoride-containing group or a combination thereof.

8. The crosslinking agent according to claim 7, wherein R1 to R4 may be the same or different and comprise a glycidyl ether, 1,2-epoxy 4-butyl ether, 1,2-epoxycyclohexane-4-methyl ether or oxetane ether group.

9.

10. A photosensitive composition comprising: a. at least one epoxy ether having a structure selected from the following I or II: b. at least one photoacid generator or photobase generator; and c. at least one solvent. Wherein R1 to R4 are the same or different and include epoxy-ether crosslinking functional groups, cycloepoxy-ether crosslinking functional groups and / or oxetane-ether crosslinking functional groups.

11. The composition according to claim 9, wherein R1 to R4 may be the same or different and comprise a glycidyl ether, 1,2-epoxy 4-butyl ether, 1,2-epoxycyclohexane-4-methyl ether or oxetane ether group.

12. The composition of claim 9, wherein R1 to R4 are the same or different, contain epoxy ether crosslinking functional groups, epoxy-ether crosslinking functional groups and / or oxetane-ether crosslinking functional groups, and wherein at least one of the hydrogens on at least one of the hydroxyphenyl groups is substituted with an iodide, a fluoride or a fluoride-containing group or a combination thereof.

13. The composition of claim 9, further comprising a nucleophilic quencher.

14. The composition of claim 12, wherein the nucleophilic quencher is triphenylsulfonium triflate or triphenylsulfonium tosylate.

15. The composition of claim 7, wherein the at least one solvent comprises an ester, ethyl acetate, an ether, an ether-ester, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether.

16. The photosensitive composition according to claim 9, further comprising at least a zwitterionic component; wherein R1 to R4 are the same or different and comprise epoxy-ether crosslinking functional groups, cycloepoxy-ether crosslinking functional groups and / or oxetane-ether crosslinking functional groups.

17. The composition of claim 15, wherein R1 to R4 are the same or different, contain epoxy ether crosslinking functional groups, epoxy-ether crosslinking functional groups and / or oxetane-ether crosslinking functional groups, and wherein at least one of the hydrogens on at least one of the hydroxyphenyl groups is substituted with an iodide, a fluoride or a fluoride-containing group or a combination thereof.

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