Abstract As high‐numerical aperture extreme UV lithography (EUVL) approaches commercial deployment, driving a need for innovation in photoresist technology, extensive research has identified tin‐oxo nanoclusters (TOCs) as promising next‐generation photoresist platforms. This study proposes a method for achieving TOC‐based photoresists that increase their solubility upon exposure to EUV radiation, addressing the current lack of suitable candidates. Lewis‐acidic alkylated TOCs undergo ligand dissociation upon exposure to high‐energy electron beams or EUV light. This structural change enhances further the Lewis acidity of the resulting compounds, enabling the selective dissolution of exposed regions in a Lewis‐basic aqueous developer to form a positive‐tone stencil. This strategy is successfully demonstrated using DSBTOC , which contains bulky counter‐anions but lacked sufficient patterning performance and stability for high‐resolution pattern formation. A modified formulation combining DSBTOC with 10 wt.% dendritic hexaphenol ( DHP ) that acts as both a Lewis base and a radical scavenger exhibited improved thin‐film properties and chemical stability. EUVL testing of films made from this mixture produced a positive‐tone stencil with a line width of 13 nm. It is expected that TOC‐based positive‐tone resists to complement their negative‐tone counterparts in producing high‐performance semiconductor chips.

Tin-Oxo Nanoclusters This illustration depicts extreme ultraviolet (EUV)-induced structural changes in a photoresist system composed of Lewis acidic tin-oxo nanoclusters and Lewis basic polyphenols. Lewis acid-base interactions stabilize the film prior to exposure, while EUV irradiation triggers partial disassembly, promoting interactions with hydroxide ions in an aqueous developer. This chemistry enables the selective dissolution of exposed areas, leading to high-resolution positive-tone patterning. More information can be found in article number 2503002 by Jin-Kyun Lee, Jin Choi, and co-workers.

Abstract As high‐numerical aperture extreme UV lithography (EUVL) approaches commercial deployment, driving a need for innovation in photoresist technology, extensive research has identified tin‐oxo nanoclusters (TOCs) as promising next‐generation photoresist platforms. This study proposes a method for achieving TOC‐based photoresists that increase their solubility upon exposure to EUV radiation, addressing the current lack of suitable candidates. Lewis‐acidic alkylated TOCs undergo ligand dissociation upon exposure to high‐energy electron beams or EUV light. This structural change enhances further the Lewis acidity of the resulting compounds, enabling the selective dissolution of exposed regions in a Lewis‐basic aqueous developer to form a positive‐tone stencil. This strategy is successfully demonstrated using DSBTOC , which contains bulky counter‐anions but lacked sufficient patterning performance and stability for high‐resolution pattern formation. A modified formulation combining DSBTOC with 10 wt.% dendritic hexaphenol ( DHP ) that acts as both a Lewis base and a radical scavenger exhibited improved thin‐film properties and chemical stability. EUVL testing of films made from this mixture produced a positive‐tone stencil with a line width of 13 nm. It is expected that TOC‐based positive‐tone resists to complement their negative‐tone counterparts in producing high‐performance semiconductor chips.

Tin-Oxo Nanoclusters This illustration depicts extreme ultraviolet (EUV)-induced structural changes in a photoresist system composed of Lewis acidic tin-oxo nanoclusters and Lewis basic polyphenols. Lewis acid-base interactions stabilize the film prior to exposure, while EUV irradiation triggers partial disassembly, promoting interactions with hydroxide ions in an aqueous developer. This chemistry enables the selective dissolution of exposed areas, leading to high-resolution positive-tone patterning. More information can be found in article number 2503002 by Jin-Kyun Lee, Jin Choi, and co-workers.

Abstract To unlock the full potential of extreme ultraviolet lithography (EUVL) utilizing high numerical aperture (NA) optics, tin‐oxo nanoclusters (TOCs) have emerged as a promising platform for photoresists (PRs). Although TOC‐based PRs offer distinct advantages, their intrinsic Lewis acidity must be carefully managed to prevent undesirable interactions during lithographic processing. To address this, fluoroalkylated TOCs are devised, exploiting the unique properties of carbon–fluorine (C–F) bonds. By employing targeted counter‐anion selection, N‐TOC6 is synthesized, a material exhibiting robust etch resistance and solubility‐switching behavior under EUV exposure, demonstrating the potential of fabricating sub‐10 nm patterns. Supported by 19 F NMR and XPS analyses, it is proposed that the presence of C–F bonds reduces the affinity of Sn atoms for airborne Lewis basic molecules by forming coordination contacts with the Lewis acidic Sn centers, thereby improving pattern stability post‐exposure. Additionally, N‐TOC6 exhibits chemical orthogonality with non‐fluorinated TOCs, facilitating bilayer stacking that enhances EUVL sensitivity. This study highlights the critical role of fluorine chemistry in achieving high‐performance, energy‐efficient lithographic materials for next‐generation chip manufacturing in the artificial intelligence era.

We explored chemical strategies to promote intermolecular cross-linking induced by fluorinated alkyl units under ionizing radiation. To this end, we synthesized a compound containing two fluoroalkyl moieties and two vinylsilyl groups, which exhibited more efficient cross-linking under accelerated electron-beam irradiation compared to vinyl-lacking analogues. Under extreme ultraviolet irradiation, the vinylsilyl-containing compound was similarly converted into a cross-linked, insoluble material, enabling the formation of sub-20 nm structures.

In this study, we propose a strategy to achieve positive Metal Oxide Resists (pMORs) based on Tin-Oxo Nanoclusters (TOCs) for Extreme Ultraviolet (EUV) lithography in high-performance semiconductor integrated circuit manufacturing. TOC possesses Lewis acidic properties and becomes more strongly acidic upon ligand dissociation when exposed to high-energy radiation, such as electron beam (e-beam) and EUV. During the subsequent development process using an aqueous solution of Tetramethylammonium Hydroxide (TMAH), a Lewis base, the exposed regions undergo Lewis acid-base interactions, leading to increased hydrophilicity. Ultimately, this results in enhanced solubility, enabling the formation of positive-tone patterns. To address the limitations of TOCs, particularly in terms of process margin and chemical stability, we mixed TOCs with small organic molecules containing phenolic hydroxyl groups, which act as Lewis bases. This modification effectively mitigated the shortcomings of TOCs. A TOC formulation containing 10% Dendritic Polyphenol (DPP) exhibited an improved dissolution contrast while simultaneously enhancing chemical stability. Using this in EUV lithography, we successfully achieved high resolution positive-tone patterns with a line width of 13 nm.

Astrophysical neutrinos may be produced during the coalescence of compact objects, in particular those involving neutron stars. Such mergers have been observed through gravitational wave detections by the LIGO-Virgo-KAGRA interferometers. The ANTARES and KM3NeT deep-sea neutrino telescopes are sensitive to neutrino interactions in a wide range of energies, from MeV to PeV. In this contribution, recent searches for correlation in time and space between neutrinos and gravitational wave signals are reviewed. In particular, the results of follow-ups with the KM3NeT real-time system for alerts from the fourth observing run of LIGO-Virgo-KAGRA will be reported for the first time. Additionally, prospects for future studies using archival data from both neutrino and gravitational wave detectors will be outlined.

In order to have a high-quality crystallinity for boosting the device performance, the metal-induced lateral crystallization (MILC), using Ni becomes a critical process in semiconductor industries. Simulating full process has difficulties because of scale difference between nanometer-scale atomistic process and micrometer-scale device. In this study, we first present full device scale simulation of MILC process, using efficient atomistic kinetic lattice Monte Carlo simulation. Balance between thermodynamics and kinetics reveals that the crystallization rate is dominated by the energetically stable interfaces. Moreover, we found the dynamic instability of the MILC process, which could potentially fail the device fabrication in a few micrometer scale.