The Photopolymer Science and Technology Award No. 212100, the Best Paper Award 2021, was presented to Tomotaka Tsuchimura (FUJIFILM Corporation) for his outstanding contribution published in Journal of Photopolymer Science and Technology, 33, (2020) 15-26, entitled “Recent Progress in Photo-Acid Generators for Advanced Photopolymer Materials”.

The Photopolymer Science and Technology Award No. 222100, the Best Paper Award 2021, was presented to Seihou Jinnai and Yutaka Ie (The Institute of Scientific and Industrial Research (SANKEN), Osaka University) for their outstanding contribution published in Journal of Photopolymer Science and Technology, 34, (2021) 285-290, entitled “Synthesis, Properties, and Photovoltaic Characteristics of Arch- and S-shaped Naphthobisthiadiazole-based Acceptors”.

The Photopolymer Science and Technology Award No. 232100, the Best Paper Award 2022, was presented to Atsunori Nakamoto, Shinji Yamakawa, Tetsuo Harada, and Takeo Watanabe (Center for EUV Lithography, Laboratory of Advanced Science and Technology for Industry, University of Hyogo) for their outstanding contribution published in Journal of Photopolymer Science and Technology, 35, (2022) 61-65, entitled “Grazing-Incidence Soft-X-ray Scattering for the Chemical Structure Size Distribution Analysis in EUV Resist”.

We forecast that the semiconductor manufacturing equipment market in 2023 will shrink by 20% year-on-year, grow by 15% in 2024, and grow by 20% in 2025.

The semiconductor manufacturing equipment market is currently in an adjustment phase, and semiconductor manufacturers are putting the brakes on capital investment. Therefore, we believe that the medium- to long-term growth potential of semiconductors and manufacturing equipment will not be damaged, and that the manufacturing equipment industry will return to a growth trajectory after a temporary adjustment.

Microneedles made of polymer materials are attracting attention as minimally invasive medical devices for painless access to the body. To apply microneedles to in-body optical sensing, microneedles with a high aspect ratio (base diameter: 500 μm, height: 2 mm) containing platinum octaethylporphyrin, a phosphorescent probe for oxygen were fabricated using poly(l-lactic acid), a bioabsorbable polymer by vacuum-assisted micromolding process. The tip of the microneedle was excited with UV laser (wavelength: 375 nm), and the quenching time of the phosphorescence was measured by an avalanche photodiode and an oscilloscope at different oxygen partial pressures. The obtained phosphorescence lifetimes at the microneedle tip were approximately 100 μs and the relationship between phosphorescence lifetime and oxygen partial pressure was confirmed to follow the Stern-Volmer equation. This study suggests that microneedles could be applied as a minimally invasive in-body measurement tool by adding optical sensing capabilities to them.

In order to detect substances using microfluidic devices, fluidic filters with microcapillary arrays with a high aspect ratio were fabricated using deep X-ray lithography. Also, the pressure required to move the solution held on the filter to the lower reservoir was 1～10 kPa in the 10～60 µm capillary diameter range. The microcapillary arrays enable vertical fluid control by integrating various unit chemical operations such as valves, reservoirs, mixers, and reaction fields, where the capillary wall surface was used as a reaction field for highly sensitive detection of the nonylphenol. As a result, it was possible to detect concentrations near the natural environmental existence values defined by The Ministry of the Environment, Japan. This would allow the device to be used for the detection of environmental substances. We also detected mouse IgG using a fluidic filter and found the possibility of detecting enzymatic reactions with a trace amount of reagent.

The spatial distribution observation of resist thin films is important for developing high-performance EUV resists with low line-width roughness property. In our previous study on resist spatial distribution evaluation, aggregation at the micrometer scale was indicated. We developed the reflection-type soft X-ray projection microscope equipped with a capillary mirror optics for focusing. The spatial resolution of this microscope was evaluated in a spatial resolution of a several micrometers. A thin film of a positive-tone chemically amplified resist coated on a glass substrate was observed by this microscope, which had not been patterned. The observation photon energy was around the carbon K-edge absorption region (280 – 300 eV). Non-uniform spatial distribution by reflection mode was observed with a size of several-ten micrometers, which indicated the carbon material aggregation. The micrometer-scale aggregation observation in the resist thin film was very significant to achieve low line-width roughness (LWR).

We examined the synthesis and resist properties of various polyacetals. By the polyaddition of the PDP, TDP, PFPD as A₂ monomers with BVEP (B₂ monomer), TVPM (B₃ monomer), BCA[4]-VE (A₄ monomer), and BCA[8]-VE (A₈ monomer) were investigated to give corresponding linear type [poly(PDP-co-BVEP), poly(TDP-co-BVEP), poly(PFPD-co-BVEP)], hyperbranched type [poly(PDP-co-TVPM), poly(TDP-co-TVPM), poly(PFPD-co-TVPM), and botryosin type [poly(PDP-co-BCA[4]-VE), poly(TDP-co-BCA[4]-VE), poly(PFPD-co-BCA[4]-VE), poly(PDP-co-BCA[8]-VE), poly(TDP-co-BCA[8]-VE), and poly(PFPD-co-BCA[8]-VE)], respectively. The synthesized polyacetals had good physical properties (thermal stability, solubility and film-forming ability) and good film-thickness loss property. Their resist sensitivities in the EB exposure system were higher, i.e., E₀ = 10 μC/cm² for poly(PDP-co-BVEP), (TDP-co-BVEP) and poly(PFPD-co-BVEP), E₀ = 30 μC/cm² for poly(PDP-co-TVPM), poly(PFPD-co-TVPM), poly(PFPD-co-BCA[4]-VE) and poly(PFPD-co-BCA[8]-VE), E₀ = 50 μC/cm² for poly(PDP-co-BCA[4]-VE) and poly(PDP-co-BCA[8]-VE), indicating that these resist materials are good candidate to offer higher resolution resist pattern.

For the development of low line width roughness (LWR) resist, it is necessary to achieve uniform spatial distribution of chemical components in resist thin films at the nanometer scale. To evaluate the chemical distribution, we have developed the resonant soft X-ray scattering (RSoXS) technique. In this study, we evaluated the chemical distribution in five resist thin films spin-coated on a silicon wafer by reflection-mode RSoXS at NewSUBARU synchrotron light facility. The samples were also measured by X-ray absorption spectroscopy. At the reflection-mode RSoXS, the scattered light from the sample surface was recorded by the soft X-ray CMOS camera. The grazing angle of incidence was set to 5 degrees for the sample. The scattering profile for each sample represents the chemical aggregation of the resist polymer. A non-chemically amplified resist had low chemical aggregation, and chemically amplified resist had higher chemical aggregation due to its hydroxyl group of base polymers.

Post-synthesis or post-extreme ultraviolet (EUV)-exposure chemical analysis is necessary to develop resist materials on the next-generation EUV lithography. It is effective to use the X-ray analysis method for a resist coated on a Si wafer. In this paper, the photoacid generator (PAG) unit in the PAG bound type resist is analyzed by the X-ray absorption spectroscopy (XAS). As a result, the amount of anion species in PAG was estimated by sulfur K-edge (S K-edge) XAS spectrum. Further, the chemical structure of resist after the EUV irradiation was suggested by carbon K-edge (C K-edge) and sulfur L-edge (S L-edge) XAS spectra.

Since 2019, EUV lithography with a wavelength of 13.5 nm has been used for the mass production of 7 nm+ node semiconductor logic devices, and pattern processing of 16-nm-half pitch and below is also possible. According to IRDS, further miniaturization is still required by 2037. In EUVL, the most important issue is the development of resists with high sensitivity, high resolution, and low line-width roughness, simultaneously. At the NewSUBARU synchrotron light facility, the exposure tool on EUV interference lithography was developed to replicate EUV resist patterns, which can evaluate the resolution and line-width roughness performance. In this study, it is reported that the current results and status of this tool, especially on the improvement of the exposure shot numbers with a new grating holder and exposure-process automation by developing specific software program. As a result, the exposure shot numbers were improved to 48 shots, which were more than three times larger than those of the previous condition.

Low stochastics, high sensitivity photoresists remain a goal for EUV lithography. Here we contrast two positive photoresist systems, polypeptoids (PPs) and poly(phthalaldehyde)s (PPAs), both of which are selected to minimize chemical stochastics. In the former, a chemically amplified resist with identical molecular weight, composition, and sequence is studied. In the latter, a PPA homopolymer enables preparation of a chemically homogeneous resist which can be chemically scissioned in exposed areas. We report the results of exposure of these materials to DUV, e-beam and EUV radiation and physical changes that occur. In addition, we highlight unexpected observations of the role of sequence on lithographic performance.