Journal of Photopolymer Science and Technology
Online ISSN : 1349-6336
Print ISSN : 0914-9244
ISSN-L : 0914-9244
Current issue
Displaying 1-6 of 6 articles from this issue
  • Masahiro Furutani, Wataru Usui, Chiharu Nishibata
    2024 Volume 37 Issue 6 Pages 567
    Published: December 25, 2024
    Released on J-STAGE: January 25, 2025
    JOURNAL FREE ACCESS

    The authors noticed that structures of monomers 1 and 2 were incorrect after published in J. Photopolym. Sci. Technol., 36 (2023) 267-270. The correct structure of 1 (having a 2-hydroxy or 2-chloropyridyl group) cannot be decided without additional analyses (Fig. 1). On the other hand, the correct structure of 2 is shown in Fig. 2, found after additional MS measurements. Thus, the authors decided to retract the paper. The authors regret any confusion that this issue causes and apologize to the scientific community.

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  • Masahiro Furutani, Miku Matsui, Wataru Usui
    2024 Volume 37 Issue 6 Pages 569-572
    Published: December 25, 2024
    Released on J-STAGE: January 25, 2025
    JOURNAL FREE ACCESS

    Photo-adhesive materials for adhesion between dissimilar materials have been desired in industrial manufacturing. We designed and synthesized a methacryl monomer having a 6-chloropyridyl group. A photo-adhesive material was prepared with the monomer, 2-hydroxyethyl methacrylate and a photo-radical initiator. Photo-adhesion was performed between a glass substrate and another substrate (glass, metals, and polymers), with 2 J/cm2 of UV irradiation at a wavelength of 365 nm. Shear stress of 5-12 MPa was recorded, which would result from formation of cured adhesive layer in a radical UV curing process. XPS spectral measurement in the N1s region showed that 6-chloropyridyl group would interact with copper surface through nitrogen atom of the pyridine ring.

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  • Takuya Mishima, Sawa Matsuura, Naoto Iwata, Seiichi Furumi
    2024 Volume 37 Issue 6 Pages 573-578
    Published: December 25, 2024
    Released on J-STAGE: January 25, 2025
    JOURNAL FREE ACCESS

    In this study, colloidal crystal (CC) films with visible light reflection were successfully fabricated by casting the suspension of silica particles surface-modified with poly(2-ethylhexyl acrylate) (PEHA) chains on the surface of glass substrate. The reflection peak wavelength could be easily tuned by changing the molecular weight of PEHA. Additionally, the CC films with visible reflection could be formed on the glass substrates owing to the intrinsic physical property of strong adhesion of PEHA. From these results, it was suggested that such PEHA-grafted silica particles can be practically used as the paintable color materials.

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  • Ryuta Shiga, Shinji Yamakawa, Tetsuo Harada, Takeo Watanabe
    2024 Volume 37 Issue 6 Pages 579-584
    Published: December 25, 2024
    Released on J-STAGE: January 25, 2025
    JOURNAL FREE ACCESS

    Challenges of EUV lithography include the development of resists with high resolution, high sensitivity, low line-width roughness, and low outgassing. Thus, our research group has developed various evaluation systems installed at the NewSUBARU synchrotron radiation facility and promoted research for EUV lithography. In particular, BL03 is a beamline specialized for EUV flood exposure for 4-inch wafer and used to evaluate sensitivity and outgassing of resists.

    At the EUV flood exposure tool, the synchrotron radiation light is monochromated to EUV with seven reflections by Mo/Si multilayer mirrors. The centroid wavelength of the total reflectivity spectrum is 13.57 nm. The beam size on the sample surface is 3 mm (H) × 4 mm (V), and the EUV irradiation intensity is estimated to be 0.5 mW/cm2 at the storage ring current of 350 mA. We can take max 25 shots for each sample by moving the sample and obtain a contrast curve. About outgassing evaluation, the highly sensitive quadrupole mass spectrometer (QMS) that can measure the mass numbers of ion species from 1 to 512 is equipped in this system, and we can analyze outgassing component under EUV irradiation. This system supports fundamental EUV resist development including screening of newly developed resists.

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  • Tsukasa Sasakura, Shinji Yamakawa, Tetsuo Harada, Takeo Watanabe
    2024 Volume 37 Issue 6 Pages 585-590
    Published: December 25, 2024
    Released on J-STAGE: January 25, 2025
    JOURNAL FREE ACCESS

    The critical issue in EUV resists is the suppression of line width roughness (LWR). The one of the factors contributing to LWR is the aggregation and segregation of chemical compositions in resist thin films. Our group has reported to evaluate the spatial chemical composition distribution inside the resist thin films by resonant soft X-ray scattering (RSoXS). As a result, an aggregation distribution on the order of tens of nanometers was confirmed in the resist thin film due to its chemical composition. However, the scattering information obtained by RSoXS method is average information about the resist thin film, and it was difficult to determine what type of aggregation form the actual aggregation takes, such as spheres or lamellae. We focused on the photoemission electron microscopy (PEEM), which is powerful evaluation tool to observe chemical information on sample surface. Although there have been no reports on PEEM observation of resist surface, that PEEM would allow us to observe the agglomerated structure of the chemical composition on the resist surface.

    In this study, we challenged to observe the carbon distribution of polyhydroxystyrene-co-(tert-butyl acrylate) (PHS-TBA), which is used as a base polymer for EUV resists. Two samples with different compositions have been observed by PEEM with UV (5.2 eV) and synchrotron radiation (281, 288, and 301 eV) as light source. With a field of view of 874 µm, we observed the carbon distribution on the resist surface with the synchrotron light.

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  • Yuri Ebuchi, Shinji Yamakawa, Tetsuo Harada, Takeo Watanabe
    2024 Volume 37 Issue 6 Pages 591-595
    Published: December 25, 2024
    Released on J-STAGE: January 25, 2025
    JOURNAL FREE ACCESS

    An important issue in EUV resist is the development of low line width roughness (LWR) resists. One of the factors that worsen LWR is hypothesized to be the non-uniform distribution of functional groups within the resist. Therefore, it is required for the development of low LWR resist that the controlling of the spatial distribution of resist component materials on the nanometer scale.

    We have been reported the evaluation of the amount of the chemical component, such as aggregation and segregation, using the reflection-mode resonant soft X-ray scattering (RSoXS) measurement system installed at BL10 of the New SUBARU synchrotron radiation facility. The reflection-mode RSoXS measurement technique allows for the scattering information for each functional group through the resonant absorption phenomenon induced by the corresponding incident photon energy. The RSoXS measurements were performed using only an incident photon energy of 280 eV in our previous reports. In this study, we evaluated RSoXS measurements at various incident photon energies around 280 eV to evaluate the aggregation distribution of the resist from several pieces of information, such as carbon, non-carbon, surface region and inside region.

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