The Society of Photopolymer
Science and Technology - SPST

ICPST-42 (2025) KEYNOTE AND INVITED TALKS

A1. Next Generation Lithography, EB Lithography and Nanotechnology

Symposium Chair: Masayuki ENDO (E Litho Research)

A2. Nanobiotechnology

Symposium Chair: Takanori ICHIKI (The University of Tokyo), Kensuke OSADA (National Institutes for Quantum Science and Technology)

Invited speaker: Kazuma Yasuhara (NAIST)

Invited speaker biography: Dr. Kazuma Yasuhara is an Associate Professor at Nara Institute of Science and Technology (NAIST). He earned his Ph.D. in Science from NAIST in 2008. He served as an Assistant Professor at NAIST (2009–2018) and was a Visiting Assistant Professor at University of California San Francisco (2013–2014). Since 2018, he has been an Associate Professor at NAIST. His research focuses on designing lipid membrane-active macromolecules and their physicochemical characterization.

Presentation title: Lipid Nanodiscs Formed by Lipoprotein-Mimetic Polymers and Their Applications in Drug Delivery

Author(s): Kazuma Yasuhara, Nara Institute of Science and Technology

Abstract: Lipid nanodiscs are the smallest lipid bilayer assemblies formed in aqueous solution. In this study, we designed amphiphilic polymethacrylate derivatives for lipid nanodisc formation. The optimal polymer, selected through library screening, formed discoidal lipid membranes with diameters of several tens of nanometers. We demonstrated that the polymer-based nanodiscs can be used for analyzing membrane-binding amyloidogenic peptides and as nanocarriers for molecular delivery into intact cells.

Invited speaker: Shan Gao (QST)

Invited speaker biography: Dr. Gao Shan is a postdoctoral researcher at the National Institutes for Quantum Science and Technology (QST). His research focuses on the development of polymer-based drug delivery systems and their applications in MRI diagnosis and cancer therapy. Gao holds two Ph.D. degrees in mechanical engineering and life engineering, respectively. His current interests lie in interdisciplinary investigations on pre-symptomatic diagnosis and therapy of chronic diseases.

Presentation title: Nano-Sized Contrast Agent Based on a Novel Self-Folding Macromolecular Architecture for MRI-Based Cancer Diagnosis

Author(s) and affiliation(s): Shan Gao 1, Yutaka Miura 2, Akira Sumiyoshi 1, Nobuhiro Nishiyama 2, Ichio Aoki 1 and Kensuke Osada 1, 1 National Institutes for Quantum Science and Technology and 2 Institute of Science Tokyo

Abstract: In this study, a nano-sized contrast agent was developed based on a novel self-folding macromolecular drug carrier (SMDC) architecture with a size of 5–10 nm for MRI-based cancer diagnosis. The SMDC forms via the intramolecular self-folding of a designed random copolymer in water. Gadolinium chelates were incorporated into the SMDC to serve as a contrast agent, and its improved relaxivity and enhanced tumor accumulation were elucidated. The feasibility of this nano-sized contrast agent was demonstrated by the contrast enhancement effect in MRI for cancer.

Invited speaker: Liqiu Ma (QST)

Invited speaker biography: Liqiu Ma, Ph.D., is currently a Senior Researcher at the National Institutes for Quantum Science and Technology (QST) in Japan. He has received several prestigious awards, including the Young Scientist Award from the Japanese Radiation Research Society. With extensive expertise in the cutting-edge field of particle beam-based immunotherapy, Dr. Ma has spent many years advancing innovative technologies in "particle beam cancer treatment." His research has led to a series of continuous, original, and internationally influential contributions.

Presentation title: Optimal radiation dose to induce the abscopal effect through the combination of carbon-ion radiotherapy and immune checkpoint therapy

Author(s) and affiliation(s): Liqiu Ma 1,2, Lin Xie 1, Kensuke Osada 1, Yukari Yoshida 2, Akihisa Takahashi 2 and Takashi Shimokawa 1, 1 Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology (QST), 2 Gunma University Heavy Ion Medical Center

Abstract: Although carbon-ion radiotherapy (CIRT) has shown good outcomes, metastasis control remains a crucial issue. This study evaluated the abscopal effect of combining CIRT with immune checkpoint therapy (ICT) at different radiation doses. Tumor-bearing mice were treated with 3 Gy or 10 Gy of CIRT, followed by ICT. High-dose CIRT combined with anti-CTLA4 antibody showed excellent local control but no abscopal effect. In contrast, 3 Gy CIRT with anti-CTLA4 antibody reduced the volume of distant tumors by 40%, suggesting an optimal dose for inducing the abscopal effect.

Invited speaker: Satoshi Yamaguchi (Osaka University)

Invited speaker biography: Dr. Satoshi Yamaguchi earned his Ph.D. in Engineering from The University of Tokyo in 2004. He served as a Postdoctoral fellow at Kyushu University and Kyoto University in Prof. Itaru Hamachi group (2004–2005). In 2006, he earned an academic position as an Assistant professor at the University of Tokyo, and was promoted to Lecturer (2012) and Associate Professor (2019). Since 2024, he has been a Professor at SANKEN in Osaka University. His research focuses on photoresponsive chemical tools for manipulation of biopolymers and living cells and for spatio-temporal analysis of living systems.

Presentation title: Photo-responsive cell anchoring surface for single-cell phenotype analysis

Author(s) and affiliation(s): Satoshi Yamaguchi, Osaka University

Abstract: Advances in genetic analysis technologies have led to increasing attention on the heterogeneity of individual cells within cell populations in recent years. As a result, techniques for analyzing the phenotype of cells at the single-cell level are becoming increasingly important. We have previously developed light-responsive cell anchoring surfaces. In this presentation, I will introduce our research on constructing a single-cell array using light-activatable cell ancho surfaces, and acquiring time-series image data at the single-cell level to study the phenotypes of cells.

Invited speaker: Robert L. Brainard (University at Albany)

Invited speaker biography: Prof. Rrof. Robert Brainard received his B.S. in Chemistry from U.C. Berkeley and a Ph.D. in Chemistry while working with Professor G. Whitesides at MIT and Harvard University. Following his post-doctoral studies with Professor R. Madix at Stanford University, he worked for Polaroid and Shipley/RHEM in the areas of: DUV, EUV and E-Beam Photoresists. Prof. Brainard is now a Professor at University at Albany studying: EUV photoresist exposure mechanisms; High quantum efficiency EUV photoresists; Acid amplifiers for use in EUV Lithography; Design and synthesis of photo-imageable hydrogels for cell growth; Molecular Organometallic Resists for EUV (MORE).

Presentation title: Bio Roll-Up: Self-Assembly of Hydrogel Photoresists

Author(s) and affiliation(s): Shaheen Hasan¹, Chase Brisbois², Kelly Carufe³, Abigail Johnson², Julia Garrison², Lauren Sfakis², Victoria Brunner², McKenzie Albrecht⁴, Aishwarya Panneerselvam², Yubing Xie², Robert Brainard², ¹Rensselaer Polytechnic Institute, ²University at Albany, ³Yale University, ⁴SUNY Polytechnic

Abstract: Researchers have explored a variety of stimuli to manipulate the differentiation of stem cells, including changing chemical components, temperature shifts, and hydrogel elasticity, and in particular, substrate curvature to regulate cell shape. Here we describe our early efforts to create a self-assembly platform which can evaluate how changes in shape in terms of curvature can affect the differentiation of stem cells. Our ultimate objective is to create a two-layer stacks of hydrogel photoresists, that can be patterned into rectangles (~2 mm x 3 mm), upon which cells can be seeded, grow and proliferate. Then, at a time of our choosing, we can initiate self-assembly without harming the cells, creating tubes of living cells. Here, we describe multiple stages of advancing this technology exploring: composition of hydrogel, composition of self-assembly media, and several approaches for controlling the timing of self-assembly including “speed bumps” and redox-controlled disulfide linkages. Our earliest example of self-assembly only occurred in pH 3 HCl, but it is not suitable for cell culture. Through optimization of the polymer structure of hydrogel photoresists, we were able to demonstrate self-assembly that occurs in 1X phosphate buffer solution which is at a neutral pH and is isotonic with cells.

A3. Directed Self Assembly (DSA)

- Self-Assembly Materials and Processes (DSA, BCP, SAM, ASD, Infiltration, Nanostructured Materials, Advanced Devices using Self Assembly, etc.) -

Symposium Chairs: Seiji NAGAHARA (ASML Japan) , Teruaki HAYAKAWA (Institute of Science Tokyo), and Takehiro SESHIMO (Tokyo Ohka Kogyo)

Keynote speaker: Diederik Maas (TNO)

Invited speaker biography: Dr. Diederik Maas presently is Senior Systems Architect with TNO Industry, targeting Semicon metrology challenges. From 1998-2006 he was Senior Scientist at Philips Research, where he developed an Electrostatic Aberration Corrector for LV-SEM.
His Ph.D. degree from the University of Amsterdam is for work that was performed at AMOLF involving coherent control of atomic and molecular excitations using chirped ultrashort infrared laser pulses.
His undergraduate work involved experimental studies of the fractional quantum Hall effect on quantum dots that he made using electron beam lithography (See front cover Physics Today, March 1992).

Presentation title: IR-AFM metrology on latent images in DSA and EUVL photoresist

Author(s) and affiliation(s): Diederik Maas¹, Maarten van Es¹, Komal Pandey¹, Adam (Chung Bin) Chuang¹, Takehiro Seshimo², and Teruaki Hayakawa³,¹Netherlands Organisation for Applied Scientific Research – TNO, ²Tokyo Ohka Kogyo, ³Institute of Science Tokyo

Abstract: Resist stochastics ultimately limit patterning, a result of interplay of resist composition, exposure, bake and development. Metrologies like OCD and CD-SEM only measure uniformity after development, offering limited process control. But each step modifies molecular bonds, leaving IR (5-20 µm) fingerprints in activated chemical structures. When combining IR & AFM, nearfield effects resolve alterations at the nm scale. We show how IR-AFM offers chemical selectivity and lateral resolution to resolve modifications in latent DSA and EUVL images, even before PEB and development.

Invited speaker: Redouane Borsali (POLYNAT CARNOT INSTITUTE)

Invited speaker biography: Dr. Redouane Borsali is the DIRECTOR OF POLYNAT CARNOT INSTITUTE, GRENOBLE, FRANCE, CO-DIRECTOR OF IRP-CNRS-UGA-NTU “GREEN MATERIAL INTITUTE” TAIPEI, TAIWAN, SELF-ASSEMBLY OF GLYCOPOLMER GROUP LEADER IN GRENOBLE. He earned his Ph.D. in polymer sciences at Louis Pasteur University at Strasbourg and spent a post-doctoral position at the Max-Planck-Institute in Mainz, Germany. He also was a visiting Professor at Stanford University, California, USA & and Visiting Scientist at IBM, Almaden, CA, USA. Expertise: Self-assemblies of Carbohydrate-based block copolymers (BCP) systems, leading to: Nanostructured Thin films: highlight of properties/applications in nano-electronics including: (smart surfaces, nanolithography, photovoltaic, memory transistors, HR-biosensors, etc.…), Directed Self-Assembly (DSA), Nanoparticles (micelles) & Polymersomes & their properties/applications in cosmetic/biomedical

Presentation title: Self-assembly of Carbohydrate Block Copolymers: From Glyconanoparticles to thin films to photonic crystals

Author(s) and affiliation(s): Redouane Borsali, POLYNAT CARNOT INSTITUTE, GRENOBLE, FRANCE

Abstract: The self-assembly of carbohydrate block copolymer systems at the nanoscale level via the bottom-up approach, has allowed the conception of novel nanostructured biomaterials. We will present recent results on the self-assemblies of carbohydrate-based block copolymer leading to nanoparticles presenting different shapes (spherical, cubic, …), highly nanostructured thin films for nanobioelectronic applications and more recently brush-like glycopolymers exhibiting photonic crystals behavior leading to colored materials.

A4. Computational / Analytical Approach for Lithography Processes

Symposium Chairs: Kenji YOSHIMOTO (Kanazawa University), and Sosuke OSAWA (JSR)

Invited speaker: Momoji Kubo (Tohoku University)

Invited speaker biography: Dr. Momoji kubo received Master degree from Kyoto University and Ph.D. degree from Tohoku University. In 2008 he was promoted to full professor at Tohoku University. Since 2017, he has been director of the supercomputer center in Institute for Materials Research, Tohoku University. He majors in high-performance computing and superlarge-scale simulation technologies. He had been appointed as a leader of one of the supercomputer “Post-K” projects from 2016 to 2020 and he has also been appointed as a leader of one of the supercomputer “Fugaku” projects from 2023 to 2026.

Presentation title: Neural Network Molecular Dynamics Simulations on Synthesis Process of MoS₂ Thin Films from Molybdenum Ditiocarbamate Molecules

Author(s) and affiliation(s): Momoji Kubo, Tohoku University

Abstract: Two-dimensional MoS₂ thin film has gained much attention as not only semiconductor materials but also super-low friction materials. However, its ability is significantly influenced by the quality of the MoS₂ thin film. Therefore, the synthesis process of the MoS₂ thin film should be clarified and optimized on atomic scale. In the present study, we applied our in-house neural network molecular dynamics simulation code “Laich+” to investigating the synthesis process of two-dimensional MoS₂ thin films from molybdenum ditiocarbamate molecules.

Invited speaker: Wim Tel (ASML)

Invited speaker biography: Wim Tel has been working at ASML for over 25 years. His work experience has ranged from development, system engineering to product management seeing various aspects of this company and the industry in which it operates. In the 25 years Wim Tel has worked in the fields of imaging, patterning, overlay, metrology and digital applications.

Presentation title: Incorporating advanced scanner models in semiconductor manufacturing

Author(s) and affiliation(s): Wim Tel, Rob Faessen, Philipp Strack, Pieter Smorenberg, Jaap Karssenberg, Hakki Ergun Cekli, Seiji Nagahara, ASML holding Netherlands

Abstract: Semiconductor device manufacturing seems to be on a collision course between ever more aggressive processing and tightening of specifications. This puts ultimate pressure on correctability. In order to maximally exploit the correction capability of the lithography tool a new scanner control paradigm is proposed. This includes a more holistic view on lithography which maximizes the correctability and co-optimize key performance parameters as well as the use of highly accurate scanner simulation models

Invited speaker: Yuqing Jin (Osaka University)

Invited speaker biography: Yuqing Jin is a Ph.D. student at Osaka University and a DC1 researcher of JSPS. Her research interests include photoresist materials, lithography technology, and computational chemistry. She has published her work in journals such as Applied Physics Express (APEX) and has presented at SPIE conferences in the United States, where she received the Best Student Presentation Award.

Presentation title: Formulation of Developer Solutions Using Integrated Computational Approaches

Author(s) and affiliation(s): Yuqing Jin1, Takehiro Masuda1, Yuko Tsutsui Ito1, Takahiro Kozawa1, Takashi Hasebe2, Kazuo Sakamoto2, Makoto Muramatsu2, 1 SANKEN, Osaka University, 2 Tokyo Electron Kyusyu Limited

Abstract: Novel photoresist and developers are being developed to further shrink the feature size. This study evaluated various developers to improve pattern quality, examining the resulting line-and-space patterns via the Hough transform and evaluating SEM images. Quartz crystal microbalance simulations, including frequency and impedance changes, further illuminated how developer chemistry influences lithographic performance. This work established a method to investigate key insights into how developer chemistry influences lithography performance.

Invited speaker: Masaaki Yasuda (Osaka Metropolitan University)

Invited speaker biography: N/A

Presentation title: Molecular dynamics study of early stages of development process

Author(s) and affiliation(s): Masaaki Yasuda, Ryuki Tanaka, Kousei Tada, and Hiroto Wakamatsu, Osaka Metropolitan University, Japan

Abstract: The early stage of the development process in lithography was analyzed by molecular dynamics simulation. The penetration of developer molecules into the resist, the swelling of the resist, and the removal of the resist molecules were analyzed. We also investigated the differences in molecular behavior depending on the type of resist and developer.

A5. EUV Lithography

Symposium Chairs: Takeo WATANABE (University of Hyogo), Hiroto KUDO (Kansai University), Yoshio KAWAI (Shin-Etsu Chemical), Taku HIRAYAMA (HOYA), Shinji YAMAKAWA (University of Hyogo), Sosuke OSAWA (JSR), and Ethan Choong Bong (CB) Lee (Samsung SDI)

Invited speaker: Danilo De Simone (IMEC)

Invited speaker biography: Danilo De Simone is scientific director at imec. He has 25 years of experience in the semiconductor R&D field and his work has produced over 150 scientific and technical papers in the field of lithographic materials and advanced patterning. Before imec, he worked for the industry for STMicroelectronics, Numonyx and Micron Technology. He is editorial board member of the Journal of Micro/Nanopatterning, Materials, and Metrology (JM3), member of SPIE committee for the Patterning Materials and Processes program and member of the International Advisory Board of the Photopolymer Science and Technology Conference (ICPST).

Presentation title: Patterning materials in the era of high NA EUV Lithography

Author(s) and affiliation(s): Danilo De Simone, IMEC, Belgium

Abstract: In the last years, a patterning roadmap and a large ecosystem was established at imec to enable the device dimensional scaling by using the high NA EUVL technology and tackle its challenges. The high NA EUVL Lab was open in June 2024, and it started delivering to imec its first wafers, showing its potential by printing sub-12nm features. In this work the progress on the patterning activities is illustrated with focus on the lithographic processes and materials in the era of high NA EUV lithography.

Invited speaker: Hiroshi Kawata (KEK)

Invited speaker biography: Prof. Hiroshi Kawata is an honorary professor and a researcher belonging to the Innovation Center for Applied Superconducting Accelerator at KEK. He received his doctorate degree from Tokyo Institute of Technology in 1982. He moved to the Photon Factory in KEK in 1983 and contributed to research based on synchrotron radiation. He became a project leader of KEK’s future light source ERL project since 2006 and has contributed to the development of EUV-FEL designing work since 2014.

Presentation title: EUV-FEL as a future light source for advanced lithography

Author(s) and affiliation(s): Hiroshi Kawata, Yosuke Honda, Norio Nakamura, Ryukou Kato, Hiroshi Sakai, Kimichika Tsuchiya, Yoshinori Tanimoto, Miho Shimada, Masahiro Yamamoto, Takanori Tanikawa, Olga Tanaka, Takashi Obina, Shinichiro Michizono, High Energy Accelerator Research Organization (KEK)

Abstract: The future light source for advanced lithography should have the following performances: high power more than 1kW to reduce stochastic variation, polarization control, wavelength tunability and cost reduction of the running cost per scanner. To conclude, EUV-FEL is a most promising candidate, so our group has done design work and R&Ds to realize the EUV-FEL. At the conference, we will present our latest development status.

Invited speaker: Toshiyuki Taniuchi (University of Tokyo)

Invited speaker biography: Dr. Toshiyuki Taniuchi is a Project Associate Professor at the University of Tokyo. Earning his Ph.D. from the School of Engineering at the university, he specialized in studying magnetic materials by photoemission electron microscopy (PEEM) with synchrotron X-rays. His postdoctoral work at the Institute for Solid State Physics was dedicated to developing ultrahigh-resolution PEEM using lasers. Currently, in his role within the social cooperation research department, he focuses on nanomaterial imaging with laser-based PEEM, in collaboration with the Hitachi Group.

Presentation title: Resist imaging by laser-based photoemission electron microscopy

Author(s) and affiliation(s): Toshiyuki Taniuchi, The University of Tokyo

Abstract: The research presents a new high-throughput imaging method for resist using Photoemission electron microscopy (PEEM). By combining a continuous wave laser with an aberration corrector, this laser-PEEM system achieves spatial resolution below 3 nm. Due to PEEM's high sensitivity to chemical states, it enables the observation of not only developed patterns but also latent images before development, demonstrating its versatility as a projection-type microscopy tool for lithography.

Invited speaker: Rachel Snyder (DuPont Electronics & Industrial)

Invited speaker biography: N/A

Presentation title: Double Amplification Resists from Acid-Catalyzed Chain-Unzipping of Polyphthalaldehyde-Based Polymers

Author(s) and affiliation(s): Rachel Snyder 1, Shintaro Yamada 1, MingQi Li 1, Kyung Hee Oh 2, Jae Hyun Kim 2, Madan Biradar 3, Gokhan Sagdic 3, Christopher K. Ober 3, 1 DuPont Electronics & Industrial, 2 SK hynix Inc., 3 Cornell University

Abstract: Next-generation “double amplification resists” (DARs) use acid catalysis to initiate spontaneous depolymerization and offer a promising strategy for high resolution patterning and fast throughput in EUV lithography. We developed a series of DARs using polyphthalaldehyde derivatives and compared their performance to chemically amplified resists (CARs). In this paper, we will discuss the advantages of DARs, focusing on the resist mechanism and insights from KrF studies. We also describe how polymer design impacts resist performance in EUV lithography.

Invited speaker: Michael J. Eller (California State University, Northridge)

Invited speaker biography: Prof. Michael J. Eller (B.S., Chemistry Iowa State University 2007; Ph.D., Chemistry Texas A&M University 2012) is an Assistant Professor in the Department of Chemistry and Biochemistry at California State University, Northridge. His research interests are centered on developing instrumental and data analysis methods for examining molecules at the nanoscale using Secondary Ion Mass Spectrometry. In 2017 he received the Beynon prize for the best published paper in Rapid Communications in Mass Spectrometry. He has authored over 43 peer reviewed articles, is the current president of the North American SIMS Society and co-chair the 2025 North American SIMS Workshop.

Presentation title: Inspection of next generation hybrid EUV resists with NP-SIMS

Author(s) and affiliation(s): Gregrey Swieca 1, Won-Il Lee 2, Shixian Ha 2, Nikhil Tiwale 3, Chang-Yong Nam 2,3, and Michael J. Eller, 1. California State University, Northridge, 2. Stony Brook University 3. Brookhaven National Laboratory

Abstract: Novel organic-inorganic hybrid resists are receiving much attention as they exhibit high EUV sensitivity and improved etch resistance. Nano-projectile secondary ion mass spectrometry (NPSIMS) is a variant of traditional SIMS for nanoscale inspection of next-generation hybrid resists with lateral resolution to meet the needs of state of the art for EUV patterning. We applied NP-SIMS to study samples of PMMA infiltrated with varying amounts of InOx via vapor-phase infiltration (VPI) and examined the uniformity of In infiltration and the formation of In clusters in PMMA.

Invited speaker: Robert L. Brainard (University at Albany)

Presentation title: Double-Deprotected Acids: Polymeric Esters and Acid Amplifiers

Author(s) and affiliation(s): Seth Kruger¹, Brian Cardineau², William Earley⁴, Kenji Hosoi³, Koichi Miyauchi³, Robert L. Brainard⁴, ¹NYCREATES, ²Inpria, ³Central Glass, ⁴University at Albany

Abstract: We describe two strategies for improving the capabilities of chemically amplified resists based on the use of double-deprotected blocking groups on sulfonic acids and carboxylic acids. Although these molecules share a similar blocking-group, we customize these compounds to take advantage of two different decomposition mechanisms, autocatalysis and higher order reactions. Both mechanisms have the potential to produce patterns with improved resolution and LER. Autocatalysis is achieved by incorporation of acid amplifiers (AAs) into the photoresist formulation and has been shown previously to improve the lithographic performance of photoresists. Here, we present new acid amplifiers that produce highly-fluorinated, strong sulfonic acids that are 100,000x more stable than previously reported compounds. Higher order reactions are achieved by utilizing novel blocking groups that require two acid-catalyzed steps to be removed. When both steps occur with comparable reaction rates, the overall reaction should be “higher order” (£ 1.85). We call these resist systems Double-Deprotected Chemically AMplified Photoresists (DD-CAMP). We present the synthesis and lithographic evaluation of multiple DD-CAMP photoresists.

Invited speaker: Mark Neisser (Tsinghua University)

Invited speaker biography: Prof. Mark Neisser is chair professor in the School of Integrated Circuits at Tsinghua University. He is also the Director of the Photoresist lab at the Integrated Circuit Research Platform at the International Innovation Center of Tsinghua University, Shanghai. He received his B.S. degree in chemistry from Cornell University and his M.S. and Ph.D. degrees in chemistry from the University of Michigan. He is the author of more than 30 patents, over 100 journal papers and has co-authored two book chapters. He is the chairman of the IRDS roadmap committee for lithography and patterning.

Presentation title: Current Challenges in Photoresist

Author(s) and affiliation(s): Mark Neisser^1,2 , ¹Tsinghua University, ²International Institute of Tsinghua University, Shanghai

Abstract: The current challenges of photoresist relate to stochastics, imaging dose, process windows, and achieving adequate etch resistance. Stochastics not only forces higher dose to print as feature sizes shrink but produces defects that are hard to measure and find. Defects can be such that they are only seen after etch. Metal based positive tone resist is desirable, but not easily accomplished. The sources of these issues and some approaches to possible solutions are discussed along with some relevant simulation and experimental work.

Invited speaker: Cheng Wang (LBNL)

Invited speaker biography: Dr. Cheng Wang is a Physicist Staff Scientist at the ALS, LBNL, and a Principal Investigator at the CHiPPS EFRC. He received his B.S. in physics from Jilin University, China (2002), and his Ph.D. from North Carolina State University (2008). He pioneered Resonant Soft X-ray Scattering (RSoXS) for soft materials, establishing the world’s first dedicated RSoXS facility at ALS. His expertise advances soft X-ray metrology through synchrotron-based operando X-ray scattering, microscopy, and spectroscopy, providing critical insights into morphology, chemistry, and interfacial structures of complex materials and processes, including organic electronics, block copolymers, catalysis, photoresists and EUV lithography.

Presentation title: Characterization of latent image of photoresist via critical-dimension resonant soft X-ray scattering

Author(s) and affiliation(s): Qi Zhang, Kas Andrle, Weilun Chao, Zhengxing Peng, Warren Holcomb, Ryan Miyakawa, Dinesh Kumar, Alexander Hexemer, Patrick Naulleau, Bruno La Fontaine, Ricardo Ruiz, Cheng Wang, Lawrence Berkeley National Lab, 1 Cyclotron Rd, Berkeley, CA, 94720, USA

Abstract: Metrology is essential for accurate characterization and optimization of EUV lithography as critical dimensions shrink below 10 nm. We introduce CD-RSoXS, combining near-edge X-ray absorption fine structure spectroscopy, scatterometry, and multiphysics modeling, to non-destructively probe the 3D structure and chemistry of nanostructures across EUV lithography stages—latent imaging, post-exposure bake, and development—providing crucial insights into stochastic variations driven by material property, processing, chemistry, and photon/electron-induced effects.

Invited speaker: Yoshihiko Yamagata (Kyushu University)

Invited speaker biography: Dr. Yukihiko Yamagata is Associate Professor of Kyushu University. He received B. S. and M. S. degrees from Kumamoto University, and Ph. D. degree from Kyushu University, Japan, in 1986, 1988, and 1991, respectively. In April 1991 he was appointed as a Research Associate at Kumamoto University and was promoted to Associate Professor in June 1995 at the same university. In May 2001, he became an Associate professor at Kyushu University. He is engaged in research on the development of measurement techniques using laser and optical methods for discharge plasmas, semiconductor devices and so on.

Presentation title: New Activity of EUV Light Source for Semiconductor Manufacturing in Kyushu-University

Author(s) and affiliation(s): Yukihiko Yamagata 1, Hakaru Mizoguchi 1,2, Kentaro Tomita 3, Daisuke Nakamura 1, Takeshi Higashiguchi 4, Atsushi Sunahara 5, Katsunobu Nishihara 6, Takashi Toshima 2, Hiroki Kondo 1, Takuji Sakamoto 2, Tanemasa Asano 2 and Masaharu Shiratani 1,2, 1 Kyushu University, 2 EUV Photon Co. Ltd., 3 Hokkaido University, 4 Utsunomiya University, 5 Purdue University, USA, 6 Osaka University

Abstract: A new EUV exposure research center "EUV Photon Co." has been established to support material development for EUV lithography. An EUV exposure system is being prepared for this purpose. The second topic focuses on Sn plasma dynamics studied using Thomson scattering measurements. Our group demonstrated the possibility of achieving CE 10 % through both simulation and experiment last year. These results suggest further potential for improving EUV output and CE. Finally, a high power EUV source research program in collaboration with Riken and other universities will be described.

A6. Nanoimprint

Symposium Chairs: Yoshihiko HIRAI (Osaka Metropolitan University), Jun TANIGUCHI (Tokyo University of Science), Satoshi TAKEI (Toyama Prefectural University), and Sosuke OSAWA (JSR) , and Kazuma Kurihara (AIST)

Invited speaker: Akifumi Aono (Mitsui Chemicals)

Invited speaker biography: Mr. Akifumi Aono works in Imaging Solutions Department, Innovative Solution Center for ICT, R&D Center, a Mitsui Chemicals, Inc. His research interest includes optical polymer wafers for AR Glasses.

Presentation title: Optical polymer wafers for waveguide of AR Glasses

Author(s) and affiliation(s): Akifumi Aono, Eiichiro Hikosaka, Takeshi Shinkai, Takashi Kasai, Akihiro Muramatsu, Mitsui Chemicals, Inc.

Abstract: We have developed new optical grade polymer wafer, a lightweight, durable, and scalable alternative to traditional glass wafers for waveguides of AR glasses. In this report, we will discuss how polymer wafer works seamlessly in the nanoimprint lithography process and functions effectively as a waveguide.

A7. 193 nm Lithography Extension

Symposium Chair: Yoshio KAWAI (Shin-Etsu Chemical)

A8. Photopolymers in 3-D Printing/ Additive Manufacturing

Symposium Chair: Takumi UENO (Shinshu University)

Invited speaker: Masaru Mukai (Yokohama National University)

Invited speaker biography: Dr. Masaru Mukai received a Ph.D. in Science from Nara Institute of Science and Technology in 2009. He worked as a postdoctoral fellow at AIST and Lehigh University, then as a research assistant professor at Kyushu University. Since January 2021, he has held the same position at Yokohama National University. His research focuses on biofunctional chemistry and materials science, particularly developing resins for micro-photolithography.

Presentation title: Initiator-free recyclable resin available for two-photon lithography

Author(s) and affiliation(s): Masaru Mukai 1, Wakana Miyadai 2, Shoji Maruo 1, 1 Faculty of Engineering, Yokohama National University 2 Graduate School of Engineering Science, Yokohama National University

Abstract: Rapid manufacturing with stereolithography is gaining attention, increasing demand for high-precision large-scalemodeling. However, cured resins are difficult to reuse. While reusable resins are being developed, they require radical polymerization initiators, causing material changes. This study presents a photocurable resin that can be recycled without an initiator, offering a sustainable solution for high-precision two-photon lithography.

A9. Strategies and Materials for Advanced Packaging, Next Generation MEMS, Flexible Devices

Symposium Chairs: Takumi UENO (Shinshu University), Sanjay Malik (SCREEN SPE USA), and Kuniharu TAKEI (Hokkaido University),

Kenote speaker: Takumi Mikawa (SCREEN Semiconductor Solutions)

Keynote speaker biography: Takumi Mikawa is an Executive Officer of R&D strategy / IP strategy in SCREEN Semiconductor Solutions. His interest is to develop process solutions based on the semiconductor equipment, collaborating with his partners such as imec, IBM and academia. He is also interested in the sustainable technology, and a leader of ESH/S of Silicon Device Roadmap committee of Japan (SRDJ). His background is the emerging memories, FeRAM and ReRAM at Panasonic Corporation. He is also a patent attorney and he has lectured an intellectual property in Wakayama University as a visiting professor.

Presentation title: Creating Innovation for Sustainable World in Partnership with Semiconductor Eco System

Author(s) and affiliation(s): Takumi Mikawa, SCREEN Semiconductor Solutions, Japan

Abstract: Recent advances in generative AI are driving device scaling, 3D stacking and system integration. Those have a wide impact on the development of technology from material suppliers to system vendors. More complex device structures and new materials are explored for next generation. In order to meet high customer requirements, we need to develop the innovative wet cleaning solutions such as removal of smaller particle and extremely high etching selectivity/uniformity. Also, working on environmental issues has been increasingly important. Our Semiconductor Eco System. by collaborating with institutes, suppliers, and academia, we can create innovation for sustainable world in partnership to provide customer value. In the case of device scaling, as Moore’s law slows down, new approaches are required to achieve higher performance and lower power consumption in semiconductor devices. Gate-all-around (GAA) FETs are replacing FinFETs as the architecture of today, and CFETs are expected to follow. A key process is to manage SiGe process with different concentrations. We are developing wet cleaning solutions for new material with imec and chemical vendors. In the case of carbon footprints, we still have a big gap under current global implemented politics to achieve net zero in 2050. Furthermore, CO₂ emissions are estimated to increase with scaling device due to more process steps. Semiconductor industry needs to contribute carbon neutrality across the broad supply chain. We have developed chemical reduction by recycling cabinet and efficient circulation system to reclaim in the tool. Our CO₂ emissions are mostly SCOPE3, so we need more collaborations with material suppliers and component manufacturers at upstream, and chip manufacturers at downstream in the supply chain. Wet process development in advanced ecosystems is essential to achieve high yields at leading-edge nodes, no damage to device, and a low carbon footprint during fabrication.

Invited speaker: Takenori Fujiwara (Toray Industries)

Invited speaker biography: Dr. Takenori Fujiwara has more than 20 years of experience in the electronics industry. The bulk of his career has been centered on materials R&D for use in microelectronics, optics, MWMS and display technologies, spanning a variety of senior technology. He is familiar with high heat resistance polymers (polyimides and spin on glass (SOG)) and other various materials. He has spent time developing incubation technologies in consortium as follows: 1. TPEC (Tsukuba Power Electronics Constellations) in Japan: He had worked on a 500C heat resistance photoresist for high heat ion implantation and a stress buffer coating of polyimide for SiC power semiconductors. 2. IME (Institute of Microelectronics) in Singapore. He has collaborated with IME for 10 years though consortiums of FOWLP, 3DIC, Intelligent power module, AiP, Chiplet and Hybridbonding. The materials, such as RDL dielectrics, temporary bonding de-bonding materials, non-conductive films and thermal interface materials and so on are evaluated there. He has published numerous advanced semiconductor material papers and holds various patents for the materials and ancillary development work. He is a team builder who combines strong business and technical acumen with excellent relationship skills. He holds a Ph.D. in material engineering from Nagoya University (2008).

Presentation title: The Development of Novel Polymer Materials for Advanced MEMS Packaging

Author(s) and affiliation(s): Takenori Fujiwara, Toray Industries, Inc.

Abstract: This talk covers the trends and challenges specific to advanced packaging polymer materials technology, including cavity formation and multi-stacked dielectric layers for MEMS devices. We will introduce polymer material property and processing technology how to make the organic cavity structure by using permanent dry film resist with tenting lamination and photolithography process or polymer sealing technology and so on. We will also report that feature of MEMS packaging properties.

Invited speaker: Natsuki Toda (Resonac Corporation)

Invited speaker biography: In 2020, Natsuki Toda joined Resonac Corporation (formerly Hitachi Chemical Co., Ltd.) and has been in charge of photo-sensitive dry film for PCB circuit formation since then.

Presentation title: Development of a Novel Negative-Tone Dry Film Resist with PVA Layer for Wiring with 1.5/1.5 µm Line/Space

Author(s) and affiliation(s): Natsuki Toda, Kei Togasaki, Kensuke Yoshihara, Yosuke Kaguchi, Ayane Mochizuki, Kanako Funai, Hitoshi Onozeki, Kenichi Iwashita1, 1Resonac Corporation

Abstract: The semiconductor package substrate requires high-density connections to enhance signal transmission speed, and 2.xD packages with fine redistribution layers (Line/Space = 2/2μm or less) are attracting attention from the market. In order to form fine wiring with high precisions, our company has developed a negative-tone dry film with a protective layer consisting mainly of polyvinyl alcohol (PVA) as a new technology. In this presentation, we will discuss the functions of PVA and the wiring formation characteristics of this dry film.

Invited speaker: Guillermo Fernandez Zapico (TSMC Japan 3DIC)

Invited speaker biography: Dr. Guillermo Fernandez Zapico took Ph.D. in Mechanical Engineering from Madrid Politecnica University. Currently working in TSMC Japan 3DIC Center as material-process engineer focused on advanced packaging.

Presentation title: Carrier warpage improvement using non-photosensitive dielectric material for high I/O density organic RDL

Author(s) and affiliation(s): Guillermo Fernández 1, 1 TSMC Japan 3DIC

Abstract: In this study, we demonstrated that non-photosensitive polyimide material can effectively reduce the warpage in the RDL fabrication process. It was also demonstrated that crack initiation risk on stack via can be reduced. Last, via opening ability was experimentally tested by excimer laser and plasma dry etching techniques, both methods allowed via size equivalent to conventional photosensitive dielectrics.

Invited speaker: Masayoshi Nishimoto (Resonac Corporation)

Invited speaker biography: N/A

Presentation title: Hybrid Integration for Advanced Electronic-Photonic Packaging

Author(s) and affiliation(s): Yuma Yoshida , Taiga Sakamoto, Masahiro Matsunaga, Takashi Kawamori, Masayoshi Nishimoto, Resonac Corporation

Abstract: This presentation focuses on the challenges in hybrid integration for electronic-photonic packaging, particularly integrating optical and electronic components into a single package. As demand grows for higher bandwidth, lower latency, and reduced power consumption, photonic-electronic integration advances. However, challenges like thermal management, signal integrity, and scalability remain. The presentation explores solutions, emphasizing advanced packaging techniques, material innovations, and design considerations.

Invited speaker: Yugo Kubo (Sumitomo Electric Industries)

Invited speaker biography: N/A

Presentation title: Atomic-level analysis of Cu/polyimide interface under high temperature storage and the investigation of adhesion degradation mechanism.

Author(s) and affiliation(s): Yugo Kubo, Sumitomo Electric Industries, Ltd.

Abstract: Understanding the interfacial state of Cu/polyimide is crucial in the development of semiconductor packaging. We formed a Cu thin film on a polyimide substrate using a vacuum evaporation method and thoroughly investigated the microscopic changes over time of the "oxidation diffusion layer" generated by heating it at 150°C in the atmosphere, utilizing cutting-edge analytical techniques. In this presentation, I will discuss the mechanisms behind the decrease in interfacial adhesion that occurs with the growth of the "oxidation diffusion layer".

Invited speaker: Toshiyuki Ogata (TAIYO HOLDINGS)

Invited speaker biography: N/A

Presentation title: Development of Negative-tone Photosensitive Dielectric Materials for Fine Pitch RDL in Chiplet Integration

Author(s) and affiliation(s): Toshiyuki Ogata, 3D Packaging Materials Project, Research Division, TAIYO HOLDINGS CO., LTD.

Abstract: In this work, we developed negative-tone photosensitive dielectric material with fine resolution and high insulation reliability for Fine Pitch Redistribution Layers (RDL) in Chiplet Integration. We achieved 0.7 micrometer L/S patterns with an aspect ratio of 3.7 using an i-line stepper. Further, we developed a test vehicle with 1 micrometer L/S patterns using the semi-additive process and evaluated the insulation reliability using a biased highly accelerated stress test (BHAST).

A10. Chemistry for Advanced Photopolymer Science

Symposium Chairs: Haruyuki OKAMURA (Osaka Metropolitan University), Takashi KARATSU (Chiba University), and Akinori SHIBUYA (FUJIFILM)

Invited speaker: Zhiquan Li (Guangdong University of Technology)

Invited speaker biography: Dr. Zhiquan Li, Full Professor at Guangdong University of Technology, specializes in advanced photosensitive materials research. His work encompasses novel photocatalysts, photoinitiators, and functional photopolymers, with applications spanning photopolymerization and micro/nanofabrication through 3D printing and photoresist technologies. He has published over 80 papers with 3,000+ citations (h-index: 30) and holds 10 patents, four of which have been successfully commercialized.

Presentation title: NIR induced anionic photopolymerization based on upconversion photochemistry

Author(s) and affiliation(s): Quanping Xie1, Yaoxin Huang1, Pin Yang1, Zhiquan Li1, 1 Guangdong Provincial Key Laboratory of Functional Soft Condensed Matter, School of Materials and Energy, Guangdong University of Technology

Abstract: NIR light-induced polymerization offers significant advantages including deep penetration capability, minimal energy loss, and reduced biological damage compared to UV systems. This study explores an anionic photopolymerization system, integrating photobase generation with upconversion mechanisms to achieve efficient polymerization under NIR irradiation. The research demonstrates promising applications in deep-curing processes, composite material fabrication, and functional material preparation, enriching the toolbox of photopolymerization.

Invited speaker: Xavier Allonas (University of Haute Alsace)

Invited speaker biography: Xavier Allonas is working in the field of photopolymer science and molecular photochemistry, my current research interests are i) the primary processes involved in photopolymerization, photoinduced electron transfer, triplet-triplet energy transfer, hydrogen abstraction and addition of radicals onto double bonds probed by time resolved laser spectroscopies, and ii) kinetics of photopolymerization reaction, thermodynamical properties of photopolymers, formulation and development of photopolymerizable resins for coatings, laser imaging, holography and 3D printing. +200 papers were published up to now.

Presentation title: Breaking boundaries of photoinitiators: new ways to improve the reactivity of radical photopolymerization

Author(s) and affiliation(s): Xavier Allonas, University of Haute Alsace, Mulhouse, France

Abstract: In this paper, we investigate different ways to increase the reactivity of Type I or Type II photoinitiators by introducing new latent reactive additives leading to additional initiating radicals, promoting singlet-singlet resonance energy transfer of Type I photoinitiators, overcoming diffusional limit in Type II photoinitiating system by pre-associating ion-pairs, … It is shown that high photopolymerization rates can be achieved even at very low light irradiances.

A11. Organic and Hybrid Materials for Photovoltaic and Optoelectronic Devices

Symposium Chairs: Itaru OSAKA (Hiroshima University), and Hideo OHKITA (Kyoto University)

Invited speaker: Feng He (Southern University of Science and Technology)

Invited speaker biography: Dr. Feng He is a professor in the Department of Chemistry at Southern University of Science and Technology, and also a recipient of the National Science Fund for Distinguished Young Scholars. Dr. He's research group focuses on the regulation of non-covalent interactions of organic functional materials. They have advanced the application of these materials in organic photovoltaics and the 2D/3D self-assembly micro/nanomaterials. To date, he has published over 200 papers in leading international journals such as Joule, J. Am. Chem. Soc., Nat. Commun., Adv. Mater., Angew. Chem. Int. Edit. and CCS Chem., with over 10000 citations.

Presentation title: Chlorine-mediated organic conjugated materials and quasi-planar heterojunction devices

Author(s) and affiliation(s): Feng He, Southern University of Science and Technology

Abstract: We have developed a series of material systems with specific transport structures by controlling the arrangement and aggregation of organic optoelectronic molecules through the Cl∙∙∙S and Cl∙∙∙π interactions. In particular, we discovered a three-dimensional (3D) network structure in the model molecules with specific chlorine-mediated intermolecular interactions. This aggregated state provides more transport junctions and channels for intermolecular electron hopping, which will increase the exciton diffusion distance and effectively improve mobility.

Invited speaker: Ryota Kabe (OIST)

Invited speaker biography: Dr. Ryota Kabe is an Assistant Professor at the Okinawa Institute of Science and Technology Graduate University (OIST), where he leads the Organic Optoelectronics Unit. He obtained his Bachelor degree from Kansai University (2005), Master degree from Osaka University (2007), and Ph.D. from Kyushu University (2010). Dr. Kabe’s postdoctoral research included positions at Bowling Green State University (2010–2011), the Max Planck Institute for Polymer Research (2011–2012), and Kyushu University (2012–2014). He then served as an Assistant Professor at Kyushu University, collaborating with Prof. Chihaya Adachi from 2014 to 2019. In 2019, he joined OIST to advance research in organic optoelectronics. His research focuses on the design and synthesis of novel organic materials, the manipulation of organic exciton dynamics, and their implementation in next-generation optoelectronic devices.

Presentation title: Charge Accumulation Behavior and Persistent Luminescence in Organic Materials

Author(s) and affiliation(s): Ryota Kabe, OIST

Abstract: Photoinduced charge generation is a crucial process in solar cells, photosynthesis, and persistent luminescent materials. In organic materials, charge separation typically occurs at the electron donor/acceptor interface. While the generated charges can readily disappear via charge recombination, suppressing recombination enables the realization of a stable charge-separated state. Gradual charge recombination leads to persistent luminescence. y analyzing this luminescence behavior, we have elucidated the charge separation and recombination processes.

Invited speaker: Kazuhiro Marumoto (Univ. of Tsukuba)

Invited speaker biography: Kazuhiro Marumoto has completed his Ph.D. from Osaka University, Japan, and worked as an Assistant Professor at Nagoya University, Japan. He is a Professor of Department of Materials Science, Institute of Pure and Applied Sciences, University of Tsukuba, and Center Director of Research Center for Organic-Inorganic Quantum Spin Science and Technology (OIQSST), University of Tsukuba. He has published more than 200 papers in journals and is serving as Vice President of Asia Pacific EPR/ESR Society (APES), Representative of The Society of Electron Spin Science and Technology (SEST), Japan, and an editorial board member of Scientific Reports.

Presentation title: ESR analysis of charge-transporting materials in non-fullerene organic solar cells

Author(s) and affiliation(s): Atsushi Sato 1, Kazuhiro Marumoto 1,2,3, 1 Dep. Mater. Sci., Univ. of Tsukuba, Japan, 2 OIQSST, Univ. of Tsukuba, Japan, 3 TREMS, Univ. of Tsukuba, Japan

Abstract: The power conversion efficiencies (PCEs) of non-fullerene organic solar cells have exceeded 20% and further improvement is expected. Although various insights for PCE improvements have been reported, those for stability of solar cell performance are still lacking. In the present study, for clarifying the degradation mechanism, we studied the correlation between charge states and degradation behavior in non-fullerene organic solar cells using operando electron spin resonance spectroscopy.

Invited speaker: Martin Heeney (KAUST)

Invited speaker biography: Prof. Martin Heeney is a Professor of Chemical Science at King Abdullah University of Science and Technology (KAUST). His research interests include the design, synthesis and characterization of conjugated materials for a variety of applications. He has published over 400 research papers, 5 book chapters and over 100 patents. He has been named five times by Thomson Reuters as a Highly Cited researcher in the field of Materials Science, is a recipient of the RSC Corday-Morgan (2013) medal, the RSC Material Chemistry mid-career award (2020) and the Macro group UK medal (2020).

Presentation title: Design of low complexity active materials for photovoltaic applications

Author(s) and affiliation(s): Division of Physical Sciences and Engineering. King Abdullah University of Science and Technology (KAUST)

Abstract: The overall efficiency of organic photovoltaic (OPV) devices has made impressive progress in recent years, but often active materials now require complex, multi-step synthesis, potentially limiting their application. We report approaches to prepare building blocks in just one or two steps, allowing the preparation of conjugated polymers of low synthetic complexity which can be readily upscaled. I will highlight how this approach can be used to readily build libraries of conjugated polymers to more rapidly identify promising materials for application in OPV.

Invited speaker: Azusa Muraoka (Japan Women's University)

Invited speaker biography: Prof. Azusa Muraoka received her Ph.D. from the University of Tokyo. After working as a postdoctoral researcher in France, she held positions at Meiji University and the University of Tokyo before joining the Department of Mathematics, Physics, and Computer Science at Japan Women's University in 2015, becoming a professor in 2024. Her research focuses on the molecular properties of energy conversion materials and charge transfer exciton dynamics using DFT. She collaborates internationally, has received several awards, including the 2024 Japan Society for Computational Chemistry Award, and contributes to major programs such as "Fugaku" and NEDO.

Presentation title: Influence of Vibronic Interactions on Charge Transfer Excitons in Nonfullerene Organic Photovoltaics

Author(s) and affiliation(s): Azusa Muraoka, Japan Women's University, Japan

Abstract: We investigated photoinduced charge transfer (CT) states and dissociation processes at the donor/acceptor (D/A) interface of PTB7/BTAx nonfullerene organic thin-film solar cells using DFT and TD-DFT calculations. We focused on the CT distances, electron coupling in the CT state generated by photoexcitation and the Huang–Rhys (HR) factors that describe the non-adiabatic processes associated with vibronic interactions. The results reveal important insights into controlling CT exciton dynamics and optimizing charge separation for improved device performance.

Invited speaker: Yasuhiro Tachibana (RMIT University, Osaka University)

Invited speaker biography: Prof. Yasuhiro Tachibana received his B. Eng. (1992) and M. Eng. (1995) in applied chemistry at Osaka University, and Ph.D. degree (2000) at Imperial College London, U K. In 2002, he moved to Osaka University as an Assistant Professor, and promoted to an Associate Professor in 2004. He moved to RMIT University, Australia, and promoted to Professor in 2020. Prof. Tachibana has authored more than >110 publications of peer-reviewed journal papers, patents and book chapters. His publications receive a total of >11,000 citations with h-index of 44.

Presentation title: Charge carrier dynamics at lead halide perovskite

Author(s) and affiliation(s): Yasuhiro Tachiana1,2, 1 RMIT University, Australia, 2 Osaka University, Japan

Abstract: Lead halide perovskite has shown superior optical properties such as high extinction coefficients, slow hot carrier relaxation, long electron-hole lifetime and high charge carrier mobilities. However, mechanisms of charge carrier transport and interfacial electron-hole recombination have hardly been clarified. In this presentation, we will quantitatively demonstrate how charge carriers can be transported, and separated and recombine at the perovskite interfaces.

Invited speaker: Seihou Jinnai (Osaka Univeristy)

Invited speaker biography: Dr. Seihou Jinnai is an Assistant Professor of Department of Soft Nanomaterials (Ie group) in the Institute of Scientific and Industrial Research (SANKEN), Osaka University, Japan. He received his Ph.D. degree from Osaka University in 2017 under the supervision of Professor Yoshio Aso. After he engaged in research on functional organic dyes as a corporate researcher at Orient Chemical Industries Co., Ltd. from 2016 to 2019, he joined the laboratory of Professor Yutaka Ie. His research focus is development of new π-conjugated compounds and systems for organic electronics and photo-functional applications.

Presentation title: Development of Fused-Ring Acceptors for Green-Light Wavelength-Selective Organic Solar Cells

Author(s) and affiliation(s): Seihou Jinnai, Yuto Shiono, and Yutaka Ie, Osaka Univeristy, Japan

Abstract: We are developing green-light wavelength-selective organic solar cells (OSCs) that are compatible with crop growth and electric power generation. In this study, we designed and synthesized fused-ring electron acceptors with absorption band in the green-light wavelength region (500-600 nm) and suitable electron acceptability for the combination with P3HT. OSC devices based on developed fused-ring electron acceptors and P3HT showed typical OSC characteristics.

Invited speaker: Tomokazu Umeyama (University of Hyogo)

Invited speaker biography: Prof. Tomokazu Umeyama received his BS (1999), MS (2001), and Ph.D. (2004) in Polymer Chemistry from Kyoto University. Upon completing his doctoral degree, he joined the Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, where he served as an Assistant Professor (2004–2013) and later as an Associate Professor (2013–2021). From 2010 to 2014, he was also a PRESTO researcher at the Japan Science and Technology Agency (JST). In 2021, he was appointed as a Professor at the Department of Applied Chemistry, Graduate School of Engineering, University of Hyogo.

Presentation title: Synthesis and Photovoltaic Properties of Non-Fullerene Acceptors with Quinoxaline-Based Central Unit

Author(s) and affiliation(s): Tomokazu Umeyama 1, Kaho Yasuzato 1, Seiya Sugiura 1, Kenta Yamada 1, Jun-ichi Inamoto 1, Shunjiro Fujii 1, Wataru Suzuki 1, 1 University of Hyogo, Japan

Abstract: We developed acceptor-donor-acceptor’-donor-acceptor (A-D-A’-D-A) type non-fullerene acceptors (NFAs) featuring a quinoxaline-based central A’ unit such as benzo[g]quinoxaline. Photovoltaic properties of such NFAs were investigated in detail.

Invited speaker: Cheng-Liang Liu (National Taiwan University)

Invited speaker biography: N/A

Presentation title: Organic/Hybrid Thermoelectric Materials and Devices

Author(s) and affiliation(s): Cheng-Liang Liu, National Taiwan University, Tiwan

Abstract: Organic thermoelectric materials can directly transform the waste heat into electrical power without causing any pollution. In my talk, we outline the design strategies which aim to develop high-performing organic semiconductors and their materials in organic thermoelectrics. A series of solution-processed organic semiconducting molecules are reported. Doping organic semiconductors, conjugated polymer composites, and gels with ionic salt or redox couples are used to achieve enhanced thermoelectric performance.

Invited speaker: Qing Shen (The University of Electro-Communications)

Invited speaker biography: N/A

Presentation title: Enhancement of Organic Solar Cell Efficiency via Incorporation of Lead Sulfide Quantum Dots

Author(s) and affiliation(s): Qing Shen 1, Kei Takahashi 1, Yuyao Wei 1, Taro Toyoda 1 and Shuzi Hayase 1, 1 The University of Electro-Communications, Japan

Abstract: One approach to improving the power conversion efficiency (PCE) of organic solar cells (OSCs) is the incorporation of additives that enhance light absorption and active layer morphology. In this study, we incorporated lead sulfide quantum dots (PbS QDs) into a PM6:Y6-based active layer to enhance PCE. Our results showed that adding PbS QDs improved efficiency. We further analyzed photovoltaic characteristics to elucidate the underlying mechanism, providing insights into the role of quantum dots in OSC performance.

A12. Fundamentals and Applications of Biomimetics Materials and Processes

Symposium Chairs: Hiroyuki MAYAMA (Asahikawa Medical University), Atsushi SEKIGUCHI (Lithotech Japan), and Takayuki MUROSAKI (Asahikawa Medical University)

Invited speaker: Toshimitsu Sakurai (Civil Engineering Research Institute for Cold Region)

Invited speaker biography: N/A

Presentation title: Superhydrophobic PDMS using femtosecond laser-processed surface molds for anti-icing

Author(s) and affiliation(s): Toshimitsu Sakurai 1, Toshihiro Somekawa 2, Yuji Hirai 3, Hiroki Matsushita 1, 1 Civil Engineering Research Institute for Cold Region, 2 Institute for Laser Technology / Institute of Laser Engineering, Osaka University, 3 Chitose Institute of Science and Technology

A13. Polyimides and High Thermally Stable Resins

Symposium Chair: Teruaki HAYAKAWA (Institute of Science Tokyo)

B1 (Japanese). Polyimides and High Thermally Stable Resins -Functionalization and Practical Applications- ポリイミド及び高温耐熱樹脂ー機能化と応用ー

Symposium Chairs: Teruaki HAYAKAWA (Institute of Science Tokyo), Hitoshi ARAKI (Toray), and Kenji MIYAO (Sumitomo Bakelite)

Invited speaker: Tomoya Higashihara (Yamagata University)

Invited speaker biography: Dr. Tomoya Higashihara received the B. Eng., M. Eng., and D. Eng. degrees from Tokyo Institute of Technology (Tokyo Tech) in 2000, 2002, and 2005, respectively. After posdoc in University of Massachusetts Lowell, he promoted to an Assist. Professor at Tokyo Tech in 2008. He was then promoted to Assoc. Professor and Professor at Yamagata University in 2013 and 2019, respectively. His research interests include condensation polymerization and organic electronics. He has contributed to publish 270 papers, 21 books, and 39 patents.

Presentation title: Nonstoichiometric Step-Growth Polymerization Based on Intramolecular Catalyst Transfer System

Author(s) and affiliation(s): Tomoya Higashihara, Yamagata University

Abstract: In this study, an intramolecular catalyst transfer system has been developed to achieve atypical nonstoichiometric step-growth polymerization based on the Migita-Kosugi-Stille coupling reaction using distannylated- or metal-free thiophene-based monomers and an excess of dibromo monomers, obtaining semiconducting alternating polymers with much higher molecular weights than theoretical values based on Carothers/Flory theory.

B2 (Japanese). Plasma Photochemistry and Functionalization of Polymer Surfaces

Symposium Chairs: Shin-ichi KONDO (Gifu Pharmaceutical University)

B3 (Japanese). General Scopes of Photopolymer Science and Technology一般講演

Symposium Chairs: Masashi YAMAMOTO (National Institute of Technology, Kagawa College, KIT), and Hideo HORIBE (Osaka Metropolitan University)

Invited speaker: Tatsuo Ishijima 石島達夫（金沢大学）

Invited speaker biography: N/A

Presentation title: マイクロ波励起水蒸気プラズマアッシングプロセスにおける基板ホルダへのRFバイアス電圧印加効果

Author(s) and affiliation(s): 石島達夫 1, 1 金沢大学

Abstract: 水を原料とするマイクロ波励起プラズマによるアッシングプロセス法は，薬液を利用しないために環境負荷を低減し，熱によるデバイスダメージを低減できる利点を有する。近年，レジスト膜として炭素系の硬化膜の利用が検討されており，更なる除去速度の向上が求められている。本研究では基板ホルダにRFバイアス(1 MHz, 27 MHz)を印加することでレジスト除去速度を向上させるための研究開発を行った。

For the keynote and invited speakers: If the information needs to be updated, please contact Symposium Chair of each symposium.