Slide 1: Effect of Residual Solvent on Exposure Sensitivity under EUV and Low-Energy Electron Irradiation in PHS-Boc Resists
Effect of Residual Solvent on Exposure Sensitivity under EUV and Low-Energy Electron Irradiation in PHS-Boc Resists Kouji Kuramoto 1), Ryuichi Yamasaki 2) Shinji Yamakawa 2), Tetsuo Harada 2) 1) KH Neochem Co., Ltd. 「化学の力」で、よりよい明日を実現する。 2) Center for EUV Lithography, Laboratory of Advanced Science a
Slide 2: Outline
Outline 1. Background and Objectives 2. Sample Preparation 3. Thin-Film Characterization - Residual Solvent by Thermal Desorption GC-MS - Chemical Composition Distribution by RSoXS - Film Density by XRR 4. Sensitivity Evaluation - EUV Exposure - LEEFET 5. Summary 2026.6.26 (Fri) ICPST-43 Program No.
Slide 3: Outline
Outline 1. Background and Objectives 2. Sample Preparation 3. Thin-Film Characterization - Residual Solvent by Thermal Desorption GC-MS - Chemical Composition Distribution by RSoXS - Film Density by XRR 4. Sensitivity Evaluation - EUV Exposure - LEEFET 5. Summary 2026.6.26 (Fri) ICPST-43 Program No.
Slide 4: Background and Objectives
Background and Objectives ✓ Non-uniform chemical composition distributions in resist thin films can contribute to line-width roughness (LWR) in EUV lithography. ✓ We hypothesized that solvent polarity and residual solvent can affect thin-film homogeneity and provide a route to reducing LWR. ✓ In thi
Slide 5: Measurement Platform at NewSUBARU
Measurement Platform at NewSUBARU Schematic Illustration of the NewSUBARU facility This study was conducted using instruments at the Electron Injection Line NewSUBARU synchrotron radiation facility. Thin-Film Characterization ✓ BL-10 : RSoXS for evaluating chemical composition Electron Storage Ring
Slide 6: Outline
Outline 1. Background and Objectives 2. Sample Preparation 3. Thin-Film Characterization - Residual Solvent by Thermal Desorption GC-MS - Chemical Composition Distribution by RSoXS - Film Density by XRR 4. Sensitivity Evaluation - EUV Exposure - LEEFET 5. Summary 2026.6.26 (Fri) ICPST-43 Program No.
Slide 7: Sample Preparation
Sample Preparation Materials List Structure / Name PGME PGMEA TPST PHS-Boc (Mw 19k) Boiling point (˚C) 120 146 - - Vapor pressure (kPa@20 ˚C) 1.2 0.5 - - ✓This slide summarizes the materials used in this study. ✓PGME and PGMEA were selected as coating solvents. These two solvents have different boil
Slide 8: Sample Preparation
Sample Preparation Preparation of 50-nm-Thick Resist Thin Films for Evaluation Preparation of Exposure / Post- Process Spin Coating Post-Apply Bake (PAB) Development / Rinse Coating Solution Exposure Bake (PEB) ・ x wt% PHS-Boc ･ Coated on Si ･ Solvent removal ・ EUV or low-energy electron 2.38 wt% TM
Slide 9: Outline
Outline 1. Background and Objectives 2. Sample Preparation 3. Thin-Film Characterization - Residual Solvent by Thermal Desorption GC-MS - Chemical Composition Distribution by RSoXS - Film Density by XRR 4. Sensitivity Evaluation - EUV Exposure - LEEFET 5. Summary 2026.6.26 (Fri) ICPST-43 Program No.
Slide 10: Measurement of Residual Solvent by Thermal Desorption GC-MS
Measurement of Residual Solvent by Thermal Desorption GC-MS Coating Concentration PAB Temperature Residual Solvent Content Solvent (wt%) (˚C) (ppb) a) PGME 1.5 70 8 PGMEA 2.2 70 64 PGMEA 2.2 120 29 a) : Quantified using nitrogen standard gas containing 10 ppb toluene-d8 as an internal standard. ✓ Th
Slide 11: RSoXS Measurement System
RSoXS Measurement System ✓ RSoXS detects nanoscale chemical heterogeneity through resonant soft-X-ray scattering. ✓ The measurement principle was introduced in presentation E2-5-4; here I focus on the energy conditions in this study. Incident energy XAS was used to select the incident energy. Measur
Slide 12: RSoXS Measurement Results
RSoXS Measurement Results PHS-Boc (solvent, PAB Temp.) S01 : PGME, 90℃ S02 : PGME, 120℃ S03 : PGMEA, 90℃ Intensity Scattering vector (nm-1) ✓ At q = 0.05–0.1 nm⁻¹, steeper profiles were observed for the higher-PAB sample and for PGMEA compared with PGME. ✓ This suggests increased chemical compositio
Slide 13: About XRR Measurement
About XRR Measurement ✓ X-ray reflectivity (XRR) provides film thickness, average film density, and surface/interface roughness from low- angle X-ray reflection profiles. Incident X-ray Reflected X-ray Reflectivity Thin Film Si Wafer 2 θ [deg] Source: Shimadzu Techno-Research, Inc. website We used X
Slide 14: XRR Measurement Results
XRR Measurement Results Sample preparation for XRR measurements Process After PAB Vacuum treatment in LEEFET After PEB The resist-coated Si wafer was cut into The sample was placed in LEEFET and After vacuum treatment, the sample Content 1-cm-wide pieces and mounted on kept under vacuum for 30 min b
Slide 15: Outline
Outline 1. Background and Objectives 2. Sample Preparation 3. Thin-Film Characterization - Residual Solvent by Thermal Desorption GC-MS - Chemical Composition Distribution by RSoXS - Film Density by XRR 4. Sensitivity Evaluation - EUV Exposure - LEEFET 5. Summary 2026.6.26 (Fri) ICPST-43 Program No.
Slide 16: EUV Exposure Results
EUV Exposure Results • Sensitivity curves were prepared after EUV exposure and development. • The vertical axis shows the film-thickness loss ratio: [(T0 – T) / T0] × 100. • Here, T0 is the unexposed film thickness and T is the exposed film thickness. Effect of residual solvent Effect of solvent spe
Slide 17: LEEFET Experimental Method
LEEFET Experimental Method • LEEFET is an electron irradiation system independent of the NewSUBARU beamlines. • It enables evaluation of low-energy-electron-induced effects related to EUV exposure. (acc. voltage: 92eV) Stage Moving * The sample is irradiated with the electron beam while the stage is
Slide 18: LEEFET Measurement Results
LEEFET Measurement Results ✓ For the sensitivity curves, the vertical axis shows film-thickness loss, T0 – T (nm). ✓ Horizontal shifts indicate sensitivity differences, while differences in vertical loss suggest differences in electron penetration behavior. Effect of residual solvent Effect of solve
Slide 19: Outline
Outline 1. Background and Objectives 2. Sample Preparation 3. Thin-Film Characterization - Residual Solvent by Thermal Desorption GC-MS - Chemical Composition Distribution by RSoXS - Film Density by XRR 4. Sensitivity Evaluation - EUV Exposure - LEEFET 5. Summary 2026.6.26 (Fri) ICPST-43 Program No.
Slide 20: Summary
Summary ✓ Residual solvent content depended on PAB temperature and solvent species. ✓ RSoXS indicated changes in chemical composition distribution or aggregation state in the resist thin film. ✓ XRR showed that sensitivity differences cannot be explained by average film density alone. ✓ EUV and LEEF
Slide 21: Thank you for your attention.
Thank you for your attention. 2026.6.26 (Fri) ICPST-43 Program No. E2-6-2 . Copyright © KH NeoChem All Rights Reserved. 20