POS1-1167
Exposure-Dependent Solubility Switching in Photoacid Generator-Free, Positive-Tone Photoresists Based on Imidazolium–Mn(II) Carboxylate Coordination
When and Where
Nov 30, -0001
12:00am - 12:00am
Presenter(s)
Seung Hoon Lee (Kyungpook National University)
Co-Author(s)
Abstract
In this study, a photoacid generator-free (PAG-free) metal–organic hybrid positive-tone photoresist was designed to induce exposure-dependent solubility changes with an imidazolium-containing methacrylate terpolymer and a Mn(II) carboxylate component. The terpolymer was synthesized from methyl methacrylate (MMA), imidazolium-functionalized methacrylate, and benzyl methacrylate (BzMA). MMA served as a film-forming matrix, while imidazolium-functionalized methacrylate provided ionic affinity toward the polar developer. BzMA was introduced as a minor aromatic comonomer to contribute aromatic units for deep-ultraviolet (DUV) absorption. The Mn(II) carboxylate component was incorporated to control film cohesion, developer resistance, and dissolution behavior through coordination and ionic interactions with imidazolium domains, thereby stabilizing unexposed regions. Malic acid was used as a small-molecule ligand to modulate the Mn(II) coordination environment and support the photosensitive response. After DUV exposure and thermal treatment, changes in the Mn–carboxylate coordination structure and the imidazolium environment were expected to increase the solubility of the exposed regions in an isopropyl alcohol/water (IPA/H2O) developer, enabling tetramethylammonium hydroxide-free (TMAH-free) positive-tone development.
The terpolymer structure was confirmed by 1H nuclear magnetic resonance (1H NMR) spectroscopy, while DUV absorption near 248 nm was evaluated by ultraviolet–visible (UV-vis) spectroscopy. Changes in carboxylate coordination and the chemical states of Mn, O, and imidazolium-derived N were investigated by Fourier-transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). Film morphology, residual film, and development behavior in the IPA/H2O developer were evaluated by scanning electron microscopy (SEM). This study presents a PAG-free and TMAH-free hybrid photoresist strategy based on imidazolium-mediated solubility modulation and Mn(II)–carboxylate coordination.
(This work was supported by Korea Institute for Advancement of Technology(KIAT) grant funded by the Korea Government(MOTIE) (RS-2024-00419967, HRD Program for Industrial Innovation.)
The terpolymer structure was confirmed by 1H nuclear magnetic resonance (1H NMR) spectroscopy, while DUV absorption near 248 nm was evaluated by ultraviolet–visible (UV-vis) spectroscopy. Changes in carboxylate coordination and the chemical states of Mn, O, and imidazolium-derived N were investigated by Fourier-transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). Film morphology, residual film, and development behavior in the IPA/H2O developer were evaluated by scanning electron microscopy (SEM). This study presents a PAG-free and TMAH-free hybrid photoresist strategy based on imidazolium-mediated solubility modulation and Mn(II)–carboxylate coordination.
(This work was supported by Korea Institute for Advancement of Technology(KIAT) grant funded by the Korea Government(MOTIE) (RS-2024-00419967, HRD Program for Industrial Innovation.)
