ORS2-0477
Advanced Characterization of Photoresist Novolak Polymers via Advanced Polymer Chromatography Coupled with Multi-Angle Light Scattering, Differential Viscometry, and Refractive Index Detection
Topic
S2. High-End Characterization/Polymer Physics/Properties
When and Where
Oct 1, 2026
12:00 - 12:15
Room 103
Session Chairs
Soo-Hyung CHOI
Presenter(s)
Yukyung Jung (Waters Corporation)
Co-Author(s)
Abstract
Novolak resins are critical matrix components in g-line and i-line photoresists, where molecular weight (MW), molecular weight distribution (MWD), and oligomeric content fundamentally dictate dissolution kinetics and lithographic resolution. In this study, we established an advanced, high-resolution analytical workflow using the Waters ACQUITY APC™ system integrated online with Wyatt omniDAWN™ multi-angle light scattering (MALS) photometer, microViscoStar™ differential viscometer, and microOptilab™ differential refractive index (dRI) detector to comprehensively characterize low and high MW Novolak polymer samples. Both resins exhibited a discrete fraction of high-molecular-weight species (~25–27 kDa) alongside their main polymer peaks with heterogeneous MWDs. To overcome non-ideal separation and coelution in the critical oligomeric region, chromatographic conditions were optimized by introducing a dual 45 Å column configuration (125+45+45 Å). This multi-column setup substantially improved the separation of oligomers and resolved a possible dimer species eluting at 9.1 minutes (~200 Da), enabling precise quantification. Under optimized conditions, the total weight-average molar mass (Mw) and dispersity (Ð) were determined to be 5.5 ± 0.2 kDa (Ð = 6.08) for the High MW resin, and 2.5 ± 0.0 kDa (Ð = 3.23) for the Low MW resin. Additionally, in-line viscometry successfully determined the weight-average hydrodynamic radii to be 1.6 nm and 1.3 nm, respectively, overcoming the lower limit of MALS. This study demonstrates a robust and reproducible APC-MALS methodology for structural optimization and quality control of advanced electronic chemicals.
