Repair processes on next generation EUV materials

In the realm of next-generation EUV masks, several material candidates show promising absorber behaviors, ranging from binary to phase-shift types. However, the mask repair process presents challenges when managing wafer windows for repaired defects. Precious profile control, high repair-defect durability and clean reticle surface need to be sustained to ensure lithography processes window. In this paper, several materials' opaque defect etching is evaluated by using ZEISS e-beam based MeRiT^® neXT repair tools, which offer an optimal physico-chemical process with right precursor chemistry and an optimized scanning of the e-beam over the surface to ensure repair quality. Moreover, longer repair time for next generation masks also challenges post-repair clean yield due to poor wettability from etching byproduct redeposition on reticle surface. Thus, we control a plasma flushing vacuum chamber application to eliminate surface wettability degradation, ensuring high post-repair clean yield. Our comprehensive strategy not only addresses current challenges with better reticle quality and longer lifetime but also paves the way for the seamless integration of advanced EUV mask materials into the future of semiconductor lithography.