Hybrid metal-organic clusters resist for next-generation high-NA EUV lithography

Extreme ultraviolet (EUV) lithography, predominantly with the advent of high-NA systems, imposes stringent requirements on photoresists to overcome the resolution-line-edge roughness (RLS) sensitivity trade-off for next-generation (NG) technology nodes. Hybrid metal-organic clusters (MOC) resists, particularly antimony (Sb)- based MOCs functionalized with a crosslinkable organic ligand, have emerged as promising NG, EUV (λ~13.5nm) resists owing to higher EUV absorption and tunable molecular properties, with ligand-level control of solubility and cross-link architecture. We report the design, synthesis, and analysis of Sb-MOCs functionalized with organic ligands, using SCXRD and patterned via EBL as a prelude to EUV benchmarking. The minimum feature size of half-pitch (hp) line patterns was evaluated for an EBL-exposed negative-tone resist developed in different developer media. Development was carried out in DI water (pH = 7.2) for 30 s, and in n-heptane and iso-octane for 120s. Minimum hp line widths of 25nm, 45nm, and 45nm were achieved at exposure doses of 700 μC/cm², 800 μC/cm², and 4000 μC/cm² for DI water, n-heptane, and iso-octane developers, respectively. The corresponding line edge roughness (LER) values for the minimum achievable hp line patterns were 4.26 ± 0.12nm for the 25nm patterns developed in DI water. For the 45 nm patterns developed in n-heptane and iso-octane, the LER values were 3.87 ± 0.23nm and 5.73 ± 0.48nm, respectively. The high-resolution pattern fidelity underscores the Sb-MOC resists as a scalable platform for sub-25nm patterning in high-NA, EUV lithography, offering a pathway to extend semiconductor scaling toward the sub-10nm technology node.