Polarity‐engineered Sn‐Ti cluster photoresists for sub‐10‐nm high‐resolution lithography

Abstract High‐performance photoresists are essential for advancing semiconductor technology into the sub‐3‐nm process node. However, photoresist performance has long been constrained by the trade‐off among resolution (R), line edge roughness (L), and sensitivity (S), with the simultaneous enhancement of sensitivity and resolution remains a challenge. In this study, we propose a strategy to overcome the RLS trade‐off by enhancing the polarity of metal‐oxo clusters. A series of Sn‐Ti clusters with increasing polarity were synthesized by adjusting the bridging ligands and reducing the number of low‐polarity ligands. Experimental results confirm that, as the developer polarity decreases, higher polar Sn‐Ti clusters exhibit a more pronounced enhancement in sensitivity. The highest‐polarity cluster, TS‐3, undergoes a significant polarity switch upon exposure, enabling simultaneous improvement in sensitivity and resolution under lower‐polarity developers, ultimately breaking the conventional RLS trade‐off. TS‐3 delivers superior patterning performance in both electron beam lithography and extreme‐ultraviolet lithography, with a minimum linewidth of 8 nm. This study enhances the understanding of the solubility‐transition mechanism in cluster photoresists and provides a new approach for the development of high‐performance photoresists.