Synthesis and Characterizations of a Nonalkyl Tin Oxo Cluster and its Application as High EUV Absorption Coefficient and Etch Resistant Inorganic Resist for EUV Lithography.

We introduce a novel nonalkyl tin oxo cluster, CNU-TOC-01(4C-C), synthesized through a reflux-based solution reaction using SnCl, HO, and pyrazole, which permits scalable production and molecular customization. Using field desorption-time-of-flight mass spectrometry (FD-TOF MS) and small-angle X-ray scattering (SAXS), CNU-TOC-01(4C-C) is characterized as a cyclic cluster with the molecular formula SnCl(CNH)(CNH)HO. The cluster size was measured to be 11.