Multinuclear Tin-Based Macrocyclic Organometallic Resist for EUV Photolithography

Abstract

We report a new photoresist based on a multinuclear tin-based macrocyclic complex and its performance for extreme UV (EUV) photolithography. The new photoresist has a trinuclear macrocyclic structure containing three salicylhydroxamic acid ligands and six Sn–CH₃ bonds, which was confirmed by multinuclear nuclear magnetic resonance (NMR) and FT-IR spectroscopies and single-crystal X-ray diffraction study. The resist exhibited good humidity, air, and thermal stabilities, while showing good photochemical reactivity. Photochemical cross-linking of the resist was confirmed by X-ray photoelectron and solid-state NMR spectroscopic analyses. EUV photolithography with the 44 nm-thick film on a silicon wafer revealed a line-edge-roughness (LER) of 1.1 nm in a 20 nm half-pitch pattern. The Z-factor, a metric that gauges the performance of photoresists by considering the tradeoff between resolution, LER, and sensitivity (RLS), was estimated to be 1.28 × 10^–8 mJ·nm³, indicating its great performance compared to the EUV photoresists reported in the literature.