Dissociative electron attachment and dissociative ionization of CF3AuCNC(CH3)3, a potential FEBID precursor for gold deposition

Abstract

Appreciable effort is currently committed to designing suitable organometallic precursors for fabrication of metallic nanostructures with focused electron beam induced deposition (FEBID)—a direct write method with high potential for 3D patterning. In this context, the initial interaction of the potential precursor with low energy electrons is critical and the extent of electron-induced ligand loss determines the composition of the resulting deposits. Specifically of interest are gold-containing precursors, as the optoelectronic properties of gold provide potential for a variety of plasmonic and light enhancing applications of 3D nanostructures. Here, we study low energy electron-induced fragmentation of CF₃AuCNC(CH₃)₃ through dissociative ionization (DI) and dissociative electron attachment (DEA) in the gas phase under single collision conditions and under conditions where collisional stabilization is provided. We further compare the fragmentation patterns observed under these conditions with the composition of deposits formed from this precursor under FEBID conditions. In DI, a significant difference in relative intensities is found under single collision conditions as compared to conditions where collisional stabilization is provided, while under both these conditions, only the same DEA channel is open. Comparison with the composition of deposits formed under FEBID conditions shows that the initial electron-induced fragmentation processes are not directly reflected in the deposit’s composition. Rather, we expect these to determine the initial composition of immobilized fragments, while the final composition of the deposit is determined by electron-induced secondary and tertiary reactions caused by further irradiation after immobilization.

Graphical abstract