Dose and energy dependence of mechanical properties of focused electron-beam-induced pillar depositsfrom Cu(C5HF6O2)2

Abstract

Bending and vibration tests performed inside a scanning electron microscopewere used to mechanically characterize high aspect pillars grown byfocused electron-beam- (FEB) induced deposition from the precursorCu(C5HF6O2)2. Supported by finite element (FE) analysis the Young’s modulus was determined fromload–deflection measurements using cantilever-based force sensing and the material densityfrom additional resonance vibration analysis. The pillar material consisted of acarbonaceous (C-, O-, F-, H-containing) matrix which embeds 5–10 at.% Cu deposited at5 and 20 keV primary electron energy and 100 pA beam current, depending onprimary electron energy. The Young’s moduli of the FEB deposits increased from17 ± 6 to25 ± 8 GPa with increasing electron dose. The density of the carbonaceousmatrix shows a dependence on the primary electron energy:1.2 ± 0.3 g cm−3 (5 keV)and 2.2 ± 0.5 g cm−3 (20 keV). At a given primary energy a correlation with the irradiation dose is found.Quality factors determined from the phase relation at resonance of the fundamental pillarvibration mode were in the range of 150–600 and correlated to the deposited irradiationenergy.