Purification of EBID structures of noble metals by electron beam post-irradiation under oxygen flux

S. Mehendale, J.J.L. Mulders, P.H.F. Trompenaars
FEI Electron Optics, NL

Keywords: EBID, Pt, Au, Purification


Although Electron Beam Induced Deposition (EBID) is considered as a single-step process for creation of three-dimensional nanostructures of different materials, direct deposition of highly pure metallic structures had been rarely achieved. Typically, use precursors such as MePtCpMe3, or Me2Au(acac) results in C- rich depositions with 15 at.% of Pt and 20 at.% Au respectively. We report a post treatment: electron beam post-irradiation under oxygen flux which is very efficient in purifying Pt grown by EBID at annealing temperatures as low as 120 C. A pure Pt structure of desired dimensions can be created by stacking up individually purified thin Pt structures. The resistivity of the Pt structure fabricated by this method (70±8 µΩ.cm) is comparable to that of pure bulk Pt (10.62 µΩ.cm). A thin Au EBID structure deposited on Si substrate can be completely purified by this post-treatment, even at room temperature. Further experiments will be carried out in order to create pure Au structures suitable for applications in nano-photonics and the electrical measurements will be done. This post-treatment might be used as a guideline for purification of C-rich EBID structures.