Nanoscale electrical properties of epitaxial Cu₃Ge film

Cu₃Ge has been pursued as next-generation interconnection/contact material due to its high thermal stability, low bulk resistivity and diffusion barrier property. Improvements in electrical performance and structure of Cu₃Ge have attracted great attention in the past decades. Despite the remarkable progress in Cu₃Ge fabrication on various substrates by different deposition methods, polycrystalline films with excess Ge were frequently obtained. Moreover, the characterization of nanoscale electrical properties remains challenging. Here we show the fabrication of epitaxial Cu₃Ge thin film and its nanoscale electrical properties, which are directly correlated with localized film microstructures and supported by HRTEM observations. The average resistivity and work function of epitaxial Cu₃Ge thin film are measured to be 6 ± 1 μωcm and ∼4.47 ± 0.02 eV respectively, qualifying it as a good alternative to Cu.