Helium ion microscope characterization for Cu / low-k interconnects - SE imaging and focused helium ion beam luminescence detection -

Several novel imaging modes of the recently developed helium ion microscope (HIM) 1) were explored that may make the HIM a tool of particular value to Cu / low-k (dielectric constant) interconnect structures. Mechanism of the “through dielectric” (2) imaging of the Cu interconnects underneath the low-k SiOC film was proposed, and materials contrast in the low-k regions between Cu lines was imaged which might reflect damaged low-k areas. Furthermore possibility of detection of luminescence induced by the focused helium ion beam using the HIM for materials property characterizations was studied for the first time.