An Innovative High Resistance Via Defect Finding Methodology with Nano-probing on FIB Recess Sample and TEM Lamella

The conventional 2-point (2-pt) nano-probing with layer-by-layer inspection is no longer a feasible solution to locate a via void defect within via-metal interconnect. This paper presents the approach of utilizing and innovating the existing Transmission Electron Microscopy (TEM) lamella to enable 2-pt nano-probing to be performed at cross section view. This methodology does not only facilitate the defect finding within the via-metal interconnect, it also reduces the risk of missing the defect entirely due to the defect mechanism. The standard practice of multi-layer nano-probing capability with access to two metal layers is also presented in this paper on a Focused Ion Beam (FIB) recess sample.