In-Situ TEM Electrical Characterization of Void Formation and Growth Along Cu Interconnect Via: FIB Based Sample Preparation Method

An experimental setup is presented, that allows in-situ Transition Electron Microscopy (TEM) investigation of void formation and growth within fully embedded interconnect structure, as a response to an external bias. A special TEM holder is employed to perform in-situ I-V measurements across the Via, simultaneously monitoring the morphological and chemical changes surrounding the void. This work presents in detail a Focused Ion Beam (FIB) based sample preparation method that allows the analysis of a Cu single Via structure found in the advanced microelectronic 14nm FinFET technology, as well as preliminary TEM observations.