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In situ approach to characterization of nanoscale electromigration

Ismail Gobulukoglu, University of Nebraska - Lincoln


An in situ technique is presented for observing microstructure and morphology changes in metal conductors, with nanoscale spatial resolution, during electromigration testing. The technique is based on using a field-emission scanning transmission electron microscope (STEM) as a nano-laboratory to enable full microstructural characterization during electromigration testing. Initial steps in the validation of the approach included surface-mediated in situ electron beam-induced organometallic chemical vapor deposition (e-OMCVD) of Al-containing wires and with high edge acuity, uniform thickness, and with widths as small as 15 nm. In situ imaging of 100 nm thick Al films annealed at 350°C demonstrates that an image resolution of better than 10 nm should readily be attainable in passivated nanoscale interconnects during electromigration studies. Using a high-resolution four-wire resistance measurement facility, designed as part of the research, during in situ microstructural observation of a electromigration testing of a model interconnect, several conclusions were drawn, the main one being that void growth resulted in a stable neck that carried a current density of 11.5 MA/cm2 at temperatures above 210°C, whereas significant electromigration damage had started at only 1.5 MA/cm2 at lower temperatures. With only very slight modification, the approach is also highly appropriate for in situ studies of electron transport in nanoscale wires and contacts as well as for nanometer-scale studies of fundamental aspects of electromigration in thin film conductors. ^

Subject Area

Engineering, Materials Science

Recommended Citation

Gobulukoglu, Ismail, "In situ approach to characterization of nanoscale electromigration" (2002). ETD collection for University of Nebraska - Lincoln. AAI3070127.