Development of a multifunctional nanoindenter integrated in-situ Scanning Electron Microscope - application to the monitoring of piezoresponse and electro-mechanical failures

International audience ; The rising complexity of multi-material structures integrated into multi-functional devices requires the devel­opment of dedicated characterization tools capable of simultaneously monitoring different physical magnitudeswith a relevant spatial resolution. This paper reports the development and the application of an original in­strument based on a nanoindenter coupled with fine electrical measurements and integrated in-situ a ScanningElectron Microscope (SEM). The performances and capabilities of this home-developed instrument are illustratedthrough two different case studies.First, a micrometer-scale piezoelectric structure made up of wurtzite-single crystalline AlN islands grown ontop of conductive Si pillars is tested. In-situ SEM imaging is used to precisely position the indenting probe onthese individual islands, while the instrument sensitivity and repeatability are used to monitor their low-signalpiezoresponse. Effective piezoelectric coefficients are also extracted for different loading/unloading conditions.Secondly a Si 3N4/AlSiCu/SiO2 stack, which is standardly integrated as a passivation structure on top of mi­croelectronic chips, is electrically and mechanically stressed and monitored up to its failure. The mechanicalfailure mechanisms (buried or emerging cracks) are discriminated thanks to the real-time SEM imaging of theindentation test. The instrument high sensitivity is used to monitor early current leakages that are attributed toconduction paths induced by mechanical failures.Combining high electro-mechanical sensitivity and precise probe positioning appears as an efficient way tomonitor and analyze low-level electrical responses of small-scale structures. This approach paves the way to thefine characterization of micro/nano-systems displaying mechanically-driven electrical properties (conductionmechanism, leakage, breakdown,) like 2D-materials, dielectrics in microelectronic devices, strain-sensors,enamelled Litz wires,.