Revealing microstructural changes in copper power metallizations under thermo-mechanical fatigue using in-situ scanning 3D-XRD

In the semiconductor industry, the demand for new technologies requires a deep understanding of physical mechanisms affecting device performance. Short-circuit events in power electronic applications induce thermo-mechanical stresses. If these events occur frequently, they can lead to degradation of metallization layers. To enhance the reliability of future technologies, it's essential to investigate this fatigue behavior. Therefore, test chips have been developed to enable stressing and in-situ characterization of Cu metallization layers, during thermo-mech. cycling. The non-destructive Scanning 3D X-ray Diffraction technique has the potential to monitor microstructural evolution within the metallization layer, throughout the degradation process of a functional device. Combined with detailed Dark Field X-ray Microscopy and Laboratory X-ray Computed Tomography measurements, the study provides multiscale insights under thermo-mechanical fatigue of Cu under high strain rate conditions.