Simultaneous Thermomechanical Mapping via Optical Pumping for Subsurface Defect Identification

Abstract Advancements in microelectronics necessitate novel failure analysis techniques sensitive to the specific failure physics. Thermo-mechanical failure is a well-known issue in heterogeneously integrated microelectronics, which often requires destructive failure analysis to identify. Here, we demonstrate thermo-mechanical heat response (T-MeHR) as a non-destructive failure analysis method which combines pump-probe thermoreflectance with optical interferometry. In particular, we are able to map subsurface defects in a silicon-silicon direct bonded system and find that the simultaneously acquired thermal and mechanical signals provide complementary profiles dictated by the defect severity and size.