Full-Field Through-Chip IR-Thermography-based Quality Testing & Failure Analysis on Electroplated Aluminium Interconnects for Cryogenic Applications in Ion-Trap Quantum Computers

This paper addresses thermal transient IR thermography as full-field and non-destructive failure analytical technique to determine the bond quality of microelectronic joints, exploiting the transparency of a silicon chip for MIR photons. The method is exemplified for C2C bonded electroplated Aluminium joints as they could come in as a novel joining technology for 3D heterogeneously integrated Cryo-SiP architectures for ion-trap based quantum computers. We have evaluated the method experimentally for different thermosonic bond parameters and validated it by metallographic sectioning. First results are shown. We could derive that the phase and amplitude image could be used to detect defects in the joints with good sensitivity and within reasonable testing times. This method could have potential to determine zero-hour quality of such joints during inline testing.