Magnetic microscopy for ICs failure analysis : comparative case studies using SQUID, GMR and MTJ systems

Magnetic field based techniques have shown great capabilities for investigation of current flows in ICs. After reviewing the performances of SQUID, GMR (hard disk head technologies) and MTJ existing sensors, we present results obtained on various case studies. This comparison shows the benefit of each approach according to each case study (packaged devices, flip-chip circuits,...). Finally we discuss the obtained results to classify current techniques, optimal domain of applications and advantages.