In this paper different methods and novel tools for failure localisation and high resolution material analysis for open TSV interconnects will be discussed. The paper shows the application of enhanced methods for the localisation of sidewall shorts in open TSV structures by adapted Photoemission Microscopy (PEM), Lock-in Thermography (LIT) and Electron Beam Absorbed Imaging (EBAC). In addition, a new highly efficient target preparation technique is presented, which allows the combination of Laser and FIB milling, in order to access TSV sidewall defects. Finally the use of this technique is demonstrated in a failure analysis case study.