The aim of this work package is to establish a metrological framework for the fabrication and 3D characterisation of heterogeneous structures and devices. Techniques like secondary ion mass spectrometry (SIMS) and atom probe tomography (APT), even if pushed at state-of-the-art limits in resolution and sensitivity, fail in the detailed 3D reconstruction and analysis of organic/inorganic multiple layers. In this work package, different model systems at the micro- and nano scale are produced and characterised with novel metrological approaches (3D TopoSIMS and FIB/SIMS) identifying the chemical structure by traceable methods. Optimised FIB cutting of the reference materials and SIMS analysis layer by layer will lead to a complete 3D reconstruction of the model systems revealing topography, matrix effects, resolution and sensitivity and chemical structural modification. An exploratory investigation by Atom probe of the 3D inorganic-organic model systems will also be carried out, in complement with 3D SIMS analysis.