The aim of this work package is to establish traceable measurements for the characterisation of 3D micro- and nano structured materials, which are used and developed in the work packages above. At PTB, the physically traceable characterisation technique of reference-free Grazing Incidence X-Ray Fluorescence (GIXRF) spectrometry is available to measure mass depositions and elemental depth profiles of nanolayered materials. Reference-free GIXRF is based on radiometrically calibrated instrumentation and a physical modelling of the interaction of X-rays with matter using atomic fundamental parameters. Because of the physical traceability of reference-free GIXRF, this technique can be used as a primary method of measurement to quantify the composition of calibration samples with an in-depth resolution of a few nanometres. In order to enable the transfer of GIXRF’s physical traceability to characterisation techniques with a 3D spatial resolution, appropriate calibration samples with a regular 3D pattern and calibration procedures will be developed and tested. In particular, a high homogeneity of the 3D nano structures, in respect to their dimension and composition, have to be ensured in order to transfer the quantitative GIXRF results obtained on a large number of equal 3D structures to the 3D characterisation results obtained from single 3D structures. By using calibration samples qualified by a reference technique, a chemical traceability of the 3D characterisation techniques will be established. Due to the different kinds of materials and 3D characterisation techniques of interest in this project, several dedicated calibration samples and calibration procedures have to be developed in this work package. In the case of 3D nanoSIMS and 3D TopoSIMS, it is planned to develop heterogeneous materials representing typical applications including buried organic interfaces and heterogeneous materials. In the case of Atom Probe Tomography the focus will be on inorganic semiconductor materials with regular 3D nano structures, similar to Fin-FETs. These kinds of calibration samples will be optimised for a reliable sample preparation, which is required for atom probe tomography, such as FIB cutting. In addition to the provision of traceability to the work of the other technical work packages, the tasks of this work package will generate the metrological basis for the certification of new reference materials and for the standardisation of calibration procedures for 3D characterisation techniques with a spatial resolution at the nanometre scale.