3D correlative morphological and elemental characterization of materials at the deep submicrometre scale

This paper shows how X-ray computed nanotomography (CNT) can be correlated with focused ion beam time-of-flight secondary ion mass spectrometry (FIB-TOF-SIMS) tomography on the same sample to investigate both the morphological and elemental structure. This methodology is applicable to relatively large specimens with dimensions of several tens of microns whilst maintaining a high spatial resolution of the order of 100 nm. However, combining X-ray CNT and FIB-TOF-SIMS tomography requires innovative sample preparation protocols to allow both experiments to be conducted on exactly the same sample without chemically or structurally modifying the sample between measurements. Moreover, dedicated algorithms have been developed for effective data fusion that is biased with nine degrees of freedom. This methodology has been tested using a porous and heterogeneous solid oxide fuel cell (SOFC) that has features varying in size by three orders of magnitude - from hundreds of nanometre large pores and grains to tens of micron wide functional layers. Lay description Deep understanding of physical and chemical properties is essential for optimizing fabrication processes and efficiency of materials and devices. Although, many characterization tools exist they each have their strengths and weaknesses and cannot provide a complete description of the structure of a material when used alone. Therefore, correlative approaches that combine two or more techniques are of increasing interest in scientific and industrial communities. In this paper we present an innovative methodology that allows the three-dimensional morphological and chemical structure of a sample to be obtained at spatial resolutions of the order of 100 nm. This has been achieved by using the state-of-the-art X-ray Computed Nano-Tomography (CNT) and Focused Ion Beam Time-Of-Flight Secondary Ion Mass Spectrometry (FIB-TOF-SIMS). This kind of studies have been initially dedicated to needs of microelectronics and new energy conversion devices but can be applied to any solid materials.