Correlative SEM/AFM/EDS Microscopy—Combining High-Performance Methods for Nanoscale Measurements

In modern material characterization, the combination of analytical methods for qualitative and quantitative evaluation has become essential. Correlative microscopy, in particular, has emerged as a potent technique for acquiring complementary information simultaneously. This study focuses on the integration of two of the most potent microscopy techniques – SEM (Scanning Electron Microscopy) and AFM (Atomic Force Microscopy) – to gain novel insights into the micro- and nanoscale features of samples with the highest resolution. [1-2] However, coupling these two methods presents significant challenges, particularly in terms of the required instrumentation. Typically, SEM and AFM are used separately, leading to difficulties in achieving true spatial correlation of the obtained results.<br/><br/>This study introduces the potential of a combined inspection device – the FusionScope – that seamlessly combines SEM and AFM for the characterization and process control of micro- and nanostructures. Utilizing self-sensing piezoresistive cantilever technology for the AFM scanner, we achieved complete electrical measurement of the cantilever deflection signal. [3] A shared coordinate system between SEM and AFM enables the simultaneous acquisition of data directly at the region of interest. This capability is further enhanced by the integration of Energy Dispersive X-Ray Spectroscopy (EDS), which allows the direct correlation of EDS and AFM data with nanometer precision. Traditional optical methods fail at this point, a challenge effectively addressed by the SEM/AFM combination.<br/><br/>We will present a series of novel case studies demonstrating the advantages of this innovative tool for interactive, correlative <i>in-situ</i> characterization of various materials and nanostructures at the nanoscale using SEM and AFM. Additionally, we will showcase how EDS integration advances measurement capabilities by correlating chemical information with AFM data. Specifically, we will present results from the <i>in-situ</i> characterization of nanowires, 2-D thin film materials, and multilayer samples, highlighting their electrical, magnetic, topographic, mechanical, and chemical properties. The SEM facilitates the easy localization of single or multiple surface features, while <i>in-situ</i> AFM characterizes various "visible" and "hidden" surface and bulk properties. EDS integration further enhances the ability to link chemical information directly to AFM data.<br/><br/>Moreover, we will briefly discuss advanced tip fabrication techniques, such as focused electron beam induced deposition (FEBID), to illustrate how correlated measurements can benefit from fine-tuning the tip properties. [4] Given its broad range of applications in the inspection and process control of various materials and components, we expect that this new inspection device will become a key tool for future correlative SEM, AFM, and EDS analysis.<br/><br/>The characterization of mechanical and electrical properties linked together with EDS data can give innovative insights into the properties of materials in many research fields like material development, battery research or life science. Our SEM/AFM/EDS tool can provide detailed insights into the properties, thereby advancing our understanding and development of next-generation materials.<br/><br/>[1] D. Yablon, et al., Microscopy and Analysis – EMEA, <b>29</b>, 14-18 (2017).<br/>[2] S. H. Andany, et al., Beilstein Journal of Nanotechnology, <b>11</b>, 1272-1279 (2020).<br/>[3] M. Dukic, et al., Scientific Reports, <b>5</b> (1), 16393 (2015).<br/>[4] L. M. Seewald, et al., Nanomaterials, <b>12</b> (24), 4477 (2022).