Nanoscale Three-Dimensional Imaging of Integrated Circuits using a Scanning Electron Microscope and Transition-Edge Sensor Spectrometer

• Main Authors: Nakamura, Nathan, Szypryt, Paul, Dagel, Amber L, Alpert, Bradley K, Bennett, Douglas A, Doriese, W. Bertrand, Durkin, Malcolm, Fowler, Joseph W, Fox, Dylan T, Gard, Johnathon D, Goodner, Ryan N, Harris, J. Zachariah, Hilton, Gene C, Jimenez, Edward S, Kernen, Burke L, Larson, Kurt W, Levine, Zachary H, McArthur, Daniel, Morgan, Kelsey M, O'Neil, Galen C, Ortiz, Nathan J, Pappas, Christine G, Reintsema, Carl D, Schmidt, Daniel R, Schultz, Peter A, Thompson, Kyle R, Ullom, Joel N, Vale, Leila, Vaughan, Courtenay T, Walker, Christopher, Weber, Joel C, Wheeler, Jason W, Swetz, Daniel S
• Format: Journal Article
• Language: English
• Published: 20.12.2022
• Subjects: Physics - Instrumentation and Detectors
• DOI: 10.48550/arxiv.2212.10591

X-ray nanotomography is a powerful tool for the characterization of nanoscale materials and structures, but is difficult to implement due to competing requirements on X-ray flux and spot size. Due to this constraint, state-of-the-art nanotomography is predominantly performed at large synchrotron facilities. We present a laboratory-scale nanotomography instrument that achieves nanoscale spatial resolution while changing the limitations of conventional tomography tools. The instrument combines the electron beam of a scanning electron microscope (SEM) with the precise, broadband X-ray detection of a superconducting transition-edge sensor (TES) microcalorimeter. The electron beam generates a highly focused X-ray spot in a metal target held micrometers away from the sample of interest, while the TES spectrometer isolates target photons with high signal-to-noise. This combination of a focused X-ray spot, energy-resolved X-ray detection, and unique system geometry enable nanoscale, element-specific X-ray imaging in a compact footprint. The proof-of-concept for this approach to X-ray nanotomography is demonstrated by imaging 160 nm features in three dimensions in 6 layers of a Cu-SiO2 integrated circuit, and a path towards finer resolution and enhanced imaging capabilities is discussed.