학술논문

Nanoscale Three-Dimensional Imaging of Integrated Circuits Using a Scanning Electron Microscope and Transition-Edge Sensor Spectrometer
Document Type
Academic Journal
Source
Sensors. May, 2024, Vol. 24 Issue 9
Subject
Standard IC
Integrated circuit fabrication
Integrated circuits
Semiconductor chips
Integrated circuit fabrication
Language
English
ISSN
1424-8220
Abstract
X-ray nanotomography is a powerful tool for the characterization of nanoscale materials and structures, but it is difficult to implement due to the competing requirements of 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 addressing 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 on a metal target held micrometers away from the sample of interest, while the TES spectrometer isolates target photons with a high signal-to-noise ratio. This combination of a focused X-ray spot, energy-resolved X-ray detection, and unique system geometry enables 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 six layers of a Cu-SiO[sub.2] integrated circuit, and a path toward finer resolution and enhanced imaging capabilities is discussed.
Author(s): Nathan Nakamura (corresponding author) [1,2,*]; Paul Szypryt [1,2]; Amber L. Dagel [3]; Bradley K. Alpert [1]; Douglas A. Bennett [1]; William Bertrand Doriese [1]; Malcolm Durkin [1,2]; Joseph W. [...]