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Broadband, high-resolution x-ray spectra from samples excited by the electron beam of a scanning electron microscope were obtained with an NTD germanium-based microcalorimeter. An energy resolution of 8 eV was used to resolve completely the silicon Kα from the tungsten Mα x-rays. This performance will make it possible to analyze efficiently the composition of thin films and surface contaminants by using low electron excitation energies.

Scanning electron microscope (SEM)-based x-ray analyzers have employed wavelength-dispersive x-ray (WDX) diffractometers or energy-dispersive x-ray (EDX) detectors as the spectrally resolving elements. In spite of their relatively poor energy resolution (ΔE = 130 eV at 6 keV), the solid-state EDX instruments have enjoyed much wider use than the WDX systems (ΔE = 1-10 eV) because of their convenience and efficiency. A microcalorimeter detector with 95% quantum efficiency at 6 keV has been developed that can produce spectra with an energy resolution of 7 eV over the broad energy band of 0.2-20 keV. This performance will advance the state-of-the-art for elemental analysis by virtue of its 20-fold increase in x-ray energy resolution. When coupled to an SEM it will permit the evolution of a new generation of microanalysis tools with greatly improved spatial resolution and increased sensitivity for minor elemental constituents. Since it will allow the SEM to operate at low electron energies, it will provide the ability to identify unambiguously x-ray signatures from a mixture of light and heavy elements. The latest performance of these detectors is presented along with a discussion of how they will eventually improve SEM-based microanalysis for small particle defect review and sub-micron depth studies.