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Description
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The structural characterization and the chemical analysis at the nanometer scale are of highest relevance in multiple fields, that can be as diverse as high-resolution imaging of dopant distributions in complex electronic devices, the generation of chemical maps of sub-cellular structures in biological samples to understand the underlying physiological processes, or isotopic ratio measurements at the nano-scale in geological samples. The following key characteristics are required and enabled in our instrument developments: (1) highest spatial resolution, (2) excellent chemical sensitivity, (3) high dynamic range and (4) isotopic selectivity. Secondary Ion Mass Spectrometry (SIMS) is an extremely powerful technique for analyzing surfaces, owing to its ability to detect all elements from H to U and to differentiate between isotopes, its excellent sensitivity and its high dynamic range. SIMS analyses can be performed in different modes: acquisition of mass spectra, depth profiling, 2D and 3D chemical imaging. Adding SIMS capability to focused ion beam (FIB) instruments offers a number of interesting possibilities, including highly sensitive analytics, highest resolution SIMS imaging (∼10 nm), in-situ process control during patterning and milling, and direct correlation of SIMS data with data obtained by other analytical or imaging techniques on the same instrument, such as high-resolution secondary electron (SE) images, back-scattered electron (BSE) images or Energy-Dispersive X-Ray Spectroscopy (EDX) spectra. In this global context, we developed several generations of double focusing magnetic sector SIMS systems. The latest generation is equipped with a novel continuous focal plane detector. This SIMS system allows for the detection of all masses in parallel for each single pixel, resulting in acquisition times as low as 1 s to obtain a full mass spectrum or 2 min to obtain a 512 x 512 pixel SIMS image with highest signal-to-noise ratio and excellent dynamic range. The advantages over time-of-flight (TOF) systems include the ability of working in the DC mode (providing significantly higher secondary ion (SI) counts for a given analysis duration) and higher overall transmission, resulting in significantly better sensitivity. This SIMS system is now operating on several multi-modal FIB platforms (Figure 1), including Thermo Fisher DualBeam systems [1], ZEISS ORION NanoFab Helium Ion Microscope [2-4], the zeroK SIMS:ZERO platform [5] and the RAITH VELION. The FIB columns of these instruments cover a diverse range of ion species: He, Li, Ne, Si, Ar, Ga, Ge, Xe, Cs, Au, Bi. Due to their differences in size, mass and chemical reactivity, they lead to differences in sputter yields, fragmentation, dimensions of the collision cascades triggered in the sample and ionization probabilities of the sputtered atoms and molecules. Here, we will review the performance of the different instruments with a focus on new developments, showcase methodologies for high-resolution 3D chemical imaging, present a number of examples from various fields of applications (nanoparticles, battery materials, photovoltaics, micro-electronics, tissue and sub-cellular imaging in biology, geology, …) (Figure 2) and give an outlook on new trends and prospects. (2024-07-24)
***This entry has been automatically imported via Infodoc(ASO) CSV by LIST harvest scripts. Please refer to https://doi.org/10.1093/mam/ozae044.236 for the original and latest version of the dataset and data downloads*** (2026-06-24)
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