edfas.org ELECTRONIC DEVICE FAILURE ANALYSIS | VOLUME 27 NO. 2 8 A NOVEL ION MICROSCOPE FOR HIGH-RESOLUTION ION IMAGING AND SIMS NANOANALYTICS WITH PRECISE SAMPLE NAVIGATION Peter Gnauck, Alexander Ost, and Torsten Richter Raith GmbH, Dortmund, Germany peter.gnauck@raith.com EDFAAO (2025) 2:8-12 1537-0755/$19.00 ©ASM International® INTRODUCTION Understanding nanoscale materials and their transformation processes requires advanced techniques with high lateral resolution and sensitivity. Recent advancements in focused ion beam (FIB) technologies, combined with secondary ion mass spectrometry (SIMS), have significantly enhanced the ability to visualize and analyze nanoscopic 3D structures. SIMS, a powerful analytical technique, employs primary ions to sputter sample surfaces, generating secondary ions that are separated by a mass analyzer to provide detailed elemental information. This technique offers high sensitivity and a wide dynamic range, making it indispensable for recording mass spectra, depth profiling, and 2D/3D imaging. The integration of high-resolution ion microscopy, in-situ SIMS, and a high-precision laser interferometer stage has facilitated the correlation of topographic and chemical information at the highest spatial resolution, thereby advancing our understanding of materials in various fields, including semiconductor technology.[1] This article introduces a novel system that integrates high-resolution 2D/3D imaging and SIMS nanoanalysis. This system uniquely combines a liquid metal alloy ion source (LMAIS),[2] a dedicated magnetic sector SIMS unit, and a laser interferometer-controlled sample stage. The LMAIS technology enables the emission of multiple ion species simultaneously from a single source, which are then separated using a Wien filter. This setup allows for the quick selection and switching between ion species, facilitating the use of heavy ions like Bi+ or Au+ for sample delayering, and lighter ions like Li+ or Si2+ for high-resolution imaging.[3] These capabilities enable the generation of 3D volume reconstructions of samples from individual image planes. The maximum field of view for all ions is 200 µm at 35 keV landing energy. The SIMS unit is equipped with an extraction optic that transfers the generated secondary ions through a mass analyzer to a focal plane detector, allowing the parallel acquisition of full mass spectra for each scanned pixel within the field of view. This system’s ability to switch between reactive primary ion species to maximize positive or negative ionization of sputtered particles further enhances its analytical capabilities.[4] The small beam diameter of the lightest primary ions (Li+ or Si2+) supports high spatial resolution imaging in SIMS (<20 nm), while the low penetration Fig. 1 Schematic setup of the instrument: Vertical FIB column with LMAIS, high precision laser interferometer stage and SIMS unit with extraction and transfer optic, magnetic sector, and continuous focal plate detector.
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