Secondary ion mass spectrometry on the helium ion microscope: A feasibility study of ion extraction J. Vac. Sci. Technol. B 30, 06F602 (2012); 10.1116/1.4754309Effect of sample bias on backscattered ion spectroscopy in the helium ion microscope

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A wide acceptance angle first-order reflectron lens has been incorporated into a three-dimensional atom probe ͑3DAP͒ to provide improved mass resolution. This new 3DAP instrument is capable of resolving isotopes in the mass spectrum, with resolutions better than m/⌬mϭ500 full width at half maximum and 250 full width at 10% maximum. However, use of a reflectron for energy compensation within an imaging system means that improvements in mass resolution result in degradation of the spatial resolution. This article addresses the detailed design of the energy compensated 3DAP, and the minimization and compensation of chromatic aberrations in the imaging performance of the instrument. Some applications of the new instrument are included to illustrate its capabilities in the atomic-scale analysis of engineering alloys.

The authors demonstrate that silicon nitride membranes can be folded out of plane into three-dimensional structures by helium ion implantation. The folds have a radius of 1μm and can be directed both up or down by varying implant energy.

The newly introduced ORION™ helium ion microscope has been used for high resolution imaging and nanofabrication. More recently, an energy sensitive detector has been developed that permits the measurement of the energy spectrum of the backscattered helium ions. The spectra can be analyzed directly or compared with the simulated spectra from hypothetical models of the specimen. The technique can provide information about the elemental composition of the specimen or structural information (for example, layer thickness) of the specimen.