Laser assisted field evaporation of oxides in atom probe analysis

Chen, Y.M.; Ohkubo, T.; Hono, K.

doi:10.1016/j.ultramic.2010.12.013

Cited by 66 publications

(45 citation statements)

References 22 publications

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“…Additionally,peaks for molecules of Mn andOwith different charge states are found, as typically observed for oxides. [18,19,[30][31][32][33] Theh ydrogen assigned to the peaks at m/z = 1, 2, and 3amu most likely stems from residual gas in the chamber, which is field ionized at the sample apex and does not originate from the analyzed material itself. [34,35] At m/z = 69 amu, as ignal from Ga is visible in the overall mass spectrum.…”

Section: Compositionmentioning

confidence: 99%

Three‐Dimensional Microstructural Characterization of Lithium Manganese Oxide with Atom Probe Tomography

et al. 2016

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The microstructure of the active material of Li‐ion batteries has a crucial influence on local ion‐transport processes but is not yet well characterized. Atom probe tomography (APT), a method combining sub‐nanometer spatial resolution with sub‐parts‐per‐thousand chemical resolution is well suited for 3 D microstructural characterization. Herein, the results of the characterization of lithium (nickel)manganese oxides [L(N)MO] with APT are presented. Structural and chemical defects of different dimensions such as the segregation of Na impurities to grain boundaries and the appearance of a Ni‐rich foreign phase are detected. Furthermore, a lamellar microstructure correlated to fluctuations in the local Li content was observed, and its influence on Li transport in the material is discussed. In defect‐free regions, the lattice planes of LMO are reconstructed for the first time, and the high spatial resolution of APT is revealed. Thus, the results demonstrate the potential of APT for the 3 D microstructural characterization of LMO.

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Section: Compositionmentioning

confidence: 99%

Three‐Dimensional Microstructural Characterization of Lithium Manganese Oxide with Atom Probe Tomography

et al. 2016

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“…The field of application of APT has dramatically increased, building on a vast body of work on metallic materials and alloys. Recent articles have reviewed the impact APT onto physical metallurgy or metallic alloys (Cerezo et al, 2007b; Seidman, 2007), as well as its capabilities for ceramics, semiconductor and devices characterization (Hono et al, 2011;Kelly et al, 2007;Larson et al, 2011aLarson et al, , 2011b, and I would like to refer readers to those seminal articles. Current studies are increasingly making use of a vast array of characterisation techniques, at multiple scales, with the view to correlate information from i.e.…”

Section: Discussionmentioning

confidence: 99%

“…Here again, some obvious clusters of keywords form, with i.e. semiconductors and solar cells closer to the methods development, laser and field evaporation that are being intensely researched to have a better grasp on the fundamental mechanisms underpinning the field evaporation of poorconductors (Chen et al, 2011;Kelly et al, 2014;Silaeva et al, 2014). Another interesting point that arises from analyzing such diagrams is how APT is now used to complement other techniques: terms related to differential scanning calorimetry, scanning & transmission electron microscopy, X-ray diffraction and small-angle scattering, as well as atomistic simulations, such as (kinetic) Monte Carlo, molecular dynamics or density functional theory, can all be found.…”

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confidence: 99%

A Brief Overview of Atom Probe Tomography Research

Gault

2016

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Atom probe tomography (APT) has been fast rising in prominence over the past decade as a key tool for nanoscale analytical characterization of a range of materials systems. APT provides three-dimensional mapping of the atom distribution in a small volume of solid material. The technique has evolved, with the incorporation of laser pulsing capabilities, and, combined with progress in specimen preparation, APT is now able to analyse a very range of materials, beyond metals and alloys that used to be its core applications. The present article aims to provide an overview of the technique, providing a brief historical perspective, discussing recent progress leading to the state-of-the-art, some perspectives on its evolution, with targeted examples of applications.Key Words: Atom probe tomography, Field evaporation, Materials characterization, Microscopy, Nanoscale Gault B 118The specimen is progressively destroyed, almost atom-byatom, and the atom probe microscope collects the timeof-flight and impact position of each ion. Processing of the data translates the time-of-flight into a mass-to-charge ratio, and the position is used to build a tomographic, atomically resolved image of the evaporated volume (Bas et al., 1995;Larson et al., 2013), represented as a point-cloud where every point is an atom that has been elementally identified and repositioned with a high degree of precision (Gault et al., 2010b). INSTRUMENTAL DESIGNEarly designs of the technique, usually referred to as atomprobe field ion microscopes or one-dimensional (1D) atom probe (Miller, 2000;Müller et al., 1968), had a very narrow field-of-view and really only provided linear compositional measurement in the depth of the sample, within a region of interest located by field-ion microscopy (Brenner & Goodman, 1971). APT was truly enabled by the implementation of position-sensitive, time-resolved particle detectors by Cerezo et al. (1988) followed by Blavette et al. (1993), and modern microscopes are equipped with delayline detectors (Da Costa et al., 2005; Jagutzki et al., 2002). The incorporation of micro-channel plates (MCPs) in the design of such detectors, to convert the impact of a single-ion into a cascade of up to millions of electrons, limits the efficiency approximately to the open area of the MCPs, so between 50%~80%. The MCPs are operated in saturated mode, which ensures almost no mass or atomic number sensitivity for ions in the range of 2~3 kV up to 15~20 kV up to several hundreds of Da, and the loss of ions is therefore nonspecific and assumed to be random and hence not affecting the technique's capacity to precisely measure the elemental composition. In order to increase the mass resolution of the technique, limited by the energy spread of the emitted ions, reflectron-lenses were fitted onto atom probes (Bémont et al., 2003;Cerezo et al., 1998;Panayi, 2006). A reflectron acts as an electrostatic mirror: ions penetrate inside a region containing a well-defined electric field in which ions are progressively slowed down until they are returne...

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“…It should be mentioned that although APT has been increasingly employed to study semiconductor materials, there are intense debates with regard to fundamental mechanisms and issues in relation to chemical composition quantification. 32,40,41 It has been found that the laser energy has a significant effect on the detection of light elements in nitrides 37,42 and oxides 43 . Therefore in this work, providing consistency with our earlier studies, 30 Figure 4a is a 3D reconstruction of the APT data arising from the uppermost layers of the as-grown wafer.…”

Section: A Analysis Of Processed Device Structuresmentioning

confidence: 99%

Nanoscale structural and chemical analysis of F-implanted enhancement-mode InAlN/GaN heterostructure field effect transistors

Tang

Lee

Guiney

et al. 2018

Journal of Applied Physics

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We investigate the impact of a fluorine plasma treatment used to obtain enhancement-mode operation on the structure and chemistry at the nanometer and atomic scales of an InAlN/GaN field effect transistor. The fluorine plasma treatment is successful in that enhancement mode operation is achieved with a +2.8 V threshold voltage. However, the InAlN barrier layers are observed to have been damaged by the fluorine treatment with their thickness being reduced by up to 50%. The treatment also led to oxygen incorporation within the InAlN barrier layers. Furthermore, even in the as-grown structure, Ga was unintentionally incorporated during the growth of the InAlN barrier. The impact of both the reduced barrier thickness and the incorporated Ga within the barrier on the transistor properties has been evaluated theoretically and compared to the experimentally determined two-dimensional electron gas density and threshold voltage of the transistor. For devices without fluorine treatment, the two-dimensional electron gas density is better predicted if the quaternary nature of the barrier is taken into account. For the fluorine treated device, not only the changes to the barrier layer thickness and composition, but also the fluorine doping needs to be considered to predict device performance. These studies reveal the factors influencing the performance of these specific transistor structures and highlight the strengths of the applied nanoscale characterisation techniques in revealing information relevant to device performance.

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Laser assisted field evaporation of oxides in atom probe analysis

Cited by 66 publications

References 22 publications

Three‐Dimensional Microstructural Characterization of Lithium Manganese Oxide with Atom Probe Tomography

Three‐Dimensional Microstructural Characterization of Lithium Manganese Oxide with Atom Probe Tomography

A Brief Overview of Atom Probe Tomography Research

Nanoscale structural and chemical analysis of F-implanted enhancement-mode InAlN/GaN heterostructure field effect transistors

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