Position-Sensitive Atom Probe and Stem Analysis of the Microchemistry of GaInAs/Inp Quantum Wells

ABSTRACTThe recently developed techniques of pulsed laser atom probe microanalysis (PLAP) and position sensitive atom probe (POSAP) have been applied to the study of quantum well interfaces in samples that have also been well characterised by the more conventional techniques of TEM and STEM. These techniques have the potential for providing chemical information with a spatial resolution of better than 2nm, but the atom probe has the ability to independently resolve morphological and microchemical features of interfaces in three dimensions.This paper presents results taken from GaInAs/lnP MOCVD-grown samples, comparing information on well composition, and on the chemical abruptness and morphological roughness of interfaces using complementary analysis techniques. We have concentrated on obtaining reliable quantitative data on the phosphorous content of the GaInAs wells and on the gallium and arsenic contents of the InP barrier layers.

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Characterisation of multilayer materials using a position-sensitive atom probe

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100176253 ◽

1990 ◽

Vol 48 (4) ◽

pp. 624-625

Author(s):

RAD Mackenzie ◽

G D W Smith ◽

A. Cerezo ◽

J A Liddle ◽

CRM Grovenor ◽

...

Keyword(s):

Quantum Well ◽

Quantum Wells ◽

Spatial Information ◽

Chemical Vapour ◽

Atom Probe ◽

Organic Chemical ◽

Growth Stages ◽

Multiple Quantum ◽

Quartz Wool ◽

Position Sensitive

The position sensitive atom probe (POSAP), described briefly elsewhere in these proceedings, permits both chemical and spatial information in three dimensions to be recorded from a small volume of material. This technique is particularly applicable to situations where there are fine scale variations in composition present in the material under investigation. We report the application of the POSAP to the characterisation of semiconductor multiple quantum wells and metallic multilayers.The application of devices prepared from quantum well materials depends on the ability to accurately control both the quantum well composition and the quality of the interfaces between the well and barrier layers. A series of metal organic chemical vapour deposition (MOCVD) grown GaInAs-InP quantum wells were examined after being prepared under three different growth conditions. These samples were observed using the POSAP in order to study both the composition of the wells and the interface morphology. The first set of wells examined were prepared in a conventional reactor to which a quartz wool baffle had been added to promote gas intermixing. The effect of this was to hold a volume of gas within the chamber between growth stages, leading to a structure where the wells had a composition of GalnAsP lattice matched to the InP barriers, and where the interfaces were very indistinct. A POSAP image showing a well in this sample is shown in figure 1. The second set of wells were grown in the same reactor but with the quartz wool baffle removed. This set of wells were much better defined, as can be seen in figure 2, and the wells were much closer to the intended composition, but still with measurable levels of phosphorus. The final set of wells examined were prepared in a reactor where the design had the effect of minimizing the recirculating volume of gas. In this case there was again further improvement in the well quality. It also appears that the left hand side of the well in figure 2 is more abrupt than the right hand side, indicating that the switchover at this interface from barrier to well growth is more abrupt than the switchover at the other interface.

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Atom probe reveals the structure of Inx Ga1–xN based quantum wells in three dimensions

physica status solidi (b) ◽

10.1002/pssb.200778595 ◽

2008 ◽

Vol 245 (5) ◽

pp. 861-867 ◽

Cited By ~ 12

Author(s):

M. J. Galtrey ◽

R. A. Oliver ◽

M. J. Kappers ◽

C. McAleese ◽

D. Zhu ◽

...

Keyword(s):

Quantum Wells ◽

Atom Probe ◽

Three Dimensions

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Ultra-high resolution chemical analysis by field-ion atom probe/position sensitive atom probe techniques

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100086738 ◽

1991 ◽

Vol 49 ◽

pp. 486-487

Author(s):

C.R.M. Grovenor ◽

A. Cerezo ◽

J.A. Liddle ◽

R.A.D. Mackenzie ◽

M.G. Hetherington ◽

...

Keyword(s):

High Resolution ◽

Sample Surface ◽

Atom Probe ◽

Three Dimensions ◽

Very High Spatial Resolution ◽

Chemical Profiles ◽

Position Sensitive ◽

Field Ion Microscope ◽

Very High

The use of field ion microscopy based techniques in the study of the structure and chemistry of metallic and semiconducting materials with very high resolution is now well documented. The particular features of these techniques which result in the achievement of very high spatial resolution in images and chemical profiles are; the intrinsic magnification in a conventional field ion microscope of at least 106, the plane-by-plane desorption characteristic of field evaporation processes, and the excellent chemical specificity in a modern atom probe. In addition, we have developed in Oxford a new detector system for field ion based equipment in which both the chemical identity of evaporated ions and the position on the sample surface from which they were evaporated can be established. This allows the reconstruction of the evaporated volume in three dimensions, and this technique has been christened the Position Sensitive Atom Probe, POSAP. This abstract presents the results of two typical experiments illustrating the very high quality of the chemical data that can be obtained in both conventional atom probe and POSAP facilities.

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Characterization of Nanoporous Materials with Atom Probe Tomography

Microscopy and Microanalysis ◽

10.1017/s1431927615000501 ◽

2015 ◽

Vol 21 (3) ◽

pp. 557-563 ◽

Cited By ~ 13

Author(s):

Björn Pfeiffer ◽

Torben Erichsen ◽

Eike Epler ◽

Cynthia A. Volkert ◽

Piet Trompenaars ◽

...

Keyword(s):

Atom Probe Tomography ◽

Focused Ion Beam ◽

Ion Beam ◽

Atom Probe ◽

Nanoporous Materials ◽

Three Dimensions ◽

Chemical Information ◽

Nanoporous Material ◽

Open Cell ◽

Dicobalt Octacarbonyl

AbstractA method to characterize open-cell nanoporous materials with atom probe tomography (APT) has been developed. For this, open-cell nanoporous gold with pore diameters of around 50 nm was used as a model system, and filled by electron beam-induced deposition (EBID) to obtain a compact material. Two different EBID precursors were successfully tested—dicobalt octacarbonyl [Co2(CO)8] and diiron nonacarbonyl [Fe2(CO)9]. Penetration and filling depth are sufficient for focused ion beam-based APT sample preparation. With this approach, stable APT analysis of the nanoporous material can be performed. Reconstruction reveals the composition of the deposited precursor and the nanoporous material, as well as chemical information of the interfaces between them. Thus, it is shown that, using an appropriate EBID process, local chemical information in three dimensions with sub-nanometer resolution can be obtained from nanoporous materials using APT.

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Recent developments in position-sensitive atom-probe microanalysis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171870 ◽

1994 ◽

Vol 52 ◽

pp. 828-829

Author(s):

G. D. W. Smith ◽

A. Cerezo ◽

T. J. Godfrey ◽

R. Setna ◽

J. M. Hyde ◽

...

Keyword(s):

Three Dimensional ◽

Atom Probe ◽

Atomic Scale ◽

Three Dimensions ◽

Single Atom ◽

Position Sensing ◽

Recent Developments ◽

Position Sensitive ◽

New Generation ◽

Serial Mode

The difficulties associated with the aperture geometry of the conventional atom probe have been overcome by the introduction of a new generation of wide-angle, single-atom sensitivity, positionsensitive detectors. With the aid of such detectors, it is now possible to map the locations and identitiesof atoms over regions of solid surface up to 50 nm in diameter. The nanometer-scale chemistry of successive atomic layers can be investigated during the process of field evaporation. We therefore have the new and exciting ability to investigate the atomic-scale chemistry of solids in three dimensions. The first three-dimensional atom probe is the PoSAP (Position Sensitive Atom Probe), developed at Oxford by Cerezo and Smith. In this instrument, position sensing is carried out by means of a wedge-and-strip anode assembly, located directly behind the double microchannel plate used for primary ion detection and time of flight measurement. The detector readout functions in serial mode. Only one ioncan be successfully detected and identified for each evaporation pulse which is applied to the specimen

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Challenges Associated with the Characterisation of Nanocrystalline Materials Using Atom Probe Tomography

Materials Science Forum ◽

10.4028/www.scientific.net/msf.654-656.2366 ◽

2010 ◽

Vol 654-656 ◽

pp. 2366-2369 ◽

Cited By ~ 4

Author(s):

Feng Zai Tang ◽

Talukder Alam ◽

Michael P. Moody ◽

Baptiste Gault ◽

Julie M. Cairney

Keyword(s):

Quantitative Analysis ◽

Atom Probe Tomography ◽

Nanocrystalline Materials ◽

Atom Probe ◽

Atomic Scale ◽

Three Dimensions ◽

Specimen Preparation ◽

Compositional Information

Atom probe tomography provides compositional information in three dimensions at the atomic scale, and is therefore extremely suited to the study of nanocrystalline materials. In this paper we present atom probe results from the investigation of nanocomposite TiSi¬Nx coatings and nanocrystalline Al. We address some of the major challenges associated with the study of nanocrystalline materials, including specimen preparation, visualisation, common artefacts in the data and approaches to quantitative analysis. We also discuss the potential for the technique to relate crystallographic information to the compositional maps.

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Nanoscale electrochemical response of lithium-ion cathodes: a combined study using C-AFM and SIMS

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.9.154 ◽

2018 ◽

Vol 9 ◽

pp. 1623-1628 ◽

Cited By ~ 2

Author(s):

Jonathan Op de Beeck ◽

Nouha Labyedh ◽

Alfonso Sepúlveda ◽

Valentina Spampinato ◽

Alexis Franquet ◽

...

Keyword(s):

Energy Storage ◽

Solid State ◽

Lithium Ion ◽

Chemical Information ◽

Battery Cell ◽

Individual Layer ◽

Analysis Techniques ◽

Starting Point ◽

Li Ion ◽

The Impact

The continuous demand for improved performance in energy storage is driving the evolution of Li-ion battery technology toward emerging battery architectures such as 3D all-solid-state microbatteries (ASB). Being based on solid-state ionic processes in thin films, these new energy storage devices require adequate materials analysis techniques to study ionic and electronic phenomena. This is key to facilitate their commercial introduction. For example, in the case of cathode materials, structural, electrical and chemical information must be probed at the nanoscale and in the same area, to identify the ionic processes occurring inside each individual layer and understand the impact on the entire battery cell. In this work, we pursue this objective by using two well established nanoscale analysis techniques namely conductive atomic force microscopy (C-AFM) and secondary ion mass spectrometry (SIMS). We present a platform to study Li-ion composites with nanometer resolution that allows one to sense a multitude of key characteristics including structural, electrical and chemical information. First, we demonstrate the capability of a biased AFM tip to perform field-induced ionic migration in thin (cathode) films and its diagnosis through the observation of the local resistance change. The latter is ascribed to the internal rearrangement of Li-ions under the effect of a strong and localized electric field. Second, the combination of C-AFM and SIMS is used to correlate electrical conductivity and local chemistry in different cathodes for application in ASB. Finally, a promising starting point towards quantitative electrochemical information starting from C-AFM is indicated.

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Analysis Techniques For Nanoscale Solute Clustering In Atom Probe Tomography

Microscopy and Microanalysis ◽

10.1017/s1431927607075770 ◽

2007 ◽

Vol 13 (S02) ◽

Author(s):

A Ceguerra ◽

M Moody ◽

L Stephenson ◽

SP Ringer

Keyword(s):

Atom Probe Tomography ◽

Atom Probe ◽

Analysis Techniques

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Analysis of Radiation Damage in Light Water Reactors: Comparison of Cluster Analysis Methods for the Analysis of Atom Probe Data

Microscopy and Microanalysis ◽

10.1017/s1431927616012678 ◽

2017 ◽

Vol 23 (2) ◽

pp. 366-375 ◽

Cited By ~ 15

Author(s):

Jonathan M. Hyde ◽

Gérald DaCosta ◽

Constantinos Hatzoglou ◽

Hannah Weekes ◽

Bertrand Radiguet ◽

...

Keyword(s):

Cluster Analysis ◽

Radiation Damage ◽

Defect Formation ◽

Chemical Species ◽

Atom Probe ◽

Three Dimensions ◽

Multiple Sources ◽

Damage Models ◽

Combining Data ◽

Water Reactors

AbstractIrradiation of reactor pressure vessel (RPV) steels causes the formation of nanoscale microstructural features (termed radiation damage), which affect the mechanical properties of the vessel. A key tool for characterizing these nanoscale features is atom probe tomography (APT), due to its high spatial resolution and the ability to identify different chemical species in three dimensions. Microstructural observations using APT can underpin development of a mechanistic understanding of defect formation. However, with atom probe analyses there are currently multiple methods for analyzing the data. This can result in inconsistencies between results obtained from different researchers and unnecessary scatter when combining data from multiple sources. This makes interpretation of results more complex and calibration of radiation damage models challenging. In this work simulations of a range of different microstructures are used to directly compare different cluster analysis algorithms and identify their strengths and weaknesses.

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