Application of Focused Ion Beam to Atom Probe Tomography Specimen Preparation from Mechanically Alloyed Powders

2007 ◽  
Vol 13 (5) ◽  
pp. 347-353 ◽  
Author(s):  
Pyuck-Pa Choi ◽  
Tala'at Al-Kassab ◽  
Young-Soon Kwon ◽  
Ji-Soon Kim ◽  
Reiner Kirchheim
Keyword(s):  
Atom Probe Tomography ◽  
Structural Changes ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Atom Probe ◽  
High Energy ◽  
Specimen Preparation ◽  
Mechanically Alloyed ◽  
Cross Sectional ◽  
Beam Currents

Focused ion-beam milling has been applied to prepare needle-shaped atom probe tomography specimens from mechanically alloyed powders without the use of embedding media. The lift-out technique known from transmission electron microscopy specimen preparation was modified to cut micron-sized square cross-sectional blanks out of single powder particles. A sequence of rectangular cuts and annular milling showed the highest efficiency for sharpening the blanks to tips. First atom probe results on a Fe95Cu5 powder mechanically alloyed in a high-energy planetary ball mill for 20 h have been obtained. Concentration profiles taken from this powder sample showed that the Cu distribution is inhomogeneous on a nanoscale and that the mechanical alloying process has not been completed yet. In addition, small clusters of oxygen, stemming from the ball milling process, have been detected. Annular milling with 30 keV Ga ions and beam currents ≥50 pA was found to cause the formation of an amorphous surface layer, whereas no structural changes could be observed for beam currents ≤10 pA.

The Effect of Implanted Gallium on the Recrystallization of Amorphous Layers formed during FIB Milling of Silicon

2001 ◽  
Vol 7 (S2) ◽  
pp. 958-959
Author(s):  
S. Rubanov ◽  
P.R. Munroe
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Amorphous Layer ◽  
High Energy ◽  
Specimen Preparation ◽  
Silicon Sample ◽  
Cross Sectional ◽  
Wide Range ◽  
Average Size ◽  
Beam Currents

The focused ion beam (FIB) miller allows preparation of site-specific transmission electron microscopy (TEM) specimens from a wide range of materials in both cross-sectional and planar configurations [1,2]. However, radiation damage during exposure to the high-energy gallium beam may result in the formation of amorphous regions on thin film specimens. The thickness of such damage layers, on both sides of a TEM specimen, is comparable with the thickness required for lattice imaging. For example, the thickness of an amorphous layer in Si after 30 kV Ga+ FIB processing has been reported in the range from 15 [3] to 28 nm [4]. This problem limits the capabilities of FIB sample fabrication.The aim of this study was to investigate, in detail, the structure, composition and the thickness of the damage layers in Si specimens after milling with a gallium ion beam. Using a FEI xP200 FIB system, with 30 kV Ga+ ions, a row of trenches on a silicon sample was milled under different beam currents ranging from 150 to 6600 pA. The average size of such trenches was 15×10 μm wide and 1 μm deep. The trenches were then removed from the FIB and sputter coated with a thick Au film to preserve the trench surfaces from further damage during subsequent TEM specimen preparation steps. Cross-sectional TEM specimens of the trench walls were then prepared using standard FIB procedures [5]. Observations were made using a Philips CM 200 Field Emission Gun TEM operating at an accelerating voltage of 200 kV.

scholarly journals Practical Issues for Atom Probe Tomography Analysis of III-Nitride Semiconductor Materials

2015 ◽  
Vol 21 (3) ◽  
pp. 544-556 ◽  
Author(s):  
Fengzai Tang ◽  
Michael P. Moody ◽  
Tomas L. Martin ◽  
Paul A.J. Bagot ◽  
Menno J. Kappers ◽  
...  
Keyword(s):  
Atom Probe Tomography ◽  
Focused Ion Beam ◽  
Laser Energy ◽  
Ion Beam ◽  
Atom Probe ◽  
Specimen Preparation ◽  
Chemical Compositions ◽  
Pole Structure ◽  
Gan Heterostructure ◽  
Ga Content

AbstractVarious practical issues affecting atom probe tomography (APT) analysis of III-nitride semiconductors have been studied as part of an investigation using a c-plane InAlN/GaN heterostructure. Specimen preparation was undertaken using a focused ion beam microscope with a mono-isotopic Ga source. This enabled the unambiguous observation of implantation damage induced by sample preparation. In the reconstructed InAlN layer Ga implantation was demonstrated for the standard “clean-up” voltage (5 kV), but this was significantly reduced by using a lower voltage (e.g., 1 kV). The characteristics of APT data from the desorption maps to the mass spectra and measured chemical compositions were examined within the GaN buffer layer underlying the InAlN layer in both pulsed laser and pulsed voltage modes. The measured Ga content increased monotonically with increasing laser pulse energy and voltage pulse fraction within the examined ranges. The best results were obtained at very low laser energy, with the Ga content close to the expected stoichiometric value for GaN and the associated desorption map showing a clear crystallographic pole structure.

scholarly journals Laser-assisted atom probe tomography of semiconductors: The impact of the focused-ion beam specimen preparation

2018 ◽  
Vol 188 ◽  
pp. 19-23 ◽  
Author(s):  
J. Bogdanowicz ◽  
A. Kumar ◽  
C. Fleischmann ◽  
M. Gilbert ◽  
J. Houard ◽  
...  
Keyword(s):  
Atom Probe Tomography ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Atom Probe ◽  
Beam Specimen ◽  
Specimen Preparation ◽  
The Impact

Implementing Transmission Electron Backscatter Diffraction for Atom Probe Tomography

2016 ◽  
Vol 22 (3) ◽  
pp. 583-588 ◽  
Author(s):  
Katherine P. Rice ◽  
Yimeng Chen ◽  
Ty J. Prosa ◽  
David J. Larson
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Atom Probe Tomography ◽  
Focused Ion Beam ◽  
Electron Backscatter Diffraction ◽  
Ion Beam ◽  
Atom Probe ◽  
Specimen Preparation ◽  
Inconel 600 ◽  
Transmission Electron

AbstractThere are advantages to performing transmission electron backscattering diffraction (tEBSD) in conjunction with focused ion beam-based specimen preparation for atom probe tomography (APT). Although tEBSD allows users to identify the position and character of grain boundaries, which can then be combined with APT to provide full chemical and orientation characterization of grain boundaries, tEBSD can also provide imaging information that improves the APT specimen preparation process by insuring proper placement of the targeted grain boundary within an APT specimen. In this report we discuss sample tilt angles, ion beam milling energies, and other considerations to optimize Kikuchi diffraction pattern quality for the APT specimen geometry. Coordinated specimen preparation and analysis of a grain boundary in a Ni-based Inconel 600 alloy is used to illustrate the approach revealing a 50° misorientation and trace element segregation to the grain boundary.

Modern Focused-Ion-Beam-Based Site-Specific Specimen Preparation for Atom Probe Tomography

2017 ◽  
Vol 23 (2) ◽  
pp. 194-209 ◽  
Author(s):  
Ty J. Prosa ◽  
David J. Larson
Keyword(s):  
Atom Probe Tomography ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Short Review ◽  
Atom Probe ◽  
Specimen Preparation ◽  
Transmission Electron ◽  
Milling Method ◽  
Key Steps ◽  
Backscatter Diffraction

AbstractApproximately 30 years after the first use of focused ion beam (FIB) instruments to prepare atom probe tomography specimens, this technique has grown to be used by hundreds of researchers around the world. This past decade has seen tremendous advances in atom probe applications, enabled by the continued development of FIB-based specimen preparation methodologies. In this work, we provide a short review of the origin of the FIB method and the standard methods used today for lift-out and sharpening, using the annular milling method as applied to atom probe tomography specimens. Key steps for enabling correlative analysis with transmission electron-beam backscatter diffraction, transmission electron microscopy, and atom probe tomography are presented, and strategies for preparing specimens for modern microelectronic device structures are reviewed and discussed in detail. Examples are used for discussion of the steps for each of these methods. We conclude with examples of the challenges presented by complex topologies such as nanowires, nanoparticles, and organic materials.

Comparison of Focused Ion Beam and Conventional Techniques on Tem Specimen Preparation of Metal-Ceramic Interfaces

1998 ◽  
Vol 4 (S2) ◽  
pp. 860-861 ◽  
Author(s):  
A. Ramirez de Arellano López ◽  
W.-A. Chiou ◽  
K. T. Faber
Keyword(s):  
Focused Ion Beam ◽  
Ceramic Coating ◽  
Steel Substrate ◽  
Ion Beam ◽  
Specimen Preparation ◽  
Inhomogeneous Materials ◽  
Cross Sectional ◽  
Fine Grain ◽  
Basic Industry ◽  
Coated Surface

The results of TEM analyses of materials are critically dependent on the quality of the sample prepared. Although numerous techniques have been developed in the last two decades, differential thinning of inhomogeneous materials remains a serious problem. Recently, focused ion beam (FIB) technique has been introduced for cross-sectional sample preparation for TEM and SEM.A novel system for depositing a fine-grain (∼ 200 nm) ceramic coating on a metal surface via a patent pending Small-Particle Plasma Spray (SPPS) technique has been developed at the Basic Industry Research Laboratory of Northwestern University. To understand the properties of the coated surface, the ceramic/metal interface and the microstructure of the ceramic coating must be investigated. This paper presents a comparison of the microstructure of an A12O3 coating on a mild steel substrate prepared using conventional and FEB techniques.

Automated Sample Depth Targeting with Low kV Cleaning by Focused Ion Beam Microscopy for Atom Probe Tomography

2020 ◽  
Author(s):  
Woo Jun Kwon ◽  
Jisu Ryu ◽  
Christopher H. Kang ◽  
Michael B. Schmidt ◽  
Nicholas Croy
Keyword(s):  
Sample Preparation ◽  
Atom Probe Tomography ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Region Of Interest ◽  
Atom Probe ◽  
Sample Volume ◽  
Cleaning Process ◽  
Site Specific ◽  
Sample Depth

Abstract Focused ion beam (FIB) microscopy is an essential technique for the site-specific sample preparation of atom probe tomography (APT). The site specific APT and automated APT sample preparation by FIB have allowed increased APT sample volume. In the workflow of APT sampling, it is very critical to control depth of the sample where exact region of interest (ROI) for accurate APT analysis. Very precise depth control is required at low kV cleaning process in order to remove the damaged layer by previous high kV FIB process steps. We found low kV cleaning process with 5 kV and followed by 2kV beam conditions delivers better control to reached exact ROI on Z direction. This understanding is key to make APT sample with fully automated fashion.

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