Depth Sectioning of Individual Dopant Atoms with Aberration-Corrected Scanning Transmission Electron Microscopy

Xin, HL; Intaraprasonk, Varat; Muller, DA

doi:10.1017/s1431927607073631

Cited by 9 publications

(17 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If the shape of the electron probe is not strongly altered by interactions with the sample, an ADF-STEM image can be simulated by using the intensity profile of the unperturbed incident beam as the PSF and convolving it with the specimen. This model is often referred to as an incoherent linear imaging model Black & Linfoot, 1957;Loane et al, 1988;Hillyard & Silcox, 1993;Kirkland, 1998;Xin et al, 2008c;Xin & Muller, 2009!. In a traditional aberration-uncorrected ADF-STEM, the depth of focus is generally much larger than the thickness of 3D Imaging in Aberration-Corrected Electron Microscopes 447 the sample~Fig.…”

Section: D Incoherent Linear Imaging Modelmentioning

confidence: 99%

“…The difference is dramatic as channeling conditions can alter the probe shape so strongly as to sometimes create a nodal point where one would expect it to reach its maximum, or vice versa. As channeling can transform a maximum in the probe profile into a minimum or multiple maxima at incorrect locations~Voyles et al, 2003;Nellist et al, 2008b;Xin et al, 2008bXin et al, , 2008cLupini et al, 2009!, unexpected artifacts can be created when depth sectioning crystalline materials. This is demonstrated in Figure 5b, where the depth-sectioning profile of a single hafnium atom in crystalline silicon~c-Si!…”

Section: Depth Sectioning Of Individual Atoms and Extended Featuresmentioning

confidence: 99%

“…a hafnium atom replaces a silicon atom in c-Si at z ϭ153 Å at zero degree tilt.~c! The sample has been tilted to 28 away from the @110# zone axis.~Panels b and c are reproduced from results published in Xin et al, 2008c.! In the following subsections, we will review and develop a mathematical and a pictorial understanding of the contrast formation mechanisms and the information transfer limit of different SCEM imaging modes.…”

Section: Scem-based Techniquesmentioning

confidence: 99%

“…This short depth of focus could potentially enable a three-dimensional~3D! reconstruction of the underlying sample from a depth sectioning series~van Benthem et al, 2005;Einspahr & Voyles, 2006;Intaraprasonk et al, 2008;Xin et al, 2008c;Behan et al, 2009;Xin & Muller, 2009!. In addition to STEM depth sectioning, there is also interest in the development of scanning confocal electron microscopes~SCEMs! in hopes of further improving the depth resolution~Frigo et Nellist et al, 2006Nellist et al, , 2008aNellist et al, , 2008bCosgriff et al, 2008;D'Alfonso et al, 2008;Takeguchi et al, 2008;Hashimoto et al, 2009;Xin & Muller, 2009;Zaluzec et al, 2009!. A SCEM would use two lenses: one prespecimen lens focusing the electron beam onto the sample and a second postspecimen lens collecting the transmitted electrons forming an image of the perturbed "probe" on the back image plane.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Three-Dimensional Imaging in Aberration-Corrected Electron Microscopes

Xin

Muller

2010

Microsc Microanal

View full text Add to dashboard Cite

This article focuses on the development of a transparent and uniform understanding of possibilities for three-dimensional (3D) imaging in scanning transmission and confocal electron microscopes (STEMs and SCEMs), with an emphasis on the annular dark-field STEM (ADF-STEM), bright-field SCEM (BF-SCEM), and ADF-SCEM configurations. The incoherent imaging approximation and a 3D linear imaging model for ADF-STEM are reviewed. A 3D phase contrast model for coherent-SCEM as well as a pictorial way to find boundaries of information transfer in reciprocal space are reviewed and applied to both BF- and ADF-SCEM to study their 3D point spread functions and contrast transfer functions (CTFs). ADF-STEM is capable of detecting the depths of dopant atoms in amorphous materials but can fail for crystalline materials when channeling substantially modifies the electron propagation. For the imaging of extended (i.e., nonpointlike) features, ADF-STEM and BF-SCEM exhibit strong elongation artifacts due to the missing cone of information. ADF-SCEM shows an improvement over ADF-STEM/BF-SCEM due to its differential phase contrast eliminating slowly varying backgrounds, an effect that partially suppresses the elongation artifacts. However, the 3D CTF still has a cone of missing information that will result in some residual feature elongation as has been observed in A. Hashimoto et al., J Appl Phys 160(8), 086101 (2009).

show abstract

Section: D Incoherent Linear Imaging Modelmentioning

confidence: 99%

Section: Depth Sectioning Of Individual Atoms and Extended Featuresmentioning

confidence: 99%

Section: Scem-based Techniquesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Three-Dimensional Imaging in Aberration-Corrected Electron Microscopes

Xin

Muller

2010

Microsc Microanal

View full text Add to dashboard Cite

show abstract

“…However, objects in focus are rendered sharper in the resulting image. The tradeoff between depth of field and lateral resolution can be problematic for biological samples with a large specimen thickness, especially for tomography (Hyun, et al, 2008); for determining the size distribution of catalysts nanoparticles on electrode supports; or high resolution electron microscopy where the depth of field becomes extremely small (Behan, et al, 2009;Xin, et al, 2008;Xin & Muller, 2009). The lateral resolution improves inversely proportional to the semi-angle of convergence, α max , while the depth of field has a more rapidly-diminishing inverse squared relationship.…”

Section: Introductionmentioning

confidence: 99%

Extended Depth of Field for High-Resolution Scanning Transmission Electron Microscopy

2010

View full text Add to dashboard Cite

Aberration-corrected scanning transmission electron microscopes (STEMs) provide sub-Angstrom lateral resolution; however, the large convergence angle greatly reduces the depth of field. For microscopes with a small depth of field, information outside of the focal plane quickly becomes blurred and less defined. It may not be possible to image some samples entirely in focus. Extended depth-of-field techniques, however, allow a single image, with all areas in focus, to be extracted from a series of images focused at a range of depths. In recent years, a variety of algorithmic approaches have been employed for bright-field optical microscopy. Here, we demonstrate that some established optical microscopy methods can also be applied to extend the ∼ 6 nm depth of focus of a 100 kV 5th-order aberration-corrected STEM (α max = 33 mrad) to image Pt-Co nanoparticles on a thick vulcanized carbon support. These techniques allow us to automatically obtain a single image with all the particles in focus as well as a complimentary topography map.

show abstract

Electron-optical sectioning for three-dimensional imaging of crystal defect structures

Nellist

2017

Materials Science in Semiconductor Processing

View full text Add to dashboard Cite

The depth of field of an optical imaging system is proportional to the inverse square of the numerical aperture. The development of electron-optical devices to correct for the inherent spherical aberration of electron optics has led to a dramatic increase in numerical aperture that therefore also result in dramatic reductions in depth of field. The depth of field of a state-of-the-art system may now reach below 5 nm. An opportunity is therefore created to measure three-dimensional information about a sample by focusing on specific layers within the sample, a process known as optical sectioning. In this short review, we examine some of the properties of the technique, and illustrate its use with a range of applications to semiconducting materials that have been presented in the literature.

show abstract

Depth Sectioning of Individual Dopant Atoms with Aberration-Corrected Scanning Transmission Electron Microscopy

Cited by 9 publications

References 4 publications

Three-Dimensional Imaging in Aberration-Corrected Electron Microscopes

Three-Dimensional Imaging in Aberration-Corrected Electron Microscopes

Extended Depth of Field for High-Resolution Scanning Transmission Electron Microscopy

Electron-optical sectioning for three-dimensional imaging of crystal defect structures

Contact Info

Product

Resources

About