High-energy-resolution monochromator for aberration-corrected scanning transmission electron microscopy/electron energy-loss spectroscopy

2009 ◽  
Vol 367 (1903) ◽  
pp. 3683-3697 ◽  
Author(s):  
Ondrej L. Krivanek ◽  
Jonathan P. Ursin ◽  
Neil J. Bacon ◽  
George J. Corbin ◽  
Niklas Dellby ◽  
...  
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Energy Resolution ◽  
Electron Energy Loss Spectroscopy ◽  
High Energy ◽  
High Energy Resolution ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Electron Energy Loss

An all-magnetic monochromator/spectrometer system for sub-30 meV energy-resolution electron energy-loss spectroscopy in the scanning transmission electron microscope is described. It will link the energy being selected by the monochromator to the energy being analysed by the spectrometer, without resorting to decelerating the electron beam. This will allow it to attain spectral energy stability comparable to systems using monochromators and spectrometers that are raised to near the high voltage of the instrument. It will also be able to correct the chromatic aberration of the probe-forming column. It should be able to provide variable energy resolution down to approximately 10 meV and spatial resolution less than 1 Å.

Analysis of AlxGa1-xN nanowires through simulated methods of scanning transmission electron microscopy and electron energy-loss spectroscopy

2013 ◽  
Vol 6 (1) ◽  
Author(s):  
R. Kumar ◽  
P.J. Phillips ◽  
R.F. Klie
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Scanning Transmission Electron Microscopy ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Electron Energy Loss

AlxGa1-xN nanowires have promising applications in ultraviolet light emitting diodes (LEDs). However, these nanowires are not typical p-n junction semiconductors, but rather rely on varying concentrations of Al versus Ga to produce electron hole pairs. More information on the atomic structure is needed to better understand the properties of these nanowires. In this study, AlxGa1-xN nanowires were imaged using scanning transmission electron microscopy (STEM) and compared to computer simulated STEM images to obtain physical information on the nanowires. Electron energy-loss spectroscopy (EELS) and FEFF9 computer simulations were also performed to better understand the structural and chemical properties of the nanowires. Results from these simulations showed that changes in the chemical ordering of the nanowires were responsible for changes in intensity and resolution in the images. These intensity and resolution trends were not a result of interface effects. This will help to further characterize nanowires in the future.

ELECTRON ENERGY LOSS SPECTROSCOPY AND ANNULAR DARK FIELD IMAGING AT A NANOMETER RESOLUTION IN A SCANNING TRANSMISSION ELECTRON MICROSCOPE

2000 ◽  
Vol 07 (04) ◽  
pp. 475-494 ◽  
Author(s):  
O. STÉPHAN ◽  
A. GLOTER ◽  
D. IMHOFF ◽  
M. KOCIAK ◽  
C. MORY ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Energy Loss ◽  
Electron Energy ◽  
Transmission Electron Microscope ◽  
Electron Energy Loss Spectroscopy ◽  
Scanning Transmission Electron Microscope ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Electron Energy Loss

The basics of electron energy loss spectroscopy (EELS) performed in the context of a scanning transmission electron microscope are described. This includes instrumentation, information contained in an EELS spectrum, data acquisition and processing, and some illustrations by a few examples.

Antimony Delta Doping by Scanning Transmission Electron Microscopy and Electron Energy Loss Spectroscopy

1999 ◽  
Vol 5 (S2) ◽  
pp. 614-615
Author(s):  
R.R. Vanfleet ◽  
D. Muller ◽  
H.-J. Gossmann ◽  
J. Silcox
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Spatial Resolution ◽  
Electron Energy Loss Spectroscopy ◽  
Two Dimensional ◽  
Layer Width ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Electron Energy Loss

MBE techniques allow the fabrication of exceptionally sharp compositional changes such as delta doped layers in semiconductors. Producing these spatially confined doped layers is critical to many innovative device designs. The spatial confinement of these delta doped structures can be less than the measurement resolution of the currently standard SIMS and RBS techniques. This allows only the upper limits on the layer width to be measured. These SIMS and RBS methods are also inadequate for the two dimensional information desired for future device design and development. More recently developed techniques such as Scanning Capacitance Microscopy and spreading resistance measurement give two dimensional information but have similar spatial resolution issues. The Z-contrast nature of Annular Dark Field (ADF) imaging with the complimentary technique of Electron Energy Loss Spectroscopy (EELS) in the Scanning Transmission Electron Microscope (STEM) shows promise for two dimensional dopant profiling with spatial resolution on the atomic scale.

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