scholarly journals Nanoscale temperature mapping in operating microelectronic devices

Science ◽  
2015 ◽  
Vol 347 (6222) ◽  
pp. 629-632 ◽  
Author(s):  
Matthew Mecklenburg ◽  
William A. Hubbard ◽  
E. R. White ◽  
Rohan Dhall ◽  
Stephen B. Cronin ◽  
...  
Keyword(s):  
Local Density ◽  
Scanning Transmission Electron Microscope ◽  
Microelectronic Devices ◽  
Transmission Electron ◽  
Glass Bulb ◽  
Statistical Precision ◽  
Bulk Plasmon ◽  
Scanning Transmission ◽  
Nanoscale Features ◽  
Electron Energy Loss

Modern microelectronic devices have nanoscale features that dissipate power nonuniformly, but fundamental physical limits frustrate efforts to detect the resulting temperature gradients. Contact thermometers disturb the temperature of a small system, while radiation thermometers struggle to beat the diffraction limit. Exploiting the same physics as Fahrenheit’s glass-bulb thermometer, we mapped the thermal expansion of Joule-heated, 80-nanometer-thick aluminum wires by precisely measuring changes in density. With a scanning transmission electron microscope and electron energy loss spectroscopy, we quantified the local density via the energy of aluminum’s bulk plasmon. Rescaling density to temperature yields maps with a statistical precision of 3 kelvin/hertz−1/2, an accuracy of 10%, and nanometer-scale resolution. Many common metals and semiconductors have sufficiently sharp plasmon resonances to serve as their own thermometers.

Low Energy Loss Structure of Small Aluminum Particles

1980 ◽  
Vol 38 ◽  
pp. 126-127 ◽  
Author(s):  
P.E. Batson ◽  
M.M.J. Treacy
Keyword(s):  
Energy Loss ◽  
Scanning Transmission Electron Microscope ◽  
Low Energy ◽  
Aluminum Particles ◽  
Transmission Electron ◽  
Bulk Plasmon ◽  
Close Proximity ◽  
Spatial Quantization ◽  
Scanning Transmission ◽  
Electron Energy Loss

Usually, configuration effects are ignored in microanalytical work. That is, the energy loss mechanisms in small volumes are expected to be similar to those in large volumes. However, it is shown elsewhere in these proceedings1 that this assumption is not valid for bulk plasmons in small Al spheres. In fact, ‘configurational’ energy loss effects can dominate the low energy loss region when probing small volumes. These effects include: surface plasmons, bulk plasmon spatial quantization, Schottky barriers, and any other mechanisms that rely on the close proximity of surfaces or interfaces. We have examined the energy loss structure for ˜200Å Al particles (formed as explained in Ref. 1) with the VG Microscopes, Ltd. HB5 scanning transmission electron microscope at 100KeV. The particles consist of single crystal Al cores covered by ˜40Å of Al2O3, and possibly further covered by 5-15Å of carbon contamination. We obtained electron energy loss spectra (EELS), and inelastic scattering images of the particles to correlate the observed EELS structure with the spatial structure and to make a tentative identification of the losses. The spectra were recorded with a probe angular diameter of 8mR (1.4Å−1) and an energy loss resolution of 0.7eV. The images were recorded with an energy loss resolution of 2eV.

High Spatial Resolution Compositional Analysis at Interfaces

1980 ◽  
Vol 38 ◽  
pp. 356-359
Author(s):  
John B. Vander Sande ◽  
Thomas F. Kelly ◽  
Douglas Imeson
Keyword(s):  
Electron Microscope ◽  
High Spatial Resolution ◽  
Compositional Analysis ◽  
Scanning Transmission Electron Microscope ◽  
Thin Specimen ◽  
X Ray ◽  
Volume Of Interest ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Electron Energy Loss

In the scanning transmission electron microscope (STEM) a fine probe of electrons is scanned across the thin specimen, or the probe is stationarily placed on a volume of interest, and various products of the electron-specimen interaction are then collected and used for image formation or microanalysis. The microanalysis modes usually employed in STEM include, but are not restricted to, energy dispersive X-ray analysis, electron energy loss spectroscopy, and microdiffraction.

Variation of the ELNES Under Channeling Conditions

2001 ◽  
Vol 7 (S2) ◽  
pp. 342-343
Author(s):  
S. Köstlmeier ◽  
S. Nufer ◽  
T. Gemming ◽  
M. Rühle
Keyword(s):  
Incident Beam ◽  
Scanning Transmission Electron Microscope ◽  
Orientation Dependence ◽  
Beam Direction ◽  
Rotation Axes ◽  
Transmission Electron ◽  
Anisotropic Solid ◽  
Scanning Transmission ◽  
Electron Energy Loss ◽  
Acceleration Voltage

The orientation dependence of the fine structure of the Al L1 and L2,3 electron energy loss (EELS) edges in (α-Al2O3 has been investigated by measurements with a dedicated scanning transmission electron microscope (VG HB501 STEM, 100 keV acceleration voltage). α-Al2O3 is an anisotropic solid with a complicated alternating stacking sequence of fee Al and hcp O planes along the [0001] direction [1]. This distingiushes the [0001] direction crystallographically, as the highest-order three-fold rotation axes (C3) of the trigonal crystal structure are parallel to [0001], whereas all other symmetry elements are of lower order. Group theory predicts, that more stringent symmetry selection rules apply when electronic transitions are excited by irradiation parallel to the low-index [0001] zone axis than by irradiation along any other arbitrary direction.Yet, even for a low-energy EELS edge (θE = 0.4 mrad) both scattering parallel and perpendicular to the incident beam direction are likely.

Nanochemistry of Ceria Abrasive Particles

2004 ◽  
Vol 818 ◽  
Author(s):  
Shelley R. Gilliss ◽  
James Bentley ◽  
C. Barry
Keyword(s):  
Electron Microscope ◽  
Scanning Transmission Electron Microscope ◽  
White Line ◽  
Abrasive Particles ◽  
Transmission Electron ◽  
Line Intensity Ratio ◽  
Cerium Ion ◽  
Scanning Transmission ◽  
Electron Energy Loss ◽  
Rare Earth Impurities

AbstractSurfaces of ceria (CeO2) particles have been studied by electron energy-loss spectroscopy in a field-emission gun scanning transmission electron microscope. All the ceria particles analyzed contained Ce3+ at the surface. Rare-earth impurities such as La were enriched at the surface and were observed for particles ranging from tens to hundreds of nanometers in size. The oxidation state of the cerium ion is measured from the Ce M5/M4white-line intensity ratio.

Optimization of Acquisition Parameters for Atomic-Column Electron Energy-Loss Spectrum Imaging in a JEM-2200FS Aberration-Corrected Scanning Transmission Electron Microscope

2008 ◽  
Vol 14 (S2) ◽  
pp. 1400-1401 ◽  
Author(s):  
M Watanabe ◽  
M Kanno ◽  
D Ackland ◽  
CJ Kiely ◽  
DB Williams
Keyword(s):  
Electron Microscope ◽  
New Mexico ◽  
Energy Loss ◽  
Scanning Transmission Electron Microscope ◽  
Atomic Column ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Spectrum Imaging ◽  
Electron Energy Loss ◽  
Aberration Corrected

Extended abstract of a paper presented at Microscopy and Microanalysis 2008 in Albuquerque, New Mexico, USA, August 3 – August 7, 2008

Surface resonance channelling in scanning reflection electron microscopy

1988 ◽  
Vol 46 ◽  
pp. 692-693
Author(s):  
J.M. Cowley ◽  
P.A. Crozier
Keyword(s):  
Electron Microscopy ◽  
Crystal Surface ◽  
Scanning Transmission Electron Microscope ◽  
Diffraction Effect ◽  
Transmission Electron ◽  
Surface Resonance ◽  
Scanning Transmission ◽  
Reflection Electron Microscopy ◽  
Resolution Imaging ◽  
Electron Energy Loss

The phenomena of the channelling of electrons along planes or rows of atoms in the surface layers of crystals has been investigated recently in relation to microdiffraction and RHEED, REM, (reflection electron microscopy) and REELS (reflection electron energy loss spectroscopy) by using a conventional TEM in the reflection mode.The renewed interest in this phenomenon, known for many years, is the evidence from calculations of dynamical diffraction effect at surfaces that the electrons may be channelled along the topmost layers of atoms on a crystal surface and that the RHEED, REM and REELS signals may thus be sensitive to the structure and composition of the surface layer. These techniques may therefore provide a powerful new approach to the study of surfaces in which surface microanalysis and diffraction studies may be combined with nanometer-resolution imaging.An investigation has now been made of the analogous techniques which may be applied to the study of surfaces by use of a scanning transmission electron microscope.

Nanometer Scale Composition Variations in Ge Quantum Dots on Si(100)

2002 ◽  
Vol 727 ◽  
Author(s):  
Yangting Zhang ◽  
Margaret Floyd ◽  
Jeff Drucker ◽  
P.A. Crozier ◽  
David J. Smith ◽  
...  
Keyword(s):  
Scanning Transmission Electron Microscope ◽  
Island Size ◽  
Force Microscopy ◽  
Atomic Force ◽  
Linear Behavior ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Electron Energy Loss ◽  
Substrate Temperatures ◽  
Scale Composition

AbstractElectron-energy-loss spectroscopy (EELS) in a scanning transmission electron microscope (STEM) was used to measure nm-scale composition variations in Ge/Si(100) islands grown by molecular beam epitaxy (MBE) at substrate temperatures 400°C ≤T ≤700°C and a growth rate of 1.4 ML/min (1 monolayer, ML=6.78x1014 atoms / cm2). These measurements were correlated with island ensemble morphology determined by atomic force microscopy (AFM). The average Si concentration of the islands and Si/Ge interface width increased monotonically with growth temperature. Integrated island volumes measured by AFM were proportional to the equivalent Ge coverage, øGe, with slopes greater than one for the higher deposition temperatures. This result confirms that the islands grow faster than the Ge deposition rate. Linear behavior of the island volume vs. øGe curves implies that the average Ge composition is independent of island size. The volume at which islands change shape from pyramids to domes correlates well with the average Ge content of the islands in the context of simple strain-scaling arguments. For T=700°C, rapid Si interdiffusion precludes formation of pure Ge pyramids for growth at 1.4 ML/min. Growth at 4.8 ML/min kinetically stabilizes pure Ge pyramid clusters, allowing their formation prior to Si interdiffusion.

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