scholarly journals Oxidation of Si nanocrystals fabricated by ultra-low energy ion implantation in thin SiO2 layers

2004 ◽  
Vol 830 ◽  
Author(s):  
H. Coffin ◽  
C. Bonafos ◽  
S. Schamm ◽  
N. Cherkashin ◽  
M. Respaud ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Structural Characteristics ◽  
Scanning Transmission Electron Microscope ◽  
Chemical Oxidation ◽  
Low Energy ◽  
Annealing Duration ◽  
Spatially Resolved ◽  
Transmission Electron ◽  
Si Nanocrystals ◽  
Scanning Transmission

ABSTRACTThe effect of annealing in diluted oxygen on the structural characteristics of thin silicon dioxide layers with embedded Si nanocrystals fabricated by ultra-low energy ion implantation (1 keV) is reported. The nanocrystal characteristics (size, density, coverage) have been measured by spatially resolved Electron Energy Loss Spectroscopy using the spectrum-imaging mode of a Scanning Transmission Electron Microscope. Their evolution has been studied as a function of the annealing duration under N2+O2 at 900°C. An extended spherical Deal-Grove model for the self-limiting oxidation of embedded silicon nanocrystals has been carried out. It shows that stress effects, due to the deformation of the oxide, slows down the chemical oxidation rate and leads to a self-limiting oxide growth. The model predictions show a good agreement with the experimental results.

Microstructural and Compositional Characterization of SiC-On-Insulator Structures

1999 ◽  
Vol 5 (S2) ◽  
pp. 770-771
Author(s):  
Manabu Ishimaru ◽  
Robert M. Dickerson ◽  
Kurt E. Sickafus
Keyword(s):  
Ion Implantation ◽  
Integrated Circuit ◽  
High Speed ◽  
Scanning Transmission Electron Microscope ◽  
Oxygen Ions ◽  
Oxygen Ion ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Oxygen Ion Implantation

As the size of Si integrated circuit structures is continually reduced, interest in semiconductor-oninsulator (SOI) structures has heightened. SOI structures have already been developed for Si using oxygen ion implantation. However, the application of Si devices is limited due to the physical properties of Si. As an alternative to Si, SiC is a potentially important semiconductor for high-power, high-speed, and high-temperature electronic devices. Therefore, this material is a candidate for expanding the capabilities of Si-based technology. In this study, we performed oxygen ion implantation into bulk SiC to produce SiC-on-insulator structures. We examined the microstructures and compositional distributions in implanted specimens using transmission electron microscopy and a scanning transmission electron microscope equipped with an energy-dispersive X-ray spectrometer (STEM-EDX).Figures 1(a) and 2(a) show bright-field images of 6H-SiC implanted with 180 keV oxygen ions at 650 °C to fluences of 7xl017 and 1.4xl018 cm−2, respectively. Three regions with distinct image contrast are apparent in Figs. 1(a) and 2(a), as indicated by A, B, and C.

Identification of site-specific isotopic labels by vibrational spectroscopy in the electron microscope

Science ◽  
2019 ◽  
Vol 363 (6426) ◽  
pp. 525-528 ◽  
Author(s):  
Jordan A. Hachtel ◽  
Jingsong Huang ◽  
Ilja Popovs ◽  
Santa Jansone-Popova ◽  
Jong K. Keum ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Spatial Resolution ◽  
Theoretical Calculations ◽  
Scanning Transmission Electron Microscope ◽  
Real Space ◽  
Site Specific ◽  
Spatially Resolved ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Isotopic Labels

The identification of isotopic labels by conventional macroscopic techniques lacks spatial resolution and requires relatively large quantities of material for measurements. We recorded the vibrational spectra of an α amino acid, l-alanine, with damage-free “aloof” electron energy-loss spectroscopy in a scanning transmission electron microscope to directly resolve carbon-site–specific isotopic labels in real space with nanoscale spatial resolution. An isotopic red shift of 4.8 ± 0.4 milli–electron volts in C–O asymmetric stretching modes was observed for 13C-labeled l-alanine at the carboxylate carbon site, which was confirmed by macroscopic infrared spectroscopy and theoretical calculations. The accurate measurement of this shift opens the door to nondestructive, site-specific, spatially resolved identification of isotopically labeled molecules with the electron microscope.

Evolution of Quantum Electronic Features with the Size of Silicon Nanoparticles Embedded in a SiO2 Layer Obtained by Low Energy Ion Implantation

2005 ◽  
Vol 108-109 ◽  
pp. 71-76 ◽  
Author(s):  
Jeremie Grisolia ◽  
M. Shalchian ◽  
G. Benassayag ◽  
H. Coffin ◽  
Caroline Bonafos ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Electrical Transport ◽  
Silicon Nanoparticles ◽  
Structural Characteristics ◽  
Tunneling Current ◽  
Mos Capacitor ◽  
Quantum Electronic ◽  
Ultralow Energy ◽  
Spatially Resolved ◽  
Transmission Electron

In this paper, we have studied the evolution of quantum electronic features with the size of silicon nanoparticles embedded in an ultra-thin SiO2 layer. These nanoparticles were synthesized by ultralow energy (1 KeV) ion implantation and annealing. Their size was modified using the effect of annealing under slightly oxidizing ambient (N2+O2). Material characterization techniques including transmission electron microscopy (TEM) Fresnel imaging and spatially resolved electron energy loss spectroscopy (EELS) have been used to evaluate the effects of oxidation on structural characteristics of nanocrystal layer. Electrical transport characteristics have been measured on few (less than two hundred) nanoparticles by exploiting a nanoscale MOS capacitor as a probe. Top electrode of this nanoscale capacitor (100 nm x 100 nm) was patterned over the samples by electron-beam nanolithography. Room temperature I-V and I-t characteristics of these structures exhibit discrete current peaks which have been interpreted by quantized charging of the nanoparticles and electrostatic interaction between the trapped charges and the tunneling current. The effects of progressive oxidation on these current features have been studied and discussed.

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.

Manipulation of 2D arrays of Si nanocrystals by ultra-low-energy ion beam-synthesis for nonvolatile memories applications

2004 ◽  
Vol 830 ◽  
Author(s):  
C. Bonafos ◽  
N. Cherkashin ◽  
M. Carrada ◽  
H. Coffin ◽  
G. Ben Assayag ◽  
...  
Keyword(s):  
Ion Beam ◽  
Oxide Thickness ◽  
Scanning Transmission Electron Microscope ◽  
Low Energy ◽  
Oxide Semiconductor ◽  
Characterization Methods ◽  
Spatially Resolved ◽  
Scanning Transmission ◽  
Fine Control ◽  
2D Arrays

ABSTRACTIn silicon nanocrystal (nc) based metal-oxide-semiconductor (MOS) memory structures a fine control of the Si nc location in the gate oxide is required for the pinpointing of optimal device architectures. In this work, we show how to manipulate and control the depth-position, size and surface density of two dimensional (2D) arrays of Si ncs embedded in thin (<10 nm) SiO2 layers, fabricated by ultra-low-energy (typically 1 keV) ion implantation and subsequent annealing. Particular emphasis is placed upon the influence of implantation, annealing conditions and oxide thickness on the nanocrystal characteristics (e.g. size, density) and the charge storage properties of associated MOS structures. Structural investigation is performed by using specific characterization methods including Fresnel imaging for the measurement of the injection distance between the substrate and the nc band, as well as spatially resolved Electron Energy Loss Spectroscopy using the spectrum-imaging mode of a Scanning Transmission Electron Microscope to evaluate the size distribution and density of the ncs.

Tuning Fifth-Order Aberrations in a Quadrupole-Octupole Corrector

2012 ◽  
Vol 18 (4) ◽  
pp. 699-704 ◽  
Author(s):  
Andrew R. Lupini ◽  
Stephen J. Pennycook
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Spherical Aberration ◽  
Scanning Transmission Electron Microscope ◽  
Low Energy ◽  
Third Order ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Electron Microscopes ◽  
Fifth Order

AbstractThe resolution of conventional electron microscopes is usually limited by spherical aberration. Microscopes equipped with aberration correctors are then primarily limited by higher order, chromatic, and misalignment aberrations. In particular the Nion third-order aberration correctors installed on machines with a low energy spread and possessing sophisticated alignment software were limited by the uncorrected fifth-order aberrations. Here we show how the Nion fifth-order aberration corrector can be used to adjust and reduce some of the fourth- and fifth-order aberrations in a probe-corrected scanning transmission electron microscope.

Analytical electron microscopy of planar faults in SrO-doped CaTiO3

1997 ◽  
Vol 12 (9) ◽  
pp. 2438-2446 ◽  
Author(s):  
M. Čeh ◽  
H. Gu ◽  
H. Müllejans ◽  
A. Rečnik
Keyword(s):  
Electron Microscopy ◽  
Perovskite Phase ◽  
Analytical Electron Microscopy ◽  
Scanning Transmission Electron Microscope ◽  
Extended Defects ◽  
Spatially Resolved ◽  
Transmission Electron ◽  
Analytical Electron ◽  
Scanning Transmission ◽  
Ca Ions

Oxide-rich planar faults within a perovskite matrix are the prevailing type of extended defects in polycrystalline SrO-doped CaTiO3. These defects form, depending on the temperature of sintering, random networks, or ordered structures. The chemistry of the polytypoid, the isolated planar faults, and the perovskite phase have been studied by spatially resolved electron energy-loss and energy-dispersive x-ray spectroscopies using a dedicated scanning transmission electron microscope. We have found that Sr ions from SrO additions preferably substitute Ca in the CaTiO3 lattice, thus forming a solid solution (Ca1–xSrx)TiO3. The surplus of Ca ions forms single and ordered CaO-rich planar faults in the host (Ca1–xSrx)TiO3 phase. Whereas the excess Ca segregates in a form of single planar faults at lower temperatures, it forms a stable polytypoidic phase at higher temperatures. For materials having up to 25 mol% of SrO additions, this phase has (Ca1–xSrx)4Ti3O10 composition, comprising a sequence of CaO faults followed by three (Ca1–xSrx)TiO3 perovskite layers. Analytical electron microscopy revealed that the composition of the single planar faults, formed at lower temperatures, is identical to that of polytypoids, which are stable at higher sintering temperatures.

Direct Imaging of “Explosively” Propagating Buried Molten Layers In Amorphous Silicon Using Optical, Tem And Ion Backscattering Measurements

1985 ◽  
Vol 51 ◽  
Author(s):  
D. H. Lowndes ◽  
G. E. Jellison ◽  
S. J. Pennycook ◽  
S. P. Withrow ◽  
D. N. Mashburn ◽  
...  
Keyword(s):  
Laser Energy ◽  
Maximum Velocity ◽  
Scanning Transmission Electron Microscope ◽  
Time Resolved ◽  
Spatially Resolved ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Subsequent Motion ◽  
Z Contrast ◽  
Ion Backscattering

ABSTRACTThe behavior of pulsed laser-induced “explosively” propagating buried molten layers (BL) in ion implantation-amorphized silicon has been studied in a time- and spatially-resolved way, using nanosecond time-resolved reflectivity measurements, “Z-contrast” scanning transmission electron microscope (STEM) imaging of implanted Cu ions transported by the BL, and helium ion backscattering measurements. Infrared (1152 nm) reflectivity measurements allow the initial formation and subsequent motion of the BL to be followed continuously in time. The BL velocity is found to be a function of both its depth below the surface and of the incident KrF laser energy density (El); a maximum velocity of about 14 m/s is observed, implying an undercoolingvelocity relationship of about 14 K/(m/s). Z-contrast STEM measurements show that the final BL thickness is less than 15 nm. Time-resolved optical, TEM and ion backscattering measurements of the final BL depth, as a function of E1, are also found to be in excellent agreement with one another.

Highly spatially resolved Cathodoluminescence of Single GaN Quantum Dots directly performed in a Scanning Transmission Electron Microscope

2012 ◽  
Vol 18 (S2) ◽  
pp. 1878-1879 ◽  
Author(s):  
G. Schmidt ◽  
M. Müller ◽  
F. Bertram ◽  
P. Veit ◽  
S. Petzold ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Scanning Transmission Electron Microscope ◽  
Scanning Transmission Electron ◽  
Spatially Resolved ◽  
Transmission Electron ◽  
Scanning Transmission

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

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