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.

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.

Transfer optics for high spatial resolution electron spectroscopy

1988 ◽  
Vol 46 ◽  
pp. 666-667
Author(s):  
G. G. Hembree ◽  
Luo Chuan Hong ◽  
P.A. Bennett ◽  
J.A. Venables
Keyword(s):  
Magnetic Field ◽  
Scanning Transmission Electron Microscope ◽  
Low Energy ◽  
Objective Lens ◽  
State University ◽  
Arizona State University ◽  
Initial Field ◽  
Resolution Electron ◽  
Scanning Transmission ◽  
Low Energy Electrons

A new field emission scanning transmission electron microscope has been constructed for the NSF HREM facility at Arizona State University. The microscope is to be used for studies of surfaces, and incorporates several surface-related features, including provision for analysis of secondary and Auger electrons; these electrons are collected through the objective lens from either side of the sample, using the parallelizing action of the magnetic field. This collimates all the low energy electrons, which spiral in the high magnetic field. Given an initial field Bi∼1T, and a final (parallelizing) field Bf∼0.01T, all electrons emerge into a cone of semi-angle θf≤6°. The main practical problem in the way of using this well collimated beam of low energy (0-2keV) electrons is that it is travelling along the path of the (100keV) probing electron beam. To collect and analyze them, they must be deflected off the beam path with minimal effect on the probe position.

scholarly journals An Analysis of Li Ion Secondary Battery Materials by Using Focused Ion Beam Micro-sampling Technique and Cold Field Emission Scanning Transmission Electron Microscope

2010 ◽  
Vol 16 (S2) ◽  
pp. 214-215
Author(s):  
T Tanigaki ◽  
K Ito ◽  
K Nakamura ◽  
Y Nagakubo ◽  
J Azuma ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Sampling Technique ◽  
Scanning Transmission Electron Microscope ◽  
Battery Materials ◽  
Secondary Battery ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Li Ion

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

Failure Analysis of a SiC MOS Capacitor with a Poly-Si Gate Electrode

2016 ◽  
Vol 858 ◽  
pp. 485-488
Author(s):  
Soshi Sato ◽  
Kikuo Yamabe ◽  
Tetsuo Endoh ◽  
Masaaki Niwa
Keyword(s):  
Electron Microscope ◽  
Dielectric Breakdown ◽  
Scanning Transmission Electron Microscope ◽  
Oxide Semiconductor ◽  
Constant Current ◽  
Gate Electrode ◽  
Cross Sectional ◽  
Emission Analysis ◽  
Time Dependent Dielectric Breakdown ◽  
Scanning Transmission

The failure mechanism of a SiC metal-oxide-semiconductor capacitor with a poly-Si gate electrode was investigated by time-dependent dielectric breakdown testing under a 200-nA constant current stress. The capacitor exhibited both hard and soft breakdowns. After dielectric breakdown in both cases, adjacent concaves were observed on the capacitor with a field-emission scanning electron microscope. Additional optical beam-induced resistance changes and photo-emission analysis of a capacitor after hard-breakdown located a failure point on the periphery of a group of adjacent concaves. Cross-sectional scanning transmission electron microscope observation revealed that a narrow, vertical defect had formed at this point on the SiC substrate.

scholarly journals Stem-EDX and FIB-SEM Tomography of ALLVAC 718Plus Superalloy

2016 ◽  
Vol 61 (2) ◽  
pp. 535-542 ◽  
Author(s):  
A. Kruk ◽  
G. Cempura ◽  
S. Lech ◽  
A. Czyrska -Filemonowicz
Keyword(s):  
Electron Microscope ◽  
Focused Ion Beam ◽  
Electron Tomography ◽  
Ion Beam ◽  
High Strength ◽  
Strengthening Mechanism ◽  
Scanning Transmission Electron Microscope ◽  
Particle Analysis ◽  
Transmission Electron ◽  
Scanning Transmission

Abstract Allvac 718Plus (718Plus) is a high strength, corrosion resistant nickel- based superalloy used for application in power generation, aeronautics and aerospace industry. The 718Plus microstructure consists of a γ matrix with γ’-Ni3(Al,Ti) and some δ- Ni3Nb phases as well as lamellar particles (η-Ni3Ti, η*-Ni6AlNb or Ni6(Al,Ti)Nb) precipitated at the grain boundaries. The primary strengthening mechanism for this alloy is a precipitation hardening, therefore size and distribution of precipitates are critical for the performance of the alloy. The aim of this study was to characterize precipitates in the 718Plus superalloy using Scanning Transmission Electron Microscope combined with Energy Dispersive X-ray Spectroscopy (STEM-EDX) and Focused Ion Beam Scanning Electron Microscope (FIB-SEM). The STEM-EDX and FIB-SEM tomography techniques were used for 3D imaging and metrology of the precipitates. Transmission electron microscopy and EDX spectroscopy were used to reveal details of the 718Plus microstructure and allow determine chemical composition of the phases. The study showed that electron tomography techniques permit to obtain complementary information about microstructural features (precipitates size, shape and their 3D distribution) in the reconstructed volume with comparison to conventional particle analysis methods, e.g. quantitative TEM and SEM metallography

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.

FIB Micro-Pillar Sampling of Si Devices and its 3D Observation

2003 ◽  
Author(s):  
T. Yaguchi ◽  
T. Kamino ◽  
T. Ohnishi ◽  
T. Hashimoto ◽  
K. Umemura ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Three Dimensional ◽  
Sampling Technique ◽  
Scanning Transmission Electron Microscope ◽  
Dark Field ◽  
Limiting Factor ◽  
Sem Images ◽  
Cross Sectional ◽  
Scanning Transmission

Abstract A novel technique for three-dimensional structural and elemental analyses using a dedicated focused ion beam (FIB) and scanning transmission electron microscope (STEM) has been developed. The system employs an FIB-STEM compatible sample holder with sample stage rotation mechanism. A piece of sample (micro sample) is extracted from the area to be characterized by the micro-sampling technique [1-3]. The micro sample is then transferred onto the tip of the stage (needle stage) and bonded by FIB assisted metal deposition. STEM observation of the micro sample is carried out after trimming the sample into a micro-pillar 2-5 micron squared in cross-section and 10 -15 micron in length (micro-pillar sample). High angle annular dark field (HAADF) STEM, bright field STEM and secondary electron microscopy (SEM) images are obtained at 200kV resulting in threedimensional and cross sectional representations of the microsample. The geometry of the sample and the needle stage allows observation of the sample from all directions. The specific site can be located for further FIB milling whenever it is required. Since the operator can choose materials for the needle stage, the geometry of the original specimen is not a limiting factor for quantitative energy dispersive X-ray (EDX) analysis.

The Method for Retaining an Intermittent Electrical Failure Signature during the Interconnect Immobilization Process throughout Failure Analysis

2009 ◽  
Author(s):  
Julie Schuchman ◽  
Julie Willis
Keyword(s):  
Sample Preparation ◽  
First Generation ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Scanning Transmission Electron Microscope ◽  
Electrical Failure ◽  
Dual Beam ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Material Sample

Abstract This paper deals primarily with the difficulties and solutions to scanning transmission electron microscope (STEM) sample preparation by dual beam focused ion beam. Approximately twenty major challenges were encountered spanning hardware, software, and material sample preparation. The main focus is upon the variety of challenges which are encountered in trying to implement automated STEM and TEM sample fabrication with minimal operator input and the engineering solutions implemented to overcome these challenges. The automated STEM script has evolved significantly from the first generation attempt and is described in more detail in this paper. The mechanical, software, and materials challenges encountered are also presented. The paper highlights a mechanical issue with the ion aperture motor mechanism, which required extensive troubleshooting to fully diagnose and correct. A long standing software routine had to be modified to fully enable script automation by extending the beam dwell time of the automatic brightness contrast routine.

scholarly journals Characterization of online high dynamic range imaging for laser-driven ion beam diagnostics using visible light

2017 ◽  
Vol 3 (2) ◽  
pp. 343-346
Author(s):  
Franz Englbrecht ◽  
Felix Balling ◽  
Thomas Federico Rösch ◽  
Matthias Würl ◽  
Florian Hans Lindner ◽  
...  
Keyword(s):  
Spatial Information ◽  
Dynamic Range ◽  
Ion Beam ◽  
Complementary Metal Oxide Semiconductor ◽  
Laser Pulses ◽  
High Dynamic Range ◽  
Oxide Semiconductor ◽  
Beam Diagnostics ◽  
Spatially Resolved ◽  
Single Frame

AbstractLaser-driven acceleration of particle beams is an emerging modality under research for biomedical applications. The spatially resolved diagnostics of laser-accelerated proton bunches is crucial for their application. The RadEye detector, featuring up to 10 cm x 5 cm area of online complementary metal-oxide-semiconductor (CMOS) detector made of 48 μm pixels, is established for x-ray, proton and ion beam diagnostics. We exploit the usually undesired ‘Image lag’ phenomenon of incomplete pixel reset to generate 2D-images with a larger dynamic range than the single frame range of 12-bit. Using 532 nm laser pulses and computer simulations for single-slit diffraction, calibration factors to stack multiple readouts were successfully derived to quantitatively reconstruct spatial information about an optical beam and hence extend the dynamic range of the detector compared to a single frame. The final goal is focus quantification for a permanent magnet quadrupole system for protons and terawatt (TW-class) laser focus diagnostics.

n-wells voltage contrast imaging with a Focused Ion Beam

2003 ◽  
Vol 792 ◽  
Author(s):  
Erwan Le Roy ◽  
Mark Thompson
Keyword(s):  
Integrated Circuits ◽  
Focused Ion Beam ◽  
Silicon Oxide ◽  
Ion Beam ◽  
Oxide Thickness ◽  
Oxide Semiconductor ◽  
Contrast Imaging ◽  
Oxide Interface ◽  
Capacitive Properties ◽  
Capacitive Effect

Using a focused ion beam (FIB), secondary electron (SE) imaging of n-wells under oxide from the backside of thinned integrated circuits without electrical bias was accomplished. From the backside, the n-wells were initially observed at a remaining silicon thickness ∼4.5μm, which correlates to the actual implant depth where n and p carrier concentrations are equal. When the wells were FIB imaged, contrast appeared dark relative to the p substrate. During deposition of the oxide film, the n-well brightness changed from dark relative to the p-substrate, to bright. It appears that initially during this deposition step the interaction volume of the beam reached the silicon/oxide interface to create tunneling electrons. This phenomenon dominated the capacitive effect. Then as the film thickness increased the capacitive effect prevailed. The imaging structure is analogous to a Metal-Oxide-Semiconductor (MOS) capacitor. The n- and p-MOS capacitive properties yielded a permanent imaging contrast. At an optimized oxide thickness (130nm), the n-wells appear white relative to the p-substrate with a contrast up to 85% {(Ip-substrate − In-wells)/(Ipsubstrate + In-wells)}.

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