Phosphorus Diffusion From Doped Si1−xGex, Films into Silicon

1999 ◽  
Vol 568 ◽  
Author(s):  
S. Kobayashi ◽  
M. Iizuka ◽  
T. Aoki ◽  
N. Mikoshiba ◽  
M. Sakuraba ◽  
...  
Keyword(s):  
Differential Resistance ◽  
High Concentration ◽  
Phosphorus Diffusion ◽  
P Concentration ◽  
Diffusion Characteristics ◽  
P Diffusion ◽  
Concentration Diffusion ◽  
Secondary Ion ◽  
Diffusion Profiles

ABSTRACTPhosphorus diffusion from in-situ doped Si1−xGex epitaxial films into Si at 800°C was investigated using secondary ion mass spectroscopy and differential resistance measurements. The surface P concentration in the diffused layer in Si was higher than the P concentration in the Si1−xGex, film in the present conditions, which signifies the segregation of P from the Si1−xGex, film into Si. The segregation coefficient, defined as the ratio of the active P concentration in the Si to that in the Si1−xGex, film, was about 2.5 in the case of the Si0.75Ge0.25 film as a diffusion source and increased with increasing Ge fraction. The P diffusion profiles in Si were normalized by x/√, even though the segregation of P occurred. The high concentration diffusion characteristics of P in Si were similar to those reported by using conventional diffusion sources.

Investigation of Ge, As, and Au Diffusion in Non-Alloyed Epitaxial Au-Ge Ohmic Contacts to n-GaAs Using Secondary Ion Mass Spectroscopy Backside Sputter Depth-Profiling

1991 ◽  
Vol 240 ◽  
Author(s):  
H. S. LEE ◽  
R. T. Lareau ◽  
S. N. Schauer ◽  
R. P. Moerkirk ◽  
K. A. Jones ◽  
...  
Keyword(s):  
Ohmic Contacts ◽  
Ion Beam ◽  
Depth Profiling ◽  
Depth Resolution ◽  
High Concentration ◽  
Ohmic Behavior ◽  
Preferential Sputtering ◽  
Specific Contact ◽  
Secondary Ion ◽  
Diffusion Profiles

ABSTRACTA SIMS backside sputter depth-profile technique using marker layers is employed to characterize the diffusion profiles of the Ge, As, and Au in the Au-Ge contacts after annealing at 320 C for various times. This technique overcomes difficulties such as ion beam mixing and preferential sputtering and results in high depth resolution measurements since diffusion profiles are measured from low to high concentration. Localized reactions in the form of islands were observed across the surface of the contact after annealing and were composed of Au, Ge, and As, as determined by SIMS imaging and Auger depth profiling. Backside SIMS profiles indicate both Ge and Au diffusion into the GaAs substrate in the isalnd regions. Ohmic behavior was obtained after a 3 hour anneal with a the lowest average specific contact resistivity found to be ∼ 7 × 100−6 Ω- cm2.

Optics-Free Visualization of Proteins in Single Cells by Time of Flight-Secondary Ion Mass Spectrometry Coupled with Genetically Encoded Chemical Tags

2020 ◽  
Author(s):  
Feifei Jia ◽  
Jie Wang ◽  
Yanyan Zhang ◽  
Qun Luo ◽  
Luyu Qi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Single Cells ◽  
Time Of Flight ◽  
E Coli ◽  
Tof Sims ◽  
Ion Mass Spectrometry ◽  
Chemical Tags ◽  
Secondary Ion

<p></p><p><i>In situ</i> visualization of proteins of interest at single cell level is attractive in cell biology, molecular biology and biomedicine, which usually involves photon, electron or X-ray based imaging methods. Herein, we report an optics-free strategy that images a specific protein in single cells by time of flight-secondary ion mass spectrometry (ToF-SIMS) following genetic incorporation of fluorine-containing unnatural amino acids as a chemical tag into the protein via genetic code expansion technique. The method was developed and validated by imaging GFP in E. coli and human HeLa cancer cells, and then utilized to visualize the distribution of chemotaxis protein CheA in E. coli cells and the interaction between high mobility group box 1 protein and cisplatin damaged DNA in HeLa cells. The present work highlights the power of ToF-SIMS imaging combined with genetically encoded chemical tags for <i>in situ </i>visualization of proteins of interest as well as the interactions between proteins and drugs or drug damaged DNA in single cells.</p><p></p>

Calibration Method for Elemental Quantification

2000 ◽  
Vol 6 (S2) ◽  
pp. 536-537
Author(s):  
C. B. Vartuli ◽  
F. A. Stevie ◽  
L. A. Giannuzzi ◽  
T. L. Shofner ◽  
B. M. Purcell ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Peak Concentration ◽  
Energy Dispersive Spectrometry ◽  
Secondary Ion Mass Spectrometry ◽  
Rutherford Backscattering Spectrometry ◽  
Calibration Method ◽  
High Dose ◽  
High Concentration ◽  
Borophosphosilicate Glass ◽  
Secondary Ion

Energy Dispersive Spectrometry (EDS) is generally calibrated for quantification using elemental standards. This can introduce errors when quantifying non-elemental samples and does not provide an accurate detection limit. In addition, variations between analysis tools can lead to values that differ considerably, especially for trace elements. By creating a standard with an exact trace composition, many of the errors inherent in EDS quantification measurements can be eliminated.The standards are created by high dose ion implantation. For ions implanted into silicon, a dose of 1E16 cm-2 results in a peak concentration of approximately 1E21 cm-3 or 2% atomic. The exact concentration can be determined using other methods, such as Rutherford Backscattering Spectrometry (RBS) or Secondary Ion Mass Spectrometry (SIMS). For this study, SIMS analyses were made using a CAMECA IMS-6f magnetic sector. Measurement protocols were used that were developed for high concentration measurements, such as B and P in borophosphosilicate glass (BPSG).

scholarly journals Start-up Strategies for Anaerobic Ammonia Oxidation (Anammox) in In-Situ Nitrogen Removal from Polluted Groundwater in Rare Earth Mining Areas

2021 ◽  
Vol 13 (8) ◽  
pp. 4591
Author(s):  
Shuanglei Huang ◽  
Daishe Wu
Keyword(s):  
Rare Earth ◽  
Low Temperature ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Ex Situ ◽  
High Concentration ◽  
Low Concentration ◽  
Start Up ◽  
Anammox Activity

The tremendous input of ammonium and rare earth element (REE) ions released by the enormous consumption of (NH4)2SO4 in in situ leaching for ion-adsorption RE mining caused serious ground and surface water contamination. Anaerobic ammonium oxidation (anammox) was a sustainable in situ technology that can reduce this nitrogen pollution. In this research, in situ, semi in situ, and ex situ method of inoculation that included low-concentration (0.02 mg·L−1) and high-concentration (0.10 mg·L−1) lanthanum (La)(III) were adopted to explore effective start-up strategies for starting up anammox reactors seeded with activated sludge and anammox sludge. The reactors were refrigerated for 30 days at 4 °C to investigate the effects of La(III) during a period of low-temperature. The results showed that the in situ and semi in situ enrichment strategies with the addition of La(III) at a low-concentration La(III) addition (0.02 mg·L−1) reduced the length of time required to reactivate the sludge until it reached a state of stable anammox activity and high nitrogen removal efficiency by 60–71 days. The addition of La(III) promoted the formation of sludge floc with a compact structure that enabled it to resist the adverse effects of low temperature and so to maintain a high abundance of AnAOB and microbacterial community diversity of sludge during refrigeration period. The addition of La(III) at a high concentration caused the cellular percentage of AnAOB to decrease from 54.60 ± 6.19% to 17.35 ± 6.69% during the enrichment and reduced nitrogen removal efficiency to an unrecoverable level to post-refrigeration.

scholarly journals Transport and Electromechanical Properties of Ca3TaGa3Si2O14 Piezoelectric Crystals at Extreme Temperatures

MRS Advances ◽  
2019 ◽  
Vol 4 (09) ◽  
pp. 515-521
Author(s):  
Yuriy Suhak ◽  
Ward L. Johnson ◽  
Andrei Sotnikov ◽  
Hagen Schmidt ◽  
Holger Fritze
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Tone Burst ◽  
Total Conductivity ◽  
Transport Mechanisms ◽  
Electromechanical Properties ◽  
Self Diffusion ◽  
Oxygen Ion ◽  
Piezoelectric Strain ◽  
Secondary Ion ◽  
Diffusion Profiles

ABSTRACTTransport mechanisms in structurally ordered piezoelectric Ca3TaGa3Si2O14 (CTGS) single crystals are studied in the temperature range of 1000-1300 °C by application of the isotope 18O as a tracer and subsequent analysis of diffusion profiles of this isotope using secondary ion mass spectrometry (SIMS). Determined oxygen self-diffusion coefficients enable calculation of oxygen ion contribution to the total conductivity, which is shown to be small. Since very low contributions of the cations have to be expected, the total conductivity must be dominated by electron transport. Ion and electron conductivities are governed by different mechanisms with activation energies (1.9±0.1) eV and (1.2±0.07) eV, respectively. Further, the electromechanical losses are studied as a function of temperature by means of impedance spectroscopy on samples with electrodes and a contactless tone-burst excitation technique. At temperatures above 650 °C the conductivity-related losses are dominant. Finally, the operation of CTGS resonators is demonstrated at cryogenic temperatures and materials piezoelectric strain constants are determined from 4.2 K to room temperature.

Hydrogen-induced amorphization and embrittlement resistance in Ti-based in situ composite with bcc-phase in an amorphous matrix

2007 ◽  
Vol 22 (2) ◽  
pp. 428-436 ◽  
Author(s):  
S. Jayalakshmi ◽  
J.P. Ahn ◽  
K.B. Kim ◽  
E. Fleury
Keyword(s):  
Hydrogen Embrittlement ◽  
Amorphous Alloys ◽  
Amorphous Matrix ◽  
Mechanical Tests ◽  
High Concentration ◽  
High Hydrogen ◽  
In Situ Composite ◽  
Bcc Phase ◽  
Embrittlement Resistance

We report the hydrogenation characteristics and mechanical properties of Ti50Zr25Cu25 in situ composite ribbons, composed of β-Ti crystalline phase dispersed in an amorphous matrix. Upon cathodic charging at room temperature, high hydrogen absorption up to ∼60 at.% (H/M = ∼1.2) is obtained. At such a high concentration, hydrogen-induced amorphization occurs. Mechanical tests conducted on the composite with varying hydrogen concentrations indicate that the Ti50Zr25Cu25 alloy is significantly resistant to hydrogen embrittlement when compared to conventional amorphous alloys. A possible mechanism that would contribute toward hydrogen-induced amorphization and hydrogen embrittlement is discussed.

Phosphate biogeochemical barrier for uranium in situ immobilization in an aquifer nearby sludge repository

2021 ◽  
Author(s):  
Grigory Artemiev ◽  
Alexey Safonov ◽  
Nadezhda Popova
Keyword(s):  
Essential Elements ◽  
Ion Concentration ◽  
Soluble Form ◽  
High Concentration ◽  
Rapid Reduction ◽  
Near Surface ◽  
Nitrate Ions ◽  
Uranium Migration ◽  
Storage Facilities

&lt;p&gt;Uranium migration in the oxidized environment of near-surface groundwater is a typical problem of many radiochemical, ore mining and ore processing enterprises that have sludge storage facilities on their territory. Uranium migration, as a rule, occurs against a high salt background due to the composition of the sludge: primarily, nitrate and sulfate anions and calcium cations. One of the ways to prevent the uranium pollution is geochemical or engineering barriers. For uranium immobilization, it is necessary to create conditions for its reduction to a slightly soluble form of uraninite and further mineralization, for example, in the phosphate form. An important factor contributing to the rapid reduction of uranium is a in the redox potential decreasing and the removal of nitrate ions, which can be achieved through the activation of microflora. It should be added that phosphate itself is one of the essential elements for the development of microflora. This work was carried out in relation to the upper aquifer (7-12 m) near the sludge storage facilities of ChMZ, which is engaged in uranium processing and enrichment. One of the problems of this aquifer, in addition to the high concentration of nitrate ions (up to 15 g / l), is the high velocity of formation waters.&lt;br&gt;In laboratory conditions, the compositions of injection solutions were selected containing sources of organic matter to stimulate the microbiota development and phosphates for uranium mineralization. When developing the injection composition, special attention was paid to assessing the formation of calcite deposits in aquifer conditions to partially reduce the filtration parameters of the horizon and reduce the rate of movement of formation waters. This must be achieved to ensure the possibility of long-term deposition of uranium and removal of nitrate. The composition of the optimal solution was selected and in a series of model experiments the mineral phases containing the lowest hydrated form of the uranium-containing phosphate mineral meta-otenite were obtained.&lt;br&gt;In situ mineral phosphate barrier Formation field tests were carried out in water horizon conditions in a volume of 100m3 by injection of an organic and phosphates mixture. As a result, at the first stage of field work, a significant decreasing nitrate ion concentration, and reducing conditions formation coupled with the dissolved uranium concentration of decreasing were noted.&lt;/p&gt;

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