Damage to Crystalline Silicon Following Implantation by Low Energy Silicon Ions

1992 ◽  
Vol 262 ◽  
Author(s):  
Y. Levine ◽  
N. Herbots ◽  
S. Dunham
Keyword(s):  
Deposition Time ◽  
Defect Formation ◽  
Crystalline Silicon ◽  
Focal Point ◽  
Low Energy ◽  
Dose Ratio ◽  
New Approach ◽  
Silicon Ions ◽  
Constant Source ◽  
Interaction Surface

ABSTRACTA new approach to investigate low energy defect formation and annealing in a crystal is developed, based on experimental observations of the total number of interstitials. The model is applied to damage in crystalline silicon caused by low energy implantation of Si-atoms during 40eV implants at 300°Kand 685°K. The model has two versions, analytical and computational, and includes two kinds of diffusing species, self-interstitials and vacancies, their interaction, surface motion of the growing crystal, and a constant source of defects. The source was calculated using a modified TRIM code (TRJMCSR). The focal point of the analysis is the number of interstitials per ion dose surviving at the end of the deposition time (damage to dose ratio or DDR, which is found to be an informative quantity and can be calculated for more sophisticated models including precipitation.

Damage-to-dose ratio after low energy silicon ion implantation into crystalline silicon

1993 ◽  
Vol 8 (9) ◽  
pp. 2305-2309 ◽  
Author(s):  
Y. Levin ◽  
N. Herbots ◽  
S. Dunham
Keyword(s):  
Ion Implantation ◽  
Crystalline Silicon ◽  
Crystal Surface ◽  
Effective Diffusivity ◽  
Low Energy ◽  
Parallel Computer ◽  
Analytic Approximation ◽  
Dose Ratio ◽  
Experimental Conditions ◽  
Diffusion Of Vacancies

In this work, we develop a model describing the diffusion of vacancies and self-interstitials and their recombination during ion implantation. The model includes the effect of the moving surface due to regrowth and the defect generation rate as a function of depth based on Monte Carlo simulations. The results are compared to experimental measurements of the damage-to-dose ratio (DDR) after low energy, 40 eV, silicon ion implantation into silicon at 300 and 685 K. We have derived an analytic approximation which agrees with the results of the computational model, implemented on a CM-2 parallel computer. We find that the calculated effective diffusivity, the main adjustable parameter in the simulations, is much lower than predicted based on extrapolation from experiments at higher temperatures. We attribute this difference to the aggregation of self-interstitials. We also find that the effect of interstitial-vacancy recombination on DDR is negligible under the experimental conditions considered; however, the crystal surface motion has a significant impact on the results.

Observation of oversaturation-induced defect formation in tungsten irradiated by low energy deuterium ion

2016 ◽  
Vol 69 (4) ◽  
pp. 518-524 ◽  
Author(s):  
Younggil Jin ◽  
Jae-Min Song ◽  
Ki-Baek Roh ◽  
Nam-Kyun Kim ◽  
Hyun-Joon Roh ◽  
...  
Keyword(s):  
Defect Formation ◽  
Low Energy

Using 1H and 13C NMR chemical shifts to determine cyclic peptide conformations: a combined molecular dynamics and quantum mechanics approach

2018 ◽  
Vol 20 (20) ◽  
pp. 14003-14012 ◽  
Author(s):  
Q. Nhu N. Nguyen ◽  
Joshua Schwochert ◽  
Dean J. Tantillo ◽  
R. Scott Lokey
Keyword(s):  
Molecular Dynamics ◽  
Density Functional ◽  
Cyclic Peptide ◽  
Chemical Shifts ◽  
Low Energy ◽  
Functional Prediction ◽  
1H And 13C Nmr ◽  
New Approach ◽  
Solution Structures ◽  
Peptide Conformations

Conformational analysis from NMR and density-functional prediction of low-energy ensembles (CANDLE), a new approach for determining solution structures.

Defect Formation by Ion Implantation in Cz-Si Studied by a Monoenergetic Positron Beam

1992 ◽  
Vol 262 ◽  
Author(s):  
A. Uedono ◽  
Y. Ujihira ◽  
L. Wei ◽  
Y. Tabuki ◽  
S. Tanigawa ◽  
...  
Keyword(s):  
Oxygen Vacancy ◽  
Ion Implantation ◽  
Defect Formation ◽  
Positron Beam ◽  
Low Energy ◽  
Doppler Broadening ◽  
Positron Energy ◽  
Annealing Experiments ◽  
Incident Positron ◽  
Ion Implanted

ABSTRACTVacancy-type defects in ion implanted Si were studied by a monoenergetic positron beam. The depth-distributions of the defects were obtained from measurements of Doppler broadening profiles of the positron annihilation as a function of incident positron energy. The results showed that a size of vacany-clusters introduced by 150-keV P+-ion implantation was found to be smaller than that introduced by 2-MeV P+-ion implantation. This was attributed to an overlap of collision cascades in low-energy (150 keV) ion implanted specimens. From isochronal annealing experiments for 80-keV B+- and 150-keV P+-ion implanted specimens, the defected region was removed by 1200 °C annealing, however, for 2-MeV P+-implanted specimen, two-types of oxygen-vacancy complexes were found to coexist even after 1200 °C annealing.

Bi-Crystal Compensation Method for the Over-Response of Solid-State Dosimetry

2014 ◽  
Vol 605 ◽  
pp. 540-543 ◽  
Author(s):  
Ruo Xi Wang ◽  
Patrick Pittet ◽  
Julien Ribouton ◽  
Guo Neng Lu ◽  
Jean Marc Galvan ◽  
...  
Keyword(s):  
Solid State ◽  
Measured Data ◽  
Compensation Method ◽  
Low Energy ◽  
Field Size ◽  
Reference Curve ◽  
Pencil Beam ◽  
Dose Ratio ◽  
Highly Sensitive

Solid-state dosimetry employs highly sensitive semiconductors such as Gallium Nitride (GaN) and Silicon (Si), but they have a common drawback of over response compared to tissues for low-energy scattered photons, which induces inacceptable errors for radiotherapy application. To tackle this issue, we propose a compensation method consisting in using two different materials of dosimetric interest with different atomic numbers. Their responses are denoted as SC1 and SC2. The response ratio SC1/water as a function of the ratio SC1/SC2 exhibits a monotonic curve that can serve as reference to compensate the over-response of SC1. To validate this method, we have studied the dosimetric response of GaN (0.1 mm3) and Si crystals (2.5 mm3) by simulations, using a validated model based on the general cavity theory in a homogeneous water phantom. The dosimetric response of GaN and Si calculated using the model has errors within 2.5% compared to measured data. The local fluence spectra have been obtained by convolution of pencil beam kernel built by Monte Carlo simulations for different clinical irradiation conditions with field size (from 5×5 cm2up to 20×20 cm2) at depth in the phantom (from 2 cm to 25 cm). The obtained results confirm a monotone relationship between GaN/water dose ratio and GaN/Si dose ratio. The reference curve is independent of irradiation conditions (field size, dosimeter position...), and allows determination of compensation value by identification.

scholarly journals The Birth of the Soviet School of European Integration Studies. Part 2

2020 ◽  
pp. 46-53
Author(s):  
Yuri Borko ◽  
Keyword(s):  
European Integration ◽  
Economic Integration ◽  
World Economy ◽  
Focal Point ◽  
Custom Union ◽  
Soviet Leadership ◽  
New Approach ◽  
Bilateral Relations ◽  
The Common ◽  
Integration Problems

The first part of the article shows that in the mid-1960s some Soviet researchers of the European integration problems concluded that integration did not correspond to the Leninist-Stalinist theory of the general crisis of capitalism. On the contrary, it corresponded to some Western concepts of the custom union, the common market, and economic integration. A new approach to the European integration studies was offered by the Institute of World Economy and International Relation (IMEMO), established in 1956. For many decades IMEMO was serving as the focal point for the European integration studies, and was providing the Soviet leadership with analytical information. The number of inquiries from authorities increased significantly. Firstly, it can be explained by the achievements of integration. Secondly, it was due to the growth of economic cooperation between the USSR and the EEC. Thirdly, Moscow defined new foreign policy priorities towards Western countries including Europe. There were two turning-points of bilateral relations: with France – in 1966, and with Germany – in 1969. The Organization for security and cooperation in Europe (OSCE) was established during final session of the top-level Conference of European States in Helsinki in August 1975. Fourthly, experience of the EEC was relevant for the COMECON

Correlation between carbon incorporation and defect formation in quasi-single crystalline silicon

2012 ◽  
Author(s):  
Yuki Tsuchiya ◽  
Hiroki Kusunoki ◽  
Naoto Miyazaki ◽  
Takashi Sameshima ◽  
Tomihisa Tachibana ◽  
...  
Keyword(s):  
Defect Formation ◽  
Crystalline Silicon ◽  
Single Crystalline Silicon ◽  
Carbon Incorporation ◽  
Single Crystalline

Electronically Stimulated Degradation of Crystalline Silicon Solar Cells

2005 ◽  
Vol 864 ◽  
Author(s):  
J. Schmidt ◽  
K. Bothe ◽  
D. Macdonald ◽  
J. Adey ◽  
R. Jones ◽  
...  
Keyword(s):  
Solar Cells ◽  
Defect Formation ◽  
Crystalline Silicon ◽  
Short Review ◽  
Current Status ◽  
Silicon Solar Cells ◽  
Cell Parameters ◽  
Crystalline Silicon Solar Cells ◽  
Characteristic Features ◽  
Oxygen Complexes

AbstractCarrier lifetime degradation in crystalline silicon solar cells under illumination with white light is a frequently observed phenomenon. Two main causes of such degradation effects have been identified in the past, both of them being electronically driven and both related to the most common acceptor element, boron, in silicon: (i) the dissociation of iron-boron pairs and (ii) the formation of recombination-active boron-oxygen complexes. While the first mechanism is particularly relevant in metal-contaminated solar-grade multicrystalline silicon materials, the latter process is important in monocrystalline Czochralski-grown silicon, rich in oxygen. This paper starts with a short review of the characteristic features of the two processes. We then briefly address the effect of iron-boron dissociation on solar cell parameters. Regarding the boron-oxygen-related degradation, the current status of the physical understanding of the defect formation process and the defect structure are presented. Finally, we discuss different strategies for effectively avoiding the degradation.

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