Point-Defect Migration in Crystalline Si: Impurity Content, Surface and Stress Effects

1998 ◽  
Vol 532 ◽  
Author(s):  
S. Coffa ◽  
S. Libertino ◽  
A. La Magna ◽  
V. Privitera ◽  
G. Mannino ◽  
...  
Keyword(s):  
Point Defect ◽  
Leakage Current ◽  
Room Temperature ◽  
Ion Irradiation ◽  
Deep Level ◽  
Ion Beam ◽  
Impurity Content ◽  
Ex Situ ◽  
Defect Migration

ABSTRACTThe results of several recent experiments aimed at assessing the room temperature migration properties of interstitials (D) and vacancies (V) in ion implanted crystalline Si are reviewed. We show that combining the results of ex-situ techniques (deep level transient spectroscopy and spreading resistance profilometry) and in-situ leakage current measurements new and interesting information can be achieved. It has been found that at room temperature I and V, generated by an ion beam, undergo fast long range migration (with diffusivities higher than 10−1 cm2/sec) which is interrupted by trapping at impurities (C, O) or dopant atoms and by recombination at surface. Analysis of two-dimensional migration of point defects injected through a photolithographically defined mask shows that a strong I recombination (characterized by a coefficient of 30 μm−1) occurs at the sample surface. Moreover, we have found that the strain field induced by an oxide or a nitride mask significantly affects defect migration and produces a strong anisotropy of the defect diffusivity tensor. Finally, using in-situ leakage current measuremens, performed both during and just after ion irradiation, the time scale of point defect evolution at room temperature has been determined and defect diffusivities evaluated. The implications of these results on our current understanding of defect and diffusion phenomena in Si are discussed.

Point Defects Migration and Agglomeration in Si at Room Temperature: The Role of Surface and Impurity Content

1997 ◽  
Vol 469 ◽  
Author(s):  
V. Privitera ◽  
S. Coffa ◽  
K. Kyllesbech Larsen ◽  
S. Libertino ◽  
G. Mannino ◽  
...  
Keyword(s):  
Point Defects ◽  
Room Temperature ◽  
Deep Level ◽  
Ion Beam ◽  
Impurity Content ◽  
Sample Surface ◽  
Defect Migration ◽  
Transient Spectroscopy ◽  
Dopant Atoms

ABSTRACTOur recent work on the room temperature migration and trapping phenomena of self-interstitials and vacancies in crystalline Si is reviewed. Spreading resistance profiling and deep level transient spectroscopy measurements were used to monitor the interaction of ion beam generated defects with dopant atoms, intrinsic impurities (i.e. O and C), pre-existing defect marker layers and sample surface. We have found that both interstitials and vacancies undergo fast long range migration which is interrupted by trapping at impurities and by recombination at defects or at the surface. Effective defect migration lengths as large as 5 μm at room temperature have been observed in highly pure, defect free epitaxial Si samples. A lower limit of 1×10−10 cm2/sec for the room temperature diffusivity of self-interstitials has been determined. Furthermore, by monitoring the migration and interaction processes of point defects injected through a mask, we have established that surface acts as an effective sink for the migrating Si self interstitials.

scholarly journals Ion-Irradiation-Induced Amorphization Of Cadmium Niobate Pyrochlore

2000 ◽  
Vol 650 ◽  
Author(s):  
A. Meldrum ◽  
K. Beaty ◽  
L. A. Boatner ◽  
C. W. White
Keyword(s):  
Electron Microscope ◽  
Ambient Temperature ◽  
Transmission Electron Microscope ◽  
Room Temperature ◽  
Ion Irradiation ◽  
Ex Situ ◽  
Temperature Dependent ◽  
Transmission Electron ◽  
Ion Energies

ABSTRACTIrradiation-induced amorphization of Cd2Nb2O7 pyrochlore was investigated by means of in-situ temperature-dependent ion-irradiation experiments in a transmission electron microscope, combined with ex-situ ion-implantation (at ambient temperature) and RBS/channeling analysis. The in-situ experiments were performed using Ne or Xe ions with energies of 280 and 1200 keV, respectively. For the bulk implantation experiments, the incident ion energies were 70 keV (Ne+) and 320 keV (Xe2+). The critical amorphization temperature for Cd2Nb2O7 is ∼480 K (280 keV Ne+) or ∼620 K (1200 keV Xe2+). The dose for in-situ amorphization at room temperature is 0.22 dpa for Xe2+, but is 0.65 dpa for Ne+ irradiation. Both types of experiments suggest a cascade overlap mechanism of amorphization. The results were analyzed in light of available models for the crystalline-to-amorphous transformation and were compared to previous ionirradiation experiments on other pyrochlore compositions.

Ion Beam Induced Structural and Electrical Modifications in Crystalline and Amorphous Silicon

1993 ◽  
Vol 316 ◽  
Author(s):  
S. Coffa ◽  
A. Battaglia ◽  
F. Priolo
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Ion Irradiation ◽  
Deep Level ◽  
Ion Beam ◽  
Defect Structures ◽  
Transmission Electron ◽  
Defect Accumulation ◽  
Amorphous Si ◽  
Transient Spectroscopy

ABSTRACTThe mechanisms of defect accumulation and dynamic annealing in ion-implanted crystalline and amorphous Si are elucidated by performing conductivity and Raman spec-trascopy measurements in-situ during ion irradiation. In amorphous Si the entire gamut of defect structures has been characterized by analyzing the annealing kinetics from 77 K to ~ 800 K both during and after irradiation. Moreover the modifications in the electronic properties of crystalline Si produced by ion-irradiation have been investigated. The use of in-situ techniques in combination with transmission electron microscopy and deep-level transient spectroscopy allowed us to demonstrate the correlation between structural and electrical defects produced by ion-irradiation in Si.

scholarly journals Effects of Displacing Radiation on Graphite Observed Using in situ Transmission Electron Microscopy

2012 ◽  
Vol 1383 ◽  
Author(s):  
J.A. Hinks ◽  
A.N. Jones ◽  
S.E. Donnelly
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Standard Model ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Dimensional Change ◽  
Defect Migration ◽  
Transmission Electron ◽  
The Standard Model

ABSTRACTGraphite is used as a moderator and structural component in the United Kingdom’s fleet of Advanced Gas-Cooled Reactors (AGRs) and features in two Generation IV reactor concepts: the Very High Temperature Reactor (VHTR) and the Molten Salt Reactor (MSR). Under the temperature and neutron irradiation conditions of an AGR, nuclear-grade graphite demonstrates significant changes to it mechanical, thermal and electrical properties. These changes include considerable dimensional change with expansion in the c-direction and contraction in the a/b-directions. As the United Kingdom’s AGRs approach their scheduled decommissioning dates, it is essential that this behaviour be understood in order to determine under what reactor conditions their operating lifetimes can be safely extended.Two models have been proposed for the dimensional change in graphite due to displacing radiation: the “Standard Model” and “Ruck and Tuck”. The Standard Model draws on a conventional model of Frenkel pair production, point defect migration and agglomeration but fails to explain several key experimental observations. The Ruck and Tuck model has been proposed by M.I. Heggie et al. and is based upon the movement of basal dislocation to create folds in the “graphene” sheets and seeks not only to account for the dimension change but also the other phenomena not explained by the Standard Model.In order to test the validity of these models, work is underway to gather experimental evidence of the microstructural evolution of graphite under displacing radiation. One of the primary techniques for this is transmission electron microscopy with in situ ion irradiation. This paper presents the results of electron irradiation at a range of energies (performed in order to separate the effects of the electron and ion beams) and of combined electron and ion beam irradiation.

In situ Transmission Electron Microscopy Investigation of Radiation Effects

2005 ◽  
Vol 20 (7) ◽  
pp. 1654-1683 ◽  
Author(s):  
R.C. Birtcher ◽  
M.A. Kirk ◽  
K. Furuya ◽  
G.R. Lumpkin ◽  
M-O. Ruault
Keyword(s):  
Radiation Effects ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Ex Situ ◽  
In Situ Observation ◽  
Dislocation Loops ◽  
Transmission Electron ◽  
Microscopy Investigation ◽  
Ion Impact

In situ observation is of great value in the study of radiation damage utilizing electron or ion irradiation. We summarize the facilities and give examples of work found around the world. In situ observations of irradiation behavior have fallen into two broad classes. One class consists of long-term irradiation, with observations of microstructural evolution as a function of the radiation dose in which the advantage of in situ observation has been the maintenance of specimen position, orientation, and temperature. A second class has involved the recording of individual damage events in situations in which subsequent evolution would render the correct interpretation of ex situ observations impossible. In this review, examples of the first class of observation include ion-beam amorphization, damage accumulation, plastic flow, implant precipitation, precipitate evolution under irradiation, and damage recovery by thermal annealing. Examples of the second class of observation include single isolated ion impacts that produce defects in the form of dislocation loops, amorphous zones, or surface craters, and single ion impact-sputtering events. Experiments in both classes of observations attempt to reveal the kinetics underlying damage production, accumulation, and evolution.

Electron and ion irradiation-induced dissolution of mechanical twins in the intermetalic U3Si: An in situ HVEM study

1989 ◽  
Vol 47 ◽  
pp. 652-653
Author(s):  
Charles W. Allen ◽  
Robert C. Birtcher
Keyword(s):  
Elevated Temperatures ◽  
Ion Irradiation ◽  
Ion Beam ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Heavy Ion ◽  
High Energy ◽  
Mechanical Twinning ◽  
In Situ Experiments

The uranium silicides, including U3Si, are under study as candidate low enrichment nuclear fuels. Ion beam simulations of the in-reactor behavior of such materials are performed because a similar damage structure can be produced in hours by energetic heavy ions which requires years in actual reactor tests. This contribution treats one aspect of the microstructural behavior of U3Si under high energy electron irradiation and low dose energetic heavy ion irradiation and is based on in situ experiments, performed at the HVEM-Tandem User Facility at Argonne National Laboratory. This Facility interfaces a 2 MV Tandem ion accelerator and a 0.6 MV ion implanter to a 1.2 MeV AEI high voltage electron microscope, which allows a wide variety of in situ ion beam experiments to be performed with simultaneous irradiation and electron microscopy or diffraction.At elevated temperatures, U3Si exhibits the ordered AuCu3 structure. On cooling below 1058 K, the intermetallic transforms, evidently martensitically, to a body-centered tetragonal structure (alternatively, the structure may be described as face-centered tetragonal, which would be fcc except for a 1 pet tetragonal distortion). Mechanical twinning accompanies the transformation; however, diferences between electron diffraction patterns from twinned and non-twinned martensite plates could not be distinguished.

scholarly journals In Situ Grain Growth of Nanograined Magnetite under Ion Irradiation at Room Temperature and 500 ℃

2021 ◽  
Vol 27 (S1) ◽  
pp. 2640-2643
Author(s):  
Chris McRobie ◽  
Ryan Schoell ◽  
Tiffany Kaspar ◽  
Daniel Schreiber ◽  
Djamel Kaoumi
Keyword(s):  
Grain Growth ◽  
Room Temperature ◽  
Ion Irradiation

Structural Quality And Electrical Behavior Of Epitaxial High-κ Y2O3 / Si(001)

2002 ◽  
Vol 745 ◽  
Author(s):  
G. Vellianitis ◽  
G. Apostolopoulos ◽  
A. Dimoulas ◽  
K. Argyropoulos ◽  
B. Mereu ◽  
...  
Keyword(s):  
Leakage Current ◽  
Wide Band ◽  
Amorphous Layer ◽  
Ex Situ ◽  
Structural Quality ◽  
Wide Band Gap ◽  
Annealing Temperatures ◽  
Grown Sample ◽  
Transistor Fabrication

ABSTRACTY2O3 thin films were grown directly on Si (001) by MBE and annealed in-situ under UHV at various annealing temperatures. The samples were investigated in-situ by RHEED and ex-situ by HRTEM. A 7 to 15 Å thick non-uniform interfacial amorphous layer is observed in the as-grown sample. After annealing at 490°C under UHV for 30 minutes the amorphous layer is reduced and a sharp Y2O3/Si interface is obtained. At higher annealing temperatures, YSi2 islands start to form at the Y2O3/Si interface. I-V measurements performed on generic MIS structures show that the annealed samples exhibit higher leakage current density than the as-grown sample, due to reduction of the wide band gap interfacial layer. Leakage current densities in annealed samples remain below 1A/cm2, which is acceptable for future high-κ transistor fabrication.

Study of scalable IBS nanopatterning mechanisms for III-V semiconductors using in-situ surface characterization

2011 ◽  
Vol 1354 ◽  
Author(s):  
Jean Paul Allain ◽  
Osman El-Atwani ◽  
Alex Cimaroli ◽  
Daniel L. Rokusek ◽  
Sami Ortoleva ◽  
...  
Keyword(s):  
Surface Chemistry ◽  
Surface Characterization ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Low Energy ◽  
Self Organization ◽  
Beam Parameter ◽  
Ion Beam Sputtering

ABSTRACTIon-beam sputtering (IBS) has been studied as a means for scalable, mask-less nanopatterning of surfaces. Patterning at the nanoscale has been achieved for numerous types of materials including: semiconductors, metals and insulators. Although much work has been focused on tailoring nanopatterning by systematic ion-beam parameter manipulation, limited work has addressed elucidating on the underlying mechanisms for self-organization of multi-component surfaces. In particular there has been little attention to correlate the surface chemistry variation during ion irradiation with the evolution of surface morphology and nanoscale self-organization. Moreover the role of surface impurities on patterning is not well known and characterization during the time-scale of modification remains challenging. This work summarizes an in-situ approach to characterize the evolution of surface chemistry during irradiation and its correlation to surface nanopatterning for a variety of multi-components surfaces. The work highlights the importance and role of surface impurities in nanopatterning of a surface during low-energy ion irradiation. In particular, it shows the importance of irradiation-driven mechanisms in GaSb(100) nanopatterning by low-energy ions and how the study of these systems can be impacted by oxide formation.

Setup for in situ deep level transient spectroscopy of semiconductors during swift heavy ion irradiation

2008 ◽  
Vol 79 (5) ◽  
pp. 056103 ◽  
Author(s):  
Sandeep Kumar ◽  
Sugam Kumar ◽  
Y. S. Katharria ◽  
C. P. Safvan ◽  
D. Kanjilal
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Ion Irradiation ◽  
Deep Level ◽  
Heavy Ion ◽  
Swift Heavy Ion Irradiation ◽  
Heavy Ion Irradiation ◽  
Swift Heavy Ion ◽  
Transient Spectroscopy
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