Defects and Phase Change Induced by Giant Electronic Excitations With GeV Ions And 30MeV Cluster Beam

1996 ◽  
Vol 439 ◽  
Author(s):  
P. Thevenard ◽  
M. Beranger ◽  
B. Canut ◽  
S. M. M. Ramos ◽  
N. Bonardi ◽  
...  
Keyword(s):  
Rutherford Backscattering Spectrometry ◽  
Electronic Energy ◽  
Extended Defects ◽  
Electronic Excitations ◽  
Dislocation Loops ◽  
Nuclear Collisions ◽  
Transmission Electron ◽  
F Center ◽  
Different Temperatures ◽  
Solid State Parameters

AbstractMgO and LiNbO 3 single crystals were bombarded with GeV swift heavy ions (Pb, Gd) and 30MeV C60 clusters to study the damage production induced by giant electronic processes at stopping power up to 100keV/nm. The defect creation was characterized by optical absorption, transmission electron microscopy (TEM) and Rutherford backscattering spectrometry in channeling geometry (RBS-C). In MgO point defects (F type centers) and extended defects (dislocation loops) were created by ionization processes in addition to those associated with nuclear collisions. The F-center concentration induced by electronic energy excitations was studied at different temperatures and as a function of the particle electronic energy losses. TEM revealed that dislocation loops were produced close to the particle trajectories and amorphization was never observed. On the opposite, in LiNbO3 continuous amorphous tracks were evidenced above a threshold near 5keV/nm. The dependance of this effects with various solid state parameters will be discussed.

Room Temperature Damage, Annealing and Dislocation Growth in Silicon

1994 ◽  
Vol 373 ◽  
Author(s):  
R.G. Elliman ◽  
I.V. Mitchell
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Rutherford Backscattering Spectrometry ◽  
Extended Defects ◽  
High Temperature Annealing ◽  
Primary Defect ◽  
Implantation Temperature ◽  
Transmission Electron ◽  
Sensitive Function ◽  
Temperature Damage

AbstractThe concentration of residual defects produced by self ion implantation of silicon has been shown to be a sensitive function of implantation temperature at temperatures near room temperature. In this study samples were heated to temperatures of 20°C and 60°C and implanted with 540 keV Si ions to a fluence of 2x1015Si.cm-2 using a constant scanned ion flux of 0.2 μA.cm-2. The resultant primary defect concentrations, measured by Rutherford backscattering spectrometry and channelling (RBS-C), were 2.3±0.1x1022 cm-l and 1.8±0.2x1021 cm-3, respectively, i.e. a reduction by a factor of σ13 for a temperature increase of 40°C. Such differences were not evident in the concentration of secondary defects formed by annealing these samples at 900°C for 15 minutes: the defect concentrations were equal within the experimental uncertainties of the RBS-C and transmission electron microscopy (TEM) measurements. This result appears to lead to the surprising conclusion that the number of displaced atoms that survive high temperature annealing to form extended defects is largely independent of the dynamic annealing processes operating during implantation but depends instead on parameters which scale with the ion fluence.

Study of the Effects of a Two-Step Anneal on the End of Range Defects in Silicon

2002 ◽  
Vol 717 ◽  
Author(s):  
Renata A. Camillo-Castillo ◽  
Kevin. S. Jones ◽  
Mark E. Law ◽  
Leonard M. Rubin
Keyword(s):  
Defect Density ◽  
Low Energy ◽  
Extended Defects ◽  
Dislocation Loops ◽  
Extended Defect ◽  
Enhanced Diffusion ◽  
Interstitial Concentration ◽  
Transmission Electron ◽  
Concentration Peak ◽  
Scale Down

AbstractTransient enhanced diffusion (TED) is a challenge that the semi-conductor industry has been faced with for more than two decades. Numerous investigations have been conducted to better understand the mechanisms that govern this phenomenon, so that scale down can be acheived. {311} type defects and dislocation loops are known interstitial sources that drive TED and dopants such as B utilize these interstitials to diffuse throughout the Si lattice. It has been reported that a two-step anneal on Ge preamorphized Si with ultra-low energy B implants has resulted in shallower junction depths. This study examines whether the pre-anneal step has a measurable effect on the end of range defects. Si wafers were preamorphized with Ge at 10, 12, 15, 20 and 30keV at a dose of 1x1015cm-2 and subsequently implanted with 1x1015cm-2 1keV B. Furnace anneals were performed at 450, 550, 650 and 750°C; the samples were then subjected to a spike RTA at 950°C. The implant damage was analyzed using Quantitative Transmission Electron Microscopy (QTEM). At the low energy Ge preamorphization, little damage is observed. However at the higher energies the microstructure is populated with extended defects. The defects evolve into elongated loops as the preanneal temperature increases. Both the extended defect density and the trapped interstitial concentration peak at a preanneal temperature of 550°C, suggesting that this may be an optimal condition for trapping interstitials.

Synthesis of Si1-xGex-on-Insulator by 74Ge+ Ion Implantation in a Simox Substrate

1993 ◽  
Vol 316 ◽  
Author(s):  
C.J. Patel ◽  
C.D. Marsh ◽  
U. Magnusson ◽  
C. Jeynes ◽  
M. Ostling ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Defect Density ◽  
Rutherford Backscattering Spectrometry ◽  
Final Heat Treatment ◽  
Conductivity Measurements ◽  
Band Gap Engineering ◽  
High Defect Density ◽  
Transmission Electron ◽  
Different Temperatures

ABSTRACTA single crystalline Si1-xGex overlayer on insulator is realised by the implantation of germanium into a SIMOX (Separation by IMplantation of OXygen) substrate. Two SIMOX samples were implanted with 74Ge+ at elevated temperature (≈600°C), and subsequently annealed at different temperatures and anneal ambients. The microstructure, stoichiometry, and conductivity of the Si1-xGex over-layer were studied using transmission electron microscopy, Rutherford backscattering spectrometry/ion channelling and two-probe conductivity measurements. As a result of lattice reordering after final heat treatment, and despite high defect density observed in the XTEM microstructure, the measured conductivity of the over-layer is higher than of the starting SIMOX material. These results suggest a possibility of band-gap engineering by synthesis of Si1-xGex-on-insulator.

Behavior of Dopant-Related Defects in AlGaAs Superlattices

1989 ◽  
Vol 163 ◽  
Author(s):  
N.D. Theodore ◽  
P. Mei ◽  
S.A. Schwarz ◽  
C.B. Carter ◽  
C. Palmstrom ◽  
...  
Keyword(s):  
Time Behavior ◽  
Dislocation Loops ◽  
Silicon Doping ◽  
Transmission Electron ◽  
Mixing Behavior ◽  
High Resolution Tem ◽  
Different Temperatures ◽  
Time Periods ◽  
Silicon Doped ◽  
Temperature Time

AbstractDuring the course of investigation of the mixing of highly silicon-doped GaAs/AlAs superlattices, defects such as dislocation loops and Si-rich precipitates were found to form in the specimens. These defects formed at particular doping levels upon annealing of the samples. The presence of the defects can be related to changes in mixing behavior. In the present study, transmission electron microscopy has been used to characterize the defects. Superlattices with varying silicon doping levels were annealed at different temperatures for varying time-periods, to observe the temperature-time behavior of the dislocation loops. The defects aggregate preferentially in the GaAs as opposed to the AlAs in the superlattice. A number of the dislocation-loops were investigated using high-resolution TEM. All the loops observed were interstitial in nature.

Damage Generation by Electronic Excitations in Crystalline Metals

1992 ◽  
Vol 279 ◽  
Author(s):  
A. Dunlop ◽  
D. Lesueur
Keyword(s):  
Energy Deposition ◽  
Electronic Excitation ◽  
Electronic System ◽  
Electronic Energy ◽  
Electronic Excitations ◽  
Nuclear Collisions ◽  
Slowing Down ◽  
Tentative Model ◽  
Long Time ◽  
Damage Processes

EXTENDED ABSTRACTThis paper will give a rapid overview of the main experimental results concerning the effects of high electronic energy deposition in metallic targets and present a tentative model based on the Coulomb explosion mechanism. More detailed reviews have been made recently concerning both the experiments [1–3] and the theoretical model [4].High levels of localized energy deposition in electronic excitation are easily obtained using GeV heavy ions which during their slowing-down typically transfer a few keV/Å to the electronic system of the target and a few eV/Å in elastic collisions with target nuclei. In insulators and organic materials, it is well-known that both slowing-down processes contribute to damage creation, whereas in metals it has been claimed for a long time that the sole nuclear collisions are involved in damage processes. Although this last assertion remains true for some metals such as Cu, Ag, W, Cu3Au …[2], high levels of electronic excitation can induce a partial annealing of the defects resulting from nuclear collisions in Fe, Ni, Nb, Pt…. lead to additional defect creation in Fe, Co, Zr, Ti… [2] or even to phase transformations in NiZr2 [5], Ni3B[6], NiTi [7], Ti [8]… In the following, we shall only focuss on the last two effects.

Evolution of nucleation sites and bubble precursors in silicon as a function of helium implanted dose

2002 ◽  
Vol 719 ◽  
Author(s):  
Changlong Liu ◽  
R. Delamare ◽  
E. Ntsoenzok ◽  
G. Regula ◽  
B. Pichaud ◽  
...  
Keyword(s):  
Thermal Annealing ◽  
Dose Range ◽  
Nuclear Reaction Analysis ◽  
Extended Defects ◽  
Dislocation Loops ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Nucleation Sites ◽  
Dose Dependent ◽  
Subsequent Thermal Annealing

Abstract(111) oriented silicon samples were implanted at room temperature with 1.55 MeV 3He ions in the dose range of 5×1015 to 5×1016/cm2. Cross-sectional transmission electron microscopy (XTEM) was used to study the evolution of bubbles and extended defects during subsequent thermal annealing at 800°C and 900°C for 30min. The He desorption from bubbles and bubble precursors was measured by means of nuclear reaction analysis (NRA). TEM observations show that no bubbles were observed in Si implanted at doses lower than 1×1016/cm2, while a well-defined cavity band was formed after implantation at 5×1016/cm2 and subsequent thermal annealing. At the intermediary dose of 2×1016/cm2, however, the evolution of bubbles and extended defects is quite different. The bubbles prefer to nucleate in large planar clusters surrounded by a high density of dislocation loops emerging from them. The clusters of bubbles act as the sources of the dislocation loops. NRA measurements indicate that the He desorption behavior is also dose-dependent. The He desorption is achieved much faster in low dose implanted Si. The results are qualitatively discussed.

Damage in Refractory Oxides and ion Beam Mixing at Metal-Oxide Interfaces Induced by Gev Ions and 20 Mev Cluster Beam

1995 ◽  
Vol 396 ◽  
Author(s):  
P.A. Thevenard ◽  
M. Beranger ◽  
B. Canut ◽  
S.M.M. Ramos
Keyword(s):  
Metal Oxide ◽  
Ion Beam ◽  
Strong Dependence ◽  
Electronic Energy ◽  
Extended Defects ◽  
Electronic Excitations ◽  
Oxide Interfaces ◽  
Atomic Displacements ◽  
Refractory Oxides ◽  
High Level

AbstractDefect creation in refractory oxides known to be unsensitive to radiolysis, was shown to take place by high level electronic excitations induced by swift heavy ions or energetic cluster bombardments. Depending on the oxide a threshold in electronic energy loss for damage production was observed : MgO 22 keV/nm, AI2O3 20 keV/nm and LiNbO3 6 keV/nm. A very strong dependence on the energy deposited for the defect production was evidenced above the threshold. In MgO, both point and extended defects were created whereas in AI2O3 only extended defects were observed and in LiNbO3 amorphization in the ion track was evidenced.Atomic displacements due to the giant electronic excitations can be revealed at metal-oxide interfaces in the case of Na nanoprecipitates embedded in MgO single crystals.

Defect clustering in GaN irradiated with O+ ions

2002 ◽  
Vol 17 (11) ◽  
pp. 2945-2952 ◽  
Author(s):  
C. M. Wang ◽  
W. Jiang ◽  
W. J. Weber ◽  
L. E. Thomas
Keyword(s):  
Point Defects ◽  
Basal Plane ◽  
Room Temperature ◽  
Dynamic Recovery ◽  
Stacking Faults ◽  
Extended Defects ◽  
Dislocation Loops ◽  
Defect Clusters ◽  
Transmission Electron ◽  
High Resolution Tem

Transmission electron microscopy (TEM) was used to study microstructures formed in GaN irradiated with 600-keV O+ ions at room temperature. Three types of defect clusters were identified in the irradiated GaN: (i) basal-plane stacking faults with dimensions ranging from 5 to 30 nm, (ii) pyramidal dislocation loops, and (iii) local regions of highly disordered material. High-resolution TEM imaging clearly revealed that one type of the basal-plane stacking faults corresponded to insertion of one extra Ga–N basal plane in the otherwise perfect GaN lattice. The interpretation of these results indicated that interstitials of both Ga and N preferentially condensed on the basal plane to form a new layer of Ga–N under these irradiation conditions. The formation of these extended defects and their interactions with the point defects produced during irradiation contributed to a dramatic increase in the dynamic recovery of point defects in GaN at room temperature.

Silicon Light Emissions from Boron Implant-Induced Extended Defects

2005 ◽  
Vol 864 ◽  
Author(s):  
G. Z. Pan ◽  
R. P. Ostroumov ◽  
L. P. Ren ◽  
Y. G. Lian ◽  
K. L. Wang
Keyword(s):  
Room Temperature ◽  
Light Emission ◽  
Extended Defects ◽  
Dislocation Loops ◽  
Plan View ◽  
Annealing Conditions ◽  
Peak Intensity ◽  
Transmission Electron ◽  
Different Types ◽  
Dislocation Defect

AbstractWe studied the electroluminescence (EL) of boron-implanted p-n junction Si LEDs in correlation with the implant-induced extended defects of different types. By varying the post implant annealing conditions to tune the extended defects and by using plan-view transmission electron microscopy to identify them, we found that {113} defects along Si<110> are the ones that result in strong silicon light emission of the p-n junction Si LEDs other than {111} perfect prismatic and {111} faulted Frank dislocation loops. The EL peak intensity at about 1.1 eV of {113} defect-engineered Si LEDs is about twenty-five times higher than that of dislocation defect-engineered Si LEDs. The EL measured at temperatures from room temperature to 4 K indicated that the emissions related to the extended defects are from silicon band edge radiative recombination.

Annealing Of Radiation Damage in Tungsten

1970 ◽  
Vol 28 ◽  
pp. 412-413
Author(s):  
Robert C. Rau ◽  
John Moteff
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Radiation Damage ◽  
Thermal Annealing ◽  
Neutron Fluence ◽  
Dislocation Loops ◽  
Defect Clusters ◽  
Polycrystalline Tungsten ◽  
Transmission Electron ◽  
Radiation Induced

Transmission electron microscopy has been used to study the thermal annealing of radiation induced defect clusters in polycrystalline tungsten. Specimens were taken from cylindrical tensile bars which had been irradiated to a fast (E > 1 MeV) neutron fluence of 4.2 × 1019 n/cm2 at 70°C, annealed for one hour at various temperatures in argon, and tensile tested at 240°C in helium. Foils from both the unstressed button heads and the reduced areas near the fracture were examined.Figure 1 shows typical microstructures in button head foils. In the unannealed condition, Fig. 1(a), a dispersion of fine dot clusters was present. Annealing at 435°C, Fig. 1(b), produced an apparent slight decrease in cluster concentration, but annealing at 740°C, Fig. 1(C), resulted in a noticeable densification of the clusters. Finally, annealing at 900°C and 1040°C, Figs. 1(d) and (e), caused a definite decrease in cluster concentration and led to the formation of resolvable dislocation loops.

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