The Kinetics and Microstructure of Ion Beam Induced Crystallisation of Silicon

1985 ◽  
Vol 45 ◽  
Author(s):  
J.S. Williams ◽  
W.L. Brown ◽  
R. G. Elliman ◽  
R. V. Knoell ◽  
D.M. Maher ◽  
...  
Keyword(s):  
Activation Energy ◽  
Crystal Growth ◽  
Growth Kinetics ◽  
Temperature Regime ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Extended Defects ◽  
Dislocation Loops ◽  
Nucleation Sites ◽  
Higher Temperature

ABSTRACTThis paper reviews recent detailed investigations into the crystal growth kinetics and the microstructure of ion-beam-stimulated epitaxial crystallisation of silicon. Beam-induced crystallisation at temperatures between 200-400°C is found to be characterised by an activation energy of 0.24eV. Furthermore, in this temperature regime, crystal growth on (100) silicon is found to be free of extended defects except for a sharp hand of dislocation loops centred about the range of the ions employed to stimulate crystallisation. A higher temperature regime (>400°C) is observed in which the growth kinetics are less well defined but appear to be associated with an apparent activation energy of >0.5eV. In this regime, extended defects are observed to extend from the ion range to the surface. Results are presented which strongly suggest that nuclear energy deposition precisely at the amorphous-crystalline interface is responsible for crystallisation under ion irradiation. It is argued that the major fraction (2.4eV) of the thermal-only activation energy for epitaxial crystallisation of silicon is likely to be associated with the formation of nucleation sites for growth, a step which is achieved athermally under ion irradiation. In addition, the growth rate per unit ion fluence is found to be independent of substrate orientation at temperatures <450°C and independent of doping concentration for temperatures <400°C. These results are consistent with our proposed model for beam-induced crystallisation.

scholarly journals Ion Irradiation-Induced Microstructural Evolution of Ni–Mo–Cr Low Alloy Steels

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2268
Author(s):  
Hongying Sun ◽  
Penghui Lei ◽  
Guang Ran ◽  
Hui Wang ◽  
Jiyun Zheng ◽  
...  
Keyword(s):  
Irradiation Dose ◽  
Focused Ion Beam ◽  
Ion Irradiation ◽  
Ion Beam ◽  
High Strength ◽  
Positron Annihilation Spectroscopy ◽  
Small Scale ◽  
Low Alloy Steels ◽  
Dislocation Loops ◽  
S Parameter

As leading candidates of sheet steels for advanced nuclear reactors, three types of Ni–Mo–Cr high-strength low alloy (HSLA) steels named as CNST1, CNST2 and CNSS3 were irradiated by 400 keV Fe+ with peak fluence to 1.4 × 1014, 3.5 × 1014 and 7.0 × 1014 ions/cm2, respectively. The distribution and morphology of the defects induced by the sample preparation method and Fe+ irradiation dose were investigated by transmission electron microscopy (TEM) and positron-annihilation spectroscopy (PAS). TEM samples were prepared with two methods, i.e., a focused ion beam (FIB) technique and the electroplating and twin-jet electropolishing (ETE) method. Point defects and dislocation loops were observed in CNST1, CNST2 and CNSS3 samples prepared via FIB. On the other hand, samples prepared via the ETE method revealed that a smaller number of defects was observed in CNST1, CNST2 and almost no defects were observed in CNST3. It is indicated that artifact defects could be introduced by FIB preparation. The PAS S-W plots showed that the existence of two types of defects after ion implantation included small-scale defects such as vacancies, vacancy clusters, dislocation loops and large-sized defects. The S parameter of irradiated steels showed a clear saturation in PAS response with increasing Fe+ dose. At the same irradiation dose, higher values of the S-parameter were achieved in CNST1 and CNST2 samples when compared to that in CNSS3 samples. The mechanism and evolution behavior of irradiation-induced defects were analyzed and discussed.

Organic-Inorganic Nanocomposites Based on Iron Containing Clusters and Biomolecules

1995 ◽  
Vol 48 (4) ◽  
pp. 783 ◽  
Author(s):  
P Chan ◽  
W Chuaanusorn ◽  
M Nesterova ◽  
P Sipos ◽  
TG Stpierre ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Chondroitin Sulfate ◽  
Iron Sulfide ◽  
Nucleation And Growth ◽  
Protein Cage ◽  
Structural Order ◽  
Nucleation Sites ◽  
Inorganic Nanocomposites ◽  
Higher Temperature ◽  
Inorganic Clusters

Biopolymers, such as the protein ferritin and the polysaccharides chondroitin sulfate and chitosan, have been used to control the nucleation and growth of nanoscale iron(III) hydroxide clusters. The biopolymers can provide nucleation sites, that in some cases are spatially defined by the shape of the polymer, and/or defined volumes within which crystal growth of the iron(III) hydroxide can proceed. The product inorganic clusters are bound to the organic polymers which both keep them in solution and prevent aggregation. The morphology of the clusters (spheres or rods) and the uniformity of their dimensions are determined by the biopolymer chosen. The temperature of formation is shown to have an effect on the structure of the clusters, a higher temperature resulting in larger inorganic clusters with a higher degree of structural order. Iron(III) hydroxide clusters in ferritin cages can be partially transformed to iron sulfide by reaction with H2S gas while remaining in the protein cage.

scholarly journals Effects of the Surface on Displacement Cascades Produced by Heavy-Ion Irradiation of Ni3Al and Cu3Au

1996 ◽  
Vol 439 ◽  
Author(s):  
S. Müller ◽  
M. L. Jenkins ◽  
C. Abromeit ◽  
H. Wollenberger
Keyword(s):  
Ion Irradiation ◽  
Incident Angle ◽  
Ion Beam ◽  
Heavy Ion ◽  
Small Population ◽  
Dislocation Loops ◽  
Near Surface ◽  
Ion Energy ◽  
Heavy Ion Irradiation ◽  
Transmission Electron

AbstractStereo transmission electron microscopy has been used to characterise the distribution in depth of disordered zones and associated dislocation loops in the ordered alloys Ni3Al and Cu3Au after heavy ion irradiation, most extensively for Ni3Al irradiated with 50 keV Ta+ ions at a temperature of 573 K. The Cu3Au specimen was irradiated with 50 keV Ni+ ions at an incident angle of 45° at a temperature of 373 K. In Ni3Al the defect yield, i.e. the probability for a disordered zone to contain a loop was found to be strongly dependent on the depth of the zone in the foil, varying from about 0.7 for near-surface zones to about 0.2 in the bulk. The sizes and shapes of disordered zones were only weakly dependent on depth, except for a small population of zones very near the surface which were strongly elongated parallel to the incident ion beam. In Cu3Au the surface had a smaller but still significant effect on the defect yield. The dependence of the tranverse disordered zone diameter d on ion energy E for Ta+ irradiation of NiA was found to follow a relationship d = k1, E1/α with k, = 2.4 ± 0.4 and α = 3.3 ± 0.4. A similar relationship with the same value of α is valid for a wide variety of incident ion/target combinations found in the literature.

Ion Beam Induced Amorphization and Crystallization Processes in Silicon and GaAs

1986 ◽  
Vol 74 ◽  
Author(s):  
R. G. Elliman ◽  
J. S. Williams ◽  
S. T. Johnson ◽  
E. Nygren
Keyword(s):  
Crystal Growth ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Amorphous Layer ◽  
Poor Quality ◽  
Layer By Layer ◽  
Epitaxial Crystallization ◽  
Non Linear ◽  
Thickness Layer

AbstractThin amorphous layers in crystalline Si and GaAs substates have been irradiated at selected temperatures with 1.5 MeV Ne+ ions to induce either epitaxial crystallization or amorphization. In Si, such irradiation can induce complete epitaxial crystallization of a 1000 A surface amorphous layer for temperatures typically >200°C whereas, at significantly lower temperatures, layer-by-layer amorphization results. Although epitaxial crystallization can also be stimulated in GaAs by ion irradiation at temperatures >65°C, the process is non-linear with ion dose and results in poor quality crystal growth for amorphous layers greater than a few hundred Angstroms in thickness. Layer-by-layer amorphization has not been observed in GaAs.

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.

Investigation of NEV Au++ implanted silicon

1990 ◽  
Vol 48 (4) ◽  
pp. 654-655
Author(s):  
T.L. Alford ◽  
N.D. Theodore ◽  
J.W. Mayer ◽  
C.B. Carter ◽  
N.W. Cheung
Keyword(s):  
Ion Irradiation ◽  
Ion Beam ◽  
Amorphous Layer ◽  
Copper Sample ◽  
Extended Defects ◽  
Ion Beam Irradiation ◽  
Beam Path ◽  
Significant Difference ◽  
Different Types ◽  
Lattice Damage

There has recently been increasing use of MeV ion beams for materials modification. When compared to more common lower, keV-energy implantation, MeV-ion irradiation has a broader variation in the type of damage along the ion path. This is because of the more significant difference between damage and range distributions in the case of MeV implants as opposed to keV implants. Previous works showed that MeV-implanted Si-ions react differently with various types of lattice damage in silicon; interactions range from simple point-defect annihilation to the formation of extended defects. Earlier investigations of Au implanted into previously amorphized silicon have observed Au segregation as a result of its being expelled from the recrystallizing amorphous layer during ion-beam irradiation. In this study, the interaction of MeV Au++ atoms with the different types of damage produced along the MeV-ion beam path is investigated.Silicon (100) single crystal wafers were given a HF dip and were then mounted on a copper sample stage; the stage functions as a heat-sink. The stage together with the specimen was then placed in a Tandem ion-implanter. The specimens were implanted with gold; implant-energies varied from 1.8 - 4.4 MeV and fluences ranged between 0.1 - 10×1016 Au++/cm2.

scholarly journals The displacement field associated with the freezing of a melt and its role in determining crystal growth kinetics

2020 ◽  
Vol 117 (7) ◽  
pp. 3421-3426 ◽  
Author(s):  
Gang Sun ◽  
Alexander Hawken ◽  
Peter Harrowell
Keyword(s):  
Activation Energy ◽  
Crystal Growth ◽  
Growth Kinetics ◽  
Optimal Transport ◽  
Atomic Diffusion ◽  
Bulk Liquid ◽  
Face Centered Cubic ◽  
Atomic Displacements ◽  
Assignment Algorithm ◽  
Crystal Growth Kinetics

The atomic displacements associated with the freezing of metals and salts are calculated by treating crystal growth as an assignment problem through the use of an optimal transport algorithm. Converting these displacements into timescales based on the dynamics of the bulk liquid, we show that we can predict the activation energy for crystal growth rates, including activation energies significantly smaller than those for atomic diffusion in the liquid. The exception to this success, pure metals that freeze into face-centered cubic crystals with little to no activation energy, are discussed. The atomic displacements generated by the assignment algorithm allows us to quantify the key roles of crystal structure and liquid caging length in determining the temperature dependence of crystal growth kinetics.

Effect of Implant Energy on Silicon Defect Evolution

1997 ◽  
Vol 469 ◽  
Author(s):  
J. Desroches ◽  
V. Krishnamoorthy ◽  
K. S. Jones ◽  
C. Jasper
Keyword(s):  
Activation Energy ◽  
Primary Source ◽  
Extended Defects ◽  
Dislocation Loops ◽  
Dose Ratio ◽  
Cross Sectional ◽  
Plan View ◽  
Enhanced Diffusion ◽  
Defect Evolution ◽  
The Relationship

ABSTRACTRecent studies on the relationship between defect evolution and transient enhanced diffusion (TED) have lead to the discovery that, for sub-amorphous Si+ implants, atoms released by extended defects (i.e. {311}'s) are a primary source of interstitials for TED. In this paper, the effect of implant energy on the interstitials stored in {311} defects is reported. Silicon wafers were implanted with Si+ at fluences of 1×1014/cm2 and 2×1014/cm2 and energies of 30, 50 and 100 keV. Rapid thermal anneals (RTA) and furnace anneals were performed at times ranging from a few minutes to several hours, at temperatures of 700°, 750° and 800°C. Cross-sectional and plan-view TEM was used to obtain microstructural information. The extended defects observed upon annealing consisted of both {311} defects and dislocation loops. It was found that the ratio of the interstitials bound by extended defects and the implant dose was 0.3. Changing the implant energy did not change the total number of interstitials trapped in both types of defects combined. There was a noticeable variation in the type of defect that dominated each implant regime, despite the constant value of the trapped interstitial to dose ratio. For an RTA of 5 min. at 750°C, the ratio of {311} “rod-like” defects to dislocation loops in the 2×1014/cm2 sample unexpectedly increased as the energy increased from 30 to 50 keV.Longer furnace anneals were employed to determine the activation energy of {311} dissolution. Our data suggests a slightly higher activation energy for {311} dissolution of approximately 4.2 eV versus the previously reported 3.6 eV, however, this difference may be within experimental error.

The Role of Low-Energy Ion/Surface Interactions During Crystal Growth from the Vapor Phase: Effects on Microchemistry and Microstructure

1989 ◽  
Vol 165 ◽  
Author(s):  
J. E. Greene ◽  
J.-E. Sundgren
Keyword(s):  
Crystal Growth ◽  
Vapor Phase ◽  
Growth Kinetics ◽  
Film Growth ◽  
Ion Irradiation ◽  
Chemical Vapor ◽  
Low Energy ◽  
Enhanced Diffusion ◽  
Preferential Sputtering

Low-energy (≤ 200 eV) ion irradiation during crystal growth from the vapor phase can be used to provide new chemical reaction pathways, modify film-growth kinetics, and, hence, controllably alter the physical properties of films deposited by a variety of techniques. The latter includes sputter deposition, ion plating, plasma-assisted chemical vapor deposition (PA-CVD), primary-ion deposition (PID), and molecular-beam epitaxy (MBE) using accelerated beam sources. Ion/surface interaction effects such as ion-induced chemistry, trapping, recoil implantation, preferential sputtering, collisional mixing, enhanced diffusion, and alteration in segregation behavior are used to interpret and model experimental results concerning the effects of low-energy particle bombardment on nucleation and growth kinetics, elemental incorporation probabilities, compositional depth distributions, and the growth of metastable phases.

scholarly journals Thermal kinetics of micro-defects in He-ion implanted W and W5Re alloys

Tungsten ◽  
2021 ◽  
Author(s):  
Yong-Li Liu ◽  
Ya-Min Song ◽  
Lei Li ◽  
Ruo-Yu Bai ◽  
Peng Zhang ◽  
...  
Keyword(s):  
Positron Annihilation ◽  
Annealing Temperature ◽  
Thermal Evolution ◽  
Ion Irradiation ◽  
Positron Annihilation Spectroscopy ◽  
Vacancy Cluster ◽  
Dislocation Loops ◽  
Positron Annihilation Lifetime ◽  
Vacancy Clusters ◽  
Nucleation Sites

AbstractTo investigate the thermal evolution of vacancy-type defects in He-ion irradiated W and W5Re alloy, different isochronal annealing treatments from 373 to 1273 K were conducted on the irradiated materials. Positron annihilation spectroscopy including positron annihilation lifetime spectroscopy and Doppler broadening spectroscopy were mainly used to characterize the micro-defects evolution. The results showed that the thermal evolution characteristics of defects in both W and W5Re were similar. After He-ion irradiation, mono-vacancies with positron annihilation lifetime of ~ 190 ps were detected in W, together with a large amount of dislocation loops with positron annihilation lifetime of ~ 150 ps in W5Re alloys. The coarsening of vacancy clusters at the expense of small vacancy clusters was the main thermal evolution feature of vacancy-type defects in both W and W5Re when annealing temperature increased to 1073 K. In this progress, the positron annihilation lifetime increased to ~ 350 ps (clusters composed of 4 –8 mono-vacancies) in both W and W5Re. As the temperature increased to 1273 K, the positron annihilation lifetime decreased to ~ 240 ps, which was attributed to a significant population reduction of the dislocation loops, the dissociation of large HenVm complexes and the annealing of micro-voids in both W and W5Re. The vacancy-type defects in W5Re were more susceptible to the annealing temperature because of the formation of vacancy cluster-Re complexes. Re clusters in irradiated W5Re alloy could serve as the nucleation sites of He bubbles, which promoted the swelling and protrusion formation on the surface.

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