Ion Irradiation of GeSi/Si Strained-Layer Heterostructures

1998 ◽  
Vol 540 ◽  
Author(s):  
J.M. Glaskol ◽  
R. G. Elliman ◽  
J. Zou ◽  
D.J.H. Cockayne ◽  
J. D. Fitz Gerald
Keyword(s):  
Ion Irradiation ◽  
Strain Relaxation ◽  
Compressive Strain ◽  
High Energy ◽  
Alloy Layer ◽  
Strained Layer ◽  
Projected Range ◽  
Annealing Conditions ◽  
Temperature Irradiation ◽  
Energy Irradiation

AbstractThe strain in GeSi/Si strained layer heterostructures is studied as a function of ion-irradiation and thermal annealing conditions and correlated with the defect microstructure in the GeSi alloy layer. For room temperature irradiation, compressive strain within the alloy layer increases with increasing ion fluence for both low (projected range of ions within the alloy layer) and high energy (projected range of the ions greater than alloy thickness) irradiation. In contrast, elevated temperature irradiation results in an increase in strain for low-energy irradiation, but a decrease for high-energy irradiation. For example, strain relaxation is observed in layers irradiated with I MeV 28Si+ at 253 °C. During subsequent annealing to 750 °C, the strain is partially recovered but relaxes again at temperatures > 750°C. This behavior is shown to be consistent with the evolution of intrinsic (vacancy-type) defects within the alloy layer.

The Effect Of Ion-Implantation Induced Defects On Strain Relaxation In GexSi1−x/Si Heterostuctures

1996 ◽  
Vol 442 ◽  
Author(s):  
J. M. Glasko ◽  
J. Zou ◽  
D. J. H. Cockayne ◽  
J. Fitz Gerald ◽  
P. KringhøJ ◽  
...  
Keyword(s):  
Thermal Annealing ◽  
Ion Irradiation ◽  
Strain Relaxation ◽  
High Energy ◽  
Alloy Layer ◽  
Misfit Dislocations ◽  
Thermally Induced ◽  
Energy Irradiation ◽  
Induced Defects ◽  
Subsequent Thermal Annealing

AbstractThis study examined the effect of ion irradiation and subsequent thermal annealing on GeSi/Si strained-layer heterostructures. Comparison between samples irradiated at 253°C with low energy (23 keV) and high energy (1.0 MeV) Si ions showed that damage within the alloy layer increases the strain whereas irradiation through the layer/substrate interface decreases the strain. Loop-like defects formed at the GeSi/Si interface during high energy irradiation and interacting segments of these defects were shown to have edge character with Burgers vector a/2<110>. These defects are believed responsible for the observed strain relief. Irradiation was also shown to affect strain relaxation kinetics and defect morphologies during subsequent thermal annealing. For example, after annealing to 900°C, un-irradiated material contained thermally-induced misfit dislocations, while ion-irradiated samples showed no such dislocations.

Band Gap Engineering of Nano Scale AlGaN Epitaxial Layers by Swift Heavy Ion Irradiation

2009 ◽  
Vol 1181 ◽  
Author(s):  
SATHISH N ◽  
Devaraju G ◽  
Srinivasa Rao N ◽  
Anand Pathak ◽  
Andrzej Turos ◽  
...  
Keyword(s):  
Optical Properties ◽  
Defect Density ◽  
Ion Irradiation ◽  
Compressive Strain ◽  
Heavy Ion ◽  
High Energy ◽  
Epitaxial Layers ◽  
Algan Layer ◽  
Before And After ◽  
Energy Irradiation

AbstractEpitaxial AlGaN/GaN layers grown by MBE on SiC substrates were irradiated with 150 MeV Ag ions at a fluence of 5×1012 ions/cm2. AlGaN/GaN MQWs were grown on Sapphire substrate by MOCVD and irradiated with 200 MeV Au8+ ions at a fluence of 5×1011 ions/cm2 . These samples were used to study the effects of SHI on optical properties of AlGaN/GaN based nano structures. RBS/Channelling strain measurements were carried out at off normal axis of irradiated and unirradiated samples. In as grown samples, AlGaN layer is partially relaxed with a small compressive strain. After irradiation this compressive strain increases by 0.22% in AlGaN layer. Incident ion energy dependence of dechannelling parameter shows E1/2 dependence, which corresponds to the dislocations. Defect densities were calculated from the E1/2 graph. As a result of irradiation defect density increased on both GaN and AlGaN layer. Optical properties of AlGaN/GaN MQWs before and after irradiation have been analyzed using PL. This study shows that SHI increase the confinement effects in the MQWs and intensity of the active layer of the MQWs luminescence is increased by one order. This may be due to the induced strain in GaN and AlGaN layers. Some unwanted yellow luminescence has also been introduced by the SHI possibly due the point defects or defect luminescence from the induced dislocations in GaN bulk epitaxial layers. In this study, we present some new results concerning high energy irradiation on AlGaN/GaN heterostructures and MQWs characterized by RBS/Channelling and PL.

The Differences between the InyGa1−yAs/GaAs Interface and GaAs/InyGa1−yAs Interface in Superlattice over a InxGa1−xAs (x

1996 ◽  
Vol 442 ◽  
Author(s):  
X.J Wang ◽  
L.X Zheng ◽  
Z.B Xiao ◽  
Z.P Zhang ◽  
X.W Hu ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Strain Relaxation ◽  
Compressive Strain ◽  
Critical Value ◽  
Alloy Layer ◽  
Relaxation Model ◽  
Indium Composition ◽  
Partial Dislocations ◽  
The Difference ◽  
First Time

AbstractThe InyGa1−yAs/GaAs superlattice on InxGa1−x.As (x<y) buffer layer was grown by MOCVD. The well layer is under compressive strain and the barrier layer is under tensile strain. However, both layers do not exceed the calculated critical value based on the M−yAs interface was smoother than the InyGa1−yAs/GaAs interface; the Indium composition gradual region at the GaAs/InyGal1−yAs interface was narrower than that at the InyGa 1−yAs/GaAs interface; in InyGa1−yAs alloy layer, the Indium composition near the GaAs/InyGa1-yAs interface was higher than that near another interface. For the first time, we explained the composition profile in this kind of superlattice based on the indium segregation theory. A new strain relaxation model, in which the 30-degree and 90-degree shockley partial dislocations were taken into account under both tensile and compressive strains, was presented to explain the difference of the smoothness between the GaAs/InyGa1−yAs interface and the InyGa 1−yAs/GaAs interface.

scholarly journals Damage Growth in Si During Self-Ion Irradiation: a Study of Ion Effects Over an Extended Energy Range

1989 ◽  
Vol 147 ◽  
Author(s):  
O. W. Holland ◽  
M. K. El-Ghor ◽  
C. W. White
Keyword(s):  
Ion Irradiation ◽  
High Energy ◽  
Medium Energy ◽  
Damage Growth ◽  
Ion Channeling ◽  
Energy Irradiation ◽  
Ion Effects ◽  
Complete Annealing ◽  
High Energy Irradiation

AbstractDamage nucleation/growth in single-crystal Si during ion irradiation is discussed. For MeV ions, the rate of growth as was well as the damage morphology are shown to vary widely along the track of the ion. This is attributed to a change in the dominant, defect-related reactions as the ion penetrates the crystal. The nature of these reactions were elucidated by studying the interaction of MeV ions with different types of defects. The defects were introduced into the Si crystal prior to high-energy irradiation by self-ion implantation at a medium energy (100 keV). Varied damage morphologies were produced by implanting different ion fluences. Electron microscopy and ion-channeling measurements, in conjunction with annealing studies, were used to characterize the damage. Subtle changes in the predamage morphology are shown to result in markedly different responses to the high-energy irradiation, ranging from complete annealing of the damage to rapid growth. These divergent responses occur over a narrow range of dose (2–3 × 1014 cm-2) of the medium-energy ions; this range also marks a transition in the growth behavior of the damage during the predamaging implantation. A model is proposed which accounts for these observations and provides insight into ion-induced growth of amorphous layers in Si and the role of the amorphous/crystalline interface in this process.

scholarly journals Effects of He+ and H+ Co-Implantation with High Energy on Blisters and Craters of Si and SiO2-On-Si Wafers

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 671
Author(s):  
Rui Huang ◽  
Tian Lan ◽  
Chong Li ◽  
Jing Li ◽  
Zhiyong Wang
Keyword(s):  
Raman Spectroscopy ◽  
Surface Morphology ◽  
Annealing Temperature ◽  
High Energy ◽  
Transfer Layer ◽  
Implantation Energy ◽  
Force Microscopy ◽  
Projected Range ◽  
Annealing Conditions ◽  
Atomic Force

In this paper, effects of He+ and H+ co-implantation with high implantation energy on surface blisters and craters at different annealing conditions are systematically investigated. Surface morphology as well as defect microstructure are observed and analyzed by various approaches, such as scanning electron microscopy (SEM), optical microscopy (OM), atomic force microscopy (AFM), and Raman spectroscopy. It is found that after 500 °C annealing and above for 1 h, surface blisters and exfoliation are observed for Si and SiO2-on-Si wafers except for the samples implanted with only He+ ions. AFM images reveal that the heights of blisters in Si and SiO2-on-Si wafers are 432 nm and 397 nm respectively and the thickness of transfer layer is at the depth of about 1.4 μm, which is consistent with the projected range of He+ and H+ ions. Raman spectroscopy demonstrates that higher annealing temperature can lead to a stronger intensity of the VH2 peak. Under the same implantation parameters, surface morphology of Si and SiO2-on-Si wafers is different after annealing process. This phenomenon is discussed in detail.

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.

Transmission Electron Microscopy characterization of epitaxial III-V semiconductor thin films grown on Si(100) by ion-assisted deposition

1990 ◽  
Vol 48 (4) ◽  
pp. 686-687
Author(s):  
L. Hultman ◽  
C.-H. Choi ◽  
R. Kaspi ◽  
R. Ai ◽  
S.A. Barnett
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Irradiation ◽  
High Energy ◽  
Nucleation Mechanism ◽  
Layer By Layer ◽  
Extended Defect ◽  
Island Formation ◽  
Si Substrates ◽  
Transmission Electron

III-V semiconductor films nucleate by the Stranski-Krastanov (SK) mechanism on Si substrates. Many of the extended defects present in the films are believed to result from the island formation and coalescence stage of SK growth. We have recently shown that low (-30 eV) energy, high flux (4 ions per deposited atom), Ar ion irradiation during nucleation of III-V semiconductors on Si substrates prolongs the 1ayer-by-layer stage of SK nucleation, leading to a decrease in extended defect densities. Furthermore, the epitaxial temperature was reduced by >100°C due to ion irradiation. The effect of ion bombardment on the nucleation mechanism was explained as being due to ion-induced dissociation of three-dimensional islands and ion-enhanced surface diffusion.For the case of InAs grown at 380°C on Si(100) (11% lattice mismatch), where island formation is expected after ≤ 1 monolayer (ML) during molecular beam epitaxy (MBE), in-situ reflection high-energy electron diffraction (RHEED) showed that 28 eV Ar ion irradiation prolonged the layer-by-layer stage of SK nucleation up to 10 ML. Otherion energies maintained layer-by-layer growth to lesser thicknesses. The ion-induced change in nucleation mechanism resulted in smoother surfaces and improved the crystalline perfection of thicker films as shown by transmission electron microscopy and X-ray rocking curve studies.

scholarly journals Ion tracks in silicon formed by much lower energy deposition than the track formation threshold

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
H. Amekura ◽  
M. Toulemonde ◽  
K. Narumi ◽  
R. Li ◽  
A. Chiba ◽  
...  
Keyword(s):  
Nuclear Energy ◽  
Energy Deposition ◽  
Ion Irradiation ◽  
High Energy ◽  
Electronic Energy ◽  
Synergy Effect ◽  
Ion Tracks ◽  
Track Formation ◽  
Low Energies ◽  
High Energy Ions

AbstractDamaged regions of cylindrical shapes called ion tracks, typically in nano-meters wide and tens micro-meters long, are formed along the ion trajectories in many insulators, when high energy ions in the electronic stopping regime are injected. In most cases, the ion tracks were assumed as consequences of dense electronic energy deposition from the high energy ions, except some cases where the synergy effect with the nuclear energy deposition plays an important role. In crystalline Si (c-Si), no tracks have been observed with any monomer ions up to GeV. Tracks are formed in c-Si under 40 MeV fullerene (C60) cluster ion irradiation, which provides much higher energy deposition than monomer ions. The track diameter decreases with decreasing the ion energy until they disappear at an extrapolated value of ~ 17 MeV. However, here we report the track formation of 10 nm in diameter under C60 ion irradiation of 6 MeV, i.e., much lower than the extrapolated threshold. The diameters of 10 nm were comparable to those under 40 MeV C60 irradiation. Furthermore, the tracks formed by 6 MeV C60 irradiation consisted of damaged crystalline, while those formed by 40 MeV C60 irradiation were amorphous. The track formation was observed down to 1 MeV and probably lower with decreasing the track diameters. The track lengths were much shorter than those expected from the drop of Se below the threshold. These track formations at such low energies cannot be explained by the conventional purely electronic energy deposition mechanism, indicating another origin, e.g., the synergy effect between the electronic and nuclear energy depositions, or dual transitions of transient melting and boiling.

Structural change by high-energy ion irradiation and post-annealing in EuBa2Cu3Oy

2002 ◽  
Vol 378-381 ◽  
pp. 527-530 ◽  
Author(s):  
H Sato ◽  
N Ishikawa ◽  
A Iwase ◽  
Y Chimi ◽  
T Hashimoto ◽  
...  
Keyword(s):  
Structural Change ◽  
Ion Irradiation ◽  
High Energy ◽  
Post Annealing
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