Dechannealing Study of Nanocrystalline Si:H Layers Produced by High Dose Hydrogen Irradiation of Silicon Crystals

1998 ◽  
Vol 536 ◽  
Author(s):  
V. P. Popov ◽  
A. K. Gutakovsky ◽  
I. V. Antonova ◽  
K. S. Zhuravlev ◽  
E. V. Spesivtsev ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Rutherford Backscattering Spectrometry ◽  
Nanocrystalline Structure ◽  
Structural Defects ◽  
High Dose ◽  
Silicon Crystals ◽  
Strong Energy ◽  
Transmission Electron ◽  
Hydrogen Implantation

AbstractA study of Si:H layers formed by high dose hydrogen implantation (up to 3x107cm-2) using pulsed beams with mean currents up 40 mA/cm2 was carried out in the present work. The Rutherford backscattering spectrometry (RBS), channeling of He ions, and transmission electron microscopy (TEM) were used to study the implanted silicon, and to identify the structural defects (a-Si islands and nanocrystallites). Implantation regimes used in this work lead to creation of the layers, which contain hydrogen concentrations higher than 15 at.% as well as the high defect concentrations. As a result, the nano- and microcavities that are created in the silicon fill with hydrogen. Annealing of this silicon removes the radiation defects and leads to a nanocrystalline structure of implanted layer. A strong energy dependence of dechanneling, connected with formation of quasi nanocrystallites, which have mutual small angle disorientation (<1.50), was found after moderate annealing in the range 200-500°C. The nanocrystalline regions are in the range of 2-4 nm were estimated on the basis of the suggested dechanneling model and transmission electron microscopy (TEM) measurements. Correlation between spectroscopic ellipsometry, visible photoluminescence, and sizes of nanocrystallites in hydrogenated nc-Si:H is observed.

Formation of Excess Donors During High-Dose 74Ge+ Ion Implantation

1994 ◽  
Vol 354 ◽  
Author(s):  
Z. Xia ◽  
E. Ristolainen ◽  
R. Elliman ◽  
H. Ronkainen ◽  
S. Eränen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Structural Defects ◽  
High Dose ◽  
Donor Concentration ◽  
Materials Analysis ◽  
Si Substrates ◽  
Transmission Electron ◽  
Activation Annealing ◽  
Secondary Ion

AbstractRecently observations that high-dose Ge implantations into Si substrates caused the n-type carrier concentration to increase were attributed to residual structural defects after activation annealing [7,12]. However, co-implantation of an n-type impurity is another possibility. The origin of this excess donor concentration has been studied in this work. The possibilities of residual defects versus implantation of impurities have been investigated using two different implanters and materials analysis. Comparison of data from different implanters showed that the concentration of excess donors was sensitive to the implanter configuration. Furthermore, transmission electron microscopy (TEM), Rutherford backscattering channeling (RBS-C), and spreading resistance profiling (SRP) data showed that the excess donor effect was related to impurities rather than residual defects. Secondary-ion mass spectroscopy (SIMS) and SRP measurements confirmed that impurities such as 75As ions were present after implants. This impurity easily explains the excess donor concentration when 75Ge implants are performed into silicon wafers doped with phosphorous.

Citrate Stabilized Silver Nanoparticles

2011 ◽  
Vol 3 (3) ◽  
pp. 15-28 ◽  
Author(s):  
Nabraj Bhattarai ◽  
Subarna Khanal ◽  
Pushpa Raj Pudasaini ◽  
Shanna Pahl ◽  
Dulce Romero-Urbina
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Colloidal Solution ◽  
Measurement Techniques ◽  
Structural Defects ◽  
Potential Measurement ◽  
Transmission Electron

Citrate stabilized silver (Ag) colloidal solution were synthesized and characterized for crystallographic and surface properties by using transmission electron microscopy (TEM) and zeta potential measurement techniques. TEM investigation depicted the size of Ago ranges from 5 to 50 nm with smaller particles having single crystal structure while larger particles with structural defects (such as multiply twinned, high coalescence and Moire patterns). ?-potential measurement confirms the presence of Ag+ in nAg stock solution. The shift in ?-potential measurement by +25.1 mV in the filtered solution suggests the presence of Ag+ in Ago nanoparticles.

scholarly journals Thermal Annealing of High Dose P Implantation in 4H-SiC

2019 ◽  
Vol 963 ◽  
pp. 399-402 ◽  
Author(s):  
Cristiano Calabretta ◽  
Massimo Zimbone ◽  
Eric G. Barbagiovanni ◽  
Simona Boninelli ◽  
Nicolò Piluso ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Raman Spectroscopy ◽  
Ion Implantation ◽  
Epitaxial Layer ◽  
Point Defects ◽  
High Dose ◽  
Double Step ◽  
Post Annealing ◽  
Transmission Electron

In this work, we have studied the crystal defectiveness and doping activation subsequent to ion implantation and post-annealing by using various techniques including photoluminescence (PL), Raman spectroscopy and transmission electron microscopy (TEM). The aim of this work was to test the effectiveness of double step annealing to reduce the density of point defects generated during the annealing of a P implanted 4H-SiC epitaxial layer. The outcome of this work evidences that neither the first 1 hour isochronal annealing at 1650 - 1700 - 1750 °C, nor the second one at 1500 °C for times between 4 hour and 14 hour were able to recover a satisfactory crystallinity of the sample and achieve dopant activations exceeding 1%.

Synthesis of NiSi2 by 6 MeV Ni implantation into silicon

1988 ◽  
Vol 3 (6) ◽  
pp. 1238-1246 ◽  
Author(s):  
J. K. N. Lindner ◽  
E. H. te Kaat
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Depth Distribution ◽  
Depth Profiling ◽  
Type A ◽  
High Dose ◽  
Metal Atoms ◽  
Transmission Electron ◽  
Defective Layer ◽  
Lattice Planes

Six MeV high-dose Ni implantation into silicon has been applied to synthesize deep-buried metallic layers. These layers have been analyzed by optical reflectivity and spreading resistance depth profiling as well as transmission electron microscopy and cross-section transmission electron microscopy. Already in the as-implanted state, at target temperatures of 450 K and doses above 1017 Ni/cm2, epitaxial precipitates of NiSi2 are formed. They grow in type-A and type-B orientations. In addition to these polyhedral crystallites, thin NiSi2 platelets on {111} lattice planes exist. At a dose of 1.3 × 1018 Ni/cm2, a continuous but highly defective layer of epitaxial NiSi2 is formed by coalescence of mainly type-A precipitates at the maximum of the Ni profile. Investigations indicate that damage gettering of nickel atoms as well as the atomic density increase during implantation influence the depth distribution of implanted metal atoms. Moreover, a suppression of silicon amorphization by nickel is evident.

Formation of Nanovoids and Nanocolumns in High Dose Hydrogen Implanted ZnO Bulk Crystals

2006 ◽  
Vol 957 ◽  
Author(s):  
Rajendra Singh ◽  
R. Scholz ◽  
U. Gösele ◽  
S. H. Christiansen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Dose ◽  
Hydrogen Ions ◽  
Bulk Crystals ◽  
Cross Sectional ◽  
Projected Range ◽  
Transmission Electron ◽  
Wafer Surfaces ◽  
Post Implantation

ABSTRACTZnO(0001) bulk crystals were implanted with 100 keV H2+ ions with various doses in the range of 5×1016 to 3×1017 cm-2. The ZnO crystals implanted up to a dose of 2.2×1017 cm-2 did not show any surface exfoliation, even after post-implantation annealing at temperatures up to 800°C for 1 h while those crystals implanted with a dose of 2.8×1017 cm-2 or higher exhibited exfoliated surfaces already in the as-implanted state. In a narrow dose window in between, controlled exfoliation could be obtained upon post-implantation annealing only. Cross-sectional transmission electron microscopy (XTEM) of the implanted ZnO samples showed that a large number of nanovoids were formed within the implantation-induced damage band. These nanovoids served as precursors for the formation of microcracks leading to the exfoliation of ZnO wafer surfaces. In addition to the nanovoids, elongated nanocolumns perpendicular to the ZnO wafer surfaces were also observed. These nanocolumns showed diameters of up to 10 nm and lengths of up to 500 nm. The nanocolumns were found in the ZnO wafer even well beyond the projected range of hydrogen ions.

High Resolution Transmission Electron Microscopy of Proton Implanted Gallium Arsenide

1985 ◽  
Vol 46 ◽  
Author(s):  
D. K. Sadana ◽  
J. M. Zavada ◽  
H. A. Jenkinson ◽  
T. Sands
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Phenomenological Model ◽  
Room Temperature ◽  
Stacking Faults ◽  
High Dose ◽  
Cross Sectional ◽  
Projected Range ◽  
Transmission Electron

AbstractHigh resolution transmission electron microscopy (HRTEM) has been performed on cross-sectional specimens from high dose (1016 cm−2) H+ implanted (100) GaAs (300 keV at room temperature). It was found that annealing at 500°C created small (20-50Å) loops on {111} near the projected range (Rp)(3.2 μm). At 550-600°C, voids surrounded by stacking faults, microtwins and perfect dislocations were observed near the Rp. A phenomenological model explaining the observed results is proposed.

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