Structural Defects in Laser Annealed Arsenic Implanted Silicon

1990 ◽  
Vol 209 ◽  
Author(s):  
J. M. Tonnerre ◽  
M. Matsuura ◽  
G. S. Cargill III ◽  
L. W. Hobbs
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Structural Defects ◽  
Dislocation Loops ◽  
Double Crystal ◽  
Rocking Curve ◽  
X Ray ◽  
Positive Strain ◽  
Transmission Electron ◽  
Heavily Doped

ABSTRACTLaser annealed arsenic implanted silicon specimens with doses ranging from 6×1015 to 7×1016 As/cm 2 have been investigated by transmission electron microscopy (TEM) and double crystal xray diffractometry (DCD). For the highest implant dose, laser powers ranging from 1.1 to 2.2 J/cm 2 have been used. Experimental observations show two new features for this kind of specimen. First, in some cases, TEM micrographs evidence small (˜50Å diameter) precipitate-like defects and/or dislocation loops confined within the heavily doped region. Second, in some cases, DCD shows a positive strain in addition to the negative strain attributed to 90% As in substitutional sites. X-ray rocking-curve simulations reveal that the negative strain drops to zero around 1000Å before the end of the As distribution. This might be related to the presence of Si interstitials in the deepest region of the As distribution.

Conversion of platelets into dislocation loops and voidite formation in type IaB diamonds

1995 ◽  
Vol 449 (1936) ◽  
pp. 295-313 ◽  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Local Mode ◽  
Diamond Structure ◽  
Dislocation Loops ◽  
X Ray ◽  
Regular Type ◽  
Transmission Electron ◽  
Stable Conditions ◽  
The One

Type la natural diamonds have been heated in the temperature range of 2400-2700°C under stabilizing pressures. The specimens studied are mainly regular type IaB diamonds. Transmission electron microscopy studies of treated speci­mens show that platelets are converted to interstitial ½ a 0 <011> dislocation loops; voidites are also formed. When all the platelets have been converted, the ex­perimental features associated with them also disappear, i. e. the X-ray extra reflections (spikes), the B' local-mode absorption and the lattice absorption in the one-phonon region termed the D spectrum. It is discovered that when diamonds are heated under graphite-stable rather than diamond-stable conditions, the rate of conversion is considerably enhanced; for instance, at 2650°C there is an increase in the rate of about three orders of magnitude. This enhancement is considered to be due to the instability of the diamond structure itself and a reason for this enhancement is suggested.

Stability of Heavily Doped Si Formed by As+ Implantation and Rapid Thermal Annealing

1985 ◽  
Vol 52 ◽  
Author(s):  
Muhammad Z. Numan ◽  
Z. H. Lu ◽  
W. K. Chu ◽  
D. Fathy ◽  
J. J. Wortman
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Thermal Annealing ◽  
Dislocation Loops ◽  
Sheet Resistivity ◽  
Furnace Annealing ◽  
Transmission Electron ◽  
Heavily Doped ◽  
Sheet Resistance Measurement ◽  
Short Time

ABSTRACTDeactivation of ion implanted and rapid thermal annealed (RTA) metastable arsenic in silicon during subsequent furnace annealing has been studied by sheet resistance measurement, Rutherford backs cat t ering/ channeling (RBS), and transmission electron microscopy (TEM). Following RTA, thermal annealing induces deactivation of the dopant which increases the sheet resistivity monotonically with temperature for a very short time, Dislocation loops are formed near the peak of As concentration at post-anneal temperatures of 750°C or higher, where deactivation rate is fast. At lower temperatures deactivation is accompanied by displacement of As atoms, possibly forming clusters.

scholarly journals Microstructure Evolution in He-Implanted Si at 600 °C Followed by 1000 °C Annealing

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5107
Author(s):  
Zhen Yang ◽  
Zhiping Zou ◽  
Zeyang Zhang ◽  
Yubo Xing ◽  
Tao Wang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Single Crystal ◽  
Microstructure Evolution ◽  
Cavity Growth ◽  
Stacking Fault ◽  
Structural Defects ◽  
Dislocation Loops ◽  
Transmission Electron

Si single crystal was implanted with 230 keV He+ ions to a fluence of 5 × 1016/cm2 at 600 °C. The structural defects in Si implanted with He at 600 °C and then annealed at 1000 °C were investigated by transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The microstructure of an as-implanted sample is provided for comparison. After annealing, rod-like defects were diminished, while tangled dislocations and large dislocation loops appeared. Dislocation lines trapped by cavities were directly observed. The cavities remained stable except for a transition of shape, from octahedron to tetrakaidecahedron. Stacking-fault tetrahedrons were found simultaneously. Cavity growth was independent of dislocations. The evolution of observed lattice defects is discussed.

scholarly journals Sol-Gel Derived Eu3+-Doped Gd2Ti2O7Pyrochlore Nanopowders

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Sanja Ćulubrk ◽  
Željka Antić ◽  
Vesna Lojpur ◽  
Milena Marinović-Cincović ◽  
Miroslav D. Dramićanin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Structural Changes ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Structural Defects ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Synthesis

Herein we presented hydrolytic sol-gel synthesis and photoluminescent properties of Eu3+-doped Gd2Ti2O7pyrochlore nanopowders. According to Gd2Ti2O7precursor gel thermal analysis a temperature of 840°C is identified for the formation of the crystalline pyrochlore phase. Obtained samples were systematically characterized by powder X-ray diffraction, scanning and transmission electron microscopy, and photoluminescence spectroscopy. The powders consist of well-crystalline cubic nanocrystallites of approximately 20 nm in size as evidenced from X-ray diffraction. The scanning and transmission electron microscopy shows that investigated Eu3+-doped Gd2Ti2O7nanopowders consist of compact, dense aggregates composed entirely of nanoparticles with variable both shape and dimension. The influence of Eu3+ions concentration on the optical properties, namely, photoluminescence emission and decay time, is measured and discussed. Emission intensity as a function of Eu3+ions concentration shows that Gd2Ti2O7host can accept Eu3+ions in concentrations up to 10 at.%. On the other hand, lifetime values are similar up to 3 at.% (~2.7 ms) and experience decrease at higher concentrations (2.4 ms for 10 at.% Eu3+). Moreover, photoluminescent spectra and lifetime values clearly revealed presence of structural defects in sol-gel derived materials proposing photoluminescent spectroscopy as a sensitive tool for monitoring structural changes in both steady state and lifetime domains.

Tem Study of Temperature Influence on The Crystalline Quality of InGaAs/Si Epilayers

1992 ◽  
Vol 263 ◽  
Author(s):  
A. Vila ◽  
A. Cornet ◽  
J.R. Morante ◽  
D.I. Westwood
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Molecular Beam ◽  
Temperature Influence ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
X Ray ◽  
Transmission Electron ◽  
Different Temperatures

ABSTRACTA Transmission Electron Microscopy (TEM) study of In0.53Ga0.47As Molecular Beam Epitaxy films grown at different temperatures onto misoriented Si (100) substrates is presented. The evolution of the density of the different kind of defects is discussed as a function of the growth temperature in the range between 200 and 500° C. The results are compared with the characterization techniques of Double Crystal X-Ray Diffraction and Hall effect.

Orientation Dependence of CdTe/Si Grown by MBE

1995 ◽  
Vol 399 ◽  
Author(s):  
L. A. Almeida ◽  
Y. P. Chen ◽  
J. P. Faurie ◽  
David J. Smith ◽  
S.-C. Y. Tsen ◽  
...  
Keyword(s):  
Growth Conditions ◽  
Orientation Dependence ◽  
Structural Defects ◽  
X Ray Diffraction ◽  
Substrate Preparation ◽  
Double Crystal ◽  
Interface Quality ◽  
Rocking Curve ◽  
X Ray ◽  
Transmission Electron

ABSTRACTIn this study CdTe (111)B was grown by molecular beam epitaxy on vicinal Si(001) substrates, with a variety of substrate tilt angles (θ), and tilt directions (φ) relative to [110]. Layer quality, and content of double-domain and microtwin defects were evaluated by double crystal rocking curve (DCRC) full width at half maximum (FWHM) and x-ray diffraction, respectively. Transmission electron microscopy (TEM) was used to study interface quality and the nature of structural defects as a function of epilayer thickness. In the present investigation, substrate preparation and growth conditions, particularly initiation conditions, are correlated with Si (001) tilt. It has been found that oxide desorption processes can depend strongly on θ, especially for larger values of θ (> 4°). Currently, we routinely produce single domain, twin-free CdTe(111)B epilayers on vicinal Si (001) substrates.

Structural Defects in Ion Implanted 4H-SiC Epilayers

2000 ◽  
Vol 640 ◽  
Author(s):  
P. O. Å. Persson ◽  
W. Skorupa ◽  
D. Panknin ◽  
A. Kuznetsov ◽  
A. Hallén ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Annealing Process ◽  
Ion Concentration ◽  
Electrical Activation ◽  
Structural Defects ◽  
Dislocation Loops ◽  
Transmission Electron ◽  
Residual Damage ◽  
Vacancy Concentrations

ABSTRACTTransmission electron microscopy (TEM) was used to investigate Al, Ar, C and Si ionimplanted 4H-SiC epilayers. After the implantation the samples were thermally annealed for 30 minutes at 1700°C. During the annealing process dislocation loops are formed and the generation of such dislocation loops upon annealing, is investigated with respect to dopant electrical activation, peak ion concentration and calculated interstitial/vacancy concentrations. It is concluded that the dislocation loops are generated as the result of a combination of residual damage and excess interstitials generated in a “plus one” (+1) process.

Characterization Of Single Crystal Epitaxial Aluminum Nitride Thin Films On Sapphire, Silicon Carbide And Silicon Substrates By X-Ray Double Crystal Diffractometry And Transmission Electron Microscopy

1995 ◽  
Vol 39 ◽  
pp. 645-651
Author(s):  
J. Chaudhuri ◽  
R. Thokala ◽  
J. H. Edgar ◽  
B. S. Sywe
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Thin Films ◽  
Residual Stress ◽  
Transmission Electron Microscopy ◽  
Silicon Carbide ◽  
Defect Density ◽  
Double Crystal ◽  
X Ray ◽  
Transmission Electron

Epitaxial AIN thin films grown on sapphire, silicon and silicon carbide substrates were studied using x-ray double crystal diffractometry and transmission electron microscopy to compare the structure, residual stress and defect concentration in these thin films. The AIN thin films was found to have a wurtzite type of structure with a small distortion in lattice parameters which results in a small residual stress of the order of 109 dynes/cm2 in the film. The strain due to lattice parameter mismatch between the substrate and film is too small to account for the residual stress present. The calculated stress from the difference in thermal expansion coefficients between the film and substrate agrees well with the experimental values. Both the x-ray and transmission electron microscopy measurements indicate a low defect density in the AIN thin film grown on 6H-SiC substrate which could be attributed to the small difference in lattice parameters between AIN and 6H-SiC. The defect density in the AIN thin film grown on other substrates were considerably higher. This is the first report of the successful growth of single crystal AIN thin films with such a low concentration of defect density.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

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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