Dislocations Nucleating Growth in Liquid Phase Epitaxy of Gallium Arsenide

1993 ◽  
Vol 312 ◽  
Author(s):  
Werner Möhling ◽  
H. Weishart ◽  
E. Bauser
Keyword(s):  
Gallium Arsenide ◽  
Liquid Phase ◽  
Liquid Phase Epitaxy ◽  
Crystal Surface ◽  
Double Crystal ◽  
Growth Interface ◽  
Growth Step ◽  
Burgers Vector ◽  
X Ray ◽  
Back Reflection

AbstractDislocations in GaAs are analysed by X-ray topography in order to relate their nature to their efficiency in generating growth steps. The analysis is mainly based on comparing double crystal back reflection images of the defects to calculated misorientations of the crystal surface which are caused at the outcrop. All types of dislocations are equally effective provided their Burgers vector has a component normal to the growth interface. Concentric growth step patterns, which develop in varying numbers on different samples are not caused by substrate dislocations.

Vertical stress in liquid-phase epitaxy Si layers on SiO2/Si evaluated by X-ray double-crystal topography

1995 ◽  
Vol 28 (4A) ◽  
pp. A50-A55 ◽  
Author(s):  
R Kohler ◽  
B Jenichen ◽  
H Raidt ◽  
E Bauser ◽  
N Nagel
Keyword(s):  
Liquid Phase ◽  
Liquid Phase Epitaxy ◽  
Vertical Stress ◽  
Double Crystal ◽  
X Ray

scholarly journals X RAY DOUBLE CRYSTAL DIFFRACTION STUDY OF (BiTm)3(FeGa)5O12 MAGNETIC GARNET FILMS GROWN BY LIQUID PHASE EPITAXY

1989 ◽  
Vol 38 (10) ◽  
pp. 1704
Author(s):  
TIAN LIANG-GUANG ◽  
LIU XIANG-LIN ◽  
XU SHUN-SHENG ◽  
HAN XIAO-XI
Keyword(s):  
Liquid Phase ◽  
Diffraction Study ◽  
Liquid Phase Epitaxy ◽  
Double Crystal ◽  
X Ray ◽  
Garnet Films ◽  
Magnetic Garnet

Characterization and on-line adjustment of the sagittal-bent Laue crystal profile

2018 ◽  
Vol 25 (5) ◽  
pp. 1346-1353
Author(s):  
Weiwei Dong ◽  
Quan Cai ◽  
Fugui Yang ◽  
Xu Liu ◽  
Jiaowang Yang ◽  
...  
Keyword(s):  
Ray Tracing ◽  
Crystal Surface ◽  
Great Influence ◽  
High Energy ◽  
Double Crystal ◽  
X Ray ◽  
Bent Crystal ◽  
On Line ◽  
Condition Adjustment ◽  
Anticlastic Curvature

The sagittal-bent Laue monochromator can provide an ideal way to focus high-energy X-ray beams. However, the anticlastic curvature induced by sagittal bending has a great influence on the crystal performance. Thus, characterizing the bent-crystal shape is very important for predicting the performance of the bent-crystal monochromator. In this paper the crystal profile is measured by off-line optical metrology and on-line X-ray experiments. The off-line results showed that the bent-crystal surface could be well fitted to a saddle surface apart from a redundant cubic term which was related to the different couples applied on the crystal. On-line characterization of the meridional and the sagittal radius of the bent crystal includes double-crystal topography and ray-tracing measurement. In addition, the double-crystal topography experiment could be used as a quick diagnostic method for the bending condition adjustment. The sagittal radius of the bent crystal was characterized through a ray-tracing experiment by using a particularly designed tungsten mask. Moreover, rocking curves under different bending conditions were measured as well. The results were highly consistent with analytical results derived from the elastic theory. Furthermore, radii along different vertical positions under various bending conditions were measured and showed a quadratic relationship between the vertical positions and the meridional radii.

Investigation on Large-Sized Sapphire Crystalline Perfection by X-Ray Double-Crystal Diffraction Method

2007 ◽  
Vol 353-358 ◽  
pp. 1521-1524 ◽  
Author(s):  
Gui Gen Wang ◽  
Ming Fu Zhang ◽  
Hong Bo Zuo ◽  
Xiao Dong He ◽  
Jie Cai Han ◽  
...  
Keyword(s):  
Simulation Analysis ◽  
Crystal Surface ◽  
Diffraction Method ◽  
Sapphire Crystal ◽  
Crystalline Perfection ◽  
Double Crystal ◽  
X Ray ◽  
Infrared Spectral ◽  
Growth Method ◽  
Small Temperature Gradient

The large-sized sapphire (Ø225×205 mm, 27.5 kg) was grown successfully by SAPMAC method (sapphire growth technique with micro-pulling and shoulder-expanding at cooled center). The surface quality of the specimens was characterized by micro-Raman spectroscopy, and double crystal X-ray diffractometry (DCD) was utilized to investigate its crystalline perfection. The measurement of rocking curves was performed on various specimens from different region of large sapphire boule. The experimental results showed that CMP (chemo-mechanical polishing) with subsequent suitable chemically etching can develop the best-quality sapphire crystal surface and the values of FWHM obtained by conventional DCD were in the range from 27” to 58”. The infrared spectral transmission (2.0-4.5 5m) of sapphire crystal exceeded 82%. It is confirmed of SAPMAC growth method characteristics with in-situ annealing, small temperature gradient and low residual stress level by numerical simulation analysis.

X‐ray diffraction studies of the epitaxy ofa/b‐axes oriented YBa2Cu3O7−δfilms grown by liquid phase epitaxy

1994 ◽  
Vol 75 (10) ◽  
pp. 5243-5248 ◽  
Author(s):  
F. Sandiumenge ◽  
C. Dubs ◽  
P. Görnert ◽  
S. Galí
Keyword(s):  
Liquid Phase ◽  
Liquid Phase Epitaxy ◽  
X Ray Diffraction ◽  
X Ray

Correlation of Surface Morphologies with Mn Compositions of Ga1-xMnxAs Epilayers Grown by Liquid Phase Epitaxy

2002 ◽  
Vol 719 ◽  
Author(s):  
Hwa-Mok Kim ◽  
Jae-Hyeon Leem ◽  
Sung Woo Choi ◽  
Deuk Young Kim ◽  
Tae-Won Kang
Keyword(s):  
Liquid Phase ◽  
Liquid Phase Epitaxy ◽  
Mixed Solvent ◽  
Diluted Magnetic Semiconductor ◽  
Magnetic Semiconductor ◽  
Energy Dispersive ◽  
Surface Layers ◽  
X Ray ◽  
Diluted Magnetic ◽  
Surface Morphologies

AbstractIn this letter, we investigated the correlation between as-grown surface morphologies and Mn compositions of Ga1-xMnxAs epilayers - a III-V diluted magnetic semiconductor - grown by liquid phase epitaxy (LPE). Ga1-xMnxAs epilayers were grown at 595 °C from 50 % Ga + 50 % Bi mixed solvent. The grown layers were characterized by energy dispersive x-ray analysis (EDS) and atomic forced microscopy (AFM). The Mn composition measured by EDS after growth process was varied from 1 to 7 %. As increasing Mn composition surface morphologies of as-grown Ga1-xMnxAs epilayers were varied. At higher Mn compositions, the morphology of the surface layers degrades strongly, preventing removal of the solution-melt from it. Key words: LPE, as-grown, surface morphology, Mn composition, Ga1-xMnxAs, energy-dispersive x-ray analysis (EDS), atomic forced microscopy (AFM).

Studies of c-Axis Threading Screw Dislocations in Hexagonal SiC

2008 ◽  
Vol 1069 ◽  
Author(s):  
Yi Chen ◽  
Xianrong Huang ◽  
Ning Zhang ◽  
Govindhan Dhanaraj ◽  
Edward Sanchez ◽  
...  
Keyword(s):  
Ray Tracing ◽  
Grazing Incidence ◽  
Screw Dislocations ◽  
Burgers Vector ◽  
X Ray ◽  
Back Reflection ◽  
Partial Dislocations ◽  
Ray Tracing Simulation ◽  
Vector Magnitude

ABSTRACTIn our study, closed-core threading screw dislocations and micropipes were studied using synchrotron x-ray topography of various geometries. The Burgers vector magnitude of TSDs can be quantitatively determined from their dimensions in back-reflection x-ray topography, based on ray-tracing simulation and this has been verified by the images of elementary TSDs. Dislocation senses of closed-core threading screw dislocations and micropipes can be revealed by grazing-incidence x-ray topography. The threading screw dislocations can be converted into Frank partial dislocations on the basal planes and this has been confirmed by transmission synchrotron x-ray topography.

scholarly journals High-resolution X-ray diffraction study of AlxGa1−xSb alloys grown by liquid-phase epitaxy

2008 ◽  
Vol 64 (a1) ◽  
pp. C592-C592
Author(s):  
M. Rojas ◽  
E. Momox ◽  
R. Delgado ◽  
V. Gayou ◽  
A. Orduna ◽  
...  
Keyword(s):  
Liquid Phase ◽  
High Resolution ◽  
Diffraction Study ◽  
Liquid Phase Epitaxy ◽  
X Ray Diffraction ◽  
X Ray
Sign in / Sign up

Export Citation Format

Share Document