Combined Application of Section and Projection Topography to Defect Analysis in PVT-Grown 4H-SiC

2012 ◽  
Vol 1433 ◽  
Author(s):  
H. Wang ◽  
F. Wu ◽  
S. Byrappa ◽  
S. Shun ◽  
B. Raghothamachar ◽  
...  
Keyword(s):  
Single Crystals ◽  
Three Dimensional ◽  
Stacking Faults ◽  
Defect Analysis ◽  
Beam Radiation ◽  
Screw Dislocations ◽  
Combined Application ◽  
Edge Dislocations ◽  
Section Topography

ABSTRACTThe combined application of section and projection topography carried out using synchrotron white beam radiation can be a powerful tool for the determination of the three-dimensional configurations of defects in single crystals. In this paper, we present examples of the application of this combination of techniques to the analysis of defect configurations in PVT-grown 4H-SiC wafers cut perpendicular and parallel to the growth axis. Detailed correlation between section and projection topography of threading screw dislocations (TSDs) is presented with particular emphasis being laid on the determination of the signs of the dislocations. Further, information can also be determined regarding the position of the dislocations within the crystal depth. In addition, similar correlation is presented for threading edge dislocations (TEDs) and basal plane dislocations (BPDs). The section topography images of dislocations can comprise direct, intermediary and dynamical contrast and all three types are observed. The application to the study of stacking faults will be also discussed in detail.

Three-dimensional visualization of the inner structure of single crystals by step-scanning white X-ray section topography

2006 ◽  
Vol 13 (6) ◽  
pp. 484-488 ◽  
Author(s):  
Taihei Mukaide ◽  
Kentaro Kajiwara ◽  
Takashi Noma ◽  
Kazuhiro Takada
Keyword(s):  
Single Crystals ◽  
Three Dimensional ◽  
X Ray ◽  
Section Topography

Three-dimensional reciprocal space mapping with a two-dimensional detector as a low-latency tool for investigating the influence of growth parameters on defects in semipolar GaN

2015 ◽  
Vol 48 (4) ◽  
pp. 1000-1010 ◽  
Author(s):  
Sondes Bauer ◽  
Sergey Lazarev ◽  
Martin Bauer ◽  
Tobias Meisch ◽  
Marian Caliebe ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Stacking Faults ◽  
Vapour Phase ◽  
Stacking Fault ◽  
Space Mapping ◽  
Reciprocal Space ◽  
Reciprocal Space Mapping ◽  
Partial Dislocations ◽  
Semipolar Gan

A rapid nondestructive defect assessment and quantification method based on X-ray diffraction and three-dimensional reciprocal-space mapping has been established. A fast read-out two-dimensional detector with a high dynamic range of 20 bits, in combination with a powerful data analysis software package, is set up to provide fast feedback to crystal growers with the goal of supporting the development of reduced defect density GaN growth techniques. This would contribute strongly to the improvement of the crystal quality of epitaxial structures and therefore of optoelectronic properties. The method of normalized three-dimensional reciprocal-space mapping is found to be a reliable tool which shows clearly the influence of the parameters of the metal–organic vapour phase epitaxial and hydride vapour phase epitaxial (HVPE) growth methods on the extent of the diffuse scattering streak. This method enables determination of the basal stacking faults and an exploration of the presence of other types of defect such as partial dislocations and prismatic stacking faults. Three-dimensional reciprocal-space mapping is specifically used in the manuscript to determine basal stacking faults quantitatively and to discuss the presence of partial dislocations. This newly developed method has been applied to semipolar GaN structures grown on patterned sapphire substrates (PSSs). The fitting of the diffuse scattering intensity profiles along the stacking fault streaks with simulations based on a Monte Carlo approach has delivered an accurate determination of the basal plane stacking fault density. Three-dimensional reciprocal-space mapping is shown to be a method sensitive to the influence of crystallographic surface orientation on basal stacking fault densities during investigation of semipolar (11{\overline 2}2) GaN grown on anr-plane (1{\overline 1}02) PSS and semipolar (10{\overline 1}1) GaN grown on ann-plane (11{\overline 2}3) PSS. Moreover, the influence of HVPE overgrowth at reduced temperature on the quality of semipolar (11{\overline 2}2) GaN has been studied.

Determination of the Origin of Dislocation Related Luminescence from Silicon Using Regular Dislocation Networks

2009 ◽  
Vol 156-158 ◽  
pp. 567-572 ◽  
Author(s):  
Teimuraz Mchedlidze ◽  
Oleg Kononchuk ◽  
Tzanimir Arguirov ◽  
Maxim Trushin ◽  
Manfred Reiche ◽  
...  
Keyword(s):  
Wafer Bonding ◽  
Radiative Recombination ◽  
Twist Angle ◽  
Screw Dislocations ◽  
Impurity Atoms ◽  
Si Photonics ◽  
Direct Wafer Bonding ◽  
Edge Dislocations ◽  
Dislocation Related Luminescence

The investigation of regular dislocation networks (DN) formed by direct wafer bonding suggests that the D1 and D2 peaks of dislocation-related luminescence (DRL) in silicon is linked to screw dislocations, whereas edge dislocations are responsible for D3 and D4 DRL peaks. Non-radiative recombination activity in DN could be attributed to edge dislocations and could be related to enhanced ability of these dislocations to getter impurity atoms. Obtained relation of DRL intensity with the density of screw dislocations suggests existence of the optimum twist angle for the wafer-bonding geometry for which the DRL intensity has a maximum. The dependence of DRL intensity on the spacing between screw dislocations has the maximum at about 7 nm. Reported radiative and non-radiative recombination properties of DN present substantial interest not only for possible LED applications in all-Si photonics but also for photovoltaics, since DNs represent a model system for grain boundaries controlling carrier lifetime in microcrystalline-Si material.

Interaction of 6H-Type Stacking Faults with Threading Screw Dislocations in PVT-Grown 4H-SiC Single Crystals

2012 ◽  
Vol 717-720 ◽  
pp. 411-414
Author(s):  
Shinya Sato ◽  
T. Fujimoto ◽  
H. Tsuge ◽  
M. Katsuno ◽  
W. Ohashi
Keyword(s):  
High Resolution ◽  
Single Crystals ◽  
Room Temperature ◽  
Stacking Faults ◽  
Screw Dislocations ◽  
X Ray

6H-type stacking faults (SFs) observed in PVT-grown 4H-SiC ingle crystals were investigated using Photoluminescence (PL) microscopy at room temperature. Structural analyses using high resolution X-ray topography have revealed that there exist no (n=4, 8) component in Burger’s vectors of the 6H-type SFs we observed, strongly suggesting that the 6H-type SFs are constructed either by insertions of very thin 6H-type foreign polytype inclusions or by successive repetitions of Shockley-type in-plane glides.

Structural Transformation from TSDs to Frank-Type Stacking Faults by Giant Bunched Steps in PVT-Grown 4H-SiC Single Crystals

2016 ◽  
Vol 858 ◽  
pp. 97-100 ◽  
Author(s):  
Shinya Sato ◽  
Tatsuo Fujimoto ◽  
Hiroshi Tsuge ◽  
Masakazu Katsuno ◽  
Masashi Nakabayashi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Single Crystals ◽  
Structural Transformation ◽  
Stacking Faults ◽  
Stacking Sequence ◽  
Screw Dislocations ◽  
X Ray ◽  
Transmission Electron ◽  
High Resolution Tem ◽  
Stacking Structure

Structural transformation from threading screw dislocations (TSDs) to stacking faults (SFs) has been investigated for PVT-grown 4H-SiC single crystals using X-ray topography and transmission electron microscopy (TEM). The transformation of TSDs is induced by the structural interference with bunched surface macrosteps over 100 nm in height. The stacking sequence of a SF was determined to be (433) in Zadanov's notation by using high-resolution TEM. Our detailed analyses revealed that the (433) stacking structure can be constructed by a combination of five faults including both four Frank type faults and one Shockley type fault.

Determination of Burgers Vector of Screw Dislocations in 6H-SiC Single Crystals by Synchrotron White Beam X-Ray Topography

1996 ◽  
Vol 437 ◽  
Author(s):  
W. Si ◽  
M. Dudley ◽  
C. Carter ◽  
R. Glass ◽  
V. Tsvetkov
Keyword(s):  
Single Crystals ◽  
Dislocation Core ◽  
Line Defect ◽  
Screw Dislocations ◽  
Burgers Vector ◽  
X Ray ◽  
White Beam ◽  
Lattice Planes ◽  
Vector Magnitude

AbstractIndividual screw dislocations along the [0001] axis in 6H-SiC single crystals have been characterized by means of Synchrotron White Beam X-ray Topography (SWBXT). The magnitude of the Burgers vector was determined from: (1) the diameter of circular diffraction-contrast images of dislocations in back-reflection topographs, (2) the width of bi-modal images associated with screw dislocations in transmission topographs, (3) the magnitude of the tilt of the lattice planes on both sides of dislocation core in projection topographs, and (4) also the magnitude of the tilt of the lattice planes in section topographs. All of the four methods showed reasonable consistency. The sense of the Burgers vector can also be deduced from the abovementioned tilt of the lattice planes. Results revealed that in 6H-SiC a variety of screw dislocations can be found with Burgers vector magnitude ranging from 1c to 7c (c is the lattice constant along [0001] axis). This work demonstrates that SWBXT can be used as a quantitative technique for detailed analyses of line defect configurations.

Three-Dimensional Imaging of Extended Defects in 4H-SiC

2016 ◽  
Vol 858 ◽  
pp. 361-366 ◽  
Author(s):  
Ryohei Tanuma ◽  
Masahiro Nagano ◽  
Isaho Kamata ◽  
Hidekazu Tsuchida
Keyword(s):  
3D Imaging ◽  
Second Harmonic ◽  
Three Dimensional ◽  
Stacking Faults ◽  
Band Edge Emission ◽  
Extended Defects ◽  
Edge Emission ◽  
3D Images ◽  
Two Photon ◽  
Edge Dislocations

This paper describes 3D imaging of extended defects in 4H-SiC using optical second-harmonic generation (SHG) and two-photon-exited photoluminescence (2PPL). SHG selectively yields the 3D images of 3C-inclusions in a 4H-SiC epilayer, while 2PPL provides 3D images of 3C-inclusions, 8H stacking faults and single Shockley stacking faults. 2PPL band-edge emission visualizes dislocation lines of threading screw dislocations and threading edge dislocations, the tilt angles of which are evaluated.

scholarly journals Determination of the Formation of the 1/6[031] Extrinsic Stacking Faults in Deformed YBa2Cu3O7−δ

1990 ◽  
Vol 183 ◽  
Author(s):  
M. J. Kramer ◽  
E. P. Kvam ◽  
L. S. Chumbley
Keyword(s):  
High Temperature ◽  
High Temperature Superconductor ◽  
Stacking Faults ◽  
Stacking Fault ◽  
Processing Conditions ◽  
Partial Dislocations ◽  
Transmission Electron ◽  
Edge Dislocations ◽  
Image Simulations

AbstractMechanial deformation of the YBa2Cu3O7−δ high temperature superconductor under a number of different processing conditions resulted in the formation of <100> and <110> edge dislocations, both having a (001) slip plane. Subsequent high temperature annealing at 900°C resulted in the formation of extrinsic stacking faults with a large separation of the partial dislocations, up to 0.35 μm, suggesting a very low minimum stacking fault energy of 1.2 × 10−2 J/m2. High resolution transmission electron microscopy (HRTEM) in conjunction with image simulations revealed that the stacking faults were comprised of an extra CuO plane between the Ba layers with an offset of b/2. The stacking fault vector of 1/6[031] requires some separation of the <010> Burgers vectors into the c-axis direction. A model in which [010] separates into 1/6[031] + 1/[031] is consistent with the observed stacking faults.

Conformation of Ribosomes from Escherichia Coli

1974 ◽  
Vol 32 ◽  
pp. 210-211
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Binding Sites ◽  
Ribosomal Proteins ◽  
Fluorescent Dyes ◽  
Protein Biosynthesis ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Dimensional Structure ◽  
Complete Understanding ◽  
And Function

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.

Sign in / Sign up

Export Citation Format

Share Document