Analysis of Basal Plane Bending and Basal Plane Dislocations in 4H-SiC Single Crystals

2009 ◽  
Vol 48 (6) ◽  
pp. 065503 ◽  
Author(s):  
Noboru Ohtani ◽  
Masakazu Katsuno ◽  
Tatsuo Fujimoto ◽  
Masashi Nakabayashi ◽  
Hiroshi Tsuge ◽  
...  
Keyword(s):  
Single Crystals ◽  
Basal Plane ◽  
Plane Bending

Basal plane bending of 4H-SiC single crystals grown by sublimation method with different seed attachment methods

CrystEngComm ◽  
2018 ◽  
Vol 20 (43) ◽  
pp. 6957-6962 ◽  
Author(s):  
Xianglong Yang ◽  
Jinying Yu ◽  
Xiufang Chen ◽  
Yan Peng ◽  
Xiaobo Hu ◽  
...  
Keyword(s):  
High Resolution ◽  
Single Crystals ◽  
Basal Plane ◽  
X Ray ◽  
Sublimation Method ◽  
Plane Bending

Basal plane bending of 4H-SiC single crystals grown using the sublimation method on an open or closed backside seed was measured using high-resolution X-ray diffractometry.

Origin of basal plane bending in hexagonal silicon carbide single crystals

2008 ◽  
Vol 310 (18) ◽  
pp. 4126-4131 ◽  
Author(s):  
J.W. Lee ◽  
M. Skowronski ◽  
E.K. Sanchez ◽  
G. Chung
Keyword(s):  
Silicon Carbide ◽  
Single Crystals ◽  
Basal Plane ◽  
Plane Bending

Basal plane bending of 6H-SiC single crystals observed by synchrotron radiation X-ray topography

2009 ◽  
Vol 42 (6) ◽  
pp. 1068-1072 ◽  
Author(s):  
Lina Ning ◽  
Xiaobo Hu ◽  
Yingmin Wang ◽  
Xiangang Xu ◽  
Yuqiang Gao ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Single Crystals ◽  
Basal Plane ◽  
Synchrotron Radiation Beam ◽  
Radiation Beam ◽  
X Ray ◽  
Plane Bending ◽  
Spherical Curvature ◽  
Good Agreement

Basal plane bending is a structural defect in SiC single crystals caused mainly by the thermal mismatch between seed and holder, which deteriorates the quality of the wafers and blocks their applications. In this paper, basal plane bending was detected by high-resolution X-ray diffractometry (HRXRD) and transmission synchrotron white-beam X-ray topography (SWBXT). HRXRD reveals that the (0001) Si face is a concave sphere and SWBXT shows that the shapes of the Laue spots are different from that of the cross section of the synchrotron radiation beam. On the basis of a spherical curvature model for a (0001) 6H-SiC single crystal, the shapes of the Laue spots were simulated. The results are in good agreement with the experimental observations. Thus, SWBXT is an effective method for detecting basal plane bending.

The stability of dislocation networks under various oxygen-doping conditions in superconducting Bi2Sr2CaCu2Oy single crystals and their influence on the flux pinning properties

1994 ◽  
Vol 52 ◽  
pp. 802-803
Author(s):  
Y. Feng ◽  
X. Y. Cai ◽  
R. J. Kelley ◽  
D. C. Larbalestier
Keyword(s):  
Single Crystals ◽  
Oxygen Content ◽  
Basal Plane ◽  
Flux Pinning ◽  
Pinning Centers ◽  
Before And After ◽  
Anomalous Peak ◽  
Basal Plane Dislocation ◽  
The Stability ◽  
Further Development

The issue of strong flux pinning is crucial to the further development of high critical current density Bi-Sr-Ca-Cu-O (BSCCO) superconductors in conductor-like applications, yet the pinning mechanisms are still much debated. Anomalous peaks in the M-H (magnetization vs. magnetic field) loops are commonly observed in Bi2Sr2CaCu2Oy (Bi-2212) single crystals. Oxygen vacancies may be effective flux pinning centers in BSCCO, as has been found in YBCO. However, it has also been proposed that basal-plane dislocation networks also act as effective pinning centers. Yang et al. proposed that the characteristic scale of the basal-plane dislocation networksmay strongly depend on oxygen content and the anomalous peak in the M-H loop at ˜20-30K may be due tothe flux pinning of decoupled two-dimensional pancake vortices by the dislocation networks. In light of this, we have performed an insitu observation on the dislocation networks precisely at the same region before and after annealing in air, vacuumand oxygen, in order to verify whether the dislocation networks change with varying oxygen content Inall cases, we have not found any noticeable changes in dislocation structure, regardless of the drastic changes in Tc and the anomalous magnetization. Therefore, it does not appear that the anomalous peak in the M-H loops is controlled by the basal-plane dislocation networks.

Synchrotron X-Ray Topography Study on the Relationship between Local Basal Plane Bending and Basal Plane Dislocations in PVT-Grown 4H-SiC Substrate Wafers

2020 ◽  
Vol 1004 ◽  
pp. 393-400
Author(s):  
Tuerxun Ailihumaer ◽  
Hongyu Peng ◽  
Balaji Raghothamachar ◽  
Michael Dudley ◽  
Gilyong Chung ◽  
...  
Keyword(s):  
Basal Plane ◽  
Local Strain ◽  
Grazing Incidence ◽  
Peak Shift ◽  
Linear Mapping ◽  
Incidence Geometry ◽  
Convex Shape ◽  
X Ray ◽  
Black And White ◽  
Plane Bending

Synchrotron monochromatic beam X-ray topography (SMBXT) in grazing incidence geometry shows black and white contrast for basal plane dislocations (BPDs) with Burgers vectors of opposite signs as demonstrated using ray tracing simulations. The inhomogeneous distribution of these dislocations is associated with the concave/convex shape of the basal plane. Therefore, the distribution of these two BPD types were examined for several 6-inch diameter 4H-SiC substrates and the net BPD density distribution was used for evaluating the nature and magnitude of basal plane bending in these wafers. Results show different bending behaviors along the two radial directions - [110] and [100] directions, indicating the existence of non-isotropic bending. Linear mapping of the peak shift of the 0008 reflection along the two directions was carried out using HRXRD to correlate with the results from the SMBXT measurements. Basal-plane-tilt angle calculated using the net BPD density derived from SMBXT shows a good correlation with those obtained from HRXRD measurements, which further confirmed that bending in basal plane is caused by the non-uniform distribution of BPDs. Regions of severe bending were found to be associated with both large tilt angles (95% black contrast BPDs to 5% white contrast BPDs) and abrupt changes in a and c lattice parameters i.e. local strain.

Spatial variation of lattice plane bending of 4H-SiC substrates

CrystEngComm ◽  
2017 ◽  
Vol 19 (27) ◽  
pp. 3844-3849 ◽  
Author(s):  
Yingxin Cui ◽  
Xiaobo Hu ◽  
Xuejian Xie ◽  
Rongkun Wang ◽  
Xiangang Xu
Keyword(s):  
High Resolution ◽  
Spatial Variation ◽  
Basal Plane ◽  
Lattice Plane ◽  
X Ray ◽  
Plane Bending

Basal plane bending of on- and off-axis 4H-SiC substrates was measured by high-resolution X-ray diffractometry (HRXRD).

Characterization of Defect Structures in SiC Single Crystals Using Synchrotron X-Ray Topography

1993 ◽  
Vol 307 ◽  
Author(s):  
S. Wang ◽  
M. Dudley ◽  
C. Carter ◽  
D. Asbury ◽  
C. Fazit
Keyword(s):  
Detailed Analysis ◽  
Single Crystals ◽  
Basal Plane ◽  
Defect Structures ◽  
Dislocation Generation ◽  
Screw Dislocations ◽  
X Ray ◽  
White Beam

ABSTRACTSynchrotron white beam X-ray topography has been used to characterize defect structures in 6H-SiC wafers grown on (0001) seeds. Two major types of defects are observed: super screw dislocations approximately perpendicular to the basal plane and dislocation networks lying in the basal plane. The super screw dislocations, which have open cores, are growth dislocations. These dislocations act as sources and/or sinks for the glide dislocation networks. Detailed analysis and discussion of dislocation generation phenomena and Burgers vectors will be presented.

scholarly journals Interference Phenomena in Deformed Single Crystals of Ice

1971 ◽  
Vol 10 (59) ◽  
pp. 269-286 ◽  
Author(s):  
G. J. Readings ◽  
J. T. Bartlett
Keyword(s):  
Optical Properties ◽  
Simple Model ◽  
Single Crystals ◽  
Uniaxial Compression ◽  
Basal Plane ◽  
Quantitative Agreement ◽  
Optic Axis ◽  
Interference Fringes ◽  
Alternative Hypotheses ◽  
Active Contribution

AbstractWhen rectangular single crystals of ice were subjected to uniaxial compression parallel to their Long axes and viewed between crossed polarizers, interference fringes were often observed. Some of these interference bands were associated with grain boundaries formed as a result of “kinking”. These can be explained in terms of the known anisotropic optical properties of ice and the change in the orientation of the optic axis across the boundary. This case has been analysed in detail with the aid of Jones’ calculus and good quantitative agreement exists between the theory and the experimental observations.Other interference bands were observed parallel to the trace of the basal plane on the surface of some deformed crystals. Alternative hypotheses for the explanation of this phenomenon have been considered and it seems probable that these bands are a result of slight random misorientations between adjacent slip lamellae. Applying Jones’ calculus to a simple model of such a deformed crystal indicates that the required misorientations are of the order of 1º If this explanation is correct, it implies that dislocations with non-basal Burgers vectors (probablyc[0001]) make an active contribution to the deformation.

Relationship Between Basal Plane Dislocation Distribution and Local Basal Plane Bending in PVT-Grown 4H-SiC Crystals

2020 ◽  
Vol 49 (6) ◽  
pp. 3455-3464
Author(s):  
Tuerxun Ailihumaer ◽  
Hongyu Peng ◽  
Balaji Raghothamachar ◽  
Michael Dudley ◽  
Gilyong Chung ◽  
...  
Keyword(s):  
Basal Plane ◽  
Dislocation Distribution ◽  
Basal Plane Dislocation ◽  
Plane Bending
Sign in / Sign up

Export Citation Format

Share Document