The Characterization of Defects in Silicon Carbide Crystals by X-Ray Topography in the Back-Reflection Geometry

2004 ◽  
Vol 230-232 ◽  
pp. 1-16 ◽  
Author(s):  
William M. Vetter
Keyword(s):  
Silicon Carbide ◽  
Computer Algorithms ◽  
Reflection Mode ◽  
X Ray ◽  
Back Reflection ◽  
Device Structures ◽  
Reflection Geometry ◽  
Grade Silicon ◽  
Favorable Conditions

Synchrotron white-beam x-ray topographs taken in the back-reflection mode have proved a powerful tool in the study of defects in semiconductor-grade silicon carbide crystals. Capable of mapping the distribution of axial dislocations across a wafer's area (notably the devastating micropipe defect), it can also provide information on their natures. Under favorable conditions, various other types of defect may be observed in back-reflection topographs of SiC, among which are subgrain boundaries, inclusions, and basal plane dislocations. Observed defect images in backreflection topographs may be simulated using relatively simple computer algorithms based on ray tracing. It has been possible to use back-reflection topographs of SiC substrates with device structures deposited upon them to relate the incidence of defects to device failure.

X-ray Polytype Examination of SiC Bulk Crystals in Back-Reflection Geometry

1996 ◽  
Vol 29 (4) ◽  
pp. 378-382
Author(s):  
L. Dressler ◽  
K. Goetz ◽  
J. Kräusslich
Keyword(s):  
Bulk Crystals ◽  
X Ray ◽  
Back Reflection ◽  
Reflection Geometry

Characterization of silicon on insulator substrates using reflection mode double-crystal X-ray topography

1991 ◽  
Vol 206 (1-2) ◽  
pp. 27-33 ◽  
Author(s):  
David I. Ma ◽  
George J. Campisi ◽  
Syed B. Qadri ◽  
Martin C. Peckerar
Keyword(s):  
Silicon On Insulator ◽  
Reflection Mode ◽  
Double Crystal ◽  
X Ray

Characterization Of Micropipes And Other Defect Structures In 6H-SiC Through Fluorescence Microscopy

1995 ◽  
Vol 406 ◽  
Author(s):  
W. D. Vetter ◽  
M. Dudley ◽  
T.- F. Wong ◽  
J. T. Frderich
Keyword(s):  
Silicon Carbide ◽  
Fluorescence Microscopy ◽  
Laser Scanning ◽  
Laser Scanning Confocal Microscopy ◽  
Defect Structures ◽  
X Ray ◽  
Scanning Confocal Microscopy ◽  
Low Viscosity ◽  
Dye Staining

AbstractCrystals of silicon carbide, and other polytypic materials often have micropipes associated with screw dislocations of large Burgers vectors running along their axial dimensions. These defects are considered the most deleterious to the performance of SiC semiconductor devices.Optical micrographs of micropipes in silicon carbide crystals are ordinarily faint. To obtain micrographs showing higher contrast and detail, laser scanning confocal microscopy (LSCM) and simple fluorescence microscopy were used on 6H-SiC single crystals after infiltrating them with a low-viscosity epoxy containing a fluorescent dye. “Staining” the micropipes rendered them much more visible both in fluorescence and conventional optical microscopies. Details of their structures and shapes were revealed, and their dimensions were measured accurately, using LSCM and other, less sophisticated, fluorescence microscopies. Other voids present, such as microcracks, were also visualized. Observations by this optical technique were related to information obtained by synchrotron white beam x-ray topography.

scholarly journals Characterization of 4H Silicon Carbide Films Grown by Solvent-Laser Heated Floating Zone

2012 ◽  
Vol 1433 ◽  
Author(s):  
Andrew A. Woodworth ◽  
Ali Sayir ◽  
Philip G. Neudeck ◽  
Balaji Raghothamachar ◽  
Michael Dudley
Keyword(s):  
Silicon Carbide ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Growth Front ◽  
Electrical Performance ◽  
Floating Zone ◽  
X Ray ◽  
Growth Method ◽  
Laser Heated

ABSTRACTCommercially available bulk silicon carbide (SiC) has a high number (>2000/cm2) of screw dislocations (SD) that have been linked to degradation of high-field power device electrical performance properties. Researchers at the NASA Glenn Research Center have proposed a method to mass-produce significantly higher quality bulk SiC. In order for this bulk growth method to become reality, growth of long single crystal SiC fibers must first be achieved. Therefore, a new growth method, Solvent-Laser Heated Floating Zone (Solvent-LHFZ), has been implemented. While some of the initial Solvent-LHFZ results have recently been reported, this paper focuses on further characterization of grown crystals and their growth fronts. To this end, secondary ion mass spectroscopy (SIMS) depth profiles, cross section analysis by focused ion beam (FIB) milling and mechanical polishing, and orientation and structural characterization by X-ray transmission Laue diffraction patterns and X-ray topography were used. Results paint a picture of a chaotic growth front, with Fe incorporation dependant on C concentration.

scholarly journals A 3.5 kV Thyristor in 4H-SiC with a JTE Periphery

2005 ◽  
Vol 483-485 ◽  
pp. 1005-1008
Author(s):  
Pierre Brosselard ◽  
Thierry Bouchet ◽  
Dominique Planson ◽  
Sigo Scharnholz ◽  
Gontran Pâques ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
High Voltage ◽  
Electrical Characterization ◽  
Electrical Strength ◽  
Oxide Charge ◽  
Blocking Voltage ◽  
Simulation Based ◽  
Device Structures ◽  
Silicon Silicon

Overcoming the physical limits of silicon, silicon carbide shows a high potential for making high voltage thyristors. After a simulation based optimization of the main thyristor parameters, including JTE protection and a SiO2 layer passivation, 4H-SiC GTO thyristors were realized and characterized. Designed for a theoretical blocking capability of nearly 6 kV, the electrical characterization of all device structures revealed a maximum blocking voltage of 3.5 kV. Comparing simulation and measurement suggests that a negative oxide charge density of ~ 2×1012 cm-2 causes the decrease in electrical strength.

scholarly journals Structural characterization of liquid phase sintered silicon carbide by high-resolution X-ray diffractometry

Cerâmica ◽  
2005 ◽  
Vol 51 (318) ◽  
pp. 168-172 ◽  
Author(s):  
C. A. Kelly ◽  
P. A. Suzuki ◽  
S. Ribeiro ◽  
S. Kycia
Keyword(s):  
Silicon Carbide ◽  
High Resolution ◽  
Mixed Oxide ◽  
Beta Phase ◽  
Alpha Phase ◽  
X Ray Diffraction ◽  
Solid Solution Formation ◽  
X Ray ◽  
Synchrotron Light

Silicon carbide (SiC) was sintered using two different additives: AlN-Y2O3 or AlN-CRE2O3. CRE2O3 is a mixed oxide formed by Y2O3 and rare-earth oxides. The crystalline structures of the phases were analyzed by high-resolution X-ray diffraction using synchrotron light source. The results of the Rietveld refinement of the mixed oxide show a solid solution formation. In both silicon carbide samples prepared using AlN-Y2O3 or AlN-CRE2O3 3C (beta-phase) and 6H (alpha-phase) polytypes were found. The structural and microstructural results for both samples were similar. This is an indication of the viability of the use of CRE2O3 in substitution for Y2O3 as additive to obtain dense materials.

Characterization of dislocations by double crystal X-ray topography in back reflection

1991 ◽  
Vol 123 (2) ◽  
pp. 379-392 ◽  
Author(s):  
V. M. Kaganer ◽  
W. Möhling
Keyword(s):  
Double Crystal ◽  
X Ray ◽  
Back Reflection

scholarly journals Multifractal characterization of epitaxial silicon carbide on silicon

2017 ◽  
Vol 35 (3) ◽  
pp. 539-547
Author(s):  
Ştefan Ţălu ◽  
Sebastian Stach ◽  
Shikhgasan Ramazanov ◽  
Dinara Sobola ◽  
Guseyn Ramazanov
Keyword(s):  
Silicon Carbide ◽  
Surface Condition ◽  
Three Dimensional ◽  
Epitaxial Silicon ◽  
Large Area ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Nano Size

AbstractThe purpose of this study was to investigate the topography of silicon carbide films at two steps of growth. The topography was measured by atomic force microscopy. The data were processed for extraction of information about surface condition and changes in topography during the films growth. Multifractal geometry was used to characterize three-dimensional micro- and nano-size features of the surface. X-ray measurements and Raman spectroscopy were performed for analysis of the films composition. Two steps of morphology evolution during the growth were analyzed by multifractal analysis. The results contribute to the fabrication of silicon carbide large area substrates for micro- and nanoelectronic applications.

Characterization of 100 mm Diameter 4H-Silicon Carbide Crystals with Extremely Low Basal Plane Dislocation Density

2010 ◽  
Vol 645-648 ◽  
pp. 291-294 ◽  
Author(s):  
Michael Dudley ◽  
Ning Zhang ◽  
Yu Zhang ◽  
Balaji Raghothamachar ◽  
Sha Yan Byrapa ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Dislocation Density ◽  
Basal Plane ◽  
X Ray ◽  
Repetitive Process ◽  
Basal Plane Dislocation ◽  
And Behavior ◽  
New Generation ◽  
Edge Dislocations

Synchrotron White Beam X-ray Topography (SWBXT) studies are presented of basal plane dislocation (BPD) configurations and behavior in a new generation of 100mm diameter, 4H-SiC wafers with extremely low BPD densities (3-4 x 102 cm-2). The conversion of non-screw oriented, glissile BPDs into sessile threading edge dislocations (TEDs) is observed to provide pinning points for the operation of single ended Frank-Read sources. In some regions, once converted TEDs are observed to re-convert back into BPDs in a repetitive process which provides multiple BPD pinning points.

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