Lateral/vertical Homoepitaxial Growth on 4H-SiC Surfaces Controlled by Dislocations

2008 ◽  
Vol 1069 ◽  
Author(s):  
Yoosuf N. Picard ◽  
Andrew J. Trunek ◽  
Philip G. Neudeck ◽  
Mark E. Twigg
Keyword(s):  
Film Growth ◽  
Electron Backscatter Diffraction ◽  
Side Wall ◽  
Chemical Vapor ◽  
Film Structure ◽  
Atomic Step ◽  
Contrast Imaging ◽  
Screw Dislocations ◽  
Side Walls ◽  
Backscatter Diffraction

ABSTRACTThis paper reports the influence of screw dislocations on the lateral/vertical growth behavior of chemical vapor deposited (CVD) on-axis homoepitaxial 4H-SiC films grown on patterned mesas. Electron channeling contrast imaging (ECCI) was utilized to image both atomic steps and dislocations while the film structure/orientation was determined using electron backscatter diffraction (EBSD). The presence and position of screw dislocations within the mesa impacted the resultant film thickness, lateral shape, and atomic step morphology. Mesa side walls that incline inwards due to faceting during screw-dislocation driven vertical film growth can intersect with the dislocation step sources near the side walls. If this occurs for all screw dislocations on a mesa, we observe a transition towards laterally dominated growth that produces webbed structures and films surfaces exhibiting significantly lower step densities. Transition from vertical to lateral dominated growth is consistent with ECCI imaged dislocation very near a mesa side wall.

Nondestructive defect measurement and surface analysis of 3C-SiC on Si (001) by electron channeling contrast imaging

2008 ◽  
Vol 1068 ◽  
Author(s):  
Yoosuf N. Picard ◽  
Christopher Locke ◽  
Christopher L. Frewin ◽  
Rachael L. Myers-Ward ◽  
Joshua D. Caldwell ◽  
...  
Keyword(s):  
Electron Backscatter Diffraction ◽  
Substrate Surface ◽  
Film Surface ◽  
Chemical Vapor ◽  
Atomic Step ◽  
Contrast Imaging ◽  
Electron Channeling ◽  
Dislocation Densities ◽  
Backscatter Diffraction ◽  
Sic Films

ABSTRACTThe electron channeling contrast imaging (ECCI) technique was utilized to investigate atomic step morphologies and dislocation densities in 3C-SiC films grown by chemical vapor deposition (CVD) on Si (001) substrates. ECCI in this study was performed inside a commercial scanning electron microscope using an electron backscatter diffraction (EBSD) system equipped with forescatter diode detectors. This approach allowed simultaneous imaging of atomic steps, verified by atomic force microscopy, and dislocations at the film surface. EBSD analysis verified the orientation and monocrystalline quality of the 3C-SiC films. Dislocation densities in 3C-SiC films were measured locally using ECCI, with qualitative verification by x-ray diffraction. Differences in the dislocation density across a 50 mm diameter 3C-SiC film could be attributed to subtle variations during the carbonization process across the substrate surface.

Crystalline Quality and Surface Morphology of 3C-SiC Films on Si Evaluated by Electron Channeling Contrast Imaging

2009 ◽  
Vol 615-617 ◽  
pp. 435-438
Author(s):  
Yoosuf N. Picard ◽  
Christopher Locke ◽  
Christopher L. Frewin ◽  
Mark E. Twigg ◽  
Stephen E. Saddow
Keyword(s):  
Surface Morphology ◽  
Electron Backscatter Diffraction ◽  
Chemical Vapor ◽  
Nondestructive Method ◽  
Crystalline Quality ◽  
Atomic Step ◽  
Contrast Imaging ◽  
Electron Channeling ◽  
Si Substrates ◽  
Sic Films

Electron channeling contrast imaging (ECCI) has been utilized to evaluate the surface morphology and crystalline quality of 3C-SiC films grown by chemical vapor deposition (CVD) on (100) and (111) Si substrates. ECCI in this study was performed using an electron backscatter diffraction (EBSD) system equipped with forescatter diode detectors and mounted inside a commercial scanning electron microscope (SEM). This nondestructive method permits direct dislocation imaging through local fluctuations in forescattered electron yield attributable to lattice strain. Coordinated ECCI, SEM, and EBSD analysis of film surfaces allowed correlations between film orientation, surface morphology, and dislocation behavior. Evidence of lateral dislocations parallel to <110> directions and atomic step pinning by dislocations was observed.

Sensitivity of Thermal Conductivity of Carbon Nanotubes to Defect Concentrations and Heat-Treatment

2012 ◽  
Author(s):  
Michael F. P. Bifano ◽  
Jungkyu Park ◽  
Vikas Prakash
Keyword(s):  
Thermal Conductivity ◽  
Heat Treatment ◽  
Interatomic Potential ◽  
Side Wall ◽  
Chemical Vapor ◽  
Md Simulations ◽  
Heat Treated ◽  
Side Walls ◽  
Non Equilibrium Molecular Dynamics ◽  
Vacancy Concentrations

In the present study, classical MD simulations using reverse non-equilibrium molecular dynamics with the AIREBO interatomic potential are used to investigate the sensitivity of thermal conductivity in SWCNTs to side-wall defect concentration and heat-treatment. Two types of defects are investigated. First, the thermal conductivity of (6,6) SWCNTs is obtained as a function of concentration of chemisorbed hydrogen adatoms. Secondly, the thermal conductivity is obtained as a function of point-vacancy concentrations. The results of the studies show that 2 atom% of hydrogenation and 1.5–2% vacancy concentrations have very similar detrimental effects on the thermal conductivity of SWCNT. Vacancy repair is evident with heat treatment, and heat-treatments at 3000°C for up to 22 ns are found to transform point vacancies into various types of non-hexagonal side-wall defects; this vacancy repair is accompanied by a ca. 10% increase in thermal conductivity. Thermal conductivity measurements in both heat-treated and non-heat treated chemical vapor deposition grown MWCNTs are also reviewed. The results suggest that CNT thermal conductivity can be drastically increased if measures are taken to remove common defects from the SWCNT side-walls.

The application of electron backscatter diffraction and orientation contrast imaging in the SEM to textural problems in rocks

1999 ◽  
Vol 84 (11-12) ◽  
pp. 1741-1759 ◽  
Author(s):  
David J. Prior ◽  
Alan P. Boyle ◽  
Frank Brenker ◽  
Michael C. Cheadle ◽  
Austin Day ◽  
...  
Keyword(s):  
Electron Backscatter Diffraction ◽  
Contrast Imaging ◽  
Orientation Contrast ◽  
Electron Backscatter ◽  
Backscatter Diffraction

scholarly journals Novel −75°C SEM cooling stage: application for martensitic transformation in steel

Microscopy ◽  
2020 ◽  
Author(s):  
Kaneaki Tsuzazki ◽  
Motomichi Koyama ◽  
Ryosuke Sasaki ◽  
Keiichiro Nakafuji ◽  
Kazushi Oie ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
Electron Backscatter Diffraction ◽  
Dislocation Slip ◽  
In Situ Observation ◽  
Contrast Imaging ◽  
Cooling Stage ◽  
Electron Channelling ◽  
Electron Backscatter ◽  
Backscatter Diffraction

Abstract Microstructural changes during the martensitic transformation from face-centred cubic (FCC) to body-centred cubic (BCC) in an Fe-31Ni alloy were observed by scanning electron microscopy (SEM) with a newly developed Peltier stage available at temperatures to  −75°C. Electron channelling contrast imaging (ECCI) was utilized for the in situ observation during cooling. Electron backscatter diffraction analysis at ambient temperature (20°C) after the transformation was performed for the crystallographic characterization. A uniform dislocation slip in the FCC matrix associated with the transformation was detected at −57°C. Gradual growth of a BCC martensite was recognized upon cooling from −57°C to −63°C.

Characterizing Slip Transfer In Commercially Pure Titanium Using High Resolution Electron Backscatter Diffraction (HR-EBSD) and Electron Channeling Contrast Imaging (ECCI)

2012 ◽  
Vol 18 (S2) ◽  
pp. 702-703 ◽  
Author(s):  
J.R. Seal ◽  
T. Bieler ◽  
M. Crimp ◽  
B. Britton ◽  
A. Wilkinson
Keyword(s):  
High Resolution ◽  
Electron Backscatter Diffraction ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Contrast Imaging ◽  
Commercially Pure ◽  
Slip Transfer ◽  
Resolution Electron ◽  
Electron Backscatter ◽  
Backscatter Diffraction

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

Characterisation of nitride thin films by electron backscatter diffraction and electron channelling contrast imaging

2006 ◽  
Vol 22 (11) ◽  
pp. 1352-1358 ◽  
Author(s):  
C. Trager-Cowan ◽  
F. Sweeney ◽  
A. Winkelmann ◽  
A. J. Wilkinson ◽  
P. W. Trimby ◽  
...  
Keyword(s):  
Thin Films ◽  
Electron Backscatter Diffraction ◽  
Contrast Imaging ◽  
Electron Channelling ◽  
Electron Backscatter ◽  
Backscatter Diffraction
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