The Influence of the Temperature Gradient on the Defect Structure of 3C-SiC Grown Heteroepitaxially on 6H-SiC by Sublimation Epitaxy

2010 ◽  
Vol 645-648 ◽  
pp. 367-370 ◽  
Author(s):  
Maya Marinova ◽  
Alkyoni Mantzari ◽  
Milena Beshkova ◽  
Mikael Syväjärvi ◽  
Rositza Yakimova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Temperature Gradient ◽  
Defect Structure ◽  
Temperature Gradients ◽  
Structural Quality ◽  
Fault Density ◽  
Transmission Electron

In the present work the structural quality of 3C-SiC layers grown by sublimation epitaxy is studied by means of conventional and high resolution transmission electron microscopy. The layers were grown on Si-face 6H-SiC nominally on-axis substrates at a temperature of 2000°C and different temperature gradients, ranging from 5 to 8 °C /mm. The influence of the temperature gradient on the structural quality of the layers is discussed. The formation of specific twin complexes and conditions for lower stacking fault density are investigated.

Characterization and Growth Mechanism of B12As2 Epitaxial Layers Grown on (1-100) 15R-SiC

2008 ◽  
Vol 1069 ◽  
Author(s):  
Hui Chen ◽  
Guan Wang ◽  
Michael Dudley ◽  
Zhou Xu ◽  
James. H. Edgar ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Growth Mechanism ◽  
Heteroepitaxial Growth ◽  
High Quality ◽  
X Ray ◽  
Transmission Electron ◽  
Substrate Choice

ABSTRACTA systematic study is presented of the heteroepitaxial growth of B12As2 on m-plane 15R-SiC. In contrast to previous studies of B12As2 on other substrates, including (100) Si, (110) Si, (111) Si and (0001) 6H-SiC, single crystalline and untwinned B12As2 was achieved on m-plane 15R-SiC. Observations of IBA on m-plane (1100)15R-SiC by synchrotron white beam x-ray topography (SWBXT) and high resolution transmission electron microscopy (HRTEM) confirm the good quality of the films on the 15R-SiC substrates. The growth mechanism of IBA on m-plane 15R-SiC is discussed. This work demonstrates that m-plane 15R-SiC is potentially a good substrate choice to grow high quality B12As2 epilayers.

Structural and Optical Investigation of VLS Grown (111) 3C-SiC Layers on 6H-SiC Substrates in Sn-Based Melts

2011 ◽  
Vol 679-680 ◽  
pp. 165-168
Author(s):  
Maya Marinova ◽  
Alkyoni Mantzari ◽  
Jian Wu Sun ◽  
Jean Lorenzzi ◽  
Ariadne Andreadou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Depth Distribution ◽  
Structural Quality ◽  
Optical Investigation ◽  
Dopant Incorporation ◽  
Fault Density ◽  
Transmission Electron ◽  
Melt Composition ◽  
Low Temperature Photoluminescence

The current communication focuses on the investigation of 3C-SiC layers grown by the Vapour-Liquid-Solid mechanism on on-axis Si-face 6H-SiC substrates in SiSn melts with different compositions and at different growth temperatures. The layers are studied by Transmission Electron Microscopy and Low Temperature Photoluminescence. It was found that for melts with Sn concentration higher than 60 at% large Sn-related precipitates are formed. The depth distribution of the Sn precipitates strongly depends not only on the melt composition but also on the growth temperature. Their formation strongly influences the stacking fault density and the dopant incorporation in the layers. Lower Sn concentrations combined with higher growth temperatures should result in 3C-SiC layer with enhanced structural quality.

Grain Boundary Dislocation Structure and Motion in an Aluminum Σ=3 [011] Bicrystal

1996 ◽  
Vol 466 ◽  
Author(s):  
D. L. Medlin ◽  
S. M. Foiles ◽  
C. B. Carter
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Grain Boundary ◽  
Twin Boundary ◽  
Defect Structure ◽  
Boundary Dislocation ◽  
Structure And Motion ◽  
Transmission Electron ◽  
Atomistic Calculations

ABSTRACTHigh-resolution transmission electron microscopy (HRTEM) observations are presented of a/3[111] grain-boundary dislocations in an aluminum Σ=3[011] bicrystal. These dislocations are present on both (111) (coherent twin) and (211) (incoherent twin) facets of the bicrystal boundary. The dislocations on the coherent twin facet migrate by a climb process that increases the thickness of the twinned material. These dislocations originate on a Σ=3 (211) incoherent twin boundary where they are closely spaced and dissociated in a wide core configuration. Atomistic calculations of the defect structure and interaction of multiple a/3[111] grain boundary dislocations are discussed.

TEM Investigation of the 3C/6H-SiC Transformation Interface in Layers Grown by Sublimation Epitaxy

2010 ◽  
Vol 163 ◽  
pp. 97-100 ◽  
Author(s):  
Maya Marinova ◽  
Alkyoni Mantzari ◽  
Milena Beshkova ◽  
Mikael Syväjärvi ◽  
Rositza Yakimova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Growth Conditions ◽  
Temperature Gradients ◽  
Transmission Electron

In the present work Conventional and High Resolution Transmission Electron Microscopy has been used to examine the structure and types of interfaces between 3C-SiC and 6H-SiC for samples grown by Sublimation Epitaxy. The layers were grown on on-axis 6H-SiC substrates at different temperature gradients. The changed growth conditions influence on the nucleation of 3C-SiC on the 6H-SiC substrates and their competition with nucleation of 6H-SiC islands. Three specific types of 3C/6H-SiC interfaces were observed and the implications of these observations are discussed.

Fabrication and Characterization of Gold Nano-gaps for ssDNA Immobilization and Hybridization Detection

2011 ◽  
Vol 14 (3) ◽  
pp. 191-196 ◽  
Author(s):  
Th. S. Dhahi ◽  
U. Hashim ◽  
N. M. Ahmed ◽  
H. Nazma
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Conformational Changes ◽  
Electrical Contact ◽  
Resolution Enhancement ◽  
Transmission Electron ◽  
Resolution Imaging

We develop a method for fabricating the nano-gaps directly by using just photolithography and wet etching processes without any nano lithography or difficult techniques. It shows that this resolution enhancement allows one to fabricate metal electrodes with separation from arbitrarily large to fewer than one hundred nanometers. Furthermore, because these nano-gaps are on a thin film, they can be imaged with high-resolution transmission electron microscopy (HRTEM). Efforts toward achieving electrical contact to nanostructures have been active for over a decade. Even though several devices based on “nano-gaps” – two gaps separated by a nanometer-scale distance - have been demonstrated, their realization has remained a significant challenge. Even the best methods are highly labor-intensive and suffer from low yield and poor geometrical control. Most nano-gaps are also incompatible with high resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM). As a consequence, the proof of the nano-gap quality and content in past studies has been indirect. High-resolution imaging is therefore required to ensure the quality of nano-gaps and to be able to identify possible artifacts. This project presents a unique vertical nano-gap biosensor that can detect changes in DNA structure. Using a size reduction to interrogate samples between the nano-scale gaps, this biosensor will be sensitive enough to record the conformational changes for ss-DNA.

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