Improved Epilayer Surface Morphology on 2˚ Off-Cut 4H-SiC Substrates

2014 ◽  
Vol 778-780 ◽  
pp. 206-209 ◽  
Author(s):  
Louise Lilja ◽  
Jawad ul Hassan ◽  
Erik Janzén ◽  
J. Peder Bergman
Keyword(s):  
Surface Morphology ◽  
Defect Density ◽  
Hydrogen Atmosphere ◽  
Pure Hydrogen ◽  
Morphological Defects ◽  
Homoepitaxial Layers ◽  
Epilayer Surface

Homoepitaxial layers of 4H-SiC were grown with horizontal hot-wall CVD on 2˚ off-cut substrates, with the purpose of improving the surface morphology of the epilayers and reducing the density of surface morphological defects. In-situ etching conditions in either pure hydrogen or in a mixture of silane and hydrogen prior to the growth were compared as well as C/Si ratios in the range 0.8 to 1.0 during growth. The smoothest epilayer surface, together with lowest defect density, was achieved with growth at a C/Si ratio of 0.9 after an in-situ etching in pure hydrogen atmosphere.

4H-SiC Homoepitaxial Growth on Vicinal-Off Angled Si-Face Substrate

2010 ◽  
Vol 645-648 ◽  
pp. 99-102 ◽  
Author(s):  
Kazutoshi Kojima ◽  
Sachiko Ito ◽  
Junji Senzaki ◽  
Hajime Okumura
Keyword(s):  
Surface Morphology ◽  
Epitaxial Growth ◽  
Growth Temperature ◽  
Growth Conditions ◽  
Step Bunching ◽  
Homoepitaxial Growth ◽  
Blocking Voltage ◽  
Basal Plane Dislocation ◽  
Epilayer Surface

We have carried out detailed investigations of 4H-SiC homoepitaxial growth on vicinal off-angled Si-face substrates. We found that the surface morphology of the substrate just after in-situ H2 etching was also affected by the value of the vicinal-off angle. Growth conditions consisting of a low C/Si ratio and a low growth temperature were effective in suppressing macro step bunching at the grown epilayer surface. We also demonstrated epitaxial growth without step bunching on a 2-inch 4H-SiC Si-face substrate with a vicinal off angle of 0.79o. Ni Schottky barrier diodes fabricated on an as-grown epilayer had a blocking voltage above 1000V and a leakage current of less than 5x10-7A/cm2. We also investigated the propagation of basal plane dislocation from the vicinal off angled substrate into the epitaxial layer.

Cathodoluminescence of Catalyst Crystallites

1982 ◽  
Vol 40 ◽  
pp. 664-665
Author(s):  
E.D. Boyes ◽  
P.L. Gai ◽  
D.B. Darby ◽  
C. Warwick
Keyword(s):  
Defect Density ◽  
Chemical Properties ◽  
Operating Conditions ◽  
Semiconductor Materials ◽  
Environmental Cell ◽  
High Resolution Structure ◽  
Commercially Important ◽  
Crystallographic Defects ◽  
Resolution Structure

The extended crystallographic defects introduced into some oxide catalysts under operating conditions may be a consequence and accommodation of the changes produced by the catalytic activity, rather than always being the origin of the reactivity. Operation without such defects has been established for the commercially important tellurium molybdate system. in addition it is clear that the point defect density and the electronic structure can both have a significant influence on the chemical properties and hence on the effectiveness (activity and selectivity) of the material as a catalyst. SEM/probe techniques more commonly applied to semiconductor materials, have been investigated to supplement the information obtained from in-situ environmental cell HVEM, ultra-high resolution structure imaging and more conventional AEM and EPMA chemical microanalysis.

An in situ and ex situ TEM study of the formation of thin cobalt silicide films by molecular beam epitaxy on the silicon (100) surface

1988 ◽  
Vol 46 ◽  
pp. 884-885
Author(s):  
D. Loretto ◽  
J. M. Gibson ◽  
S. M. Yalisove ◽  
R. T. Tung
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Defect Density ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Ex Situ ◽  
Metal Base ◽  
In Situ Experiments ◽  
Potential Applications

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.

Growth of Epitaxial IrSi3 Layers on Si(111)

1989 ◽  
Vol 160 ◽  
Author(s):  
T. L. Lin ◽  
C. W. Nieh
Keyword(s):  
Surface Morphology ◽  
Molecular Beam ◽  
Solid Phase ◽  
Single Mode ◽  
Growth Conditions ◽  
Tem Analysis ◽  
Mbe Growth ◽  
Good Surface ◽  
Transmission Electron

AbstractEpitaxial IrSi3 films have been grown on Si (111) by molecular beam epitaxy (MBE) at temperatures ranging from 630 to 800 °C and by solid phase epitaxy (SPE) at 500 °C. Good surface morphology was observed for IrSi3 layers grown by MBE at temperatures below 680 °C, and an increasing tendency to form islands is noted in samples grown at higher temperatures. Transmission electron microscopy (TEM) analysis reveals that the IrSi3 layers grow epitaxially on Si(111) with three epitaxial modes depending on the growth conditions. For IrSi3 layers grown by MBE at 630 °C, two epitaxial modes were observed with ~ 50% area coverage for each mode. Single mode epitaxial growth was achieved at a higher MBE growth temperature, but with island formation in the IrSi3 layer. A template technique was used with MBE to improve the IrSi3 surface morphology at higher growth temperatures. Furthermore, single-crystal IrSi3 was grown on Si(111) at 500 °C by SPE, with annealing performed in-situ in a TEM chamber.

Surface morphology of As-deposited and laser-damaged dielectric mirror coatings studied in-situ by atomic force microscopy

1992 ◽  
Author(s):  
Mark R. Kozlowski ◽  
Michael C. Staggs ◽  
Mehdi Balooch ◽  
Robert J. Tench ◽  
Wigbert J. Siekhaus
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Morphology ◽  
Force Microscopy ◽  
Dielectric Mirror ◽  
Atomic Force

Characterization of diamond thin films: Diamond phase identification, surface morphology, and defect structures

1989 ◽  
Vol 4 (2) ◽  
pp. 373-384 ◽  
Author(s):  
B. E. Williams ◽  
J. T. Glass
Keyword(s):  
Electron Microscopy ◽  
Surface Morphology ◽  
Methane Concentration ◽  
Microwave Plasma ◽  
Defect Density ◽  
Diamond Films ◽  
Hydrogen Gas ◽  
Phase Identification ◽  
Diamond Crystals ◽  
Thin Carbon

Thin carbon films grown from a low pressure methane-hydrogen gas mixture by microwave plasma enhanced CVD have been examined by Auger electron spectroscopy, secondary ion mass spectrometry, electron and x-ray diffraction, electron energy loss spectroscopy, and electron microscopy. They were determined to be similar to natural diamond in terms of composition, structure, and bonding. The surface morphology of the diamond films was a function of position on the sample surface and the methane concentration in the feedgas. Well-faceted diamond crystals were observed near the center of the sample whereas a less faceted, cauliflower texture was observed near the edge of the sample, presumably due to variations in temperature across the surface of the sample. Regarding methane concentration effects, threefold {111} faceted diamond crystals were predominant on a film grown at 0.3% CH4 in H2 while fourfold {100} facets were observed on films grown in 1.0% and 2.0% CH4 in H2. Transmission electron microscopy of the diamond films has shown that the majority of diamond crystals have a very high defect density comprised of {111} twins, {111} stacking faults, and dislocations. In addition, cross-sectional TEM has revealed a 50 Å epitaxial layer of β3–SiC at the diamond-silicon interface of a film grown with 0.3% CH4 in H2 while no such layer was observed on a diamond film grown in 2.0% CH4 in H2.

scholarly journals In-Situ X-ray Diffraction Measurement for Pure Niobium Metal in High Temperature Hydrogen Atmosphere

2006 ◽  
Vol 70 (6) ◽  
pp. 467-472 ◽  
Author(s):  
Tomonori Nambu ◽  
Nobue Shimizu ◽  
Hisakazu Ezaki ◽  
Hiroshi Yukawa ◽  
Masahiko Morinaga ◽  
...  
Keyword(s):  
High Temperature ◽  
Hydrogen Atmosphere ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pure Niobium

scholarly journals An in situ spectroscopic erosion yield measurement with applications to sputtering and surface morphology alterations

1989 ◽  
Vol 7 (1) ◽  
pp. 21-26 ◽  
Author(s):  
W. K. Leung ◽  
Y. Hirooka ◽  
R. W. Conn ◽  
D. M. Goebel ◽  
B. Labombard ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Yield Measurement

The Research of Non-Oriented Electrical Steel Processed by Stress Relief Annealing Experiments

2014 ◽  
Vol 887-888 ◽  
pp. 252-256
Author(s):  
Zhun Li ◽  
Jing Liu ◽  
Shi De Li ◽  
Ze Lin Zheng
Keyword(s):  
Magnetic Properties ◽  
Electrical Steel ◽  
Core Loss ◽  
Reference Method ◽  
Stress Relief ◽  
Hydrogen Atmosphere ◽  
Silicon Steel ◽  
Pure Hydrogen ◽  
Final Annealing ◽  
Annealing Experiments

A high grade non-oriented electrical steel final annealing product was processed by stress relief annealing experiments under pure hydrogen atmosphere using different process parameters. The samples were compared in the aspects of magnetic properties and anisotropy, then analyzed the phenomena concerned with grain size, texture and precipitates aspects. The experiments showed that the samples magnetic properties were most improved in the 850 degrees stress relief annealing experiment, thus providing a reference method for non-oriented silicon steel stress relief annealing experiments and to obtain low core loss non-oriented silicon steel.

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