Homoepitaxial Growth of Crystalline Ge Films through a Liquid Metal Medium at Low Temperature

1990 ◽  
Vol 204 ◽  
Author(s):  
Fulin Xiong ◽  
Jene A. Golovehenko ◽  
Frans Spaepen
Keyword(s):  
Electron Microscopy ◽  
Low Temperature ◽  
Liquid Metal ◽  
Eutectic Point ◽  
High Growth ◽  
High Energy ◽  
High Growth Rate ◽  
Semiconductor Interface ◽  
Cross Sectional ◽  
Crystalline Films

ABSTRACTCrystalline films of Ge have been homoepitaxially grown through a liquid Au medium by the so-called vapor-liquid-solid (VLS) mechanism at relatively low temperature (400-450 °C). During the process, the Ge vapor is delivered by a molecular beam evaporator and the liquid phase in the system is formed at the interface by heating a Au metal film above its eutectic point with the semiconductor. This process has a potential of a high growth rate at low temperature. The growth process and the crystallinity of the films were monitored in situ by high energy ion backscattering and channeling. The surface morphology and quality of the films were examined by scanning electron microscopy and cross-sectional transmission electron microscopy. The experimental results are presented, together with a discussion of the growth mechanism and the nature of the liquid metal-semiconductor interface.

Low Temperature Deposition of Polycrystalline Silicon Thin Films Prepared by Hot Wire Cell Method

1998 ◽  
Vol 536 ◽  
Author(s):  
M. Ichikawa ◽  
J. Takeshita ◽  
A. Yamada ◽  
M. Konagai
Keyword(s):  
Low Temperature ◽  
Polycrystalline Silicon ◽  
High Growth ◽  
Columnar Structure ◽  
High Growth Rate ◽  
Silicon Films ◽  
Hot Wire ◽  
Cross Sectional ◽  
Cell Method ◽  
Polycrystalline Silicon Films

AbstractHot wire (HW) cell method has been newly developed and successfully applied to grow polycrystalline silicon films at a low temperature with a relatively high growth rate. In the HWcell method, silane is decomposed by reaction with a heated tungsten wire placed near the substrate. It is found that polycrystalline silicon films can be obtained at substrate temperatures of 175-400°C without hydrogen dilution. The film crystallinity is changed from polycrystalline to amorphous with decreasing the total pressure. The X-ray analysis clearly showed that the films grown at the filament temperature of 1700°C have a very strong (220) preferential orientation. The films consist of large grains as well as small grains, and it was found from cross-sectional SEM that the films have columnar structure. These results suggested that the HW-cell method would be a promising candidate to grow device-grade polycrystalline silicon films for photovoltaic application.

scholarly journals Influence of Adding Encapsulated Phase Change Materials in Aerial Lime Based Mortars

2013 ◽  
Vol 687 ◽  
pp. 255-261 ◽  
Author(s):  
Sandra Cunha ◽  
José Barroso Aguiar ◽  
Victor Ferreira ◽  
António Tadeu
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Renewable Energy Sources ◽  
High Growth ◽  
High Energy ◽  
High Growth Rate ◽  
Aesthetic Appearance ◽  
Hardened State ◽  
High Energy Consumption

Increasingly in a society with a high growth rate and standards of comfort, the need to minimize the currently high energy consumption by taking advantage of renewable energy sources arises. The mortars with incorporation of phase change materials (PCM) have the ability to regulate the temperature inside buildings, contributing for an increase in the level of thermal comfort and reduction of the use of heating, ventilation and air conditioning (HVAC) equipment, using only the energy supplied by the sun. However, the incorporation of PCM in mortars modifies some of its characteristics. Therefore, the main objective of this study was the characterization of mortars doped with two different phase change materials. Specific properties of different PCM, such as particle size, shape and enthalpy were studied, as well as the properties of the fresh and hardened state of these mortars. Nine different compositions were developed which were initially doped with microcapsules of PCM A and subsequently doped with microcapsules of PCM B. It was possible to observe that the incorporation of phase change materials in mortars causes differences in properties such as compressive strength, flexural strength and shrinkage. After the study of the behaviour of these mortars with the incorporation of two different phase change materials, it was possible to select the composition with a better compromise between its aesthetic appearance, physical and mechanical characteristics.

scholarly journals High growth rate hydride vapor phase epitaxy at low temperature through use of uncracked hydrides

2018 ◽  
Vol 112 (4) ◽  
pp. 042101 ◽  
Author(s):  
Kevin L. Schulte ◽  
Anna Braun ◽  
John Simon ◽  
Aaron J. Ptak
Keyword(s):  
Growth Rate ◽  
Low Temperature ◽  
Vapor Phase ◽  
High Growth ◽  
High Growth Rate ◽  
Vapor Phase Epitaxy ◽  
Hydride Vapor Phase Epitaxy

Analysis and Reduction of Stacking Faults in Fast Epitaxial Growth

2016 ◽  
Vol 858 ◽  
pp. 173-176 ◽  
Author(s):  
Hideyuki Uehigashi ◽  
Keisuke Fukada ◽  
Masahiko Ito ◽  
Isaho Kamata ◽  
Hiroaki Fujibayashi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Growth Rate ◽  
Epitaxial Growth ◽  
Stacking Faults ◽  
High Growth ◽  
High Growth Rate ◽  
X Ray ◽  
Crystalline Defects ◽  
Transmission Electron

We have developed a single-wafer vertical epitaxial reactor which realizes high-throughput production of 4H-SiC epitaxial layer (epilayer) with a high growth rate [1,2]. In this paper, in order to evaluate the crystalline defects which can affect the characteristics of devices, we investigated the formation of variety of in-grown stacking faults (SFs) in detail. Synchrotron X-ray topography, photoluminescence (PL) and transmission electron microscopy are employed to analyze the SFs and the origins of the SF formation are discussed. The result in reducing in-grown SFs in fast epitaxial growth is also shown.

In-Grown Stacking Faults Identified in 4H-SiC Epilayers Grown at High Growth Rate

2010 ◽  
Vol 645-648 ◽  
pp. 287-290 ◽  
Author(s):  
Gan Feng ◽  
Jun Suda ◽  
Tsunenobu Kimoto
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Stacking Faults ◽  
High Growth ◽  
High Growth Rate ◽  
Emission Peak ◽  
Formation Model ◽  
Intensity Mapping ◽  
Transmission Electron ◽  
Pl Emission

In-grown stacking faults (IGSFs) in thick 4H-SiC epilayers grown at high growth rates have been characterized by micro-photoluminescence (micro-PL) spectroscopy and its intensity mapping. Strong PL emissions from the IGSFs are observed even at room temperature. Three kinds of IGSFs have been identified in the samples based on the micro-PL spectra. Each IGSF shows the specific PL emission peak located at 460 nm, 480 nm, and 500 nm, respectively. The shapes, distributions, and densities of IGSFs in the epilayers are revealed by the micro-PL intensity mapping. The stacking sequences of three IGSFs have been determined as (4,4), (3,5), and (6,2) in the Zhadonov’s notation, respectively, by high-resolution transmission electron microscopy observations. Three identified IGSFs are then classified as quadruple Shockley SFs, triple Shockley SFs, and double Shockley SFs, respectively, based on the shear formation model.

Low Temperature in Situ Cleaning of Si(100) Surfaces and Transmission Electron Microscopy of Subsequent Growth of Epitaxial Germanium

1988 ◽  
Vol 116 ◽  
Author(s):  
R.A. Rudder ◽  
S.V. Hattangady ◽  
J.B. Posthill ◽  
R.J. Markunas
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Temperature ◽  
Carbonaceous Material ◽  
High Energy ◽  
Wafer Surface ◽  
Hydrogen Treatment ◽  
Heteroepitaxial Growth ◽  
Transmission Electron

AbstractA low temperature process for cleaning Si(100) surfaces has been developed. It involves a combination of a modified hot RCA wet chemistry treatment and an in situ hydrogen treatment for the removal of oxides and carbonaceous material from the Si surface. While this treatment is successful in producing reflection high energy electron diffraction patterns which show 1/2-order reconstruction lines, subsequent Ge heteroepitaxial growth at 300°C contains a high density of microtwins. Transmission electron microscopy reveals that most of the microtwins do not propagate to the wafer surface. Furthermore, the Ge/Si interface is not abrupt, and there are regions that do not appear crystalline. This suggests that some contamination is still present on the Si(100) surface after the in situ hydrogen treatments.

Growth and Structure of Al/MgO Interfaces

1994 ◽  
Vol 357 ◽  
Author(s):  
T. Wagner ◽  
M. Ruhle
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Diffraction ◽  
High Vacuum ◽  
High Energy ◽  
Ultra High Vacuum ◽  
Structural Defects ◽  
Cross Sectional ◽  
Aluminum Films ◽  
Transmission Electron

AbstractThe A1/MgO system has been used as a model system to study growth processes and structure at metal/ceramic interfaces. Aluminum films were grown on air-cleaved MgO (100) substrates in ultra high vacuum (UHV) by molecular beam epitaxy (MBE). The substrates and films were characterized by reflection high energy electron diffraction (RHEED), x-ray diffraction (XRD), conventional transmission electron microscopy (CTEM), and high resolution transmission electron microscopy (HREM). XRD measurements exhibited a pronounced {100} texture. Employing electron diffraction in the TEM on cross sectional samples, we observed the following orientation relationship between Al and MgO: (100)A1 II (100)MgO; [010]A1 II [010]MgO. The atomistic structure of the interface was investigated by HREM. Regions of structural defects can be identified clearly at the interface.

scholarly journals Low temperature sintering of mechanically activated BaCO3-TiO2

2002 ◽  
Vol 34 (1) ◽  
pp. 73-77 ◽  
Author(s):  
Vera Pavlovic ◽  
Biljana Stojanovic ◽  
Vladimir Pavlovic ◽  
Ljiljana Zivkovic ◽  
Momcilo Ristic
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Temperature ◽  
Mechanical Activation ◽  
Heating Rate ◽  
High Energy ◽  
Crystallographic Data ◽  
Low Temperature Sintering ◽  
Stoichiometric Mixture ◽  
Scanning Electron

In this article low temperature sintering of mechanically activated BaCO3-TiO2 system was studied. A stoichiometric mixture of BaCO3 and TiO2 powders was mechanically activated in a high-energy vibromill for 0, 30, 90 and 180 min, calcined at 800oC for 1 h and reaction sintered at 1100oC and 1200oC for 2 h (heating rate of 10oC/min). Phase compositions and crystallographic data of initial, activated, calcinated and sintered specimens were obtained by the XRPD method. It was noticed that mechanical activation enhanced and lowered the temperature of the formation of tetragonal BaTiO3. Scanning electron microscopy was used to study and characterize microstructures of the samples.

scholarly journals Effects of MOVPE Growth Conditions on GaN Layers Doped with Germanium

2020 ◽  
Author(s):  
Dario Schiavon ◽  
Elżbieta Litwin-Staszewska ◽  
Rafał Jakieła ◽  
Szymon Grzanka ◽  
Piotr Perlin
Keyword(s):  
Growth Rate ◽  
High Temperature ◽  
Low Temperature ◽  
Surface Morphology ◽  
Growth Temperature ◽  
High Growth ◽  
Growth Conditions ◽  
High Growth Rate ◽  
Pit Formation ◽  
Movpe Growth

The effect of growth temperature and precursor flows on the doping level and surface morphology of Ge-doped GaN layers was researched. The results show that germanium is more readily incorporated at low temperature, high growth rate and high V/III ratio, thus revealing a similar behavior to what was previously observed for indium. V-pit formation can be blocked at high temperature but also at low V/III ratio, the latter of which however causing step bunching.

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